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