1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 *  V4L2 controls support header.
4 *
5 *  Copyright (C) 2010  Hans Verkuil <hverkuil@xs4all.nl>
6 */
7
8#ifndef _V4L2_CTRLS_H
9#define _V4L2_CTRLS_H
10
11#include <linux/list.h>
12#include <linux/mutex.h>
13#include <linux/videodev2.h>
14#include <media/media-request.h>
15
16/*
17 * Include the stateless codec compound control definitions.
18 * This will move to the public headers once this API is fully stable.
19 */
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>
25
26/* forward references */
27struct file;
28struct poll_table_struct;
29struct v4l2_ctrl;
30struct v4l2_ctrl_handler;
31struct v4l2_ctrl_helper;
32struct v4l2_fh;
33struct v4l2_fwnode_device_properties;
34struct v4l2_subdev;
35struct v4l2_subscribed_event;
36struct video_device;
37
38/**
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.
62 */
63union v4l2_ctrl_ptr {
64	s32 *p_s32;
65	s64 *p_s64;
66	u8 *p_u8;
67	u16 *p_u16;
68	u32 *p_u32;
69	char *p_char;
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;
84	void *p;
85	const void *p_const;
86};
87
88/**
89 * v4l2_ctrl_ptr_create() - Helper function to return a v4l2_ctrl_ptr from a
90 * void pointer
91 * @ptr:	The void pointer
92 */
93static inline union v4l2_ctrl_ptr v4l2_ctrl_ptr_create(void *ptr)
94{
95	union v4l2_ctrl_ptr p = { .p = ptr };
96
97	return p;
98}
99
100/**
101 * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
102 *
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
106 *		continuously.
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.
113 */
114struct 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);
118};
119
120/**
121 * struct v4l2_ctrl_type_ops - The control type operations that the driver
122 *			       has to provide.
123 *
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
128 *	otherwise.
129 */
130struct 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);
139};
140
141/**
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.
144 *
145 * @ctrl: pointer to struct &v4l2_ctrl
146 * @priv: control private data
147 *
148 * This typedef definition is used as an argument to v4l2_ctrl_notify()
149 * and as an argument at struct &v4l2_ctrl_handler.
150 */
151typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
152
153/**
154 * struct v4l2_ctrl - The control structure.
155 *
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
169 *		this flag.
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
175 *		uses ctrl->val).
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
213 *		must be NULL.
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
234 *		through a pointer.
235 * @p_new:	The control's new value represented via a union which provides
236 *		a standard way of accessing control types
237 *		through a pointer.
238 */
239struct v4l2_ctrl {
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;
246
247	unsigned int done:1;
248
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;
260
261	const struct v4l2_ctrl_ops *ops;
262	const struct v4l2_ctrl_type_ops *type_ops;
263	u32 id;
264	const char *name;
265	enum v4l2_ctrl_type type;
266	s64 minimum, maximum, default_value;
267	u32 elems;
268	u32 elem_size;
269	u32 dims[V4L2_CTRL_MAX_DIMS];
270	u32 nr_of_dims;
271	union {
272		u64 step;
273		u64 menu_skip_mask;
274	};
275	union {
276		const char * const *qmenu;
277		const s64 *qmenu_int;
278	};
279	unsigned long flags;
280	void *priv;
281	s32 val;
282	struct {
283		s32 val;
284	} cur;
285
286	union v4l2_ctrl_ptr p_def;
287	union v4l2_ctrl_ptr p_new;
288	union v4l2_ctrl_ptr p_cur;
289};
290
291/**
292 * struct v4l2_ctrl_ref - The control reference.
293 *
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.
314 *
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.
318 */
319struct 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;
324	bool from_other_dev;
325	bool req_done;
326	bool valid_p_req;
327	union v4l2_ctrl_ptr p_req;
328};
329
330/**
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.
334 *
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
342 *		optimization.
343 * @buckets:	Buckets for the hashing. Allows for quick control lookup.
344 * @notify:	A notify callback that is called whenever the control changes
345 *		value.
346 *		Note that the handler's lock is held when the notify function
347 *		is called!
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.
362 */
363struct v4l2_ctrl_handler {
364	struct mutex _lock;
365	struct mutex *lock;
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;
371	void *notify_priv;
372	u16 nr_of_buckets;
373	int error;
374	bool request_is_queued;
375	struct list_head requests;
376	struct list_head requests_queued;
377	struct media_request_object req_obj;
378};
379
380/**
381 * struct v4l2_ctrl_config - Control configuration structure.
382 *
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
405 *		must be NULL.
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.
410 */
411struct v4l2_ctrl_config {
412	const struct v4l2_ctrl_ops *ops;
413	const struct v4l2_ctrl_type_ops *type_ops;
414	u32 id;
415	const char *name;
416	enum v4l2_ctrl_type type;
417	s64 min;
418	s64 max;
419	u64 step;
420	s64 def;
421	union v4l2_ctrl_ptr p_def;
422	u32 dims[V4L2_CTRL_MAX_DIMS];
423	u32 elem_size;
424	u32 flags;
425	u64 menu_skip_mask;
426	const char * const *qmenu;
427	const s64 *qmenu_int;
428	unsigned int is_private:1;
429};
430
431/**
432 * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
433 *
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
442 *
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.
446 *
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
449 * the type.
450 *
451 * .. note::
452 *
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.
456 */
457void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
458		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
459
460
461/**
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.
473 *
474 * .. attention::
475 *
476 *    Never use this call directly, always use the v4l2_ctrl_handler_init()
477 *    macro that hides the @key and @name arguments.
478 *
479 * Return: returns an error if the buckets could not be allocated. This
480 * error will also be stored in @hdl->error.
481 */
482int 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);
485
486#ifdef CONFIG_LOCKDEP
487
488/**
489 * v4l2_ctrl_handler_init - helper function to create a static struct
490 *	 &lock_class_key and calls v4l2_ctrl_handler_init_class()
491 *
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.
500 *
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
503 * validador.
504 *
505 * Use this helper function to initialize a control handler.
506 */
507#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
508(									\
509	({								\
510		static struct lock_class_key _key;			\
511		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
512					&_key,				\
513					KBUILD_BASENAME ":"		\
514					__stringify(__LINE__) ":"	\
515					"(" #hdl ")->_lock");		\
516	})								\
517)
518#else
519#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
520	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
521#endif
522
523/**
524 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
525 * the control list.
526 * @hdl:	The control handler.
527 *
528 * Does nothing if @hdl == NULL.
529 */
530void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
531
532/**
533 * v4l2_ctrl_lock() - Helper function to lock the handler
534 * associated with the control.
535 * @ctrl:	The control to lock.
536 */
537static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
538{
539	mutex_lock(ctrl->handler->lock);
540}
541
542/**
543 * v4l2_ctrl_unlock() - Helper function to unlock the handler
544 * associated with the control.
545 * @ctrl:	The control to unlock.
546 */
547static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
548{
549	mutex_unlock(ctrl->handler->lock);
550}
551
552/**
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.
558 *
559 * Button controls will be skipped, as are read-only controls.
560 *
561 * If @hdl == NULL, then this just returns 0.
562 */
563int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
564
565/**
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.
569 *
570 * Button controls will be skipped, as are read-only controls.
571 *
572 * If @hdl == NULL, then this just returns 0.
573 */
574int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
575
576/**
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
582 *		used.
583 *
584 * For use with VIDIOC_LOG_STATUS.
585 *
586 * Does nothing if @hdl == NULL.
587 */
588void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
589				  const char *prefix);
590
591/**
592 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
593 *	control.
594 *
595 * @hdl:	The control handler.
596 * @cfg:	The control's configuration data.
597 * @priv:	The control's driver-specific private data.
598 *
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).
601 */
602struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
603				       const struct v4l2_ctrl_config *cfg,
604				       void *priv);
605
606/**
607 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
608 *	control.
609 *
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.
617 *
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).
621 *
622 * If @id refers to a menu control, then this function will return NULL.
623 *
624 * Use v4l2_ctrl_new_std_menu() when adding menu controls.
625 */
626struct 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,
629				    s64 def);
630
631/**
632 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
633 *	menu control.
634 *
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.
646 *
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.
649 *
650 * If @id refers to a non-menu control, then this function will return NULL.
651 */
652struct 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);
655
656/**
657 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
658 *	with driver specific menu.
659 *
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.
672 *
673 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
674 * menu of this control.
675 *
676 */
677struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
678					       const struct v4l2_ctrl_ops *ops,
679					       u32 id, u8 max,
680					       u64 mask, u8 def,
681					       const char * const *qmenu);
682
683/**
684 * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
685 *      compound control.
686 *
687 * @hdl:       The control handler.
688 * @ops:       The control ops.
689 * @id:        The control ID.
690 * @p_def:     The control's default value.
691 *
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.
696 *
697 */
698struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
699					     const struct v4l2_ctrl_ops *ops,
700					     u32 id,
701					     const union v4l2_ctrl_ptr p_def);
702
703/**
704 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
705 *
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.
712 *
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.
715 *
716 * If @id refers to a non-integer-menu control, then this function will
717 * return %NULL.
718 */
719struct 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);
723
724/**
725 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
726 *	used when adding a control handler.
727 *
728 * @ctrl: pointer to struct &v4l2_ctrl.
729 */
730
731typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
732
733/**
734 * v4l2_ctrl_add_handler() - Add all controls from handler @add to
735 *	handler @hdl.
736 *
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
742 *		device than @hdl.
743 *
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).
749 */
750int 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);
754
755/**
756 * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
757 *
758 * @ctrl:	The control that is filtered.
759 *
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.
763 *
764 * This function is to be used with v4l2_ctrl_add_handler().
765 */
766bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
767
768/**
769 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
770 *	to that cluster.
771 *
772 * @ncontrols:	The number of controls in this cluster.
773 * @controls:	The cluster control array of size @ncontrols.
774 */
775void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
776
777
778/**
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.
781 *
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
786 *		manual setting.
787 * @set_volatile: If true, then all controls except the first auto control will
788 *		be volatile.
789 *
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.
794 *
795 * The behavior of such controls is as follows:
796 *
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).
800 *
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.
804 *
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.
808 */
809void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
810			    struct v4l2_ctrl **controls,
811			    u8 manual_val, bool set_volatile);
812
813
814/**
815 * v4l2_ctrl_find() - Find a control with the given ID.
816 *
817 * @hdl:	The control handler.
818 * @id:	The control ID to find.
819 *
820 * If @hdl == NULL this will return NULL as well. Will lock the handler so
821 * do not use from inside &v4l2_ctrl_ops.
822 */
823struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
824
825/**
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.
829 *
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.
834 *
835 * This function assumes that the control handler is locked.
836 */
837void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
838
839/**
840 * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
841 *
842 * @ctrl:	The control to (de)activate.
843 * @grabbed:	True if the control should become grabbed.
844 *
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
849 * driver.
850 *
851 * This function assumes that the control handler is locked by the caller.
852 */
853void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
854
855/**
856 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
857 *
858 * @ctrl:	The control to (de)activate.
859 * @grabbed:	True if the control should become grabbed.
860 *
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
865 * driver.
866 *
867 * This function assumes that the control handler is not locked and will
868 * take the lock itself.
869 */
870static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
871{
872	if (!ctrl)
873		return;
874
875	v4l2_ctrl_lock(ctrl);
876	__v4l2_ctrl_grab(ctrl, grabbed);
877	v4l2_ctrl_unlock(ctrl);
878}
879
880/**
881 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
882 *
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.
888 *
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.
892 *
893 * An error is returned if one of the range arguments is invalid for this
894 * control type.
895 *
896 * The caller is responsible for acquiring the control handler mutex on behalf
897 * of __v4l2_ctrl_modify_range().
898 */
899int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
900			     s64 min, s64 max, u64 step, s64 def);
901
902/**
903 * v4l2_ctrl_modify_range() - Update the range of a control.
904 *
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.
910 *
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.
914 *
915 * An error is returned if one of the range arguments is invalid for this
916 * control type.
917 *
918 * This function assumes that the control handler is not locked and will
919 * take the lock itself.
920 */
921static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
922					 s64 min, s64 max, u64 step, s64 def)
923{
924	int rval;
925
926	v4l2_ctrl_lock(ctrl);
927	rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
928	v4l2_ctrl_unlock(ctrl);
929
930	return rval;
931}
932
933/**
934 * v4l2_ctrl_notify() - Function to set a notify callback for a control.
935 *
936 * @ctrl:	The control.
937 * @notify:	The callback function.
938 * @priv:	The callback private handle, passed as argument to the callback.
939 *
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
942 * be removed.
943 *
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.
946 */
947void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
948		      void *priv);
949
950/**
951 * v4l2_ctrl_get_name() - Get the name of the control
952 *
953 * @id:		The control ID.
954 *
955 * This function returns the name of the given control ID or NULL if it isn't
956 * a known control.
957 */
958const char *v4l2_ctrl_get_name(u32 id);
959
960/**
961 * v4l2_ctrl_get_menu() - Get the menu string array of the control
962 *
963 * @id:		The control ID.
964 *
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.
967 */
968const char * const *v4l2_ctrl_get_menu(u32 id);
969
970/**
971 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
972 *
973 * @id:		The control ID.
974 * @len:	The size of the integer array.
975 *
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.
978 */
979const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
980
981/**
982 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
983 *	within a driver.
984 *
985 * @ctrl:	The control.
986 *
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.
990 *
991 * This function is for integer type controls only.
992 */
993s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
994
995/**
996 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
997 *
998 * @ctrl:	The control.
999 * @val:	The new value.
1000 *
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.
1004 *
1005 * This function is for integer type controls only.
1006 */
1007int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1008
1009/**
1010 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1011 *	within a driver.
1012 * @ctrl:	The control.
1013 * @val:	The new value.
1014 *
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.
1018 *
1019 * This function is for integer type controls only.
1020 */
1021static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1022{
1023	int rval;
1024
1025	v4l2_ctrl_lock(ctrl);
1026	rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1027	v4l2_ctrl_unlock(ctrl);
1028
1029	return rval;
1030}
1031
1032/**
1033 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1034 *	from within a driver.
1035 *
1036 * @ctrl:	The control.
1037 *
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.
1041 *
1042 * This function is for 64-bit integer type controls only.
1043 */
1044s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1045
1046/**
1047 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1048 *
1049 * @ctrl:	The control.
1050 * @val:	The new value.
1051 *
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.
1055 *
1056 * This function is for 64-bit integer type controls only.
1057 */
1058int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1059
1060/**
1061 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1062 *	from within a driver.
1063 *
1064 * @ctrl:	The control.
1065 * @val:	The new value.
1066 *
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.
1070 *
1071 * This function is for 64-bit integer type controls only.
1072 */
1073static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1074{
1075	int rval;
1076
1077	v4l2_ctrl_lock(ctrl);
1078	rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1079	v4l2_ctrl_unlock(ctrl);
1080
1081	return rval;
1082}
1083
1084/**
1085 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1086 *
1087 * @ctrl:	The control.
1088 * @s:		The new string.
1089 *
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.
1093 *
1094 * This function is for string type controls only.
1095 */
1096int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1097
1098/**
1099 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1100 *	 from within a driver.
1101 *
1102 * @ctrl:	The control.
1103 * @s:		The new string.
1104 *
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.
1108 *
1109 * This function is for string type controls only.
1110 */
1111static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1112{
1113	int rval;
1114
1115	v4l2_ctrl_lock(ctrl);
1116	rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1117	v4l2_ctrl_unlock(ctrl);
1118
1119	return rval;
1120}
1121
1122/**
1123 * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1124 *
1125 * @ctrl: The control.
1126 * @type: The type of the data.
1127 * @p:    The new compound payload.
1128 *
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.
1132 *
1133 * This function is for compound type controls only.
1134 */
1135int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1136				enum v4l2_ctrl_type type, const void *p);
1137
1138/**
1139 * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1140 *	from within a driver.
1141 *
1142 * @ctrl: The control.
1143 * @type: The type of the data.
1144 * @p:    The new compound payload.
1145 *
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.
1149 *
1150 * This function is for compound type controls only.
1151 */
1152static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1153					    enum v4l2_ctrl_type type,
1154					    const void *p)
1155{
1156	int rval;
1157
1158	v4l2_ctrl_lock(ctrl);
1159	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1160	v4l2_ctrl_unlock(ctrl);
1161
1162	return rval;
1163}
1164
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))
1170
1171/* Internal helper functions that deal with control events. */
1172extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1173
1174/**
1175 * v4l2_ctrl_replace - Function to be used as a callback to
1176 *	&struct v4l2_subscribed_event_ops replace\(\)
1177 *
1178 * @old: pointer to struct &v4l2_event with the reported
1179 *	 event;
1180 * @new: pointer to struct &v4l2_event with the modified
1181 *	 event;
1182 */
1183void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1184
1185/**
1186 * v4l2_ctrl_merge - Function to be used as a callback to
1187 *	&struct v4l2_subscribed_event_ops merge(\)
1188 *
1189 * @old: pointer to struct &v4l2_event with the reported
1190 *	 event;
1191 * @new: pointer to struct &v4l2_event with the merged
1192 *	 event;
1193 */
1194void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1195
1196/**
1197 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1198 *
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.
1202 *
1203 * Can be used as a vidioc_log_status function that just dumps all controls
1204 * associated with the filehandle.
1205 */
1206int v4l2_ctrl_log_status(struct file *file, void *fh);
1207
1208/**
1209 * v4l2_ctrl_subscribe_event - Subscribes to an event
1210 *
1211 *
1212 * @fh: pointer to struct v4l2_fh
1213 * @sub: pointer to &struct v4l2_event_subscription
1214 *
1215 * Can be used as a vidioc_subscribe_event function that just subscribes
1216 * control events.
1217 */
1218int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1219				const struct v4l2_event_subscription *sub);
1220
1221/**
1222 * v4l2_ctrl_poll - function to be used as a callback to the poll()
1223 *	That just polls for control events.
1224 *
1225 * @file: pointer to struct file
1226 * @wait: pointer to struct poll_table_struct
1227 */
1228__poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1229
1230/**
1231 * v4l2_ctrl_request_setup - helper function to apply control values in a request
1232 *
1233 * @req: The request
1234 * @parent: The parent control handler ('priv' in media_request_object_find())
1235 *
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
1239 * devices.
1240 */
1241int v4l2_ctrl_request_setup(struct media_request *req,
1242			     struct v4l2_ctrl_handler *parent);
1243
1244/**
1245 * v4l2_ctrl_request_complete - Complete a control handler request object
1246 *
1247 * @req: The request
1248 * @parent: The parent control handler ('priv' in media_request_object_find())
1249 *
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.
1253 *
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
1256 * request object.
1257 */
1258void v4l2_ctrl_request_complete(struct media_request *req,
1259				struct v4l2_ctrl_handler *parent);
1260
1261/**
1262 * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1263 *
1264 * @req: The request
1265 * @parent: The parent control handler ('priv' in media_request_object_find())
1266 *
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.
1270 *
1271 * If the request is not in state VALIDATING or QUEUED, then this function
1272 * will always return NULL.
1273 *
1274 * Note that in state VALIDATING the req_queue_mutex is held, so
1275 * no objects can be added or deleted from the request.
1276 *
1277 * In state QUEUED it is the driver that will have to ensure this.
1278 */
1279struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1280					struct v4l2_ctrl_handler *parent);
1281
1282/**
1283 * v4l2_ctrl_request_hdl_put - Put the control handler
1284 *
1285 * @hdl: Put this control handler
1286 *
1287 * This function released the control handler previously obtained from'
1288 * v4l2_ctrl_request_hdl_find().
1289 */
1290static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1291{
1292	if (hdl)
1293		media_request_object_put(&hdl->req_obj);
1294}
1295
1296/**
1297 * v4l2_ctrl_request_ctrl_find() - Find a control with the given ID.
1298 *
1299 * @hdl: The control handler from the request.
1300 * @id: The ID of the control to find.
1301 *
1302 * This function returns a pointer to the control if this control is
1303 * part of the request or NULL otherwise.
1304 */
1305struct v4l2_ctrl *
1306v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1307
1308/* Helpers for ioctl_ops */
1309
1310/**
1311 * v4l2_queryctrl - Helper function to implement
1312 *	:ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1313 *
1314 * @hdl: pointer to &struct v4l2_ctrl_handler
1315 * @qc: pointer to &struct v4l2_queryctrl
1316 *
1317 * If hdl == NULL then they will all return -EINVAL.
1318 */
1319int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1320
1321/**
1322 * v4l2_query_ext_ctrl - Helper function to implement
1323 *	 :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1324 *
1325 * @hdl: pointer to &struct v4l2_ctrl_handler
1326 * @qc: pointer to &struct v4l2_query_ext_ctrl
1327 *
1328 * If hdl == NULL then they will all return -EINVAL.
1329 */
1330int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1331			struct v4l2_query_ext_ctrl *qc);
1332
1333/**
1334 * v4l2_querymenu - Helper function to implement
1335 *	:ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1336 *
1337 * @hdl: pointer to &struct v4l2_ctrl_handler
1338 * @qm: pointer to &struct v4l2_querymenu
1339 *
1340 * If hdl == NULL then they will all return -EINVAL.
1341 */
1342int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1343
1344/**
1345 * v4l2_g_ctrl - Helper function to implement
1346 *	:ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1347 *
1348 * @hdl: pointer to &struct v4l2_ctrl_handler
1349 * @ctrl: pointer to &struct v4l2_control
1350 *
1351 * If hdl == NULL then they will all return -EINVAL.
1352 */
1353int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1354
1355/**
1356 * v4l2_s_ctrl - Helper function to implement
1357 *	:ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1358 *
1359 * @fh: pointer to &struct v4l2_fh
1360 * @hdl: pointer to &struct v4l2_ctrl_handler
1361 *
1362 * @ctrl: pointer to &struct v4l2_control
1363 *
1364 * If hdl == NULL then they will all return -EINVAL.
1365 */
1366int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1367		struct v4l2_control *ctrl);
1368
1369/**
1370 * v4l2_g_ext_ctrls - Helper function to implement
1371 *	:ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1372 *
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
1377 *
1378 * If hdl == NULL then they will all return -EINVAL.
1379 */
1380int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1381		     struct media_device *mdev, struct v4l2_ext_controls *c);
1382
1383/**
1384 * v4l2_try_ext_ctrls - Helper function to implement
1385 *	:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1386 *
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
1391 *
1392 * If hdl == NULL then they will all return -EINVAL.
1393 */
1394int 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);
1398
1399/**
1400 * v4l2_s_ext_ctrls - Helper function to implement
1401 *	:ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1402 *
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
1408 *
1409 * If hdl == NULL then they will all return -EINVAL.
1410 */
1411int 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);
1415
1416/**
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.
1420 *
1421 * @sd: pointer to &struct v4l2_subdev
1422 * @fh: pointer to &struct v4l2_fh
1423 * @sub: pointer to &struct v4l2_event_subscription
1424 */
1425int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1426				     struct v4l2_event_subscription *sub);
1427
1428/**
1429 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1430 *	 handler.
1431 *
1432 * @sd: pointer to &struct v4l2_subdev
1433 */
1434int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1435
1436/**
1437 * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1438 *				       properties
1439 *
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
1443 *
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
1446 * a value.
1447 *
1448 * Currently the following v4l2 controls are parsed and registered:
1449 * - V4L2_CID_CAMERA_ORIENTATION
1450 * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1451 *
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.
1455 *
1456 * Return: 0 on success, a negative error code on failure.
1457 */
1458int 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);
1461#endif
1462