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Commit 8ec4bee7 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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[media] v4l2-ctrls.h: fully document the header file 

There are lots of undocumented stuff on this header.

Document them.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 6d85d7d7
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include/media/v4l2-ctrls.h
View file @ 8ec4bee7
/*
V4L2 controls support header.
Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* V4L2 controls support header.
*
* Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _V4L2_CTRLS_H
......@@ -58,6 +54,7 @@ union v4l2_ctrl_ptr {
/**
* struct v4l2_ctrl_ops - The control operations that the driver has to provide.
*
* @g_volatile_ctrl: Get a new value for this control. Generally only relevant
* for volatile (and usually read-only) controls such as a control
* that returns the current signal strength which changes
......@@ -82,7 +79,8 @@ struct v4l2_ctrl_ops {
* @equal: return true if both values are equal.
* @init: initialize the value.
* @log: log the value.
* @validate: validate the value. Return 0 on success and a negative value otherwise.
* @validate: validate the value. Return 0 on success and a negative value
* otherwise.
*/
struct v4l2_ctrl_type_ops {
bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
......@@ -99,6 +97,7 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
/**
* struct v4l2_ctrl - The control structure.
*
* @node: The list node.
* @ev_subs: The list of control event subscriptions.
* @handler: The handler that owns the control.
......@@ -106,7 +105,7 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
* @ncontrols: Number of controls in cluster array.
* @done: Internal flag: set for each processed control.
* @is_new: Set when the user specified a new value for this control. It
* is also set when called from v4l2_ctrl_handler_setup. Drivers
* is also set when called from v4l2_ctrl_handler_setup(). Drivers
* should never set this flag.
* @has_changed: Set when the current value differs from the new value. Drivers
* should never use this flag.
......@@ -119,9 +118,10 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
* set this flag directly.
* @is_int: If set, then this control has a simple integer value (i.e. it
* uses ctrl->val).
* @is_string: If set, then this control has type V4L2_CTRL_TYPE_STRING.
* @is_ptr: If set, then this control is an array and/or has type >= V4L2_CTRL_COMPOUND_TYPES
* and/or has type V4L2_CTRL_TYPE_STRING. In other words, struct
* @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
* @is_ptr: If set, then this control is an array and/or has type >=
* %V4L2_CTRL_COMPOUND_TYPES
* and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
* v4l2_ext_control uses field p to point to the data.
* @is_array: If set, then this control contains an N-dimensional array.
* @has_volatiles: If set, then one or more members of the cluster are volatile.
......@@ -177,7 +177,8 @@ struct v4l2_ctrl {
struct list_head ev_subs;
struct v4l2_ctrl_handler *handler;
struct v4l2_ctrl **cluster;
unsigned ncontrols;
unsigned int ncontrols;
unsigned int done:1;
unsigned int is_new:1;
......@@ -223,10 +224,12 @@ struct v4l2_ctrl {
/**
* struct v4l2_ctrl_ref - The control reference.
*
* @node: List node for the sorted list.
* @next: Single-link list node for the hash.
* @ctrl: The actual control information.
* @helper: Pointer to helper struct. Used internally in prepare_ext_ctrls().
* @helper: Pointer to helper struct. Used internally in
* prepare_ext_ctrls().
*
* Each control handler has a list of these refs. The list_head is used to
* keep a sorted-by-control-ID list of all controls, while the next pointer
......@@ -243,6 +246,7 @@ struct v4l2_ctrl_ref {
* struct v4l2_ctrl_handler - The control handler keeps track of all the
* controls: both the controls owned by the handler and those inherited
* from other handlers.
*
* @_lock: Default for "lock".
* @lock: Lock to control access to this handler and its controls.
* May be replaced by the user right after init.
......@@ -252,7 +256,8 @@ struct v4l2_ctrl_ref {
* control is needed multiple times, so this is a simple
* optimization.
* @buckets: Buckets for the hashing. Allows for quick control lookup.
* @notify: A notify callback that is called whenever the control changes value.
* @notify: A notify callback that is called whenever the control changes
* value.
* Note that the handler's lock is held when the notify function
* is called!
* @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
......@@ -274,6 +279,7 @@ struct v4l2_ctrl_handler {
/**
* struct v4l2_ctrl_config - Control configuration structure.
*
* @ops: The control ops.
* @type_ops: The control type ops. Only needed for compound controls.
* @id: The control ID.
......@@ -320,17 +326,28 @@ struct v4l2_ctrl_config {
unsigned int is_private:1;
};
/*
* v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
/**
* v4l2_ctrl_fill - Fill in the control fields based on the control ID.
*
* @id: ID of the control
* @name: name of the control
* @type: type of the control
* @min: minimum value for the control
* @max: maximum value for the control
* @step: control step
* @def: default value for the control
* @flags: flags to be used on the control
*
* This works for all standard V4L2 controls.
* For non-standard controls it will only fill in the given arguments
* and @name will be NULL.
* and @name will be %NULL.
*
* This function will overwrite the contents of @name, @type and @flags.
* The contents of @min, @max, @step and @def may be modified depending on
* the type.
*
* .. note::
*
* Do not use in drivers! It is used internally for backwards compatibility
* control handling only. Once all drivers are converted to use the new
* control framework this function will no longer be exported.
......@@ -359,7 +376,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
* macro that hides the @key and @name arguments.
*/
int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
unsigned nr_of_controls_hint,
unsigned int nr_of_controls_hint,
struct lock_class_key *key, const char *name);
#ifdef CONFIG_LOCKDEP
......@@ -437,6 +454,7 @@ void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
/**
* v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
* control.
*
* @hdl: The control handler.
* @cfg: The control's configuration data.
* @priv: The control's driver-specific private data.
......@@ -445,10 +463,13 @@ void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
* and @hdl->error is set to the error code (if it wasn't set already).
*/
struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_config *cfg, void *priv);
const struct v4l2_ctrl_config *cfg,
void *priv);
/**
* v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control.
* v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
* control.
*
* @hdl: The control handler.
* @ops: The control ops.
* @id: The control ID.
......@@ -467,10 +488,13 @@ struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
*/
struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
u32 id, s64 min, s64 max, u64 step, s64 def);
u32 id, s64 min, s64 max, u64 step,
s64 def);
/**
* v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control.
* v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
* menu control.
*
* @hdl: The control handler.
* @ops: The control ops.
* @id: The control ID.
......@@ -495,6 +519,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
/**
* v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
* with driver specific menu.
*
* @hdl: The control handler.
* @ops: The control ops.
* @id: The control ID.
......@@ -513,11 +538,14 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
*
*/
struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops, u32 id, u8 max,
u64 mask, u8 def, const char * const *qmenu);
const struct v4l2_ctrl_ops *ops,
u32 id, u8 max,
u64 mask, u8 def,
const char * const *qmenu);
/**
* v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
*
* @hdl: The control handler.
* @ops: The control ops.
* @id: The control ID.
......@@ -528,17 +556,20 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
* Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
* takes as an argument an array of integers determining the menu items.
*
* If @id refers to a non-integer-menu control, then this function will return NULL.
* If @id refers to a non-integer-menu control, then this function will
* return %NULL.
*/
struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
u32 id, u8 max, u8 def, const s64 *qmenu_int);
u32 id, u8 max, u8 def,
const s64 *qmenu_int);
typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
/**
* v4l2_ctrl_add_handler() - Add all controls from handler @add to
* handler @hdl.
*
* @hdl: The control handler.
* @add: The control handler whose controls you want to add to
* the @hdl control handler.
......@@ -556,6 +587,7 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
/**
* v4l2_ctrl_radio_filter() - Standard filter for radio controls.
*
* @ctrl: The control that is filtered.
*
* This will return true for any controls that are valid for radio device
......@@ -567,16 +599,19 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
/**
* v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster.
* v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
* to that cluster.
*
* @ncontrols: The number of controls in this cluster.
* @controls: The cluster control array of size @ncontrols.
*/
void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);
void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
/**
* v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to
* that cluster and set it up for autofoo/foo-type handling.
* v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
* to that cluster and set it up for autofoo/foo-type handling.
*
* @ncontrols: The number of controls in this cluster.
* @controls: The cluster control array of size @ncontrols. The first control
* must be the 'auto' control (e.g. autogain, autoexposure, etc.)
......@@ -604,12 +639,14 @@ void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);
* 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 ncontrols, struct v4l2_ctrl **controls,
void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
struct v4l2_ctrl **controls,
u8 manual_val, bool set_volatile);
/**
* v4l2_ctrl_find() - Find a control with the given ID.
*
* @hdl: The control handler.
* @id: The control ID to find.
*
......@@ -634,6 +671,7 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
/**
* v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
*
* @ctrl: The control to (de)activate.
* @grabbed: True if the control should become grabbed.
*
......@@ -673,6 +711,7 @@ int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
/**
* v4l2_ctrl_modify_range() - Update the range of a control.
*
* @ctrl: The control to update.
* @min: The control's minimum value.
* @max: The control's maximum value.
......@@ -703,6 +742,7 @@ static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
/**
* v4l2_ctrl_notify() - Function to set a notify callback for a control.
*
* @ctrl: The control.
* @notify: The callback function.
* @priv: The callback private handle, passed as argument to the callback.
......@@ -714,10 +754,12 @@ static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
* There can be only one notify. If another already exists, then a WARN_ON
* will be issued and the function will do nothing.
*/
void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv);
void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
void *priv);
/**
* v4l2_ctrl_get_name() - Get the name of the control
*
* @id: The control ID.
*
* This function returns the name of the given control ID or NULL if it isn't
......@@ -727,6 +769,7 @@ const char *v4l2_ctrl_get_name(u32 id);
/**
* v4l2_ctrl_get_menu() - Get the menu string array of the control
*
* @id: The control ID.
*
* This function returns the NULL-terminated menu string array name of the
......@@ -736,6 +779,7 @@ const char * const *v4l2_ctrl_get_menu(u32 id);
/**
* v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
*
* @id: The control ID.
* @len: The size of the integer array.
*
......@@ -745,7 +789,9 @@ const char * const *v4l2_ctrl_get_menu(u32 id);
const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
/**
* v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
* v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
* within a driver.
*
* @ctrl: The control.
*
* This returns the control's value safely by going through the control
......@@ -758,8 +804,9 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
/**
* __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
*
* @ctrl: The control.
* @val: The new value.
* @val: TheControls name new value.
*
* This sets the control's new value safely by going through the control
* framework. This function assumes the control's handler is already locked,
......@@ -769,7 +816,9 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
*/
int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
/** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver.
/**
* v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
* within a driver.
* @ctrl: The control.
* @val: The new value.
*
......@@ -793,6 +842,7 @@ static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
/**
* v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
* from within a driver.
*
* @ctrl: The control.
*
* This returns the control's value safely by going through the control
......@@ -817,7 +867,8 @@ s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
*/
int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
/** v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
/**
* v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
* from within a driver.
*
* @ctrl: The control.
......@@ -840,7 +891,8 @@ static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
return rval;
}
/** __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
/**
* __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
*
* @ctrl: The control.
* @s: The new string.
......@@ -853,12 +905,13 @@ static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
*/
int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
/** v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
/**
* v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
* from within a driver.
*
* @ctrl: The control.
* @s: The new string.
*
*Controls name
* This sets the control's new string safely by going through the control
* framework. This function will lock the control's handler, so it cannot be
* used from within the &v4l2_ctrl_ops functions.
......@@ -878,39 +931,179 @@ static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
/* Internal helper functions that deal with control events. */
extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
/**
* v4l2_ctrl_replace - Function to be used as a callback to
* &struct v4l2_subscribed_event_ops replace\(\)
*
* @old: pointer to :ref:`struct v4l2_event <v4l2-event>` with the reported
* event;
* @new: pointer to :ref:`struct v4l2_event <v4l2-event>` with the modified
* event;
*/
void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
/**
* v4l2_ctrl_merge - Function to be used as a callback to
* &struct v4l2_subscribed_event_ops merge(\)
*
* @old: pointer to :ref:`struct v4l2_event <v4l2-event>` with the reported
* event;
* @new: pointer to :ref:`struct v4l2_event <v4l2-event>` with the merged
* event;
*/
void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
/* Can be used as a vidioc_log_status function that just dumps all controls
associated with the filehandle. */
/**
* v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
*
* @file: pointer to struct file
* @fh: unused. Kept just to be compatible to the arguments expected by
* &struct v4l2_ioctl_ops.vidioc_log_status.
*
* Can be used as a vidioc_log_status function that just dumps all controls
* associated with the filehandle.
*/
int v4l2_ctrl_log_status(struct file *file, void *fh);
/* Can be used as a vidioc_subscribe_event function that just subscribes
control events. */
/**
* v4l2_ctrl_subscribe_event - Subscribes to an event
*
*
* @fh: pointer to struct v4l2_fh
* @sub: pointer to &struct v4l2_event_subscription
*
* Can be used as a vidioc_subscribe_event function that just subscribes
* control events.
*/
int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
const struct v4l2_event_subscription *sub);
/* Can be used as a poll function that just polls for control events. */
/**
* v4l2_ctrl_poll - function to be used as a callback to the poll()
* That just polls for control events.
*
* @file: pointer to struct file
* @wait: pointer to struct poll_table_struct
*/
unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
/* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
/* Helpers for ioctl_ops */
/**
* v4l2_queryctrl - Helper function to implement
* :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
*
* @hdl: pointer to &struct v4l2_ctrl_handler
* @qc: pointer to &struct v4l2_queryctrl
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctrl *qc);
/**
* v4l2_query_ext_ctrl - Helper function to implement
* :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
*
* @hdl: pointer to &struct v4l2_ctrl_handler
* @qc: pointer to &struct v4l2_query_ext_ctrl
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
struct v4l2_query_ext_ctrl *qc);
/**
* v4l2_querymenu - Helper function to implement
* :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
*
* @hdl: pointer to &struct v4l2_ctrl_handler
* @qm: pointer to &struct v4l2_querymenu
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
/**
* v4l2_g_ctrl - Helper function to implement
* :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
*
* @hdl: pointer to &struct v4l2_ctrl_handler
* @ctrl: pointer to &struct v4l2_control
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
/**
* v4l2_s_ctrl - Helper function to implement
* :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
*
* @fh: pointer to &struct v4l2_fh
* @hdl: pointer to &struct v4l2_ctrl_handler
*
* @ctrl: pointer to &struct v4l2_control
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
struct v4l2_control *ctrl);
int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
/**
* v4l2_g_ext_ctrls - Helper function to implement
* :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
*
* @hdl: pointer to &struct v4l2_ctrl_handler
* @c: pointer to &struct v4l2_ext_controls
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *c);
/**
* v4l2_try_ext_ctrls - Helper function to implement
* :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
*
* @hdl: pointer to &struct v4l2_ctrl_handler
* @c: pointer to &struct v4l2_ext_controls
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *c);
/**
* v4l2_s_ext_ctrls - Helper function to implement
* :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
*
* @fh: pointer to &struct v4l2_fh
* @hdl: pointer to &struct v4l2_ctrl_handler
* @c: pointer to &struct v4l2_ext_controls
*
* If hdl == NULL then they will all return -EINVAL.
*/
int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *c);
/* Can be used as a subscribe_event function that just subscribes control
events. */
/**
* v4l2_ctrl_subdev_subscribe_event - Helper function to implement
* as a &struct v4l2_subdev_core_ops subscribe_event function
* that just subscribes control events.
*
* @sd: pointer to &struct v4l2_subdev
* @fh: pointer to &struct v4l2_fh
* @sub: pointer to &struct v4l2_event_subscription
*/
int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
struct v4l2_event_subscription *sub);
/* Log all controls owned by subdev's control handler. */
/**
* v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
* handler.
*
* @sd: pointer to &struct v4l2_subdev
*/
int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
#endif
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