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 17 #ifndef _V4L2_CTRLS_H 18 #define _V4L2_CTRLS_H 19 20 #include <linux/list.h> 21 #include <linux/mutex.h> 22 #include <linux/videodev2.h> 23 24 /* forward references */ 25 struct file; 26 struct v4l2_ctrl_handler; 27 struct v4l2_ctrl_helper; 28 struct v4l2_ctrl; 29 struct video_device; 30 struct v4l2_subdev; 31 struct v4l2_subscribed_event; 32 struct v4l2_fh; 33 struct poll_table_struct; 34 35 /** 36 * union v4l2_ctrl_ptr - A pointer to a control value. 37 * @p_s32: Pointer to a 32-bit signed value. 38 * @p_s64: Pointer to a 64-bit signed value. 39 * @p_u8: Pointer to a 8-bit unsigned value. 40 * @p_u16: Pointer to a 16-bit unsigned value. 41 * @p_u32: Pointer to a 32-bit unsigned value. 42 * @p_char: Pointer to a string. 43 * @p: Pointer to a compound value. 44 */ 45 union v4l2_ctrl_ptr { 46 s32 *p_s32; 47 s64 *p_s64; 48 u8 *p_u8; 49 u16 *p_u16; 50 u32 *p_u32; 51 char *p_char; 52 void *p; 53 }; 54 55 /** 56 * struct v4l2_ctrl_ops - The control operations that the driver has to provide. 57 * 58 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant 59 * for volatile (and usually read-only) controls such as a control 60 * that returns the current signal strength which changes 61 * continuously. 62 * If not set, then the currently cached value will be returned. 63 * @try_ctrl: Test whether the control's value is valid. Only relevant when 64 * the usual min/max/step checks are not sufficient. 65 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The 66 * ctrl->handler->lock is held when these ops are called, so no 67 * one else can access controls owned by that handler. 68 */ 69 struct v4l2_ctrl_ops { 70 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl); 71 int (*try_ctrl)(struct v4l2_ctrl *ctrl); 72 int (*s_ctrl)(struct v4l2_ctrl *ctrl); 73 }; 74 75 /** 76 * struct v4l2_ctrl_type_ops - The control type operations that the driver 77 * has to provide. 78 * 79 * @equal: return true if both values are equal. 80 * @init: initialize the value. 81 * @log: log the value. 82 * @validate: validate the value. Return 0 on success and a negative value 83 * otherwise. 84 */ 85 struct v4l2_ctrl_type_ops { 86 bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx, 87 union v4l2_ctrl_ptr ptr1, 88 union v4l2_ctrl_ptr ptr2); 89 void (*init)(const struct v4l2_ctrl *ctrl, u32 idx, 90 union v4l2_ctrl_ptr ptr); 91 void (*log)(const struct v4l2_ctrl *ctrl); 92 int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx, 93 union v4l2_ctrl_ptr ptr); 94 }; 95 96 /** 97 * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function 98 * that should be called when a control value has changed. 99 * 100 * @ctrl: pointer to struct &v4l2_ctrl 101 * @priv: control private data 102 * 103 * This typedef definition is used as an argument to v4l2_ctrl_notify() 104 * and as an argument at struct &v4l2_ctrl_handler. 105 */ 106 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv); 107 108 /** 109 * struct v4l2_ctrl - The control structure. 110 * 111 * @node: The list node. 112 * @ev_subs: The list of control event subscriptions. 113 * @handler: The handler that owns the control. 114 * @cluster: Point to start of cluster array. 115 * @ncontrols: Number of controls in cluster array. 116 * @done: Internal flag: set for each processed control. 117 * @is_new: Set when the user specified a new value for this control. It 118 * is also set when called from v4l2_ctrl_handler_setup(). Drivers 119 * should never set this flag. 120 * @has_changed: Set when the current value differs from the new value. Drivers 121 * should never use this flag. 122 * @is_private: If set, then this control is private to its handler and it 123 * will not be added to any other handlers. Drivers can set 124 * this flag. 125 * @is_auto: If set, then this control selects whether the other cluster 126 * members are in 'automatic' mode or 'manual' mode. This is 127 * used for autogain/gain type clusters. Drivers should never 128 * set this flag directly. 129 * @is_int: If set, then this control has a simple integer value (i.e. it 130 * uses ctrl->val). 131 * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING. 132 * @is_ptr: If set, then this control is an array and/or has type >= 133 * %V4L2_CTRL_COMPOUND_TYPES 134 * and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct 135 * v4l2_ext_control uses field p to point to the data. 136 * @is_array: If set, then this control contains an N-dimensional array. 137 * @has_volatiles: If set, then one or more members of the cluster are volatile. 138 * Drivers should never touch this flag. 139 * @call_notify: If set, then call the handler's notify function whenever the 140 * control's value changes. 141 * @manual_mode_value: If the is_auto flag is set, then this is the value 142 * of the auto control that determines if that control is in 143 * manual mode. So if the value of the auto control equals this 144 * value, then the whole cluster is in manual mode. Drivers should 145 * never set this flag directly. 146 * @ops: The control ops. 147 * @type_ops: The control type ops. 148 * @id: The control ID. 149 * @name: The control name. 150 * @type: The control type. 151 * @minimum: The control's minimum value. 152 * @maximum: The control's maximum value. 153 * @default_value: The control's default value. 154 * @step: The control's step value for non-menu controls. 155 * @elems: The number of elements in the N-dimensional array. 156 * @elem_size: The size in bytes of the control. 157 * @dims: The size of each dimension. 158 * @nr_of_dims:The number of dimensions in @dims. 159 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 160 * easy to skip menu items that are not valid. If bit X is set, 161 * then menu item X is skipped. Of course, this only works for 162 * menus with <= 32 menu items. There are no menus that come 163 * close to that number, so this is OK. Should we ever need more, 164 * then this will have to be extended to a u64 or a bit array. 165 * @qmenu: A const char * array for all menu items. Array entries that are 166 * empty strings ("") correspond to non-existing menu items (this 167 * is in addition to the menu_skip_mask above). The last entry 168 * must be NULL. 169 * @flags: The control's flags. 170 * @cur: The control's current value. 171 * @val: The control's new s32 value. 172 * @priv: The control's private pointer. For use by the driver. It is 173 * untouched by the control framework. Note that this pointer is 174 * not freed when the control is deleted. Should this be needed 175 * then a new internal bitfield can be added to tell the framework 176 * to free this pointer. 177 * @p_cur: The control's current value represented via a union with 178 * provides a standard way of accessing control types 179 * through a pointer. 180 * @p_new: The control's new value represented via a union with provides 181 * a standard way of accessing control types 182 * through a pointer. 183 */ 184 struct v4l2_ctrl { 185 /* Administrative fields */ 186 struct list_head node; 187 struct list_head ev_subs; 188 struct v4l2_ctrl_handler *handler; 189 struct v4l2_ctrl **cluster; 190 unsigned int ncontrols; 191 192 unsigned int done:1; 193 194 unsigned int is_new:1; 195 unsigned int has_changed:1; 196 unsigned int is_private:1; 197 unsigned int is_auto:1; 198 unsigned int is_int:1; 199 unsigned int is_string:1; 200 unsigned int is_ptr:1; 201 unsigned int is_array:1; 202 unsigned int has_volatiles:1; 203 unsigned int call_notify:1; 204 unsigned int manual_mode_value:8; 205 206 const struct v4l2_ctrl_ops *ops; 207 const struct v4l2_ctrl_type_ops *type_ops; 208 u32 id; 209 const char *name; 210 enum v4l2_ctrl_type type; 211 s64 minimum, maximum, default_value; 212 u32 elems; 213 u32 elem_size; 214 u32 dims[V4L2_CTRL_MAX_DIMS]; 215 u32 nr_of_dims; 216 union { 217 u64 step; 218 u64 menu_skip_mask; 219 }; 220 union { 221 const char * const *qmenu; 222 const s64 *qmenu_int; 223 }; 224 unsigned long flags; 225 void *priv; 226 s32 val; 227 struct { 228 s32 val; 229 } cur; 230 231 union v4l2_ctrl_ptr p_new; 232 union v4l2_ctrl_ptr p_cur; 233 }; 234 235 /** 236 * struct v4l2_ctrl_ref - The control reference. 237 * 238 * @node: List node for the sorted list. 239 * @next: Single-link list node for the hash. 240 * @ctrl: The actual control information. 241 * @helper: Pointer to helper struct. Used internally in 242 * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``. 243 * 244 * Each control handler has a list of these refs. The list_head is used to 245 * keep a sorted-by-control-ID list of all controls, while the next pointer 246 * is used to link the control in the hash's bucket. 247 */ 248 struct v4l2_ctrl_ref { 249 struct list_head node; 250 struct v4l2_ctrl_ref *next; 251 struct v4l2_ctrl *ctrl; 252 struct v4l2_ctrl_helper *helper; 253 }; 254 255 /** 256 * struct v4l2_ctrl_handler - The control handler keeps track of all the 257 * controls: both the controls owned by the handler and those inherited 258 * from other handlers. 259 * 260 * @_lock: Default for "lock". 261 * @lock: Lock to control access to this handler and its controls. 262 * May be replaced by the user right after init. 263 * @ctrls: The list of controls owned by this handler. 264 * @ctrl_refs: The list of control references. 265 * @cached: The last found control reference. It is common that the same 266 * control is needed multiple times, so this is a simple 267 * optimization. 268 * @buckets: Buckets for the hashing. Allows for quick control lookup. 269 * @notify: A notify callback that is called whenever the control changes 270 * value. 271 * Note that the handler's lock is held when the notify function 272 * is called! 273 * @notify_priv: Passed as argument to the v4l2_ctrl notify callback. 274 * @nr_of_buckets: Total number of buckets in the array. 275 * @error: The error code of the first failed control addition. 276 */ 277 struct v4l2_ctrl_handler { 278 struct mutex _lock; 279 struct mutex *lock; 280 struct list_head ctrls; 281 struct list_head ctrl_refs; 282 struct v4l2_ctrl_ref *cached; 283 struct v4l2_ctrl_ref **buckets; 284 v4l2_ctrl_notify_fnc notify; 285 void *notify_priv; 286 u16 nr_of_buckets; 287 int error; 288 }; 289 290 /** 291 * struct v4l2_ctrl_config - Control configuration structure. 292 * 293 * @ops: The control ops. 294 * @type_ops: The control type ops. Only needed for compound controls. 295 * @id: The control ID. 296 * @name: The control name. 297 * @type: The control type. 298 * @min: The control's minimum value. 299 * @max: The control's maximum value. 300 * @step: The control's step value for non-menu controls. 301 * @def: The control's default value. 302 * @dims: The size of each dimension. 303 * @elem_size: The size in bytes of the control. 304 * @flags: The control's flags. 305 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 306 * easy to skip menu items that are not valid. If bit X is set, 307 * then menu item X is skipped. Of course, this only works for 308 * menus with <= 64 menu items. There are no menus that come 309 * close to that number, so this is OK. Should we ever need more, 310 * then this will have to be extended to a bit array. 311 * @qmenu: A const char * array for all menu items. Array entries that are 312 * empty strings ("") correspond to non-existing menu items (this 313 * is in addition to the menu_skip_mask above). The last entry 314 * must be NULL. 315 * @qmenu_int: A const s64 integer array for all menu items of the type 316 * V4L2_CTRL_TYPE_INTEGER_MENU. 317 * @is_private: If set, then this control is private to its handler and it 318 * will not be added to any other handlers. 319 */ 320 struct v4l2_ctrl_config { 321 const struct v4l2_ctrl_ops *ops; 322 const struct v4l2_ctrl_type_ops *type_ops; 323 u32 id; 324 const char *name; 325 enum v4l2_ctrl_type type; 326 s64 min; 327 s64 max; 328 u64 step; 329 s64 def; 330 u32 dims[V4L2_CTRL_MAX_DIMS]; 331 u32 elem_size; 332 u32 flags; 333 u64 menu_skip_mask; 334 const char * const *qmenu; 335 const s64 *qmenu_int; 336 unsigned int is_private:1; 337 }; 338 339 /** 340 * v4l2_ctrl_fill - Fill in the control fields based on the control ID. 341 * 342 * @id: ID of the control 343 * @name: name of the control 344 * @type: type of the control 345 * @min: minimum value for the control 346 * @max: maximum value for the control 347 * @step: control step 348 * @def: default value for the control 349 * @flags: flags to be used on the control 350 * 351 * This works for all standard V4L2 controls. 352 * For non-standard controls it will only fill in the given arguments 353 * and @name will be %NULL. 354 * 355 * This function will overwrite the contents of @name, @type and @flags. 356 * The contents of @min, @max, @step and @def may be modified depending on 357 * the type. 358 * 359 * .. note:: 360 * 361 * Do not use in drivers! It is used internally for backwards compatibility 362 * control handling only. Once all drivers are converted to use the new 363 * control framework this function will no longer be exported. 364 */ 365 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, 366 s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags); 367 368 369 /** 370 * v4l2_ctrl_handler_init_class() - Initialize the control handler. 371 * @hdl: The control handler. 372 * @nr_of_controls_hint: A hint of how many controls this handler is 373 * expected to refer to. This is the total number, so including 374 * any inherited controls. It doesn't have to be precise, but if 375 * it is way off, then you either waste memory (too many buckets 376 * are allocated) or the control lookup becomes slower (not enough 377 * buckets are allocated, so there are more slow list lookups). 378 * It will always work, though. 379 * @key: Used by the lock validator if CONFIG_LOCKDEP is set. 380 * @name: Used by the lock validator if CONFIG_LOCKDEP is set. 381 * 382 * .. attention:: 383 * 384 * Never use this call directly, always use the v4l2_ctrl_handler_init() 385 * macro that hides the @key and @name arguments. 386 * 387 * Return: returns an error if the buckets could not be allocated. This 388 * error will also be stored in @hdl->error. 389 */ 390 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl, 391 unsigned int nr_of_controls_hint, 392 struct lock_class_key *key, const char *name); 393 394 #ifdef CONFIG_LOCKDEP 395 396 /** 397 * v4l2_ctrl_handler_init - helper function to create a static struct 398 * &lock_class_key and calls v4l2_ctrl_handler_init_class() 399 * 400 * @hdl: The control handler. 401 * @nr_of_controls_hint: A hint of how many controls this handler is 402 * expected to refer to. This is the total number, so including 403 * any inherited controls. It doesn't have to be precise, but if 404 * it is way off, then you either waste memory (too many buckets 405 * are allocated) or the control lookup becomes slower (not enough 406 * buckets are allocated, so there are more slow list lookups). 407 * It will always work, though. 408 * 409 * This helper function creates a static struct &lock_class_key and 410 * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock 411 * validador. 412 * 413 * Use this helper function to initialize a control handler. 414 */ 415 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \ 416 ( \ 417 ({ \ 418 static struct lock_class_key _key; \ 419 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, \ 420 &_key, \ 421 KBUILD_BASENAME ":" \ 422 __stringify(__LINE__) ":" \ 423 "(" #hdl ")->_lock"); \ 424 }) \ 425 ) 426 #else 427 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint) \ 428 v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL) 429 #endif 430 431 /** 432 * v4l2_ctrl_handler_free() - Free all controls owned by the handler and free 433 * the control list. 434 * @hdl: The control handler. 435 * 436 * Does nothing if @hdl == NULL. 437 */ 438 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl); 439 440 /** 441 * v4l2_ctrl_lock() - Helper function to lock the handler 442 * associated with the control. 443 * @ctrl: The control to lock. 444 */ 445 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl) 446 { 447 mutex_lock(ctrl->handler->lock); 448 } 449 450 /** 451 * v4l2_ctrl_unlock() - Helper function to unlock the handler 452 * associated with the control. 453 * @ctrl: The control to unlock. 454 */ 455 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl) 456 { 457 mutex_unlock(ctrl->handler->lock); 458 } 459 460 /** 461 * __v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging 462 * to the handler to initialize the hardware to the current control values. The 463 * caller is responsible for acquiring the control handler mutex on behalf of 464 * __v4l2_ctrl_handler_setup(). 465 * @hdl: The control handler. 466 * 467 * Button controls will be skipped, as are read-only controls. 468 * 469 * If @hdl == NULL, then this just returns 0. 470 */ 471 int __v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl); 472 473 /** 474 * v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging 475 * to the handler to initialize the hardware to the current control values. 476 * @hdl: The control handler. 477 * 478 * Button controls will be skipped, as are read-only controls. 479 * 480 * If @hdl == NULL, then this just returns 0. 481 */ 482 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl); 483 484 /** 485 * v4l2_ctrl_handler_log_status() - Log all controls owned by the handler. 486 * @hdl: The control handler. 487 * @prefix: The prefix to use when logging the control values. If the 488 * prefix does not end with a space, then ": " will be added 489 * after the prefix. If @prefix == NULL, then no prefix will be 490 * used. 491 * 492 * For use with VIDIOC_LOG_STATUS. 493 * 494 * Does nothing if @hdl == NULL. 495 */ 496 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, 497 const char *prefix); 498 499 /** 500 * v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2 501 * control. 502 * 503 * @hdl: The control handler. 504 * @cfg: The control's configuration data. 505 * @priv: The control's driver-specific private data. 506 * 507 * If the &v4l2_ctrl struct could not be allocated then NULL is returned 508 * and @hdl->error is set to the error code (if it wasn't set already). 509 */ 510 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, 511 const struct v4l2_ctrl_config *cfg, 512 void *priv); 513 514 /** 515 * v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu 516 * control. 517 * 518 * @hdl: The control handler. 519 * @ops: The control ops. 520 * @id: The control ID. 521 * @min: The control's minimum value. 522 * @max: The control's maximum value. 523 * @step: The control's step value 524 * @def: The control's default value. 525 * 526 * If the &v4l2_ctrl struct could not be allocated, or the control 527 * ID is not known, then NULL is returned and @hdl->error is set to the 528 * appropriate error code (if it wasn't set already). 529 * 530 * If @id refers to a menu control, then this function will return NULL. 531 * 532 * Use v4l2_ctrl_new_std_menu() when adding menu controls. 533 */ 534 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, 535 const struct v4l2_ctrl_ops *ops, 536 u32 id, s64 min, s64 max, u64 step, 537 s64 def); 538 539 /** 540 * v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 541 * menu control. 542 * 543 * @hdl: The control handler. 544 * @ops: The control ops. 545 * @id: The control ID. 546 * @max: The control's maximum value. 547 * @mask: The control's skip mask for menu controls. This makes it 548 * easy to skip menu items that are not valid. If bit X is set, 549 * then menu item X is skipped. Of course, this only works for 550 * menus with <= 64 menu items. There are no menus that come 551 * close to that number, so this is OK. Should we ever need more, 552 * then this will have to be extended to a bit array. 553 * @def: The control's default value. 554 * 555 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value 556 * determines which menu items are to be skipped. 557 * 558 * If @id refers to a non-menu control, then this function will return NULL. 559 */ 560 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, 561 const struct v4l2_ctrl_ops *ops, 562 u32 id, u8 max, u64 mask, u8 def); 563 564 /** 565 * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control 566 * with driver specific menu. 567 * 568 * @hdl: The control handler. 569 * @ops: The control ops. 570 * @id: The control ID. 571 * @max: The control's maximum value. 572 * @mask: The control's skip mask for menu controls. This makes it 573 * easy to skip menu items that are not valid. If bit X is set, 574 * then menu item X is skipped. Of course, this only works for 575 * menus with <= 64 menu items. There are no menus that come 576 * close to that number, so this is OK. Should we ever need more, 577 * then this will have to be extended to a bit array. 578 * @def: The control's default value. 579 * @qmenu: The new menu. 580 * 581 * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific 582 * menu of this control. 583 * 584 */ 585 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl, 586 const struct v4l2_ctrl_ops *ops, 587 u32 id, u8 max, 588 u64 mask, u8 def, 589 const char * const *qmenu); 590 591 /** 592 * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control. 593 * 594 * @hdl: The control handler. 595 * @ops: The control ops. 596 * @id: The control ID. 597 * @max: The control's maximum value. 598 * @def: The control's default value. 599 * @qmenu_int: The control's menu entries. 600 * 601 * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly 602 * takes as an argument an array of integers determining the menu items. 603 * 604 * If @id refers to a non-integer-menu control, then this function will 605 * return %NULL. 606 */ 607 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, 608 const struct v4l2_ctrl_ops *ops, 609 u32 id, u8 max, u8 def, 610 const s64 *qmenu_int); 611 612 /** 613 * typedef v4l2_ctrl_filter - Typedef to define the filter function to be 614 * used when adding a control handler. 615 * 616 * @ctrl: pointer to struct &v4l2_ctrl. 617 */ 618 619 typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl); 620 621 /** 622 * v4l2_ctrl_add_handler() - Add all controls from handler @add to 623 * handler @hdl. 624 * 625 * @hdl: The control handler. 626 * @add: The control handler whose controls you want to add to 627 * the @hdl control handler. 628 * @filter: This function will filter which controls should be added. 629 * 630 * Does nothing if either of the two handlers is a NULL pointer. 631 * If @filter is NULL, then all controls are added. Otherwise only those 632 * controls for which @filter returns true will be added. 633 * In case of an error @hdl->error will be set to the error code (if it 634 * wasn't set already). 635 */ 636 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl, 637 struct v4l2_ctrl_handler *add, 638 v4l2_ctrl_filter filter); 639 640 /** 641 * v4l2_ctrl_radio_filter() - Standard filter for radio controls. 642 * 643 * @ctrl: The control that is filtered. 644 * 645 * This will return true for any controls that are valid for radio device 646 * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM 647 * transmitter class controls. 648 * 649 * This function is to be used with v4l2_ctrl_add_handler(). 650 */ 651 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl); 652 653 /** 654 * v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging 655 * to that cluster. 656 * 657 * @ncontrols: The number of controls in this cluster. 658 * @controls: The cluster control array of size @ncontrols. 659 */ 660 void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls); 661 662 663 /** 664 * v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging 665 * to that cluster and set it up for autofoo/foo-type handling. 666 * 667 * @ncontrols: The number of controls in this cluster. 668 * @controls: The cluster control array of size @ncontrols. The first control 669 * must be the 'auto' control (e.g. autogain, autoexposure, etc.) 670 * @manual_val: The value for the first control in the cluster that equals the 671 * manual setting. 672 * @set_volatile: If true, then all controls except the first auto control will 673 * be volatile. 674 * 675 * Use for control groups where one control selects some automatic feature and 676 * the other controls are only active whenever the automatic feature is turned 677 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs 678 * red and blue balance, etc. 679 * 680 * The behavior of such controls is as follows: 681 * 682 * When the autofoo control is set to automatic, then any manual controls 683 * are set to inactive and any reads will call g_volatile_ctrl (if the control 684 * was marked volatile). 685 * 686 * When the autofoo control is set to manual, then any manual controls will 687 * be marked active, and any reads will just return the current value without 688 * going through g_volatile_ctrl. 689 * 690 * In addition, this function will set the %V4L2_CTRL_FLAG_UPDATE flag 691 * on the autofoo control and %V4L2_CTRL_FLAG_INACTIVE on the foo control(s) 692 * if autofoo is in auto mode. 693 */ 694 void v4l2_ctrl_auto_cluster(unsigned int ncontrols, 695 struct v4l2_ctrl **controls, 696 u8 manual_val, bool set_volatile); 697 698 699 /** 700 * v4l2_ctrl_find() - Find a control with the given ID. 701 * 702 * @hdl: The control handler. 703 * @id: The control ID to find. 704 * 705 * If @hdl == NULL this will return NULL as well. Will lock the handler so 706 * do not use from inside &v4l2_ctrl_ops. 707 */ 708 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id); 709 710 /** 711 * v4l2_ctrl_activate() - Make the control active or inactive. 712 * @ctrl: The control to (de)activate. 713 * @active: True if the control should become active. 714 * 715 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically. 716 * Does nothing if @ctrl == NULL. 717 * This will usually be called from within the s_ctrl op. 718 * The V4L2_EVENT_CTRL event will be generated afterwards. 719 * 720 * This function assumes that the control handler is locked. 721 */ 722 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); 723 724 /** 725 * v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed. 726 * 727 * @ctrl: The control to (de)activate. 728 * @grabbed: True if the control should become grabbed. 729 * 730 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically. 731 * Does nothing if @ctrl == NULL. 732 * The V4L2_EVENT_CTRL event will be generated afterwards. 733 * This will usually be called when starting or stopping streaming in the 734 * driver. 735 * 736 * This function assumes that the control handler is not locked and will 737 * take the lock itself. 738 */ 739 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed); 740 741 /** 742 *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range() 743 * 744 * @ctrl: The control to update. 745 * @min: The control's minimum value. 746 * @max: The control's maximum value. 747 * @step: The control's step value 748 * @def: The control's default value. 749 * 750 * Update the range of a control on the fly. This works for control types 751 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the 752 * @step value is interpreted as a menu_skip_mask. 753 * 754 * An error is returned if one of the range arguments is invalid for this 755 * control type. 756 * 757 * This function assumes that the control handler is not locked and will 758 * take the lock itself. 759 */ 760 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl, 761 s64 min, s64 max, u64 step, s64 def); 762 763 /** 764 * v4l2_ctrl_modify_range() - Update the range of a control. 765 * 766 * @ctrl: The control to update. 767 * @min: The control's minimum value. 768 * @max: The control's maximum value. 769 * @step: The control's step value 770 * @def: The control's default value. 771 * 772 * Update the range of a control on the fly. This works for control types 773 * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the 774 * @step value is interpreted as a menu_skip_mask. 775 * 776 * An error is returned if one of the range arguments is invalid for this 777 * control type. 778 * 779 * This function assumes that the control handler is not locked and will 780 * take the lock itself. 781 */ 782 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl, 783 s64 min, s64 max, u64 step, s64 def) 784 { 785 int rval; 786 787 v4l2_ctrl_lock(ctrl); 788 rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def); 789 v4l2_ctrl_unlock(ctrl); 790 791 return rval; 792 } 793 794 /** 795 * v4l2_ctrl_notify() - Function to set a notify callback for a control. 796 * 797 * @ctrl: The control. 798 * @notify: The callback function. 799 * @priv: The callback private handle, passed as argument to the callback. 800 * 801 * This function sets a callback function for the control. If @ctrl is NULL, 802 * then it will do nothing. If @notify is NULL, then the notify callback will 803 * be removed. 804 * 805 * There can be only one notify. If another already exists, then a WARN_ON 806 * will be issued and the function will do nothing. 807 */ 808 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, 809 void *priv); 810 811 /** 812 * v4l2_ctrl_get_name() - Get the name of the control 813 * 814 * @id: The control ID. 815 * 816 * This function returns the name of the given control ID or NULL if it isn't 817 * a known control. 818 */ 819 const char *v4l2_ctrl_get_name(u32 id); 820 821 /** 822 * v4l2_ctrl_get_menu() - Get the menu string array of the control 823 * 824 * @id: The control ID. 825 * 826 * This function returns the NULL-terminated menu string array name of the 827 * given control ID or NULL if it isn't a known menu control. 828 */ 829 const char * const *v4l2_ctrl_get_menu(u32 id); 830 831 /** 832 * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control 833 * 834 * @id: The control ID. 835 * @len: The size of the integer array. 836 * 837 * This function returns the integer array of the given control ID or NULL if it 838 * if it isn't a known integer menu control. 839 */ 840 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len); 841 842 /** 843 * v4l2_ctrl_g_ctrl() - Helper function to get the control's value from 844 * within a driver. 845 * 846 * @ctrl: The control. 847 * 848 * This returns the control's value safely by going through the control 849 * framework. This function will lock the control's handler, so it cannot be 850 * used from within the &v4l2_ctrl_ops functions. 851 * 852 * This function is for integer type controls only. 853 */ 854 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); 855 856 /** 857 * __v4l2_ctrl_s_ctrl() - Unlocked variant of v4l2_ctrl_s_ctrl(). 858 * 859 * @ctrl: The control. 860 * @val: TheControls name new value. 861 * 862 * This sets the control's new value safely by going through the control 863 * framework. This function assumes the control's handler is already locked, 864 * allowing it to be used from within the &v4l2_ctrl_ops functions. 865 * 866 * This function is for integer type controls only. 867 */ 868 int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); 869 870 /** 871 * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from 872 * within a driver. 873 * @ctrl: The control. 874 * @val: The new value. 875 * 876 * This sets the control's new value safely by going through the control 877 * framework. This function will lock the control's handler, so it cannot be 878 * used from within the &v4l2_ctrl_ops functions. 879 * 880 * This function is for integer type controls only. 881 */ 882 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val) 883 { 884 int rval; 885 886 v4l2_ctrl_lock(ctrl); 887 rval = __v4l2_ctrl_s_ctrl(ctrl, val); 888 v4l2_ctrl_unlock(ctrl); 889 890 return rval; 891 } 892 893 /** 894 * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit control's value 895 * from within a driver. 896 * 897 * @ctrl: The control. 898 * 899 * This returns the control's value safely by going through the control 900 * framework. This function will lock the control's handler, so it cannot be 901 * used from within the &v4l2_ctrl_ops functions. 902 * 903 * This function is for 64-bit integer type controls only. 904 */ 905 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl); 906 907 /** 908 * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64(). 909 * 910 * @ctrl: The control. 911 * @val: The new value. 912 * 913 * This sets the control's new value safely by going through the control 914 * framework. This function assumes the control's handler is already locked, 915 * allowing it to be used from within the &v4l2_ctrl_ops functions. 916 * 917 * This function is for 64-bit integer type controls only. 918 */ 919 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val); 920 921 /** 922 * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value 923 * from within a driver. 924 * 925 * @ctrl: The control. 926 * @val: The new value. 927 * 928 * This sets the control's new value safely by going through the control 929 * framework. This function will lock the control's handler, so it cannot be 930 * used from within the &v4l2_ctrl_ops functions. 931 * 932 * This function is for 64-bit integer type controls only. 933 */ 934 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val) 935 { 936 int rval; 937 938 v4l2_ctrl_lock(ctrl); 939 rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val); 940 v4l2_ctrl_unlock(ctrl); 941 942 return rval; 943 } 944 945 /** 946 * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string(). 947 * 948 * @ctrl: The control. 949 * @s: The new string. 950 * 951 * This sets the control's new string safely by going through the control 952 * framework. This function assumes the control's handler is already locked, 953 * allowing it to be used from within the &v4l2_ctrl_ops functions. 954 * 955 * This function is for string type controls only. 956 */ 957 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s); 958 959 /** 960 * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value 961 * from within a driver. 962 * 963 * @ctrl: The control. 964 * @s: The new string. 965 *Controls name 966 * This sets the control's new string safely by going through the control 967 * framework. This function will lock the control's handler, so it cannot be 968 * used from within the &v4l2_ctrl_ops functions. 969 * 970 * This function is for string type controls only. 971 */ 972 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s) 973 { 974 int rval; 975 976 v4l2_ctrl_lock(ctrl); 977 rval = __v4l2_ctrl_s_ctrl_string(ctrl, s); 978 v4l2_ctrl_unlock(ctrl); 979 980 return rval; 981 } 982 983 /* Internal helper functions that deal with control events. */ 984 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops; 985 986 /** 987 * v4l2_ctrl_replace - Function to be used as a callback to 988 * &struct v4l2_subscribed_event_ops replace\(\) 989 * 990 * @old: pointer to struct &v4l2_event with the reported 991 * event; 992 * @new: pointer to struct &v4l2_event with the modified 993 * event; 994 */ 995 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new); 996 997 /** 998 * v4l2_ctrl_merge - Function to be used as a callback to 999 * &struct v4l2_subscribed_event_ops merge(\) 1000 * 1001 * @old: pointer to struct &v4l2_event with the reported 1002 * event; 1003 * @new: pointer to struct &v4l2_event with the merged 1004 * event; 1005 */ 1006 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new); 1007 1008 /** 1009 * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl 1010 * 1011 * @file: pointer to struct file 1012 * @fh: unused. Kept just to be compatible to the arguments expected by 1013 * &struct v4l2_ioctl_ops.vidioc_log_status. 1014 * 1015 * Can be used as a vidioc_log_status function that just dumps all controls 1016 * associated with the filehandle. 1017 */ 1018 int v4l2_ctrl_log_status(struct file *file, void *fh); 1019 1020 /** 1021 * v4l2_ctrl_subscribe_event - Subscribes to an event 1022 * 1023 * 1024 * @fh: pointer to struct v4l2_fh 1025 * @sub: pointer to &struct v4l2_event_subscription 1026 * 1027 * Can be used as a vidioc_subscribe_event function that just subscribes 1028 * control events. 1029 */ 1030 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh, 1031 const struct v4l2_event_subscription *sub); 1032 1033 /** 1034 * v4l2_ctrl_poll - function to be used as a callback to the poll() 1035 * That just polls for control events. 1036 * 1037 * @file: pointer to struct file 1038 * @wait: pointer to struct poll_table_struct 1039 */ 1040 unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait); 1041 1042 /* Helpers for ioctl_ops */ 1043 1044 /** 1045 * v4l2_queryctrl - Helper function to implement 1046 * :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl 1047 * 1048 * @hdl: pointer to &struct v4l2_ctrl_handler 1049 * @qc: pointer to &struct v4l2_queryctrl 1050 * 1051 * If hdl == NULL then they will all return -EINVAL. 1052 */ 1053 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc); 1054 1055 /** 1056 * v4l2_query_ext_ctrl - Helper function to implement 1057 * :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl 1058 * 1059 * @hdl: pointer to &struct v4l2_ctrl_handler 1060 * @qc: pointer to &struct v4l2_query_ext_ctrl 1061 * 1062 * If hdl == NULL then they will all return -EINVAL. 1063 */ 1064 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, 1065 struct v4l2_query_ext_ctrl *qc); 1066 1067 /** 1068 * v4l2_querymenu - Helper function to implement 1069 * :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl 1070 * 1071 * @hdl: pointer to &struct v4l2_ctrl_handler 1072 * @qm: pointer to &struct v4l2_querymenu 1073 * 1074 * If hdl == NULL then they will all return -EINVAL. 1075 */ 1076 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm); 1077 1078 /** 1079 * v4l2_g_ctrl - Helper function to implement 1080 * :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl 1081 * 1082 * @hdl: pointer to &struct v4l2_ctrl_handler 1083 * @ctrl: pointer to &struct v4l2_control 1084 * 1085 * If hdl == NULL then they will all return -EINVAL. 1086 */ 1087 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl); 1088 1089 /** 1090 * v4l2_s_ctrl - Helper function to implement 1091 * :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl 1092 * 1093 * @fh: pointer to &struct v4l2_fh 1094 * @hdl: pointer to &struct v4l2_ctrl_handler 1095 * 1096 * @ctrl: pointer to &struct v4l2_control 1097 * 1098 * If hdl == NULL then they will all return -EINVAL. 1099 */ 1100 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 1101 struct v4l2_control *ctrl); 1102 1103 /** 1104 * v4l2_g_ext_ctrls - Helper function to implement 1105 * :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl 1106 * 1107 * @hdl: pointer to &struct v4l2_ctrl_handler 1108 * @c: pointer to &struct v4l2_ext_controls 1109 * 1110 * If hdl == NULL then they will all return -EINVAL. 1111 */ 1112 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, 1113 struct v4l2_ext_controls *c); 1114 1115 /** 1116 * v4l2_try_ext_ctrls - Helper function to implement 1117 * :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl 1118 * 1119 * @hdl: pointer to &struct v4l2_ctrl_handler 1120 * @c: pointer to &struct v4l2_ext_controls 1121 * 1122 * If hdl == NULL then they will all return -EINVAL. 1123 */ 1124 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, 1125 struct v4l2_ext_controls *c); 1126 1127 /** 1128 * v4l2_s_ext_ctrls - Helper function to implement 1129 * :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl 1130 * 1131 * @fh: pointer to &struct v4l2_fh 1132 * @hdl: pointer to &struct v4l2_ctrl_handler 1133 * @c: pointer to &struct v4l2_ext_controls 1134 * 1135 * If hdl == NULL then they will all return -EINVAL. 1136 */ 1137 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 1138 struct v4l2_ext_controls *c); 1139 1140 /** 1141 * v4l2_ctrl_subdev_subscribe_event - Helper function to implement 1142 * as a &struct v4l2_subdev_core_ops subscribe_event function 1143 * that just subscribes control events. 1144 * 1145 * @sd: pointer to &struct v4l2_subdev 1146 * @fh: pointer to &struct v4l2_fh 1147 * @sub: pointer to &struct v4l2_event_subscription 1148 */ 1149 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh, 1150 struct v4l2_event_subscription *sub); 1151 1152 /** 1153 * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control 1154 * handler. 1155 * 1156 * @sd: pointer to &struct v4l2_subdev 1157 */ 1158 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd); 1159 1160 #endif 1161