Re: [PATCH 4/4 v2][FOR 3.1] v4l2: add blackfin capture bridge driver

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On Mon, 19 Sep 2011, Scott Jiang wrote:

> this is a v4l2 bridge driver for Blackfin video capture device,
> support ppi interface
> 
> Signed-off-by: Scott Jiang <scott.jiang.linux@xxxxxxxxx>

Ok, I know, coming up with new comments to old code in a patch is bad, 
sorry about that... But, I think, Hans has requested some changes too, so, 
you anyway will be doing a v3.

> ---
>  drivers/media/video/Kconfig                 |    2 +
>  drivers/media/video/Makefile                |    2 +
>  drivers/media/video/blackfin/Kconfig        |   10 +
>  drivers/media/video/blackfin/Makefile       |    2 +
>  drivers/media/video/blackfin/bfin_capture.c | 1114 +++++++++++++++++++++++++++
>  drivers/media/video/blackfin/ppi.c          |  201 +++++
>  include/media/blackfin/bfin_capture.h       |   33 +
>  include/media/blackfin/ppi.h                |   63 ++
>  8 files changed, 1427 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/media/video/blackfin/Kconfig
>  create mode 100644 drivers/media/video/blackfin/Makefile
>  create mode 100644 drivers/media/video/blackfin/bfin_capture.c
>  create mode 100644 drivers/media/video/blackfin/ppi.c
>  create mode 100644 include/media/blackfin/bfin_capture.h
>  create mode 100644 include/media/blackfin/ppi.h
> 
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index 1c03abf..52cd491 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -602,6 +602,8 @@ source "drivers/media/video/davinci/Kconfig"
>  
>  source "drivers/media/video/omap/Kconfig"
>  
> +source "drivers/media/video/blackfin/Kconfig"
> +
>  source "drivers/media/video/bt8xx/Kconfig"
>  
>  config VIDEO_PMS
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index 03b55ed..227a700 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -177,6 +177,8 @@ obj-$(CONFIG_VIDEO_SAMSUNG_S5P_FIMC) 	+= s5p-fimc/
>  obj-$(CONFIG_VIDEO_SAMSUNG_S5P_MFC)	+= s5p-mfc/
>  obj-$(CONFIG_VIDEO_SAMSUNG_S5P_TV)	+= s5p-tv/
>  
> +obj-$(CONFIG_BLACKFIN)                  += blackfin/

Please, use TABs

> +
>  obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
>  
>  obj-$(CONFIG_VIDEO_SH_VOU)		+= sh_vou.o
> diff --git a/drivers/media/video/blackfin/Kconfig b/drivers/media/video/blackfin/Kconfig
> new file mode 100644
> index 0000000..ecd5323
> --- /dev/null
> +++ b/drivers/media/video/blackfin/Kconfig
> @@ -0,0 +1,10 @@
> +config VIDEO_BLACKFIN_CAPTURE
> +	tristate "Blackfin Video Capture Driver"
> +	depends on VIDEO_V4L2 && BLACKFIN && I2C
> +	select VIDEOBUF2_DMA_CONTIG
> +	help
> +	  V4L2 bridge driver for Blackfin video capture device.
> +	  Choose PPI or EPPI as its interface.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called bfin_video_capture.
> diff --git a/drivers/media/video/blackfin/Makefile b/drivers/media/video/blackfin/Makefile
> new file mode 100644
> index 0000000..aa3a0a2
> --- /dev/null
> +++ b/drivers/media/video/blackfin/Makefile
> @@ -0,0 +1,2 @@
> +bfin_video_capture-objs := bfin_capture.o ppi.o
> +obj-$(CONFIG_VIDEO_BLACKFIN_CAPTURE) += bfin_video_capture.o
> diff --git a/drivers/media/video/blackfin/bfin_capture.c b/drivers/media/video/blackfin/bfin_capture.c
> new file mode 100644
> index 0000000..30ed8bb
> --- /dev/null
> +++ b/drivers/media/video/blackfin/bfin_capture.c
> @@ -0,0 +1,1114 @@
> +/*
> + * Analog Devices video capture driver
> + *
> + * Copyright (c) 2011 Analog Devices Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/fs.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/time.h>
> +#include <linux/types.h>
> +
> +#include <media/v4l2-chip-ident.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include <asm/dma.h>
> +
> +#include <media/blackfin/bfin_capture.h>
> +
> +#define CAPTURE_DRV_NAME        "bfin_capture"
> +#define BCAP_MIN_NUM_BUF        2
> +
> +struct bcap_format {
> +	u8 *desc;

No need for "u8," use "char" instead - you use it for strings.

> +	u32 pixelformat;
> +	enum v4l2_mbus_pixelcode mbus_code;
> +	int bpp; /* bits per pixel */
> +};
> +
> +struct bcap_buffer {
> +	struct vb2_buffer vb;
> +	struct list_head list;
> +};
> +
> +struct bcap_device {
> +	/* capture device instance */
> +	struct v4l2_device v4l2_dev;
> +	/* device node data */
> +	struct video_device *video_dev;
> +	/* sub device instance */
> +	struct v4l2_subdev *sd;
> +	/* capture config */
> +	struct bfin_capture_config *cfg;
> +	/* ppi interface */
> +	struct ppi_if *ppi;
> +	/* current input */
> +	unsigned int cur_input;
> +	/* current selected standard */
> +	v4l2_std_id std;
> +	/* used to store pixel format */
> +	struct v4l2_pix_format fmt;
> +	/* bits per pixel*/
> +	int bpp;
> +	/* pointing to current video buffer */
> +	struct bcap_buffer *cur_frm;
> +	/* pointing to next video buffer */
> +	struct bcap_buffer *next_frm;
> +	/* buffer queue used in videobuf2 */
> +	struct vb2_queue buffer_queue;
> +	/* allocator-specific contexts for each plane */
> +	struct vb2_alloc_ctx *alloc_ctx;
> +	/* queue of filled frames */
> +	struct list_head dma_queue;
> +	/* used in videobuf2 callback */
> +	spinlock_t lock;
> +	/* used to access capture device */
> +	struct mutex mutex;
> +	/* used to wait ppi to complete one transfer */
> +	struct completion comp;
> +	/* number of users performing IO */
> +	unsigned int io_usrs;
> +	/* number of open instances of the device */
> +	unsigned int usrs;
> +	/* indicate whether streaming has started */
> +	bool started;
> +};
> +
> +struct bcap_fh {
> +	struct v4l2_fh fh;
> +	struct bcap_device *bcap_dev;
> +	/* indicates whether this file handle is doing IO */
> +	bool io_allowed;
> +};
> +
> +static const struct bcap_format bcap_formats[] = {
> +	{
> +		.desc        = "YCbCr 4:2:2 Interleaved UYVY",
> +		.pixelformat = V4L2_PIX_FMT_UYVY,
> +		.mbus_code   = V4L2_MBUS_FMT_UYVY8_2X8,
> +		.bpp         = 16,
> +	},
> +	{
> +		.desc        = "YCbCr 4:2:2 Interleaved YUYV",
> +		.pixelformat = V4L2_PIX_FMT_YUYV,
> +		.mbus_code   = V4L2_MBUS_FMT_YUYV8_2X8,
> +		.bpp         = 16,
> +	},
> +	{
> +		.desc        = "RGB 565",
> +		.pixelformat = V4L2_PIX_FMT_RGB565,
> +		.mbus_code   = V4L2_MBUS_FMT_RGB565_2X8_LE,
> +		.bpp         = 16,
> +	},
> +	{
> +		.desc        = "RGB 444",
> +		.pixelformat = V4L2_PIX_FMT_RGB444,
> +		.mbus_code   = V4L2_MBUS_FMT_RGB444_2X8_PADHI_LE,
> +		.bpp         = 16,
> +	},
> +
> +};
> +#define BCAP_MAX_FMTS ARRAY_SIZE(bcap_formats)
> +
> +static irqreturn_t bcap_isr(int irq, void *dev_id);
> +
> +static struct bcap_buffer *to_bcap_vb(struct vb2_buffer *vb)
> +{
> +	return container_of(vb, struct bcap_buffer, vb);
> +}
> +
> +static int bcap_open(struct file *file)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct video_device *vfd = bcap_dev->video_dev;
> +	struct v4l2_mbus_framefmt mbus_fmt;
> +	struct v4l2_pix_format *pixfmt = &bcap_dev->fmt;
> +	const struct bcap_format *bcap_fmt;
> +	struct bcap_fh *bcap_fh;
> +	int ret, i;
> +
> +	if (!bcap_dev->sd) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "No sub device registered\n");
> +		return -ENODEV;
> +	}
> +
> +	/* if first open, query format of subdevice as default format */
> +	if (!bcap_dev->usrs) {
> +		ret = v4l2_subdev_call(bcap_dev->sd, video,
> +					g_mbus_fmt, &mbus_fmt);
> +		if (ret < 0)
> +			return ret;
> +
> +		for (i = 0; i < BCAP_MAX_FMTS; i++) {
> +			if (mbus_fmt.code != bcap_formats[i].mbus_code)
> +				continue;
> +			bcap_fmt = &bcap_formats[i];
> +			v4l2_fill_pix_format(pixfmt, &mbus_fmt);
> +			pixfmt->pixelformat = bcap_fmt->pixelformat;
> +			pixfmt->bytesperline = pixfmt->width * bcap_fmt->bpp / 8;
> +			pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
> +			break;
> +		}
> +		if (i == BCAP_MAX_FMTS) {
> +			v4l2_err(&bcap_dev->v4l2_dev,
> +					"subdev fmt is not supported by bcap\n");
> +			return -EINVAL;
> +		}

Now, this looks ugly to me. Maybe this would be better:

		for (i = 0; i < BCAP_MAX_FMTS; i++)
			if (mbus_fmt.code == bcap_formats[i].mbus_code)
				break;
		if (i == BCAP_MAX_FMTS) {
			v4l2_err(&bcap_dev->v4l2_dev,
					"subdev fmt is not supported by bcap\n");
			return -EINVAL;
		}
		bcap_fmt = &bcap_formats[i];
		v4l2_fill_pix_format(pixfmt, &mbus_fmt);
		...

> +	}
> +
> +	bcap_fh = kzalloc(sizeof(*bcap_fh), GFP_KERNEL);
> +	if (!bcap_fh) {
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +			 "unable to allocate memory for file handle object\n");
> +		return -ENOMEM;
> +	}
> +
> +	v4l2_fh_init(&bcap_fh->fh, vfd);
> +
> +	/* store pointer to v4l2_fh in private_data member of file */
> +	file->private_data = &bcap_fh->fh;
> +	v4l2_fh_add(&bcap_fh->fh);
> +	bcap_fh->bcap_dev = bcap_dev;
> +	bcap_dev->usrs++;
> +	bcap_fh->io_allowed = false;
> +	return 0;
> +}
> +
> +static int bcap_release(struct file *file)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_fh *fh = file->private_data;
> +	struct bcap_fh *bcap_fh = container_of(fh, struct bcap_fh, fh);
> +
> +	/* if this instance is doing IO */
> +	if (bcap_fh->io_allowed) {
> +		vb2_queue_release(&bcap_dev->buffer_queue);
> +		bcap_dev->io_usrs = 0;
> +	}
> +
> +	bcap_dev->usrs--;
> +	file->private_data = NULL;
> +	v4l2_fh_del(&bcap_fh->fh);
> +	v4l2_fh_exit(&bcap_fh->fh);
> +	kfree(bcap_fh);
> +	return 0;
> +}
> +
> +static int bcap_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return vb2_mmap(&bcap_dev->buffer_queue, vma);
> +}
> +
> +#ifndef CONFIG_MMU
> +static unsigned long bcap_get_unmapped_area(struct file *file,
> +					    unsigned long addr,
> +					    unsigned long len,
> +					    unsigned long pgoff,
> +					    unsigned long flags)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return vb2_get_unmapped_area(&bcap_dev->buffer_queue,
> +				     addr,
> +				     len,
> +				     pgoff,
> +				     flags);
> +}
> +#endif
> +
> +static unsigned int bcap_poll(struct file *file, poll_table *wait)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	if (bcap_dev->started)
> +		return vb2_poll(&bcap_dev->buffer_queue, file, wait);
> +	return 0;
> +}
> +
> +static int bcap_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
> +				unsigned int *nplanes, unsigned long sizes[],
> +				void *alloc_ctxs[])
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vq);
> +
> +	if (*nbuffers < BCAP_MIN_NUM_BUF)
> +		*nbuffers = BCAP_MIN_NUM_BUF;
> +
> +	*nplanes = 1;
> +	sizes[0] = bcap_dev->fmt.sizeimage;
> +	alloc_ctxs[0] = bcap_dev->alloc_ctx;
> +
> +	return 0;
> +}
> +
> +static int bcap_buffer_init(struct vb2_buffer *vb)
> +{
> +	struct bcap_buffer *buf = to_bcap_vb(vb);
> +
> +	INIT_LIST_HEAD(&buf->list);
> +	return 0;
> +}
> +
> +static int bcap_buffer_prepare(struct vb2_buffer *vb)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vb->vb2_queue);
> +	struct bcap_buffer *buf = to_bcap_vb(vb);
> +	unsigned long size;
> +
> +	size = bcap_dev->fmt.sizeimage;
> +	if (vb2_plane_size(vb, 0) < size) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "buffer too small (%lu < %lu)\n",
> +				vb2_plane_size(vb, 0), size);
> +		return -EINVAL;
> +	}
> +	vb2_set_plane_payload(&buf->vb, 0, size);
> +
> +	return 0;
> +}
> +
> +static void bcap_buffer_queue(struct vb2_buffer *vb)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vb->vb2_queue);
> +	struct bcap_buffer *buf = to_bcap_vb(vb);
> +	unsigned long flags = 0;

No need to initialise, same everywhere below.

> +
> +	spin_lock_irqsave(&bcap_dev->lock, flags);
> +	list_add_tail(&buf->list, &bcap_dev->dma_queue);
> +	spin_unlock_irqrestore(&bcap_dev->lock, flags);
> +}
> +
> +static void bcap_buffer_cleanup(struct vb2_buffer *vb)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vb->vb2_queue);
> +	struct bcap_buffer *buf = to_bcap_vb(vb);
> +	unsigned long flags = 0;
> +
> +	spin_lock_irqsave(&bcap_dev->lock, flags);
> +	list_del_init(&buf->list);
> +	spin_unlock_irqrestore(&bcap_dev->lock, flags);
> +}
> +
> +static void bcap_lock(struct vb2_queue *vq)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vq);
> +	mutex_lock(&bcap_dev->mutex);
> +}
> +
> +static void bcap_unlock(struct vb2_queue *vq)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vq);
> +	mutex_unlock(&bcap_dev->mutex);
> +}
> +
> +static int bcap_start_streaming(struct vb2_queue *vq)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vq);
> +	struct ppi_if *ppi = bcap_dev->ppi;
> +	struct ppi_params params;
> +	int ret;
> +
> +	/* enable streamon on the sub device */
> +	ret = v4l2_subdev_call(bcap_dev->sd, video, s_stream, 1);
> +	if (ret && (ret != -ENOIOCTLCMD)) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "stream on failed in subdev\n");
> +		return ret;
> +	}
> +
> +	/* attach ppi DMA irq handler */
> +	ret = ppi->ops->attach_irq(ppi, bcap_isr);
> +	if (ret < 0) {
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +				"Error in attaching interrupt handler\n");
> +		return -EFAULT;
> +	}
> +
> +	/* set ppi params */
> +	params.width = bcap_dev->fmt.width;
> +	params.height = bcap_dev->fmt.height;
> +	params.bpp = bcap_dev->bpp;
> +	params.ppi_control = bcap_dev->cfg->ppi_control;
> +	ret = ppi->ops->set_params(ppi, &params);

Why are you using these ppi operations at all? why not just call functions 
directly? Are you expecting a different implementation in the future?

> +	if (ret < 0) {
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +				"Error in setting ppi params\n");
> +		ppi->ops->detach_irq(ppi);
> +		return -EINVAL;

return ret?

> +	}
> +
> +	INIT_COMPLETION(bcap_dev->comp);
> +	return 0;
> +}
> +
> +static int bcap_stop_streaming(struct vb2_queue *vq)
> +{
> +	struct bcap_device *bcap_dev = vb2_get_drv_priv(vq);
> +	struct ppi_if *ppi = bcap_dev->ppi;
> +	int ret;
> +
> +	if (!bcap_dev->started)
> +		return 0;
> +
> +	bcap_dev->started = false;
> +	wait_for_completion(&bcap_dev->comp);
> +	ppi->ops->stop(ppi);
> +	ppi->ops->detach_irq(ppi);
> +	ret = v4l2_subdev_call(bcap_dev->sd, video, s_stream, 0);
> +	if (ret && (ret != -ENOIOCTLCMD))
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +				"stream off failed in subdev\n");
> +
> +	/* release all active buffers */
> +	while (!list_empty(&bcap_dev->dma_queue)) {
> +		bcap_dev->next_frm = list_entry(bcap_dev->dma_queue.next,
> +						struct bcap_buffer, list);
> +		list_del(&bcap_dev->next_frm->list);
> +		vb2_buffer_done(&bcap_dev->next_frm->vb, VB2_BUF_STATE_ERROR);
> +	}
> +	return 0;
> +}
> +
> +static struct vb2_ops bcap_video_qops = {
> +	.queue_setup            = bcap_queue_setup,
> +	.buf_init               = bcap_buffer_init,
> +	.buf_prepare            = bcap_buffer_prepare,
> +	.buf_cleanup            = bcap_buffer_cleanup,
> +	.buf_queue              = bcap_buffer_queue,
> +	.wait_prepare           = bcap_unlock,
> +	.wait_finish            = bcap_lock,
> +	.start_streaming        = bcap_start_streaming,
> +	.stop_streaming         = bcap_stop_streaming,
> +};
> +
> +static int bcap_reqbufs(struct file *file, void *priv,
> +			struct v4l2_requestbuffers *req_buf)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_fh *fh = file->private_data;
> +	struct bcap_fh *bcap_fh = container_of(fh, struct bcap_fh, fh);
> +
> +	if (bcap_dev->io_usrs != 0) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "Only one IO user allowed\n");
> +		return -EBUSY;
> +	}
> +
> +	bcap_fh->io_allowed = true;
> +	bcap_dev->io_usrs = 1;
> +
> +	return vb2_reqbufs(&bcap_dev->buffer_queue, req_buf);
> +}
> +
> +static int bcap_querybuf(struct file *file, void *priv,
> +				struct v4l2_buffer *buf)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return vb2_querybuf(&bcap_dev->buffer_queue, buf);
> +}
> +
> +static int bcap_qbuf(struct file *file, void *priv,
> +			struct v4l2_buffer *buf)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_fh *fh = file->private_data;
> +	struct bcap_fh *bcap_fh = container_of(fh, struct bcap_fh, fh);
> +
> +	if (!bcap_fh->io_allowed)
> +		return -EACCES;
> +
> +	return vb2_qbuf(&bcap_dev->buffer_queue, buf);
> +}
> +
> +static int bcap_dqbuf(struct file *file, void *priv,
> +			struct v4l2_buffer *buf)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_fh *fh = file->private_data;
> +	struct bcap_fh *bcap_fh = container_of(fh, struct bcap_fh, fh);
> +
> +	if (!bcap_fh->io_allowed)
> +		return -EACCES;
> +
> +	return vb2_dqbuf(&bcap_dev->buffer_queue,
> +				buf, file->f_flags & O_NONBLOCK);
> +}
> +
> +static irqreturn_t bcap_isr(int irq, void *dev_id)
> +{
> +	struct ppi_if *ppi = dev_id;
> +	struct bcap_device *bcap_dev = ppi->priv;
> +	struct timeval timevalue;
> +	struct vb2_buffer *vb = &bcap_dev->cur_frm->vb;
> +	dma_addr_t addr;
> +
> +	spin_lock(&bcap_dev->lock);
> +
> +	if (bcap_dev->cur_frm != bcap_dev->next_frm) {
> +		do_gettimeofday(&timevalue);
> +		vb->v4l2_buf.timestamp = timevalue;
> +		vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
> +		bcap_dev->cur_frm = bcap_dev->next_frm;
> +	}
> +
> +	ppi->ops->stop(ppi);
> +
> +	if (!bcap_dev->started) {
> +		complete(&bcap_dev->comp);
> +	} else {
> +		if (!list_empty(&bcap_dev->dma_queue)) {
> +			bcap_dev->next_frm = list_entry(bcap_dev->dma_queue.next,
> +						struct bcap_buffer, list);
> +			list_del(&bcap_dev->next_frm->list);
> +			addr = vb2_dma_contig_plane_paddr(&bcap_dev->next_frm->vb, 0);

vb2_dma_contig_plane_dma_addr(), you might want to rebase your work on top 
of

git://linuxtv.org/media_tree.git / staging/for_v3.2

> +			ppi->ops->update_addr(ppi, (unsigned long)addr);
> +		}
> +		ppi->ops->start(ppi);
> +	}
> +
> +	spin_unlock(&bcap_dev->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int bcap_streamon(struct file *file, void *priv,
> +				enum v4l2_buf_type buf_type)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct bcap_fh *fh = file->private_data;
> +	struct ppi_if *ppi = bcap_dev->ppi;
> +	dma_addr_t addr;
> +	int ret;
> +
> +	if (!fh->io_allowed)
> +		return -EACCES;
> +
> +	if (bcap_dev->started)
> +		return -EBUSY;
> +
> +	/* call streamon to start streaming in videobuf */
> +	ret = vb2_streamon(&bcap_dev->buffer_queue, buf_type);
> +	if (ret)
> +		return ret;
> +
> +	/* if dma queue is empty, return error */
> +	if (list_empty(&bcap_dev->dma_queue)) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "dma queue is empty\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	/* get the next frame from the dma queue */
> +	bcap_dev->next_frm = list_entry(bcap_dev->dma_queue.next,
> +					struct bcap_buffer, list);
> +	bcap_dev->cur_frm = bcap_dev->next_frm;
> +	/* remove buffer from the dma queue */
> +	list_del(&bcap_dev->cur_frm->list);
> +	addr = vb2_dma_contig_plane_paddr(&bcap_dev->cur_frm->vb, 0);

ditto: ..._dma_addr()

> +	/* update DMA address */
> +	ppi->ops->update_addr(ppi, (unsigned long)addr);
> +	/* enable ppi */
> +	ppi->ops->start(ppi);
> +	bcap_dev->started = true;

Even if ov2640's .s_stream() operation is a NOP, you still might want to 
call it here and in streamoff() below.

> +
> +	return 0;
> +err:
> +	vb2_streamoff(&bcap_dev->buffer_queue, buf_type);
> +	return ret;
> +}
> +
> +static int bcap_streamoff(struct file *file, void *priv,
> +				enum v4l2_buf_type buf_type)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct bcap_fh *fh = file->private_data;
> +
> +	if (!fh->io_allowed)
> +		return -EACCES;
> +
> +	if (!bcap_dev->started)
> +		return -EINVAL;
> +
> +	return vb2_streamoff(&bcap_dev->buffer_queue, buf_type);
> +}
> +
> +static int bcap_queryctrl(struct file *file, void *priv,
> +				struct v4l2_queryctrl *qctrl)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return v4l2_subdev_call(bcap_dev->sd, core, queryctrl, qctrl);
> +}
> +
> +static int bcap_g_ctrl(struct file *file, void *priv,
> +			struct v4l2_control *ctrl)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return v4l2_subdev_call(bcap_dev->sd, core, g_ctrl, ctrl);
> +}
> +
> +static int bcap_s_ctrl(struct file *file, void *priv,
> +			struct v4l2_control *ctrl)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return v4l2_subdev_call(bcap_dev->sd, core, s_ctrl, ctrl);
> +}
> +
> +static int bcap_querystd(struct file *file, void *priv, v4l2_std_id *std)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	int ret;
> +
> +	ret = v4l2_subdev_call(bcap_dev->sd, video, querystd, std);
> +	return ret;
> +}
> +
> +static int bcap_g_std(struct file *file, void *priv, v4l2_std_id *std)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	if (bcap_dev->std) {
> +		*std = bcap_dev->std;
> +		return 0;
> +	} else
> +		return -EINVAL;

Either add braces or change to something like

	if (!bcap_dev->std)
		return -EINVAL;

	*std = bcap_dev->std;
	return 0;

> +}
> +
> +static int bcap_s_std(struct file *file, void *priv, v4l2_std_id *std)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	int ret;
> +
> +	/* if streaming is started, return error */
> +	if (bcap_dev->started) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "Streaming is started\n");
> +		return -EBUSY;
> +	}
> +
> +	ret = v4l2_subdev_call(bcap_dev->sd, core, s_std, *std);
> +	if (ret < 0)
> +		return ret;
> +
> +	bcap_dev->std = *std;
> +	return 0;
> +}
> +
> +static int bcap_enum_input(struct file *file, void *priv,
> +				struct v4l2_input *input)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct bfin_capture_config *config = bcap_dev->cfg;
> +	int ret;
> +	u32 status;
> +
> +	if (input->index >= config->num_inputs)
> +		return -EINVAL;
> +
> +	*input = config->inputs[input->index];
> +	/* get input status */
> +	ret = v4l2_subdev_call(bcap_dev->sd, video, g_input_status, &status);
> +	if (!ret)
> +		input->status = status;
> +	return 0;
> +}
> +
> +static int bcap_g_input(struct file *file, void *priv, unsigned int *index)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	*index = bcap_dev->cur_input;
> +	return 0;
> +}
> +
> +static int bcap_s_input(struct file *file, void *priv, unsigned int index)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct bfin_capture_config *config = bcap_dev->cfg;
> +	struct bcap_route *route;
> +	int ret;
> +
> +	/* if streaming is started, return error */
> +	if (bcap_dev->started) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "Streaming is started\n");
> +		return -EBUSY;
> +	}
> +
> +	if (index >= config->num_inputs)
> +		return -EINVAL;
> +
> +	route = &config->routes[index];
> +	ret = v4l2_subdev_call(bcap_dev->sd, video, s_routing,
> +				route->input, route->output, 0);
> +	if ((ret < 0) && (ret != -ENOIOCTLCMD)) {

Superfluous parenthesis

> +		v4l2_err(&bcap_dev->v4l2_dev, "Failed to set input\n");
> +		return ret;
> +	}
> +	bcap_dev->cur_input = index;
> +	return 0;
> +}
> +
> +static int bcap_try_format(struct bcap_device *bcap,
> +				struct v4l2_pix_format *pixfmt,
> +				enum v4l2_mbus_pixelcode *mbus_code,
> +				int *bpp)
> +{
> +	const struct bcap_format *fmt;
> +	struct v4l2_mbus_framefmt mbus_fmt;
> +	int ret, i;
> +
> +	for (i = 0; i < BCAP_MAX_FMTS; i++) {
> +		if (pixfmt->pixelformat != bcap_formats[i].pixelformat)
> +			continue;

IMHO, also here this would look prettier:

	for (...)
		if (...)
			break;

	if (i == MAX)
		return -EINVAL;

	...
	return 0;

But in fact .try_fmt() shouldn't fail. I would only consider failing, if 
the subdevice failed - then you have no chance. Otherwise just pick up any 
format you like, but do not fail.

> +		fmt = &bcap_formats[i];
> +		if (mbus_code)
> +			*mbus_code = fmt->mbus_code;
> +		if (bpp)
> +			*bpp = fmt->bpp;
> +		v4l2_fill_mbus_format(&mbus_fmt, pixfmt, fmt->mbus_code);
> +		ret = v4l2_subdev_call(bcap->sd, video,
> +					try_mbus_fmt, &mbus_fmt);
> +		if (ret < 0)
> +			return ret;
> +		v4l2_fill_pix_format(pixfmt, &mbus_fmt);
> +		pixfmt->bytesperline = pixfmt->width * fmt->bpp / 8;
> +		pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
> +		return 0;
> +	}
> +	return -EINVAL;
> +}
> +
> +static int bcap_enum_fmt_vid_cap(struct file *file, void  *priv,
> +					struct v4l2_fmtdesc *fmt)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	enum v4l2_mbus_pixelcode mbus_code;
> +	u32 index = fmt->index;
> +	int ret, i;
> +
> +	ret = v4l2_subdev_call(bcap_dev->sd, video,
> +				enum_mbus_fmt, index, &mbus_code);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < BCAP_MAX_FMTS; i++) {
> +		if (mbus_code != bcap_formats[i].mbus_code)
> +			continue;

ditto - loop formatting

> +		fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +		strlcpy(fmt->description,
> +			bcap_formats[index].desc,
> +			sizeof(fmt->description));
> +		fmt->pixelformat = bcap_formats[index].pixelformat;
> +		return 0;
> +	}
> +	v4l2_err(&bcap_dev->v4l2_dev,
> +			"subdev fmt is not supported by bcap\n");
> +	return -EINVAL;
> +}
> +
> +static int bcap_try_fmt_vid_cap(struct file *file, void *priv,
> +					struct v4l2_format *fmt)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_pix_format *pixfmt = &fmt->fmt.pix;
> +
> +	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	return bcap_try_format(bcap_dev, pixfmt, NULL, NULL);
> +}
> +
> +static int bcap_g_fmt_vid_cap(struct file *file, void *priv,
> +				struct v4l2_format *fmt)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_mbus_framefmt mbus_fmt;
> +	const struct bcap_format *bcap_fmt;
> +	struct v4l2_pix_format *pixfmt = &fmt->fmt.pix;
> +	int ret, i;
> +
> +	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	ret = v4l2_subdev_call(bcap_dev->sd, video,
> +				g_mbus_fmt, &mbus_fmt);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < BCAP_MAX_FMTS; i++) {
> +		if (mbus_fmt.code != bcap_formats[i].mbus_code)

-"-

> +			continue;
> +		bcap_fmt = &bcap_formats[i];
> +		v4l2_fill_pix_format(pixfmt, &mbus_fmt);
> +		pixfmt->pixelformat = bcap_fmt->pixelformat;
> +		pixfmt->bytesperline = pixfmt->width * bcap_fmt->bpp / 8;
> +		pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
> +		return 0;
> +	}
> +	v4l2_err(&bcap_dev->v4l2_dev,
> +			"subdev fmt is not supported by bcap\n");
> +	return -EINVAL;

g_fmt() should not be failing either, but you're stuck here in case the 
subdevice returns an unsupported format. That's why in soc-camera we first 
perform some initial format negotiation at probe time - also like Hans has 
suggested - then you know at all times, that you have a valid 
configuration, or you just fail probing straight away.

> +}
> +
> +static int bcap_s_fmt_vid_cap(struct file *file, void *priv,
> +				struct v4l2_format *fmt)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	struct v4l2_mbus_framefmt mbus_fmt;
> +	enum v4l2_mbus_pixelcode mbus_code;
> +	struct v4l2_pix_format *pixfmt = &fmt->fmt.pix;
> +	int ret, bpp;
> +
> +	/* if streaming is started, return error */
> +	if (bcap_dev->started) {
> +		v4l2_err(&bcap_dev->v4l2_dev, "Streaming is started\n");
> +		return -EBUSY;
> +	}
> +
> +	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +	/* see if format works */
> +	ret = bcap_try_format(bcap_dev, pixfmt, &mbus_code, &bpp);
> +	if (ret < 0)
> +		return ret;
> +
> +	v4l2_fill_mbus_format(&mbus_fmt, pixfmt, mbus_code);
> +	ret = v4l2_subdev_call(bcap_dev->sd, video, s_mbus_fmt, &mbus_fmt);
> +	if (ret < 0)
> +		return ret;

the subdevice might have changed geometry and the pixel code - just like 
ov2640 does. You, probably, want to double-check the result.

> +	bcap_dev->fmt = *pixfmt;
> +	bcap_dev->bpp = bpp;
> +	return 0;
> +}
> +
> +static int bcap_querycap(struct file *file, void  *priv,
> +				struct v4l2_capability *cap)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
> +	strlcpy(cap->driver, CAPTURE_DRV_NAME, sizeof(cap->driver));
> +	strlcpy(cap->bus_info, "Blackfin Platform", sizeof(cap->bus_info));
> +	strlcpy(cap->card, bcap_dev->cfg->card_name, sizeof(cap->card));
> +	return 0;
> +}
> +
> +static int bcap_cropcap(struct file *file, void *priv,
> +			struct v4l2_cropcap *crop)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	if (crop->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +
> +	return v4l2_subdev_call(bcap_dev->sd, video, cropcap, crop);
> +}

Hm, does it make much sense to support cropcap and not to support g_crop 
or s_crop? Not sure what others do in this case, or whether the spec says 
anything about it, but if you cannot crop, it would be logical to return 
defrect == bounds from cropcap.

> +
> +static int bcap_g_parm(struct file *file, void *fh,
> +				struct v4l2_streamparm *a)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +	return v4l2_subdev_call(bcap_dev->sd, video, g_parm, a);
> +}
> +
> +static int bcap_s_parm(struct file *file, void *fh,
> +				struct v4l2_streamparm *a)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +		return -EINVAL;
> +	return v4l2_subdev_call(bcap_dev->sd, video, s_parm, a);
> +}
> +
> +static int bcap_g_chip_ident(struct file *file, void *priv,
> +		struct v4l2_dbg_chip_ident *chip)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	chip->ident = V4L2_IDENT_NONE;
> +	chip->revision = 0;
> +	if (chip->match.type != V4L2_CHIP_MATCH_I2C_DRIVER &&
> +			chip->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
> +		return -EINVAL;
> +
> +	return v4l2_subdev_call(bcap_dev->sd, core,
> +			g_chip_ident, chip);
> +}
> +
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +static int bcap_dbg_g_register(struct file *file, void *priv,
> +		struct v4l2_dbg_register *reg)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return v4l2_subdev_call(bcap_dev->sd, core,
> +			g_register, reg);
> +}
> +
> +static int bcap_dbg_s_register(struct file *file, void *priv,
> +		struct v4l2_dbg_register *reg)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +
> +	return v4l2_subdev_call(bcap_dev->sd, core,
> +			s_register, reg);
> +}
> +#endif
> +
> +static int bcap_log_status(struct file *file, void *priv)
> +{
> +	struct bcap_device *bcap_dev = video_drvdata(file);
> +	/* status for sub devices */
> +	v4l2_device_call_all(&bcap_dev->v4l2_dev, 0, core, log_status);
> +	return 0;
> +}
> +
> +static const struct v4l2_ioctl_ops bcap_ioctl_ops = {
> +	.vidioc_querycap         = bcap_querycap,
> +	.vidioc_g_fmt_vid_cap    = bcap_g_fmt_vid_cap,
> +	.vidioc_enum_fmt_vid_cap = bcap_enum_fmt_vid_cap,
> +	.vidioc_s_fmt_vid_cap    = bcap_s_fmt_vid_cap,
> +	.vidioc_try_fmt_vid_cap  = bcap_try_fmt_vid_cap,
> +	.vidioc_enum_input       = bcap_enum_input,
> +	.vidioc_g_input          = bcap_g_input,
> +	.vidioc_s_input          = bcap_s_input,
> +	.vidioc_querystd         = bcap_querystd,
> +	.vidioc_s_std            = bcap_s_std,
> +	.vidioc_g_std            = bcap_g_std,
> +	.vidioc_queryctrl        = bcap_queryctrl,
> +	.vidioc_g_ctrl           = bcap_g_ctrl,
> +	.vidioc_s_ctrl           = bcap_s_ctrl,
> +	.vidioc_reqbufs          = bcap_reqbufs,
> +	.vidioc_querybuf         = bcap_querybuf,
> +	.vidioc_qbuf             = bcap_qbuf,
> +	.vidioc_dqbuf            = bcap_dqbuf,
> +	.vidioc_streamon         = bcap_streamon,
> +	.vidioc_streamoff        = bcap_streamoff,
> +	.vidioc_cropcap          = bcap_cropcap,
> +	.vidioc_g_parm           = bcap_g_parm,
> +	.vidioc_s_parm           = bcap_s_parm,
> +	.vidioc_g_chip_ident     = bcap_g_chip_ident,
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +	.vidioc_g_register       = bcap_dbg_g_register,
> +	.vidioc_s_register       = bcap_dbg_s_register,
> +#endif
> +	.vidioc_log_status       = bcap_log_status,
> +};
> +
> +static struct v4l2_file_operations bcap_fops = {
> +	.owner = THIS_MODULE,
> +	.open = bcap_open,
> +	.release = bcap_release,
> +	.unlocked_ioctl = video_ioctl2,
> +	.mmap = bcap_mmap,
> +#ifndef CONFIG_MMU
> +	.get_unmapped_area = bcap_get_unmapped_area,
> +#endif
> +	.poll = bcap_poll
> +};
> +
> +static int __devinit bcap_probe(struct platform_device *pdev)
> +{
> +	struct bcap_device *bcap_dev;
> +	struct video_device *vfd;
> +	struct i2c_adapter *i2c_adap;
> +	struct bfin_capture_config *config;
> +	struct vb2_queue *q;
> +	int ret;
> +
> +	config = pdev->dev.platform_data;
> +	if (!config) {
> +		v4l2_err(pdev->dev.driver, "Unable to get board config\n");
> +		return -ENODEV;
> +	}
> +
> +	bcap_dev = kzalloc(sizeof(*bcap_dev), GFP_KERNEL);
> +	if (!bcap_dev) {
> +		v4l2_err(pdev->dev.driver, "Unable to alloc bcap_dev\n");
> +		return -ENOMEM;
> +	}
> +
> +	bcap_dev->cfg = config;
> +
> +	bcap_dev->ppi = ppi_create_instance(config->ppi_info);
> +	if (!bcap_dev->ppi) {
> +		v4l2_err(pdev->dev.driver, "Unable to create ppi\n");
> +		ret = -ENODEV;
> +		goto err_free_dev;
> +	}
> +	bcap_dev->ppi->priv = bcap_dev;
> +
> +	bcap_dev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
> +	if (IS_ERR(bcap_dev->alloc_ctx)) {
> +		ret = PTR_ERR(bcap_dev->alloc_ctx);
> +		goto err_free_ppi;
> +	}
> +
> +	vfd = video_device_alloc();
> +	if (!vfd) {
> +		ret = -ENOMEM;
> +		v4l2_err(pdev->dev.driver, "Unable to alloc video device\n");
> +		goto err_cleanup_ctx;
> +	}
> +
> +	/* initialize field of video device */
> +	vfd->release            = video_device_release;
> +	vfd->fops               = &bcap_fops;
> +	vfd->ioctl_ops          = &bcap_ioctl_ops;
> +	vfd->tvnorms            = 0;
> +	vfd->v4l2_dev           = &bcap_dev->v4l2_dev;
> +	set_bit(V4L2_FL_USE_FH_PRIO, &vfd->flags);
> +	strncpy(vfd->name, CAPTURE_DRV_NAME, sizeof(vfd->name));
> +	bcap_dev->video_dev     = vfd;
> +
> +	ret = v4l2_device_register(&pdev->dev, &bcap_dev->v4l2_dev);
> +	if (ret) {
> +		v4l2_err(pdev->dev.driver,
> +				"Unable to register v4l2 device\n");
> +		goto err_release_vdev;
> +	}
> +	v4l2_info(&bcap_dev->v4l2_dev, "v4l2 device registered\n");
> +
> +	spin_lock_init(&bcap_dev->lock);
> +	/* initialize queue */
> +	q = &bcap_dev->buffer_queue;
> +	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	q->io_modes = VB2_MMAP;
> +	q->drv_priv = bcap_dev;
> +	q->buf_struct_size = sizeof(struct bcap_buffer);
> +	q->ops = &bcap_video_qops;
> +	q->mem_ops = &vb2_dma_contig_memops;
> +
> +	vb2_queue_init(q);
> +
> +	mutex_init(&bcap_dev->mutex);
> +	init_completion(&bcap_dev->comp);
> +
> +	/* init video dma queues */
> +	INIT_LIST_HEAD(&bcap_dev->dma_queue);
> +
> +	vfd->lock = &bcap_dev->mutex;
> +
> +	/* register video device */
> +	ret = video_register_device(bcap_dev->video_dev, VFL_TYPE_GRABBER, -1);
> +	if (ret) {
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +				"Unable to register video device\n");
> +		goto err_unreg_v4l2;
> +	}
> +	video_set_drvdata(bcap_dev->video_dev, bcap_dev);
> +	v4l2_info(&bcap_dev->v4l2_dev, "video device registered as: %s\n",
> +			video_device_node_name(vfd));
> +
> +	/* load up the subdevice */
> +	i2c_adap = i2c_get_adapter(config->i2c_adapter_id);
> +	if (!i2c_adap) {
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +				"Unable to find i2c adapter\n");
> +		goto err_unreg_vdev;
> +
> +	}
> +	bcap_dev->sd = v4l2_i2c_new_subdev_board(&bcap_dev->v4l2_dev,
> +						 i2c_adap,
> +						 &config->board_info,
> +						 NULL);
> +	if (bcap_dev->sd) {
> +		int i;
> +		/* update tvnorms from the sub devices */
> +		for (i = 0; i < config->num_inputs; i++)
> +			vfd->tvnorms |= config->inputs[i].std;
> +		/* set default std */
> +		bcap_dev->std = vfd->tvnorms;
> +	} else {
> +		v4l2_err(&bcap_dev->v4l2_dev,
> +				"Unable to register sub device\n");
> +		goto err_unreg_vdev;
> +	}
> +	v4l2_info(&bcap_dev->v4l2_dev, "v4l2 sub device registered\n");
> +	return 0;
> +err_unreg_vdev:
> +	video_unregister_device(bcap_dev->video_dev);
> +err_unreg_v4l2:
> +	v4l2_device_unregister(&bcap_dev->v4l2_dev);
> +err_release_vdev:
> +	if (!video_is_registered(bcap_dev->video_dev))
> +		video_device_release(bcap_dev->video_dev);

this is strange: if you come here from err_unreg_vdev, 
video_unregister_device() will be called, then the device's release 
method, i.e., video_device_release(), right? That will call 
kfree(bcap_dev->video_dev). Then you arrive here and try to dereference a 
freed pointer... Or am I missing something?If I'm right, setting video_dev 
= NULL just above err_unreg_v4l2 shall avoid this problem.

> +err_cleanup_ctx:
> +	vb2_dma_contig_cleanup_ctx(bcap_dev->alloc_ctx);
> +err_free_ppi:
> +	ppi_delete_instance(bcap_dev->ppi);
> +err_free_dev:
> +	kfree(bcap_dev);
> +	return ret;
> +}
> +
> +static int __devexit bcap_remove(struct platform_device *pdev)
> +{
> +	struct v4l2_device *v4l2_dev = platform_get_drvdata(pdev);
> +	struct bcap_device *bcap_dev = container_of(v4l2_dev,
> +						struct bcap_device, v4l2_dev);
> +
> +	video_unregister_device(bcap_dev->video_dev);
> +	v4l2_device_unregister(v4l2_dev);
> +	vb2_dma_contig_cleanup_ctx(bcap_dev->alloc_ctx);
> +	ppi_delete_instance(bcap_dev->ppi);
> +	kfree(bcap_dev);
> +	return 0;
> +}
> +
> +static struct platform_driver bcap_driver = {
> +	.driver = {
> +		.name   = CAPTURE_DRV_NAME,
> +		.owner = THIS_MODULE,

bad alignment

> +	},
> +	.probe = bcap_probe,
> +	.remove = __devexit_p(bcap_remove),
> +};
> +
> +static __init int bcap_init(void)
> +{
> +	return platform_driver_register(&bcap_driver);
> +}
> +
> +static __exit void bcap_exit(void)
> +{
> +	platform_driver_unregister(&bcap_driver);
> +}
> +
> +module_init(bcap_init);
> +module_exit(bcap_exit);
> +
> +MODULE_DESCRIPTION("Analog Devices blackfin video capture driver");
> +MODULE_AUTHOR("Scott Jiang <Scott.Jiang.Linux@xxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/media/video/blackfin/ppi.c b/drivers/media/video/blackfin/ppi.c
> new file mode 100644
> index 0000000..3b5f43e
> --- /dev/null
> +++ b/drivers/media/video/blackfin/ppi.c
> @@ -0,0 +1,201 @@
> +/*
> + * ppi.c Analog Devices Parallel Peripheral Interface driver

So, you expect to have other interfaces (serial or something), which would 
be implementing the same operations and attach to your bfin_capture.c 
instead of ppi.c?

> + *
> + * Copyright (c) 2011 Analog Devices Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +#include <linux/slab.h>
> +
> +#include <asm/bfin_ppi.h>
> +#include <asm/blackfin.h>
> +#include <asm/cacheflush.h>
> +#include <asm/dma.h>
> +#include <asm/portmux.h>
> +
> +#include <media/blackfin/ppi.h>
> +
> +static int ppi_attach_irq(struct ppi_if *ppi, irq_handler_t handler);
> +static void ppi_detach_irq(struct ppi_if *ppi);
> +static int ppi_start(struct ppi_if *ppi);
> +static int ppi_stop(struct ppi_if *ppi);
> +static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params);
> +static void ppi_update_addr(struct ppi_if *ppi, unsigned long addr);
> +
> +static const struct ppi_ops ppi_ops = {
> +	.attach_irq = ppi_attach_irq,
> +	.detach_irq = ppi_detach_irq,
> +	.start = ppi_start,
> +	.stop = ppi_stop,
> +	.set_params = ppi_set_params,
> +	.update_addr = ppi_update_addr,
> +};
> +
> +static irqreturn_t ppi_irq_err(int irq, void *dev_id)
> +{
> +	struct ppi_if *ppi = dev_id;
> +	const struct ppi_info *info = ppi->info;
> +	unsigned short status;
> +
> +	if (!strcmp(info->name, "ppi")) {
> +		struct bfin_ppi_regs __iomem *reg =
> +			(struct bfin_ppi_regs __iomem *)info->base;
> +		status = bfin_read16(reg->status);
> +		if (printk_ratelimit())
> +			pr_info("%s: status = 0x%x\n", __func__, status);

You don't want this in the mainline version...

> +		bfin_write16(&reg->status, 0xff);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int ppi_attach_irq(struct ppi_if *ppi, irq_handler_t handler)
> +{
> +	const struct ppi_info *info = ppi->info;
> +
> +	if (request_dma(info->dma_ch, "PPI_DMA") < 0) {
> +		pr_err("Unable to allocate DMA channel for PPI\n");
> +		return -EBUSY;

Why don't you propagate return code from request_dma()?

> +	}
> +	set_dma_callback(info->dma_ch, handler, ppi);
> +
> +	if (request_irq(info->irq_err, ppi_irq_err, IRQF_DISABLED,

AFAIK, IRQF_DISABLED is gone from the kernel.

> +				"PPI ERROR", ppi)) {
> +		pr_err("Unable to allocate IRQ for PPI\n");
> +		free_dma(info->dma_ch);
> +		return -EBUSY;

ditto ret = request_irq()...

> +	}
> +	return 0;
> +}
> +
> +static void ppi_detach_irq(struct ppi_if *ppi)
> +{
> +	const struct ppi_info *info = ppi->info;
> +
> +	free_irq(info->irq_err, ppi);
> +	free_dma(info->dma_ch);
> +}
> +
> +static int ppi_start(struct ppi_if *ppi)
> +{
> +	const struct ppi_info *info = ppi->info;
> +
> +	/* enable DMA */
> +	enable_dma(info->dma_ch);
> +
> +	/* enable PPI */
> +	ppi->ppi_control |= PORT_EN;
> +	if (!strcmp(info->name, "ppi")) {
> +		struct bfin_ppi_regs __iomem *reg =
> +			(struct bfin_ppi_regs __iomem *)info->base;

Cannot you declare base as "void __iomem *" or something similar to avoid 
all these casts?

> +		bfin_write16(&reg->control, ppi->ppi_control);
> +	}
> +
> +	SSYNC();
> +	return 0;
> +}
> +
> +static int ppi_stop(struct ppi_if *ppi)
> +{
> +	const struct ppi_info *info = ppi->info;
> +
> +	/* disable PPI */
> +	ppi->ppi_control &= ~PORT_EN;
> +	if (!strcmp(info->name, "ppi")) {

Wouldn't an "enum ppi_type" be better with the ability to do

	switch (type) {
	case PPI:
		...
	case EPPI:
		...
	}

?

> +		struct bfin_ppi_regs __iomem *reg =
> +			(struct bfin_ppi_regs __iomem *)info->base;
> +		bfin_write16(&reg->control, ppi->ppi_control);
> +	}
> +
> +	/* disable DMA */
> +	clear_dma_irqstat(info->dma_ch);
> +	disable_dma(info->dma_ch);
> +
> +	SSYNC();
> +	return 0;
> +}
> +
> +static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
> +{
> +	const struct ppi_info *info = ppi->info;
> +
> +	ppi->bytes_per_line = params->width * params->bpp / 8;
> +	ppi->lines_per_frame = params->height;
> +
> +	/* config DMA */
> +	ppi->dma_config = (DMA_FLOW_STOP | WNR | RESTART | DMA2D | DI_EN);
> +	if (params->ppi_control & DMA32) {
> +		ppi->dma_config |= WDSIZE_32;
> +		set_dma_x_count(info->dma_ch, ppi->bytes_per_line >> 2);
> +		set_dma_x_modify(info->dma_ch, 4);
> +		set_dma_y_modify(info->dma_ch, 4);
> +	} else {
> +		ppi->dma_config |= WDSIZE_16;
> +		set_dma_x_count(info->dma_ch, ppi->bytes_per_line >> 1);
> +		set_dma_x_modify(info->dma_ch, 2);
> +		set_dma_y_modify(info->dma_ch, 2);
> +	}
> +	set_dma_y_count(info->dma_ch, ppi->lines_per_frame);
> +	set_dma_config(info->dma_ch, ppi->dma_config);
> +
> +	/* config PPI */
> +	ppi->ppi_control = params->ppi_control & ~PORT_EN;
> +	if (!strcmp(info->name, "ppi")) {
> +		struct bfin_ppi_regs __iomem *reg =
> +			(struct bfin_ppi_regs __iomem *)info->base;
> +		bfin_write16(&reg->control, ppi->ppi_control);
> +		bfin_write16(&reg->count, ppi->bytes_per_line - 1);
> +		bfin_write16(&reg->frame, ppi->lines_per_frame);
> +	}
> +
> +	SSYNC();
> +	return 0;
> +}
> +
> +static void ppi_update_addr(struct ppi_if *ppi, unsigned long addr)
> +{
> +	set_dma_start_addr(ppi->info->dma_ch, addr);
> +}
> +
> +struct ppi_if *ppi_create_instance(const struct ppi_info *info)
> +{
> +	struct ppi_if *ppi;
> +
> +	if (!info || !info->name || !info->pin_req)
> +		return NULL;
> +
> +	if (peripheral_request_list(info->pin_req, KBUILD_MODNAME)) {
> +		pr_err("request peripheral failed\n");
> +		return NULL;
> +	}
> +
> +	ppi = kzalloc(sizeof(*ppi), GFP_KERNEL);
> +	if (!ppi) {
> +		peripheral_free_list(info->pin_req);
> +		pr_err("unable to allocate memory for ppi handle\n");
> +		return NULL;
> +	}
> +	ppi->ops = &ppi_ops;
> +	ppi->info = info;
> +
> +	pr_info("ppi probe success\n");
> +	return ppi;
> +}
> +
> +void ppi_delete_instance(struct ppi_if *ppi)
> +{
> +	peripheral_free_list(ppi->info->pin_req);
> +	kfree(ppi);
> +}
> diff --git a/include/media/blackfin/bfin_capture.h b/include/media/blackfin/bfin_capture.h
> new file mode 100644
> index 0000000..0905837
> --- /dev/null
> +++ b/include/media/blackfin/bfin_capture.h
> @@ -0,0 +1,33 @@
> +#ifndef _BFIN_CAPTURE_H_
> +#define _BFIN_CAPTURE_H_
> +
> +#include <linux/i2c.h>
> +#include <linux/videodev2.h>
> +
> +#include <media/blackfin/ppi.h>

Looks like you only really need i2c.h, for others you can just 
forward-declare structs.

> +
> +struct bcap_route {
> +	u32 input;
> +	u32 output;
> +};
> +
> +struct bfin_capture_config {
> +	/* card name */
> +	char *card_name;
> +	/* inputs available at the sub device */
> +	struct v4l2_input *inputs;
> +	/* number of inputs supported */
> +	int num_inputs;
> +	/* routing information for each input */
> +	struct bcap_route *routes;
> +	/* i2c bus adapter no */
> +	int i2c_adapter_id;
> +	/* i2c subdevice board info */
> +	struct i2c_board_info board_info;
> +	/* ppi board info */
> +	const struct ppi_info *ppi_info;
> +	/* ppi control */
> +	unsigned short ppi_control;
> +};
> +
> +#endif
> diff --git a/include/media/blackfin/ppi.h b/include/media/blackfin/ppi.h
> new file mode 100644
> index 0000000..4e7711a
> --- /dev/null
> +++ b/include/media/blackfin/ppi.h
> @@ -0,0 +1,63 @@
> +/*
> + * Analog Devices PPI header file
> + *
> + * Copyright (c) 2011 Analog Devices Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +#ifndef _PPI_H_
> +#define _PPI_H_
> +
> +#include <linux/interrupt.h>
> +
> +struct ppi_if;
> +
> +struct ppi_params {
> +	int width;
> +	int height;
> +	int bpp;
> +	unsigned short ppi_control;
> +};
> +
> +struct ppi_ops {
> +	int (*attach_irq)(struct ppi_if *ppi, irq_handler_t handler);
> +	void (*detach_irq)(struct ppi_if *ppi);
> +	int (*start)(struct ppi_if *ppi);
> +	int (*stop)(struct ppi_if *ppi);
> +	int (*set_params)(struct ppi_if *ppi, struct ppi_params *params);
> +	void (*update_addr)(struct ppi_if *ppi, unsigned long addr);
> +};
> +
> +struct ppi_info {
> +	const char *name; /* ppi or eppi */
> +	int dma_ch;
> +	int irq_err;
> +	unsigned long base;
> +	const unsigned short *pin_req;
> +};
> +
> +struct ppi_if {
> +	int dma_config;
> +	int bytes_per_line;
> +	int lines_per_frame;
> +	unsigned short ppi_control;
> +	const struct ppi_ops *ops;
> +	const struct ppi_info *info;
> +	void *priv;
> +};
> +
> +struct ppi_if *ppi_create_instance(const struct ppi_info *info);
> +void ppi_delete_instance(struct ppi_if *ppi);
> +#endif
> -- 
> 1.7.0.4

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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