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Commit 2257e180 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] v4l2-ctrls: document some extra data structures 



The typedefs and a macro are not defined. While here, improve a
few bits on the documentation.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 9fa7235f

include/media/v4l2-ctrls.h

+44 −7
Original line number Diff line number Diff line
@@ -93,6 +93,16 @@ struct v4l2_ctrl_type_ops { 
			union v4l2_ctrl_ptr ptr);

};



/**

 * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function

 *	that should be called when a control value has changed.

 *

 * @ctrl: pointer to struct &v4l2_ctrl

 * @priv: control private data

 *

 * This typedef definition is used as an argument to v4l2_ctrl_notify()

 * and as an argument at struct &v4l2_ctrl_handler.

 */

typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);



/**
@@ -369,17 +379,38 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, 
 * @key:	Used by the lock validator if CONFIG_LOCKDEP is set.

 * @name:	Used by the lock validator if CONFIG_LOCKDEP is set.

 *

 * Returns an error if the buckets could not be allocated. This error will

 * also be stored in @hdl->error.

 * .. attention::

 *

 * Never use this call directly, always use the v4l2_ctrl_handler_init

 *    Never use this call directly, always use the v4l2_ctrl_handler_init()

 *    macro that hides the @key and @name arguments.

 *

 * Return: returns an error if the buckets could not be allocated. This

 * error will also be stored in @hdl->error.

 */

int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,

				 unsigned int nr_of_controls_hint,

				 struct lock_class_key *key, const char *name);



#ifdef CONFIG_LOCKDEP



/**

 * v4l2_ctrl_handler_init -

 *

 * @hdl:	The control handler.

 * @nr_of_controls_hint: A hint of how many controls this handler is

 *		expected to refer to. This is the total number, so including

 *		any inherited controls. It doesn't have to be precise, but if

 *		it is way off, then you either waste memory (too many buckets

 *		are allocated) or the control lookup becomes slower (not enough

 *		buckets are allocated, so there are more slow list lookups).

 *		It will always work, though.

 *

 * This helper function creates a static struct &lock_class_key and

 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock

 * validador.

 *

 * Use this helper function to initialize a control handler.

 */

#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\

(									\

	({								\
@@ -564,6 +595,13 @@ struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, 
					 u32 id, u8 max, u8 def,

					 const s64 *qmenu_int);



/**

 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be

 *	used when adding a control handler.

 *

 * @ctrl: pointer to struct &v4l2_ctrl.

 */



typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);



/**
@@ -635,8 +673,8 @@ void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls); 
 * be marked active, and any reads will just return the current value without

 * going through g_volatile_ctrl.

 *

 * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag

 * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s)

 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag

 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)

 * if autofoo is in auto mode.

 */

void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
@@ -686,7 +724,6 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); 
 */

void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);





/**

 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()

 *