xref: /openbmc/linux/include/media/v4l2-ctrls.h (revision 2208f39c)
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_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  */
63 union 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  */
93 static 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  */
114 struct v4l2_ctrl_ops {
115 	int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
116 	int (*try_ctrl)(struct v4l2_ctrl *ctrl);
117 	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
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  */
130 struct v4l2_ctrl_type_ops {
131 	bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
132 		      union v4l2_ctrl_ptr ptr1,
133 		      union v4l2_ctrl_ptr ptr2);
134 	void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
135 		     union v4l2_ctrl_ptr ptr);
136 	void (*log)(const struct v4l2_ctrl *ctrl);
137 	int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
138 			union v4l2_ctrl_ptr ptr);
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  */
151 typedef 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  */
239 struct 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  * @req:	If set, this refers to another request that sets this control.
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 should be applied when the request
310  *		is executed, or to the value of the control at the time
311  *		that the request was completed.
312  *
313  * Each control handler has a list of these refs. The list_head is used to
314  * keep a sorted-by-control-ID list of all controls, while the next pointer
315  * is used to link the control in the hash's bucket.
316  */
317 struct v4l2_ctrl_ref {
318 	struct list_head node;
319 	struct v4l2_ctrl_ref *next;
320 	struct v4l2_ctrl *ctrl;
321 	struct v4l2_ctrl_helper *helper;
322 	bool from_other_dev;
323 	bool req_done;
324 	struct v4l2_ctrl_ref *req;
325 	union v4l2_ctrl_ptr p_req;
326 };
327 
328 /**
329  * struct v4l2_ctrl_handler - The control handler keeps track of all the
330  *	controls: both the controls owned by the handler and those inherited
331  *	from other handlers.
332  *
333  * @_lock:	Default for "lock".
334  * @lock:	Lock to control access to this handler and its controls.
335  *		May be replaced by the user right after init.
336  * @ctrls:	The list of controls owned by this handler.
337  * @ctrl_refs:	The list of control references.
338  * @cached:	The last found control reference. It is common that the same
339  *		control is needed multiple times, so this is a simple
340  *		optimization.
341  * @buckets:	Buckets for the hashing. Allows for quick control lookup.
342  * @notify:	A notify callback that is called whenever the control changes
343  *		value.
344  *		Note that the handler's lock is held when the notify function
345  *		is called!
346  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
347  * @nr_of_buckets: Total number of buckets in the array.
348  * @error:	The error code of the first failed control addition.
349  * @request_is_queued: True if the request was queued.
350  * @requests:	List to keep track of open control handler request objects.
351  *		For the parent control handler (@req_obj.req == NULL) this
352  *		is the list header. When the parent control handler is
353  *		removed, it has to unbind and put all these requests since
354  *		they refer to the parent.
355  * @requests_queued: List of the queued requests. This determines the order
356  *		in which these controls are applied. Once the request is
357  *		completed it is removed from this list.
358  * @req_obj:	The &struct media_request_object, used to link into a
359  *		&struct media_request. This request object has a refcount.
360  */
361 struct v4l2_ctrl_handler {
362 	struct mutex _lock;
363 	struct mutex *lock;
364 	struct list_head ctrls;
365 	struct list_head ctrl_refs;
366 	struct v4l2_ctrl_ref *cached;
367 	struct v4l2_ctrl_ref **buckets;
368 	v4l2_ctrl_notify_fnc notify;
369 	void *notify_priv;
370 	u16 nr_of_buckets;
371 	int error;
372 	bool request_is_queued;
373 	struct list_head requests;
374 	struct list_head requests_queued;
375 	struct media_request_object req_obj;
376 };
377 
378 /**
379  * struct v4l2_ctrl_config - Control configuration structure.
380  *
381  * @ops:	The control ops.
382  * @type_ops:	The control type ops. Only needed for compound controls.
383  * @id:	The control ID.
384  * @name:	The control name.
385  * @type:	The control type.
386  * @min:	The control's minimum value.
387  * @max:	The control's maximum value.
388  * @step:	The control's step value for non-menu controls.
389  * @def:	The control's default value.
390  * @p_def:	The control's default value for compound controls.
391  * @dims:	The size of each dimension.
392  * @elem_size:	The size in bytes of the control.
393  * @flags:	The control's flags.
394  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
395  *		easy to skip menu items that are not valid. If bit X is set,
396  *		then menu item X is skipped. Of course, this only works for
397  *		menus with <= 64 menu items. There are no menus that come
398  *		close to that number, so this is OK. Should we ever need more,
399  *		then this will have to be extended to a bit array.
400  * @qmenu:	A const char * array for all menu items. Array entries that are
401  *		empty strings ("") correspond to non-existing menu items (this
402  *		is in addition to the menu_skip_mask above). The last entry
403  *		must be NULL.
404  * @qmenu_int:	A const s64 integer array for all menu items of the type
405  *		V4L2_CTRL_TYPE_INTEGER_MENU.
406  * @is_private: If set, then this control is private to its handler and it
407  *		will not be added to any other handlers.
408  */
409 struct v4l2_ctrl_config {
410 	const struct v4l2_ctrl_ops *ops;
411 	const struct v4l2_ctrl_type_ops *type_ops;
412 	u32 id;
413 	const char *name;
414 	enum v4l2_ctrl_type type;
415 	s64 min;
416 	s64 max;
417 	u64 step;
418 	s64 def;
419 	union v4l2_ctrl_ptr p_def;
420 	u32 dims[V4L2_CTRL_MAX_DIMS];
421 	u32 elem_size;
422 	u32 flags;
423 	u64 menu_skip_mask;
424 	const char * const *qmenu;
425 	const s64 *qmenu_int;
426 	unsigned int is_private:1;
427 };
428 
429 /**
430  * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
431  *
432  * @id: ID of the control
433  * @name: pointer to be filled with a string with the name of the control
434  * @type: pointer for storing the type of the control
435  * @min: pointer for storing the minimum value for the control
436  * @max: pointer for storing the maximum value for the control
437  * @step: pointer for storing the control step
438  * @def: pointer for storing the default value for the control
439  * @flags: pointer for storing the flags to be used on the control
440  *
441  * This works for all standard V4L2 controls.
442  * For non-standard controls it will only fill in the given arguments
443  * and @name content will be set to %NULL.
444  *
445  * This function will overwrite the contents of @name, @type and @flags.
446  * The contents of @min, @max, @step and @def may be modified depending on
447  * the type.
448  *
449  * .. note::
450  *
451  *    Do not use in drivers! It is used internally for backwards compatibility
452  *    control handling only. Once all drivers are converted to use the new
453  *    control framework this function will no longer be exported.
454  */
455 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
456 		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
457 
458 
459 /**
460  * v4l2_ctrl_handler_init_class() - Initialize the control handler.
461  * @hdl:	The control handler.
462  * @nr_of_controls_hint: A hint of how many controls this handler is
463  *		expected to refer to. This is the total number, so including
464  *		any inherited controls. It doesn't have to be precise, but if
465  *		it is way off, then you either waste memory (too many buckets
466  *		are allocated) or the control lookup becomes slower (not enough
467  *		buckets are allocated, so there are more slow list lookups).
468  *		It will always work, though.
469  * @key:	Used by the lock validator if CONFIG_LOCKDEP is set.
470  * @name:	Used by the lock validator if CONFIG_LOCKDEP is set.
471  *
472  * .. attention::
473  *
474  *    Never use this call directly, always use the v4l2_ctrl_handler_init()
475  *    macro that hides the @key and @name arguments.
476  *
477  * Return: returns an error if the buckets could not be allocated. This
478  * error will also be stored in @hdl->error.
479  */
480 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
481 				 unsigned int nr_of_controls_hint,
482 				 struct lock_class_key *key, const char *name);
483 
484 #ifdef CONFIG_LOCKDEP
485 
486 /**
487  * v4l2_ctrl_handler_init - helper function to create a static struct
488  *	 &lock_class_key and calls v4l2_ctrl_handler_init_class()
489  *
490  * @hdl:	The control handler.
491  * @nr_of_controls_hint: A hint of how many controls this handler is
492  *		expected to refer to. This is the total number, so including
493  *		any inherited controls. It doesn't have to be precise, but if
494  *		it is way off, then you either waste memory (too many buckets
495  *		are allocated) or the control lookup becomes slower (not enough
496  *		buckets are allocated, so there are more slow list lookups).
497  *		It will always work, though.
498  *
499  * This helper function creates a static struct &lock_class_key and
500  * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
501  * validador.
502  *
503  * Use this helper function to initialize a control handler.
504  */
505 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
506 (									\
507 	({								\
508 		static struct lock_class_key _key;			\
509 		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
510 					&_key,				\
511 					KBUILD_BASENAME ":"		\
512 					__stringify(__LINE__) ":"	\
513 					"(" #hdl ")->_lock");		\
514 	})								\
515 )
516 #else
517 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
518 	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
519 #endif
520 
521 /**
522  * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
523  * the control list.
524  * @hdl:	The control handler.
525  *
526  * Does nothing if @hdl == NULL.
527  */
528 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
529 
530 /**
531  * v4l2_ctrl_lock() - Helper function to lock the handler
532  * associated with the control.
533  * @ctrl:	The control to lock.
534  */
535 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
536 {
537 	mutex_lock(ctrl->handler->lock);
538 }
539 
540 /**
541  * v4l2_ctrl_unlock() - Helper function to unlock the handler
542  * associated with the control.
543  * @ctrl:	The control to unlock.
544  */
545 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
546 {
547 	mutex_unlock(ctrl->handler->lock);
548 }
549 
550 /**
551  * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
552  * to the handler to initialize the hardware to the current control values. The
553  * caller is responsible for acquiring the control handler mutex on behalf of
554  * __v4l2_ctrl_handler_setup().
555  * @hdl:	The control handler.
556  *
557  * Button controls will be skipped, as are read-only controls.
558  *
559  * If @hdl == NULL, then this just returns 0.
560  */
561 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
562 
563 /**
564  * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
565  * to the handler to initialize the hardware to the current control values.
566  * @hdl:	The control handler.
567  *
568  * Button controls will be skipped, as are read-only controls.
569  *
570  * If @hdl == NULL, then this just returns 0.
571  */
572 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
573 
574 /**
575  * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
576  * @hdl:	The control handler.
577  * @prefix:	The prefix to use when logging the control values. If the
578  *		prefix does not end with a space, then ": " will be added
579  *		after the prefix. If @prefix == NULL, then no prefix will be
580  *		used.
581  *
582  * For use with VIDIOC_LOG_STATUS.
583  *
584  * Does nothing if @hdl == NULL.
585  */
586 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
587 				  const char *prefix);
588 
589 /**
590  * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
591  *	control.
592  *
593  * @hdl:	The control handler.
594  * @cfg:	The control's configuration data.
595  * @priv:	The control's driver-specific private data.
596  *
597  * If the &v4l2_ctrl struct could not be allocated then NULL is returned
598  * and @hdl->error is set to the error code (if it wasn't set already).
599  */
600 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
601 				       const struct v4l2_ctrl_config *cfg,
602 				       void *priv);
603 
604 /**
605  * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
606  *	control.
607  *
608  * @hdl:	The control handler.
609  * @ops:	The control ops.
610  * @id:		The control ID.
611  * @min:	The control's minimum value.
612  * @max:	The control's maximum value.
613  * @step:	The control's step value
614  * @def:	The control's default value.
615  *
616  * If the &v4l2_ctrl struct could not be allocated, or the control
617  * ID is not known, then NULL is returned and @hdl->error is set to the
618  * appropriate error code (if it wasn't set already).
619  *
620  * If @id refers to a menu control, then this function will return NULL.
621  *
622  * Use v4l2_ctrl_new_std_menu() when adding menu controls.
623  */
624 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
625 				    const struct v4l2_ctrl_ops *ops,
626 				    u32 id, s64 min, s64 max, u64 step,
627 				    s64 def);
628 
629 /**
630  * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
631  *	menu control.
632  *
633  * @hdl:	The control handler.
634  * @ops:	The control ops.
635  * @id:		The control ID.
636  * @max:	The control's maximum value.
637  * @mask:	The control's skip mask for menu controls. This makes it
638  *		easy to skip menu items that are not valid. If bit X is set,
639  *		then menu item X is skipped. Of course, this only works for
640  *		menus with <= 64 menu items. There are no menus that come
641  *		close to that number, so this is OK. Should we ever need more,
642  *		then this will have to be extended to a bit array.
643  * @def:	The control's default value.
644  *
645  * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
646  * determines which menu items are to be skipped.
647  *
648  * If @id refers to a non-menu control, then this function will return NULL.
649  */
650 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
651 					 const struct v4l2_ctrl_ops *ops,
652 					 u32 id, u8 max, u64 mask, u8 def);
653 
654 /**
655  * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
656  *	with driver specific menu.
657  *
658  * @hdl:	The control handler.
659  * @ops:	The control ops.
660  * @id:	The control ID.
661  * @max:	The control's maximum value.
662  * @mask:	The control's skip mask for menu controls. This makes it
663  *		easy to skip menu items that are not valid. If bit X is set,
664  *		then menu item X is skipped. Of course, this only works for
665  *		menus with <= 64 menu items. There are no menus that come
666  *		close to that number, so this is OK. Should we ever need more,
667  *		then this will have to be extended to a bit array.
668  * @def:	The control's default value.
669  * @qmenu:	The new menu.
670  *
671  * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
672  * menu of this control.
673  *
674  */
675 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
676 					       const struct v4l2_ctrl_ops *ops,
677 					       u32 id, u8 max,
678 					       u64 mask, u8 def,
679 					       const char * const *qmenu);
680 
681 /**
682  * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
683  *      compound control.
684  *
685  * @hdl:       The control handler.
686  * @ops:       The control ops.
687  * @id:        The control ID.
688  * @p_def:     The control's default value.
689  *
690  * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
691  * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
692  * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
693  * compound control should be all zeroes.
694  *
695  */
696 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
697 					     const struct v4l2_ctrl_ops *ops,
698 					     u32 id,
699 					     const union v4l2_ctrl_ptr p_def);
700 
701 /**
702  * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
703  *
704  * @hdl:	The control handler.
705  * @ops:	The control ops.
706  * @id:	The control ID.
707  * @max:	The control's maximum value.
708  * @def:	The control's default value.
709  * @qmenu_int:	The control's menu entries.
710  *
711  * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
712  * takes as an argument an array of integers determining the menu items.
713  *
714  * If @id refers to a non-integer-menu control, then this function will
715  * return %NULL.
716  */
717 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
718 					 const struct v4l2_ctrl_ops *ops,
719 					 u32 id, u8 max, u8 def,
720 					 const s64 *qmenu_int);
721 
722 /**
723  * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
724  *	used when adding a control handler.
725  *
726  * @ctrl: pointer to struct &v4l2_ctrl.
727  */
728 
729 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
730 
731 /**
732  * v4l2_ctrl_add_handler() - Add all controls from handler @add to
733  *	handler @hdl.
734  *
735  * @hdl:	The control handler.
736  * @add:	The control handler whose controls you want to add to
737  *		the @hdl control handler.
738  * @filter:	This function will filter which controls should be added.
739  * @from_other_dev: If true, then the controls in @add were defined in another
740  *		device than @hdl.
741  *
742  * Does nothing if either of the two handlers is a NULL pointer.
743  * If @filter is NULL, then all controls are added. Otherwise only those
744  * controls for which @filter returns true will be added.
745  * In case of an error @hdl->error will be set to the error code (if it
746  * wasn't set already).
747  */
748 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
749 			  struct v4l2_ctrl_handler *add,
750 			  v4l2_ctrl_filter filter,
751 			  bool from_other_dev);
752 
753 /**
754  * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
755  *
756  * @ctrl:	The control that is filtered.
757  *
758  * This will return true for any controls that are valid for radio device
759  * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
760  * transmitter class controls.
761  *
762  * This function is to be used with v4l2_ctrl_add_handler().
763  */
764 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
765 
766 /**
767  * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
768  *	to that cluster.
769  *
770  * @ncontrols:	The number of controls in this cluster.
771  * @controls:	The cluster control array of size @ncontrols.
772  */
773 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
774 
775 
776 /**
777  * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
778  *	to that cluster and set it up for autofoo/foo-type handling.
779  *
780  * @ncontrols:	The number of controls in this cluster.
781  * @controls:	The cluster control array of size @ncontrols. The first control
782  *		must be the 'auto' control (e.g. autogain, autoexposure, etc.)
783  * @manual_val: The value for the first control in the cluster that equals the
784  *		manual setting.
785  * @set_volatile: If true, then all controls except the first auto control will
786  *		be volatile.
787  *
788  * Use for control groups where one control selects some automatic feature and
789  * the other controls are only active whenever the automatic feature is turned
790  * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
791  * red and blue balance, etc.
792  *
793  * The behavior of such controls is as follows:
794  *
795  * When the autofoo control is set to automatic, then any manual controls
796  * are set to inactive and any reads will call g_volatile_ctrl (if the control
797  * was marked volatile).
798  *
799  * When the autofoo control is set to manual, then any manual controls will
800  * be marked active, and any reads will just return the current value without
801  * going through g_volatile_ctrl.
802  *
803  * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
804  * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
805  * if autofoo is in auto mode.
806  */
807 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
808 			    struct v4l2_ctrl **controls,
809 			    u8 manual_val, bool set_volatile);
810 
811 
812 /**
813  * v4l2_ctrl_find() - Find a control with the given ID.
814  *
815  * @hdl:	The control handler.
816  * @id:	The control ID to find.
817  *
818  * If @hdl == NULL this will return NULL as well. Will lock the handler so
819  * do not use from inside &v4l2_ctrl_ops.
820  */
821 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
822 
823 /**
824  * v4l2_ctrl_activate() - Make the control active or inactive.
825  * @ctrl:	The control to (de)activate.
826  * @active:	True if the control should become active.
827  *
828  * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
829  * Does nothing if @ctrl == NULL.
830  * This will usually be called from within the s_ctrl op.
831  * The V4L2_EVENT_CTRL event will be generated afterwards.
832  *
833  * This function assumes that the control handler is locked.
834  */
835 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
836 
837 /**
838  * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
839  *
840  * @ctrl:	The control to (de)activate.
841  * @grabbed:	True if the control should become grabbed.
842  *
843  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
844  * Does nothing if @ctrl == NULL.
845  * The V4L2_EVENT_CTRL event will be generated afterwards.
846  * This will usually be called when starting or stopping streaming in the
847  * driver.
848  *
849  * This function assumes that the control handler is locked by the caller.
850  */
851 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
852 
853 /**
854  * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
855  *
856  * @ctrl:	The control to (de)activate.
857  * @grabbed:	True if the control should become grabbed.
858  *
859  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
860  * Does nothing if @ctrl == NULL.
861  * The V4L2_EVENT_CTRL event will be generated afterwards.
862  * This will usually be called when starting or stopping streaming in the
863  * driver.
864  *
865  * This function assumes that the control handler is not locked and will
866  * take the lock itself.
867  */
868 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
869 {
870 	if (!ctrl)
871 		return;
872 
873 	v4l2_ctrl_lock(ctrl);
874 	__v4l2_ctrl_grab(ctrl, grabbed);
875 	v4l2_ctrl_unlock(ctrl);
876 }
877 
878 /**
879  *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
880  *
881  * @ctrl:	The control to update.
882  * @min:	The control's minimum value.
883  * @max:	The control's maximum value.
884  * @step:	The control's step value
885  * @def:	The control's default value.
886  *
887  * Update the range of a control on the fly. This works for control types
888  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
889  * @step value is interpreted as a menu_skip_mask.
890  *
891  * An error is returned if one of the range arguments is invalid for this
892  * control type.
893  *
894  * The caller is responsible for acquiring the control handler mutex on behalf
895  * of __v4l2_ctrl_modify_range().
896  */
897 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
898 			     s64 min, s64 max, u64 step, s64 def);
899 
900 /**
901  * v4l2_ctrl_modify_range() - Update the range of a control.
902  *
903  * @ctrl:	The control to update.
904  * @min:	The control's minimum value.
905  * @max:	The control's maximum value.
906  * @step:	The control's step value
907  * @def:	The control's default value.
908  *
909  * Update the range of a control on the fly. This works for control types
910  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
911  * @step value is interpreted as a menu_skip_mask.
912  *
913  * An error is returned if one of the range arguments is invalid for this
914  * control type.
915  *
916  * This function assumes that the control handler is not locked and will
917  * take the lock itself.
918  */
919 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
920 					 s64 min, s64 max, u64 step, s64 def)
921 {
922 	int rval;
923 
924 	v4l2_ctrl_lock(ctrl);
925 	rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
926 	v4l2_ctrl_unlock(ctrl);
927 
928 	return rval;
929 }
930 
931 /**
932  * v4l2_ctrl_notify() - Function to set a notify callback for a control.
933  *
934  * @ctrl:	The control.
935  * @notify:	The callback function.
936  * @priv:	The callback private handle, passed as argument to the callback.
937  *
938  * This function sets a callback function for the control. If @ctrl is NULL,
939  * then it will do nothing. If @notify is NULL, then the notify callback will
940  * be removed.
941  *
942  * There can be only one notify. If another already exists, then a WARN_ON
943  * will be issued and the function will do nothing.
944  */
945 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
946 		      void *priv);
947 
948 /**
949  * v4l2_ctrl_get_name() - Get the name of the control
950  *
951  * @id:		The control ID.
952  *
953  * This function returns the name of the given control ID or NULL if it isn't
954  * a known control.
955  */
956 const char *v4l2_ctrl_get_name(u32 id);
957 
958 /**
959  * v4l2_ctrl_get_menu() - Get the menu string array of the control
960  *
961  * @id:		The control ID.
962  *
963  * This function returns the NULL-terminated menu string array name of the
964  * given control ID or NULL if it isn't a known menu control.
965  */
966 const char * const *v4l2_ctrl_get_menu(u32 id);
967 
968 /**
969  * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
970  *
971  * @id:		The control ID.
972  * @len:	The size of the integer array.
973  *
974  * This function returns the integer array of the given control ID or NULL if it
975  * if it isn't a known integer menu control.
976  */
977 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
978 
979 /**
980  * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
981  *	within a driver.
982  *
983  * @ctrl:	The control.
984  *
985  * This returns the control's value safely by going through the control
986  * framework. This function will lock the control's handler, so it cannot be
987  * used from within the &v4l2_ctrl_ops functions.
988  *
989  * This function is for integer type controls only.
990  */
991 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
992 
993 /**
994  * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
995  *
996  * @ctrl:	The control.
997  * @val:	The new value.
998  *
999  * This sets the control's new value safely by going through the control
1000  * framework. This function assumes the control's handler is already locked,
1001  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1002  *
1003  * This function is for integer type controls only.
1004  */
1005 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1006 
1007 /**
1008  * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1009  *	within a driver.
1010  * @ctrl:	The control.
1011  * @val:	The new value.
1012  *
1013  * This sets the control's new value safely by going through the control
1014  * framework. This function will lock the control's handler, so it cannot be
1015  * used from within the &v4l2_ctrl_ops functions.
1016  *
1017  * This function is for integer type controls only.
1018  */
1019 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1020 {
1021 	int rval;
1022 
1023 	v4l2_ctrl_lock(ctrl);
1024 	rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1025 	v4l2_ctrl_unlock(ctrl);
1026 
1027 	return rval;
1028 }
1029 
1030 /**
1031  * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1032  *	from within a driver.
1033  *
1034  * @ctrl:	The control.
1035  *
1036  * This returns the control's value safely by going through the control
1037  * framework. This function will lock the control's handler, so it cannot be
1038  * used from within the &v4l2_ctrl_ops functions.
1039  *
1040  * This function is for 64-bit integer type controls only.
1041  */
1042 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1043 
1044 /**
1045  * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1046  *
1047  * @ctrl:	The control.
1048  * @val:	The new value.
1049  *
1050  * This sets the control's new value safely by going through the control
1051  * framework. This function assumes the control's handler is already locked,
1052  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1053  *
1054  * This function is for 64-bit integer type controls only.
1055  */
1056 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1057 
1058 /**
1059  * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1060  *	from within a driver.
1061  *
1062  * @ctrl:	The control.
1063  * @val:	The new value.
1064  *
1065  * This sets the control's new value safely by going through the control
1066  * framework. This function will lock the control's handler, so it cannot be
1067  * used from within the &v4l2_ctrl_ops functions.
1068  *
1069  * This function is for 64-bit integer type controls only.
1070  */
1071 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1072 {
1073 	int rval;
1074 
1075 	v4l2_ctrl_lock(ctrl);
1076 	rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1077 	v4l2_ctrl_unlock(ctrl);
1078 
1079 	return rval;
1080 }
1081 
1082 /**
1083  * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1084  *
1085  * @ctrl:	The control.
1086  * @s:		The new string.
1087  *
1088  * This sets the control's new string safely by going through the control
1089  * framework. This function assumes the control's handler is already locked,
1090  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1091  *
1092  * This function is for string type controls only.
1093  */
1094 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1095 
1096 /**
1097  * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1098  *	 from within a driver.
1099  *
1100  * @ctrl:	The control.
1101  * @s:		The new string.
1102  *
1103  * This sets the control's new string safely by going through the control
1104  * framework. This function will lock the control's handler, so it cannot be
1105  * used from within the &v4l2_ctrl_ops functions.
1106  *
1107  * This function is for string type controls only.
1108  */
1109 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1110 {
1111 	int rval;
1112 
1113 	v4l2_ctrl_lock(ctrl);
1114 	rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1115 	v4l2_ctrl_unlock(ctrl);
1116 
1117 	return rval;
1118 }
1119 
1120 /**
1121  * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1122  *
1123  * @ctrl: The control.
1124  * @type: The type of the data.
1125  * @p:    The new compound payload.
1126  *
1127  * This sets the control's new compound payload safely by going through the
1128  * control framework. This function assumes the control's handler is already
1129  * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1130  *
1131  * This function is for compound type controls only.
1132  */
1133 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1134 				enum v4l2_ctrl_type type, const void *p);
1135 
1136 /**
1137  * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1138  *	from within a driver.
1139  *
1140  * @ctrl: The control.
1141  * @type: The type of the data.
1142  * @p:    The new compound payload.
1143  *
1144  * This sets the control's new compound payload safely by going through the
1145  * control framework. This function will lock the control's handler, so it
1146  * cannot be used from within the &v4l2_ctrl_ops functions.
1147  *
1148  * This function is for compound type controls only.
1149  */
1150 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1151 					    enum v4l2_ctrl_type type,
1152 					    const void *p)
1153 {
1154 	int rval;
1155 
1156 	v4l2_ctrl_lock(ctrl);
1157 	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1158 	v4l2_ctrl_unlock(ctrl);
1159 
1160 	return rval;
1161 }
1162 
1163 /* Helper defines for area type controls */
1164 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1165 	__v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1166 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1167 	v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1168 
1169 /* Internal helper functions that deal with control events. */
1170 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1171 
1172 /**
1173  * v4l2_ctrl_replace - Function to be used as a callback to
1174  *	&struct v4l2_subscribed_event_ops replace\(\)
1175  *
1176  * @old: pointer to struct &v4l2_event with the reported
1177  *	 event;
1178  * @new: pointer to struct &v4l2_event with the modified
1179  *	 event;
1180  */
1181 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1182 
1183 /**
1184  * v4l2_ctrl_merge - Function to be used as a callback to
1185  *	&struct v4l2_subscribed_event_ops merge(\)
1186  *
1187  * @old: pointer to struct &v4l2_event with the reported
1188  *	 event;
1189  * @new: pointer to struct &v4l2_event with the merged
1190  *	 event;
1191  */
1192 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1193 
1194 /**
1195  * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1196  *
1197  * @file: pointer to struct file
1198  * @fh: unused. Kept just to be compatible to the arguments expected by
1199  *	&struct v4l2_ioctl_ops.vidioc_log_status.
1200  *
1201  * Can be used as a vidioc_log_status function that just dumps all controls
1202  * associated with the filehandle.
1203  */
1204 int v4l2_ctrl_log_status(struct file *file, void *fh);
1205 
1206 /**
1207  * v4l2_ctrl_subscribe_event - Subscribes to an event
1208  *
1209  *
1210  * @fh: pointer to struct v4l2_fh
1211  * @sub: pointer to &struct v4l2_event_subscription
1212  *
1213  * Can be used as a vidioc_subscribe_event function that just subscribes
1214  * control events.
1215  */
1216 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1217 				const struct v4l2_event_subscription *sub);
1218 
1219 /**
1220  * v4l2_ctrl_poll - function to be used as a callback to the poll()
1221  *	That just polls for control events.
1222  *
1223  * @file: pointer to struct file
1224  * @wait: pointer to struct poll_table_struct
1225  */
1226 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1227 
1228 /**
1229  * v4l2_ctrl_request_setup - helper function to apply control values in a request
1230  *
1231  * @req: The request
1232  * @parent: The parent control handler ('priv' in media_request_object_find())
1233  *
1234  * This is a helper function to call the control handler's s_ctrl callback with
1235  * the control values contained in the request. Do note that this approach of
1236  * applying control values in a request is only applicable to memory-to-memory
1237  * devices.
1238  */
1239 int v4l2_ctrl_request_setup(struct media_request *req,
1240 			     struct v4l2_ctrl_handler *parent);
1241 
1242 /**
1243  * v4l2_ctrl_request_complete - Complete a control handler request object
1244  *
1245  * @req: The request
1246  * @parent: The parent control handler ('priv' in media_request_object_find())
1247  *
1248  * This function is to be called on each control handler that may have had a
1249  * request object associated with it, i.e. control handlers of a driver that
1250  * supports requests.
1251  *
1252  * The function first obtains the values of any volatile controls in the control
1253  * handler and attach them to the request. Then, the function completes the
1254  * request object.
1255  */
1256 void v4l2_ctrl_request_complete(struct media_request *req,
1257 				struct v4l2_ctrl_handler *parent);
1258 
1259 /**
1260  * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1261  *
1262  * @req: The request
1263  * @parent: The parent control handler ('priv' in media_request_object_find())
1264  *
1265  * This function finds the control handler in the request. It may return
1266  * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1267  * with the returned handler pointer.
1268  *
1269  * If the request is not in state VALIDATING or QUEUED, then this function
1270  * will always return NULL.
1271  *
1272  * Note that in state VALIDATING the req_queue_mutex is held, so
1273  * no objects can be added or deleted from the request.
1274  *
1275  * In state QUEUED it is the driver that will have to ensure this.
1276  */
1277 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1278 					struct v4l2_ctrl_handler *parent);
1279 
1280 /**
1281  * v4l2_ctrl_request_hdl_put - Put the control handler
1282  *
1283  * @hdl: Put this control handler
1284  *
1285  * This function released the control handler previously obtained from'
1286  * v4l2_ctrl_request_hdl_find().
1287  */
1288 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1289 {
1290 	if (hdl)
1291 		media_request_object_put(&hdl->req_obj);
1292 }
1293 
1294 /**
1295  * v4l2_ctrl_request_ctrl_find() - Find a control with the given ID.
1296  *
1297  * @hdl: The control handler from the request.
1298  * @id: The ID of the control to find.
1299  *
1300  * This function returns a pointer to the control if this control is
1301  * part of the request or NULL otherwise.
1302  */
1303 struct v4l2_ctrl *
1304 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1305 
1306 /* Helpers for ioctl_ops */
1307 
1308 /**
1309  * v4l2_queryctrl - Helper function to implement
1310  *	:ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1311  *
1312  * @hdl: pointer to &struct v4l2_ctrl_handler
1313  * @qc: pointer to &struct v4l2_queryctrl
1314  *
1315  * If hdl == NULL then they will all return -EINVAL.
1316  */
1317 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1318 
1319 /**
1320  * v4l2_query_ext_ctrl - Helper function to implement
1321  *	 :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1322  *
1323  * @hdl: pointer to &struct v4l2_ctrl_handler
1324  * @qc: pointer to &struct v4l2_query_ext_ctrl
1325  *
1326  * If hdl == NULL then they will all return -EINVAL.
1327  */
1328 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1329 			struct v4l2_query_ext_ctrl *qc);
1330 
1331 /**
1332  * v4l2_querymenu - Helper function to implement
1333  *	:ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1334  *
1335  * @hdl: pointer to &struct v4l2_ctrl_handler
1336  * @qm: pointer to &struct v4l2_querymenu
1337  *
1338  * If hdl == NULL then they will all return -EINVAL.
1339  */
1340 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1341 
1342 /**
1343  * v4l2_g_ctrl - Helper function to implement
1344  *	:ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1345  *
1346  * @hdl: pointer to &struct v4l2_ctrl_handler
1347  * @ctrl: pointer to &struct v4l2_control
1348  *
1349  * If hdl == NULL then they will all return -EINVAL.
1350  */
1351 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1352 
1353 /**
1354  * v4l2_s_ctrl - Helper function to implement
1355  *	:ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1356  *
1357  * @fh: pointer to &struct v4l2_fh
1358  * @hdl: pointer to &struct v4l2_ctrl_handler
1359  *
1360  * @ctrl: pointer to &struct v4l2_control
1361  *
1362  * If hdl == NULL then they will all return -EINVAL.
1363  */
1364 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1365 		struct v4l2_control *ctrl);
1366 
1367 /**
1368  * v4l2_g_ext_ctrls - Helper function to implement
1369  *	:ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1370  *
1371  * @hdl: pointer to &struct v4l2_ctrl_handler
1372  * @vdev: pointer to &struct video_device
1373  * @mdev: pointer to &struct media_device
1374  * @c: pointer to &struct v4l2_ext_controls
1375  *
1376  * If hdl == NULL then they will all return -EINVAL.
1377  */
1378 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1379 		     struct media_device *mdev, struct v4l2_ext_controls *c);
1380 
1381 /**
1382  * v4l2_try_ext_ctrls - Helper function to implement
1383  *	:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1384  *
1385  * @hdl: pointer to &struct v4l2_ctrl_handler
1386  * @vdev: pointer to &struct video_device
1387  * @mdev: pointer to &struct media_device
1388  * @c: pointer to &struct v4l2_ext_controls
1389  *
1390  * If hdl == NULL then they will all return -EINVAL.
1391  */
1392 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1393 		       struct video_device *vdev,
1394 		       struct media_device *mdev,
1395 		       struct v4l2_ext_controls *c);
1396 
1397 /**
1398  * v4l2_s_ext_ctrls - Helper function to implement
1399  *	:ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1400  *
1401  * @fh: pointer to &struct v4l2_fh
1402  * @hdl: pointer to &struct v4l2_ctrl_handler
1403  * @vdev: pointer to &struct video_device
1404  * @mdev: pointer to &struct media_device
1405  * @c: pointer to &struct v4l2_ext_controls
1406  *
1407  * If hdl == NULL then they will all return -EINVAL.
1408  */
1409 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1410 		     struct video_device *vdev,
1411 		     struct media_device *mdev,
1412 		     struct v4l2_ext_controls *c);
1413 
1414 /**
1415  * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1416  *	as a &struct v4l2_subdev_core_ops subscribe_event function
1417  *	that just subscribes control events.
1418  *
1419  * @sd: pointer to &struct v4l2_subdev
1420  * @fh: pointer to &struct v4l2_fh
1421  * @sub: pointer to &struct v4l2_event_subscription
1422  */
1423 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1424 				     struct v4l2_event_subscription *sub);
1425 
1426 /**
1427  * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1428  *	 handler.
1429  *
1430  * @sd: pointer to &struct v4l2_subdev
1431  */
1432 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1433 
1434 /**
1435  * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1436  *				       properties
1437  *
1438  * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1439  * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1440  * @p: pointer to &struct v4l2_fwnode_device_properties
1441  *
1442  * This function registers controls associated to device properties, using the
1443  * property values contained in @p parameter, if the property has been set to
1444  * a value.
1445  *
1446  * Currently the following v4l2 controls are parsed and registered:
1447  * - V4L2_CID_CAMERA_ORIENTATION
1448  * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1449  *
1450  * Controls already registered by the caller with the @hdl control handler are
1451  * not overwritten. Callers should register the controls they want to handle
1452  * themselves before calling this function.
1453  *
1454  * Return: 0 on success, a negative error code on failure.
1455  */
1456 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1457 				    const struct v4l2_ctrl_ops *ctrl_ops,
1458 				    const struct v4l2_fwnode_device_properties *p);
1459 #endif
1460