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>
26 * Include the mpeg2 stateless codec compound control definitions.
27 * This will move to the public headers once this API is fully stable.
29 #include <media/mpeg2-ctrls.h>
31 /* forward references */
33 struct v4l2_ctrl_handler;
34 struct v4l2_ctrl_helper;
38 struct v4l2_subscribed_event;
40 struct poll_table_struct;
43 * union v4l2_ctrl_ptr - A pointer to a control value.
44 * @p_s32: Pointer to a 32-bit signed value.
45 * @p_s64: Pointer to a 64-bit signed value.
46 * @p_u8: Pointer to a 8-bit unsigned value.
47 * @p_u16: Pointer to a 16-bit unsigned value.
48 * @p_u32: Pointer to a 32-bit unsigned value.
49 * @p_char: Pointer to a string.
50 * @p_mpeg2_slice_params: Pointer to a MPEG2 slice parameters structure.
51 * @p_mpeg2_quantization: Pointer to a MPEG2 quantization data structure.
52 * @p: Pointer to a compound value.
61 struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
62 struct v4l2_ctrl_mpeg2_quantization *p_mpeg2_quantization;
67 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
69 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
70 * for volatile (and usually read-only) controls such as a control
71 * that returns the current signal strength which changes
73 * If not set, then the currently cached value will be returned.
74 * @try_ctrl: Test whether the control's value is valid. Only relevant when
75 * the usual min/max/step checks are not sufficient.
76 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
77 * ctrl->handler->lock is held when these ops are called, so no
78 * one else can access controls owned by that handler.
80 struct v4l2_ctrl_ops {
81 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
82 int (*try_ctrl)(struct v4l2_ctrl *ctrl);
83 int (*s_ctrl)(struct v4l2_ctrl *ctrl);
87 * struct v4l2_ctrl_type_ops - The control type operations that the driver
90 * @equal: return true if both values are equal.
91 * @init: initialize the value.
92 * @log: log the value.
93 * @validate: validate the value. Return 0 on success and a negative value
96 struct v4l2_ctrl_type_ops {
97 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
98 union v4l2_ctrl_ptr ptr1,
99 union v4l2_ctrl_ptr ptr2);
100 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
101 union v4l2_ctrl_ptr ptr);
102 void (*log)(const struct v4l2_ctrl *ctrl);
103 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
104 union v4l2_ctrl_ptr ptr);
108 * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
109 * that should be called when a control value has changed.
111 * @ctrl: pointer to struct &v4l2_ctrl
112 * @priv: control private data
114 * This typedef definition is used as an argument to v4l2_ctrl_notify()
115 * and as an argument at struct &v4l2_ctrl_handler.
117 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
120 * struct v4l2_ctrl - The control structure.
122 * @node: The list node.
123 * @ev_subs: The list of control event subscriptions.
124 * @handler: The handler that owns the control.
125 * @cluster: Point to start of cluster array.
126 * @ncontrols: Number of controls in cluster array.
127 * @done: Internal flag: set for each processed control.
128 * @is_new: Set when the user specified a new value for this control. It
129 * is also set when called from v4l2_ctrl_handler_setup(). Drivers
130 * should never set this flag.
131 * @has_changed: Set when the current value differs from the new value. Drivers
132 * should never use this flag.
133 * @is_private: If set, then this control is private to its handler and it
134 * will not be added to any other handlers. Drivers can set
136 * @is_auto: If set, then this control selects whether the other cluster
137 * members are in 'automatic' mode or 'manual' mode. This is
138 * used for autogain/gain type clusters. Drivers should never
139 * set this flag directly.
140 * @is_int: If set, then this control has a simple integer value (i.e. it
142 * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
143 * @is_ptr: If set, then this control is an array and/or has type >=
144 * %V4L2_CTRL_COMPOUND_TYPES
145 * and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
146 * v4l2_ext_control uses field p to point to the data.
147 * @is_array: If set, then this control contains an N-dimensional array.
148 * @has_volatiles: If set, then one or more members of the cluster are volatile.
149 * Drivers should never touch this flag.
150 * @call_notify: If set, then call the handler's notify function whenever the
151 * control's value changes.
152 * @manual_mode_value: If the is_auto flag is set, then this is the value
153 * of the auto control that determines if that control is in
154 * manual mode. So if the value of the auto control equals this
155 * value, then the whole cluster is in manual mode. Drivers should
156 * never set this flag directly.
157 * @ops: The control ops.
158 * @type_ops: The control type ops.
159 * @id: The control ID.
160 * @name: The control name.
161 * @type: The control type.
162 * @minimum: The control's minimum value.
163 * @maximum: The control's maximum value.
164 * @default_value: The control's default value.
165 * @step: The control's step value for non-menu controls.
166 * @elems: The number of elements in the N-dimensional array.
167 * @elem_size: The size in bytes of the control.
168 * @dims: The size of each dimension.
169 * @nr_of_dims:The number of dimensions in @dims.
170 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
171 * easy to skip menu items that are not valid. If bit X is set,
172 * then menu item X is skipped. Of course, this only works for
173 * menus with <= 32 menu items. There are no menus that come
174 * close to that number, so this is OK. Should we ever need more,
175 * then this will have to be extended to a u64 or a bit array.
176 * @qmenu: A const char * array for all menu items. Array entries that are
177 * empty strings ("") correspond to non-existing menu items (this
178 * is in addition to the menu_skip_mask above). The last entry
180 * Used only if the @type is %V4L2_CTRL_TYPE_MENU.
181 * @qmenu_int: A 64-bit integer array for with integer menu items.
182 * The size of array must be equal to the menu size, e. g.:
183 * :math:`ceil(\frac{maximum - minimum}{step}) + 1`.
184 * Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
185 * @flags: The control's flags.
186 * @cur: Structure to store the current value.
187 * @cur.val: The control's current value, if the @type is represented via
188 * a u32 integer (see &enum v4l2_ctrl_type).
189 * @val: The control's new s32 value.
190 * @priv: The control's private pointer. For use by the driver. It is
191 * untouched by the control framework. Note that this pointer is
192 * not freed when the control is deleted. Should this be needed
193 * then a new internal bitfield can be added to tell the framework
194 * to free this pointer.
195 * @p_cur: The control's current value represented via a union which
196 * provides a standard way of accessing control types
198 * @p_new: The control's new value represented via a union which provides
199 * a standard way of accessing control types
203 /* Administrative fields */
204 struct list_head node;
205 struct list_head ev_subs;
206 struct v4l2_ctrl_handler *handler;
207 struct v4l2_ctrl **cluster;
208 unsigned int ncontrols;
212 unsigned int is_new:1;
213 unsigned int has_changed:1;
214 unsigned int is_private:1;
215 unsigned int is_auto:1;
216 unsigned int is_int:1;
217 unsigned int is_string:1;
218 unsigned int is_ptr:1;
219 unsigned int is_array:1;
220 unsigned int has_volatiles:1;
221 unsigned int call_notify:1;
222 unsigned int manual_mode_value:8;
224 const struct v4l2_ctrl_ops *ops;
225 const struct v4l2_ctrl_type_ops *type_ops;
228 enum v4l2_ctrl_type type;
229 s64 minimum, maximum, default_value;
232 u32 dims[V4L2_CTRL_MAX_DIMS];
239 const char * const *qmenu;
240 const s64 *qmenu_int;
249 union v4l2_ctrl_ptr p_new;
250 union v4l2_ctrl_ptr p_cur;
254 * struct v4l2_ctrl_ref - The control reference.
256 * @node: List node for the sorted list.
257 * @next: Single-link list node for the hash.
258 * @ctrl: The actual control information.
259 * @helper: Pointer to helper struct. Used internally in
260 * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
261 * @from_other_dev: If true, then @ctrl was defined in another
262 * device than the &struct v4l2_ctrl_handler.
263 * @req_done: Internal flag: if the control handler containing this control
264 * reference is bound to a media request, then this is set when
265 * the control has been applied. This prevents applying controls
266 * from a cluster with multiple controls twice (when the first
267 * control of a cluster is applied, they all are).
268 * @req: If set, this refers to another request that sets this control.
269 * @p_req: If the control handler containing this control reference
270 * is bound to a media request, then this points to the
271 * value of the control that should be applied when the request
272 * is executed, or to the value of the control at the time
273 * that the request was completed.
275 * Each control handler has a list of these refs. The list_head is used to
276 * keep a sorted-by-control-ID list of all controls, while the next pointer
277 * is used to link the control in the hash's bucket.
279 struct v4l2_ctrl_ref {
280 struct list_head node;
281 struct v4l2_ctrl_ref *next;
282 struct v4l2_ctrl *ctrl;
283 struct v4l2_ctrl_helper *helper;
286 struct v4l2_ctrl_ref *req;
287 union v4l2_ctrl_ptr p_req;
291 * struct v4l2_ctrl_handler - The control handler keeps track of all the
292 * controls: both the controls owned by the handler and those inherited
293 * from other handlers.
295 * @_lock: Default for "lock".
296 * @lock: Lock to control access to this handler and its controls.
297 * May be replaced by the user right after init.
298 * @ctrls: The list of controls owned by this handler.
299 * @ctrl_refs: The list of control references.
300 * @cached: The last found control reference. It is common that the same
301 * control is needed multiple times, so this is a simple
303 * @buckets: Buckets for the hashing. Allows for quick control lookup.
304 * @notify: A notify callback that is called whenever the control changes
306 * Note that the handler's lock is held when the notify function
308 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
309 * @nr_of_buckets: Total number of buckets in the array.
310 * @error: The error code of the first failed control addition.
311 * @request_is_queued: True if the request was queued.
312 * @requests: List to keep track of open control handler request objects.
313 * For the parent control handler (@req_obj.req == NULL) this
314 * is the list header. When the parent control handler is
315 * removed, it has to unbind and put all these requests since
316 * they refer to the parent.
317 * @requests_queued: List of the queued requests. This determines the order
318 * in which these controls are applied. Once the request is
319 * completed it is removed from this list.
320 * @req_obj: The &struct media_request_object, used to link into a
321 * &struct media_request. This request object has a refcount.
323 struct v4l2_ctrl_handler {
326 struct list_head ctrls;
327 struct list_head ctrl_refs;
328 struct v4l2_ctrl_ref *cached;
329 struct v4l2_ctrl_ref **buckets;
330 v4l2_ctrl_notify_fnc notify;
334 bool request_is_queued;
335 struct list_head requests;
336 struct list_head requests_queued;
337 struct media_request_object req_obj;
341 * struct v4l2_ctrl_config - Control configuration structure.
343 * @ops: The control ops.
344 * @type_ops: The control type ops. Only needed for compound controls.
345 * @id: The control ID.
346 * @name: The control name.
347 * @type: The control type.
348 * @min: The control's minimum value.
349 * @max: The control's maximum value.
350 * @step: The control's step value for non-menu controls.
351 * @def: The control's default value.
352 * @dims: The size of each dimension.
353 * @elem_size: The size in bytes of the control.
354 * @flags: The control's flags.
355 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
356 * easy to skip menu items that are not valid. If bit X is set,
357 * then menu item X is skipped. Of course, this only works for
358 * menus with <= 64 menu items. There are no menus that come
359 * close to that number, so this is OK. Should we ever need more,
360 * then this will have to be extended to a bit array.
361 * @qmenu: A const char * array for all menu items. Array entries that are
362 * empty strings ("") correspond to non-existing menu items (this
363 * is in addition to the menu_skip_mask above). The last entry
365 * @qmenu_int: A const s64 integer array for all menu items of the type
366 * V4L2_CTRL_TYPE_INTEGER_MENU.
367 * @is_private: If set, then this control is private to its handler and it
368 * will not be added to any other handlers.
370 struct v4l2_ctrl_config {
371 const struct v4l2_ctrl_ops *ops;
372 const struct v4l2_ctrl_type_ops *type_ops;
375 enum v4l2_ctrl_type type;
380 u32 dims[V4L2_CTRL_MAX_DIMS];
384 const char * const *qmenu;
385 const s64 *qmenu_int;
386 unsigned int is_private:1;
390 * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
392 * @id: ID of the control
393 * @name: pointer to be filled with a string with the name of the control
394 * @type: pointer for storing the type of the control
395 * @min: pointer for storing the minimum value for the control
396 * @max: pointer for storing the maximum value for the control
397 * @step: pointer for storing the control step
398 * @def: pointer for storing the default value for the control
399 * @flags: pointer for storing the flags to be used on the control
401 * This works for all standard V4L2 controls.
402 * For non-standard controls it will only fill in the given arguments
403 * and @name content will be set to %NULL.
405 * This function will overwrite the contents of @name, @type and @flags.
406 * The contents of @min, @max, @step and @def may be modified depending on
411 * Do not use in drivers! It is used internally for backwards compatibility
412 * control handling only. Once all drivers are converted to use the new
413 * control framework this function will no longer be exported.
415 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
416 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
420 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
421 * @hdl: The control handler.
422 * @nr_of_controls_hint: A hint of how many controls this handler is
423 * expected to refer to. This is the total number, so including
424 * any inherited controls. It doesn't have to be precise, but if
425 * it is way off, then you either waste memory (too many buckets
426 * are allocated) or the control lookup becomes slower (not enough
427 * buckets are allocated, so there are more slow list lookups).
428 * It will always work, though.
429 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
430 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
434 * Never use this call directly, always use the v4l2_ctrl_handler_init()
435 * macro that hides the @key and @name arguments.
437 * Return: returns an error if the buckets could not be allocated. This
438 * error will also be stored in @hdl->error.
440 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
441 unsigned int nr_of_controls_hint,
442 struct lock_class_key *key, const char *name);
444 #ifdef CONFIG_LOCKDEP
447 * v4l2_ctrl_handler_init - helper function to create a static struct
448 * &lock_class_key and calls v4l2_ctrl_handler_init_class()
450 * @hdl: The control handler.
451 * @nr_of_controls_hint: A hint of how many controls this handler is
452 * expected to refer to. This is the total number, so including
453 * any inherited controls. It doesn't have to be precise, but if
454 * it is way off, then you either waste memory (too many buckets
455 * are allocated) or the control lookup becomes slower (not enough
456 * buckets are allocated, so there are more slow list lookups).
457 * It will always work, though.
459 * This helper function creates a static struct &lock_class_key and
460 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
463 * Use this helper function to initialize a control handler.
465 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
468 static struct lock_class_key _key; \
469 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
471 KBUILD_BASENAME ":" \
472 __stringify(__LINE__) ":" \
473 "(" #hdl ")->_lock"); \
477 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
478 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
482 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
484 * @hdl: The control handler.
486 * Does nothing if @hdl == NULL.
488 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
491 * v4l2_ctrl_lock() - Helper function to lock the handler
492 * associated with the control.
493 * @ctrl: The control to lock.
495 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
497 mutex_lock(ctrl->handler->lock);
501 * v4l2_ctrl_unlock() - Helper function to unlock the handler
502 * associated with the control.
503 * @ctrl: The control to unlock.
505 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
507 mutex_unlock(ctrl->handler->lock);
511 * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
512 * to the handler to initialize the hardware to the current control values. The
513 * caller is responsible for acquiring the control handler mutex on behalf of
514 * __v4l2_ctrl_handler_setup().
515 * @hdl: The control handler.
517 * Button controls will be skipped, as are read-only controls.
519 * If @hdl == NULL, then this just returns 0.
521 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
524 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
525 * to the handler to initialize the hardware to the current control values.
526 * @hdl: The control handler.
528 * Button controls will be skipped, as are read-only controls.
530 * If @hdl == NULL, then this just returns 0.
532 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
535 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
536 * @hdl: The control handler.
537 * @prefix: The prefix to use when logging the control values. If the
538 * prefix does not end with a space, then ": " will be added
539 * after the prefix. If @prefix == NULL, then no prefix will be
542 * For use with VIDIOC_LOG_STATUS.
544 * Does nothing if @hdl == NULL.
546 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
550 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
553 * @hdl: The control handler.
554 * @cfg: The control's configuration data.
555 * @priv: The control's driver-specific private data.
557 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
558 * and @hdl->error is set to the error code (if it wasn't set already).
560 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
561 const struct v4l2_ctrl_config *cfg,
565 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
568 * @hdl: The control handler.
569 * @ops: The control ops.
570 * @id: The control ID.
571 * @min: The control's minimum value.
572 * @max: The control's maximum value.
573 * @step: The control's step value
574 * @def: The control's default value.
576 * If the &v4l2_ctrl struct could not be allocated, or the control
577 * ID is not known, then NULL is returned and @hdl->error is set to the
578 * appropriate error code (if it wasn't set already).
580 * If @id refers to a menu control, then this function will return NULL.
582 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
584 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
585 const struct v4l2_ctrl_ops *ops,
586 u32 id, s64 min, s64 max, u64 step,
590 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
593 * @hdl: The control handler.
594 * @ops: The control ops.
595 * @id: The control ID.
596 * @max: The control's maximum value.
597 * @mask: The control's skip mask for menu controls. This makes it
598 * easy to skip menu items that are not valid. If bit X is set,
599 * then menu item X is skipped. Of course, this only works for
600 * menus with <= 64 menu items. There are no menus that come
601 * close to that number, so this is OK. Should we ever need more,
602 * then this will have to be extended to a bit array.
603 * @def: The control's default value.
605 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
606 * determines which menu items are to be skipped.
608 * If @id refers to a non-menu control, then this function will return NULL.
610 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
611 const struct v4l2_ctrl_ops *ops,
612 u32 id, u8 max, u64 mask, u8 def);
615 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
616 * with driver specific menu.
618 * @hdl: The control handler.
619 * @ops: The control ops.
620 * @id: The control ID.
621 * @max: The control's maximum value.
622 * @mask: The control's skip mask for menu controls. This makes it
623 * easy to skip menu items that are not valid. If bit X is set,
624 * then menu item X is skipped. Of course, this only works for
625 * menus with <= 64 menu items. There are no menus that come
626 * close to that number, so this is OK. Should we ever need more,
627 * then this will have to be extended to a bit array.
628 * @def: The control's default value.
629 * @qmenu: The new menu.
631 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
632 * menu of this control.
635 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
636 const struct v4l2_ctrl_ops *ops,
639 const char * const *qmenu);
642 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
644 * @hdl: The control handler.
645 * @ops: The control ops.
646 * @id: The control ID.
647 * @max: The control's maximum value.
648 * @def: The control's default value.
649 * @qmenu_int: The control's menu entries.
651 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
652 * takes as an argument an array of integers determining the menu items.
654 * If @id refers to a non-integer-menu control, then this function will
657 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
658 const struct v4l2_ctrl_ops *ops,
659 u32 id, u8 max, u8 def,
660 const s64 *qmenu_int);
663 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
664 * used when adding a control handler.
666 * @ctrl: pointer to struct &v4l2_ctrl.
669 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
672 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
675 * @hdl: The control handler.
676 * @add: The control handler whose controls you want to add to
677 * the @hdl control handler.
678 * @filter: This function will filter which controls should be added.
679 * @from_other_dev: If true, then the controls in @add were defined in another
682 * Does nothing if either of the two handlers is a NULL pointer.
683 * If @filter is NULL, then all controls are added. Otherwise only those
684 * controls for which @filter returns true will be added.
685 * In case of an error @hdl->error will be set to the error code (if it
686 * wasn't set already).
688 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
689 struct v4l2_ctrl_handler *add,
690 v4l2_ctrl_filter filter,
691 bool from_other_dev);
694 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
696 * @ctrl: The control that is filtered.
698 * This will return true for any controls that are valid for radio device
699 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
700 * transmitter class controls.
702 * This function is to be used with v4l2_ctrl_add_handler().
704 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
707 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
710 * @ncontrols: The number of controls in this cluster.
711 * @controls: The cluster control array of size @ncontrols.
713 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
717 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
718 * to that cluster and set it up for autofoo/foo-type handling.
720 * @ncontrols: The number of controls in this cluster.
721 * @controls: The cluster control array of size @ncontrols. The first control
722 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
723 * @manual_val: The value for the first control in the cluster that equals the
725 * @set_volatile: If true, then all controls except the first auto control will
728 * Use for control groups where one control selects some automatic feature and
729 * the other controls are only active whenever the automatic feature is turned
730 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
731 * red and blue balance, etc.
733 * The behavior of such controls is as follows:
735 * When the autofoo control is set to automatic, then any manual controls
736 * are set to inactive and any reads will call g_volatile_ctrl (if the control
737 * was marked volatile).
739 * When the autofoo control is set to manual, then any manual controls will
740 * be marked active, and any reads will just return the current value without
741 * going through g_volatile_ctrl.
743 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
744 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
745 * if autofoo is in auto mode.
747 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
748 struct v4l2_ctrl **controls,
749 u8 manual_val, bool set_volatile);
753 * v4l2_ctrl_find() - Find a control with the given ID.
755 * @hdl: The control handler.
756 * @id: The control ID to find.
758 * If @hdl == NULL this will return NULL as well. Will lock the handler so
759 * do not use from inside &v4l2_ctrl_ops.
761 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
764 * v4l2_ctrl_activate() - Make the control active or inactive.
765 * @ctrl: The control to (de)activate.
766 * @active: True if the control should become active.
768 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
769 * Does nothing if @ctrl == NULL.
770 * This will usually be called from within the s_ctrl op.
771 * The V4L2_EVENT_CTRL event will be generated afterwards.
773 * This function assumes that the control handler is locked.
775 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
778 * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
780 * @ctrl: The control to (de)activate.
781 * @grabbed: True if the control should become grabbed.
783 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
784 * Does nothing if @ctrl == NULL.
785 * The V4L2_EVENT_CTRL event will be generated afterwards.
786 * This will usually be called when starting or stopping streaming in the
789 * This function assumes that the control handler is locked by the caller.
791 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
794 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
796 * @ctrl: The control to (de)activate.
797 * @grabbed: True if the control should become grabbed.
799 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
800 * Does nothing if @ctrl == NULL.
801 * The V4L2_EVENT_CTRL event will be generated afterwards.
802 * This will usually be called when starting or stopping streaming in the
805 * This function assumes that the control handler is not locked and will
806 * take the lock itself.
808 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
813 v4l2_ctrl_lock(ctrl);
814 __v4l2_ctrl_grab(ctrl, grabbed);
815 v4l2_ctrl_unlock(ctrl);
819 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
821 * @ctrl: The control to update.
822 * @min: The control's minimum value.
823 * @max: The control's maximum value.
824 * @step: The control's step value
825 * @def: The control's default value.
827 * Update the range of a control on the fly. This works for control types
828 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
829 * @step value is interpreted as a menu_skip_mask.
831 * An error is returned if one of the range arguments is invalid for this
834 * The caller is responsible for acquiring the control handler mutex on behalf
835 * of __v4l2_ctrl_modify_range().
837 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
838 s64 min, s64 max, u64 step, s64 def);
841 * v4l2_ctrl_modify_range() - Update the range of a control.
843 * @ctrl: The control to update.
844 * @min: The control's minimum value.
845 * @max: The control's maximum value.
846 * @step: The control's step value
847 * @def: The control's default value.
849 * Update the range of a control on the fly. This works for control types
850 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
851 * @step value is interpreted as a menu_skip_mask.
853 * An error is returned if one of the range arguments is invalid for this
856 * This function assumes that the control handler is not locked and will
857 * take the lock itself.
859 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
860 s64 min, s64 max, u64 step, s64 def)
864 v4l2_ctrl_lock(ctrl);
865 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
866 v4l2_ctrl_unlock(ctrl);
872 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
874 * @ctrl: The control.
875 * @notify: The callback function.
876 * @priv: The callback private handle, passed as argument to the callback.
878 * This function sets a callback function for the control. If @ctrl is NULL,
879 * then it will do nothing. If @notify is NULL, then the notify callback will
882 * There can be only one notify. If another already exists, then a WARN_ON
883 * will be issued and the function will do nothing.
885 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
889 * v4l2_ctrl_get_name() - Get the name of the control
891 * @id: The control ID.
893 * This function returns the name of the given control ID or NULL if it isn't
896 const char *v4l2_ctrl_get_name(u32 id);
899 * v4l2_ctrl_get_menu() - Get the menu string array of the control
901 * @id: The control ID.
903 * This function returns the NULL-terminated menu string array name of the
904 * given control ID or NULL if it isn't a known menu control.
906 const char * const *v4l2_ctrl_get_menu(u32 id);
909 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
911 * @id: The control ID.
912 * @len: The size of the integer array.
914 * This function returns the integer array of the given control ID or NULL if it
915 * if it isn't a known integer menu control.
917 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
920 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
923 * @ctrl: The control.
925 * This returns the control's value safely by going through the control
926 * framework. This function will lock the control's handler, so it cannot be
927 * used from within the &v4l2_ctrl_ops functions.
929 * This function is for integer type controls only.
931 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
934 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
936 * @ctrl: The control.
937 * @val: TheControls name new value.
939 * This sets the control's new value safely by going through the control
940 * framework. This function assumes the control's handler is already locked,
941 * allowing it to be used from within the &v4l2_ctrl_ops functions.
943 * This function is for integer type controls only.
945 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
948 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
950 * @ctrl: The control.
951 * @val: The new value.
953 * This sets the control's new value safely by going through the control
954 * framework. This function will lock the control's handler, so it cannot be
955 * used from within the &v4l2_ctrl_ops functions.
957 * This function is for integer type controls only.
959 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
963 v4l2_ctrl_lock(ctrl);
964 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
965 v4l2_ctrl_unlock(ctrl);
971 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
972 * from within a driver.
974 * @ctrl: The control.
976 * This returns the control's value safely by going through the control
977 * framework. This function will lock the control's handler, so it cannot be
978 * used from within the &v4l2_ctrl_ops functions.
980 * This function is for 64-bit integer type controls only.
982 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
985 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
987 * @ctrl: The control.
988 * @val: The new value.
990 * This sets the control's new value safely by going through the control
991 * framework. This function assumes the control's handler is already locked,
992 * allowing it to be used from within the &v4l2_ctrl_ops functions.
994 * This function is for 64-bit integer type controls only.
996 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
999 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1000 * from within a driver.
1002 * @ctrl: The control.
1003 * @val: The new value.
1005 * This sets the control's new value safely by going through the control
1006 * framework. This function will lock the control's handler, so it cannot be
1007 * used from within the &v4l2_ctrl_ops functions.
1009 * This function is for 64-bit integer type controls only.
1011 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1015 v4l2_ctrl_lock(ctrl);
1016 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1017 v4l2_ctrl_unlock(ctrl);
1023 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1025 * @ctrl: The control.
1026 * @s: The new string.
1028 * This sets the control's new string safely by going through the control
1029 * framework. This function assumes the control's handler is already locked,
1030 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1032 * This function is for string type controls only.
1034 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1037 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1038 * from within a driver.
1040 * @ctrl: The control.
1041 * @s: The new string.
1043 * This sets the control's new string safely by going through the control
1044 * framework. This function will lock the control's handler, so it cannot be
1045 * used from within the &v4l2_ctrl_ops functions.
1047 * This function is for string type controls only.
1049 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1053 v4l2_ctrl_lock(ctrl);
1054 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1055 v4l2_ctrl_unlock(ctrl);
1060 /* Internal helper functions that deal with control events. */
1061 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1064 * v4l2_ctrl_replace - Function to be used as a callback to
1065 * &struct v4l2_subscribed_event_ops replace\(\)
1067 * @old: pointer to struct &v4l2_event with the reported
1069 * @new: pointer to struct &v4l2_event with the modified
1072 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1075 * v4l2_ctrl_merge - Function to be used as a callback to
1076 * &struct v4l2_subscribed_event_ops merge(\)
1078 * @old: pointer to struct &v4l2_event with the reported
1080 * @new: pointer to struct &v4l2_event with the merged
1083 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1086 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1088 * @file: pointer to struct file
1089 * @fh: unused. Kept just to be compatible to the arguments expected by
1090 * &struct v4l2_ioctl_ops.vidioc_log_status.
1092 * Can be used as a vidioc_log_status function that just dumps all controls
1093 * associated with the filehandle.
1095 int v4l2_ctrl_log_status(struct file *file, void *fh);
1098 * v4l2_ctrl_subscribe_event - Subscribes to an event
1101 * @fh: pointer to struct v4l2_fh
1102 * @sub: pointer to &struct v4l2_event_subscription
1104 * Can be used as a vidioc_subscribe_event function that just subscribes
1107 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1108 const struct v4l2_event_subscription *sub);
1111 * v4l2_ctrl_poll - function to be used as a callback to the poll()
1112 * That just polls for control events.
1114 * @file: pointer to struct file
1115 * @wait: pointer to struct poll_table_struct
1117 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1120 * v4l2_ctrl_request_setup - helper function to apply control values in a request
1123 * @parent: The parent control handler ('priv' in media_request_object_find())
1125 * This is a helper function to call the control handler's s_ctrl callback with
1126 * the control values contained in the request. Do note that this approach of
1127 * applying control values in a request is only applicable to memory-to-memory
1130 void v4l2_ctrl_request_setup(struct media_request *req,
1131 struct v4l2_ctrl_handler *parent);
1134 * v4l2_ctrl_request_complete - Complete a control handler request object
1137 * @parent: The parent control handler ('priv' in media_request_object_find())
1139 * This function is to be called on each control handler that may have had a
1140 * request object associated with it, i.e. control handlers of a driver that
1141 * supports requests.
1143 * The function first obtains the values of any volatile controls in the control
1144 * handler and attach them to the request. Then, the function completes the
1147 void v4l2_ctrl_request_complete(struct media_request *req,
1148 struct v4l2_ctrl_handler *parent);
1151 * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1154 * @parent: The parent control handler ('priv' in media_request_object_find())
1156 * This function finds the control handler in the request. It may return
1157 * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1158 * with the returned handler pointer.
1160 * If the request is not in state VALIDATING or QUEUED, then this function
1161 * will always return NULL.
1163 * Note that in state VALIDATING the req_queue_mutex is held, so
1164 * no objects can be added or deleted from the request.
1166 * In state QUEUED it is the driver that will have to ensure this.
1168 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1169 struct v4l2_ctrl_handler *parent);
1172 * v4l2_ctrl_request_hdl_put - Put the control handler
1174 * @hdl: Put this control handler
1176 * This function released the control handler previously obtained from'
1177 * v4l2_ctrl_request_hdl_find().
1179 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1182 media_request_object_put(&hdl->req_obj);
1186 * v4l2_ctrl_request_ctrl_find() - Find a control with the given ID.
1188 * @hdl: The control handler from the request.
1189 * @id: The ID of the control to find.
1191 * This function returns a pointer to the control if this control is
1192 * part of the request or NULL otherwise.
1195 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1197 /* Helpers for ioctl_ops */
1200 * v4l2_queryctrl - Helper function to implement
1201 * :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1203 * @hdl: pointer to &struct v4l2_ctrl_handler
1204 * @qc: pointer to &struct v4l2_queryctrl
1206 * If hdl == NULL then they will all return -EINVAL.
1208 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1211 * v4l2_query_ext_ctrl - Helper function to implement
1212 * :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1214 * @hdl: pointer to &struct v4l2_ctrl_handler
1215 * @qc: pointer to &struct v4l2_query_ext_ctrl
1217 * If hdl == NULL then they will all return -EINVAL.
1219 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1220 struct v4l2_query_ext_ctrl *qc);
1223 * v4l2_querymenu - Helper function to implement
1224 * :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1226 * @hdl: pointer to &struct v4l2_ctrl_handler
1227 * @qm: pointer to &struct v4l2_querymenu
1229 * If hdl == NULL then they will all return -EINVAL.
1231 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1234 * v4l2_g_ctrl - Helper function to implement
1235 * :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1237 * @hdl: pointer to &struct v4l2_ctrl_handler
1238 * @ctrl: pointer to &struct v4l2_control
1240 * If hdl == NULL then they will all return -EINVAL.
1242 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1245 * v4l2_s_ctrl - Helper function to implement
1246 * :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1248 * @fh: pointer to &struct v4l2_fh
1249 * @hdl: pointer to &struct v4l2_ctrl_handler
1251 * @ctrl: pointer to &struct v4l2_control
1253 * If hdl == NULL then they will all return -EINVAL.
1255 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1256 struct v4l2_control *ctrl);
1259 * v4l2_g_ext_ctrls - Helper function to implement
1260 * :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1262 * @hdl: pointer to &struct v4l2_ctrl_handler
1263 * @mdev: pointer to &struct media_device
1264 * @c: pointer to &struct v4l2_ext_controls
1266 * If hdl == NULL then they will all return -EINVAL.
1268 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
1269 struct v4l2_ext_controls *c);
1272 * v4l2_try_ext_ctrls - Helper function to implement
1273 * :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1275 * @hdl: pointer to &struct v4l2_ctrl_handler
1276 * @mdev: pointer to &struct media_device
1277 * @c: pointer to &struct v4l2_ext_controls
1279 * If hdl == NULL then they will all return -EINVAL.
1281 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1282 struct media_device *mdev,
1283 struct v4l2_ext_controls *c);
1286 * v4l2_s_ext_ctrls - Helper function to implement
1287 * :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1289 * @fh: pointer to &struct v4l2_fh
1290 * @hdl: pointer to &struct v4l2_ctrl_handler
1291 * @mdev: pointer to &struct media_device
1292 * @c: pointer to &struct v4l2_ext_controls
1294 * If hdl == NULL then they will all return -EINVAL.
1296 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1297 struct media_device *mdev,
1298 struct v4l2_ext_controls *c);
1301 * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1302 * as a &struct v4l2_subdev_core_ops subscribe_event function
1303 * that just subscribes control events.
1305 * @sd: pointer to &struct v4l2_subdev
1306 * @fh: pointer to &struct v4l2_fh
1307 * @sub: pointer to &struct v4l2_event_subscription
1309 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1310 struct v4l2_event_subscription *sub);
1313 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1316 * @sd: pointer to &struct v4l2_subdev
1318 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);