media: v4l2-subdev: Verify arguments in v4l2_subdev_call()

Correctness of format type (try or active) and pad number parameters
passed to subdevice operation callbacks is now verified only for IOCTL
calls.  However, those callbacks are also used by drivers, e.g., V4L2
host interfaces.

Since both subdev_do_ioctl() and drivers are using v4l2_subdev_call()
macro while calling subdevice operations, move those parameter checks
from subdev_do_ioctl() to v4l2_subdev_call() so we can avoid taking care
of those checks inside drivers.

Define a wrapper function for each operation callback in scope, then
gather those wrappers in a static v4l2_subdev_ops structure so the
v4l2_subdev_call() macro can find them easy if provided.
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

include/media/v4l2-subdev.h

@@ -1082,6 +1082,8 @@ void v4l2_subdev_free_pad_config(struct v4l2_subdev_pad_config *cfg);
 void v4l2_subdev_init(struct v4l2_subdev *sd,
 		      const struct v4l2_subdev_ops *ops);
 
+extern const struct v4l2_subdev_ops v4l2_subdev_call_wrappers;
+
 /**
  * v4l2_subdev_call - call an operation of a v4l2_subdev.
  *
@@ -1103,6 +1105,10 @@ void v4l2_subdev_init(struct v4l2_subdev *sd,
 			__result = -ENODEV;				\
 		else if (!(__sd->ops->o && __sd->ops->o->f))		\
 			__result = -ENOIOCTLCMD;			\
+		else if (v4l2_subdev_call_wrappers.o &&			\
+			 v4l2_subdev_call_wrappers.o->f)		\
+			__result = v4l2_subdev_call_wrappers.o->f(	\
+							__sd, ##args);	\
 		else							\
 			__result = __sd->ops->o->f(__sd, ##args);	\
 		__result;						\