xref: /openbmc/linux/include/media/v4l2-ctrls.h (revision 59b4412f)
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 */
27 struct file;
28 struct poll_table_struct;
29 struct v4l2_ctrl;
30 struct v4l2_ctrl_handler;
31 struct v4l2_ctrl_helper;
32 struct v4l2_fh;
33 struct v4l2_fwnode_device_properties;
34 struct v4l2_subdev;
35 struct v4l2_subscribed_event;
36 struct 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_vp8_frame_header:		Pointer to a VP8 frame header structure.
55  * @p_hevc_sps:			Pointer to an HEVC sequence parameter set structure.
56  * @p_hevc_pps:			Pointer to an HEVC picture parameter set structure.
57  * @p_hevc_slice_params:	Pointer to an HEVC slice parameters structure.
58  * @p_area:			Pointer to an area.
59  * @p:				Pointer to a compound value.
60  * @p_const:			Pointer to a constant compound value.
61  */
62 union v4l2_ctrl_ptr {
63 	s32 *p_s32;
64 	s64 *p_s64;
65 	u8 *p_u8;
66 	u16 *p_u16;
67 	u32 *p_u32;
68 	char *p_char;
69 	struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
70 	struct v4l2_ctrl_mpeg2_quantization *p_mpeg2_quantization;
71 	struct v4l2_ctrl_fwht_params *p_fwht_params;
72 	struct v4l2_ctrl_h264_sps *p_h264_sps;
73 	struct v4l2_ctrl_h264_pps *p_h264_pps;
74 	struct v4l2_ctrl_h264_scaling_matrix *p_h264_scaling_matrix;
75 	struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
76 	struct v4l2_ctrl_h264_decode_params *p_h264_decode_params;
77 	struct v4l2_ctrl_vp8_frame_header *p_vp8_frame_header;
78 	struct v4l2_ctrl_hevc_sps *p_hevc_sps;
79 	struct v4l2_ctrl_hevc_pps *p_hevc_pps;
80 	struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
81 	struct v4l2_area *p_area;
82 	void *p;
83 	const void *p_const;
84 };
85 
86 /**
87  * v4l2_ctrl_ptr_create() - Helper function to return a v4l2_ctrl_ptr from a
88  * void pointer
89  * @ptr:	The void pointer
90  */
91 static inline union v4l2_ctrl_ptr v4l2_ctrl_ptr_create(void *ptr)
92 {
93 	union v4l2_ctrl_ptr p = { .p = ptr };
94 
95 	return p;
96 }
97 
98 /**
99  * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
100  *
101  * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
102  *		for volatile (and usually read-only) controls such as a control
103  *		that returns the current signal strength which changes
104  *		continuously.
105  *		If not set, then the currently cached value will be returned.
106  * @try_ctrl:	Test whether the control's value is valid. Only relevant when
107  *		the usual min/max/step checks are not sufficient.
108  * @s_ctrl:	Actually set the new control value. s_ctrl is compulsory. The
109  *		ctrl->handler->lock is held when these ops are called, so no
110  *		one else can access controls owned by that handler.
111  */
112 struct v4l2_ctrl_ops {
113 	int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
114 	int (*try_ctrl)(struct v4l2_ctrl *ctrl);
115 	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
116 };
117 
118 /**
119  * struct v4l2_ctrl_type_ops - The control type operations that the driver
120  *			       has to provide.
121  *
122  * @equal: return true if both values are equal.
123  * @init: initialize the value.
124  * @log: log the value.
125  * @validate: validate the value. Return 0 on success and a negative value
126  *	otherwise.
127  */
128 struct v4l2_ctrl_type_ops {
129 	bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
130 		      union v4l2_ctrl_ptr ptr1,
131 		      union v4l2_ctrl_ptr ptr2);
132 	void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
133 		     union v4l2_ctrl_ptr ptr);
134 	void (*log)(const struct v4l2_ctrl *ctrl);
135 	int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
136 			union v4l2_ctrl_ptr ptr);
137 };
138 
139 /**
140  * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
141  *	that should be called when a control value has changed.
142  *
143  * @ctrl: pointer to struct &v4l2_ctrl
144  * @priv: control private data
145  *
146  * This typedef definition is used as an argument to v4l2_ctrl_notify()
147  * and as an argument at struct &v4l2_ctrl_handler.
148  */
149 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
150 
151 /**
152  * struct v4l2_ctrl - The control structure.
153  *
154  * @node:	The list node.
155  * @ev_subs:	The list of control event subscriptions.
156  * @handler:	The handler that owns the control.
157  * @cluster:	Point to start of cluster array.
158  * @ncontrols:	Number of controls in cluster array.
159  * @done:	Internal flag: set for each processed control.
160  * @is_new:	Set when the user specified a new value for this control. It
161  *		is also set when called from v4l2_ctrl_handler_setup(). Drivers
162  *		should never set this flag.
163  * @has_changed: Set when the current value differs from the new value. Drivers
164  *		should never use this flag.
165  * @is_private: If set, then this control is private to its handler and it
166  *		will not be added to any other handlers. Drivers can set
167  *		this flag.
168  * @is_auto:   If set, then this control selects whether the other cluster
169  *		members are in 'automatic' mode or 'manual' mode. This is
170  *		used for autogain/gain type clusters. Drivers should never
171  *		set this flag directly.
172  * @is_int:    If set, then this control has a simple integer value (i.e. it
173  *		uses ctrl->val).
174  * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
175  * @is_ptr:	If set, then this control is an array and/or has type >=
176  *		%V4L2_CTRL_COMPOUND_TYPES
177  *		and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
178  *		v4l2_ext_control uses field p to point to the data.
179  * @is_array: If set, then this control contains an N-dimensional array.
180  * @has_volatiles: If set, then one or more members of the cluster are volatile.
181  *		Drivers should never touch this flag.
182  * @call_notify: If set, then call the handler's notify function whenever the
183  *		control's value changes.
184  * @manual_mode_value: If the is_auto flag is set, then this is the value
185  *		of the auto control that determines if that control is in
186  *		manual mode. So if the value of the auto control equals this
187  *		value, then the whole cluster is in manual mode. Drivers should
188  *		never set this flag directly.
189  * @ops:	The control ops.
190  * @type_ops:	The control type ops.
191  * @id:	The control ID.
192  * @name:	The control name.
193  * @type:	The control type.
194  * @minimum:	The control's minimum value.
195  * @maximum:	The control's maximum value.
196  * @default_value: The control's default value.
197  * @step:	The control's step value for non-menu controls.
198  * @elems:	The number of elements in the N-dimensional array.
199  * @elem_size:	The size in bytes of the control.
200  * @dims:	The size of each dimension.
201  * @nr_of_dims:The number of dimensions in @dims.
202  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
203  *		easy to skip menu items that are not valid. If bit X is set,
204  *		then menu item X is skipped. Of course, this only works for
205  *		menus with <= 32 menu items. There are no menus that come
206  *		close to that number, so this is OK. Should we ever need more,
207  *		then this will have to be extended to a u64 or a bit array.
208  * @qmenu:	A const char * array for all menu items. Array entries that are
209  *		empty strings ("") correspond to non-existing menu items (this
210  *		is in addition to the menu_skip_mask above). The last entry
211  *		must be NULL.
212  *		Used only if the @type is %V4L2_CTRL_TYPE_MENU.
213  * @qmenu_int:	A 64-bit integer array for with integer menu items.
214  *		The size of array must be equal to the menu size, e. g.:
215  *		:math:`ceil(\frac{maximum - minimum}{step}) + 1`.
216  *		Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
217  * @flags:	The control's flags.
218  * @cur:	Structure to store the current value.
219  * @cur.val:	The control's current value, if the @type is represented via
220  *		a u32 integer (see &enum v4l2_ctrl_type).
221  * @val:	The control's new s32 value.
222  * @priv:	The control's private pointer. For use by the driver. It is
223  *		untouched by the control framework. Note that this pointer is
224  *		not freed when the control is deleted. Should this be needed
225  *		then a new internal bitfield can be added to tell the framework
226  *		to free this pointer.
227  * @p_def:	The control's default value represented via a union which
228  *		provides a standard way of accessing control types
229  *		through a pointer (for compound controls only).
230  * @p_cur:	The control's current value represented via a union which
231  *		provides a standard way of accessing control types
232  *		through a pointer.
233  * @p_new:	The control's new value represented via a union which provides
234  *		a standard way of accessing control types
235  *		through a pointer.
236  */
237 struct v4l2_ctrl {
238 	/* Administrative fields */
239 	struct list_head node;
240 	struct list_head ev_subs;
241 	struct v4l2_ctrl_handler *handler;
242 	struct v4l2_ctrl **cluster;
243 	unsigned int ncontrols;
244 
245 	unsigned int done:1;
246 
247 	unsigned int is_new:1;
248 	unsigned int has_changed:1;
249 	unsigned int is_private:1;
250 	unsigned int is_auto:1;
251 	unsigned int is_int:1;
252 	unsigned int is_string:1;
253 	unsigned int is_ptr:1;
254 	unsigned int is_array:1;
255 	unsigned int has_volatiles:1;
256 	unsigned int call_notify:1;
257 	unsigned int manual_mode_value:8;
258 
259 	const struct v4l2_ctrl_ops *ops;
260 	const struct v4l2_ctrl_type_ops *type_ops;
261 	u32 id;
262 	const char *name;
263 	enum v4l2_ctrl_type type;
264 	s64 minimum, maximum, default_value;
265 	u32 elems;
266 	u32 elem_size;
267 	u32 dims[V4L2_CTRL_MAX_DIMS];
268 	u32 nr_of_dims;
269 	union {
270 		u64 step;
271 		u64 menu_skip_mask;
272 	};
273 	union {
274 		const char * const *qmenu;
275 		const s64 *qmenu_int;
276 	};
277 	unsigned long flags;
278 	void *priv;
279 	s32 val;
280 	struct {
281 		s32 val;
282 	} cur;
283 
284 	union v4l2_ctrl_ptr p_def;
285 	union v4l2_ctrl_ptr p_new;
286 	union v4l2_ctrl_ptr p_cur;
287 };
288 
289 /**
290  * struct v4l2_ctrl_ref - The control reference.
291  *
292  * @node:	List node for the sorted list.
293  * @next:	Single-link list node for the hash.
294  * @ctrl:	The actual control information.
295  * @helper:	Pointer to helper struct. Used internally in
296  *		``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
297  * @from_other_dev: If true, then @ctrl was defined in another
298  *		device than the &struct v4l2_ctrl_handler.
299  * @req_done:	Internal flag: if the control handler containing this control
300  *		reference is bound to a media request, then this is set when
301  *		the control has been applied. This prevents applying controls
302  *		from a cluster with multiple controls twice (when the first
303  *		control of a cluster is applied, they all are).
304  * @req:	If set, this refers to another request that sets this control.
305  * @p_req:	If the control handler containing this control reference
306  *		is bound to a media request, then this points to the
307  *		value of the control that should be applied when the request
308  *		is executed, or to the value of the control at the time
309  *		that the request was completed.
310  *
311  * Each control handler has a list of these refs. The list_head is used to
312  * keep a sorted-by-control-ID list of all controls, while the next pointer
313  * is used to link the control in the hash's bucket.
314  */
315 struct v4l2_ctrl_ref {
316 	struct list_head node;
317 	struct v4l2_ctrl_ref *next;
318 	struct v4l2_ctrl *ctrl;
319 	struct v4l2_ctrl_helper *helper;
320 	bool from_other_dev;
321 	bool req_done;
322 	struct v4l2_ctrl_ref *req;
323 	union v4l2_ctrl_ptr p_req;
324 };
325 
326 /**
327  * struct v4l2_ctrl_handler - The control handler keeps track of all the
328  *	controls: both the controls owned by the handler and those inherited
329  *	from other handlers.
330  *
331  * @_lock:	Default for "lock".
332  * @lock:	Lock to control access to this handler and its controls.
333  *		May be replaced by the user right after init.
334  * @ctrls:	The list of controls owned by this handler.
335  * @ctrl_refs:	The list of control references.
336  * @cached:	The last found control reference. It is common that the same
337  *		control is needed multiple times, so this is a simple
338  *		optimization.
339  * @buckets:	Buckets for the hashing. Allows for quick control lookup.
340  * @notify:	A notify callback that is called whenever the control changes
341  *		value.
342  *		Note that the handler's lock is held when the notify function
343  *		is called!
344  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
345  * @nr_of_buckets: Total number of buckets in the array.
346  * @error:	The error code of the first failed control addition.
347  * @request_is_queued: True if the request was queued.
348  * @requests:	List to keep track of open control handler request objects.
349  *		For the parent control handler (@req_obj.req == NULL) this
350  *		is the list header. When the parent control handler is
351  *		removed, it has to unbind and put all these requests since
352  *		they refer to the parent.
353  * @requests_queued: List of the queued requests. This determines the order
354  *		in which these controls are applied. Once the request is
355  *		completed it is removed from this list.
356  * @req_obj:	The &struct media_request_object, used to link into a
357  *		&struct media_request. This request object has a refcount.
358  */
359 struct v4l2_ctrl_handler {
360 	struct mutex _lock;
361 	struct mutex *lock;
362 	struct list_head ctrls;
363 	struct list_head ctrl_refs;
364 	struct v4l2_ctrl_ref *cached;
365 	struct v4l2_ctrl_ref **buckets;
366 	v4l2_ctrl_notify_fnc notify;
367 	void *notify_priv;
368 	u16 nr_of_buckets;
369 	int error;
370 	bool request_is_queued;
371 	struct list_head requests;
372 	struct list_head requests_queued;
373 	struct media_request_object req_obj;
374 };
375 
376 /**
377  * struct v4l2_ctrl_config - Control configuration structure.
378  *
379  * @ops:	The control ops.
380  * @type_ops:	The control type ops. Only needed for compound controls.
381  * @id:	The control ID.
382  * @name:	The control name.
383  * @type:	The control type.
384  * @min:	The control's minimum value.
385  * @max:	The control's maximum value.
386  * @step:	The control's step value for non-menu controls.
387  * @def:	The control's default value.
388  * @p_def:	The control's default value for compound controls.
389  * @dims:	The size of each dimension.
390  * @elem_size:	The size in bytes of the control.
391  * @flags:	The control's flags.
392  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
393  *		easy to skip menu items that are not valid. If bit X is set,
394  *		then menu item X is skipped. Of course, this only works for
395  *		menus with <= 64 menu items. There are no menus that come
396  *		close to that number, so this is OK. Should we ever need more,
397  *		then this will have to be extended to a bit array.
398  * @qmenu:	A const char * array for all menu items. Array entries that are
399  *		empty strings ("") correspond to non-existing menu items (this
400  *		is in addition to the menu_skip_mask above). The last entry
401  *		must be NULL.
402  * @qmenu_int:	A const s64 integer array for all menu items of the type
403  *		V4L2_CTRL_TYPE_INTEGER_MENU.
404  * @is_private: If set, then this control is private to its handler and it
405  *		will not be added to any other handlers.
406  */
407 struct v4l2_ctrl_config {
408 	const struct v4l2_ctrl_ops *ops;
409 	const struct v4l2_ctrl_type_ops *type_ops;
410 	u32 id;
411 	const char *name;
412 	enum v4l2_ctrl_type type;
413 	s64 min;
414 	s64 max;
415 	u64 step;
416 	s64 def;
417 	union v4l2_ctrl_ptr p_def;
418 	u32 dims[V4L2_CTRL_MAX_DIMS];
419 	u32 elem_size;
420 	u32 flags;
421 	u64 menu_skip_mask;
422 	const char * const *qmenu;
423 	const s64 *qmenu_int;
424 	unsigned int is_private:1;
425 };
426 
427 /**
428  * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
429  *
430  * @id: ID of the control
431  * @name: pointer to be filled with a string with the name of the control
432  * @type: pointer for storing the type of the control
433  * @min: pointer for storing the minimum value for the control
434  * @max: pointer for storing the maximum value for the control
435  * @step: pointer for storing the control step
436  * @def: pointer for storing the default value for the control
437  * @flags: pointer for storing the flags to be used on the control
438  *
439  * This works for all standard V4L2 controls.
440  * For non-standard controls it will only fill in the given arguments
441  * and @name content will be set to %NULL.
442  *
443  * This function will overwrite the contents of @name, @type and @flags.
444  * The contents of @min, @max, @step and @def may be modified depending on
445  * the type.
446  *
447  * .. note::
448  *
449  *    Do not use in drivers! It is used internally for backwards compatibility
450  *    control handling only. Once all drivers are converted to use the new
451  *    control framework this function will no longer be exported.
452  */
453 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
454 		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
455 
456 
457 /**
458  * v4l2_ctrl_handler_init_class() - Initialize the control handler.
459  * @hdl:	The control handler.
460  * @nr_of_controls_hint: A hint of how many controls this handler is
461  *		expected to refer to. This is the total number, so including
462  *		any inherited controls. It doesn't have to be precise, but if
463  *		it is way off, then you either waste memory (too many buckets
464  *		are allocated) or the control lookup becomes slower (not enough
465  *		buckets are allocated, so there are more slow list lookups).
466  *		It will always work, though.
467  * @key:	Used by the lock validator if CONFIG_LOCKDEP is set.
468  * @name:	Used by the lock validator if CONFIG_LOCKDEP is set.
469  *
470  * .. attention::
471  *
472  *    Never use this call directly, always use the v4l2_ctrl_handler_init()
473  *    macro that hides the @key and @name arguments.
474  *
475  * Return: returns an error if the buckets could not be allocated. This
476  * error will also be stored in @hdl->error.
477  */
478 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
479 				 unsigned int nr_of_controls_hint,
480 				 struct lock_class_key *key, const char *name);
481 
482 #ifdef CONFIG_LOCKDEP
483 
484 /**
485  * v4l2_ctrl_handler_init - helper function to create a static struct
486  *	 &lock_class_key and calls v4l2_ctrl_handler_init_class()
487  *
488  * @hdl:	The control handler.
489  * @nr_of_controls_hint: A hint of how many controls this handler is
490  *		expected to refer to. This is the total number, so including
491  *		any inherited controls. It doesn't have to be precise, but if
492  *		it is way off, then you either waste memory (too many buckets
493  *		are allocated) or the control lookup becomes slower (not enough
494  *		buckets are allocated, so there are more slow list lookups).
495  *		It will always work, though.
496  *
497  * This helper function creates a static struct &lock_class_key and
498  * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
499  * validador.
500  *
501  * Use this helper function to initialize a control handler.
502  */
503 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
504 (									\
505 	({								\
506 		static struct lock_class_key _key;			\
507 		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
508 					&_key,				\
509 					KBUILD_BASENAME ":"		\
510 					__stringify(__LINE__) ":"	\
511 					"(" #hdl ")->_lock");		\
512 	})								\
513 )
514 #else
515 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
516 	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
517 #endif
518 
519 /**
520  * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
521  * the control list.
522  * @hdl:	The control handler.
523  *
524  * Does nothing if @hdl == NULL.
525  */
526 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
527 
528 /**
529  * v4l2_ctrl_lock() - Helper function to lock the handler
530  * associated with the control.
531  * @ctrl:	The control to lock.
532  */
533 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
534 {
535 	mutex_lock(ctrl->handler->lock);
536 }
537 
538 /**
539  * v4l2_ctrl_unlock() - Helper function to unlock the handler
540  * associated with the control.
541  * @ctrl:	The control to unlock.
542  */
543 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
544 {
545 	mutex_unlock(ctrl->handler->lock);
546 }
547 
548 /**
549  * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
550  * to the handler to initialize the hardware to the current control values. The
551  * caller is responsible for acquiring the control handler mutex on behalf of
552  * __v4l2_ctrl_handler_setup().
553  * @hdl:	The control handler.
554  *
555  * Button controls will be skipped, as are read-only controls.
556  *
557  * If @hdl == NULL, then this just returns 0.
558  */
559 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
560 
561 /**
562  * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
563  * to the handler to initialize the hardware to the current control values.
564  * @hdl:	The control handler.
565  *
566  * Button controls will be skipped, as are read-only controls.
567  *
568  * If @hdl == NULL, then this just returns 0.
569  */
570 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
571 
572 /**
573  * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
574  * @hdl:	The control handler.
575  * @prefix:	The prefix to use when logging the control values. If the
576  *		prefix does not end with a space, then ": " will be added
577  *		after the prefix. If @prefix == NULL, then no prefix will be
578  *		used.
579  *
580  * For use with VIDIOC_LOG_STATUS.
581  *
582  * Does nothing if @hdl == NULL.
583  */
584 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
585 				  const char *prefix);
586 
587 /**
588  * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
589  *	control.
590  *
591  * @hdl:	The control handler.
592  * @cfg:	The control's configuration data.
593  * @priv:	The control's driver-specific private data.
594  *
595  * If the &v4l2_ctrl struct could not be allocated then NULL is returned
596  * and @hdl->error is set to the error code (if it wasn't set already).
597  */
598 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
599 				       const struct v4l2_ctrl_config *cfg,
600 				       void *priv);
601 
602 /**
603  * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
604  *	control.
605  *
606  * @hdl:	The control handler.
607  * @ops:	The control ops.
608  * @id:		The control ID.
609  * @min:	The control's minimum value.
610  * @max:	The control's maximum value.
611  * @step:	The control's step value
612  * @def:	The control's default value.
613  *
614  * If the &v4l2_ctrl struct could not be allocated, or the control
615  * ID is not known, then NULL is returned and @hdl->error is set to the
616  * appropriate error code (if it wasn't set already).
617  *
618  * If @id refers to a menu control, then this function will return NULL.
619  *
620  * Use v4l2_ctrl_new_std_menu() when adding menu controls.
621  */
622 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
623 				    const struct v4l2_ctrl_ops *ops,
624 				    u32 id, s64 min, s64 max, u64 step,
625 				    s64 def);
626 
627 /**
628  * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
629  *	menu control.
630  *
631  * @hdl:	The control handler.
632  * @ops:	The control ops.
633  * @id:		The control ID.
634  * @max:	The control's maximum value.
635  * @mask:	The control's skip mask for menu controls. This makes it
636  *		easy to skip menu items that are not valid. If bit X is set,
637  *		then menu item X is skipped. Of course, this only works for
638  *		menus with <= 64 menu items. There are no menus that come
639  *		close to that number, so this is OK. Should we ever need more,
640  *		then this will have to be extended to a bit array.
641  * @def:	The control's default value.
642  *
643  * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
644  * determines which menu items are to be skipped.
645  *
646  * If @id refers to a non-menu control, then this function will return NULL.
647  */
648 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
649 					 const struct v4l2_ctrl_ops *ops,
650 					 u32 id, u8 max, u64 mask, u8 def);
651 
652 /**
653  * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
654  *	with driver specific menu.
655  *
656  * @hdl:	The control handler.
657  * @ops:	The control ops.
658  * @id:	The control ID.
659  * @max:	The control's maximum value.
660  * @mask:	The control's skip mask for menu controls. This makes it
661  *		easy to skip menu items that are not valid. If bit X is set,
662  *		then menu item X is skipped. Of course, this only works for
663  *		menus with <= 64 menu items. There are no menus that come
664  *		close to that number, so this is OK. Should we ever need more,
665  *		then this will have to be extended to a bit array.
666  * @def:	The control's default value.
667  * @qmenu:	The new menu.
668  *
669  * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
670  * menu of this control.
671  *
672  */
673 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
674 					       const struct v4l2_ctrl_ops *ops,
675 					       u32 id, u8 max,
676 					       u64 mask, u8 def,
677 					       const char * const *qmenu);
678 
679 /**
680  * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
681  *      compound control.
682  *
683  * @hdl:       The control handler.
684  * @ops:       The control ops.
685  * @id:        The control ID.
686  * @p_def:     The control's default value.
687  *
688  * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
689  * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
690  * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
691  * compound control should be all zeroes.
692  *
693  */
694 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
695 					     const struct v4l2_ctrl_ops *ops,
696 					     u32 id,
697 					     const union v4l2_ctrl_ptr p_def);
698 
699 /**
700  * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
701  *
702  * @hdl:	The control handler.
703  * @ops:	The control ops.
704  * @id:	The control ID.
705  * @max:	The control's maximum value.
706  * @def:	The control's default value.
707  * @qmenu_int:	The control's menu entries.
708  *
709  * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
710  * takes as an argument an array of integers determining the menu items.
711  *
712  * If @id refers to a non-integer-menu control, then this function will
713  * return %NULL.
714  */
715 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
716 					 const struct v4l2_ctrl_ops *ops,
717 					 u32 id, u8 max, u8 def,
718 					 const s64 *qmenu_int);
719 
720 /**
721  * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
722  *	used when adding a control handler.
723  *
724  * @ctrl: pointer to struct &v4l2_ctrl.
725  */
726 
727 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
728 
729 /**
730  * v4l2_ctrl_add_handler() - Add all controls from handler @add to
731  *	handler @hdl.
732  *
733  * @hdl:	The control handler.
734  * @add:	The control handler whose controls you want to add to
735  *		the @hdl control handler.
736  * @filter:	This function will filter which controls should be added.
737  * @from_other_dev: If true, then the controls in @add were defined in another
738  *		device than @hdl.
739  *
740  * Does nothing if either of the two handlers is a NULL pointer.
741  * If @filter is NULL, then all controls are added. Otherwise only those
742  * controls for which @filter returns true will be added.
743  * In case of an error @hdl->error will be set to the error code (if it
744  * wasn't set already).
745  */
746 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
747 			  struct v4l2_ctrl_handler *add,
748 			  v4l2_ctrl_filter filter,
749 			  bool from_other_dev);
750 
751 /**
752  * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
753  *
754  * @ctrl:	The control that is filtered.
755  *
756  * This will return true for any controls that are valid for radio device
757  * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
758  * transmitter class controls.
759  *
760  * This function is to be used with v4l2_ctrl_add_handler().
761  */
762 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
763 
764 /**
765  * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
766  *	to that cluster.
767  *
768  * @ncontrols:	The number of controls in this cluster.
769  * @controls:	The cluster control array of size @ncontrols.
770  */
771 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
772 
773 
774 /**
775  * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
776  *	to that cluster and set it up for autofoo/foo-type handling.
777  *
778  * @ncontrols:	The number of controls in this cluster.
779  * @controls:	The cluster control array of size @ncontrols. The first control
780  *		must be the 'auto' control (e.g. autogain, autoexposure, etc.)
781  * @manual_val: The value for the first control in the cluster that equals the
782  *		manual setting.
783  * @set_volatile: If true, then all controls except the first auto control will
784  *		be volatile.
785  *
786  * Use for control groups where one control selects some automatic feature and
787  * the other controls are only active whenever the automatic feature is turned
788  * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
789  * red and blue balance, etc.
790  *
791  * The behavior of such controls is as follows:
792  *
793  * When the autofoo control is set to automatic, then any manual controls
794  * are set to inactive and any reads will call g_volatile_ctrl (if the control
795  * was marked volatile).
796  *
797  * When the autofoo control is set to manual, then any manual controls will
798  * be marked active, and any reads will just return the current value without
799  * going through g_volatile_ctrl.
800  *
801  * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
802  * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
803  * if autofoo is in auto mode.
804  */
805 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
806 			    struct v4l2_ctrl **controls,
807 			    u8 manual_val, bool set_volatile);
808 
809 
810 /**
811  * v4l2_ctrl_find() - Find a control with the given ID.
812  *
813  * @hdl:	The control handler.
814  * @id:	The control ID to find.
815  *
816  * If @hdl == NULL this will return NULL as well. Will lock the handler so
817  * do not use from inside &v4l2_ctrl_ops.
818  */
819 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
820 
821 /**
822  * v4l2_ctrl_activate() - Make the control active or inactive.
823  * @ctrl:	The control to (de)activate.
824  * @active:	True if the control should become active.
825  *
826  * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
827  * Does nothing if @ctrl == NULL.
828  * This will usually be called from within the s_ctrl op.
829  * The V4L2_EVENT_CTRL event will be generated afterwards.
830  *
831  * This function assumes that the control handler is locked.
832  */
833 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
834 
835 /**
836  * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
837  *
838  * @ctrl:	The control to (de)activate.
839  * @grabbed:	True if the control should become grabbed.
840  *
841  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
842  * Does nothing if @ctrl == NULL.
843  * The V4L2_EVENT_CTRL event will be generated afterwards.
844  * This will usually be called when starting or stopping streaming in the
845  * driver.
846  *
847  * This function assumes that the control handler is locked by the caller.
848  */
849 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
850 
851 /**
852  * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
853  *
854  * @ctrl:	The control to (de)activate.
855  * @grabbed:	True if the control should become grabbed.
856  *
857  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
858  * Does nothing if @ctrl == NULL.
859  * The V4L2_EVENT_CTRL event will be generated afterwards.
860  * This will usually be called when starting or stopping streaming in the
861  * driver.
862  *
863  * This function assumes that the control handler is not locked and will
864  * take the lock itself.
865  */
866 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
867 {
868 	if (!ctrl)
869 		return;
870 
871 	v4l2_ctrl_lock(ctrl);
872 	__v4l2_ctrl_grab(ctrl, grabbed);
873 	v4l2_ctrl_unlock(ctrl);
874 }
875 
876 /**
877  *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
878  *
879  * @ctrl:	The control to update.
880  * @min:	The control's minimum value.
881  * @max:	The control's maximum value.
882  * @step:	The control's step value
883  * @def:	The control's default value.
884  *
885  * Update the range of a control on the fly. This works for control types
886  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
887  * @step value is interpreted as a menu_skip_mask.
888  *
889  * An error is returned if one of the range arguments is invalid for this
890  * control type.
891  *
892  * The caller is responsible for acquiring the control handler mutex on behalf
893  * of __v4l2_ctrl_modify_range().
894  */
895 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
896 			     s64 min, s64 max, u64 step, s64 def);
897 
898 /**
899  * v4l2_ctrl_modify_range() - Update the range of a control.
900  *
901  * @ctrl:	The control to update.
902  * @min:	The control's minimum value.
903  * @max:	The control's maximum value.
904  * @step:	The control's step value
905  * @def:	The control's default value.
906  *
907  * Update the range of a control on the fly. This works for control types
908  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
909  * @step value is interpreted as a menu_skip_mask.
910  *
911  * An error is returned if one of the range arguments is invalid for this
912  * control type.
913  *
914  * This function assumes that the control handler is not locked and will
915  * take the lock itself.
916  */
917 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
918 					 s64 min, s64 max, u64 step, s64 def)
919 {
920 	int rval;
921 
922 	v4l2_ctrl_lock(ctrl);
923 	rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
924 	v4l2_ctrl_unlock(ctrl);
925 
926 	return rval;
927 }
928 
929 /**
930  * v4l2_ctrl_notify() - Function to set a notify callback for a control.
931  *
932  * @ctrl:	The control.
933  * @notify:	The callback function.
934  * @priv:	The callback private handle, passed as argument to the callback.
935  *
936  * This function sets a callback function for the control. If @ctrl is NULL,
937  * then it will do nothing. If @notify is NULL, then the notify callback will
938  * be removed.
939  *
940  * There can be only one notify. If another already exists, then a WARN_ON
941  * will be issued and the function will do nothing.
942  */
943 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
944 		      void *priv);
945 
946 /**
947  * v4l2_ctrl_get_name() - Get the name of the control
948  *
949  * @id:		The control ID.
950  *
951  * This function returns the name of the given control ID or NULL if it isn't
952  * a known control.
953  */
954 const char *v4l2_ctrl_get_name(u32 id);
955 
956 /**
957  * v4l2_ctrl_get_menu() - Get the menu string array of the control
958  *
959  * @id:		The control ID.
960  *
961  * This function returns the NULL-terminated menu string array name of the
962  * given control ID or NULL if it isn't a known menu control.
963  */
964 const char * const *v4l2_ctrl_get_menu(u32 id);
965 
966 /**
967  * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
968  *
969  * @id:		The control ID.
970  * @len:	The size of the integer array.
971  *
972  * This function returns the integer array of the given control ID or NULL if it
973  * if it isn't a known integer menu control.
974  */
975 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
976 
977 /**
978  * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
979  *	within a driver.
980  *
981  * @ctrl:	The control.
982  *
983  * This returns the control's value safely by going through the control
984  * framework. This function will lock the control's handler, so it cannot be
985  * used from within the &v4l2_ctrl_ops functions.
986  *
987  * This function is for integer type controls only.
988  */
989 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
990 
991 /**
992  * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
993  *
994  * @ctrl:	The control.
995  * @val:	The new value.
996  *
997  * This sets the control's new value safely by going through the control
998  * framework. This function assumes the control's handler is already locked,
999  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1000  *
1001  * This function is for integer type controls only.
1002  */
1003 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1004 
1005 /**
1006  * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1007  *	within a driver.
1008  * @ctrl:	The control.
1009  * @val:	The new value.
1010  *
1011  * This sets the control's new value safely by going through the control
1012  * framework. This function will lock the control's handler, so it cannot be
1013  * used from within the &v4l2_ctrl_ops functions.
1014  *
1015  * This function is for integer type controls only.
1016  */
1017 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1018 {
1019 	int rval;
1020 
1021 	v4l2_ctrl_lock(ctrl);
1022 	rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1023 	v4l2_ctrl_unlock(ctrl);
1024 
1025 	return rval;
1026 }
1027 
1028 /**
1029  * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1030  *	from within a driver.
1031  *
1032  * @ctrl:	The control.
1033  *
1034  * This returns the control's value safely by going through the control
1035  * framework. This function will lock the control's handler, so it cannot be
1036  * used from within the &v4l2_ctrl_ops functions.
1037  *
1038  * This function is for 64-bit integer type controls only.
1039  */
1040 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1041 
1042 /**
1043  * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1044  *
1045  * @ctrl:	The control.
1046  * @val:	The new value.
1047  *
1048  * This sets the control's new value safely by going through the control
1049  * framework. This function assumes the control's handler is already locked,
1050  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1051  *
1052  * This function is for 64-bit integer type controls only.
1053  */
1054 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1055 
1056 /**
1057  * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1058  *	from within a driver.
1059  *
1060  * @ctrl:	The control.
1061  * @val:	The new value.
1062  *
1063  * This sets the control's new value safely by going through the control
1064  * framework. This function will lock the control's handler, so it cannot be
1065  * used from within the &v4l2_ctrl_ops functions.
1066  *
1067  * This function is for 64-bit integer type controls only.
1068  */
1069 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1070 {
1071 	int rval;
1072 
1073 	v4l2_ctrl_lock(ctrl);
1074 	rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1075 	v4l2_ctrl_unlock(ctrl);
1076 
1077 	return rval;
1078 }
1079 
1080 /**
1081  * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1082  *
1083  * @ctrl:	The control.
1084  * @s:		The new string.
1085  *
1086  * This sets the control's new string safely by going through the control
1087  * framework. This function assumes the control's handler is already locked,
1088  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1089  *
1090  * This function is for string type controls only.
1091  */
1092 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1093 
1094 /**
1095  * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1096  *	 from within a driver.
1097  *
1098  * @ctrl:	The control.
1099  * @s:		The new string.
1100  *
1101  * This sets the control's new string safely by going through the control
1102  * framework. This function will lock the control's handler, so it cannot be
1103  * used from within the &v4l2_ctrl_ops functions.
1104  *
1105  * This function is for string type controls only.
1106  */
1107 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1108 {
1109 	int rval;
1110 
1111 	v4l2_ctrl_lock(ctrl);
1112 	rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1113 	v4l2_ctrl_unlock(ctrl);
1114 
1115 	return rval;
1116 }
1117 
1118 /**
1119  * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1120  *
1121  * @ctrl: The control.
1122  * @type: The type of the data.
1123  * @p:    The new compound payload.
1124  *
1125  * This sets the control's new compound payload safely by going through the
1126  * control framework. This function assumes the control's handler is already
1127  * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1128  *
1129  * This function is for compound type controls only.
1130  */
1131 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1132 				enum v4l2_ctrl_type type, const void *p);
1133 
1134 /**
1135  * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1136  *	from within a driver.
1137  *
1138  * @ctrl: The control.
1139  * @type: The type of the data.
1140  * @p:    The new compound payload.
1141  *
1142  * This sets the control's new compound payload safely by going through the
1143  * control framework. This function will lock the control's handler, so it
1144  * cannot be used from within the &v4l2_ctrl_ops functions.
1145  *
1146  * This function is for compound type controls only.
1147  */
1148 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1149 					    enum v4l2_ctrl_type type,
1150 					    const void *p)
1151 {
1152 	int rval;
1153 
1154 	v4l2_ctrl_lock(ctrl);
1155 	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1156 	v4l2_ctrl_unlock(ctrl);
1157 
1158 	return rval;
1159 }
1160 
1161 /* Helper defines for area type controls */
1162 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1163 	__v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1164 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1165 	v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1166 
1167 /* Internal helper functions that deal with control events. */
1168 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1169 
1170 /**
1171  * v4l2_ctrl_replace - Function to be used as a callback to
1172  *	&struct v4l2_subscribed_event_ops replace\(\)
1173  *
1174  * @old: pointer to struct &v4l2_event with the reported
1175  *	 event;
1176  * @new: pointer to struct &v4l2_event with the modified
1177  *	 event;
1178  */
1179 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1180 
1181 /**
1182  * v4l2_ctrl_merge - Function to be used as a callback to
1183  *	&struct v4l2_subscribed_event_ops merge(\)
1184  *
1185  * @old: pointer to struct &v4l2_event with the reported
1186  *	 event;
1187  * @new: pointer to struct &v4l2_event with the merged
1188  *	 event;
1189  */
1190 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1191 
1192 /**
1193  * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1194  *
1195  * @file: pointer to struct file
1196  * @fh: unused. Kept just to be compatible to the arguments expected by
1197  *	&struct v4l2_ioctl_ops.vidioc_log_status.
1198  *
1199  * Can be used as a vidioc_log_status function that just dumps all controls
1200  * associated with the filehandle.
1201  */
1202 int v4l2_ctrl_log_status(struct file *file, void *fh);
1203 
1204 /**
1205  * v4l2_ctrl_subscribe_event - Subscribes to an event
1206  *
1207  *
1208  * @fh: pointer to struct v4l2_fh
1209  * @sub: pointer to &struct v4l2_event_subscription
1210  *
1211  * Can be used as a vidioc_subscribe_event function that just subscribes
1212  * control events.
1213  */
1214 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1215 				const struct v4l2_event_subscription *sub);
1216 
1217 /**
1218  * v4l2_ctrl_poll - function to be used as a callback to the poll()
1219  *	That just polls for control events.
1220  *
1221  * @file: pointer to struct file
1222  * @wait: pointer to struct poll_table_struct
1223  */
1224 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1225 
1226 /**
1227  * v4l2_ctrl_request_setup - helper function to apply control values in a request
1228  *
1229  * @req: The request
1230  * @parent: The parent control handler ('priv' in media_request_object_find())
1231  *
1232  * This is a helper function to call the control handler's s_ctrl callback with
1233  * the control values contained in the request. Do note that this approach of
1234  * applying control values in a request is only applicable to memory-to-memory
1235  * devices.
1236  */
1237 int v4l2_ctrl_request_setup(struct media_request *req,
1238 			     struct v4l2_ctrl_handler *parent);
1239 
1240 /**
1241  * v4l2_ctrl_request_complete - Complete a control handler request object
1242  *
1243  * @req: The request
1244  * @parent: The parent control handler ('priv' in media_request_object_find())
1245  *
1246  * This function is to be called on each control handler that may have had a
1247  * request object associated with it, i.e. control handlers of a driver that
1248  * supports requests.
1249  *
1250  * The function first obtains the values of any volatile controls in the control
1251  * handler and attach them to the request. Then, the function completes the
1252  * request object.
1253  */
1254 void v4l2_ctrl_request_complete(struct media_request *req,
1255 				struct v4l2_ctrl_handler *parent);
1256 
1257 /**
1258  * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1259  *
1260  * @req: The request
1261  * @parent: The parent control handler ('priv' in media_request_object_find())
1262  *
1263  * This function finds the control handler in the request. It may return
1264  * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1265  * with the returned handler pointer.
1266  *
1267  * If the request is not in state VALIDATING or QUEUED, then this function
1268  * will always return NULL.
1269  *
1270  * Note that in state VALIDATING the req_queue_mutex is held, so
1271  * no objects can be added or deleted from the request.
1272  *
1273  * In state QUEUED it is the driver that will have to ensure this.
1274  */
1275 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1276 					struct v4l2_ctrl_handler *parent);
1277 
1278 /**
1279  * v4l2_ctrl_request_hdl_put - Put the control handler
1280  *
1281  * @hdl: Put this control handler
1282  *
1283  * This function released the control handler previously obtained from'
1284  * v4l2_ctrl_request_hdl_find().
1285  */
1286 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1287 {
1288 	if (hdl)
1289 		media_request_object_put(&hdl->req_obj);
1290 }
1291 
1292 /**
1293  * v4l2_ctrl_request_ctrl_find() - Find a control with the given ID.
1294  *
1295  * @hdl: The control handler from the request.
1296  * @id: The ID of the control to find.
1297  *
1298  * This function returns a pointer to the control if this control is
1299  * part of the request or NULL otherwise.
1300  */
1301 struct v4l2_ctrl *
1302 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1303 
1304 /* Helpers for ioctl_ops */
1305 
1306 /**
1307  * v4l2_queryctrl - Helper function to implement
1308  *	:ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1309  *
1310  * @hdl: pointer to &struct v4l2_ctrl_handler
1311  * @qc: pointer to &struct v4l2_queryctrl
1312  *
1313  * If hdl == NULL then they will all return -EINVAL.
1314  */
1315 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1316 
1317 /**
1318  * v4l2_query_ext_ctrl - Helper function to implement
1319  *	 :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1320  *
1321  * @hdl: pointer to &struct v4l2_ctrl_handler
1322  * @qc: pointer to &struct v4l2_query_ext_ctrl
1323  *
1324  * If hdl == NULL then they will all return -EINVAL.
1325  */
1326 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1327 			struct v4l2_query_ext_ctrl *qc);
1328 
1329 /**
1330  * v4l2_querymenu - Helper function to implement
1331  *	:ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1332  *
1333  * @hdl: pointer to &struct v4l2_ctrl_handler
1334  * @qm: pointer to &struct v4l2_querymenu
1335  *
1336  * If hdl == NULL then they will all return -EINVAL.
1337  */
1338 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1339 
1340 /**
1341  * v4l2_g_ctrl - Helper function to implement
1342  *	:ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1343  *
1344  * @hdl: pointer to &struct v4l2_ctrl_handler
1345  * @ctrl: pointer to &struct v4l2_control
1346  *
1347  * If hdl == NULL then they will all return -EINVAL.
1348  */
1349 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1350 
1351 /**
1352  * v4l2_s_ctrl - Helper function to implement
1353  *	:ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1354  *
1355  * @fh: pointer to &struct v4l2_fh
1356  * @hdl: pointer to &struct v4l2_ctrl_handler
1357  *
1358  * @ctrl: pointer to &struct v4l2_control
1359  *
1360  * If hdl == NULL then they will all return -EINVAL.
1361  */
1362 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1363 		struct v4l2_control *ctrl);
1364 
1365 /**
1366  * v4l2_g_ext_ctrls - Helper function to implement
1367  *	:ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1368  *
1369  * @hdl: pointer to &struct v4l2_ctrl_handler
1370  * @vdev: pointer to &struct video_device
1371  * @mdev: pointer to &struct media_device
1372  * @c: pointer to &struct v4l2_ext_controls
1373  *
1374  * If hdl == NULL then they will all return -EINVAL.
1375  */
1376 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1377 		     struct media_device *mdev, struct v4l2_ext_controls *c);
1378 
1379 /**
1380  * v4l2_try_ext_ctrls - Helper function to implement
1381  *	:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1382  *
1383  * @hdl: pointer to &struct v4l2_ctrl_handler
1384  * @vdev: pointer to &struct video_device
1385  * @mdev: pointer to &struct media_device
1386  * @c: pointer to &struct v4l2_ext_controls
1387  *
1388  * If hdl == NULL then they will all return -EINVAL.
1389  */
1390 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1391 		       struct video_device *vdev,
1392 		       struct media_device *mdev,
1393 		       struct v4l2_ext_controls *c);
1394 
1395 /**
1396  * v4l2_s_ext_ctrls - Helper function to implement
1397  *	:ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1398  *
1399  * @fh: pointer to &struct v4l2_fh
1400  * @hdl: pointer to &struct v4l2_ctrl_handler
1401  * @vdev: pointer to &struct video_device
1402  * @mdev: pointer to &struct media_device
1403  * @c: pointer to &struct v4l2_ext_controls
1404  *
1405  * If hdl == NULL then they will all return -EINVAL.
1406  */
1407 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1408 		     struct video_device *vdev,
1409 		     struct media_device *mdev,
1410 		     struct v4l2_ext_controls *c);
1411 
1412 /**
1413  * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1414  *	as a &struct v4l2_subdev_core_ops subscribe_event function
1415  *	that just subscribes control events.
1416  *
1417  * @sd: pointer to &struct v4l2_subdev
1418  * @fh: pointer to &struct v4l2_fh
1419  * @sub: pointer to &struct v4l2_event_subscription
1420  */
1421 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1422 				     struct v4l2_event_subscription *sub);
1423 
1424 /**
1425  * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1426  *	 handler.
1427  *
1428  * @sd: pointer to &struct v4l2_subdev
1429  */
1430 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1431 
1432 /**
1433  * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1434  *				       properties
1435  *
1436  * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1437  * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1438  * @p: pointer to &struct v4l2_fwnode_device_properties
1439  *
1440  * This function registers controls associated to device properties, using the
1441  * property values contained in @p parameter, if the property has been set to
1442  * a value.
1443  *
1444  * Currently the following v4l2 controls are parsed and registered:
1445  * - V4L2_CID_CAMERA_ORIENTATION
1446  * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1447  *
1448  * Controls already registered by the caller with the @hdl control handler are
1449  * not overwritten. Callers should register the controls they want to handle
1450  * themselves before calling this function.
1451  *
1452  * Return: 0 on success, a negative error code on failure.
1453  */
1454 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1455 				    const struct v4l2_ctrl_ops *ctrl_ops,
1456 				    const struct v4l2_fwnode_device_properties *p);
1457 #endif
1458