media: subdev: Add checks for subdev features

Add some checks to verify that the subdev driver implements required
features.

A subdevice that supports streams (V4L2_SUBDEV_FL_STREAMS) must do one
of the following:

- Implement neither .enable/disable_streams() nor .s_stream(), if the
  subdev is part of a video driver that uses an internal method to
  enable the subdev.
- Implement only .enable/disable_streams(), if support for legacy
  sink-side subdevices is not needed.
- Implement .enable/disable_streams() and .s_stream(), if support for
  legacy sink-side subdevices is needed.

At the moment the framework doesn't check this requirement. Add the
check.

Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
This commit is contained in:
Tomi Valkeinen 2024-04-24 18:39:06 +03:00 committed by Hans Verkuil
parent 68e36241b7
commit e003fd9c1e

View File

@ -1588,6 +1588,33 @@ int __v4l2_subdev_init_finalize(struct v4l2_subdev *sd, const char *name,
struct lock_class_key *key)
{
struct v4l2_subdev_state *state;
struct device *dev = sd->dev;
bool has_disable_streams;
bool has_enable_streams;
bool has_s_stream;
/* Check that the subdevice implements the required features */
has_s_stream = v4l2_subdev_has_op(sd, video, s_stream);
has_enable_streams = v4l2_subdev_has_op(sd, pad, enable_streams);
has_disable_streams = v4l2_subdev_has_op(sd, pad, disable_streams);
if (has_enable_streams != has_disable_streams) {
dev_err(dev,
"subdev '%s' must implement both or neither of .enable_streams() and .disable_streams()\n",
sd->name);
return -EINVAL;
}
if (sd->flags & V4L2_SUBDEV_FL_STREAMS) {
if (has_s_stream && !has_enable_streams) {
dev_err(dev,
"subdev '%s' must implement .enable/disable_streams()\n",
sd->name);
return -EINVAL;
}
}
state = __v4l2_subdev_state_alloc(sd, name, key);
if (IS_ERR(state))