[media] vivi: support control events

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

drivers/media/video/vivi.c

@@ -31,6 +31,7 @@
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
 #include <media/v4l2-common.h>
 
 #define VIVI_MODULE_NAME "vivi"
@@ -978,12 +979,26 @@ static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
 	if (i >= NUM_INPUTS)
 		return -EINVAL;
 
+	if (i == dev->input)
+		return 0;
+
 	dev->input = i;
 	precalculate_bars(dev);
 	precalculate_line(dev);
 	return 0;
 }
 
+static int vidioc_subscribe_event(struct v4l2_fh *fh,
+				struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_CTRL:
+		return v4l2_ctrl_subscribe_fh(fh, sub, 0);
+	default:
+		return -EINVAL;
+	}
+}
+
 /* --- controls ---------------------------------------------- */
 
 static int vivi_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
@@ -1022,10 +1037,17 @@ static unsigned int
 vivi_poll(struct file *file, struct poll_table_struct *wait)
 {
 	struct vivi_dev *dev = video_drvdata(file);
+	struct v4l2_fh *fh = file->private_data;
 	struct vb2_queue *q = &dev->vb_vidq;
+	unsigned int res;
 
 	dprintk(dev, 1, "%s\n", __func__);
-	return vb2_poll(q, file, wait);
+	res = vb2_poll(q, file, wait);
+	if (v4l2_event_pending(fh))
+		res |= POLLPRI;
+	else
+		poll_wait(file, &fh->events->wait, wait);
+	return res;
 }
 
 static int vivi_close(struct file *file)
@@ -1156,6 +1178,8 @@ static const struct v4l2_ioctl_ops vivi_ioctl_ops = {
 	.vidioc_s_input       = vidioc_s_input,
 	.vidioc_streamon      = vidioc_streamon,
 	.vidioc_streamoff     = vidioc_streamoff,
+	.vidioc_subscribe_event = vidioc_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 };
 
 static struct video_device vivi_template = {