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/videodev2.h> 26 27 /* forward references */ 28 struct file; 29 struct v4l2_ctrl_handler; 30 struct v4l2_ctrl_helper; 31 struct v4l2_ctrl; 32 struct video_device; 33 struct v4l2_subdev; 34 struct v4l2_subscribed_event; 35 struct v4l2_fh; 36 struct poll_table_struct; 37 38 /** struct v4l2_ctrl_ops - The control operations that the driver has to provide. 39 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant 40 * for volatile (and usually read-only) controls such as a control 41 * that returns the current signal strength which changes 42 * continuously. 43 * If not set, then the currently cached value will be returned. 44 * @try_ctrl: Test whether the control's value is valid. Only relevant when 45 * the usual min/max/step checks are not sufficient. 46 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The 47 * ctrl->handler->lock is held when these ops are called, so no 48 * one else can access controls owned by that handler. 49 */ 50 struct v4l2_ctrl_ops { 51 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl); 52 int (*try_ctrl)(struct v4l2_ctrl *ctrl); 53 int (*s_ctrl)(struct v4l2_ctrl *ctrl); 54 }; 55 56 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv); 57 58 /** struct v4l2_ctrl - The control structure. 59 * @node: The list node. 60 * @ev_subs: The list of control event subscriptions. 61 * @handler: The handler that owns the control. 62 * @cluster: Point to start of cluster array. 63 * @ncontrols: Number of controls in cluster array. 64 * @done: Internal flag: set for each processed control. 65 * @is_new: Set when the user specified a new value for this control. It 66 * is also set when called from v4l2_ctrl_handler_setup. Drivers 67 * should never set this flag. 68 * @is_private: If set, then this control is private to its handler and it 69 * will not be added to any other handlers. Drivers can set 70 * this flag. 71 * @is_auto: If set, then this control selects whether the other cluster 72 * members are in 'automatic' mode or 'manual' mode. This is 73 * used for autogain/gain type clusters. Drivers should never 74 * set this flag directly. 75 * @has_volatiles: If set, then one or more members of the cluster are volatile. 76 * Drivers should never touch this flag. 77 * @call_notify: If set, then call the handler's notify function whenever the 78 * control's value changes. 79 * @manual_mode_value: If the is_auto flag is set, then this is the value 80 * of the auto control that determines if that control is in 81 * manual mode. So if the value of the auto control equals this 82 * value, then the whole cluster is in manual mode. Drivers should 83 * never set this flag directly. 84 * @ops: The control ops. 85 * @id: The control ID. 86 * @name: The control name. 87 * @type: The control type. 88 * @minimum: The control's minimum value. 89 * @maximum: The control's maximum value. 90 * @default_value: The control's default value. 91 * @step: The control's step value for non-menu controls. 92 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 93 * easy to skip menu items that are not valid. If bit X is set, 94 * then menu item X is skipped. Of course, this only works for 95 * menus with <= 32 menu items. There are no menus that come 96 * close to that number, so this is OK. Should we ever need more, 97 * then this will have to be extended to a u64 or a bit array. 98 * @qmenu: A const char * array for all menu items. Array entries that are 99 * empty strings ("") correspond to non-existing menu items (this 100 * is in addition to the menu_skip_mask above). The last entry 101 * must be NULL. 102 * @flags: The control's flags. 103 * @cur: The control's current value. 104 * @val: The control's new s32 value. 105 * @val64: The control's new s64 value. 106 * @string: The control's new string value. 107 * @priv: The control's private pointer. For use by the driver. It is 108 * untouched by the control framework. Note that this pointer is 109 * not freed when the control is deleted. Should this be needed 110 * then a new internal bitfield can be added to tell the framework 111 * to free this pointer. 112 */ 113 struct v4l2_ctrl { 114 /* Administrative fields */ 115 struct list_head node; 116 struct list_head ev_subs; 117 struct v4l2_ctrl_handler *handler; 118 struct v4l2_ctrl **cluster; 119 unsigned ncontrols; 120 unsigned int done:1; 121 122 unsigned int is_new:1; 123 unsigned int is_private:1; 124 unsigned int is_auto:1; 125 unsigned int has_volatiles:1; 126 unsigned int call_notify:1; 127 unsigned int manual_mode_value:8; 128 129 const struct v4l2_ctrl_ops *ops; 130 u32 id; 131 const char *name; 132 enum v4l2_ctrl_type type; 133 s32 minimum, maximum, default_value; 134 union { 135 u32 step; 136 u32 menu_skip_mask; 137 }; 138 union { 139 const char * const *qmenu; 140 const s64 *qmenu_int; 141 }; 142 unsigned long flags; 143 union { 144 s32 val; 145 s64 val64; 146 char *string; 147 } cur; 148 union { 149 s32 val; 150 s64 val64; 151 char *string; 152 }; 153 void *priv; 154 }; 155 156 /** struct v4l2_ctrl_ref - The control reference. 157 * @node: List node for the sorted list. 158 * @next: Single-link list node for the hash. 159 * @ctrl: The actual control information. 160 * @helper: Pointer to helper struct. Used internally in prepare_ext_ctrls(). 161 * 162 * Each control handler has a list of these refs. The list_head is used to 163 * keep a sorted-by-control-ID list of all controls, while the next pointer 164 * is used to link the control in the hash's bucket. 165 */ 166 struct v4l2_ctrl_ref { 167 struct list_head node; 168 struct v4l2_ctrl_ref *next; 169 struct v4l2_ctrl *ctrl; 170 struct v4l2_ctrl_helper *helper; 171 }; 172 173 /** struct v4l2_ctrl_handler - The control handler keeps track of all the 174 * controls: both the controls owned by the handler and those inherited 175 * from other handlers. 176 * @_lock: Default for "lock". 177 * @lock: Lock to control access to this handler and its controls. 178 * May be replaced by the user right after init. 179 * @ctrls: The list of controls owned by this handler. 180 * @ctrl_refs: The list of control references. 181 * @cached: The last found control reference. It is common that the same 182 * control is needed multiple times, so this is a simple 183 * optimization. 184 * @buckets: Buckets for the hashing. Allows for quick control lookup. 185 * @notify: A notify callback that is called whenever the control changes value. 186 * Note that the handler's lock is held when the notify function 187 * is called! 188 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback. 189 * @nr_of_buckets: Total number of buckets in the array. 190 * @error: The error code of the first failed control addition. 191 */ 192 struct v4l2_ctrl_handler { 193 struct mutex _lock; 194 struct mutex *lock; 195 struct list_head ctrls; 196 struct list_head ctrl_refs; 197 struct v4l2_ctrl_ref *cached; 198 struct v4l2_ctrl_ref **buckets; 199 v4l2_ctrl_notify_fnc notify; 200 void *notify_priv; 201 u16 nr_of_buckets; 202 int error; 203 }; 204 205 /** struct v4l2_ctrl_config - Control configuration structure. 206 * @ops: The control ops. 207 * @id: The control ID. 208 * @name: The control name. 209 * @type: The control type. 210 * @min: The control's minimum value. 211 * @max: The control's maximum value. 212 * @step: The control's step value for non-menu controls. 213 * @def: The control's default value. 214 * @flags: The control's flags. 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 * @is_private: If set, then this control is private to its handler and it 226 * will not be added to any other handlers. 227 */ 228 struct v4l2_ctrl_config { 229 const struct v4l2_ctrl_ops *ops; 230 u32 id; 231 const char *name; 232 enum v4l2_ctrl_type type; 233 s32 min; 234 s32 max; 235 u32 step; 236 s32 def; 237 u32 flags; 238 u32 menu_skip_mask; 239 const char * const *qmenu; 240 const s64 *qmenu_int; 241 unsigned int is_private:1; 242 }; 243 244 /** v4l2_ctrl_fill() - Fill in the control fields based on the control ID. 245 * 246 * This works for all standard V4L2 controls. 247 * For non-standard controls it will only fill in the given arguments 248 * and @name will be NULL. 249 * 250 * This function will overwrite the contents of @name, @type and @flags. 251 * The contents of @min, @max, @step and @def may be modified depending on 252 * the type. 253 * 254 * Do not use in drivers! It is used internally for backwards compatibility 255 * control handling only. Once all drivers are converted to use the new 256 * control framework this function will no longer be exported. 257 */ 258 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, 259 s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags); 260 261 262 /** v4l2_ctrl_handler_init_class() - Initialize the control handler. 263 * @hdl: The control handler. 264 * @nr_of_controls_hint: A hint of how many controls this handler is 265 * expected to refer to. This is the total number, so including 266 * any inherited controls. It doesn't have to be precise, but if 267 * it is way off, then you either waste memory (too many buckets 268 * are allocated) or the control lookup becomes slower (not enough 269 * buckets are allocated, so there are more slow list lookups). 270 * It will always work, though. 271 * @key: Used by the lock validator if CONFIG_LOCKDEP is set. 272 * @name: Used by the lock validator if CONFIG_LOCKDEP is set. 273 * 274 * Returns an error if the buckets could not be allocated. This error will 275 * also be stored in @hdl->error. 276 * 277 * Never use this call directly, always use the v4l2_ctrl_handler_init 278 * macro that hides the @key and @name arguments. 279 */ 280 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl, 281 unsigned nr_of_controls_hint, 282 struct lock_class_key *key, const char *name); 283 284 #ifdef CONFIG_LOCKDEP 285 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \ 286 ( \ 287 ({ \ 288 static struct lock_class_key _key; \ 289 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \ 290 &_key, \ 291 KBUILD_BASENAME ":" \ 292 __stringify(__LINE__) ":" \ 293 "(" #hdl ")->_lock"); \ 294 }) \ 295 ) 296 #else 297 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \ 298 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL) 299 #endif 300 301 /** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free 302 * the control list. 303 * @hdl: The control handler. 304 * 305 * Does nothing if @hdl == NULL. 306 */ 307 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl); 308 309 /** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging 310 * to the handler to initialize the hardware to the current control values. 311 * @hdl: The control handler. 312 * 313 * Button controls will be skipped, as are read-only controls. 314 * 315 * If @hdl == NULL, then this just returns 0. 316 */ 317 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl); 318 319 /** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler. 320 * @hdl: The control handler. 321 * @prefix: The prefix to use when logging the control values. If the 322 * prefix does not end with a space, then ": " will be added 323 * after the prefix. If @prefix == NULL, then no prefix will be 324 * used. 325 * 326 * For use with VIDIOC_LOG_STATUS. 327 * 328 * Does nothing if @hdl == NULL. 329 */ 330 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, 331 const char *prefix); 332 333 /** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2 334 * control. 335 * @hdl: The control handler. 336 * @cfg: The control's configuration data. 337 * @priv: The control's driver-specific private data. 338 * 339 * If the &v4l2_ctrl struct could not be allocated then NULL is returned 340 * and @hdl->error is set to the error code (if it wasn't set already). 341 */ 342 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, 343 const struct v4l2_ctrl_config *cfg, void *priv); 344 345 /** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control. 346 * @hdl: The control handler. 347 * @ops: The control ops. 348 * @id: The control ID. 349 * @min: The control's minimum value. 350 * @max: The control's maximum value. 351 * @step: The control's step value 352 * @def: The control's default value. 353 * 354 * If the &v4l2_ctrl struct could not be allocated, or the control 355 * ID is not known, then NULL is returned and @hdl->error is set to the 356 * appropriate error code (if it wasn't set already). 357 * 358 * If @id refers to a menu control, then this function will return NULL. 359 * 360 * Use v4l2_ctrl_new_std_menu() when adding menu controls. 361 */ 362 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, 363 const struct v4l2_ctrl_ops *ops, 364 u32 id, s32 min, s32 max, u32 step, s32 def); 365 366 /** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control. 367 * @hdl: The control handler. 368 * @ops: The control ops. 369 * @id: The control ID. 370 * @max: The control's maximum value. 371 * @mask: The control's skip mask for menu controls. This makes it 372 * easy to skip menu items that are not valid. If bit X is set, 373 * then menu item X is skipped. Of course, this only works for 374 * menus with <= 32 menu items. There are no menus that come 375 * close to that number, so this is OK. Should we ever need more, 376 * then this will have to be extended to a u64 or a bit array. 377 * @def: The control's default value. 378 * 379 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value 380 * determines which menu items are to be skipped. 381 * 382 * If @id refers to a non-menu control, then this function will return NULL. 383 */ 384 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, 385 const struct v4l2_ctrl_ops *ops, 386 u32 id, s32 max, s32 mask, s32 def); 387 388 /** v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control 389 * with driver specific menu. 390 * @hdl: The control handler. 391 * @ops: The control ops. 392 * @id: The control ID. 393 * @max: The control's maximum value. 394 * @mask: The control's skip mask for menu controls. This makes it 395 * easy to skip menu items that are not valid. If bit X is set, 396 * then menu item X is skipped. Of course, this only works for 397 * menus with <= 32 menu items. There are no menus that come 398 * close to that number, so this is OK. Should we ever need more, 399 * then this will have to be extended to a u64 or a bit array. 400 * @def: The control's default value. 401 * @qmenu: The new menu. 402 * 403 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific 404 * menu of this control. 405 * 406 */ 407 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl, 408 const struct v4l2_ctrl_ops *ops, u32 id, s32 max, 409 s32 mask, s32 def, const char * const *qmenu); 410 411 /** v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control. 412 * @hdl: The control handler. 413 * @ops: The control ops. 414 * @id: The control ID. 415 * @max: The control's maximum value. 416 * @def: The control's default value. 417 * @qmenu_int: The control's menu entries. 418 * 419 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly 420 * takes as an argument an array of integers determining the menu items. 421 * 422 * If @id refers to a non-integer-menu control, then this function will return NULL. 423 */ 424 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, 425 const struct v4l2_ctrl_ops *ops, 426 u32 id, s32 max, s32 def, const s64 *qmenu_int); 427 428 /** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler. 429 * @hdl: The control handler. 430 * @ctrl: The control to add. 431 * 432 * It will return NULL if it was unable to add the control reference. 433 * If the control already belonged to the handler, then it will do 434 * nothing and just return @ctrl. 435 */ 436 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl, 437 struct v4l2_ctrl *ctrl); 438 439 /** v4l2_ctrl_add_handler() - Add all controls from handler @add to 440 * handler @hdl. 441 * @hdl: The control handler. 442 * @add: The control handler whose controls you want to add to 443 * the @hdl control handler. 444 * @filter: This function will filter which controls should be added. 445 * 446 * Does nothing if either of the two handlers is a NULL pointer. 447 * If @filter is NULL, then all controls are added. Otherwise only those 448 * controls for which @filter returns true will be added. 449 * In case of an error @hdl->error will be set to the error code (if it 450 * wasn't set already). 451 */ 452 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl, 453 struct v4l2_ctrl_handler *add, 454 bool (*filter)(const struct v4l2_ctrl *ctrl)); 455 456 /** v4l2_ctrl_radio_filter() - Standard filter for radio controls. 457 * @ctrl: The control that is filtered. 458 * 459 * This will return true for any controls that are valid for radio device 460 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM 461 * transmitter class controls. 462 * 463 * This function is to be used with v4l2_ctrl_add_handler(). 464 */ 465 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl); 466 467 /** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster. 468 * @ncontrols: The number of controls in this cluster. 469 * @controls: The cluster control array of size @ncontrols. 470 */ 471 void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls); 472 473 474 /** v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to 475 * that cluster and set it up for autofoo/foo-type handling. 476 * @ncontrols: The number of controls in this cluster. 477 * @controls: The cluster control array of size @ncontrols. The first control 478 * must be the 'auto' control (e.g. autogain, autoexposure, etc.) 479 * @manual_val: The value for the first control in the cluster that equals the 480 * manual setting. 481 * @set_volatile: If true, then all controls except the first auto control will 482 * be volatile. 483 * 484 * Use for control groups where one control selects some automatic feature and 485 * the other controls are only active whenever the automatic feature is turned 486 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs 487 * red and blue balance, etc. 488 * 489 * The behavior of such controls is as follows: 490 * 491 * When the autofoo control is set to automatic, then any manual controls 492 * are set to inactive and any reads will call g_volatile_ctrl (if the control 493 * was marked volatile). 494 * 495 * When the autofoo control is set to manual, then any manual controls will 496 * be marked active, and any reads will just return the current value without 497 * going through g_volatile_ctrl. 498 * 499 * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag 500 * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s) 501 * if autofoo is in auto mode. 502 */ 503 void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls, 504 u8 manual_val, bool set_volatile); 505 506 507 /** v4l2_ctrl_find() - Find a control with the given ID. 508 * @hdl: The control handler. 509 * @id: The control ID to find. 510 * 511 * If @hdl == NULL this will return NULL as well. Will lock the handler so 512 * do not use from inside &v4l2_ctrl_ops. 513 */ 514 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id); 515 516 /** v4l2_ctrl_activate() - Make the control active or inactive. 517 * @ctrl: The control to (de)activate. 518 * @active: True if the control should become active. 519 * 520 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically. 521 * Does nothing if @ctrl == NULL. 522 * This will usually be called from within the s_ctrl op. 523 * The V4L2_EVENT_CTRL event will be generated afterwards. 524 * 525 * This function assumes that the control handler is locked. 526 */ 527 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); 528 529 /** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed. 530 * @ctrl: The control to (de)activate. 531 * @grabbed: True if the control should become grabbed. 532 * 533 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically. 534 * Does nothing if @ctrl == NULL. 535 * The V4L2_EVENT_CTRL event will be generated afterwards. 536 * This will usually be called when starting or stopping streaming in the 537 * driver. 538 * 539 * This function assumes that the control handler is not locked and will 540 * take the lock itself. 541 */ 542 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed); 543 544 /** v4l2_ctrl_modify_range() - Update the range of a control. 545 * @ctrl: The control to update. 546 * @min: The control's minimum value. 547 * @max: The control's maximum value. 548 * @step: The control's step value 549 * @def: The control's default value. 550 * 551 * Update the range of a control on the fly. This works for control types 552 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the 553 * @step value is interpreted as a menu_skip_mask. 554 * 555 * An error is returned if one of the range arguments is invalid for this 556 * control type. 557 * 558 * This function assumes that the control handler is not locked and will 559 * take the lock itself. 560 */ 561 int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl, 562 s32 min, s32 max, u32 step, s32 def); 563 564 /** v4l2_ctrl_lock() - Helper function to lock the handler 565 * associated with the control. 566 * @ctrl: The control to lock. 567 */ 568 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl) 569 { 570 mutex_lock(ctrl->handler->lock); 571 } 572 573 /** v4l2_ctrl_lock() - Helper function to unlock the handler 574 * associated with the control. 575 * @ctrl: The control to unlock. 576 */ 577 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl) 578 { 579 mutex_unlock(ctrl->handler->lock); 580 } 581 582 /** v4l2_ctrl_notify() - Function to set a notify callback for a control. 583 * @ctrl: The control. 584 * @notify: The callback function. 585 * @priv: The callback private handle, passed as argument to the callback. 586 * 587 * This function sets a callback function for the control. If @ctrl is NULL, 588 * then it will do nothing. If @notify is NULL, then the notify callback will 589 * be removed. 590 * 591 * There can be only one notify. If another already exists, then a WARN_ON 592 * will be issued and the function will do nothing. 593 */ 594 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv); 595 596 /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver. 597 * @ctrl: The control. 598 * 599 * This returns the control's value safely by going through the control 600 * framework. This function will lock the control's handler, so it cannot be 601 * used from within the &v4l2_ctrl_ops functions. 602 * 603 * This function is for integer type controls only. 604 */ 605 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); 606 607 /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver. 608 * @ctrl: The control. 609 * @val: The new value. 610 * 611 * This set the control's new value safely by going through the control 612 * framework. This function will lock the control's handler, so it cannot be 613 * used from within the &v4l2_ctrl_ops functions. 614 * 615 * This function is for integer type controls only. 616 */ 617 int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); 618 619 /** v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value from within a driver. 620 * @ctrl: The control. 621 * 622 * This returns the control's value safely by going through the control 623 * framework. This function will lock the control's handler, so it cannot be 624 * used from within the &v4l2_ctrl_ops functions. 625 * 626 * This function is for 64-bit integer type controls only. 627 */ 628 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl); 629 630 /** v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value from within a driver. 631 * @ctrl: The control. 632 * @val: The new value. 633 * 634 * This set the control's new value safely by going through the control 635 * framework. This function will lock the control's handler, so it cannot be 636 * used from within the &v4l2_ctrl_ops functions. 637 * 638 * This function is for 64-bit integer type controls only. 639 */ 640 int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val); 641 642 /* Internal helper functions that deal with control events. */ 643 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops; 644 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new); 645 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new); 646 647 /* Can be used as a vidioc_log_status function that just dumps all controls 648 associated with the filehandle. */ 649 int v4l2_ctrl_log_status(struct file *file, void *fh); 650 651 /* Can be used as a vidioc_subscribe_event function that just subscribes 652 control events. */ 653 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh, 654 const struct v4l2_event_subscription *sub); 655 656 /* Can be used as a poll function that just polls for control events. */ 657 unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait); 658 659 /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */ 660 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc); 661 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm); 662 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl); 663 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 664 struct v4l2_control *ctrl); 665 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); 666 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); 667 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 668 struct v4l2_ext_controls *c); 669 670 /* Helpers for subdevices. If the associated ctrl_handler == NULL then they 671 will all return -EINVAL. */ 672 int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc); 673 int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm); 674 int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 675 int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 676 int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 677 int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); 678 int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); 679 680 /* Can be used as a subscribe_event function that just subscribes control 681 events. */ 682 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh, 683 struct v4l2_event_subscription *sub); 684 685 /* Log all controls owned by subdev's control handler. */ 686 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd); 687 688 #endif 689