media: subdev: add active state to struct v4l2_subdev

Add a new 'active_state' field to struct v4l2_subdev to which we can
store the active state of a subdev. This will place the subdev
configuration into a known place, allowing us to use the state directly
from the v4l2 framework, thus simplifying the drivers.

Also add functions v4l2_subdev_init_finalize() and
v4l2_subdev_cleanup(), which will allocate and free the active state.
The functions are named in a generic way so that they can be also used
for other subdev initialization work.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index a1494999352b..5ac447b3038c 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -906,6 +906,27 @@ void __v4l2_subdev_state_free(struct v4l2_subdev_state *state)
 }
 EXPORT_SYMBOL_GPL(__v4l2_subdev_state_free);
 
+int v4l2_subdev_init_finalize(struct v4l2_subdev *sd)
+{
+	struct v4l2_subdev_state *state;
+
+	state = __v4l2_subdev_state_alloc(sd);
+	if (IS_ERR(state))
+		return PTR_ERR(state);
+
+	sd->active_state = state;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_init_finalize);
+
+void v4l2_subdev_cleanup(struct v4l2_subdev *sd)
+{
+	__v4l2_subdev_state_free(sd->active_state);
+	sd->active_state = NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_cleanup);
+
 #endif /* CONFIG_MEDIA_CONTROLLER */
 
 void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops)