[media] vb2: drop v4l2_format argument from queue_setup

The queue_setup callback has a void pointer that is just for V4L2
and is the pointer to the v4l2_format struct that was passed to
VIDIOC_CREATE_BUFS. The idea was that drivers would use the information
from that struct to buffers suitable for the requested format.

After the vb2 split series this pointer is now a void pointer,
which is ugly, and the reality is that all existing drivers will
effectively just look at the sizeimage field of v4l2_format.

To make this more generic the queue_setup callback is changed:
the void pointer is dropped, instead if the *num_planes argument
is 0, then use the current format size, if it is non-zero, then
it contains the number of requested planes and the sizes array
contains the requested sizes. If either is unsupported, then return
-EINVAL, otherwise use the requested size(s).

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/em28xx/em28xx-video.c

@@ -871,30 +871,19 @@ static void res_free(struct em28xx *dev, enum v4l2_buf_type f_type)
 	Videobuf2 operations
    ------------------------------------------------------------------*/
 
-static int queue_setup(struct vb2_queue *vq, const void *parg,
+static int queue_setup(struct vb2_queue *vq,
 		       unsigned int *nbuffers, unsigned int *nplanes,
 		       unsigned int sizes[], void *alloc_ctxs[])
 {
-	const struct v4l2_format *fmt = parg;
 	struct em28xx *dev = vb2_get_drv_priv(vq);
 	struct em28xx_v4l2 *v4l2 = dev->v4l2;
-	unsigned long size;
-
-	if (fmt)
-		size = fmt->fmt.pix.sizeimage;
-	else
-		size =
+	unsigned long size =
 		    (v4l2->width * v4l2->height * v4l2->format->depth + 7) >> 3;
 
-	if (size == 0)
-		return -EINVAL;
-
-	if (0 == *nbuffers)
-		*nbuffers = 32;
-
+	if (*nplanes)
+		return sizes[0] < size ? -EINVAL : 0;
 	*nplanes = 1;
 	sizes[0] = size;
-
 	return 0;
 }