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.
20 #include <linux/list.h>
21 #include <linux/mutex.h>
22 #include <linux/videodev2.h>
23 #include <media/media-request.h>
25 /* forward references */
27 struct v4l2_ctrl_handler;
28 struct v4l2_ctrl_helper;
32 struct v4l2_subscribed_event;
34 struct poll_table_struct;
37 * union v4l2_ctrl_ptr - A pointer to a control value.
38 * @p_s32: Pointer to a 32-bit signed value.
39 * @p_s64: Pointer to a 64-bit signed value.
40 * @p_u8: Pointer to a 8-bit unsigned value.
41 * @p_u16: Pointer to a 16-bit unsigned value.
42 * @p_u32: Pointer to a 32-bit unsigned value.
43 * @p_char: Pointer to a string.
44 * @p_mpeg2_slice_params: Pointer to a MPEG2 slice parameters structure.
45 * @p_mpeg2_quantization: Pointer to a MPEG2 quantization data structure.
46 * @p: Pointer to a compound value.
55 struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
56 struct v4l2_ctrl_mpeg2_quantization *p_mpeg2_quantization;
61 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
63 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
64 * for volatile (and usually read-only) controls such as a control
65 * that returns the current signal strength which changes
67 * If not set, then the currently cached value will be returned.
68 * @try_ctrl: Test whether the control's value is valid. Only relevant when
69 * the usual min/max/step checks are not sufficient.
70 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
71 * ctrl->handler->lock is held when these ops are called, so no
72 * one else can access controls owned by that handler.
74 struct v4l2_ctrl_ops {
75 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
76 int (*try_ctrl)(struct v4l2_ctrl *ctrl);
77 int (*s_ctrl)(struct v4l2_ctrl *ctrl);
81 * struct v4l2_ctrl_type_ops - The control type operations that the driver
84 * @equal: return true if both values are equal.
85 * @init: initialize the value.
86 * @log: log the value.
87 * @validate: validate the value. Return 0 on success and a negative value
90 struct v4l2_ctrl_type_ops {
91 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
92 union v4l2_ctrl_ptr ptr1,
93 union v4l2_ctrl_ptr ptr2);
94 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
95 union v4l2_ctrl_ptr ptr);
96 void (*log)(const struct v4l2_ctrl *ctrl);
97 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
98 union v4l2_ctrl_ptr ptr);
102 * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
103 * that should be called when a control value has changed.
105 * @ctrl: pointer to struct &v4l2_ctrl
106 * @priv: control private data
108 * This typedef definition is used as an argument to v4l2_ctrl_notify()
109 * and as an argument at struct &v4l2_ctrl_handler.
111 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
114 * struct v4l2_ctrl - The control structure.
116 * @node: The list node.
117 * @ev_subs: The list of control event subscriptions.
118 * @handler: The handler that owns the control.
119 * @cluster: Point to start of cluster array.
120 * @ncontrols: Number of controls in cluster array.
121 * @done: Internal flag: set for each processed control.
122 * @is_new: Set when the user specified a new value for this control. It
123 * is also set when called from v4l2_ctrl_handler_setup(). Drivers
124 * should never set this flag.
125 * @has_changed: Set when the current value differs from the new value. Drivers
126 * should never use this flag.
127 * @is_private: If set, then this control is private to its handler and it
128 * will not be added to any other handlers. Drivers can set
130 * @is_auto: If set, then this control selects whether the other cluster
131 * members are in 'automatic' mode or 'manual' mode. This is
132 * used for autogain/gain type clusters. Drivers should never
133 * set this flag directly.
134 * @is_int: If set, then this control has a simple integer value (i.e. it
136 * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
137 * @is_ptr: If set, then this control is an array and/or has type >=
138 * %V4L2_CTRL_COMPOUND_TYPES
139 * and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
140 * v4l2_ext_control uses field p to point to the data.
141 * @is_array: If set, then this control contains an N-dimensional array.
142 * @has_volatiles: If set, then one or more members of the cluster are volatile.
143 * Drivers should never touch this flag.
144 * @call_notify: If set, then call the handler's notify function whenever the
145 * control's value changes.
146 * @manual_mode_value: If the is_auto flag is set, then this is the value
147 * of the auto control that determines if that control is in
148 * manual mode. So if the value of the auto control equals this
149 * value, then the whole cluster is in manual mode. Drivers should
150 * never set this flag directly.
151 * @ops: The control ops.
152 * @type_ops: The control type ops.
153 * @id: The control ID.
154 * @name: The control name.
155 * @type: The control type.
156 * @minimum: The control's minimum value.
157 * @maximum: The control's maximum value.
158 * @default_value: The control's default value.
159 * @step: The control's step value for non-menu controls.
160 * @elems: The number of elements in the N-dimensional array.
161 * @elem_size: The size in bytes of the control.
162 * @dims: The size of each dimension.
163 * @nr_of_dims:The number of dimensions in @dims.
164 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
165 * easy to skip menu items that are not valid. If bit X is set,
166 * then menu item X is skipped. Of course, this only works for
167 * menus with <= 32 menu items. There are no menus that come
168 * close to that number, so this is OK. Should we ever need more,
169 * then this will have to be extended to a u64 or a bit array.
170 * @qmenu: A const char * array for all menu items. Array entries that are
171 * empty strings ("") correspond to non-existing menu items (this
172 * is in addition to the menu_skip_mask above). The last entry
174 * Used only if the @type is %V4L2_CTRL_TYPE_MENU.
175 * @qmenu_int: A 64-bit integer array for with integer menu items.
176 * The size of array must be equal to the menu size, e. g.:
177 * :math:`ceil(\frac{maximum - minimum}{step}) + 1`.
178 * Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
179 * @flags: The control's flags.
180 * @cur: Structure to store the current value.
181 * @cur.val: The control's current value, if the @type is represented via
182 * a u32 integer (see &enum v4l2_ctrl_type).
183 * @val: The control's new s32 value.
184 * @priv: The control's private pointer. For use by the driver. It is
185 * untouched by the control framework. Note that this pointer is
186 * not freed when the control is deleted. Should this be needed
187 * then a new internal bitfield can be added to tell the framework
188 * to free this pointer.
189 * @p_cur: The control's current value represented via a union which
190 * provides a standard way of accessing control types
192 * @p_new: The control's new value represented via a union which provides
193 * a standard way of accessing control types
197 /* Administrative fields */
198 struct list_head node;
199 struct list_head ev_subs;
200 struct v4l2_ctrl_handler *handler;
201 struct v4l2_ctrl **cluster;
202 unsigned int ncontrols;
206 unsigned int is_new:1;
207 unsigned int has_changed:1;
208 unsigned int is_private:1;
209 unsigned int is_auto:1;
210 unsigned int is_int:1;
211 unsigned int is_string:1;
212 unsigned int is_ptr:1;
213 unsigned int is_array:1;
214 unsigned int has_volatiles:1;
215 unsigned int call_notify:1;
216 unsigned int manual_mode_value:8;
218 const struct v4l2_ctrl_ops *ops;
219 const struct v4l2_ctrl_type_ops *type_ops;
222 enum v4l2_ctrl_type type;
223 s64 minimum, maximum, default_value;
226 u32 dims[V4L2_CTRL_MAX_DIMS];
233 const char * const *qmenu;
234 const s64 *qmenu_int;
243 union v4l2_ctrl_ptr p_new;
244 union v4l2_ctrl_ptr p_cur;
248 * struct v4l2_ctrl_ref - The control reference.
250 * @node: List node for the sorted list.
251 * @next: Single-link list node for the hash.
252 * @ctrl: The actual control information.
253 * @helper: Pointer to helper struct. Used internally in
254 * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
255 * @from_other_dev: If true, then @ctrl was defined in another
256 * device than the &struct v4l2_ctrl_handler.
257 * @req_done: Internal flag: if the control handler containing this control
258 * reference is bound to a media request, then this is set when
259 * the control has been applied. This prevents applying controls
260 * from a cluster with multiple controls twice (when the first
261 * control of a cluster is applied, they all are).
262 * @req: If set, this refers to another request that sets this control.
263 * @p_req: If the control handler containing this control reference
264 * is bound to a media request, then this points to the
265 * value of the control that should be applied when the request
266 * is executed, or to the value of the control at the time
267 * that the request was completed.
269 * Each control handler has a list of these refs. The list_head is used to
270 * keep a sorted-by-control-ID list of all controls, while the next pointer
271 * is used to link the control in the hash's bucket.
273 struct v4l2_ctrl_ref {
274 struct list_head node;
275 struct v4l2_ctrl_ref *next;
276 struct v4l2_ctrl *ctrl;
277 struct v4l2_ctrl_helper *helper;
280 struct v4l2_ctrl_ref *req;
281 union v4l2_ctrl_ptr p_req;
285 * struct v4l2_ctrl_handler - The control handler keeps track of all the
286 * controls: both the controls owned by the handler and those inherited
287 * from other handlers.
289 * @_lock: Default for "lock".
290 * @lock: Lock to control access to this handler and its controls.
291 * May be replaced by the user right after init.
292 * @ctrls: The list of controls owned by this handler.
293 * @ctrl_refs: The list of control references.
294 * @cached: The last found control reference. It is common that the same
295 * control is needed multiple times, so this is a simple
297 * @buckets: Buckets for the hashing. Allows for quick control lookup.
298 * @notify: A notify callback that is called whenever the control changes
300 * Note that the handler's lock is held when the notify function
302 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
303 * @nr_of_buckets: Total number of buckets in the array.
304 * @error: The error code of the first failed control addition.
305 * @request_is_queued: True if the request was queued.
306 * @requests: List to keep track of open control handler request objects.
307 * For the parent control handler (@req_obj.req == NULL) this
308 * is the list header. When the parent control handler is
309 * removed, it has to unbind and put all these requests since
310 * they refer to the parent.
311 * @requests_queued: List of the queued requests. This determines the order
312 * in which these controls are applied. Once the request is
313 * completed it is removed from this list.
314 * @req_obj: The &struct media_request_object, used to link into a
315 * &struct media_request. This request object has a refcount.
317 struct v4l2_ctrl_handler {
320 struct list_head ctrls;
321 struct list_head ctrl_refs;
322 struct v4l2_ctrl_ref *cached;
323 struct v4l2_ctrl_ref **buckets;
324 v4l2_ctrl_notify_fnc notify;
328 bool request_is_queued;
329 struct list_head requests;
330 struct list_head requests_queued;
331 struct media_request_object req_obj;
335 * struct v4l2_ctrl_config - Control configuration structure.
337 * @ops: The control ops.
338 * @type_ops: The control type ops. Only needed for compound controls.
339 * @id: The control ID.
340 * @name: The control name.
341 * @type: The control type.
342 * @min: The control's minimum value.
343 * @max: The control's maximum value.
344 * @step: The control's step value for non-menu controls.
345 * @def: The control's default value.
346 * @dims: The size of each dimension.
347 * @elem_size: The size in bytes of the control.
348 * @flags: The control's flags.
349 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
350 * easy to skip menu items that are not valid. If bit X is set,
351 * then menu item X is skipped. Of course, this only works for
352 * menus with <= 64 menu items. There are no menus that come
353 * close to that number, so this is OK. Should we ever need more,
354 * then this will have to be extended to a bit array.
355 * @qmenu: A const char * array for all menu items. Array entries that are
356 * empty strings ("") correspond to non-existing menu items (this
357 * is in addition to the menu_skip_mask above). The last entry
359 * @qmenu_int: A const s64 integer array for all menu items of the type
360 * V4L2_CTRL_TYPE_INTEGER_MENU.
361 * @is_private: If set, then this control is private to its handler and it
362 * will not be added to any other handlers.
364 struct v4l2_ctrl_config {
365 const struct v4l2_ctrl_ops *ops;
366 const struct v4l2_ctrl_type_ops *type_ops;
369 enum v4l2_ctrl_type type;
374 u32 dims[V4L2_CTRL_MAX_DIMS];
378 const char * const *qmenu;
379 const s64 *qmenu_int;
380 unsigned int is_private:1;
384 * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
386 * @id: ID of the control
387 * @name: pointer to be filled with a string with the name of the control
388 * @type: pointer for storing the type of the control
389 * @min: pointer for storing the minimum value for the control
390 * @max: pointer for storing the maximum value for the control
391 * @step: pointer for storing the control step
392 * @def: pointer for storing the default value for the control
393 * @flags: pointer for storing the flags to be used on the control
395 * This works for all standard V4L2 controls.
396 * For non-standard controls it will only fill in the given arguments
397 * and @name content will be set to %NULL.
399 * This function will overwrite the contents of @name, @type and @flags.
400 * The contents of @min, @max, @step and @def may be modified depending on
405 * Do not use in drivers! It is used internally for backwards compatibility
406 * control handling only. Once all drivers are converted to use the new
407 * control framework this function will no longer be exported.
409 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
410 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
414 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
415 * @hdl: The control handler.
416 * @nr_of_controls_hint: A hint of how many controls this handler is
417 * expected to refer to. This is the total number, so including
418 * any inherited controls. It doesn't have to be precise, but if
419 * it is way off, then you either waste memory (too many buckets
420 * are allocated) or the control lookup becomes slower (not enough
421 * buckets are allocated, so there are more slow list lookups).
422 * It will always work, though.
423 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
424 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
428 * Never use this call directly, always use the v4l2_ctrl_handler_init()
429 * macro that hides the @key and @name arguments.
431 * Return: returns an error if the buckets could not be allocated. This
432 * error will also be stored in @hdl->error.
434 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
435 unsigned int nr_of_controls_hint,
436 struct lock_class_key *key, const char *name);
438 #ifdef CONFIG_LOCKDEP
441 * v4l2_ctrl_handler_init - helper function to create a static struct
442 * &lock_class_key and calls v4l2_ctrl_handler_init_class()
444 * @hdl: The control handler.
445 * @nr_of_controls_hint: A hint of how many controls this handler is
446 * expected to refer to. This is the total number, so including
447 * any inherited controls. It doesn't have to be precise, but if
448 * it is way off, then you either waste memory (too many buckets
449 * are allocated) or the control lookup becomes slower (not enough
450 * buckets are allocated, so there are more slow list lookups).
451 * It will always work, though.
453 * This helper function creates a static struct &lock_class_key and
454 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
457 * Use this helper function to initialize a control handler.
459 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
462 static struct lock_class_key _key; \
463 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
465 KBUILD_BASENAME ":" \
466 __stringify(__LINE__) ":" \
467 "(" #hdl ")->_lock"); \
471 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
472 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
476 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
478 * @hdl: The control handler.
480 * Does nothing if @hdl == NULL.
482 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
485 * v4l2_ctrl_lock() - Helper function to lock the handler
486 * associated with the control.
487 * @ctrl: The control to lock.
489 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
491 mutex_lock(ctrl->handler->lock);
495 * v4l2_ctrl_unlock() - Helper function to unlock the handler
496 * associated with the control.
497 * @ctrl: The control to unlock.
499 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
501 mutex_unlock(ctrl->handler->lock);
505 * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
506 * to the handler to initialize the hardware to the current control values. The
507 * caller is responsible for acquiring the control handler mutex on behalf of
508 * __v4l2_ctrl_handler_setup().
509 * @hdl: The control handler.
511 * Button controls will be skipped, as are read-only controls.
513 * If @hdl == NULL, then this just returns 0.
515 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
518 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
519 * to the handler to initialize the hardware to the current control values.
520 * @hdl: The control handler.
522 * Button controls will be skipped, as are read-only controls.
524 * If @hdl == NULL, then this just returns 0.
526 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
529 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
530 * @hdl: The control handler.
531 * @prefix: The prefix to use when logging the control values. If the
532 * prefix does not end with a space, then ": " will be added
533 * after the prefix. If @prefix == NULL, then no prefix will be
536 * For use with VIDIOC_LOG_STATUS.
538 * Does nothing if @hdl == NULL.
540 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
544 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
547 * @hdl: The control handler.
548 * @cfg: The control's configuration data.
549 * @priv: The control's driver-specific private data.
551 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
552 * and @hdl->error is set to the error code (if it wasn't set already).
554 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
555 const struct v4l2_ctrl_config *cfg,
559 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
562 * @hdl: The control handler.
563 * @ops: The control ops.
564 * @id: The control ID.
565 * @min: The control's minimum value.
566 * @max: The control's maximum value.
567 * @step: The control's step value
568 * @def: The control's default value.
570 * If the &v4l2_ctrl struct could not be allocated, or the control
571 * ID is not known, then NULL is returned and @hdl->error is set to the
572 * appropriate error code (if it wasn't set already).
574 * If @id refers to a menu control, then this function will return NULL.
576 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
578 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
579 const struct v4l2_ctrl_ops *ops,
580 u32 id, s64 min, s64 max, u64 step,
584 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
587 * @hdl: The control handler.
588 * @ops: The control ops.
589 * @id: The control ID.
590 * @max: The control's maximum value.
591 * @mask: The control's skip mask for menu controls. This makes it
592 * easy to skip menu items that are not valid. If bit X is set,
593 * then menu item X is skipped. Of course, this only works for
594 * menus with <= 64 menu items. There are no menus that come
595 * close to that number, so this is OK. Should we ever need more,
596 * then this will have to be extended to a bit array.
597 * @def: The control's default value.
599 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
600 * determines which menu items are to be skipped.
602 * If @id refers to a non-menu control, then this function will return NULL.
604 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
605 const struct v4l2_ctrl_ops *ops,
606 u32 id, u8 max, u64 mask, u8 def);
609 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
610 * with driver specific menu.
612 * @hdl: The control handler.
613 * @ops: The control ops.
614 * @id: The control ID.
615 * @max: The control's maximum value.
616 * @mask: The control's skip mask for menu controls. This makes it
617 * easy to skip menu items that are not valid. If bit X is set,
618 * then menu item X is skipped. Of course, this only works for
619 * menus with <= 64 menu items. There are no menus that come
620 * close to that number, so this is OK. Should we ever need more,
621 * then this will have to be extended to a bit array.
622 * @def: The control's default value.
623 * @qmenu: The new menu.
625 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
626 * menu of this control.
629 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
630 const struct v4l2_ctrl_ops *ops,
633 const char * const *qmenu);
636 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
638 * @hdl: The control handler.
639 * @ops: The control ops.
640 * @id: The control ID.
641 * @max: The control's maximum value.
642 * @def: The control's default value.
643 * @qmenu_int: The control's menu entries.
645 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
646 * takes as an argument an array of integers determining the menu items.
648 * If @id refers to a non-integer-menu control, then this function will
651 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
652 const struct v4l2_ctrl_ops *ops,
653 u32 id, u8 max, u8 def,
654 const s64 *qmenu_int);
657 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
658 * used when adding a control handler.
660 * @ctrl: pointer to struct &v4l2_ctrl.
663 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
666 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
669 * @hdl: The control handler.
670 * @add: The control handler whose controls you want to add to
671 * the @hdl control handler.
672 * @filter: This function will filter which controls should be added.
673 * @from_other_dev: If true, then the controls in @add were defined in another
676 * Does nothing if either of the two handlers is a NULL pointer.
677 * If @filter is NULL, then all controls are added. Otherwise only those
678 * controls for which @filter returns true will be added.
679 * In case of an error @hdl->error will be set to the error code (if it
680 * wasn't set already).
682 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
683 struct v4l2_ctrl_handler *add,
684 v4l2_ctrl_filter filter,
685 bool from_other_dev);
688 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
690 * @ctrl: The control that is filtered.
692 * This will return true for any controls that are valid for radio device
693 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
694 * transmitter class controls.
696 * This function is to be used with v4l2_ctrl_add_handler().
698 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
701 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
704 * @ncontrols: The number of controls in this cluster.
705 * @controls: The cluster control array of size @ncontrols.
707 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
711 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
712 * to that cluster and set it up for autofoo/foo-type handling.
714 * @ncontrols: The number of controls in this cluster.
715 * @controls: The cluster control array of size @ncontrols. The first control
716 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
717 * @manual_val: The value for the first control in the cluster that equals the
719 * @set_volatile: If true, then all controls except the first auto control will
722 * Use for control groups where one control selects some automatic feature and
723 * the other controls are only active whenever the automatic feature is turned
724 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
725 * red and blue balance, etc.
727 * The behavior of such controls is as follows:
729 * When the autofoo control is set to automatic, then any manual controls
730 * are set to inactive and any reads will call g_volatile_ctrl (if the control
731 * was marked volatile).
733 * When the autofoo control is set to manual, then any manual controls will
734 * be marked active, and any reads will just return the current value without
735 * going through g_volatile_ctrl.
737 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
738 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
739 * if autofoo is in auto mode.
741 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
742 struct v4l2_ctrl **controls,
743 u8 manual_val, bool set_volatile);
747 * v4l2_ctrl_find() - Find a control with the given ID.
749 * @hdl: The control handler.
750 * @id: The control ID to find.
752 * If @hdl == NULL this will return NULL as well. Will lock the handler so
753 * do not use from inside &v4l2_ctrl_ops.
755 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
758 * v4l2_ctrl_activate() - Make the control active or inactive.
759 * @ctrl: The control to (de)activate.
760 * @active: True if the control should become active.
762 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
763 * Does nothing if @ctrl == NULL.
764 * This will usually be called from within the s_ctrl op.
765 * The V4L2_EVENT_CTRL event will be generated afterwards.
767 * This function assumes that the control handler is locked.
769 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
772 * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
774 * @ctrl: The control to (de)activate.
775 * @grabbed: True if the control should become grabbed.
777 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
778 * Does nothing if @ctrl == NULL.
779 * The V4L2_EVENT_CTRL event will be generated afterwards.
780 * This will usually be called when starting or stopping streaming in the
783 * This function assumes that the control handler is locked by the caller.
785 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
788 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
790 * @ctrl: The control to (de)activate.
791 * @grabbed: True if the control should become grabbed.
793 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
794 * Does nothing if @ctrl == NULL.
795 * The V4L2_EVENT_CTRL event will be generated afterwards.
796 * This will usually be called when starting or stopping streaming in the
799 * This function assumes that the control handler is not locked and will
800 * take the lock itself.
802 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
807 v4l2_ctrl_lock(ctrl);
808 __v4l2_ctrl_grab(ctrl, grabbed);
809 v4l2_ctrl_unlock(ctrl);
813 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
815 * @ctrl: The control to update.
816 * @min: The control's minimum value.
817 * @max: The control's maximum value.
818 * @step: The control's step value
819 * @def: The control's default value.
821 * Update the range of a control on the fly. This works for control types
822 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
823 * @step value is interpreted as a menu_skip_mask.
825 * An error is returned if one of the range arguments is invalid for this
828 * The caller is responsible for acquiring the control handler mutex on behalf
829 * of __v4l2_ctrl_modify_range().
831 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
832 s64 min, s64 max, u64 step, s64 def);
835 * v4l2_ctrl_modify_range() - Update the range of a control.
837 * @ctrl: The control to update.
838 * @min: The control's minimum value.
839 * @max: The control's maximum value.
840 * @step: The control's step value
841 * @def: The control's default value.
843 * Update the range of a control on the fly. This works for control types
844 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
845 * @step value is interpreted as a menu_skip_mask.
847 * An error is returned if one of the range arguments is invalid for this
850 * This function assumes that the control handler is not locked and will
851 * take the lock itself.
853 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
854 s64 min, s64 max, u64 step, s64 def)
858 v4l2_ctrl_lock(ctrl);
859 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
860 v4l2_ctrl_unlock(ctrl);
866 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
868 * @ctrl: The control.
869 * @notify: The callback function.
870 * @priv: The callback private handle, passed as argument to the callback.
872 * This function sets a callback function for the control. If @ctrl is NULL,
873 * then it will do nothing. If @notify is NULL, then the notify callback will
876 * There can be only one notify. If another already exists, then a WARN_ON
877 * will be issued and the function will do nothing.
879 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
883 * v4l2_ctrl_get_name() - Get the name of the control
885 * @id: The control ID.
887 * This function returns the name of the given control ID or NULL if it isn't
890 const char *v4l2_ctrl_get_name(u32 id);
893 * v4l2_ctrl_get_menu() - Get the menu string array of the control
895 * @id: The control ID.
897 * This function returns the NULL-terminated menu string array name of the
898 * given control ID or NULL if it isn't a known menu control.
900 const char * const *v4l2_ctrl_get_menu(u32 id);
903 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
905 * @id: The control ID.
906 * @len: The size of the integer array.
908 * This function returns the integer array of the given control ID or NULL if it
909 * if it isn't a known integer menu control.
911 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
914 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
917 * @ctrl: The control.
919 * This returns the control's value safely by going through the control
920 * framework. This function will lock the control's handler, so it cannot be
921 * used from within the &v4l2_ctrl_ops functions.
923 * This function is for integer type controls only.
925 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
928 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
930 * @ctrl: The control.
931 * @val: TheControls name new value.
933 * This sets the control's new value safely by going through the control
934 * framework. This function assumes the control's handler is already locked,
935 * allowing it to be used from within the &v4l2_ctrl_ops functions.
937 * This function is for integer type controls only.
939 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
942 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
944 * @ctrl: The control.
945 * @val: The new value.
947 * This sets the control's new value safely by going through the control
948 * framework. This function will lock the control's handler, so it cannot be
949 * used from within the &v4l2_ctrl_ops functions.
951 * This function is for integer type controls only.
953 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
957 v4l2_ctrl_lock(ctrl);
958 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
959 v4l2_ctrl_unlock(ctrl);
965 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
966 * from within a driver.
968 * @ctrl: The control.
970 * This returns the control's value safely by going through the control
971 * framework. This function will lock the control's handler, so it cannot be
972 * used from within the &v4l2_ctrl_ops functions.
974 * This function is for 64-bit integer type controls only.
976 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
979 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
981 * @ctrl: The control.
982 * @val: The new value.
984 * This sets the control's new value safely by going through the control
985 * framework. This function assumes the control's handler is already locked,
986 * allowing it to be used from within the &v4l2_ctrl_ops functions.
988 * This function is for 64-bit integer type controls only.
990 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
993 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
994 * from within a driver.
996 * @ctrl: The control.
997 * @val: The new value.
999 * This sets the control's new value safely by going through the control
1000 * framework. This function will lock the control's handler, so it cannot be
1001 * used from within the &v4l2_ctrl_ops functions.
1003 * This function is for 64-bit integer type controls only.
1005 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1009 v4l2_ctrl_lock(ctrl);
1010 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1011 v4l2_ctrl_unlock(ctrl);
1017 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1019 * @ctrl: The control.
1020 * @s: The new string.
1022 * This sets the control's new string safely by going through the control
1023 * framework. This function assumes the control's handler is already locked,
1024 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1026 * This function is for string type controls only.
1028 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1031 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1032 * from within a driver.
1034 * @ctrl: The control.
1035 * @s: The new string.
1037 * This sets the control's new string safely by going through the control
1038 * framework. This function will lock the control's handler, so it cannot be
1039 * used from within the &v4l2_ctrl_ops functions.
1041 * This function is for string type controls only.
1043 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1047 v4l2_ctrl_lock(ctrl);
1048 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1049 v4l2_ctrl_unlock(ctrl);
1054 /* Internal helper functions that deal with control events. */
1055 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1058 * v4l2_ctrl_replace - Function to be used as a callback to
1059 * &struct v4l2_subscribed_event_ops replace\(\)
1061 * @old: pointer to struct &v4l2_event with the reported
1063 * @new: pointer to struct &v4l2_event with the modified
1066 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1069 * v4l2_ctrl_merge - Function to be used as a callback to
1070 * &struct v4l2_subscribed_event_ops merge(\)
1072 * @old: pointer to struct &v4l2_event with the reported
1074 * @new: pointer to struct &v4l2_event with the merged
1077 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1080 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1082 * @file: pointer to struct file
1083 * @fh: unused. Kept just to be compatible to the arguments expected by
1084 * &struct v4l2_ioctl_ops.vidioc_log_status.
1086 * Can be used as a vidioc_log_status function that just dumps all controls
1087 * associated with the filehandle.
1089 int v4l2_ctrl_log_status(struct file *file, void *fh);
1092 * v4l2_ctrl_subscribe_event - Subscribes to an event
1095 * @fh: pointer to struct v4l2_fh
1096 * @sub: pointer to &struct v4l2_event_subscription
1098 * Can be used as a vidioc_subscribe_event function that just subscribes
1101 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1102 const struct v4l2_event_subscription *sub);
1105 * v4l2_ctrl_poll - function to be used as a callback to the poll()
1106 * That just polls for control events.
1108 * @file: pointer to struct file
1109 * @wait: pointer to struct poll_table_struct
1111 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1114 * v4l2_ctrl_request_setup - helper function to apply control values in a request
1117 * @parent: The parent control handler ('priv' in media_request_object_find())
1119 * This is a helper function to call the control handler's s_ctrl callback with
1120 * the control values contained in the request. Do note that this approach of
1121 * applying control values in a request is only applicable to memory-to-memory
1124 void v4l2_ctrl_request_setup(struct media_request *req,
1125 struct v4l2_ctrl_handler *parent);
1128 * v4l2_ctrl_request_complete - Complete a control handler request object
1131 * @parent: The parent control handler ('priv' in media_request_object_find())
1133 * This function is to be called on each control handler that may have had a
1134 * request object associated with it, i.e. control handlers of a driver that
1135 * supports requests.
1137 * The function first obtains the values of any volatile controls in the control
1138 * handler and attach them to the request. Then, the function completes the
1141 void v4l2_ctrl_request_complete(struct media_request *req,
1142 struct v4l2_ctrl_handler *parent);
1145 * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1148 * @parent: The parent control handler ('priv' in media_request_object_find())
1150 * This function finds the control handler in the request. It may return
1151 * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1152 * with the returned handler pointer.
1154 * If the request is not in state VALIDATING or QUEUED, then this function
1155 * will always return NULL.
1157 * Note that in state VALIDATING the req_queue_mutex is held, so
1158 * no objects can be added or deleted from the request.
1160 * In state QUEUED it is the driver that will have to ensure this.
1162 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1163 struct v4l2_ctrl_handler *parent);
1166 * v4l2_ctrl_request_hdl_put - Put the control handler
1168 * @hdl: Put this control handler
1170 * This function released the control handler previously obtained from'
1171 * v4l2_ctrl_request_hdl_find().
1173 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1176 media_request_object_put(&hdl->req_obj);
1180 * v4l2_ctrl_request_ctrl_find() - Find a control with the given ID.
1182 * @hdl: The control handler from the request.
1183 * @id: The ID of the control to find.
1185 * This function returns a pointer to the control if this control is
1186 * part of the request or NULL otherwise.
1189 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1191 /* Helpers for ioctl_ops */
1194 * v4l2_queryctrl - Helper function to implement
1195 * :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1197 * @hdl: pointer to &struct v4l2_ctrl_handler
1198 * @qc: pointer to &struct v4l2_queryctrl
1200 * If hdl == NULL then they will all return -EINVAL.
1202 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1205 * v4l2_query_ext_ctrl - Helper function to implement
1206 * :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1208 * @hdl: pointer to &struct v4l2_ctrl_handler
1209 * @qc: pointer to &struct v4l2_query_ext_ctrl
1211 * If hdl == NULL then they will all return -EINVAL.
1213 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1214 struct v4l2_query_ext_ctrl *qc);
1217 * v4l2_querymenu - Helper function to implement
1218 * :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1220 * @hdl: pointer to &struct v4l2_ctrl_handler
1221 * @qm: pointer to &struct v4l2_querymenu
1223 * If hdl == NULL then they will all return -EINVAL.
1225 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1228 * v4l2_g_ctrl - Helper function to implement
1229 * :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1231 * @hdl: pointer to &struct v4l2_ctrl_handler
1232 * @ctrl: pointer to &struct v4l2_control
1234 * If hdl == NULL then they will all return -EINVAL.
1236 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1239 * v4l2_s_ctrl - Helper function to implement
1240 * :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1242 * @fh: pointer to &struct v4l2_fh
1243 * @hdl: pointer to &struct v4l2_ctrl_handler
1245 * @ctrl: pointer to &struct v4l2_control
1247 * If hdl == NULL then they will all return -EINVAL.
1249 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1250 struct v4l2_control *ctrl);
1253 * v4l2_g_ext_ctrls - Helper function to implement
1254 * :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1256 * @hdl: pointer to &struct v4l2_ctrl_handler
1257 * @mdev: pointer to &struct media_device
1258 * @c: pointer to &struct v4l2_ext_controls
1260 * If hdl == NULL then they will all return -EINVAL.
1262 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
1263 struct v4l2_ext_controls *c);
1266 * v4l2_try_ext_ctrls - Helper function to implement
1267 * :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1269 * @hdl: pointer to &struct v4l2_ctrl_handler
1270 * @mdev: pointer to &struct media_device
1271 * @c: pointer to &struct v4l2_ext_controls
1273 * If hdl == NULL then they will all return -EINVAL.
1275 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1276 struct media_device *mdev,
1277 struct v4l2_ext_controls *c);
1280 * v4l2_s_ext_ctrls - Helper function to implement
1281 * :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1283 * @fh: pointer to &struct v4l2_fh
1284 * @hdl: pointer to &struct v4l2_ctrl_handler
1285 * @mdev: pointer to &struct media_device
1286 * @c: pointer to &struct v4l2_ext_controls
1288 * If hdl == NULL then they will all return -EINVAL.
1290 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1291 struct media_device *mdev,
1292 struct v4l2_ext_controls *c);
1295 * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1296 * as a &struct v4l2_subdev_core_ops subscribe_event function
1297 * that just subscribes control events.
1299 * @sd: pointer to &struct v4l2_subdev
1300 * @fh: pointer to &struct v4l2_fh
1301 * @sub: pointer to &struct v4l2_event_subscription
1303 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1304 struct v4l2_event_subscription *sub);
1307 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1310 * @sd: pointer to &struct v4l2_subdev
1312 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);