Maxime,
Thank you for the patch.
Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote on Thu [2018-Feb-15 14:33:35 +0100]:
> The Cadence CSI-2 RX Controller is an hardware block meant to be used as a
> bridge between a CSI-2 bus and pixel grabbers.
>
> It supports operating with internal or external D-PHY, with up to 4 lanes,
> or without any D-PHY. The current code only supports the latter case.
>
> It also support dynamic mapping of the CSI-2 virtual channels to the
> associated pixel grabbers, but that isn't allowed at the moment either.
>
> Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
> ---
> drivers/media/platform/Kconfig | 1 +
> drivers/media/platform/Makefile | 2 +
> drivers/media/platform/cadence/Kconfig | 17 +
> drivers/media/platform/cadence/Makefile | 1 +
> drivers/media/platform/cadence/cdns-csi2rx.c | 499 +++++++++++++++++++++++++++
> 5 files changed, 520 insertions(+)
> create mode 100644 drivers/media/platform/cadence/Kconfig
> create mode 100644 drivers/media/platform/cadence/Makefile
> create mode 100644 drivers/media/platform/cadence/cdns-csi2rx.c
>
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index 614fbef08ddc..c001b646d441 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -26,6 +26,7 @@ config VIDEO_VIA_CAMERA
> #
> # Platform multimedia device configuration
> #
> +source "drivers/media/platform/cadence/Kconfig"
>
> source "drivers/media/platform/davinci/Kconfig"
>
> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> index 7f3080437be6..3d29082fcf72 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -3,6 +3,8 @@
> # Makefile for the video capture/playback device drivers.
> #
>
> +obj-$(CONFIG_VIDEO_CADENCE) += cadence/
> +
> obj-$(CONFIG_VIDEO_M32R_AR_M64278) += arv.o
>
> obj-$(CONFIG_VIDEO_VIA_CAMERA) += via-camera.o
> diff --git a/drivers/media/platform/cadence/Kconfig b/drivers/media/platform/cadence/Kconfig
> new file mode 100644
> index 000000000000..18f061e5cbd1
> --- /dev/null
> +++ b/drivers/media/platform/cadence/Kconfig
> @@ -0,0 +1,17 @@
> +config VIDEO_CADENCE
> + bool "Cadence Video Devices"
> +
> +if VIDEO_CADENCE
> +
> +config VIDEO_CADENCE_CSI2RX
> + tristate "Cadence MIPI-CSI2 RX Controller"
> + depends on MEDIA_CONTROLLER
> + depends on VIDEO_V4L2_SUBDEV_API
> + select V4L2_FWNODE
> + help
> + Support for the Cadence MIPI CSI2 Receiver controller.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called cdns-csi2rx.
> +
> +endif
> diff --git a/drivers/media/platform/cadence/Makefile b/drivers/media/platform/cadence/Makefile
> new file mode 100644
> index 000000000000..99a4086b7448
> --- /dev/null
> +++ b/drivers/media/platform/cadence/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_VIDEO_CADENCE_CSI2RX) += cdns-csi2rx.o
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> new file mode 100644
> index 000000000000..99662e1a536b
> --- /dev/null
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -0,0 +1,499 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Driver for Cadence MIPI-CSI2 RX Controller v1.3
> + *
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + */
> +
> +#include <linux/atomic.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_graph.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-subdev.h>
> +
> +#define CSI2RX_DEVICE_CFG_REG 0x000
> +
> +#define CSI2RX_SOFT_RESET_REG 0x004
> +#define CSI2RX_SOFT_RESET_PROTOCOL BIT(1)
> +#define CSI2RX_SOFT_RESET_FRONT BIT(0)
> +
> +#define CSI2RX_STATIC_CFG_REG 0x008
> +#define CSI2RX_STATIC_CFG_DLANE_MAP(llane, plane) ((plane) << (16 + (llane) * 4))
> +#define CSI2RX_STATIC_CFG_LANES_MASK GENMASK(11, 8)
> +
> +#define CSI2RX_STREAM_BASE(n) (((n) + 1) * 0x100)
> +
> +#define CSI2RX_STREAM_CTRL_REG(n) (CSI2RX_STREAM_BASE(n) + 0x000)
> +#define CSI2RX_STREAM_CTRL_START BIT(0)
> +
> +#define CSI2RX_STREAM_DATA_CFG_REG(n) (CSI2RX_STREAM_BASE(n) + 0x008)
> +#define CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT BIT(31)
> +#define CSI2RX_STREAM_DATA_CFG_VC_SELECT(n) BIT((n) + 16)
> +
> +#define CSI2RX_STREAM_CFG_REG(n) (CSI2RX_STREAM_BASE(n) + 0x00c)
> +#define CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF (1 << 8)
> +
> +#define CSI2RX_LANES_MAX 4
> +#define CSI2RX_STREAMS_MAX 4
> +
> +enum csi2rx_pads {
> + CSI2RX_PAD_SINK,
> + CSI2RX_PAD_SOURCE_STREAM0,
> + CSI2RX_PAD_SOURCE_STREAM1,
> + CSI2RX_PAD_SOURCE_STREAM2,
> + CSI2RX_PAD_SOURCE_STREAM3,
> + CSI2RX_PAD_MAX,
> +};
> +
> +struct csi2rx_priv {
> + struct device *dev;
> + unsigned int count;
> +
> + /*
> + * Used to prevent race conditions between multiple,
> + * concurrent calls to start and stop.
> + */
> + struct mutex lock;
> +
> + void __iomem *base;
> + struct clk *sys_clk;
> + struct clk *p_clk;
> + struct clk *pixel_clk[CSI2RX_STREAMS_MAX];
> + struct phy *dphy;
> +
> + u8 lanes[CSI2RX_LANES_MAX];
> + u8 num_lanes;
> + u8 max_lanes;
> + u8 max_streams;
> + bool has_internal_dphy;
> +
> + struct v4l2_subdev subdev;
> + struct v4l2_async_notifier notifier;
> + struct media_pad pads[CSI2RX_PAD_MAX];
> +
> + /* Remote source */
> + struct v4l2_async_subdev asd;
> + struct v4l2_subdev *source_subdev;
> + int source_pad;
> +};
> +
> +static inline
> +struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
> +{
> + return container_of(subdev, struct csi2rx_priv, subdev);
> +}
> +
> +static void csi2rx_reset(struct csi2rx_priv *csi2rx)
> +{
> + writel(CSI2RX_SOFT_RESET_PROTOCOL | CSI2RX_SOFT_RESET_FRONT,
> + csi2rx->base + CSI2RX_SOFT_RESET_REG);
> +
> + udelay(10);
> +
> + writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
> +}
> +
> +static int csi2rx_start(struct csi2rx_priv *csi2rx)
> +{
> + unsigned int i;
> + unsigned long lanes_used = 0;
> + u32 reg;
> + int ret;
> +
> + ret = clk_prepare_enable(csi2rx->p_clk);
> + if (ret)
> + return ret;
> +
> + csi2rx_reset(csi2rx);
> +
> + reg = csi2rx->num_lanes << 8;
> + for (i = 0; i < csi2rx->num_lanes; i++) {
> + reg |= CSI2RX_STATIC_CFG_DLANE_MAP(i, csi2rx->lanes[i]);
> + set_bit(csi2rx->lanes[i], &lanes_used);
> + }
> +
> + /*
> + * Even the unused lanes need to be mapped. In order to avoid
> + * to map twice to the same physical lane, keep the lanes used
> + * in the previous loop, and only map unused physical lanes to
> + * the rest of our logical lanes.
> + */
> + for (i = csi2rx->num_lanes; i < csi2rx->max_lanes; i++) {
> + unsigned int idx = find_first_zero_bit(&lanes_used,
> + sizeof(lanes_used));
> + set_bit(idx, &lanes_used);
> + reg |= CSI2RX_STATIC_CFG_DLANE_MAP(i, i + 1);
> + }
> +
> + writel(reg, csi2rx->base + CSI2RX_STATIC_CFG_REG);
> +
> + ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true);
> + if (ret)
> + goto err_disable_pclk;
> +
> + /*
> + * Create a static mapping between the CSI virtual channels
> + * and the output stream.
> + *
> + * This should be enhanced, but v4l2 lacks the support for
> + * changing that mapping dynamically.
> + *
> + * We also cannot enable and disable independant streams here,
> + * hence the reference counting.
> + */
> + for (i = 0; i < csi2rx->max_streams; i++) {
> + ret = clk_prepare_enable(csi2rx->pixel_clk[i]);
> + if (ret)
> + goto err_disable_pixclk;
> +
> + writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF,
> + csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
> +
> + writel(CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT |
> + CSI2RX_STREAM_DATA_CFG_VC_SELECT(i),
> + csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
> +
> + writel(CSI2RX_STREAM_CTRL_START,
> + csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
> + }
> +
> + ret = clk_prepare_enable(csi2rx->sys_clk);
> + if (ret)
> + goto err_disable_pixclk;
> +
> + clk_disable_unprepare(csi2rx->p_clk);
> +
> + return 0;
> +
> +err_disable_pixclk:
> + for (; i >= 0; i--)
> + clk_disable_unprepare(csi2rx->pixel_clk[i]);
> +
> +err_disable_pclk:
> + clk_disable_unprepare(csi2rx->p_clk);
> +
> + return ret;
> +}
> +
> +static int csi2rx_stop(struct csi2rx_priv *csi2rx)
> +{
> + unsigned int i;
> +
> + clk_prepare_enable(csi2rx->p_clk);
> + clk_disable_unprepare(csi2rx->sys_clk);
> +
> + for (i = 0; i < csi2rx->max_streams; i++) {
> + writel(0, csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
> +
> + clk_disable_unprepare(csi2rx->pixel_clk[i]);
> + }
> +
> + clk_disable_unprepare(csi2rx->p_clk);
> +
> + return v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false);
> +}
> +
> +static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
> +{
> + struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> + int ret = 0;
> +
> + mutex_lock(&csi2rx->lock);
> +
> + if (enable) {
> + /*
> + * If we're not the first users, there's no need to
> + * enable the whole controller.
> + */
> + if (!csi2rx->count) {
> + ret = csi2rx_start(csi2rx);
> + if (ret)
> + goto out;
> + }
> +
> + csi2rx->count++;
> + } else {
> + csi2rx->count--;
> +
> + /*
> + * Let the last user turn off the lights.
> + */
> + if (!csi2rx->count) {
> + ret = csi2rx_stop(csi2rx);
> + if (ret)
> + goto out;
> + }
> + }
> +
> +out:
> + mutex_unlock(&csi2rx->lock);
> + return ret;
> +}
> +
> +static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
> + .s_stream = csi2rx_s_stream,
> +};
> +
> +static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
> + .video = &csi2rx_video_ops,
> +};
> +
> +static int csi2rx_async_bound(struct v4l2_async_notifier *notifier,
> + struct v4l2_subdev *s_subdev,
> + struct v4l2_async_subdev *asd)
> +{
> + struct v4l2_subdev *subdev = notifier->sd;
> + struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
> +
> + csi2rx->source_pad = media_entity_get_fwnode_pad(&s_subdev->entity,
> + s_subdev->fwnode,
> + MEDIA_PAD_FL_SOURCE);
> + if (csi2rx->source_pad < 0) {
> + dev_err(csi2rx->dev, "Couldn't find output pad for subdev %s\n",
> + s_subdev->name);
> + return csi2rx->source_pad;
> + }
> +
> + csi2rx->source_subdev = s_subdev;
> +
> + dev_dbg(csi2rx->dev, "Bound %s pad: %d\n", s_subdev->name,
> + csi2rx->source_pad);
> +
> + return media_create_pad_link(&csi2rx->source_subdev->entity,
> + csi2rx->source_pad,
> + &csi2rx->subdev.entity, 0,
> + MEDIA_LNK_FL_ENABLED |
> + MEDIA_LNK_FL_IMMUTABLE);
> +}
> +
> +static const struct v4l2_async_notifier_operations csi2rx_notifier_ops = {
> + .bound = csi2rx_async_bound,
> +};
> +
> +static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
> + struct platform_device *pdev)
> +{
> + struct resource *res;
> + unsigned char i;
> + u32 dev_cfg;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + csi2rx->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(csi2rx->base))
> + return PTR_ERR(csi2rx->base);
> +
> + csi2rx->sys_clk = devm_clk_get(&pdev->dev, "sys_clk");
> + if (IS_ERR(csi2rx->sys_clk)) {
> + dev_err(&pdev->dev, "Couldn't get sys clock\n");
> + return PTR_ERR(csi2rx->sys_clk);
> + }
> +
> + csi2rx->p_clk = devm_clk_get(&pdev->dev, "p_clk");
> + if (IS_ERR(csi2rx->p_clk)) {
> + dev_err(&pdev->dev, "Couldn't get P clock\n");
> + return PTR_ERR(csi2rx->p_clk);
> + }
> +
> + csi2rx->dphy = devm_phy_optional_get(&pdev->dev, "dphy");
> + if (IS_ERR(csi2rx->dphy)) {
> + dev_err(&pdev->dev, "Couldn't get external D-PHY\n");
> + return PTR_ERR(csi2rx->dphy);
> + }
> +
> + /*
> + * FIXME: Once we'll have external D-PHY support, the check
> + * will need to be removed.
> + */
> + if (csi2rx->dphy) {
> + dev_err(&pdev->dev, "External D-PHY not supported yet\n");
> + return -EINVAL;
> + }
> +
> + clk_prepare_enable(csi2rx->p_clk);
> + dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> + clk_disable_unprepare(csi2rx->p_clk);
> +
> + csi2rx->max_lanes = dev_cfg & 7;
> + if (csi2rx->max_lanes > CSI2RX_LANES_MAX) {
> + dev_err(&pdev->dev, "Invalid number of lanes: %u\n",
> + csi2rx->max_lanes);
> + return -EINVAL;
> + }
> +
> + csi2rx->max_streams = (dev_cfg >> 4) & 7;
> + if (csi2rx->max_streams > CSI2RX_STREAMS_MAX) {
> + dev_err(&pdev->dev, "Invalid number of streams: %u\n",
> + csi2rx->max_streams);
> + return -EINVAL;
> + }
> +
> + csi2rx->has_internal_dphy = dev_cfg & BIT(3) ? true : false;
> +
> + /*
> + * FIXME: Once we'll have internal D-PHY support, the check
> + * will need to be removed.
> + */
> + if (csi2rx->has_internal_dphy) {
> + dev_err(&pdev->dev, "Internal D-PHY not supported yet\n");
> + return -EINVAL;
> + }
As one of the more critical thing is usually how the CSI2 Receiver interact
with a DPHY when can we expect this part of the driver to be implemented?
Regards,
Benoit
[snip]
