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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2009-12-09 12:38:49 +0100
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-03-22 00:32:42 +0100
commit2096a5dcf9704f5a86ecba37169eb813aaf0431c (patch)
tree21e7d870302a7c6748667a785b465a7a84805228 /drivers/media/video/v4l2-device.c
parent[media] v4l: subdev: Don't require core operations (diff)
downloadlinux-2096a5dcf9704f5a86ecba37169eb813aaf0431c.tar.xz
linux-2096a5dcf9704f5a86ecba37169eb813aaf0431c.zip
[media] v4l: subdev: Add device node support
Create a device node named subdevX for every registered subdev. As the device node is registered before the subdev core::s_config function is called, return -EGAIN on open until initialization completes. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Vimarsh Zutshi <vimarsh.zutshi@gmail.com> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/v4l2-device.c')
-rw-r--r--drivers/media/video/v4l2-device.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
index ce64fe16bc60..8c0ad8b372d8 100644
--- 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);