[PATCH 2/3] usb: gadget: uvc: add g_parm and s_parm for frame interval

[Michael Grzeschik]

The uvc gadget driver is lacking the information which frame interval
was set by the host. We add this information by implementing the g_parm
and s_parm callbacks.

Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
---
 drivers/usb/gadget/function/uvc.h      |  1 +
 drivers/usb/gadget/function/uvc_v4l2.c | 52 ++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index cb35687b11e7e..d153bd9e35e31 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -97,6 +97,7 @@ struct uvc_video {
 	unsigned int width;
 	unsigned int height;
 	unsigned int imagesize;
+	unsigned int interval;
 	struct mutex mutex;	/* protects frame parameters */
 
 	unsigned int uvc_num_requests;
diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index a024aecb76dc3..5b579ec1f5040 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -307,6 +307,56 @@ uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
 	return ret;
 }
 
+static int uvc_v4l2_g_parm(struct file *file, void *fh,
+			    struct v4l2_streamparm *parm)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	struct v4l2_fract timeperframe;
+
+	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	/* Return the actual frame period. */
+	timeperframe.numerator = video->interval;
+	timeperframe.denominator = 10000000;
+	v4l2_simplify_fraction(&timeperframe.numerator,
+		&timeperframe.denominator, 8, 333);
+
+	uvcg_dbg(&uvc->func, "Getting frame interval of %u/%u (%u)\n",
+		timeperframe.numerator, timeperframe.denominator,
+		video->interval);
+
+	parm->parm.output.timeperframe = timeperframe;
+	parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
+
+	return 0;
+}
+
+static int uvc_v4l2_s_parm(struct file *file, void *fh,
+			    struct v4l2_streamparm *parm)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_device *uvc = video_get_drvdata(vdev);
+	struct uvc_video *video = &uvc->video;
+	struct v4l2_fract timeperframe;
+
+	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	timeperframe = parm->parm.output.timeperframe;
+
+	video->interval = v4l2_fraction_to_interval(timeperframe.numerator,
+		timeperframe.denominator);
+
+	uvcg_dbg(&uvc->func, "Setting frame interval to %u/%u (%u)\n",
+		timeperframe.numerator, timeperframe.denominator,
+		video->interval);
+
+	return 0;
+}
+
 static int
 uvc_v4l2_enum_frameintervals(struct file *file, void *fh,
 		struct v4l2_frmivalenum *fival)
@@ -577,6 +627,8 @@ const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops = {
 	.vidioc_dqbuf = uvc_v4l2_dqbuf,
 	.vidioc_streamon = uvc_v4l2_streamon,
 	.vidioc_streamoff = uvc_v4l2_streamoff,
+	.vidioc_s_parm = uvc_v4l2_s_parm,
+	.vidioc_g_parm = uvc_v4l2_g_parm,
 	.vidioc_subscribe_event = uvc_v4l2_subscribe_event,
 	.vidioc_unsubscribe_event = uvc_v4l2_unsubscribe_event,
 	.vidioc_default = uvc_v4l2_ioctl_default,

-- 
2.39.2