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