1 /* 2 V4L2 device support header. 3 4 Copyright (C) 2008 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_DEVICE_H 22 #define _V4L2_DEVICE_H 23 24 #include <media/media-device.h> 25 #include <media/v4l2-subdev.h> 26 #include <media/v4l2-dev.h> 27 28 #define V4L2_DEVICE_NAME_SIZE (20 + 16) 29 30 struct v4l2_ctrl_handler; 31 32 /** 33 * struct v4l2_device - main struct to for V4L2 device drivers 34 * 35 * @dev: pointer to struct device. 36 * @mdev: pointer to struct media_device 37 * @subdevs: used to keep track of the registered subdevs 38 * @lock: lock this struct; can be used by the driver as well 39 * if this struct is embedded into a larger struct. 40 * @name: unique device name, by default the driver name + bus ID 41 * @notify: notify operation called by some sub-devices. 42 * @ctrl_handler: The control handler. May be %NULL. 43 * @prio: Device's priority state 44 * @ref: Keep track of the references to this struct. 45 * @release: Release function that is called when the ref count 46 * goes to 0. 47 * 48 * Each instance of a V4L2 device should create the v4l2_device struct, 49 * either stand-alone or embedded in a larger struct. 50 * 51 * It allows easy access to sub-devices (see v4l2-subdev.h) and provides 52 * basic V4L2 device-level support. 53 * 54 * .. note:: 55 * 56 * #) @dev->driver_data points to this struct. 57 * #) @dev might be %NULL if there is no parent device 58 */ 59 struct v4l2_device { 60 struct device *dev; 61 #if defined(CONFIG_MEDIA_CONTROLLER) 62 struct media_device *mdev; 63 #endif 64 struct list_head subdevs; 65 spinlock_t lock; 66 char name[V4L2_DEVICE_NAME_SIZE]; 67 void (*notify)(struct v4l2_subdev *sd, 68 unsigned int notification, void *arg); 69 struct v4l2_ctrl_handler *ctrl_handler; 70 struct v4l2_prio_state prio; 71 struct kref ref; 72 void (*release)(struct v4l2_device *v4l2_dev); 73 }; 74 75 /** 76 * v4l2_device_get - gets a V4L2 device reference 77 * 78 * @v4l2_dev: pointer to struct &v4l2_device 79 * 80 * This is an ancillary routine meant to increment the usage for the 81 * struct &v4l2_device pointed by @v4l2_dev. 82 */ 83 static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) 84 { 85 kref_get(&v4l2_dev->ref); 86 } 87 88 /** 89 * v4l2_device_put - putss a V4L2 device reference 90 * 91 * @v4l2_dev: pointer to struct &v4l2_device 92 * 93 * This is an ancillary routine meant to decrement the usage for the 94 * struct &v4l2_device pointed by @v4l2_dev. 95 */ 96 int v4l2_device_put(struct v4l2_device *v4l2_dev); 97 98 /** 99 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data 100 * point to @v4l2_dev. 101 * 102 * @dev: pointer to struct &device 103 * @v4l2_dev: pointer to struct &v4l2_device 104 * 105 * .. note:: 106 * @dev may be %NULL in rare cases (ISA devices). 107 * In such case the caller must fill in the @v4l2_dev->name field 108 * before calling this function. 109 */ 110 int __must_check v4l2_device_register(struct device *dev, 111 struct v4l2_device *v4l2_dev); 112 113 /** 114 * v4l2_device_set_name - Optional function to initialize the 115 * name field of struct &v4l2_device 116 * 117 * @v4l2_dev: pointer to struct &v4l2_device 118 * @basename: base name for the device name 119 * @instance: pointer to a static atomic_t var with the instance usage for 120 * the device driver. 121 * 122 * v4l2_device_set_name() initializes the name field of struct &v4l2_device 123 * using the driver name and a driver-global atomic_t instance. 124 * 125 * This function will increment the instance counter and returns the 126 * instance value used in the name. 127 * 128 * Example: 129 * 130 * static atomic_t drv_instance = ATOMIC_INIT(0); 131 * 132 * ... 133 * 134 * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance); 135 * 136 * The first time this is called the name field will be set to foo0 and 137 * this function returns 0. If the name ends with a digit (e.g. cx18), 138 * then the name will be set to cx18-0 since cx180 would look really odd. 139 */ 140 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 141 atomic_t *instance); 142 143 /** 144 * v4l2_device_disconnect - Change V4L2 device state to disconnected. 145 * 146 * @v4l2_dev: pointer to struct v4l2_device 147 * 148 * Should be called when the USB parent disconnects. 149 * Since the parent disappears, this ensures that @v4l2_dev doesn't have 150 * an invalid parent pointer. 151 * 152 * .. note:: This function sets @v4l2_dev->dev to NULL. 153 */ 154 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 155 156 /** 157 * v4l2_device_unregister - Unregister all sub-devices and any other 158 * resources related to @v4l2_dev. 159 * 160 * @v4l2_dev: pointer to struct v4l2_device 161 */ 162 void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 163 164 /** 165 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device. 166 * 167 * @v4l2_dev: pointer to struct &v4l2_device 168 * @sd: pointer to &struct v4l2_subdev 169 * 170 * While registered, the subdev module is marked as in-use. 171 * 172 * An error is returned if the module is no longer loaded on any attempts 173 * to register it. 174 */ 175 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 176 struct v4l2_subdev *sd); 177 178 /** 179 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device. 180 * 181 * @sd: pointer to &struct v4l2_subdev 182 * 183 * .. note :: 184 * 185 * Can also be called if the subdev wasn't registered. In such 186 * case, it will do nothing. 187 */ 188 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 189 190 /** 191 * v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs 192 * of the v4l2 device that are marked with 193 * the %V4L2_SUBDEV_FL_HAS_DEVNODE flag. 194 * 195 * @v4l2_dev: pointer to struct v4l2_device 196 */ 197 int __must_check 198 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); 199 200 /** 201 * v4l2_subdev_notify - Sends a notification to v4l2_device. 202 * 203 * @sd: pointer to &struct v4l2_subdev 204 * @notification: type of notification. Please notice that the notification 205 * type is driver-specific. 206 * @arg: arguments for the notification. Those are specific to each 207 * notification type. 208 */ 209 static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, 210 unsigned int notification, void *arg) 211 { 212 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) 213 sd->v4l2_dev->notify(sd, notification, arg); 214 } 215 216 /* Helper macros to iterate over all subdevs. */ 217 218 /** 219 * v4l2_device_for_each_subdev - Helper macro that interates over all 220 * sub-devices of a given &v4l2_device. 221 * 222 * @sd: pointer that will be filled by the macro with all 223 * &struct v4l2_subdev pointer used as an iterator by the loop. 224 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 225 * 226 * This macro iterates over all sub-devices owned by the @v4l2_dev device. 227 * It acts as a for loop iterator and executes the next statement with 228 * the @sd variable pointing to each sub-device in turn. 229 */ 230 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 231 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 232 233 /** 234 * __v4l2_device_call_subdevs_p - Calls the specified operation for 235 * all subdevs matching the condition. 236 * 237 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 238 * @sd: pointer that will be filled by the macro with all 239 * &struct v4l2_subdev pointer used as an iterator by the loop. 240 * @cond: condition to be match 241 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 242 * Each element there groups a set of operations functions. 243 * @f: operation function that will be called if @cond matches. 244 * The operation functions are defined in groups, according to 245 * each element at &struct v4l2_subdev_ops. 246 * @args...: arguments for @f. 247 * 248 * Ignore any errors. 249 * 250 * Note: subdevs cannot be added or deleted while walking 251 * the subdevs list. 252 */ 253 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 254 do { \ 255 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 256 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 257 (sd)->ops->o->f((sd) , ##args); \ 258 } while (0) 259 260 /** 261 * __v4l2_device_call_subdevs - Calls the specified operation for 262 * all subdevs matching the condition. 263 * 264 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 265 * @cond: condition to be match 266 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 267 * Each element there groups a set of operations functions. 268 * @f: operation function that will be called if @cond matches. 269 * The operation functions are defined in groups, according to 270 * each element at &struct v4l2_subdev_ops. 271 * @args...: arguments for @f. 272 * 273 * Ignore any errors. 274 * 275 * Note: subdevs cannot be added or deleted while walking 276 * the subdevs list. 277 */ 278 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 279 do { \ 280 struct v4l2_subdev *__sd; \ 281 \ 282 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 283 f , ##args); \ 284 } while (0) 285 286 /** 287 * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for 288 * all subdevs matching the condition. 289 * 290 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 291 * @sd: pointer that will be filled by the macro with all 292 * &struct v4l2_subdev sub-devices associated with @v4l2_dev. 293 * @cond: condition to be match 294 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 295 * Each element there groups a set of operations functions. 296 * @f: operation function that will be called if @cond matches. 297 * The operation functions are defined in groups, according to 298 * each element at &struct v4l2_subdev_ops. 299 * @args...: arguments for @f. 300 * 301 * Return: 302 * 303 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 304 * for any subdevice, then abort and return with that error code, zero 305 * otherwise. 306 * 307 * Note: subdevs cannot be added or deleted while walking 308 * the subdevs list. 309 */ 310 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 311 ({ \ 312 long __err = 0; \ 313 \ 314 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 315 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 316 __err = (sd)->ops->o->f((sd) , ##args); \ 317 if (__err && __err != -ENOIOCTLCMD) \ 318 break; \ 319 } \ 320 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 321 }) 322 323 /** 324 * __v4l2_device_call_subdevs_until_err - Calls the specified operation for 325 * all subdevs matching the condition. 326 * 327 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 328 * @cond: condition to be match 329 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 330 * Each element there groups a set of operations functions. 331 * @f: operation function that will be called if @cond matches. 332 * The operation functions are defined in groups, according to 333 * each element at &struct v4l2_subdev_ops. 334 * @args...: arguments for @f. 335 * 336 * Return: 337 * 338 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 339 * for any subdevice, then abort and return with that error code, 340 * zero otherwise. 341 * 342 * Note: subdevs cannot be added or deleted while walking 343 * the subdevs list. 344 */ 345 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 346 ({ \ 347 struct v4l2_subdev *__sd; \ 348 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 349 f , ##args); \ 350 }) 351 352 /** 353 * v4l2_device_call_all - Calls the specified operation for 354 * all subdevs matching the &v4l2_subdev.grp_id, as assigned 355 * by the bridge driver. 356 * 357 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 358 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 359 * Use 0 to match them all. 360 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 361 * Each element there groups a set of operations functions. 362 * @f: operation function that will be called if @cond matches. 363 * The operation functions are defined in groups, according to 364 * each element at &struct v4l2_subdev_ops. 365 * @args...: arguments for @f. 366 * 367 * Ignore any errors. 368 * 369 * Note: subdevs cannot be added or deleted while walking 370 * the subdevs list. 371 */ 372 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 373 do { \ 374 struct v4l2_subdev *__sd; \ 375 \ 376 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 377 !(grpid) || __sd->grp_id == (grpid), o, f , \ 378 ##args); \ 379 } while (0) 380 381 /** 382 * v4l2_device_call_until_err - Calls the specified operation for 383 * all subdevs matching the &v4l2_subdev.grp_id, as assigned 384 * by the bridge driver, until an error occurs. 385 * 386 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 387 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 388 * Use 0 to match them all. 389 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 390 * Each element there groups a set of operations functions. 391 * @f: operation function that will be called if @cond matches. 392 * The operation functions are defined in groups, according to 393 * each element at &struct v4l2_subdev_ops. 394 * @args...: arguments for @f. 395 * 396 * Return: 397 * 398 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 399 * for any subdevice, then abort and return with that error code, 400 * zero otherwise. 401 * 402 * Note: subdevs cannot be added or deleted while walking 403 * the subdevs list. 404 */ 405 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 406 ({ \ 407 struct v4l2_subdev *__sd; \ 408 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 409 !(grpid) || __sd->grp_id == (grpid), o, f , \ 410 ##args); \ 411 }) 412 413 /** 414 * v4l2_device_mask_call_all - Calls the specified operation for 415 * all subdevices where a group ID matches a specified bitmask. 416 * 417 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 418 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 419 * group ID to be matched. Use 0 to match them all. 420 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 421 * Each element there groups a set of operations functions. 422 * @f: operation function that will be called if @cond matches. 423 * The operation functions are defined in groups, according to 424 * each element at &struct v4l2_subdev_ops. 425 * @args...: arguments for @f. 426 * 427 * Ignore any errors. 428 * 429 * Note: subdevs cannot be added or deleted while walking 430 * the subdevs list. 431 */ 432 #define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \ 433 do { \ 434 struct v4l2_subdev *__sd; \ 435 \ 436 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 437 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 438 ##args); \ 439 } while (0) 440 441 /** 442 * v4l2_device_mask_call_until_err - Calls the specified operation for 443 * all subdevices where a group ID matches a specified bitmask. 444 * 445 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 446 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 447 * group ID to be matched. Use 0 to match them all. 448 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 449 * Each element there groups a set of operations functions. 450 * @f: operation function that will be called if @cond matches. 451 * The operation functions are defined in groups, according to 452 * each element at &struct v4l2_subdev_ops. 453 * @args...: arguments for @f. 454 * 455 * Return: 456 * 457 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 458 * for any subdevice, then abort and return with that error code, 459 * zero otherwise. 460 * 461 * Note: subdevs cannot be added or deleted while walking 462 * the subdevs list. 463 */ 464 #define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \ 465 ({ \ 466 struct v4l2_subdev *__sd; \ 467 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 468 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 469 ##args); \ 470 }) 471 472 473 /** 474 * v4l2_device_has_op - checks if any subdev with matching grpid has a 475 * given ops. 476 * 477 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 478 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 479 * Use 0 to match them all. 480 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 481 * Each element there groups a set of operations functions. 482 * @f: operation function that will be called if @cond matches. 483 * The operation functions are defined in groups, according to 484 * each element at &struct v4l2_subdev_ops. 485 */ 486 #define v4l2_device_has_op(v4l2_dev, grpid, o, f) \ 487 ({ \ 488 struct v4l2_subdev *__sd; \ 489 bool __result = false; \ 490 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 491 if ((grpid) && __sd->grp_id != (grpid)) \ 492 continue; \ 493 if (v4l2_subdev_has_op(__sd, o, f)) { \ 494 __result = true; \ 495 break; \ 496 } \ 497 } \ 498 __result; \ 499 }) 500 501 /** 502 * v4l2_device_mask_has_op - checks if any subdev with matching group 503 * mask has a given ops. 504 * 505 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 506 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 507 * group ID to be matched. Use 0 to match them all. 508 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 509 * Each element there groups a set of operations functions. 510 * @f: operation function that will be called if @cond matches. 511 * The operation functions are defined in groups, according to 512 * each element at &struct v4l2_subdev_ops. 513 */ 514 #define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \ 515 ({ \ 516 struct v4l2_subdev *__sd; \ 517 bool __result = false; \ 518 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 519 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \ 520 continue; \ 521 if (v4l2_subdev_has_op(__sd, o, f)) { \ 522 __result = true; \ 523 break; \ 524 } \ 525 } \ 526 __result; \ 527 }) 528 529 #endif 530