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[v4] media:uvc_driver: add uvc support on no-mmu arch

Message ID 1303463331-5024-1-git-send-email-lliubbo@gmail.com (mailing list archive)
State RFC
Headers show

Commit Message

Bob Liu April 22, 2011, 9:08 a.m. UTC
UVC driver used to have partial no-mmu arch support, but it's removed by
commit c29fcff3daafbf46d64a543c1950bbd206ad8c1c.

This patch added them back and expanded to fully support no-mmu arch, so that
uvc cameras can be used on no-mmu platforms like Blackfin.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
---
 drivers/media/video/uvc/uvc_queue.c |   26 +++++++++++++++++++++++++-
 drivers/media/video/uvc/uvc_v4l2.c  |   13 +++++++++++++
 drivers/media/video/uvc/uvcvideo.h  |    6 ++++++
 drivers/media/video/v4l2-dev.c      |   18 ++++++++++++++++++
 include/media/v4l2-dev.h            |    2 ++
 5 files changed, 64 insertions(+), 1 deletions(-)

Comments

Laurent Pinchart April 29, 2011, 8:10 a.m. UTC | #1
Hi Bob,

Thanks for the patch.

On Friday 22 April 2011 11:08:51 Bob Liu wrote:
> UVC driver used to have partial no-mmu arch support, but it's removed by
> commit c29fcff3daafbf46d64a543c1950bbd206ad8c1c.
> 
> This patch added them back and expanded to fully support no-mmu arch, so
> that uvc cameras can be used on no-mmu platforms like Blackfin.
> 
> Signed-off-by: Bob Liu <lliubbo@gmail.com>
> ---
>  drivers/media/video/uvc/uvc_queue.c |   26 +++++++++++++++++++++++++-
>  drivers/media/video/uvc/uvc_v4l2.c  |   13 +++++++++++++
>  drivers/media/video/uvc/uvcvideo.h  |    6 ++++++
>  drivers/media/video/v4l2-dev.c      |   18 ++++++++++++++++++
>  include/media/v4l2-dev.h            |    2 ++
>  5 files changed, 64 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/media/video/uvc/uvc_queue.c
> b/drivers/media/video/uvc/uvc_queue.c index f14581b..caf8f6f 100644
> --- a/drivers/media/video/uvc/uvc_queue.c
> +++ b/drivers/media/video/uvc/uvc_queue.c
> @@ -424,7 +424,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue,
> struct vm_area_struct *vma) break;
>  	}
> 
> -	if (i == queue->count || size != queue->buf_size) {
> +	if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) {
>  		ret = -EINVAL;
>  		goto done;
>  	}
> @@ -436,6 +436,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue,
> struct vm_area_struct *vma) vma->vm_flags |= VM_IO;
> 
>  	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> +#ifdef CONFIG_MMU
>  	while (size > 0) {
>  		page = vmalloc_to_page((void *)addr);
>  		if ((ret = vm_insert_page(vma, start, page)) < 0)
> @@ -445,6 +446,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue,
> struct vm_area_struct *vma) addr += PAGE_SIZE;
>  		size -= PAGE_SIZE;
>  	}
> +#endif
> 
>  	vma->vm_ops = &uvc_vm_ops;
>  	vma->vm_private_data = buffer;
> @@ -489,6 +491,28 @@ done:
>  }
> 
>  /*
> + * Get unmapped area.
> + *
> + * NO-MMU arch need this function to make mmap() work correctly.
> + */
> +unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
> +		unsigned long addr, unsigned long len, unsigned long pgoff)

Please guard this function with

#ifndef CONFIG_MMU

> +{
> +	struct uvc_buffer *buffer;
> +	unsigned int i;
> +
> +	mutex_lock(&queue->mutex);
> +	for (i = 0; i < queue->count; ++i) {
> +		buffer = &queue->buffer[i];
> +		if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
> +			break;
> +	}

If pgoff doesn't correspond to any existing buffer, you will end up returning 
the address of the last buffer. Shouldn't you return an error instead ?

> +	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> +	mutex_unlock(&queue->mutex);
> +	return addr;
> +}
> +
> +/*
>   * Enable or disable the video buffers queue.
>   *
>   * The queue must be enabled before starting video acquisition and must be
> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> b/drivers/media/video/uvc/uvc_v4l2.c index 9005a8d..9efab61 100644
> --- a/drivers/media/video/uvc/uvc_v4l2.c
> +++ b/drivers/media/video/uvc/uvc_v4l2.c
> @@ -1081,6 +1081,18 @@ static unsigned int uvc_v4l2_poll(struct file *file,
> poll_table *wait) return uvc_queue_poll(&stream->queue, file, wait);
>  }

#ifndef CONFIG_MMU
> +static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
> +		unsigned long addr, unsigned long len, unsigned long pgoff,
> +		unsigned long flags)
> +{
> +	struct uvc_fh *handle = file->private_data;
> +	struct uvc_streaming *stream = handle->stream;
> +
> +	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
> +
> +	return uvc_queue_get_unmapped_area(&stream->queue, addr, len, pgoff);
> +}
#endif

>  const struct v4l2_file_operations uvc_fops = {
>  	.owner		= THIS_MODULE,
>  	.open		= uvc_v4l2_open,
> @@ -1089,5 +1101,6 @@ const struct v4l2_file_operations uvc_fops = {
>  	.read		= uvc_v4l2_read,
>  	.mmap		= uvc_v4l2_mmap,
>  	.poll		= uvc_v4l2_poll,
#ifndef CONFIG_MMU
> +	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
#endif
>  };
> 
> diff --git a/drivers/media/video/uvc/uvcvideo.h
> b/drivers/media/video/uvc/uvcvideo.h index 45f01e7..48a2378 100644
> --- a/drivers/media/video/uvc/uvcvideo.h
> +++ b/drivers/media/video/uvc/uvcvideo.h
> @@ -580,6 +580,12 @@ extern int uvc_queue_mmap(struct uvc_video_queue
> *queue, struct vm_area_struct *vma);
>  extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
>  		struct file *file, poll_table *wait);
> +#ifdef CONFIG_MMU
> +#define uvc_queue_get_unmapped_area NULL
> +#else

And remove the CONFIG_MMU guard here.

> +extern unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue
> *queue, +		unsigned long addr, unsigned long len, unsigned long pgoff);
> +#endif
>  extern int uvc_queue_allocated(struct uvc_video_queue *queue);
>  static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
>  {
> diff --git a/drivers/media/video/v4l2-dev.c
> b/drivers/media/video/v4l2-dev.c index 498e674..221e73f 100644
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c

Please split the patch in two. The first part should be a revert of 
c29fcff3daafbf46d64a543c1950bbd206ad8c1c, the second one should be the 
uvcvideo code.
diff mbox

Patch

diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
index f14581b..caf8f6f 100644
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -424,7 +424,7 @@  int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 			break;
 	}
 
-	if (i == queue->count || size != queue->buf_size) {
+	if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) {
 		ret = -EINVAL;
 		goto done;
 	}
@@ -436,6 +436,7 @@  int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 	vma->vm_flags |= VM_IO;
 
 	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+#ifdef CONFIG_MMU
 	while (size > 0) {
 		page = vmalloc_to_page((void *)addr);
 		if ((ret = vm_insert_page(vma, start, page)) < 0)
@@ -445,6 +446,7 @@  int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 		addr += PAGE_SIZE;
 		size -= PAGE_SIZE;
 	}
+#endif
 
 	vma->vm_ops = &uvc_vm_ops;
 	vma->vm_private_data = buffer;
@@ -489,6 +491,28 @@  done:
 }
 
 /*
+ * Get unmapped area.
+ *
+ * NO-MMU arch need this function to make mmap() work correctly.
+ */
+unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+		unsigned long addr, unsigned long len, unsigned long pgoff)
+{
+	struct uvc_buffer *buffer;
+	unsigned int i;
+
+	mutex_lock(&queue->mutex);
+	for (i = 0; i < queue->count; ++i) {
+		buffer = &queue->buffer[i];
+		if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
+			break;
+	}
+	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+	mutex_unlock(&queue->mutex);
+	return addr;
+}
+
+/*
  * Enable or disable the video buffers queue.
  *
  * The queue must be enabled before starting video acquisition and must be
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 9005a8d..9efab61 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -1081,6 +1081,18 @@  static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
 	return uvc_queue_poll(&stream->queue, file, wait);
 }
 
+static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_streaming *stream = handle->stream;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
+
+	return uvc_queue_get_unmapped_area(&stream->queue, addr, len, pgoff);
+}
+
 const struct v4l2_file_operations uvc_fops = {
 	.owner		= THIS_MODULE,
 	.open		= uvc_v4l2_open,
@@ -1089,5 +1101,6 @@  const struct v4l2_file_operations uvc_fops = {
 	.read		= uvc_v4l2_read,
 	.mmap		= uvc_v4l2_mmap,
 	.poll		= uvc_v4l2_poll,
+	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
 };
 
diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
index 45f01e7..48a2378 100644
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -580,6 +580,12 @@  extern int uvc_queue_mmap(struct uvc_video_queue *queue,
 		struct vm_area_struct *vma);
 extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
 		struct file *file, poll_table *wait);
+#ifdef CONFIG_MMU
+#define uvc_queue_get_unmapped_area NULL
+#else
+extern unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+		unsigned long addr, unsigned long len, unsigned long pgoff);
+#endif
 extern int uvc_queue_allocated(struct uvc_video_queue *queue);
 static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
 {
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 498e674..221e73f 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -368,6 +368,23 @@  static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
 	return ret;
 }
 
+#ifdef CONFIG_MMU
+#define v4l2_get_unmapped_area NULL
+#else
+static unsigned long v4l2_get_unmapped_area(struct file *filp,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct video_device *vdev = video_devdata(filp);
+
+	if (!vdev->fops->get_unmapped_area)
+		return -ENOSYS;
+	if (!video_is_registered(vdev))
+		return -ENODEV;
+	return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+#endif
+
 /* Override for the open function */
 static int v4l2_open(struct inode *inode, struct file *filp)
 {
@@ -452,6 +469,7 @@  static const struct file_operations v4l2_fops = {
 	.write = v4l2_write,
 	.open = v4l2_open,
 	.mmap = v4l2_mmap,
+	.get_unmapped_area = v4l2_get_unmapped_area,
 	.unlocked_ioctl = v4l2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = v4l2_compat_ioctl32,
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 8266d5a..0616a43 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -63,6 +63,8 @@  struct v4l2_file_operations {
 	long (*ioctl) (struct file *, unsigned int, unsigned long);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
+	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
+			unsigned long, unsigned long, unsigned long);
 	int (*open) (struct file *);
 	int (*release) (struct file *);
 };