diff mbox series

[v8,16/16] media: ti: Add CSI2RX support for J721E

Message ID 20230731-upstream_csi-v8-16-fb7d3661c2c9@ti.com
State Superseded
Headers show
Series CSI2RX support on J721E and AM62 | expand

Commit Message

Jai Luthra July 31, 2023, 8:29 a.m. UTC
From: Pratyush Yadav <p.yadav@ti.com>

TI's J721E uses the Cadence CSI2RX and DPHY peripherals to facilitate
capture over a CSI-2 bus.

The Cadence CSI2RX IP acts as a bridge between the TI specific parts and
the CSI-2 protocol parts. TI then has a wrapper on top of this bridge
called the SHIM layer. It takes in data from stream 0, repacks it, and
sends it to memory over PSI-L DMA.

This driver acts as the "front end" to V4L2 client applications. It
implements the required ioctls and buffer operations, passes the
necessary calls on to the bridge, programs the SHIM layer, and performs
DMA via the dmaengine API to finally return the data to a buffer
supplied by the application.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Co-authored-by: Vaishnav Achath <vaishnav.a@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Co-authored-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
---
v7->v8:
- Move after dt-bindings to keep the series bisectable
- Rename compatible to "ti,j721e-csi2rx-shim" to distinguish from the
  SoC-specific CSI2RX bridge compatible
- Make myself the Maintainer
- Support RAW8 and RAW10 formats, and setting the pixel-unwrap size on
  SHIM (RAW10 is stored in 16-bit containers, while RAW8 in 8-bit containers)
- Fix enum_fmt_vid_cap() to respect CAP_IO_MC and only list pixelformats
  matching the mbus formats set on the subdev.
- Fix enum_framesizes() to stop enumerating more than a single framesize
  (reject non-zero fsize->index)
- Simplify notifier bound fucntion to use v4l2_create_fwnode_links_to_pad()
  and inline the video_register() method
- Add support for draining the DMA with an extra buffer, to get rid of
  stale data in the pipeline on stream stop (or when frames start
  getting dropped due to load)
- Queue all available buffers to DMAEngine in the callback, also use a
  separate "submitted" queue to track all buffers submitted to DMA
- Use video_device_pipeline_start() instead of media_pipeline_start()
- Drop support for VB_READ
- Print issues in link validation as DEBUG instead of ERROR
- s/async_subdev/async_connection

 MAINTAINERS                                        |    7 +
 drivers/media/platform/ti/Kconfig                  |   12 +
 drivers/media/platform/ti/Makefile                 |    1 +
 drivers/media/platform/ti/j721e-csi2rx/Makefile    |    2 +
 .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 1127 ++++++++++++++++++++
 5 files changed, 1149 insertions(+)

Comments

Tomi Valkeinen Aug. 2, 2023, 11:04 a.m. UTC | #1
On 31/07/2023 11:29, Jai Luthra wrote:
> From: Pratyush Yadav <p.yadav@ti.com>
> 
> TI's J721E uses the Cadence CSI2RX and DPHY peripherals to facilitate
> capture over a CSI-2 bus.
> 
> The Cadence CSI2RX IP acts as a bridge between the TI specific parts and
> the CSI-2 protocol parts. TI then has a wrapper on top of this bridge
> called the SHIM layer. It takes in data from stream 0, repacks it, and
> sends it to memory over PSI-L DMA.
> 
> This driver acts as the "front end" to V4L2 client applications. It
> implements the required ioctls and buffer operations, passes the
> necessary calls on to the bridge, programs the SHIM layer, and performs
> DMA via the dmaengine API to finally return the data to a buffer
> supplied by the application.
> 
> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> Co-authored-by: Vaishnav Achath <vaishnav.a@ti.com>
> Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
> Co-authored-by: Jai Luthra <j-luthra@ti.com>
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> ---
> v7->v8:
> - Move after dt-bindings to keep the series bisectable
> - Rename compatible to "ti,j721e-csi2rx-shim" to distinguish from the
>    SoC-specific CSI2RX bridge compatible
> - Make myself the Maintainer
> - Support RAW8 and RAW10 formats, and setting the pixel-unwrap size on
>    SHIM (RAW10 is stored in 16-bit containers, while RAW8 in 8-bit containers)
> - Fix enum_fmt_vid_cap() to respect CAP_IO_MC and only list pixelformats
>    matching the mbus formats set on the subdev.
> - Fix enum_framesizes() to stop enumerating more than a single framesize
>    (reject non-zero fsize->index)
> - Simplify notifier bound fucntion to use v4l2_create_fwnode_links_to_pad()
>    and inline the video_register() method
> - Add support for draining the DMA with an extra buffer, to get rid of
>    stale data in the pipeline on stream stop (or when frames start
>    getting dropped due to load)
> - Queue all available buffers to DMAEngine in the callback, also use a
>    separate "submitted" queue to track all buffers submitted to DMA
> - Use video_device_pipeline_start() instead of media_pipeline_start()
> - Drop support for VB_READ
> - Print issues in link validation as DEBUG instead of ERROR
> - s/async_subdev/async_connection
> 
>   MAINTAINERS                                        |    7 +
>   drivers/media/platform/ti/Kconfig                  |   12 +
>   drivers/media/platform/ti/Makefile                 |    1 +
>   drivers/media/platform/ti/j721e-csi2rx/Makefile    |    2 +
>   .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 1127 ++++++++++++++++++++
>   5 files changed, 1149 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d7b867c57920..1c2d75c30ce7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -21445,6 +21445,13 @@ F:	Documentation/devicetree/bindings/media/i2c/ti,ds90*
>   F:	drivers/media/i2c/ds90*
>   F:	include/media/i2c/ds90*
>   
> +TI J721E CSI2RX DRIVER
> +M:	Jai Luthra <j-luthra@ti.com>
> +L:	linux-media@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/media/ti,j721e-csi2rx.yaml
> +F:	drivers/media/platform/ti/j721e-csi2rx/
> +
>   TI KEYSTONE MULTICORE NAVIGATOR DRIVERS
>   M:	Nishanth Menon <nm@ti.com>
>   M:	Santosh Shilimkar <ssantosh@kernel.org>
> diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
> index e1ab56c3be1f..42c908f6e1ae 100644
> --- a/drivers/media/platform/ti/Kconfig
> +++ b/drivers/media/platform/ti/Kconfig
> @@ -63,6 +63,18 @@ config VIDEO_TI_VPE_DEBUG
>   	help
>   	  Enable debug messages on VPE driver.
>   
> +config VIDEO_TI_J721E_CSI2RX
> +	tristate "TI J721E CSI2RX wrapper layer driver"
> +	depends on VIDEO_DEV && VIDEO_V4L2_SUBDEV_API
> +	depends on MEDIA_SUPPORT && MEDIA_CONTROLLER
> +	depends on PHY_CADENCE_DPHY_RX && VIDEO_CADENCE_CSI2RX
> +	depends on ARCH_K3 || COMPILE_TEST
> +	select VIDEOBUF2_DMA_CONTIG
> +	select V4L2_FWNODE
> +	help
> +	  Support for TI CSI2RX wrapper layer. This just enables the wrapper driver.
> +	  The Cadence CSI2RX bridge driver needs to be enabled separately.
> +
>   source "drivers/media/platform/ti/am437x/Kconfig"
>   source "drivers/media/platform/ti/davinci/Kconfig"
>   source "drivers/media/platform/ti/omap/Kconfig"
> diff --git a/drivers/media/platform/ti/Makefile b/drivers/media/platform/ti/Makefile
> index 98c5fe5c40d6..8a2f74c9380e 100644
> --- a/drivers/media/platform/ti/Makefile
> +++ b/drivers/media/platform/ti/Makefile
> @@ -3,5 +3,6 @@ obj-y += am437x/
>   obj-y += cal/
>   obj-y += vpe/
>   obj-y += davinci/
> +obj-y += j721e-csi2rx/
>   obj-y += omap/
>   obj-y += omap3isp/
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/Makefile b/drivers/media/platform/ti/j721e-csi2rx/Makefile
> new file mode 100644
> index 000000000000..377afc1d6280
> --- /dev/null
> +++ b/drivers/media/platform/ti/j721e-csi2rx/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_VIDEO_TI_J721E_CSI2RX) += j721e-csi2rx.o
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> new file mode 100644
> index 000000000000..29f1879cfc25
> --- /dev/null
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -0,0 +1,1127 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TI CSI2RX Shim Wrapper Driver
> + *
> + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/

You can update the year above.

> + * Author: Pratyush Yadav <p.yadav@ti.com>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/dmaengine.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +
> +#include <media/mipi-csi2.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-mc.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#define TI_CSI2RX_MODULE_NAME		"j721e-csi2rx"
> +
> +#define SHIM_CNTL			0x10
> +#define SHIM_CNTL_PIX_RST		BIT(0)
> +
> +#define SHIM_DMACNTX			0x20
> +#define SHIM_DMACNTX_EN			BIT(31)
> +#define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
> +#define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
> +#define SHIM_DMACNTX_FMT		GENMASK(5, 0)
> +#define SHIM_DMACNTX_UYVY		0
> +#define SHIM_DMACNTX_VYUY		1
> +#define SHIM_DMACNTX_YUYV		2
> +#define SHIM_DMACNTX_YVYU		3
> +#define SHIM_DMACNTX_SIZE_8		0
> +#define SHIM_DMACNTX_SIZE_16		1
> +#define SHIM_DMACNTX_SIZE_32		2
> +
> +#define SHIM_PSI_CFG0			0x24
> +#define SHIM_PSI_CFG0_SRC_TAG		GENMASK(15, 0)
> +#define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
> +
> +#define PSIL_WORD_SIZE_BYTES		16
> +/*
> + * There are no hard limits on the width or height. The DMA engine can handle
> + * all sizes. The max width and height are arbitrary numbers for this driver.
> + * Use 16K * 16K as the arbitrary limit. It is large enough that it is unlikely
> + * the limit will be hit in practice.
> + */
> +#define MAX_WIDTH_BYTES			SZ_16K
> +#define MAX_HEIGHT_LINES		SZ_16K
> +
> +#define DRAIN_TIMEOUT_MS		50
> +
> +struct ti_csi2rx_fmt {
> +	u32				fourcc;	/* Four character code. */
> +	u32				code;	/* Mbus code. */
> +	u32				csi_dt;	/* CSI Data type. */
> +	u8				bpp;	/* Bits per pixel. */
> +	u8				size;	/* Data size shift when unpacking. */
> +};
> +
> +struct ti_csi2rx_buffer {
> +	/* Common v4l2 buffer. Must be first. */
> +	struct vb2_v4l2_buffer		vb;
> +	struct list_head		list;
> +	struct ti_csi2rx_dev		*csi;
> +};
> +
> +enum ti_csi2rx_dma_state {
> +	TI_CSI2RX_DMA_STOPPED,	/* Streaming not started yet. */
> +	TI_CSI2RX_DMA_IDLE,	/* Streaming but no pending DMA operation. */
> +	TI_CSI2RX_DMA_ACTIVE,	/* Streaming and pending DMA operation. */
> +};
> +
> +struct ti_csi2rx_dma {
> +	/* Protects all fields in this struct. */
> +	spinlock_t			lock;
> +	struct dma_chan			*chan;
> +	/* Buffers queued to the driver, waiting to be processed by DMA. */
> +	struct list_head		queue;
> +	enum ti_csi2rx_dma_state	state;
> +	/*
> +	 * Queue of buffers submitted to DMA engine.
> +	 */
> +	struct list_head		submitted;
> +};
> +
> +struct ti_csi2rx_dev {
> +	struct device			*dev;
> +	void __iomem			*shim;
> +	struct v4l2_device		v4l2_dev;
> +	struct video_device		vdev;
> +	struct media_device		mdev;
> +	struct media_pipeline		pipe;
> +	struct media_pad		pad;
> +	struct v4l2_async_notifier	notifier;
> +	struct v4l2_subdev		*subdev;

I think "source_subdev" is a better name, to make it clear it's not 
referring to a subdev owned by this driver.

> +	struct vb2_queue		vidq;
> +	struct mutex			mutex; /* To serialize ioctls. */
> +	struct v4l2_format		v_fmt;
> +	struct ti_csi2rx_dma		dma;
> +	u32				sequence;
> +};
> +
> +static const struct ti_csi2rx_fmt formats[] = {
> +	{
> +		.fourcc			= V4L2_PIX_FMT_YUYV,
> +		.code			= MEDIA_BUS_FMT_YUYV8_1X16,
> +		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_UYVY,
> +		.code			= MEDIA_BUS_FMT_UYVY8_1X16,
> +		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_YVYU,
> +		.code			= MEDIA_BUS_FMT_YVYU8_1X16,
> +		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_VYUY,
> +		.code			= MEDIA_BUS_FMT_VYUY8_1X16,
> +		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SBGGR8,
> +		.code			= MEDIA_BUS_FMT_SBGGR8_1X8,
> +		.csi_dt			= MIPI_CSI2_DT_RAW8,
> +		.bpp			= 8,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SGBRG8,
> +		.code			= MEDIA_BUS_FMT_SGBRG8_1X8,
> +		.csi_dt			= MIPI_CSI2_DT_RAW8,
> +		.bpp			= 8,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SGRBG8,
> +		.code			= MEDIA_BUS_FMT_SGRBG8_1X8,
> +		.csi_dt			= MIPI_CSI2_DT_RAW8,
> +		.bpp			= 8,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SRGGB8,
> +		.code			= MEDIA_BUS_FMT_SRGGB8_1X8,
> +		.csi_dt			= MIPI_CSI2_DT_RAW8,
> +		.bpp			= 8,
> +		.size			= SHIM_DMACNTX_SIZE_8,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SBGGR10,
> +		.code			= MEDIA_BUS_FMT_SBGGR10_1X10,
> +		.csi_dt			= MIPI_CSI2_DT_RAW10,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_16,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SGBRG10,
> +		.code			= MEDIA_BUS_FMT_SGBRG10_1X10,
> +		.csi_dt			= MIPI_CSI2_DT_RAW10,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_16,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SGRBG10,
> +		.code			= MEDIA_BUS_FMT_SGRBG10_1X10,
> +		.csi_dt			= MIPI_CSI2_DT_RAW10,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_16,
> +	}, {
> +		.fourcc			= V4L2_PIX_FMT_SRGGB10,
> +		.code			= MEDIA_BUS_FMT_SRGGB10_1X10,
> +		.csi_dt			= MIPI_CSI2_DT_RAW10,
> +		.bpp			= 16,
> +		.size			= SHIM_DMACNTX_SIZE_16,
> +	},
> +
> +	/* More formats can be supported but they are not listed for now. */
> +};
> +
> +static const unsigned int num_formats = ARRAY_SIZE(formats);
> +
> +/* Forward declaration needed by ti_csi2rx_dma_callback. */
> +static int ti_csi2rx_start_dma(struct ti_csi2rx_dev *csi,
> +			       struct ti_csi2rx_buffer *buf);
> +
> +static const struct ti_csi2rx_fmt *find_format_by_pix(u32 pixelformat)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < num_formats; i++) {
> +		if (formats[i].fourcc == pixelformat)
> +			return &formats[i];
> +	}
> +
> +	return NULL;
> +}
> +
> +static const struct ti_csi2rx_fmt *find_format_by_code(u32 code)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < num_formats; i++) {
> +		if (formats[i].code == code)
> +			return &formats[i];
> +	}
> +
> +	return NULL;
> +}
> +
> +static void ti_csi2rx_fill_fmt(const struct ti_csi2rx_fmt *csi_fmt,
> +			       struct v4l2_format *v4l2_fmt)
> +{
> +	struct v4l2_pix_format *pix = &v4l2_fmt->fmt.pix;
> +	unsigned int pixels_in_word;
> +	u8 bpp = csi_fmt->bpp;
> +	u32 bpl;
> +
> +	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / bpp;
> +
> +	pix->width = clamp_t(unsigned int, pix->width,
> +			     pixels_in_word,
> +			     MAX_WIDTH_BYTES * 8 / bpp);
> +	pix->width = rounddown(pix->width, pixels_in_word);
> +
> +	pix->height = clamp_t(unsigned int, pix->height, 1, MAX_HEIGHT_LINES);
> +
> +	v4l2_fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	pix->pixelformat = csi_fmt->fourcc;
> +	pix->colorspace = V4L2_COLORSPACE_SRGB;
> +	pix->sizeimage = pix->height * pix->width * (bpp / 8);
> +
> +	bpl = (pix->width * ALIGN(bpp, 8)) >> 3;

You do "/ 8" and "* 8" elsewhere in the function, so I think it makes 
sense to "/ 8" here too, instead of ">> 3".

Is this correct? Why is aligned bpp used here, but when calculating 
sizeimage, bpp is not aligned?

> +	pix->bytesperline = ALIGN(bpl, 16);

Why align to 16?

Shouldn't sizeimage usually be bytesperline * height?

You could add a few comments here to clarify all the aligns, roundings 
and clampings.

> +}
> +
> +static int ti_csi2rx_querycap(struct file *file, void *priv,
> +			      struct v4l2_capability *cap)
> +{
> +	strscpy(cap->driver, TI_CSI2RX_MODULE_NAME, sizeof(cap->driver));
> +	strscpy(cap->card, TI_CSI2RX_MODULE_NAME, sizeof(cap->card));
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_enum_fmt_vid_cap(struct file *file, void *priv,
> +				      struct v4l2_fmtdesc *f)
> +{
> +	const struct ti_csi2rx_fmt *fmt = NULL;
> +
> +	if (f->mbus_code) {
> +		if (f->index > 0)
> +			return -EINVAL;

This fails to enumerate the formats if mbus_code is set, doesn't it?

> +
> +		fmt = find_format_by_code(f->mbus_code);
> +	} else {
> +		if (f->index >= num_formats)
> +			return -EINVAL;
> +
> +		fmt = &formats[f->index];
> +	}
> +
> +	if (!fmt)
> +		return -EINVAL;
> +
> +	f->pixelformat = fmt->fourcc;
> +	memset(f->reserved, 0, sizeof(f->reserved));
> +	f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_g_fmt_vid_cap(struct file *file, void *prov,
> +				   struct v4l2_format *f)
> +{
> +	struct ti_csi2rx_dev *csi = video_drvdata(file);
> +
> +	*f = csi->v_fmt;
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_try_fmt_vid_cap(struct file *file, void *priv,
> +				     struct v4l2_format *f)
> +{
> +	const struct ti_csi2rx_fmt *fmt;
> +
> +	/*
> +	 * Default to the first format if the requested pixel format code isn't
> +	 * supported.
> +	 */
> +	fmt = find_format_by_pix(f->fmt.pix.pixelformat);
> +	if (!fmt)
> +		fmt = &formats[0];
> +
> +	if (f->fmt.pix.field == V4L2_FIELD_ANY)
> +		f->fmt.pix.field = V4L2_FIELD_NONE;
> +
> +	if (f->fmt.pix.field != V4L2_FIELD_NONE)
> +		/* Interlaced formats are not supported. */
> +		f->fmt.pix.field = V4L2_FIELD_NONE;

Can't you just always set the field to V4L2_FIELD_NONE?

> +	ti_csi2rx_fill_fmt(fmt, f);
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_s_fmt_vid_cap(struct file *file, void *priv,
> +				   struct v4l2_format *f)
> +{
> +	struct ti_csi2rx_dev *csi = video_drvdata(file);
> +	struct vb2_queue *q = &csi->vidq;
> +	int ret;
> +
> +	if (vb2_is_busy(q))
> +		return -EBUSY;
> +
> +	ret = ti_csi2rx_try_fmt_vid_cap(file, priv, f);
> +	if (ret < 0)
> +		return ret;
> +
> +	csi->v_fmt = *f;
> +
> +	return 0;
> +}
> +
> +static int ti_csi2rx_enum_framesizes(struct file *file, void *fh,
> +				     struct v4l2_frmsizeenum *fsize)
> +{
> +	const struct ti_csi2rx_fmt *fmt;
> +	unsigned int pixels_in_word;
> +	u8 bpp;
> +
> +	fmt = find_format_by_pix(fsize->pixel_format);
> +	if (!fmt || fsize->index != 0)
> +		return -EINVAL;
> +
> +	bpp = ALIGN(fmt->bpp, 8);
> +
> +	/*
> +	 * Number of pixels in one PSI-L word. The transfer happens in multiples
> +	 * of PSI-L word sizes.
> +	 */
> +	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / bpp;
> +
> +	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
> +	fsize->stepwise.min_width = pixels_in_word;
> +	fsize->stepwise.max_width = rounddown(MAX_WIDTH_BYTES * 8 / bpp,
> +					      pixels_in_word);
> +	fsize->stepwise.step_width = pixels_in_word;
> +	fsize->stepwise.min_height = 1;
> +	fsize->stepwise.max_height = MAX_HEIGHT_LINES;
> +	fsize->stepwise.step_height = 1;
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ioctl_ops csi_ioctl_ops = {
> +	.vidioc_querycap      = ti_csi2rx_querycap,
> +	.vidioc_enum_fmt_vid_cap = ti_csi2rx_enum_fmt_vid_cap,
> +	.vidioc_try_fmt_vid_cap = ti_csi2rx_try_fmt_vid_cap,
> +	.vidioc_g_fmt_vid_cap = ti_csi2rx_g_fmt_vid_cap,
> +	.vidioc_s_fmt_vid_cap = ti_csi2rx_s_fmt_vid_cap,
> +	.vidioc_enum_framesizes = ti_csi2rx_enum_framesizes,
> +	.vidioc_reqbufs       = vb2_ioctl_reqbufs,
> +	.vidioc_create_bufs   = vb2_ioctl_create_bufs,
> +	.vidioc_prepare_buf   = vb2_ioctl_prepare_buf,
> +	.vidioc_querybuf      = vb2_ioctl_querybuf,
> +	.vidioc_qbuf          = vb2_ioctl_qbuf,
> +	.vidioc_dqbuf         = vb2_ioctl_dqbuf,
> +	.vidioc_expbuf        = vb2_ioctl_expbuf,
> +	.vidioc_streamon      = vb2_ioctl_streamon,
> +	.vidioc_streamoff     = vb2_ioctl_streamoff,
> +};
> +
> +static const struct v4l2_file_operations csi_fops = {
> +	.owner = THIS_MODULE,
> +	.open = v4l2_fh_open,
> +	.release = vb2_fop_release,
> +	.read = vb2_fop_read,
> +	.poll = vb2_fop_poll,
> +	.unlocked_ioctl = video_ioctl2,
> +	.mmap = vb2_fop_mmap,
> +};
> +
> +static int csi_async_notifier_bound(struct v4l2_async_notifier *notifier,
> +				    struct v4l2_subdev *subdev,
> +				    struct v4l2_async_connection *asc)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
> +
> +	csi->subdev = subdev;
> +
> +	return 0;
> +}
> +
> +static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
> +{
> +	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
> +	struct video_device *vdev = &csi->vdev;
> +	int ret;
> +
> +	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
> +	if (ret)
> +		return ret;
> +
> +	ret = v4l2_create_fwnode_links_to_pad(csi->subdev, &csi->pad,
> +					      MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
> +
> +	if (ret) {
> +		video_unregister_device(vdev);
> +		return ret;
> +	}
> +
> +	return v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
> +}
> +
> +static const struct v4l2_async_notifier_operations csi_async_notifier_ops = {
> +	.bound = csi_async_notifier_bound,
> +	.complete = csi_async_notifier_complete,
> +};
> +
> +static int ti_csi2rx_init_subdev(struct ti_csi2rx_dev *csi)

This is misnamed. ti_csi2rx_async_notifier_register()?

> +{
> +	struct fwnode_handle *fwnode;
> +	struct v4l2_async_connection *asc;
> +	struct device_node *node;
> +	int ret;
> +
> +	node = of_get_child_by_name(csi->dev->of_node, "csi-bridge");
> +	if (!node)
> +		return -EINVAL;
> +
> +	fwnode = of_fwnode_handle(node);
> +	if (!fwnode) {
> +		of_node_put(node);
> +		return -EINVAL;
> +	}
> +
> +	v4l2_async_nf_init(&csi->notifier, &csi->v4l2_dev);
> +	csi->notifier.ops = &csi_async_notifier_ops;
> +
> +	asc = v4l2_async_nf_add_fwnode(&csi->notifier, fwnode,
> +				       struct v4l2_async_connection);
> +	of_node_put(node);
> +	if (IS_ERR(asc)) {
> +		v4l2_async_nf_cleanup(&csi->notifier);
> +		return PTR_ERR(asc);
> +	}
> +
> +	ret = v4l2_async_nf_register(&csi->notifier);
> +	if (ret) {
> +		v4l2_async_nf_cleanup(&csi->notifier);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void ti_csi2rx_setup_shim(struct ti_csi2rx_dev *csi)
> +{
> +	const struct ti_csi2rx_fmt *fmt;
> +	unsigned int reg;
> +
> +	fmt = find_format_by_pix(csi->v_fmt.fmt.pix.pixelformat);
> +	if (!fmt) {
> +		dev_err(csi->dev, "Unknown format\n");
> +		return;
> +	}

The error print here is rather vague, and as there's no error code 
returned, the caller doesn't handle the error.

> +
> +	/* De-assert the pixel interface reset. */
> +	reg = SHIM_CNTL_PIX_RST;
> +	writel(reg, csi->shim + SHIM_CNTL);
> +
> +	reg = SHIM_DMACNTX_EN;
> +	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, fmt->csi_dt);
> +
> +	/*
> +	 * Using the values from the documentation gives incorrect ordering for
> +	 * the luma and chroma components. In practice, the "reverse" format
> +	 * gives the correct image. So for example, if the image is in UYVY, the
> +	 * reverse would be YVYU.
> +	 */
> +	switch (fmt->fourcc) {
> +	case V4L2_PIX_FMT_UYVY:
> +		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
> +					SHIM_DMACNTX_YVYU);
> +		break;
> +	case V4L2_PIX_FMT_VYUY:
> +		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
> +					SHIM_DMACNTX_YUYV);
> +		break;
> +	case V4L2_PIX_FMT_YUYV:
> +		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
> +					SHIM_DMACNTX_VYUY);
> +		break;
> +	case V4L2_PIX_FMT_YVYU:
> +		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
> +					SHIM_DMACNTX_UYVY);
> +		break;
> +	default:
> +		/* Ignore if not YUV 4:2:2 */
> +		break;
> +	}
> +
> +	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
> +
> +	writel(reg, csi->shim + SHIM_DMACNTX);
> +
> +	reg = FIELD_PREP(SHIM_PSI_CFG0_SRC_TAG, 0) |
> +	      FIELD_PREP(SHIM_PSI_CFG0_DST_TAG, 0);
> +	writel(reg, csi->shim + SHIM_PSI_CFG0);
> +}
> +
> +static void ti_csi2rx_drain_callback(void *param)
> +{
> +	struct completion *drain_complete = param;
> +
> +	complete(drain_complete);
> +}
> +
> +static int ti_csi2rx_drain_dma(struct ti_csi2rx_dev *csi)
> +{

I think it would be good to explain in a comment somewhere what why this 
dma draining is needed and how it works.

> +	struct dma_async_tx_descriptor *desc;
> +	struct device *dev = csi->dma.chan->device->dev;
> +	struct completion drain_complete;
> +	void *buf;
> +	size_t len = csi->v_fmt.fmt.pix.sizeimage;
> +	dma_addr_t addr;
> +	dma_cookie_t cookie;
> +	int ret;
> +
> +	init_completion(&drain_complete);
> +
> +	buf = dma_alloc_coherent(dev, len, &addr, GFP_KERNEL | GFP_ATOMIC);
> +	if (!buf)
> +		return -ENOMEM;

If I understand right, this is called when the streaming is stopped, but 
could also be called on frame drops? You're allocating a DMA buffer for 
a full frame. Large runtime DMA buffer allocations are a bit scary. What 
happens if it fails?

Is it possible to preallocate, or use smaller buffers (perhaps with 
multiple dma operations) to do the flush?

The dma doesn't support writing to a constant address, does it (in which 
case a very small buffer would suffice)?

  Tomi
Sakari Ailus Aug. 2, 2023, 11:14 a.m. UTC | #2
Moi,

On Wed, Aug 02, 2023 at 02:04:57PM +0300, Tomi Valkeinen wrote:
> > +static int ti_csi2rx_enum_fmt_vid_cap(struct file *file, void *priv,
> > +				      struct v4l2_fmtdesc *f)
> > +{
> > +	const struct ti_csi2rx_fmt *fmt = NULL;
> > +
> > +	if (f->mbus_code) {
> > +		if (f->index > 0)
> > +			return -EINVAL;
> 
> This fails to enumerate the formats if mbus_code is set, doesn't it?

This is intentional: if the mbus_code field is set, you're supposed to get
only format(s) corresponding to that mbus code.

> 
> > +
> > +		fmt = find_format_by_code(f->mbus_code);
> > +	} else {
> > +		if (f->index >= num_formats)
> > +			return -EINVAL;
> > +
> > +		fmt = &formats[f->index];
> > +	}
> > +
> > +	if (!fmt)
> > +		return -EINVAL;
> > +
> > +	f->pixelformat = fmt->fourcc;
> > +	memset(f->reserved, 0, sizeof(f->reserved));
> > +	f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> > +
> > +	return 0;
> > +}
Tomi Valkeinen Aug. 2, 2023, 12:09 p.m. UTC | #3
On 02/08/2023 14:14, Sakari Ailus wrote:
> Moi,
> 
> On Wed, Aug 02, 2023 at 02:04:57PM +0300, Tomi Valkeinen wrote:
>>> +static int ti_csi2rx_enum_fmt_vid_cap(struct file *file, void *priv,
>>> +				      struct v4l2_fmtdesc *f)
>>> +{
>>> +	const struct ti_csi2rx_fmt *fmt = NULL;
>>> +
>>> +	if (f->mbus_code) {
>>> +		if (f->index > 0)
>>> +			return -EINVAL;
>>
>> This fails to enumerate the formats if mbus_code is set, doesn't it?
> 
> This is intentional: if the mbus_code field is set, you're supposed to get
> only format(s) corresponding to that mbus code.

Right. But the above code doesn't do that, does it? It will only return 
the first format, and error for anything else. Ah, the driver only 
supports a single mbus code per fourcc. In that case it's ok.

  Tomi

>>
>>> +
>>> +		fmt = find_format_by_code(f->mbus_code);
>>> +	} else {
>>> +		if (f->index >= num_formats)
>>> +			return -EINVAL;
>>> +
>>> +		fmt = &formats[f->index];
>>> +	}
>>> +
>>> +	if (!fmt)
>>> +		return -EINVAL;
>>> +
>>> +	f->pixelformat = fmt->fourcc;
>>> +	memset(f->reserved, 0, sizeof(f->reserved));
>>> +	f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>>> +
>>> +	return 0;
>>> +}
>
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index d7b867c57920..1c2d75c30ce7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21445,6 +21445,13 @@  F:	Documentation/devicetree/bindings/media/i2c/ti,ds90*
 F:	drivers/media/i2c/ds90*
 F:	include/media/i2c/ds90*
 
+TI J721E CSI2RX DRIVER
+M:	Jai Luthra <j-luthra@ti.com>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/media/ti,j721e-csi2rx.yaml
+F:	drivers/media/platform/ti/j721e-csi2rx/
+
 TI KEYSTONE MULTICORE NAVIGATOR DRIVERS
 M:	Nishanth Menon <nm@ti.com>
 M:	Santosh Shilimkar <ssantosh@kernel.org>
diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
index e1ab56c3be1f..42c908f6e1ae 100644
--- a/drivers/media/platform/ti/Kconfig
+++ b/drivers/media/platform/ti/Kconfig
@@ -63,6 +63,18 @@  config VIDEO_TI_VPE_DEBUG
 	help
 	  Enable debug messages on VPE driver.
 
+config VIDEO_TI_J721E_CSI2RX
+	tristate "TI J721E CSI2RX wrapper layer driver"
+	depends on VIDEO_DEV && VIDEO_V4L2_SUBDEV_API
+	depends on MEDIA_SUPPORT && MEDIA_CONTROLLER
+	depends on PHY_CADENCE_DPHY_RX && VIDEO_CADENCE_CSI2RX
+	depends on ARCH_K3 || COMPILE_TEST
+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_FWNODE
+	help
+	  Support for TI CSI2RX wrapper layer. This just enables the wrapper driver.
+	  The Cadence CSI2RX bridge driver needs to be enabled separately.
+
 source "drivers/media/platform/ti/am437x/Kconfig"
 source "drivers/media/platform/ti/davinci/Kconfig"
 source "drivers/media/platform/ti/omap/Kconfig"
diff --git a/drivers/media/platform/ti/Makefile b/drivers/media/platform/ti/Makefile
index 98c5fe5c40d6..8a2f74c9380e 100644
--- a/drivers/media/platform/ti/Makefile
+++ b/drivers/media/platform/ti/Makefile
@@ -3,5 +3,6 @@  obj-y += am437x/
 obj-y += cal/
 obj-y += vpe/
 obj-y += davinci/
+obj-y += j721e-csi2rx/
 obj-y += omap/
 obj-y += omap3isp/
diff --git a/drivers/media/platform/ti/j721e-csi2rx/Makefile b/drivers/media/platform/ti/j721e-csi2rx/Makefile
new file mode 100644
index 000000000000..377afc1d6280
--- /dev/null
+++ b/drivers/media/platform/ti/j721e-csi2rx/Makefile
@@ -0,0 +1,2 @@ 
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VIDEO_TI_J721E_CSI2RX) += j721e-csi2rx.o
diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
new file mode 100644
index 000000000000..29f1879cfc25
--- /dev/null
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -0,0 +1,1127 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI CSI2RX Shim Wrapper Driver
+ *
+ * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
+ *
+ * Author: Pratyush Yadav <p.yadav@ti.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <media/mipi-csi2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
+#include <media/videobuf2-dma-contig.h>
+
+#define TI_CSI2RX_MODULE_NAME		"j721e-csi2rx"
+
+#define SHIM_CNTL			0x10
+#define SHIM_CNTL_PIX_RST		BIT(0)
+
+#define SHIM_DMACNTX			0x20
+#define SHIM_DMACNTX_EN			BIT(31)
+#define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
+#define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
+#define SHIM_DMACNTX_FMT		GENMASK(5, 0)
+#define SHIM_DMACNTX_UYVY		0
+#define SHIM_DMACNTX_VYUY		1
+#define SHIM_DMACNTX_YUYV		2
+#define SHIM_DMACNTX_YVYU		3
+#define SHIM_DMACNTX_SIZE_8		0
+#define SHIM_DMACNTX_SIZE_16		1
+#define SHIM_DMACNTX_SIZE_32		2
+
+#define SHIM_PSI_CFG0			0x24
+#define SHIM_PSI_CFG0_SRC_TAG		GENMASK(15, 0)
+#define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
+
+#define PSIL_WORD_SIZE_BYTES		16
+/*
+ * There are no hard limits on the width or height. The DMA engine can handle
+ * all sizes. The max width and height are arbitrary numbers for this driver.
+ * Use 16K * 16K as the arbitrary limit. It is large enough that it is unlikely
+ * the limit will be hit in practice.
+ */
+#define MAX_WIDTH_BYTES			SZ_16K
+#define MAX_HEIGHT_LINES		SZ_16K
+
+#define DRAIN_TIMEOUT_MS		50
+
+struct ti_csi2rx_fmt {
+	u32				fourcc;	/* Four character code. */
+	u32				code;	/* Mbus code. */
+	u32				csi_dt;	/* CSI Data type. */
+	u8				bpp;	/* Bits per pixel. */
+	u8				size;	/* Data size shift when unpacking. */
+};
+
+struct ti_csi2rx_buffer {
+	/* Common v4l2 buffer. Must be first. */
+	struct vb2_v4l2_buffer		vb;
+	struct list_head		list;
+	struct ti_csi2rx_dev		*csi;
+};
+
+enum ti_csi2rx_dma_state {
+	TI_CSI2RX_DMA_STOPPED,	/* Streaming not started yet. */
+	TI_CSI2RX_DMA_IDLE,	/* Streaming but no pending DMA operation. */
+	TI_CSI2RX_DMA_ACTIVE,	/* Streaming and pending DMA operation. */
+};
+
+struct ti_csi2rx_dma {
+	/* Protects all fields in this struct. */
+	spinlock_t			lock;
+	struct dma_chan			*chan;
+	/* Buffers queued to the driver, waiting to be processed by DMA. */
+	struct list_head		queue;
+	enum ti_csi2rx_dma_state	state;
+	/*
+	 * Queue of buffers submitted to DMA engine.
+	 */
+	struct list_head		submitted;
+};
+
+struct ti_csi2rx_dev {
+	struct device			*dev;
+	void __iomem			*shim;
+	struct v4l2_device		v4l2_dev;
+	struct video_device		vdev;
+	struct media_device		mdev;
+	struct media_pipeline		pipe;
+	struct media_pad		pad;
+	struct v4l2_async_notifier	notifier;
+	struct v4l2_subdev		*subdev;
+	struct vb2_queue		vidq;
+	struct mutex			mutex; /* To serialize ioctls. */
+	struct v4l2_format		v_fmt;
+	struct ti_csi2rx_dma		dma;
+	u32				sequence;
+};
+
+static const struct ti_csi2rx_fmt formats[] = {
+	{
+		.fourcc			= V4L2_PIX_FMT_YUYV,
+		.code			= MEDIA_BUS_FMT_YUYV8_1X16,
+		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_UYVY,
+		.code			= MEDIA_BUS_FMT_UYVY8_1X16,
+		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_YVYU,
+		.code			= MEDIA_BUS_FMT_YVYU8_1X16,
+		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_VYUY,
+		.code			= MEDIA_BUS_FMT_VYUY8_1X16,
+		.csi_dt			= MIPI_CSI2_DT_YUV422_8B,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SBGGR8,
+		.code			= MEDIA_BUS_FMT_SBGGR8_1X8,
+		.csi_dt			= MIPI_CSI2_DT_RAW8,
+		.bpp			= 8,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SGBRG8,
+		.code			= MEDIA_BUS_FMT_SGBRG8_1X8,
+		.csi_dt			= MIPI_CSI2_DT_RAW8,
+		.bpp			= 8,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SGRBG8,
+		.code			= MEDIA_BUS_FMT_SGRBG8_1X8,
+		.csi_dt			= MIPI_CSI2_DT_RAW8,
+		.bpp			= 8,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SRGGB8,
+		.code			= MEDIA_BUS_FMT_SRGGB8_1X8,
+		.csi_dt			= MIPI_CSI2_DT_RAW8,
+		.bpp			= 8,
+		.size			= SHIM_DMACNTX_SIZE_8,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SBGGR10,
+		.code			= MEDIA_BUS_FMT_SBGGR10_1X10,
+		.csi_dt			= MIPI_CSI2_DT_RAW10,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_16,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SGBRG10,
+		.code			= MEDIA_BUS_FMT_SGBRG10_1X10,
+		.csi_dt			= MIPI_CSI2_DT_RAW10,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_16,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SGRBG10,
+		.code			= MEDIA_BUS_FMT_SGRBG10_1X10,
+		.csi_dt			= MIPI_CSI2_DT_RAW10,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_16,
+	}, {
+		.fourcc			= V4L2_PIX_FMT_SRGGB10,
+		.code			= MEDIA_BUS_FMT_SRGGB10_1X10,
+		.csi_dt			= MIPI_CSI2_DT_RAW10,
+		.bpp			= 16,
+		.size			= SHIM_DMACNTX_SIZE_16,
+	},
+
+	/* More formats can be supported but they are not listed for now. */
+};
+
+static const unsigned int num_formats = ARRAY_SIZE(formats);
+
+/* Forward declaration needed by ti_csi2rx_dma_callback. */
+static int ti_csi2rx_start_dma(struct ti_csi2rx_dev *csi,
+			       struct ti_csi2rx_buffer *buf);
+
+static const struct ti_csi2rx_fmt *find_format_by_pix(u32 pixelformat)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_formats; i++) {
+		if (formats[i].fourcc == pixelformat)
+			return &formats[i];
+	}
+
+	return NULL;
+}
+
+static const struct ti_csi2rx_fmt *find_format_by_code(u32 code)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_formats; i++) {
+		if (formats[i].code == code)
+			return &formats[i];
+	}
+
+	return NULL;
+}
+
+static void ti_csi2rx_fill_fmt(const struct ti_csi2rx_fmt *csi_fmt,
+			       struct v4l2_format *v4l2_fmt)
+{
+	struct v4l2_pix_format *pix = &v4l2_fmt->fmt.pix;
+	unsigned int pixels_in_word;
+	u8 bpp = csi_fmt->bpp;
+	u32 bpl;
+
+	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / bpp;
+
+	pix->width = clamp_t(unsigned int, pix->width,
+			     pixels_in_word,
+			     MAX_WIDTH_BYTES * 8 / bpp);
+	pix->width = rounddown(pix->width, pixels_in_word);
+
+	pix->height = clamp_t(unsigned int, pix->height, 1, MAX_HEIGHT_LINES);
+
+	v4l2_fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	pix->pixelformat = csi_fmt->fourcc;
+	pix->colorspace = V4L2_COLORSPACE_SRGB;
+	pix->sizeimage = pix->height * pix->width * (bpp / 8);
+
+	bpl = (pix->width * ALIGN(bpp, 8)) >> 3;
+	pix->bytesperline = ALIGN(bpl, 16);
+}
+
+static int ti_csi2rx_querycap(struct file *file, void *priv,
+			      struct v4l2_capability *cap)
+{
+	strscpy(cap->driver, TI_CSI2RX_MODULE_NAME, sizeof(cap->driver));
+	strscpy(cap->card, TI_CSI2RX_MODULE_NAME, sizeof(cap->card));
+
+	return 0;
+}
+
+static int ti_csi2rx_enum_fmt_vid_cap(struct file *file, void *priv,
+				      struct v4l2_fmtdesc *f)
+{
+	const struct ti_csi2rx_fmt *fmt = NULL;
+
+	if (f->mbus_code) {
+		if (f->index > 0)
+			return -EINVAL;
+
+		fmt = find_format_by_code(f->mbus_code);
+	} else {
+		if (f->index >= num_formats)
+			return -EINVAL;
+
+		fmt = &formats[f->index];
+	}
+
+	if (!fmt)
+		return -EINVAL;
+
+	f->pixelformat = fmt->fourcc;
+	memset(f->reserved, 0, sizeof(f->reserved));
+	f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+	return 0;
+}
+
+static int ti_csi2rx_g_fmt_vid_cap(struct file *file, void *prov,
+				   struct v4l2_format *f)
+{
+	struct ti_csi2rx_dev *csi = video_drvdata(file);
+
+	*f = csi->v_fmt;
+
+	return 0;
+}
+
+static int ti_csi2rx_try_fmt_vid_cap(struct file *file, void *priv,
+				     struct v4l2_format *f)
+{
+	const struct ti_csi2rx_fmt *fmt;
+
+	/*
+	 * Default to the first format if the requested pixel format code isn't
+	 * supported.
+	 */
+	fmt = find_format_by_pix(f->fmt.pix.pixelformat);
+	if (!fmt)
+		fmt = &formats[0];
+
+	if (f->fmt.pix.field == V4L2_FIELD_ANY)
+		f->fmt.pix.field = V4L2_FIELD_NONE;
+
+	if (f->fmt.pix.field != V4L2_FIELD_NONE)
+		/* Interlaced formats are not supported. */
+		f->fmt.pix.field = V4L2_FIELD_NONE;
+
+	ti_csi2rx_fill_fmt(fmt, f);
+
+	return 0;
+}
+
+static int ti_csi2rx_s_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_format *f)
+{
+	struct ti_csi2rx_dev *csi = video_drvdata(file);
+	struct vb2_queue *q = &csi->vidq;
+	int ret;
+
+	if (vb2_is_busy(q))
+		return -EBUSY;
+
+	ret = ti_csi2rx_try_fmt_vid_cap(file, priv, f);
+	if (ret < 0)
+		return ret;
+
+	csi->v_fmt = *f;
+
+	return 0;
+}
+
+static int ti_csi2rx_enum_framesizes(struct file *file, void *fh,
+				     struct v4l2_frmsizeenum *fsize)
+{
+	const struct ti_csi2rx_fmt *fmt;
+	unsigned int pixels_in_word;
+	u8 bpp;
+
+	fmt = find_format_by_pix(fsize->pixel_format);
+	if (!fmt || fsize->index != 0)
+		return -EINVAL;
+
+	bpp = ALIGN(fmt->bpp, 8);
+
+	/*
+	 * Number of pixels in one PSI-L word. The transfer happens in multiples
+	 * of PSI-L word sizes.
+	 */
+	pixels_in_word = PSIL_WORD_SIZE_BYTES * 8 / bpp;
+
+	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
+	fsize->stepwise.min_width = pixels_in_word;
+	fsize->stepwise.max_width = rounddown(MAX_WIDTH_BYTES * 8 / bpp,
+					      pixels_in_word);
+	fsize->stepwise.step_width = pixels_in_word;
+	fsize->stepwise.min_height = 1;
+	fsize->stepwise.max_height = MAX_HEIGHT_LINES;
+	fsize->stepwise.step_height = 1;
+
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops csi_ioctl_ops = {
+	.vidioc_querycap      = ti_csi2rx_querycap,
+	.vidioc_enum_fmt_vid_cap = ti_csi2rx_enum_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap = ti_csi2rx_try_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap = ti_csi2rx_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap = ti_csi2rx_s_fmt_vid_cap,
+	.vidioc_enum_framesizes = ti_csi2rx_enum_framesizes,
+	.vidioc_reqbufs       = vb2_ioctl_reqbufs,
+	.vidioc_create_bufs   = vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf   = vb2_ioctl_prepare_buf,
+	.vidioc_querybuf      = vb2_ioctl_querybuf,
+	.vidioc_qbuf          = vb2_ioctl_qbuf,
+	.vidioc_dqbuf         = vb2_ioctl_dqbuf,
+	.vidioc_expbuf        = vb2_ioctl_expbuf,
+	.vidioc_streamon      = vb2_ioctl_streamon,
+	.vidioc_streamoff     = vb2_ioctl_streamoff,
+};
+
+static const struct v4l2_file_operations csi_fops = {
+	.owner = THIS_MODULE,
+	.open = v4l2_fh_open,
+	.release = vb2_fop_release,
+	.read = vb2_fop_read,
+	.poll = vb2_fop_poll,
+	.unlocked_ioctl = video_ioctl2,
+	.mmap = vb2_fop_mmap,
+};
+
+static int csi_async_notifier_bound(struct v4l2_async_notifier *notifier,
+				    struct v4l2_subdev *subdev,
+				    struct v4l2_async_connection *asc)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
+
+	csi->subdev = subdev;
+
+	return 0;
+}
+
+static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(notifier->v4l2_dev->dev);
+	struct video_device *vdev = &csi->vdev;
+	int ret;
+
+	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
+	if (ret)
+		return ret;
+
+	ret = v4l2_create_fwnode_links_to_pad(csi->subdev, &csi->pad,
+					      MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
+
+	if (ret) {
+		video_unregister_device(vdev);
+		return ret;
+	}
+
+	return v4l2_device_register_subdev_nodes(&csi->v4l2_dev);
+}
+
+static const struct v4l2_async_notifier_operations csi_async_notifier_ops = {
+	.bound = csi_async_notifier_bound,
+	.complete = csi_async_notifier_complete,
+};
+
+static int ti_csi2rx_init_subdev(struct ti_csi2rx_dev *csi)
+{
+	struct fwnode_handle *fwnode;
+	struct v4l2_async_connection *asc;
+	struct device_node *node;
+	int ret;
+
+	node = of_get_child_by_name(csi->dev->of_node, "csi-bridge");
+	if (!node)
+		return -EINVAL;
+
+	fwnode = of_fwnode_handle(node);
+	if (!fwnode) {
+		of_node_put(node);
+		return -EINVAL;
+	}
+
+	v4l2_async_nf_init(&csi->notifier, &csi->v4l2_dev);
+	csi->notifier.ops = &csi_async_notifier_ops;
+
+	asc = v4l2_async_nf_add_fwnode(&csi->notifier, fwnode,
+				       struct v4l2_async_connection);
+	of_node_put(node);
+	if (IS_ERR(asc)) {
+		v4l2_async_nf_cleanup(&csi->notifier);
+		return PTR_ERR(asc);
+	}
+
+	ret = v4l2_async_nf_register(&csi->notifier);
+	if (ret) {
+		v4l2_async_nf_cleanup(&csi->notifier);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void ti_csi2rx_setup_shim(struct ti_csi2rx_dev *csi)
+{
+	const struct ti_csi2rx_fmt *fmt;
+	unsigned int reg;
+
+	fmt = find_format_by_pix(csi->v_fmt.fmt.pix.pixelformat);
+	if (!fmt) {
+		dev_err(csi->dev, "Unknown format\n");
+		return;
+	}
+
+	/* De-assert the pixel interface reset. */
+	reg = SHIM_CNTL_PIX_RST;
+	writel(reg, csi->shim + SHIM_CNTL);
+
+	reg = SHIM_DMACNTX_EN;
+	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, fmt->csi_dt);
+
+	/*
+	 * Using the values from the documentation gives incorrect ordering for
+	 * the luma and chroma components. In practice, the "reverse" format
+	 * gives the correct image. So for example, if the image is in UYVY, the
+	 * reverse would be YVYU.
+	 */
+	switch (fmt->fourcc) {
+	case V4L2_PIX_FMT_UYVY:
+		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
+					SHIM_DMACNTX_YVYU);
+		break;
+	case V4L2_PIX_FMT_VYUY:
+		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
+					SHIM_DMACNTX_YUYV);
+		break;
+	case V4L2_PIX_FMT_YUYV:
+		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
+					SHIM_DMACNTX_VYUY);
+		break;
+	case V4L2_PIX_FMT_YVYU:
+		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
+					SHIM_DMACNTX_UYVY);
+		break;
+	default:
+		/* Ignore if not YUV 4:2:2 */
+		break;
+	}
+
+	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
+
+	writel(reg, csi->shim + SHIM_DMACNTX);
+
+	reg = FIELD_PREP(SHIM_PSI_CFG0_SRC_TAG, 0) |
+	      FIELD_PREP(SHIM_PSI_CFG0_DST_TAG, 0);
+	writel(reg, csi->shim + SHIM_PSI_CFG0);
+}
+
+static void ti_csi2rx_drain_callback(void *param)
+{
+	struct completion *drain_complete = param;
+
+	complete(drain_complete);
+}
+
+static int ti_csi2rx_drain_dma(struct ti_csi2rx_dev *csi)
+{
+	struct dma_async_tx_descriptor *desc;
+	struct device *dev = csi->dma.chan->device->dev;
+	struct completion drain_complete;
+	void *buf;
+	size_t len = csi->v_fmt.fmt.pix.sizeimage;
+	dma_addr_t addr;
+	dma_cookie_t cookie;
+	int ret;
+
+	init_completion(&drain_complete);
+
+	buf = dma_alloc_coherent(dev, len, &addr, GFP_KERNEL | GFP_ATOMIC);
+	if (!buf)
+		return -ENOMEM;
+
+	desc = dmaengine_prep_slave_single(csi->dma.chan, addr, len,
+					   DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		ret = -EIO;
+		goto out;
+	}
+
+	desc->callback = ti_csi2rx_drain_callback;
+	desc->callback_param = &drain_complete;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret)
+		goto out;
+
+	dma_async_issue_pending(csi->dma.chan);
+
+	if (!wait_for_completion_timeout(&drain_complete,
+					 msecs_to_jiffies(DRAIN_TIMEOUT_MS))) {
+		dmaengine_terminate_sync(csi->dma.chan);
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+out:
+	dma_free_coherent(dev, len, buf, addr);
+	return ret;
+}
+
+static void ti_csi2rx_dma_callback(void *param)
+{
+	struct ti_csi2rx_buffer *buf = param;
+	struct ti_csi2rx_dev *csi = buf->csi;
+	struct ti_csi2rx_dma *dma = &csi->dma;
+	unsigned long flags;
+
+	/*
+	 * TODO: Derive the sequence number from the CSI2RX frame number
+	 * hardware monitor registers.
+	 */
+	buf->vb.vb2_buf.timestamp = ktime_get_ns();
+	buf->vb.sequence = csi->sequence++;
+
+	spin_lock_irqsave(&dma->lock, flags);
+
+	WARN_ON(!list_is_first(&buf->list, &dma->submitted));
+	vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
+	list_del(&buf->list);
+
+	/* If there are more buffers to process then start their transfer. */
+	while (!list_empty(&dma->queue)) {
+		buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
+
+		if (ti_csi2rx_start_dma(csi, buf)) {
+			dev_err(csi->dev, "Failed to queue the next buffer for DMA\n");
+			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+		} else {
+			list_move_tail(&buf->list, &dma->submitted);
+		}
+	}
+
+	if (list_empty(&dma->submitted))
+		dma->state = TI_CSI2RX_DMA_IDLE;
+
+	spin_unlock_irqrestore(&dma->lock, flags);
+}
+
+static int ti_csi2rx_start_dma(struct ti_csi2rx_dev *csi,
+			       struct ti_csi2rx_buffer *buf)
+{
+	unsigned long addr;
+	struct dma_async_tx_descriptor *desc;
+	size_t len = csi->v_fmt.fmt.pix.sizeimage;
+	dma_cookie_t cookie;
+	int ret = 0;
+
+	addr = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
+	desc = dmaengine_prep_slave_single(csi->dma.chan, addr, len,
+					   DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EIO;
+
+	desc->callback = ti_csi2rx_dma_callback;
+	desc->callback_param = buf;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret)
+		return ret;
+
+	dma_async_issue_pending(csi->dma.chan);
+
+	return 0;
+}
+
+static void ti_csi2rx_cleanup_buffers(struct ti_csi2rx_dev *csi,
+				      enum vb2_buffer_state buf_state)
+{
+	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_buffer *buf, *tmp;
+	enum ti_csi2rx_dma_state state;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&dma->lock, flags);
+	state = csi->dma.state;
+	dma->state = TI_CSI2RX_DMA_STOPPED;
+	spin_unlock_irqrestore(&dma->lock, flags);
+
+	if (state != TI_CSI2RX_DMA_STOPPED) {
+		ret = ti_csi2rx_drain_dma(csi);
+		if (ret)
+			dev_dbg(csi->dev,
+				"Failed to drain DMA. Next frame might be bogus\n");
+	}
+	ret = dmaengine_terminate_sync(csi->dma.chan);
+	if (ret)
+		dev_err(csi->dev, "Failed to stop DMA: %d\n", ret);
+
+	spin_lock_irqsave(&dma->lock, flags);
+	list_for_each_entry_safe(buf, tmp, &csi->dma.queue, list) {
+		list_del(&buf->list);
+		vb2_buffer_done(&buf->vb.vb2_buf, buf_state);
+	}
+	list_for_each_entry_safe(buf, tmp, &csi->dma.submitted, list) {
+		list_del(&buf->list);
+		vb2_buffer_done(&buf->vb.vb2_buf, buf_state);
+	}
+	spin_unlock_irqrestore(&dma->lock, flags);
+}
+
+static int ti_csi2rx_queue_setup(struct vb2_queue *q, unsigned int *nbuffers,
+				 unsigned int *nplanes, unsigned int sizes[],
+				 struct device *alloc_devs[])
+{
+	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(q);
+	unsigned int size = csi->v_fmt.fmt.pix.sizeimage;
+
+	if (*nplanes) {
+		if (sizes[0] < size)
+			return -EINVAL;
+		size = sizes[0];
+	}
+
+	*nplanes = 1;
+	sizes[0] = size;
+
+	return 0;
+}
+
+static int ti_csi2rx_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long size = csi->v_fmt.fmt.pix.sizeimage;
+
+	if (vb2_plane_size(vb, 0) < size) {
+		dev_err(csi->dev, "Data will not fit into plane\n");
+		return -EINVAL;
+	}
+
+	vb2_set_plane_payload(vb, 0, size);
+	return 0;
+}
+
+static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
+{
+	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vb->vb2_queue);
+	struct ti_csi2rx_buffer *buf;
+	struct ti_csi2rx_dma *dma = &csi->dma;
+	bool restart_dma = false;
+	unsigned long flags = 0;
+	int ret;
+
+	buf = container_of(vb, struct ti_csi2rx_buffer, vb.vb2_buf);
+	buf->csi = csi;
+
+	spin_lock_irqsave(&dma->lock, flags);
+	/*
+	 * Usually the DMA callback takes care of queueing the pending buffers.
+	 * But if DMA has stalled due to lack of buffers, restart it now.
+	 */
+	if (dma->state == TI_CSI2RX_DMA_IDLE) {
+		/*
+		 * Do not restart DMA with the lock held because
+		 * ti_csi2rx_drain_dma() might block when allocating a buffer.
+		 * There won't be a race on queueing DMA anyway since the
+		 * callback is not being fired.
+		 */
+		restart_dma = true;
+		dma->state = TI_CSI2RX_DMA_ACTIVE;
+	} else {
+		list_add_tail(&buf->list, &dma->queue);
+	}
+	spin_unlock_irqrestore(&dma->lock, flags);
+
+	if (restart_dma) {
+		/*
+		 * Once frames start dropping, some data gets stuck in the DMA
+		 * pipeline somewhere. So the first DMA transfer after frame
+		 * drops gives a partial frame. This is obviously not useful to
+		 * the application and will only confuse it. Issue a DMA
+		 * transaction to drain that up.
+		 */
+		ret = ti_csi2rx_drain_dma(csi);
+		if (ret)
+			dev_warn(csi->dev,
+				 "Failed to drain DMA. Next frame might be bogus\n");
+
+		ret = ti_csi2rx_start_dma(csi, buf);
+		if (ret) {
+			dev_err(csi->dev, "Failed to start DMA: %d\n", ret);
+			spin_lock_irqsave(&dma->lock, flags);
+			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+			dma->state = TI_CSI2RX_DMA_IDLE;
+			spin_unlock_irqrestore(&dma->lock, flags);
+		} else {
+			spin_lock_irqsave(&dma->lock, flags);
+			list_add_tail(&buf->list, &dma->submitted);
+			spin_unlock_irqrestore(&dma->lock, flags);
+		}
+	}
+}
+
+static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vq);
+	struct ti_csi2rx_dma *dma = &csi->dma;
+	struct ti_csi2rx_buffer *buf;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&dma->lock, flags);
+	if (list_empty(&dma->queue))
+		ret = -EIO;
+	spin_unlock_irqrestore(&dma->lock, flags);
+	if (ret)
+		return ret;
+
+	ret = video_device_pipeline_start(&csi->vdev, &csi->pipe);
+	if (ret)
+		goto err;
+
+	ti_csi2rx_setup_shim(csi);
+
+	csi->sequence = 0;
+
+	spin_lock_irqsave(&dma->lock, flags);
+	buf = list_entry(dma->queue.next, struct ti_csi2rx_buffer, list);
+
+	ret = ti_csi2rx_start_dma(csi, buf);
+	if (ret) {
+		dev_err(csi->dev, "Failed to start DMA: %d\n", ret);
+		spin_unlock_irqrestore(&dma->lock, flags);
+		goto err_pipeline;
+	}
+
+	list_move_tail(&buf->list, &dma->submitted);
+	dma->state = TI_CSI2RX_DMA_ACTIVE;
+	spin_unlock_irqrestore(&dma->lock, flags);
+
+	ret = v4l2_subdev_call(csi->subdev, video, s_stream, 1);
+	if (ret)
+		goto err_dma;
+
+	return 0;
+
+err_dma:
+	dmaengine_terminate_sync(csi->dma.chan);
+	writel(0, csi->shim + SHIM_DMACNTX);
+err_pipeline:
+	video_device_pipeline_stop(&csi->vdev);
+err:
+	ti_csi2rx_cleanup_buffers(csi, VB2_BUF_STATE_QUEUED);
+	return ret;
+}
+
+static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
+{
+	struct ti_csi2rx_dev *csi = vb2_get_drv_priv(vq);
+	int ret;
+
+	video_device_pipeline_stop(&csi->vdev);
+
+	writel(0, csi->shim + SHIM_CNTL);
+	writel(0, csi->shim + SHIM_DMACNTX);
+
+	ret = v4l2_subdev_call(csi->subdev, video, s_stream, 0);
+	if (ret)
+		dev_err(csi->dev, "Failed to stop subdev stream\n");
+
+	ti_csi2rx_cleanup_buffers(csi, VB2_BUF_STATE_ERROR);
+}
+
+static const struct vb2_ops csi_vb2_qops = {
+	.queue_setup = ti_csi2rx_queue_setup,
+	.buf_prepare = ti_csi2rx_buffer_prepare,
+	.buf_queue = ti_csi2rx_buffer_queue,
+	.start_streaming = ti_csi2rx_start_streaming,
+	.stop_streaming = ti_csi2rx_stop_streaming,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+};
+
+static int ti_csi2rx_init_vb2q(struct ti_csi2rx_dev *csi)
+{
+	struct vb2_queue *q = &csi->vidq;
+	int ret;
+
+	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	q->io_modes = VB2_MMAP | VB2_DMABUF;
+	q->drv_priv = csi;
+	q->buf_struct_size = sizeof(struct ti_csi2rx_buffer);
+	q->ops = &csi_vb2_qops;
+	q->mem_ops = &vb2_dma_contig_memops;
+	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	q->dev = dmaengine_get_dma_device(csi->dma.chan);
+	q->lock = &csi->mutex;
+	q->min_buffers_needed = 1;
+
+	ret = vb2_queue_init(q);
+	if (ret)
+		return ret;
+
+	csi->vdev.queue = q;
+
+	return 0;
+}
+
+static int ti_csi2rx_link_validate(struct media_link *link)
+{
+	struct media_entity *entity = link->sink->entity;
+	struct video_device *vdev = media_entity_to_video_device(entity);
+	struct ti_csi2rx_dev *csi = container_of(vdev, struct ti_csi2rx_dev, vdev);
+	struct v4l2_pix_format *csi_fmt = &csi->v_fmt.fmt.pix;
+	struct v4l2_subdev_format source_fmt = {};
+	const struct ti_csi2rx_fmt *ti_fmt;
+	int ret;
+
+	ret = v4l2_subdev_link_validate_get_format(link->source, 0,
+						   &source_fmt, false);
+	if (ret)
+		return ret;
+
+	if (source_fmt.format.width != csi_fmt->width) {
+		dev_dbg(csi->dev, "Width does not match (source %u, sink %u)\n",
+			source_fmt.format.width, csi_fmt->width);
+		return -EPIPE;
+	}
+
+	if (source_fmt.format.height != csi_fmt->height) {
+		dev_dbg(csi->dev, "Height does not match (source %u, sink %u)\n",
+			source_fmt.format.height, csi_fmt->height);
+		return -EPIPE;
+	}
+
+	if (source_fmt.format.field != csi_fmt->field &&
+	    csi_fmt->field != V4L2_FIELD_NONE) {
+		dev_dbg(csi->dev, "Field does not match (source %u, sink %u)\n",
+			source_fmt.format.field, csi_fmt->field);
+		return -EPIPE;
+	}
+
+	ti_fmt = find_format_by_code(source_fmt.format.code);
+	if (!ti_fmt) {
+		dev_dbg(csi->dev, "Media bus format 0x%x not supported\n",
+			source_fmt.format.code);
+		return -EPIPE;
+	}
+
+	if (ti_fmt->fourcc != csi_fmt->pixelformat) {
+		dev_dbg(csi->dev,
+			"Cannot transform source fmt 0x%x to sink fmt 0x%x\n",
+			ti_fmt->fourcc, csi_fmt->pixelformat);
+		return -EPIPE;
+	}
+
+	return 0;
+}
+
+static const struct media_entity_operations ti_csi2rx_video_entity_ops = {
+	.link_validate = ti_csi2rx_link_validate,
+};
+
+static int ti_csi2rx_init_dma(struct ti_csi2rx_dev *csi)
+{
+	struct dma_slave_config cfg = {
+		.src_addr_width = DMA_SLAVE_BUSWIDTH_16_BYTES,
+	};
+	int ret;
+
+	INIT_LIST_HEAD(&csi->dma.queue);
+	INIT_LIST_HEAD(&csi->dma.submitted);
+	spin_lock_init(&csi->dma.lock);
+
+	csi->dma.state = TI_CSI2RX_DMA_STOPPED;
+
+	csi->dma.chan = dma_request_chan(csi->dev, "rx0");
+	if (IS_ERR(csi->dma.chan))
+		return PTR_ERR(csi->dma.chan);
+
+	ret = dmaengine_slave_config(csi->dma.chan, &cfg);
+	if (ret) {
+		dma_release_channel(csi->dma.chan);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ti_csi2rx_v4l2_init(struct ti_csi2rx_dev *csi)
+{
+	struct media_device *mdev = &csi->mdev;
+	struct video_device *vdev = &csi->vdev;
+	const struct ti_csi2rx_fmt *fmt;
+	struct v4l2_pix_format *pix_fmt = &csi->v_fmt.fmt.pix;
+	int ret;
+
+	fmt = find_format_by_pix(V4L2_PIX_FMT_UYVY);
+	if (!fmt)
+		return -EINVAL;
+
+	pix_fmt->width = 640;
+	pix_fmt->height = 480;
+	pix_fmt->field = V4L2_FIELD_NONE;
+
+	ti_csi2rx_fill_fmt(fmt, &csi->v_fmt);
+
+	mdev->dev = csi->dev;
+	mdev->hw_revision = 1;
+	strscpy(mdev->model, "TI-CSI2RX", sizeof(mdev->model));
+
+	media_device_init(mdev);
+
+	strscpy(vdev->name, TI_CSI2RX_MODULE_NAME, sizeof(vdev->name));
+	vdev->v4l2_dev = &csi->v4l2_dev;
+	vdev->vfl_dir = VFL_DIR_RX;
+	vdev->fops = &csi_fops;
+	vdev->ioctl_ops = &csi_ioctl_ops;
+	vdev->release = video_device_release_empty;
+	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
+			    V4L2_CAP_IO_MC;
+	vdev->lock = &csi->mutex;
+	video_set_drvdata(vdev, csi);
+
+	csi->pad.flags = MEDIA_PAD_FL_SINK;
+	vdev->entity.ops = &ti_csi2rx_video_entity_ops;
+	ret = media_entity_pads_init(&csi->vdev.entity, 1, &csi->pad);
+	if (ret)
+		return ret;
+
+	csi->v4l2_dev.mdev = mdev;
+
+	ret = v4l2_device_register(csi->dev, &csi->v4l2_dev);
+	if (ret)
+		return ret;
+
+	ret = media_device_register(mdev);
+	if (ret) {
+		v4l2_device_unregister(&csi->v4l2_dev);
+		media_device_cleanup(mdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void ti_csi2rx_cleanup_dma(struct ti_csi2rx_dev *csi)
+{
+	dma_release_channel(csi->dma.chan);
+}
+
+static void ti_csi2rx_cleanup_v4l2(struct ti_csi2rx_dev *csi)
+{
+	media_device_unregister(&csi->mdev);
+	v4l2_device_unregister(&csi->v4l2_dev);
+	media_device_cleanup(&csi->mdev);
+}
+
+static void ti_csi2rx_cleanup_subdev(struct ti_csi2rx_dev *csi)
+{
+	v4l2_async_nf_unregister(&csi->notifier);
+	v4l2_async_nf_cleanup(&csi->notifier);
+}
+
+static void ti_csi2rx_cleanup_vb2q(struct ti_csi2rx_dev *csi)
+{
+	vb2_queue_release(&csi->vidq);
+}
+
+static int ti_csi2rx_probe(struct platform_device *pdev)
+{
+	struct ti_csi2rx_dev *csi;
+	struct resource *res;
+	int ret;
+
+	csi = devm_kzalloc(&pdev->dev, sizeof(*csi), GFP_KERNEL);
+	if (!csi)
+		return -ENOMEM;
+
+	csi->dev = &pdev->dev;
+	platform_set_drvdata(pdev, csi);
+
+	mutex_init(&csi->mutex);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	csi->shim = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(csi->shim)) {
+		ret = PTR_ERR(csi->shim);
+		goto err_mutex;
+	}
+
+	ret = ti_csi2rx_init_dma(csi);
+	if (ret)
+		goto err_mutex;
+
+	ret = ti_csi2rx_v4l2_init(csi);
+	if (ret)
+		goto err_dma;
+
+	ret = ti_csi2rx_init_vb2q(csi);
+	if (ret)
+		goto err_v4l2;
+
+	ret = ti_csi2rx_init_subdev(csi);
+	if (ret)
+		goto err_vb2q;
+
+	ret = of_platform_populate(csi->dev->of_node, NULL, NULL, csi->dev);
+	if (ret) {
+		dev_err(csi->dev, "Failed to create children: %d\n", ret);
+		goto err_subdev;
+	}
+
+	return 0;
+
+err_subdev:
+	ti_csi2rx_cleanup_subdev(csi);
+err_vb2q:
+	ti_csi2rx_cleanup_vb2q(csi);
+err_v4l2:
+	ti_csi2rx_cleanup_v4l2(csi);
+err_dma:
+	ti_csi2rx_cleanup_dma(csi);
+err_mutex:
+	mutex_destroy(&csi->mutex);
+	return ret;
+}
+
+static int ti_csi2rx_remove(struct platform_device *pdev)
+{
+	struct ti_csi2rx_dev *csi = platform_get_drvdata(pdev);
+
+	video_unregister_device(&csi->vdev);
+
+	ti_csi2rx_cleanup_vb2q(csi);
+	ti_csi2rx_cleanup_subdev(csi);
+	ti_csi2rx_cleanup_v4l2(csi);
+	ti_csi2rx_cleanup_dma(csi);
+
+	mutex_destroy(&csi->mutex);
+
+	return 0;
+}
+
+static const struct of_device_id ti_csi2rx_of_match[] = {
+	{ .compatible = "ti,j721e-csi2rx-shim", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ti_csi2rx_of_match);
+
+static struct platform_driver ti_csi2rx_pdrv = {
+	.probe = ti_csi2rx_probe,
+	.remove = ti_csi2rx_remove,
+	.driver = {
+		.name = TI_CSI2RX_MODULE_NAME,
+		.of_match_table = ti_csi2rx_of_match,
+	},
+};
+
+module_platform_driver(ti_csi2rx_pdrv);
+
+MODULE_DESCRIPTION("TI J721E CSI2 RX Driver");
+MODULE_AUTHOR("Pratyush Yadav <p.yadav@ti.com>");
+MODULE_LICENSE("GPL");