[media] v4l2: add v4l2_prio_state to v4l2_device and video_device

Integrate the v4l2_prio_state into the core, ready for use.

One struct v4l2_prio_state is added to v4l2_device and a pointer
to a prio state is added to video_device.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/v4l2-dev.c

@@ -573,6 +573,12 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
 			vdev->parent = vdev->v4l2_dev->dev;
 		if (vdev->ctrl_handler == NULL)
 			vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
+		/* If the prio state pointer is NULL, and if the driver doesn't
+		   handle priorities itself, then use the v4l2_device prio
+		   state. */
+		if (vdev->prio == NULL && vdev->ioctl_ops &&
+				vdev->ioctl_ops->vidioc_s_priority == NULL)
+			vdev->prio = &vdev->v4l2_dev->prio;
 	}
 
 	/* Part 2: find a free minor, device node number and device index. */

drivers/media/video/v4l2-device.c

@@ -36,6 +36,7 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
 	INIT_LIST_HEAD(&v4l2_dev->subdevs);
 	spin_lock_init(&v4l2_dev->lock);
 	mutex_init(&v4l2_dev->ioctl_lock);
+	v4l2_prio_init(&v4l2_dev->prio);
 	v4l2_dev->dev = dev;
 	if (dev == NULL) {
 		/* If dev == NULL, then name must be filled in by the caller */

include/media/v4l2-dev.h

@@ -89,6 +89,9 @@ struct video_device
 	/* Control handler associated with this device node. May be NULL. */
 	struct v4l2_ctrl_handler *ctrl_handler;
 
+	/* Priority state. If NULL, then v4l2_dev->prio will be used. */
+	struct v4l2_prio_state *prio;
+
 	/* device info */
 	char name[32];
 	int vfl_type;

include/media/v4l2-device.h

@@ -23,6 +23,7 @@
 
 #include <media/media-device.h>
 #include <media/v4l2-subdev.h>
+#include <media/v4l2-dev.h>
 
 /* Each instance of a V4L2 device should create the v4l2_device struct,
    either stand-alone or embedded in a larger struct.
@@ -55,6 +56,8 @@ struct v4l2_device {
 			unsigned int notification, void *arg);
 	/* The control handler. May be NULL. */
 	struct v4l2_ctrl_handler *ctrl_handler;
+	/* Device's priority state */
+	struct v4l2_prio_state prio;
 	/* BKL replacement mutex. Temporary solution only. */
 	struct mutex ioctl_lock;
 };