[media] uvcvideo: Add VIDIOC_[GS]_PRIORITY support

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 49 insertions, 0 deletions

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index ae24f7d70b03..22f14d286fbb 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1562,6 +1562,7 @@ static int uvc_scan_device(struct uvc_device *dev)
                 INIT_LIST_HEAD(&chain->entities);
                 mutex_init(&chain->ctrl_mutex);
                 chain->dev = dev;
+                v4l2_prio_init(&chain->prio);
 
                 if (uvc_scan_chain(chain, term) < 0) {
                         kfree(chain);
@@ -1722,6 +1723,8 @@ static int uvc_register_video(struct uvc_device *dev,
         vdev->v4l2_dev = &dev->vdev;
         vdev->fops = &uvc_fops;
         vdev->release = uvc_release;
+        vdev->prio = &stream->chain->prio;
+        set_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags);
         if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
                 vdev->vfl_dir = VFL_DIR_TX;
         strlcpy(vdev->name, dev->name, sizeof vdev->name);
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index bf9d07393139..8e056046bc20 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -576,6 +576,19 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 break;
         }
 
+        /* Priority */
+        case VIDIOC_G_PRIORITY:
+                *(u32 *)arg = v4l2_prio_max(vdev->prio);
+                break;
+
+        case VIDIOC_S_PRIORITY:
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
+                return v4l2_prio_change(vdev->prio, &handle->vfh.prio,
+                                        *(u32 *)arg);
+
         /* Get, Set & Query control */
         case VIDIOC_QUERYCTRL:
                 return uvc_query_v4l2_ctrl(chain, arg);
@@ -606,6 +619,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 struct v4l2_control *ctrl = arg;
                 struct v4l2_ext_control xctrl;
 
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 memset(&xctrl, 0, sizeof xctrl);
                 xctrl.id = ctrl->id;
                 xctrl.value = ctrl->value;
@@ -653,6 +670,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
         }
 
         case VIDIOC_S_EXT_CTRLS:
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+                /* Fall through */
         case VIDIOC_TRY_EXT_CTRLS:
         {
                 struct v4l2_ext_controls *ctrls = arg;
@@ -747,6 +768,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
         {
                 u32 input = *(u32 *)arg + 1;
 
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 if ((ret = uvc_acquire_privileges(handle)) < 0)
                         return ret;
 
@@ -800,6 +825,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
         }
 
         case VIDIOC_S_FMT:
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 if ((ret = uvc_acquire_privileges(handle)) < 0)
                         return ret;
 
@@ -902,6 +931,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 return uvc_v4l2_get_streamparm(stream, arg);
 
         case VIDIOC_S_PARM:
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 if ((ret = uvc_acquire_privileges(handle)) < 0)
                         return ret;
 
@@ -936,6 +969,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 
         /* Buffers & streaming */
         case VIDIOC_REQBUFS:
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 if ((ret = uvc_acquire_privileges(handle)) < 0)
                         return ret;
 
@@ -981,6 +1018,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 if (*type != stream->type)
                         return -EINVAL;
 
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 if (!uvc_has_privileges(handle))
                         return -EBUSY;
 
@@ -999,6 +1040,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 if (*type != stream->type)
                         return -EINVAL;
 
+                ret = v4l2_prio_check(vdev->prio, handle->vfh.prio);
+                if (ret < 0)
+                        return ret;
+
                 if (!uvc_has_privileges(handle))
                         return -EBUSY;
 
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a6c561f631a0..006ae274d22e 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -372,6 +372,7 @@ struct uvc_video_chain {
 
         struct mutex ctrl_mutex;                /* Protects ctrl.info */
 
+        struct v4l2_prio_state prio;            /* V4L2 priority state */
         u32 caps;                               /* V4L2 chain-wide caps */
 };