1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * V4L2 controls support header.
5 * Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl>
11 #include <linux/list.h>
12 #include <linux/mutex.h>
13 #include <linux/videodev2.h>
14 #include <media/media-request.h>
17 * Include the stateless codec compound control definitions.
18 * This will move to the public headers once this API is fully stable.
20 #include <media/hevc-ctrls.h>
22 /* forward references */
24 struct poll_table_struct;
26 struct v4l2_ctrl_handler;
27 struct v4l2_ctrl_helper;
29 struct v4l2_fwnode_device_properties;
31 struct v4l2_subscribed_event;
35 * union v4l2_ctrl_ptr - A pointer to a control value.
36 * @p_s32: Pointer to a 32-bit signed value.
37 * @p_s64: Pointer to a 64-bit signed value.
38 * @p_u8: Pointer to a 8-bit unsigned value.
39 * @p_u16: Pointer to a 16-bit unsigned value.
40 * @p_u32: Pointer to a 32-bit unsigned value.
41 * @p_char: Pointer to a string.
42 * @p_mpeg2_sequence: Pointer to a MPEG2 sequence structure.
43 * @p_mpeg2_picture: Pointer to a MPEG2 picture structure.
44 * @p_mpeg2_quantisation: Pointer to a MPEG2 quantisation data structure.
45 * @p_fwht_params: Pointer to a FWHT stateless parameters structure.
46 * @p_h264_sps: Pointer to a struct v4l2_ctrl_h264_sps.
47 * @p_h264_pps: Pointer to a struct v4l2_ctrl_h264_pps.
48 * @p_h264_scaling_matrix: Pointer to a struct v4l2_ctrl_h264_scaling_matrix.
49 * @p_h264_slice_params: Pointer to a struct v4l2_ctrl_h264_slice_params.
50 * @p_h264_decode_params: Pointer to a struct v4l2_ctrl_h264_decode_params.
51 * @p_h264_pred_weights: Pointer to a struct v4l2_ctrl_h264_pred_weights.
52 * @p_vp8_frame: Pointer to a VP8 frame params structure.
53 * @p_hevc_sps: Pointer to an HEVC sequence parameter set structure.
54 * @p_hevc_pps: Pointer to an HEVC picture parameter set structure.
55 * @p_hevc_slice_params: Pointer to an HEVC slice parameters structure.
56 * @p_hdr10_cll: Pointer to an HDR10 Content Light Level structure.
57 * @p_hdr10_mastering: Pointer to an HDR10 Mastering Display structure.
58 * @p_area: Pointer to an area.
59 * @p: Pointer to a compound value.
60 * @p_const: Pointer to a constant compound value.
69 struct v4l2_ctrl_mpeg2_sequence *p_mpeg2_sequence;
70 struct v4l2_ctrl_mpeg2_picture *p_mpeg2_picture;
71 struct v4l2_ctrl_mpeg2_quantisation *p_mpeg2_quantisation;
72 struct v4l2_ctrl_fwht_params *p_fwht_params;
73 struct v4l2_ctrl_h264_sps *p_h264_sps;
74 struct v4l2_ctrl_h264_pps *p_h264_pps;
75 struct v4l2_ctrl_h264_scaling_matrix *p_h264_scaling_matrix;
76 struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
77 struct v4l2_ctrl_h264_decode_params *p_h264_decode_params;
78 struct v4l2_ctrl_h264_pred_weights *p_h264_pred_weights;
79 struct v4l2_ctrl_vp8_frame *p_vp8_frame;
80 struct v4l2_ctrl_hevc_sps *p_hevc_sps;
81 struct v4l2_ctrl_hevc_pps *p_hevc_pps;
82 struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
83 struct v4l2_ctrl_hdr10_cll_info *p_hdr10_cll;
84 struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
85 struct v4l2_area *p_area;
91 * v4l2_ctrl_ptr_create() - Helper function to return a v4l2_ctrl_ptr from a
93 * @ptr: The void pointer
95 static inline union v4l2_ctrl_ptr v4l2_ctrl_ptr_create(void *ptr)
97 union v4l2_ctrl_ptr p = { .p = ptr };
103 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
105 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
106 * for volatile (and usually read-only) controls such as a control
107 * that returns the current signal strength which changes
109 * If not set, then the currently cached value will be returned.
110 * @try_ctrl: Test whether the control's value is valid. Only relevant when
111 * the usual min/max/step checks are not sufficient.
112 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
113 * ctrl->handler->lock is held when these ops are called, so no
114 * one else can access controls owned by that handler.
116 struct v4l2_ctrl_ops {
117 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
118 int (*try_ctrl)(struct v4l2_ctrl *ctrl);
119 int (*s_ctrl)(struct v4l2_ctrl *ctrl);
123 * struct v4l2_ctrl_type_ops - The control type operations that the driver
126 * @equal: return true if both values are equal.
127 * @init: initialize the value.
128 * @log: log the value.
129 * @validate: validate the value. Return 0 on success and a negative value
132 struct v4l2_ctrl_type_ops {
133 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
134 union v4l2_ctrl_ptr ptr1,
135 union v4l2_ctrl_ptr ptr2);
136 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
137 union v4l2_ctrl_ptr ptr);
138 void (*log)(const struct v4l2_ctrl *ctrl);
139 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
140 union v4l2_ctrl_ptr ptr);
144 * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
145 * that should be called when a control value has changed.
147 * @ctrl: pointer to struct &v4l2_ctrl
148 * @priv: control private data
150 * This typedef definition is used as an argument to v4l2_ctrl_notify()
151 * and as an argument at struct &v4l2_ctrl_handler.
153 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
156 * struct v4l2_ctrl - The control structure.
158 * @node: The list node.
159 * @ev_subs: The list of control event subscriptions.
160 * @handler: The handler that owns the control.
161 * @cluster: Point to start of cluster array.
162 * @ncontrols: Number of controls in cluster array.
163 * @done: Internal flag: set for each processed control.
164 * @is_new: Set when the user specified a new value for this control. It
165 * is also set when called from v4l2_ctrl_handler_setup(). Drivers
166 * should never set this flag.
167 * @has_changed: Set when the current value differs from the new value. Drivers
168 * should never use this flag.
169 * @is_private: If set, then this control is private to its handler and it
170 * will not be added to any other handlers. Drivers can set
172 * @is_auto: If set, then this control selects whether the other cluster
173 * members are in 'automatic' mode or 'manual' mode. This is
174 * used for autogain/gain type clusters. Drivers should never
175 * set this flag directly.
176 * @is_int: If set, then this control has a simple integer value (i.e. it
178 * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
179 * @is_ptr: If set, then this control is an array and/or has type >=
180 * %V4L2_CTRL_COMPOUND_TYPES
181 * and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
182 * v4l2_ext_control uses field p to point to the data.
183 * @is_array: If set, then this control contains an N-dimensional array.
184 * @is_dyn_array: If set, then this control contains a dynamically sized 1-dimensional array.
185 * If this is set, then @is_array is also set.
186 * @has_volatiles: If set, then one or more members of the cluster are volatile.
187 * Drivers should never touch this flag.
188 * @call_notify: If set, then call the handler's notify function whenever the
189 * control's value changes.
190 * @manual_mode_value: If the is_auto flag is set, then this is the value
191 * of the auto control that determines if that control is in
192 * manual mode. So if the value of the auto control equals this
193 * value, then the whole cluster is in manual mode. Drivers should
194 * never set this flag directly.
195 * @ops: The control ops.
196 * @type_ops: The control type ops.
197 * @id: The control ID.
198 * @name: The control name.
199 * @type: The control type.
200 * @minimum: The control's minimum value.
201 * @maximum: The control's maximum value.
202 * @default_value: The control's default value.
203 * @step: The control's step value for non-menu controls.
204 * @elems: The number of elements in the N-dimensional array.
205 * @elem_size: The size in bytes of the control.
206 * @new_elems: The number of elements in p_new. This is the same as @elems,
207 * except for dynamic arrays. In that case it is in the range of
208 * 1 to @p_dyn_alloc_elems.
209 * @dims: The size of each dimension.
210 * @nr_of_dims:The number of dimensions in @dims.
211 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
212 * easy to skip menu items that are not valid. If bit X is set,
213 * then menu item X is skipped. Of course, this only works for
214 * menus with <= 32 menu items. There are no menus that come
215 * close to that number, so this is OK. Should we ever need more,
216 * then this will have to be extended to a u64 or a bit array.
217 * @qmenu: A const char * array for all menu items. Array entries that are
218 * empty strings ("") correspond to non-existing menu items (this
219 * is in addition to the menu_skip_mask above). The last entry
221 * Used only if the @type is %V4L2_CTRL_TYPE_MENU.
222 * @qmenu_int: A 64-bit integer array for with integer menu items.
223 * The size of array must be equal to the menu size, e. g.:
224 * :math:`ceil(\frac{maximum - minimum}{step}) + 1`.
225 * Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
226 * @flags: The control's flags.
227 * @priv: The control's private pointer. For use by the driver. It is
228 * untouched by the control framework. Note that this pointer is
229 * not freed when the control is deleted. Should this be needed
230 * then a new internal bitfield can be added to tell the framework
231 * to free this pointer.
232 * @p_dyn: Pointer to the dynamically allocated array. Only valid if
233 * @is_dyn_array is true.
234 * @p_dyn_alloc_elems: The number of elements in the dynamically allocated
235 * array for both the cur and new values. So @p_dyn is actually
236 * sized for 2 * @p_dyn_alloc_elems * @elem_size. Only valid if
237 * @is_dyn_array is true.
238 * @cur: Structure to store the current value.
239 * @cur.val: The control's current value, if the @type is represented via
240 * a u32 integer (see &enum v4l2_ctrl_type).
241 * @val: The control's new s32 value.
242 * @p_def: The control's default value represented via a union which
243 * provides a standard way of accessing control types
244 * through a pointer (for compound controls only).
245 * @p_cur: The control's current value represented via a union which
246 * provides a standard way of accessing control types
248 * @p_new: The control's new value represented via a union which provides
249 * a standard way of accessing control types
253 /* Administrative fields */
254 struct list_head node;
255 struct list_head ev_subs;
256 struct v4l2_ctrl_handler *handler;
257 struct v4l2_ctrl **cluster;
258 unsigned int ncontrols;
262 unsigned int is_new:1;
263 unsigned int has_changed:1;
264 unsigned int is_private:1;
265 unsigned int is_auto:1;
266 unsigned int is_int:1;
267 unsigned int is_string:1;
268 unsigned int is_ptr:1;
269 unsigned int is_array:1;
270 unsigned int is_dyn_array:1;
271 unsigned int has_volatiles:1;
272 unsigned int call_notify:1;
273 unsigned int manual_mode_value:8;
275 const struct v4l2_ctrl_ops *ops;
276 const struct v4l2_ctrl_type_ops *type_ops;
279 enum v4l2_ctrl_type type;
280 s64 minimum, maximum, default_value;
284 u32 dims[V4L2_CTRL_MAX_DIMS];
291 const char * const *qmenu;
292 const s64 *qmenu_int;
297 u32 p_dyn_alloc_elems;
303 union v4l2_ctrl_ptr p_def;
304 union v4l2_ctrl_ptr p_new;
305 union v4l2_ctrl_ptr p_cur;
309 * struct v4l2_ctrl_ref - The control reference.
311 * @node: List node for the sorted list.
312 * @next: Single-link list node for the hash.
313 * @ctrl: The actual control information.
314 * @helper: Pointer to helper struct. Used internally in
315 * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
316 * @from_other_dev: If true, then @ctrl was defined in another
317 * device than the &struct v4l2_ctrl_handler.
318 * @req_done: Internal flag: if the control handler containing this control
319 * reference is bound to a media request, then this is set when
320 * the control has been applied. This prevents applying controls
321 * from a cluster with multiple controls twice (when the first
322 * control of a cluster is applied, they all are).
323 * @p_req_valid: If set, then p_req contains the control value for the request.
324 * @p_req_dyn_enomem: If set, then p_req is invalid since allocating space for
325 * a dynamic array failed. Attempting to read this value shall
326 * result in ENOMEM. Only valid if ctrl->is_dyn_array is true.
327 * @p_req_dyn_alloc_elems: The number of elements allocated for the dynamic
328 * array. Only valid if @p_req_valid and ctrl->is_dyn_array are
330 * @p_req_elems: The number of elements in @p_req. This is the same as
331 * ctrl->elems, except for dynamic arrays. In that case it is in
332 * the range of 1 to @p_req_dyn_alloc_elems. Only valid if
333 * @p_req_valid is true.
334 * @p_req: If the control handler containing this control reference
335 * is bound to a media request, then this points to the
336 * value of the control that must be applied when the request
337 * is executed, or to the value of the control at the time
338 * that the request was completed. If @p_req_valid is false,
339 * then this control was never set for this request and the
340 * control will not be updated when this request is applied.
342 * Each control handler has a list of these refs. The list_head is used to
343 * keep a sorted-by-control-ID list of all controls, while the next pointer
344 * is used to link the control in the hash's bucket.
346 struct v4l2_ctrl_ref {
347 struct list_head node;
348 struct v4l2_ctrl_ref *next;
349 struct v4l2_ctrl *ctrl;
350 struct v4l2_ctrl_helper *helper;
354 bool p_req_dyn_enomem;
355 u32 p_req_dyn_alloc_elems;
357 union v4l2_ctrl_ptr p_req;
361 * struct v4l2_ctrl_handler - The control handler keeps track of all the
362 * controls: both the controls owned by the handler and those inherited
363 * from other handlers.
365 * @_lock: Default for "lock".
366 * @lock: Lock to control access to this handler and its controls.
367 * May be replaced by the user right after init.
368 * @ctrls: The list of controls owned by this handler.
369 * @ctrl_refs: The list of control references.
370 * @cached: The last found control reference. It is common that the same
371 * control is needed multiple times, so this is a simple
373 * @buckets: Buckets for the hashing. Allows for quick control lookup.
374 * @notify: A notify callback that is called whenever the control changes
376 * Note that the handler's lock is held when the notify function
378 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
379 * @nr_of_buckets: Total number of buckets in the array.
380 * @error: The error code of the first failed control addition.
381 * @request_is_queued: True if the request was queued.
382 * @requests: List to keep track of open control handler request objects.
383 * For the parent control handler (@req_obj.ops == NULL) this
384 * is the list header. When the parent control handler is
385 * removed, it has to unbind and put all these requests since
386 * they refer to the parent.
387 * @requests_queued: List of the queued requests. This determines the order
388 * in which these controls are applied. Once the request is
389 * completed it is removed from this list.
390 * @req_obj: The &struct media_request_object, used to link into a
391 * &struct media_request. This request object has a refcount.
393 struct v4l2_ctrl_handler {
396 struct list_head ctrls;
397 struct list_head ctrl_refs;
398 struct v4l2_ctrl_ref *cached;
399 struct v4l2_ctrl_ref **buckets;
400 v4l2_ctrl_notify_fnc notify;
404 bool request_is_queued;
405 struct list_head requests;
406 struct list_head requests_queued;
407 struct media_request_object req_obj;
411 * struct v4l2_ctrl_config - Control configuration structure.
413 * @ops: The control ops.
414 * @type_ops: The control type ops. Only needed for compound controls.
415 * @id: The control ID.
416 * @name: The control name.
417 * @type: The control type.
418 * @min: The control's minimum value.
419 * @max: The control's maximum value.
420 * @step: The control's step value for non-menu controls.
421 * @def: The control's default value.
422 * @p_def: The control's default value for compound controls.
423 * @dims: The size of each dimension.
424 * @elem_size: The size in bytes of the control.
425 * @flags: The control's flags.
426 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
427 * easy to skip menu items that are not valid. If bit X is set,
428 * then menu item X is skipped. Of course, this only works for
429 * menus with <= 64 menu items. There are no menus that come
430 * close to that number, so this is OK. Should we ever need more,
431 * then this will have to be extended to a bit array.
432 * @qmenu: A const char * array for all menu items. Array entries that are
433 * empty strings ("") correspond to non-existing menu items (this
434 * is in addition to the menu_skip_mask above). The last entry
436 * @qmenu_int: A const s64 integer array for all menu items of the type
437 * V4L2_CTRL_TYPE_INTEGER_MENU.
438 * @is_private: If set, then this control is private to its handler and it
439 * will not be added to any other handlers.
441 struct v4l2_ctrl_config {
442 const struct v4l2_ctrl_ops *ops;
443 const struct v4l2_ctrl_type_ops *type_ops;
446 enum v4l2_ctrl_type type;
451 union v4l2_ctrl_ptr p_def;
452 u32 dims[V4L2_CTRL_MAX_DIMS];
456 const char * const *qmenu;
457 const s64 *qmenu_int;
458 unsigned int is_private:1;
462 * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
464 * @id: ID of the control
465 * @name: pointer to be filled with a string with the name of the control
466 * @type: pointer for storing the type of the control
467 * @min: pointer for storing the minimum value for the control
468 * @max: pointer for storing the maximum value for the control
469 * @step: pointer for storing the control step
470 * @def: pointer for storing the default value for the control
471 * @flags: pointer for storing the flags to be used on the control
473 * This works for all standard V4L2 controls.
474 * For non-standard controls it will only fill in the given arguments
475 * and @name content will be set to %NULL.
477 * This function will overwrite the contents of @name, @type and @flags.
478 * The contents of @min, @max, @step and @def may be modified depending on
483 * Do not use in drivers! It is used internally for backwards compatibility
484 * control handling only. Once all drivers are converted to use the new
485 * control framework this function will no longer be exported.
487 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
488 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
492 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
493 * @hdl: The control handler.
494 * @nr_of_controls_hint: A hint of how many controls this handler is
495 * expected to refer to. This is the total number, so including
496 * any inherited controls. It doesn't have to be precise, but if
497 * it is way off, then you either waste memory (too many buckets
498 * are allocated) or the control lookup becomes slower (not enough
499 * buckets are allocated, so there are more slow list lookups).
500 * It will always work, though.
501 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
502 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
506 * Never use this call directly, always use the v4l2_ctrl_handler_init()
507 * macro that hides the @key and @name arguments.
509 * Return: returns an error if the buckets could not be allocated. This
510 * error will also be stored in @hdl->error.
512 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
513 unsigned int nr_of_controls_hint,
514 struct lock_class_key *key, const char *name);
516 #ifdef CONFIG_LOCKDEP
519 * v4l2_ctrl_handler_init - helper function to create a static struct
520 * &lock_class_key and calls v4l2_ctrl_handler_init_class()
522 * @hdl: The control handler.
523 * @nr_of_controls_hint: A hint of how many controls this handler is
524 * expected to refer to. This is the total number, so including
525 * any inherited controls. It doesn't have to be precise, but if
526 * it is way off, then you either waste memory (too many buckets
527 * are allocated) or the control lookup becomes slower (not enough
528 * buckets are allocated, so there are more slow list lookups).
529 * It will always work, though.
531 * This helper function creates a static struct &lock_class_key and
532 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
535 * Use this helper function to initialize a control handler.
537 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
540 static struct lock_class_key _key; \
541 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
543 KBUILD_BASENAME ":" \
544 __stringify(__LINE__) ":" \
545 "(" #hdl ")->_lock"); \
549 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
550 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
554 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
556 * @hdl: The control handler.
558 * Does nothing if @hdl == NULL.
560 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
563 * v4l2_ctrl_lock() - Helper function to lock the handler
564 * associated with the control.
565 * @ctrl: The control to lock.
567 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
569 mutex_lock(ctrl->handler->lock);
573 * v4l2_ctrl_unlock() - Helper function to unlock the handler
574 * associated with the control.
575 * @ctrl: The control to unlock.
577 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
579 mutex_unlock(ctrl->handler->lock);
583 * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
584 * to the handler to initialize the hardware to the current control values. The
585 * caller is responsible for acquiring the control handler mutex on behalf of
586 * __v4l2_ctrl_handler_setup().
587 * @hdl: The control handler.
589 * Button controls will be skipped, as are read-only controls.
591 * If @hdl == NULL, then this just returns 0.
593 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
596 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
597 * to the handler to initialize the hardware to the current control values.
598 * @hdl: The control handler.
600 * Button controls will be skipped, as are read-only controls.
602 * If @hdl == NULL, then this just returns 0.
604 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
607 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
608 * @hdl: The control handler.
609 * @prefix: The prefix to use when logging the control values. If the
610 * prefix does not end with a space, then ": " will be added
611 * after the prefix. If @prefix == NULL, then no prefix will be
614 * For use with VIDIOC_LOG_STATUS.
616 * Does nothing if @hdl == NULL.
618 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
622 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
625 * @hdl: The control handler.
626 * @cfg: The control's configuration data.
627 * @priv: The control's driver-specific private data.
629 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
630 * and @hdl->error is set to the error code (if it wasn't set already).
632 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
633 const struct v4l2_ctrl_config *cfg,
637 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
640 * @hdl: The control handler.
641 * @ops: The control ops.
642 * @id: The control ID.
643 * @min: The control's minimum value.
644 * @max: The control's maximum value.
645 * @step: The control's step value
646 * @def: The control's default value.
648 * If the &v4l2_ctrl struct could not be allocated, or the control
649 * ID is not known, then NULL is returned and @hdl->error is set to the
650 * appropriate error code (if it wasn't set already).
652 * If @id refers to a menu control, then this function will return NULL.
654 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
656 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
657 const struct v4l2_ctrl_ops *ops,
658 u32 id, s64 min, s64 max, u64 step,
662 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
665 * @hdl: The control handler.
666 * @ops: The control ops.
667 * @id: The control ID.
668 * @max: The control's maximum value.
669 * @mask: The control's skip mask for menu controls. This makes it
670 * easy to skip menu items that are not valid. If bit X is set,
671 * then menu item X is skipped. Of course, this only works for
672 * menus with <= 64 menu items. There are no menus that come
673 * close to that number, so this is OK. Should we ever need more,
674 * then this will have to be extended to a bit array.
675 * @def: The control's default value.
677 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
678 * determines which menu items are to be skipped.
680 * If @id refers to a non-menu control, then this function will return NULL.
682 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
683 const struct v4l2_ctrl_ops *ops,
684 u32 id, u8 max, u64 mask, u8 def);
687 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
688 * with driver specific menu.
690 * @hdl: The control handler.
691 * @ops: The control ops.
692 * @id: The control ID.
693 * @max: The control's maximum value.
694 * @mask: The control's skip mask for menu controls. This makes it
695 * easy to skip menu items that are not valid. If bit X is set,
696 * then menu item X is skipped. Of course, this only works for
697 * menus with <= 64 menu items. There are no menus that come
698 * close to that number, so this is OK. Should we ever need more,
699 * then this will have to be extended to a bit array.
700 * @def: The control's default value.
701 * @qmenu: The new menu.
703 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
704 * menu of this control.
707 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
708 const struct v4l2_ctrl_ops *ops,
711 const char * const *qmenu);
714 * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
717 * @hdl: The control handler.
718 * @ops: The control ops.
719 * @id: The control ID.
720 * @p_def: The control's default value.
722 * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
723 * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
724 * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
725 * compound control should be all zeroes.
728 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
729 const struct v4l2_ctrl_ops *ops,
731 const union v4l2_ctrl_ptr p_def);
734 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
736 * @hdl: The control handler.
737 * @ops: The control ops.
738 * @id: The control ID.
739 * @max: The control's maximum value.
740 * @def: The control's default value.
741 * @qmenu_int: The control's menu entries.
743 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
744 * takes as an argument an array of integers determining the menu items.
746 * If @id refers to a non-integer-menu control, then this function will
749 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
750 const struct v4l2_ctrl_ops *ops,
751 u32 id, u8 max, u8 def,
752 const s64 *qmenu_int);
755 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
756 * used when adding a control handler.
758 * @ctrl: pointer to struct &v4l2_ctrl.
761 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
764 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
767 * @hdl: The control handler.
768 * @add: The control handler whose controls you want to add to
769 * the @hdl control handler.
770 * @filter: This function will filter which controls should be added.
771 * @from_other_dev: If true, then the controls in @add were defined in another
774 * Does nothing if either of the two handlers is a NULL pointer.
775 * If @filter is NULL, then all controls are added. Otherwise only those
776 * controls for which @filter returns true will be added.
777 * In case of an error @hdl->error will be set to the error code (if it
778 * wasn't set already).
780 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
781 struct v4l2_ctrl_handler *add,
782 v4l2_ctrl_filter filter,
783 bool from_other_dev);
786 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
788 * @ctrl: The control that is filtered.
790 * This will return true for any controls that are valid for radio device
791 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
792 * transmitter class controls.
794 * This function is to be used with v4l2_ctrl_add_handler().
796 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
799 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
802 * @ncontrols: The number of controls in this cluster.
803 * @controls: The cluster control array of size @ncontrols.
805 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
809 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
810 * to that cluster and set it up for autofoo/foo-type handling.
812 * @ncontrols: The number of controls in this cluster.
813 * @controls: The cluster control array of size @ncontrols. The first control
814 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
815 * @manual_val: The value for the first control in the cluster that equals the
817 * @set_volatile: If true, then all controls except the first auto control will
820 * Use for control groups where one control selects some automatic feature and
821 * the other controls are only active whenever the automatic feature is turned
822 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
823 * red and blue balance, etc.
825 * The behavior of such controls is as follows:
827 * When the autofoo control is set to automatic, then any manual controls
828 * are set to inactive and any reads will call g_volatile_ctrl (if the control
829 * was marked volatile).
831 * When the autofoo control is set to manual, then any manual controls will
832 * be marked active, and any reads will just return the current value without
833 * going through g_volatile_ctrl.
835 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
836 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
837 * if autofoo is in auto mode.
839 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
840 struct v4l2_ctrl **controls,
841 u8 manual_val, bool set_volatile);
845 * v4l2_ctrl_find() - Find a control with the given ID.
847 * @hdl: The control handler.
848 * @id: The control ID to find.
850 * If @hdl == NULL this will return NULL as well. Will lock the handler so
851 * do not use from inside &v4l2_ctrl_ops.
853 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
856 * v4l2_ctrl_activate() - Make the control active or inactive.
857 * @ctrl: The control to (de)activate.
858 * @active: True if the control should become active.
860 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
861 * Does nothing if @ctrl == NULL.
862 * This will usually be called from within the s_ctrl op.
863 * The V4L2_EVENT_CTRL event will be generated afterwards.
865 * This function assumes that the control handler is locked.
867 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
870 * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
872 * @ctrl: The control to (de)activate.
873 * @grabbed: True if the control should become grabbed.
875 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
876 * Does nothing if @ctrl == NULL.
877 * The V4L2_EVENT_CTRL event will be generated afterwards.
878 * This will usually be called when starting or stopping streaming in the
881 * This function assumes that the control handler is locked by the caller.
883 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
886 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
888 * @ctrl: The control to (de)activate.
889 * @grabbed: True if the control should become grabbed.
891 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
892 * Does nothing if @ctrl == NULL.
893 * The V4L2_EVENT_CTRL event will be generated afterwards.
894 * This will usually be called when starting or stopping streaming in the
897 * This function assumes that the control handler is not locked and will
898 * take the lock itself.
900 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
905 v4l2_ctrl_lock(ctrl);
906 __v4l2_ctrl_grab(ctrl, grabbed);
907 v4l2_ctrl_unlock(ctrl);
911 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
913 * @ctrl: The control to update.
914 * @min: The control's minimum value.
915 * @max: The control's maximum value.
916 * @step: The control's step value
917 * @def: The control's default value.
919 * Update the range of a control on the fly. This works for control types
920 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
921 * @step value is interpreted as a menu_skip_mask.
923 * An error is returned if one of the range arguments is invalid for this
926 * The caller is responsible for acquiring the control handler mutex on behalf
927 * of __v4l2_ctrl_modify_range().
929 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
930 s64 min, s64 max, u64 step, s64 def);
933 * v4l2_ctrl_modify_range() - Update the range of a control.
935 * @ctrl: The control to update.
936 * @min: The control's minimum value.
937 * @max: The control's maximum value.
938 * @step: The control's step value
939 * @def: The control's default value.
941 * Update the range of a control on the fly. This works for control types
942 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
943 * @step value is interpreted as a menu_skip_mask.
945 * An error is returned if one of the range arguments is invalid for this
948 * This function assumes that the control handler is not locked and will
949 * take the lock itself.
951 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
952 s64 min, s64 max, u64 step, s64 def)
956 v4l2_ctrl_lock(ctrl);
957 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
958 v4l2_ctrl_unlock(ctrl);
964 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
966 * @ctrl: The control.
967 * @notify: The callback function.
968 * @priv: The callback private handle, passed as argument to the callback.
970 * This function sets a callback function for the control. If @ctrl is NULL,
971 * then it will do nothing. If @notify is NULL, then the notify callback will
974 * There can be only one notify. If another already exists, then a WARN_ON
975 * will be issued and the function will do nothing.
977 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
981 * v4l2_ctrl_get_name() - Get the name of the control
983 * @id: The control ID.
985 * This function returns the name of the given control ID or NULL if it isn't
988 const char *v4l2_ctrl_get_name(u32 id);
991 * v4l2_ctrl_get_menu() - Get the menu string array of the control
993 * @id: The control ID.
995 * This function returns the NULL-terminated menu string array name of the
996 * given control ID or NULL if it isn't a known menu control.
998 const char * const *v4l2_ctrl_get_menu(u32 id);
1001 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
1003 * @id: The control ID.
1004 * @len: The size of the integer array.
1006 * This function returns the integer array of the given control ID or NULL if it
1007 * if it isn't a known integer menu control.
1009 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
1012 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
1015 * @ctrl: The control.
1017 * This returns the control's value safely by going through the control
1018 * framework. This function will lock the control's handler, so it cannot be
1019 * used from within the &v4l2_ctrl_ops functions.
1021 * This function is for integer type controls only.
1023 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
1026 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
1028 * @ctrl: The control.
1029 * @val: The new value.
1031 * This sets the control's new value safely by going through the control
1032 * framework. This function assumes the control's handler is already locked,
1033 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1035 * This function is for integer type controls only.
1037 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1040 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1042 * @ctrl: The control.
1043 * @val: The new value.
1045 * This sets the control's new value safely by going through the control
1046 * framework. This function will lock the control's handler, so it cannot be
1047 * used from within the &v4l2_ctrl_ops functions.
1049 * This function is for integer type controls only.
1051 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1055 v4l2_ctrl_lock(ctrl);
1056 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1057 v4l2_ctrl_unlock(ctrl);
1063 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1064 * from within a driver.
1066 * @ctrl: The control.
1068 * This returns the control's value safely by going through the control
1069 * framework. This function will lock the control's handler, so it cannot be
1070 * used from within the &v4l2_ctrl_ops functions.
1072 * This function is for 64-bit integer type controls only.
1074 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1077 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1079 * @ctrl: The control.
1080 * @val: The new value.
1082 * This sets the control's new value safely by going through the control
1083 * framework. This function assumes the control's handler is already locked,
1084 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1086 * This function is for 64-bit integer type controls only.
1088 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1091 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1092 * from within a driver.
1094 * @ctrl: The control.
1095 * @val: The new value.
1097 * This sets the control's new value safely by going through the control
1098 * framework. This function will lock the control's handler, so it cannot be
1099 * used from within the &v4l2_ctrl_ops functions.
1101 * This function is for 64-bit integer type controls only.
1103 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1107 v4l2_ctrl_lock(ctrl);
1108 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1109 v4l2_ctrl_unlock(ctrl);
1115 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1117 * @ctrl: The control.
1118 * @s: The new string.
1120 * This sets the control's new string safely by going through the control
1121 * framework. This function assumes the control's handler is already locked,
1122 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1124 * This function is for string type controls only.
1126 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1129 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1130 * from within a driver.
1132 * @ctrl: The control.
1133 * @s: The new string.
1135 * This sets the control's new string safely by going through the control
1136 * framework. This function will lock the control's handler, so it cannot be
1137 * used from within the &v4l2_ctrl_ops functions.
1139 * This function is for string type controls only.
1141 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1145 v4l2_ctrl_lock(ctrl);
1146 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1147 v4l2_ctrl_unlock(ctrl);
1153 * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1155 * @ctrl: The control.
1156 * @type: The type of the data.
1157 * @p: The new compound payload.
1159 * This sets the control's new compound payload safely by going through the
1160 * control framework. This function assumes the control's handler is already
1161 * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1163 * This function is for compound type controls only.
1165 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1166 enum v4l2_ctrl_type type, const void *p);
1169 * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1170 * from within a driver.
1172 * @ctrl: The control.
1173 * @type: The type of the data.
1174 * @p: The new compound payload.
1176 * This sets the control's new compound payload safely by going through the
1177 * control framework. This function will lock the control's handler, so it
1178 * cannot be used from within the &v4l2_ctrl_ops functions.
1180 * This function is for compound type controls only.
1182 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1183 enum v4l2_ctrl_type type,
1188 v4l2_ctrl_lock(ctrl);
1189 rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1190 v4l2_ctrl_unlock(ctrl);
1195 /* Helper defines for area type controls */
1196 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1197 __v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1198 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1199 v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1201 /* Internal helper functions that deal with control events. */
1202 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1205 * v4l2_ctrl_replace - Function to be used as a callback to
1206 * &struct v4l2_subscribed_event_ops replace\(\)
1208 * @old: pointer to struct &v4l2_event with the reported
1210 * @new: pointer to struct &v4l2_event with the modified
1213 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1216 * v4l2_ctrl_merge - Function to be used as a callback to
1217 * &struct v4l2_subscribed_event_ops merge(\)
1219 * @old: pointer to struct &v4l2_event with the reported
1221 * @new: pointer to struct &v4l2_event with the merged
1224 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1227 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1229 * @file: pointer to struct file
1230 * @fh: unused. Kept just to be compatible to the arguments expected by
1231 * &struct v4l2_ioctl_ops.vidioc_log_status.
1233 * Can be used as a vidioc_log_status function that just dumps all controls
1234 * associated with the filehandle.
1236 int v4l2_ctrl_log_status(struct file *file, void *fh);
1239 * v4l2_ctrl_subscribe_event - Subscribes to an event
1242 * @fh: pointer to struct v4l2_fh
1243 * @sub: pointer to &struct v4l2_event_subscription
1245 * Can be used as a vidioc_subscribe_event function that just subscribes
1248 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1249 const struct v4l2_event_subscription *sub);
1252 * v4l2_ctrl_poll - function to be used as a callback to the poll()
1253 * That just polls for control events.
1255 * @file: pointer to struct file
1256 * @wait: pointer to struct poll_table_struct
1258 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1261 * v4l2_ctrl_request_setup - helper function to apply control values in a request
1264 * @parent: The parent control handler ('priv' in media_request_object_find())
1266 * This is a helper function to call the control handler's s_ctrl callback with
1267 * the control values contained in the request. Do note that this approach of
1268 * applying control values in a request is only applicable to memory-to-memory
1271 int v4l2_ctrl_request_setup(struct media_request *req,
1272 struct v4l2_ctrl_handler *parent);
1275 * v4l2_ctrl_request_complete - Complete a control handler request object
1278 * @parent: The parent control handler ('priv' in media_request_object_find())
1280 * This function is to be called on each control handler that may have had a
1281 * request object associated with it, i.e. control handlers of a driver that
1282 * supports requests.
1284 * The function first obtains the values of any volatile controls in the control
1285 * handler and attach them to the request. Then, the function completes the
1288 void v4l2_ctrl_request_complete(struct media_request *req,
1289 struct v4l2_ctrl_handler *parent);
1292 * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1295 * @parent: The parent control handler ('priv' in media_request_object_find())
1297 * This function finds the control handler in the request. It may return
1298 * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1299 * with the returned handler pointer.
1301 * If the request is not in state VALIDATING or QUEUED, then this function
1302 * will always return NULL.
1304 * Note that in state VALIDATING the req_queue_mutex is held, so
1305 * no objects can be added or deleted from the request.
1307 * In state QUEUED it is the driver that will have to ensure this.
1309 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1310 struct v4l2_ctrl_handler *parent);
1313 * v4l2_ctrl_request_hdl_put - Put the control handler
1315 * @hdl: Put this control handler
1317 * This function released the control handler previously obtained from'
1318 * v4l2_ctrl_request_hdl_find().
1320 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1323 media_request_object_put(&hdl->req_obj);
1327 * v4l2_ctrl_request_hdl_ctrl_find() - Find a control with the given ID.
1329 * @hdl: The control handler from the request.
1330 * @id: The ID of the control to find.
1332 * This function returns a pointer to the control if this control is
1333 * part of the request or NULL otherwise.
1336 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1338 /* Helpers for ioctl_ops */
1341 * v4l2_queryctrl - Helper function to implement
1342 * :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1344 * @hdl: pointer to &struct v4l2_ctrl_handler
1345 * @qc: pointer to &struct v4l2_queryctrl
1347 * If hdl == NULL then they will all return -EINVAL.
1349 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1352 * v4l2_query_ext_ctrl - Helper function to implement
1353 * :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1355 * @hdl: pointer to &struct v4l2_ctrl_handler
1356 * @qc: pointer to &struct v4l2_query_ext_ctrl
1358 * If hdl == NULL then they will all return -EINVAL.
1360 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1361 struct v4l2_query_ext_ctrl *qc);
1364 * v4l2_querymenu - Helper function to implement
1365 * :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1367 * @hdl: pointer to &struct v4l2_ctrl_handler
1368 * @qm: pointer to &struct v4l2_querymenu
1370 * If hdl == NULL then they will all return -EINVAL.
1372 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1375 * v4l2_g_ctrl - Helper function to implement
1376 * :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1378 * @hdl: pointer to &struct v4l2_ctrl_handler
1379 * @ctrl: pointer to &struct v4l2_control
1381 * If hdl == NULL then they will all return -EINVAL.
1383 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1386 * v4l2_s_ctrl - Helper function to implement
1387 * :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1389 * @fh: pointer to &struct v4l2_fh
1390 * @hdl: pointer to &struct v4l2_ctrl_handler
1392 * @ctrl: pointer to &struct v4l2_control
1394 * If hdl == NULL then they will all return -EINVAL.
1396 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1397 struct v4l2_control *ctrl);
1400 * v4l2_g_ext_ctrls - Helper function to implement
1401 * :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1403 * @hdl: pointer to &struct v4l2_ctrl_handler
1404 * @vdev: pointer to &struct video_device
1405 * @mdev: pointer to &struct media_device
1406 * @c: pointer to &struct v4l2_ext_controls
1408 * If hdl == NULL then they will all return -EINVAL.
1410 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1411 struct media_device *mdev, struct v4l2_ext_controls *c);
1414 * v4l2_try_ext_ctrls - Helper function to implement
1415 * :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1417 * @hdl: pointer to &struct v4l2_ctrl_handler
1418 * @vdev: pointer to &struct video_device
1419 * @mdev: pointer to &struct media_device
1420 * @c: pointer to &struct v4l2_ext_controls
1422 * If hdl == NULL then they will all return -EINVAL.
1424 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1425 struct video_device *vdev,
1426 struct media_device *mdev,
1427 struct v4l2_ext_controls *c);
1430 * v4l2_s_ext_ctrls - Helper function to implement
1431 * :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1433 * @fh: pointer to &struct v4l2_fh
1434 * @hdl: pointer to &struct v4l2_ctrl_handler
1435 * @vdev: pointer to &struct video_device
1436 * @mdev: pointer to &struct media_device
1437 * @c: pointer to &struct v4l2_ext_controls
1439 * If hdl == NULL then they will all return -EINVAL.
1441 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1442 struct video_device *vdev,
1443 struct media_device *mdev,
1444 struct v4l2_ext_controls *c);
1447 * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1448 * as a &struct v4l2_subdev_core_ops subscribe_event function
1449 * that just subscribes control events.
1451 * @sd: pointer to &struct v4l2_subdev
1452 * @fh: pointer to &struct v4l2_fh
1453 * @sub: pointer to &struct v4l2_event_subscription
1455 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1456 struct v4l2_event_subscription *sub);
1459 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1462 * @sd: pointer to &struct v4l2_subdev
1464 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1467 * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1470 * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1471 * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1472 * @p: pointer to &struct v4l2_fwnode_device_properties
1474 * This function registers controls associated to device properties, using the
1475 * property values contained in @p parameter, if the property has been set to
1478 * Currently the following v4l2 controls are parsed and registered:
1479 * - V4L2_CID_CAMERA_ORIENTATION
1480 * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1482 * Controls already registered by the caller with the @hdl control handler are
1483 * not overwritten. Callers should register the controls they want to handle
1484 * themselves before calling this function.
1486 * Return: 0 on success, a negative error code on failure.
1488 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1489 const struct v4l2_ctrl_ops *ctrl_ops,
1490 const struct v4l2_fwnode_device_properties *p);