v4l2-ctrls.h 36.1 KB
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/*
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 *  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.
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 */

#ifndef _V4L2_CTRLS_H
#define _V4L2_CTRLS_H

#include <linux/list.h>
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#include <linux/mutex.h>
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#include <linux/videodev2.h>
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/* forward references */
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struct file;
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struct v4l2_ctrl_handler;
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struct v4l2_ctrl_helper;
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struct v4l2_ctrl;
struct video_device;
struct v4l2_subdev;
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struct v4l2_subscribed_event;
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struct v4l2_fh;
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struct poll_table_struct;
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/**
 * union v4l2_ctrl_ptr - A pointer to a control value.
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 * @p_s32:	Pointer to a 32-bit signed value.
 * @p_s64:	Pointer to a 64-bit signed value.
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 * @p_u8:	Pointer to a 8-bit unsigned value.
 * @p_u16:	Pointer to a 16-bit unsigned value.
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 * @p_u32:	Pointer to a 32-bit unsigned value.
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 * @p_char:	Pointer to a string.
 * @p:		Pointer to a compound value.
 */
union v4l2_ctrl_ptr {
	s32 *p_s32;
	s64 *p_s64;
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	u8 *p_u8;
	u16 *p_u16;
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	u32 *p_u32;
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	char *p_char;
	void *p;
};

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/**
 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
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 *
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 * @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
 *		continuously.
 *		If not set, then the currently cached value will be returned.
 * @try_ctrl:	Test whether the control's value is valid. Only relevant when
 *		the usual min/max/step checks are not sufficient.
 * @s_ctrl:	Actually set the new control value. s_ctrl is compulsory. The
 *		ctrl->handler->lock is held when these ops are called, so no
 *		one else can access controls owned by that handler.
 */
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struct v4l2_ctrl_ops {
	int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
	int (*try_ctrl)(struct v4l2_ctrl *ctrl);
	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
};

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/**
 * struct v4l2_ctrl_type_ops - The control type operations that the driver
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 *			       has to provide.
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 *
 * @equal: return true if both values are equal.
 * @init: initialize the value.
 * @log: log the value.
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 * @validate: validate the value. Return 0 on success and a negative value
 *	otherwise.
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 */
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struct v4l2_ctrl_type_ops {
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	bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
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		      union v4l2_ctrl_ptr ptr1,
		      union v4l2_ctrl_ptr ptr2);
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	void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
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		     union v4l2_ctrl_ptr ptr);
	void (*log)(const struct v4l2_ctrl *ctrl);
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	int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
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			union v4l2_ctrl_ptr ptr);
};

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

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/**
 * struct v4l2_ctrl - The control structure.
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 *
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 * @node:	The list node.
 * @ev_subs:	The list of control event subscriptions.
 * @handler:	The handler that owns the control.
 * @cluster:	Point to start of cluster array.
 * @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
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 *		is also set when called from v4l2_ctrl_handler_setup(). Drivers
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 *		should never set this flag.
 * @has_changed: Set when the current value differs from the new value. Drivers
 *		should never use this flag.
 * @is_private: If set, then this control is private to its handler and it
 *		will not be added to any other handlers. Drivers can set
 *		this flag.
 * @is_auto:   If set, then this control selects whether the other cluster
 *		members are in 'automatic' mode or 'manual' mode. This is
 *		used for autogain/gain type clusters. Drivers should never
 *		set this flag directly.
 * @is_int:    If set, then this control has a simple integer value (i.e. it
 *		uses ctrl->val).
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 * @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
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 *		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.
 *		Drivers should never touch this flag.
 * @call_notify: If set, then call the handler's notify function whenever the
 *		control's value changes.
 * @manual_mode_value: If the is_auto flag is set, then this is the value
 *		of the auto control that determines if that control is in
 *		manual mode. So if the value of the auto control equals this
 *		value, then the whole cluster is in manual mode. Drivers should
 *		never set this flag directly.
 * @ops:	The control ops.
 * @type_ops:	The control type ops.
 * @id:	The control ID.
 * @name:	The control name.
 * @type:	The control type.
 * @minimum:	The control's minimum value.
 * @maximum:	The control's maximum value.
 * @default_value: The control's default value.
 * @step:	The control's step value for non-menu controls.
 * @elems:	The number of elements in the N-dimensional array.
 * @elem_size:	The size in bytes of the control.
 * @dims:	The size of each dimension.
 * @nr_of_dims:The number of dimensions in @dims.
 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
 *		easy to skip menu items that are not valid. If bit X is set,
 *		then menu item X is skipped. Of course, this only works for
 *		menus with <= 32 menu items. There are no menus that come
 *		close to that number, so this is OK. Should we ever need more,
 *		then this will have to be extended to a u64 or a bit array.
 * @qmenu:	A const char * array for all menu items. Array entries that are
 *		empty strings ("") correspond to non-existing menu items (this
 *		is in addition to the menu_skip_mask above). The last entry
 *		must be NULL.
 * @flags:	The control's flags.
 * @cur:	The control's current value.
 * @val:	The control's new s32 value.
 * @priv:	The control's private pointer. For use by the driver. It is
 *		untouched by the control framework. Note that this pointer is
 *		not freed when the control is deleted. Should this be needed
 *		then a new internal bitfield can be added to tell the framework
 *		to free this pointer.
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 * @p_cur:	The control's current value represented via an union with
 *		provides a standard way of accessing control types
 *		through a pointer.
 * @p_new:	The control's new value represented via an union with provides
 *		a standard way of accessing control types
 *		through a pointer.
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 */
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struct v4l2_ctrl {
	/* Administrative fields */
	struct list_head node;
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	struct list_head ev_subs;
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	struct v4l2_ctrl_handler *handler;
	struct v4l2_ctrl **cluster;
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	unsigned int ncontrols;

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	unsigned int done:1;

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	unsigned int is_new:1;
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	unsigned int has_changed:1;
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	unsigned int is_private:1;
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	unsigned int is_auto:1;
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	unsigned int is_int:1;
	unsigned int is_string:1;
	unsigned int is_ptr:1;
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	unsigned int is_array:1;
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	unsigned int has_volatiles:1;
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	unsigned int call_notify:1;
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	unsigned int manual_mode_value:8;
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	const struct v4l2_ctrl_ops *ops;
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	const struct v4l2_ctrl_type_ops *type_ops;
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	u32 id;
	const char *name;
	enum v4l2_ctrl_type type;
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	s64 minimum, maximum, default_value;
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	u32 elems;
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	u32 elem_size;
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	u32 dims[V4L2_CTRL_MAX_DIMS];
	u32 nr_of_dims;
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	union {
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		u64 step;
		u64 menu_skip_mask;
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	};
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	union {
		const char * const *qmenu;
		const s64 *qmenu_int;
	};
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	unsigned long flags;
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	void *priv;
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	s32 val;
	struct {
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		s32 val;
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	} cur;
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	union v4l2_ctrl_ptr p_new;
	union v4l2_ctrl_ptr p_cur;
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};

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/**
 * struct v4l2_ctrl_ref - The control reference.
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 *
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 * @node:	List node for the sorted list.
 * @next:	Single-link list node for the hash.
 * @ctrl:	The actual control information.
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 * @helper:	Pointer to helper struct. Used internally in
 *		prepare_ext_ctrls().
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 *
 * 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
 * is used to link the control in the hash's bucket.
 */
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struct v4l2_ctrl_ref {
	struct list_head node;
	struct v4l2_ctrl_ref *next;
	struct v4l2_ctrl *ctrl;
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	struct v4l2_ctrl_helper *helper;
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};

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/**
 * struct v4l2_ctrl_handler - The control handler keeps track of all the
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 *	controls: both the controls owned by the handler and those inherited
 *	from other handlers.
 *
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 * @_lock:	Default for "lock".
 * @lock:	Lock to control access to this handler and its controls.
 *		May be replaced by the user right after init.
 * @ctrls:	The list of controls owned by this handler.
 * @ctrl_refs:	The list of control references.
 * @cached:	The last found control reference. It is common that the same
 *		control is needed multiple times, so this is a simple
 *		optimization.
 * @buckets:	Buckets for the hashing. Allows for quick control lookup.
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 * @notify:	A notify callback that is called whenever the control changes
 *		value.
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 *		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.
 * @nr_of_buckets: Total number of buckets in the array.
 * @error:	The error code of the first failed control addition.
 */
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struct v4l2_ctrl_handler {
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	struct mutex _lock;
	struct mutex *lock;
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	struct list_head ctrls;
	struct list_head ctrl_refs;
	struct v4l2_ctrl_ref *cached;
	struct v4l2_ctrl_ref **buckets;
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	v4l2_ctrl_notify_fnc notify;
	void *notify_priv;
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	u16 nr_of_buckets;
	int error;
};

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/**
 * struct v4l2_ctrl_config - Control configuration structure.
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 *
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 * @ops:	The control ops.
 * @type_ops:	The control type ops. Only needed for compound controls.
 * @id:	The control ID.
 * @name:	The control name.
 * @type:	The control type.
 * @min:	The control's minimum value.
 * @max:	The control's maximum value.
 * @step:	The control's step value for non-menu controls.
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 * @def:	The control's default value.
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 * @dims:	The size of each dimension.
 * @elem_size:	The size in bytes of the control.
 * @flags:	The control's flags.
 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
 *		easy to skip menu items that are not valid. If bit X is set,
 *		then menu item X is skipped. Of course, this only works for
 *		menus with <= 64 menu items. There are no menus that come
 *		close to that number, so this is OK. Should we ever need more,
 *		then this will have to be extended to a bit array.
 * @qmenu:	A const char * array for all menu items. Array entries that are
 *		empty strings ("") correspond to non-existing menu items (this
 *		is in addition to the menu_skip_mask above). The last entry
 *		must be NULL.
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 * @qmenu_int:	A const s64 integer array for all menu items of the type
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 *		V4L2_CTRL_TYPE_INTEGER_MENU.
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 * @is_private: If set, then this control is private to its handler and it
 *		will not be added to any other handlers.
 */
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struct v4l2_ctrl_config {
	const struct v4l2_ctrl_ops *ops;
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	const struct v4l2_ctrl_type_ops *type_ops;
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	u32 id;
	const char *name;
	enum v4l2_ctrl_type type;
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	s64 min;
	s64 max;
	u64 step;
	s64 def;
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	u32 dims[V4L2_CTRL_MAX_DIMS];
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	u32 elem_size;
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	u32 flags;
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	u64 menu_skip_mask;
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	const char * const *qmenu;
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	const s64 *qmenu_int;
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	unsigned int is_private:1;
};

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/**
 * 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
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 *
 * This works for all standard V4L2 controls.
 * For non-standard controls it will only fill in the given arguments
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 * and @name will be %NULL.
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 *
 * 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.
 *
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 * .. 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.
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 */
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void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
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		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
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/**
 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
 * @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.
 * @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.
 *
 * Never use this call directly, always use the v4l2_ctrl_handler_init
 * macro that hides the @key and @name arguments.
 */
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int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
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				 unsigned int nr_of_controls_hint,
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				 struct lock_class_key *key, const char *name);

#ifdef CONFIG_LOCKDEP
#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
(									\
	({								\
		static struct lock_class_key _key;			\
		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
					&_key,				\
					KBUILD_BASENAME ":"		\
					__stringify(__LINE__) ":"	\
					"(" #hdl ")->_lock");		\
	})								\
)
#else
#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
#endif
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/**
 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
 * the control list.
 * @hdl:	The control handler.
 *
 * Does nothing if @hdl == NULL.
 */
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void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);

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/**
 * v4l2_ctrl_lock() - Helper function to lock the handler
 * associated with the control.
 * @ctrl:	The control to lock.
 */
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static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
{
	mutex_lock(ctrl->handler->lock);
}

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/**
 * v4l2_ctrl_unlock() - Helper function to unlock the handler
 * associated with the control.
 * @ctrl:	The control to unlock.
 */
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static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
{
	mutex_unlock(ctrl->handler->lock);
}

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/**
 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
 * to the handler to initialize the hardware to the current control values.
 * @hdl:	The control handler.
 *
 * Button controls will be skipped, as are read-only controls.
 *
 * If @hdl == NULL, then this just returns 0.
 */
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int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);

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/**
 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
 * @hdl:	The control handler.
 * @prefix:	The prefix to use when logging the control values. If the
 *		prefix does not end with a space, then ": " will be added
 *		after the prefix. If @prefix == NULL, then no prefix will be
 *		used.
 *
 * For use with VIDIOC_LOG_STATUS.
 *
 * Does nothing if @hdl == NULL.
 */
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void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
				  const char *prefix);

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/**
 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
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 *	control.
 *
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 * @hdl:	The control handler.
 * @cfg:	The control's configuration data.
 * @priv:	The control's driver-specific private data.
 *
 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
 * and @hdl->error is set to the error code (if it wasn't set already).
 */
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struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
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				       const struct v4l2_ctrl_config *cfg,
				       void *priv);
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/**
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 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
 *	control.
 *
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 * @hdl:	The control handler.
 * @ops:	The control ops.
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 * @id:		The control ID.
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 * @min:	The control's minimum value.
 * @max:	The control's maximum value.
 * @step:	The control's step value
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 * @def:	The control's default value.
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 *
 * If the &v4l2_ctrl struct could not be allocated, or the control
 * ID is not known, then NULL is returned and @hdl->error is set to the
 * appropriate error code (if it wasn't set already).
 *
 * If @id refers to a menu control, then this function will return NULL.
 *
 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
 */
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struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
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				    const struct v4l2_ctrl_ops *ops,
				    u32 id, s64 min, s64 max, u64 step,
				    s64 def);
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/**
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 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
 *	menu control.
 *
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 * @hdl:	The control handler.
 * @ops:	The control ops.
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 * @id:		The control ID.
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 * @max:	The control's maximum value.
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 * @mask:	The control's skip mask for menu controls. This makes it
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 *		easy to skip menu items that are not valid. If bit X is set,
 *		then menu item X is skipped. Of course, this only works for
 *		menus with <= 64 menu items. There are no menus that come
 *		close to that number, so this is OK. Should we ever need more,
 *		then this will have to be extended to a bit array.
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 * @def:	The control's default value.
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 *
 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
 * determines which menu items are to be skipped.
 *
 * If @id refers to a non-menu control, then this function will return NULL.
 */
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struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
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					 const struct v4l2_ctrl_ops *ops,
					 u32 id, u8 max, u64 mask, u8 def);
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/**
 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
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 *	with driver specific menu.
 *
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 * @hdl:	The control handler.
 * @ops:	The control ops.
 * @id:	The control ID.
 * @max:	The control's maximum value.
 * @mask:	The control's skip mask for menu controls. This makes it
 *		easy to skip menu items that are not valid. If bit X is set,
 *		then menu item X is skipped. Of course, this only works for
 *		menus with <= 64 menu items. There are no menus that come
 *		close to that number, so this is OK. Should we ever need more,
 *		then this will have to be extended to a bit array.
 * @def:	The control's default value.
 * @qmenu:	The new menu.
 *
 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
 * menu of this control.
 *
 */
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struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
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					       const struct v4l2_ctrl_ops *ops,
					       u32 id, u8 max,
					       u64 mask, u8 def,
					       const char * const *qmenu);
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/**
 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
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 *
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 * @hdl:	The control handler.
 * @ops:	The control ops.
 * @id:	The control ID.
 * @max:	The control's maximum value.
 * @def:	The control's default value.
 * @qmenu_int:	The control's menu entries.
 *
 * 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.
 *
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 * If @id refers to a non-integer-menu control, then this function will
 * return %NULL.
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 */
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struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
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					 const struct v4l2_ctrl_ops *ops,
					 u32 id, u8 max, u8 def,
					 const s64 *qmenu_int);
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typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);

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/**
 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
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 *	handler @hdl.
 *
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 * @hdl:	The control handler.
 * @add:	The control handler whose controls you want to add to
 *		the @hdl control handler.
 * @filter:	This function will filter which controls should be added.
 *
 * Does nothing if either of the two handlers is a NULL pointer.
 * If @filter is NULL, then all controls are added. Otherwise only those
 * controls for which @filter returns true will be added.
 * In case of an error @hdl->error will be set to the error code (if it
 * wasn't set already).
 */
584
int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
585
			  struct v4l2_ctrl_handler *add,
586
			  v4l2_ctrl_filter filter);
587

588 589
/**
 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
590
 *
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 * @ctrl:	The control that is filtered.
 *
 * This will return true for any controls that are valid for radio device
 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
 * transmitter class controls.
 *
 * This function is to be used with v4l2_ctrl_add_handler().
 */
599
bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
600

601
/**
602 603 604
 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
 *	to that cluster.
 *
605
 * @ncontrols:	The number of controls in this cluster.
606
 * @controls:	The cluster control array of size @ncontrols.
607
 */
608
void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
609 610


611
/**
612 613 614
 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
 *	to that cluster and set it up for autofoo/foo-type handling.
 *
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 * @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.)
 * @manual_val: The value for the first control in the cluster that equals the
 *		manual setting.
 * @set_volatile: If true, then all controls except the first auto control will
 *		be volatile.
 *
 * Use for control groups where one control selects some automatic feature and
 * the other controls are only active whenever the automatic feature is turned
 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
 * red and blue balance, etc.
 *
 * The behavior of such controls is as follows:
 *
 * When the autofoo control is set to automatic, then any manual controls
 * are set to inactive and any reads will call g_volatile_ctrl (if the control
 * was marked volatile).
 *
 * When the autofoo control is set to manual, then any manual controls will
 * 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)
 * if autofoo is in auto mode.
 */
642 643 644
void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
			    struct v4l2_ctrl **controls,
			    u8 manual_val, bool set_volatile);
645 646


647 648
/**
 * v4l2_ctrl_find() - Find a control with the given ID.
649
 *
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 * @hdl:	The control handler.
 * @id:	The control ID to find.
 *
 * If @hdl == NULL this will return NULL as well. Will lock the handler so
 * do not use from inside &v4l2_ctrl_ops.
 */
656 657
struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);

658 659 660 661 662 663 664 665 666 667 668 669
/**
 * v4l2_ctrl_activate() - Make the control active or inactive.
 * @ctrl:	The control to (de)activate.
 * @active:	True if the control should become active.
 *
 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
 * Does nothing if @ctrl == NULL.
 * This will usually be called from within the s_ctrl op.
 * The V4L2_EVENT_CTRL event will be generated afterwards.
 *
 * This function assumes that the control handler is locked.
 */
670 671
void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);

672 673
/**
 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
674
 *
675 676 677 678 679 680 681 682 683 684 685 686
 * @ctrl:	The control to (de)activate.
 * @grabbed:	True if the control should become grabbed.
 *
 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
 * Does nothing if @ctrl == NULL.
 * The V4L2_EVENT_CTRL event will be generated afterwards.
 * This will usually be called when starting or stopping streaming in the
 * driver.
 *
 * This function assumes that the control handler is not locked and will
 * take the lock itself.
 */
687 688
void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);

689

690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708
/**
 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
 *
 * @ctrl:	The control to update.
 * @min:	The control's minimum value.
 * @max:	The control's maximum value.
 * @step:	The control's step value
 * @def:	The control's default value.
 *
 * Update the range of a control on the fly. This works for control types
 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
 * @step value is interpreted as a menu_skip_mask.
 *
 * An error is returned if one of the range arguments is invalid for this
 * control type.
 *
 * This function assumes that the control handler is not locked and will
 * take the lock itself.
 */
709 710 711
int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
			     s64 min, s64 max, u64 step, s64 def);

712 713
/**
 * v4l2_ctrl_modify_range() - Update the range of a control.
714
 *
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730
 * @ctrl:	The control to update.
 * @min:	The control's minimum value.
 * @max:	The control's maximum value.
 * @step:	The control's step value
 * @def:	The control's default value.
 *
 * Update the range of a control on the fly. This works for control types
 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
 * @step value is interpreted as a menu_skip_mask.
 *
 * An error is returned if one of the range arguments is invalid for this
 * control type.
 *
 * This function assumes that the control handler is not locked and will
 * take the lock itself.
 */
731 732 733 734 735 736 737 738 739 740 741
static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
					 s64 min, s64 max, u64 step, s64 def)
{
	int rval;

	v4l2_ctrl_lock(ctrl);
	rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
	v4l2_ctrl_unlock(ctrl);

	return rval;
}
742

743 744
/**
 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
745
 *
746 747 748 749 750 751 752 753 754 755 756
 * @ctrl:	The control.
 * @notify:	The callback function.
 * @priv:	The callback private handle, passed as argument to the callback.
 *
 * This function sets a callback function for the control. If @ctrl is NULL,
 * then it will do nothing. If @notify is NULL, then the notify callback will
 * be removed.
 *
 * There can be only one notify. If another already exists, then a WARN_ON
 * will be issued and the function will do nothing.
 */
757 758
void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
		      void *priv);
759

760 761
/**
 * v4l2_ctrl_get_name() - Get the name of the control
762
 *
763 764 765 766 767 768 769
 * @id:		The control ID.
 *
 * This function returns the name of the given control ID or NULL if it isn't
 * a known control.
 */
const char *v4l2_ctrl_get_name(u32 id);

770 771
/**
 * v4l2_ctrl_get_menu() - Get the menu string array of the control
772
 *
773 774 775 776 777 778 779
 * @id:		The control ID.
 *
 * This function returns the NULL-terminated menu string array name of the
 * given control ID or NULL if it isn't a known menu control.
 */
const char * const *v4l2_ctrl_get_menu(u32 id);

780 781
/**
 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
782
 *
783 784 785 786 787 788 789 790
 * @id:		The control ID.
 * @len:	The size of the integer array.
 *
 * This function returns the integer array of the given control ID or NULL if it
 * if it isn't a known integer menu control.
 */
const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);

791
/**
792 793 794
 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
 *	within a driver.
 *
795 796 797 798 799 800 801 802
 * @ctrl:	The control.
 *
 * This returns the control's value 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.
 *
 * This function is for integer type controls only.
 */
803 804
s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);

805 806
/**
 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
807
 *
808
 * @ctrl:	The control.
809
 * @val:	TheControls name new value.
810
 *
811 812 813
 * This sets the control's new value safely by going through the control
 * framework. This function assumes the control's handler is already locked,
 * allowing it to be used from within the &v4l2_ctrl_ops functions.
814 815 816
 *
 * This function is for integer type controls only.
 */
817
int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
818

819 820 821
/**
 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
 *	within a driver.
822 823 824
 * @ctrl:	The control.
 * @val:	The new value.
 *
825
 * This sets the control's new value safely by going through the control
826 827 828 829 830
 * framework. This function will lock the control's handler, so it cannot be
 * used from within the &v4l2_ctrl_ops functions.
 *
 * This function is for integer type controls only.
 */
831 832 833 834 835 836 837 838 839 840
static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
{
	int rval;

	v4l2_ctrl_lock(ctrl);
	rval = __v4l2_ctrl_s_ctrl(ctrl, val);
	v4l2_ctrl_unlock(ctrl);

	return rval;
}
841

842 843 844
/**
 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
 *	from within a driver.
845
 *
846 847 848 849 850 851 852 853
 * @ctrl:	The control.
 *
 * This returns the control's value 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.
 *
 * This function is for 64-bit integer type controls only.
 */
854 855
s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);

856 857 858 859 860 861
/**
 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
 *
 * @ctrl:	The control.
 * @val:	The new value.
 *
862 863 864
 * This sets the control's new value safely by going through the control
 * framework. This function assumes the control's handler is already locked,
 * allowing it to be used from within the &v4l2_ctrl_ops functions.
865 866 867
 *
 * This function is for 64-bit integer type controls only.
 */
868 869
int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);

870 871
/**
 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
872 873 874 875 876
 *	from within a driver.
 *
 * @ctrl:	The control.
 * @val:	The new value.
 *
877
 * This sets the control's new value safely by going through the control
878 879 880 881 882
 * framework. This function will lock the control's handler, so it cannot be
 * used from within the &v4l2_ctrl_ops functions.
 *
 * This function is for 64-bit integer type controls only.
 */
883 884 885 886 887 888 889 890 891 892
static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
{
	int rval;

	v4l2_ctrl_lock(ctrl);
	rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
	v4l2_ctrl_unlock(ctrl);

	return rval;
}
893

894 895
/**
 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
896 897 898 899
 *
 * @ctrl:	The control.
 * @s:		The new string.
 *
900 901 902
 * This sets the control's new string safely by going through the control
 * framework. This function assumes the control's handler is already locked,
 * allowing it to be used from within the &v4l2_ctrl_ops functions.
903 904 905
 *
 * This function is for string type controls only.
 */
906 907
int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);

908 909
/**
 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
910 911 912 913
 *	 from within a driver.
 *
 * @ctrl:	The control.
 * @s:		The new string.
914
 *Controls name
915
 * This sets the control's new string safely by going through the control
916 917 918 919 920
 * framework. This function will lock the control's handler, so it cannot be
 * used from within the &v4l2_ctrl_ops functions.
 *
 * This function is for string type controls only.
 */
921 922 923 924 925 926 927 928 929 930 931
static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
{
	int rval;

	v4l2_ctrl_lock(ctrl);
	rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
	v4l2_ctrl_unlock(ctrl);

	return rval;
}

932
/* Internal helper functions that deal with control events. */
933
extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
934 935 936 937 938 939 940 941 942 943

/**
 * 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;
 */
944
void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
945 946 947 948 949 950 951 952 953 954

/**
 * 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;
 */
955
void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
956

957 958 959 960 961 962 963 964 965 966
/**
 * 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.
 */
967 968
int v4l2_ctrl_log_status(struct file *file, void *fh);

969 970 971 972 973 974 975 976 977 978
/**
 * 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.
 */
979
int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
980
				const struct v4l2_event_subscription *sub);
981

982 983 984 985 986 987 988
/**
 * 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
 */
989 990
unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);

991 992 993 994 995 996 997 998 999 1000 1001
/* 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.
 */
1002
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024

/**
 * 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.
 */
1025
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1026 1027 1028 1029 1030 1031 1032 1033 1034 1035

/**
 * 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.
 */
1036
int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048

/**
 * 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.
 */
1049
int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085
		struct v4l2_control *ctrl);

/**
 * 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.
 */
1086
int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1087
		     struct v4l2_ext_controls *c);
1088

1089 1090 1091 1092 1093 1094 1095 1096 1097
/**
 * 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
 */
1098 1099 1100
int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
				     struct v4l2_event_subscription *sub);

1101 1102 1103 1104 1105 1106
/**
 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
 *	 handler.
 *
 * @sd: pointer to &struct v4l2_subdev
 */
1107 1108
int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);

1109
#endif