xref: /linux/include/media/v4l2-ctrls.h (revision 23c48a124b469cee2eb0c75e6d22d366d1caa118)
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 /* forward references */
17 struct file;
18 struct poll_table_struct;
19 struct v4l2_ctrl;
20 struct v4l2_ctrl_handler;
21 struct v4l2_ctrl_helper;
22 struct v4l2_fh;
23 struct v4l2_fwnode_device_properties;
24 struct v4l2_subdev;
25 struct v4l2_subscribed_event;
26 struct video_device;
27 
28 /**
29  * union v4l2_ctrl_ptr - A pointer to a control value.
30  * @p_s32:			Pointer to a 32-bit signed value.
31  * @p_s64:			Pointer to a 64-bit signed value.
32  * @p_u8:			Pointer to a 8-bit unsigned value.
33  * @p_u16:			Pointer to a 16-bit unsigned value.
34  * @p_u32:			Pointer to a 32-bit unsigned value.
35  * @p_char:			Pointer to a string.
36  * @p_mpeg2_sequence:		Pointer to a MPEG2 sequence structure.
37  * @p_mpeg2_picture:		Pointer to a MPEG2 picture structure.
38  * @p_mpeg2_quantisation:	Pointer to a MPEG2 quantisation data structure.
39  * @p_fwht_params:		Pointer to a FWHT stateless parameters structure.
40  * @p_h264_sps:			Pointer to a struct v4l2_ctrl_h264_sps.
41  * @p_h264_pps:			Pointer to a struct v4l2_ctrl_h264_pps.
42  * @p_h264_scaling_matrix:	Pointer to a struct v4l2_ctrl_h264_scaling_matrix.
43  * @p_h264_slice_params:	Pointer to a struct v4l2_ctrl_h264_slice_params.
44  * @p_h264_decode_params:	Pointer to a struct v4l2_ctrl_h264_decode_params.
45  * @p_h264_pred_weights:	Pointer to a struct v4l2_ctrl_h264_pred_weights.
46  * @p_vp8_frame:		Pointer to a VP8 frame params structure.
47  * @p_vp9_compressed_hdr_probs:	Pointer to a VP9 frame compressed header probs structure.
48  * @p_vp9_frame:		Pointer to a VP9 frame params structure.
49  * @p_hevc_sps:			Pointer to an HEVC sequence parameter set structure.
50  * @p_hevc_pps:			Pointer to an HEVC picture parameter set structure.
51  * @p_hevc_slice_params:	Pointer to an HEVC slice parameters structure.
52  * @p_hdr10_cll:		Pointer to an HDR10 Content Light Level structure.
53  * @p_hdr10_mastering:		Pointer to an HDR10 Mastering Display structure.
54  * @p_area:			Pointer to an area.
55  * @p:				Pointer to a compound value.
56  * @p_const:			Pointer to a constant compound value.
57  */
58 union v4l2_ctrl_ptr {
59 	s32 *p_s32;
60 	s64 *p_s64;
61 	u8 *p_u8;
62 	u16 *p_u16;
63 	u32 *p_u32;
64 	char *p_char;
65 	struct v4l2_ctrl_mpeg2_sequence *p_mpeg2_sequence;
66 	struct v4l2_ctrl_mpeg2_picture *p_mpeg2_picture;
67 	struct v4l2_ctrl_mpeg2_quantisation *p_mpeg2_quantisation;
68 	struct v4l2_ctrl_fwht_params *p_fwht_params;
69 	struct v4l2_ctrl_h264_sps *p_h264_sps;
70 	struct v4l2_ctrl_h264_pps *p_h264_pps;
71 	struct v4l2_ctrl_h264_scaling_matrix *p_h264_scaling_matrix;
72 	struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
73 	struct v4l2_ctrl_h264_decode_params *p_h264_decode_params;
74 	struct v4l2_ctrl_h264_pred_weights *p_h264_pred_weights;
75 	struct v4l2_ctrl_vp8_frame *p_vp8_frame;
76 	struct v4l2_ctrl_hevc_sps *p_hevc_sps;
77 	struct v4l2_ctrl_hevc_pps *p_hevc_pps;
78 	struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
79 	struct v4l2_ctrl_vp9_compressed_hdr *p_vp9_compressed_hdr_probs;
80 	struct v4l2_ctrl_vp9_frame *p_vp9_frame;
81 	struct v4l2_ctrl_hdr10_cll_info *p_hdr10_cll;
82 	struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
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  * @is_dyn_array: If set, then this control contains a dynamically sized 1-dimensional array.
183  *		If this is set, then @is_array is also set.
184  * @has_volatiles: If set, then one or more members of the cluster are volatile.
185  *		Drivers should never touch this flag.
186  * @call_notify: If set, then call the handler's notify function whenever the
187  *		control's value changes.
188  * @manual_mode_value: If the is_auto flag is set, then this is the value
189  *		of the auto control that determines if that control is in
190  *		manual mode. So if the value of the auto control equals this
191  *		value, then the whole cluster is in manual mode. Drivers should
192  *		never set this flag directly.
193  * @ops:	The control ops.
194  * @type_ops:	The control type ops.
195  * @id:	The control ID.
196  * @name:	The control name.
197  * @type:	The control type.
198  * @minimum:	The control's minimum value.
199  * @maximum:	The control's maximum value.
200  * @default_value: The control's default value.
201  * @step:	The control's step value for non-menu controls.
202  * @elems:	The number of elements in the N-dimensional array.
203  * @elem_size:	The size in bytes of the control.
204  * @new_elems:	The number of elements in p_new. This is the same as @elems,
205  *		except for dynamic arrays. In that case it is in the range of
206  *		1 to @p_dyn_alloc_elems.
207  * @dims:	The size of each dimension.
208  * @nr_of_dims:The number of dimensions in @dims.
209  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
210  *		easy to skip menu items that are not valid. If bit X is set,
211  *		then menu item X is skipped. Of course, this only works for
212  *		menus with <= 32 menu items. There are no menus that come
213  *		close to that number, so this is OK. Should we ever need more,
214  *		then this will have to be extended to a u64 or a bit array.
215  * @qmenu:	A const char * array for all menu items. Array entries that are
216  *		empty strings ("") correspond to non-existing menu items (this
217  *		is in addition to the menu_skip_mask above). The last entry
218  *		must be NULL.
219  *		Used only if the @type is %V4L2_CTRL_TYPE_MENU.
220  * @qmenu_int:	A 64-bit integer array for with integer menu items.
221  *		The size of array must be equal to the menu size, e. g.:
222  *		:math:`ceil(\frac{maximum - minimum}{step}) + 1`.
223  *		Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
224  * @flags:	The control's flags.
225  * @priv:	The control's private pointer. For use by the driver. It is
226  *		untouched by the control framework. Note that this pointer is
227  *		not freed when the control is deleted. Should this be needed
228  *		then a new internal bitfield can be added to tell the framework
229  *		to free this pointer.
230  * @p_dyn:	Pointer to the dynamically allocated array. Only valid if
231  *		@is_dyn_array is true.
232  * @p_dyn_alloc_elems: The number of elements in the dynamically allocated
233  *		array for both the cur and new values. So @p_dyn is actually
234  *		sized for 2 * @p_dyn_alloc_elems * @elem_size. Only valid if
235  *		@is_dyn_array is true.
236  * @cur:	Structure to store the current value.
237  * @cur.val:	The control's current value, if the @type is represented via
238  *		a u32 integer (see &enum v4l2_ctrl_type).
239  * @val:	The control's new s32 value.
240  * @p_def:	The control's default value represented via a union which
241  *		provides a standard way of accessing control types
242  *		through a pointer (for compound controls only).
243  * @p_cur:	The control's current value represented via a union which
244  *		provides a standard way of accessing control types
245  *		through a pointer.
246  * @p_new:	The control's new value represented via a union which provides
247  *		a standard way of accessing control types
248  *		through a pointer.
249  */
250 struct v4l2_ctrl {
251 	/* Administrative fields */
252 	struct list_head node;
253 	struct list_head ev_subs;
254 	struct v4l2_ctrl_handler *handler;
255 	struct v4l2_ctrl **cluster;
256 	unsigned int ncontrols;
257 
258 	unsigned int done:1;
259 
260 	unsigned int is_new:1;
261 	unsigned int has_changed:1;
262 	unsigned int is_private:1;
263 	unsigned int is_auto:1;
264 	unsigned int is_int:1;
265 	unsigned int is_string:1;
266 	unsigned int is_ptr:1;
267 	unsigned int is_array:1;
268 	unsigned int is_dyn_array:1;
269 	unsigned int has_volatiles:1;
270 	unsigned int call_notify:1;
271 	unsigned int manual_mode_value:8;
272 
273 	const struct v4l2_ctrl_ops *ops;
274 	const struct v4l2_ctrl_type_ops *type_ops;
275 	u32 id;
276 	const char *name;
277 	enum v4l2_ctrl_type type;
278 	s64 minimum, maximum, default_value;
279 	u32 elems;
280 	u32 elem_size;
281 	u32 new_elems;
282 	u32 dims[V4L2_CTRL_MAX_DIMS];
283 	u32 nr_of_dims;
284 	union {
285 		u64 step;
286 		u64 menu_skip_mask;
287 	};
288 	union {
289 		const char * const *qmenu;
290 		const s64 *qmenu_int;
291 	};
292 	unsigned long flags;
293 	void *priv;
294 	void *p_dyn;
295 	u32 p_dyn_alloc_elems;
296 	s32 val;
297 	struct {
298 		s32 val;
299 	} cur;
300 
301 	union v4l2_ctrl_ptr p_def;
302 	union v4l2_ctrl_ptr p_new;
303 	union v4l2_ctrl_ptr p_cur;
304 };
305 
306 /**
307  * struct v4l2_ctrl_ref - The control reference.
308  *
309  * @node:	List node for the sorted list.
310  * @next:	Single-link list node for the hash.
311  * @ctrl:	The actual control information.
312  * @helper:	Pointer to helper struct. Used internally in
313  *		``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
314  * @from_other_dev: If true, then @ctrl was defined in another
315  *		device than the &struct v4l2_ctrl_handler.
316  * @req_done:	Internal flag: if the control handler containing this control
317  *		reference is bound to a media request, then this is set when
318  *		the control has been applied. This prevents applying controls
319  *		from a cluster with multiple controls twice (when the first
320  *		control of a cluster is applied, they all are).
321  * @p_req_valid: If set, then p_req contains the control value for the request.
322  * @p_req_dyn_enomem: If set, then p_req is invalid since allocating space for
323  *		a dynamic array failed. Attempting to read this value shall
324  *		result in ENOMEM. Only valid if ctrl->is_dyn_array is true.
325  * @p_req_dyn_alloc_elems: The number of elements allocated for the dynamic
326  *		array. Only valid if @p_req_valid and ctrl->is_dyn_array are
327  *		true.
328  * @p_req_elems: The number of elements in @p_req. This is the same as
329  *		ctrl->elems, except for dynamic arrays. In that case it is in
330  *		the range of 1 to @p_req_dyn_alloc_elems. Only valid if
331  *		@p_req_valid is true.
332  * @p_req:	If the control handler containing this control reference
333  *		is bound to a media request, then this points to the
334  *		value of the control that must be applied when the request
335  *		is executed, or to the value of the control at the time
336  *		that the request was completed. If @p_req_valid is false,
337  *		then this control was never set for this request and the
338  *		control will not be updated when this request is applied.
339  *
340  * Each control handler has a list of these refs. The list_head is used to
341  * keep a sorted-by-control-ID list of all controls, while the next pointer
342  * is used to link the control in the hash's bucket.
343  */
344 struct v4l2_ctrl_ref {
345 	struct list_head node;
346 	struct v4l2_ctrl_ref *next;
347 	struct v4l2_ctrl *ctrl;
348 	struct v4l2_ctrl_helper *helper;
349 	bool from_other_dev;
350 	bool req_done;
351 	bool p_req_valid;
352 	bool p_req_dyn_enomem;
353 	u32 p_req_dyn_alloc_elems;
354 	u32 p_req_elems;
355 	union v4l2_ctrl_ptr p_req;
356 };
357 
358 /**
359  * struct v4l2_ctrl_handler - The control handler keeps track of all the
360  *	controls: both the controls owned by the handler and those inherited
361  *	from other handlers.
362  *
363  * @_lock:	Default for "lock".
364  * @lock:	Lock to control access to this handler and its controls.
365  *		May be replaced by the user right after init.
366  * @ctrls:	The list of controls owned by this handler.
367  * @ctrl_refs:	The list of control references.
368  * @cached:	The last found control reference. It is common that the same
369  *		control is needed multiple times, so this is a simple
370  *		optimization.
371  * @buckets:	Buckets for the hashing. Allows for quick control lookup.
372  * @notify:	A notify callback that is called whenever the control changes
373  *		value.
374  *		Note that the handler's lock is held when the notify function
375  *		is called!
376  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
377  * @nr_of_buckets: Total number of buckets in the array.
378  * @error:	The error code of the first failed control addition.
379  * @request_is_queued: True if the request was queued.
380  * @requests:	List to keep track of open control handler request objects.
381  *		For the parent control handler (@req_obj.ops == NULL) this
382  *		is the list header. When the parent control handler is
383  *		removed, it has to unbind and put all these requests since
384  *		they refer to the parent.
385  * @requests_queued: List of the queued requests. This determines the order
386  *		in which these controls are applied. Once the request is
387  *		completed it is removed from this list.
388  * @req_obj:	The &struct media_request_object, used to link into a
389  *		&struct media_request. This request object has a refcount.
390  */
391 struct v4l2_ctrl_handler {
392 	struct mutex _lock;
393 	struct mutex *lock;
394 	struct list_head ctrls;
395 	struct list_head ctrl_refs;
396 	struct v4l2_ctrl_ref *cached;
397 	struct v4l2_ctrl_ref **buckets;
398 	v4l2_ctrl_notify_fnc notify;
399 	void *notify_priv;
400 	u16 nr_of_buckets;
401 	int error;
402 	bool request_is_queued;
403 	struct list_head requests;
404 	struct list_head requests_queued;
405 	struct media_request_object req_obj;
406 };
407 
408 /**
409  * struct v4l2_ctrl_config - Control configuration structure.
410  *
411  * @ops:	The control ops.
412  * @type_ops:	The control type ops. Only needed for compound controls.
413  * @id:	The control ID.
414  * @name:	The control name.
415  * @type:	The control type.
416  * @min:	The control's minimum value.
417  * @max:	The control's maximum value.
418  * @step:	The control's step value for non-menu controls.
419  * @def:	The control's default value.
420  * @p_def:	The control's default value for compound controls.
421  * @dims:	The size of each dimension.
422  * @elem_size:	The size in bytes of the control.
423  * @flags:	The control's flags.
424  * @menu_skip_mask: The control's skip mask for menu controls. This makes it
425  *		easy to skip menu items that are not valid. If bit X is set,
426  *		then menu item X is skipped. Of course, this only works for
427  *		menus with <= 64 menu items. There are no menus that come
428  *		close to that number, so this is OK. Should we ever need more,
429  *		then this will have to be extended to a bit array.
430  * @qmenu:	A const char * array for all menu items. Array entries that are
431  *		empty strings ("") correspond to non-existing menu items (this
432  *		is in addition to the menu_skip_mask above). The last entry
433  *		must be NULL.
434  * @qmenu_int:	A const s64 integer array for all menu items of the type
435  *		V4L2_CTRL_TYPE_INTEGER_MENU.
436  * @is_private: If set, then this control is private to its handler and it
437  *		will not be added to any other handlers.
438  */
439 struct v4l2_ctrl_config {
440 	const struct v4l2_ctrl_ops *ops;
441 	const struct v4l2_ctrl_type_ops *type_ops;
442 	u32 id;
443 	const char *name;
444 	enum v4l2_ctrl_type type;
445 	s64 min;
446 	s64 max;
447 	u64 step;
448 	s64 def;
449 	union v4l2_ctrl_ptr p_def;
450 	u32 dims[V4L2_CTRL_MAX_DIMS];
451 	u32 elem_size;
452 	u32 flags;
453 	u64 menu_skip_mask;
454 	const char * const *qmenu;
455 	const s64 *qmenu_int;
456 	unsigned int is_private:1;
457 };
458 
459 /**
460  * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
461  *
462  * @id: ID of the control
463  * @name: pointer to be filled with a string with the name of the control
464  * @type: pointer for storing the type of the control
465  * @min: pointer for storing the minimum value for the control
466  * @max: pointer for storing the maximum value for the control
467  * @step: pointer for storing the control step
468  * @def: pointer for storing the default value for the control
469  * @flags: pointer for storing the flags to be used on the control
470  *
471  * This works for all standard V4L2 controls.
472  * For non-standard controls it will only fill in the given arguments
473  * and @name content will be set to %NULL.
474  *
475  * This function will overwrite the contents of @name, @type and @flags.
476  * The contents of @min, @max, @step and @def may be modified depending on
477  * the type.
478  *
479  * .. note::
480  *
481  *    Do not use in drivers! It is used internally for backwards compatibility
482  *    control handling only. Once all drivers are converted to use the new
483  *    control framework this function will no longer be exported.
484  */
485 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
486 		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
487 
488 
489 /**
490  * v4l2_ctrl_handler_init_class() - Initialize the control handler.
491  * @hdl:	The control handler.
492  * @nr_of_controls_hint: A hint of how many controls this handler is
493  *		expected to refer to. This is the total number, so including
494  *		any inherited controls. It doesn't have to be precise, but if
495  *		it is way off, then you either waste memory (too many buckets
496  *		are allocated) or the control lookup becomes slower (not enough
497  *		buckets are allocated, so there are more slow list lookups).
498  *		It will always work, though.
499  * @key:	Used by the lock validator if CONFIG_LOCKDEP is set.
500  * @name:	Used by the lock validator if CONFIG_LOCKDEP is set.
501  *
502  * .. attention::
503  *
504  *    Never use this call directly, always use the v4l2_ctrl_handler_init()
505  *    macro that hides the @key and @name arguments.
506  *
507  * Return: returns an error if the buckets could not be allocated. This
508  * error will also be stored in @hdl->error.
509  */
510 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
511 				 unsigned int nr_of_controls_hint,
512 				 struct lock_class_key *key, const char *name);
513 
514 #ifdef CONFIG_LOCKDEP
515 
516 /**
517  * v4l2_ctrl_handler_init - helper function to create a static struct
518  *	 &lock_class_key and calls v4l2_ctrl_handler_init_class()
519  *
520  * @hdl:	The control handler.
521  * @nr_of_controls_hint: A hint of how many controls this handler is
522  *		expected to refer to. This is the total number, so including
523  *		any inherited controls. It doesn't have to be precise, but if
524  *		it is way off, then you either waste memory (too many buckets
525  *		are allocated) or the control lookup becomes slower (not enough
526  *		buckets are allocated, so there are more slow list lookups).
527  *		It will always work, though.
528  *
529  * This helper function creates a static struct &lock_class_key and
530  * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
531  * validador.
532  *
533  * Use this helper function to initialize a control handler.
534  */
535 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
536 (									\
537 	({								\
538 		static struct lock_class_key _key;			\
539 		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
540 					&_key,				\
541 					KBUILD_BASENAME ":"		\
542 					__stringify(__LINE__) ":"	\
543 					"(" #hdl ")->_lock");		\
544 	})								\
545 )
546 #else
547 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
548 	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
549 #endif
550 
551 /**
552  * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
553  * the control list.
554  * @hdl:	The control handler.
555  *
556  * Does nothing if @hdl == NULL.
557  */
558 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
559 
560 /**
561  * v4l2_ctrl_lock() - Helper function to lock the handler
562  * associated with the control.
563  * @ctrl:	The control to lock.
564  */
565 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
566 {
567 	mutex_lock(ctrl->handler->lock);
568 }
569 
570 /**
571  * v4l2_ctrl_unlock() - Helper function to unlock the handler
572  * associated with the control.
573  * @ctrl:	The control to unlock.
574  */
575 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
576 {
577 	mutex_unlock(ctrl->handler->lock);
578 }
579 
580 /**
581  * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
582  * to the handler to initialize the hardware to the current control values. The
583  * caller is responsible for acquiring the control handler mutex on behalf of
584  * __v4l2_ctrl_handler_setup().
585  * @hdl:	The control handler.
586  *
587  * Button controls will be skipped, as are read-only controls.
588  *
589  * If @hdl == NULL, then this just returns 0.
590  */
591 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
592 
593 /**
594  * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
595  * to the handler to initialize the hardware to the current control values.
596  * @hdl:	The control handler.
597  *
598  * Button controls will be skipped, as are read-only controls.
599  *
600  * If @hdl == NULL, then this just returns 0.
601  */
602 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
603 
604 /**
605  * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
606  * @hdl:	The control handler.
607  * @prefix:	The prefix to use when logging the control values. If the
608  *		prefix does not end with a space, then ": " will be added
609  *		after the prefix. If @prefix == NULL, then no prefix will be
610  *		used.
611  *
612  * For use with VIDIOC_LOG_STATUS.
613  *
614  * Does nothing if @hdl == NULL.
615  */
616 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
617 				  const char *prefix);
618 
619 /**
620  * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
621  *	control.
622  *
623  * @hdl:	The control handler.
624  * @cfg:	The control's configuration data.
625  * @priv:	The control's driver-specific private data.
626  *
627  * If the &v4l2_ctrl struct could not be allocated then NULL is returned
628  * and @hdl->error is set to the error code (if it wasn't set already).
629  */
630 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
631 				       const struct v4l2_ctrl_config *cfg,
632 				       void *priv);
633 
634 /**
635  * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
636  *	control.
637  *
638  * @hdl:	The control handler.
639  * @ops:	The control ops.
640  * @id:		The control ID.
641  * @min:	The control's minimum value.
642  * @max:	The control's maximum value.
643  * @step:	The control's step value
644  * @def:	The control's default value.
645  *
646  * If the &v4l2_ctrl struct could not be allocated, or the control
647  * ID is not known, then NULL is returned and @hdl->error is set to the
648  * appropriate error code (if it wasn't set already).
649  *
650  * If @id refers to a menu control, then this function will return NULL.
651  *
652  * Use v4l2_ctrl_new_std_menu() when adding menu controls.
653  */
654 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
655 				    const struct v4l2_ctrl_ops *ops,
656 				    u32 id, s64 min, s64 max, u64 step,
657 				    s64 def);
658 
659 /**
660  * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
661  *	menu control.
662  *
663  * @hdl:	The control handler.
664  * @ops:	The control ops.
665  * @id:		The control ID.
666  * @max:	The control's maximum value.
667  * @mask:	The control's skip mask for menu controls. This makes it
668  *		easy to skip menu items that are not valid. If bit X is set,
669  *		then menu item X is skipped. Of course, this only works for
670  *		menus with <= 64 menu items. There are no menus that come
671  *		close to that number, so this is OK. Should we ever need more,
672  *		then this will have to be extended to a bit array.
673  * @def:	The control's default value.
674  *
675  * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
676  * determines which menu items are to be skipped.
677  *
678  * If @id refers to a non-menu control, then this function will return NULL.
679  */
680 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
681 					 const struct v4l2_ctrl_ops *ops,
682 					 u32 id, u8 max, u64 mask, u8 def);
683 
684 /**
685  * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
686  *	with driver specific menu.
687  *
688  * @hdl:	The control handler.
689  * @ops:	The control ops.
690  * @id:	The control ID.
691  * @max:	The control's maximum value.
692  * @mask:	The control's skip mask for menu controls. This makes it
693  *		easy to skip menu items that are not valid. If bit X is set,
694  *		then menu item X is skipped. Of course, this only works for
695  *		menus with <= 64 menu items. There are no menus that come
696  *		close to that number, so this is OK. Should we ever need more,
697  *		then this will have to be extended to a bit array.
698  * @def:	The control's default value.
699  * @qmenu:	The new menu.
700  *
701  * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
702  * menu of this control.
703  *
704  */
705 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
706 					       const struct v4l2_ctrl_ops *ops,
707 					       u32 id, u8 max,
708 					       u64 mask, u8 def,
709 					       const char * const *qmenu);
710 
711 /**
712  * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
713  *      compound control.
714  *
715  * @hdl:       The control handler.
716  * @ops:       The control ops.
717  * @id:        The control ID.
718  * @p_def:     The control's default value.
719  *
720  * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
721  * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
722  * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
723  * compound control should be all zeroes.
724  *
725  */
726 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
727 					     const struct v4l2_ctrl_ops *ops,
728 					     u32 id,
729 					     const union v4l2_ctrl_ptr p_def);
730 
731 /**
732  * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
733  *
734  * @hdl:	The control handler.
735  * @ops:	The control ops.
736  * @id:	The control ID.
737  * @max:	The control's maximum value.
738  * @def:	The control's default value.
739  * @qmenu_int:	The control's menu entries.
740  *
741  * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
742  * takes as an argument an array of integers determining the menu items.
743  *
744  * If @id refers to a non-integer-menu control, then this function will
745  * return %NULL.
746  */
747 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
748 					 const struct v4l2_ctrl_ops *ops,
749 					 u32 id, u8 max, u8 def,
750 					 const s64 *qmenu_int);
751 
752 /**
753  * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
754  *	used when adding a control handler.
755  *
756  * @ctrl: pointer to struct &v4l2_ctrl.
757  */
758 
759 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
760 
761 /**
762  * v4l2_ctrl_add_handler() - Add all controls from handler @add to
763  *	handler @hdl.
764  *
765  * @hdl:	The control handler.
766  * @add:	The control handler whose controls you want to add to
767  *		the @hdl control handler.
768  * @filter:	This function will filter which controls should be added.
769  * @from_other_dev: If true, then the controls in @add were defined in another
770  *		device than @hdl.
771  *
772  * Does nothing if either of the two handlers is a NULL pointer.
773  * If @filter is NULL, then all controls are added. Otherwise only those
774  * controls for which @filter returns true will be added.
775  * In case of an error @hdl->error will be set to the error code (if it
776  * wasn't set already).
777  */
778 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
779 			  struct v4l2_ctrl_handler *add,
780 			  v4l2_ctrl_filter filter,
781 			  bool from_other_dev);
782 
783 /**
784  * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
785  *
786  * @ctrl:	The control that is filtered.
787  *
788  * This will return true for any controls that are valid for radio device
789  * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
790  * transmitter class controls.
791  *
792  * This function is to be used with v4l2_ctrl_add_handler().
793  */
794 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
795 
796 /**
797  * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
798  *	to that cluster.
799  *
800  * @ncontrols:	The number of controls in this cluster.
801  * @controls:	The cluster control array of size @ncontrols.
802  */
803 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
804 
805 
806 /**
807  * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
808  *	to that cluster and set it up for autofoo/foo-type handling.
809  *
810  * @ncontrols:	The number of controls in this cluster.
811  * @controls:	The cluster control array of size @ncontrols. The first control
812  *		must be the 'auto' control (e.g. autogain, autoexposure, etc.)
813  * @manual_val: The value for the first control in the cluster that equals the
814  *		manual setting.
815  * @set_volatile: If true, then all controls except the first auto control will
816  *		be volatile.
817  *
818  * Use for control groups where one control selects some automatic feature and
819  * the other controls are only active whenever the automatic feature is turned
820  * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
821  * red and blue balance, etc.
822  *
823  * The behavior of such controls is as follows:
824  *
825  * When the autofoo control is set to automatic, then any manual controls
826  * are set to inactive and any reads will call g_volatile_ctrl (if the control
827  * was marked volatile).
828  *
829  * When the autofoo control is set to manual, then any manual controls will
830  * be marked active, and any reads will just return the current value without
831  * going through g_volatile_ctrl.
832  *
833  * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
834  * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
835  * if autofoo is in auto mode.
836  */
837 void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
838 			    struct v4l2_ctrl **controls,
839 			    u8 manual_val, bool set_volatile);
840 
841 
842 /**
843  * v4l2_ctrl_find() - Find a control with the given ID.
844  *
845  * @hdl:	The control handler.
846  * @id:	The control ID to find.
847  *
848  * If @hdl == NULL this will return NULL as well. Will lock the handler so
849  * do not use from inside &v4l2_ctrl_ops.
850  */
851 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
852 
853 /**
854  * v4l2_ctrl_activate() - Make the control active or inactive.
855  * @ctrl:	The control to (de)activate.
856  * @active:	True if the control should become active.
857  *
858  * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
859  * Does nothing if @ctrl == NULL.
860  * This will usually be called from within the s_ctrl op.
861  * The V4L2_EVENT_CTRL event will be generated afterwards.
862  *
863  * This function assumes that the control handler is locked.
864  */
865 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
866 
867 /**
868  * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
869  *
870  * @ctrl:	The control to (de)activate.
871  * @grabbed:	True if the control should become grabbed.
872  *
873  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
874  * Does nothing if @ctrl == NULL.
875  * The V4L2_EVENT_CTRL event will be generated afterwards.
876  * This will usually be called when starting or stopping streaming in the
877  * driver.
878  *
879  * This function assumes that the control handler is locked by the caller.
880  */
881 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
882 
883 /**
884  * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
885  *
886  * @ctrl:	The control to (de)activate.
887  * @grabbed:	True if the control should become grabbed.
888  *
889  * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
890  * Does nothing if @ctrl == NULL.
891  * The V4L2_EVENT_CTRL event will be generated afterwards.
892  * This will usually be called when starting or stopping streaming in the
893  * driver.
894  *
895  * This function assumes that the control handler is not locked and will
896  * take the lock itself.
897  */
898 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
899 {
900 	if (!ctrl)
901 		return;
902 
903 	v4l2_ctrl_lock(ctrl);
904 	__v4l2_ctrl_grab(ctrl, grabbed);
905 	v4l2_ctrl_unlock(ctrl);
906 }
907 
908 /**
909  *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
910  *
911  * @ctrl:	The control to update.
912  * @min:	The control's minimum value.
913  * @max:	The control's maximum value.
914  * @step:	The control's step value
915  * @def:	The control's default value.
916  *
917  * Update the range of a control on the fly. This works for control types
918  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
919  * @step value is interpreted as a menu_skip_mask.
920  *
921  * An error is returned if one of the range arguments is invalid for this
922  * control type.
923  *
924  * The caller is responsible for acquiring the control handler mutex on behalf
925  * of __v4l2_ctrl_modify_range().
926  */
927 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
928 			     s64 min, s64 max, u64 step, s64 def);
929 
930 /**
931  * v4l2_ctrl_modify_range() - Update the range of a control.
932  *
933  * @ctrl:	The control to update.
934  * @min:	The control's minimum value.
935  * @max:	The control's maximum value.
936  * @step:	The control's step value
937  * @def:	The control's default value.
938  *
939  * Update the range of a control on the fly. This works for control types
940  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
941  * @step value is interpreted as a menu_skip_mask.
942  *
943  * An error is returned if one of the range arguments is invalid for this
944  * control type.
945  *
946  * This function assumes that the control handler is not locked and will
947  * take the lock itself.
948  */
949 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
950 					 s64 min, s64 max, u64 step, s64 def)
951 {
952 	int rval;
953 
954 	v4l2_ctrl_lock(ctrl);
955 	rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
956 	v4l2_ctrl_unlock(ctrl);
957 
958 	return rval;
959 }
960 
961 /**
962  * v4l2_ctrl_notify() - Function to set a notify callback for a control.
963  *
964  * @ctrl:	The control.
965  * @notify:	The callback function.
966  * @priv:	The callback private handle, passed as argument to the callback.
967  *
968  * This function sets a callback function for the control. If @ctrl is NULL,
969  * then it will do nothing. If @notify is NULL, then the notify callback will
970  * be removed.
971  *
972  * There can be only one notify. If another already exists, then a WARN_ON
973  * will be issued and the function will do nothing.
974  */
975 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
976 		      void *priv);
977 
978 /**
979  * v4l2_ctrl_get_name() - Get the name of the control
980  *
981  * @id:		The control ID.
982  *
983  * This function returns the name of the given control ID or NULL if it isn't
984  * a known control.
985  */
986 const char *v4l2_ctrl_get_name(u32 id);
987 
988 /**
989  * v4l2_ctrl_get_menu() - Get the menu string array of the control
990  *
991  * @id:		The control ID.
992  *
993  * This function returns the NULL-terminated menu string array name of the
994  * given control ID or NULL if it isn't a known menu control.
995  */
996 const char * const *v4l2_ctrl_get_menu(u32 id);
997 
998 /**
999  * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
1000  *
1001  * @id:		The control ID.
1002  * @len:	The size of the integer array.
1003  *
1004  * This function returns the integer array of the given control ID or NULL if it
1005  * if it isn't a known integer menu control.
1006  */
1007 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
1008 
1009 /**
1010  * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
1011  *	within a driver.
1012  *
1013  * @ctrl:	The control.
1014  *
1015  * This returns the control's value safely by going through the control
1016  * framework. This function will lock the control's handler, so it cannot be
1017  * used from within the &v4l2_ctrl_ops functions.
1018  *
1019  * This function is for integer type controls only.
1020  */
1021 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
1022 
1023 /**
1024  * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
1025  *
1026  * @ctrl:	The control.
1027  * @val:	The new value.
1028  *
1029  * This sets the control's new value safely by going through the control
1030  * framework. This function assumes the control's handler is already locked,
1031  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1032  *
1033  * This function is for integer type controls only.
1034  */
1035 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1036 
1037 /**
1038  * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1039  *	within a driver.
1040  * @ctrl:	The control.
1041  * @val:	The new value.
1042  *
1043  * This sets the control's new value safely by going through the control
1044  * framework. This function will lock the control's handler, so it cannot be
1045  * used from within the &v4l2_ctrl_ops functions.
1046  *
1047  * This function is for integer type controls only.
1048  */
1049 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1050 {
1051 	int rval;
1052 
1053 	v4l2_ctrl_lock(ctrl);
1054 	rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1055 	v4l2_ctrl_unlock(ctrl);
1056 
1057 	return rval;
1058 }
1059 
1060 /**
1061  * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1062  *	from within a driver.
1063  *
1064  * @ctrl:	The control.
1065  *
1066  * This returns the control's value safely by going through the control
1067  * framework. This function will lock the control's handler, so it cannot be
1068  * used from within the &v4l2_ctrl_ops functions.
1069  *
1070  * This function is for 64-bit integer type controls only.
1071  */
1072 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1073 
1074 /**
1075  * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1076  *
1077  * @ctrl:	The control.
1078  * @val:	The new value.
1079  *
1080  * This sets the control's new value safely by going through the control
1081  * framework. This function assumes the control's handler is already locked,
1082  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1083  *
1084  * This function is for 64-bit integer type controls only.
1085  */
1086 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1087 
1088 /**
1089  * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1090  *	from within a driver.
1091  *
1092  * @ctrl:	The control.
1093  * @val:	The new value.
1094  *
1095  * This sets the control's new value safely by going through the control
1096  * framework. This function will lock the control's handler, so it cannot be
1097  * used from within the &v4l2_ctrl_ops functions.
1098  *
1099  * This function is for 64-bit integer type controls only.
1100  */
1101 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1102 {
1103 	int rval;
1104 
1105 	v4l2_ctrl_lock(ctrl);
1106 	rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1107 	v4l2_ctrl_unlock(ctrl);
1108 
1109 	return rval;
1110 }
1111 
1112 /**
1113  * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1114  *
1115  * @ctrl:	The control.
1116  * @s:		The new string.
1117  *
1118  * This sets the control's new string safely by going through the control
1119  * framework. This function assumes the control's handler is already locked,
1120  * allowing it to be used from within the &v4l2_ctrl_ops functions.
1121  *
1122  * This function is for string type controls only.
1123  */
1124 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1125 
1126 /**
1127  * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1128  *	 from within a driver.
1129  *
1130  * @ctrl:	The control.
1131  * @s:		The new string.
1132  *
1133  * This sets the control's new string safely by going through the control
1134  * framework. This function will lock the control's handler, so it cannot be
1135  * used from within the &v4l2_ctrl_ops functions.
1136  *
1137  * This function is for string type controls only.
1138  */
1139 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1140 {
1141 	int rval;
1142 
1143 	v4l2_ctrl_lock(ctrl);
1144 	rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1145 	v4l2_ctrl_unlock(ctrl);
1146 
1147 	return rval;
1148 }
1149 
1150 /**
1151  * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1152  *
1153  * @ctrl: The control.
1154  * @type: The type of the data.
1155  * @p:    The new compound payload.
1156  *
1157  * This sets the control's new compound payload safely by going through the
1158  * control framework. This function assumes the control's handler is already
1159  * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1160  *
1161  * This function is for compound type controls only.
1162  */
1163 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1164 				enum v4l2_ctrl_type type, const void *p);
1165 
1166 /**
1167  * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1168  *	from within a driver.
1169  *
1170  * @ctrl: The control.
1171  * @type: The type of the data.
1172  * @p:    The new compound payload.
1173  *
1174  * This sets the control's new compound payload safely by going through the
1175  * control framework. This function will lock the control's handler, so it
1176  * cannot be used from within the &v4l2_ctrl_ops functions.
1177  *
1178  * This function is for compound type controls only.
1179  */
1180 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1181 					    enum v4l2_ctrl_type type,
1182 					    const void *p)
1183 {
1184 	int rval;
1185 
1186 	v4l2_ctrl_lock(ctrl);
1187 	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1188 	v4l2_ctrl_unlock(ctrl);
1189 
1190 	return rval;
1191 }
1192 
1193 /* Helper defines for area type controls */
1194 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1195 	__v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1196 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1197 	v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1198 
1199 /* Internal helper functions that deal with control events. */
1200 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1201 
1202 /**
1203  * v4l2_ctrl_replace - Function to be used as a callback to
1204  *	&struct v4l2_subscribed_event_ops replace\(\)
1205  *
1206  * @old: pointer to struct &v4l2_event with the reported
1207  *	 event;
1208  * @new: pointer to struct &v4l2_event with the modified
1209  *	 event;
1210  */
1211 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1212 
1213 /**
1214  * v4l2_ctrl_merge - Function to be used as a callback to
1215  *	&struct v4l2_subscribed_event_ops merge(\)
1216  *
1217  * @old: pointer to struct &v4l2_event with the reported
1218  *	 event;
1219  * @new: pointer to struct &v4l2_event with the merged
1220  *	 event;
1221  */
1222 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1223 
1224 /**
1225  * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1226  *
1227  * @file: pointer to struct file
1228  * @fh: unused. Kept just to be compatible to the arguments expected by
1229  *	&struct v4l2_ioctl_ops.vidioc_log_status.
1230  *
1231  * Can be used as a vidioc_log_status function that just dumps all controls
1232  * associated with the filehandle.
1233  */
1234 int v4l2_ctrl_log_status(struct file *file, void *fh);
1235 
1236 /**
1237  * v4l2_ctrl_subscribe_event - Subscribes to an event
1238  *
1239  *
1240  * @fh: pointer to struct v4l2_fh
1241  * @sub: pointer to &struct v4l2_event_subscription
1242  *
1243  * Can be used as a vidioc_subscribe_event function that just subscribes
1244  * control events.
1245  */
1246 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1247 				const struct v4l2_event_subscription *sub);
1248 
1249 /**
1250  * v4l2_ctrl_poll - function to be used as a callback to the poll()
1251  *	That just polls for control events.
1252  *
1253  * @file: pointer to struct file
1254  * @wait: pointer to struct poll_table_struct
1255  */
1256 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1257 
1258 /**
1259  * v4l2_ctrl_request_setup - helper function to apply control values in a request
1260  *
1261  * @req: The request
1262  * @parent: The parent control handler ('priv' in media_request_object_find())
1263  *
1264  * This is a helper function to call the control handler's s_ctrl callback with
1265  * the control values contained in the request. Do note that this approach of
1266  * applying control values in a request is only applicable to memory-to-memory
1267  * devices.
1268  */
1269 int v4l2_ctrl_request_setup(struct media_request *req,
1270 			     struct v4l2_ctrl_handler *parent);
1271 
1272 /**
1273  * v4l2_ctrl_request_complete - Complete a control handler request object
1274  *
1275  * @req: The request
1276  * @parent: The parent control handler ('priv' in media_request_object_find())
1277  *
1278  * This function is to be called on each control handler that may have had a
1279  * request object associated with it, i.e. control handlers of a driver that
1280  * supports requests.
1281  *
1282  * The function first obtains the values of any volatile controls in the control
1283  * handler and attach them to the request. Then, the function completes the
1284  * request object.
1285  */
1286 void v4l2_ctrl_request_complete(struct media_request *req,
1287 				struct v4l2_ctrl_handler *parent);
1288 
1289 /**
1290  * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1291  *
1292  * @req: The request
1293  * @parent: The parent control handler ('priv' in media_request_object_find())
1294  *
1295  * This function finds the control handler in the request. It may return
1296  * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
1297  * with the returned handler pointer.
1298  *
1299  * If the request is not in state VALIDATING or QUEUED, then this function
1300  * will always return NULL.
1301  *
1302  * Note that in state VALIDATING the req_queue_mutex is held, so
1303  * no objects can be added or deleted from the request.
1304  *
1305  * In state QUEUED it is the driver that will have to ensure this.
1306  */
1307 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1308 					struct v4l2_ctrl_handler *parent);
1309 
1310 /**
1311  * v4l2_ctrl_request_hdl_put - Put the control handler
1312  *
1313  * @hdl: Put this control handler
1314  *
1315  * This function released the control handler previously obtained from'
1316  * v4l2_ctrl_request_hdl_find().
1317  */
1318 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1319 {
1320 	if (hdl)
1321 		media_request_object_put(&hdl->req_obj);
1322 }
1323 
1324 /**
1325  * v4l2_ctrl_request_hdl_ctrl_find() - Find a control with the given ID.
1326  *
1327  * @hdl: The control handler from the request.
1328  * @id: The ID of the control to find.
1329  *
1330  * This function returns a pointer to the control if this control is
1331  * part of the request or NULL otherwise.
1332  */
1333 struct v4l2_ctrl *
1334 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1335 
1336 /* Helpers for ioctl_ops */
1337 
1338 /**
1339  * v4l2_queryctrl - Helper function to implement
1340  *	:ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1341  *
1342  * @hdl: pointer to &struct v4l2_ctrl_handler
1343  * @qc: pointer to &struct v4l2_queryctrl
1344  *
1345  * If hdl == NULL then they will all return -EINVAL.
1346  */
1347 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1348 
1349 /**
1350  * v4l2_query_ext_ctrl - Helper function to implement
1351  *	 :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1352  *
1353  * @hdl: pointer to &struct v4l2_ctrl_handler
1354  * @qc: pointer to &struct v4l2_query_ext_ctrl
1355  *
1356  * If hdl == NULL then they will all return -EINVAL.
1357  */
1358 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1359 			struct v4l2_query_ext_ctrl *qc);
1360 
1361 /**
1362  * v4l2_querymenu - Helper function to implement
1363  *	:ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1364  *
1365  * @hdl: pointer to &struct v4l2_ctrl_handler
1366  * @qm: pointer to &struct v4l2_querymenu
1367  *
1368  * If hdl == NULL then they will all return -EINVAL.
1369  */
1370 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1371 
1372 /**
1373  * v4l2_g_ctrl - Helper function to implement
1374  *	:ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1375  *
1376  * @hdl: pointer to &struct v4l2_ctrl_handler
1377  * @ctrl: pointer to &struct v4l2_control
1378  *
1379  * If hdl == NULL then they will all return -EINVAL.
1380  */
1381 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1382 
1383 /**
1384  * v4l2_s_ctrl - Helper function to implement
1385  *	:ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1386  *
1387  * @fh: pointer to &struct v4l2_fh
1388  * @hdl: pointer to &struct v4l2_ctrl_handler
1389  *
1390  * @ctrl: pointer to &struct v4l2_control
1391  *
1392  * If hdl == NULL then they will all return -EINVAL.
1393  */
1394 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1395 		struct v4l2_control *ctrl);
1396 
1397 /**
1398  * v4l2_g_ext_ctrls - Helper function to implement
1399  *	:ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1400  *
1401  * @hdl: pointer to &struct v4l2_ctrl_handler
1402  * @vdev: pointer to &struct video_device
1403  * @mdev: pointer to &struct media_device
1404  * @c: pointer to &struct v4l2_ext_controls
1405  *
1406  * If hdl == NULL then they will all return -EINVAL.
1407  */
1408 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1409 		     struct media_device *mdev, struct v4l2_ext_controls *c);
1410 
1411 /**
1412  * v4l2_try_ext_ctrls - Helper function to implement
1413  *	:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1414  *
1415  * @hdl: pointer to &struct v4l2_ctrl_handler
1416  * @vdev: pointer to &struct video_device
1417  * @mdev: pointer to &struct media_device
1418  * @c: pointer to &struct v4l2_ext_controls
1419  *
1420  * If hdl == NULL then they will all return -EINVAL.
1421  */
1422 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1423 		       struct video_device *vdev,
1424 		       struct media_device *mdev,
1425 		       struct v4l2_ext_controls *c);
1426 
1427 /**
1428  * v4l2_s_ext_ctrls - Helper function to implement
1429  *	:ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1430  *
1431  * @fh: pointer to &struct v4l2_fh
1432  * @hdl: pointer to &struct v4l2_ctrl_handler
1433  * @vdev: pointer to &struct video_device
1434  * @mdev: pointer to &struct media_device
1435  * @c: pointer to &struct v4l2_ext_controls
1436  *
1437  * If hdl == NULL then they will all return -EINVAL.
1438  */
1439 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1440 		     struct video_device *vdev,
1441 		     struct media_device *mdev,
1442 		     struct v4l2_ext_controls *c);
1443 
1444 /**
1445  * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1446  *	as a &struct v4l2_subdev_core_ops subscribe_event function
1447  *	that just subscribes control events.
1448  *
1449  * @sd: pointer to &struct v4l2_subdev
1450  * @fh: pointer to &struct v4l2_fh
1451  * @sub: pointer to &struct v4l2_event_subscription
1452  */
1453 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1454 				     struct v4l2_event_subscription *sub);
1455 
1456 /**
1457  * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1458  *	 handler.
1459  *
1460  * @sd: pointer to &struct v4l2_subdev
1461  */
1462 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1463 
1464 /**
1465  * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1466  *				       properties
1467  *
1468  * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1469  * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1470  * @p: pointer to &struct v4l2_fwnode_device_properties
1471  *
1472  * This function registers controls associated to device properties, using the
1473  * property values contained in @p parameter, if the property has been set to
1474  * a value.
1475  *
1476  * Currently the following v4l2 controls are parsed and registered:
1477  * - V4L2_CID_CAMERA_ORIENTATION
1478  * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1479  *
1480  * Controls already registered by the caller with the @hdl control handler are
1481  * not overwritten. Callers should register the controls they want to handle
1482  * themselves before calling this function.
1483  *
1484  * Return: 0 on success, a negative error code on failure.
1485  */
1486 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1487 				    const struct v4l2_ctrl_ops *ctrl_ops,
1488 				    const struct v4l2_fwnode_device_properties *p);
1489 #endif
1490