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 /** struct v4l2_ctrl - The control structure. 57 * @node: The list node. 58 * @ev_subs: The list of control event subscriptions. 59 * @handler: The handler that owns the control. 60 * @cluster: Point to start of cluster array. 61 * @ncontrols: Number of controls in cluster array. 62 * @done: Internal flag: set for each processed control. 63 * @is_new: Set when the user specified a new value for this control. It 64 * is also set when called from v4l2_ctrl_handler_setup. Drivers 65 * should never set this flag. 66 * @is_private: If set, then this control is private to its handler and it 67 * will not be added to any other handlers. Drivers can set 68 * this flag. 69 * @is_auto: If set, then this control selects whether the other cluster 70 * members are in 'automatic' mode or 'manual' mode. This is 71 * used for autogain/gain type clusters. Drivers should never 72 * set this flag directly. 73 * @has_volatiles: If set, then one or more members of the cluster are volatile. 74 * Drivers should never touch this flag. 75 * @manual_mode_value: If the is_auto flag is set, then this is the value 76 * of the auto control that determines if that control is in 77 * manual mode. So if the value of the auto control equals this 78 * value, then the whole cluster is in manual mode. Drivers should 79 * never set this flag directly. 80 * @ops: The control ops. 81 * @id: The control ID. 82 * @name: The control name. 83 * @type: The control type. 84 * @minimum: The control's minimum value. 85 * @maximum: The control's maximum value. 86 * @default_value: The control's default value. 87 * @step: The control's step value for non-menu controls. 88 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 89 * easy to skip menu items that are not valid. If bit X is set, 90 * then menu item X is skipped. Of course, this only works for 91 * menus with <= 32 menu items. There are no menus that come 92 * close to that number, so this is OK. Should we ever need more, 93 * then this will have to be extended to a u64 or a bit array. 94 * @qmenu: A const char * array for all menu items. Array entries that are 95 * empty strings ("") correspond to non-existing menu items (this 96 * is in addition to the menu_skip_mask above). The last entry 97 * must be NULL. 98 * @flags: The control's flags. 99 * @cur: The control's current value. 100 * @val: The control's new s32 value. 101 * @val64: The control's new s64 value. 102 * @string: The control's new string value. 103 * @priv: The control's private pointer. For use by the driver. It is 104 * untouched by the control framework. Note that this pointer is 105 * not freed when the control is deleted. Should this be needed 106 * then a new internal bitfield can be added to tell the framework 107 * to free this pointer. 108 */ 109 struct v4l2_ctrl { 110 /* Administrative fields */ 111 struct list_head node; 112 struct list_head ev_subs; 113 struct v4l2_ctrl_handler *handler; 114 struct v4l2_ctrl **cluster; 115 unsigned ncontrols; 116 unsigned int done:1; 117 118 unsigned int is_new:1; 119 unsigned int is_private:1; 120 unsigned int is_auto:1; 121 unsigned int has_volatiles:1; 122 unsigned int manual_mode_value:8; 123 124 const struct v4l2_ctrl_ops *ops; 125 u32 id; 126 const char *name; 127 enum v4l2_ctrl_type type; 128 s32 minimum, maximum, default_value; 129 union { 130 u32 step; 131 u32 menu_skip_mask; 132 }; 133 union { 134 const char * const *qmenu; 135 const s64 *qmenu_int; 136 }; 137 unsigned long flags; 138 union { 139 s32 val; 140 s64 val64; 141 char *string; 142 } cur; 143 union { 144 s32 val; 145 s64 val64; 146 char *string; 147 }; 148 void *priv; 149 }; 150 151 /** struct v4l2_ctrl_ref - The control reference. 152 * @node: List node for the sorted list. 153 * @next: Single-link list node for the hash. 154 * @ctrl: The actual control information. 155 * @helper: Pointer to helper struct. Used internally in prepare_ext_ctrls(). 156 * 157 * Each control handler has a list of these refs. The list_head is used to 158 * keep a sorted-by-control-ID list of all controls, while the next pointer 159 * is used to link the control in the hash's bucket. 160 */ 161 struct v4l2_ctrl_ref { 162 struct list_head node; 163 struct v4l2_ctrl_ref *next; 164 struct v4l2_ctrl *ctrl; 165 struct v4l2_ctrl_helper *helper; 166 }; 167 168 /** struct v4l2_ctrl_handler - The control handler keeps track of all the 169 * controls: both the controls owned by the handler and those inherited 170 * from other handlers. 171 * @_lock: Default for "lock". 172 * @lock: Lock to control access to this handler and its controls. 173 * May be replaced by the user right after init. 174 * @ctrls: The list of controls owned by this handler. 175 * @ctrl_refs: The list of control references. 176 * @cached: The last found control reference. It is common that the same 177 * control is needed multiple times, so this is a simple 178 * optimization. 179 * @buckets: Buckets for the hashing. Allows for quick control lookup. 180 * @nr_of_buckets: Total number of buckets in the array. 181 * @error: The error code of the first failed control addition. 182 */ 183 struct v4l2_ctrl_handler { 184 struct mutex _lock; 185 struct mutex *lock; 186 struct list_head ctrls; 187 struct list_head ctrl_refs; 188 struct v4l2_ctrl_ref *cached; 189 struct v4l2_ctrl_ref **buckets; 190 u16 nr_of_buckets; 191 int error; 192 }; 193 194 /** struct v4l2_ctrl_config - Control configuration structure. 195 * @ops: The control ops. 196 * @id: The control ID. 197 * @name: The control name. 198 * @type: The control type. 199 * @min: The control's minimum value. 200 * @max: The control's maximum value. 201 * @step: The control's step value for non-menu controls. 202 * @def: The control's default value. 203 * @flags: The control's flags. 204 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 205 * easy to skip menu items that are not valid. If bit X is set, 206 * then menu item X is skipped. Of course, this only works for 207 * menus with <= 32 menu items. There are no menus that come 208 * close to that number, so this is OK. Should we ever need more, 209 * then this will have to be extended to a u64 or a bit array. 210 * @qmenu: A const char * array for all menu items. Array entries that are 211 * empty strings ("") correspond to non-existing menu items (this 212 * is in addition to the menu_skip_mask above). The last entry 213 * must be NULL. 214 * @is_private: If set, then this control is private to its handler and it 215 * will not be added to any other handlers. 216 */ 217 struct v4l2_ctrl_config { 218 const struct v4l2_ctrl_ops *ops; 219 u32 id; 220 const char *name; 221 enum v4l2_ctrl_type type; 222 s32 min; 223 s32 max; 224 u32 step; 225 s32 def; 226 u32 flags; 227 u32 menu_skip_mask; 228 const char * const *qmenu; 229 const s64 *qmenu_int; 230 unsigned int is_private:1; 231 }; 232 233 /** v4l2_ctrl_fill() - Fill in the control fields based on the control ID. 234 * 235 * This works for all standard V4L2 controls. 236 * For non-standard controls it will only fill in the given arguments 237 * and @name will be NULL. 238 * 239 * This function will overwrite the contents of @name, @type and @flags. 240 * The contents of @min, @max, @step and @def may be modified depending on 241 * the type. 242 * 243 * Do not use in drivers! It is used internally for backwards compatibility 244 * control handling only. Once all drivers are converted to use the new 245 * control framework this function will no longer be exported. 246 */ 247 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, 248 s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags); 249 250 251 /** v4l2_ctrl_handler_init() - Initialize the control handler. 252 * @hdl: The control handler. 253 * @nr_of_controls_hint: A hint of how many controls this handler is 254 * expected to refer to. This is the total number, so including 255 * any inherited controls. It doesn't have to be precise, but if 256 * it is way off, then you either waste memory (too many buckets 257 * are allocated) or the control lookup becomes slower (not enough 258 * buckets are allocated, so there are more slow list lookups). 259 * It will always work, though. 260 * 261 * Returns an error if the buckets could not be allocated. This error will 262 * also be stored in @hdl->error. 263 */ 264 int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl, 265 unsigned nr_of_controls_hint); 266 267 /** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free 268 * the control list. 269 * @hdl: The control handler. 270 * 271 * Does nothing if @hdl == NULL. 272 */ 273 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl); 274 275 /** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging 276 * to the handler to initialize the hardware to the current control values. 277 * @hdl: The control handler. 278 * 279 * Button controls will be skipped, as are read-only controls. 280 * 281 * If @hdl == NULL, then this just returns 0. 282 */ 283 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl); 284 285 /** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler. 286 * @hdl: The control handler. 287 * @prefix: The prefix to use when logging the control values. If the 288 * prefix does not end with a space, then ": " will be added 289 * after the prefix. If @prefix == NULL, then no prefix will be 290 * used. 291 * 292 * For use with VIDIOC_LOG_STATUS. 293 * 294 * Does nothing if @hdl == NULL. 295 */ 296 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, 297 const char *prefix); 298 299 /** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2 300 * control. 301 * @hdl: The control handler. 302 * @cfg: The control's configuration data. 303 * @priv: The control's driver-specific private data. 304 * 305 * If the &v4l2_ctrl struct could not be allocated then NULL is returned 306 * and @hdl->error is set to the error code (if it wasn't set already). 307 */ 308 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, 309 const struct v4l2_ctrl_config *cfg, void *priv); 310 311 /** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control. 312 * @hdl: The control handler. 313 * @ops: The control ops. 314 * @id: The control ID. 315 * @min: The control's minimum value. 316 * @max: The control's maximum value. 317 * @step: The control's step value 318 * @def: The control's default value. 319 * 320 * If the &v4l2_ctrl struct could not be allocated, or the control 321 * ID is not known, then NULL is returned and @hdl->error is set to the 322 * appropriate error code (if it wasn't set already). 323 * 324 * If @id refers to a menu control, then this function will return NULL. 325 * 326 * Use v4l2_ctrl_new_std_menu() when adding menu controls. 327 */ 328 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, 329 const struct v4l2_ctrl_ops *ops, 330 u32 id, s32 min, s32 max, u32 step, s32 def); 331 332 /** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control. 333 * @hdl: The control handler. 334 * @ops: The control ops. 335 * @id: The control ID. 336 * @max: The control's maximum value. 337 * @mask: The control's skip mask for menu controls. This makes it 338 * easy to skip menu items that are not valid. If bit X is set, 339 * then menu item X is skipped. Of course, this only works for 340 * menus with <= 32 menu items. There are no menus that come 341 * close to that number, so this is OK. Should we ever need more, 342 * then this will have to be extended to a u64 or a bit array. 343 * @def: The control's default value. 344 * 345 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value 346 * determines which menu items are to be skipped. 347 * 348 * If @id refers to a non-menu control, then this function will return NULL. 349 */ 350 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, 351 const struct v4l2_ctrl_ops *ops, 352 u32 id, s32 max, s32 mask, s32 def); 353 354 /** v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control 355 * with driver specific menu. 356 * @hdl: The control handler. 357 * @ops: The control ops. 358 * @id: The control ID. 359 * @max: The control's maximum value. 360 * @mask: The control's skip mask for menu controls. This makes it 361 * easy to skip menu items that are not valid. If bit X is set, 362 * then menu item X is skipped. Of course, this only works for 363 * menus with <= 32 menu items. There are no menus that come 364 * close to that number, so this is OK. Should we ever need more, 365 * then this will have to be extended to a u64 or a bit array. 366 * @def: The control's default value. 367 * @qmenu: The new menu. 368 * 369 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific 370 * menu of this control. 371 * 372 */ 373 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl, 374 const struct v4l2_ctrl_ops *ops, u32 id, s32 max, 375 s32 mask, s32 def, const char * const *qmenu); 376 377 /** v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control. 378 * @hdl: The control handler. 379 * @ops: The control ops. 380 * @id: The control ID. 381 * @max: The control's maximum value. 382 * @def: The control's default value. 383 * @qmenu_int: The control's menu entries. 384 * 385 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly 386 * takes as an argument an array of integers determining the menu items. 387 * 388 * If @id refers to a non-integer-menu control, then this function will return NULL. 389 */ 390 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, 391 const struct v4l2_ctrl_ops *ops, 392 u32 id, s32 max, s32 def, const s64 *qmenu_int); 393 394 /** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler. 395 * @hdl: The control handler. 396 * @ctrl: The control to add. 397 * 398 * It will return NULL if it was unable to add the control reference. 399 * If the control already belonged to the handler, then it will do 400 * nothing and just return @ctrl. 401 */ 402 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl, 403 struct v4l2_ctrl *ctrl); 404 405 /** v4l2_ctrl_add_handler() - Add all controls from handler @add to 406 * handler @hdl. 407 * @hdl: The control handler. 408 * @add: The control handler whose controls you want to add to 409 * the @hdl control handler. 410 * @filter: This function will filter which controls should be added. 411 * 412 * Does nothing if either of the two handlers is a NULL pointer. 413 * If @filter is NULL, then all controls are added. Otherwise only those 414 * controls for which @filter returns true will be added. 415 * In case of an error @hdl->error will be set to the error code (if it 416 * wasn't set already). 417 */ 418 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl, 419 struct v4l2_ctrl_handler *add, 420 bool (*filter)(const struct v4l2_ctrl *ctrl)); 421 422 /** v4l2_ctrl_radio_filter() - Standard filter for radio controls. 423 * @ctrl: The control that is filtered. 424 * 425 * This will return true for any controls that are valid for radio device 426 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM 427 * transmitter class controls. 428 * 429 * This function is to be used with v4l2_ctrl_add_handler(). 430 */ 431 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl); 432 433 /** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster. 434 * @ncontrols: The number of controls in this cluster. 435 * @controls: The cluster control array of size @ncontrols. 436 */ 437 void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls); 438 439 440 /** v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to 441 * that cluster and set it up for autofoo/foo-type handling. 442 * @ncontrols: The number of controls in this cluster. 443 * @controls: The cluster control array of size @ncontrols. The first control 444 * must be the 'auto' control (e.g. autogain, autoexposure, etc.) 445 * @manual_val: The value for the first control in the cluster that equals the 446 * manual setting. 447 * @set_volatile: If true, then all controls except the first auto control will 448 * be volatile. 449 * 450 * Use for control groups where one control selects some automatic feature and 451 * the other controls are only active whenever the automatic feature is turned 452 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs 453 * red and blue balance, etc. 454 * 455 * The behavior of such controls is as follows: 456 * 457 * When the autofoo control is set to automatic, then any manual controls 458 * are set to inactive and any reads will call g_volatile_ctrl (if the control 459 * was marked volatile). 460 * 461 * When the autofoo control is set to manual, then any manual controls will 462 * be marked active, and any reads will just return the current value without 463 * going through g_volatile_ctrl. 464 * 465 * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag 466 * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s) 467 * if autofoo is in auto mode. 468 */ 469 void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls, 470 u8 manual_val, bool set_volatile); 471 472 473 /** v4l2_ctrl_find() - Find a control with the given ID. 474 * @hdl: The control handler. 475 * @id: The control ID to find. 476 * 477 * If @hdl == NULL this will return NULL as well. Will lock the handler so 478 * do not use from inside &v4l2_ctrl_ops. 479 */ 480 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id); 481 482 /** v4l2_ctrl_activate() - Make the control active or inactive. 483 * @ctrl: The control to (de)activate. 484 * @active: True if the control should become active. 485 * 486 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically. 487 * Does nothing if @ctrl == NULL. 488 * This will usually be called from within the s_ctrl op. 489 * The V4L2_EVENT_CTRL event will be generated afterwards. 490 * 491 * This function assumes that the control handler is locked. 492 */ 493 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); 494 495 /** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed. 496 * @ctrl: The control to (de)activate. 497 * @grabbed: True if the control should become grabbed. 498 * 499 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically. 500 * Does nothing if @ctrl == NULL. 501 * The V4L2_EVENT_CTRL event will be generated afterwards. 502 * This will usually be called when starting or stopping streaming in the 503 * driver. 504 * 505 * This function assumes that the control handler is not locked and will 506 * take the lock itself. 507 */ 508 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed); 509 510 /** v4l2_ctrl_lock() - Helper function to lock the handler 511 * associated with the control. 512 * @ctrl: The control to lock. 513 */ 514 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl) 515 { 516 mutex_lock(ctrl->handler->lock); 517 } 518 519 /** v4l2_ctrl_lock() - Helper function to unlock the handler 520 * associated with the control. 521 * @ctrl: The control to unlock. 522 */ 523 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl) 524 { 525 mutex_unlock(ctrl->handler->lock); 526 } 527 528 /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver. 529 * @ctrl: The control. 530 * 531 * This returns the control's value safely by going through the control 532 * framework. This function will lock the control's handler, so it cannot be 533 * used from within the &v4l2_ctrl_ops functions. 534 * 535 * This function is for integer type controls only. 536 */ 537 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); 538 539 /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver. 540 * @ctrl: The control. 541 * @val: The new value. 542 * 543 * This set the control's new value safely by going through the control 544 * framework. This function will lock the control's handler, so it cannot be 545 * used from within the &v4l2_ctrl_ops functions. 546 * 547 * This function is for integer type controls only. 548 */ 549 int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); 550 551 /** v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value from within a driver. 552 * @ctrl: The control. 553 * 554 * This returns the control's value safely by going through the control 555 * framework. This function will lock the control's handler, so it cannot be 556 * used from within the &v4l2_ctrl_ops functions. 557 * 558 * This function is for 64-bit integer type controls only. 559 */ 560 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl); 561 562 /** v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value from within a driver. 563 * @ctrl: The control. 564 * @val: The new value. 565 * 566 * This set the control's new value safely by going through the control 567 * framework. This function will lock the control's handler, so it cannot be 568 * used from within the &v4l2_ctrl_ops functions. 569 * 570 * This function is for 64-bit integer type controls only. 571 */ 572 int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val); 573 574 /* Internal helper functions that deal with control events. */ 575 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops; 576 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new); 577 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new); 578 579 /* Can be used as a vidioc_log_status function that just dumps all controls 580 associated with the filehandle. */ 581 int v4l2_ctrl_log_status(struct file *file, void *fh); 582 583 /* Can be used as a vidioc_subscribe_event function that just subscribes 584 control events. */ 585 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh, 586 const struct v4l2_event_subscription *sub); 587 588 /* Can be used as a poll function that just polls for control events. */ 589 unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait); 590 591 /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */ 592 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc); 593 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm); 594 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl); 595 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 596 struct v4l2_control *ctrl); 597 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); 598 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); 599 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 600 struct v4l2_ext_controls *c); 601 602 /* Helpers for subdevices. If the associated ctrl_handler == NULL then they 603 will all return -EINVAL. */ 604 int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc); 605 int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm); 606 int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 607 int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 608 int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 609 int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); 610 int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); 611 612 #endif 613