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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.
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
*/
#ifndef _V4L2_CTRLS_H
#define _V4L2_CTRLS_H
#include <linux/list.h>
#include <linux/videodev2.h>
/* forward references */
struct file;
struct v4l2_ctrl_handler;
struct v4l2_ctrl_helper;
struct v4l2_ctrl;
struct video_device;
struct v4l2_subdev;
struct v4l2_subscribed_event;
struct v4l2_fh;
struct poll_table_struct;
/** 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
* 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.
*/
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);
};
/** 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.
* @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
* is also set when called from v4l2_ctrl_handler_setup. Drivers
* should never set 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.
* @has_volatiles: If set, then one or more members of the cluster are volatile.
* Drivers should never touch this flag.
* @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.
* @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.
* @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.
* @val64: The control's new s64 value.
* @string: The control's new string 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.
*/
struct v4l2_ctrl {
/* Administrative fields */
struct list_head node;
struct list_head ev_subs;
struct v4l2_ctrl_handler *handler;
struct v4l2_ctrl **cluster;
unsigned ncontrols;
unsigned int done:1;
unsigned int is_new:1;
unsigned int is_private:1;
unsigned int is_auto:1;
unsigned int has_volatiles:1;
unsigned int manual_mode_value:8;
const struct v4l2_ctrl_ops *ops;
u32 id;
const char *name;
enum v4l2_ctrl_type type;
s32 minimum, maximum, default_value;
union {
u32 step;
u32 menu_skip_mask;
};
union {
const char * const *qmenu;
const s64 *qmenu_int;
};
unsigned long flags;
union {
s32 val;
s64 val64;
char *string;
} cur;
union {
s32 val;
s64 val64;
char *string;
};
void *priv;
};
/** 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().
*
* 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.
*/
struct v4l2_ctrl_ref {
struct list_head node;
struct v4l2_ctrl_ref *next;
struct v4l2_ctrl *ctrl;
struct v4l2_ctrl_helper *helper;
};
/** 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.
* @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.
* @nr_of_buckets: Total number of buckets in the array.
* @error: The error code of the first failed control addition.
*/
struct v4l2_ctrl_handler {
struct mutex _lock;
struct mutex *lock;
struct list_head ctrls;
struct list_head ctrl_refs;
struct v4l2_ctrl_ref *cached;
struct v4l2_ctrl_ref **buckets;
u16 nr_of_buckets;
int error;
};
/** struct v4l2_ctrl_config - Control configuration structure.
* @ops: The control ops.
* @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.
* @def: The control's default value.
* @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 <= 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.
* @is_private: If set, then this control is private to its handler and it
* will not be added to any other handlers.
*/
struct v4l2_ctrl_config {
const struct v4l2_ctrl_ops *ops;
u32 id;
const char *name;
enum v4l2_ctrl_type type;
s32 min;
s32 max;
u32 step;
s32 def;
u32 flags;
u32 menu_skip_mask;
const char * const *qmenu;
const s64 *qmenu_int;
unsigned int is_private:1;
};
/** v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
*
* This works for all standard V4L2 controls.
* For non-standard controls it will only fill in the given arguments
* 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.
*
* 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.
*/
void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags);
/** v4l2_ctrl_handler_init() - 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.
*
* Returns an error if the buckets could not be allocated. This error will
* also be stored in @hdl->error.
*/
int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl,
unsigned nr_of_controls_hint);
/** 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.
*/
void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
/** 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.
*/
int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
/** 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.
*/
void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
const char *prefix);
/** 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.
*
* 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).
*/
struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_config *cfg, void *priv);
/** 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.
* @min: The control's minimum value.
* @max: The control's maximum value.
* @step: The control's step value
* @def: The control's default value.
*
* 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.
*/
struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
u32 id, s32 min, s32 max, u32 step, s32 def);
/** 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.
* @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 <= 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.
* @def: The control's default value.
*
* 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.
*/
struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
u32
|