Commit 982c0487 authored by Tomi Valkeinen's avatar Tomi Valkeinen Committed by Mauro Carvalho Chehab
Browse files

media: subdev: Add v4l2_subdev_call_state_try() macro 



Add a helper macro for the situations where a non-MC driver needs to
call a state-operation (operation which takes a subdev state as a
parameter) in try-context in another subdev.

The macro allocates a new subdev state for the called subdev and frees
the state afterwards.

An example use case is a media platform driver testing if a
v4l2_subdev_format would be accepted by a source subdev.

This should not be used in MC drivers.

Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Tested-by: default avatarMarek Vasut <marex@denx.de>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent dbae22e2

include/media/v4l2-subdev.h

+34 −0
Original line number Diff line number Diff line
@@ -1433,6 +1433,40 @@ extern const struct v4l2_subdev_ops v4l2_subdev_call_wrappers; 
		__result;						\

	})



/**

 * v4l2_subdev_call_state_try - call an operation of a v4l2_subdev which

 *				takes state as a parameter, passing the

 *				subdev a newly allocated try state.

 *

 * @sd: pointer to the &struct v4l2_subdev

 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.

 *     Each element there groups a set of callbacks functions.

 * @f: callback function to be called.

 *     The callback functions are defined in groups, according to

 *     each element at &struct v4l2_subdev_ops.

 * @args: arguments for @f.

 *

 * This is similar to v4l2_subdev_call_state_active(), except that as this

 * version allocates a new state, this is only usable for

 * V4L2_SUBDEV_FORMAT_TRY use cases.

 *

 * Note: only legacy non-MC drivers may need this macro.

 */

#define v4l2_subdev_call_state_try(sd, o, f, args...)                 \

	({                                                            \

		int __result;                                         \

		static struct lock_class_key __key;                   \

		const char *name = KBUILD_BASENAME                    \

			":" __stringify(__LINE__) ":state->lock";     \

		struct v4l2_subdev_state *state =                     \

			__v4l2_subdev_state_alloc(sd, name, &__key);  \

		v4l2_subdev_lock_state(state);                        \

		__result = v4l2_subdev_call(sd, o, f, state, ##args); \

		v4l2_subdev_unlock_state(state);                      \

		__v4l2_subdev_state_free(state);                      \

		__result;                                             \

	})



/**

 * v4l2_subdev_has_op - Checks if a subdev defines a certain operation.

 *