[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: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab 2016-08-29 17:26:15 -03:00
parent 9fa7235f88
commit 2257e18010
1 changed files with 44 additions and 7 deletions

View File

@ -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
* macro that hides the @key and @name arguments.
* 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()
*