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/mpeg2-ctrls.h>
21 #include <media/fwht-ctrls.h>
22 #include <media/h264-ctrls.h>
23 #include <media/vp8-ctrls.h>
24 #include <media/hevc-ctrls.h>
26 /* forward references */
28 struct poll_table_struct;
30 struct v4l2_ctrl_handler;
31 struct v4l2_ctrl_helper;
33 struct v4l2_fwnode_device_properties;
35 struct v4l2_subscribed_event;
39 * union v4l2_ctrl_ptr - A pointer to a control value.
40 * @p_s32: Pointer to a 32-bit signed value.
41 * @p_s64: Pointer to a 64-bit signed value.
42 * @p_u8: Pointer to a 8-bit unsigned value.
43 * @p_u16: Pointer to a 16-bit unsigned value.
44 * @p_u32: Pointer to a 32-bit unsigned value.
45 * @p_char: Pointer to a string.
46 * @p_mpeg2_slice_params: Pointer to a MPEG2 slice parameters structure.
47 * @p_mpeg2_quantization: Pointer to a MPEG2 quantization data structure.
48 * @p_fwht_params: Pointer to a FWHT stateless parameters structure.
49 * @p_h264_sps: Pointer to a struct v4l2_ctrl_h264_sps.
50 * @p_h264_pps: Pointer to a struct v4l2_ctrl_h264_pps.
51 * @p_h264_scaling_matrix: Pointer to a struct v4l2_ctrl_h264_scaling_matrix.
52 * @p_h264_slice_params: Pointer to a struct v4l2_ctrl_h264_slice_params.
53 * @p_h264_decode_params: Pointer to a struct v4l2_ctrl_h264_decode_params.
54 * @p_h264_pred_weights: Pointer to a struct v4l2_ctrl_h264_pred_weights.
55 * @p_vp8_frame_header: Pointer to a VP8 frame header structure.
56 * @p_hevc_sps: Pointer to an HEVC sequence parameter set structure.
57 * @p_hevc_pps: Pointer to an HEVC picture parameter set structure.
58 * @p_hevc_slice_params: Pointer to an HEVC slice parameters structure.
59 * @p_area: Pointer to an area.
60 * @p: Pointer to a compound value.
61 * @p_const: Pointer to a constant compound value.
70 struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
71 struct v4l2_ctrl_mpeg2_quantization *p_mpeg2_quantization;
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_header *p_vp8_frame_header;
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_area *p_area;
89 * v4l2_ctrl_ptr_create() - Helper function to return a v4l2_ctrl_ptr from a
91 * @ptr: The void pointer
93 static inline union v4l2_ctrl_ptr v4l2_ctrl_ptr_create(void *ptr)
95 union v4l2_ctrl_ptr p = { .p = ptr };
101 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
103 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
104 * for volatile (and usually read-only) controls such as a control
105 * that returns the current signal strength which changes
107 * If not set, then the currently cached value will be returned.
108 * @try_ctrl: Test whether the control's value is valid. Only relevant when
109 * the usual min/max/step checks are not sufficient.
110 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
111 * ctrl->handler->lock is held when these ops are called, so no
112 * one else can access controls owned by that handler.
114 struct v4l2_ctrl_ops {
115 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
116 int (*try_ctrl)(struct v4l2_ctrl *ctrl);
117 int (*s_ctrl)(struct v4l2_ctrl *ctrl);
121 * struct v4l2_ctrl_type_ops - The control type operations that the driver
124 * @equal: return true if both values are equal.
125 * @init: initialize the value.
126 * @log: log the value.
127 * @validate: validate the value. Return 0 on success and a negative value
130 struct v4l2_ctrl_type_ops {
131 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
132 union v4l2_ctrl_ptr ptr1,
133 union v4l2_ctrl_ptr ptr2);
134 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
135 union v4l2_ctrl_ptr ptr);
136 void (*log)(const struct v4l2_ctrl *ctrl);
137 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
138 union v4l2_ctrl_ptr ptr);
142 * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
143 * that should be called when a control value has changed.
145 * @ctrl: pointer to struct &v4l2_ctrl
146 * @priv: control private data
148 * This typedef definition is used as an argument to v4l2_ctrl_notify()
149 * and as an argument at struct &v4l2_ctrl_handler.
151 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
154 * struct v4l2_ctrl - The control structure.
156 * @node: The list node.
157 * @ev_subs: The list of control event subscriptions.
158 * @handler: The handler that owns the control.
159 * @cluster: Point to start of cluster array.
160 * @ncontrols: Number of controls in cluster array.
161 * @done: Internal flag: set for each processed control.
162 * @is_new: Set when the user specified a new value for this control. It
163 * is also set when called from v4l2_ctrl_handler_setup(). Drivers
164 * should never set this flag.
165 * @has_changed: Set when the current value differs from the new value. Drivers
166 * should never use this flag.
167 * @is_private: If set, then this control is private to its handler and it
168 * will not be added to any other handlers. Drivers can set
170 * @is_auto: If set, then this control selects whether the other cluster
171 * members are in 'automatic' mode or 'manual' mode. This is
172 * used for autogain/gain type clusters. Drivers should never
173 * set this flag directly.
174 * @is_int: If set, then this control has a simple integer value (i.e. it
176 * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
177 * @is_ptr: If set, then this control is an array and/or has type >=
178 * %V4L2_CTRL_COMPOUND_TYPES
179 * and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
180 * v4l2_ext_control uses field p to point to the data.
181 * @is_array: If set, then this control contains an N-dimensional array.
182 * @has_volatiles: If set, then one or more members of the cluster are volatile.
183 * Drivers should never touch this flag.
184 * @call_notify: If set, then call the handler's notify function whenever the
185 * control's value changes.
186 * @manual_mode_value: If the is_auto flag is set, then this is the value
187 * of the auto control that determines if that control is in
188 * manual mode. So if the value of the auto control equals this
189 * value, then the whole cluster is in manual mode. Drivers should
190 * never set this flag directly.
191 * @ops: The control ops.
192 * @type_ops: The control type ops.
193 * @id: The control ID.
194 * @name: The control name.
195 * @type: The control type.
196 * @minimum: The control's minimum value.
197 * @maximum: The control's maximum value.
198 * @default_value: The control's default value.
199 * @step: The control's step value for non-menu controls.
200 * @elems: The number of elements in the N-dimensional array.
201 * @elem_size: The size in bytes of the control.
202 * @dims: The size of each dimension.
203 * @nr_of_dims:The number of dimensions in @dims.
204 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
205 * easy to skip menu items that are not valid. If bit X is set,
206 * then menu item X is skipped. Of course, this only works for
207 * menus with <= 32 menu items. There are no menus that come
208 * close to that number, so this is OK. Should we ever need more,
209 * then this will have to be extended to a u64 or a bit array.
210 * @qmenu: A const char * array for all menu items. Array entries that are
211 * empty strings ("") correspond to non-existing menu items (this
212 * is in addition to the menu_skip_mask above). The last entry
214 * Used only if the @type is %V4L2_CTRL_TYPE_MENU.
215 * @qmenu_int: A 64-bit integer array for with integer menu items.
216 * The size of array must be equal to the menu size, e. g.:
217 * :math:`ceil(\frac{maximum - minimum}{step}) + 1`.
218 * Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
219 * @flags: The control's flags.
220 * @cur: Structure to store the current value.
221 * @cur.val: The control's current value, if the @type is represented via
222 * a u32 integer (see &enum v4l2_ctrl_type).
223 * @val: The control's new s32 value.
224 * @priv: The control's private pointer. For use by the driver. It is
225 * untouched by the control framework. Note that this pointer is
226 * not freed when the control is deleted. Should this be needed
227 * then a new internal bitfield can be added to tell the framework
228 * to free this pointer.
229 * @p_def: The control's default value represented via a union which
230 * provides a standard way of accessing control types
231 * through a pointer (for compound controls only).
232 * @p_cur: The control's current value represented via a union which
233 * provides a standard way of accessing control types
235 * @p_new: The control's new value represented via a union which provides
236 * a standard way of accessing control types
240 /* Administrative fields */
241 struct list_head node;
242 struct list_head ev_subs;
243 struct v4l2_ctrl_handler *handler;
244 struct v4l2_ctrl **cluster;
245 unsigned int ncontrols;
249 unsigned int is_new:1;
250 unsigned int has_changed:1;
251 unsigned int is_private:1;
252 unsigned int is_auto:1;
253 unsigned int is_int:1;
254 unsigned int is_string:1;
255 unsigned int is_ptr:1;
256 unsigned int is_array:1;
257 unsigned int has_volatiles:1;
258 unsigned int call_notify:1;
259 unsigned int manual_mode_value:8;
261 const struct v4l2_ctrl_ops *ops;
262 const struct v4l2_ctrl_type_ops *type_ops;
265 enum v4l2_ctrl_type type;
266 s64 minimum, maximum, default_value;
269 u32 dims[V4L2_CTRL_MAX_DIMS];
276 const char * const *qmenu;
277 const s64 *qmenu_int;
286 union v4l2_ctrl_ptr p_def;
287 union v4l2_ctrl_ptr p_new;
288 union v4l2_ctrl_ptr p_cur;
292 * struct v4l2_ctrl_ref - The control reference.
294 * @node: List node for the sorted list.
295 * @next: Single-link list node for the hash.
296 * @ctrl: The actual control information.
297 * @helper: Pointer to helper struct. Used internally in
298 * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
299 * @from_other_dev: If true, then @ctrl was defined in another
300 * device than the &struct v4l2_ctrl_handler.
301 * @req_done: Internal flag: if the control handler containing this control
302 * reference is bound to a media request, then this is set when
303 * the control has been applied. This prevents applying controls
304 * from a cluster with multiple controls twice (when the first
305 * control of a cluster is applied, they all are).
306 * @valid_p_req: If set, then p_req contains the control value for the request.
307 * @p_req: If the control handler containing this control reference
308 * is bound to a media request, then this points to the
309 * value of the control that must be applied when the request
310 * is executed, or to the value of the control at the time
311 * that the request was completed. If @valid_p_req is false,
312 * then this control was never set for this request and the
313 * control will not be updated when this request is applied.
315 * Each control handler has a list of these refs. The list_head is used to
316 * keep a sorted-by-control-ID list of all controls, while the next pointer
317 * is used to link the control in the hash's bucket.
319 struct v4l2_ctrl_ref {
320 struct list_head node;
321 struct v4l2_ctrl_ref *next;
322 struct v4l2_ctrl *ctrl;
323 struct v4l2_ctrl_helper *helper;
327 union v4l2_ctrl_ptr p_req;
331 * struct v4l2_ctrl_handler - The control handler keeps track of all the
332 * controls: both the controls owned by the handler and those inherited
333 * from other handlers.
335 * @_lock: Default for "lock".
336 * @lock: Lock to control access to this handler and its controls.
337 * May be replaced by the user right after init.
338 * @ctrls: The list of controls owned by this handler.
339 * @ctrl_refs: The list of control references.
340 * @cached: The last found control reference. It is common that the same
341 * control is needed multiple times, so this is a simple
343 * @buckets: Buckets for the hashing. Allows for quick control lookup.
344 * @notify: A notify callback that is called whenever the control changes
346 * Note that the handler's lock is held when the notify function
348 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
349 * @nr_of_buckets: Total number of buckets in the array.
350 * @error: The error code of the first failed control addition.
351 * @request_is_queued: True if the request was queued.
352 * @requests: List to keep track of open control handler request objects.
353 * For the parent control handler (@req_obj.ops == NULL) this
354 * is the list header. When the parent control handler is
355 * removed, it has to unbind and put all these requests since
356 * they refer to the parent.
357 * @requests_queued: List of the queued requests. This determines the order
358 * in which these controls are applied. Once the request is
359 * completed it is removed from this list.
360 * @req_obj: The &struct media_request_object, used to link into a
361 * &struct media_request. This request object has a refcount.
363 struct v4l2_ctrl_handler {
366 struct list_head ctrls;
367 struct list_head ctrl_refs;
368 struct v4l2_ctrl_ref *cached;
369 struct v4l2_ctrl_ref **buckets;
370 v4l2_ctrl_notify_fnc notify;
374 bool request_is_queued;
375 struct list_head requests;
376 struct list_head requests_queued;
377 struct media_request_object req_obj;
381 * struct v4l2_ctrl_config - Control configuration structure.
383 * @ops: The control ops.
384 * @type_ops: The control type ops. Only needed for compound controls.
385 * @id: The control ID.
386 * @name: The control name.
387 * @type: The control type.
388 * @min: The control's minimum value.
389 * @max: The control's maximum value.
390 * @step: The control's step value for non-menu controls.
391 * @def: The control's default value.
392 * @p_def: The control's default value for compound controls.
393 * @dims: The size of each dimension.
394 * @elem_size: The size in bytes of the control.
395 * @flags: The control's flags.
396 * @menu_skip_mask: The control's skip mask for menu controls. This makes it
397 * easy to skip menu items that are not valid. If bit X is set,
398 * then menu item X is skipped. Of course, this only works for
399 * menus with <= 64 menu items. There are no menus that come
400 * close to that number, so this is OK. Should we ever need more,
401 * then this will have to be extended to a bit array.
402 * @qmenu: A const char * array for all menu items. Array entries that are
403 * empty strings ("") correspond to non-existing menu items (this
404 * is in addition to the menu_skip_mask above). The last entry
406 * @qmenu_int: A const s64 integer array for all menu items of the type
407 * V4L2_CTRL_TYPE_INTEGER_MENU.
408 * @is_private: If set, then this control is private to its handler and it
409 * will not be added to any other handlers.
411 struct v4l2_ctrl_config {
412 const struct v4l2_ctrl_ops *ops;
413 const struct v4l2_ctrl_type_ops *type_ops;
416 enum v4l2_ctrl_type type;
421 union v4l2_ctrl_ptr p_def;
422 u32 dims[V4L2_CTRL_MAX_DIMS];
426 const char * const *qmenu;
427 const s64 *qmenu_int;
428 unsigned int is_private:1;
432 * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
434 * @id: ID of the control
435 * @name: pointer to be filled with a string with the name of the control
436 * @type: pointer for storing the type of the control
437 * @min: pointer for storing the minimum value for the control
438 * @max: pointer for storing the maximum value for the control
439 * @step: pointer for storing the control step
440 * @def: pointer for storing the default value for the control
441 * @flags: pointer for storing the flags to be used on the control
443 * This works for all standard V4L2 controls.
444 * For non-standard controls it will only fill in the given arguments
445 * and @name content will be set to %NULL.
447 * This function will overwrite the contents of @name, @type and @flags.
448 * The contents of @min, @max, @step and @def may be modified depending on
453 * Do not use in drivers! It is used internally for backwards compatibility
454 * control handling only. Once all drivers are converted to use the new
455 * control framework this function will no longer be exported.
457 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
458 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
462 * v4l2_ctrl_handler_init_class() - Initialize the control handler.
463 * @hdl: The control handler.
464 * @nr_of_controls_hint: A hint of how many controls this handler is
465 * expected to refer to. This is the total number, so including
466 * any inherited controls. It doesn't have to be precise, but if
467 * it is way off, then you either waste memory (too many buckets
468 * are allocated) or the control lookup becomes slower (not enough
469 * buckets are allocated, so there are more slow list lookups).
470 * It will always work, though.
471 * @key: Used by the lock validator if CONFIG_LOCKDEP is set.
472 * @name: Used by the lock validator if CONFIG_LOCKDEP is set.
476 * Never use this call directly, always use the v4l2_ctrl_handler_init()
477 * macro that hides the @key and @name arguments.
479 * Return: returns an error if the buckets could not be allocated. This
480 * error will also be stored in @hdl->error.
482 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
483 unsigned int nr_of_controls_hint,
484 struct lock_class_key *key, const char *name);
486 #ifdef CONFIG_LOCKDEP
489 * v4l2_ctrl_handler_init - helper function to create a static struct
490 * &lock_class_key and calls v4l2_ctrl_handler_init_class()
492 * @hdl: The control handler.
493 * @nr_of_controls_hint: A hint of how many controls this handler is
494 * expected to refer to. This is the total number, so including
495 * any inherited controls. It doesn't have to be precise, but if
496 * it is way off, then you either waste memory (too many buckets
497 * are allocated) or the control lookup becomes slower (not enough
498 * buckets are allocated, so there are more slow list lookups).
499 * It will always work, though.
501 * This helper function creates a static struct &lock_class_key and
502 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
505 * Use this helper function to initialize a control handler.
507 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
510 static struct lock_class_key _key; \
511 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \
513 KBUILD_BASENAME ":" \
514 __stringify(__LINE__) ":" \
515 "(" #hdl ")->_lock"); \
519 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \
520 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
524 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
526 * @hdl: The control handler.
528 * Does nothing if @hdl == NULL.
530 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
533 * v4l2_ctrl_lock() - Helper function to lock the handler
534 * associated with the control.
535 * @ctrl: The control to lock.
537 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
539 mutex_lock(ctrl->handler->lock);
543 * v4l2_ctrl_unlock() - Helper function to unlock the handler
544 * associated with the control.
545 * @ctrl: The control to unlock.
547 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
549 mutex_unlock(ctrl->handler->lock);
553 * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
554 * to the handler to initialize the hardware to the current control values. The
555 * caller is responsible for acquiring the control handler mutex on behalf of
556 * __v4l2_ctrl_handler_setup().
557 * @hdl: The control handler.
559 * Button controls will be skipped, as are read-only controls.
561 * If @hdl == NULL, then this just returns 0.
563 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
566 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
567 * to the handler to initialize the hardware to the current control values.
568 * @hdl: The control handler.
570 * Button controls will be skipped, as are read-only controls.
572 * If @hdl == NULL, then this just returns 0.
574 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
577 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
578 * @hdl: The control handler.
579 * @prefix: The prefix to use when logging the control values. If the
580 * prefix does not end with a space, then ": " will be added
581 * after the prefix. If @prefix == NULL, then no prefix will be
584 * For use with VIDIOC_LOG_STATUS.
586 * Does nothing if @hdl == NULL.
588 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
592 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
595 * @hdl: The control handler.
596 * @cfg: The control's configuration data.
597 * @priv: The control's driver-specific private data.
599 * If the &v4l2_ctrl struct could not be allocated then NULL is returned
600 * and @hdl->error is set to the error code (if it wasn't set already).
602 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
603 const struct v4l2_ctrl_config *cfg,
607 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
610 * @hdl: The control handler.
611 * @ops: The control ops.
612 * @id: The control ID.
613 * @min: The control's minimum value.
614 * @max: The control's maximum value.
615 * @step: The control's step value
616 * @def: The control's default value.
618 * If the &v4l2_ctrl struct could not be allocated, or the control
619 * ID is not known, then NULL is returned and @hdl->error is set to the
620 * appropriate error code (if it wasn't set already).
622 * If @id refers to a menu control, then this function will return NULL.
624 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
626 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
627 const struct v4l2_ctrl_ops *ops,
628 u32 id, s64 min, s64 max, u64 step,
632 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
635 * @hdl: The control handler.
636 * @ops: The control ops.
637 * @id: The control ID.
638 * @max: The control's maximum value.
639 * @mask: The control's skip mask for menu controls. This makes it
640 * easy to skip menu items that are not valid. If bit X is set,
641 * then menu item X is skipped. Of course, this only works for
642 * menus with <= 64 menu items. There are no menus that come
643 * close to that number, so this is OK. Should we ever need more,
644 * then this will have to be extended to a bit array.
645 * @def: The control's default value.
647 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
648 * determines which menu items are to be skipped.
650 * If @id refers to a non-menu control, then this function will return NULL.
652 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
653 const struct v4l2_ctrl_ops *ops,
654 u32 id, u8 max, u64 mask, u8 def);
657 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
658 * with driver specific menu.
660 * @hdl: The control handler.
661 * @ops: The control ops.
662 * @id: The control ID.
663 * @max: The control's maximum value.
664 * @mask: The control's skip mask for menu controls. This makes it
665 * easy to skip menu items that are not valid. If bit X is set,
666 * then menu item X is skipped. Of course, this only works for
667 * menus with <= 64 menu items. There are no menus that come
668 * close to that number, so this is OK. Should we ever need more,
669 * then this will have to be extended to a bit array.
670 * @def: The control's default value.
671 * @qmenu: The new menu.
673 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
674 * menu of this control.
677 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
678 const struct v4l2_ctrl_ops *ops,
681 const char * const *qmenu);
684 * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
687 * @hdl: The control handler.
688 * @ops: The control ops.
689 * @id: The control ID.
690 * @p_def: The control's default value.
692 * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
693 * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
694 * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
695 * compound control should be all zeroes.
698 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
699 const struct v4l2_ctrl_ops *ops,
701 const union v4l2_ctrl_ptr p_def);
704 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
706 * @hdl: The control handler.
707 * @ops: The control ops.
708 * @id: The control ID.
709 * @max: The control's maximum value.
710 * @def: The control's default value.
711 * @qmenu_int: The control's menu entries.
713 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
714 * takes as an argument an array of integers determining the menu items.
716 * If @id refers to a non-integer-menu control, then this function will
719 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
720 const struct v4l2_ctrl_ops *ops,
721 u32 id, u8 max, u8 def,
722 const s64 *qmenu_int);
725 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
726 * used when adding a control handler.
728 * @ctrl: pointer to struct &v4l2_ctrl.
731 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
734 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
737 * @hdl: The control handler.
738 * @add: The control handler whose controls you want to add to
739 * the @hdl control handler.
740 * @filter: This function will filter which controls should be added.
741 * @from_other_dev: If true, then the controls in @add were defined in another
744 * Does nothing if either of the two handlers is a NULL pointer.
745 * If @filter is NULL, then all controls are added. Otherwise only those
746 * controls for which @filter returns true will be added.
747 * In case of an error @hdl->error will be set to the error code (if it
748 * wasn't set already).
750 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
751 struct v4l2_ctrl_handler *add,
752 v4l2_ctrl_filter filter,
753 bool from_other_dev);
756 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
758 * @ctrl: The control that is filtered.
760 * This will return true for any controls that are valid for radio device
761 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
762 * transmitter class controls.
764 * This function is to be used with v4l2_ctrl_add_handler().
766 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
769 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
772 * @ncontrols: The number of controls in this cluster.
773 * @controls: The cluster control array of size @ncontrols.
775 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
779 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
780 * to that cluster and set it up for autofoo/foo-type handling.
782 * @ncontrols: The number of controls in this cluster.
783 * @controls: The cluster control array of size @ncontrols. The first control
784 * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
785 * @manual_val: The value for the first control in the cluster that equals the
787 * @set_volatile: If true, then all controls except the first auto control will
790 * Use for control groups where one control selects some automatic feature and
791 * the other controls are only active whenever the automatic feature is turned
792 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
793 * red and blue balance, etc.
795 * The behavior of such controls is as follows:
797 * When the autofoo control is set to automatic, then any manual controls
798 * are set to inactive and any reads will call g_volatile_ctrl (if the control
799 * was marked volatile).
801 * When the autofoo control is set to manual, then any manual controls will
802 * be marked active, and any reads will just return the current value without
803 * going through g_volatile_ctrl.
805 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
806 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
807 * if autofoo is in auto mode.
809 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
810 struct v4l2_ctrl **controls,
811 u8 manual_val, bool set_volatile);
815 * v4l2_ctrl_find() - Find a control with the given ID.
817 * @hdl: The control handler.
818 * @id: The control ID to find.
820 * If @hdl == NULL this will return NULL as well. Will lock the handler so
821 * do not use from inside &v4l2_ctrl_ops.
823 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
826 * v4l2_ctrl_activate() - Make the control active or inactive.
827 * @ctrl: The control to (de)activate.
828 * @active: True if the control should become active.
830 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
831 * Does nothing if @ctrl == NULL.
832 * This will usually be called from within the s_ctrl op.
833 * The V4L2_EVENT_CTRL event will be generated afterwards.
835 * This function assumes that the control handler is locked.
837 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
840 * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
842 * @ctrl: The control to (de)activate.
843 * @grabbed: True if the control should become grabbed.
845 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
846 * Does nothing if @ctrl == NULL.
847 * The V4L2_EVENT_CTRL event will be generated afterwards.
848 * This will usually be called when starting or stopping streaming in the
851 * This function assumes that the control handler is locked by the caller.
853 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
856 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
858 * @ctrl: The control to (de)activate.
859 * @grabbed: True if the control should become grabbed.
861 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
862 * Does nothing if @ctrl == NULL.
863 * The V4L2_EVENT_CTRL event will be generated afterwards.
864 * This will usually be called when starting or stopping streaming in the
867 * This function assumes that the control handler is not locked and will
868 * take the lock itself.
870 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
875 v4l2_ctrl_lock(ctrl);
876 __v4l2_ctrl_grab(ctrl, grabbed);
877 v4l2_ctrl_unlock(ctrl);
881 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
883 * @ctrl: The control to update.
884 * @min: The control's minimum value.
885 * @max: The control's maximum value.
886 * @step: The control's step value
887 * @def: The control's default value.
889 * Update the range of a control on the fly. This works for control types
890 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
891 * @step value is interpreted as a menu_skip_mask.
893 * An error is returned if one of the range arguments is invalid for this
896 * The caller is responsible for acquiring the control handler mutex on behalf
897 * of __v4l2_ctrl_modify_range().
899 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
900 s64 min, s64 max, u64 step, s64 def);
903 * v4l2_ctrl_modify_range() - Update the range of a control.
905 * @ctrl: The control to update.
906 * @min: The control's minimum value.
907 * @max: The control's maximum value.
908 * @step: The control's step value
909 * @def: The control's default value.
911 * Update the range of a control on the fly. This works for control types
912 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
913 * @step value is interpreted as a menu_skip_mask.
915 * An error is returned if one of the range arguments is invalid for this
918 * This function assumes that the control handler is not locked and will
919 * take the lock itself.
921 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
922 s64 min, s64 max, u64 step, s64 def)
926 v4l2_ctrl_lock(ctrl);
927 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
928 v4l2_ctrl_unlock(ctrl);
934 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
936 * @ctrl: The control.
937 * @notify: The callback function.
938 * @priv: The callback private handle, passed as argument to the callback.
940 * This function sets a callback function for the control. If @ctrl is NULL,
941 * then it will do nothing. If @notify is NULL, then the notify callback will
944 * There can be only one notify. If another already exists, then a WARN_ON
945 * will be issued and the function will do nothing.
947 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
951 * v4l2_ctrl_get_name() - Get the name of the control
953 * @id: The control ID.
955 * This function returns the name of the given control ID or NULL if it isn't
958 const char *v4l2_ctrl_get_name(u32 id);
961 * v4l2_ctrl_get_menu() - Get the menu string array of the control
963 * @id: The control ID.
965 * This function returns the NULL-terminated menu string array name of the
966 * given control ID or NULL if it isn't a known menu control.
968 const char * const *v4l2_ctrl_get_menu(u32 id);
971 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
973 * @id: The control ID.
974 * @len: The size of the integer array.
976 * This function returns the integer array of the given control ID or NULL if it
977 * if it isn't a known integer menu control.
979 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
982 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
985 * @ctrl: The control.
987 * This returns the control's value safely by going through the control
988 * framework. This function will lock the control's handler, so it cannot be
989 * used from within the &v4l2_ctrl_ops functions.
991 * This function is for integer type controls only.
993 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
996 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
998 * @ctrl: The control.
999 * @val: The new value.
1001 * This sets the control's new value safely by going through the control
1002 * framework. This function assumes the control's handler is already locked,
1003 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1005 * This function is for integer type controls only.
1007 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1010 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1012 * @ctrl: The control.
1013 * @val: The new value.
1015 * This sets the control's new value safely by going through the control
1016 * framework. This function will lock the control's handler, so it cannot be
1017 * used from within the &v4l2_ctrl_ops functions.
1019 * This function is for integer type controls only.
1021 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1025 v4l2_ctrl_lock(ctrl);
1026 rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1027 v4l2_ctrl_unlock(ctrl);
1033 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1034 * from within a driver.
1036 * @ctrl: The control.
1038 * This returns the control's value safely by going through the control
1039 * framework. This function will lock the control's handler, so it cannot be
1040 * used from within the &v4l2_ctrl_ops functions.
1042 * This function is for 64-bit integer type controls only.
1044 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1047 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1049 * @ctrl: The control.
1050 * @val: The new value.
1052 * This sets the control's new value safely by going through the control
1053 * framework. This function assumes the control's handler is already locked,
1054 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1056 * This function is for 64-bit integer type controls only.
1058 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1061 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1062 * from within a driver.
1064 * @ctrl: The control.
1065 * @val: The new value.
1067 * This sets the control's new value safely by going through the control
1068 * framework. This function will lock the control's handler, so it cannot be
1069 * used from within the &v4l2_ctrl_ops functions.
1071 * This function is for 64-bit integer type controls only.
1073 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1077 v4l2_ctrl_lock(ctrl);
1078 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1079 v4l2_ctrl_unlock(ctrl);
1085 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1087 * @ctrl: The control.
1088 * @s: The new string.
1090 * This sets the control's new string safely by going through the control
1091 * framework. This function assumes the control's handler is already locked,
1092 * allowing it to be used from within the &v4l2_ctrl_ops functions.
1094 * This function is for string type controls only.
1096 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1099 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1100 * from within a driver.
1102 * @ctrl: The control.
1103 * @s: The new string.
1105 * This sets the control's new string safely by going through the control
1106 * framework. This function will lock the control's handler, so it cannot be
1107 * used from within the &v4l2_ctrl_ops functions.
1109 * This function is for string type controls only.
1111 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1115 v4l2_ctrl_lock(ctrl);
1116 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1117 v4l2_ctrl_unlock(ctrl);
1123 * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1125 * @ctrl: The control.
1126 * @type: The type of the data.
1127 * @p: The new compound payload.
1129 * This sets the control's new compound payload safely by going through the
1130 * control framework. This function assumes the control's handler is already
1131 * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1133 * This function is for compound type controls only.
1135 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1136 enum v4l2_ctrl_type type, const void *p);
1139 * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1140 * from within a driver.
1142 * @ctrl: The control.
1143 * @type: The type of the data.
1144 * @p: The new compound payload.
1146 * This sets the control's new compound payload safely by going through the
1147 * control framework. This function will lock the control's handler, so it
1148 * cannot be used from within the &v4l2_ctrl_ops functions.
1150 * This function is for compound type controls only.
1152 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1153 enum v4l2_ctrl_type type,
1158 v4l2_ctrl_lock(ctrl);
1159 rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1160 v4l2_ctrl_unlock(ctrl);
1165 /* Helper defines for area type controls */
1166 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1167 __v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1168 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1169 v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1171 /* Internal helper functions that deal with control events. */
1172 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1175 * v4l2_ctrl_replace - Function to be used as a callback to
1176 * &struct v4l2_subscribed_event_ops replace\(\)
1178 * @old: pointer to struct &v4l2_event with the reported
1180 * @new: pointer to struct &v4l2_event with the modified
1183 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1186 * v4l2_ctrl_merge - Function to be used as a callback to
1187 * &struct v4l2_subscribed_event_ops merge(\)
1189 * @old: pointer to struct &v4l2_event with the reported
1191 * @new: pointer to struct &v4l2_event with the merged
1194 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1197 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1199 * @file: pointer to struct file
1200 * @fh: unused. Kept just to be compatible to the arguments expected by
1201 * &struct v4l2_ioctl_ops.vidioc_log_status.
1203 * Can be used as a vidioc_log_status function that just dumps all controls
1204 * associated with the filehandle.
1206 int v4l2_ctrl_log_status(struct file *file, void *fh);
1209 * v4l2_ctrl_subscribe_event - Subscribes to an event
1212 * @fh: pointer to struct v4l2_fh
1213 * @sub: pointer to &struct v4l2_event_subscription
1215 * Can be used as a vidioc_subscribe_event function that just subscribes
1218 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1219 const struct v4l2_event_subscription *sub);
1222 * v4l2_ctrl_poll - function to be used as a callback to the poll()
1223 * That just polls for control events.
1225 * @file: pointer to struct file
1226 * @wait: pointer to struct poll_table_struct
1228 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1231 * v4l2_ctrl_request_setup - helper function to apply control values in a request
1234 * @parent: The parent control handler ('priv' in media_request_object_find())
1236 * This is a helper function to call the control handler's s_ctrl callback with
1237 * the control values contained in the request. Do note that this approach of
1238 * applying control values in a request is only applicable to memory-to-memory
1241 int v4l2_ctrl_request_setup(struct media_request *req,
1242 struct v4l2_ctrl_handler *parent);
1245 * v4l2_ctrl_request_complete - Complete a control handler request object
1248 * @parent: The parent control handler ('priv' in media_request_object_find())
1250 * This function is to be called on each control handler that may have had a
1251 * request object associated with it, i.e. control handlers of a driver that
1252 * supports requests.
1254 * The function first obtains the values of any volatile controls in the control
1255 * handler and attach them to the request. Then, the function completes the
1258 void v4l2_ctrl_request_complete(struct media_request *req,
1259 struct v4l2_ctrl_handler *parent);
1262 * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1265 * @parent: The parent control handler ('priv' in media_request_object_find())
1267 * This function finds the control handler in the request. It may return
1268 * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1269 * with the returned handler pointer.
1271 * If the request is not in state VALIDATING or QUEUED, then this function
1272 * will always return NULL.
1274 * Note that in state VALIDATING the req_queue_mutex is held, so
1275 * no objects can be added or deleted from the request.
1277 * In state QUEUED it is the driver that will have to ensure this.
1279 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1280 struct v4l2_ctrl_handler *parent);
1283 * v4l2_ctrl_request_hdl_put - Put the control handler
1285 * @hdl: Put this control handler
1287 * This function released the control handler previously obtained from'
1288 * v4l2_ctrl_request_hdl_find().
1290 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1293 media_request_object_put(&hdl->req_obj);
1297 * v4l2_ctrl_request_ctrl_find() - Find a control with the given ID.
1299 * @hdl: The control handler from the request.
1300 * @id: The ID of the control to find.
1302 * This function returns a pointer to the control if this control is
1303 * part of the request or NULL otherwise.
1306 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1308 /* Helpers for ioctl_ops */
1311 * v4l2_queryctrl - Helper function to implement
1312 * :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1314 * @hdl: pointer to &struct v4l2_ctrl_handler
1315 * @qc: pointer to &struct v4l2_queryctrl
1317 * If hdl == NULL then they will all return -EINVAL.
1319 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1322 * v4l2_query_ext_ctrl - Helper function to implement
1323 * :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1325 * @hdl: pointer to &struct v4l2_ctrl_handler
1326 * @qc: pointer to &struct v4l2_query_ext_ctrl
1328 * If hdl == NULL then they will all return -EINVAL.
1330 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1331 struct v4l2_query_ext_ctrl *qc);
1334 * v4l2_querymenu - Helper function to implement
1335 * :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1337 * @hdl: pointer to &struct v4l2_ctrl_handler
1338 * @qm: pointer to &struct v4l2_querymenu
1340 * If hdl == NULL then they will all return -EINVAL.
1342 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1345 * v4l2_g_ctrl - Helper function to implement
1346 * :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1348 * @hdl: pointer to &struct v4l2_ctrl_handler
1349 * @ctrl: pointer to &struct v4l2_control
1351 * If hdl == NULL then they will all return -EINVAL.
1353 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1356 * v4l2_s_ctrl - Helper function to implement
1357 * :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1359 * @fh: pointer to &struct v4l2_fh
1360 * @hdl: pointer to &struct v4l2_ctrl_handler
1362 * @ctrl: pointer to &struct v4l2_control
1364 * If hdl == NULL then they will all return -EINVAL.
1366 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1367 struct v4l2_control *ctrl);
1370 * v4l2_g_ext_ctrls - Helper function to implement
1371 * :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1373 * @hdl: pointer to &struct v4l2_ctrl_handler
1374 * @vdev: pointer to &struct video_device
1375 * @mdev: pointer to &struct media_device
1376 * @c: pointer to &struct v4l2_ext_controls
1378 * If hdl == NULL then they will all return -EINVAL.
1380 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1381 struct media_device *mdev, struct v4l2_ext_controls *c);
1384 * v4l2_try_ext_ctrls - Helper function to implement
1385 * :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1387 * @hdl: pointer to &struct v4l2_ctrl_handler
1388 * @vdev: pointer to &struct video_device
1389 * @mdev: pointer to &struct media_device
1390 * @c: pointer to &struct v4l2_ext_controls
1392 * If hdl == NULL then they will all return -EINVAL.
1394 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1395 struct video_device *vdev,
1396 struct media_device *mdev,
1397 struct v4l2_ext_controls *c);
1400 * v4l2_s_ext_ctrls - Helper function to implement
1401 * :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1403 * @fh: pointer to &struct v4l2_fh
1404 * @hdl: pointer to &struct v4l2_ctrl_handler
1405 * @vdev: pointer to &struct video_device
1406 * @mdev: pointer to &struct media_device
1407 * @c: pointer to &struct v4l2_ext_controls
1409 * If hdl == NULL then they will all return -EINVAL.
1411 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1412 struct video_device *vdev,
1413 struct media_device *mdev,
1414 struct v4l2_ext_controls *c);
1417 * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1418 * as a &struct v4l2_subdev_core_ops subscribe_event function
1419 * that just subscribes control events.
1421 * @sd: pointer to &struct v4l2_subdev
1422 * @fh: pointer to &struct v4l2_fh
1423 * @sub: pointer to &struct v4l2_event_subscription
1425 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1426 struct v4l2_event_subscription *sub);
1429 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1432 * @sd: pointer to &struct v4l2_subdev
1434 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1437 * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1440 * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1441 * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1442 * @p: pointer to &struct v4l2_fwnode_device_properties
1444 * This function registers controls associated to device properties, using the
1445 * property values contained in @p parameter, if the property has been set to
1448 * Currently the following v4l2 controls are parsed and registered:
1449 * - V4L2_CID_CAMERA_ORIENTATION
1450 * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1452 * Controls already registered by the caller with the @hdl control handler are
1453 * not overwritten. Callers should register the controls they want to handle
1454 * themselves before calling this function.
1456 * Return: 0 on success, a negative error code on failure.
1458 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1459 const struct v4l2_ctrl_ops *ctrl_ops,
1460 const struct v4l2_fwnode_device_properties *p);