From e219a712bc06dc68ecccb3085cb91438bee2466a Mon Sep 17 00:00:00 2001 From: Michael Grzeschik Date: Sat, 10 Sep 2022 00:13:35 +0200 Subject: [PATCH] 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: Michael Grzeschik Link: https://lore.kernel.org/r/20220909221335.15033-5-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/uvc_v4l2.c | 110 +++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c index 417655e..c4ed48d 100644 --- a/drivers/usb/gadget/function/uvc_v4l2.c +++ b/drivers/usb/gadget/function/uvc_v4l2.c @@ -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 */ @@ -215,6 +284,46 @@ uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt) } 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, -- 2.7.4