summaryrefslogtreecommitdiffstats
path: root/include/media/v4l2-ctrls.h
blob: c630345e9fd2c427c0b4acf558d04d3ae968f33d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
/*
    V4L2 controls support header.

    Copyright (C) 2010  Hans Verkuil <hverkuil@xs4all.nl>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef _V4L2_CTRLS_H
#define _V4L2_CTRLS_H

#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>

/* forward references */
struct file;
struct v4l2_ctrl_handler;
struct v4l2_ctrl_helper;
struct v4l2_ctrl;
struct video_device;
struct v4l2_subdev;
struct v4l2_subscribed_event;
struct v4l2_fh;
struct poll_table_struct;

/** union v4l2_ctrl_ptr - A pointer to a control value.
 * @p_s32:	Pointer to a 32-bit signed value.
 * @p_s64:	Pointer to a 64-bit signed value.
 * @p_u8:	Pointer to a 8-bit unsigned value.
 * @p_u16:	Pointer to a 16-bit unsigned value.
 * @p_char:	Pointer to a string.
 * @p:		Pointer to a compound value.
 */
union v4l2_ctrl_ptr {
	s32 *p_s32;
	s64 *p_s64;
	u8 *p_u8;
	u16 *p_u16;
	char *p_char;
	void *p;
};

/** struct v4l2_ctrl_ops - The control operations that the driver has to provide.
  * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
  *		for volatile (and usually read-only) controls such as a control
  *		that returns the current signal strength which changes
  *		continuously.
  *		If not set, then the currently cached value will be returned.
  * @try_ctrl:	Test whether the control's value is valid. Only relevant when
  *		the usual min/max/step checks are not sufficient.
  * @s_ctrl:	Actually set the new control value. s_ctrl is compulsory. The
  *		ctrl->handler->lock is held when these ops are called, so no
  *		one else can access controls owned by that handler.
  */
struct v4l2_ctrl_ops {
	int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
	int (*try_ctrl)(struct v4l2_ctrl *ctrl);
	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
};

/** struct v4l2_ctrl_type_ops - The control type operations that the driver has to provide.
  * @equal: return true if both values are equal.
  * @init: initialize the value.
  * @log: log the value.
  * @validate: validate the value. Return 0 on success and a negative value otherwise.
  */
struct v4l2_ctrl_type_ops {
	bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
		      union v4l2_ctrl_ptr ptr1,
		      union v4l2_ctrl_ptr ptr2);
	void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
		     union v4l2_ctrl_ptr ptr);
	void (*log)(const struct v4l2_ctrl *ctrl);
	int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
			union v4l2_ctrl_ptr ptr);
};

typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);

/** struct v4l2_ctrl - The control structure.
  * @node:	The list node.
  * @ev_subs:	The list of control event subscriptions.
  * @handler:	The handler that owns the control.
  * @cluster:	Point to start of cluster array.
  * @ncontrols:	Number of controls in cluster array.
  * @done:	Internal flag: set for each processed control.
  * @is_new:	Set when the user specified a new value for this control. It
  *		is also set when called from v4l2_ctrl_handler_setup. Drivers
  *		should never set this flag.
  * @has_changed: Set when the current value differs from the new value. Drivers
  *		should never use this flag.
  * @is_private: If set, then this control is private to its handler and it
  *		will not be added to any other handlers. Drivers can set
  *		this flag.
  * @is_auto:   If set, then this control selects whether the other cluster
  *		members are in 'automatic' mode or 'manual' mode. This is
  *		used for autogain/gain type clusters. Drivers should never
  *		set this flag directly.
  * @is_int:    If set, then this control has a simple integer value (i.e. it
  *		uses ctrl->val).
  * @is_string: If set, then this control has type V4L2_CTRL_TYPE_STRING.
  * @is_ptr:	If set, then this control is an array and/or has type >= V4L2_CTRL_COMPOUND_TYPES
  *		and/or has type V4L2_CTRL_TYPE_STRING. In other words, struct
  *		v4l2_ext_control uses field p to point to the data.
  * @is_array: If set, then this control contains an N-dimensional array.
  * @has_volatiles: If set, then one or more members of the cluster are volatile.
  *		Drivers should never touch this flag.
  * @call_notify: If set, then call the handler's notify function whenever the
  *		control's value changes.
  * @manual_mode_value: If the is_auto flag is set, then this is the value
  *		of the auto control that determines if that control is in
  *		manual mode. So if the value of the auto control equals this
  *		value, then the whole cluster is in manual mode. Drivers should
  *		never set this flag directly.
  * @ops:	The control ops.
  * @type_ops:	The control type ops.
  * @id:	The control ID.
  * @name:	The control name.
  * @type:	The control type.
  * @minimum:	The control's minimum value.
  * @maximum:	The control's maximum value.
  * @default_value: The control's default value.
  * @step:	The control's step value for non-menu controls.
  * @elems:	The number of elements in the N-dimensional array.
  * @elem_size:	The size in bytes of the control.
  * @dims:	The size of each dimension.
  * @nr_of_dims:The number of dimensions in @dims.
  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
  *		easy to skip menu items that are not valid. If bit X is set,
  *		then menu item X is skipped. Of course, this only works for
  *		menus with <= 32 menu items. There are no menus that come
  *		close to that number, so this is OK. Should we ever need more,
  *		then this will have to be extended to a u64 or a bit array.
  * @qmenu:	A const char * array for all menu items. Array entries that are
  *		empty strings ("") correspond to non-existing menu items (this
  *		is in addition to the menu_skip_mask above). The last entry
  *		must be NULL.
  * @flags:	The control's flags.
  * @cur:	The control's current value.
  * @val:	The control's new s32 value.
  * @val64:	The control's new s64 value.
  * @priv:	The control's private pointer. For use by the driver. It is
  *		untouched by the control framework. Note that this pointer is
  *		not freed when the control is deleted. Should this be needed
  *		then a new internal bitfield can be added to tell the framework
  *		to free this pointer.
  */
struct v4l2_ctrl {
	/* Administrative fields */
	struct list_head node;
	struct list_head ev_subs;
	struct v4l2_ctrl_handler *handler;
	struct v4l2_ctrl **cluster;
	unsigned ncontrols;
	unsigned int done:1;

	unsigned int is_new:1;
	unsigned int has_changed:1;
	unsigned int is_private:1;
	unsigned int is_auto:1;
	unsigned int is_int:1;
	unsigned int is_string:1;
	unsigned int is_ptr:1;
	unsigned int is_array:1;
	unsigned int has_volatiles:1;
	unsigned int call_notify:1;
	unsigned int manual_mode_value:8;

	const struct v4l2_ctrl_ops *ops;
	const struct v4l2_ctrl_type_ops *type_ops;
	u32 id;
	const char *name;
	enum v4l2_ctrl_type type;
	s64 minimum, maximum, default_value;
	u32 elems;
	u32 elem_size;
	u32 dims[V4L2_CTRL_MAX_DIMS];
	u32 nr_of_dims;
	union {
		u64 step;
		u64 menu_skip_mask;
	};
	union {
		const char * const *qmenu;
		const s64 *qmenu_int;
	};
	unsigned long flags;
	void *priv;
	s32 val;
	struct {
		s32 val;
	} cur;

	union v4l2_ctrl_ptr p_new;
	union v4l2_ctrl_ptr p_cur;
};

/** struct v4l2_ctrl_ref - The control reference.
  * @node:	List node for the sorted list.
  * @next:	Single-link list node for the hash.
  * @ctrl:	The actual control information.
  * @helper:	Pointer to helper struct. Used internally in prepare_ext_ctrls().
  *
  * Each control handler has a list of these refs. The list_head is used to
  * keep a sorted-by-control-ID list of all controls, while the next pointer
  * is used to link the control in the hash's bucket.
  */
struct v4l2_ctrl_ref {
	struct list_head node;
	struct v4l2_ctrl_ref *next;
	struct v4l2_ctrl *ctrl;
	struct v4l2_ctrl_helper *helper;
};

/** struct v4l2_ctrl_handler - The control handler keeps track of all the
  * controls: both the controls owned by the handler and those inherited
  * from other handlers.
  * @_lock:	Default for "lock".
  * @lock:	Lock to control access to this handler and its controls.
  *		May be replaced by the user right after init.
  * @ctrls:	The list of controls owned by this handler.
  * @ctrl_refs:	The list of control references.
  * @cached:	The last found control reference. It is common that the same
  *		control is needed multiple times, so this is a simple
  *		optimization.
  * @buckets:	Buckets for the hashing. Allows for quick control lookup.
  * @notify:	A notify callback that is called whenever the control changes value.
  *		Note that the handler's lock is held when the notify function
  *		is called!
  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
  * @nr_of_buckets: Total number of buckets in the array.
  * @error:	The error code of the first failed control addition.
  */
struct v4l2_ctrl_handler {
	struct mutex _lock;
	struct mutex *lock;
	struct list_head ctrls;
	struct list_head ctrl_refs;
	struct v4l2_ctrl_ref *cached;
	struct v4l2_ctrl_ref **buckets;
	v4l2_ctrl_notify_fnc notify;
	void *notify_priv;
	u16 nr_of_buckets;
	int error;
};

/** struct v4l2_ctrl_config - Control configuration structure.
  * @ops:	The control ops.
  * @type_ops:	The control type ops. Only needed for compound controls.
  * @id:	The control ID.
  * @name:	The control name.
  * @type:	The control type.
  * @min:	The control's minimum value.
  * @max:	The control's maximum value.
  * @step:	The control's step value for non-menu controls.
  * @def: 	The control's default value.
  * @dims:	The size of each dimension.
  * @elem_size:	The size in bytes of the control.
  * @flags:	The control's flags.
  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
  *		easy to skip menu items that are not valid. If bit X is set,
  *		then menu item X is skipped. Of course, this only works for
  *		menus with <= 64 menu items. There are no menus that come
  *		close to that number, so this is OK. Should we ever need more,
  *		then this will have to be extended to a bit array.
  * @qmenu:	A const char * array for all menu items. Array entries that are
  *		empty strings ("") correspond to non-existing menu items (this
  *		is in addition to the menu_skip_mask above). The last entry
  *		must be NULL.
  * @is_private: If set, then this control is private to its handler and it
  *		will not be added to any other handlers.
  */
struct v4l2_ctrl_config {
	const struct v4l2_ctrl_ops *ops;
	const struct v4l2_ctrl_type_ops *type_ops;
	u32 id;
	const char *name;
	enum v4l2_ctrl_type type;
	s64 min;
	s64 max;
	u64 step;
	s64 def;
	u32 dims[V4L2_CTRL_MAX_DIMS];
	u32 elem_size;
	u32 flags;
	u64 menu_skip_mask;
	const char * const *qmenu;
	const s64 *qmenu_int;
	unsigned int is_private:1;
};

/** v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
  *
  * This works for all standard V4L2 controls.
  * For non-standard controls it will only fill in the given arguments
  * and @name will be NULL.
  *
  * This function will overwrite the contents of @name, @type and @flags.
  * The contents of @min, @max, @step and @def may be modified depending on
  * the type.
  *
  * Do not use in drivers! It is used internally for backwards compatibility
  * control handling only. Once all drivers are converted to use the new
  * control framework this function will no longer be exported.
  */
void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);


/** v4l2_ctrl_handler_init_class() - Initialize the control handler.
  * @hdl:	The control handler.
  * @nr_of_controls_hint: A hint of how many controls this handler is
  *		expected to refer to. This is the total number, so including
  *		any inherited controls. It doesn't have to be precise, but if
  *		it is way off, then you either waste memory (too many buckets
  *		are allocated) or the control lookup becomes slower (not enough
  *		buckets are allocated, so there are more slow list lookups).
  *		It will always work, though.
  * @key:	Used by the lock validator if CONFIG_LOCKDEP is set.
  * @name:	Used by the lock validator if CONFIG_LOCKDEP is set.
  *
  * Returns an error if the buckets could not be allocated. This error will
  * also be stored in @hdl->error.
  *
  * Never use this call directly, always use the v4l2_ctrl_handler_init
  * macro that hides the @key and @name arguments.
  */
int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
				 unsigned nr_of_controls_hint,
				 struct lock_class_key *key, const char *name);

#ifdef CONFIG_LOCKDEP
#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
(									\
	({								\
		static struct lock_class_key _key;			\
		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
					&_key,				\
					KBUILD_BASENAME ":"		\
					__stringify(__LINE__) ":"	\
					"(" #hdl ")->_lock");		\
	})								\
)
#else
#define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
#endif

/** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
  * the control list.
  * @hdl:	The control handler.
  *
  * Does nothing if @hdl == NULL.
  */
void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);

/** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
  * to the handler to initialize the hardware to the current control values.
  * @hdl:	The control handler.
  *
  * Button controls will be skipped, as are read-only controls.
  *
  * If @hdl == NULL, then this just returns 0.
  */
int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);

/** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
  * @hdl:	The control handler.
  * @prefix:	The prefix to use when logging the control values. If the
  *		prefix does not end with a space, then ": " will be added
  *		after the prefix. If @prefix == NULL, then no prefix will be
  *		used.
  *
  * For use with VIDIOC_LOG_STATUS.
  *
  * Does nothing if @hdl == NULL.
  */
void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
				  const char *prefix);

/** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
  * control.
  * @hdl:	The control handler.
  * @cfg:	The control's configuration data.
  * @priv:	The control's driver-specific private data.
  *
  * If the &v4l2_ctrl struct could not be allocated then NULL is returned
  * and @hdl->error is set to the error code (if it wasn't set already).
  */
struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
			const struct v4l2_ctrl_config *cfg, void *priv);

/** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control.
  * @hdl:	The control handler.
  * @ops:	The control ops.
  * @id:	The control ID.
  * @min:	The control's minimum value.
  * @max:	The control's maximum value.
  * @step:	The control's step value
  * @def: 	The control's default value.
  *
  * If the &v4l2_ctrl struct could not be allocated, or the control
  * ID is not known, then NULL is returned and @hdl->error is set to the
  * appropriate error code (if it wasn't set already).
  *
  * If @id refers to a menu control, then this function will return NULL.
  *
  * Use v4l2_ctrl_new_std_menu() when adding menu controls.
  */
struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
			const struct v4l2_ctrl_ops *ops,
			u32 id, s64 min, s64 max, u64 step, s64 def);

/** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control.
  * @hdl:	The control handler.
  * @ops:	The control ops.
  * @id:	The control ID.
  * @max:	The control's maximum value.
  * @mask: 	The control's skip mask for menu controls. This makes it
  *		easy to skip menu items that are not valid. If bit X is set,
  *		then menu item X is skipped. Of course, this only works for
  *		menus with <= 64 menu items. There are no menus that come
  *		close to that number, so this is OK. Should we ever need more,
  *		then this will have to be extended to a bit array.
  * @def: 	The control's default value.
  *
  * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
  * determines which menu items are to be skipped.
  *
  * If @id refers to a non-menu control, then this function will return NULL.
  */
struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
			const struct v4l2_ctrl_ops *ops,
			u32 id, u8 max, u64 mask, u8 def);

/** v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
  * with driver specific menu.
  * @hdl:	The control handler.
  * @ops:	The control ops.
  * @id:	The control ID.
  * @max:	The control's maximum value.
  * @mask:	The control's skip mask for menu controls. This makes it
  *		easy to skip menu items that are not valid. If bit X is set,
  *		then menu item X is skipped. Of course, this only works for
  *		menus with <= 64 menu items. There are no menus that come
  *		close to that number, so this is OK. Should we ever need more,
  *		then this will have to be extended to a bit array.
  * @def:	The control's default value.
  * @qmenu:	The new menu.
  *
  * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
  * menu of this control.
  *
  */
struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
			const struct v4l2_ctrl_ops *ops, u32 id, u8 max,
			u64 mask, u8 def, const char * const *qmenu);

/** v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
  * @hdl:	The control handler.
  * @ops:	The control ops.
  * @id:	The control ID.
  * @max:	The control's maximum value.
  * @def:	The control's default value.
  * @qmenu_int:	The control's menu entries.
  *
  * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
  * takes as an argument an array of integers determining the menu items.
  *
  * If @id refers to a non-integer-menu control, then this function will return NULL.
  */
struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
			const struct v4l2_ctrl_ops *ops,
			u32 id, u8 max, u8 def, const s64 *qmenu_int);

/** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler.
  * @hdl:	The control handler.
  * @ctrl:	The control to add.
  *
  * It will return NULL if it was unable to add the control reference.
  * If the control already belonged to the handler, then it will do
  * nothing and just return @ctrl.
  */
struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
					  struct v4l2_ctrl *ctrl);

/** v4l2_ctrl_add_handler() - Add all controls from handler @add to
  * handler @hdl.
  * @hdl:	The control handler.
  * @add:	The control handler whose controls you want to add to
  *		the @hdl control handler.
  * @filter:	This function will filter which controls should be added.
  *
  * Does nothing if either of the two handlers is a NULL pointer.
  * If @filter is NULL, then all controls are added. Otherwise only those
  * controls for which @filter returns true will be added.
  * In case of an error @hdl->error will be set to the error code (if it
  * wasn't set already).
  */
int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
			  struct v4l2_ctrl_handler *add,
			  bool (*filter)(const struct v4l2_ctrl *ctrl));

/** v4l2_ctrl_radio_filter() - Standard filter for radio controls.
  * @ctrl:	The control that is filtered.
  *
  * This will return true for any controls that are valid for radio device
  * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
  * transmitter class controls.
  *
  * This function is to be used with v4l2_ctrl_add_handler().
  */
bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);

/** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster.
  * @ncontrols:	The number of controls in this cluster.
  * @controls: 	The cluster control array of size @ncontrols.
  */
void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);


/** v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to
  * that cluster and set it up for autofoo/foo-type handling.
  * @ncontrols:	The number of controls in this cluster.
  * @controls:	The cluster control array of size @ncontrols. The first control
  *		must be the 'auto' control (e.g. autogain, autoexposure, etc.)
  * @manual_val: The value for the first control in the cluster that equals the
  *		manual setting.
  * @set_volatile: If true, then all controls except the first auto control will
  *		be volatile.
  *
  * Use for control groups where one control selects some automatic feature and
  * the other controls are only active whenever the automatic feature is turned
  * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
  * red and blue balance, etc.
  *
  * The behavior of such controls is as follows:
  *
  * When the autofoo control is set to automatic, then any manual controls
  * are set to inactive and any reads will call g_volatile_ctrl (if the control
  * was marked volatile).
  *
  * When the autofoo control is set to manual, then any manual controls will
  * be marked active, and any reads will just return the current value without
  * going through g_volatile_ctrl.
  *
  * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag
  * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
  * if autofoo is in auto mode.
  */
void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
			u8 manual_val, bool set_volatile);


/** v4l2_ctrl_find() - Find a control with the given ID.
  * @hdl:	The control handler.
  * @id:	The control ID to find.
  *
  * If @hdl == NULL this will return NULL as well. Will lock the handler so
  * do not use from inside &v4l2_ctrl_ops.
  */
struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);

/** v4l2_ctrl_activate() - Make the control active or inactive.
  * @ctrl:	The control to (de)activate.
  * @active:	True if the control should become active.
  *
  * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
  * Does nothing if @ctrl == NULL.
  * This will usually be called from within the s_ctrl op.
  * The V4L2_EVENT_CTRL event will be generated afterwards.
  *
  * This function assumes that the control handler is locked.
  */
void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);

/** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
  * @ctrl:	The control to (de)activate.
  * @grabbed:	True if the control should become grabbed.
  *
  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
  * Does nothing if @ctrl == NULL.
  * The V4L2_EVENT_CTRL event will be generated afterwards.
  * This will usually be called when starting or stopping streaming in the
  * driver.
  *
  * This function assumes that the control handler is not locked and will
  * take the lock itself.
  */
void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);

/** v4l2_ctrl_modify_range() - Update the range of a control.
  * @ctrl:	The control to update.
  * @min:	The control's minimum value.
  * @max:	The control's maximum value.
  * @step:	The control's step value
  * @def:	The control's default value.
  *
  * Update the range of a control on the fly. This works for control types
  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
  * @step value is interpreted as a menu_skip_mask.
  *
  * An error is returned if one of the range arguments is invalid for this
  * control type.
  *
  * This function assumes that the control handler is not locked and will
  * take the lock itself.
  */
int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
			s64 min, s64 max, u64 step, s64 def);

/** v4l2_ctrl_lock() - Helper function to lock the handler
  * associated with the control.
  * @ctrl:	The control to lock.
  */
static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
{
	mutex_lock(ctrl->handler->lock);
}

/** v4l2_ctrl_unlock() - Helper function to unlock the handler
  * associated with the control.
  * @ctrl:	The control to unlock.
  */
static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
{
	mutex_unlock(ctrl->handler->lock);
}

/** v4l2_ctrl_notify() - Function to set a notify callback for a control.
  * @ctrl:	The control.
  * @notify:	The callback function.
  * @priv:	The callback private handle, passed as argument to the callback.
  *
  * This function sets a callback function for the control. If @ctrl is NULL,
  * then it will do nothing. If @notify is NULL, then the notify callback will
  * be removed.
  *
  * There can be only one notify. If another already exists, then a WARN_ON
  * will be issued and the function will do nothing.
  */
void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv);

/** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
  * @ctrl:	The control.
  *
  * This returns the control's value safely by going through the control
  * framework. This function will lock the control's handler, so it cannot be
  * used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for integer type controls only.
  */
s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);

/** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver.
  * @ctrl:	The control.
  * @val:	The new value.
  *
  * This set the control's new value safely by going through the control
  * framework. This function will lock the control's handler, so it cannot be
  * used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for integer type controls only.
  */
int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);

/** v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value from within a driver.
  * @ctrl:	The control.
  *
  * This returns the control's value safely by going through the control
  * framework. This function will lock the control's handler, so it cannot be
  * used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for 64-bit integer type controls only.
  */
s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);

/** v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value from within a driver.
  * @ctrl:	The control.
  * @val:	The new value.
  *
  * This set the control's new value safely by going through the control
  * framework. This function will lock the control's handler, so it cannot be
  * used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for 64-bit integer type controls only.
  */
int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);

/* Internal helper functions that deal with control events. */
extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);

/* Can be used as a vidioc_log_status function that just dumps all controls
   associated with the filehandle. */
int v4l2_ctrl_log_status(struct file *file, void *fh);

/* Can be used as a vidioc_subscribe_event function that just subscribes
   control events. */
int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
				const struct v4l2_event_subscription *sub);

/* Can be used as a poll function that just polls for control events. */
unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);

/* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctrl *qc);
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
						struct v4l2_control *ctrl);
int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
						struct v4l2_ext_controls *c);

/* Helpers for subdevices. If the associated ctrl_handler == NULL then they
   will all return -EINVAL. */
int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);

/* Can be used as a subscribe_event function that just subscribes control
   events. */
int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
				     struct v4l2_event_subscription *sub);

/* Log all controls owned by subdev's control handler. */
int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);

#endif
OpenPOWER on IntegriCloud