> 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@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vimarsh Zutshi <vimarsh.zutshi@xxxxxxxxx>
> ---
> drivers/media/video/Makefile | 2 +-
> drivers/media/video/v4l2-common.c | 3 ++
> drivers/media/video/v4l2-dev.c | 5 +++
> drivers/media/video/v4l2-device.c | 27 +++++++++++++++-
> drivers/media/video/v4l2-subdev.c | 65
> +++++++++++++++++++++++++++++++++++++
> include/media/v4l2-dev.h | 3 +-
> include/media/v4l2-subdev.h | 10 ++++++
> 7 files changed, 112 insertions(+), 3 deletions(-)
...
> diff --git a/drivers/media/video/v4l2-device.c
> b/drivers/media/video/v4l2-device.c
> index 5a7dc4a..685fa82 100644
> --- a/drivers/media/video/v4l2-device.c
> +++ b/drivers/media/video/v4l2-device.c
> @@ -115,18 +115,40 @@ EXPORT_SYMBOL_GPL(v4l2_device_unregister);
> int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
> struct v4l2_subdev *sd)
> {
> + struct video_device *vdev;
> + int ret;
> +
> /* 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;
> spin_lock(&v4l2_dev->lock);
> list_add_tail(&sd->list, &v4l2_dev->subdevs);
> spin_unlock(&v4l2_dev->lock);
> - return 0;
> +
> + /* Register the device node. */
> + vdev = &sd->devnode;
> + snprintf(vdev->name, sizeof(vdev->name), "subdev");
> + vdev->parent = v4l2_dev->dev;
> + vdev->fops = &v4l2_subdev_fops;
> + vdev->release = video_device_release_empty;
> + ret = video_register_device(vdev, VFL_TYPE_SUBDEV, -1);
> + if (ret < 0) {
> + spin_lock(&v4l2_dev->lock);
> + list_del(&sd->list);
> + spin_unlock(&v4l2_dev->lock);
> + sd->v4l2_dev = NULL;
> + module_put(sd->owner);
> + }
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
>
I'm missing one thing here: in this code the subdev device node is always
registered. But for most subdev drivers there is no need for a device
node. This should really be explicitly turned on by the subdev driver
itself.
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
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