[media] v4l: subdev: Add device node support

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / video / v4l2-device.c

diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
index ce64fe16bc604137d3522af06931ab562983865c..8c0ad8b372d864645b88d3decb9a0e2047c2f15c 100644 (file)
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -124,16 +124,20 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
        /* Check for valid input */
        if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
                return -EINVAL;
+
        /* Warn if we apparently re-register a subdev */
        WARN_ON(sd->v4l2_dev != NULL);
+
        if (!try_module_get(sd->owner))
                return -ENODEV;
+
        sd->v4l2_dev = v4l2_dev;
        if (sd->internal_ops && sd->internal_ops->registered) {
                err = sd->internal_ops->registered(sd);
                if (err)
                        return err;
        }
+
        /* This just returns 0 if either of the two args is NULL */
        err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
        if (err) {
@@ -141,24 +145,57 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
                        sd->internal_ops->unregistered(sd);
                return err;
        }
+
        spin_lock(&v4l2_dev->lock);
        list_add_tail(&sd->list, &v4l2_dev->subdevs);
        spin_unlock(&v4l2_dev->lock);
+
        return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
 
+int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
+{
+       struct video_device *vdev;
+       struct v4l2_subdev *sd;
+       int err;
+
+       /* Register a device node for every subdev marked with the
+        * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
+        */
+       list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
+               if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
+                       continue;
+
+               vdev = &sd->devnode;
+               strlcpy(vdev->name, sd->name, sizeof(vdev->name));
+               vdev->v4l2_dev = v4l2_dev;
+               vdev->fops = &v4l2_subdev_fops;
+               vdev->release = video_device_release_empty;
+               err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
+                                             sd->owner);
+               if (err < 0)
+                       return err;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
+
 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
 {
        /* return if it isn't registered */
        if (sd == NULL || sd->v4l2_dev == NULL)
                return;
+
        spin_lock(&sd->v4l2_dev->lock);
        list_del(&sd->list);
        spin_unlock(&sd->v4l2_dev->lock);
        if (sd->internal_ops && sd->internal_ops->unregistered)
                sd->internal_ops->unregistered(sd);
        sd->v4l2_dev = NULL;
+
+       video_unregister_device(&sd->devnode);
        module_put(sd->owner);
 }
 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);