2 V4L2 controls support header.
4 Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/list.h>
25 #include <linux/mutex.h>
26 #include <linux/videodev2.h>
28 /* forward references */
30 struct v4l2_ctrl_handler;
31 struct v4l2_ctrl_helper;
35 struct v4l2_subscribed_event;
37 struct poll_table_struct;
40 * union v4l2_ctrl_ptr - A pointer to a control value.
41 * @p_s32: Pointer to a 32-bit signed value.
42 * @p_s64: Pointer to a 64-bit signed value.
43 * @p_u8: Pointer to a 8-bit unsigned value.
44 * @p_u16: Pointer to a 16-bit unsigned value.
45 * @p_u32: Pointer to a 32-bit unsigned value.
46 * @p_char: Pointer to a string.
47 * @p: Pointer to a compound value.
60 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
61 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
62 * for volatile (and usually read-only) controls such as a control
63 * that returns the current signal strength which changes
65 * If not set, then the currently cached value will be returned.
66 * @try_ctrl: Test whether the control's value is valid. Only relevant when
67 * the usual min/max/step checks are not sufficient.
68 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
69 * ctrl->handler->lock is held when these ops are called, so no
70 * one else can access controls owned by that handler.
72 struct v4l2_ctrl_ops {
73 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
74 int (*try_ctrl)(struct v4l2_ctrl *ctrl);
75 int (*s_ctrl)(struct v4l2_ctrl *ctrl);
79 * struct v4l2_ctrl_type_ops - The control type operations that the driver
82 * @equal: return true if both values are equal.
83 * @init: initialize the value.
84 * @log: log the value.
85 * @validate: validate the value. Return 0 on success and a negative value otherwise.
87 struct v4l2_ctrl_type_ops {
88 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
89 union v4l2_ctrl_ptr ptr1,
90 union v4l2_ctrl_ptr ptr2);
91 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
92 union v4l2_ctrl_ptr ptr);
93 void (*log)(const struct v4l2_ctrl *ctrl);
94 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
95 union v4l2_ctrl_ptr ptr);
98 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
101 * struct v4l2_ctrl - The control structure.
102 * @node: The list node.
103 * @ev_subs: The list of control event subscriptions.
104 * @handler: The handler that owns the control.
105 * @cluster: Point to start of cluster array.
106 * @ncontrols: Number of controls in cluster array.
107 * @done: Internal flag: set for each processed control.
108 * @is_new: Set when the user specified a new value for this control. It
109 * is also set when called from v4l2_ctrl_handler_setup. Drivers
110 * should never set this flag.
111 * @has_changed: Set when the current value differs from the new value. Drivers
112 * should never use this flag.
113 * @is_private: If set, then this control is private to its handler and it
114 * will not be added to any other handlers. Drivers can set
116 * @is_auto: If set, then this control selects whether the other cluster
117 * members are in 'automatic' mode or 'manual' mode. This is
118 * used for autogain/gain type clusters. Drivers should never
119 * set this flag directly.
120 * @is_int: If set, then this control has a simple integer value (i.e. it
122 * @is_string: If set, then this control has type V4L2_CTRL_TYPE_STRING.
123 * @is_ptr: If set, then this control is an array and/or has type >= V4L2_CTRL_COMPOUND_TYPES
124 * and/or has type V4L2_CTRL_TYPE_STRING. In other words, struct
125 * v4l2_ext_control uses field p to point to the data.
126 * @is_array: If set, then this control contains an N-dimensional array.
127 * @has_volatiles: If set, then one or more members of the cluster are volatile.
128 * Drivers should never touch this flag.
129 * @call_notify: If set, then call the handler's notify function whenever the
130 * control's value changes.
131 * @manual_mode_value: If the is_auto flag is set, then this is the value
132 * of the auto control that determines if that control is in
133 * manual mode. So if the value of the auto control equals this
134 * value, then the whole cluster is in manual mode. Drivers should
135 * never set this flag directly.
136 * @ops: The control ops.
137 * @type_ops: The control type ops.
138 * @id: The control ID.
139 * @name: The control name.
140 * @type: The control type.
141 * @minimum: The control's minimum value.
142 * @maximum: The control's maximum value.
143 * @default_value: The control's default value.
144 * @step: The control's step value for non-menu controls.
145 * @elems: The number of elements in the N-dimensional array.
146 * @elem_size: The size in bytes of the control.
147 * @dims: The size of each dimension.
148 * @nr_of_dims:The number of dimensions in @dims.
149 * @max_stores:The maximum number of configuration stores of this control.
150 * @nr_of_stores: The number of allocated configuration stores of this control.
151 * @store: The configuration store that the control op operates on.
152 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
153 * easy to skip menu items that are not valid. If bit X is set,
154 * then menu item X is skipped. Of course, this only works for
155 * menus with <= 32 menu items. There are no menus that come
156 * close to that number, so this is OK. Should we ever need more,
157 * then this will have to be extended to a u64 or a bit array.
158 * @qmenu: A const char * array for all menu items. Array entries that are
159 * empty strings ("") correspond to non-existing menu items (this
160 * is in addition to the menu_skip_mask above). The last entry
162 * @flags: The control's flags.
163 * @cur: The control's current value.
164 * @val: The control's new s32 value.
165 * @priv: The control's private pointer. For use by the driver. It is
166 * untouched by the control framework. Note that this pointer is
167 * not freed when the control is deleted. Should this be needed
168 * then a new internal bitfield can be added to tell the framework
169 * to free this pointer.
170 * @p_cur: The control's current value represented via an union with
171 * provides a standard way of accessing control types
173 * @p_new: The control's new value represented via an union with provides
174 * a standard way of accessing control types
178 /* Administrative fields */
179 struct list_head node;
180 struct list_head ev_subs;
181 struct v4l2_ctrl_handler *handler;
182 struct v4l2_ctrl **cluster;
186 unsigned int is_new:1;
187 unsigned int has_changed:1;
188 unsigned int is_private:1;
189 unsigned int is_auto:1;
190 unsigned int is_int:1;
191 unsigned int is_string:1;
192 unsigned int is_ptr:1;
193 unsigned int is_array:1;
194 unsigned int has_volatiles:1;
195 unsigned int call_notify:1;
196 unsigned int manual_mode_value:8;
198 const struct v4l2_ctrl_ops *ops;
199 const struct v4l2_ctrl_type_ops *type_ops;
202 enum v4l2_ctrl_type type;
203 s64 minimum, maximum, default_value;
206 u32 dims[V4L2_CTRL_MAX_DIMS];
216 const char * const *qmenu;
217 const s64 *qmenu_int;
226 union v4l2_ctrl_ptr p_new;
227 union v4l2_ctrl_ptr p_cur;
228 union v4l2_ctrl_ptr *p_stores;
232 * struct v4l2_ctrl_ref - The control reference.
233 * @node: List node for the sorted list.
234 * @next: Single-link list node for the hash.
235 * @ctrl: The actual control information.
236 * @helper: Pointer to helper struct. Used internally in prepare_ext_ctrls().
238 * Each control handler has a list of these refs. The list_head is used to
239 * keep a sorted-by-control-ID list of all controls, while the next pointer
240 * is used to link the control in the hash's bucket.
242 struct v4l2_ctrl_ref {
243 struct list_head node;
244 struct v4l2_ctrl_ref *next;
245 struct v4l2_ctrl *ctrl;
246 struct v4l2_ctrl_helper *helper;
250 * struct v4l2_ctrl_handler - The control handler keeps track of all the
251 * controls: both the controls owned by the handler and those inherited
252 * from other handlers.
253 * @_lock: Default for "lock".
254 * @lock: Lock to control access to this handler and its controls.
255 * May be replaced by the user right after init.
256 * @ctrls: The list of controls owned by this handler.
257 * @ctrl_refs: The list of control references.
258 * @cached: The last found control reference. It is common that the same
259 * control is needed multiple times, so this is a simple
261 * @buckets: Buckets for the hashing. Allows for quick control lookup.
262 * @notify: A notify callback that is called whenever the control changes value.
263 * Note that the handler's lock is held when the notify function
265 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
266 * @nr_of_buckets: Total number of buckets in the array.
267 * @error: The error code of the first failed control addition.
269 struct v4l2_ctrl_handler {
272 struct list_head ctrls;
273 struct list_head ctrl_refs;
274 struct v4l2_ctrl_ref *cached;
275 struct v4l2_ctrl_ref **buckets;
276 v4l2_ctrl_notify_fnc notify;
283 * struct v4l2_ctrl_config - Control configuration structure.
284 * @ops: The control ops.
285 * @type_ops: The control type ops. Only needed for compound controls.
286 * @id: The control ID.
287 * @name: The control name.
288 * @type: The control type.
289 * @min: The control's minimum value.
290 * @max: The control's maximum value.
291 * @step: The control's step value for non-menu controls.
292 * @def: The control's default value.
293 * @dims: The size of each dimension.
294 * @elem_size: The size in bytes of the control.
295 * @max_stores: The maximum number of stores allowed.
296 * @flags: The control's flags.
297 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
298 * easy to skip menu items that are not valid. If bit X is set,
299 * then menu item X is skipped. Of course, this only works for
300 * menus with <= 64 menu items. There are no menus that come
301 * close to that number, so this is OK. Should we ever need more,
302 * then this will have to be extended to a bit array.
303 * @qmenu: A const char * array for all menu items. Array entries that are
304 * empty strings ("") correspond to non-existing menu items (this
305 * is in addition to the menu_skip_mask above). The last entry
307 * @qmenu_int: A const s64 integer array for all menu items of the type
308 * V4L2_CTRL_TYPE_INTEGER_MENU.
309 * @is_private: If set, then this control is private to its handler and it
310 * will not be added to any other handlers.
312 struct v4l2_ctrl_config {
313 const struct v4l2_ctrl_ops *ops;
314 const struct v4l2_ctrl_type_ops *type_ops;
317 enum v4l2_ctrl_type type;
322 u32 dims[V4L2_CTRL_MAX_DIMS];
327 const char * const *qmenu;
328 const s64 *qmenu_int;
329 unsigned int is_private:1;
333 * v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
335 * This works for all standard V4L2 controls.
336 * For non-standard controls it will only fill in the given arguments
337 * and @name will be NULL.
339 * This function will overwrite the contents of @name, @type and @flags.
340 * The contents of @min, @max, @step and @def may be modified depending on
343 * Do not use in drivers! It is used internally for backwards compatibility
344 * control handling only. Once all drivers are converted to use the new
345 * control framework this function will no longer be exported.
347 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
348 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
352 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
353 * @hdl: The control handler.
354 * @nr_of_controls_hint: A hint of how many controls this handler is
355 * expected to refer to. This is the total number, so including
356 * any inherited controls. It doesn't have to be precise, but if
357 * it is way off, then you either waste memory (too many buckets
358 * are allocated) or the control lookup becomes slower (not enough
359 * buckets are allocated, so there are more slow list lookups).
360 * It will always work, though.
361 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
362 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
364 * Returns an error if the buckets could not be allocated. This error will
365 * also be stored in @hdl->error.
367 * Never use this call directly, always use the v4l2_ctrl_handler_init
368 * macro that hides the @key and @name arguments.
370 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
371 unsigned nr_of_controls_hint,
372 struct lock_class_key *key, const char *name);
374 #ifdef CONFIG_LOCKDEP
375 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
378 static struct lock_class_key _key; \
379 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
381 KBUILD_BASENAME ":" \
382 __stringify(__LINE__) ":" \
383 "(" #hdl ")->_lock"); \
387 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
388 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
392 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
394 * @hdl: The control handler.
396 * Does nothing if @hdl == NULL.
398 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
401 * v4l2_ctrl_lock() - Helper function to lock the handler
402 * associated with the control.
403 * @ctrl: The control to lock.
405 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
407 mutex_lock(ctrl->handler->lock);
411 * v4l2_ctrl_unlock() - Helper function to unlock the handler
412 * associated with the control.
413 * @ctrl: The control to unlock.
415 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
417 mutex_unlock(ctrl->handler->lock);
421 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
422 * to the handler to initialize the hardware to the current control values.
423 * @hdl: The control handler.
425 * Button controls will be skipped, as are read-only controls.
427 * If @hdl == NULL, then this just returns 0.
429 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
432 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
433 * @hdl: The control handler.
434 * @prefix: The prefix to use when logging the control values. If the
435 * prefix does not end with a space, then ": " will be added
436 * after the prefix. If @prefix == NULL, then no prefix will be
439 * For use with VIDIOC_LOG_STATUS.
441 * Does nothing if @hdl == NULL.
443 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
447 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
449 * @hdl: The control handler.
450 * @cfg: The control's configuration data.
451 * @priv: The control's driver-specific private data.
453 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
454 * and @hdl->error is set to the error code (if it wasn't set already).
456 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
457 const struct v4l2_ctrl_config *cfg, void *priv);
460 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control.
461 * @hdl: The control handler.
462 * @ops: The control ops.
463 * @id: The control ID.
464 * @min: The control's minimum value.
465 * @max: The control's maximum value.
466 * @step: The control's step value
467 * @def: The control's default value.
469 * If the &v4l2_ctrl struct could not be allocated, or the control
470 * ID is not known, then NULL is returned and @hdl->error is set to the
471 * appropriate error code (if it wasn't set already).
473 * If @id refers to a menu control, then this function will return NULL.
475 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
477 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
478 const struct v4l2_ctrl_ops *ops,
479 u32 id, s64 min, s64 max, u64 step, s64 def);
482 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control.
483 * @hdl: The control handler.
484 * @ops: The control ops.
485 * @id: The control ID.
486 * @max: The control's maximum value.
487 * @mask: The control's skip mask for menu controls. This makes it
488 * easy to skip menu items that are not valid. If bit X is set,
489 * then menu item X is skipped. Of course, this only works for
490 * menus with <= 64 menu items. There are no menus that come
491 * close to that number, so this is OK. Should we ever need more,
492 * then this will have to be extended to a bit array.
493 * @def: The control's default value.
495 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
496 * determines which menu items are to be skipped.
498 * If @id refers to a non-menu control, then this function will return NULL.
500 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
501 const struct v4l2_ctrl_ops *ops,
502 u32 id, u8 max, u64 mask, u8 def);
505 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
506 * with driver specific menu.
507 * @hdl: The control handler.
508 * @ops: The control ops.
509 * @id: The control ID.
510 * @max: The control's maximum value.
511 * @mask: The control's skip mask for menu controls. This makes it
512 * easy to skip menu items that are not valid. If bit X is set,
513 * then menu item X is skipped. Of course, this only works for
514 * menus with <= 64 menu items. There are no menus that come
515 * close to that number, so this is OK. Should we ever need more,
516 * then this will have to be extended to a bit array.
517 * @def: The control's default value.
518 * @qmenu: The new menu.
520 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
521 * menu of this control.
524 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
525 const struct v4l2_ctrl_ops *ops, u32 id, u8 max,
526 u64 mask, u8 def, const char * const *qmenu);
529 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
530 * @hdl: The control handler.
531 * @ops: The control ops.
532 * @id: The control ID.
533 * @max: The control's maximum value.
534 * @def: The control's default value.
535 * @qmenu_int: The control's menu entries.
537 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
538 * takes as an argument an array of integers determining the menu items.
540 * If @id refers to a non-integer-menu control, then this function will return NULL.
542 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
543 const struct v4l2_ctrl_ops *ops,
544 u32 id, u8 max, u8 def, const s64 *qmenu_int);
547 * v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler.
548 * @hdl: The control handler.
549 * @ctrl: The control to add.
551 * It will return NULL if it was unable to add the control reference.
552 * If the control already belonged to the handler, then it will do
553 * nothing and just return @ctrl.
555 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
556 struct v4l2_ctrl *ctrl);
559 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
561 * @hdl: The control handler.
562 * @add: The control handler whose controls you want to add to
563 * the @hdl control handler.
564 * @filter: This function will filter which controls should be added.
566 * Does nothing if either of the two handlers is a NULL pointer.
567 * If @filter is NULL, then all controls are added. Otherwise only those
568 * controls for which @filter returns true will be added.
569 * In case of an error @hdl->error will be set to the error code (if it
570 * wasn't set already).
572 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
573 struct v4l2_ctrl_handler *add,
574 bool (*filter)(const struct v4l2_ctrl *ctrl));
577 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
578 * @ctrl: The control that is filtered.
580 * This will return true for any controls that are valid for radio device
581 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
582 * transmitter class controls.
584 * This function is to be used with v4l2_ctrl_add_handler().
586 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
589 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster.
590 * @ncontrols: The number of controls in this cluster.
591 * @controls: The cluster control array of size @ncontrols.
593 void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);
597 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to
598 * that cluster and set it up for autofoo/foo-type handling.
599 * @ncontrols: The number of controls in this cluster.
600 * @controls: The cluster control array of size @ncontrols. The first control
601 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
602 * @manual_val: The value for the first control in the cluster that equals the
604 * @set_volatile: If true, then all controls except the first auto control will
607 * Use for control groups where one control selects some automatic feature and
608 * the other controls are only active whenever the automatic feature is turned
609 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
610 * red and blue balance, etc.
612 * The behavior of such controls is as follows:
614 * When the autofoo control is set to automatic, then any manual controls
615 * are set to inactive and any reads will call g_volatile_ctrl (if the control
616 * was marked volatile).
618 * When the autofoo control is set to manual, then any manual controls will
619 * be marked active, and any reads will just return the current value without
620 * going through g_volatile_ctrl.
622 * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag
623 * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
624 * if autofoo is in auto mode.
626 void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
627 u8 manual_val, bool set_volatile);
631 * v4l2_ctrl_find() - Find a control with the given ID.
632 * @hdl: The control handler.
633 * @id: The control ID to find.
635 * If @hdl == NULL this will return NULL as well. Will lock the handler so
636 * do not use from inside &v4l2_ctrl_ops.
638 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
641 * v4l2_ctrl_activate() - Make the control active or inactive.
642 * @ctrl: The control to (de)activate.
643 * @active: True if the control should become active.
645 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
646 * Does nothing if @ctrl == NULL.
647 * This will usually be called from within the s_ctrl op.
648 * The V4L2_EVENT_CTRL event will be generated afterwards.
650 * This function assumes that the control handler is locked.
652 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
655 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
656 * @ctrl: The control to (de)activate.
657 * @grabbed: True if the control should become grabbed.
659 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
660 * Does nothing if @ctrl == NULL.
661 * The V4L2_EVENT_CTRL event will be generated afterwards.
662 * This will usually be called when starting or stopping streaming in the
665 * This function assumes that the control handler is not locked and will
666 * take the lock itself.
668 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
672 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
674 * @ctrl: The control to update.
675 * @min: The control's minimum value.
676 * @max: The control's maximum value.
677 * @step: The control's step value
678 * @def: The control's default value.
680 * Update the range of a control on the fly. This works for control types
681 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
682 * @step value is interpreted as a menu_skip_mask.
684 * An error is returned if one of the range arguments is invalid for this
687 * This function assumes that the control handler is not locked and will
688 * take the lock itself.
690 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
691 s64 min, s64 max, u64 step, s64 def);
694 * v4l2_ctrl_modify_range() - Update the range of a control.
695 * @ctrl: The control to update.
696 * @min: The control's minimum value.
697 * @max: The control's maximum value.
698 * @step: The control's step value
699 * @def: The control's default value.
701 * Update the range of a control on the fly. This works for control types
702 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
703 * @step value is interpreted as a menu_skip_mask.
705 * An error is returned if one of the range arguments is invalid for this
708 * This function assumes that the control handler is not locked and will
709 * take the lock itself.
711 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
712 s64 min, s64 max, u64 step, s64 def)
716 v4l2_ctrl_lock(ctrl);
717 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
718 v4l2_ctrl_unlock(ctrl);
724 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
725 * @ctrl: The control.
726 * @notify: The callback function.
727 * @priv: The callback private handle, passed as argument to the callback.
729 * This function sets a callback function for the control. If @ctrl is NULL,
730 * then it will do nothing. If @notify is NULL, then the notify callback will
733 * There can be only one notify. If another already exists, then a WARN_ON
734 * will be issued and the function will do nothing.
736 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv);
739 * v4l2_ctrl_get_name() - Get the name of the control
740 * @id: The control ID.
742 * This function returns the name of the given control ID or NULL if it isn't
745 const char *v4l2_ctrl_get_name(u32 id);
748 * v4l2_ctrl_get_menu() - Get the menu string array of the control
749 * @id: The control ID.
751 * This function returns the NULL-terminated menu string array name of the
752 * given control ID or NULL if it isn't a known menu control.
754 const char * const *v4l2_ctrl_get_menu(u32 id);
757 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
758 * @id: The control ID.
759 * @len: The size of the integer array.
761 * This function returns the integer array of the given control ID or NULL if it
762 * if it isn't a known integer menu control.
764 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
767 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
768 * @ctrl: The control.
770 * This returns the control's value safely by going through the control
771 * framework. This function will lock the control's handler, so it cannot be
772 * used from within the &v4l2_ctrl_ops functions.
774 * This function is for integer type controls only.
776 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
779 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
780 * @ctrl: The control.
781 * @val: The new value.
783 * This set the control's new value safely by going through the control
784 * framework. This function will lock the control's handler, so it cannot be
785 * used from within the &v4l2_ctrl_ops functions.
787 * This function is for integer type controls only.
789 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
791 /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver.
792 * @ctrl: The control.
793 * @val: The new value.
795 * This set the control's new value safely by going through the control
796 * framework. This function will lock the control's handler, so it cannot be
797 * used from within the &v4l2_ctrl_ops functions.
799 * This function is for integer type controls only.
801 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
805 v4l2_ctrl_lock(ctrl);
806 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
807 v4l2_ctrl_unlock(ctrl);
813 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
814 * from within a driver.
815 * @ctrl: The control.
817 * This returns the control's value safely by going through the control
818 * framework. This function will lock the control's handler, so it cannot be
819 * used from within the &v4l2_ctrl_ops functions.
821 * This function is for 64-bit integer type controls only.
823 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
826 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
828 * @ctrl: The control.
829 * @val: The new value.
831 * This set the control's new value safely by going through the control
832 * framework. This function will lock the control's handler, so it cannot be
833 * used from within the &v4l2_ctrl_ops functions.
835 * This function is for 64-bit integer type controls only.
837 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
839 /** v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
840 * from within a driver.
842 * @ctrl: The control.
843 * @val: The new value.
845 * This set the control's new value safely by going through the control
846 * framework. This function will lock the control's handler, so it cannot be
847 * used from within the &v4l2_ctrl_ops functions.
849 * This function is for 64-bit integer type controls only.
851 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
855 v4l2_ctrl_lock(ctrl);
856 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
857 v4l2_ctrl_unlock(ctrl);
862 /** __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
864 * @ctrl: The control.
865 * @s: The new string.
867 * This set the control's new string safely by going through the control
868 * framework. This function will lock the control's handler, so it cannot be
869 * used from within the &v4l2_ctrl_ops functions.
871 * This function is for string type controls only.
873 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
875 /** v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
876 * from within a driver.
878 * @ctrl: The control.
879 * @s: The new string.
881 * This set the control's new string safely by going through the control
882 * framework. This function will lock the control's handler, so it cannot be
883 * used from within the &v4l2_ctrl_ops functions.
885 * This function is for string type controls only.
887 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
891 v4l2_ctrl_lock(ctrl);
892 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
893 v4l2_ctrl_unlock(ctrl);
898 static inline void v4l2_ctrl_set_max_stores(struct v4l2_ctrl *ctrl, u16 max_stores)
900 ctrl->max_stores = max_stores;
903 int v4l2_ctrl_apply_store(struct v4l2_ctrl_handler *hdl, unsigned store);
905 /* Internal helper functions that deal with control events. */
906 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
907 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
908 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
910 /* Can be used as a vidioc_log_status function that just dumps all controls
911 associated with the filehandle. */
912 int v4l2_ctrl_log_status(struct file *file, void *fh);
914 /* Can be used as a vidioc_subscribe_event function that just subscribes
916 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
917 const struct v4l2_event_subscription *sub);
919 /* Can be used as a poll function that just polls for control events. */
920 unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
922 /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
923 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
924 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctrl *qc);
925 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
926 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
927 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
928 struct v4l2_control *ctrl);
929 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
930 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
931 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
932 struct v4l2_ext_controls *c);
934 /* Helpers for subdevices. If the associated ctrl_handler == NULL then they
935 will all return -EINVAL. */
936 int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
937 int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
938 int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
939 int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
940 int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
941 int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
942 int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
944 /* Can be used as a subscribe_event function that just subscribes control
946 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
947 struct v4l2_event_subscription *sub);
949 /* Log all controls owned by subdev's control handler. */
950 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);