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_h264_sps: Pointer to a struct v4l2_ctrl_h264_sps.
48 * @p_h264_pps: Pointer to a struct v4l2_ctrl_h264_pps.
49 * @p_h264_scal_mtrx: Pointer to a struct v4l2_ctrl_h264_scaling_matrix.
50 * @p_h264_slice_param: Pointer to a struct v4l2_ctrl_h264_slice_param.
51 * @p_h264_decode_param: Pointer to a struct v4l2_ctrl_h264_decode_param.
52 * @p_vp8_frame_hdr: Pointer to a struct v4l2_ctrl_vp8_frame_hdr.
53 * @p: Pointer to a compound value.
62 struct v4l2_ctrl_h264_sps *p_h264_sps;
63 struct v4l2_ctrl_h264_pps *p_h264_pps;
64 struct v4l2_ctrl_h264_scaling_matrix *p_h264_scal_mtrx;
65 struct v4l2_ctrl_h264_slice_param *p_h264_slice_param;
66 struct v4l2_ctrl_h264_decode_param *p_h264_decode_param;
67 struct v4l2_ctrl_vp8_frame_hdr *p_vp8_frame_hdr;
72 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
73 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
74 * for volatile (and usually read-only) controls such as a control
75 * that returns the current signal strength which changes
77 * If not set, then the currently cached value will be returned.
78 * @try_ctrl: Test whether the control's value is valid. Only relevant when
79 * the usual min/max/step checks are not sufficient.
80 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
81 * ctrl->handler->lock is held when these ops are called, so no
82 * one else can access controls owned by that handler.
84 struct v4l2_ctrl_ops {
85 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
86 int (*try_ctrl)(struct v4l2_ctrl *ctrl);
87 int (*s_ctrl)(struct v4l2_ctrl *ctrl);
91 * struct v4l2_ctrl_type_ops - The control type operations that the driver
94 * @equal: return true if both values are equal.
95 * @init: initialize the value.
96 * @log: log the value.
97 * @validate: validate the value. Return 0 on success and a negative value otherwise.
99 struct v4l2_ctrl_type_ops {
100 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
101 union v4l2_ctrl_ptr ptr1,
102 union v4l2_ctrl_ptr ptr2);
103 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
104 union v4l2_ctrl_ptr ptr);
105 void (*log)(const struct v4l2_ctrl *ctrl);
106 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
107 union v4l2_ctrl_ptr ptr);
110 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
113 * struct v4l2_ctrl - The control structure.
114 * @node: The list node.
115 * @ev_subs: The list of control event subscriptions.
116 * @handler: The handler that owns the control.
117 * @cluster: Point to start of cluster array.
118 * @ncontrols: Number of controls in cluster array.
119 * @done: Internal flag: set for each processed control.
120 * @is_new: Set when the user specified a new value for this control. It
121 * is also set when called from v4l2_ctrl_handler_setup. Drivers
122 * should never set this flag.
123 * @has_changed: Set when the current value differs from the new value. Drivers
124 * should never use this flag.
125 * @is_private: If set, then this control is private to its handler and it
126 * will not be added to any other handlers. Drivers can set
128 * @is_auto: If set, then this control selects whether the other cluster
129 * members are in 'automatic' mode or 'manual' mode. This is
130 * used for autogain/gain type clusters. Drivers should never
131 * set this flag directly.
132 * @is_int: If set, then this control has a simple integer value (i.e. it
134 * @is_string: If set, then this control has type V4L2_CTRL_TYPE_STRING.
135 * @is_ptr: If set, then this control is an array and/or has type >= V4L2_CTRL_COMPOUND_TYPES
136 * and/or has type V4L2_CTRL_TYPE_STRING. In other words, struct
137 * v4l2_ext_control uses field p to point to the data.
138 * @is_array: If set, then this control contains an N-dimensional array.
139 * @has_volatiles: If set, then one or more members of the cluster are volatile.
140 * Drivers should never touch this flag.
141 * @call_notify: If set, then call the handler's notify function whenever the
142 * control's value changes.
143 * @manual_mode_value: If the is_auto flag is set, then this is the value
144 * of the auto control that determines if that control is in
145 * manual mode. So if the value of the auto control equals this
146 * value, then the whole cluster is in manual mode. Drivers should
147 * never set this flag directly.
148 * @ops: The control ops.
149 * @type_ops: The control type ops.
150 * @id: The control ID.
151 * @name: The control name.
152 * @type: The control type.
153 * @minimum: The control's minimum value.
154 * @maximum: The control's maximum value.
155 * @default_value: The control's default value.
156 * @step: The control's step value for non-menu controls.
157 * @elems: The number of elements in the N-dimensional array.
158 * @elem_size: The size in bytes of the control.
159 * @dims: The size of each dimension.
160 * @nr_of_dims:The number of dimensions in @dims.
161 * @max_stores:The maximum number of configuration stores of this control.
162 * @nr_of_stores: The number of allocated configuration stores of this control.
163 * @store: The configuration store that the control op operates on.
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 * @flags: The control's flags.
175 * @cur: The control's current value.
176 * @val: The control's new s32 value.
177 * @priv: The control's private pointer. For use by the driver. It is
178 * untouched by the control framework. Note that this pointer is
179 * not freed when the control is deleted. Should this be needed
180 * then a new internal bitfield can be added to tell the framework
181 * to free this pointer.
182 * @p_cur: The control's current value represented via an union with
183 * provides a standard way of accessing control types
185 * @p_new: The control's new value represented via an union with provides
186 * a standard way of accessing control types
190 /* Administrative fields */
191 struct list_head node;
192 struct list_head ev_subs;
193 struct v4l2_ctrl_handler *handler;
194 struct v4l2_ctrl **cluster;
198 unsigned int is_new:1;
199 unsigned int has_changed:1;
200 unsigned int is_private:1;
201 unsigned int is_auto:1;
202 unsigned int is_int:1;
203 unsigned int is_string:1;
204 unsigned int is_ptr:1;
205 unsigned int is_array:1;
206 unsigned int has_volatiles:1;
207 unsigned int call_notify:1;
208 unsigned int manual_mode_value:8;
210 const struct v4l2_ctrl_ops *ops;
211 const struct v4l2_ctrl_type_ops *type_ops;
214 enum v4l2_ctrl_type type;
215 s64 minimum, maximum, default_value;
218 u32 dims[V4L2_CTRL_MAX_DIMS];
228 const char * const *qmenu;
229 const s64 *qmenu_int;
238 union v4l2_ctrl_ptr p_new;
239 union v4l2_ctrl_ptr p_cur;
240 union v4l2_ctrl_ptr *p_stores;
244 * struct v4l2_ctrl_ref - The control reference.
245 * @node: List node for the sorted list.
246 * @next: Single-link list node for the hash.
247 * @ctrl: The actual control information.
248 * @helper: Pointer to helper struct. Used internally in prepare_ext_ctrls().
250 * Each control handler has a list of these refs. The list_head is used to
251 * keep a sorted-by-control-ID list of all controls, while the next pointer
252 * is used to link the control in the hash's bucket.
254 struct v4l2_ctrl_ref {
255 struct list_head node;
256 struct v4l2_ctrl_ref *next;
257 struct v4l2_ctrl *ctrl;
258 struct v4l2_ctrl_helper *helper;
262 * struct v4l2_ctrl_handler - The control handler keeps track of all the
263 * controls: both the controls owned by the handler and those inherited
264 * from other handlers.
265 * @_lock: Default for "lock".
266 * @lock: Lock to control access to this handler and its controls.
267 * May be replaced by the user right after init.
268 * @ctrls: The list of controls owned by this handler.
269 * @ctrl_refs: The list of control references.
270 * @cached: The last found control reference. It is common that the same
271 * control is needed multiple times, so this is a simple
273 * @buckets: Buckets for the hashing. Allows for quick control lookup.
274 * @notify: A notify callback that is called whenever the control changes value.
275 * Note that the handler's lock is held when the notify function
277 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
278 * @nr_of_buckets: Total number of buckets in the array.
279 * @error: The error code of the first failed control addition.
281 struct v4l2_ctrl_handler {
284 struct list_head ctrls;
285 struct list_head ctrl_refs;
286 struct v4l2_ctrl_ref *cached;
287 struct v4l2_ctrl_ref **buckets;
288 v4l2_ctrl_notify_fnc notify;
295 * struct v4l2_ctrl_config - Control configuration structure.
296 * @ops: The control ops.
297 * @type_ops: The control type ops. Only needed for compound controls.
298 * @id: The control ID.
299 * @name: The control name.
300 * @type: The control type.
301 * @min: The control's minimum value.
302 * @max: The control's maximum value.
303 * @step: The control's step value for non-menu controls.
304 * @def: The control's default value.
305 * @dims: The size of each dimension.
306 * @elem_size: The size in bytes of the control.
307 * @max_stores: The maximum number of stores allowed.
308 * @flags: The control's flags.
309 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
310 * easy to skip menu items that are not valid. If bit X is set,
311 * then menu item X is skipped. Of course, this only works for
312 * menus with <= 64 menu items. There are no menus that come
313 * close to that number, so this is OK. Should we ever need more,
314 * then this will have to be extended to a bit array.
315 * @qmenu: A const char * array for all menu items. Array entries that are
316 * empty strings ("") correspond to non-existing menu items (this
317 * is in addition to the menu_skip_mask above). The last entry
319 * @qmenu_int: A const s64 integer array for all menu items of the type
320 * V4L2_CTRL_TYPE_INTEGER_MENU.
321 * @is_private: If set, then this control is private to its handler and it
322 * will not be added to any other handlers.
324 struct v4l2_ctrl_config {
325 const struct v4l2_ctrl_ops *ops;
326 const struct v4l2_ctrl_type_ops *type_ops;
329 enum v4l2_ctrl_type type;
334 u32 dims[V4L2_CTRL_MAX_DIMS];
339 const char * const *qmenu;
340 const s64 *qmenu_int;
341 unsigned int is_private:1;
345 * v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
347 * This works for all standard V4L2 controls.
348 * For non-standard controls it will only fill in the given arguments
349 * and @name will be NULL.
351 * This function will overwrite the contents of @name, @type and @flags.
352 * The contents of @min, @max, @step and @def may be modified depending on
355 * Do not use in drivers! It is used internally for backwards compatibility
356 * control handling only. Once all drivers are converted to use the new
357 * control framework this function will no longer be exported.
359 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
360 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
364 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
365 * @hdl: The control handler.
366 * @nr_of_controls_hint: A hint of how many controls this handler is
367 * expected to refer to. This is the total number, so including
368 * any inherited controls. It doesn't have to be precise, but if
369 * it is way off, then you either waste memory (too many buckets
370 * are allocated) or the control lookup becomes slower (not enough
371 * buckets are allocated, so there are more slow list lookups).
372 * It will always work, though.
373 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
374 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
376 * Returns an error if the buckets could not be allocated. This error will
377 * also be stored in @hdl->error.
379 * Never use this call directly, always use the v4l2_ctrl_handler_init
380 * macro that hides the @key and @name arguments.
382 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
383 unsigned nr_of_controls_hint,
384 struct lock_class_key *key, const char *name);
386 #ifdef CONFIG_LOCKDEP
387 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
390 static struct lock_class_key _key; \
391 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
393 KBUILD_BASENAME ":" \
394 __stringify(__LINE__) ":" \
395 "(" #hdl ")->_lock"); \
399 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
400 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
404 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
406 * @hdl: The control handler.
408 * Does nothing if @hdl == NULL.
410 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
413 * v4l2_ctrl_lock() - Helper function to lock the handler
414 * associated with the control.
415 * @ctrl: The control to lock.
417 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
419 mutex_lock(ctrl->handler->lock);
423 * v4l2_ctrl_unlock() - Helper function to unlock the handler
424 * associated with the control.
425 * @ctrl: The control to unlock.
427 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
429 mutex_unlock(ctrl->handler->lock);
433 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
434 * to the handler to initialize the hardware to the current control values.
435 * @hdl: The control handler.
437 * Button controls will be skipped, as are read-only controls.
439 * If @hdl == NULL, then this just returns 0.
441 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
444 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
445 * @hdl: The control handler.
446 * @prefix: The prefix to use when logging the control values. If the
447 * prefix does not end with a space, then ": " will be added
448 * after the prefix. If @prefix == NULL, then no prefix will be
451 * For use with VIDIOC_LOG_STATUS.
453 * Does nothing if @hdl == NULL.
455 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
459 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
461 * @hdl: The control handler.
462 * @cfg: The control's configuration data.
463 * @priv: The control's driver-specific private data.
465 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
466 * and @hdl->error is set to the error code (if it wasn't set already).
468 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
469 const struct v4l2_ctrl_config *cfg, void *priv);
472 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control.
473 * @hdl: The control handler.
474 * @ops: The control ops.
475 * @id: The control ID.
476 * @min: The control's minimum value.
477 * @max: The control's maximum value.
478 * @step: The control's step value
479 * @def: The control's default value.
481 * If the &v4l2_ctrl struct could not be allocated, or the control
482 * ID is not known, then NULL is returned and @hdl->error is set to the
483 * appropriate error code (if it wasn't set already).
485 * If @id refers to a menu control, then this function will return NULL.
487 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
489 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
490 const struct v4l2_ctrl_ops *ops,
491 u32 id, s64 min, s64 max, u64 step, s64 def);
494 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control.
495 * @hdl: The control handler.
496 * @ops: The control ops.
497 * @id: The control ID.
498 * @max: The control's maximum value.
499 * @mask: The control's skip mask for menu controls. This makes it
500 * easy to skip menu items that are not valid. If bit X is set,
501 * then menu item X is skipped. Of course, this only works for
502 * menus with <= 64 menu items. There are no menus that come
503 * close to that number, so this is OK. Should we ever need more,
504 * then this will have to be extended to a bit array.
505 * @def: The control's default value.
507 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
508 * determines which menu items are to be skipped.
510 * If @id refers to a non-menu control, then this function will return NULL.
512 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
513 const struct v4l2_ctrl_ops *ops,
514 u32 id, u8 max, u64 mask, u8 def);
517 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
518 * with driver specific menu.
519 * @hdl: The control handler.
520 * @ops: The control ops.
521 * @id: The control ID.
522 * @max: The control's maximum value.
523 * @mask: The control's skip mask for menu controls. This makes it
524 * easy to skip menu items that are not valid. If bit X is set,
525 * then menu item X is skipped. Of course, this only works for
526 * menus with <= 64 menu items. There are no menus that come
527 * close to that number, so this is OK. Should we ever need more,
528 * then this will have to be extended to a bit array.
529 * @def: The control's default value.
530 * @qmenu: The new menu.
532 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
533 * menu of this control.
536 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
537 const struct v4l2_ctrl_ops *ops, u32 id, u8 max,
538 u64 mask, u8 def, const char * const *qmenu);
541 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
542 * @hdl: The control handler.
543 * @ops: The control ops.
544 * @id: The control ID.
545 * @max: The control's maximum value.
546 * @def: The control's default value.
547 * @qmenu_int: The control's menu entries.
549 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
550 * takes as an argument an array of integers determining the menu items.
552 * If @id refers to a non-integer-menu control, then this function will return NULL.
554 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
555 const struct v4l2_ctrl_ops *ops,
556 u32 id, u8 max, u8 def, const s64 *qmenu_int);
559 * v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler.
560 * @hdl: The control handler.
561 * @ctrl: The control to add.
563 * It will return NULL if it was unable to add the control reference.
564 * If the control already belonged to the handler, then it will do
565 * nothing and just return @ctrl.
567 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
568 struct v4l2_ctrl *ctrl);
571 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
573 * @hdl: The control handler.
574 * @add: The control handler whose controls you want to add to
575 * the @hdl control handler.
576 * @filter: This function will filter which controls should be added.
578 * Does nothing if either of the two handlers is a NULL pointer.
579 * If @filter is NULL, then all controls are added. Otherwise only those
580 * controls for which @filter returns true will be added.
581 * In case of an error @hdl->error will be set to the error code (if it
582 * wasn't set already).
584 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
585 struct v4l2_ctrl_handler *add,
586 bool (*filter)(const struct v4l2_ctrl *ctrl));
589 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
590 * @ctrl: The control that is filtered.
592 * This will return true for any controls that are valid for radio device
593 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
594 * transmitter class controls.
596 * This function is to be used with v4l2_ctrl_add_handler().
598 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
601 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster.
602 * @ncontrols: The number of controls in this cluster.
603 * @controls: The cluster control array of size @ncontrols.
605 void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);
609 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to
610 * that cluster and set it up for autofoo/foo-type handling.
611 * @ncontrols: The number of controls in this cluster.
612 * @controls: The cluster control array of size @ncontrols. The first control
613 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
614 * @manual_val: The value for the first control in the cluster that equals the
616 * @set_volatile: If true, then all controls except the first auto control will
619 * Use for control groups where one control selects some automatic feature and
620 * the other controls are only active whenever the automatic feature is turned
621 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
622 * red and blue balance, etc.
624 * The behavior of such controls is as follows:
626 * When the autofoo control is set to automatic, then any manual controls
627 * are set to inactive and any reads will call g_volatile_ctrl (if the control
628 * was marked volatile).
630 * When the autofoo control is set to manual, then any manual controls will
631 * be marked active, and any reads will just return the current value without
632 * going through g_volatile_ctrl.
634 * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag
635 * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
636 * if autofoo is in auto mode.
638 void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
639 u8 manual_val, bool set_volatile);
643 * v4l2_ctrl_find() - Find a control with the given ID.
644 * @hdl: The control handler.
645 * @id: The control ID to find.
647 * If @hdl == NULL this will return NULL as well. Will lock the handler so
648 * do not use from inside &v4l2_ctrl_ops.
650 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
653 * v4l2_ctrl_activate() - Make the control active or inactive.
654 * @ctrl: The control to (de)activate.
655 * @active: True if the control should become active.
657 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
658 * Does nothing if @ctrl == NULL.
659 * This will usually be called from within the s_ctrl op.
660 * The V4L2_EVENT_CTRL event will be generated afterwards.
662 * This function assumes that the control handler is locked.
664 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
667 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
668 * @ctrl: The control to (de)activate.
669 * @grabbed: True if the control should become grabbed.
671 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
672 * Does nothing if @ctrl == NULL.
673 * The V4L2_EVENT_CTRL event will be generated afterwards.
674 * This will usually be called when starting or stopping streaming in the
677 * This function assumes that the control handler is not locked and will
678 * take the lock itself.
680 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
684 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
686 * @ctrl: The control to update.
687 * @min: The control's minimum value.
688 * @max: The control's maximum value.
689 * @step: The control's step value
690 * @def: The control's default value.
692 * Update the range of a control on the fly. This works for control types
693 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
694 * @step value is interpreted as a menu_skip_mask.
696 * An error is returned if one of the range arguments is invalid for this
699 * This function assumes that the control handler is not locked and will
700 * take the lock itself.
702 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
703 s64 min, s64 max, u64 step, s64 def);
706 * v4l2_ctrl_modify_range() - Update the range of a control.
707 * @ctrl: The control to update.
708 * @min: The control's minimum value.
709 * @max: The control's maximum value.
710 * @step: The control's step value
711 * @def: The control's default value.
713 * Update the range of a control on the fly. This works for control types
714 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
715 * @step value is interpreted as a menu_skip_mask.
717 * An error is returned if one of the range arguments is invalid for this
720 * This function assumes that the control handler is not locked and will
721 * take the lock itself.
723 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
724 s64 min, s64 max, u64 step, s64 def)
728 v4l2_ctrl_lock(ctrl);
729 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
730 v4l2_ctrl_unlock(ctrl);
736 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
737 * @ctrl: The control.
738 * @notify: The callback function.
739 * @priv: The callback private handle, passed as argument to the callback.
741 * This function sets a callback function for the control. If @ctrl is NULL,
742 * then it will do nothing. If @notify is NULL, then the notify callback will
745 * There can be only one notify. If another already exists, then a WARN_ON
746 * will be issued and the function will do nothing.
748 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv);
751 * v4l2_ctrl_get_name() - Get the name of the control
752 * @id: The control ID.
754 * This function returns the name of the given control ID or NULL if it isn't
757 const char *v4l2_ctrl_get_name(u32 id);
760 * v4l2_ctrl_get_menu() - Get the menu string array of the control
761 * @id: The control ID.
763 * This function returns the NULL-terminated menu string array name of the
764 * given control ID or NULL if it isn't a known menu control.
766 const char * const *v4l2_ctrl_get_menu(u32 id);
769 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
770 * @id: The control ID.
771 * @len: The size of the integer array.
773 * This function returns the integer array of the given control ID or NULL if it
774 * if it isn't a known integer menu control.
776 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
779 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
780 * @ctrl: The control.
782 * This returns the control's value safely by going through the control
783 * framework. This function will lock the control's handler, so it cannot be
784 * used from within the &v4l2_ctrl_ops functions.
786 * This function is for integer type controls only.
788 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
791 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
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 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
803 /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver.
804 * @ctrl: The control.
805 * @val: The new value.
807 * This set the control's new value safely by going through the control
808 * framework. This function will lock the control's handler, so it cannot be
809 * used from within the &v4l2_ctrl_ops functions.
811 * This function is for integer type controls only.
813 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
817 v4l2_ctrl_lock(ctrl);
818 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
819 v4l2_ctrl_unlock(ctrl);
825 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
826 * from within a driver.
827 * @ctrl: The control.
829 * This returns the control's value safely by going through the control
830 * framework. This function will lock the control's handler, so it cannot be
831 * used from within the &v4l2_ctrl_ops functions.
833 * This function is for 64-bit integer type controls only.
835 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
838 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
840 * @ctrl: The control.
841 * @val: The new value.
843 * This set the control's new value safely by going through the control
844 * framework. This function will lock the control's handler, so it cannot be
845 * used from within the &v4l2_ctrl_ops functions.
847 * This function is for 64-bit integer type controls only.
849 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
851 /** v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
852 * from within a driver.
854 * @ctrl: The control.
855 * @val: The new value.
857 * This set the control's new value safely by going through the control
858 * framework. This function will lock the control's handler, so it cannot be
859 * used from within the &v4l2_ctrl_ops functions.
861 * This function is for 64-bit integer type controls only.
863 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
867 v4l2_ctrl_lock(ctrl);
868 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
869 v4l2_ctrl_unlock(ctrl);
874 /** __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
876 * @ctrl: The control.
877 * @s: The new string.
879 * This set the control's new string safely by going through the control
880 * framework. This function will lock the control's handler, so it cannot be
881 * used from within the &v4l2_ctrl_ops functions.
883 * This function is for string type controls only.
885 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
887 /** v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
888 * from within a driver.
890 * @ctrl: The control.
891 * @s: The new string.
893 * This set the control's new string safely by going through the control
894 * framework. This function will lock the control's handler, so it cannot be
895 * used from within the &v4l2_ctrl_ops functions.
897 * This function is for string type controls only.
899 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
903 v4l2_ctrl_lock(ctrl);
904 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
905 v4l2_ctrl_unlock(ctrl);
910 static inline void v4l2_ctrl_set_max_stores(struct v4l2_ctrl *ctrl, u16 max_stores)
912 ctrl->max_stores = max_stores;
915 int v4l2_ctrl_apply_store(struct v4l2_ctrl_handler *hdl, unsigned store);
917 /* Internal helper functions that deal with control events. */
918 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
919 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
920 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
922 /* Can be used as a vidioc_log_status function that just dumps all controls
923 associated with the filehandle. */
924 int v4l2_ctrl_log_status(struct file *file, void *fh);
926 /* Can be used as a vidioc_subscribe_event function that just subscribes
928 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
929 const struct v4l2_event_subscription *sub);
931 /* Can be used as a poll function that just polls for control events. */
932 unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
934 /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
935 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
936 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctrl *qc);
937 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
938 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
939 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
940 struct v4l2_control *ctrl);
941 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
942 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
943 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
944 struct v4l2_ext_controls *c);
946 /* Helpers for subdevices. If the associated ctrl_handler == NULL then they
947 will all return -EINVAL. */
948 int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
949 int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
950 int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
951 int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
952 int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
953 int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
954 int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
956 /* Can be used as a subscribe_event function that just subscribes control
958 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
959 struct v4l2_event_subscription *sub);
961 /* Log all controls owned by subdev's control handler. */
962 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);