1 /* 2 V4L2 controls support header. 3 4 Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl> 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 21 #ifndef _V4L2_CTRLS_H 22 #define _V4L2_CTRLS_H 23 24 #include <linux/list.h> 25 #include <linux/device.h> 26 #include <linux/videodev2.h> 27 28 /* forward references */ 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 37 /** struct v4l2_ctrl_ops - The control operations that the driver has to provide. 38 * @g_volatile_ctrl: Get a new value for this control. Generally only relevant 39 * for volatile (and usually read-only) controls such as a control 40 * that returns the current signal strength which changes 41 * continuously. 42 * If not set, then the currently cached value will be returned. 43 * @try_ctrl: Test whether the control's value is valid. Only relevant when 44 * the usual min/max/step checks are not sufficient. 45 * @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The 46 * ctrl->handler->lock is held when these ops are called, so no 47 * one else can access controls owned by that handler. 48 */ 49 struct v4l2_ctrl_ops { 50 int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl); 51 int (*try_ctrl)(struct v4l2_ctrl *ctrl); 52 int (*s_ctrl)(struct v4l2_ctrl *ctrl); 53 }; 54 55 /** struct v4l2_ctrl - The control structure. 56 * @node: The list node. 57 * @ev_subs: The list of control event subscriptions. 58 * @handler: The handler that owns the control. 59 * @cluster: Point to start of cluster array. 60 * @ncontrols: Number of controls in cluster array. 61 * @done: Internal flag: set for each processed control. 62 * @is_new: Set when the user specified a new value for this control. It 63 * is also set when called from v4l2_ctrl_handler_setup. Drivers 64 * should never set this flag. 65 * @is_private: If set, then this control is private to its handler and it 66 * will not be added to any other handlers. Drivers can set 67 * this flag. 68 * @is_volatile: If set, then this control is volatile. This means that the 69 * control's current value cannot be cached and needs to be 70 * retrieved through the g_volatile_ctrl op. Drivers can set 71 * this flag. 72 * @is_auto: If set, then this control selects whether the other cluster 73 * members are in 'automatic' mode or 'manual' mode. This is 74 * used for autogain/gain type clusters. Drivers should never 75 * set this flag directly. 76 * @manual_mode_value: If the is_auto flag is set, then this is the value 77 * of the auto control that determines if that control is in 78 * manual mode. So if the value of the auto control equals this 79 * value, then the whole cluster is in manual mode. Drivers should 80 * never set this flag directly. 81 * @ops: The control ops. 82 * @id: The control ID. 83 * @name: The control name. 84 * @type: The control type. 85 * @minimum: The control's minimum value. 86 * @maximum: The control's maximum value. 87 * @default_value: The control's default value. 88 * @step: The control's step value for non-menu controls. 89 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 90 * easy to skip menu items that are not valid. If bit X is set, 91 * then menu item X is skipped. Of course, this only works for 92 * menus with <= 32 menu items. There are no menus that come 93 * close to that number, so this is OK. Should we ever need more, 94 * then this will have to be extended to a u64 or a bit array. 95 * @qmenu: A const char * array for all menu items. Array entries that are 96 * empty strings ("") correspond to non-existing menu items (this 97 * is in addition to the menu_skip_mask above). The last entry 98 * must be NULL. 99 * @flags: The control's flags. 100 * @cur: The control's current value. 101 * @val: The control's new s32 value. 102 * @val64: The control's new s64 value. 103 * @string: The control's new string value. 104 * @priv: The control's private pointer. For use by the driver. It is 105 * untouched by the control framework. Note that this pointer is 106 * not freed when the control is deleted. Should this be needed 107 * then a new internal bitfield can be added to tell the framework 108 * to free this pointer. 109 */ 110 struct v4l2_ctrl { 111 /* Administrative fields */ 112 struct list_head node; 113 struct list_head ev_subs; 114 struct v4l2_ctrl_handler *handler; 115 struct v4l2_ctrl **cluster; 116 unsigned ncontrols; 117 unsigned int done:1; 118 119 unsigned int is_new:1; 120 unsigned int is_private:1; 121 unsigned int is_volatile:1; 122 unsigned int is_auto:1; 123 unsigned int manual_mode_value:8; 124 125 const struct v4l2_ctrl_ops *ops; 126 u32 id; 127 const char *name; 128 enum v4l2_ctrl_type type; 129 s32 minimum, maximum, default_value; 130 union { 131 u32 step; 132 u32 menu_skip_mask; 133 }; 134 const char * const *qmenu; 135 unsigned long flags; 136 union { 137 s32 val; 138 s64 val64; 139 char *string; 140 } cur; 141 union { 142 s32 val; 143 s64 val64; 144 char *string; 145 }; 146 void *priv; 147 }; 148 149 /** struct v4l2_ctrl_ref - The control reference. 150 * @node: List node for the sorted list. 151 * @next: Single-link list node for the hash. 152 * @ctrl: The actual control information. 153 * @helper: Pointer to helper struct. Used internally in prepare_ext_ctrls(). 154 * 155 * Each control handler has a list of these refs. The list_head is used to 156 * keep a sorted-by-control-ID list of all controls, while the next pointer 157 * is used to link the control in the hash's bucket. 158 */ 159 struct v4l2_ctrl_ref { 160 struct list_head node; 161 struct v4l2_ctrl_ref *next; 162 struct v4l2_ctrl *ctrl; 163 struct v4l2_ctrl_helper *helper; 164 }; 165 166 /** struct v4l2_ctrl_handler - The control handler keeps track of all the 167 * controls: both the controls owned by the handler and those inherited 168 * from other handlers. 169 * @lock: Lock to control access to this handler and its controls. 170 * @ctrls: The list of controls owned by this handler. 171 * @ctrl_refs: The list of control references. 172 * @cached: The last found control reference. It is common that the same 173 * control is needed multiple times, so this is a simple 174 * optimization. 175 * @buckets: Buckets for the hashing. Allows for quick control lookup. 176 * @nr_of_buckets: Total number of buckets in the array. 177 * @error: The error code of the first failed control addition. 178 */ 179 struct v4l2_ctrl_handler { 180 struct mutex lock; 181 struct list_head ctrls; 182 struct list_head ctrl_refs; 183 struct v4l2_ctrl_ref *cached; 184 struct v4l2_ctrl_ref **buckets; 185 u16 nr_of_buckets; 186 int error; 187 }; 188 189 /** struct v4l2_ctrl_config - Control configuration structure. 190 * @ops: The control ops. 191 * @id: The control ID. 192 * @name: The control name. 193 * @type: The control type. 194 * @min: The control's minimum value. 195 * @max: The control's maximum value. 196 * @step: The control's step value for non-menu controls. 197 * @def: The control's default value. 198 * @flags: The control's flags. 199 * @menu_skip_mask: The control's skip mask for menu controls. This makes it 200 * easy to skip menu items that are not valid. If bit X is set, 201 * then menu item X is skipped. Of course, this only works for 202 * menus with <= 32 menu items. There are no menus that come 203 * close to that number, so this is OK. Should we ever need more, 204 * then this will have to be extended to a u64 or a bit array. 205 * @qmenu: A const char * array for all menu items. Array entries that are 206 * empty strings ("") correspond to non-existing menu items (this 207 * is in addition to the menu_skip_mask above). The last entry 208 * must be NULL. 209 * @is_private: If set, then this control is private to its handler and it 210 * will not be added to any other handlers. 211 * @is_volatile: If set, then this control is volatile. This means that the 212 * control's current value cannot be cached and needs to be 213 * retrieved through the g_volatile_ctrl op. 214 */ 215 struct v4l2_ctrl_config { 216 const struct v4l2_ctrl_ops *ops; 217 u32 id; 218 const char *name; 219 enum v4l2_ctrl_type type; 220 s32 min; 221 s32 max; 222 u32 step; 223 s32 def; 224 u32 flags; 225 u32 menu_skip_mask; 226 const char * const *qmenu; 227 unsigned int is_private:1; 228 unsigned int is_volatile:1; 229 }; 230 231 /** v4l2_ctrl_fill() - Fill in the control fields based on the control ID. 232 * 233 * This works for all standard V4L2 controls. 234 * For non-standard controls it will only fill in the given arguments 235 * and @name will be NULL. 236 * 237 * This function will overwrite the contents of @name, @type and @flags. 238 * The contents of @min, @max, @step and @def may be modified depending on 239 * the type. 240 * 241 * Do not use in drivers! It is used internally for backwards compatibility 242 * control handling only. Once all drivers are converted to use the new 243 * control framework this function will no longer be exported. 244 */ 245 void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, 246 s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags); 247 248 249 /** v4l2_ctrl_handler_init() - Initialize the control handler. 250 * @hdl: The control handler. 251 * @nr_of_controls_hint: A hint of how many controls this handler is 252 * expected to refer to. This is the total number, so including 253 * any inherited controls. It doesn't have to be precise, but if 254 * it is way off, then you either waste memory (too many buckets 255 * are allocated) or the control lookup becomes slower (not enough 256 * buckets are allocated, so there are more slow list lookups). 257 * It will always work, though. 258 * 259 * Returns an error if the buckets could not be allocated. This error will 260 * also be stored in @hdl->error. 261 */ 262 int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl, 263 unsigned nr_of_controls_hint); 264 265 /** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free 266 * the control list. 267 * @hdl: The control handler. 268 * 269 * Does nothing if @hdl == NULL. 270 */ 271 void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl); 272 273 /** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging 274 * to the handler to initialize the hardware to the current control values. 275 * @hdl: The control handler. 276 * 277 * Button controls will be skipped, as are read-only controls. 278 * 279 * If @hdl == NULL, then this just returns 0. 280 */ 281 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl); 282 283 /** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler. 284 * @hdl: The control handler. 285 * @prefix: The prefix to use when logging the control values. If the 286 * prefix does not end with a space, then ": " will be added 287 * after the prefix. If @prefix == NULL, then no prefix will be 288 * used. 289 * 290 * For use with VIDIOC_LOG_STATUS. 291 * 292 * Does nothing if @hdl == NULL. 293 */ 294 void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, 295 const char *prefix); 296 297 /** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2 298 * control. 299 * @hdl: The control handler. 300 * @cfg: The control's configuration data. 301 * @priv: The control's driver-specific private data. 302 * 303 * If the &v4l2_ctrl struct could not be allocated then NULL is returned 304 * and @hdl->error is set to the error code (if it wasn't set already). 305 */ 306 struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, 307 const struct v4l2_ctrl_config *cfg, void *priv); 308 309 /** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control. 310 * @hdl: The control handler. 311 * @ops: The control ops. 312 * @id: The control ID. 313 * @min: The control's minimum value. 314 * @max: The control's maximum value. 315 * @step: The control's step value 316 * @def: The control's default value. 317 * 318 * If the &v4l2_ctrl struct could not be allocated, or the control 319 * ID is not known, then NULL is returned and @hdl->error is set to the 320 * appropriate error code (if it wasn't set already). 321 * 322 * If @id refers to a menu control, then this function will return NULL. 323 * 324 * Use v4l2_ctrl_new_std_menu() when adding menu controls. 325 */ 326 struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, 327 const struct v4l2_ctrl_ops *ops, 328 u32 id, s32 min, s32 max, u32 step, s32 def); 329 330 /** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control. 331 * @hdl: The control handler. 332 * @ops: The control ops. 333 * @id: The control ID. 334 * @max: The control's maximum value. 335 * @mask: The control's skip mask for menu controls. This makes it 336 * easy to skip menu items that are not valid. If bit X is set, 337 * then menu item X is skipped. Of course, this only works for 338 * menus with <= 32 menu items. There are no menus that come 339 * close to that number, so this is OK. Should we ever need more, 340 * then this will have to be extended to a u64 or a bit array. 341 * @def: The control's default value. 342 * 343 * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value 344 * determines which menu items are to be skipped. 345 * 346 * If @id refers to a non-menu control, then this function will return NULL. 347 */ 348 struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, 349 const struct v4l2_ctrl_ops *ops, 350 u32 id, s32 max, s32 mask, s32 def); 351 352 /** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler. 353 * @hdl: The control handler. 354 * @ctrl: The control to add. 355 * 356 * It will return NULL if it was unable to add the control reference. 357 * If the control already belonged to the handler, then it will do 358 * nothing and just return @ctrl. 359 */ 360 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl, 361 struct v4l2_ctrl *ctrl); 362 363 /** v4l2_ctrl_add_handler() - Add all controls from handler @add to 364 * handler @hdl. 365 * @hdl: The control handler. 366 * @add: The control handler whose controls you want to add to 367 * the @hdl control handler. 368 * 369 * Does nothing if either of the two is a NULL pointer. 370 * In case of an error @hdl->error will be set to the error code (if it 371 * wasn't set already). 372 */ 373 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl, 374 struct v4l2_ctrl_handler *add); 375 376 377 /** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster. 378 * @ncontrols: The number of controls in this cluster. 379 * @controls: The cluster control array of size @ncontrols. 380 */ 381 void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls); 382 383 384 /** v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to 385 * that cluster and set it up for autofoo/foo-type handling. 386 * @ncontrols: The number of controls in this cluster. 387 * @controls: The cluster control array of size @ncontrols. The first control 388 * must be the 'auto' control (e.g. autogain, autoexposure, etc.) 389 * @manual_val: The value for the first control in the cluster that equals the 390 * manual setting. 391 * @set_volatile: If true, then all controls except the first auto control will 392 * have is_volatile set to true. If false, then is_volatile will not 393 * be touched. 394 * 395 * Use for control groups where one control selects some automatic feature and 396 * the other controls are only active whenever the automatic feature is turned 397 * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs 398 * red and blue balance, etc. 399 * 400 * The behavior of such controls is as follows: 401 * 402 * When the autofoo control is set to automatic, then any manual controls 403 * are set to inactive and any reads will call g_volatile_ctrl (if the control 404 * was marked volatile). 405 * 406 * When the autofoo control is set to manual, then any manual controls will 407 * be marked active, and any reads will just return the current value without 408 * going through g_volatile_ctrl. 409 * 410 * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag 411 * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s) 412 * if autofoo is in auto mode. 413 */ 414 void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls, 415 u8 manual_val, bool set_volatile); 416 417 418 /** v4l2_ctrl_find() - Find a control with the given ID. 419 * @hdl: The control handler. 420 * @id: The control ID to find. 421 * 422 * If @hdl == NULL this will return NULL as well. Will lock the handler so 423 * do not use from inside &v4l2_ctrl_ops. 424 */ 425 struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id); 426 427 /** v4l2_ctrl_activate() - Make the control active or inactive. 428 * @ctrl: The control to (de)activate. 429 * @active: True if the control should become active. 430 * 431 * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically. 432 * Does nothing if @ctrl == NULL. 433 * This will usually be called from within the s_ctrl op. 434 * The V4L2_EVENT_CTRL event will be generated afterwards. 435 * 436 * This function assumes that the control handler is locked. 437 */ 438 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); 439 440 /** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed. 441 * @ctrl: The control to (de)activate. 442 * @grabbed: True if the control should become grabbed. 443 * 444 * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically. 445 * Does nothing if @ctrl == NULL. 446 * The V4L2_EVENT_CTRL event will be generated afterwards. 447 * This will usually be called when starting or stopping streaming in the 448 * driver. 449 * 450 * This function assumes that the control handler is not locked and will 451 * take the lock itself. 452 */ 453 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed); 454 455 /** v4l2_ctrl_lock() - Helper function to lock the handler 456 * associated with the control. 457 * @ctrl: The control to lock. 458 */ 459 static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl) 460 { 461 mutex_lock(&ctrl->handler->lock); 462 } 463 464 /** v4l2_ctrl_lock() - Helper function to unlock the handler 465 * associated with the control. 466 * @ctrl: The control to unlock. 467 */ 468 static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl) 469 { 470 mutex_unlock(&ctrl->handler->lock); 471 } 472 473 /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver. 474 * @ctrl: The control. 475 * 476 * This returns the control's value safely by going through the control 477 * framework. This function will lock the control's handler, so it cannot be 478 * used from within the &v4l2_ctrl_ops functions. 479 * 480 * This function is for integer type controls only. 481 */ 482 s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl); 483 484 /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver. 485 * @ctrl: The control. 486 * @val: The new value. 487 * 488 * This set the control's new value safely by going through the control 489 * framework. This function will lock the control's handler, so it cannot be 490 * used from within the &v4l2_ctrl_ops functions. 491 * 492 * This function is for integer type controls only. 493 */ 494 int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val); 495 496 /* Internal helper functions that deal with control events. */ 497 void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl, 498 struct v4l2_subscribed_event *sev); 499 void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl, 500 struct v4l2_subscribed_event *sev); 501 502 /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */ 503 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc); 504 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm); 505 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl); 506 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 507 struct v4l2_control *ctrl); 508 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); 509 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c); 510 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 511 struct v4l2_ext_controls *c); 512 513 /* Helpers for subdevices. If the associated ctrl_handler == NULL then they 514 will all return -EINVAL. */ 515 int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc); 516 int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm); 517 int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 518 int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 519 int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs); 520 int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); 521 int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl); 522 523 #endif 524