Hi Maxime,
Thanks for the update. Please see my comments below.
On Wed, Feb 07, 2018 at 03:24:37PM +0100, Maxime Ripard wrote:
> 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 former 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.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
> ---
> drivers/media/platform/Kconfig | 1 +
> drivers/media/platform/Makefile | 2 +
> drivers/media/platform/cadence/Kconfig | 12 +
> drivers/media/platform/cadence/Makefile | 1 +
> drivers/media/platform/cadence/cdns-csi2rx.c | 472 +++++++++++++++++++++++++++
> 5 files changed, 488 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 fd0c99859d6f..6e790a317fbc 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 003b0bb2cddf..1cd2984c55d1 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-$(CONFIG_VIDEO_VIA_CAMERA) += via-camera.o
> diff --git a/drivers/media/platform/cadence/Kconfig b/drivers/media/platform/cadence/Kconfig
> new file mode 100644
> index 000000000000..d1b6bbb6a0eb
> --- /dev/null
> +++ b/drivers/media/platform/cadence/Kconfig
> @@ -0,0 +1,12 @@
> +config VIDEO_CADENCE
> + bool "Cadence Video Devices"
> +
> +if VIDEO_CADENCE
> +
> +config VIDEO_CADENCE_CSI2RX
> + tristate "Cadence MIPI-CSI2 RX Controller v1.3"
> + depends on MEDIA_CONTROLLER
> + depends on VIDEO_V4L2_SUBDEV_API
> + select V4L2_FWNODE
Some explanation would be nice here.
> +
> +endif
> diff --git a/drivers/media/platform/cadence/Makefile b/drivers/media/platform/cadence/Makefile
> new file mode 100644
> index 000000000000..99a4086b7448
> --- /dev/null
> +++ b/drivers/media/platform/cadence/Makefile
> @@ -0,0 +1 @@
> +obj-$(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..c532583cc1a6
> --- /dev/null
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -0,0 +1,472 @@
> +// 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;
> + atomic_t count;
> +
> + 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);
> +
> + usleep_range(10, 20);
> +
> + writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
> +}
> +
> +static int csi2rx_start(struct csi2rx_priv *csi2rx)
> +{
> + unsigned int i;
> + unsigned long lanes_used;
> + u32 reg;
> + int ret;
> +
> + /*
> + * We're not the first users, there's no need to enable the
> + * whole controller.
> + */
> + if (atomic_inc_return(&csi2rx->count) > 1)
> + return 0;
> +
> + clk_prepare_enable(csi2rx->p_clk);
> +
> + 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)
> + return ret;
> +
> + /*
> + * 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++) {
> + clk_prepare_enable(csi2rx->pixel_clk[i]);
> +
> + 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));
> + }
> +
> + clk_prepare_enable(csi2rx->sys_clk);
> +
> + clk_disable_unprepare(csi2rx->p_clk);
> +
> + return 0;
> +}
> +
> +static int csi2rx_stop(struct csi2rx_priv *csi2rx)
> +{
> + unsigned int i;
> +
> + /*
> + * Let the last user turn off the lights
> + */
> + if (!atomic_dec_and_test(&csi2rx->count))
> + return 0;
> +
> + clk_prepare_enable(csi2rx->p_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 *sd, int enable)
> +{
> + struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(sd);
> + int ret;
> +
> + if (enable)
> + ret = csi2rx_start(csi2rx);
> + else
> + ret = csi2rx_stop(csi2rx);
> +
> + 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 reg;
> +
> + 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);
> + reg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> + clk_disable_unprepare(csi2rx->p_clk);
> +
> + csi2rx->max_lanes = (reg & 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 = ((reg >> 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 = (reg & 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;
> + }
> +
> + for (i = 0; i < csi2rx->max_streams; i++) {
> + char clk_name[16];
> +
> + snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
> + csi2rx->pixel_clk[i] = devm_clk_get(&pdev->dev, clk_name);
> + if (IS_ERR(csi2rx->pixel_clk[i])) {
> + dev_err(&pdev->dev, "Couldn't get clock %s\n", clk_name);
> + return PTR_ERR(csi2rx->pixel_clk[i]);
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
> +{
> + struct v4l2_fwnode_endpoint v4l2_ep;
> + struct fwnode_handle *fwh;
> + struct device_node *ep;
> + int ret;
> +
> + ep = of_graph_get_endpoint_by_regs(csi2rx->dev->of_node, 0, 0);
> + if (!ep)
> + return -EINVAL;
> +
> + fwh = of_fwnode_handle(ep);
> + ret = v4l2_fwnode_endpoint_parse(fwh, &v4l2_ep);
> + if (ret) {
> + dev_err(csi2rx->dev, "Could not parse v4l2 endpoint\n");
> + of_node_put(ep);
> + return ret;
> + }
> +
> + if (v4l2_ep.bus_type != V4L2_MBUS_CSI2) {
> + dev_err(csi2rx->dev, "Unsupported media bus type: 0x%x\n",
> + v4l2_ep.bus_type);
> + of_node_put(ep);
> + return -EINVAL;
> + }
> +
> + memcpy(csi2rx->lanes, v4l2_ep.bus.mipi_csi2.data_lanes,
> + sizeof(csi2rx->lanes));
> + csi2rx->num_lanes = v4l2_ep.bus.mipi_csi2.num_data_lanes;
> + if (csi2rx->num_lanes > csi2rx->max_lanes) {
> + dev_err(csi2rx->dev, "Unsupported number of data-lanes: %d\n",
> + csi2rx->num_lanes);
> + of_node_put(ep);
> + return -EINVAL;
> + }
> +
> + csi2rx->asd.match.fwnode.fwnode = fwnode_graph_get_remote_port_parent(fwh);
> + csi2rx->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> + of_node_put(ep);
> +
> + csi2rx->notifier.subdevs = devm_kzalloc(csi2rx->dev,
> + sizeof(*csi2rx->notifier.subdevs),
> + GFP_KERNEL);
> + if (!csi2rx->notifier.subdevs)
> + return -ENOMEM;
> +
> + csi2rx->notifier.subdevs[0] = &csi2rx->asd;
> + csi2rx->notifier.num_subdevs = 1;
> + csi2rx->notifier.ops = &csi2rx_notifier_ops;
> +
> + return v4l2_async_subdev_notifier_register(&csi2rx->subdev,
> + &csi2rx->notifier);
I think you're missing unregistration of the notifier.
> +}
> +
> +static int csi2rx_probe(struct platform_device *pdev)
> +{
> + struct csi2rx_priv *csi2rx;
> + unsigned int i;
> + int ret;
> +
> + /*
> + * Since the v4l2_subdev structure is embedded in our
> + * csi2rx_priv structure, and that the structure is exposed to
> + * the user-space, we cannot just use the devm_variant
> + * here. Indeed, that would lead to a use-after-free in a
> + * open() - unbind - close() pattern.
> + */
The sub-devices are unbound before the master driver may be removed. That
comment is only partially true; there are a bunch of other issues related
to removing media entities and V4L2 sub-devices that cannot be addressed in
drivers only, IMHO you could simply remove the comment.
> + csi2rx = kzalloc(sizeof(*csi2rx), GFP_KERNEL);
> + if (!csi2rx)
> + return -ENOMEM;
> + platform_set_drvdata(pdev, csi2rx);
> + csi2rx->dev = &pdev->dev;
> +
> + ret = csi2rx_get_resources(csi2rx, pdev);
> + if (ret)
> + goto err_free_priv;
> +
> + ret = csi2rx_parse_dt(csi2rx);
> + if (ret)
> + goto err_free_priv;
> +
> + csi2rx->subdev.owner = THIS_MODULE;
> + csi2rx->subdev.dev = &pdev->dev;
> + v4l2_subdev_init(&csi2rx->subdev, &csi2rx_subdev_ops);
> + v4l2_set_subdevdata(&csi2rx->subdev, &pdev->dev);
> + snprintf(csi2rx->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s.%s",
> + KBUILD_MODNAME, dev_name(&pdev->dev));
> +
> + /* Create our media pads */
> + csi2rx->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
> + csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> + for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
> + csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
> +
> + ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,
> + csi2rx->pads);
> + if (ret)
> + goto err_free_priv;
> +
> + ret = v4l2_async_register_subdev(&csi2rx->subdev);
> + if (ret < 0)
> + goto err_free_priv;
> +
> + dev_info(&pdev->dev,
> + "Probed CSI2RX with %u/%u lanes, %u streams, %s D-PHY\n",
> + csi2rx->num_lanes, csi2rx->max_lanes, csi2rx->max_streams,
> + csi2rx->has_internal_dphy ? "internal" : "no");
> +
> + return 0;
> +
> +err_free_priv:
> + kfree(csi2rx);
> + return ret;
> +}
> +
> +static int csi2rx_remove(struct platform_device *pdev)
> +{
> + struct csi2rx_priv *csi2rx = platform_get_drvdata(pdev);
> +
> + v4l2_async_unregister_subdev(&csi2rx->subdev);
> + kfree(csi2rx);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id csi2rx_of_table[] = {
> + { .compatible = "cdns,csi2rx" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, csi2rx_of_table);
> +
> +static struct platform_driver csi2rx_driver = {
> + .probe = csi2rx_probe,
> + .remove = csi2rx_remove,
> +
> + .driver = {
> + .name = "cdns-csi2rx",
> + .of_match_table = csi2rx_of_table,
> + },
> +};
> +module_platform_driver(csi2rx_driver);
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx
