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0996517c HV |
1 | /* |
2 | V4L2 controls support header. | |
3 | ||
4 | Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl> | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
19 | */ | |
20 | ||
21 | #ifndef _V4L2_CTRLS_H | |
22 | #define _V4L2_CTRLS_H | |
23 | ||
24 | #include <linux/list.h> | |
25 | #include <linux/device.h> | |
26 | ||
27 | /* forward references */ | |
28 | struct v4l2_ctrl_handler; | |
29 | struct v4l2_ctrl; | |
30 | struct video_device; | |
31 | struct v4l2_subdev; | |
32 | ||
33 | /** struct v4l2_ctrl_ops - The control operations that the driver has to provide. | |
34 | * @g_volatile_ctrl: Get a new value for this control. Generally only relevant | |
35 | * for volatile (and usually read-only) controls such as a control | |
36 | * that returns the current signal strength which changes | |
37 | * continuously. | |
38 | * If not set, then the currently cached value will be returned. | |
39 | * @try_ctrl: Test whether the control's value is valid. Only relevant when | |
40 | * the usual min/max/step checks are not sufficient. | |
41 | * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The | |
42 | * ctrl->handler->lock is held when these ops are called, so no | |
43 | * one else can access controls owned by that handler. | |
44 | */ | |
45 | struct v4l2_ctrl_ops { | |
46 | int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl); | |
47 | int (*try_ctrl)(struct v4l2_ctrl *ctrl); | |
48 | int (*s_ctrl)(struct v4l2_ctrl *ctrl); | |
49 | }; | |
50 | ||
51 | /** struct v4l2_ctrl - The control structure. | |
52 | * @node: The list node. | |
53 | * @handler: The handler that owns the control. | |
54 | * @cluster: Point to start of cluster array. | |
55 | * @ncontrols: Number of controls in cluster array. | |
56 | * @has_new: Internal flag: set when there is a valid new value. | |
57 | * @done: Internal flag: set for each processed control. | |
58 | * @is_private: If set, then this control is private to its handler and it | |
59 | * will not be added to any other handlers. Drivers can set | |
60 | * this flag. | |
61 | * @is_volatile: If set, then this control is volatile. This means that the | |
62 | * control's current value cannot be cached and needs to be | |
63 | * retrieved through the g_volatile_ctrl op. Drivers can set | |
64 | * this flag. | |
65 | * @ops: The control ops. | |
66 | * @id: The control ID. | |
67 | * @name: The control name. | |
68 | * @type: The control type. | |
69 | * @minimum: The control's minimum value. | |
70 | * @maximum: The control's maximum value. | |
71 | * @default_value: The control's default value. | |
72 | * @step: The control's step value for non-menu controls. | |
73 | * @menu_skip_mask: The control's skip mask for menu controls. This makes it | |
74 | * easy to skip menu items that are not valid. If bit X is set, | |
75 | * then menu item X is skipped. Of course, this only works for | |
76 | * menus with <= 32 menu items. There are no menus that come | |
77 | * close to that number, so this is OK. Should we ever need more, | |
78 | * then this will have to be extended to a u64 or a bit array. | |
79 | * @qmenu: A const char * array for all menu items. Array entries that are | |
80 | * empty strings ("") correspond to non-existing menu items (this | |
81 | * is in addition to the menu_skip_mask above). The last entry | |
82 | * must be NULL. | |
83 | * @flags: The control's flags. | |
84 | * @cur: The control's current value. | |
85 | * @val: The control's new s32 value. | |
86 | * @val64: The control's new s64 value. | |
87 | * @string: The control's new string value. | |
88 | * @priv: The control's private pointer. For use by the driver. It is | |
89 | * untouched by the control framework. Note that this pointer is | |
90 | * not freed when the control is deleted. Should this be needed | |
91 | * then a new internal bitfield can be added to tell the framework | |
92 | * to free this pointer. | |
93 | */ | |
94 | struct v4l2_ctrl { | |
95 | /* Administrative fields */ | |
96 | struct list_head node; | |
97 | struct v4l2_ctrl_handler *handler; | |
98 | struct v4l2_ctrl **cluster; | |
99 | unsigned ncontrols; | |
100 | unsigned int has_new:1; | |
101 | unsigned int done:1; | |
102 | ||
103 | unsigned int is_private:1; | |
104 | unsigned int is_volatile:1; | |
105 | ||
106 | const struct v4l2_ctrl_ops *ops; | |
107 | u32 id; | |
108 | const char *name; | |
109 | enum v4l2_ctrl_type type; | |
110 | s32 minimum, maximum, default_value; | |
111 | union { | |
112 | u32 step; | |
113 | u32 menu_skip_mask; | |
114 | }; | |
513521ea | 115 | const char * const *qmenu; |
0996517c HV |
116 | unsigned long flags; |
117 | union { | |
118 | s32 val; | |
119 | s64 val64; | |
120 | char *string; | |
121 | } cur; | |
122 | union { | |
123 | s32 val; | |
124 | s64 val64; | |
125 | char *string; | |
126 | }; | |
127 | void *priv; | |
128 | }; | |
129 | ||
130 | /** struct v4l2_ctrl_ref - The control reference. | |
131 | * @node: List node for the sorted list. | |
132 | * @next: Single-link list node for the hash. | |
133 | * @ctrl: The actual control information. | |
134 | * | |
135 | * Each control handler has a list of these refs. The list_head is used to | |
136 | * keep a sorted-by-control-ID list of all controls, while the next pointer | |
137 | * is used to link the control in the hash's bucket. | |
138 | */ | |
139 | struct v4l2_ctrl_ref { | |
140 | struct list_head node; | |
141 | struct v4l2_ctrl_ref *next; | |
142 | struct v4l2_ctrl *ctrl; | |
143 | }; | |
144 | ||
145 | /** struct v4l2_ctrl_handler - The control handler keeps track of all the | |
146 | * controls: both the controls owned by the handler and those inherited | |
147 | * from other handlers. | |
148 | * @lock: Lock to control access to this handler and its controls. | |
149 | * @ctrls: The list of controls owned by this handler. | |
150 | * @ctrl_refs: The list of control references. | |
151 | * @cached: The last found control reference. It is common that the same | |
152 | * control is needed multiple times, so this is a simple | |
153 | * optimization. | |
154 | * @buckets: Buckets for the hashing. Allows for quick control lookup. | |
155 | * @nr_of_buckets: Total number of buckets in the array. | |
156 | * @error: The error code of the first failed control addition. | |
157 | */ | |
158 | struct v4l2_ctrl_handler { | |
159 | struct mutex lock; | |
160 | struct list_head ctrls; | |
161 | struct list_head ctrl_refs; | |
162 | struct v4l2_ctrl_ref *cached; | |
163 | struct v4l2_ctrl_ref **buckets; | |
164 | u16 nr_of_buckets; | |
165 | int error; | |
166 | }; | |
167 | ||
168 | /** struct v4l2_ctrl_config - Control configuration structure. | |
169 | * @ops: The control ops. | |
170 | * @id: The control ID. | |
171 | * @name: The control name. | |
172 | * @type: The control type. | |
173 | * @min: The control's minimum value. | |
174 | * @max: The control's maximum value. | |
175 | * @step: The control's step value for non-menu controls. | |
176 | * @def: The control's default value. | |
177 | * @flags: The control's flags. | |
178 | * @menu_skip_mask: The control's skip mask for menu controls. This makes it | |
179 | * easy to skip menu items that are not valid. If bit X is set, | |
180 | * then menu item X is skipped. Of course, this only works for | |
181 | * menus with <= 32 menu items. There are no menus that come | |
182 | * close to that number, so this is OK. Should we ever need more, | |
183 | * then this will have to be extended to a u64 or a bit array. | |
184 | * @qmenu: A const char * array for all menu items. Array entries that are | |
185 | * empty strings ("") correspond to non-existing menu items (this | |
186 | * is in addition to the menu_skip_mask above). The last entry | |
187 | * must be NULL. | |
188 | * @is_private: If set, then this control is private to its handler and it | |
189 | * will not be added to any other handlers. | |
190 | * @is_volatile: If set, then this control is volatile. This means that the | |
191 | * control's current value cannot be cached and needs to be | |
192 | * retrieved through the g_volatile_ctrl op. | |
193 | */ | |
194 | struct v4l2_ctrl_config { | |
195 | const struct v4l2_ctrl_ops *ops; | |
196 | u32 id; | |
197 | const char *name; | |
198 | enum v4l2_ctrl_type type; | |
199 | s32 min; | |
200 | s32 max; | |
201 | u32 step; | |
202 | s32 def; | |
203 | u32 flags; | |
204 | u32 menu_skip_mask; | |
513521ea | 205 | const char * const *qmenu; |
0996517c HV |
206 | unsigned int is_private:1; |
207 | unsigned int is_volatile:1; | |
208 | }; | |
209 | ||
210 | /** v4l2_ctrl_fill() - Fill in the control fields based on the control ID. | |
211 | * | |
212 | * This works for all standard V4L2 controls. | |
213 | * For non-standard controls it will only fill in the given arguments | |
214 | * and @name will be NULL. | |
215 | * | |
216 | * This function will overwrite the contents of @name, @type and @flags. | |
217 | * The contents of @min, @max, @step and @def may be modified depending on | |
218 | * the type. | |
219 | * | |
220 | * Do not use in drivers! It is used internally for backwards compatibility | |
221 | * control handling only. Once all drivers are converted to use the new | |
222 | * control framework this function will no longer be exported. | |
223 | */ | |
224 | void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, | |
225 | s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags); | |
226 | ||
227 | ||
228 | /** v4l2_ctrl_handler_init() - Initialize the control handler. | |
229 | * @hdl: The control handler. | |
230 | * @nr_of_controls_hint: A hint of how many controls this handler is | |
231 | * expected to refer to. This is the total number, so including | |
232 | * any inherited controls. It doesn't have to be precise, but if | |
233 | * it is way off, then you either waste memory (too many buckets | |
234 | * are allocated) or the control lookup becomes slower (not enough | |
235 | * buckets are allocated, so there are more slow list lookups). | |
236 | * It will always work, though. | |
237 | * | |
238 | * Returns an error if the buckets could not be allocated. This error will | |
239 | * also be stored in @hdl->error. | |
240 | */ | |
241 | int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl, | |
242 | unsigned nr_of_controls_hint); | |
243 | ||
244 | /** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free | |
245 | * the control list. | |
246 | * @hdl: The control handler. | |
247 | * | |
248 | * Does nothing if @hdl == NULL. | |
249 | */ | |
250 | void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl); | |
251 | ||
252 | /** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging | |
253 | * to the handler to initialize the hardware to the current control values. | |
254 | * @hdl: The control handler. | |
255 | * | |
256 | * Button controls will be skipped, as are read-only controls. | |
257 | * | |
258 | * If @hdl == NULL, then this just returns 0. | |
259 | */ | |
260 | int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl); | |
261 | ||
262 | /** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler. | |
263 | * @hdl: The control handler. | |
264 | * @prefix: The prefix to use when logging the control values. If the | |
265 | * prefix does not end with a space, then ": " will be added | |
266 | * after the prefix. If @prefix == NULL, then no prefix will be | |
267 | * used. | |
268 | * | |
269 | * For use with VIDIOC_LOG_STATUS. | |
270 | * | |
271 | * Does nothing if @hdl == NULL. | |
272 | */ | |
273 | void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, | |
274 | const char *prefix); | |
275 | ||
276 | /** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2 | |
277 | * control. | |
278 | * @hdl: The control handler. | |
279 | * @cfg: The control's configuration data. | |
280 | * @priv: The control's driver-specific private data. | |
281 | * | |
282 | * If the &v4l2_ctrl struct could not be allocated then NULL is returned | |
283 | * and @hdl->error is set to the error code (if it wasn't set already). | |
284 | */ | |
285 | struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, | |
286 | const struct v4l2_ctrl_config *cfg, void *priv); | |
287 | ||
288 | /** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control. | |
289 | * @hdl: The control handler. | |
290 | * @ops: The control ops. | |
291 | * @id: The control ID. | |
292 | * @min: The control's minimum value. | |
293 | * @max: The control's maximum value. | |
294 | * @step: The control's step value | |
295 | * @def: The control's default value. | |
296 | * | |
297 | * If the &v4l2_ctrl struct could not be allocated, or the control | |
298 | * ID is not known, then NULL is returned and @hdl->error is set to the | |
299 | * appropriate error code (if it wasn't set already). | |
300 | * | |
301 | * If @id refers to a menu control, then this function will return NULL. | |
302 | * | |
303 | * Use v4l2_ctrl_new_std_menu() when adding menu controls. | |
304 | */ | |
305 | struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, | |
306 | const struct v4l2_ctrl_ops *ops, | |
307 | u32 id, s32 min, s32 max, u32 step, s32 def); | |
308 | ||
309 | /** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control. | |
310 | * @hdl: The control handler. | |
311 | * @ops: The control ops. | |
312 | * @id: The control ID. | |
313 | * @max: The control's maximum value. | |
314 | * @mask: The control's skip mask for menu controls. This makes it | |
315 | * easy to skip menu items that are not valid. If bit X is set, | |
316 | * then menu item X is skipped. Of course, this only works for | |
317 | * menus with <= 32 menu items. There are no menus that come | |
318 | * close to that number, so this is OK. Should we ever need more, | |
319 | * then this will have to be extended to a u64 or a bit array. | |
320 | * @def: The control's default value. | |
321 | * | |
322 | * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value | |
323 | * determines which menu items are to be skipped. | |
324 | * | |
325 | * If @id refers to a non-menu control, then this function will return NULL. | |
326 | */ | |
327 | struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, | |
328 | const struct v4l2_ctrl_ops *ops, | |
329 | u32 id, s32 max, s32 mask, s32 def); | |
330 | ||
331 | /** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler. | |
332 | * @hdl: The control handler. | |
333 | * @ctrl: The control to add. | |
334 | * | |
335 | * It will return NULL if it was unable to add the control reference. | |
336 | * If the control already belonged to the handler, then it will do | |
337 | * nothing and just return @ctrl. | |
338 | */ | |
339 | struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl, | |
340 | struct v4l2_ctrl *ctrl); | |
341 | ||
342 | /** v4l2_ctrl_add_handler() - Add all controls from handler @add to | |
343 | * handler @hdl. | |
344 | * @hdl: The control handler. | |
345 | * @add: The control handler whose controls you want to add to | |
346 | * the @hdl control handler. | |
347 | * | |
348 | * Does nothing if either of the two is a NULL pointer. | |
349 | * In case of an error @hdl->error will be set to the error code (if it | |
350 | * wasn't set already). | |
351 | */ | |
352 | int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl, | |
353 | struct v4l2_ctrl_handler *add); | |
354 | ||
355 | ||
356 | /** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster. | |
357 | * @ncontrols: The number of controls in this cluster. | |
358 | * @controls: The cluster control array of size @ncontrols. | |
359 | */ | |
360 | void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls); | |
361 | ||
362 | ||
363 | /** v4l2_ctrl_find() - Find a control with the given ID. | |
364 | * @hdl: The control handler. | |
365 | * @id: The control ID to find. | |
366 | * | |
367 | * If @hdl == NULL this will return NULL as well. Will lock the handler so | |
368 | * do not use from inside &v4l2_ctrl_ops. | |
369 | */ | |
370 | struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id); | |
371 | ||
372 | /** v4l2_ctrl_activate() - Make the control active or inactive. | |
373 | * @ctrl: The control to (de)activate. | |
374 | * @active: True if the control should become active. | |
375 | * | |
376 | * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically. | |
377 | * Does nothing if @ctrl == NULL. | |
378 | * This will usually be called from within the s_ctrl op. | |
379 | * | |
380 | * This function can be called regardless of whether the control handler | |
381 | * is locked or not. | |
382 | */ | |
383 | void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); | |
384 | ||
385 | /** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed. | |
386 | * @ctrl: The control to (de)activate. | |
387 | * @grabbed: True if the control should become grabbed. | |
388 | * | |
389 | * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically. | |
390 | * Does nothing if @ctrl == NULL. | |
391 | * This will usually be called when starting or stopping streaming in the | |
392 | * driver. | |
393 | * | |
394 | * This function can be called regardless of whether the control handler | |
395 | * is locked or not. | |
396 | */ | |
397 | void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed); | |
398 | ||
399 | /** v4l2_ctrl_lock() - Helper function to lock the handler | |
400 | * associated with the control. | |
401 | * @ctrl: The control to lock. | |
402 | */ | |
403 | static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl) | |
404 | { | |
405 | mutex_lock(&ctrl->handler->lock); | |
406 | } | |
407 | ||
408 | /** v4l2_ctrl_lock() - Helper function to unlock the handler | |
409 | * associated with the control. | |
410 | * @ctrl: The control to unlock. | |
411 | */ | |
412 | static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl) | |
413 | { | |
414 | mutex_unlock(&ctrl->handler->lock); | |
415 | } | |
416 | ||
417 | /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver. | |
418 | * @ctrl: The control. | |
419 | * | |
420 | * This returns the control's value safely by going through the control | |
421 | * framework. This function will lock the control's handler, so it cannot be | |
422 | * used from within the &v4l2_ctrl_ops functions. | |
423 | * | |
424 | * This function is for integer type controls only. | |
425 | */ | |
426 | s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); | |
427 | ||
428 | /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver. | |
429 | * @ctrl: The control. | |
430 | * @val: The new value. | |
431 | * | |
432 | * This set the control's new value safely by going through the control | |
433 | * framework. This function will lock the control's handler, so it cannot be | |
434 | * used from within the &v4l2_ctrl_ops functions. | |
435 | * | |
436 | * This function is for integer type controls only. | |
437 | */ | |
438 | int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); | |
439 | ||
440 | ||
441 | /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */ | |
442 | int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc); | |
443 | int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm); | |
444 | int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl); | |
445 | int v4l2_s_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl); | |
446 | int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); | |
447 | int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); | |
448 | int v4l2_s_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); | |
449 | ||
450 | /* Helpers for subdevices. If the associated ctrl_handler == NULL then they | |
451 | will all return -EINVAL. */ | |
452 | int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc); | |
453 | int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm); | |
454 | int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); | |
455 | int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); | |
456 | int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); | |
457 | int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); | |
458 | int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); | |
459 | ||
460 | #endif |