Re: [PATCH v5 05/16] media: mali-c55: Add Mali-C55 ISP driver

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Hi Dan,

On Mon, Jun 17, 2024 at 12:41:11PM +0100, Daniel Scally wrote:
> Hi Laurent - sorry, should have included everything in the last reply rather than responding 
> piecemeal. Some more responses and questions below

No worries.

> On 30/05/2024 01:15, Laurent Pinchart wrote:
> > Hi Dan,
> >
> > Thank you for the patch.
> >
> > On Wed, May 29, 2024 at 04:28:47PM +0100, Daniel Scally wrote:
> >> Add a driver for Arm's Mali-C55 Image Signal Processor. The driver is
> >> V4L2 and Media Controller compliant and creates subdevices to manage
> >> the ISP itself, its internal test pattern generator as well as the
> >> crop, scaler and output format functionality for each of its two
> >> output devices.
> >>
> >> Acked-by: Nayden Kanchev <nayden.kanchev@xxxxxxx>
> >> Co-developed-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>
> >> Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>
> >> Signed-off-by: Daniel Scally <dan.scally@xxxxxxxxxxxxxxxx>
> >> ---
> >> Changes in v5:
> >>
> >> 	- Reworked input formats - previously we allowed representing input data
> >> 	  as any 8-16 bit format. Now we only allow input data to be represented
> >> 	  by the new 20-bit bayer formats, which is corrected to the equivalent
> >> 	  16-bit format in RAW bypass mode.
> >> 	- Stopped bypassing blocks that we haven't added supporting parameters
> >> 	  for yet.
> >> 	- Addressed most of Sakari's comments from the list
> >>
> >> Changes not yet made in v5:
> >>
> >> 	- The output pipelines can still be started and stopped independently of
> >> 	  one another - I'd like to discuss that more.
> >> 	- the TPG subdev still uses .s_stream() - I need to rebase onto a tree
> >> 	  with working .enable_streams() for a single-source-pad subdevice.
> >>
> >> Changes in v4:
> >>
> >> 	- Reworked mali_c55_update_bits() to internally perform the bit-shift
> >
> > I really don't like that, it makes the code very confusing, even more so
> > as it differs from regmap_update_bits().
> >
> > Look at this for instance:
> >
> > 	mali_c55_update_bits(mali_c55, MALI_C55_REG_MCU_CONFIG,
> > 			     MALI_C55_REG_MCU_CONFIG_OVERRIDE_MASK,
> > 			     MALI_C55_REG_MCU_CONFIG_OVERRIDE_MASK);
> >
> > It only works by change because MALI_C55_REG_MCU_CONFIG_OVERRIDE_MASK is
> > BIT(0).
> >
> > Sorry, I know it will be painful, but this change needs to be reverted.
> >
> >> 	- Reworked the resizer to allow cropping during streaming
> >> 	- Fixed a bug in NV12 output
> >>
> >> Changes in v3:
> >>
> >> 	- Mostly minor fixes suggested by Sakari
> >> 	- Fixed the sequencing of vb2 buffers to be synchronised across the two
> >> 	  capture devices.
> >>
> >> Changes in v2:
> >>
> >> 	- Clock handling
> >> 	- Fixed the warnings raised by the kernel test robot
> >>
> >>   drivers/media/platform/Kconfig                |   1 +
> >>   drivers/media/platform/Makefile               |   1 +
> >>   drivers/media/platform/arm/Kconfig            |   5 +
> >>   drivers/media/platform/arm/Makefile           |   2 +
> >>   drivers/media/platform/arm/mali-c55/Kconfig   |  18 +
> >>   drivers/media/platform/arm/mali-c55/Makefile  |   9 +
> >>   .../platform/arm/mali-c55/mali-c55-capture.c  | 951 ++++++++++++++++++
> >>   .../platform/arm/mali-c55/mali-c55-common.h   | 266 +++++
> >>   .../platform/arm/mali-c55/mali-c55-core.c     | 767 ++++++++++++++
> >>   .../platform/arm/mali-c55/mali-c55-isp.c      | 611 +++++++++++
> >>   .../arm/mali-c55/mali-c55-registers.h         | 258 +++++
> >>   .../arm/mali-c55/mali-c55-resizer-coefs.h     | 382 +++++++
> >>   .../platform/arm/mali-c55/mali-c55-resizer.c  | 779 ++++++++++++++
> >>   .../platform/arm/mali-c55/mali-c55-tpg.c      | 402 ++++++++
> >>   14 files changed, 4452 insertions(+)
> >>   create mode 100644 drivers/media/platform/arm/Kconfig
> >>   create mode 100644 drivers/media/platform/arm/Makefile
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/Kconfig
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/Makefile
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-capture.c
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-common.h
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-core.c
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-isp.c
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-registers.h
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-resizer-coefs.h
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-resizer.c
> >>   create mode 100644 drivers/media/platform/arm/mali-c55/mali-c55-tpg.c
> >
> > I've skipped review of capture.c and resizer.c as I already have plenty
> > of comments for the other files, and it's getting late. I'll try to
> > review the rest tomorrow.
> >
> >> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> >> index 2d79bfc68c15..c929169766aa 100644
> >> --- a/drivers/media/platform/Kconfig
> >> +++ b/drivers/media/platform/Kconfig
> >> @@ -65,6 +65,7 @@ config VIDEO_MUX
> >>   source "drivers/media/platform/allegro-dvt/Kconfig"
> >>   source "drivers/media/platform/amlogic/Kconfig"
> >>   source "drivers/media/platform/amphion/Kconfig"
> >> +source "drivers/media/platform/arm/Kconfig"
> >>   source "drivers/media/platform/aspeed/Kconfig"
> >>   source "drivers/media/platform/atmel/Kconfig"
> >>   source "drivers/media/platform/broadcom/Kconfig"
> >> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> >> index da17301f7439..9a647abd5218 100644
> >> --- a/drivers/media/platform/Makefile
> >> +++ b/drivers/media/platform/Makefile
> >> @@ -8,6 +8,7 @@
> >>   obj-y += allegro-dvt/
> >>   obj-y += amlogic/
> >>   obj-y += amphion/
> >> +obj-y += arm/
> >>   obj-y += aspeed/
> >>   obj-y += atmel/
> >>   obj-y += broadcom/
> >> diff --git a/drivers/media/platform/arm/Kconfig b/drivers/media/platform/arm/Kconfig
> >> new file mode 100644
> >> index 000000000000..4f0764c329c7
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/Kconfig
> >> @@ -0,0 +1,5 @@
> >> +# SPDX-License-Identifier: GPL-2.0-only
> >> +
> >> +comment "ARM media platform drivers"
> >> +
> >> +source "drivers/media/platform/arm/mali-c55/Kconfig"
> >> diff --git a/drivers/media/platform/arm/Makefile b/drivers/media/platform/arm/Makefile
> >> new file mode 100644
> >> index 000000000000..8cc4918725ef
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/Makefile
> >> @@ -0,0 +1,2 @@
> >> +# SPDX-License-Identifier: GPL-2.0-only
> >> +obj-y += mali-c55/
> >> diff --git a/drivers/media/platform/arm/mali-c55/Kconfig b/drivers/media/platform/arm/mali-c55/Kconfig
> >> new file mode 100644
> >> index 000000000000..602085e28b01
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/Kconfig
> >> @@ -0,0 +1,18 @@
> >> +# SPDX-License-Identifier: GPL-2.0-only
> >> +config VIDEO_MALI_C55
> >> +	tristate "ARM Mali-C55 Image Signal Processor driver"
> >> +	depends on V4L_PLATFORM_DRIVERS
> >> +	depends on VIDEO_DEV && OF
> >> +	depends on ARCH_VEXPRESS || COMPILE_TEST
> >> +	select MEDIA_CONTROLLER
> >> +	select VIDEO_V4L2_SUBDEV_API
> >> +	select VIDEOBUF2_DMA_CONTIG
> >> +	select VIDEOBUF2_VMALLOC
> >> +	select V4L2_FWNODE
> >> +	select GENERIC_PHY_MIPI_DPHY
> >
> > Alphabetical order ?
> >
> >> +	default n
> >
> > That's the default, you don't have to specify ti.
> >
> >> +	help
> >> +	  Enable this to support Arm's Mali-C55 Image Signal Processor.
> >> +
> >> +	  To compile this driver as a module, choose M here: the module
> >> +	  will be called mali-c55.
> >> diff --git a/drivers/media/platform/arm/mali-c55/Makefile b/drivers/media/platform/arm/mali-c55/Makefile
> >> new file mode 100644
> >> index 000000000000..77dcb2fbf0f4
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/Makefile
> >> @@ -0,0 +1,9 @@
> >> +# SPDX-License-Identifier: GPL-2.0
> >> +
> >> +mali-c55-y := mali-c55-capture.o \
> >> +	      mali-c55-core.o \
> >> +	      mali-c55-isp.o \
> >> +	      mali-c55-tpg.o \
> >> +	      mali-c55-resizer.o
> >
> > Alphabetical order here too.
> >
> >> +
> >> +obj-$(CONFIG_VIDEO_MALI_C55) += mali-c55.o
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-capture.c b/drivers/media/platform/arm/mali-c55/mali-c55-capture.c
> >> new file mode 100644
> >> index 000000000000..1d539ac9c498
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-capture.c
> >> @@ -0,0 +1,951 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Video capture devices
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#include <linux/cleanup.h>
> >> +#include <linux/minmax.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/string.h>
> >> +#include <linux/videodev2.h>
> >> +
> >> +#include <media/v4l2-dev.h>
> >> +#include <media/v4l2-event.h>
> >> +#include <media/v4l2-ioctl.h>
> >> +#include <media/v4l2-subdev.h>
> >> +#include <media/videobuf2-core.h>
> >> +#include <media/videobuf2-dma-contig.h>
> >> +
> >> +#include "mali-c55-common.h"
> >> +#include "mali-c55-registers.h"
> >> +
> >> +static const struct mali_c55_fmt mali_c55_fmts[] = {
> >> +	/*
> >> +	 * This table is missing some entries which need further work or
> >> +	 * investigation:
> >> +	 *
> >> +	 * Base mode 1 is a backwards V4L2_PIX_FMT_XRGB32 with no V4L2 equivalent
> >> +	 * Base mode 5 is "Generic Data"
> >> +	 * Base mode 8 is a backwards V4L2_PIX_FMT_XYUV32 - no V4L2 equivalent
> >> +	 * Base mode 9 seems to have no V4L2 equivalent
> >> +	 * Base mode 17, 19 and 20 describe formats which seem to have no V4L2
> >> +	 * equivalent
> >> +	 */
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_ARGB2101010,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_RGB121212_1X36,
> >> +			MEDIA_BUS_FMT_RGB202020_1X60,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_A2R10G10B10,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_RGB565,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_RGB121212_1X36,
> >> +			MEDIA_BUS_FMT_RGB202020_1X60,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_RGB565,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_BGR24,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_RGB121212_1X36,
> >> +			MEDIA_BUS_FMT_RGB202020_1X60,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_RGB24,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_YUYV,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_YUV10_1X30,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_YUY2,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_UYVY,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_YUV10_1X30,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_UYVY,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_Y210,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_YUV10_1X30,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_Y210,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	/*
> >> +	 * This is something of a hack, the ISP thinks it's running NV12M but
> >> +	 * by setting uv_plane = 0 we simply discard that planes and only output
> >> +	 * the Y-plane.
> >> +	 */
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_GREY,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_YUV10_1X30,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_NV12_21,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_NV12M,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_YUV10_1X30,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_NV12_21,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT1
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_NV21M,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_YUV10_1X30,
> >> +		},
> >> +		.is_raw = false,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_NV12_21,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT2
> >> +		}
> >> +	},
> >> +	/*
> >> +	 * RAW uncompressed formats are all packed in 16 bpp.
> >> +	 * TODO: Expand this list to encompass all possible RAW formats.
> >> +	 */
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_SRGGB16,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_SRGGB16_1X16,
> >> +		},
> >> +		.is_raw = true,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_RAW16,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_SBGGR16,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_SBGGR16_1X16,
> >> +		},
> >> +		.is_raw = true,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_RAW16,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_SGBRG16,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_SGBRG16_1X16,
> >> +		},
> >> +		.is_raw = true,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_RAW16,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +	{
> >> +		.fourcc = V4L2_PIX_FMT_SGRBG16,
> >> +		.mbus_codes = {
> >> +			MEDIA_BUS_FMT_SGRBG16_1X16,
> >> +		},
> >> +		.is_raw = true,
> >> +		.registers = {
> >> +			.base_mode = MALI_C55_OUTPUT_RAW16,
> >> +			.uv_plane = MALI_C55_OUTPUT_PLANE_ALT0
> >> +		}
> >> +	},
> >> +};
> >> +
> >> +static bool mali_c55_mbus_code_can_produce_fmt(const struct mali_c55_fmt *fmt,
> >> +					       u32 code)
> >> +{
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(fmt->mbus_codes); i++) {
> >> +		if (fmt->mbus_codes[i] == code)
> >> +			return true;
> >> +	}
> >> +
> >> +	return false;
> >> +}
> >> +
> >> +bool mali_c55_format_is_raw(unsigned int mbus_code)
> >> +{
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55_fmts); i++) {
> >> +		if (mali_c55_fmts[i].mbus_codes[0] == mbus_code)
> >> +			return mali_c55_fmts[i].is_raw;
> >> +	}
> >> +
> >> +	return false;
> >> +}
> >> +
> >> +static const struct mali_c55_fmt *mali_c55_format_from_pix(const u32 pixelformat)
> >> +{
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55_fmts); i++) {
> >> +		if (mali_c55_fmts[i].fourcc == pixelformat)
> >> +			return &mali_c55_fmts[i];
> >> +	}
> >> +
> >> +	/*
> >> +	 * If we find no matching pixelformat, we'll just default to the first
> >> +	 * one for now.
> >> +	 */
> >> +
> >> +	return &mali_c55_fmts[0];
> >> +}
> >> +
> >> +static const char * const capture_device_names[] = {
> >> +	"mali-c55 fr",
> >> +	"mali-c55 ds",
> >> +	"mali-c55 3a stats",
> >> +	"mali-c55 params",
> >> +};
> >> +
> >> +static const char *mali_c55_cap_dev_to_name(struct mali_c55_cap_dev *cap)
> >> +{
> >> +	if (cap->reg_offset == MALI_C55_CAP_DEV_FR_REG_OFFSET)
> >> +		return capture_device_names[0];
> >> +
> >> +	if (cap->reg_offset == MALI_C55_CAP_DEV_DS_REG_OFFSET)
> >> +		return capture_device_names[1];
> >> +
> >> +	return "params/stat not supported yet";
> >> +}
> >> +
> >> +static int mali_c55_link_validate(struct media_link *link)
> >> +{
> >> +	struct video_device *vdev =
> >> +		media_entity_to_video_device(link->sink->entity);
> >> +	struct mali_c55_cap_dev *cap_dev = video_get_drvdata(vdev);
> >> +	struct v4l2_subdev *sd =
> >> +		media_entity_to_v4l2_subdev(link->source->entity);
> >> +	const struct v4l2_pix_format_mplane *pix_mp;
> >> +	const struct mali_c55_fmt *cap_fmt;
> >> +	struct v4l2_subdev_format sd_fmt = {
> >> +		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> >> +		.pad = link->source->index,
> >> +	};
> >> +	int ret;
> >> +
> >> +	ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, &sd_fmt);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	pix_mp = &cap_dev->mode.pix_mp;
> >> +	cap_fmt = cap_dev->mode.capture_fmt;
> >> +
> >> +	if (sd_fmt.format.width != pix_mp->width ||
> >> +	    sd_fmt.format.height != pix_mp->height) {
> >> +		dev_dbg(cap_dev->mali_c55->dev,
> >> +			"link '%s':%u -> '%s':%u not valid: %ux%u != %ux%u\n",
> >> +			link->source->entity->name, link->source->index,
> >> +			link->sink->entity->name, link->sink->index,
> >> +			sd_fmt.format.width, sd_fmt.format.height,
> >> +			pix_mp->width, pix_mp->height);
> >> +		return -EPIPE;
> >> +	}
> >> +
> >> +	if (!mali_c55_mbus_code_can_produce_fmt(cap_fmt, sd_fmt.format.code)) {
> >> +		dev_dbg(cap_dev->mali_c55->dev,
> >> +			"link '%s':%u -> '%s':%u not valid: mbus_code 0x%04x cannot produce pixel format %p4cc\n",
> >> +			link->source->entity->name, link->source->index,
> >> +			link->sink->entity->name, link->sink->index,
> >> +			sd_fmt.format.code, &pix_mp->pixelformat);
> >> +		return -EPIPE;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct media_entity_operations mali_c55_media_ops = {
> >> +	.link_validate = mali_c55_link_validate,
> >> +};
> >> +
> >> +static int mali_c55_vb2_queue_setup(struct vb2_queue *q, unsigned int *num_buffers,
> >> +				    unsigned int *num_planes, unsigned int sizes[],
> >> +				    struct device *alloc_devs[])
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = q->drv_priv;
> >> +	unsigned int i;
> >> +
> >> +	if (*num_planes) {
> >> +		if (*num_planes != cap_dev->mode.pix_mp.num_planes)
> >> +			return -EINVAL;
> >> +
> >> +		for (i = 0; i < cap_dev->mode.pix_mp.num_planes; i++)
> >> +			if (sizes[i] < cap_dev->mode.pix_mp.plane_fmt[i].sizeimage)
> >> +				return -EINVAL;
> >> +	} else {
> >> +		*num_planes = cap_dev->mode.pix_mp.num_planes;
> >> +		for (i = 0; i < cap_dev->mode.pix_mp.num_planes; i++)
> >> +			sizes[i] = cap_dev->mode.pix_mp.plane_fmt[i].sizeimage;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void mali_c55_buf_queue(struct vb2_buffer *vb)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = vb2_get_drv_priv(vb->vb2_queue);
> >> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> >> +	struct mali_c55_buffer *buf = container_of(vbuf,
> >> +						   struct mali_c55_buffer, vb);
> >> +	unsigned int i;
> >> +
> >> +	buf->plane_done[MALI_C55_PLANE_Y] = false;
> >> +
> >> +	/*
> >> +	 * If we're in a single-plane format we flag the other plane as done
> >> +	 * already so it's dequeued appropriately later
> >> +	 */
> >> +	buf->plane_done[MALI_C55_PLANE_UV] = cap_dev->mode.pix_mp.num_planes <= 1;
> >> +
> >> +	for (i = 0; i < cap_dev->mode.pix_mp.num_planes; i++) {
> >> +		unsigned long size = cap_dev->mode.pix_mp.plane_fmt[i].sizeimage;
> >> +
> >> +		vb2_set_plane_payload(vb, i, size);
> >> +	}
> >> +
> >> +	spin_lock(&cap_dev->buffers.lock);
> >> +	list_add_tail(&buf->queue, &cap_dev->buffers.queue);
> >> +	spin_unlock(&cap_dev->buffers.lock);
> >> +}
> >> +
> >> +static int mali_c55_buf_init(struct vb2_buffer *vb)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = vb2_get_drv_priv(vb->vb2_queue);
> >> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> >> +	struct mali_c55_buffer *buf = container_of(vbuf,
> >> +						   struct mali_c55_buffer, vb);
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < cap_dev->mode.pix_mp.num_planes; i++)
> >> +		buf->addrs[i] = vb2_dma_contig_plane_dma_addr(vb, i);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +void mali_c55_set_next_buffer(struct mali_c55_cap_dev *cap_dev)
> >> +{
> >> +	struct mali_c55 *mali_c55 = cap_dev->mali_c55;
> >> +
> >> +	guard(spinlock)(&cap_dev->buffers.lock);
> >> +
> >> +	cap_dev->buffers.curr = cap_dev->buffers.next;
> >> +	cap_dev->buffers.next = NULL;
> >> +
> >> +	if (!list_empty(&cap_dev->buffers.queue)) {
> >> +		struct v4l2_pix_format_mplane *pix_mp;
> >> +		const struct v4l2_format_info *info;
> >> +		u32 *addrs;
> >> +
> >> +		pix_mp = &cap_dev->mode.pix_mp;
> >> +		info = v4l2_format_info(pix_mp->pixelformat);
> >> +
> >> +		mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_Y_WRITER_MODE(cap_dev->reg_offset),
> >> +				MALI_C55_WRITER_FRAME_WRITE_MASK, 0x01);
> >> +		if (cap_dev->mode.capture_fmt->registers.uv_plane)
> >> +			mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_UV_WRITER_MODE(cap_dev->reg_offset),
> >> +				MALI_C55_WRITER_FRAME_WRITE_MASK, 0x01);
> >> +
> >> +		cap_dev->buffers.next = list_first_entry(&cap_dev->buffers.queue,
> >> +							 struct mali_c55_buffer,
> >> +							 queue);
> >> +		list_del(&cap_dev->buffers.next->queue);
> >> +
> >> +		addrs = cap_dev->buffers.next->addrs;
> >> +		mali_c55_write(mali_c55,
> >> +			MALI_C55_REG_Y_WRITER_BANKS_BASE(cap_dev->reg_offset),
> >> +			addrs[MALI_C55_PLANE_Y]);
> >> +		mali_c55_write(mali_c55,
> >> +			MALI_C55_REG_UV_WRITER_BANKS_BASE(cap_dev->reg_offset),
> >> +			addrs[MALI_C55_PLANE_UV]);
> >> +		mali_c55_write(mali_c55,
> >> +			MALI_C55_REG_Y_WRITER_OFFSET(cap_dev->reg_offset),
> >> +			pix_mp->width * info->bpp[MALI_C55_PLANE_Y]);
> >> +		mali_c55_write(mali_c55,
> >> +			MALI_C55_REG_UV_WRITER_OFFSET(cap_dev->reg_offset),
> >> +			pix_mp->width * info->bpp[MALI_C55_PLANE_UV]
> >> +			/ info->hdiv);
> >> +	} else {
> >> +		/*
> >> +		 * If we underflow then we can tell the ISP that we don't want
> >> +		 * to write out the next frame.
> >> +		 */
> >> +		mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_Y_WRITER_MODE(cap_dev->reg_offset),
> >> +				MALI_C55_WRITER_FRAME_WRITE_MASK, 0x00);
> >> +		mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_UV_WRITER_MODE(cap_dev->reg_offset),
> >> +				MALI_C55_WRITER_FRAME_WRITE_MASK, 0x00);
> >> +	}
> >> +}
> >> +
> >> +static void mali_c55_handle_buffer(struct mali_c55_buffer *curr_buf,
> >> +				   unsigned int framecount)
> >> +{
> >> +	curr_buf->vb.vb2_buf.timestamp = ktime_get_boottime_ns();
> >> +	curr_buf->vb.field = V4L2_FIELD_NONE;
> >> +	curr_buf->vb.sequence = framecount;
> >> +	vb2_buffer_done(&curr_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
> >> +}
> >> +
> >> +/**
> >> + * mali_c55_set_plane_done - mark the plane as written and process the buffer if
> >> + *			     both planes are finished.
> >> + * @cap_dev:  pointer to the fr or ds pipe output
> >> + * @plane:    the plane to mark as completed
> >> + *
> >> + * The Mali C55 ISP has muliplanar outputs for some formats that come with two
> >> + * separate "buffer write completed" interrupts - we need to flag each plane's
> >> + * completion and check whether both planes are done - if so, complete the buf
> >> + * in vb2.
> >> + */
> >> +void mali_c55_set_plane_done(struct mali_c55_cap_dev *cap_dev,
> >> +			     enum mali_c55_planes plane)
> >> +{
> >> +	struct mali_c55_isp *isp = &cap_dev->mali_c55->isp;
> >> +	struct mali_c55_buffer *curr_buf;
> >> +
> >> +	guard(spinlock)(&cap_dev->buffers.lock);
> >> +	curr_buf = cap_dev->buffers.curr;
> >> +
> >> +	/*
> >> +	 * This _should_ never happen. If no buffer was available from vb2 then
> >> +	 * we tell the ISP not to bother writing the next frame, which means the
> >> +	 * interrupts that call this function should never trigger. If it does
> >> +	 * happen then one of our assumptions is horribly wrong - complain
> >> +	 * loudly and do nothing.
> >> +	 */
> >> +	if (!curr_buf) {
> >> +		dev_err(cap_dev->mali_c55->dev, "%s null buffer in %s()\n",
> >> +			mali_c55_cap_dev_to_name(cap_dev), __func__);
> >> +		return;
> >> +	}
> >> +
> >> +	/* If the other plane is also done... */
> >> +	if (curr_buf->plane_done[~plane & 1]) {
> >> +		mali_c55_handle_buffer(curr_buf, isp->frame_sequence);
> >> +		cap_dev->buffers.curr = NULL;
> >> +		isp->frame_sequence++;
> >> +	} else {
> >> +		curr_buf->plane_done[plane] = true;
> >> +	}
> >> +}
> >> +
> >> +static void mali_c55_cap_dev_stream_disable(struct mali_c55_cap_dev *cap_dev)
> >> +{
> >> +	struct mali_c55 *mali_c55 = cap_dev->mali_c55;
> >> +
> >> +	mali_c55_update_bits(mali_c55,
> >> +			     MALI_C55_REG_Y_WRITER_MODE(cap_dev->reg_offset),
> >> +			     MALI_C55_WRITER_FRAME_WRITE_MASK, 0x00);
> >> +	mali_c55_update_bits(mali_c55,
> >> +			     MALI_C55_REG_UV_WRITER_MODE(cap_dev->reg_offset),
> >> +			     MALI_C55_WRITER_FRAME_WRITE_MASK, 0x00);
> >> +}
> >> +
> >> +static void mali_c55_cap_dev_stream_enable(struct mali_c55_cap_dev *cap_dev)
> >> +{
> >> +	struct mali_c55 *mali_c55 = cap_dev->mali_c55;
> >> +
> >> +	/*
> >> +	 * The Mali ISP can hold up to 5 buffer addresses and simply cycle
> >> +	 * through them, but it's not clear to me that the vb2 queue _guarantees_
> >> +	 * it will queue buffers to the driver in a fixed order, and ensuring
> >> +	 * we call vb2_buffer_done() for the right buffer seems to me to add
> >> +	 * pointless complexity given in multi-context mode we'd need to
> >> +	 * re-write those registers every frame anyway...so we tell the ISP to
> >> +	 * use a single register and update it for each frame.
> >> +	 */
> >> +	mali_c55_update_bits(mali_c55,
> >> +			MALI_C55_REG_Y_WRITER_BANKS_CONFIG(cap_dev->reg_offset),
> >> +			MALI_C55_REG_Y_WRITER_MAX_BANKS_MASK, 0);
> >> +	mali_c55_update_bits(mali_c55,
> >> +			MALI_C55_REG_UV_WRITER_BANKS_CONFIG(cap_dev->reg_offset),
> >> +			MALI_C55_REG_UV_WRITER_MAX_BANKS_MASK, 0);
> >> +
> >> +	/*
> >> +	 * We only queue a buffer in the streamon path if this is the first of
> >> +	 * the capture devices to start streaming. If the ISP is already running
> >> +	 * then we rely on the ISP_START interrupt to queue the first buffer for
> >> +	 * this capture device.
> >> +	 */
> >> +	if (mali_c55->pipe.start_count == 1)
> >> +		mali_c55_set_next_buffer(cap_dev);
> >> +}
> >> +
> >> +static void mali_c55_cap_dev_return_buffers(struct mali_c55_cap_dev *cap_dev,
> >> +					    enum vb2_buffer_state state)
> >> +{
> >> +	struct mali_c55_buffer *buf, *tmp;
> >> +
> >> +	guard(spinlock)(&cap_dev->buffers.lock);
> >> +
> >> +	if (cap_dev->buffers.curr) {
> >> +		vb2_buffer_done(&cap_dev->buffers.curr->vb.vb2_buf,
> >> +				state);
> >> +		cap_dev->buffers.curr = NULL;
> >> +	}
> >> +
> >> +	if (cap_dev->buffers.next) {
> >> +		vb2_buffer_done(&cap_dev->buffers.next->vb.vb2_buf,
> >> +				state);
> >> +		cap_dev->buffers.next = NULL;
> >> +	}
> >> +
> >> +	list_for_each_entry_safe(buf, tmp, &cap_dev->buffers.queue, queue) {
> >> +		list_del(&buf->queue);
> >> +		vb2_buffer_done(&buf->vb.vb2_buf, state);
> >> +	}
> >> +}
> >> +
> >> +static int mali_c55_vb2_start_streaming(struct vb2_queue *q, unsigned int count)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = q->drv_priv;
> >> +	struct mali_c55 *mali_c55 = cap_dev->mali_c55;
> >> +	struct mali_c55_resizer *rzr = cap_dev->rzr;
> >> +	struct mali_c55_isp *isp = &mali_c55->isp;
> >> +	int ret;
> >> +
> >> +	guard(mutex)(&isp->lock);
> >> +
> >> +	ret = pm_runtime_resume_and_get(mali_c55->dev);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ret = video_device_pipeline_start(&cap_dev->vdev,
> >> +					  &cap_dev->mali_c55->pipe);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "%s failed to start media pipeline\n",
> >> +			mali_c55_cap_dev_to_name(cap_dev));
> >> +		goto err_pm_put;
> >> +	}
> >> +
> >> +	mali_c55_cap_dev_stream_enable(cap_dev);
> >> +	mali_c55_rzr_start_stream(rzr);
> >> +
> >> +	/*
> >> +	 * We only start the ISP if we're the only capture device that's
> >> +	 * streaming. Otherwise, it'll already be active.
> >> +	 */
> >> +	if (mali_c55->pipe.start_count == 1) {
> >> +		ret = mali_c55_isp_start_stream(isp);
> >> +		if (ret)
> >> +			goto err_disable_cap_dev;
> >> +	}
> >> +
> >> +	return 0;
> >> +
> >> +err_disable_cap_dev:
> >> +	mali_c55_cap_dev_stream_disable(cap_dev);
> >> +	video_device_pipeline_stop(&cap_dev->vdev);
> >> +err_pm_put:
> >> +	pm_runtime_put(mali_c55->dev);
> >> +	mali_c55_cap_dev_return_buffers(cap_dev, VB2_BUF_STATE_QUEUED);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static void mali_c55_vb2_stop_streaming(struct vb2_queue *q)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = q->drv_priv;
> >> +	struct mali_c55 *mali_c55 = cap_dev->mali_c55;
> >> +	struct mali_c55_resizer *rzr = cap_dev->rzr;
> >> +	struct mali_c55_isp *isp = &mali_c55->isp;
> >> +
> >> +	guard(mutex)(&isp->lock);
> >> +
> >> +	/*
> >> +	 * If one of the other capture nodes is streaming, we shouldn't
> >> +	 * disable the ISP here.
> >> +	 */
> >> +	if (mali_c55->pipe.start_count == 1)
> >> +		mali_c55_isp_stop_stream(&mali_c55->isp);
> >> +
> >> +	mali_c55_rzr_stop_stream(rzr);
> >> +	mali_c55_cap_dev_stream_disable(cap_dev);
> >> +	mali_c55_cap_dev_return_buffers(cap_dev, VB2_BUF_STATE_ERROR);
> >> +	video_device_pipeline_stop(&cap_dev->vdev);
> >> +	pm_runtime_put(mali_c55->dev);
> >> +}
> >> +
> >> +static const struct vb2_ops mali_c55_vb2_ops = {
> >> +	.queue_setup		= &mali_c55_vb2_queue_setup,
> >> +	.buf_queue		= &mali_c55_buf_queue,
> >> +	.buf_init		= &mali_c55_buf_init,
> >> +	.wait_prepare		= vb2_ops_wait_prepare,
> >> +	.wait_finish		= vb2_ops_wait_finish,
> >> +	.start_streaming	= &mali_c55_vb2_start_streaming,
> >> +	.stop_streaming		= &mali_c55_vb2_stop_streaming,
> >> +};
> >> +
> >> +static const struct v4l2_file_operations mali_c55_v4l2_fops = {
> >> +	.owner = THIS_MODULE,
> >> +	.unlocked_ioctl = video_ioctl2,
> >> +	.open = v4l2_fh_open,
> >> +	.release = vb2_fop_release,
> >> +	.poll = vb2_fop_poll,
> >> +	.mmap = vb2_fop_mmap,
> >> +};
> >> +
> >> +static void mali_c55_try_fmt(struct v4l2_pix_format_mplane *pix_mp)
> >> +{
> >> +	const struct mali_c55_fmt *capture_format;
> >> +	const struct v4l2_format_info *info;
> >> +	struct v4l2_plane_pix_format *plane;
> >> +	unsigned int i;
> >> +
> >> +	capture_format = mali_c55_format_from_pix(pix_mp->pixelformat);
> >> +	pix_mp->pixelformat = capture_format->fourcc;
> >> +
> >> +	pix_mp->width = clamp(pix_mp->width, MALI_C55_MIN_WIDTH,
> >> +			      MALI_C55_MAX_WIDTH);
> >> +	pix_mp->height = clamp(pix_mp->height, MALI_C55_MIN_HEIGHT,
> >> +			       MALI_C55_MAX_HEIGHT);
> >> +
> >> +	pix_mp->field = V4L2_FIELD_NONE;
> >> +	pix_mp->colorspace = V4L2_COLORSPACE_DEFAULT;
> >> +	pix_mp->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> >> +	pix_mp->quantization = V4L2_QUANTIZATION_DEFAULT;
> >> +
> >> +	info = v4l2_format_info(pix_mp->pixelformat);
> >> +	pix_mp->num_planes = info->mem_planes;
> >> +	memset(pix_mp->plane_fmt, 0, sizeof(pix_mp->plane_fmt));
> >> +
> >> +	pix_mp->plane_fmt[0].bytesperline = info->bpp[0] * pix_mp->width;
> >> +	pix_mp->plane_fmt[0].sizeimage = info->bpp[0] * pix_mp->width
> >> +				       * pix_mp->height;
> >> +
> >> +	for (i = 1; i < info->comp_planes; i++) {
> >> +		plane = &pix_mp->plane_fmt[i];
> >> +
> >> +		plane->bytesperline = DIV_ROUND_UP(info->bpp[i] * pix_mp->width,
> >> +						   info->hdiv);
> >> +		plane->sizeimage = DIV_ROUND_UP(
> >> +					plane->bytesperline * pix_mp->height,
> >> +					info->vdiv);
> >> +	}
> >> +
> >> +	if (info->mem_planes == 1) {
> >> +		for (i = 1; i < info->comp_planes; i++) {
> >> +			plane = &pix_mp->plane_fmt[i];
> >> +			pix_mp->plane_fmt[0].sizeimage += plane->sizeimage;
> >> +		}
> >> +	}
> >> +}
> >> +
> >> +static int mali_c55_try_fmt_vid_cap_mplane(struct file *file, void *fh,
> >> +					   struct v4l2_format *f)
> >> +{
> >> +	mali_c55_try_fmt(&f->fmt.pix_mp);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void mali_c55_set_format(struct mali_c55_cap_dev *cap_dev,
> >> +				struct v4l2_pix_format_mplane *pix_mp)
> >> +{
> >> +	const struct mali_c55_fmt *capture_format;
> >> +	struct mali_c55 *mali_c55 = cap_dev->mali_c55;
> >> +	const struct v4l2_format_info *info;
> >> +
> >> +	mali_c55_try_fmt(pix_mp);
> >> +	capture_format = mali_c55_format_from_pix(pix_mp->pixelformat);
> >> +	info = v4l2_format_info(pix_mp->pixelformat);
> >> +	if (WARN_ON(!info))
> >> +		return;
> >> +
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_Y_WRITER_MODE(cap_dev->reg_offset),
> >> +		       capture_format->registers.base_mode);
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_ACTIVE_OUT_Y_SIZE(cap_dev->reg_offset),
> >> +		       MALI_C55_REG_ACTIVE_OUT_SIZE_W(pix_mp->width) |
> >> +		       MALI_C55_REG_ACTIVE_OUT_SIZE_H(pix_mp->height));
> >> +
> >> +	if (info->mem_planes > 1) {
> >> +		mali_c55_write(mali_c55,
> >> +			       MALI_C55_REG_UV_WRITER_MODE(cap_dev->reg_offset),
> >> +			       capture_format->registers.base_mode);
> >> +		mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_UV_WRITER_MODE(cap_dev->reg_offset),
> >> +				MALI_C55_WRITER_SUBMODE_MASK,
> >> +				capture_format->registers.uv_plane);
> >> +
> >> +		mali_c55_write(mali_c55,
> >> +			MALI_C55_REG_ACTIVE_OUT_UV_SIZE(cap_dev->reg_offset),
> >> +			MALI_C55_REG_ACTIVE_OUT_SIZE_W(pix_mp->width) |
> >> +			MALI_C55_REG_ACTIVE_OUT_SIZE_H(pix_mp->height));
> >> +	}
> >> +
> >> +	if (info->pixel_enc == V4L2_PIXEL_ENC_YUV) {
> >> +		/*
> >> +		 * TODO: Figure out the colour matrix coefficients and calculate
> >> +		 * and write them here.
> >> +		 */
> >> +
> >> +		mali_c55_write(mali_c55,
> >> +			       MALI_C55_REG_CS_CONV_CONFIG(cap_dev->reg_offset),
> >> +			       MALI_C55_CS_CONV_MATRIX_MASK);
> >> +
> >> +		if (info->hdiv > 1)
> >> +			mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_CS_CONV_CONFIG(cap_dev->reg_offset),
> >> +				MALI_C55_CS_CONV_HORZ_DOWNSAMPLE_MASK, 0x01);
> >> +		if (info->vdiv > 1)
> >> +			mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_CS_CONV_CONFIG(cap_dev->reg_offset),
> >> +				MALI_C55_CS_CONV_VERT_DOWNSAMPLE_MASK, 0x01);
> >> +		if (info->hdiv > 1 || info->vdiv > 1)
> >> +			mali_c55_update_bits(mali_c55,
> >> +				MALI_C55_REG_CS_CONV_CONFIG(cap_dev->reg_offset),
> >> +				MALI_C55_CS_CONV_FILTER_MASK, 0x01);
> >> +	}
> >> +
> >> +	cap_dev->mode.pix_mp = *pix_mp;
> >> +	cap_dev->mode.capture_fmt = capture_format;
> >> +}
> >> +
> >> +static int mali_c55_s_fmt_vid_cap_mplane(struct file *file, void *fh,
> >> +					 struct v4l2_format *f)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = video_drvdata(file);
> >> +
> >> +	if (vb2_is_busy(&cap_dev->queue))
> >> +		return -EBUSY;
> >> +
> >> +	mali_c55_set_format(cap_dev, &f->fmt.pix_mp);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_g_fmt_vid_cap_mplane(struct file *file, void *fh,
> >> +					 struct v4l2_format *f)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = video_drvdata(file);
> >> +
> >> +	f->fmt.pix_mp = cap_dev->mode.pix_mp;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_enum_fmt_vid_cap_mplane(struct file *file, void *fh,
> >> +					    struct v4l2_fmtdesc *f)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev = video_drvdata(file);
> >> +	unsigned int j = 0;
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55_fmts); i++) {
> >> +		if (f->mbus_code &&
> >> +		    !mali_c55_mbus_code_can_produce_fmt(&mali_c55_fmts[i],
> >> +						       f->mbus_code))
> >> +			continue;
> >> +
> >> +		/* Downscale pipe can't output RAW formats */
> >> +		if (mali_c55_fmts[i].is_raw &&
> >> +		    cap_dev->reg_offset == MALI_C55_CAP_DEV_DS_REG_OFFSET)
> >> +			continue;
> >> +
> >> +		if (j++ == f->index) {
> >> +			f->pixelformat = mali_c55_fmts[i].fourcc;
> >> +			return 0;
> >> +		}
> >> +	}
> >> +
> >> +	return -EINVAL;
> >> +}
> >> +
> >> +static int mali_c55_querycap(struct file *file, void *fh,
> >> +			     struct v4l2_capability *cap)
> >> +{
> >> +	strscpy(cap->driver, MALI_C55_DRIVER_NAME, sizeof(cap->driver));
> >> +	strscpy(cap->card, "ARM Mali-C55 ISP", sizeof(cap->card));
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_ioctl_ops mali_c55_v4l2_ioctl_ops = {
> >> +	.vidioc_reqbufs = vb2_ioctl_reqbufs,
> >> +	.vidioc_querybuf = vb2_ioctl_querybuf,
> >> +	.vidioc_create_bufs = vb2_ioctl_create_bufs,
> >> +	.vidioc_qbuf = vb2_ioctl_qbuf,
> >> +	.vidioc_expbuf = vb2_ioctl_expbuf,
> >> +	.vidioc_dqbuf = vb2_ioctl_dqbuf,
> >> +	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
> >> +	.vidioc_streamon = vb2_ioctl_streamon,
> >> +	.vidioc_streamoff = vb2_ioctl_streamoff,
> >> +	.vidioc_try_fmt_vid_cap_mplane = mali_c55_try_fmt_vid_cap_mplane,
> >> +	.vidioc_s_fmt_vid_cap_mplane = mali_c55_s_fmt_vid_cap_mplane,
> >> +	.vidioc_g_fmt_vid_cap_mplane = mali_c55_g_fmt_vid_cap_mplane,
> >> +	.vidioc_enum_fmt_vid_cap = mali_c55_enum_fmt_vid_cap_mplane,
> >> +	.vidioc_querycap = mali_c55_querycap,
> >> +	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
> >> +	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> >> +};
> >> +
> >> +int mali_c55_register_capture_devs(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct v4l2_pix_format_mplane pix_mp;
> >> +	struct mali_c55_cap_dev *cap_dev;
> >> +	struct video_device *vdev;
> >> +	struct vb2_queue *vb2q;
> >> +	unsigned int i;
> >> +	int ret;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55->cap_devs); i++) {
> >> +		cap_dev = &mali_c55->cap_devs[i];
> >> +		vdev = &cap_dev->vdev;
> >> +		vb2q = &cap_dev->queue;
> >> +
> >> +		/*
> >> +		 * The downscale output pipe is an optional block within the ISP
> >> +		 * so we need to check whether it's actually been fitted or not.
> >> +		 */
> >> +
> >> +		if (i == MALI_C55_CAP_DEV_DS &&
> >> +		    !(mali_c55->capabilities & MALI_C55_GPS_DS_PIPE_FITTED))
> >> +			continue;
> >> +
> >> +		cap_dev->mali_c55 = mali_c55;
> >> +		mutex_init(&cap_dev->lock);
> >> +		INIT_LIST_HEAD(&cap_dev->buffers.queue);
> >> +
> >> +		switch (i) {
> >> +		case MALI_C55_CAP_DEV_FR:
> >> +			cap_dev->rzr = &mali_c55->resizers[MALI_C55_RZR_FR];
> >> +			cap_dev->reg_offset = MALI_C55_CAP_DEV_FR_REG_OFFSET;
> >> +			break;
> >> +		case MALI_C55_CAP_DEV_DS:
> >> +			cap_dev->rzr = &mali_c55->resizers[MALI_C55_RZR_DS];
> >> +			cap_dev->reg_offset = MALI_C55_CAP_DEV_DS_REG_OFFSET;
> >> +			break;
> >> +		default:
> >> +			mutex_destroy(&cap_dev->lock);
> >> +			ret = -EINVAL;
> >> +			goto err_destroy_mutex;
> >> +		}
> >> +
> >> +		cap_dev->pad.flags = MEDIA_PAD_FL_SINK;
> >> +		ret = media_entity_pads_init(&cap_dev->vdev.entity, 1, &cap_dev->pad);
> >> +		if (ret) {
> >> +			mutex_destroy(&cap_dev->lock);
> >> +			goto err_destroy_mutex;
> >> +		}
> >> +
> >> +		vb2q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
> >> +		vb2q->io_modes = VB2_MMAP | VB2_DMABUF;
> >> +		vb2q->drv_priv = cap_dev;
> >> +		vb2q->mem_ops = &vb2_dma_contig_memops;
> >> +		vb2q->ops = &mali_c55_vb2_ops;
> >> +		vb2q->buf_struct_size = sizeof(struct mali_c55_buffer);
> >> +		vb2q->min_queued_buffers = 1;
> >> +		vb2q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> >> +		vb2q->lock = &cap_dev->lock;
> >> +		vb2q->dev = mali_c55->dev;
> >> +
> >> +		ret = vb2_queue_init(vb2q);
> >> +		if (ret) {
> >> +			dev_err(mali_c55->dev, "%s vb2 queue init failed\n",
> >> +				mali_c55_cap_dev_to_name(cap_dev));
> >> +			goto err_cleanup_media_entity;
> >> +		}
> >> +
> >> +		strscpy(cap_dev->vdev.name, capture_device_names[i],
> >> +			sizeof(cap_dev->vdev.name));
> >> +		vdev->release = video_device_release_empty;
> >> +		vdev->fops = &mali_c55_v4l2_fops;
> >> +		vdev->ioctl_ops = &mali_c55_v4l2_ioctl_ops;
> >> +		vdev->lock = &cap_dev->lock;
> >> +		vdev->v4l2_dev = &mali_c55->v4l2_dev;
> >> +		vdev->queue = &cap_dev->queue;
> >> +		vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE_MPLANE |
> >> +				    V4L2_CAP_STREAMING | V4L2_CAP_IO_MC;
> >> +		vdev->entity.ops = &mali_c55_media_ops;
> >> +		video_set_drvdata(vdev, cap_dev);
> >> +
> >> +		memset(&pix_mp, 0, sizeof(pix_mp));
> >> +		pix_mp.pixelformat = V4L2_PIX_FMT_RGB565;
> >> +		pix_mp.width = MALI_C55_DEFAULT_WIDTH;
> >> +		pix_mp.height = MALI_C55_DEFAULT_HEIGHT;
> >> +		mali_c55_set_format(cap_dev, &pix_mp);
> >> +
> >> +		ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
> >> +		if (ret) {
> >> +			dev_err(mali_c55->dev,
> >> +				"%s failed to register video device\n",
> >> +				mali_c55_cap_dev_to_name(cap_dev));
> >> +			goto err_release_vb2q;
> >> +		}
> >> +	}
> >> +
> >> +	return 0;
> >> +
> >> +err_release_vb2q:
> >> +	vb2_queue_release(vb2q);
> >> +err_cleanup_media_entity:
> >> +	media_entity_cleanup(&cap_dev->vdev.entity);
> >> +err_destroy_mutex:
> >> +	mutex_destroy(&cap_dev->lock);
> >> +	mali_c55_unregister_capture_devs(mali_c55);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +void mali_c55_unregister_capture_devs(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_cap_dev *cap_dev;
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55->cap_devs); i++) {
> >> +		cap_dev = &mali_c55->cap_devs[i];
> >> +
> >> +		if (!video_is_registered(&cap_dev->vdev))
> >> +			continue;
> >> +
> >> +		vb2_video_unregister_device(&cap_dev->vdev);
> >> +		media_entity_cleanup(&cap_dev->vdev.entity);
> >> +		mutex_destroy(&cap_dev->lock);
> >> +	}
> >> +}
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-common.h b/drivers/media/platform/arm/mali-c55/mali-c55-common.h
> >> new file mode 100644
> >> index 000000000000..2d0c4d152beb
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-common.h
> >> @@ -0,0 +1,266 @@
> >> +/* SPDX-License-Identifier: GPL-2.0 */
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Common definitions
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#ifndef _MALI_C55_COMMON_H
> >> +#define _MALI_C55_COMMON_H
> >> +
> >> +#include <linux/clk.h>
> >> +#include <linux/io.h>
> >> +#include <linux/list.h>
> >> +#include <linux/mutex.h>
> >> +#include <linux/scatterlist.h>
> >
> > I don't think this is needed. You're however missing spinlock.h.
> >
> >> +#include <linux/videodev2.h>
> >> +
> >> +#include <media/media-device.h>
> >> +#include <media/v4l2-async.h>
> >> +#include <media/v4l2-ctrls.h>
> >> +#include <media/v4l2-dev.h>
> >> +#include <media/v4l2-device.h>
> >> +#include <media/v4l2-subdev.h>
> >> +#include <media/videobuf2-core.h>
> >> +#include <media/videobuf2-v4l2.h>
> >> +
> >> +#define MALI_C55_DRIVER_NAME		"mali-c55"
> >> +
> >> +/* min and max values for the image sizes */
> >> +#define MALI_C55_MIN_WIDTH		640U
> >> +#define MALI_C55_MIN_HEIGHT		480U
> >> +#define MALI_C55_MAX_WIDTH		8192U
> >> +#define MALI_C55_MAX_HEIGHT		8192U
> >> +#define MALI_C55_DEFAULT_WIDTH		1920U
> >> +#define MALI_C55_DEFAULT_HEIGHT		1080U
> >> +
> >> +#define MALI_C55_DEFAULT_MEDIA_BUS_FMT	MEDIA_BUS_FMT_RGB121212_1X36
> >> +
> >> +struct mali_c55;
> >> +struct mali_c55_cap_dev;
> >> +struct platform_device;
> >
> > You should also forward-declare
> >
> > struct device;
> > struct dma_chan;
> > struct resource;
> >
> >> +
> >> +static const char * const mali_c55_clk_names[] = {
> >> +	"aclk",
> >> +	"hclk",
> >> +};
> >
> > This will end up duplicating the array in each compilation unit, not
> > great. Move it to mali-c55-core.c. You use it in this file just for its
> > size, replace that with a macro that defines the size, or allocate
> > mali_c55.clks dynamically with devm_kcalloc().
> >
> >> +
> >> +enum mali_c55_interrupts {
> >> +	MALI_C55_IRQ_ISP_START,
> >> +	MALI_C55_IRQ_ISP_DONE,
> >> +	MALI_C55_IRQ_MCM_ERROR,
> >> +	MALI_C55_IRQ_BROKEN_FRAME_ERROR,
> >> +	MALI_C55_IRQ_MET_AF_DONE,
> >> +	MALI_C55_IRQ_MET_AEXP_DONE,
> >> +	MALI_C55_IRQ_MET_AWB_DONE,
> >> +	MALI_C55_IRQ_AEXP_1024_DONE,
> >> +	MALI_C55_IRQ_IRIDIX_MET_DONE,
> >> +	MALI_C55_IRQ_LUT_INIT_DONE,
> >> +	MALI_C55_IRQ_FR_Y_DONE,
> >> +	MALI_C55_IRQ_FR_UV_DONE,
> >> +	MALI_C55_IRQ_DS_Y_DONE,
> >> +	MALI_C55_IRQ_DS_UV_DONE,
> >> +	MALI_C55_IRQ_LINEARIZATION_DONE,
> >> +	MALI_C55_IRQ_RAW_FRONTEND_DONE,
> >> +	MALI_C55_IRQ_NOISE_REDUCTION_DONE,
> >> +	MALI_C55_IRQ_IRIDIX_DONE,
> >> +	MALI_C55_IRQ_BAYER2RGB_DONE,
> >> +	MALI_C55_IRQ_WATCHDOG_TIMER,
> >> +	MALI_C55_IRQ_FRAME_COLLISION,
> >> +	MALI_C55_IRQ_UNUSED,
> >> +	MALI_C55_IRQ_DMA_ERROR,
> >> +	MALI_C55_IRQ_INPUT_STOPPED,
> >> +	MALI_C55_IRQ_MET_AWB_TARGET1_HIT,
> >> +	MALI_C55_IRQ_MET_AWB_TARGET2_HIT,
> >> +	MALI_C55_NUM_IRQ_BITS
> >
> > Those are register bits, I think they belong to mali-c55-registers.h,
> > and should probably be macros instead of an enum.
> >
> >> +};
> >> +
> >> +enum mali_c55_isp_pads {
> >> +	MALI_C55_ISP_PAD_SINK_VIDEO,
> >
> > As there's a single sink pad, maybe MALI_C55_ISP_PAD_SINK ? Ah, you're
> > probably preparing for ISP parameters support. It's fine.
> >
> >> +	MALI_C55_ISP_PAD_SOURCE,
> >
> > Then maybe this should be named MALI_C55_ISP_PAD_SOURCE_VIDEO as I
> > assume there will be a stats source pad.
> >
> >> +	MALI_C55_ISP_PAD_SOURCE_BYPASS,
> >> +	MALI_C55_ISP_NUM_PADS,
> >> +};
> >> +
> >> +struct mali_c55_tpg {
> >> +	struct mali_c55 *mali_c55;
> >> +	struct v4l2_subdev sd;
> >> +	struct media_pad pad;
> >> +	struct mutex lock;
> >> +	struct mali_c55_tpg_ctrls {
> >> +		struct v4l2_ctrl_handler handler;
> >> +		struct v4l2_ctrl *test_pattern;
> >
> > Set but never used. You can drop it.
> >
> >> +		struct v4l2_ctrl *hblank;
> >
> > Set and used only once, in the same function. You can make it a local
> > variable.
> >
> >> +		struct v4l2_ctrl *vblank;
> >> +	} ctrls;
> >> +};
> >
> > I wonder if this file should be split, with mali-c55-capture.h,
> > mali-c55-core.h, mali-c55-isp.h, ... I think it could increase
> > readability by clearly separating the different elements. Up to you.
> >
> >> +
> >> +struct mali_c55_isp {
> >> +	struct mali_c55 *mali_c55;
> >> +	struct v4l2_subdev sd;
> >> +	struct media_pad pads[MALI_C55_ISP_NUM_PADS];
> >> +	struct media_pad *remote_src;
> >> +	struct v4l2_async_notifier notifier;
> >
> > I'm tempted to move the notifier to mali_c55, as it's related to
> > components external to the whole ISP, not to the ISP subdev itself.
> > Could you give it a try, to see if it could be done without any drawback
> > ?
> 
> This seems to work fine.
> 
> >
> >> +	struct mutex lock;
> >
> > Locks require a comment to explain what they protect. Same below where
> > applicable (for both mutexes and spinlocks).
> >
> >> +	unsigned int frame_sequence;
> >> +};
> >> +
> >> +enum mali_c55_resizer_ids {
> >> +	MALI_C55_RZR_FR,
> >> +	MALI_C55_RZR_DS,
> >> +	MALI_C55_NUM_RZRS,
> >
> > The usual abbreviation for "resizer" in drivers/media/ is "rsz", not
> > "rzr". I would have said we can leave it as-is as changing it would be a
> > bit annoying, but I then realized that "rzr" is not just unusual, it's
> > actually not used at all. Would you mind applying a sed globally ? :-)
> >
> >> +};
> >> +
> >> +enum mali_c55_rzr_pads {
> >
> > Same enums/structs use abbreviations, some don't. Consistency would
> > help.
> >
> >> +	MALI_C55_RZR_SINK_PAD,
> >> +	MALI_C55_RZR_SOURCE_PAD,
> >> +	MALI_C55_RZR_SINK_BYPASS_PAD,
> >> +	MALI_C55_RZR_NUM_PADS
> >> +};
> >> +
> >> +struct mali_c55_resizer {
> >> +	struct mali_c55 *mali_c55;
> >> +	struct mali_c55_cap_dev *cap_dev;
> >> +	enum mali_c55_resizer_ids id;
> >> +	struct v4l2_subdev sd;
> >> +	struct media_pad pads[MALI_C55_RZR_NUM_PADS];
> >> +	unsigned int num_routes;
> >> +	bool streaming;
> >> +};
> >> +
> >> +enum mali_c55_cap_devs {
> >> +	MALI_C55_CAP_DEV_FR,
> >> +	MALI_C55_CAP_DEV_DS,
> >> +	MALI_C55_NUM_CAP_DEVS
> >> +};
> >> +
> >> +struct mali_c55_fmt {
> >
> > mali_c55_format_info would be a better name I think, as this stores
> > format information, not formats.
> >
> >> +	u32 fourcc;
> >> +	unsigned int mbus_codes[2];
> >
> > A comment to explain why we have two media bus codes would be useful.
> > You can document the whole structure if desired :-)
> >
> >> +	bool is_raw;
> >> +	struct mali_c55_fmt_registers {
> >
> > Make it an anonymous structure, it's never used anywhere else.
> >
> >> +		unsigned int base_mode;
> >> +		unsigned int uv_plane;
> >
> > If those are register field values, use u32 instead of unsigned int.
> >
> >> +	} registers;
> >
> > It's funny, we tend to abbreviate different things, I would have used
> > "regs" here but written "format" in full in the structure name :-)
> >
> >> +};
> >> +
> >> +enum mali_c55_isp_bayer_order {
> >> +	MALI_C55_BAYER_ORDER_RGGB,
> >> +	MALI_C55_BAYER_ORDER_GRBG,
> >> +	MALI_C55_BAYER_ORDER_GBRG,
> >> +	MALI_C55_BAYER_ORDER_BGGR
> >
> > These are registers values too, they belong to mali-c55-registers.h.
> >
> >> +};
> >> +
> >> +struct mali_c55_isp_fmt {
> >
> > mali_c55_isp_format_info
> >
> >> +	u32 code;
> >> +	enum v4l2_pixel_encoding encoding;
> >
> > Here you use v4l2_pixel_encoding, for mali_c55_fmt you use is_raw. Maybe
> > pick the same option for both structures ?
> >
> >> +	enum mali_c55_isp_bayer_order order;
> >> +};
> >> +
> >> +enum mali_c55_planes {
> >> +	MALI_C55_PLANE_Y,
> >> +	MALI_C55_PLANE_UV,
> >> +	MALI_C55_NUM_PLANES
> >> +};
> >> +
> >> +struct mali_c55_buffer {
> >> +	struct vb2_v4l2_buffer vb;
> >> +	bool plane_done[MALI_C55_NUM_PLANES];
> >
> > I think tracking the pending state would simplify the logic in
> > mali_c55_set_plane_done(), which would become
> >
> > 	curr_buf->plane_pending[plane] = false;
> >
> > 	if (!curr_buf->plane_pending[0] && !curr_buf->plane_pending[1]) {
> > 		mali_c55_handle_buffer(curr_buf, isp->frame_sequence);
> > 		cap_dev->buffers.curr = NULL;
> > 		isp->frame_sequence++;
> > 	}
> >
> > Or a counter may be even easier (and would consume less memory).
>
> I'll do the counter; a  similar function in the stats code does so already.
>
> >> +	struct list_head queue;
> >> +	u32 addrs[MALI_C55_NUM_PLANES];
> >
> > This stores DMA addresses, use dma_addr_t.
> >
> >> +};
> >> +
> >> +struct mali_c55_cap_dev {
> >> +	struct mali_c55 *mali_c55;
> >> +	struct mali_c55_resizer *rzr;
> >> +	struct video_device vdev;
> >> +	struct media_pad pad;
> >> +	struct vb2_queue queue;
> >> +	struct mutex lock;
> >> +	unsigned int reg_offset;
> >
> > Manual handling of the offset everywhere, with parametric macros for the
> > resizer register addresses, isn't very nice. Introduce resizer-specific
> > accessors and capture-specific accessors (mali_c55_rsz_write(), ...)
> > that take a mali_c55_resizer or mali_c55_cap_dev pointer, and handle the
> > offset there. The register macros should loose their offset parameter.
> >
> > You could also use a single set of accessors that would become
> > path/output-specific (mali_c55_path_write() ? mali_c55_output_write()
> > ?), that may make the code easier to read.
> >
> > You can also replace reg_offset with a void __iomem * base, which would
> > avoid the computation at runtime.
> >
> >> +
> >> +	struct mali_c55_mode {
> >
> > Make the structure anonymous.
> >
> >> +		const struct mali_c55_fmt *capture_fmt;
> >> +		struct v4l2_pix_format_mplane pix_mp;
> >> +	} mode;
> >
> > What's a "mode" ? I think I'd name this
> >
> > 	struct {
> > 		const struct mali_c55_fmt *info;
> > 		struct v4l2_pix_format_mplane format;
> > 	} format;
> >
> > Or you could just drop the structure and have
> >
> > 	const struct mali_c55_fmt *format_info;
> > 	struct v4l2_pix_format_mplane format;
> >
> > or something similar.
> >
> >> +
> >> +	struct {
> >> +		spinlock_t lock;
> >> +		struct list_head queue;
> >> +		struct mali_c55_buffer *curr;
> >> +		struct mali_c55_buffer *next;
> >> +	} buffers;
> >> +
> >> +	bool streaming;
> >> +};
> >> +
> >> +enum mali_c55_config_spaces {
> >> +	MALI_C55_CONFIG_PING,
> >> +	MALI_C55_CONFIG_PONG,
> >> +	MALI_C55_NUM_CONFIG_SPACES
> >
> > The last enumerator is not used.
> >
> >> +};
> >> +
> >> +struct mali_c55_ctx {
> >
> > mali_c55_context ?
> >
> >> +	struct mali_c55 *mali_c55;
> >> +	void *registers;
> >
> > Please document this structure and explain that this field points to a
> > copy of the register space in system memory, I was about to write you're
> > missing __iomem :-)
>
> Will do
>
> >> +	phys_addr_t base;
> >> +	spinlock_t lock;
> >> +	struct list_head list;
> >> +};
> >> +
> >> +struct mali_c55 {
> >> +	struct device *dev;
> >> +	struct resource *res;
> >
> > You could possibly drop this field by passing the physical address of
> > the register space from mali_c55_probe() to mali_c55_init_context() as a
> > function parameter.
> >
> >> +	void __iomem *base;
> >> +	struct dma_chan *channel;
> >> +	struct clk_bulk_data clks[ARRAY_SIZE(mali_c55_clk_names)];
> >> +
> >> +	u16 capabilities;
> >> +	struct media_device media_dev;
> >> +	struct v4l2_device v4l2_dev;
> >> +	struct media_pipeline pipe;
> >> +
> >> +	struct mali_c55_tpg tpg;
> >> +	struct mali_c55_isp isp;
> >> +	struct mali_c55_resizer resizers[MALI_C55_NUM_RZRS];
> >> +	struct mali_c55_cap_dev cap_devs[MALI_C55_NUM_CAP_DEVS];
> >> +
> >> +	struct list_head contexts;
> >> +	enum mali_c55_config_spaces next_config;
> >> +};
> >> +
> >> +void mali_c55_write(struct mali_c55 *mali_c55, unsigned int addr, u32 val);
> >> +u32 mali_c55_read(struct mali_c55 *mali_c55, unsigned int addr,
> >> +		  bool force_hardware);
> >> +void mali_c55_update_bits(struct mali_c55 *mali_c55, unsigned int addr,
> >> +			  u32 mask, u32 val);
> >> +int mali_c55_config_write(struct mali_c55_ctx *ctx,
> >> +			  enum mali_c55_config_spaces cfg_space);
> >> +
> >> +int mali_c55_register_isp(struct mali_c55 *mali_c55);
> >> +int mali_c55_register_tpg(struct mali_c55 *mali_c55);
> >> +void mali_c55_unregister_tpg(struct mali_c55 *mali_c55);
> >> +void mali_c55_unregister_isp(struct mali_c55 *mali_c55);
> >> +int mali_c55_register_resizers(struct mali_c55 *mali_c55);
> >> +void mali_c55_unregister_resizers(struct mali_c55 *mali_c55);
> >> +int mali_c55_register_capture_devs(struct mali_c55 *mali_c55);
> >> +void mali_c55_unregister_capture_devs(struct mali_c55 *mali_c55);
> >> +struct mali_c55_ctx *mali_c55_get_active_context(struct mali_c55 *mali_c55);
> >> +void mali_c55_set_plane_done(struct mali_c55_cap_dev *cap_dev,
> >> +			     enum mali_c55_planes plane);
> >> +void mali_c55_set_next_buffer(struct mali_c55_cap_dev *cap_dev);
> >> +void mali_c55_isp_queue_event_sof(struct mali_c55 *mali_c55);
> >> +
> >> +bool mali_c55_format_is_raw(unsigned int mbus_code);
> >> +void mali_c55_rzr_start_stream(struct mali_c55_resizer *rzr);
> >> +void mali_c55_rzr_stop_stream(struct mali_c55_resizer *rzr);
> >> +int mali_c55_isp_start_stream(struct mali_c55_isp *isp);
> >> +void mali_c55_isp_stop_stream(struct mali_c55_isp *isp);
> >> +
> >> +const struct mali_c55_isp_fmt *
> >> +mali_c55_isp_fmt_next(const struct mali_c55_isp_fmt *fmt);
> >> +bool mali_c55_isp_is_format_supported(unsigned int mbus_code);
> >> +#define for_each_mali_isp_fmt(fmt)\
> >
> > #define for_each_mali_isp_fmt(fmt) \
> >
> >> +	for ((fmt) = NULL; ((fmt) = mali_c55_isp_fmt_next((fmt)));)
> >
> > Looks like parentheses were on sale :-)
>
> Hah
>
> > 	for ((fmt) = NULL; (fmt) = mali_c55_isp_fmt_next(fmt); )
> >
> > This macro is used in two places only, in the mali-c55-isp.c file where
> > open-coding the loop without using mali_c55_isp_fmt_next() would be more
> > efficient, and in mali-c55-resizer.c where a function to return format
> > i'th would be more efficient. I think you can drop the macro and the
> > mali_c55_isp_fmt_next() function.
> >
> >> +
> >> +#endif /* _MALI_C55_COMMON_H */
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-core.c b/drivers/media/platform/arm/mali-c55/mali-c55-core.c
> >> new file mode 100644
> >> index 000000000000..50caf5ee7474
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-core.c
> >> @@ -0,0 +1,767 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Core driver code
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#include <linux/bitops.h>
> >> +#include <linux/cleanup.h>
> >> +#include <linux/clk.h>
> >> +#include <linux/delay.h>
> >> +#include <linux/device.h>
> >> +#include <linux/dmaengine.h>
> >> +#include <linux/dma-mapping.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/iopoll.h>
> >> +#include <linux/ioport.h>
> >> +#include <linux/mod_devicetable.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_reserved_mem.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/scatterlist.h>
> >
> > I don't think this is needed.
> >
> > Missing slab.h.
> >
> >> +#include <linux/string.h>
> >> +
> >> +#include <media/media-entity.h>
> >> +#include <media/v4l2-device.h>
> >> +#include <media/videobuf2-dma-contig.h>
> >> +
> >> +#include "mali-c55-common.h"
> >> +#include "mali-c55-registers.h"
> >> +
> >> +static const char * const mali_c55_interrupt_names[] = {
> >> +	[MALI_C55_IRQ_ISP_START] = "ISP start",
> >> +	[MALI_C55_IRQ_ISP_DONE] = "ISP done",
> >> +	[MALI_C55_IRQ_MCM_ERROR] = "Multi-context management error",
> >> +	[MALI_C55_IRQ_BROKEN_FRAME_ERROR] = "Broken frame error",
> >> +	[MALI_C55_IRQ_MET_AF_DONE] = "AF metering done",
> >> +	[MALI_C55_IRQ_MET_AEXP_DONE] = "AEXP metering done",
> >> +	[MALI_C55_IRQ_MET_AWB_DONE] = "AWB metering done",
> >> +	[MALI_C55_IRQ_AEXP_1024_DONE] = "AEXP 1024-bit histogram done",
> >> +	[MALI_C55_IRQ_IRIDIX_MET_DONE] = "Iridix metering done",
> >> +	[MALI_C55_IRQ_LUT_INIT_DONE] = "LUT memory init done",
> >> +	[MALI_C55_IRQ_FR_Y_DONE] = "Full resolution Y plane DMA done",
> >> +	[MALI_C55_IRQ_FR_UV_DONE] = "Full resolution U/V plane DMA done",
> >> +	[MALI_C55_IRQ_DS_Y_DONE] = "Downscale Y plane DMA done",
> >> +	[MALI_C55_IRQ_DS_UV_DONE] = "Downscale U/V plane DMA done",
> >> +	[MALI_C55_IRQ_LINEARIZATION_DONE] = "Linearisation done",
> >> +	[MALI_C55_IRQ_RAW_FRONTEND_DONE] = "Raw frontend processing done",
> >> +	[MALI_C55_IRQ_NOISE_REDUCTION_DONE] = "Noise reduction done",
> >> +	[MALI_C55_IRQ_IRIDIX_DONE] = "Iridix done",
> >> +	[MALI_C55_IRQ_BAYER2RGB_DONE] = "Bayer to RGB conversion done",
> >> +	[MALI_C55_IRQ_WATCHDOG_TIMER] = "Watchdog timer timed out",
> >> +	[MALI_C55_IRQ_FRAME_COLLISION] = "Frame collision error",
> >> +	[MALI_C55_IRQ_UNUSED] = "IRQ bit unused",
> >> +	[MALI_C55_IRQ_DMA_ERROR] = "DMA error",
> >> +	[MALI_C55_IRQ_INPUT_STOPPED] = "Input port safely stopped",
> >> +	[MALI_C55_IRQ_MET_AWB_TARGET1_HIT] = "AWB metering target 1 address hit",
> >> +	[MALI_C55_IRQ_MET_AWB_TARGET2_HIT] = "AWB metering target 2 address hit"
> >> +};
> >> +
> >> +static unsigned int config_space_addrs[] = {
> >
> > const
> >
> >> +	[MALI_C55_CONFIG_PING] = 0x0AB6C,
> >> +	[MALI_C55_CONFIG_PONG] = 0x22B2C,
> >
> > Lowercase hex constants.
> >
> > Don't the values belong to mali-c55-registers.h ?
> >
> >> +};
> >> +
> >> +/* System IO
> >
> > /*
> >   * System IO
> >
> >> + *
> >> + * The Mali-C55 ISP has up to two configuration register spaces (called 'ping'
> >> + * and 'pong'), with the  expectation that the 'active' space will be left
> >
> > s/the  /the /
> >
> >> + * untouched whilst a frame is being processed and the 'inactive' space
> >> + * configured ready to be passed during the blanking period before the next
> >
> > s/to be passed/to be switched to/ ?
> >
> >> + * frame processing starts. These spaces should ideally be set via DMA transfer
> >> + * from a buffer rather than through individual register set operations. There
> >> + * is also a shared global register space which should be set normally. Of
> >> + * course, the ISP might be included in a system which lacks a suitable DMA
> >> + * engine, and the second configuration space might not be fitted at all, which
> >> + * means we need to support four scenarios:
> >> + *
> >> + * 1. Multi config space, with DMA engine.
> >> + * 2. Multi config space, no DMA engine.
> >> + * 3. Single config space, with DMA engine.
> >> + * 4. Single config space, no DMA engine.
> >> + *
> >> + * The first case is very easy, but the rest present annoying problems. The best
> >> + * way to solve them seems to be simply to replicate the concept of DMAing over
> >> + * the configuration buffer even if there's no DMA engine on the board, for
> >> + * which we rely on memcpy. To facilitate this any read/write call that is made
> >> + * to an address within those config spaces should infact be directed to a
> >> + * buffer that was allocated to hold them rather than the IO memory itself. The
> >> + * actual copy of that buffer to IO mem will happen on interrupt.
> >> + */
> >> +
> >> +void mali_c55_write(struct mali_c55 *mali_c55, unsigned int addr, u32 val)
> >> +{
> >> +	struct mali_c55_ctx *ctx = mali_c55_get_active_context(mali_c55);
> >> +
> >> +	if (addr >= MALI_C55_REG_CONFIG_SPACES_OFFSET) {
> >> +		spin_lock(&ctx->lock);
> >> +		addr = (addr - MALI_C55_REG_CONFIG_SPACES_OFFSET) / 4;
> >> +		((u32 *)ctx->registers)[addr] = val;
> >> +		spin_unlock(&ctx->lock);
> >> +
> >> +		return;
> >> +	}
> >
> > Ouch. This is likely the second comment you really won't like (after the
> > comment regarding mali_c55_update_bits() at the very top). I apologize
> > in advance.
> 
> All good - it's the thinking that is painful, changing the code is easy :)
> 
> > I really don't like this. Directing writes either to hardware registers
> > or to the shadow registers in the context makes the callers of the
> > read/write accessors very hard to read. The probe code, for instance,
> > mixes writes to hardware registers and writes to the context shadow
> > registers to initialize the value of some of the shadow registers.
> >
> > I'd like to split the read/write accessors into functions that access
> > the hardware registers (that's easy) and functions that access the
> > shadow registers. I think the latter should receive a mali_c55_ctx
> > pointer instead of a mali_c55 pointer to prepare for multi-context
> > support.
> >
> > You can add WARN_ON() guards to the two sets of functions, to ensure
> > that no register from the "other" space gets passed to the wrong
> > function by mistake.
> >
> >> +
> >> +	writel(val, mali_c55->base + addr);
> >> +}
> >> +
> >> +u32 mali_c55_read(struct mali_c55 *mali_c55, unsigned int addr,
> >> +		  bool force_hardware)
> >
> > force_hardware is never set to true.
> >
> >> +{
> >> +	struct mali_c55_ctx *ctx = mali_c55_get_active_context(mali_c55);
> >> +	u32 val;
> >> +
> >> +	if (addr >= MALI_C55_REG_CONFIG_SPACES_OFFSET && !force_hardware) {
> >> +		spin_lock(&ctx->lock);
> >> +		addr = (addr - MALI_C55_REG_CONFIG_SPACES_OFFSET) / 4;
> >> +		val = ((u32 *)ctx->registers)[addr];
> >> +		spin_unlock(&ctx->lock);
> >> +
> >> +		return val;
> >> +	}
> >> +
> >> +	return readl(mali_c55->base + addr);
> >> +}
> >> +
> >> +void mali_c55_update_bits(struct mali_c55 *mali_c55, unsigned int addr,
> >> +			  u32 mask, u32 val)
> >> +{
> >> +	u32 orig, tmp;
> >> +
> >> +	orig = mali_c55_read(mali_c55, addr, false);
> >> +
> >> +	tmp = orig & ~mask;
> >> +	tmp |= (val << (ffs(mask) - 1)) & mask;
> >> +
> >> +	if (tmp != orig)
> >> +		mali_c55_write(mali_c55, addr, tmp);
> >> +}
> >> +
> >> +static int mali_c55_dma_xfer(struct mali_c55_ctx *ctx, dma_addr_t src,
> >> +			     dma_addr_t dst, enum dma_data_direction dir)
> >> +{
> >> +	struct mali_c55 *mali_c55 = ctx->mali_c55;
> >> +	struct dma_async_tx_descriptor *tx;
> >> +	enum dma_status status;
> >> +	dma_cookie_t cookie;
> >> +
> >> +	tx = dmaengine_prep_dma_memcpy(mali_c55->channel, dst, src,
> >> +				       MALI_C55_CONFIG_SPACE_SIZE, 0);
> >> +	if (!tx) {
> >> +		dev_err(mali_c55->dev, "failed to prep DMA memcpy\n");
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	cookie = dmaengine_submit(tx);
> >> +	if (dma_submit_error(cookie)) {
> >> +		dev_err(mali_c55->dev, "error submitting dma transfer\n");
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	status = dma_sync_wait(mali_c55->channel, cookie);
> >
> > I've just realized this performs a busy-wait :-S See the comment in the
> > probe function about the threaded IRQ handler. I think we'll need to
> > rework all this. It could be done on top though.
>
> It can be switched to an asynchronous transfer quite easily.
> >
> >> +	if (status != DMA_COMPLETE) {
> >> +		dev_err(mali_c55->dev, "dma transfer failed\n");
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_dma_read(struct mali_c55_ctx *ctx,
> >> +			     enum mali_c55_config_spaces cfg_space)
> >> +{
> >> +	struct mali_c55 *mali_c55 = ctx->mali_c55;
> >> +	struct device *dma_dev = mali_c55->channel->device->dev;
> >> +	dma_addr_t src = ctx->base + config_space_addrs[cfg_space];
> >> +	dma_addr_t dst;
> >> +	int ret;
> >> +
> >> +	guard(spinlock)(&ctx->lock);
> >> +
> >> +	dst = dma_map_single(dma_dev, ctx->registers,
> >> +			     MALI_C55_CONFIG_SPACE_SIZE, DMA_FROM_DEVICE);
> >> +	if (dma_mapping_error(dma_dev, dst)) {
> >> +		dev_err(mali_c55->dev, "failed to map DMA addr\n");
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	ret = mali_c55_dma_xfer(ctx, src, dst, DMA_FROM_DEVICE);
> >> +	dma_unmap_single(dma_dev, dst, MALI_C55_CONFIG_SPACE_SIZE,
> >> +			 DMA_FROM_DEVICE);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int mali_c55_dma_write(struct mali_c55_ctx *ctx,
> >> +		       enum mali_c55_config_spaces cfg_space)
> >> +{
> >> +	struct mali_c55 *mali_c55 = ctx->mali_c55;
> >> +	struct device *dma_dev = mali_c55->channel->device->dev;
> >> +	dma_addr_t dst = ctx->base + config_space_addrs[cfg_space];
> >> +	dma_addr_t src;
> >> +	int ret;
> >> +
> >> +	guard(spinlock)(&ctx->lock);
> >
> > The code below can take a large amount of time, holding a spinlock will
> > disable interrupts on the local CPU, that's not good :-(
> 
> The intention here is just to prevent the rest of the driver writing into the register space whilst 
> it's being DMA transferred to the hardware - perhaps a different means to signal it's safe is more 
> appropriate?

Are there other parts of the driver that can write to the config space,
or do all writes to the config space go through this function ?

> >> +
> >> +	src = dma_map_single(dma_dev, ctx->registers,
> >> +			     MALI_C55_CONFIG_SPACE_SIZE, DMA_TO_DEVICE);
> >> +	if (dma_mapping_error(dma_dev, src)) {
> >> +		dev_err(mali_c55->dev, "failed to map DMA addr\n");
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	ret = mali_c55_dma_xfer(ctx, src, dst, DMA_TO_DEVICE);
> >> +	dma_unmap_single(dma_dev, src, MALI_C55_CONFIG_SPACE_SIZE,
> >> +			 DMA_TO_DEVICE);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int mali_c55_config_read(struct mali_c55_ctx *ctx,
> >> +				enum mali_c55_config_spaces cfg_space)
> >> +{
> >> +	struct mali_c55 *mali_c55 = ctx->mali_c55;
> >> +
> >> +	if (mali_c55->channel) {
> >> +		return mali_c55_dma_read(ctx, cfg_space);
> >
> > As this function is used at probe time only, to initialize the context,
> > I think DMA is overkill.
>
> Agreed - I'll switch this to memcpy_fromio()
>
> >> +	} else {
> >> +		memcpy_fromio(ctx->registers,
> >> +			      mali_c55->base + config_space_addrs[cfg_space],
> >> +			      MALI_C55_CONFIG_SPACE_SIZE);
> >> +		return 0;
> >> +	}
> >> +}
> >> +
> >> +int mali_c55_config_write(struct mali_c55_ctx *ctx,
> >> +			  enum mali_c55_config_spaces cfg_space)
> >> +{
> >> +	struct mali_c55 *mali_c55 = ctx->mali_c55;
> >> +
> >> +	if (mali_c55->channel) {
> >> +		return mali_c55_dma_write(ctx, cfg_space);
> >> +	} else {
> >> +		memcpy_toio(mali_c55->base + config_space_addrs[cfg_space],
> >> +			    ctx->registers, MALI_C55_CONFIG_SPACE_SIZE);
> >> +		return 0;
> >> +	}
> >
> > Could you measure the time it typically takes to write the registers
> > using DMA compared to using memcpy_toio() ?
>
> I will test this and come back to you.
>
> >> +}
> >> +
> >> +struct mali_c55_ctx *mali_c55_get_active_context(struct mali_c55 *mali_c55)
> >> +{
> >> +	return list_first_entry(&mali_c55->contexts, struct mali_c55_ctx, list);
> >
> > I think it's too early to tell how multi-context support will look like.
> > I'm fine keeping mali_c55_get_active_context() as changing that would be
> > very intrusive (even if I think it will need to be changed), but the
> > list of contexts is neither the mechanism we'll use, nor something we
> > need now. Drop the list, embed the context in struct mali_c55, and
> > return the pointer to that single context from this function.
> >
> >> +}
> >> +
> >> +static void mali_c55_remove_links(struct mali_c55 *mali_c55)
> >> +{
> >> +	unsigned int i;
> >> +
> >> +	media_entity_remove_links(&mali_c55->tpg.sd.entity);
> >> +	media_entity_remove_links(&mali_c55->isp.sd.entity);
> >> +
> >> +	for (i = 0; i < MALI_C55_NUM_RZRS; i++)
> >> +		media_entity_remove_links(&mali_c55->resizers[i].sd.entity);
> >> +
> >> +	for (i = 0; i < MALI_C55_NUM_CAP_DEVS; i++)
> >> +		media_entity_remove_links(&mali_c55->cap_devs[i].vdev.entity);
> >> +}
> >> +
> >> +static int mali_c55_create_links(struct mali_c55 *mali_c55)
> >> +{
> >> +	int ret;
> >> +
> >> +	/* Test pattern generator to ISP */
> >> +	ret = media_create_pad_link(&mali_c55->tpg.sd.entity, 0,
> >> +				    &mali_c55->isp.sd.entity,
> >> +				    MALI_C55_ISP_PAD_SINK_VIDEO, 0);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "failed to link TPG and ISP\n");
> >> +		goto err_remove_links;
> >> +	}
> >> +
> >> +	/* Full resolution resizer pipe. */
> >> +	ret = media_create_pad_link(&mali_c55->isp.sd.entity,
> >> +			MALI_C55_ISP_PAD_SOURCE,
> >> +			&mali_c55->resizers[MALI_C55_RZR_FR].sd.entity,
> >> +			MALI_C55_RZR_SINK_PAD,
> >> +			MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "failed to link ISP and FR resizer\n");
> >> +		goto err_remove_links;
> >> +	}
> >> +
> >> +	/* Full resolution bypass. */
> >> +	ret = media_create_pad_link(&mali_c55->isp.sd.entity,
> >> +				    MALI_C55_ISP_PAD_SOURCE_BYPASS,
> >> +				    &mali_c55->resizers[MALI_C55_RZR_FR].sd.entity,
> >> +				    MALI_C55_RZR_SINK_BYPASS_PAD,
> >> +				    MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "failed to link ISP and FR resizer\n");
> >> +		goto err_remove_links;
> >> +	}
> >> +
> >> +	/* Resizer pipe to video capture nodes. */
> >> +	ret = media_create_pad_link(&mali_c55->resizers[0].sd.entity,
> >> +			MALI_C55_RZR_SOURCE_PAD,
> >> +			&mali_c55->cap_devs[MALI_C55_CAP_DEV_FR].vdev.entity,
> >> +			0, MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev,
> >> +			"failed to link FR resizer and video device\n");
> >> +		goto err_remove_links;
> >> +	}
> >> +
> >> +	/* The downscale pipe is an optional hardware block */
> >> +	if (mali_c55->capabilities & MALI_C55_GPS_DS_PIPE_FITTED) {
> >> +		ret = media_create_pad_link(&mali_c55->isp.sd.entity,
> >> +			MALI_C55_ISP_PAD_SOURCE,
> >> +			&mali_c55->resizers[MALI_C55_RZR_DS].sd.entity,
> >> +			MALI_C55_RZR_SINK_PAD,
> >> +			MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
> >> +		if (ret) {
> >> +			dev_err(mali_c55->dev,
> >> +				"failed to link ISP and DS resizer\n");
> >> +			goto err_remove_links;
> >> +		}
> >> +
> >> +		ret = media_create_pad_link(&mali_c55->resizers[1].sd.entity,
> >> +			MALI_C55_RZR_SOURCE_PAD,
> >> +			&mali_c55->cap_devs[MALI_C55_CAP_DEV_DS].vdev.entity,
> >> +			0, MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
> >> +		if (ret) {
> >> +			dev_err(mali_c55->dev,
> >> +				"failed to link DS resizer and video device\n");
> >> +			goto err_remove_links;
> >> +		}
> >> +	}
> >> +
> >> +	return 0;
> >> +
> >> +err_remove_links:
> >> +	mali_c55_remove_links(mali_c55);
> >> +	return ret;
> >> +}
> >> +
> >> +static void mali_c55_unregister_entities(struct mali_c55 *mali_c55)
> >> +{
> >> +	mali_c55_unregister_tpg(mali_c55);
> >> +	mali_c55_unregister_isp(mali_c55);
> >> +	mali_c55_unregister_resizers(mali_c55);
> >> +	mali_c55_unregister_capture_devs(mali_c55);
> >> +}
> >> +
> >> +static int mali_c55_register_entities(struct mali_c55 *mali_c55)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = mali_c55_register_tpg(mali_c55);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ret = mali_c55_register_isp(mali_c55);
> >> +	if (ret)
> >> +		goto err_unregister_entities;
> >> +
> >> +	ret = mali_c55_register_resizers(mali_c55);
> >> +	if (ret)
> >> +		goto err_unregister_entities;
> >> +
> >> +	ret = mali_c55_register_capture_devs(mali_c55);
> >> +	if (ret)
> >> +		goto err_unregister_entities;
> >> +
> >> +	ret = mali_c55_create_links(mali_c55);
> >> +	if (ret)
> >> +		goto err_unregister_entities;
> >> +
> >> +	return 0;
> >> +
> >> +err_unregister_entities:
> >> +	mali_c55_unregister_entities(mali_c55);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static u32 mali_c55_check_hwcfg(struct mali_c55 *mali_c55)
> >> +{
> >> +	u32 product, version, revision, capabilities;
> >> +
> >> +	product = mali_c55_read(mali_c55, MALI_C55_REG_PRODUCT, false);
> >> +	version = mali_c55_read(mali_c55, MALI_C55_REG_VERSION, false);
> >> +	revision = mali_c55_read(mali_c55, MALI_C55_REG_REVISION, false);
> >> +
> >> +	dev_info(mali_c55->dev, "Detected Mali-C55 ISP %u.%u.%u\n",
> >> +		 product, version, revision);
> >> +
> >> +	capabilities = mali_c55_read(mali_c55,
> >> +				     MALI_C55_REG_GLOBAL_PARAMETER_STATUS,
> >> +				     false);
> >> +	mali_c55->capabilities = (capabilities & 0xffff);
> >> +
> >> +	/* TODO: Might as well start some debugfs */
> >
> > If it's just to expose the version and capabilities, I think that's
> > overkill. It's not needed for debug purpose (you can get it from the
> > kernel log already). debugfs isn't meant to be accessible in production,
> > so an application that would need access to the information wouldn't be
> > able to use it.
> >
> >> +	dev_info(mali_c55->dev, "Mali-C55 capabilities: 0x%04x\n", capabilities);
> >
> > Combine the two messages into one.
> >
> >> +	return version;
> >> +}
> >> +
> >> +static void mali_c55_swap_next_config(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_ctx *ctx = mali_c55_get_active_context(mali_c55);
> >> +	u32 curr_config, next_config;
> >> +
> >> +	curr_config = mali_c55_read(mali_c55, MALI_C55_REG_PING_PONG_READ, false);
> >> +	curr_config = (curr_config & MALI_C55_REG_PING_PONG_READ_MASK)
> >> +		      >> (ffs(MALI_C55_REG_PING_PONG_READ_MASK) - 1);
> >> +	next_config = curr_config ^ 1;
> >> +
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_MCU_CONFIG,
> >> +			     MALI_C55_REG_MCU_CONFIG_WRITE_MASK, next_config);
> >> +	mali_c55_config_write(ctx, next_config ?
> >> +			      MALI_C55_CONFIG_PING : MALI_C55_CONFIG_PONG);
> >> +}
> >> +
> >> +static irqreturn_t mali_c55_isr(int irq, void *context)
> >> +{
> >> +	struct device *dev = context;
> >> +	struct mali_c55 *mali_c55 = dev_get_drvdata(dev);
> >> +	u32 interrupt_status;
> >> +	unsigned int i, j;
> >> +
> >> +	interrupt_status = mali_c55_read(mali_c55,
> >> +					 MALI_C55_REG_INTERRUPT_STATUS_VECTOR,
> >> +					 false);
> >> +	if (!interrupt_status)
> >> +		return IRQ_NONE;
> >> +
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INTERRUPT_CLEAR_VECTOR,
> >> +		       interrupt_status);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INTERRUPT_CLEAR, 0);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INTERRUPT_CLEAR, 1);
> >> +
> >> +	for (i = 0; i < MALI_C55_NUM_IRQ_BITS; i++) {
> >> +		if (!(interrupt_status & (1 << i)))
> >> +			continue;
> >> +
> >> +		switch (i) {
> >> +		case MALI_C55_IRQ_ISP_START:
> >> +			mali_c55_isp_queue_event_sof(mali_c55);
> >> +
> >> +			for (j = i; j < MALI_C55_NUM_CAP_DEVS; j++)
> >> +				mali_c55_set_next_buffer(&mali_c55->cap_devs[j]);
> >> +
> >> +			mali_c55_swap_next_config(mali_c55);
> >> +
> >> +			break;
> >> +		case MALI_C55_IRQ_ISP_DONE:
> >> +			/*
> >> +			 * TODO: Where the ISP has no Pong config fitted, we'd
> >> +			 * have to do the mali_c55_swap_next_config() call here.
> >> +			 */
> >> +			break;
> >> +		case MALI_C55_IRQ_FR_Y_DONE:
> >> +			mali_c55_set_plane_done(
> >> +				&mali_c55->cap_devs[MALI_C55_CAP_DEV_FR],
> >> +				MALI_C55_PLANE_Y);
> >> +			break;
> >> +		case MALI_C55_IRQ_FR_UV_DONE:
> >> +			mali_c55_set_plane_done(
> >> +				&mali_c55->cap_devs[MALI_C55_CAP_DEV_FR],
> >> +				MALI_C55_PLANE_UV);
> >> +			break;
> >> +		case MALI_C55_IRQ_DS_Y_DONE:
> >> +			mali_c55_set_plane_done(
> >> +				&mali_c55->cap_devs[MALI_C55_CAP_DEV_DS],
> >> +				MALI_C55_PLANE_Y);
> >> +			break;
> >> +		case MALI_C55_IRQ_DS_UV_DONE:
> >> +			mali_c55_set_plane_done(
> >> +				&mali_c55->cap_devs[MALI_C55_CAP_DEV_DS],
> >> +				MALI_C55_PLANE_UV);
> >> +			break;
> >> +		default:
> >> +			/*
> >> +			 * Only the above interrupts are currently unmasked. If
> >> +			 * we receive anything else here then something weird
> >> +			 * has gone on.
> >> +			 */
> >> +			dev_err(dev, "masked interrupt %s triggered\n",
> >> +				mali_c55_interrupt_names[i]);
> >> +		}
> >> +	}
> >> +
> >> +	return IRQ_HANDLED;
> >> +}
> >> +
> >> +static int mali_c55_init_context(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_ctx *ctx;
> >> +	int ret;
> >> +
> >> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> >> +	if (!ctx) {
> >> +		dev_err(mali_c55->dev, "failed to allocate new context\n");
> >
> > No need for an error message when memory allocation fails.
> >
> >> +		return -ENOMEM;
> >> +	}
> >> +
> >> +	ctx->base = mali_c55->res->start;
> >> +	ctx->mali_c55 = mali_c55;
> >> +
> >> +	ctx->registers = kzalloc(MALI_C55_CONFIG_SPACE_SIZE,
> >> +				 GFP_KERNEL | GFP_DMA);
> >> +	if (!ctx->registers) {
> >> +		ret = -ENOMEM;
> >> +		goto err_free_ctx;
> >> +	}
> >> +
> >> +	/*
> >> +	 * The allocated memory is empty, we need to load the default
> >> +	 * register settings. We just read Ping; it's identical to Pong.
> >> +	 */
> >> +	ret = mali_c55_config_read(ctx, MALI_C55_CONFIG_PING);
> >> +	if (ret)
> >> +		goto err_free_registers;
> >> +
> >> +	list_add_tail(&ctx->list, &mali_c55->contexts);
> >> +
> >> +	/*
> >> +	 * Some features of the ISP need to be disabled by default and only
> >> +	 * enabled at the same time as they're configured by a parameters buffer
> >> +	 */
> >> +
> >> +	/* Bypass the sqrt and square compression and expansion modules */
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_BYPASS_1,
> >> +			     MALI_C55_REG_BYPASS_1_FE_SQRT, 0x01);
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_BYPASS_3,
> >> +			     MALI_C55_REG_BYPASS_3_SQUARE_BE, 0x01);
> >> +
> >> +	/* Bypass the temper module */
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_BYPASS_2,
> >> +		       MALI_C55_REG_BYPASS_2_TEMPER);
> >> +
> >> +	/* Bypass the colour noise reduction  */
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_BYPASS_4,
> >> +		       MALI_C55_REG_BYPASS_4_CNR);
> >> +
> >> +	/* Disable the sinter module */
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_SINTER_CONFIG,
> >> +			     MALI_C55_SINTER_ENABLE_MASK, 0x00);
> >> +
> >> +	/* Disable the RGB Gamma module for each output */
> >> +	mali_c55_write(
> >> +		mali_c55,
> >> +		MALI_C55_REG_GAMMA_RGB_ENABLE(MALI_C55_CAP_DEV_FR_REG_OFFSET),
> >> +		0x00);
> >> +	mali_c55_write(
> >> +		mali_c55,
> >> +		MALI_C55_REG_GAMMA_RGB_ENABLE(MALI_C55_CAP_DEV_DS_REG_OFFSET),
> >> +		0x00);
> >> +
> >> +	/* Disable the colour correction matrix */
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_CCM_ENABLE, 0x00);
> >> +
> >> +	return 0;
> >> +
> >> +err_free_registers:
> >> +	kfree(ctx->registers);
> >> +err_free_ctx:
> >> +	kfree(ctx);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int mali_c55_runtime_resume(struct device *dev)
> >> +{
> >> +	struct mali_c55 *mali_c55 = dev_get_drvdata(dev);
> >> +	int ret;
> >> +
> >> +	ret = clk_bulk_prepare_enable(ARRAY_SIZE(mali_c55->clks),
> >> +				      mali_c55->clks);
> >> +	if (ret)
> >> +		dev_err(mali_c55->dev, "failed to enable clocks\n");
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int mali_c55_runtime_suspend(struct device *dev)
> >> +{
> >> +	struct mali_c55 *mali_c55 = dev_get_drvdata(dev);
> >> +
> >> +	clk_bulk_disable_unprepare(ARRAY_SIZE(mali_c55->clks), mali_c55->clks);
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct dev_pm_ops mali_c55_pm_ops = {
> >> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> >> +				pm_runtime_force_resume)
> >> +	SET_RUNTIME_PM_OPS(mali_c55_runtime_suspend, mali_c55_runtime_resume,
> >> +			   NULL)
> >> +};
> >> +
> >> +static int mali_c55_probe(struct platform_device *pdev)
> >> +{
> >> +	struct device *dev = &pdev->dev;
> >> +	struct mali_c55 *mali_c55;
> >> +	dma_cap_mask_t mask;
> >> +	u32 version;
> >> +	int ret;
> >> +	u32 val;
> >> +
> >> +	mali_c55 = devm_kzalloc(dev, sizeof(*mali_c55), GFP_KERNEL);
> >> +	if (!mali_c55)
> >> +		return dev_err_probe(dev, -ENOMEM,
> >> +				     "failed to allocate memory\n");
> >
> > 		return -ENOMEM;
> >
> > There's no need to print messages for memory allocation failures.
> >
> >> +
> >> +	mali_c55->dev = dev;
> >> +	platform_set_drvdata(pdev, mali_c55);
> >> +
> >> +	mali_c55->base = devm_platform_get_and_ioremap_resource(pdev, 0,
> >> +								&mali_c55->res);
> >> +	if (IS_ERR(mali_c55->base))
> >> +		return dev_err_probe(dev, PTR_ERR(mali_c55->base),
> >> +				     "failed to map IO memory\n");
> >> +
> >> +	ret = platform_get_irq(pdev, 0);
> >> +	if (ret < 0)
> >> +		return dev_err_probe(dev, ret, "failed to get interrupt num\n");
> >
> > s/ num// or s/num/number/
> >
> >> +
> >> +	ret = devm_request_threaded_irq(&pdev->dev, ret, NULL,
> >> +					mali_c55_isr, IRQF_ONESHOT,
> >> +					dev_driver_string(&pdev->dev),
> >> +					&pdev->dev);
> >
> > Requested the IRQ should be done much lower, after you have initialized
> > everything, or an IRQ that would fire early would have really bad
> > consequences.
> >
> > A comment to explain why you need a threaded interrupt handler would be
> > good. I assume it is due only to the need to transfer the registers
> > using DMA. I wonder if we should then split the interrupt handler in
> > two, with a non-threaded part for the operations that can run quickly,
> > and a threaded part for the reprogramming.
> 
> Instead of passing NULL for the top handler you mean?

Yes.

> > It may also be that we could just start the DMA transfer in the
> > non-threaded handler without waiting synchronously for it to complete.
> > That would be a bigger change, and would require checking race
> > conditions carefully. On the other hand, I'm a bit concerned about the
> > current implementation, have you tested what happens if the DMA transfer
> > takes too long to complete, and spans frame boundaries ?
> 
> No; I can force a delay in the DMA engine and see how it behaves. The stats buffers are currently 
> DMAd asynchronously; I don't think it'd be a huge change to make the configuration buffer handling 
> work that way too.

That would be nice. Race conditions will need to be carefully considered
(but they should, anyway).

> >> +	if (ret)
> >> +		return dev_err_probe(dev, ret, "failed to request irq\n");
> >> +
> >> +	for (unsigned int i = 0; i < ARRAY_SIZE(mali_c55_clk_names); i++)
> >> +		mali_c55->clks[i].id = mali_c55_clk_names[i];
> >> +
> >> +	ret = devm_clk_bulk_get(dev, ARRAY_SIZE(mali_c55->clks), mali_c55->clks);
> >> +	if (ret)
> >> +		return dev_err_probe(dev, ret, "failed to acquire clocks\n");
> >> +
> >> +	pm_runtime_enable(&pdev->dev);
> >> +
> >> +	ret = pm_runtime_resume_and_get(&pdev->dev);
> >> +	if (ret)
> >> +		goto err_pm_runtime_disable;
> >> +
> >> +	of_reserved_mem_device_init(dev);
> >
> > I'd move this, the vb2_dma_contig_set_max_seg_size() call and the
> > dma_cap_* calls before pm_runtime_enable() as they don't need the device
> > to be powered.
> >
> >> +	version = mali_c55_check_hwcfg(mali_c55);
> >> +	vb2_dma_contig_set_max_seg_size(dev, UINT_MAX);
> >> +
> >> +	/* Use "software only" context management. */
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_MCU_CONFIG,
> >> +			     MALI_C55_REG_MCU_CONFIG_OVERRIDE_MASK,
> >> +			     MALI_C55_REG_MCU_CONFIG_OVERRIDE_MASK);
> >
> > You handle that in mali_c55_isp_start(), does the register have to be
> > set here too ?
> >
> >> +
> >> +	dma_cap_zero(mask);
> >> +	dma_cap_set(DMA_MEMCPY, mask);
> >> +
> >> +	/*
> >> +	 * No error check, because we will just fallback on memcpy if there is
> >> +	 * no usable DMA channel on the system.
> >> +	 */
> >> +	mali_c55->channel = dma_request_channel(mask, NULL, NULL);
> >> +
> >> +	INIT_LIST_HEAD(&mali_c55->contexts);
> >> +	ret = mali_c55_init_context(mali_c55);
> >> +	if (ret)
> >> +		goto err_release_dma_channel;
> >> +
> >
> > I'd move all the code from here ...
> >
> >> +	mali_c55->media_dev.dev = dev;
> >> +	strscpy(mali_c55->media_dev.model, "ARM Mali-C55 ISP",
> >> +		sizeof(mali_c55->media_dev.model));
> >> +	mali_c55->media_dev.hw_revision = version;
> >> +
> >> +	media_device_init(&mali_c55->media_dev);
> >> +	ret = media_device_register(&mali_c55->media_dev);
> >> +	if (ret)
> >> +		goto err_cleanup_media_device;
> >> +
> >> +	mali_c55->v4l2_dev.mdev = &mali_c55->media_dev;
> >> +	ret = v4l2_device_register(dev, &mali_c55->v4l2_dev);
> >> +	if (ret) {
> >> +		dev_err(dev, "failed to register V4L2 device\n");
> >> +		goto err_unregister_media_device;
> >> +	};
> >> +
> >> +	ret = mali_c55_register_entities(mali_c55);
> >> +	if (ret) {
> >> +		dev_err(dev, "failed to register entities\n");
> >> +		goto err_unregister_v4l2_device;
> >> +	}
> >
> > ... to here to a separate function, or maybe fold it all in
> > mali_c55_register_entities() (which should the be renamed). Same thing
> > for the cleanup code.
> >
> >> +
> >> +	/* Set safe stop to ensure we're in a non-streaming state */
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INPUT_MODE_REQUEST,
> >> +		       MALI_C55_INPUT_SAFE_STOP);
> >> +	readl_poll_timeout(mali_c55->base + MALI_C55_REG_MODE_STATUS,
> >> +			   val, !val, 10 * USEC_PER_MSEC, 250 * USEC_PER_MSEC);
> >> +
> >> +	/*
> >> +	 * We're ready to process interrupts. Clear any that are set and then
> >> +	 * unmask them for processing.
> >> +	 */
> >> +	mali_c55_write(mali_c55, 0x30, 0xffffffff);
> >> +	mali_c55_write(mali_c55, 0x34, 0xffffffff);
> >> +	mali_c55_write(mali_c55, 0x40, 0x01);
> >> +	mali_c55_write(mali_c55, 0x40, 0x00);
> >
> > Please replace the register addresses with macros.
> >
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INTERRUPT_MASK_VECTOR, 0x39fc3fc);
> >
> > The value should use the interrupt bits macros.
> >
> >> +
> >> +	pm_runtime_put(&pdev->dev);
> >
> > Once power gets cut, the registers your programmed above may be lost. I
> > think you should programe them in the runtime PM resume handler.
> >
> >> +
> >> +	return 0;
> >> +
> >> +err_unregister_v4l2_device:
> >> +	v4l2_device_unregister(&mali_c55->v4l2_dev);
> >> +err_unregister_media_device:
> >> +	media_device_unregister(&mali_c55->media_dev);
> >> +err_cleanup_media_device:
> >> +	media_device_cleanup(&mali_c55->media_dev);
> >> +err_release_dma_channel:
> >> +	dma_release_channel(mali_c55->channel);
> >> +err_pm_runtime_disable:
> >> +	pm_runtime_disable(&pdev->dev);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static void mali_c55_remove(struct platform_device *pdev)
> >> +{
> >> +	struct mali_c55 *mali_c55 = platform_get_drvdata(pdev);
> >> +	struct mali_c55_ctx *ctx, *tmp;
> >> +
> >> +	list_for_each_entry_safe(ctx, tmp, &mali_c55->contexts, list) {
> >> +		list_del(&ctx->list);
> >> +		kfree(ctx->registers);
> >> +		kfree(ctx);
> >> +	}
> >> +
> >> +	mali_c55_remove_links(mali_c55);
> >> +	mali_c55_unregister_entities(mali_c55);
> >> +	v4l2_device_put(&mali_c55->v4l2_dev);
> >> +	media_device_unregister(&mali_c55->media_dev);
> >> +	media_device_cleanup(&mali_c55->media_dev);
> >> +	dma_release_channel(mali_c55->channel);
> >> +}
> >> +
> >> +static const struct of_device_id mali_c55_of_match[] = {
> >> +	{ .compatible = "arm,mali-c55", },
> >> +	{},
> >
> > 	{ /* Sentinel */ },
> >
> >> +};
> >> +MODULE_DEVICE_TABLE(of, mali_c55_of_match);
> >> +
> >> +static struct platform_driver mali_c55_driver = {
> >> +	.driver = {
> >> +		.name = "mali-c55",
> >> +		.of_match_table = of_match_ptr(mali_c55_of_match),
> >
> > Drop of_match_ptr().
> >
> >> +		.pm = &mali_c55_pm_ops,
> >> +	},
> >> +	.probe = mali_c55_probe,
> >> +	.remove_new = mali_c55_remove,
> >> +};
> >> +
> >> +module_platform_driver(mali_c55_driver);
> >
> > Blank line.
> >
> >> +MODULE_AUTHOR("Daniel Scally <dan.scally@xxxxxxxxxxxxxxxx>");
> >> +MODULE_AUTHOR("Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>");
> >> +MODULE_DESCRIPTION("ARM Mali-C55 ISP platform driver");
> >> +MODULE_LICENSE("GPL");
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-isp.c b/drivers/media/platform/arm/mali-c55/mali-c55-isp.c
> >> new file mode 100644
> >> index 000000000000..ea8b7b866e7a
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-isp.c
> >> @@ -0,0 +1,611 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Image signal processor
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#include <linux/delay.h>
> >> +#include <linux/iopoll.h>
> >> +#include <linux/property.h>
> >> +#include <linux/string.h>
> >> +
> >> +#include <media/media-entity.h>
> >> +#include <media/v4l2-common.h>
> >> +#include <media/v4l2-event.h>
> >> +#include <media/v4l2-mc.h>
> >> +#include <media/v4l2-subdev.h>
> >> +
> >> +#include "mali-c55-common.h"
> >> +#include "mali-c55-registers.h"
> >> +
> >> +static const struct mali_c55_isp_fmt mali_c55_isp_fmts[] = {
> >> +	{
> >> +		.code = MEDIA_BUS_FMT_SRGGB20_1X20,
> >> +		.order = MALI_C55_BAYER_ORDER_RGGB,
> >> +		.encoding = V4L2_PIXEL_ENC_BAYER,
> >> +	},
> >> +	{
> >> +		.code = MEDIA_BUS_FMT_SGRBG20_1X20,
> >> +		.order = MALI_C55_BAYER_ORDER_GRBG,
> >> +		.encoding = V4L2_PIXEL_ENC_BAYER,
> >> +	},
> >> +	{
> >> +		.code = MEDIA_BUS_FMT_SGBRG20_1X20,
> >> +		.order = MALI_C55_BAYER_ORDER_GBRG,
> >> +		.encoding = V4L2_PIXEL_ENC_BAYER,
> >> +	},
> >> +	{
> >> +		.code = MEDIA_BUS_FMT_SBGGR20_1X20,
> >> +		.order = MALI_C55_BAYER_ORDER_BGGR,
> >> +		.encoding = V4L2_PIXEL_ENC_BAYER,
> >> +	},
> >> +	{
> >> +		.code = MEDIA_BUS_FMT_RGB202020_1X60,
> >> +		.order = 0, /* Not relevant for this format */
> >> +		.encoding = V4L2_PIXEL_ENC_RGB,
> >> +	}
> >> +	/*
> >> +	 * TODO: Support MEDIA_BUS_FMT_YUV20_1X60 here. This is so that we can
> >> +	 * also support YUV input from a sensor passed-through to the output. At
> >> +	 * present we have no mechanism to test that though so it may have to
> >> +	 * wait a while...
> >> +	 */
> >> +};
> >> +
> >> +const struct mali_c55_isp_fmt *
> >> +mali_c55_isp_fmt_next(const struct mali_c55_isp_fmt *fmt)
> >> +{
> >> +	if (!fmt)
> >> +		fmt = &mali_c55_isp_fmts[0];
> >> +	else
> >> +		fmt++;
> >> +
> >> +	for (; fmt < &mali_c55_isp_fmts[ARRAY_SIZE(mali_c55_isp_fmts)]; fmt++)
> >> +		return fmt;
> >
> > That's peculiar.
> >
> > 	if (!fmt)
> > 		fmt = &mali_c55_isp_fmts[0];
> > 	else if (fmt < &mali_c55_isp_fmts[ARRAY_SIZE(mali_c55_isp_fmts)])
> > 		return ++fmt;
> > 	else
> > 		return NULL;
> >
> >> +
> >> +	return NULL;
> >> +}
> >> +
> >> +bool mali_c55_isp_is_format_supported(unsigned int mbus_code)
> >> +{
> >> +	const struct mali_c55_isp_fmt *isp_fmt;
> >> +
> >> +	for_each_mali_isp_fmt(isp_fmt) {
> >
> > I would open-code the loop instead of using the macro, like you do
> > below. It will be more efficient.
> >
> >> +		if (isp_fmt->code == mbus_code)
> >> +			return true;
> >> +	}
> >> +
> >> +	return false;
> >> +}
> >> +
> >> +static const struct mali_c55_isp_fmt *
> >> +mali_c55_isp_get_mbus_config_by_code(u32 code)
> >> +{
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55_isp_fmts); i++) {
> >> +		if (mali_c55_isp_fmts[i].code == code)
> >> +			return &mali_c55_isp_fmts[i];
> >> +	}
> >> +
> >> +	return NULL;
> >> +}
> >> +
> >> +static void mali_c55_isp_stop(struct mali_c55 *mali_c55)
> >> +{
> >> +	u32 val;
> >> +
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INPUT_MODE_REQUEST, MALI_C55_INPUT_SAFE_STOP);
> >
> > 	mali_c55_write(mali_c55, MALI_C55_REG_INPUT_MODE_REQUEST,
> > 		       MALI_C55_INPUT_SAFE_STOP);
> >
> >> +	readl_poll_timeout(mali_c55->base + MALI_C55_REG_MODE_STATUS,
> >> +			   val, !val, 10 * USEC_PER_MSEC, 250 * USEC_PER_MSEC);
> >> +}
> >> +
> >> +static int mali_c55_isp_start(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_ctx *ctx = mali_c55_get_active_context(mali_c55);
> >> +	const struct mali_c55_isp_fmt *cfg;
> >> +	struct v4l2_mbus_framefmt *format;
> >
> > const
> >
> >> +	struct v4l2_subdev_state *state;
> >> +	struct v4l2_rect *crop;
> >
> > const
> >
> >> +	struct v4l2_subdev *sd;
> >> +	u32 val;
> >> +	int ret;
> >> +
> >> +	sd = &mali_c55->isp.sd;
> >
> > Assign when declaring the variable.
> >
> >> +
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_MCU_CONFIG,
> >> +			     MALI_C55_REG_MCU_CONFIG_WRITE_MASK, 0x01);
> >> +
> >> +	/* Apply input windowing */
> >> +	state = v4l2_subdev_get_locked_active_state(sd);
> >
> > Using .enable_streams() (see below) you'll get this for free.
> >
> >> +	crop = v4l2_subdev_state_get_crop(state, MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +	format = v4l2_subdev_state_get_format(state,
> >> +					      MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +	cfg = mali_c55_isp_get_mbus_config_by_code(format->code);
> >> +
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_HC_START,
> >> +		       MALI_C55_HC_START(crop->left));
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_HC_SIZE,
> >> +		       MALI_C55_HC_SIZE(crop->width));
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_VC_START_SIZE,
> >> +		       MALI_C55_VC_START(crop->top) |
> >> +		       MALI_C55_VC_SIZE(crop->height));
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_BASE_ADDR,
> >> +			     MALI_C55_REG_ACTIVE_WIDTH_MASK, format->width);
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_BASE_ADDR,
> >> +			     MALI_C55_REG_ACTIVE_HEIGHT_MASK, format->height);
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_BAYER_ORDER,
> >> +			     MALI_C55_BAYER_ORDER_MASK, cfg->order);
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_INPUT_WIDTH,
> >> +			     MALI_C55_INPUT_WIDTH_MASK,
> >> +			     MALI_C55_INPUT_WIDTH_20BIT);
> >> +
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_ISP_RAW_BYPASS,
> >> +			     MALI_C55_ISP_RAW_BYPASS_BYPASS_MASK,
> >> +			     cfg->encoding == V4L2_PIXEL_ENC_RGB ?
> >> +			     MALI_C55_ISP_RAW_BYPASS_BYPASS_MASK : 0x00);
> >> +
> >> +	ret = mali_c55_config_write(ctx, MALI_C55_CONFIG_PING);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "failed to DMA config\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_INPUT_MODE_REQUEST,
> >> +		       MALI_C55_INPUT_SAFE_START);
> >> +	readl_poll_timeout(mali_c55->base + MALI_C55_REG_MODE_STATUS,
> >> +			   val, !val, 10 * USEC_PER_MSEC, 250 * USEC_PER_MSEC);
> >
> > Should you return an error in case of timeout ?
> >
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +void mali_c55_isp_stop_stream(struct mali_c55_isp *isp)
> >
> > Why is this not handled wired to .s_stream() ? Or better,
> > .enable_streams() and .disable_streams().
> 
> There didn't really seem to be much point, since nothing outside this driver is ever going to start 
> the subdev streaming...it's not like the sensor case where a separate driver might have to call some 
> operation to start it.

True, but we're moving towards recording per-stream and per-pad
streaming state in the subdev through v4l2_subdev_enable_streams() and
v4l2_subdev_disable_streams(). We will likely expand usage of that
information, so it would be nice to keep it up-to-date already.

> >> +{
> >> +	struct mali_c55 *mali_c55 = isp->mali_c55;
> >> +	struct v4l2_subdev *sd;
> >> +
> >> +	if (isp->remote_src) {
> >> +		sd = media_entity_to_v4l2_subdev(isp->remote_src->entity);
> >> +		v4l2_subdev_disable_streams(sd, isp->remote_src->index, BIT(0));
> >> +	}
> >> +	isp->remote_src = NULL;
> >> +
> >> +	mali_c55_isp_stop(mali_c55);
> >> +}
> >> +
> >> +int mali_c55_isp_start_stream(struct mali_c55_isp *isp)
> >> +{
> >> +	struct mali_c55 *mali_c55 = isp->mali_c55;
> >> +	struct media_pad *sink_pad;
> >> +	struct v4l2_subdev *sd;
> >> +	int ret;
> >> +
> >> +	sink_pad = &isp->pads[MALI_C55_ISP_PAD_SINK_VIDEO];
> >> +	isp->remote_src = media_pad_remote_pad_unique(sink_pad);
> >> +	if (IS_ERR(isp->remote_src)) {
> >
> > If you set the MUST_CONNECT flag for the MALI_C55_ISP_PAD_SINK_VIDEO pad
> > I think you can drop this check.
> >
> >> +		dev_err(mali_c55->dev, "Failed to get source for ISP\n");
> >> +		return PTR_ERR(isp->remote_src);
> >> +	}
> >> +
> >> +	sd = media_entity_to_v4l2_subdev(isp->remote_src->entity);
> >> +
> >> +	isp->frame_sequence = 0;
> >> +	ret = mali_c55_isp_start(mali_c55);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "Failed to start ISP\n");
> >> +		isp->remote_src = NULL;
> >> +		return ret;
> >> +	}
> >> +
> >> +	/*
> >> +	 * We only support a single input stream, so we can just enable the 1st
> >> +	 * entry in the streams mask.
> >> +	 */
> >> +	ret = v4l2_subdev_enable_streams(sd, isp->remote_src->index, BIT(0));
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "Failed to start ISP source\n");
> >> +		mali_c55_isp_stop(mali_c55);
> >> +		return ret;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_isp_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				       struct v4l2_subdev_state *state,
> >> +				       struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	/*
> >> +	 * Only the internal RGB processed format is allowed on the regular
> >> +	 * processing source pad.
> >> +	 */
> >> +	if (code->pad == MALI_C55_ISP_PAD_SOURCE) {
> >> +		if (code->index)
> >> +			return -EINVAL;
> >> +
> >> +		code->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +		return 0;
> >> +	}
> >> +
> >> +	/* On the sink and bypass pads all the supported formats are allowed. */
> >> +	if (code->index >= ARRAY_SIZE(mali_c55_isp_fmts))
> >> +		return -EINVAL;
> >> +
> >> +	code->code = mali_c55_isp_fmts[code->index].code;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_isp_enum_frame_size(struct v4l2_subdev *sd,
> >> +					struct v4l2_subdev_state *state,
> >> +					struct v4l2_subdev_frame_size_enum *fse)
> >> +{
> >> +	const struct mali_c55_isp_fmt *cfg;
> >> +
> >> +	if (fse->index > 0)
> >> +		return -EINVAL;
> >> +
> >> +	/*
> >> +	 * Only the internal RGB processed format is allowed on the regular
> >> +	 * processing source pad.
> >> +	 *
> >> +	 * On the sink and bypass pads all the supported formats are allowed.
> >> +	 */
> >> +	if (fse->pad == MALI_C55_ISP_PAD_SOURCE) {
> >> +		if (fse->code != MEDIA_BUS_FMT_RGB121212_1X36)
> >> +			return -EINVAL;
> >> +	} else {
> >> +		cfg = mali_c55_isp_get_mbus_config_by_code(fse->code);
> >> +		if (!cfg)
> >> +			return -EINVAL;
> >> +	}
> >> +
> >> +	fse->min_width = MALI_C55_MIN_WIDTH;
> >> +	fse->min_height = MALI_C55_MIN_HEIGHT;
> >> +	fse->max_width = MALI_C55_MAX_WIDTH;
> >> +	fse->max_height = MALI_C55_MAX_HEIGHT;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_isp_set_fmt(struct v4l2_subdev *sd,
> >> +				struct v4l2_subdev_state *state,
> >> +				struct v4l2_subdev_format *format)
> >> +{
> >> +	struct v4l2_mbus_framefmt *fmt = &format->format;
> >> +	struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> >> +	const struct mali_c55_isp_fmt *cfg;
> >> +	struct v4l2_rect *crop;
> >> +
> >> +	/*
> >> +	 * Disallow set_fmt on the source pads; format is fixed and the sizes
> >> +	 * are the result of applying the sink crop rectangle to the sink
> >> +	 * format.
> >> +	 */
> >> +	if (format->pad)
> >
> > 	if (format->pad != MALI_C55_ISP_PAD_SINK_VIDEO)
> >
> >> +		return v4l2_subdev_get_fmt(sd, state, format);
> >> +
> >> +	cfg = mali_c55_isp_get_mbus_config_by_code(fmt->code);
> >> +	if (!cfg)
> >> +		fmt->code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >> +	fmt->field = V4L2_FIELD_NONE;
> >
> > Do you intentionally allow the colorspace fields to be overwritten to
> > any value ? rkisp1_isp_set_src_fmt() and rkisp1_isp_set_sink_fmt() may
> > show you how this could be handled.
> >
> >> +
> >> +	/*
> >> +	 * Clamp sizes in the accepted limits and clamp the crop rectangle in
> >> +	 * the new sizes.
> >> +	 */
> >> +	clamp_t(unsigned int, fmt->width,
> >> +		MALI_C55_MIN_WIDTH, MALI_C55_MAX_WIDTH);
> >> +	clamp_t(unsigned int, fmt->width,
> >> +		MALI_C55_MIN_HEIGHT, MALI_C55_MAX_HEIGHT);
> >
> > clamp_t() returns a value, which you ignore. Those are no-ops. You meant
> >
> > 	fmt->width = clamp_t(unsigned int, fmt->width, MALI_C55_MIN_WIDTH,
> > 			     MALI_C55_MAX_WIDTH);
> > 	fmt->height = clamp_t(unsigned int, fmt->height, MALI_C55_MIN_HEIGHT,
> > 			      MALI_C55_MAX_HEIGHT);
> >
> > Same for every use of clamp_t() through the whole driver.
> >
> > Also, do you need clamp_t() ? I think all values are unsigned int, you
> > can use clamp().
> >
> > Are there any alignment constraints, such a multiples of two for bayer
> > formats ? Same in all the other locations where applicable.
> >
> >> +
> >> +	sink_fmt = v4l2_subdev_state_get_format(state,
> >> +						MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +	*sink_fmt = *fmt;
> >> +
> >> +	crop = v4l2_subdev_state_get_crop(state, MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +	crop->left = 0;
> >> +	crop->top = 0;
> >> +	crop->width = fmt->width;
> >> +	crop->height = fmt->height;
> >> +
> >> +	/*
> >> +	 * Propagate format to source pads. On the 'regular' output pad use
> >> +	 * the internal RGB processed format, while on the bypass pad simply
> >> +	 * replicate the ISP sink format. The sizes on both pads are the same as
> >> +	 * the ISP sink crop rectangle.
> >> +	 */
> >
> > Colorspace information will need to be propagated too.
> >
> >> +	src_fmt = v4l2_subdev_state_get_format(state, MALI_C55_ISP_PAD_SOURCE);
> >> +	src_fmt->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +	src_fmt->width = crop->width;
> >> +	src_fmt->height = crop->height;
> >> +
> >> +	src_fmt = v4l2_subdev_state_get_format(state,
> >> +					       MALI_C55_ISP_PAD_SOURCE_BYPASS);
> >> +	src_fmt->code = fmt->code;
> >> +	src_fmt->width = crop->width;
> >> +	src_fmt->height = crop->height;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_isp_get_selection(struct v4l2_subdev *sd,
> >> +				      struct v4l2_subdev_state *state,
> >> +				      struct v4l2_subdev_selection *sel)
> >> +{
> >> +	if (sel->pad || sel->target != V4L2_SEL_TGT_CROP)
> >
> > 	sel->pad != MALI_C55_ISP_PAD_SINK_VIDEO
> >
> >> +		return -EINVAL;
> >> +
> >> +	sel->r = *v4l2_subdev_state_get_crop(state, MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_isp_set_selection(struct v4l2_subdev *sd,
> >> +				      struct v4l2_subdev_state *state,
> >> +				      struct v4l2_subdev_selection *sel)
> >> +{
> >> +	struct v4l2_mbus_framefmt *src_fmt;
> >> +	struct v4l2_mbus_framefmt *fmt;
> >
> > const
> >
> >> +	struct v4l2_rect *crop;
> >> +
> >> +	if (sel->pad || sel->target != V4L2_SEL_TGT_CROP)
> >
> > Ditto.
> >
> >> +		return -EINVAL;
> >> +
> >> +	fmt = v4l2_subdev_state_get_format(state, MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +
> >> +	clamp_t(unsigned int, sel->r.left, 0, fmt->width);
> >> +	clamp_t(unsigned int, sel->r.top, 0, fmt->height);
> >> +	clamp_t(unsigned int, sel->r.width, MALI_C55_MIN_WIDTH,
> >> +		fmt->width - sel->r.left);
> >> +	clamp_t(unsigned int, sel->r.height, MALI_C55_MIN_HEIGHT,
> >> +		fmt->height - sel->r.top);
> >> +
> >> +	crop = v4l2_subdev_state_get_crop(state, MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +	*crop = sel->r;
> >> +
> >> +	/* Propagate the crop rectangle sizes to the source pad format. */
> >> +	src_fmt = v4l2_subdev_state_get_format(state, MALI_C55_ISP_PAD_SOURCE);
> >> +	src_fmt->width = crop->width;
> >> +	src_fmt->height = crop->height;
> >
> > Can you confirm that cropping doesn't affect the bypass path ?
> 
> Yes
> 
> > And maybe
> > add a comment to mention it.
> 
> Will
> 
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_pad_ops mali_c55_isp_pad_ops = {
> >> +	.enum_mbus_code		= mali_c55_isp_enum_mbus_code,
> >> +	.enum_frame_size	= mali_c55_isp_enum_frame_size,
> >> +	.get_fmt		= v4l2_subdev_get_fmt,
> >> +	.set_fmt		= mali_c55_isp_set_fmt,
> >> +	.get_selection		= mali_c55_isp_get_selection,
> >> +	.set_selection		= mali_c55_isp_set_selection,
> >> +	.link_validate		= v4l2_subdev_link_validate_default,
> >> +};
> >> +
> >> +void mali_c55_isp_queue_event_sof(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct v4l2_event event = {
> >> +		.type = V4L2_EVENT_FRAME_SYNC,
> >> +	};
> >> +
> >> +	event.u.frame_sync.frame_sequence = mali_c55->isp.frame_sequence;
> >> +	v4l2_event_queue(mali_c55->isp.sd.devnode, &event);
> >> +}
> >> +
> >> +static int
> >> +mali_c55_isp_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
> >> +			     struct v4l2_event_subscription *sub)
> >> +{
> >> +	if (sub->type != V4L2_EVENT_FRAME_SYNC)
> >> +		return -EINVAL;
> >> +
> >> +	/* V4L2_EVENT_FRAME_SYNC doesn't require an id, so zero should be set */
> >> +	if (sub->id != 0)
> >> +		return -EINVAL;
> >> +
> >> +	return v4l2_event_subscribe(fh, sub, 0, NULL);
> >> +}
> >> +
> >> +static const struct v4l2_subdev_core_ops mali_c55_isp_core_ops = {
> >> +	.subscribe_event = mali_c55_isp_subscribe_event,
> >> +	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_ops mali_c55_isp_ops = {
> >> +	.pad	= &mali_c55_isp_pad_ops,
> >> +	.core	= &mali_c55_isp_core_ops,
> >> +};
> >> +
> >> +static int mali_c55_isp_init_state(struct v4l2_subdev *sd,
> >> +				   struct v4l2_subdev_state *sd_state)
> >
> > You name this variable state in every other subdev operation handler.
> >
> >> +{
> >> +	struct v4l2_mbus_framefmt *sink_fmt, *src_fmt;
> >> +	struct v4l2_rect *in_crop;
> >> +
> >> +	sink_fmt = v4l2_subdev_state_get_format(sd_state,
> >> +						MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +	src_fmt = v4l2_subdev_state_get_format(sd_state,
> >> +					       MALI_C55_ISP_PAD_SOURCE);
> >> +	in_crop = v4l2_subdev_state_get_crop(sd_state,
> >> +					     MALI_C55_ISP_PAD_SINK_VIDEO);
> >> +
> >> +	sink_fmt->width = MALI_C55_DEFAULT_WIDTH;
> >> +	sink_fmt->height = MALI_C55_DEFAULT_HEIGHT;
> >> +	sink_fmt->field = V4L2_FIELD_NONE;
> >> +	sink_fmt->code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >
> > You should initialize the colorspace fields too. Same below.
> >
> >> +
> >> +	*v4l2_subdev_state_get_format(sd_state,
> >> +			      MALI_C55_ISP_PAD_SOURCE_BYPASS) = *sink_fmt;
> >> +
> >> +	src_fmt->width = MALI_C55_DEFAULT_WIDTH;
> >> +	src_fmt->height = MALI_C55_DEFAULT_HEIGHT;
> >> +	src_fmt->field = V4L2_FIELD_NONE;
> >> +	src_fmt->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +
> >> +	in_crop->top = 0;
> >> +	in_crop->left = 0;
> >> +	in_crop->width = MALI_C55_DEFAULT_WIDTH;
> >> +	in_crop->height = MALI_C55_DEFAULT_HEIGHT;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_internal_ops mali_c55_isp_internal_ops = {
> >> +	.init_state = mali_c55_isp_init_state,
> >> +};
> >> +
> >> +static const struct media_entity_operations mali_c55_isp_media_ops = {
> >> +	.link_validate		= v4l2_subdev_link_validate,
> >
> > 	.link_validate = v4l2_subdev_link_validate,
> >
> > to match mali_c55_isp_internal_ops.
> >
> >> +};
> >> +
> >> +static int mali_c55_isp_notifier_bound(struct v4l2_async_notifier *notifier,
> >> +				       struct v4l2_subdev *subdev,
> >> +				       struct v4l2_async_connection *asc)
> >> +{
> >> +	struct mali_c55_isp *isp = container_of(notifier,
> >> +						struct mali_c55_isp, notifier);
> >> +	struct mali_c55 *mali_c55 = isp->mali_c55;
> >> +	struct media_pad *pad = &isp->pads[MALI_C55_ISP_PAD_SINK_VIDEO];
> >> +	int ret;
> >> +
> >> +	/*
> >> +	 * By default we'll flag this link enabled and the TPG disabled, but
> >> +	 * no immutable flag because we need to be able to switch between the
> >> +	 * two.
> >> +	 */
> >> +	ret = v4l2_create_fwnode_links_to_pad(subdev, pad,
> >> +					      MEDIA_LNK_FL_ENABLED);
> >> +	if (ret)
> >> +		dev_err(mali_c55->dev, "failed to create link for %s\n",
> >> +			subdev->name);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static int mali_c55_isp_notifier_complete(struct v4l2_async_notifier *notifier)
> >> +{
> >> +	struct mali_c55_isp *isp = container_of(notifier,
> >> +						struct mali_c55_isp, notifier);
> >> +	struct mali_c55 *mali_c55 = isp->mali_c55;
> >> +
> >> +	return v4l2_device_register_subdev_nodes(&mali_c55->v4l2_dev);
> >> +}
> >> +
> >> +static const struct v4l2_async_notifier_operations mali_c55_isp_notifier_ops = {
> >> +	.bound = mali_c55_isp_notifier_bound,
> >> +	.complete = mali_c55_isp_notifier_complete,
> >> +};
> >> +
> >> +static int mali_c55_isp_parse_endpoint(struct mali_c55_isp *isp)
> >> +{
> >> +	struct mali_c55 *mali_c55 = isp->mali_c55;
> >> +	struct v4l2_async_connection *asc;
> >> +	struct fwnode_handle *ep;
> >> +	int ret;
> >> +
> >> +	v4l2_async_nf_init(&isp->notifier, &mali_c55->v4l2_dev);
> >> +
> >> +	/*
> >> +	 * The ISP should have a single endpoint pointing to some flavour of
> >> +	 * CSI-2 receiver...but for now at least we do want everything to work
> >> +	 * normally even with no sensors connected, as we have the TPG. If we
> >> +	 * don't find a sensor just warn and return success.
> >> +	 */
> >> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(mali_c55->dev),
> >> +					     0, 0, 0);
> >> +	if (!ep) {
> >> +		dev_warn(mali_c55->dev, "no local endpoint found\n");
> >> +		return 0;
> >> +	}
> >> +
> >> +	asc = v4l2_async_nf_add_fwnode_remote(&isp->notifier, ep,
> >> +					      struct v4l2_async_connection);
> >> +	if (IS_ERR(asc)) {
> >> +		dev_err(mali_c55->dev, "failed to add remote fwnode\n");
> >> +		ret = PTR_ERR(asc);
> >> +		goto err_put_ep;
> >> +	}
> >> +
> >> +	isp->notifier.ops = &mali_c55_isp_notifier_ops;
> >> +	ret = v4l2_async_nf_register(&isp->notifier);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "failed to register notifier\n");
> >> +		goto err_cleanup_nf;
> >> +	}
> >> +
> >> +	fwnode_handle_put(ep);
> >> +
> >> +	return 0;
> >> +
> >> +err_cleanup_nf:
> >> +	v4l2_async_nf_cleanup(&isp->notifier);
> >> +err_put_ep:
> >> +	fwnode_handle_put(ep);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +int mali_c55_register_isp(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_isp *isp = &mali_c55->isp;
> >> +	struct v4l2_subdev *sd = &isp->sd;
> >> +	int ret;
> >> +
> >> +	isp->mali_c55 = mali_c55;
> >> +
> >> +	v4l2_subdev_init(sd, &mali_c55_isp_ops);
> >> +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
> >> +	sd->entity.ops = &mali_c55_isp_media_ops;
> >> +	sd->entity.function = MEDIA_ENT_F_PROC_VIDEO_ISP;
> >> +	sd->internal_ops = &mali_c55_isp_internal_ops;
> >> +	strscpy(sd->name, MALI_C55_DRIVER_NAME " isp", sizeof(sd->name));
> >> +
> >> +	isp->pads[MALI_C55_ISP_PAD_SINK_VIDEO].flags = MEDIA_PAD_FL_SINK;
> >
> > The MUST_CONNECT flag would make sense here.
> >
> >> +	isp->pads[MALI_C55_ISP_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> >> +	isp->pads[MALI_C55_ISP_PAD_SOURCE_BYPASS].flags = MEDIA_PAD_FL_SOURCE;
> >> +
> >> +	ret = media_entity_pads_init(&sd->entity, MALI_C55_ISP_NUM_PADS,
> >> +				     isp->pads);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	ret = v4l2_subdev_init_finalize(sd);
> >> +	if (ret)
> >> +		goto err_cleanup_media_entity;
> >> +
> >> +	ret = v4l2_device_register_subdev(&mali_c55->v4l2_dev, sd);
> >> +	if (ret)
> >> +		goto err_cleanup_subdev;
> >> +
> >> +	ret = mali_c55_isp_parse_endpoint(isp);
> >> +	if (ret)
> >> +		goto err_cleanup_subdev;
> >
> > As noted elsewhere, I think this belongs to mali-c55-core.c.
> >
> >> +
> >> +	mutex_init(&isp->lock);
> >
> > This lock is used in mali-c55-capture.c only, that seems weird.
> 
> It's because we have two separate capture devices, who's start/stop streaming path calls into the 
> ISP subdevice's start streaming function, but has to do it after a bunch of other writes to the cap 
> device or resizer specific sections...the intention was to delay doing any of that until the ISP was 
> in a known state.

OK. Naming it capture_lock or something similar, with a comment, would
help.

> >> +
> >> +	return 0;
> >> +
> >> +err_cleanup_subdev:
> >> +	v4l2_subdev_cleanup(sd);
> >> +err_cleanup_media_entity:
> >> +	media_entity_cleanup(&sd->entity);
> >> +	isp->mali_c55 = NULL;
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +void mali_c55_unregister_isp(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_isp *isp = &mali_c55->isp;
> >> +
> >> +	if (!isp->mali_c55)
> >> +		return;
> >> +
> >> +	mutex_destroy(&isp->lock);
> >> +	v4l2_async_nf_unregister(&isp->notifier);
> >> +	v4l2_async_nf_cleanup(&isp->notifier);
> >> +	v4l2_device_unregister_subdev(&isp->sd);
> >> +	v4l2_subdev_cleanup(&isp->sd);
> >> +	media_entity_cleanup(&isp->sd.entity);
> >> +}
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-registers.h b/drivers/media/platform/arm/mali-c55/mali-c55-registers.h
> >> new file mode 100644
> >> index 000000000000..cb27abde2aa5
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-registers.h
> >> @@ -0,0 +1,258 @@
> >> +/* SPDX-License-Identifier: GPL-2.0 */
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Register definitions
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#ifndef _MALI_C55_REGISTERS_H
> >> +#define _MALI_C55_REGISTERS_H
> >> +
> >> +#include <linux/bits.h>
> >> +
> >> +/* ISP Common 0x00000 - 0x000ff */
> >> +
> >> +#define MALI_C55_REG_API				0x00000
> >> +#define MALI_C55_REG_PRODUCT				0x00004
> >> +#define MALI_C55_REG_VERSION				0x00008
> >> +#define MALI_C55_REG_REVISION				0x0000c
> >> +#define MALI_C55_REG_PULSE_MODE				0x0003c
> >> +#define MALI_C55_REG_INPUT_MODE_REQUEST			0x0009c
> >> +#define MALI_C55_INPUT_SAFE_STOP			0x00
> >> +#define MALI_C55_INPUT_SAFE_START			0x01
> >> +#define MALI_C55_REG_MODE_STATUS			0x000a0
> >> +#define MALI_C55_REG_INTERRUPT_MASK_VECTOR		0x00030
> >> +#define MALI_C55_INTERRUPT_MASK_ALL			GENMASK(31, 0)
> >> +
> >> +#define MALI_C55_REG_GLOBAL_MONITOR			0x00050
> >> +
> >> +#define MALI_C55_REG_GEN_VIDEO				0x00080
> >> +#define MALI_C55_REG_GEN_VIDEO_ON_MASK			BIT(0)
> >> +#define MALI_C55_REG_GEN_VIDEO_MULTI_MASK		BIT(1)
> >> +#define MALI_C55_REG_GEN_PREFETCH_MASK			GENMASK(31, 16)
> >> +
> >> +#define MALI_C55_REG_MCU_CONFIG				0x00020
> >> +#define MALI_C55_REG_MCU_CONFIG_OVERRIDE_MASK		BIT(0)
> >
> > #define MALI_C55_REG_MCU_CONFIG_OVERRIDE		BIT(0)
> >
> > Same in other places where applicable.
> >
> >> +#define MALI_C55_REG_MCU_CONFIG_WRITE_MASK		BIT(1)
> >> +#define MALI_C55_REG_MCU_CONFIG_WRITE_PING		BIT(1)
> >> +#define MALI_C55_REG_MCU_CONFIG_WRITE_PONG		0x00
> >> +#define MALI_C55_REG_MULTI_CONTEXT_MODE_MASK		BIT(8)
> >> +#define MALI_C55_REG_PING_PONG_READ			0x00024
> >> +#define MALI_C55_REG_PING_PONG_READ_MASK		BIT(2)
> >> +
> >> +#define MALI_C55_REG_INTERRUPT_CLEAR_VECTOR		0x00034
> >> +#define MALI_C55_REG_INTERRUPT_CLEAR			0x00040
> >> +#define MALI_C55_REG_INTERRUPT_STATUS_VECTOR		0x00044
> >> +#define MALI_C55_REG_GLOBAL_PARAMETER_STATUS		0x00068
> >> +#define MALI_C55_GPS_PONG_FITTED			BIT(0)
> >> +#define MALI_C55_GPS_WDR_FITTED				BIT(1)
> >> +#define MALI_C55_GPS_COMPRESSION_FITTED			BIT(2)
> >> +#define MALI_C55_GPS_TEMPER_FITTED			BIT(3)
> >> +#define MALI_C55_GPS_SINTER_LITE_FITTED			BIT(4)
> >> +#define MALI_C55_GPS_SINTER_FITTED			BIT(5)
> >> +#define MALI_C55_GPS_IRIDIX_LTM_FITTED			BIT(6)
> >> +#define MALI_C55_GPS_IRIDIX_GTM_FITTED			BIT(7)
> >> +#define MALI_C55_GPS_CNR_FITTED				BIT(8)
> >> +#define MALI_C55_GPS_FRSCALER_FITTED			BIT(9)
> >> +#define MALI_C55_GPS_DS_PIPE_FITTED			BIT(10)
> >> +
> >> +#define MALI_C55_REG_BLANKING				0x00084
> >> +#define MALI_C55_REG_HBLANK_MASK			GENMASK(15, 0)
> >> +#define MALI_C55_REG_VBLANK_MASK			GENMASK(31, 16)
> >> +
> >> +#define MALI_C55_REG_HC_START				0x00088
> >> +#define MALI_C55_HC_START(h)				(((h) & 0xffff) << 16)
> >> +#define MALI_C55_REG_HC_SIZE				0x0008c
> >> +#define MALI_C55_HC_SIZE(h)				((h) & 0xffff)
> >> +#define MALI_C55_REG_VC_START_SIZE			0x00094
> >> +#define MALI_C55_VC_START(v)				((v) & 0xffff)
> >> +#define MALI_C55_VC_SIZE(v)				(((v) & 0xffff) << 16)
> >> +
> >> +/* Ping/Pong Configuration Space */
> >> +#define MALI_C55_REG_BASE_ADDR				0x18e88
> >> +#define MALI_C55_REG_BYPASS_0				0x18eac
> >> +#define MALI_C55_REG_BYPASS_0_VIDEO_TEST		BIT(0)
> >> +#define MALI_C55_REG_BYPASS_0_INPUT_FMT			BIT(1)
> >> +#define MALI_C55_REG_BYPASS_0_DECOMPANDER		BIT(2)
> >> +#define MALI_C55_REG_BYPASS_0_SENSOR_OFFSET_WDR		BIT(3)
> >> +#define MALI_C55_REG_BYPASS_0_GAIN_WDR			BIT(4)
> >> +#define MALI_C55_REG_BYPASS_0_FRAME_STITCH		BIT(5)
> >> +#define MALI_C55_REG_BYPASS_1				0x18eb0
> >> +#define MALI_C55_REG_BYPASS_1_DIGI_GAIN			BIT(0)
> >> +#define MALI_C55_REG_BYPASS_1_FE_SENSOR_OFFS		BIT(1)
> >> +#define MALI_C55_REG_BYPASS_1_FE_SQRT			BIT(2)
> >> +#define MALI_C55_REG_BYPASS_1_RAW_FE			BIT(3)
> >> +#define MALI_C55_REG_BYPASS_2				0x18eb8
> >> +#define MALI_C55_REG_BYPASS_2_SINTER			BIT(0)
> >> +#define MALI_C55_REG_BYPASS_2_TEMPER			BIT(1)
> >> +#define MALI_C55_REG_BYPASS_3				0x18ebc
> >> +#define MALI_C55_REG_BYPASS_3_SQUARE_BE			BIT(0)
> >> +#define MALI_C55_REG_BYPASS_3_SENSOR_OFFSET_PRE_SH	BIT(1)
> >> +#define MALI_C55_REG_BYPASS_3_MESH_SHADING		BIT(3)
> >> +#define MALI_C55_REG_BYPASS_3_WHITE_BALANCE		BIT(4)
> >> +#define MALI_C55_REG_BYPASS_3_IRIDIX			BIT(5)
> >> +#define MALI_C55_REG_BYPASS_3_IRIDIX_GAIN		BIT(6)
> >> +#define MALI_C55_REG_BYPASS_4				0x18ec0
> >> +#define MALI_C55_REG_BYPASS_4_DEMOSAIC_RGB		BIT(1)
> >> +#define MALI_C55_REG_BYPASS_4_PF_CORRECTION		BIT(3)
> >> +#define MALI_C55_REG_BYPASS_4_CCM			BIT(4)
> >> +#define MALI_C55_REG_BYPASS_4_CNR			BIT(5)
> >> +#define MALI_C55_REG_FR_BYPASS				0x18ec4
> >> +#define MALI_C55_REG_DS_BYPASS				0x18ec8
> >> +#define MALI_C55_BYPASS_CROP				BIT(0)
> >> +#define MALI_C55_BYPASS_SCALER				BIT(1)
> >> +#define MALI_C55_BYPASS_GAMMA_RGB			BIT(2)
> >> +#define MALI_C55_BYPASS_SHARPEN				BIT(3)
> >> +#define MALI_C55_BYPASS_CS_CONV				BIT(4)
> >> +#define MALI_C55_REG_ISP_RAW_BYPASS			0x18ecc
> >> +#define MALI_C55_ISP_RAW_BYPASS_BYPASS_MASK		BIT(0)
> >> +#define MALI_C55_ISP_RAW_BYPASS_FR_BYPASS_MASK		GENMASK(9, 8)
> >> +#define MALI_C55_ISP_RAW_BYPASS_RAW_FR_BYPASS		2
> >> +#define MALI_C55_ISP_RAW_BYPASS_RGB_FR_BYPASS		1
> >> +#define MALI_C55_ISP_RAW_BYPASS_DS_PIPE_DISABLE		BIT(1)
> >> +#define MALI_C55_ISP_RAW_BYPASS_RAW_BYPASS		BIT(0)
> >> +
> >> +#define MALI_C55_REG_ACTIVE_WIDTH_MASK			0xffff
> >> +#define MALI_C55_REG_ACTIVE_HEIGHT_MASK			0xffff0000
> >> +#define MALI_C55_REG_BAYER_ORDER			0x18e8c
> >> +#define MALI_C55_BAYER_ORDER_MASK			GENMASK(1, 0)
> >> +#define MALI_C55_REG_TPG_CH0				0x18ed8
> >> +#define MALI_C55_TEST_PATTERN_ON_OFF			BIT(0)
> >> +#define MALI_C55_TEST_PATTERN_RGB_MASK			BIT(1)
> >> +#define MALI_C55_REG_TPG_R_BACKGROUND			0x18ee0
> >> +#define MALI_C55_REG_TPG_G_BACKGROUND			0x18ee4
> >> +#define MALI_C55_REG_TPG_B_BACKGROUND			0x18ee8
> >> +#define MALI_C55_TPG_BACKGROUND_MAX			0xfffff
> >> +#define MALI_C55_REG_INPUT_WIDTH			0x18f98
> >> +#define MALI_C55_INPUT_WIDTH_MASK			GENMASK(18, 16)
> >> +#define MALI_C55_INPUT_WIDTH_8BIT			0
> >> +#define MALI_C55_INPUT_WIDTH_10BIT			1
> >> +#define MALI_C55_INPUT_WIDTH_12BIT			2
> >> +#define MALI_C55_INPUT_WIDTH_14BIT			3
> >> +#define MALI_C55_INPUT_WIDTH_16BIT			4
> >> +#define MALI_C55_INPUT_WIDTH_20BIT			5
> >> +#define MALI_C55_REG_SPACE_SIZE				0x4000
> >> +#define MALI_C55_REG_CONFIG_SPACES_OFFSET		0x0ab6c
> >> +#define MALI_C55_CONFIG_SPACE_SIZE			0x1231c
> >> +
> >> +#define MALI_C55_REG_SINTER_CONFIG			0x19348
> >> +#define MALI_C55_SINTER_VIEW_FILTER_MASK		GENMASK(1, 0)
> >> +#define MALI_C55_SINTER_SCALE_MODE_MASK			GENMASK(3, 2)
> >> +#define MALI_C55_SINTER_ENABLE_MASK			BIT(4)
> >> +#define MALI_C55_SINTER_FILTER_SELECT_MASK		BIT(5)
> >> +#define MALI_C55_SINTER_INT_SELECT_MASK			BIT(6)
> >> +#define MALI_C55_SINTER_RM_ENABLE_MASK			BIT(7)
> >> +
> >> +/* Colour Correction Matrix Configuration */
> >> +#define MALI_C55_REG_CCM_ENABLE				0x1b07c
> >> +#define MALI_C55_CCM_ENABLE_MASK			BIT(0)
> >> +#define MALI_C55_REG_CCM_COEF_R_R			0x1b080
> >> +#define MALI_C55_REG_CCM_COEF_R_G			0x1b084
> >> +#define MALI_C55_REG_CCM_COEF_R_B			0x1b088
> >> +#define MALI_C55_REG_CCM_COEF_G_R			0x1b090
> >> +#define MALI_C55_REG_CCM_COEF_G_G			0x1b094
> >> +#define MALI_C55_REG_CCM_COEF_G_B			0x1b098
> >> +#define MALI_C55_REG_CCM_COEF_B_R			0x1b0a0
> >> +#define MALI_C55_REG_CCM_COEF_B_G			0x1b0a4
> >> +#define MALI_C55_REG_CCM_COEF_B_B			0x1b0a8
> >> +#define MALI_C55_CCM_COEF_MASK				GENMASK(12, 0)
> >> +#define MALI_C55_REG_CCM_ANTIFOG_GAIN_R			0x1b0b0
> >> +#define MALI_C55_REG_CCM_ANTIFOG_GAIN_G			0x1b0b4
> >> +#define MALI_C55_REG_CCM_ANTIFOG_GAIN_B			0x1b0b8
> >> +#define MALI_C55_CCM_ANTIFOG_GAIN_MASK			GENMASK(11, 0)
> >> +#define MALI_C55_REG_CCM_ANTIFOG_OFFSET_R		0x1b0c0
> >> +#define MALI_C55_REG_CCM_ANTIFOG_OFFSET_G		0x1b0c4
> >> +#define MALI_C55_REG_CCM_ANTIFOG_OFFSET_B		0x1b0c8
> >> +#define MALI_C55_CCM_ANTIFOG_OFFSET_MASK		GENMASK(11, 0)
> >> +
> >> +/*
> >> + * The Mali-C55 ISP has up to two output pipes; known as full resolution and
> >> + * down scaled. The register space for these is laid out identically, but offset
> >> + * by 372 bytes.
> >> + */
> >> +#define MALI_C55_CAP_DEV_FR_REG_OFFSET		0x0
> >> +#define MALI_C55_CAP_DEV_DS_REG_OFFSET		0x174
> >> +
> >> +#define MALI_C55_REG_CS_CONV_CONFIG(offset)		(0x1c098 + (offset))
> >> +#define MALI_C55_CS_CONV_MATRIX_MASK			BIT(0)
> >> +#define MALI_C55_CS_CONV_FILTER_MASK			BIT(1)
> >> +#define MALI_C55_CS_CONV_HORZ_DOWNSAMPLE_MASK		BIT(2)
> >> +#define MALI_C55_CS_CONV_VERT_DOWNSAMPLE_MASK		BIT(3)
> >> +#define MALI_C55_REG_Y_WRITER_MODE(offset)		(0x1c0ec + (offset))
> >> +#define MALI_C55_REG_UV_WRITER_MODE(offset)		(0x1c144 + (offset))
> >> +#define MALI_C55_WRITER_MODE_MASK			GENMASK(4, 0)
> >> +#define MALI_C55_WRITER_SUBMODE_MASK			GENMASK(7, 6)
> >> +#define MALI_C55_WRITER_FRAME_WRITE_MASK		BIT(9)
> >> +#define MALI_C55_REG_ACTIVE_OUT_Y_SIZE(offset)		(0x1c0f0 + (offset))
> >> +#define MALI_C55_REG_ACTIVE_OUT_UV_SIZE(offset)		(0x1c148 + (offset))
> >> +#define MALI_C55_REG_ACTIVE_OUT_SIZE_W(w)		((w) << 0)
> >> +#define MALI_C55_REG_ACTIVE_OUT_SIZE_H(h)		((h) << 16)
> >> +#define MALI_C55_REG_Y_WRITER_BANKS_BASE(offset)	(0x1c0f4 + (offset))
> >> +#define MALI_C55_REG_Y_WRITER_BANKS_CONFIG(offset)	(0x1c108 + (offset))
> >> +#define MALI_C55_REG_Y_WRITER_MAX_BANKS_MASK		GENMASK(2, 0)
> >> +#define MALI_C55_REG_Y_WRITER_BANKS_RESTART		BIT(3)
> >> +#define MALI_C55_REG_Y_WRITER_OFFSET(offset)		(0x1c10c + (offset))
> >> +#define MALI_C55_REG_UV_WRITER_BANKS_BASE(offset)	(0x1c14c + (offset))
> >> +#define MALI_C55_REG_UV_WRITER_BANKS_CONFIG(offset)	(0x1c160 + (offset))
> >> +#define MALI_C55_REG_UV_WRITER_MAX_BANKS_MASK		GENMASK(2, 0)
> >> +#define MALI_C55_REG_UV_WRITER_BANKS_RESTART		BIT(3)
> >> +#define MALI_C55_REG_UV_WRITER_OFFSET(offset)		(0x1c164 + (offset))
> >> +
> >> +#define MALI_C55_REG_TEST_GEN_CH0_OFF_ON
> >> +#define MALI_C55_REG_TEST_GEN_CH0_PATTERN_TYPE		0x18edc
> >> +
> >> +#define MALI_C55_REG_CROP_EN(offset)			(0x1c028 + (offset))
> >> +#define MALI_C55_CROP_ENABLE				BIT(0)
> >> +#define MALI_C55_REG_CROP_X_START(offset)		(0x1c02c + (offset))
> >> +#define MALI_C55_REG_CROP_Y_START(offset)		(0x1c030 + (offset))
> >> +#define MALI_C55_REG_CROP_X_SIZE(offset)		(0x1c034 + (offset))
> >> +#define MALI_C55_REG_CROP_Y_SIZE(offset)		(0x1c038 + (offset))
> >> +#define MALI_C55_REG_SCALER_TIMEOUT_EN(offset)		(0x1c040 + (offset))
> >> +#define MALI_C55_SCALER_TIMEOUT_EN			BIT(4)
> >> +#define MALI_C55_SCALER_TIMEOUT(t)			((t) << 16)
> >> +#define MALI_C55_REG_SCALER_IN_WIDTH(offset)		(0x1c044 + (offset))
> >> +#define MALI_C55_REG_SCALER_IN_HEIGHT(offset)		(0x1c048 + (offset))
> >> +#define MALI_C55_REG_SCALER_OUT_WIDTH(offset)		(0x1c04c + (offset))
> >> +#define MALI_C55_REG_SCALER_OUT_HEIGHT(offset)		(0x1c050 + (offset))
> >> +#define MALI_C55_REG_SCALER_HFILT_TINC(offset)		(0x1c054 + (offset))
> >> +#define MALI_C55_REG_SCALER_HFILT_COEF(offset)		(0x1c058 + (offset))
> >> +#define MALI_C55_REG_SCALER_VFILT_TINC(offset)		(0x1c05c + (offset))
> >> +#define MALI_C55_REG_SCALER_VFILT_COEF(offset)		(0x1c060 + (offset))
> >> +
> >> +#define MALI_C55_REG_GAMMA_RGB_ENABLE(offset)		(0x1c064 + (offset))
> >> +#define MALI_C55_GAMMA_ENABLE_MASK			BIT(0)
> >> +#define MALI_C55_REG_GAMMA_GAINS_1(offset)		(0x1c068 + (offset))
> >> +#define MALI_C55_GAMMA_GAIN_R_MASK			GENMASK(11, 0)
> >> +#define MALI_C55_GAMMA_GAIN_G_MASK			GENMASK(27, 16)
> >> +#define MALI_C55_REG_GAMMA_GAINS_2(offset)		(0x1c06c + (offset))
> >> +#define MALI_C55_GAMMA_GAIN_B_MASK			GENMASK(11, 0)
> >> +#define MALI_C55_REG_GAMMA_OFFSETS_1(offset)		(0x1c070 + (offset))
> >> +#define MALI_C55_GAMMA_OFFSET_R_MASK			GENMASK(11, 0)
> >> +#define MALI_C55_GAMMA_OFFSET_G_MASK			GENMASK(27, 16)
> >> +#define MALI_C55_REG_GAMMA_OFFSETS_2(offset)		(0x1c074 + (offset))
> >> +#define MALI_C55_GAMMA_OFFSET_B_MASK			GENMASK(11, 0)
> >> +
> >> +/* Output DMA Writer */
> >> +
> >> +#define MALI_C55_OUTPUT_DISABLED		0
> >> +#define MALI_C55_OUTPUT_RGB32			1
> >> +#define MALI_C55_OUTPUT_A2R10G10B10		2
> >> +#define MALI_C55_OUTPUT_RGB565			3
> >> +#define MALI_C55_OUTPUT_RGB24			4
> >> +#define MALI_C55_OUTPUT_GEN32			5
> >> +#define MALI_C55_OUTPUT_RAW16			6
> >> +#define MALI_C55_OUTPUT_AYUV			8
> >> +#define MALI_C55_OUTPUT_Y410			9
> >> +#define MALI_C55_OUTPUT_YUY2			10
> >> +#define MALI_C55_OUTPUT_UYVY			11
> >> +#define MALI_C55_OUTPUT_Y210			12
> >> +#define MALI_C55_OUTPUT_NV12_21			13
> >> +#define MALI_C55_OUTPUT_YUV_420_422		17
> >> +#define MALI_C55_OUTPUT_P210_P010		19
> >> +#define MALI_C55_OUTPUT_YUV422			20
> >
> > I'd define this just below the MALI_C55_REG_UV_WRITER_MODE register
> > macro.
> >
> >> +
> >> +#define MALI_C55_OUTPUT_PLANE_ALT0		0
> >> +#define MALI_C55_OUTPUT_PLANE_ALT1		1
> >> +#define MALI_C55_OUTPUT_PLANE_ALT2		2
> >
> > Same here ?
> >
> >> +
> >> +#endif /* _MALI_C55_REGISTERS_H */
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-resizer-coefs.h b/drivers/media/platform/arm/mali-c55/mali-c55-resizer-coefs.h
> >> new file mode 100644
> >> index 000000000000..8edae87f1e5f
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-resizer-coefs.h
> >> @@ -0,0 +1,382 @@
> >> +/* SPDX-License-Identifier: GPL-2.0 */
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Resizer Coefficients
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#ifndef _MALI_C55_RESIZER_COEFS_H
> >> +#define _MALI_C55_RESIZER_COEFS_H
> >> +
> >> +#include "mali-c55-common.h"
> >> +
> >> +#define MALI_C55_RESIZER_COEFS_NUM_BANKS	8
> >> +#define MALI_C55_RESIZER_COEFS_NUM_ENTRIES	64
> >
> > Do these belongs to mali-c55-registers.h ?
> >
> >> +
> >> +static const unsigned int mali_c55_scaler_h_filter_coefficients[8][64] = {
> >> +	{	/* Bank 0 */
> >> +		0x24fc0000, 0x0000fc24, 0x27fc0000, 0x0000fc21,
> >> +		0x28fc0000, 0x0000fd1f, 0x2cfb0000, 0x0000fd1c,
> >> +		0x2efb0000, 0x0000fd1a, 0x30fb0000, 0x0000fe17,
> >> +		0x32fb0000, 0x0000fe15, 0x35fb0000, 0x0000fe12,
> >> +		0x35fc0000, 0x0000ff10, 0x37fc0000, 0x0000ff0e,
> >> +		0x39fc0000, 0x0000ff0c, 0x3afd0000, 0x0000ff0a,
> >> +		0x3afe0000, 0x00000008, 0x3cfe0000, 0x00000006,
> >> +		0x3dff0000, 0x00000004, 0x3d000000, 0x00000003,
> >> +		0x3c020000, 0x00000002, 0x3d030000, 0x00000000,
> >> +		0x3d040000, 0x000000ff, 0x3c060000, 0x000000fe,
> >> +		0x3a080000, 0x000000fe, 0x3a0aff00, 0x000000fd,
> >> +		0x390cff00, 0x000000fc, 0x370eff00, 0x000000fc,
> >> +		0x3510ff00, 0x000000fc, 0x3512fe00, 0x000000fb,
> >> +		0x3215fe00, 0x000000fb, 0x3017fe00, 0x000000fb,
> >> +		0x2e1afd00, 0x000000fb, 0x2c1cfd00, 0x000000fb,
> >> +		0x281ffd00, 0x000000fc, 0x2721fc00, 0x000000fc,
> >> +	},
> >> +	{	/* Bank 1 */
> >> +		0x25fb0000, 0x0000fb25, 0x27fb0000, 0x0000fb23,
> >> +		0x29fb0000, 0x0000fb21, 0x2afc0000, 0x0000fb1f,
> >> +		0x2cfc0000, 0x0000fb1d, 0x2efc0000, 0x0000fb1b,
> >> +		0x2ffd0000, 0x0000fb19, 0x2ffe0000, 0x0000fc17,
> >> +		0x31fe0000, 0x0000fc15, 0x32ff0000, 0x0000fc13,
> >> +		0x3400ff00, 0x0000fc11, 0x3301ff00, 0x0000fd10,
> >> +		0x3402ff00, 0x0000fd0e, 0x3503ff00, 0x0000fd0c,
> >> +		0x3505ff00, 0x0000fd0a, 0x3506fe00, 0x0000fe09,
> >> +		0x3607fe00, 0x0000fe07, 0x3509fe00, 0x0000fe06,
> >> +		0x350afd00, 0x0000ff05, 0x350cfd00, 0x0000ff03,
> >> +		0x340efd00, 0x0000ff02, 0x3310fd00, 0x0000ff01,
> >> +		0x3411fc00, 0x0000ff00, 0x3213fc00, 0x000000ff,
> >> +		0x3115fc00, 0x000000fe, 0x2f17fc00, 0x000000fe,
> >> +		0x2f19fb00, 0x000000fd, 0x2e1bfb00, 0x000000fc,
> >> +		0x2c1dfb00, 0x000000fc, 0x2a1ffb00, 0x000000fc,
> >> +		0x2921fb00, 0x000000fb, 0x2723fb00, 0x000000fb,
> >> +	},
> >> +	{	/* Bank 2 */
> >> +		0x1f010000, 0x0000011f, 0x21010000, 0x0000001e,
> >> +		0x21020000, 0x0000001d, 0x22020000, 0x0000001c,
> >> +		0x23030000, 0x0000ff1b, 0x2404ff00, 0x0000ff1a,
> >> +		0x2504ff00, 0x0000ff19, 0x2505ff00, 0x0000ff18,
> >> +		0x2606ff00, 0x0000fe17, 0x2607ff00, 0x0000fe16,
> >> +		0x2708ff00, 0x0000fe14, 0x2709ff00, 0x0000fe13,
> >> +		0x270aff00, 0x0000fe12, 0x280bfe00, 0x0000fe11,
> >> +		0x280cfe00, 0x0000fe10, 0x280dfe00, 0x0000fe0f,
> >> +		0x280efe00, 0x0000fe0e, 0x280ffe00, 0x0000fe0d,
> >> +		0x2810fe00, 0x0000fe0c, 0x2811fe00, 0x0000fe0b,
> >> +		0x2712fe00, 0x0000ff0a, 0x2713fe00, 0x0000ff09,
> >> +		0x2714fe00, 0x0000ff08, 0x2616fe00, 0x0000ff07,
> >> +		0x2617fe00, 0x0000ff06, 0x2518ff00, 0x0000ff05,
> >> +		0x2519ff00, 0x0000ff04, 0x241aff00, 0x0000ff04,
> >> +		0x231bff00, 0x00000003, 0x221c0000, 0x00000002,
> >> +		0x211d0000, 0x00000002, 0x211e0000, 0x00000001,
> >> +	},
> >> +	{	/* Bank 3 */
> >> +		0x1b06ff00, 0x00ff061b, 0x1b07ff00, 0x00ff061a,
> >> +		0x1c07ff00, 0x00ff051a, 0x1c08ff00, 0x00ff0519,
> >> +		0x1c09ff00, 0x00ff0419, 0x1d09ff00, 0x00ff0418,
> >> +		0x1e0aff00, 0x00ff0317, 0x1e0aff00, 0x00ff0317,
> >> +		0x1e0bff00, 0x00ff0316, 0x1f0cff00, 0x00ff0215,
> >> +		0x1e0cff00, 0x00000215, 0x1e0dff00, 0x00000214,
> >> +		0x1e0e0000, 0x00000113, 0x1e0e0000, 0x00000113,
> >> +		0x1e0f0000, 0x00000112, 0x1f100000, 0x00000011,
> >> +		0x20100000, 0x00000010, 0x1f110000, 0x00000010,
> >> +		0x1e120100, 0x0000000f, 0x1e130100, 0x0000000e,
> >> +		0x1e130100, 0x0000000e, 0x1e140200, 0x0000ff0d,
> >> +		0x1e150200, 0x0000ff0c, 0x1f1502ff, 0x0000ff0c,
> >> +		0x1e1603ff, 0x0000ff0b, 0x1e1703ff, 0x0000ff0a,
> >> +		0x1e1703ff, 0x0000ff0a, 0x1d1804ff, 0x0000ff09,
> >> +		0x1c1904ff, 0x0000ff09, 0x1c1905ff, 0x0000ff08,
> >> +		0x1c1a05ff, 0x0000ff07, 0x1b1a06ff, 0x0000ff07,
> >> +	},
> >> +	{	/* Bank 4 */
> >> +		0x17090000, 0x00000917, 0x18090000, 0x00000916,
> >> +		0x170a0100, 0x00000816, 0x170a0100, 0x00000816,
> >> +		0x180b0100, 0x00000715, 0x180b0100, 0x00000715,
> >> +		0x170c0100, 0x00000715, 0x190c0100, 0x00000614,
> >> +		0x180d0100, 0x00000614, 0x190d0200, 0x00000513,
> >> +		0x180e0200, 0x00000513, 0x180e0200, 0x00000513,
> >> +		0x1a0e0200, 0x00000412, 0x190f0200, 0x00000412,
> >> +		0x190f0300, 0x00000411, 0x18100300, 0x00000411,
> >> +		0x1a100300, 0x00000310, 0x18110400, 0x00000310,
> >> +		0x19110400, 0x0000030f, 0x19120400, 0x0000020f,
> >> +		0x1a120400, 0x0000020e, 0x18130500, 0x0000020e,
> >> +		0x18130500, 0x0000020e, 0x19130500, 0x0000020d,
> >> +		0x18140600, 0x0000010d, 0x19140600, 0x0000010c,
> >> +		0x17150700, 0x0000010c, 0x18150700, 0x0000010b,
> >> +		0x18150700, 0x0000010b, 0x17160800, 0x0000010a,
> >> +		0x17160800, 0x0000010a, 0x18160900, 0x00000009,
> >> +	},
> >> +	{	/* Bank 5 */
> >> +		0x120b0300, 0x00030b12, 0x120c0300, 0x00030b11,
> >> +		0x110c0400, 0x00030b11, 0x110c0400, 0x00030b11,
> >> +		0x130c0400, 0x00020a11, 0x120d0400, 0x00020a11,
> >> +		0x110d0500, 0x00020a11, 0x110d0500, 0x00020a11,
> >> +		0x130d0500, 0x00010911, 0x130e0500, 0x00010910,
> >> +		0x120e0600, 0x00010910, 0x120e0600, 0x00010910,
> >> +		0x130e0600, 0x00010810, 0x120f0600, 0x00010810,
> >> +		0x120f0700, 0x00000810, 0x130f0700, 0x0000080f,
> >> +		0x140f0700, 0x0000070f, 0x130f0800, 0x0000070f,
> >> +		0x12100800, 0x0000070f, 0x12100801, 0x0000060f,
> >> +		0x13100801, 0x0000060e, 0x12100901, 0x0000060e,
> >> +		0x12100901, 0x0000060e, 0x13100901, 0x0000050e,
> >> +		0x13110901, 0x0000050d, 0x11110a02, 0x0000050d,
> >> +		0x11110a02, 0x0000050d, 0x12110a02, 0x0000040d,
> >> +		0x13110a02, 0x0000040c, 0x11110b03, 0x0000040c,
> >> +		0x11110b03, 0x0000040c, 0x12110b03, 0x0000030c,
> >> +	},
> >> +	{	/* Bank 6 */
> >> +		0x0b0a0805, 0x00080a0c, 0x0b0a0805, 0x00080a0c,
> >> +		0x0c0a0805, 0x00080a0b, 0x0c0a0805, 0x00080a0b,
> >> +		0x0d0a0805, 0x00070a0b, 0x0d0a0805, 0x00070a0b,
> >> +		0x0d0a0805, 0x00070a0b, 0x0c0a0806, 0x00070a0b,
> >> +		0x0b0b0806, 0x00070a0b, 0x0c0b0806, 0x0007090b,
> >> +		0x0b0b0906, 0x0007090b, 0x0b0b0906, 0x0007090b,
> >> +		0x0b0b0906, 0x0007090b, 0x0b0b0906, 0x0007090b,
> >> +		0x0b0b0906, 0x0007090b, 0x0c0b0906, 0x0006090b,
> >> +		0x0c0b0906, 0x0006090b, 0x0c0b0906, 0x0006090b,
> >> +		0x0b0b0907, 0x0006090b, 0x0b0b0907, 0x0006090b,
> >> +		0x0b0b0907, 0x0006090b, 0x0b0b0907, 0x0006090b,
> >> +		0x0b0b0907, 0x0006090b, 0x0c0b0907, 0x0006080b,
> >> +		0x0b0b0a07, 0x0006080b, 0x0c0b0a07, 0x0006080a,
> >> +		0x0d0b0a07, 0x0005080a, 0x0d0b0a07, 0x0005080a,
> >> +		0x0d0b0a07, 0x0005080a, 0x0c0b0a08, 0x0005080a,
> >> +		0x0c0b0a08, 0x0005080a, 0x0c0b0a08, 0x0005080a,
> >> +	},
> >> +	{	/* Bank 7 */
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +		0x0909090a, 0x00090909, 0x0909090a, 0x00090909,
> >> +	}
> >> +};
> >> +
> >> +static const unsigned int mali_c55_scaler_v_filter_coefficients[8][64] = {
> >> +	{	/* Bank 0 */
> >> +		0x2424fc00, 0x000000fc, 0x2721fc00, 0x000000fc,
> >> +		0x281ffd00, 0x000000fc, 0x2c1cfd00, 0x000000fb,
> >> +		0x2e1afd00, 0x000000fb, 0x3017fe00, 0x000000fb,
> >> +		0x3215fe00, 0x000000fb, 0x3512fe00, 0x000000fb,
> >> +		0x3510ff00, 0x000000fc, 0x370eff00, 0x000000fc,
> >> +		0x390cff00, 0x000000fc, 0x3a0aff00, 0x000000fd,
> >> +		0x3a080000, 0x000000fe, 0x3c060000, 0x000000fe,
> >> +		0x3d040000, 0x000000ff, 0x3d030000, 0x00000000,
> >> +		0x3c020000, 0x00000002, 0x3d000000, 0x00000003,
> >> +		0x3dff0000, 0x00000004, 0x3cfe0000, 0x00000006,
> >> +		0x3afe0000, 0x00000008, 0x3afd0000, 0x0000ff0a,
> >> +		0x39fc0000, 0x0000ff0c, 0x37fc0000, 0x0000ff0e,
> >> +		0x35fc0000, 0x0000ff10, 0x35fb0000, 0x0000fe12,
> >> +		0x32fb0000, 0x0000fe15, 0x30fb0000, 0x0000fe17,
> >> +		0x2efb0000, 0x0000fd1a, 0x2cfb0000, 0x0000fd1c,
> >> +		0x28fc0000, 0x0000fd1f, 0x27fc0000, 0x0000fc21,
> >> +	},
> >> +	{	/* Bank 1 */
> >> +		0x2525fb00, 0x000000fb, 0x2723fb00, 0x000000fb,
> >> +		0x2921fb00, 0x000000fb, 0x2a1ffb00, 0x000000fc,
> >> +		0x2c1dfb00, 0x000000fc, 0x2e1bfb00, 0x000000fc,
> >> +		0x2f19fb00, 0x000000fd, 0x2f17fc00, 0x000000fe,
> >> +		0x3115fc00, 0x000000fe, 0x3213fc00, 0x000000ff,
> >> +		0x3411fc00, 0x0000ff00, 0x3310fd00, 0x0000ff01,
> >> +		0x340efd00, 0x0000ff02, 0x350cfd00, 0x0000ff03,
> >> +		0x350afd00, 0x0000ff05, 0x3509fe00, 0x0000fe06,
> >> +		0x3607fe00, 0x0000fe07, 0x3506fe00, 0x0000fe09,
> >> +		0x3505ff00, 0x0000fd0a, 0x3503ff00, 0x0000fd0c,
> >> +		0x3402ff00, 0x0000fd0e, 0x3301ff00, 0x0000fd10,
> >> +		0x3400ff00, 0x0000fc11, 0x32ff0000, 0x0000fc13,
> >> +		0x31fe0000, 0x0000fc15, 0x2ffe0000, 0x0000fc17,
> >> +		0x2ffd0000, 0x0000fb19, 0x2efc0000, 0x0000fb1b,
> >> +		0x2cfc0000, 0x0000fb1d, 0x2afc0000, 0x0000fb1f,
> >> +		0x29fb0000, 0x0000fb21, 0x27fb0000, 0x0000fb23,
> >> +	},
> >> +	{	/* Bank 2 */
> >> +		0x1f1f0100, 0x00000001, 0x211e0000, 0x00000001,
> >> +		0x211d0000, 0x00000002, 0x221c0000, 0x00000002,
> >> +		0x231bff00, 0x00000003, 0x241aff00, 0x0000ff04,
> >> +		0x2519ff00, 0x0000ff04, 0x2518ff00, 0x0000ff05,
> >> +		0x2617fe00, 0x0000ff06, 0x2616fe00, 0x0000ff07,
> >> +		0x2714fe00, 0x0000ff08, 0x2713fe00, 0x0000ff09,
> >> +		0x2712fe00, 0x0000ff0a, 0x2811fe00, 0x0000fe0b,
> >> +		0x2810fe00, 0x0000fe0c, 0x280ffe00, 0x0000fe0d,
> >> +		0x280efe00, 0x0000fe0e, 0x280dfe00, 0x0000fe0f,
> >> +		0x280cfe00, 0x0000fe10, 0x280bfe00, 0x0000fe11,
> >> +		0x270aff00, 0x0000fe12, 0x2709ff00, 0x0000fe13,
> >> +		0x2708ff00, 0x0000fe14, 0x2607ff00, 0x0000fe16,
> >> +		0x2606ff00, 0x0000fe17, 0x2505ff00, 0x0000ff18,
> >> +		0x2504ff00, 0x0000ff19, 0x2404ff00, 0x0000ff1a,
> >> +		0x23030000, 0x0000ff1b, 0x22020000, 0x0000001c,
> >> +		0x21020000, 0x0000001d, 0x21010000, 0x0000001e,
> >> +	},
> >> +	{	/* Bank 3 */
> >> +		0x1b1b06ff, 0x0000ff06, 0x1b1a06ff, 0x0000ff07,
> >> +		0x1c1a05ff, 0x0000ff07, 0x1c1905ff, 0x0000ff08,
> >> +		0x1c1904ff, 0x0000ff09, 0x1d1804ff, 0x0000ff09,
> >> +		0x1e1703ff, 0x0000ff0a, 0x1e1703ff, 0x0000ff0a,
> >> +		0x1e1603ff, 0x0000ff0b, 0x1f1502ff, 0x0000ff0c,
> >> +		0x1e150200, 0x0000ff0c, 0x1e140200, 0x0000ff0d,
> >> +		0x1e130100, 0x0000000e, 0x1e130100, 0x0000000e,
> >> +		0x1e120100, 0x0000000f, 0x1f110000, 0x00000010,
> >> +		0x20100000, 0x00000010, 0x1f100000, 0x00000011,
> >> +		0x1e0f0000, 0x00000112, 0x1e0e0000, 0x00000113,
> >> +		0x1e0e0000, 0x00000113, 0x1e0dff00, 0x00000214,
> >> +		0x1e0cff00, 0x00000215, 0x1f0cff00, 0x00ff0215,
> >> +		0x1e0bff00, 0x00ff0316, 0x1e0aff00, 0x00ff0317,
> >> +		0x1e0aff00, 0x00ff0317, 0x1d09ff00, 0x00ff0418,
> >> +		0x1c09ff00, 0x00ff0419, 0x1c08ff00, 0x00ff0519,
> >> +		0x1c07ff00, 0x00ff051a, 0x1b07ff00, 0x00ff061a,
> >> +	},
> >> +	{	/* Bank 4 */
> >> +		0x17170900, 0x00000009, 0x18160900, 0x00000009,
> >> +		0x17160800, 0x0000010a, 0x17160800, 0x0000010a,
> >> +		0x18150700, 0x0000010b, 0x18150700, 0x0000010b,
> >> +		0x17150700, 0x0000010c, 0x19140600, 0x0000010c,
> >> +		0x18140600, 0x0000010d, 0x19130500, 0x0000020d,
> >> +		0x18130500, 0x0000020e, 0x18130500, 0x0000020e,
> >> +		0x1a120400, 0x0000020e, 0x19120400, 0x0000020f,
> >> +		0x19110400, 0x0000030f, 0x18110400, 0x00000310,
> >> +		0x1a100300, 0x00000310, 0x18100300, 0x00000411,
> >> +		0x190f0300, 0x00000411, 0x190f0200, 0x00000412,
> >> +		0x1a0e0200, 0x00000412, 0x180e0200, 0x00000513,
> >> +		0x180e0200, 0x00000513, 0x190d0200, 0x00000513,
> >> +		0x180d0100, 0x00000614, 0x190c0100, 0x00000614,
> >> +		0x170c0100, 0x00000715, 0x180b0100, 0x00000715,
> >> +		0x180b0100, 0x00000715, 0x170a0100, 0x00000816,
> >> +		0x170a0100, 0x00000816, 0x18090000, 0x00000916,
> >> +	},
> >> +	{	/* Bank 5 */
> >> +		0x12120b03, 0x0000030b, 0x12110b03, 0x0000030c,
> >> +		0x11110b03, 0x0000040c, 0x11110b03, 0x0000040c,
> >> +		0x13110a02, 0x0000040c, 0x12110a02, 0x0000040d,
> >> +		0x11110a02, 0x0000050d, 0x11110a02, 0x0000050d,
> >> +		0x13110901, 0x0000050d, 0x13100901, 0x0000050e,
> >> +		0x12100901, 0x0000060e, 0x12100901, 0x0000060e,
> >> +		0x13100801, 0x0000060e, 0x12100801, 0x0000060f,
> >> +		0x12100800, 0x0000070f, 0x130f0800, 0x0000070f,
> >> +		0x140f0700, 0x0000070f, 0x130f0700, 0x0000080f,
> >> +		0x120f0700, 0x00000810, 0x120f0600, 0x00010810,
> >> +		0x130e0600, 0x00010810, 0x120e0600, 0x00010910,
> >> +		0x120e0600, 0x00010910, 0x130e0500, 0x00010910,
> >> +		0x130d0500, 0x00010911, 0x110d0500, 0x00020a11,
> >> +		0x110d0500, 0x00020a11, 0x120d0400, 0x00020a11,
> >> +		0x130c0400, 0x00020a11, 0x110c0400, 0x00030b11,
> >> +		0x110c0400, 0x00030b11, 0x120c0300, 0x00030b11,
> >> +	},
> >> +	{	/* Bank 6 */
> >> +		0x0b0c0a08, 0x0005080a, 0x0b0c0a08, 0x0005080a,
> >> +		0x0c0b0a08, 0x0005080a, 0x0c0b0a08, 0x0005080a,
> >> +		0x0d0b0a07, 0x0005080a, 0x0d0b0a07, 0x0005080a,
> >> +		0x0d0b0a07, 0x0005080a, 0x0c0b0a07, 0x0006080a,
> >> +		0x0b0b0a07, 0x0006080b, 0x0c0b0907, 0x0006080b,
> >> +		0x0b0b0907, 0x0006090b, 0x0b0b0907, 0x0006090b,
> >> +		0x0b0b0907, 0x0006090b, 0x0b0b0907, 0x0006090b,
> >> +		0x0b0b0907, 0x0006090b, 0x0c0b0906, 0x0006090b,
> >> +		0x0c0b0906, 0x0006090b, 0x0c0b0906, 0x0006090b,
> >> +		0x0b0b0906, 0x0007090b, 0x0b0b0906, 0x0007090b,
> >> +		0x0b0b0906, 0x0007090b, 0x0b0b0906, 0x0007090b,
> >> +		0x0b0b0906, 0x0007090b, 0x0c0b0806, 0x0007090b,
> >> +		0x0b0b0806, 0x00070a0b, 0x0c0a0806, 0x00070a0b,
> >> +		0x0d0a0805, 0x00070a0b, 0x0d0a0805, 0x00070a0b,
> >> +		0x0d0a0805, 0x00070a0b, 0x0c0a0805, 0x00080a0b,
> >> +		0x0c0a0805, 0x00080a0b, 0x0c0a0805, 0x00080a0b,
> >> +	},
> >> +	{	/* Bank 7 */
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +		0x09090909, 0x000a0909, 0x09090909, 0x000a0909,
> >> +	}
> >> +};
> >> +
> >> +struct mali_c55_resizer_coef_bank {
> >> +	unsigned int bank;
> >
> > This is always equal to the index of the entry in the
> > mali_c55_coefficient_banks array, you can drop it.
> >
> >> +	unsigned int top;
> >> +	unsigned int bottom;
> >
> > The bottom value of bank N is always equal to the top value of bank N+1.
> > You can simplify this by storing a single value.
> >
> >> +};
> >> +
> >> +static const struct mali_c55_resizer_coef_bank mali_c55_coefficient_banks[] = {
> >> +	{
> >> +		.bank = 0,
> >> +		.top = 1000,
> >> +		.bottom = 770,
> >> +	},
> >> +	{
> >> +		.bank = 1,
> >> +		.top = 769,
> >> +		.bottom = 600,
> >> +	},
> >> +	{
> >> +		.bank = 2,
> >> +		.top = 599,
> >> +		.bottom = 460,
> >> +	},
> >> +	{
> >> +		.bank = 3,
> >> +		.top = 459,
> >> +		.bottom = 354,
> >> +	},
> >> +	{
> >> +		.bank = 4,
> >> +		.top = 353,
> >> +		.bottom = 273,
> >> +	},
> >> +	{
> >> +		.bank = 5,
> >> +		.top = 272,
> >> +		.bottom = 210,
> >> +	},
> >> +	{
> >> +		.bank = 6,
> >> +		.top = 209,
> >> +		.bottom = 162,
> >> +	},
> >> +	{
> >> +		.bank = 7,
> >> +		.top = 161,
> >> +		.bottom = 125,
> >> +	},
> >> +};
> >> +
> >
> > A small comment would be nice, such as
> >
> > /* Select a bank of resizer coefficients, based on the scaling ratio. */
> >
> >> +static unsigned int mali_c55_calculate_bank_num(struct mali_c55 *mali_c55,
> >
> > This function is related to the resizers. Add "rsz" somewhere in the
> > function name, and pass a resizer pointer.
> >
> >> +						unsigned int crop,
> >> +						unsigned int scale)
> >
> > I think those are the input and output sizes to the scaler. Rename them
> > to make it clearer.
> >
> >> +{
> >> +	unsigned int tmp;
> >
> > tmp is almost always a bad variable name. Please use a more descriptive
> > name, size as rsz_ratio.
> >
> >> +	unsigned int i;
> >> +
> >> +	tmp = (scale * 1000U) / crop;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55_coefficient_banks); i++) {
> >> +		if (tmp >= mali_c55_coefficient_banks[i].bottom &&
> >> +		    tmp <= mali_c55_coefficient_banks[i].top)
> >> +			return mali_c55_coefficient_banks[i].bank;
> >> +	}
> >> +
> >> +	/*
> >> +	 * We shouldn't ever get here, in theory. As we have no good choices
> >> +	 * simply warn the user and use the first bank of coefficients.
> >> +	 */
> >> +	dev_warn(mali_c55->dev, "scaling factor outside defined bounds\n");
> >> +	return 0;
> >> +}
> >
> > And everything else belongs to mali-c55-resizer.c. Drop this header
> > file.
> >
> >> +
> >> +#endif /* _MALI_C55_RESIZER_COEFS_H */
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-resizer.c b/drivers/media/platform/arm/mali-c55/mali-c55-resizer.c
> >> new file mode 100644
> >> index 000000000000..0a5a2969d3ce
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-resizer.c
> >> @@ -0,0 +1,779 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Image signal processor
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#include <linux/math.h>
> >> +#include <linux/minmax.h>
> >> +
> >> +#include <media/media-entity.h>
> >> +#include <media/v4l2-subdev.h>
> >> +
> >> +#include "mali-c55-common.h"
> >> +#include "mali-c55-registers.h"
> >> +#include "mali-c55-resizer-coefs.h"
> >> +
> >> +/* Scaling factor in Q4.20 format. */
> >> +#define MALI_C55_RZR_SCALER_FACTOR	(1U << 20)
> >> +
> >> +static const u32 rzr_non_bypass_src_fmts[] = {
> >> +	MEDIA_BUS_FMT_RGB121212_1X36,
> >> +	MEDIA_BUS_FMT_YUV10_1X30
> >> +};
> >> +
> >> +static const char * const mali_c55_resizer_names[] = {
> >> +	[MALI_C55_RZR_FR] = "resizer fr",
> >> +	[MALI_C55_RZR_DS] = "resizer ds",
> >> +};
> >> +
> >> +static int mali_c55_rzr_program_crop(struct mali_c55_resizer *rzr,
> >> +				     struct v4l2_subdev_state *state)
> >> +{
> >> +	unsigned int reg_offset = rzr->cap_dev->reg_offset;
> >> +	struct mali_c55 *mali_c55 = rzr->mali_c55;
> >> +	struct v4l2_mbus_framefmt *fmt;
> >> +	struct v4l2_rect *crop;
> >> +
> >> +	/* Verify if crop should be enabled. */
> >> +	fmt = v4l2_subdev_state_get_format(state, MALI_C55_RZR_SINK_PAD, 0);
> >> +	crop = v4l2_subdev_state_get_crop(state, MALI_C55_RZR_SINK_PAD, 0);
> >> +
> >> +	if (fmt->width == crop->width && fmt->height == crop->height)
> >> +		return MALI_C55_BYPASS_CROP;
> >> +
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_CROP_X_START(reg_offset),
> >> +		       crop->left);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_CROP_Y_START(reg_offset),
> >> +		       crop->top);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_CROP_X_SIZE(reg_offset),
> >> +		       crop->width);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_CROP_Y_SIZE(reg_offset),
> >> +		       crop->height);
> >> +
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_CROP_EN(reg_offset),
> >> +		       MALI_C55_CROP_ENABLE);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_program_resizer(struct mali_c55_resizer *rzr,
> >> +					struct v4l2_subdev_state *state)
> >> +{
> >> +	unsigned int reg_offset = rzr->cap_dev->reg_offset;
> >> +	struct mali_c55 *mali_c55 = rzr->mali_c55;
> >> +	struct v4l2_rect *crop, *scale;
> >> +	unsigned int h_bank, v_bank;
> >> +	u64 h_scale, v_scale;
> >> +
> >> +	/* Verify if scaling should be enabled. */
> >> +	crop = v4l2_subdev_state_get_crop(state, MALI_C55_RZR_SINK_PAD, 0);
> >> +	scale = v4l2_subdev_state_get_compose(state, MALI_C55_RZR_SINK_PAD, 0);
> >> +
> >> +	if (crop->width == scale->width && crop->height == scale->height)
> >> +		return MALI_C55_BYPASS_SCALER;
> >> +
> >> +	/* Program the V/H scaling factor in Q4.20 format. */
> >> +	h_scale = crop->width * MALI_C55_RZR_SCALER_FACTOR;
> >> +	v_scale = crop->height * MALI_C55_RZR_SCALER_FACTOR;
> >> +
> >> +	do_div(h_scale, scale->width);
> >> +	do_div(v_scale, scale->height);
> >> +
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_IN_WIDTH(reg_offset),
> >> +		       crop->width);
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_IN_HEIGHT(reg_offset),
> >> +		       crop->height);
> >> +
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_OUT_WIDTH(reg_offset),
> >> +		       scale->width);
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_OUT_HEIGHT(reg_offset),
> >> +		       scale->height);
> >> +
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_HFILT_TINC(reg_offset),
> >> +		       h_scale);
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_VFILT_TINC(reg_offset),
> >> +		       v_scale);
> >> +
> >> +	h_bank = mali_c55_calculate_bank_num(mali_c55, crop->width,
> >> +					     scale->width);
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_HFILT_COEF(reg_offset),
> >> +		       h_bank);
> >> +
> >> +	v_bank = mali_c55_calculate_bank_num(mali_c55, crop->height,
> >> +					     scale->height);
> >> +	mali_c55_write(mali_c55,
> >> +		       MALI_C55_REG_SCALER_VFILT_COEF(reg_offset),
> >> +		       v_bank);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void mali_c55_rzr_program(struct mali_c55_resizer *rzr,
> >> +				 struct v4l2_subdev_state *state)
> >> +{
> >> +	struct mali_c55 *mali_c55 = rzr->mali_c55;
> >> +	u32 bypass = 0;
> >> +
> >> +	/* Verify if cropping and scaling should be enabled. */
> >> +	bypass |= mali_c55_rzr_program_crop(rzr, state);
> >> +	bypass |= mali_c55_rzr_program_resizer(rzr, state);
> >> +
> >> +	mali_c55_update_bits(mali_c55, rzr->id == MALI_C55_RZR_FR ?
> >> +			     MALI_C55_REG_FR_BYPASS : MALI_C55_REG_DS_BYPASS,
> >> +			     MALI_C55_BYPASS_CROP | MALI_C55_BYPASS_SCALER,
> >> +			     bypass);
> >> +}
> >> +
> >> +/*
> >> + * Inspect the routing table to know which of the two (mutually exclusive)
> >> + * routes is enabled and return the sink pad id of the active route.
> >> + */
> >> +static unsigned int mali_c55_rzr_get_active_sink(struct v4l2_subdev_state *state)
> >> +{
> >> +	struct v4l2_subdev_krouting *routing = &state->routing;
> >> +	struct v4l2_subdev_route *route;
> >> +
> >> +	/* A single route is enabled at a time. */
> >> +	for_each_active_route(routing, route)
> >> +		return route->sink_pad;
> >> +
> >> +	return MALI_C55_RZR_SINK_PAD;
> >> +}
> >> +
> >> +static u32 mali_c55_rzr_shift_mbus_code(u32 mbus_code)
> >> +{
> >> +	u32 corrected_code = 0;
> >> +
> >> +	/*
> >> +	 * The ISP takes input in a 20-bit format, but can only output 16-bit
> >> +	 * RAW bayer data (with the 4 least significant bits from the input
> >> +	 * being lost). Return the 16-bit version of the 20-bit input formats.
> >> +	 */
> >> +	switch (mbus_code) {
> >> +	case MEDIA_BUS_FMT_SBGGR20_1X20:
> >> +		corrected_code = MEDIA_BUS_FMT_SBGGR16_1X16;
> >> +		break;
> >> +	case MEDIA_BUS_FMT_SGBRG20_1X20:
> >> +		corrected_code = MEDIA_BUS_FMT_SGBRG16_1X16;
> >> +		break;
> >> +	case MEDIA_BUS_FMT_SGRBG20_1X20:
> >> +		corrected_code = MEDIA_BUS_FMT_SGRBG16_1X16;
> >> +		break;
> >> +	case MEDIA_BUS_FMT_SRGGB20_1X20:
> >> +		corrected_code = MEDIA_BUS_FMT_SRGGB16_1X16;
> >> +		break;
> >> +	}
> >> +
> >> +	return corrected_code;
> >> +}
> >> +
> >> +static int __mali_c55_rzr_set_routing(struct v4l2_subdev *sd,
> >> +				      struct v4l2_subdev_state *state,
> >> +				      struct v4l2_subdev_krouting *routing)
> >> +{
> >> +	struct mali_c55_resizer *rzr = container_of(sd, struct mali_c55_resizer,
> >> +						    sd);
> >> +	unsigned int active_sink = UINT_MAX;
> >> +	struct v4l2_mbus_framefmt *src_fmt;
> >> +	struct v4l2_rect *crop, *compose;
> >> +	struct v4l2_subdev_route *route;
> >> +	unsigned int active_routes = 0;
> >> +	struct v4l2_mbus_framefmt *fmt;
> >> +	int ret;
> >> +
> >> +	ret = v4l2_subdev_routing_validate(sd, routing, 0);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	/* Only a single route can be enabled at a time. */
> >> +	for_each_active_route(routing, route) {
> >> +		if (++active_routes > 1) {
> >> +			dev_err(rzr->mali_c55->dev,
> >> +				"Only one route can be active");
> >> +			return -EINVAL;
> >> +		}
> >> +
> >> +		active_sink = route->sink_pad;
> >> +	}
> >> +	if (active_sink == UINT_MAX) {
> >> +		dev_err(rzr->mali_c55->dev, "One route has to be active");
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	ret = v4l2_subdev_set_routing(sd, state, routing);
> >> +	if (ret) {
> >> +		dev_err(rzr->mali_c55->dev, "Failed to set routing\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	fmt = v4l2_subdev_state_get_format(state, active_sink, 0);
> >> +	crop = v4l2_subdev_state_get_crop(state, active_sink, 0);
> >> +	compose = v4l2_subdev_state_get_compose(state, active_sink, 0);
> >> +
> >> +	fmt->width = MALI_C55_DEFAULT_WIDTH;
> >> +	fmt->height = MALI_C55_DEFAULT_HEIGHT;
> >> +	fmt->colorspace = V4L2_COLORSPACE_SRGB;
> >> +	fmt->field = V4L2_FIELD_NONE;
> >> +
> >> +	if (active_sink == MALI_C55_RZR_SINK_PAD) {
> >> +		fmt->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +
> >> +		crop->left = crop->top = 0;
> >> +		crop->width = MALI_C55_DEFAULT_WIDTH;
> >> +		crop->height = MALI_C55_DEFAULT_HEIGHT;
> >> +
> >> +		*compose = *crop;
> >> +	} else {
> >> +		fmt->code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >> +	}
> >> +
> >> +	/* Propagate the format to the source pad */
> >> +	src_fmt = v4l2_subdev_state_get_format(state, MALI_C55_RZR_SOURCE_PAD,
> >> +					       0);
> >> +	*src_fmt = *fmt;
> >> +
> >> +	/* In the event this is the bypass pad the mbus code needs correcting */
> >> +	if (active_sink == MALI_C55_RZR_SINK_BYPASS_PAD)
> >> +		src_fmt->code = mali_c55_rzr_shift_mbus_code(src_fmt->code);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				       struct v4l2_subdev_state *state,
> >> +				       struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	struct v4l2_mbus_framefmt *sink_fmt;
> >> +	const struct mali_c55_isp_fmt *fmt;
> >> +	unsigned int index = 0;
> >> +	u32 sink_pad;
> >> +
> >> +	switch (code->pad) {
> >> +	case MALI_C55_RZR_SINK_PAD:
> >> +		if (code->index)
> >> +			return -EINVAL;
> >> +
> >> +		code->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +
> >> +		return 0;
> >> +	case MALI_C55_RZR_SOURCE_PAD:
> >> +		sink_pad = mali_c55_rzr_get_active_sink(state);
> >> +		sink_fmt = v4l2_subdev_state_get_format(state, sink_pad, 0);
> >> +
> >> +		/*
> >> +		 * If the active route is from the Bypass sink pad, then the
> >> +		 * source pad is a simple passthrough of the sink format,
> >> +		 * downshifted to 16-bits.
> >> +		 */
> >> +
> >> +		if (sink_pad == MALI_C55_RZR_SINK_BYPASS_PAD) {
> >> +			if (code->index)
> >> +				return -EINVAL;
> >> +
> >> +			code->code = mali_c55_rzr_shift_mbus_code(sink_fmt->code);
> >> +			if (!code->code)
> >> +				return -EINVAL;
> >> +
> >> +			return 0;
> >> +		}
> >> +
> >> +		/*
> >> +		 * If the active route is from the non-bypass sink then we can
> >> +		 * select either RGB or conversion to YUV.
> >> +		 */
> >> +
> >> +		if (code->index >= ARRAY_SIZE(rzr_non_bypass_src_fmts))
> >> +			return -EINVAL;
> >> +
> >> +		code->code = rzr_non_bypass_src_fmts[code->index];
> >> +
> >> +		return 0;
> >> +	case MALI_C55_RZR_SINK_BYPASS_PAD:
> >> +		for_each_mali_isp_fmt(fmt) {
> >> +			if (index++ == code->index) {
> >> +				code->code = fmt->code;
> >> +				return 0;
> >> +			}
> >> +		}
> >> +
> >> +		break;
> >> +	}
> >> +
> >> +	return -EINVAL;
> >> +}
> >> +
> >> +static int mali_c55_rzr_enum_frame_size(struct v4l2_subdev *sd,
> >> +					struct v4l2_subdev_state *state,
> >> +					struct v4l2_subdev_frame_size_enum *fse)
> >> +{
> >> +	if (fse->index)
> >> +		return -EINVAL;
> >> +
> >> +	fse->max_width = MALI_C55_MAX_WIDTH;
> >> +	fse->max_height = MALI_C55_MAX_HEIGHT;
> >> +	fse->min_width = MALI_C55_MIN_WIDTH;
> >> +	fse->min_height = MALI_C55_MIN_HEIGHT;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_set_sink_fmt(struct v4l2_subdev *sd,
> >> +				     struct v4l2_subdev_state *state,
> >> +				     struct v4l2_subdev_format *format)
> >> +{
> >> +	struct v4l2_mbus_framefmt *fmt = &format->format;
> >> +	struct v4l2_rect *rect;
> >> +	unsigned int sink_pad;
> >> +
> >> +	/*
> >> +	 * Clamp to min/max and then reset crop and compose rectangles to the
> >> +	 * newly applied size.
> >> +	 */
> >> +	clamp_t(unsigned int, fmt->width,
> >> +		MALI_C55_MIN_WIDTH, MALI_C55_MAX_WIDTH);
> >> +	clamp_t(unsigned int, fmt->height,
> >> +		MALI_C55_MIN_HEIGHT, MALI_C55_MAX_HEIGHT);
> >> +
> >> +	sink_pad = mali_c55_rzr_get_active_sink(state);
> >> +	if (sink_pad == MALI_C55_RZR_SINK_PAD) {
> >> +		fmt->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +
> >> +		rect = v4l2_subdev_state_get_crop(state, MALI_C55_RZR_SINK_PAD);
> >> +		rect->left = 0;
> >> +		rect->top = 0;
> >> +		rect->width = fmt->width;
> >> +		rect->height = fmt->height;
> >> +
> >> +		rect = v4l2_subdev_state_get_compose(state,
> >> +						     MALI_C55_RZR_SINK_PAD);
> >> +		rect->left = 0;
> >> +		rect->top = 0;
> >> +		rect->width = fmt->width;
> >> +		rect->height = fmt->height;
> >> +	} else {
> >> +		/*
> >> +		 * Make sure the media bus code is one of the supported
> >> +		 * ISP input media bus codes.
> >> +		 */
> >> +		if (!mali_c55_isp_is_format_supported(fmt->code))
> >> +			fmt->code = MALI_C55_DEFAULT_MEDIA_BUS_FMT;
> >> +	}
> >> +
> >> +	*v4l2_subdev_state_get_format(state, sink_pad, 0) = *fmt;
> >> +	*v4l2_subdev_state_get_format(state, MALI_C55_RZR_SOURCE_PAD, 0) = *fmt;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_set_source_fmt(struct v4l2_subdev *sd,
> >> +				       struct v4l2_subdev_state *state,
> >> +				       struct v4l2_subdev_format *format)
> >> +{
> >> +	struct mali_c55_resizer *rzr = container_of(sd, struct mali_c55_resizer,
> >> +						    sd);
> >> +	struct v4l2_mbus_framefmt *fmt = &format->format;
> >> +	struct v4l2_mbus_framefmt *sink_fmt;
> >> +	struct v4l2_rect *crop, *compose;
> >> +	unsigned int sink_pad;
> >> +	unsigned int i;
> >> +
> >> +	sink_pad = mali_c55_rzr_get_active_sink(state);
> >> +	sink_fmt = v4l2_subdev_state_get_format(state, sink_pad, 0);
> >> +	crop = v4l2_subdev_state_get_crop(state, sink_pad, 0);
> >> +	compose = v4l2_subdev_state_get_compose(state, sink_pad, 0);
> >> +
> >> +	/* FR Bypass pipe. */
> >> +
> >> +	if (sink_pad == MALI_C55_RZR_SINK_BYPASS_PAD) {
> >> +		/*
> >> +		 * Format on the source pad is the same as the one on the
> >> +		 * sink pad, downshifted to 16-bits.
> >> +		 */
> >> +		fmt->code = mali_c55_rzr_shift_mbus_code(sink_fmt->code);
> >> +		if (!fmt->code)
> >> +			return -EINVAL;
> >> +
> >> +		/* RAW bypass disables scaling and cropping. */
> >> +		crop->top = compose->top = 0;
> >> +		crop->left = compose->left = 0;
> >> +		fmt->width = crop->width = compose->width = sink_fmt->width;
> >> +		fmt->height = crop->height = compose->height = sink_fmt->height;
> >> +
> >> +		*v4l2_subdev_state_get_format(state,
> >> +					      MALI_C55_RZR_SOURCE_PAD) = *fmt;
> >> +
> >> +		return 0;
> >> +	}
> >> +
> >> +	/* Regular processing pipe. */
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(rzr_non_bypass_src_fmts); i++) {
> >> +		if (fmt->code == rzr_non_bypass_src_fmts[i])
> >> +			break;
> >> +	}
> >> +
> >> +	if (i == ARRAY_SIZE(rzr_non_bypass_src_fmts)) {
> >> +		dev_dbg(rzr->mali_c55->dev,
> >> +			"Unsupported mbus code 0x%x: using default\n",
> >> +			fmt->code);
> >> +		fmt->code = MEDIA_BUS_FMT_RGB121212_1X36;
> >> +	}
> >> +
> >> +	/*
> >> +	 * The source pad format size comes directly from the sink pad
> >> +	 * compose rectangle.
> >> +	 */
> >> +	fmt->width = compose->width;
> >> +	fmt->height = compose->height;
> >> +
> >> +	*v4l2_subdev_state_get_format(state, MALI_C55_RZR_SOURCE_PAD) = *fmt;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_set_fmt(struct v4l2_subdev *sd,
> >> +				struct v4l2_subdev_state *state,
> >> +				struct v4l2_subdev_format *format)
> >> +{
> >> +	/*
> >> +	 * On sink pads fmt is either fixed for the 'regular' processing
> >> +	 * pad or a RAW format or 20-bit wide RGB/YUV format for the FR bypass
> >> +	 * pad.
> >> +	 *
> >> +	 * On source pad sizes are the result of crop+compose on the sink
> >> +	 * pad sizes, while the format depends on the active route.
> >> +	 */
> >> +
> >> +	if (format->pad != MALI_C55_RZR_SOURCE_PAD)
> >> +		return mali_c55_rzr_set_sink_fmt(sd, state, format);
> >> +
> >> +	return mali_c55_rzr_set_source_fmt(sd, state, format);
> >> +}
> >> +
> >> +static int mali_c55_rzr_get_selection(struct v4l2_subdev *sd,
> >> +				      struct v4l2_subdev_state *state,
> >> +				      struct v4l2_subdev_selection *sel)
> >> +{
> >> +	if (sel->pad != MALI_C55_RZR_SINK_PAD)
> >> +		return -EINVAL;
> >> +
> >> +	if (sel->target != V4L2_SEL_TGT_CROP &&
> >> +	    sel->target != V4L2_SEL_TGT_COMPOSE)
> >> +		return -EINVAL;
> >> +
> >> +	sel->r = sel->target == V4L2_SEL_TGT_CROP
> >> +	       ? *v4l2_subdev_state_get_crop(state, MALI_C55_RZR_SINK_PAD)
> >> +	       : *v4l2_subdev_state_get_compose(state, MALI_C55_RZR_SINK_PAD);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_set_selection(struct v4l2_subdev *sd,
> >> +				      struct v4l2_subdev_state *state,
> >> +				      struct v4l2_subdev_selection *sel)
> >> +{
> >> +	struct mali_c55_resizer *rzr = container_of(sd, struct mali_c55_resizer,
> >> +						    sd);
> >> +	struct v4l2_mbus_framefmt *source_fmt;
> >> +	struct v4l2_mbus_framefmt *sink_fmt;
> >> +	struct v4l2_rect *crop, *compose;
> >> +
> >> +	if (sel->pad != MALI_C55_RZR_SINK_PAD)
> >> +		return -EINVAL;
> >> +
> >> +	if (sel->target != V4L2_SEL_TGT_CROP &&
> >> +	    sel->target != V4L2_SEL_TGT_COMPOSE)
> >> +		return -EINVAL;
> >> +
> >> +	source_fmt = v4l2_subdev_state_get_format(state,
> >> +						  MALI_C55_RZR_SOURCE_PAD);
> >> +	sink_fmt = v4l2_subdev_state_get_format(state, MALI_C55_RZR_SINK_PAD);
> >> +	crop = v4l2_subdev_state_get_crop(state, MALI_C55_RZR_SINK_PAD);
> >> +	compose = v4l2_subdev_state_get_compose(state, MALI_C55_RZR_SINK_PAD);
> >> +
> >> +	/* RAW bypass disables crop/scaling. */
> >> +	if (mali_c55_format_is_raw(source_fmt->code)) {
> >> +		crop->top = compose->top = 0;
> >> +		crop->left = compose->left = 0;
> >> +		crop->width = compose->width = sink_fmt->width;
> >> +		crop->height = compose->height = sink_fmt->height;
> >> +
> >> +		sel->r = sel->target == V4L2_SEL_TGT_CROP ? *crop : *compose;
> >> +
> >> +		return 0;
> >> +	}
> >> +
> >> +	/* During streaming, it is allowed to only change the crop rectangle. */
> >> +	if (rzr->streaming && sel->target != V4L2_SEL_TGT_CROP)
> >> +		return -EINVAL;
> >> +
> >> +	 /*
> >> +	  * Update the desired target and then clamp the crop rectangle to the
> >> +	  * sink format sizes and the compose size to the crop sizes.
> >> +	  */
> >> +	if (sel->target == V4L2_SEL_TGT_CROP)
> >> +		*crop = sel->r;
> >> +	else
> >> +		*compose = sel->r;
> >> +
> >> +	clamp_t(unsigned int, crop->left, 0,  sink_fmt->width);
> >> +	clamp_t(unsigned int, crop->top, 0,  sink_fmt->height);
> >> +	clamp_t(unsigned int, crop->width, MALI_C55_MIN_WIDTH,
> >> +		sink_fmt->width - crop->left);
> >> +	clamp_t(unsigned int, crop->height, MALI_C55_MIN_HEIGHT,
> >> +		sink_fmt->height - crop->top);
> >> +
> >> +	if (rzr->streaming) {
> >> +		/*
> >> +		 * Apply at runtime a crop rectangle on the resizer's sink only
> >> +		 * if it doesn't require re-programming the scaler output sizes
> >> +		 * as it would require changing the output buffer sizes as well.
> >> +		 */
> >> +		if (sel->r.width < compose->width ||
> >> +		    sel->r.height < compose->height)
> >> +			return -EINVAL;
> >> +
> >> +		*crop = sel->r;
> >> +		mali_c55_rzr_program(rzr, state);
> >> +
> >> +		return 0;
> >> +	}
> >> +
> >> +	compose->left = 0;
> >> +	compose->top = 0;
> >> +	clamp_t(unsigned int, compose->left, 0,  sink_fmt->width);
> >> +	clamp_t(unsigned int, compose->top, 0,  sink_fmt->height);
> >> +	clamp_t(unsigned int, compose->width, crop->width / 8, crop->width);
> >> +	clamp_t(unsigned int, compose->height, crop->height / 8, crop->height);
> >> +
> >> +	sel->r = sel->target == V4L2_SEL_TGT_CROP ? *crop : *compose;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_rzr_set_routing(struct v4l2_subdev *sd,
> >> +				    struct v4l2_subdev_state *state,
> >> +				    enum v4l2_subdev_format_whence which,
> >> +				    struct v4l2_subdev_krouting *routing)
> >> +{
> >> +	if (which == V4L2_SUBDEV_FORMAT_ACTIVE &&
> >> +	    media_entity_is_streaming(&sd->entity))
> >> +		return -EBUSY;
> >> +
> >> +	return __mali_c55_rzr_set_routing(sd, state, routing);
> >> +}
> >> +
> >> +static const struct v4l2_subdev_pad_ops mali_c55_resizer_pad_ops = {
> >> +	.enum_mbus_code		= mali_c55_rzr_enum_mbus_code,
> >> +	.enum_frame_size	= mali_c55_rzr_enum_frame_size,
> >> +	.get_fmt		= v4l2_subdev_get_fmt,
> >> +	.set_fmt		= mali_c55_rzr_set_fmt,
> >> +	.get_selection		= mali_c55_rzr_get_selection,
> >> +	.set_selection		= mali_c55_rzr_set_selection,
> >> +	.set_routing		= mali_c55_rzr_set_routing,
> >> +};
> >> +
> >> +void mali_c55_rzr_start_stream(struct mali_c55_resizer *rzr)
> >> +{
> >> +	struct mali_c55 *mali_c55 = rzr->mali_c55;
> >> +	struct v4l2_subdev *sd = &rzr->sd;
> >> +	struct v4l2_subdev_state *state;
> >> +	unsigned int sink_pad;
> >> +
> >> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> >> +
> >> +	sink_pad = mali_c55_rzr_get_active_sink(state);
> >> +	if (sink_pad == MALI_C55_RZR_SINK_BYPASS_PAD) {
> >> +		/* Bypass FR pipe processing if the bypass route is active. */
> >> +		mali_c55_update_bits(mali_c55, MALI_C55_REG_ISP_RAW_BYPASS,
> >> +				     MALI_C55_ISP_RAW_BYPASS_FR_BYPASS_MASK,
> >> +				     MALI_C55_ISP_RAW_BYPASS_RAW_FR_BYPASS);
> >> +		goto unlock_state;
> >> +	}
> >> +
> >> +	/* Disable bypass and use regular processing. */
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_ISP_RAW_BYPASS,
> >> +			     MALI_C55_ISP_RAW_BYPASS_FR_BYPASS_MASK, 0);
> >> +	mali_c55_rzr_program(rzr, state);
> >> +
> >> +unlock_state:
> >> +	rzr->streaming = true;
> >> +	v4l2_subdev_unlock_state(state);
> >> +}
> >> +
> >> +void mali_c55_rzr_stop_stream(struct mali_c55_resizer *rzr)
> >> +{
> >> +	struct v4l2_subdev *sd = &rzr->sd;
> >> +	struct v4l2_subdev_state *state;
> >> +
> >> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> >> +	rzr->streaming = false;
> >> +	v4l2_subdev_unlock_state(state);
> >> +}
> >> +
> >> +static const struct v4l2_subdev_ops mali_c55_resizer_ops = {
> >> +	.pad	= &mali_c55_resizer_pad_ops,
> >> +};
> >> +
> >> +static int mali_c55_rzr_init_state(struct v4l2_subdev *sd,
> >> +				   struct v4l2_subdev_state *state)
> >> +{
> >> +	struct mali_c55_resizer *rzr = container_of(sd, struct mali_c55_resizer,
> >> +						    sd);
> >> +	struct v4l2_subdev_krouting routing = { };
> >> +	struct v4l2_subdev_route *routes;
> >> +	unsigned int i;
> >> +	int ret;
> >> +
> >> +	routes = kcalloc(rzr->num_routes, sizeof(*routes), GFP_KERNEL);
> >> +	if (!routes)
> >> +		return -ENOMEM;
> >> +
> >> +	for (i = 0; i < rzr->num_routes; ++i) {
> >> +		struct v4l2_subdev_route *route = &routes[i];
> >> +
> >> +		route->sink_pad = i
> >> +				? MALI_C55_RZR_SINK_BYPASS_PAD
> >> +				: MALI_C55_RZR_SINK_PAD;
> >> +		route->source_pad = MALI_C55_RZR_SOURCE_PAD;
> >> +		if (route->sink_pad != MALI_C55_RZR_SINK_BYPASS_PAD)
> >> +			route->flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE;
> >> +	}
> >> +
> >> +	routing.num_routes = rzr->num_routes;
> >> +	routing.routes = routes;
> >> +
> >> +	ret = __mali_c55_rzr_set_routing(sd, state, &routing);
> >> +	kfree(routes);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_internal_ops mali_c55_resizer_internal_ops = {
> >> +	.init_state = mali_c55_rzr_init_state,
> >> +};
> >> +
> >> +static void mali_c55_resizer_program_coefficients(struct mali_c55 *mali_c55,
> >> +						  unsigned int index)
> >> +{
> >> +	const unsigned int scaler_filt_coefmem_addrs[][2] = {
> >> +		[MALI_C55_RZR_FR] = {
> >> +			0x034A8, /* hfilt */
> >> +			0x044A8  /* vfilt */
> >
> > Lowercase hex constants.
> >
> >> +		},
> >> +		[MALI_C55_RZR_DS] = {
> >> +			0x014A8, /* hfilt */
> >> +			0x024A8  /* vfilt */
> >> +		},
> >> +	};
> >> +	unsigned int haddr = scaler_filt_coefmem_addrs[index][0];
> >> +	unsigned int vaddr = scaler_filt_coefmem_addrs[index][1];
> >> +	unsigned int i, j;
> >> +
> >> +	for (i = 0; i < MALI_C55_RESIZER_COEFS_NUM_BANKS; i++) {
> >> +		for (j = 0; j < MALI_C55_RESIZER_COEFS_NUM_ENTRIES; j++) {
> >> +			mali_c55_write(mali_c55, haddr,
> >> +				mali_c55_scaler_h_filter_coefficients[i][j]);
> >> +			mali_c55_write(mali_c55, vaddr,
> >> +				mali_c55_scaler_v_filter_coefficients[i][j]);
> >> +
> >> +			haddr += sizeof(u32);
> >> +			vaddr += sizeof(u32);
> >> +		}
> >> +	}
> >> +}
> >> +
> >> +int mali_c55_register_resizers(struct mali_c55 *mali_c55)
> >> +{
> >> +	unsigned int i;
> >> +	int ret;
> >> +
> >> +	for (i = 0; i < MALI_C55_NUM_RZRS; ++i) {
> >> +		struct mali_c55_resizer *rzr = &mali_c55->resizers[i];
> >> +		struct v4l2_subdev *sd = &rzr->sd;
> >> +		unsigned int num_pads = MALI_C55_RZR_NUM_PADS;
> >> +
> >> +		rzr->id = i;
> >> +		rzr->streaming = false;
> >> +
> >> +		if (rzr->id == MALI_C55_RZR_FR)
> >> +			rzr->cap_dev = &mali_c55->cap_devs[MALI_C55_CAP_DEV_FR];
> >> +		else
> >> +			rzr->cap_dev = &mali_c55->cap_devs[MALI_C55_CAP_DEV_DS];
> >> +
> >> +		mali_c55_resizer_program_coefficients(mali_c55, i);
> >> +
> >> +		v4l2_subdev_init(sd, &mali_c55_resizer_ops);
> >> +		sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE
> >> +			     | V4L2_SUBDEV_FL_STREAMS;
> >> +		sd->entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
> >> +		sd->internal_ops = &mali_c55_resizer_internal_ops;
> >> +		snprintf(sd->name, ARRAY_SIZE(sd->name), "%s %s",
> >> +			 MALI_C55_DRIVER_NAME, mali_c55_resizer_names[i]);
> >> +
> >> +		rzr->pads[MALI_C55_RZR_SINK_PAD].flags = MEDIA_PAD_FL_SINK;
> >> +		rzr->pads[MALI_C55_RZR_SOURCE_PAD].flags = MEDIA_PAD_FL_SOURCE;
> >> +
> >> +		/* Only the FR pipe has a bypass pad. */
> >> +		if (rzr->id == MALI_C55_RZR_FR) {
> >> +			rzr->pads[MALI_C55_RZR_SINK_BYPASS_PAD].flags =
> >> +							MEDIA_PAD_FL_SINK;
> >> +			rzr->num_routes = 2;
> >> +		} else {
> >> +			num_pads -= 1;
> >> +			rzr->num_routes = 1;
> >> +		}
> >> +
> >> +		ret = media_entity_pads_init(&sd->entity, num_pads, rzr->pads);
> >> +		if (ret)
> >> +			return ret;
> >> +
> >> +		ret = v4l2_subdev_init_finalize(sd);
> >> +		if (ret)
> >> +			goto err_cleanup;
> >> +
> >> +		ret = v4l2_device_register_subdev(&mali_c55->v4l2_dev, sd);
> >> +		if (ret)
> >> +			goto err_cleanup;
> >> +
> >> +		rzr->mali_c55 = mali_c55;
> >> +	}
> >> +
> >> +	return 0;
> >> +
> >> +err_cleanup:
> >> +	for (; i >= 0; --i) {
> >> +		struct mali_c55_resizer *rzr = &mali_c55->resizers[i];
> >> +		struct v4l2_subdev *sd = &rzr->sd;
> >> +
> >> +		v4l2_subdev_cleanup(sd);
> >> +		media_entity_cleanup(&sd->entity);
> >> +	}
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +void mali_c55_unregister_resizers(struct mali_c55 *mali_c55)
> >> +{
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < MALI_C55_NUM_RZRS; i++) {
> >> +		struct mali_c55_resizer *resizer = &mali_c55->resizers[i];
> >> +
> >> +		if (!resizer->mali_c55)
> >> +			continue;
> >> +
> >> +		v4l2_device_unregister_subdev(&resizer->sd);
> >> +		v4l2_subdev_cleanup(&resizer->sd);
> >> +		media_entity_cleanup(&resizer->sd.entity);
> >> +	}
> >> +}
> >> diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-tpg.c b/drivers/media/platform/arm/mali-c55/mali-c55-tpg.c
> >> new file mode 100644
> >> index 000000000000..c7e699741c6d
> >> --- /dev/null
> >> +++ b/drivers/media/platform/arm/mali-c55/mali-c55-tpg.c
> >> @@ -0,0 +1,402 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * ARM Mali-C55 ISP Driver - Test pattern generator
> >> + *
> >> + * Copyright (C) 2024 Ideas on Board Oy
> >> + */
> >> +
> >> +#include <linux/minmax.h>
> >> +#include <linux/string.h>
> >> +
> >> +#include <media/media-entity.h>
> >> +#include <media/v4l2-ctrls.h>
> >> +#include <media/v4l2-subdev.h>
> >> +
> >> +#include "mali-c55-common.h"
> >> +#include "mali-c55-registers.h"
> >> +
> >> +#define MALI_C55_TPG_SRC_PAD		0
> >> +#define MALI_C55_TPG_FIXED_HBLANK	0x20
> >> +#define MALI_C55_TPG_MAX_VBLANK		0xFFFF
> >
> > Lowercase hex constants.
> >
> >> +#define MALI_C55_TPG_PIXEL_RATE		100000000
> >
> > This should be exposed to applications using the V4L2_CID_PIXEL_RATE
> > control (read-only).
> >
> >> +
> >> +static const char * const mali_c55_tpg_test_pattern_menu[] = {
> >> +	"Flat field",
> >> +	"Horizontal gradient",
> >> +	"Vertical gradient",
> >> +	"Vertical bars",
> >> +	"Arbitrary rectangle",
> >> +	"White frame on black field"
> >> +};
> >> +
> >> +static const u32 mali_c55_tpg_mbus_codes[] = {
> >> +	MEDIA_BUS_FMT_SRGGB20_1X20,
> >> +	MEDIA_BUS_FMT_RGB202020_1X60,
> >> +};
> >> +
> >> +static void __mali_c55_tpg_calc_vblank(struct v4l2_mbus_framefmt *format,
> >> +				       int *def_vblank, int *min_vblank)
> >
> > unsigned int ?
> >
> >> +{
> >> +	unsigned int hts;
> >> +	int tgt_fps;
> >> +	int vblank;
> >> +
> >> +	hts = format->width + MALI_C55_TPG_FIXED_HBLANK;
> >> +
> >> +	/*
> >> +	 * The ISP has minimum vertical blanking requirements that must be
> >> +	 * adhered to by the TPG. The minimum is a function of the Iridix blocks
> >> +	 * clocking requirements and the width of the image and horizontal
> >> +	 * blanking, but if we assume the worst case iVariance and sVariance
> >> +	 * values then it boils down to the below.
> >> +	 */
> >> +	*min_vblank = 15 + (120500 / hts);
> >
> > I wonder if this should round up.
> 
> Maybe? I think the difference is probably too minor to have a practical effect

Just to make sure we won't have any problem by having a just too short
minimum vblank when rounding down.

> >> +
> >> +	/*
> >> +	 * We need to set a sensible default vblank for whatever format height
> >> +	 * we happen to be given from set_fmt(). This function just targets
> >> +	 * an even multiple of 15fps. If we can't get 15fps, let's target 5fps.
> >> +	 * If we can't get 5fps we'll take whatever the minimum vblank gives us.
> >> +	 */
> >> +	tgt_fps = MALI_C55_TPG_PIXEL_RATE / hts / (format->height + *min_vblank);
> >> +
> >> +	if (tgt_fps < 5)
> >> +		vblank = *min_vblank;
> >> +	else
> >> +		vblank = MALI_C55_TPG_PIXEL_RATE / hts
> >> +		       / max(rounddown(tgt_fps, 15), 5);
> >> +
> >> +	*def_vblank = ALIGN_DOWN(vblank, 2) - format->height;
> >
> > "vblank = vblank - height" doesn't seem right. The "else" branch stores
> > a vts in vblank, which doesn't seem right either. Maybe you meant
> > something like
> >
> > 	if (tgt_fps < 5)
> > 		def_vts = *min_vblank + format->height;
> > 	else
> > 		def_vts = MALI_C55_TPG_PIXEL_RATE / hts
> > 			/ max(rounddown(tgt_fps, 15), 5);
> >
> > 	*def_vblank = ALIGN_DOWN(def_vts, 2) - format->height;
> 
> I did, thank you.
> 
> >> +}
> >> +
> >> +static int mali_c55_tpg_s_ctrl(struct v4l2_ctrl *ctrl)
> >> +{
> >> +	struct mali_c55_tpg *tpg = container_of(ctrl->handler,
> >> +						struct mali_c55_tpg,
> >> +						ctrls.handler);
> >> +	struct mali_c55 *mali_c55 = container_of(tpg, struct mali_c55, tpg);
> >> +
> >
> > Should you return here if the pipeline isn't streaming ?
> 
> Yes probably; or if (pm_runtime_get_if_in_use()) would be the usual model I guess.

I think so yes.

> >> +	switch (ctrl->id) {
> >> +	case V4L2_CID_TEST_PATTERN:
> >> +		mali_c55_write(mali_c55, MALI_C55_REG_TEST_GEN_CH0_PATTERN_TYPE,
> >> +			       ctrl->val);
> >> +		break;
> >> +	case V4L2_CID_VBLANK:
> >> +		mali_c55_update_bits(mali_c55, MALI_C55_REG_BLANKING,
> >> +				     MALI_C55_REG_VBLANK_MASK, ctrl->val);
> >> +		break;
> >> +	default:
> >> +		dev_err(mali_c55->dev, "invalid V4L2 control ID\n");
> >> +		return -EINVAL;
> >
> > Can this happen ?
> 
> Not unless somebody breaks something

Then I think you can drop the error message.

> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_ctrl_ops mali_c55_tpg_ctrl_ops = {
> >> +	.s_ctrl = &mali_c55_tpg_s_ctrl,
> >> +};
> >> +
> >> +static void mali_c55_tpg_configure(struct mali_c55 *mali_c55,
> >> +				   struct v4l2_subdev *sd)
> >> +{
> >> +	struct v4l2_subdev_state *state;
> >> +	struct v4l2_mbus_framefmt *fmt;
> >> +
> >> +	/*
> >> +	 * hblank needs setting, but is a read-only control and thus won't be
> >> +	 * called during __v4l2_ctrl_handler_setup(). Do it here instead.
> >> +	 */
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_BLANKING,
> >> +			     MALI_C55_REG_HBLANK_MASK,
> >> +			     MALI_C55_TPG_FIXED_HBLANK);
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_GEN_VIDEO,
> >> +			     MALI_C55_REG_GEN_VIDEO_MULTI_MASK, 0x01);
> >> +
> >> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> >> +	fmt = v4l2_subdev_state_get_format(state, MALI_C55_TPG_SRC_PAD);
> >> +
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_TPG_CH0,
> >> +			     MALI_C55_TEST_PATTERN_RGB_MASK,
> >> +			     fmt->code == MEDIA_BUS_FMT_RGB202020_1X60 ?
> >> +					  0x01 : 0x0);
> >> +
> >> +	v4l2_subdev_unlock_state(state);
> >> +}
> >> +
> >> +static int mali_c55_tpg_s_stream(struct v4l2_subdev *sd, int enable)
> >> +{
> >> +	struct mali_c55_tpg *tpg = container_of(sd, struct mali_c55_tpg, sd);
> >> +	struct mali_c55 *mali_c55 = container_of(tpg, struct mali_c55, tpg);
> >> +
> >> +	if (!enable) {
> >> +		mali_c55_update_bits(mali_c55, MALI_C55_REG_TPG_CH0,
> >> +				MALI_C55_TEST_PATTERN_ON_OFF, 0x00);
> >> +		mali_c55_update_bits(mali_c55, MALI_C55_REG_GEN_VIDEO,
> >> +				MALI_C55_REG_GEN_VIDEO_ON_MASK, 0x00);
> >> +		return 0;
> >> +	}
> >> +
> >> +	/*
> >> +	 * One might reasonably expect the framesize to be set here
> >> +	 * given it's configurable in .set_fmt(), but it's done in the
> >> +	 * ISP subdevice's stream on func instead, as the same register
> >
> > s/func/function/
> >
> >> +	 * is also used to indicate the size of the data coming from the
> >> +	 * sensor.
> >> +	 */
> >> +	mali_c55_tpg_configure(mali_c55, sd);
> >
> > 	mali_c55_tpg_configure(tpg);
> >
> >> +	__v4l2_ctrl_handler_setup(sd->ctrl_handler);
> >> +
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_TPG_CH0,
> >> +			     MALI_C55_TEST_PATTERN_ON_OFF,
> >> +			     MALI_C55_TEST_PATTERN_ON_OFF);
> >> +	mali_c55_update_bits(mali_c55, MALI_C55_REG_GEN_VIDEO,
> >> +			     MALI_C55_REG_GEN_VIDEO_ON_MASK,
> >> +			     MALI_C55_REG_GEN_VIDEO_ON_MASK);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_video_ops mali_c55_tpg_video_ops = {
> >> +	.s_stream = &mali_c55_tpg_s_stream,
> >
> > Can we use .enable_streams() and .disable_streams() ?
> 
> Yes, with some extra patches from Tomi that Sakari is picking - I'll base on top of those for the v6.
> 
> >> +};
> >> +
> >> +static int mali_c55_tpg_enum_mbus_code(struct v4l2_subdev *sd,
> >> +				       struct v4l2_subdev_state *state,
> >> +				       struct v4l2_subdev_mbus_code_enum *code)
> >> +{
> >> +	if (code->index >= ARRAY_SIZE(mali_c55_tpg_mbus_codes))
> >> +		return -EINVAL;
> >> +
> >> +	code->code = mali_c55_tpg_mbus_codes[code->index];
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_tpg_enum_frame_size(struct v4l2_subdev *sd,
> >> +					struct v4l2_subdev_state *state,
> >> +					struct v4l2_subdev_frame_size_enum *fse)
> >> +{
> >
> > You sohuld verify here that fse->code is a supported value and return
> > -EINVAL otherwise.
> >
> >> +	if (fse->index > 0 || fse->pad > sd->entity.num_pads)
> >
> > Drop the pad check, it's done in the subdev core already.
> >
> >> +		return -EINVAL;
> >> +
> >> +	fse->min_width = MALI_C55_MIN_WIDTH;
> >> +	fse->max_width = MALI_C55_MAX_WIDTH;
> >> +	fse->min_height = MALI_C55_MIN_HEIGHT;
> >> +	fse->max_height = MALI_C55_MAX_HEIGHT;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int mali_c55_tpg_set_fmt(struct v4l2_subdev *sd,
> >> +				struct v4l2_subdev_state *state,
> >> +				struct v4l2_subdev_format *format)
> >> +{
> >> +	struct mali_c55_tpg *tpg = container_of(sd, struct mali_c55_tpg, sd);
> >> +	struct v4l2_mbus_framefmt *fmt = &format->format;
> >> +	int vblank_def, vblank_min;
> >> +	unsigned int i;
> >> +
> >> +	for (i = 0; i < ARRAY_SIZE(mali_c55_tpg_mbus_codes); i++) {
> >> +		if (fmt->code == mali_c55_tpg_mbus_codes[i])
> >> +			break;
> >> +	}
> >> +
> >> +	if (i == ARRAY_SIZE(mali_c55_tpg_mbus_codes))
> >> +		fmt->code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >> +
> >> +	/*
> >> +	 * The TPG says that the test frame timing generation logic expects a
> >> +	 * minimum framesize of 4x4 pixels, but given the rest of the ISP can't
> >> +	 * handle anything smaller than 128x128 it seems pointless to allow a
> >> +	 * smaller frame.
> >> +	 */
> >> +	clamp_t(unsigned int, fmt->width, MALI_C55_MIN_WIDTH,
> >> +		MALI_C55_MAX_WIDTH);
> >> +	clamp_t(unsigned int, fmt->height, MALI_C55_MIN_HEIGHT,
> >> +		MALI_C55_MAX_HEIGHT);
> >> +
> >> +	*v4l2_subdev_state_get_format(state, MALI_C55_TPG_SRC_PAD) = *fmt;
> >
> > You're allowing userspace to set fmt->field, as well as all the
> > colorspace parameters, to random values. I would instead do something
> > like
> >
> > 	for (i = 0; i < ARRAY_SIZE(mali_c55_tpg_mbus_codes); i++) {
> > 		if (format->format.code == mali_c55_tpg_mbus_codes[i])
> > 			break;
> > 	}
> >
> > 	if (i == ARRAY_SIZE(mali_c55_tpg_mbus_codes))
> > 		format->format.code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >
> > 	format->format.width = clamp(format->format.width,
> > 				     MALI_C55_MIN_WIDTH, MALI_C55_MAX_WIDTH);
> > 	format->format.height = clamp(format->format.height,
> > 				      MALI_C55_MIN_HEIGHT, MALI_C55_MAX_HEIGHT);
> >
> > 	fmt = v4l2_subdev_state_get_format(state, MALI_C55_TPG_SRC_PAD);
> > 	fmt->code = format->format.code;
> > 	fmt->width = format->format.width;
> > 	fmt->height = format->format.height;
> >
> > 	format->format = *fmt;
> >
> > Alternatively (which I think I like better),
> >
> > 	fmt = v4l2_subdev_state_get_format(state, MALI_C55_TPG_SRC_PAD);
> >
> > 	fmt->code = format->format.code;
> >
> > 	for (i = 0; i < ARRAY_SIZE(mali_c55_tpg_mbus_codes); i++) {
> > 		if (fmt->code == mali_c55_tpg_mbus_codes[i])
> > 			break;
> > 	}
> >
> > 	if (i == ARRAY_SIZE(mali_c55_tpg_mbus_codes))
> > 		fmt->code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >
> > 	fmt->width = clamp(format->format.width,
> > 			   MALI_C55_MIN_WIDTH, MALI_C55_MAX_WIDTH);
> > 	fmt->height = clamp(format->format.height,
> > 			    MALI_C55_MIN_HEIGHT, MALI_C55_MAX_HEIGHT);
> >
> > 	format->format = *fmt;
> >
> >> +
> >> +	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
> >> +		return 0;
> >> +
> >> +	__mali_c55_tpg_calc_vblank(fmt, &vblank_def, &vblank_min);
> >> +	__v4l2_ctrl_modify_range(tpg->ctrls.vblank, vblank_min,
> >> +				 MALI_C55_TPG_MAX_VBLANK, 1, vblank_def);
> >> +	__v4l2_ctrl_s_ctrl(tpg->ctrls.vblank, vblank_def);
> >
> > Move those three calls to a separate function, it will be reused below.
> > I'd name is mali_c55_tpg_update_vblank(). You can fold
> > __mali_c55_tpg_calc_vblank() in it.
> >
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_pad_ops mali_c55_tpg_pad_ops = {
> >> +	.enum_mbus_code		= mali_c55_tpg_enum_mbus_code,
> >> +	.enum_frame_size	= mali_c55_tpg_enum_frame_size,
> >> +	.get_fmt		= v4l2_subdev_get_fmt,
> >> +	.set_fmt		= mali_c55_tpg_set_fmt,
> >> +};
> >> +
> >> +static const struct v4l2_subdev_ops mali_c55_tpg_ops = {
> >> +	.video	= &mali_c55_tpg_video_ops,
> >> +	.pad	= &mali_c55_tpg_pad_ops,
> >> +};
> >> +
> >> +static int mali_c55_tpg_init_state(struct v4l2_subdev *sd,
> >> +				   struct v4l2_subdev_state *sd_state)
> >
> > You name this variable state in every other subdev operation handler.
> >
> >> +{
> >> +	struct v4l2_mbus_framefmt *fmt =
> >> +		v4l2_subdev_state_get_format(sd_state, MALI_C55_TPG_SRC_PAD);
> >> +
> >> +	fmt->width = MALI_C55_DEFAULT_WIDTH;
> >> +	fmt->height = MALI_C55_DEFAULT_HEIGHT;
> >> +	fmt->field = V4L2_FIELD_NONE;
> >> +	fmt->code = MEDIA_BUS_FMT_SRGGB20_1X20;
> >
> > Initialize the colorspace fields too.
> >
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const struct v4l2_subdev_internal_ops mali_c55_tpg_internal_ops = {
> >> +	.init_state = mali_c55_tpg_init_state,
> >> +};
> >> +
> >> +static int mali_c55_tpg_init_controls(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_tpg_ctrls *ctrls = &mali_c55->tpg.ctrls;
> >> +	struct v4l2_subdev *sd = &mali_c55->tpg.sd;
> >> +	struct v4l2_mbus_framefmt *format;
> >> +	struct v4l2_subdev_state *state;
> >> +	int vblank_def, vblank_min;
> >> +	int ret;
> >> +
> >> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> >> +	format = v4l2_subdev_state_get_format(state, MALI_C55_TPG_SRC_PAD);
> >> +
> >> +	ret = v4l2_ctrl_handler_init(&ctrls->handler, 1);
> >
> > You have 3 controls.
> >
> >> +	if (ret)
> >> +		goto err_unlock;
> >> +
> >> +	ctrls->test_pattern = v4l2_ctrl_new_std_menu_items(&ctrls->handler,
> >> +				&mali_c55_tpg_ctrl_ops, V4L2_CID_TEST_PATTERN,
> >> +				ARRAY_SIZE(mali_c55_tpg_test_pattern_menu) - 1,
> >> +				0, 3, mali_c55_tpg_test_pattern_menu);
> >> +
> >> +	/*
> >> +	 * We fix hblank at the minimum allowed value and control framerate
> >> +	 * solely through the vblank control.
> >> +	 */
> >> +	ctrls->hblank = v4l2_ctrl_new_std(&ctrls->handler,
> >> +				&mali_c55_tpg_ctrl_ops,
> >> +				V4L2_CID_HBLANK, MALI_C55_TPG_FIXED_HBLANK,
> >> +				MALI_C55_TPG_FIXED_HBLANK, 1,
> >> +				MALI_C55_TPG_FIXED_HBLANK);
> >> +	if (ctrls->hblank)
> >> +		ctrls->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >> +
> >> +	__mali_c55_tpg_calc_vblank(format, &vblank_def, &vblank_min);
> >
> > Drop this and initialize the control with default values. You can then
> > update the value by calling mali_c55_tpg_update_vblank() in
> > mali_c55_register_tpg().
> >
> > The reason is to share the same mutex between the control handler and
> > the subdev active state without having to add a separate mutex in the
> > mali_c55_tpg structure. The simplest way to do so is to initialize the
> > controls first, set sd->state_lock to point to the control handler lock,
> > and call v4l2_subdev_init_finalize() as the last step. As a consequence,
> > you can't access the active state when initializing controls.
> >
> > You can alternatively keep the lock in mali_c55_tpg and set
> > sd->state_lock to point to it, but I think that's more complex.
> >
> >> +	ctrls->vblank = v4l2_ctrl_new_std(&ctrls->handler,
> >> +					  &mali_c55_tpg_ctrl_ops,
> >> +					  V4L2_CID_VBLANK, vblank_min,
> >> +					  MALI_C55_TPG_MAX_VBLANK, 1,
> >> +					  vblank_def);
> >> +
> >> +	if (ctrls->handler.error) {
> >> +		dev_err(mali_c55->dev, "Error during v4l2 controls init\n");
> >> +		ret = ctrls->handler.error;
> >> +		goto err_free_handler;
> >> +	}
> >> +
> >> +	ctrls->handler.lock = &mali_c55->tpg.lock;
> >
> > Drop this and drop the mutex. The control handler will use its internal
> > mutex.
> >
> >> +	mali_c55->tpg.sd.ctrl_handler = &ctrls->handler;
> >> +
> >> +	v4l2_subdev_unlock_state(state);
> >> +
> >> +	return 0;
> >> +
> >> +err_free_handler:
> >> +	v4l2_ctrl_handler_free(&ctrls->handler);
> >> +err_unlock:
> >> +	v4l2_subdev_unlock_state(state);
> >> +	return ret;
> >> +}
> >> +
> >> +int mali_c55_register_tpg(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_tpg *tpg = &mali_c55->tpg;
> >> +	struct v4l2_subdev *sd = &tpg->sd;
> >> +	struct media_pad *pad = &tpg->pad;
> >> +	int ret;
> >> +
> >> +	mutex_init(&tpg->lock);
> >> +
> >> +	v4l2_subdev_init(sd, &mali_c55_tpg_ops);
> >> +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >> +	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
> >
> > Should we introduce a TPG function ?
> 
> Hmmm I vacillate a bit. I don't see that it would hurt right now, but on the other hand I think 
> there's some value in pretending they're sensors - on the grounds that they should be handled 
> identically as much as possible. I'd be quite wary if we ever saw "if (sd->entity.function == 
> MEDIA_ENT_F_TPG)" somewhere.

The TPG doesn't expose all the API elements we expect from raw sensors,
so we'll have userspace code that is TPG-specific. I suppose it will
look for th TPG entity by name, so we don't need a separate function.
The other part to consider is generic code looking for a raw sensor that
would pick the TPG by mistake. I'm not sure how big of a risk that would
be.

> >> +	sd->internal_ops = &mali_c55_tpg_internal_ops;
> >> +	strscpy(sd->name, MALI_C55_DRIVER_NAME " tpg", sizeof(sd->name));
> >> +
> >> +	pad->flags = MEDIA_PAD_FL_SOURCE | MEDIA_PAD_FL_MUST_CONNECT;
> >
> > I don't think MEDIA_PAD_FL_MUST_CONNECT is right.
> 
> The docs say "If this flag is set and the pad is linked to any other pad, then at least one of those 
> links must be enabled for the entity to be able to stream.", and that's the case here right?

The MEDIA_PAD_FL_MUST_CONNECT flag indicates that at least one link must
be enabled for that pad in order for the entity to be included in a
pipeline. The intent is to check in the core if, for instance, a CSI-2
RX input is connected to something, and refuse streaming if it isn't.

The TPG output needs to be connected to something for the TPG to be used
in a pipeline, but the TPG won't be in the pipeline in the first place
if its output is not connected. The flag is therefore not necessary.

> >> +	ret = media_entity_pads_init(&sd->entity, 1, pad);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev,
> >> +			"Failed to initialize media entity pads\n");
> >> +		goto err_destroy_mutex;
> >> +	}
> >> +
> >
> > 	sd->state_lock = sd->ctrl_handler->lock;
> >
> > to use the same lock for the controls and the active state. You need to
> > move this line and the v4l2_subdev_init_finalize() call after
> > mali_c55_tpg_init_controls() to get the control handler lock initialized
> > first.
> >
> >> +	ret = v4l2_subdev_init_finalize(sd);
> >> +	if (ret)
> >> +		goto err_cleanup_media_entity;
> >> +
> >> +	ret = mali_c55_tpg_init_controls(mali_c55);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev,
> >> +			"Error initialising controls\n");
> >> +		goto err_cleanup_subdev;
> >> +	}
> >> +
> >> +	ret = v4l2_device_register_subdev(&mali_c55->v4l2_dev, sd);
> >> +	if (ret) {
> >> +		dev_err(mali_c55->dev, "Failed to register tpg subdev\n");
> >> +		goto err_free_ctrl_handler;
> >> +	}
> >> +
> >> +	/*
> >> +	 * By default the colour settings lead to a very dim image that is
> >> +	 * nearly indistinguishable from black on some monitor settings. Ramp
> >> +	 * them up a bit so the image is brighter.
> >> +	 */
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_TPG_R_BACKGROUND,
> >> +		       MALI_C55_TPG_BACKGROUND_MAX);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_TPG_G_BACKGROUND,
> >> +		       MALI_C55_TPG_BACKGROUND_MAX);
> >> +	mali_c55_write(mali_c55, MALI_C55_REG_TPG_B_BACKGROUND,
> >> +		       MALI_C55_TPG_BACKGROUND_MAX);
> >> +
> >> +	tpg->mali_c55 = mali_c55;
> >> +
> >> +	return 0;
> >> +
> >> +err_free_ctrl_handler:
> >> +	v4l2_ctrl_handler_free(&tpg->ctrls.handler);
> >> +err_cleanup_subdev:
> >> +	v4l2_subdev_cleanup(sd);
> >> +err_cleanup_media_entity:
> >> +	media_entity_cleanup(&sd->entity);
> >> +err_destroy_mutex:
> >> +	mutex_destroy(&tpg->lock);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +void mali_c55_unregister_tpg(struct mali_c55 *mali_c55)
> >> +{
> >> +	struct mali_c55_tpg *tpg = &mali_c55->tpg;
> >> +
> >> +	if (!tpg->mali_c55)
> >> +		return;
> >> +
> >> +	v4l2_device_unregister_subdev(&tpg->sd);
> >> +	v4l2_subdev_cleanup(&tpg->sd);
> >> +	media_entity_cleanup(&tpg->sd.entity);
> >> +	v4l2_ctrl_handler_free(&tpg->ctrls.handler);
> >
> > Free the control handler just after v4l2_device_unregister_subdev() to
> > match the order in mali_c55_register_tpg().
> >
> >> +	mutex_destroy(&tpg->lock);
> >> +}

-- 
Regards,

Laurent Pinchart




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