[RFC 13/19] v4l2-device: Register sub-device nodes at sub-device registration time

Sakari Ailus
2017-07-18T19:04:08Z

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/media/v4l2-core/v4l2-device.c | 146 ++++++++++++++++------------------
include/media/v4l2-device.h | 12 ---
2 files changed, 67 insertions(+), 91 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 0c0c4772c00a..4da8f07fc373 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -151,70 +151,6 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister);

-int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
- struct v4l2_subdev *sd)
-{
-#if defined(CONFIG_MEDIA_CONTROLLER)
- struct media_entity *entity = &sd->entity;
-#endif
- int err;
-
- /* Check for valid input */
- if (!v4l2_dev || !sd || sd->v4l2_dev || !sd->name[0])
- return -EINVAL;
-
- /*
- * The reason to acquire the module here is to avoid unloading
- * a module of sub-device which is registered to a media
- * device. To make it possible to unload modules for media
- * devices that also register sub-devices, do not
- * try_module_get() such sub-device owners.
- */
- sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
- sd->owner == v4l2_dev->dev->driver->owner;
-
- if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
- return -ENODEV;
-
- sd->v4l2_dev = v4l2_dev;
- /* This just returns 0 if either of the two args is NULL */
- err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
- if (err)
- goto error_module;
-
-#if defined(CONFIG_MEDIA_CONTROLLER)
- /* Register the entity. */
- if (v4l2_dev->mdev) {
- err = media_device_register_entity(v4l2_dev->mdev, entity);
- if (err < 0)
- goto error_module;
- }
-#endif
-
- if (sd->internal_ops && sd->internal_ops->registered) {
- err = sd->internal_ops->registered(sd);
- if (err)
- goto error_unregister;
- }
-
- spin_lock(&v4l2_dev->lock);
- list_add_tail(&sd->list, &v4l2_dev->subdevs);
- spin_unlock(&v4l2_dev->lock);
-
- return 0;
-
-error_unregister:
-#if defined(CONFIG_MEDIA_CONTROLLER)
- media_device_unregister_entity(entity);
-#endif
-error_module:
- if (!sd->owner_v4l2_dev)
- module_put(sd->owner);
- sd->v4l2_dev = NULL;
- return err;
-}
-EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
-
static void v4l2_device_release_subdev_node(struct video_device *vdev)
{
struct v4l2_subdev *sd = video_get_drvdata(vdev);
@@ -222,8 +158,8 @@ static void v4l2_device_release_subdev_node(struct video_device *vdev)
kfree(vdev);
}

-int v4l2_device_register_subdev_node(struct v4l2_device *v4l2_dev,
- struct v4l2_subdev *sd)
+static int v4l2_device_register_subdev_node(struct v4l2_device *v4l2_dev,
+ struct v4l2_subdev *sd)
{
struct video_device *vdev;
int err;
@@ -278,31 +214,83 @@ int v4l2_device_register_subdev_node(struct v4l2_device *v4l2_dev,

return err;
}
-EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_node);

-int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
+int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
+ struct v4l2_subdev *sd)
{
- struct v4l2_subdev *sd;
+#if defined(CONFIG_MEDIA_CONTROLLER)
+ struct media_entity *entity = &sd->entity;
+#endif
int err;

- list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
- int err;
+ /* Check for valid input */
+ if (!v4l2_dev || !sd || sd->v4l2_dev || !sd->name[0])
+ return -EINVAL;

- err = v4l2_device_register_subdev_node(v4l2_dev, sd);
+ /*
+ * The reason to acquire the module here is to avoid unloading
+ * a module of sub-device which is registered to a media
+ * device. To make it possible to unload modules for media
+ * devices that also register sub-devices, do not
+ * try_module_get() such sub-device owners.
+ */
+ sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
+ sd->owner == v4l2_dev->dev->driver->owner;
+
+ if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
+ return -ENODEV;
+
+ sd->v4l2_dev = v4l2_dev;
+ /* This just returns 0 if either of the two args is NULL */
+ err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
+ if (err)
+ goto error_module;
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+ /* Register the entity. */
+ if (v4l2_dev->mdev) {
+ err = media_device_register_entity(v4l2_dev->mdev, entity);
if (err < 0)
- goto clean_up;
+ goto error_module;
}
- return 0;
+#endif

-clean_up:
- list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
- if (!sd->devnode)
- break;
- video_unregister_device(sd->devnode);
+ if (sd->internal_ops && sd->internal_ops->registered) {
+ err = sd->internal_ops->registered(sd);
+ if (err)
+ goto error_unregister;
}

+ err = v4l2_device_register_subdev_node(v4l2_dev, sd);
+ if (err)
+ goto error_subdev_node;
+
+ spin_lock(&v4l2_dev->lock);
+ list_add_tail(&sd->list, &v4l2_dev->subdevs);
+ spin_unlock(&v4l2_dev->lock);
+
+ return 0;
+
+error_subdev_node:
+ if (sd->internal_ops && sd->internal_ops->unregistered)
+ sd->internal_ops->unregistered(sd);
+
+error_unregister:
+#if defined(CONFIG_MEDIA_CONTROLLER)
+ media_device_unregister_entity(entity);
+#endif
+error_module:
+ if (!sd->owner_v4l2_dev)
+ module_put(sd->owner);
+ sd->v4l2_dev = NULL;
return err;
}
+EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
+
+int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
+{
+ return 0;
+}
EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);

void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index 8b19c1f5bacd..8ffa94009d1a 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -189,18 +189,6 @@ int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);

/**
- * v4l2_device_register_subdev_node - Registers device nodes for a subdev
- * of the v4l2 device. The call is a no-op unless the
- * %V4L2_SUBDEV_FL_HAS_DEVNODE subdev flag is set.
- *
- * @v4l2_dev: pointer to struct v4l2_device
- * @sd: pointer to struct v4l2_subdev
- */
-int __must_check
-v4l2_device_register_subdev_node(struct v4l2_device *v4l2_dev,
- struct v4l2_subdev *sd);
-
-/**
* v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs
* of the v4l2 device that are marked with
* the %V4L2_SUBDEV_FL_HAS_DEVNODE flag.
--
2.11.0