Commit e219a712 authored by Michael Grzeschik's avatar Michael Grzeschik Committed by Greg Kroah-Hartman
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usb: gadget: uvc: add v4l2 try_format api call 



This patch adds the uvc_v4l2_try_format api call to validate
the setting of v4l2_format. It will fallback to the nearest
allowed framesize.

Signed-off-by: default avatarMichael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220909221335.15033-5-m.grzeschik@pengutronix.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 588b9e85

drivers/usb/gadget/function/uvc_v4l2.c

+110 −0
Original line number Diff line number Diff line
@@ -48,6 +48,31 @@ static struct uvc_format_desc *to_uvc_format(struct uvcg_format *uformat) 
	return format;

}



static int uvc_v4l2_get_bytesperline(struct uvcg_format *uformat,

			      struct uvcg_frame *uframe)

{

	struct uvcg_uncompressed *u;



	if (uformat->type == UVCG_UNCOMPRESSED) {

		u = to_uvcg_uncompressed(&uformat->group.cg_item);

		if (!u)

			return 0;



		return u->desc.bBitsPerPixel * uframe->frame.w_width / 8;

	}



	return 0;

}



static int uvc_get_frame_size(struct uvcg_format *uformat,

		       struct uvcg_frame *uframe)

{

	unsigned int bpl = uvc_v4l2_get_bytesperline(uformat, uframe);



	return bpl ? bpl * uframe->frame.w_height :

		uframe->frame.dw_max_video_frame_buffer_size;

}



static struct uvcg_format *find_format_by_index(struct uvc_device *uvc, int index)

{

	struct uvcg_format_ptr *format;
@@ -105,6 +130,50 @@ static struct uvcg_format *find_format_by_pix(struct uvc_device *uvc, 
	return uformat;

}



static struct uvcg_frame *find_closest_frame_by_size(struct uvc_device *uvc,

					   struct uvcg_format *uformat,

					   u16 rw, u16 rh)

{

	struct uvc_video *video = &uvc->video;

	struct uvcg_format_ptr *format;

	struct uvcg_frame_ptr *frame;

	struct uvcg_frame *uframe = NULL;

	unsigned int d, maxd;



	/* Find the closest image size. The distance between image sizes is

	 * the size in pixels of the non-overlapping regions between the

	 * requested size and the frame-specified size.

	 */

	maxd = (unsigned int)-1;



	list_for_each_entry(format, &uvc->header->formats, entry) {

		if (format->fmt->type != uformat->type)

			continue;



		list_for_each_entry(frame, &format->fmt->frames, entry) {

			u16 w, h;



			w = frame->frm->frame.w_width;

			h = frame->frm->frame.w_height;



			d = min(w, rw) * min(h, rh);

			d = w*h + rw*rh - 2*d;

			if (d < maxd) {

				maxd = d;

				uframe = frame->frm;

			}



			if (maxd == 0)

				break;

		}

	}



	if (!uframe)

		uvcg_dbg(&video->uvc->func, "Unsupported size %ux%u\n", rw, rh);



	return uframe;

}



/* --------------------------------------------------------------------------

 * Requests handling

 */
@@ -214,6 +283,46 @@ uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt) 
	return 0;

}



static int

uvc_v4l2_try_format(struct file *file, void *fh, struct v4l2_format *fmt)

{

	struct video_device *vdev = video_devdata(file);

	struct uvc_device *uvc = video_get_drvdata(vdev);

	struct uvc_video *video = &uvc->video;

	struct uvcg_format *uformat;

	struct uvcg_frame *uframe;

	u8 *fcc;



	if (fmt->type != video->queue.queue.type)

		return -EINVAL;



	fcc = (u8 *)&fmt->fmt.pix.pixelformat;

	uvcg_dbg(&uvc->func, "Trying format 0x%08x (%c%c%c%c): %ux%u\n",

		fmt->fmt.pix.pixelformat,

		fcc[0], fcc[1], fcc[2], fcc[3],

		fmt->fmt.pix.width, fmt->fmt.pix.height);



	uformat = find_format_by_pix(uvc, fmt->fmt.pix.pixelformat);

	if (!uformat)

		return -EINVAL;



	uframe = find_closest_frame_by_size(uvc, uformat,

				fmt->fmt.pix.width, fmt->fmt.pix.height);

	if (!uframe)

		return -EINVAL;



	fmt->fmt.pix.width = uframe->frame.w_width;

	fmt->fmt.pix.height = uframe->frame.w_height;

	fmt->fmt.pix.field = V4L2_FIELD_NONE;

	fmt->fmt.pix.bytesperline = uvc_v4l2_get_bytesperline(uformat, uframe);

	fmt->fmt.pix.sizeimage = uvc_get_frame_size(uformat, uframe);

	fmt->fmt.pix.pixelformat = to_uvc_format(uformat)->fcc;

	fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;

	fmt->fmt.pix.priv = 0;



	return 0;

}



static int

uvc_v4l2_enum_frameintervals(struct file *file, void *fh,

		struct v4l2_frmivalenum *fival)
@@ -471,6 +580,7 @@ uvc_v4l2_ioctl_default(struct file *file, void *fh, bool valid_prio, 


const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops = {

	.vidioc_querycap = uvc_v4l2_querycap,

	.vidioc_try_fmt_vid_out = uvc_v4l2_try_format,

	.vidioc_g_fmt_vid_out = uvc_v4l2_get_format,

	.vidioc_s_fmt_vid_out = uvc_v4l2_set_format,

	.vidioc_enum_frameintervals = uvc_v4l2_enum_frameintervals,