Patchwork MEM2MEM: Add support for eMMa-PrP mem2mem operations.

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Submitter Javier Martin
Date Nov. 16, 2011, 4:23 p.m.
Message ID <1321460614-2108-1-git-send-email-javier.martin@vista-silicon.com>
Download mbox | patch
Permalink /patch/126004/
State New
Headers show

Comments

Javier Martin - Nov. 16, 2011, 4:23 p.m.
i.MX2x SoCs have a PrP which is capable of resizing and format
conversion of video frames. This driver provides support for
resizing and format conversion from YUYV to YUV420.

This operation is of the utmost importance since some of these
SoCs like i.MX27 include an H.264 video codec which only
accepts YUV420 as input.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
---
 arch/arm/mach-imx/devices-imx27.h               |    2 +
 arch/arm/plat-mxc/devices/platform-mx2-camera.c |   33 +
 arch/arm/plat-mxc/include/mach/devices-common.h |    2 +
 drivers/media/video/Kconfig                     |   11 +
 drivers/media/video/Makefile                    |    2 +
 drivers/media/video/mx2_emmaprp.c               | 1059 +++++++++++++++++++++++
 6 files changed, 1109 insertions(+), 0 deletions(-)
 create mode 100644 drivers/media/video/mx2_emmaprp.c
Sylwester Nawrocki - Nov. 18, 2011, 4:07 p.m.
Hi Javier,

Good to see non Samsung device using v4l2 mem-to-mem framework. What is your
experience, have you encountered any specific problems with it ?

And just out of curiosity, are you planning to develop video codec driver 
in v4l2 for i.MX27 as well ?

I have a few comments, please see below...

On 11/16/2011 05:23 PM, Javier Martin wrote:
> i.MX2x SoCs have a PrP which is capable of resizing and format
> conversion of video frames. This driver provides support for
> resizing and format conversion from YUYV to YUV420.
> 
> This operation is of the utmost importance since some of these
> SoCs like i.MX27 include an H.264 video codec which only
> accepts YUV420 as input.
> 
> Signed-off-by: Javier Martin<javier.martin@vista-silicon.com>
> ---
>   arch/arm/mach-imx/devices-imx27.h               |    2 +
>   arch/arm/plat-mxc/devices/platform-mx2-camera.c |   33 +
>   arch/arm/plat-mxc/include/mach/devices-common.h |    2 +
>   drivers/media/video/Kconfig                     |   11 +
>   drivers/media/video/Makefile                    |    2 +
>   drivers/media/video/mx2_emmaprp.c               | 1059 +++++++++++++++++++++++
>   6 files changed, 1109 insertions(+), 0 deletions(-)
>   create mode 100644 drivers/media/video/mx2_emmaprp.c
> 
> diff --git a/arch/arm/mach-imx/devices-imx27.h b/arch/arm/mach-imx/devices-imx27.h
> index 2f727d7..519aa36 100644
> --- a/arch/arm/mach-imx/devices-imx27.h
> +++ b/arch/arm/mach-imx/devices-imx27.h
> @@ -50,6 +50,8 @@ extern const struct imx_imx_uart_1irq_data imx27_imx_uart_data[];
>   extern const struct imx_mx2_camera_data imx27_mx2_camera_data;
>   #define imx27_add_mx2_camera(pdata)	\
>   	imx_add_mx2_camera(&imx27_mx2_camera_data, pdata)
> +#define imx27_alloc_mx2_emmaprp(pdata)	\
> +	imx_alloc_mx2_emmaprp(&imx27_mx2_camera_data)
> 
>   extern const struct imx_mxc_ehci_data imx27_mxc_ehci_otg_data;
>   #define imx27_add_mxc_ehci_otg(pdata)	\
> diff --git a/arch/arm/plat-mxc/devices/platform-mx2-camera.c b/arch/arm/plat-mxc/devices/platform-mx2-camera.c
> index b3f4828..4a8bd73 100644
> --- a/arch/arm/plat-mxc/devices/platform-mx2-camera.c
> +++ b/arch/arm/plat-mxc/devices/platform-mx2-camera.c
> @@ -6,6 +6,7 @@
>    * the terms of the GNU General Public License version 2 as published by the
>    * Free Software Foundation.
>    */
> +#include<linux/dma-mapping.h>
>   #include<mach/hardware.h>
>   #include<mach/devices-common.h>
> 
> @@ -62,3 +63,35 @@ struct platform_device *__init imx_add_mx2_camera(
>   			res, data->iobaseemmaprp ? 4 : 2,
>   			pdata, sizeof(*pdata), DMA_BIT_MASK(32));
>   }
> +
> +struct platform_device *__init imx_alloc_mx2_emmaprp(
> +		const struct imx_mx2_camera_data *data)
> +{
> +	struct resource res[] = {
> +		{
> +			.start = data->iobaseemmaprp,
> +			.end = data->iobaseemmaprp + data->iosizeemmaprp - 1,
> +			.flags = IORESOURCE_MEM,
> +		}, {
> +			.start = data->irqemmaprp,
> +			.end = data->irqemmaprp,
> +			.flags = IORESOURCE_IRQ,
> +		},
> +	};
> +	struct platform_device *pdev;
> +	int ret = -ENOMEM;
> +
> +	pdev = platform_device_alloc("m2m-emmaprp", 0);
> +	if (!pdev)
> +		goto err;
> +
> +	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
> +	if (ret)
> +		goto err;
> +
> +	return pdev;
> +err:
> +	platform_device_put(pdev);
> +	return ERR_PTR(-ENODEV);
> +
> +}
> diff --git a/arch/arm/plat-mxc/include/mach/devices-common.h b/arch/arm/plat-mxc/include/mach/devices-common.h
> index def9ba5..ce64bd5 100644
> --- a/arch/arm/plat-mxc/include/mach/devices-common.h
> +++ b/arch/arm/plat-mxc/include/mach/devices-common.h
> @@ -223,6 +223,8 @@ struct imx_mx2_camera_data {
>   struct platform_device *__init imx_add_mx2_camera(
>   		const struct imx_mx2_camera_data *data,
>   		const struct mx2_camera_platform_data *pdata);
> +struct platform_device *__init imx_alloc_mx2_emmaprp(
> +		const struct imx_mx2_camera_data *data);
> 
>   #include<mach/mxc_ehci.h>
>   struct imx_mxc_ehci_data {
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index b303a3f..6e57825 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -1107,4 +1107,15 @@ config VIDEO_SAMSUNG_S5P_MFC
>   	help
>   	    MFC 5.1 driver for V4L2.
> 
> +config VIDEO_MX2_EMMAPRP
> +	tristate "MX2 eMMa-PrP support"
> +	depends on VIDEO_DEV&&  VIDEO_V4L2&&  MACH_MX27
> +	select VIDEOBUF2_DMA_CONTIG
> +	select V4L2_MEM2MEM_DEV
> +	default n

The default is 'n' so this line is redundant.

> +	help
> +	    MX2X chips have a PrP that can be used to process buffers from
> +	    memory to memory. Operations include resizing and format
> +	    conversion.
> +
>   endif # V4L_MEM2MEM_DRIVERS
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index 117f9c4..7ae711e 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -176,6 +176,8 @@ obj-$(CONFIG_VIDEO_SH_MOBILE_CEU)	+= sh_mobile_ceu_camera.o
>   obj-$(CONFIG_VIDEO_OMAP1)		+= omap1_camera.o
>   obj-$(CONFIG_VIDEO_ATMEL_ISI)		+= atmel-isi.o
> 
> +obj-$(CONFIG_VIDEO_MX2_EMMAPRP)		+= mx2_emmaprp.o
> +
>   obj-$(CONFIG_VIDEO_SAMSUNG_S5P_FIMC) 	+= s5p-fimc/
>   obj-$(CONFIG_VIDEO_SAMSUNG_S5P_MFC)	+= s5p-mfc/
>   obj-$(CONFIG_VIDEO_SAMSUNG_S5P_TV)	+= s5p-tv/
> diff --git a/drivers/media/video/mx2_emmaprp.c b/drivers/media/video/mx2_emmaprp.c
> new file mode 100644
> index 0000000..ad65e90
> --- /dev/null
> +++ b/drivers/media/video/mx2_emmaprp.c
> @@ -0,0 +1,1059 @@
> +/*
> + * Support eMMa-PrP through mem2mem framework.
> + *
> + * eMMa-PrP is a piece of HW that allows fetching buffers
> + * from one memory location and do several operations on
> + * them such as scaling or format conversion giving, as a result
> + * a new processed buffer in another memory location.
> + *
> + * Based on mem2mem_testdev.c by Pawel Osciak.
> + *
> + * Copyright (c) 2011 Vista Silicon S.L.
> + * Javier Martin<javier.martin@vista-silicon.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the
> + * License, or (at your option) any later version
> + */
> +#include<linux/module.h>
> +#include<linux/clk.h>
> +#include<linux/slab.h>
> +#include<linux/interrupt.h>
> +
> +#include<linux/platform_device.h>
> +#include<media/v4l2-mem2mem.h>
> +#include<media/v4l2-device.h>
> +#include<media/v4l2-ioctl.h>
> +#include<media/videobuf2-dma-contig.h>
> +
> +#define MEM2MEM_TEST_MODULE_NAME "mem2mem-emmaprp"

Don't you want to use a name more specific to your device ?..

> +
> +MODULE_DESCRIPTION("mem2mem device which supports eMMa-PrP present in mx2 SoCs");
> +MODULE_AUTHOR("Javier Martin<javier.martin@vista-silicon.com");
> +MODULE_LICENSE("GPL");
> +MODULE_VERSION("0.0.1");
> +
> +static bool debug = true;
> +module_param(debug, bool, 0644);
> +
> +#define MIN_W 32
> +#define MIN_H 32
> +#define MAX_W 2040
> +#define MAX_H 2046
> +
> +#define W_ALIGN_MASK_YUV420	0x07 /* multiple of 8 */
> +#define W_ALIGN_MASK_OTHERS	0x03 /* multiple of 4 */
> +#define H_ALIGN_MASK		0x01 /* multiple of 2 */
> +
> +/* Flags that indicate a format can be used for capture/output */
> +#define MEM2MEM_CAPTURE	(1<<  0)
> +#define MEM2MEM_OUTPUT	(1<<  1)
> +
> +#define MEM2MEM_NAME		"m2m-emmaprp"
> +
> +/* In bytes, per queue */
> +#define MEM2MEM_VID_MEM_LIMIT	(16 * 1024 * 1024)

SZ_1M could also be used here, but you may as well don't like it;)

> +
> +#define dprintk(dev, fmt, arg...) \
> +	v4l2_dbg(1, debug,&dev->v4l2_dev, "%s: " fmt, __func__, ## arg)
> +
> +/* EMMA PrP */
> +#define PRP_CNTL                        0x00
...
> +#define PRP_INTR_ST_CH2OVF	(1<<  8)
> +
> +struct emmaprp_fmt {
> +	char	*name;
> +	u32	fourcc;
> +	/* Types the format can be used for */
> +	u32	types;
> +};
> +
> +static struct emmaprp_fmt formats[] = {
> +	{
> +		.name	= "YUV 4:2:0 Planar",
> +		.fourcc	= V4L2_PIX_FMT_YUV420,
> +		.types	= MEM2MEM_CAPTURE,
> +	},
> +	{
> +		.name	= "4:2:2, packed, YUYV",
> +		.fourcc	= V4L2_PIX_FMT_YUYV,
> +		.types	= MEM2MEM_OUTPUT,
> +	},
> +};
> +
> +/* Per-queue, driver-specific private data */
> +struct emmaprp_q_data {
> +	unsigned int		width;
> +	unsigned int		height;
> +	unsigned int		sizeimage;
> +	struct emmaprp_fmt	*fmt;
> +};
> +
> +enum {
> +	V4L2_M2M_SRC = 0,
> +	V4L2_M2M_DST = 1,
> +};
> +
> +/* Source and destination queue data */
> +static struct emmaprp_q_data q_data[2];

Isn't it possible to embed this data into struct emmaprp_ctx ?
struct emmaprp_ctx object is available anywhere where get_q_data() is used.

And that would have to be changed anyway in case there are multiple instances
of a device this driver binds to.

> +
> +static struct emmaprp_q_data *get_q_data(enum v4l2_buf_type type)
> +{
> +	switch (type) {
> +	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
> +		return&q_data[V4L2_M2M_SRC];
> +	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
> +		return&q_data[V4L2_M2M_DST];
> +	default:
> +		BUG();
> +	}
> +	return NULL;
> +}
> +
> +#define NUM_FORMATS ARRAY_SIZE(formats)
> +
> +static struct emmaprp_fmt *find_format(struct v4l2_format *f)
> +{
> +	struct emmaprp_fmt *fmt;
> +	unsigned int k;
> +
> +	for (k = 0; k<  NUM_FORMATS; k++) {
> +		fmt =&formats[k];
> +		if (fmt->fourcc == f->fmt.pix.pixelformat)
> +			break;
> +	}
> +
> +	if (k == NUM_FORMATS)
> +		return NULL;
> +
> +	return&formats[k];
> +}
> +
> +struct emmaprp_dev {
> +	struct v4l2_device	v4l2_dev;
> +	struct video_device	*vfd;
> +
> +	atomic_t		busy;
> +	struct mutex		dev_mutex;
> +	spinlock_t		irqlock;
> +
> +	int			irq_emma;
> +	void __iomem		*base_emma;
> +	struct clk		*clk_emma;
> +	struct resource		*res_emma;
> +
> +	struct v4l2_m2m_dev	*m2m_dev;
> +	struct vb2_alloc_ctx	*alloc_ctx;
> +};
> +
> +struct emmaprp_ctx {
> +	struct emmaprp_dev	*dev;
> +
> +	/* Abort requested by m2m */
> +	int			aborting;
> +
> +	struct v4l2_m2m_ctx	*m2m_ctx;
> +};
> +
> +/*
> + * mem2mem callbacks
> + */
> +static int emmaprp_job_ready(void *priv)
> +{
> +	struct emmaprp_ctx *ctx = priv;
> +	struct emmaprp_dev *pcdev = ctx->dev;
> +
> +	if ((v4l2_m2m_num_src_bufs_ready(ctx->m2m_ctx)>  0)
> +	&&  (v4l2_m2m_num_dst_bufs_ready(ctx->m2m_ctx)>  0)
> +	&&  (atomic_read(&pcdev->busy) == 0))
> +		return 1;
> +
> +	dprintk(pcdev, "Task not ready to run\n");
> +
> +	return 0;
> +}

It looks like only one buffer on each queue is needed for single device_run(),
i.e. you H/W doesn't need more than 2 buffers for processing. In this case
job_ready callback may be left unimplemented and you can remove the 'busy' variable
altogether. 


Here is description of the job_ready callback, from include/media/v4l2-mem2mem.h:

 * @job_ready:	optional. Should return 0 if the driver does not have a job
 *		fully prepared to run yet (i.e. it will not be able to finish a
 *		transaction without sleeping). If not provided, it will be
 *		assumed that one source and one destination buffer are all
 *		that is required for the driver to perform one full transaction.
 *		This method may not sleep.

> +
> +static void emmaprp_job_abort(void *priv)
> +{
> +	struct emmaprp_ctx *ctx = priv;
> +	struct emmaprp_dev *pcdev = ctx->dev;
> +
> +	ctx->aborting = 1;
> +
> +	dprintk(pcdev, "Aborting task\n");
> +
> +	v4l2_m2m_job_finish(pcdev->m2m_dev, ctx->m2m_ctx);
> +}
> +
> +static void emmaprp_lock(void *priv)
> +{
> +	struct emmaprp_ctx *ctx = priv;
> +	struct emmaprp_dev *pcdev = ctx->dev;
> +	mutex_lock(&pcdev->dev_mutex);
> +}
> +
> +static void emmaprp_unlock(void *priv)
> +{
> +	struct emmaprp_ctx *ctx = priv;
> +	struct emmaprp_dev *pcdev = ctx->dev;
> +	mutex_unlock(&pcdev->dev_mutex);
> +}
> +
> +static inline void emmaprp_dump_regs(struct emmaprp_dev *pcdev)
> +{
> +	dprintk(pcdev,
> +		"eMMa-PrP Registers:\n"
> +		"  SOURCE_Y_PTR = 0x%08X\n"
> +		"  SRC_FRAME_SIZE = 0x%08X\n"
> +		"  DEST_Y_PTR = 0x%08X\n"
> +		"  DEST_CR_PTR = 0x%08X\n"
> +		"  DEST_CB_PTR = 0x%08X\n"
> +		"  CH2_OUT_IMAGE_SIZE = 0x%08X\n"
> +		"  CNTL = 0x%08X\n",
> +		readl(pcdev->base_emma + PRP_SOURCE_Y_PTR),
> +		readl(pcdev->base_emma + PRP_SRC_FRAME_SIZE),
> +		readl(pcdev->base_emma + PRP_DEST_Y_PTR),
> +		readl(pcdev->base_emma + PRP_DEST_CR_PTR),
> +		readl(pcdev->base_emma + PRP_DEST_CB_PTR),
> +		readl(pcdev->base_emma + PRP_CH2_OUT_IMAGE_SIZE),
> +		readl(pcdev->base_emma + PRP_CNTL));
> +}
> +
> +static void emmaprp_device_run(void *priv)
> +{
> +	struct emmaprp_ctx *ctx = priv;
> +	struct emmaprp_q_data *s_q_data, *d_q_data;
> +	struct vb2_buffer *src_buf, *dst_buf;
> +	struct emmaprp_dev *pcdev = ctx->dev;
> +	unsigned int s_width, s_height;
> +	unsigned int d_width, d_height;
> +	unsigned int d_size;
> +	u8 *p_in, *p_out;

How about using dma_addr_t instead of (u8 *) ?

> +	u32 tmp;
> +
> +	atomic_set(&ctx->dev->busy, 1);
> +
> +	src_buf = v4l2_m2m_next_src_buf(ctx->m2m_ctx);
> +	dst_buf = v4l2_m2m_next_dst_buf(ctx->m2m_ctx);
> +
> +	s_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_OUTPUT);
> +	s_width	= s_q_data->width;
> +	s_height = s_q_data->height;
> +
> +	d_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +	d_width = d_q_data->width;
> +	d_height = d_q_data->height;
> +	d_size = d_width * d_height;
> +
> +	p_in = (u8 *)vb2_dma_contig_plane_dma_addr(src_buf, 0);
> +	p_out = (u8 *)vb2_dma_contig_plane_dma_addr(dst_buf, 0);
> +	if (!p_in || !p_out) {
> +		v4l2_err(&pcdev->v4l2_dev,
> +			 "Acquiring kernel pointers to buffers failed\n");
> +		return;
> +	}
> +
> +	/* Input frame parameters */
> +	writel(p_in, pcdev->base_emma + PRP_SOURCE_Y_PTR);
> +	writel(PRP_SIZE_WIDTH(s_width) | PRP_SIZE_HEIGHT(s_height),
> +	       pcdev->base_emma + PRP_SRC_FRAME_SIZE);
> +
> +	/* Output frame parameters */
> +	writel(p_out, pcdev->base_emma + PRP_DEST_Y_PTR);
> +	writel(p_out + d_size, pcdev->base_emma + PRP_DEST_CB_PTR);
> +	writel(p_out + d_size + (d_size>>  2),
> +	       pcdev->base_emma + PRP_DEST_CR_PTR);
> +	writel(PRP_SIZE_WIDTH(d_width) | PRP_SIZE_HEIGHT(d_height),
> +	       pcdev->base_emma + PRP_CH2_OUT_IMAGE_SIZE);
> +
> +	/* IRQ configuration */
> +	tmp = readl(pcdev->base_emma + PRP_INTR_CNTL);
> +	writel(tmp | PRP_INTR_RDERR |
> +		PRP_INTR_CH2WERR |
> +		PRP_INTR_CH2FC,
> +		pcdev->base_emma + PRP_INTR_CNTL);
> +
> +	emmaprp_dump_regs(pcdev);
> +
> +	/* Enable transfer */
> +	tmp = readl(pcdev->base_emma + PRP_CNTL);
> +	writel(tmp | PRP_CNTL_CH2_OUT_YUV420 |
> +		PRP_CNTL_DATA_IN_YUV422 |
> +		PRP_CNTL_CH2EN,
> +		pcdev->base_emma + PRP_CNTL);
> +}
> +
> +static irqreturn_t emmaprp_irq(int irq_emma, void *data)
> +{
> +	struct emmaprp_dev *pcdev = (struct emmaprp_dev *)data;

No need for casting.

> +	struct emmaprp_ctx *curr_ctx;
> +	struct vb2_buffer *src_vb, *dst_vb;
> +	unsigned long flags;
> +	u32 irqst;
> +
> +	/* Check irq flags and clear irq */
> +	irqst = readl(pcdev->base_emma + PRP_INTRSTATUS);
> +	writel(irqst, pcdev->base_emma + PRP_INTRSTATUS);
> +	dprintk(pcdev, "irqst = 0x%08x\n", irqst);
> +
> +	curr_ctx = v4l2_m2m_get_curr_priv(pcdev->m2m_dev);
> +	if (NULL == curr_ctx) {
> +		printk(KERN_ERR
> +			"Instance released before the end of transaction\n");

In new drivers, instead if printk(<LEVEL>.. pr_<level>(.. is preferred, i.e.
in this case pr_err(). 

> +		return IRQ_HANDLED;
> +	}
> +
> +	if (curr_ctx->aborting)
> +		goto irq_ok;
> +
> +	if ((irqst&  PRP_INTR_ST_RDERR) ||
> +	    (irqst&  PRP_INTR_ST_CH2WERR)) {
> +		printk(KERN_ERR
> +			"PrP bus error ocurred, this transfer is probably corrupted\n");

Ditto.

> +		writel(PRP_CNTL_SWRST, pcdev->base_emma + PRP_CNTL);
> +		goto irq_ok;
> +	}
> +
> +	if (irqst&  PRP_INTR_ST_CH2B1CI) { /* buffer ready */
> +		src_vb = v4l2_m2m_src_buf_remove(curr_ctx->m2m_ctx);
> +		dst_vb = v4l2_m2m_dst_buf_remove(curr_ctx->m2m_ctx);
> +
> +		spin_lock_irqsave(&pcdev->irqlock, flags);
> +		v4l2_m2m_buf_done(src_vb, VB2_BUF_STATE_DONE);
> +		v4l2_m2m_buf_done(dst_vb, VB2_BUF_STATE_DONE);
> +		spin_unlock_irqrestore(&pcdev->irqlock, flags);
> +		goto irq_ok;
> +	}
> +
> +irq_ok:
> +	atomic_set(&pcdev->busy, 0);
> +	v4l2_m2m_job_finish(pcdev->m2m_dev, curr_ctx->m2m_ctx);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/*
> + * video ioctls
> + */
...
> +
> +static int vidioc_try_fmt(struct v4l2_format *f, struct emmaprp_fmt *fmt)

fmt is unused in this function, perhaps this argument can be removed.

> +{
> +	enum v4l2_field field;
> +
> +	field = f->fmt.pix.field;
> +
> +	if (field == V4L2_FIELD_ANY)
> +		field = V4L2_FIELD_NONE;
> +	else if (V4L2_FIELD_NONE != field)
> +		return -EINVAL;
> +
> +	/* V4L2 specification suggests the driver corrects the format struct
> +	 * if any of the dimensions is unsupported */
> +	f->fmt.pix.field = field;
> +
> +	if (f->fmt.pix.height<  MIN_H)
> +		f->fmt.pix.height = MIN_H;
> +	else if (f->fmt.pix.height>  MAX_H)
> +		f->fmt.pix.height = MAX_H;
> +
> +	if (f->fmt.pix.width<  MIN_W)
> +		f->fmt.pix.width = MIN_W;
> +	else if (f->fmt.pix.width>  MAX_W)
> +		f->fmt.pix.width = MAX_W;

I would go for a clamp_t here, e.g. 

	f->fmt.pix.height = clamp_t(u32, f->fmt.pix.height, MIN_H, MAX_H);
	f->fmt.pix.width = clamp_t(u32, f->fmt.pix.width, MIN_W, MAX_W);

> +
> +	f->fmt.pix.height&= ~H_ALIGN_MASK;
> +	if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_YUV420) {
> +		f->fmt.pix.width&= ~W_ALIGN_MASK_YUV420;
> +		f->fmt.pix.bytesperline = f->fmt.pix.width * 3 / 2;
> +	} else { /* YUYV */
> +		f->fmt.pix.width&= ~W_ALIGN_MASK_OTHERS;
> +		f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
> +	}
> +	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
> +
> +	return 0;
> +}
> +
> +static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
> +				  struct v4l2_format *f)
> +{
> +	struct emmaprp_fmt *fmt;
> +	struct emmaprp_ctx *ctx = priv;
> +
> +	fmt = find_format(f);
> +	if (!fmt || !(fmt->types&  MEM2MEM_CAPTURE)) {
> +		v4l2_err(&ctx->dev->v4l2_dev,
> +			 "Fourcc format (0x%08x) invalid.\n",
> +			 f->fmt.pix.pixelformat);
> +		return -EINVAL;
> +	}
> +
> +	return vidioc_try_fmt(f, fmt);
> +}
> +
> +static int vidioc_try_fmt_vid_out(struct file *file, void *priv,
> +				  struct v4l2_format *f)
> +{
> +	struct emmaprp_fmt *fmt;
> +	struct emmaprp_ctx *ctx = priv;
> +
> +	fmt = find_format(f);
> +	if (!fmt || !(fmt->types&  MEM2MEM_OUTPUT)) {
> +		v4l2_err(&ctx->dev->v4l2_dev,
> +			 "Fourcc format (0x%08x) invalid.\n",
> +			 f->fmt.pix.pixelformat);
> +		return -EINVAL;
> +	}
> +
> +	return vidioc_try_fmt(f, fmt);
> +}
> +
> +static int vidioc_s_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
> +{
> +	struct emmaprp_q_data *q_data;
> +	struct vb2_queue *vq;
> +
> +	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
> +	if (!vq)
> +		return -EINVAL;
> +
> +	q_data = get_q_data(f->type);
> +	if (!q_data)
> +		return -EINVAL;
> +
> +	if (vb2_is_busy(vq)) {
> +		v4l2_err(&ctx->dev->v4l2_dev, "%s queue busy\n", __func__);
> +		return -EBUSY;
> +	}

I can't see where the format is adjusted against the device capabilities, perhaps 
something like:

	ret = vidioc_try_fmt(f, ...
	if (ret < 0)
		return ret;
would do.

> +
> +	q_data->fmt		= find_format(f);
> +	q_data->width		= f->fmt.pix.width;
> +	q_data->height		= f->fmt.pix.height;
> +	if (q_data->fmt->fourcc == V4L2_PIX_FMT_YUV420)
> +		q_data->sizeimage = q_data->width * q_data->height * 3 / 2;
> +	else /* YUYV */
> +		q_data->sizeimage = q_data->width * q_data->height * 2;
> +
> +	dprintk(ctx->dev,
> +		"Setting format for type %d, wxh: %dx%d, fmt: %d\n",
> +		f->type, q_data->width, q_data->height, q_data->fmt->fourcc);
> +
> +	return 0;
> +}
> +
...
> +/*
> + * File operations
> + */
> +static int emmaprp_open(struct file *file)
> +{
> +	struct emmaprp_dev *pcdev = video_drvdata(file);
> +	struct emmaprp_ctx *ctx = NULL;

The assignment is unnecessary.

> +
> +	ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	file->private_data = ctx;
> +	ctx->dev = pcdev;
> +
> +	ctx->m2m_ctx = v4l2_m2m_ctx_init(pcdev->m2m_dev, ctx,&queue_init);
> +
> +	if (IS_ERR(ctx->m2m_ctx)) {
> +		int ret = PTR_ERR(ctx->m2m_ctx);
> +
> +		kfree(ctx);
> +		return ret;
> +	}
> +
> +	clk_enable(pcdev->clk_emma);
> +
> +	dprintk(pcdev, "Created instance %p, m2m_ctx: %p\n", ctx, ctx->m2m_ctx);
> +
> +	return 0;
> +}
> +
...
> +
> +static int emmaprp_probe(struct platform_device *pdev)
> +{
> +	struct emmaprp_dev *pcdev;
> +	struct video_device *vfd;
> +	struct resource *res_emma;
> +	int irq_emma;
> +	int ret;
> +
> +	pcdev = kzalloc(sizeof *pcdev, GFP_KERNEL);
> +	if (!pcdev)
> +		return -ENOMEM;
> +
> +	spin_lock_init(&pcdev->irqlock);
> +
> +	pcdev->clk_emma = clk_get(NULL, "emma");
> +	if (IS_ERR(pcdev->clk_emma)) {
> +		ret = PTR_ERR(pcdev->clk_emma);
> +		goto free_dev;
> +	}
> +
> +	irq_emma = platform_get_irq(pdev, 0);
> +	res_emma = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (irq_emma<  0 || res_emma == NULL) {
> +		dev_err(&pdev->dev, "Missing platform resources data\n");
> +		ret = -ENODEV;
> +		goto free_clk;
> +	}
> +
> +	ret = v4l2_device_register(&pdev->dev,&pcdev->v4l2_dev);
> +	if (ret)
> +		goto free_clk;
> +
> +	atomic_set(&pcdev->busy, 0);
> +	mutex_init(&pcdev->dev_mutex);
> +
> +	vfd = video_device_alloc();
> +	if (!vfd) {
> +		v4l2_err(&pcdev->v4l2_dev, "Failed to allocate video device\n");
> +		ret = -ENOMEM;
> +		goto unreg_dev;
> +	}
> +
> +	*vfd = emmaprp_videodev;
> +	vfd->lock =&pcdev->dev_mutex;
> +
> +	ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);

It's to early to register a video device at this point, it should be done
as the last thing, after all needed resources are prepared. Let's imagine
the corresponding /dev/video? is opened by a user process right at this point,
would that work ?

> +	if (ret) {
> +		v4l2_err(&pcdev->v4l2_dev, "Failed to register video device\n");
> +		goto rel_vdev;
> +	}
> +
> +	video_set_drvdata(vfd, pcdev);
> +	snprintf(vfd->name, sizeof(vfd->name), "%s", emmaprp_videodev.name);
> +	pcdev->vfd = vfd;
> +	v4l2_info(&pcdev->v4l2_dev, MEM2MEM_TEST_MODULE_NAME
> +			" Device registered as /dev/video%d\n", vfd->num);
> +
> +	platform_set_drvdata(pdev, pcdev);
> +
> +	if (!request_mem_region(res_emma->start, resource_size(res_emma),
> +				MEM2MEM_NAME)) {
> +		ret = -EBUSY;
> +		goto rel_vdev;
> +	}
> +
> +	pcdev->base_emma = ioremap(res_emma->start, resource_size(res_emma));
> +	if (!pcdev->base_emma) {
> +		ret = -ENOMEM;
> +		goto rel_mem;
> +	}
> +	pcdev->irq_emma = irq_emma;
> +	pcdev->res_emma = res_emma;
> +
> +	ret = request_irq(pcdev->irq_emma, emmaprp_irq, 0,
> +			  MEM2MEM_NAME, pcdev);
> +	if (ret)
> +		goto rel_map;
> +
> +
> +	pcdev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
> +	if (IS_ERR(pcdev->alloc_ctx)) {
> +		v4l2_err(&pcdev->v4l2_dev, "Failed to alloc vb2 context\n");
> +		ret = PTR_ERR(pcdev->alloc_ctx);
> +		goto err_ctx;
> +	}
> +
> +	pcdev->m2m_dev = v4l2_m2m_init(&m2m_ops);
> +	if (IS_ERR(pcdev->m2m_dev)) {
> +		v4l2_err(&pcdev->v4l2_dev, "Failed to init mem2mem device\n");
> +		ret = PTR_ERR(pcdev->m2m_dev);
> +		goto err_m2m;
> +	}
> +
> +	q_data[V4L2_M2M_SRC].fmt =&formats[1];
> +	q_data[V4L2_M2M_DST].fmt =&formats[0];
> +
> +	return 0;
> +
> +	v4l2_m2m_release(pcdev->m2m_dev);
> +err_m2m:
> +	video_unregister_device(pcdev->vfd);
> +err_ctx:
> +	vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
> +	free_irq(pcdev->irq_emma, pcdev);
> +rel_map:
> +	iounmap(pcdev->base_emma);
> +rel_mem:
> +	release_mem_region(res_emma->start, resource_size(res_emma));
> +rel_vdev:
> +	video_device_release(vfd);
> +unreg_dev:
> +	v4l2_device_unregister(&pcdev->v4l2_dev);
> +free_clk:
> +	clk_put(pcdev->clk_emma);
> +free_dev:
> +	kfree(pcdev);
> +
> +	return ret;
> +}
> +
> +static int emmaprp_remove(struct platform_device *pdev)
> +{
> +	struct resource *res_emma;
> +	struct emmaprp_dev *pcdev =
> +		(struct emmaprp_dev *)platform_get_drvdata(pdev);

No need for type casting here.

> +
> +	v4l2_info(&pcdev->v4l2_dev, "Removing " MEM2MEM_TEST_MODULE_NAME);
> +	v4l2_m2m_release(pcdev->m2m_dev);
> +	free_irq(pcdev->irq_emma, pcdev);
> +	iounmap(pcdev->base_emma);
> +	res_emma = pcdev->res_emma;
> +	release_mem_region(res_emma->start, resource_size(res_emma));
> +	video_unregister_device(pcdev->vfd);

You may want to unregister the video device as the first, before freeing
any resources associated with it.

> +	v4l2_device_unregister(&pcdev->v4l2_dev);
> +	clk_put(pcdev->clk_emma);
> +	vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
> +
> +	kfree(pcdev);
> +
> +	return 0;
> +}

--
Regards,
Sylwester
Javier Martin - Nov. 18, 2011, 4:27 p.m.
Hi Sylwester,
thank you for your review.

On 18 November 2011 17:07, Sylwester Nawrocki <snjw23@gmail.com> wrote:
> Hi Javier,
>
> Good to see non Samsung device using v4l2 mem-to-mem framework. What is your
> experience, have you encountered any specific problems with it ?

I've found the framework quite convenient and comfortable, it
definitely saves a lot of work and coding once you understand it
properly.
For a simple device as i.MX2 eMMa-PrP a driver can be in a working
state in a couple of days. I've not found any drawbacks.

> And just out of curiosity, are you planning to develop video codec driver
> in v4l2 for i.MX27 as well ?

It depends on the result of a proof of concept we are preparing now.
But yes, it could be possible. AFAIK, Sascha Hauer (added to CC) has a
prototype driver for this one though.

> I have a few comments, please see below...

It seems I'll have to prepare a second version with all the fixes
you've pointed out which seem quite reasonable to me.

Regards.
Robert Schwebel - Nov. 18, 2011, 10:35 p.m.
On Fri, Nov 18, 2011 at 05:27:12PM +0100, javier Martin wrote:
> But yes, it could be possible. AFAIK, Sascha Hauer (added to CC) has a
> prototype driver for this one though.

Yes, we have indeed a prototype for the VPU, both on MX27 and MX53.
However, it wasn't changed to a mem2mem device yet, although that is
what needs to be done. Unfortunately, we currently do not have a
customer who would let us drive that forward, so it probably needs some
time until we find somebody and can work on that again.

rsc

Patch

diff --git a/arch/arm/mach-imx/devices-imx27.h b/arch/arm/mach-imx/devices-imx27.h
index 2f727d7..519aa36 100644
--- a/arch/arm/mach-imx/devices-imx27.h
+++ b/arch/arm/mach-imx/devices-imx27.h
@@ -50,6 +50,8 @@  extern const struct imx_imx_uart_1irq_data imx27_imx_uart_data[];
 extern const struct imx_mx2_camera_data imx27_mx2_camera_data;
 #define imx27_add_mx2_camera(pdata)	\
 	imx_add_mx2_camera(&imx27_mx2_camera_data, pdata)
+#define imx27_alloc_mx2_emmaprp(pdata)	\
+	imx_alloc_mx2_emmaprp(&imx27_mx2_camera_data)
 
 extern const struct imx_mxc_ehci_data imx27_mxc_ehci_otg_data;
 #define imx27_add_mxc_ehci_otg(pdata)	\
diff --git a/arch/arm/plat-mxc/devices/platform-mx2-camera.c b/arch/arm/plat-mxc/devices/platform-mx2-camera.c
index b3f4828..4a8bd73 100644
--- a/arch/arm/plat-mxc/devices/platform-mx2-camera.c
+++ b/arch/arm/plat-mxc/devices/platform-mx2-camera.c
@@ -6,6 +6,7 @@ 
  * the terms of the GNU General Public License version 2 as published by the
  * Free Software Foundation.
  */
+#include <linux/dma-mapping.h>
 #include <mach/hardware.h>
 #include <mach/devices-common.h>
 
@@ -62,3 +63,35 @@  struct platform_device *__init imx_add_mx2_camera(
 			res, data->iobaseemmaprp ? 4 : 2,
 			pdata, sizeof(*pdata), DMA_BIT_MASK(32));
 }
+
+struct platform_device *__init imx_alloc_mx2_emmaprp(
+		const struct imx_mx2_camera_data *data)
+{
+	struct resource res[] = {
+		{
+			.start = data->iobaseemmaprp,
+			.end = data->iobaseemmaprp + data->iosizeemmaprp - 1,
+			.flags = IORESOURCE_MEM,
+		}, {
+			.start = data->irqemmaprp,
+			.end = data->irqemmaprp,
+			.flags = IORESOURCE_IRQ,
+		},
+	};
+	struct platform_device *pdev;
+	int ret = -ENOMEM;
+
+	pdev = platform_device_alloc("m2m-emmaprp", 0);
+	if (!pdev)
+		goto err;
+
+	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
+	if (ret)
+		goto err;
+
+	return pdev;
+err:
+	platform_device_put(pdev);
+	return ERR_PTR(-ENODEV);
+
+}
diff --git a/arch/arm/plat-mxc/include/mach/devices-common.h b/arch/arm/plat-mxc/include/mach/devices-common.h
index def9ba5..ce64bd5 100644
--- a/arch/arm/plat-mxc/include/mach/devices-common.h
+++ b/arch/arm/plat-mxc/include/mach/devices-common.h
@@ -223,6 +223,8 @@  struct imx_mx2_camera_data {
 struct platform_device *__init imx_add_mx2_camera(
 		const struct imx_mx2_camera_data *data,
 		const struct mx2_camera_platform_data *pdata);
+struct platform_device *__init imx_alloc_mx2_emmaprp(
+		const struct imx_mx2_camera_data *data);
 
 #include <mach/mxc_ehci.h>
 struct imx_mxc_ehci_data {
diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index b303a3f..6e57825 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -1107,4 +1107,15 @@  config VIDEO_SAMSUNG_S5P_MFC
 	help
 	    MFC 5.1 driver for V4L2.
 
+config VIDEO_MX2_EMMAPRP
+	tristate "MX2 eMMa-PrP support"
+	depends on VIDEO_DEV && VIDEO_V4L2 && MACH_MX27
+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_MEM2MEM_DEV
+	default n
+	help
+	    MX2X chips have a PrP that can be used to process buffers from
+	    memory to memory. Operations include resizing and format
+	    conversion.
+
 endif # V4L_MEM2MEM_DRIVERS
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 117f9c4..7ae711e 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -176,6 +176,8 @@  obj-$(CONFIG_VIDEO_SH_MOBILE_CEU)	+= sh_mobile_ceu_camera.o
 obj-$(CONFIG_VIDEO_OMAP1)		+= omap1_camera.o
 obj-$(CONFIG_VIDEO_ATMEL_ISI)		+= atmel-isi.o
 
+obj-$(CONFIG_VIDEO_MX2_EMMAPRP)		+= mx2_emmaprp.o
+
 obj-$(CONFIG_VIDEO_SAMSUNG_S5P_FIMC) 	+= s5p-fimc/
 obj-$(CONFIG_VIDEO_SAMSUNG_S5P_MFC)	+= s5p-mfc/
 obj-$(CONFIG_VIDEO_SAMSUNG_S5P_TV)	+= s5p-tv/
diff --git a/drivers/media/video/mx2_emmaprp.c b/drivers/media/video/mx2_emmaprp.c
new file mode 100644
index 0000000..ad65e90
--- /dev/null
+++ b/drivers/media/video/mx2_emmaprp.c
@@ -0,0 +1,1059 @@ 
+/*
+ * Support eMMa-PrP through mem2mem framework.
+ *
+ * eMMa-PrP is a piece of HW that allows fetching buffers
+ * from one memory location and do several operations on
+ * them such as scaling or format conversion giving, as a result
+ * a new processed buffer in another memory location.
+ *
+ * Based on mem2mem_testdev.c by Pawel Osciak.
+ *
+ * Copyright (c) 2011 Vista Silicon S.L.
+ * Javier Martin <javier.martin@vista-silicon.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version
+ */
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+
+#include <linux/platform_device.h>
+#include <media/v4l2-mem2mem.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-dma-contig.h>
+
+#define MEM2MEM_TEST_MODULE_NAME "mem2mem-emmaprp"
+
+MODULE_DESCRIPTION("mem2mem device which supports eMMa-PrP present in mx2 SoCs");
+MODULE_AUTHOR("Javier Martin <javier.martin@vista-silicon.com");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.0.1");
+
+static bool debug = true;
+module_param(debug, bool, 0644);
+
+#define MIN_W 32
+#define MIN_H 32
+#define MAX_W 2040
+#define MAX_H 2046
+
+#define W_ALIGN_MASK_YUV420	0x07 /* multiple of 8 */
+#define W_ALIGN_MASK_OTHERS	0x03 /* multiple of 4 */
+#define H_ALIGN_MASK		0x01 /* multiple of 2 */
+
+/* Flags that indicate a format can be used for capture/output */
+#define MEM2MEM_CAPTURE	(1 << 0)
+#define MEM2MEM_OUTPUT	(1 << 1)
+
+#define MEM2MEM_NAME		"m2m-emmaprp"
+
+/* In bytes, per queue */
+#define MEM2MEM_VID_MEM_LIMIT	(16 * 1024 * 1024)
+
+#define dprintk(dev, fmt, arg...) \
+	v4l2_dbg(1, debug, &dev->v4l2_dev, "%s: " fmt, __func__, ## arg)
+
+/* EMMA PrP */
+#define PRP_CNTL                        0x00
+#define PRP_INTR_CNTL                   0x04
+#define PRP_INTRSTATUS                  0x08
+#define PRP_SOURCE_Y_PTR                0x0c
+#define PRP_SOURCE_CB_PTR               0x10
+#define PRP_SOURCE_CR_PTR               0x14
+#define PRP_DEST_RGB1_PTR               0x18
+#define PRP_DEST_RGB2_PTR               0x1c
+#define PRP_DEST_Y_PTR                  0x20
+#define PRP_DEST_CB_PTR                 0x24
+#define PRP_DEST_CR_PTR                 0x28
+#define PRP_SRC_FRAME_SIZE              0x2c
+#define PRP_DEST_CH1_LINE_STRIDE        0x30
+#define PRP_SRC_PIXEL_FORMAT_CNTL       0x34
+#define PRP_CH1_PIXEL_FORMAT_CNTL       0x38
+#define PRP_CH1_OUT_IMAGE_SIZE          0x3c
+#define PRP_CH2_OUT_IMAGE_SIZE          0x40
+#define PRP_SRC_LINE_STRIDE             0x44
+#define PRP_CSC_COEF_012                0x48
+#define PRP_CSC_COEF_345                0x4c
+#define PRP_CSC_COEF_678                0x50
+#define PRP_CH1_RZ_HORI_COEF1           0x54
+#define PRP_CH1_RZ_HORI_COEF2           0x58
+#define PRP_CH1_RZ_HORI_VALID           0x5c
+#define PRP_CH1_RZ_VERT_COEF1           0x60
+#define PRP_CH1_RZ_VERT_COEF2           0x64
+#define PRP_CH1_RZ_VERT_VALID           0x68
+#define PRP_CH2_RZ_HORI_COEF1           0x6c
+#define PRP_CH2_RZ_HORI_COEF2           0x70
+#define PRP_CH2_RZ_HORI_VALID           0x74
+#define PRP_CH2_RZ_VERT_COEF1           0x78
+#define PRP_CH2_RZ_VERT_COEF2           0x7c
+#define PRP_CH2_RZ_VERT_VALID           0x80
+
+#define PRP_CNTL_CH1EN          (1 << 0)
+#define PRP_CNTL_CH2EN          (1 << 1)
+#define PRP_CNTL_CSIEN          (1 << 2)
+#define PRP_CNTL_DATA_IN_YUV420 (0 << 3)
+#define PRP_CNTL_DATA_IN_YUV422 (1 << 3)
+#define PRP_CNTL_DATA_IN_RGB16  (2 << 3)
+#define PRP_CNTL_DATA_IN_RGB32  (3 << 3)
+#define PRP_CNTL_CH1_OUT_RGB8   (0 << 5)
+#define PRP_CNTL_CH1_OUT_RGB16  (1 << 5)
+#define PRP_CNTL_CH1_OUT_RGB32  (2 << 5)
+#define PRP_CNTL_CH1_OUT_YUV422 (3 << 5)
+#define PRP_CNTL_CH2_OUT_YUV420 (0 << 7)
+#define PRP_CNTL_CH2_OUT_YUV422 (1 << 7)
+#define PRP_CNTL_CH2_OUT_YUV444 (2 << 7)
+#define PRP_CNTL_CH1_LEN        (1 << 9)
+#define PRP_CNTL_CH2_LEN        (1 << 10)
+#define PRP_CNTL_SKIP_FRAME     (1 << 11)
+#define PRP_CNTL_SWRST          (1 << 12)
+#define PRP_CNTL_CLKEN          (1 << 13)
+#define PRP_CNTL_WEN            (1 << 14)
+#define PRP_CNTL_CH1BYP         (1 << 15)
+#define PRP_CNTL_IN_TSKIP(x)    ((x) << 16)
+#define PRP_CNTL_CH1_TSKIP(x)   ((x) << 19)
+#define PRP_CNTL_CH2_TSKIP(x)   ((x) << 22)
+#define PRP_CNTL_INPUT_FIFO_LEVEL(x)    ((x) << 25)
+#define PRP_CNTL_RZ_FIFO_LEVEL(x)       ((x) << 27)
+#define PRP_CNTL_CH2B1EN        (1 << 29)
+#define PRP_CNTL_CH2B2EN        (1 << 30)
+#define PRP_CNTL_CH2FEN         (1 << 31)
+
+#define PRP_SIZE_HEIGHT(x)	(x)
+#define PRP_SIZE_WIDTH(x)	((x) << 16)
+
+/* IRQ Enable and status register */
+#define PRP_INTR_RDERR          (1 << 0)
+#define PRP_INTR_CH1WERR        (1 << 1)
+#define PRP_INTR_CH2WERR        (1 << 2)
+#define PRP_INTR_CH1FC          (1 << 3)
+#define PRP_INTR_CH2FC          (1 << 5)
+#define PRP_INTR_LBOVF          (1 << 7)
+#define PRP_INTR_CH2OVF         (1 << 8)
+
+#define PRP_INTR_ST_RDERR	(1 << 0)
+#define PRP_INTR_ST_CH1WERR	(1 << 1)
+#define PRP_INTR_ST_CH2WERR	(1 << 2)
+#define PRP_INTR_ST_CH2B2CI	(1 << 3)
+#define PRP_INTR_ST_CH2B1CI	(1 << 4)
+#define PRP_INTR_ST_CH1B2CI	(1 << 5)
+#define PRP_INTR_ST_CH1B1CI	(1 << 6)
+#define PRP_INTR_ST_LBOVF	(1 << 7)
+#define PRP_INTR_ST_CH2OVF	(1 << 8)
+
+struct emmaprp_fmt {
+	char	*name;
+	u32	fourcc;
+	/* Types the format can be used for */
+	u32	types;
+};
+
+static struct emmaprp_fmt formats[] = {
+	{
+		.name	= "YUV 4:2:0 Planar",
+		.fourcc	= V4L2_PIX_FMT_YUV420,
+		.types	= MEM2MEM_CAPTURE,
+	},
+	{
+		.name	= "4:2:2, packed, YUYV",
+		.fourcc	= V4L2_PIX_FMT_YUYV,
+		.types	= MEM2MEM_OUTPUT,
+	},
+};
+
+/* Per-queue, driver-specific private data */
+struct emmaprp_q_data {
+	unsigned int		width;
+	unsigned int		height;
+	unsigned int		sizeimage;
+	struct emmaprp_fmt	*fmt;
+};
+
+enum {
+	V4L2_M2M_SRC = 0,
+	V4L2_M2M_DST = 1,
+};
+
+/* Source and destination queue data */
+static struct emmaprp_q_data q_data[2];
+
+static struct emmaprp_q_data *get_q_data(enum v4l2_buf_type type)
+{
+	switch (type) {
+	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+		return &q_data[V4L2_M2M_SRC];
+	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+		return &q_data[V4L2_M2M_DST];
+	default:
+		BUG();
+	}
+	return NULL;
+}
+
+#define NUM_FORMATS ARRAY_SIZE(formats)
+
+static struct emmaprp_fmt *find_format(struct v4l2_format *f)
+{
+	struct emmaprp_fmt *fmt;
+	unsigned int k;
+
+	for (k = 0; k < NUM_FORMATS; k++) {
+		fmt = &formats[k];
+		if (fmt->fourcc == f->fmt.pix.pixelformat)
+			break;
+	}
+
+	if (k == NUM_FORMATS)
+		return NULL;
+
+	return &formats[k];
+}
+
+struct emmaprp_dev {
+	struct v4l2_device	v4l2_dev;
+	struct video_device	*vfd;
+
+	atomic_t		busy;
+	struct mutex		dev_mutex;
+	spinlock_t		irqlock;
+
+	int			irq_emma;
+	void __iomem		*base_emma;
+	struct clk		*clk_emma;
+	struct resource		*res_emma;
+
+	struct v4l2_m2m_dev	*m2m_dev;
+	struct vb2_alloc_ctx	*alloc_ctx;
+};
+
+struct emmaprp_ctx {
+	struct emmaprp_dev	*dev;
+
+	/* Abort requested by m2m */
+	int			aborting;
+
+	struct v4l2_m2m_ctx	*m2m_ctx;
+};
+
+/*
+ * mem2mem callbacks
+ */
+static int emmaprp_job_ready(void *priv)
+{
+	struct emmaprp_ctx *ctx = priv;
+	struct emmaprp_dev *pcdev = ctx->dev;
+
+	if ((v4l2_m2m_num_src_bufs_ready(ctx->m2m_ctx) > 0)
+	    && (v4l2_m2m_num_dst_bufs_ready(ctx->m2m_ctx) > 0)
+	    && (atomic_read(&pcdev->busy) == 0))
+		return 1;
+
+	dprintk(pcdev, "Task not ready to run\n");
+
+	return 0;
+}
+
+static void emmaprp_job_abort(void *priv)
+{
+	struct emmaprp_ctx *ctx = priv;
+	struct emmaprp_dev *pcdev = ctx->dev;
+
+	ctx->aborting = 1;
+
+	dprintk(pcdev, "Aborting task\n");
+
+	v4l2_m2m_job_finish(pcdev->m2m_dev, ctx->m2m_ctx);
+}
+
+static void emmaprp_lock(void *priv)
+{
+	struct emmaprp_ctx *ctx = priv;
+	struct emmaprp_dev *pcdev = ctx->dev;
+	mutex_lock(&pcdev->dev_mutex);
+}
+
+static void emmaprp_unlock(void *priv)
+{
+	struct emmaprp_ctx *ctx = priv;
+	struct emmaprp_dev *pcdev = ctx->dev;
+	mutex_unlock(&pcdev->dev_mutex);
+}
+
+static inline void emmaprp_dump_regs(struct emmaprp_dev *pcdev)
+{
+	dprintk(pcdev,
+		"eMMa-PrP Registers:\n"
+		"  SOURCE_Y_PTR = 0x%08X\n"
+		"  SRC_FRAME_SIZE = 0x%08X\n"
+		"  DEST_Y_PTR = 0x%08X\n"
+		"  DEST_CR_PTR = 0x%08X\n"
+		"  DEST_CB_PTR = 0x%08X\n"
+		"  CH2_OUT_IMAGE_SIZE = 0x%08X\n"
+		"  CNTL = 0x%08X\n",
+		readl(pcdev->base_emma + PRP_SOURCE_Y_PTR),
+		readl(pcdev->base_emma + PRP_SRC_FRAME_SIZE),
+		readl(pcdev->base_emma + PRP_DEST_Y_PTR),
+		readl(pcdev->base_emma + PRP_DEST_CR_PTR),
+		readl(pcdev->base_emma + PRP_DEST_CB_PTR),
+		readl(pcdev->base_emma + PRP_CH2_OUT_IMAGE_SIZE),
+		readl(pcdev->base_emma + PRP_CNTL));
+}
+
+static void emmaprp_device_run(void *priv)
+{
+	struct emmaprp_ctx *ctx = priv;
+	struct emmaprp_q_data *s_q_data, *d_q_data;
+	struct vb2_buffer *src_buf, *dst_buf;
+	struct emmaprp_dev *pcdev = ctx->dev;
+	unsigned int s_width, s_height;
+	unsigned int d_width, d_height;
+	unsigned int d_size;
+	u8 *p_in, *p_out;
+	u32 tmp;
+
+	atomic_set(&ctx->dev->busy, 1);
+
+	src_buf = v4l2_m2m_next_src_buf(ctx->m2m_ctx);
+	dst_buf = v4l2_m2m_next_dst_buf(ctx->m2m_ctx);
+
+	s_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_OUTPUT);
+	s_width	= s_q_data->width;
+	s_height = s_q_data->height;
+
+	d_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_CAPTURE);
+	d_width = d_q_data->width;
+	d_height = d_q_data->height;
+	d_size = d_width * d_height;
+
+	p_in = (u8 *)vb2_dma_contig_plane_dma_addr(src_buf, 0);
+	p_out = (u8 *)vb2_dma_contig_plane_dma_addr(dst_buf, 0);
+	if (!p_in || !p_out) {
+		v4l2_err(&pcdev->v4l2_dev,
+			 "Acquiring kernel pointers to buffers failed\n");
+		return;
+	}
+
+	/* Input frame parameters */
+	writel(p_in, pcdev->base_emma + PRP_SOURCE_Y_PTR);
+	writel(PRP_SIZE_WIDTH(s_width) | PRP_SIZE_HEIGHT(s_height),
+	       pcdev->base_emma + PRP_SRC_FRAME_SIZE);
+
+	/* Output frame parameters */
+	writel(p_out, pcdev->base_emma + PRP_DEST_Y_PTR);
+	writel(p_out + d_size, pcdev->base_emma + PRP_DEST_CB_PTR);
+	writel(p_out + d_size + (d_size >> 2),
+	       pcdev->base_emma + PRP_DEST_CR_PTR);
+	writel(PRP_SIZE_WIDTH(d_width) | PRP_SIZE_HEIGHT(d_height),
+	       pcdev->base_emma + PRP_CH2_OUT_IMAGE_SIZE);
+
+	/* IRQ configuration */
+	tmp = readl(pcdev->base_emma + PRP_INTR_CNTL);
+	writel(tmp | PRP_INTR_RDERR |
+		PRP_INTR_CH2WERR |
+		PRP_INTR_CH2FC,
+		pcdev->base_emma + PRP_INTR_CNTL);
+
+	emmaprp_dump_regs(pcdev);
+
+	/* Enable transfer */
+	tmp = readl(pcdev->base_emma + PRP_CNTL);
+	writel(tmp | PRP_CNTL_CH2_OUT_YUV420 |
+		PRP_CNTL_DATA_IN_YUV422 |
+		PRP_CNTL_CH2EN,
+		pcdev->base_emma + PRP_CNTL);
+}
+
+static irqreturn_t emmaprp_irq(int irq_emma, void *data)
+{
+	struct emmaprp_dev *pcdev = (struct emmaprp_dev *)data;
+	struct emmaprp_ctx *curr_ctx;
+	struct vb2_buffer *src_vb, *dst_vb;
+	unsigned long flags;
+	u32 irqst;
+
+	/* Check irq flags and clear irq */
+	irqst = readl(pcdev->base_emma + PRP_INTRSTATUS);
+	writel(irqst, pcdev->base_emma + PRP_INTRSTATUS);
+	dprintk(pcdev, "irqst = 0x%08x\n", irqst);
+
+	curr_ctx = v4l2_m2m_get_curr_priv(pcdev->m2m_dev);
+	if (NULL == curr_ctx) {
+		printk(KERN_ERR
+			"Instance released before the end of transaction\n");
+		return IRQ_HANDLED;
+	}
+
+	if (curr_ctx->aborting)
+		goto irq_ok;
+
+	if ((irqst & PRP_INTR_ST_RDERR) ||
+	    (irqst & PRP_INTR_ST_CH2WERR)) {
+		printk(KERN_ERR
+			"PrP bus error ocurred, this transfer is probably corrupted\n");
+		writel(PRP_CNTL_SWRST, pcdev->base_emma + PRP_CNTL);
+		goto irq_ok;
+	}
+
+	if (irqst & PRP_INTR_ST_CH2B1CI) { /* buffer ready */
+		src_vb = v4l2_m2m_src_buf_remove(curr_ctx->m2m_ctx);
+		dst_vb = v4l2_m2m_dst_buf_remove(curr_ctx->m2m_ctx);
+
+		spin_lock_irqsave(&pcdev->irqlock, flags);
+		v4l2_m2m_buf_done(src_vb, VB2_BUF_STATE_DONE);
+		v4l2_m2m_buf_done(dst_vb, VB2_BUF_STATE_DONE);
+		spin_unlock_irqrestore(&pcdev->irqlock, flags);
+		goto irq_ok;
+	}
+
+irq_ok:
+	atomic_set(&pcdev->busy, 0);
+	v4l2_m2m_job_finish(pcdev->m2m_dev, curr_ctx->m2m_ctx);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * video ioctls
+ */
+static int vidioc_querycap(struct file *file, void *priv,
+			   struct v4l2_capability *cap)
+{
+	strncpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver) - 1);
+	strncpy(cap->card, MEM2MEM_NAME, sizeof(cap->card) - 1);
+	cap->bus_info[0] = 0;
+	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT
+			  | V4L2_CAP_STREAMING;
+
+	return 0;
+}
+
+static int enum_fmt(struct v4l2_fmtdesc *f, u32 type)
+{
+	int i, num;
+	struct emmaprp_fmt *fmt;
+
+	num = 0;
+
+	for (i = 0; i < NUM_FORMATS; ++i) {
+		if (formats[i].types & type) {
+			/* index-th format of type type found ? */
+			if (num == f->index)
+				break;
+			/* Correct type but haven't reached our index yet,
+			 * just increment per-type index */
+			++num;
+		}
+	}
+
+	if (i < NUM_FORMATS) {
+		/* Format found */
+		fmt = &formats[i];
+		strncpy(f->description, fmt->name, sizeof(f->description) - 1);
+		f->pixelformat = fmt->fourcc;
+		return 0;
+	}
+
+	/* Format not found */
+	return -EINVAL;
+}
+
+static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_fmtdesc *f)
+{
+	return enum_fmt(f, MEM2MEM_CAPTURE);
+}
+
+static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
+				   struct v4l2_fmtdesc *f)
+{
+	return enum_fmt(f, MEM2MEM_OUTPUT);
+}
+
+static int vidioc_g_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
+{
+	struct vb2_queue *vq;
+	struct emmaprp_q_data *q_data;
+
+	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
+	if (!vq)
+		return -EINVAL;
+
+	q_data = get_q_data(f->type);
+
+	f->fmt.pix.width	= q_data->width;
+	f->fmt.pix.height	= q_data->height;
+	f->fmt.pix.field	= V4L2_FIELD_NONE;
+	f->fmt.pix.pixelformat	= q_data->fmt->fourcc;
+	if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_YUV420)
+		f->fmt.pix.bytesperline = q_data->width * 3 / 2;
+	else /* YUYV */
+		f->fmt.pix.bytesperline = q_data->width * 2;
+	f->fmt.pix.sizeimage	= q_data->sizeimage;
+
+	return 0;
+}
+
+static int vidioc_g_fmt_vid_out(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	return vidioc_g_fmt(priv, f);
+}
+
+static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	return vidioc_g_fmt(priv, f);
+}
+
+static int vidioc_try_fmt(struct v4l2_format *f, struct emmaprp_fmt *fmt)
+{
+	enum v4l2_field field;
+
+	field = f->fmt.pix.field;
+
+	if (field == V4L2_FIELD_ANY)
+		field = V4L2_FIELD_NONE;
+	else if (V4L2_FIELD_NONE != field)
+		return -EINVAL;
+
+	/* V4L2 specification suggests the driver corrects the format struct
+	 * if any of the dimensions is unsupported */
+	f->fmt.pix.field = field;
+
+	if (f->fmt.pix.height < MIN_H)
+		f->fmt.pix.height = MIN_H;
+	else if (f->fmt.pix.height > MAX_H)
+		f->fmt.pix.height = MAX_H;
+
+	if (f->fmt.pix.width < MIN_W)
+		f->fmt.pix.width = MIN_W;
+	else if (f->fmt.pix.width > MAX_W)
+		f->fmt.pix.width = MAX_W;
+
+	f->fmt.pix.height &= ~H_ALIGN_MASK;
+	if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_YUV420) {
+		f->fmt.pix.width &= ~W_ALIGN_MASK_YUV420;
+		f->fmt.pix.bytesperline = f->fmt.pix.width * 3 / 2;
+	} else { /* YUYV */
+		f->fmt.pix.width &= ~W_ALIGN_MASK_OTHERS;
+		f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
+	}
+	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
+
+	return 0;
+}
+
+static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
+				  struct v4l2_format *f)
+{
+	struct emmaprp_fmt *fmt;
+	struct emmaprp_ctx *ctx = priv;
+
+	fmt = find_format(f);
+	if (!fmt || !(fmt->types & MEM2MEM_CAPTURE)) {
+		v4l2_err(&ctx->dev->v4l2_dev,
+			 "Fourcc format (0x%08x) invalid.\n",
+			 f->fmt.pix.pixelformat);
+		return -EINVAL;
+	}
+
+	return vidioc_try_fmt(f, fmt);
+}
+
+static int vidioc_try_fmt_vid_out(struct file *file, void *priv,
+				  struct v4l2_format *f)
+{
+	struct emmaprp_fmt *fmt;
+	struct emmaprp_ctx *ctx = priv;
+
+	fmt = find_format(f);
+	if (!fmt || !(fmt->types & MEM2MEM_OUTPUT)) {
+		v4l2_err(&ctx->dev->v4l2_dev,
+			 "Fourcc format (0x%08x) invalid.\n",
+			 f->fmt.pix.pixelformat);
+		return -EINVAL;
+	}
+
+	return vidioc_try_fmt(f, fmt);
+}
+
+static int vidioc_s_fmt(struct emmaprp_ctx *ctx, struct v4l2_format *f)
+{
+	struct emmaprp_q_data *q_data;
+	struct vb2_queue *vq;
+
+	vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
+	if (!vq)
+		return -EINVAL;
+
+	q_data = get_q_data(f->type);
+	if (!q_data)
+		return -EINVAL;
+
+	if (vb2_is_busy(vq)) {
+		v4l2_err(&ctx->dev->v4l2_dev, "%s queue busy\n", __func__);
+		return -EBUSY;
+	}
+
+	q_data->fmt		= find_format(f);
+	q_data->width		= f->fmt.pix.width;
+	q_data->height		= f->fmt.pix.height;
+	if (q_data->fmt->fourcc == V4L2_PIX_FMT_YUV420)
+		q_data->sizeimage = q_data->width * q_data->height * 3 / 2;
+	else /* YUYV */
+		q_data->sizeimage = q_data->width * q_data->height * 2;
+
+	dprintk(ctx->dev,
+		"Setting format for type %d, wxh: %dx%d, fmt: %d\n",
+		f->type, q_data->width, q_data->height, q_data->fmt->fourcc);
+
+	return 0;
+}
+
+static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	int ret;
+
+	ret = vidioc_try_fmt_vid_cap(file, priv, f);
+	if (ret)
+		return ret;
+
+	return vidioc_s_fmt(priv, f);
+}
+
+static int vidioc_s_fmt_vid_out(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	int ret;
+
+	ret = vidioc_try_fmt_vid_out(file, priv, f);
+	if (ret)
+		return ret;
+
+	return vidioc_s_fmt(priv, f);
+}
+
+static int vidioc_reqbufs(struct file *file, void *priv,
+			  struct v4l2_requestbuffers *reqbufs)
+{
+	struct emmaprp_ctx *ctx = priv;
+
+	return v4l2_m2m_reqbufs(file, ctx->m2m_ctx, reqbufs);
+}
+
+static int vidioc_querybuf(struct file *file, void *priv,
+			   struct v4l2_buffer *buf)
+{
+	struct emmaprp_ctx *ctx = priv;
+
+	return v4l2_m2m_querybuf(file, ctx->m2m_ctx, buf);
+}
+
+static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
+{
+	struct emmaprp_ctx *ctx = priv;
+
+	return v4l2_m2m_qbuf(file, ctx->m2m_ctx, buf);
+}
+
+static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
+{
+	struct emmaprp_ctx *ctx = priv;
+
+	return v4l2_m2m_dqbuf(file, ctx->m2m_ctx, buf);
+}
+
+static int vidioc_streamon(struct file *file, void *priv,
+			   enum v4l2_buf_type type)
+{
+	struct emmaprp_ctx *ctx = priv;
+
+	return v4l2_m2m_streamon(file, ctx->m2m_ctx, type);
+}
+
+static int vidioc_streamoff(struct file *file, void *priv,
+			    enum v4l2_buf_type type)
+{
+	struct emmaprp_ctx *ctx = priv;
+
+	return v4l2_m2m_streamoff(file, ctx->m2m_ctx, type);
+}
+
+static const struct v4l2_ioctl_ops emmaprp_ioctl_ops = {
+	.vidioc_querycap	= vidioc_querycap,
+
+	.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap	= vidioc_g_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap	= vidioc_try_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap	= vidioc_s_fmt_vid_cap,
+
+	.vidioc_enum_fmt_vid_out = vidioc_enum_fmt_vid_out,
+	.vidioc_g_fmt_vid_out	= vidioc_g_fmt_vid_out,
+	.vidioc_try_fmt_vid_out	= vidioc_try_fmt_vid_out,
+	.vidioc_s_fmt_vid_out	= vidioc_s_fmt_vid_out,
+
+	.vidioc_reqbufs		= vidioc_reqbufs,
+	.vidioc_querybuf	= vidioc_querybuf,
+
+	.vidioc_qbuf		= vidioc_qbuf,
+	.vidioc_dqbuf		= vidioc_dqbuf,
+
+	.vidioc_streamon	= vidioc_streamon,
+	.vidioc_streamoff	= vidioc_streamoff,
+};
+
+
+/*
+ * Queue operations
+ */
+struct vb2_dc_conf {
+	struct device           *dev;
+};
+
+static int emmaprp_queue_setup(struct vb2_queue *vq,
+				const struct v4l2_format *fmt,
+				unsigned int *nbuffers, unsigned int *nplanes,
+				unsigned int sizes[], void *alloc_ctxs[])
+{
+	struct emmaprp_ctx *ctx = vb2_get_drv_priv(vq);
+	struct emmaprp_q_data *q_data;
+	unsigned int size, count = *nbuffers;
+
+	q_data = get_q_data(vq->type);
+
+	if (q_data->fmt->fourcc == V4L2_PIX_FMT_YUV420)
+		size = q_data->width * q_data->height * 3 / 2;
+	else
+		size = q_data->width * q_data->height * 2;
+
+	while (size * count > MEM2MEM_VID_MEM_LIMIT)
+		(count)--;
+
+	*nplanes = 1;
+	*nbuffers = count;
+	sizes[0] = size;
+
+	alloc_ctxs[0] = ctx->dev->alloc_ctx;
+
+	dprintk(ctx->dev, "get %d buffer(s) of size %d each.\n", count, size);
+
+	return 0;
+}
+
+static int emmaprp_buf_prepare(struct vb2_buffer *vb)
+{
+	struct emmaprp_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+	struct emmaprp_q_data *q_data;
+
+	dprintk(ctx->dev, "type: %d\n", vb->vb2_queue->type);
+
+	q_data = get_q_data(vb->vb2_queue->type);
+
+	if (vb2_plane_size(vb, 0) < q_data->sizeimage) {
+		dprintk(ctx->dev, "%s data will not fit into plane"
+				  "(%lu < %lu)\n", __func__,
+				  vb2_plane_size(vb, 0),
+				  (long)q_data->sizeimage);
+		return -EINVAL;
+	}
+
+	vb2_set_plane_payload(vb, 0, q_data->sizeimage);
+
+	return 0;
+}
+
+static void emmaprp_buf_queue(struct vb2_buffer *vb)
+{
+	struct emmaprp_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
+	v4l2_m2m_buf_queue(ctx->m2m_ctx, vb);
+}
+
+static struct vb2_ops emmaprp_qops = {
+	.queue_setup	 = emmaprp_queue_setup,
+	.buf_prepare	 = emmaprp_buf_prepare,
+	.buf_queue	 = emmaprp_buf_queue,
+};
+
+static int queue_init(void *priv, struct vb2_queue *src_vq,
+		      struct vb2_queue *dst_vq)
+{
+	struct emmaprp_ctx *ctx = priv;
+	int ret;
+
+	memset(src_vq, 0, sizeof(*src_vq));
+	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+	src_vq->io_modes = VB2_MMAP;
+	src_vq->drv_priv = ctx;
+	src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
+	src_vq->ops = &emmaprp_qops;
+	src_vq->mem_ops = &vb2_dma_contig_memops;
+
+	ret = vb2_queue_init(src_vq);
+	if (ret)
+		return ret;
+
+	memset(dst_vq, 0, sizeof(*dst_vq));
+	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	dst_vq->io_modes = VB2_MMAP;
+	dst_vq->drv_priv = ctx;
+	dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
+	dst_vq->ops = &emmaprp_qops;
+	dst_vq->mem_ops = &vb2_dma_contig_memops;
+
+	return vb2_queue_init(dst_vq);
+}
+
+/*
+ * File operations
+ */
+static int emmaprp_open(struct file *file)
+{
+	struct emmaprp_dev *pcdev = video_drvdata(file);
+	struct emmaprp_ctx *ctx = NULL;
+
+	ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	file->private_data = ctx;
+	ctx->dev = pcdev;
+
+	ctx->m2m_ctx = v4l2_m2m_ctx_init(pcdev->m2m_dev, ctx, &queue_init);
+
+	if (IS_ERR(ctx->m2m_ctx)) {
+		int ret = PTR_ERR(ctx->m2m_ctx);
+
+		kfree(ctx);
+		return ret;
+	}
+
+	clk_enable(pcdev->clk_emma);
+
+	dprintk(pcdev, "Created instance %p, m2m_ctx: %p\n", ctx, ctx->m2m_ctx);
+
+	return 0;
+}
+
+static int emmaprp_release(struct file *file)
+{
+	struct emmaprp_dev *pcdev = video_drvdata(file);
+	struct emmaprp_ctx *ctx = file->private_data;
+
+	dprintk(pcdev, "Releasing instance %p\n", ctx);
+
+	clk_disable(pcdev->clk_emma);
+	v4l2_m2m_ctx_release(ctx->m2m_ctx);
+	kfree(ctx);
+
+	return 0;
+}
+
+static unsigned int emmaprp_poll(struct file *file,
+				 struct poll_table_struct *wait)
+{
+	struct emmaprp_ctx *ctx = file->private_data;
+
+	return v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
+}
+
+static int emmaprp_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct emmaprp_ctx *ctx = file->private_data;
+
+	return v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
+}
+
+static const struct v4l2_file_operations emmaprp_fops = {
+	.owner		= THIS_MODULE,
+	.open		= emmaprp_open,
+	.release	= emmaprp_release,
+	.poll		= emmaprp_poll,
+	.unlocked_ioctl	= video_ioctl2,
+	.mmap		= emmaprp_mmap,
+};
+
+static struct video_device emmaprp_videodev = {
+	.name		= MEM2MEM_NAME,
+	.fops		= &emmaprp_fops,
+	.ioctl_ops	= &emmaprp_ioctl_ops,
+	.minor		= -1,
+	.release	= video_device_release,
+};
+
+static struct v4l2_m2m_ops m2m_ops = {
+	.device_run	= emmaprp_device_run,
+	.job_ready	= emmaprp_job_ready,
+	.job_abort	= emmaprp_job_abort,
+	.lock		= emmaprp_lock,
+	.unlock		= emmaprp_unlock,
+};
+
+static int emmaprp_probe(struct platform_device *pdev)
+{
+	struct emmaprp_dev *pcdev;
+	struct video_device *vfd;
+	struct resource *res_emma;
+	int irq_emma;
+	int ret;
+
+	pcdev = kzalloc(sizeof *pcdev, GFP_KERNEL);
+	if (!pcdev)
+		return -ENOMEM;
+
+	spin_lock_init(&pcdev->irqlock);
+
+	pcdev->clk_emma = clk_get(NULL, "emma");
+	if (IS_ERR(pcdev->clk_emma)) {
+		ret = PTR_ERR(pcdev->clk_emma);
+		goto free_dev;
+	}
+
+	irq_emma = platform_get_irq(pdev, 0);
+	res_emma = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (irq_emma < 0 || res_emma == NULL) {
+		dev_err(&pdev->dev, "Missing platform resources data\n");
+		ret = -ENODEV;
+		goto free_clk;
+	}
+
+	ret = v4l2_device_register(&pdev->dev, &pcdev->v4l2_dev);
+	if (ret)
+		goto free_clk;
+
+	atomic_set(&pcdev->busy, 0);
+	mutex_init(&pcdev->dev_mutex);
+
+	vfd = video_device_alloc();
+	if (!vfd) {
+		v4l2_err(&pcdev->v4l2_dev, "Failed to allocate video device\n");
+		ret = -ENOMEM;
+		goto unreg_dev;
+	}
+
+	*vfd = emmaprp_videodev;
+	vfd->lock = &pcdev->dev_mutex;
+
+	ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
+	if (ret) {
+		v4l2_err(&pcdev->v4l2_dev, "Failed to register video device\n");
+		goto rel_vdev;
+	}
+
+	video_set_drvdata(vfd, pcdev);
+	snprintf(vfd->name, sizeof(vfd->name), "%s", emmaprp_videodev.name);
+	pcdev->vfd = vfd;
+	v4l2_info(&pcdev->v4l2_dev, MEM2MEM_TEST_MODULE_NAME
+			" Device registered as /dev/video%d\n", vfd->num);
+
+	platform_set_drvdata(pdev, pcdev);
+
+	if (!request_mem_region(res_emma->start, resource_size(res_emma),
+				MEM2MEM_NAME)) {
+		ret = -EBUSY;
+		goto rel_vdev;
+	}
+
+	pcdev->base_emma = ioremap(res_emma->start, resource_size(res_emma));
+	if (!pcdev->base_emma) {
+		ret = -ENOMEM;
+		goto rel_mem;
+	}
+	pcdev->irq_emma = irq_emma;
+	pcdev->res_emma = res_emma;
+
+	ret = request_irq(pcdev->irq_emma, emmaprp_irq, 0,
+			  MEM2MEM_NAME, pcdev);
+	if (ret)
+		goto rel_map;
+
+
+	pcdev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
+	if (IS_ERR(pcdev->alloc_ctx)) {
+		v4l2_err(&pcdev->v4l2_dev, "Failed to alloc vb2 context\n");
+		ret = PTR_ERR(pcdev->alloc_ctx);
+		goto err_ctx;
+	}
+
+	pcdev->m2m_dev = v4l2_m2m_init(&m2m_ops);
+	if (IS_ERR(pcdev->m2m_dev)) {
+		v4l2_err(&pcdev->v4l2_dev, "Failed to init mem2mem device\n");
+		ret = PTR_ERR(pcdev->m2m_dev);
+		goto err_m2m;
+	}
+
+	q_data[V4L2_M2M_SRC].fmt = &formats[1];
+	q_data[V4L2_M2M_DST].fmt = &formats[0];
+
+	return 0;
+
+	v4l2_m2m_release(pcdev->m2m_dev);
+err_m2m:
+	video_unregister_device(pcdev->vfd);
+err_ctx:
+	vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
+	free_irq(pcdev->irq_emma, pcdev);
+rel_map:
+	iounmap(pcdev->base_emma);
+rel_mem:
+	release_mem_region(res_emma->start, resource_size(res_emma));
+rel_vdev:
+	video_device_release(vfd);
+unreg_dev:
+	v4l2_device_unregister(&pcdev->v4l2_dev);
+free_clk:
+	clk_put(pcdev->clk_emma);
+free_dev:
+	kfree(pcdev);
+
+	return ret;
+}
+
+static int emmaprp_remove(struct platform_device *pdev)
+{
+	struct resource *res_emma;
+	struct emmaprp_dev *pcdev =
+		(struct emmaprp_dev *)platform_get_drvdata(pdev);
+
+	v4l2_info(&pcdev->v4l2_dev, "Removing " MEM2MEM_TEST_MODULE_NAME);
+	v4l2_m2m_release(pcdev->m2m_dev);
+	free_irq(pcdev->irq_emma, pcdev);
+	iounmap(pcdev->base_emma);
+	res_emma = pcdev->res_emma;
+	release_mem_region(res_emma->start, resource_size(res_emma));
+	video_unregister_device(pcdev->vfd);
+	v4l2_device_unregister(&pcdev->v4l2_dev);
+	clk_put(pcdev->clk_emma);
+	vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
+
+	kfree(pcdev);
+
+	return 0;
+}
+
+static struct platform_driver emmaprp_pdrv = {
+	.probe		= emmaprp_probe,
+	.remove		= emmaprp_remove,
+	.driver		= {
+		.name	= MEM2MEM_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static void __exit emmaprp_exit(void)
+{
+	platform_driver_unregister(&emmaprp_pdrv);
+}
+
+static int __init emmaprp_init(void)
+{
+	return platform_driver_register(&emmaprp_pdrv);
+}
+
+module_init(emmaprp_init);
+module_exit(emmaprp_exit);
+