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_av1_sequence:		Pointer to an AV1 sequence structure.
56   * @p_av1_tile_group_entry:	Pointer to an AV1 tile group entry structure.
57   * @p_av1_frame:		Pointer to an AV1 frame structure.
58   * @p_av1_film_grain:		Pointer to an AV1 film grain structure.
59   * @p:				Pointer to a compound value.
60   * @p_const:			Pointer to a constant compound value.
61   */
62  union v4l2_ctrl_ptr {
63  	s32 *p_s32;
64  	s64 *p_s64;
65  	u8 *p_u8;
66  	u16 *p_u16;
67  	u32 *p_u32;
68  	char *p_char;
69  	struct v4l2_ctrl_mpeg2_sequence *p_mpeg2_sequence;
70  	struct v4l2_ctrl_mpeg2_picture *p_mpeg2_picture;
71  	struct v4l2_ctrl_mpeg2_quantisation *p_mpeg2_quantisation;
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 *p_vp8_frame;
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_ctrl_vp9_compressed_hdr *p_vp9_compressed_hdr_probs;
84  	struct v4l2_ctrl_vp9_frame *p_vp9_frame;
85  	struct v4l2_ctrl_hdr10_cll_info *p_hdr10_cll;
86  	struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
87  	struct v4l2_area *p_area;
88  	struct v4l2_ctrl_av1_sequence *p_av1_sequence;
89  	struct v4l2_ctrl_av1_tile_group_entry *p_av1_tile_group_entry;
90  	struct v4l2_ctrl_av1_frame *p_av1_frame;
91  	struct v4l2_ctrl_av1_film_grain *p_av1_film_grain;
92  	void *p;
93  	const void *p_const;
94  };
95  
96  /**
97   * v4l2_ctrl_ptr_create() - Helper function to return a v4l2_ctrl_ptr from a
98   * void pointer
99   * @ptr:	The void pointer
100   */
v4l2_ctrl_ptr_create(void * ptr)101  static inline union v4l2_ctrl_ptr v4l2_ctrl_ptr_create(void *ptr)
102  {
103  	union v4l2_ctrl_ptr p = { .p = ptr };
104  
105  	return p;
106  }
107  
108  /**
109   * struct v4l2_ctrl_ops - The control operations that the driver has to provide.
110   *
111   * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
112   *		for volatile (and usually read-only) controls such as a control
113   *		that returns the current signal strength which changes
114   *		continuously.
115   *		If not set, then the currently cached value will be returned.
116   * @try_ctrl:	Test whether the control's value is valid. Only relevant when
117   *		the usual min/max/step checks are not sufficient.
118   * @s_ctrl:	Actually set the new control value. s_ctrl is compulsory. The
119   *		ctrl->handler->lock is held when these ops are called, so no
120   *		one else can access controls owned by that handler.
121   */
122  struct v4l2_ctrl_ops {
123  	int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
124  	int (*try_ctrl)(struct v4l2_ctrl *ctrl);
125  	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
126  };
127  
128  /**
129   * struct v4l2_ctrl_type_ops - The control type operations that the driver
130   *			       has to provide.
131   *
132   * @equal: return true if all ctrl->elems array elements are equal.
133   * @init: initialize the value for array elements from from_idx to ctrl->elems.
134   * @log: log the value.
135   * @validate: validate the value for ctrl->new_elems array elements.
136   *	Return 0 on success and a negative value otherwise.
137   */
138  struct v4l2_ctrl_type_ops {
139  	bool (*equal)(const struct v4l2_ctrl *ctrl,
140  		      union v4l2_ctrl_ptr ptr1, union v4l2_ctrl_ptr ptr2);
141  	void (*init)(const struct v4l2_ctrl *ctrl, u32 from_idx,
142  		     union v4l2_ctrl_ptr ptr);
143  	void (*log)(const struct v4l2_ctrl *ctrl);
144  	int (*validate)(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
145  };
146  
147  /**
148   * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
149   *	that should be called when a control value has changed.
150   *
151   * @ctrl: pointer to struct &v4l2_ctrl
152   * @priv: control private data
153   *
154   * This typedef definition is used as an argument to v4l2_ctrl_notify()
155   * and as an argument at struct &v4l2_ctrl_handler.
156   */
157  typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
158  
159  /**
160   * struct v4l2_ctrl - The control structure.
161   *
162   * @node:	The list node.
163   * @ev_subs:	The list of control event subscriptions.
164   * @handler:	The handler that owns the control.
165   * @cluster:	Point to start of cluster array.
166   * @ncontrols:	Number of controls in cluster array.
167   * @done:	Internal flag: set for each processed control.
168   * @is_new:	Set when the user specified a new value for this control. It
169   *		is also set when called from v4l2_ctrl_handler_setup(). Drivers
170   *		should never set this flag.
171   * @has_changed: Set when the current value differs from the new value. Drivers
172   *		should never use this flag.
173   * @is_private: If set, then this control is private to its handler and it
174   *		will not be added to any other handlers. Drivers can set
175   *		this flag.
176   * @is_auto:   If set, then this control selects whether the other cluster
177   *		members are in 'automatic' mode or 'manual' mode. This is
178   *		used for autogain/gain type clusters. Drivers should never
179   *		set this flag directly.
180   * @is_int:    If set, then this control has a simple integer value (i.e. it
181   *		uses ctrl->val).
182   * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
183   * @is_ptr:	If set, then this control is an array and/or has type >=
184   *		%V4L2_CTRL_COMPOUND_TYPES
185   *		and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
186   *		v4l2_ext_control uses field p to point to the data.
187   * @is_array: If set, then this control contains an N-dimensional array.
188   * @is_dyn_array: If set, then this control contains a dynamically sized 1-dimensional array.
189   *		If this is set, then @is_array is also set.
190   * @has_volatiles: If set, then one or more members of the cluster are volatile.
191   *		Drivers should never touch this flag.
192   * @call_notify: If set, then call the handler's notify function whenever the
193   *		control's value changes.
194   * @manual_mode_value: If the is_auto flag is set, then this is the value
195   *		of the auto control that determines if that control is in
196   *		manual mode. So if the value of the auto control equals this
197   *		value, then the whole cluster is in manual mode. Drivers should
198   *		never set this flag directly.
199   * @ops:	The control ops.
200   * @type_ops:	The control type ops.
201   * @id:	The control ID.
202   * @name:	The control name.
203   * @type:	The control type.
204   * @minimum:	The control's minimum value.
205   * @maximum:	The control's maximum value.
206   * @default_value: The control's default value.
207   * @step:	The control's step value for non-menu controls.
208   * @elems:	The number of elements in the N-dimensional array.
209   * @elem_size:	The size in bytes of the control.
210   * @new_elems:	The number of elements in p_new. This is the same as @elems,
211   *		except for dynamic arrays. In that case it is in the range of
212   *		1 to @p_array_alloc_elems.
213   * @dims:	The size of each dimension.
214   * @nr_of_dims:The number of dimensions in @dims.
215   * @menu_skip_mask: The control's skip mask for menu controls. This makes it
216   *		easy to skip menu items that are not valid. If bit X is set,
217   *		then menu item X is skipped. Of course, this only works for
218   *		menus with <= 32 menu items. There are no menus that come
219   *		close to that number, so this is OK. Should we ever need more,
220   *		then this will have to be extended to a u64 or a bit array.
221   * @qmenu:	A const char * array for all menu items. Array entries that are
222   *		empty strings ("") correspond to non-existing menu items (this
223   *		is in addition to the menu_skip_mask above). The last entry
224   *		must be NULL.
225   *		Used only if the @type is %V4L2_CTRL_TYPE_MENU.
226   * @qmenu_int:	A 64-bit integer array for with integer menu items.
227   *		The size of array must be equal to the menu size, e. g.:
228   *		:math:`ceil(\frac{maximum - minimum}{step}) + 1`.
229   *		Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
230   * @flags:	The control's flags.
231   * @priv:	The control's private pointer. For use by the driver. It is
232   *		untouched by the control framework. Note that this pointer is
233   *		not freed when the control is deleted. Should this be needed
234   *		then a new internal bitfield can be added to tell the framework
235   *		to free this pointer.
236   * @p_array:	Pointer to the allocated array. Only valid if @is_array is true.
237   * @p_array_alloc_elems: The number of elements in the allocated
238   *		array for both the cur and new values. So @p_array is actually
239   *		sized for 2 * @p_array_alloc_elems * @elem_size. Only valid if
240   *		@is_array is true.
241   * @cur:	Structure to store the current value.
242   * @cur.val:	The control's current value, if the @type is represented via
243   *		a u32 integer (see &enum v4l2_ctrl_type).
244   * @val:	The control's new s32 value.
245   * @p_def:	The control's default value represented via a union which
246   *		provides a standard way of accessing control types
247   *		through a pointer (for compound controls only).
248   * @p_cur:	The control's current value represented via a union which
249   *		provides a standard way of accessing control types
250   *		through a pointer.
251   * @p_new:	The control's new value represented via a union which provides
252   *		a standard way of accessing control types
253   *		through a pointer.
254   */
255  struct v4l2_ctrl {
256  	/* Administrative fields */
257  	struct list_head node;
258  	struct list_head ev_subs;
259  	struct v4l2_ctrl_handler *handler;
260  	struct v4l2_ctrl **cluster;
261  	unsigned int ncontrols;
262  
263  	unsigned int done:1;
264  
265  	unsigned int is_new:1;
266  	unsigned int has_changed:1;
267  	unsigned int is_private:1;
268  	unsigned int is_auto:1;
269  	unsigned int is_int:1;
270  	unsigned int is_string:1;
271  	unsigned int is_ptr:1;
272  	unsigned int is_array:1;
273  	unsigned int is_dyn_array:1;
274  	unsigned int has_volatiles:1;
275  	unsigned int call_notify:1;
276  	unsigned int manual_mode_value:8;
277  
278  	const struct v4l2_ctrl_ops *ops;
279  	const struct v4l2_ctrl_type_ops *type_ops;
280  	u32 id;
281  	const char *name;
282  	enum v4l2_ctrl_type type;
283  	s64 minimum, maximum, default_value;
284  	u32 elems;
285  	u32 elem_size;
286  	u32 new_elems;
287  	u32 dims[V4L2_CTRL_MAX_DIMS];
288  	u32 nr_of_dims;
289  	union {
290  		u64 step;
291  		u64 menu_skip_mask;
292  	};
293  	union {
294  		const char * const *qmenu;
295  		const s64 *qmenu_int;
296  	};
297  	unsigned long flags;
298  	void *priv;
299  	void *p_array;
300  	u32 p_array_alloc_elems;
301  	s32 val;
302  	struct {
303  		s32 val;
304  	} cur;
305  
306  	union v4l2_ctrl_ptr p_def;
307  	union v4l2_ctrl_ptr p_new;
308  	union v4l2_ctrl_ptr p_cur;
309  };
310  
311  /**
312   * struct v4l2_ctrl_ref - The control reference.
313   *
314   * @node:	List node for the sorted list.
315   * @next:	Single-link list node for the hash.
316   * @ctrl:	The actual control information.
317   * @helper:	Pointer to helper struct. Used internally in
318   *		``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
319   * @from_other_dev: If true, then @ctrl was defined in another
320   *		device than the &struct v4l2_ctrl_handler.
321   * @req_done:	Internal flag: if the control handler containing this control
322   *		reference is bound to a media request, then this is set when
323   *		the control has been applied. This prevents applying controls
324   *		from a cluster with multiple controls twice (when the first
325   *		control of a cluster is applied, they all are).
326   * @p_req_valid: If set, then p_req contains the control value for the request.
327   * @p_req_array_enomem: If set, then p_req is invalid since allocating space for
328   *		an array failed. Attempting to read this value shall
329   *		result in ENOMEM. Only valid if ctrl->is_array is true.
330   * @p_req_array_alloc_elems: The number of elements allocated for the
331   *		array. Only valid if @p_req_valid and ctrl->is_array are
332   *		true.
333   * @p_req_elems: The number of elements in @p_req. This is the same as
334   *		ctrl->elems, except for dynamic arrays. In that case it is in
335   *		the range of 1 to @p_req_array_alloc_elems. Only valid if
336   *		@p_req_valid is true.
337   * @p_req:	If the control handler containing this control reference
338   *		is bound to a media request, then this points to the
339   *		value of the control that must be applied when the request
340   *		is executed, or to the value of the control at the time
341   *		that the request was completed. If @p_req_valid is false,
342   *		then this control was never set for this request and the
343   *		control will not be updated when this request is applied.
344   *
345   * Each control handler has a list of these refs. The list_head is used to
346   * keep a sorted-by-control-ID list of all controls, while the next pointer
347   * is used to link the control in the hash's bucket.
348   */
349  struct v4l2_ctrl_ref {
350  	struct list_head node;
351  	struct v4l2_ctrl_ref *next;
352  	struct v4l2_ctrl *ctrl;
353  	struct v4l2_ctrl_helper *helper;
354  	bool from_other_dev;
355  	bool req_done;
356  	bool p_req_valid;
357  	bool p_req_array_enomem;
358  	u32 p_req_array_alloc_elems;
359  	u32 p_req_elems;
360  	union v4l2_ctrl_ptr p_req;
361  };
362  
363  /**
364   * struct v4l2_ctrl_handler - The control handler keeps track of all the
365   *	controls: both the controls owned by the handler and those inherited
366   *	from other handlers.
367   *
368   * @_lock:	Default for "lock".
369   * @lock:	Lock to control access to this handler and its controls.
370   *		May be replaced by the user right after init.
371   * @ctrls:	The list of controls owned by this handler.
372   * @ctrl_refs:	The list of control references.
373   * @cached:	The last found control reference. It is common that the same
374   *		control is needed multiple times, so this is a simple
375   *		optimization.
376   * @buckets:	Buckets for the hashing. Allows for quick control lookup.
377   * @notify:	A notify callback that is called whenever the control changes
378   *		value.
379   *		Note that the handler's lock is held when the notify function
380   *		is called!
381   * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
382   * @nr_of_buckets: Total number of buckets in the array.
383   * @error:	The error code of the first failed control addition.
384   * @request_is_queued: True if the request was queued.
385   * @requests:	List to keep track of open control handler request objects.
386   *		For the parent control handler (@req_obj.ops == NULL) this
387   *		is the list header. When the parent control handler is
388   *		removed, it has to unbind and put all these requests since
389   *		they refer to the parent.
390   * @requests_queued: List of the queued requests. This determines the order
391   *		in which these controls are applied. Once the request is
392   *		completed it is removed from this list.
393   * @req_obj:	The &struct media_request_object, used to link into a
394   *		&struct media_request. This request object has a refcount.
395   */
396  struct v4l2_ctrl_handler {
397  	struct mutex _lock;
398  	struct mutex *lock;
399  	struct list_head ctrls;
400  	struct list_head ctrl_refs;
401  	struct v4l2_ctrl_ref *cached;
402  	struct v4l2_ctrl_ref **buckets;
403  	v4l2_ctrl_notify_fnc notify;
404  	void *notify_priv;
405  	u16 nr_of_buckets;
406  	int error;
407  	bool request_is_queued;
408  	struct list_head requests;
409  	struct list_head requests_queued;
410  	struct media_request_object req_obj;
411  };
412  
413  /**
414   * struct v4l2_ctrl_config - Control configuration structure.
415   *
416   * @ops:	The control ops.
417   * @type_ops:	The control type ops. Only needed for compound controls.
418   * @id:	The control ID.
419   * @name:	The control name.
420   * @type:	The control type.
421   * @min:	The control's minimum value.
422   * @max:	The control's maximum value.
423   * @step:	The control's step value for non-menu controls.
424   * @def:	The control's default value.
425   * @p_def:	The control's default value for compound controls.
426   * @dims:	The size of each dimension.
427   * @elem_size:	The size in bytes of the control.
428   * @flags:	The control's flags.
429   * @menu_skip_mask: The control's skip mask for menu controls. This makes it
430   *		easy to skip menu items that are not valid. If bit X is set,
431   *		then menu item X is skipped. Of course, this only works for
432   *		menus with <= 64 menu items. There are no menus that come
433   *		close to that number, so this is OK. Should we ever need more,
434   *		then this will have to be extended to a bit array.
435   * @qmenu:	A const char * array for all menu items. Array entries that are
436   *		empty strings ("") correspond to non-existing menu items (this
437   *		is in addition to the menu_skip_mask above). The last entry
438   *		must be NULL.
439   * @qmenu_int:	A const s64 integer array for all menu items of the type
440   *		V4L2_CTRL_TYPE_INTEGER_MENU.
441   * @is_private: If set, then this control is private to its handler and it
442   *		will not be added to any other handlers.
443   */
444  struct v4l2_ctrl_config {
445  	const struct v4l2_ctrl_ops *ops;
446  	const struct v4l2_ctrl_type_ops *type_ops;
447  	u32 id;
448  	const char *name;
449  	enum v4l2_ctrl_type type;
450  	s64 min;
451  	s64 max;
452  	u64 step;
453  	s64 def;
454  	union v4l2_ctrl_ptr p_def;
455  	u32 dims[V4L2_CTRL_MAX_DIMS];
456  	u32 elem_size;
457  	u32 flags;
458  	u64 menu_skip_mask;
459  	const char * const *qmenu;
460  	const s64 *qmenu_int;
461  	unsigned int is_private:1;
462  };
463  
464  /**
465   * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
466   *
467   * @id: ID of the control
468   * @name: pointer to be filled with a string with the name of the control
469   * @type: pointer for storing the type of the control
470   * @min: pointer for storing the minimum value for the control
471   * @max: pointer for storing the maximum value for the control
472   * @step: pointer for storing the control step
473   * @def: pointer for storing the default value for the control
474   * @flags: pointer for storing the flags to be used on the control
475   *
476   * This works for all standard V4L2 controls.
477   * For non-standard controls it will only fill in the given arguments
478   * and @name content will be set to %NULL.
479   *
480   * This function will overwrite the contents of @name, @type and @flags.
481   * The contents of @min, @max, @step and @def may be modified depending on
482   * the type.
483   *
484   * .. note::
485   *
486   *    Do not use in drivers! It is used internally for backwards compatibility
487   *    control handling only. Once all drivers are converted to use the new
488   *    control framework this function will no longer be exported.
489   */
490  void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
491  		    s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
492  
493  
494  /**
495   * v4l2_ctrl_handler_init_class() - Initialize the control handler.
496   * @hdl:	The control handler.
497   * @nr_of_controls_hint: A hint of how many controls this handler is
498   *		expected to refer to. This is the total number, so including
499   *		any inherited controls. It doesn't have to be precise, but if
500   *		it is way off, then you either waste memory (too many buckets
501   *		are allocated) or the control lookup becomes slower (not enough
502   *		buckets are allocated, so there are more slow list lookups).
503   *		It will always work, though.
504   * @key:	Used by the lock validator if CONFIG_LOCKDEP is set.
505   * @name:	Used by the lock validator if CONFIG_LOCKDEP is set.
506   *
507   * .. attention::
508   *
509   *    Never use this call directly, always use the v4l2_ctrl_handler_init()
510   *    macro that hides the @key and @name arguments.
511   *
512   * Return: returns an error if the buckets could not be allocated. This
513   * error will also be stored in @hdl->error.
514   */
515  int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
516  				 unsigned int nr_of_controls_hint,
517  				 struct lock_class_key *key, const char *name);
518  
519  #ifdef CONFIG_LOCKDEP
520  
521  /**
522   * v4l2_ctrl_handler_init - helper function to create a static struct
523   *	 &lock_class_key and calls v4l2_ctrl_handler_init_class()
524   *
525   * @hdl:	The control handler.
526   * @nr_of_controls_hint: A hint of how many controls this handler is
527   *		expected to refer to. This is the total number, so including
528   *		any inherited controls. It doesn't have to be precise, but if
529   *		it is way off, then you either waste memory (too many buckets
530   *		are allocated) or the control lookup becomes slower (not enough
531   *		buckets are allocated, so there are more slow list lookups).
532   *		It will always work, though.
533   *
534   * This helper function creates a static struct &lock_class_key and
535   * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
536   * validador.
537   *
538   * Use this helper function to initialize a control handler.
539   */
540  #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
541  (									\
542  	({								\
543  		static struct lock_class_key _key;			\
544  		v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,	\
545  					&_key,				\
546  					KBUILD_BASENAME ":"		\
547  					__stringify(__LINE__) ":"	\
548  					"(" #hdl ")->_lock");		\
549  	})								\
550  )
551  #else
552  #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)		\
553  	v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
554  #endif
555  
556  /**
557   * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
558   * the control list.
559   * @hdl:	The control handler.
560   *
561   * Does nothing if @hdl == NULL.
562   */
563  void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
564  
565  /**
566   * v4l2_ctrl_lock() - Helper function to lock the handler
567   * associated with the control.
568   * @ctrl:	The control to lock.
569   */
v4l2_ctrl_lock(struct v4l2_ctrl * ctrl)570  static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
571  {
572  	mutex_lock(ctrl->handler->lock);
573  }
574  
575  /**
576   * v4l2_ctrl_unlock() - Helper function to unlock the handler
577   * associated with the control.
578   * @ctrl:	The control to unlock.
579   */
v4l2_ctrl_unlock(struct v4l2_ctrl * ctrl)580  static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
581  {
582  	mutex_unlock(ctrl->handler->lock);
583  }
584  
585  /**
586   * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
587   * to the handler to initialize the hardware to the current control values. The
588   * caller is responsible for acquiring the control handler mutex on behalf of
589   * __v4l2_ctrl_handler_setup().
590   * @hdl:	The control handler.
591   *
592   * Button controls will be skipped, as are read-only controls.
593   *
594   * If @hdl == NULL, then this just returns 0.
595   */
596  int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
597  
598  /**
599   * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
600   * to the handler to initialize the hardware to the current control values.
601   * @hdl:	The control handler.
602   *
603   * Button controls will be skipped, as are read-only controls.
604   *
605   * If @hdl == NULL, then this just returns 0.
606   */
607  int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
608  
609  /**
610   * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
611   * @hdl:	The control handler.
612   * @prefix:	The prefix to use when logging the control values. If the
613   *		prefix does not end with a space, then ": " will be added
614   *		after the prefix. If @prefix == NULL, then no prefix will be
615   *		used.
616   *
617   * For use with VIDIOC_LOG_STATUS.
618   *
619   * Does nothing if @hdl == NULL.
620   */
621  void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
622  				  const char *prefix);
623  
624  /**
625   * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
626   *	control.
627   *
628   * @hdl:	The control handler.
629   * @cfg:	The control's configuration data.
630   * @priv:	The control's driver-specific private data.
631   *
632   * If the &v4l2_ctrl struct could not be allocated then NULL is returned
633   * and @hdl->error is set to the error code (if it wasn't set already).
634   */
635  struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
636  				       const struct v4l2_ctrl_config *cfg,
637  				       void *priv);
638  
639  /**
640   * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu
641   *	control.
642   *
643   * @hdl:	The control handler.
644   * @ops:	The control ops.
645   * @id:		The control ID.
646   * @min:	The control's minimum value.
647   * @max:	The control's maximum value.
648   * @step:	The control's step value
649   * @def:	The control's default value.
650   *
651   * If the &v4l2_ctrl struct could not be allocated, or the control
652   * ID is not known, then NULL is returned and @hdl->error is set to the
653   * appropriate error code (if it wasn't set already).
654   *
655   * If @id refers to a menu control, then this function will return NULL.
656   *
657   * Use v4l2_ctrl_new_std_menu() when adding menu controls.
658   */
659  struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
660  				    const struct v4l2_ctrl_ops *ops,
661  				    u32 id, s64 min, s64 max, u64 step,
662  				    s64 def);
663  
664  /**
665   * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2
666   *	menu control.
667   *
668   * @hdl:	The control handler.
669   * @ops:	The control ops.
670   * @id:		The control ID.
671   * @max:	The control's maximum value.
672   * @mask:	The control's skip mask for menu controls. This makes it
673   *		easy to skip menu items that are not valid. If bit X is set,
674   *		then menu item X is skipped. Of course, this only works for
675   *		menus with <= 64 menu items. There are no menus that come
676   *		close to that number, so this is OK. Should we ever need more,
677   *		then this will have to be extended to a bit array.
678   * @def:	The control's default value.
679   *
680   * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
681   * determines which menu items are to be skipped.
682   *
683   * If @id refers to a non-menu control, then this function will return NULL.
684   */
685  struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
686  					 const struct v4l2_ctrl_ops *ops,
687  					 u32 id, u8 max, u64 mask, u8 def);
688  
689  /**
690   * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
691   *	with driver specific menu.
692   *
693   * @hdl:	The control handler.
694   * @ops:	The control ops.
695   * @id:	The control ID.
696   * @max:	The control's maximum value.
697   * @mask:	The control's skip mask for menu controls. This makes it
698   *		easy to skip menu items that are not valid. If bit X is set,
699   *		then menu item X is skipped. Of course, this only works for
700   *		menus with <= 64 menu items. There are no menus that come
701   *		close to that number, so this is OK. Should we ever need more,
702   *		then this will have to be extended to a bit array.
703   * @def:	The control's default value.
704   * @qmenu:	The new menu.
705   *
706   * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
707   * menu of this control.
708   *
709   */
710  struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
711  					       const struct v4l2_ctrl_ops *ops,
712  					       u32 id, u8 max,
713  					       u64 mask, u8 def,
714  					       const char * const *qmenu);
715  
716  /**
717   * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
718   *      compound control.
719   *
720   * @hdl:       The control handler.
721   * @ops:       The control ops.
722   * @id:        The control ID.
723   * @p_def:     The control's default value.
724   *
725   * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
726   * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
727   * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
728   * compound control should be all zeroes.
729   *
730   */
731  struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
732  					     const struct v4l2_ctrl_ops *ops,
733  					     u32 id,
734  					     const union v4l2_ctrl_ptr p_def);
735  
736  /**
737   * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
738   *
739   * @hdl:	The control handler.
740   * @ops:	The control ops.
741   * @id:	The control ID.
742   * @max:	The control's maximum value.
743   * @def:	The control's default value.
744   * @qmenu_int:	The control's menu entries.
745   *
746   * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
747   * takes as an argument an array of integers determining the menu items.
748   *
749   * If @id refers to a non-integer-menu control, then this function will
750   * return %NULL.
751   */
752  struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
753  					 const struct v4l2_ctrl_ops *ops,
754  					 u32 id, u8 max, u8 def,
755  					 const s64 *qmenu_int);
756  
757  /**
758   * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
759   *	used when adding a control handler.
760   *
761   * @ctrl: pointer to struct &v4l2_ctrl.
762   */
763  
764  typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
765  
766  /**
767   * v4l2_ctrl_add_handler() - Add all controls from handler @add to
768   *	handler @hdl.
769   *
770   * @hdl:	The control handler.
771   * @add:	The control handler whose controls you want to add to
772   *		the @hdl control handler.
773   * @filter:	This function will filter which controls should be added.
774   * @from_other_dev: If true, then the controls in @add were defined in another
775   *		device than @hdl.
776   *
777   * Does nothing if either of the two handlers is a NULL pointer.
778   * If @filter is NULL, then all controls are added. Otherwise only those
779   * controls for which @filter returns true will be added.
780   * In case of an error @hdl->error will be set to the error code (if it
781   * wasn't set already).
782   */
783  int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
784  			  struct v4l2_ctrl_handler *add,
785  			  v4l2_ctrl_filter filter,
786  			  bool from_other_dev);
787  
788  /**
789   * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
790   *
791   * @ctrl:	The control that is filtered.
792   *
793   * This will return true for any controls that are valid for radio device
794   * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
795   * transmitter class controls.
796   *
797   * This function is to be used with v4l2_ctrl_add_handler().
798   */
799  bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
800  
801  /**
802   * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging
803   *	to that cluster.
804   *
805   * @ncontrols:	The number of controls in this cluster.
806   * @controls:	The cluster control array of size @ncontrols.
807   */
808  void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls);
809  
810  
811  /**
812   * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging
813   *	to that cluster and set it up for autofoo/foo-type handling.
814   *
815   * @ncontrols:	The number of controls in this cluster.
816   * @controls:	The cluster control array of size @ncontrols. The first control
817   *		must be the 'auto' control (e.g. autogain, autoexposure, etc.)
818   * @manual_val: The value for the first control in the cluster that equals the
819   *		manual setting.
820   * @set_volatile: If true, then all controls except the first auto control will
821   *		be volatile.
822   *
823   * Use for control groups where one control selects some automatic feature and
824   * the other controls are only active whenever the automatic feature is turned
825   * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
826   * red and blue balance, etc.
827   *
828   * The behavior of such controls is as follows:
829   *
830   * When the autofoo control is set to automatic, then any manual controls
831   * are set to inactive and any reads will call g_volatile_ctrl (if the control
832   * was marked volatile).
833   *
834   * When the autofoo control is set to manual, then any manual controls will
835   * be marked active, and any reads will just return the current value without
836   * going through g_volatile_ctrl.
837   *
838   * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag
839   * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
840   * if autofoo is in auto mode.
841   */
842  void v4l2_ctrl_auto_cluster(unsigned int ncontrols,
843  			    struct v4l2_ctrl **controls,
844  			    u8 manual_val, bool set_volatile);
845  
846  
847  /**
848   * v4l2_ctrl_find() - Find a control with the given ID.
849   *
850   * @hdl:	The control handler.
851   * @id:	The control ID to find.
852   *
853   * If @hdl == NULL this will return NULL as well. Will lock the handler so
854   * do not use from inside &v4l2_ctrl_ops.
855   */
856  struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
857  
858  /**
859   * v4l2_ctrl_activate() - Make the control active or inactive.
860   * @ctrl:	The control to (de)activate.
861   * @active:	True if the control should become active.
862   *
863   * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
864   * Does nothing if @ctrl == NULL.
865   * This will usually be called from within the s_ctrl op.
866   * The V4L2_EVENT_CTRL event will be generated afterwards.
867   *
868   * This function assumes that the control handler is locked.
869   */
870  void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
871  
872  /**
873   * __v4l2_ctrl_grab() - Unlocked variant of v4l2_ctrl_grab.
874   *
875   * @ctrl:	The control to (de)activate.
876   * @grabbed:	True if the control should become grabbed.
877   *
878   * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
879   * Does nothing if @ctrl == NULL.
880   * The V4L2_EVENT_CTRL event will be generated afterwards.
881   * This will usually be called when starting or stopping streaming in the
882   * driver.
883   *
884   * This function assumes that the control handler is locked by the caller.
885   */
886  void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
887  
888  /**
889   * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
890   *
891   * @ctrl:	The control to (de)activate.
892   * @grabbed:	True if the control should become grabbed.
893   *
894   * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
895   * Does nothing if @ctrl == NULL.
896   * The V4L2_EVENT_CTRL event will be generated afterwards.
897   * This will usually be called when starting or stopping streaming in the
898   * driver.
899   *
900   * This function assumes that the control handler is not locked and will
901   * take the lock itself.
902   */
v4l2_ctrl_grab(struct v4l2_ctrl * ctrl,bool grabbed)903  static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
904  {
905  	if (!ctrl)
906  		return;
907  
908  	v4l2_ctrl_lock(ctrl);
909  	__v4l2_ctrl_grab(ctrl, grabbed);
910  	v4l2_ctrl_unlock(ctrl);
911  }
912  
913  /**
914   *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
915   *
916   * @ctrl:	The control to update.
917   * @min:	The control's minimum value.
918   * @max:	The control's maximum value.
919   * @step:	The control's step value
920   * @def:	The control's default value.
921   *
922   * Update the range of a control on the fly. This works for control types
923   * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
924   * @step value is interpreted as a menu_skip_mask.
925   *
926   * An error is returned if one of the range arguments is invalid for this
927   * control type.
928   *
929   * The caller is responsible for acquiring the control handler mutex on behalf
930   * of __v4l2_ctrl_modify_range().
931   */
932  int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
933  			     s64 min, s64 max, u64 step, s64 def);
934  
935  /**
936   * v4l2_ctrl_modify_range() - Update the range of a control.
937   *
938   * @ctrl:	The control to update.
939   * @min:	The control's minimum value.
940   * @max:	The control's maximum value.
941   * @step:	The control's step value
942   * @def:	The control's default value.
943   *
944   * Update the range of a control on the fly. This works for control types
945   * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
946   * @step value is interpreted as a menu_skip_mask.
947   *
948   * An error is returned if one of the range arguments is invalid for this
949   * control type.
950   *
951   * This function assumes that the control handler is not locked and will
952   * take the lock itself.
953   */
v4l2_ctrl_modify_range(struct v4l2_ctrl * ctrl,s64 min,s64 max,u64 step,s64 def)954  static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
955  					 s64 min, s64 max, u64 step, s64 def)
956  {
957  	int rval;
958  
959  	v4l2_ctrl_lock(ctrl);
960  	rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
961  	v4l2_ctrl_unlock(ctrl);
962  
963  	return rval;
964  }
965  
966  /**
967   *__v4l2_ctrl_modify_dimensions() - Unlocked variant of v4l2_ctrl_modify_dimensions()
968   *
969   * @ctrl:	The control to update.
970   * @dims:	The control's new dimensions.
971   *
972   * Update the dimensions of an array control on the fly. The elements of the
973   * array are reset to their default value, even if the dimensions are
974   * unchanged.
975   *
976   * An error is returned if @dims is invalid for this control.
977   *
978   * The caller is responsible for acquiring the control handler mutex on behalf
979   * of __v4l2_ctrl_modify_dimensions().
980   *
981   * Note: calling this function when the same control is used in pending requests
982   * is untested. It should work (a request with the wrong size of the control
983   * will drop that control silently), but it will be very confusing.
984   */
985  int __v4l2_ctrl_modify_dimensions(struct v4l2_ctrl *ctrl,
986  				  u32 dims[V4L2_CTRL_MAX_DIMS]);
987  
988  /**
989   * v4l2_ctrl_modify_dimensions() - Update the dimensions of an array control.
990   *
991   * @ctrl:	The control to update.
992   * @dims:	The control's new dimensions.
993   *
994   * Update the dimensions of an array control on the fly. The elements of the
995   * array are reset to their default value, even if the dimensions are
996   * unchanged.
997   *
998   * An error is returned if @dims is invalid for this control type.
999   *
1000   * This function assumes that the control handler is not locked and will
1001   * take the lock itself.
1002   *
1003   * Note: calling this function when the same control is used in pending requests
1004   * is untested. It should work (a request with the wrong size of the control
1005   * will drop that control silently), but it will be very confusing.
1006   */
v4l2_ctrl_modify_dimensions(struct v4l2_ctrl * ctrl,u32 dims[V4L2_CTRL_MAX_DIMS])1007  static inline int v4l2_ctrl_modify_dimensions(struct v4l2_ctrl *ctrl,
1008  					      u32 dims[V4L2_CTRL_MAX_DIMS])
1009  {
1010  	int rval;
1011  
1012  	v4l2_ctrl_lock(ctrl);
1013  	rval = __v4l2_ctrl_modify_dimensions(ctrl, dims);
1014  	v4l2_ctrl_unlock(ctrl);
1015  
1016  	return rval;
1017  }
1018  
1019  /**
1020   * v4l2_ctrl_notify() - Function to set a notify callback for a control.
1021   *
1022   * @ctrl:	The control.
1023   * @notify:	The callback function.
1024   * @priv:	The callback private handle, passed as argument to the callback.
1025   *
1026   * This function sets a callback function for the control. If @ctrl is NULL,
1027   * then it will do nothing. If @notify is NULL, then the notify callback will
1028   * be removed.
1029   *
1030   * There can be only one notify. If another already exists, then a WARN_ON
1031   * will be issued and the function will do nothing.
1032   */
1033  void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
1034  		      void *priv);
1035  
1036  /**
1037   * v4l2_ctrl_get_name() - Get the name of the control
1038   *
1039   * @id:		The control ID.
1040   *
1041   * This function returns the name of the given control ID or NULL if it isn't
1042   * a known control.
1043   */
1044  const char *v4l2_ctrl_get_name(u32 id);
1045  
1046  /**
1047   * v4l2_ctrl_get_menu() - Get the menu string array of the control
1048   *
1049   * @id:		The control ID.
1050   *
1051   * This function returns the NULL-terminated menu string array name of the
1052   * given control ID or NULL if it isn't a known menu control.
1053   */
1054  const char * const *v4l2_ctrl_get_menu(u32 id);
1055  
1056  /**
1057   * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
1058   *
1059   * @id:		The control ID.
1060   * @len:	The size of the integer array.
1061   *
1062   * This function returns the integer array of the given control ID or NULL if it
1063   * if it isn't a known integer menu control.
1064   */
1065  const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
1066  
1067  /**
1068   * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from
1069   *	within a driver.
1070   *
1071   * @ctrl:	The control.
1072   *
1073   * This returns the control's value safely by going through the control
1074   * framework. This function will lock the control's handler, so it cannot be
1075   * used from within the &v4l2_ctrl_ops functions.
1076   *
1077   * This function is for integer type controls only.
1078   */
1079  s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
1080  
1081  /**
1082   * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl().
1083   *
1084   * @ctrl:	The control.
1085   * @val:	The new value.
1086   *
1087   * This sets the control's new value safely by going through the control
1088   * framework. This function assumes the control's handler is already locked,
1089   * allowing it to be used from within the &v4l2_ctrl_ops functions.
1090   *
1091   * This function is for integer type controls only.
1092   */
1093  int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
1094  
1095  /**
1096   * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
1097   *	within a driver.
1098   * @ctrl:	The control.
1099   * @val:	The new value.
1100   *
1101   * This sets the control's new value safely by going through the control
1102   * framework. This function will lock the control's handler, so it cannot be
1103   * used from within the &v4l2_ctrl_ops functions.
1104   *
1105   * This function is for integer type controls only.
1106   */
v4l2_ctrl_s_ctrl(struct v4l2_ctrl * ctrl,s32 val)1107  static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
1108  {
1109  	int rval;
1110  
1111  	v4l2_ctrl_lock(ctrl);
1112  	rval = __v4l2_ctrl_s_ctrl(ctrl, val);
1113  	v4l2_ctrl_unlock(ctrl);
1114  
1115  	return rval;
1116  }
1117  
1118  /**
1119   * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value
1120   *	from within a driver.
1121   *
1122   * @ctrl:	The control.
1123   *
1124   * This returns the control's value safely by going through the control
1125   * framework. This function will lock the control's handler, so it cannot be
1126   * used from within the &v4l2_ctrl_ops functions.
1127   *
1128   * This function is for 64-bit integer type controls only.
1129   */
1130  s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
1131  
1132  /**
1133   * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
1134   *
1135   * @ctrl:	The control.
1136   * @val:	The new value.
1137   *
1138   * This sets the control's new value safely by going through the control
1139   * framework. This function assumes the control's handler is already locked,
1140   * allowing it to be used from within the &v4l2_ctrl_ops functions.
1141   *
1142   * This function is for 64-bit integer type controls only.
1143   */
1144  int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
1145  
1146  /**
1147   * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
1148   *	from within a driver.
1149   *
1150   * @ctrl:	The control.
1151   * @val:	The new value.
1152   *
1153   * This sets the control's new value safely by going through the control
1154   * framework. This function will lock the control's handler, so it cannot be
1155   * used from within the &v4l2_ctrl_ops functions.
1156   *
1157   * This function is for 64-bit integer type controls only.
1158   */
v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl * ctrl,s64 val)1159  static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
1160  {
1161  	int rval;
1162  
1163  	v4l2_ctrl_lock(ctrl);
1164  	rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
1165  	v4l2_ctrl_unlock(ctrl);
1166  
1167  	return rval;
1168  }
1169  
1170  /**
1171   * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
1172   *
1173   * @ctrl:	The control.
1174   * @s:		The new string.
1175   *
1176   * This sets the control's new string safely by going through the control
1177   * framework. This function assumes the control's handler is already locked,
1178   * allowing it to be used from within the &v4l2_ctrl_ops functions.
1179   *
1180   * This function is for string type controls only.
1181   */
1182  int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
1183  
1184  /**
1185   * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
1186   *	 from within a driver.
1187   *
1188   * @ctrl:	The control.
1189   * @s:		The new string.
1190   *
1191   * This sets the control's new string safely by going through the control
1192   * framework. This function will lock the control's handler, so it cannot be
1193   * used from within the &v4l2_ctrl_ops functions.
1194   *
1195   * This function is for string type controls only.
1196   */
v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl * ctrl,const char * s)1197  static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
1198  {
1199  	int rval;
1200  
1201  	v4l2_ctrl_lock(ctrl);
1202  	rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
1203  	v4l2_ctrl_unlock(ctrl);
1204  
1205  	return rval;
1206  }
1207  
1208  /**
1209   * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
1210   *
1211   * @ctrl: The control.
1212   * @type: The type of the data.
1213   * @p:    The new compound payload.
1214   *
1215   * This sets the control's new compound payload safely by going through the
1216   * control framework. This function assumes the control's handler is already
1217   * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
1218   *
1219   * This function is for compound type controls only.
1220   */
1221  int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1222  				enum v4l2_ctrl_type type, const void *p);
1223  
1224  /**
1225   * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
1226   *	from within a driver.
1227   *
1228   * @ctrl: The control.
1229   * @type: The type of the data.
1230   * @p:    The new compound payload.
1231   *
1232   * This sets the control's new compound payload safely by going through the
1233   * control framework. This function will lock the control's handler, so it
1234   * cannot be used from within the &v4l2_ctrl_ops functions.
1235   *
1236   * This function is for compound type controls only.
1237   */
v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl * ctrl,enum v4l2_ctrl_type type,const void * p)1238  static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
1239  					    enum v4l2_ctrl_type type,
1240  					    const void *p)
1241  {
1242  	int rval;
1243  
1244  	v4l2_ctrl_lock(ctrl);
1245  	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
1246  	v4l2_ctrl_unlock(ctrl);
1247  
1248  	return rval;
1249  }
1250  
1251  /* Helper defines for area type controls */
1252  #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
1253  	__v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1254  #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
1255  	v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
1256  
1257  /* Internal helper functions that deal with control events. */
1258  extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
1259  
1260  /**
1261   * v4l2_ctrl_replace - Function to be used as a callback to
1262   *	&struct v4l2_subscribed_event_ops replace\(\)
1263   *
1264   * @old: pointer to struct &v4l2_event with the reported
1265   *	 event;
1266   * @new: pointer to struct &v4l2_event with the modified
1267   *	 event;
1268   */
1269  void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
1270  
1271  /**
1272   * v4l2_ctrl_merge - Function to be used as a callback to
1273   *	&struct v4l2_subscribed_event_ops merge(\)
1274   *
1275   * @old: pointer to struct &v4l2_event with the reported
1276   *	 event;
1277   * @new: pointer to struct &v4l2_event with the merged
1278   *	 event;
1279   */
1280  void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
1281  
1282  /**
1283   * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
1284   *
1285   * @file: pointer to struct file
1286   * @fh: unused. Kept just to be compatible to the arguments expected by
1287   *	&struct v4l2_ioctl_ops.vidioc_log_status.
1288   *
1289   * Can be used as a vidioc_log_status function that just dumps all controls
1290   * associated with the filehandle.
1291   */
1292  int v4l2_ctrl_log_status(struct file *file, void *fh);
1293  
1294  /**
1295   * v4l2_ctrl_subscribe_event - Subscribes to an event
1296   *
1297   *
1298   * @fh: pointer to struct v4l2_fh
1299   * @sub: pointer to &struct v4l2_event_subscription
1300   *
1301   * Can be used as a vidioc_subscribe_event function that just subscribes
1302   * control events.
1303   */
1304  int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
1305  				const struct v4l2_event_subscription *sub);
1306  
1307  /**
1308   * v4l2_ctrl_poll - function to be used as a callback to the poll()
1309   *	That just polls for control events.
1310   *
1311   * @file: pointer to struct file
1312   * @wait: pointer to struct poll_table_struct
1313   */
1314  __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
1315  
1316  /**
1317   * v4l2_ctrl_request_setup - helper function to apply control values in a request
1318   *
1319   * @req: The request
1320   * @parent: The parent control handler ('priv' in media_request_object_find())
1321   *
1322   * This is a helper function to call the control handler's s_ctrl callback with
1323   * the control values contained in the request. Do note that this approach of
1324   * applying control values in a request is only applicable to memory-to-memory
1325   * devices.
1326   */
1327  int v4l2_ctrl_request_setup(struct media_request *req,
1328  			     struct v4l2_ctrl_handler *parent);
1329  
1330  /**
1331   * v4l2_ctrl_request_complete - Complete a control handler request object
1332   *
1333   * @req: The request
1334   * @parent: The parent control handler ('priv' in media_request_object_find())
1335   *
1336   * This function is to be called on each control handler that may have had a
1337   * request object associated with it, i.e. control handlers of a driver that
1338   * supports requests.
1339   *
1340   * The function first obtains the values of any volatile controls in the control
1341   * handler and attach them to the request. Then, the function completes the
1342   * request object.
1343   */
1344  void v4l2_ctrl_request_complete(struct media_request *req,
1345  				struct v4l2_ctrl_handler *parent);
1346  
1347  /**
1348   * v4l2_ctrl_request_hdl_find - Find the control handler in the request
1349   *
1350   * @req: The request
1351   * @parent: The parent control handler ('priv' in media_request_object_find())
1352   *
1353   * This function finds the control handler in the request. It may return
1354   * NULL if not found. When done, you must call v4l2_ctrl_request_hdl_put()
1355   * with the returned handler pointer.
1356   *
1357   * If the request is not in state VALIDATING or QUEUED, then this function
1358   * will always return NULL.
1359   *
1360   * Note that in state VALIDATING the req_queue_mutex is held, so
1361   * no objects can be added or deleted from the request.
1362   *
1363   * In state QUEUED it is the driver that will have to ensure this.
1364   */
1365  struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
1366  					struct v4l2_ctrl_handler *parent);
1367  
1368  /**
1369   * v4l2_ctrl_request_hdl_put - Put the control handler
1370   *
1371   * @hdl: Put this control handler
1372   *
1373   * This function released the control handler previously obtained from'
1374   * v4l2_ctrl_request_hdl_find().
1375   */
v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler * hdl)1376  static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
1377  {
1378  	if (hdl)
1379  		media_request_object_put(&hdl->req_obj);
1380  }
1381  
1382  /**
1383   * v4l2_ctrl_request_hdl_ctrl_find() - Find a control with the given ID.
1384   *
1385   * @hdl: The control handler from the request.
1386   * @id: The ID of the control to find.
1387   *
1388   * This function returns a pointer to the control if this control is
1389   * part of the request or NULL otherwise.
1390   */
1391  struct v4l2_ctrl *
1392  v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
1393  
1394  /* Helpers for ioctl_ops */
1395  
1396  /**
1397   * v4l2_queryctrl - Helper function to implement
1398   *	:ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
1399   *
1400   * @hdl: pointer to &struct v4l2_ctrl_handler
1401   * @qc: pointer to &struct v4l2_queryctrl
1402   *
1403   * If hdl == NULL then they will all return -EINVAL.
1404   */
1405  int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
1406  
1407  /**
1408   * v4l2_query_ext_ctrl - Helper function to implement
1409   *	 :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
1410   *
1411   * @hdl: pointer to &struct v4l2_ctrl_handler
1412   * @qc: pointer to &struct v4l2_query_ext_ctrl
1413   *
1414   * If hdl == NULL then they will all return -EINVAL.
1415   */
1416  int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
1417  			struct v4l2_query_ext_ctrl *qc);
1418  
1419  /**
1420   * v4l2_querymenu - Helper function to implement
1421   *	:ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
1422   *
1423   * @hdl: pointer to &struct v4l2_ctrl_handler
1424   * @qm: pointer to &struct v4l2_querymenu
1425   *
1426   * If hdl == NULL then they will all return -EINVAL.
1427   */
1428  int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
1429  
1430  /**
1431   * v4l2_g_ctrl - Helper function to implement
1432   *	:ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
1433   *
1434   * @hdl: pointer to &struct v4l2_ctrl_handler
1435   * @ctrl: pointer to &struct v4l2_control
1436   *
1437   * If hdl == NULL then they will all return -EINVAL.
1438   */
1439  int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
1440  
1441  /**
1442   * v4l2_s_ctrl - Helper function to implement
1443   *	:ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
1444   *
1445   * @fh: pointer to &struct v4l2_fh
1446   * @hdl: pointer to &struct v4l2_ctrl_handler
1447   *
1448   * @ctrl: pointer to &struct v4l2_control
1449   *
1450   * If hdl == NULL then they will all return -EINVAL.
1451   */
1452  int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1453  		struct v4l2_control *ctrl);
1454  
1455  /**
1456   * v4l2_g_ext_ctrls - Helper function to implement
1457   *	:ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1458   *
1459   * @hdl: pointer to &struct v4l2_ctrl_handler
1460   * @vdev: pointer to &struct video_device
1461   * @mdev: pointer to &struct media_device
1462   * @c: pointer to &struct v4l2_ext_controls
1463   *
1464   * If hdl == NULL then they will all return -EINVAL.
1465   */
1466  int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
1467  		     struct media_device *mdev, struct v4l2_ext_controls *c);
1468  
1469  /**
1470   * v4l2_try_ext_ctrls - Helper function to implement
1471   *	:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1472   *
1473   * @hdl: pointer to &struct v4l2_ctrl_handler
1474   * @vdev: pointer to &struct video_device
1475   * @mdev: pointer to &struct media_device
1476   * @c: pointer to &struct v4l2_ext_controls
1477   *
1478   * If hdl == NULL then they will all return -EINVAL.
1479   */
1480  int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
1481  		       struct video_device *vdev,
1482  		       struct media_device *mdev,
1483  		       struct v4l2_ext_controls *c);
1484  
1485  /**
1486   * v4l2_s_ext_ctrls - Helper function to implement
1487   *	:ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
1488   *
1489   * @fh: pointer to &struct v4l2_fh
1490   * @hdl: pointer to &struct v4l2_ctrl_handler
1491   * @vdev: pointer to &struct video_device
1492   * @mdev: pointer to &struct media_device
1493   * @c: pointer to &struct v4l2_ext_controls
1494   *
1495   * If hdl == NULL then they will all return -EINVAL.
1496   */
1497  int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
1498  		     struct video_device *vdev,
1499  		     struct media_device *mdev,
1500  		     struct v4l2_ext_controls *c);
1501  
1502  /**
1503   * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
1504   *	as a &struct v4l2_subdev_core_ops subscribe_event function
1505   *	that just subscribes control events.
1506   *
1507   * @sd: pointer to &struct v4l2_subdev
1508   * @fh: pointer to &struct v4l2_fh
1509   * @sub: pointer to &struct v4l2_event_subscription
1510   */
1511  int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
1512  				     struct v4l2_event_subscription *sub);
1513  
1514  /**
1515   * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
1516   *	 handler.
1517   *
1518   * @sd: pointer to &struct v4l2_subdev
1519   */
1520  int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
1521  
1522  /**
1523   * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
1524   *				       properties
1525   *
1526   * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
1527   * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
1528   * @p: pointer to &struct v4l2_fwnode_device_properties
1529   *
1530   * This function registers controls associated to device properties, using the
1531   * property values contained in @p parameter, if the property has been set to
1532   * a value.
1533   *
1534   * Currently the following v4l2 controls are parsed and registered:
1535   * - V4L2_CID_CAMERA_ORIENTATION
1536   * - V4L2_CID_CAMERA_SENSOR_ROTATION;
1537   *
1538   * Controls already registered by the caller with the @hdl control handler are
1539   * not overwritten. Callers should register the controls they want to handle
1540   * themselves before calling this function.
1541   *
1542   * Return: 0 on success, a negative error code on failure.
1543   */
1544  int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
1545  				    const struct v4l2_ctrl_ops *ctrl_ops,
1546  				    const struct v4l2_fwnode_device_properties *p);
1547  
1548  /**
1549   * v4l2_ctrl_type_op_equal - Default v4l2_ctrl_type_ops equal callback.
1550   *
1551   * @ctrl: The v4l2_ctrl pointer.
1552   * @ptr1: A v4l2 control value.
1553   * @ptr2: A v4l2 control value.
1554   *
1555   * Return: true if values are equal, otherwise false.
1556   */
1557  bool v4l2_ctrl_type_op_equal(const struct v4l2_ctrl *ctrl,
1558  			     union v4l2_ctrl_ptr ptr1, union v4l2_ctrl_ptr ptr2);
1559  
1560  /**
1561   * v4l2_ctrl_type_op_init - Default v4l2_ctrl_type_ops init callback.
1562   *
1563   * @ctrl: The v4l2_ctrl pointer.
1564   * @from_idx: Starting element index.
1565   * @ptr: The v4l2 control value.
1566   *
1567   * Return: void
1568   */
1569  void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
1570  			    union v4l2_ctrl_ptr ptr);
1571  
1572  /**
1573   * v4l2_ctrl_type_op_log - Default v4l2_ctrl_type_ops log callback.
1574   *
1575   * @ctrl: The v4l2_ctrl pointer.
1576   *
1577   * Return: void
1578   */
1579  void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl);
1580  
1581  /**
1582   * v4l2_ctrl_type_op_validate - Default v4l2_ctrl_type_ops validate callback.
1583   *
1584   * @ctrl: The v4l2_ctrl pointer.
1585   * @ptr: The v4l2 control value.
1586   *
1587   * Return: 0 on success, a negative error code on failure.
1588   */
1589  int v4l2_ctrl_type_op_validate(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
1590  
1591  #endif
1592