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 * @has_volatiles: If set, then one or more members of the cluster are volatile.
185 * Drivers should never touch this flag.
186 * @call_notify: If set, then call the handler's notify function whenever the
187 * control's value changes.
188 * @manual_mode_value: If the is_auto flag is set, then this is the value
189 * of the auto control that determines if that control is in
190 * manual mode. So if the value of the auto control equals this
191 * value, then the whole cluster is in manual mode. Drivers should
192 * never set this flag directly.
193 * @ops: The control ops.
194 * @type_ops: The control type ops.
195 * @id: The control ID.
196 * @name: The control name.
197 * @type: The control type.
198 * @minimum: The control's minimum value.
199 * @maximum: The control's maximum value.
200 * @default_value: The control's default value.
201 * @step: The control's step value for non-menu controls.
202 * @elems: The number of elements in the N-dimensional array.
203 * @elem_size: The size in bytes of the control.
204 * @dims: The size of each dimension.
205 * @nr_of_dims:The number of dimensions in @dims.
206 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
207 * easy to skip menu items that are not valid. If bit X is set,
208 * then menu item X is skipped. Of course, this only works for
209 * menus with <= 32 menu items. There are no menus that come
210 * close to that number, so this is OK. Should we ever need more,
211 * then this will have to be extended to a u64 or a bit array.
212 * @qmenu: A const char * array for all menu items. Array entries that are
213 * empty strings ("") correspond to non-existing menu items (this
214 * is in addition to the menu_skip_mask above). The last entry
216 * Used only if the @type is %V4L2_CTRL_TYPE_MENU.
217 * @qmenu_int: A 64-bit integer array for with integer menu items.
218 * The size of array must be equal to the menu size, e. g.:
219 * :math:`ceil(\frac{maximum - minimum}{step}) + 1`.
220 * Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
221 * @flags: The control's flags.
222 * @cur: Structure to store the current value.
223 * @cur.val: The control's current value, if the @type is represented via
224 * a u32 integer (see &enum v4l2_ctrl_type).
225 * @val: The control's new s32 value.
226 * @priv: The control's private pointer. For use by the driver. It is
227 * untouched by the control framework. Note that this pointer is
228 * not freed when the control is deleted. Should this be needed
229 * then a new internal bitfield can be added to tell the framework
230 * to free this pointer.
231 * @p_def: The control's default value represented via a union which
232 * provides a standard way of accessing control types
233 * through a pointer (for compound controls only).
234 * @p_cur: The control's current value represented via a union which
235 * provides a standard way of accessing control types
237 * @p_new: The control's new value represented via a union which provides
238 * a standard way of accessing control types
242 /* Administrative fields */
243 struct list_head node;
244 struct list_head ev_subs;
245 struct v4l2_ctrl_handler *handler;
246 struct v4l2_ctrl **cluster;
247 unsigned int ncontrols;
251 unsigned int is_new:1;
252 unsigned int has_changed:1;
253 unsigned int is_private:1;
254 unsigned int is_auto:1;
255 unsigned int is_int:1;
256 unsigned int is_string:1;
257 unsigned int is_ptr:1;
258 unsigned int is_array:1;
259 unsigned int has_volatiles:1;
260 unsigned int call_notify:1;
261 unsigned int manual_mode_value:8;
263 const struct v4l2_ctrl_ops *ops;
264 const struct v4l2_ctrl_type_ops *type_ops;
267 enum v4l2_ctrl_type type;
268 s64 minimum, maximum, default_value;
271 u32 dims[V4L2_CTRL_MAX_DIMS];
278 const char * const *qmenu;
279 const s64 *qmenu_int;
288 union v4l2_ctrl_ptr p_def;
289 union v4l2_ctrl_ptr p_new;
290 union v4l2_ctrl_ptr p_cur;
294 * struct v4l2_ctrl_ref - The control reference.
296 * @node: List node for the sorted list.
297 * @next: Single-link list node for the hash.
298 * @ctrl: The actual control information.
299 * @helper: Pointer to helper struct. Used internally in
300 * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
301 * @from_other_dev: If true, then @ctrl was defined in another
302 * device than the &struct v4l2_ctrl_handler.
303 * @req_done: Internal flag: if the control handler containing this control
304 * reference is bound to a media request, then this is set when
305 * the control has been applied. This prevents applying controls
306 * from a cluster with multiple controls twice (when the first
307 * control of a cluster is applied, they all are).
308 * @valid_p_req: If set, then p_req contains the control value for the request.
309 * @p_req: If the control handler containing this control reference
310 * is bound to a media request, then this points to the
311 * value of the control that must be applied when the request
312 * is executed, or to the value of the control at the time
313 * that the request was completed. If @valid_p_req is false,
314 * then this control was never set for this request and the
315 * control will not be updated when this request is applied.
317 * Each control handler has a list of these refs. The list_head is used to
318 * keep a sorted-by-control-ID list of all controls, while the next pointer
319 * is used to link the control in the hash's bucket.
321 struct v4l2_ctrl_ref {
322 struct list_head node;
323 struct v4l2_ctrl_ref *next;
324 struct v4l2_ctrl *ctrl;
325 struct v4l2_ctrl_helper *helper;
329 union v4l2_ctrl_ptr p_req;
333 * struct v4l2_ctrl_handler - The control handler keeps track of all the
334 * controls: both the controls owned by the handler and those inherited
335 * from other handlers.
337 * @_lock: Default for "lock".
338 * @lock: Lock to control access to this handler and its controls.
339 * May be replaced by the user right after init.
340 * @ctrls: The list of controls owned by this handler.
341 * @ctrl_refs: The list of control references.
342 * @cached: The last found control reference. It is common that the same
343 * control is needed multiple times, so this is a simple
345 * @buckets: Buckets for the hashing. Allows for quick control lookup.
346 * @notify: A notify callback that is called whenever the control changes
348 * Note that the handler's lock is held when the notify function
350 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
351 * @nr_of_buckets: Total number of buckets in the array.
352 * @error: The error code of the first failed control addition.
353 * @request_is_queued: True if the request was queued.
354 * @requests: List to keep track of open control handler request objects.
355 * For the parent control handler (@req_obj.ops == NULL) this
356 * is the list header. When the parent control handler is
357 * removed, it has to unbind and put all these requests since
358 * they refer to the parent.
359 * @requests_queued: List of the queued requests. This determines the order
360 * in which these controls are applied. Once the request is
361 * completed it is removed from this list.
362 * @req_obj: The &struct media_request_object, used to link into a
363 * &struct media_request. This request object has a refcount.
365 struct v4l2_ctrl_handler {
368 struct list_head ctrls;
369 struct list_head ctrl_refs;
370 struct v4l2_ctrl_ref *cached;
371 struct v4l2_ctrl_ref **buckets;
372 v4l2_ctrl_notify_fnc notify;
376 bool request_is_queued;
377 struct list_head requests;
378 struct list_head requests_queued;
379 struct media_request_object req_obj;
383 * struct v4l2_ctrl_config - Control configuration structure.
385 * @ops: The control ops.
386 * @type_ops: The control type ops. Only needed for compound controls.
387 * @id: The control ID.
388 * @name: The control name.
389 * @type: The control type.
390 * @min: The control's minimum value.
391 * @max: The control's maximum value.
392 * @step: The control's step value for non-menu controls.
393 * @def: The control's default value.
394 * @p_def: The control's default value for compound controls.
395 * @dims: The size of each dimension.
396 * @elem_size: The size in bytes of the control.
397 * @flags: The control's flags.
398 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
399 * easy to skip menu items that are not valid. If bit X is set,
400 * then menu item X is skipped. Of course, this only works for
401 * menus with <= 64 menu items. There are no menus that come
402 * close to that number, so this is OK. Should we ever need more,
403 * then this will have to be extended to a bit array.
404 * @qmenu: A const char * array for all menu items. Array entries that are
405 * empty strings ("") correspond to non-existing menu items (this
406 * is in addition to the menu_skip_mask above). The last entry
408 * @qmenu_int: A const s64 integer array for all menu items of the type
409 * V4L2_CTRL_TYPE_INTEGER_MENU.
410 * @is_private: If set, then this control is private to its handler and it
411 * will not be added to any other handlers.
413 struct v4l2_ctrl_config {
414 const struct v4l2_ctrl_ops *ops;
415 const struct v4l2_ctrl_type_ops *type_ops;
418 enum v4l2_ctrl_type type;
423 union v4l2_ctrl_ptr p_def;
424 u32 dims[V4L2_CTRL_MAX_DIMS];
428 const char * const *qmenu;
429 const s64 *qmenu_int;
430 unsigned int is_private:1;
434 * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
436 * @id: ID of the control
437 * @name: pointer to be filled with a string with the name of the control
438 * @type: pointer for storing the type of the control
439 * @min: pointer for storing the minimum value for the control
440 * @max: pointer for storing the maximum value for the control
441 * @step: pointer for storing the control step
442 * @def: pointer for storing the default value for the control
443 * @flags: pointer for storing the flags to be used on the control
445 * This works for all standard V4L2 controls.
446 * For non-standard controls it will only fill in the given arguments
447 * and @name content will be set to %NULL.
449 * This function will overwrite the contents of @name, @type and @flags.
450 * The contents of @min, @max, @step and @def may be modified depending on
455 * Do not use in drivers! It is used internally for backwards compatibility
456 * control handling only. Once all drivers are converted to use the new
457 * control framework this function will no longer be exported.
459 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
460 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
464 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
465 * @hdl: The control handler.
466 * @nr_of_controls_hint: A hint of how many controls this handler is
467 * expected to refer to. This is the total number, so including
468 * any inherited controls. It doesn't have to be precise, but if
469 * it is way off, then you either waste memory (too many buckets
470 * are allocated) or the control lookup becomes slower (not enough
471 * buckets are allocated, so there are more slow list lookups).
472 * It will always work, though.
473 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
474 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
478 * Never use this call directly, always use the v4l2_ctrl_handler_init()
479 * macro that hides the @key and @name arguments.
481 * Return: returns an error if the buckets could not be allocated. This
482 * error will also be stored in @hdl->error.
484 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
485 unsigned int nr_of_controls_hint,
486 struct lock_class_key *key, const char *name);
488 #ifdef CONFIG_LOCKDEP
491 * v4l2_ctrl_handler_init - helper function to create a static struct
492 * &lock_class_key and calls v4l2_ctrl_handler_init_class()
494 * @hdl: The control handler.
495 * @nr_of_controls_hint: A hint of how many controls this handler is
496 * expected to refer to. This is the total number, so including
497 * any inherited controls. It doesn't have to be precise, but if
498 * it is way off, then you either waste memory (too many buckets
499 * are allocated) or the control lookup becomes slower (not enough
500 * buckets are allocated, so there are more slow list lookups).
501 * It will always work, though.
503 * This helper function creates a static struct &lock_class_key and
504 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
507 * Use this helper function to initialize a control handler.
509 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
512 static struct lock_class_key _key; \
513 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
515 KBUILD_BASENAME ":" \
516 __stringify(__LINE__) ":" \
517 "(" #hdl ")->_lock"); \
521 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
522 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
526 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
528 * @hdl: The control handler.
530 * Does nothing if @hdl == NULL.
532 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
535 * v4l2_ctrl_lock() - Helper function to lock the handler
536 * associated with the control.
537 * @ctrl: The control to lock.
539 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
541 mutex_lock(ctrl->handler->lock);
545 * v4l2_ctrl_unlock() - Helper function to unlock the handler
546 * associated with the control.
547 * @ctrl: The control to unlock.
549 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
551 mutex_unlock(ctrl->handler->lock);
555 * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
556 * to the handler to initialize the hardware to the current control values. The
557 * caller is responsible for acquiring the control handler mutex on behalf of
558 * __v4l2_ctrl_handler_setup().
559 * @hdl: The control handler.
561 * Button controls will be skipped, as are read-only controls.
563 * If @hdl == NULL, then this just returns 0.
565 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
568 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
569 * to the handler to initialize the hardware to the current control values.
570 * @hdl: The control handler.
572 * Button controls will be skipped, as are read-only controls.
574 * If @hdl == NULL, then this just returns 0.
576 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
579 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
580 * @hdl: The control handler.
581 * @prefix: The prefix to use when logging the control values. If the
582 * prefix does not end with a space, then ": " will be added
583 * after the prefix. If @prefix == NULL, then no prefix will be
586 * For use with VIDIOC_LOG_STATUS.
588 * Does nothing if @hdl == NULL.
590 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
594 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
597 * @hdl: The control handler.
598 * @cfg: The control's configuration data.
599 * @priv: The control's driver-specific private data.
601 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
602 * and @hdl->error is set to the error code (if it wasn't set already).
604 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
605 const struct v4l2_ctrl_config *cfg,
609 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
612 * @hdl: The control handler.
613 * @ops: The control ops.
614 * @id: The control ID.
615 * @min: The control's minimum value.
616 * @max: The control's maximum value.
617 * @step: The control's step value
618 * @def: The control's default value.
620 * If the &v4l2_ctrl struct could not be allocated, or the control
621 * ID is not known, then NULL is returned and @hdl->error is set to the
622 * appropriate error code (if it wasn't set already).
624 * If @id refers to a menu control, then this function will return NULL.
626 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
628 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
629 const struct v4l2_ctrl_ops *ops,
630 u32 id, s64 min, s64 max, u64 step,
634 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
637 * @hdl: The control handler.
638 * @ops: The control ops.
639 * @id: The control ID.
640 * @max: The control's maximum value.
641 * @mask: The control's skip mask for menu controls. This makes it
642 * easy to skip menu items that are not valid. If bit X is set,
643 * then menu item X is skipped. Of course, this only works for
644 * menus with <= 64 menu items. There are no menus that come
645 * close to that number, so this is OK. Should we ever need more,
646 * then this will have to be extended to a bit array.
647 * @def: The control's default value.
649 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
650 * determines which menu items are to be skipped.
652 * If @id refers to a non-menu control, then this function will return NULL.
654 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
655 const struct v4l2_ctrl_ops *ops,
656 u32 id, u8 max, u64 mask, u8 def);
659 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
660 * with driver specific menu.
662 * @hdl: The control handler.
663 * @ops: The control ops.
664 * @id: The control ID.
665 * @max: The control's maximum value.
666 * @mask: The control's skip mask for menu controls. This makes it
667 * easy to skip menu items that are not valid. If bit X is set,
668 * then menu item X is skipped. Of course, this only works for
669 * menus with <= 64 menu items. There are no menus that come
670 * close to that number, so this is OK. Should we ever need more,
671 * then this will have to be extended to a bit array.
672 * @def: The control's default value.
673 * @qmenu: The new menu.
675 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
676 * menu of this control.
679 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
680 const struct v4l2_ctrl_ops *ops,
683 const char * const *qmenu);
686 * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
689 * @hdl: The control handler.
690 * @ops: The control ops.
691 * @id: The control ID.
692 * @p_def: The control's default value.
694 * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
695 * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
696 * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
697 * compound control should be all zeroes.
700 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
701 const struct v4l2_ctrl_ops *ops,
703 const union v4l2_ctrl_ptr p_def);
706 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
708 * @hdl: The control handler.
709 * @ops: The control ops.
710 * @id: The control ID.
711 * @max: The control's maximum value.
712 * @def: The control's default value.
713 * @qmenu_int: The control's menu entries.
715 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
716 * takes as an argument an array of integers determining the menu items.
718 * If @id refers to a non-integer-menu control, then this function will
721 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
722 const struct v4l2_ctrl_ops *ops,
723 u32 id, u8 max, u8 def,
724 const s64 *qmenu_int);
727 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
728 * used when adding a control handler.
730 * @ctrl: pointer to struct &v4l2_ctrl.
733 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
736 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
739 * @hdl: The control handler.
740 * @add: The control handler whose controls you want to add to
741 * the @hdl control handler.
742 * @filter: This function will filter which controls should be added.
743 * @from_other_dev: If true, then the controls in @add were defined in another
746 * Does nothing if either of the two handlers is a NULL pointer.
747 * If @filter is NULL, then all controls are added. Otherwise only those
748 * controls for which @filter returns true will be added.
749 * In case of an error @hdl->error will be set to the error code (if it
750 * wasn't set already).
752 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
753 struct v4l2_ctrl_handler *add,
754 v4l2_ctrl_filter filter,
755 bool from_other_dev);
758 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
760 * @ctrl: The control that is filtered.
762 * This will return true for any controls that are valid for radio device
763 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
764 * transmitter class controls.
766 * This function is to be used with v4l2_ctrl_add_handler().
768 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
771 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
774 * @ncontrols: The number of controls in this cluster.
775 * @controls: The cluster control array of size @ncontrols.
777 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
781 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
782 * to that cluster and set it up for autofoo/foo-type handling.
784 * @ncontrols: The number of controls in this cluster.
785 * @controls: The cluster control array of size @ncontrols. The first control
786 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
787 * @manual_val: The value for the first control in the cluster that equals the
789 * @set_volatile: If true, then all controls except the first auto control will
792 * Use for control groups where one control selects some automatic feature and
793 * the other controls are only active whenever the automatic feature is turned
794 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
795 * red and blue balance, etc.
797 * The behavior of such controls is as follows:
799 * When the autofoo control is set to automatic, then any manual controls
800 * are set to inactive and any reads will call g_volatile_ctrl (if the control
801 * was marked volatile).
803 * When the autofoo control is set to manual, then any manual controls will
804 * be marked active, and any reads will just return the current value without
805 * going through g_volatile_ctrl.
807 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
808 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
809 * if autofoo is in auto mode.
811 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
812 struct v4l2_ctrl **controls,
813 u8 manual_val, bool set_volatile);
817 * v4l2_ctrl_find() - Find a control with the given ID.
819 * @hdl: The control handler.
820 * @id: The control ID to find.
822 * If @hdl == NULL this will return NULL as well. Will lock the handler so
823 * do not use from inside &v4l2_ctrl_ops.
825 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
828 * v4l2_ctrl_activate() - Make the control active or inactive.
829 * @ctrl: The control to (de)activate.
830 * @active: True if the control should become active.
832 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
833 * Does nothing if @ctrl == NULL.
834 * This will usually be called from within the s_ctrl op.
835 * The V4L2_EVENT_CTRL event will be generated afterwards.
837 * This function assumes that the control handler is locked.
839 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
842 * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
844 * @ctrl: The control to (de)activate.
845 * @grabbed: True if the control should become grabbed.
847 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
848 * Does nothing if @ctrl == NULL.
849 * The V4L2_EVENT_CTRL event will be generated afterwards.
850 * This will usually be called when starting or stopping streaming in the
853 * This function assumes that the control handler is locked by the caller.
855 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
858 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
860 * @ctrl: The control to (de)activate.
861 * @grabbed: True if the control should become grabbed.
863 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
864 * Does nothing if @ctrl == NULL.
865 * The V4L2_EVENT_CTRL event will be generated afterwards.
866 * This will usually be called when starting or stopping streaming in the
869 * This function assumes that the control handler is not locked and will
870 * take the lock itself.
872 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
877 v4l2_ctrl_lock(ctrl);
878 __v4l2_ctrl_grab(ctrl, grabbed);
879 v4l2_ctrl_unlock(ctrl);
883 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
885 * @ctrl: The control to update.
886 * @min: The control's minimum value.
887 * @max: The control's maximum value.
888 * @step: The control's step value
889 * @def: The control's default value.
891 * Update the range of a control on the fly. This works for control types
892 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
893 * @step value is interpreted as a menu_skip_mask.
895 * An error is returned if one of the range arguments is invalid for this
898 * The caller is responsible for acquiring the control handler mutex on behalf
899 * of __v4l2_ctrl_modify_range().
901 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
902 s64 min, s64 max, u64 step, s64 def);
905 * v4l2_ctrl_modify_range() - Update the range of a control.
907 * @ctrl: The control to update.
908 * @min: The control's minimum value.
909 * @max: The control's maximum value.
910 * @step: The control's step value
911 * @def: The control's default value.
913 * Update the range of a control on the fly. This works for control types
914 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
915 * @step value is interpreted as a menu_skip_mask.
917 * An error is returned if one of the range arguments is invalid for this
920 * This function assumes that the control handler is not locked and will
921 * take the lock itself.
923 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
924 s64 min, s64 max, u64 step, s64 def)
928 v4l2_ctrl_lock(ctrl);
929 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
930 v4l2_ctrl_unlock(ctrl);
936 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
938 * @ctrl: The control.
939 * @notify: The callback function.
940 * @priv: The callback private handle, passed as argument to the callback.
942 * This function sets a callback function for the control. If @ctrl is NULL,
943 * then it will do nothing. If @notify is NULL, then the notify callback will
946 * There can be only one notify. If another already exists, then a WARN_ON
947 * will be issued and the function will do nothing.
949 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
953 * v4l2_ctrl_get_name() - Get the name of the control
955 * @id: The control ID.
957 * This function returns the name of the given control ID or NULL if it isn't
960 const char *v4l2_ctrl_get_name(u32 id);
963 * v4l2_ctrl_get_menu() - Get the menu string array of the control
965 * @id: The control ID.
967 * This function returns the NULL-terminated menu string array name of the
968 * given control ID or NULL if it isn't a known menu control.
970 const char * const *v4l2_ctrl_get_menu(u32 id);
973 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
975 * @id: The control ID.
976 * @len: The size of the integer array.
978 * This function returns the integer array of the given control ID or NULL if it
979 * if it isn't a known integer menu control.
981 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
984 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
987 * @ctrl: The control.
989 * This returns the control's value safely by going through the control
990 * framework. This function will lock the control's handler, so it cannot be
991 * used from within the &v4l2_ctrl_ops functions.
993 * This function is for integer type controls only.
995 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
998 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
1000 * @ctrl: The control.
1001 * @val: The new value.
1003 * This sets the control's new value safely by going through the control
1004 * framework. This function assumes the control's handler is already locked,
1005 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1007 * This function is for integer type controls only.
1009 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1012 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1014 * @ctrl: The control.
1015 * @val: The new value.
1017 * This sets the control's new 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 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1027 v4l2_ctrl_lock(ctrl);
1028 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1029 v4l2_ctrl_unlock(ctrl);
1035 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1036 * from within a driver.
1038 * @ctrl: The control.
1040 * This returns the control's value safely by going through the control
1041 * framework. This function will lock the control's handler, so it cannot be
1042 * used from within the &v4l2_ctrl_ops functions.
1044 * This function is for 64-bit integer type controls only.
1046 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1049 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1051 * @ctrl: The control.
1052 * @val: The new value.
1054 * This sets the control's new value safely by going through the control
1055 * framework. This function assumes the control's handler is already locked,
1056 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1058 * This function is for 64-bit integer type controls only.
1060 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1063 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1064 * from within a driver.
1066 * @ctrl: The control.
1067 * @val: The new value.
1069 * This sets the control's new value safely by going through the control
1070 * framework. This function will lock the control's handler, so it cannot be
1071 * used from within the &v4l2_ctrl_ops functions.
1073 * This function is for 64-bit integer type controls only.
1075 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1079 v4l2_ctrl_lock(ctrl);
1080 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1081 v4l2_ctrl_unlock(ctrl);
1087 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1089 * @ctrl: The control.
1090 * @s: The new string.
1092 * This sets the control's new string safely by going through the control
1093 * framework. This function assumes the control's handler is already locked,
1094 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1096 * This function is for string type controls only.
1098 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1101 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1102 * from within a driver.
1104 * @ctrl: The control.
1105 * @s: The new string.
1107 * This sets the control's new string safely by going through the control
1108 * framework. This function will lock the control's handler, so it cannot be
1109 * used from within the &v4l2_ctrl_ops functions.
1111 * This function is for string type controls only.
1113 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1117 v4l2_ctrl_lock(ctrl);
1118 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1119 v4l2_ctrl_unlock(ctrl);
1125 * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1127 * @ctrl: The control.
1128 * @type: The type of the data.
1129 * @p: The new compound payload.
1131 * This sets the control's new compound payload safely by going through the
1132 * control framework. This function assumes the control's handler is already
1133 * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1135 * This function is for compound type controls only.
1137 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1138 enum v4l2_ctrl_type type, const void *p);
1141 * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1142 * from within a driver.
1144 * @ctrl: The control.
1145 * @type: The type of the data.
1146 * @p: The new compound payload.
1148 * This sets the control's new compound payload safely by going through the
1149 * control framework. This function will lock the control's handler, so it
1150 * cannot be used from within the &v4l2_ctrl_ops functions.
1152 * This function is for compound type controls only.
1154 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1155 enum v4l2_ctrl_type type,
1160 v4l2_ctrl_lock(ctrl);
1161 rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1162 v4l2_ctrl_unlock(ctrl);
1167 /* Helper defines for area type controls */
1168 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1169 __v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1170 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1171 v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1173 /* Internal helper functions that deal with control events. */
1174 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1177 * v4l2_ctrl_replace - Function to be used as a callback to
1178 * &struct v4l2_subscribed_event_ops replace\(\)
1180 * @old: pointer to struct &v4l2_event with the reported
1182 * @new: pointer to struct &v4l2_event with the modified
1185 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1188 * v4l2_ctrl_merge - Function to be used as a callback to
1189 * &struct v4l2_subscribed_event_ops merge(\)
1191 * @old: pointer to struct &v4l2_event with the reported
1193 * @new: pointer to struct &v4l2_event with the merged
1196 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1199 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1201 * @file: pointer to struct file
1202 * @fh: unused. Kept just to be compatible to the arguments expected by
1203 * &struct v4l2_ioctl_ops.vidioc_log_status.
1205 * Can be used as a vidioc_log_status function that just dumps all controls
1206 * associated with the filehandle.
1208 int v4l2_ctrl_log_status(struct file *file, void *fh);
1211 * v4l2_ctrl_subscribe_event - Subscribes to an event
1214 * @fh: pointer to struct v4l2_fh
1215 * @sub: pointer to &struct v4l2_event_subscription
1217 * Can be used as a vidioc_subscribe_event function that just subscribes
1220 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1221 const struct v4l2_event_subscription *sub);
1224 * v4l2_ctrl_poll - function to be used as a callback to the poll()
1225 * That just polls for control events.
1227 * @file: pointer to struct file
1228 * @wait: pointer to struct poll_table_struct
1230 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1233 * v4l2_ctrl_request_setup - helper function to apply control values in a request
1236 * @parent: The parent control handler ('priv' in media_request_object_find())
1238 * This is a helper function to call the control handler's s_ctrl callback with
1239 * the control values contained in the request. Do note that this approach of
1240 * applying control values in a request is only applicable to memory-to-memory
1243 int v4l2_ctrl_request_setup(struct media_request *req,
1244 struct v4l2_ctrl_handler *parent);
1247 * v4l2_ctrl_request_complete - Complete a control handler request object
1250 * @parent: The parent control handler ('priv' in media_request_object_find())
1252 * This function is to be called on each control handler that may have had a
1253 * request object associated with it, i.e. control handlers of a driver that
1254 * supports requests.
1256 * The function first obtains the values of any volatile controls in the control
1257 * handler and attach them to the request. Then, the function completes the
1260 void v4l2_ctrl_request_complete(struct media_request *req,
1261 struct v4l2_ctrl_handler *parent);
1264 * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1267 * @parent: The parent control handler ('priv' in media_request_object_find())
1269 * This function finds the control handler in the request. It may return
1270 * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1271 * with the returned handler pointer.
1273 * If the request is not in state VALIDATING or QUEUED, then this function
1274 * will always return NULL.
1276 * Note that in state VALIDATING the req_queue_mutex is held, so
1277 * no objects can be added or deleted from the request.
1279 * In state QUEUED it is the driver that will have to ensure this.
1281 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1282 struct v4l2_ctrl_handler *parent);
1285 * v4l2_ctrl_request_hdl_put - Put the control handler
1287 * @hdl: Put this control handler
1289 * This function released the control handler previously obtained from'
1290 * v4l2_ctrl_request_hdl_find().
1292 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1295 media_request_object_put(&hdl->req_obj);
1299 * v4l2_ctrl_request_hdl_ctrl_find() - Find a control with the given ID.
1301 * @hdl: The control handler from the request.
1302 * @id: The ID of the control to find.
1304 * This function returns a pointer to the control if this control is
1305 * part of the request or NULL otherwise.
1308 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1310 /* Helpers for ioctl_ops */
1313 * v4l2_queryctrl - Helper function to implement
1314 * :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1316 * @hdl: pointer to &struct v4l2_ctrl_handler
1317 * @qc: pointer to &struct v4l2_queryctrl
1319 * If hdl == NULL then they will all return -EINVAL.
1321 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1324 * v4l2_query_ext_ctrl - Helper function to implement
1325 * :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1327 * @hdl: pointer to &struct v4l2_ctrl_handler
1328 * @qc: pointer to &struct v4l2_query_ext_ctrl
1330 * If hdl == NULL then they will all return -EINVAL.
1332 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1333 struct v4l2_query_ext_ctrl *qc);
1336 * v4l2_querymenu - Helper function to implement
1337 * :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1339 * @hdl: pointer to &struct v4l2_ctrl_handler
1340 * @qm: pointer to &struct v4l2_querymenu
1342 * If hdl == NULL then they will all return -EINVAL.
1344 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1347 * v4l2_g_ctrl - Helper function to implement
1348 * :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1350 * @hdl: pointer to &struct v4l2_ctrl_handler
1351 * @ctrl: pointer to &struct v4l2_control
1353 * If hdl == NULL then they will all return -EINVAL.
1355 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1358 * v4l2_s_ctrl - Helper function to implement
1359 * :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1361 * @fh: pointer to &struct v4l2_fh
1362 * @hdl: pointer to &struct v4l2_ctrl_handler
1364 * @ctrl: pointer to &struct v4l2_control
1366 * If hdl == NULL then they will all return -EINVAL.
1368 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1369 struct v4l2_control *ctrl);
1372 * v4l2_g_ext_ctrls - Helper function to implement
1373 * :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1375 * @hdl: pointer to &struct v4l2_ctrl_handler
1376 * @vdev: pointer to &struct video_device
1377 * @mdev: pointer to &struct media_device
1378 * @c: pointer to &struct v4l2_ext_controls
1380 * If hdl == NULL then they will all return -EINVAL.
1382 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1383 struct media_device *mdev, struct v4l2_ext_controls *c);
1386 * v4l2_try_ext_ctrls - Helper function to implement
1387 * :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1389 * @hdl: pointer to &struct v4l2_ctrl_handler
1390 * @vdev: pointer to &struct video_device
1391 * @mdev: pointer to &struct media_device
1392 * @c: pointer to &struct v4l2_ext_controls
1394 * If hdl == NULL then they will all return -EINVAL.
1396 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1397 struct video_device *vdev,
1398 struct media_device *mdev,
1399 struct v4l2_ext_controls *c);
1402 * v4l2_s_ext_ctrls - Helper function to implement
1403 * :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1405 * @fh: pointer to &struct v4l2_fh
1406 * @hdl: pointer to &struct v4l2_ctrl_handler
1407 * @vdev: pointer to &struct video_device
1408 * @mdev: pointer to &struct media_device
1409 * @c: pointer to &struct v4l2_ext_controls
1411 * If hdl == NULL then they will all return -EINVAL.
1413 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1414 struct video_device *vdev,
1415 struct media_device *mdev,
1416 struct v4l2_ext_controls *c);
1419 * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1420 * as a &struct v4l2_subdev_core_ops subscribe_event function
1421 * that just subscribes control events.
1423 * @sd: pointer to &struct v4l2_subdev
1424 * @fh: pointer to &struct v4l2_fh
1425 * @sub: pointer to &struct v4l2_event_subscription
1427 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1428 struct v4l2_event_subscription *sub);
1431 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1434 * @sd: pointer to &struct v4l2_subdev
1436 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1439 * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1442 * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1443 * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1444 * @p: pointer to &struct v4l2_fwnode_device_properties
1446 * This function registers controls associated to device properties, using the
1447 * property values contained in @p parameter, if the property has been set to
1450 * Currently the following v4l2 controls are parsed and registered:
1451 * - V4L2_CID_CAMERA_ORIENTATION
1452 * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1454 * Controls already registered by the caller with the @hdl control handler are
1455 * not overwritten. Callers should register the controls they want to handle
1456 * themselves before calling this function.
1458 * Return: 0 on success, a negative error code on failure.
1460 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1461 const struct v4l2_ctrl_ops *ctrl_ops,
1462 const struct v4l2_fwnode_device_properties *p);