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, may be NULL. 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 struct media_device *mdev; 62 struct list_head subdevs; 63 spinlock_t lock; 64 char name[V4L2_DEVICE_NAME_SIZE]; 65 void (*notify)(struct v4l2_subdev *sd, 66 unsigned int notification, void *arg); 67 struct v4l2_ctrl_handler *ctrl_handler; 68 struct v4l2_prio_state prio; 69 struct kref ref; 70 void (*release)(struct v4l2_device *v4l2_dev); 71 }; 72 73 /** 74 * v4l2_device_get - gets a V4L2 device reference 75 * 76 * @v4l2_dev: pointer to struct &v4l2_device 77 * 78 * This is an ancillary routine meant to increment the usage for the 79 * struct &v4l2_device pointed by @v4l2_dev. 80 */ 81 static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) 82 { 83 kref_get(&v4l2_dev->ref); 84 } 85 86 /** 87 * v4l2_device_put - putss a V4L2 device reference 88 * 89 * @v4l2_dev: pointer to struct &v4l2_device 90 * 91 * This is an ancillary routine meant to decrement the usage for the 92 * struct &v4l2_device pointed by @v4l2_dev. 93 */ 94 int v4l2_device_put(struct v4l2_device *v4l2_dev); 95 96 /** 97 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data 98 * point to @v4l2_dev. 99 * 100 * @dev: pointer to struct &device 101 * @v4l2_dev: pointer to struct &v4l2_device 102 * 103 * .. note:: 104 * @dev may be %NULL in rare cases (ISA devices). 105 * In such case the caller must fill in the @v4l2_dev->name field 106 * before calling this function. 107 */ 108 int __must_check v4l2_device_register(struct device *dev, 109 struct v4l2_device *v4l2_dev); 110 111 /** 112 * v4l2_device_set_name - Optional function to initialize the 113 * name field of struct &v4l2_device 114 * 115 * @v4l2_dev: pointer to struct &v4l2_device 116 * @basename: base name for the device name 117 * @instance: pointer to a static atomic_t var with the instance usage for 118 * the device driver. 119 * 120 * v4l2_device_set_name() initializes the name field of struct &v4l2_device 121 * using the driver name and a driver-global atomic_t instance. 122 * 123 * This function will increment the instance counter and returns the 124 * instance value used in the name. 125 * 126 * Example: 127 * 128 * static atomic_t drv_instance = ATOMIC_INIT(0); 129 * 130 * ... 131 * 132 * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance); 133 * 134 * The first time this is called the name field will be set to foo0 and 135 * this function returns 0. If the name ends with a digit (e.g. cx18), 136 * then the name will be set to cx18-0 since cx180 would look really odd. 137 */ 138 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, 139 atomic_t *instance); 140 141 /** 142 * v4l2_device_disconnect - Change V4L2 device state to disconnected. 143 * 144 * @v4l2_dev: pointer to struct v4l2_device 145 * 146 * Should be called when the USB parent disconnects. 147 * Since the parent disappears, this ensures that @v4l2_dev doesn't have 148 * an invalid parent pointer. 149 * 150 * .. note:: This function sets @v4l2_dev->dev to NULL. 151 */ 152 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); 153 154 /** 155 * v4l2_device_unregister - Unregister all sub-devices and any other 156 * resources related to @v4l2_dev. 157 * 158 * @v4l2_dev: pointer to struct v4l2_device 159 */ 160 void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 161 162 /** 163 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device. 164 * 165 * @v4l2_dev: pointer to struct &v4l2_device 166 * @sd: pointer to &struct v4l2_subdev 167 * 168 * While registered, the subdev module is marked as in-use. 169 * 170 * An error is returned if the module is no longer loaded on any attempts 171 * to register it. 172 */ 173 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, 174 struct v4l2_subdev *sd); 175 176 /** 177 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device. 178 * 179 * @sd: pointer to &struct v4l2_subdev 180 * 181 * .. note :: 182 * 183 * Can also be called if the subdev wasn't registered. In such 184 * case, it will do nothing. 185 */ 186 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 187 188 /** 189 * v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs 190 * of the v4l2 device that are marked with 191 * the %V4L2_SUBDEV_FL_HAS_DEVNODE flag. 192 * 193 * @v4l2_dev: pointer to struct v4l2_device 194 */ 195 int __must_check 196 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); 197 198 /** 199 * v4l2_subdev_notify - Sends a notification to v4l2_device. 200 * 201 * @sd: pointer to &struct v4l2_subdev 202 * @notification: type of notification. Please notice that the notification 203 * type is driver-specific. 204 * @arg: arguments for the notification. Those are specific to each 205 * notification type. 206 */ 207 static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, 208 unsigned int notification, void *arg) 209 { 210 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) 211 sd->v4l2_dev->notify(sd, notification, arg); 212 } 213 214 /** 215 * v4l2_device_supports_requests - Test if requests are supported. 216 * 217 * @v4l2_dev: pointer to struct v4l2_device 218 */ 219 static inline bool v4l2_device_supports_requests(struct v4l2_device *v4l2_dev) 220 { 221 return v4l2_dev->mdev && v4l2_dev->mdev->ops && 222 v4l2_dev->mdev->ops->req_queue; 223 } 224 225 /* Helper macros to iterate over all subdevs. */ 226 227 /** 228 * v4l2_device_for_each_subdev - Helper macro that interates over all 229 * sub-devices of a given &v4l2_device. 230 * 231 * @sd: pointer that will be filled by the macro with all 232 * &struct v4l2_subdev pointer used as an iterator by the loop. 233 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 234 * 235 * This macro iterates over all sub-devices owned by the @v4l2_dev device. 236 * It acts as a for loop iterator and executes the next statement with 237 * the @sd variable pointing to each sub-device in turn. 238 */ 239 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 240 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 241 242 /** 243 * __v4l2_device_call_subdevs_p - Calls the specified operation for 244 * all subdevs matching the condition. 245 * 246 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 247 * @sd: pointer that will be filled by the macro with all 248 * &struct v4l2_subdev pointer used as an iterator by the loop. 249 * @cond: condition to be match 250 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 251 * Each element there groups a set of operations functions. 252 * @f: operation function that will be called if @cond matches. 253 * The operation functions are defined in groups, according to 254 * each element at &struct v4l2_subdev_ops. 255 * @args...: arguments for @f. 256 * 257 * Ignore any errors. 258 * 259 * Note: subdevs cannot be added or deleted while walking 260 * the subdevs list. 261 */ 262 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 263 do { \ 264 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 265 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 266 (sd)->ops->o->f((sd) , ##args); \ 267 } while (0) 268 269 /** 270 * __v4l2_device_call_subdevs - Calls the specified operation for 271 * all subdevs matching the condition. 272 * 273 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 274 * @cond: condition to be match 275 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 276 * Each element there groups a set of operations functions. 277 * @f: operation function that will be called if @cond matches. 278 * The operation functions are defined in groups, according to 279 * each element at &struct v4l2_subdev_ops. 280 * @args...: arguments for @f. 281 * 282 * Ignore any errors. 283 * 284 * Note: subdevs cannot be added or deleted while walking 285 * the subdevs list. 286 */ 287 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 288 do { \ 289 struct v4l2_subdev *__sd; \ 290 \ 291 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 292 f , ##args); \ 293 } while (0) 294 295 /** 296 * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for 297 * all subdevs matching the condition. 298 * 299 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 300 * @sd: pointer that will be filled by the macro with all 301 * &struct v4l2_subdev sub-devices associated with @v4l2_dev. 302 * @cond: condition to be match 303 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 304 * Each element there groups a set of operations functions. 305 * @f: operation function that will be called if @cond matches. 306 * The operation functions are defined in groups, according to 307 * each element at &struct v4l2_subdev_ops. 308 * @args...: arguments for @f. 309 * 310 * Return: 311 * 312 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 313 * for any subdevice, then abort and return with that error code, zero 314 * otherwise. 315 * 316 * Note: subdevs cannot be added or deleted while walking 317 * the subdevs list. 318 */ 319 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 320 ({ \ 321 long __err = 0; \ 322 \ 323 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 324 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 325 __err = (sd)->ops->o->f((sd) , ##args); \ 326 if (__err && __err != -ENOIOCTLCMD) \ 327 break; \ 328 } \ 329 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 330 }) 331 332 /** 333 * __v4l2_device_call_subdevs_until_err - Calls the specified operation for 334 * all subdevs matching the condition. 335 * 336 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 337 * @cond: condition to be match 338 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 339 * Each element there groups a set of operations functions. 340 * @f: operation function that will be called if @cond matches. 341 * The operation functions are defined in groups, according to 342 * each element at &struct v4l2_subdev_ops. 343 * @args...: arguments for @f. 344 * 345 * Return: 346 * 347 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 348 * for any subdevice, then abort and return with that error code, 349 * zero otherwise. 350 * 351 * Note: subdevs cannot be added or deleted while walking 352 * the subdevs list. 353 */ 354 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 355 ({ \ 356 struct v4l2_subdev *__sd; \ 357 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 358 f , ##args); \ 359 }) 360 361 /** 362 * v4l2_device_call_all - Calls the specified operation for 363 * all subdevs matching the &v4l2_subdev.grp_id, as assigned 364 * by the bridge driver. 365 * 366 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 367 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 368 * Use 0 to match them all. 369 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 370 * Each element there groups a set of operations functions. 371 * @f: operation function that will be called if @cond matches. 372 * The operation functions are defined in groups, according to 373 * each element at &struct v4l2_subdev_ops. 374 * @args...: arguments for @f. 375 * 376 * Ignore any errors. 377 * 378 * Note: subdevs cannot be added or deleted while walking 379 * the subdevs list. 380 */ 381 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 382 do { \ 383 struct v4l2_subdev *__sd; \ 384 \ 385 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 386 !(grpid) || __sd->grp_id == (grpid), o, f , \ 387 ##args); \ 388 } while (0) 389 390 /** 391 * v4l2_device_call_until_err - Calls the specified operation for 392 * all subdevs matching the &v4l2_subdev.grp_id, as assigned 393 * by the bridge driver, until an error occurs. 394 * 395 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 396 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 397 * Use 0 to match them all. 398 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 399 * Each element there groups a set of operations functions. 400 * @f: operation function that will be called if @cond matches. 401 * The operation functions are defined in groups, according to 402 * each element at &struct v4l2_subdev_ops. 403 * @args...: arguments for @f. 404 * 405 * Return: 406 * 407 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 408 * for any subdevice, then abort and return with that error code, 409 * zero otherwise. 410 * 411 * Note: subdevs cannot be added or deleted while walking 412 * the subdevs list. 413 */ 414 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 415 ({ \ 416 struct v4l2_subdev *__sd; \ 417 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 418 !(grpid) || __sd->grp_id == (grpid), o, f , \ 419 ##args); \ 420 }) 421 422 /** 423 * v4l2_device_mask_call_all - Calls the specified operation for 424 * all subdevices where a group ID matches a specified bitmask. 425 * 426 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 427 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 428 * group ID to be matched. Use 0 to match them all. 429 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 430 * Each element there groups a set of operations functions. 431 * @f: operation function that will be called if @cond matches. 432 * The operation functions are defined in groups, according to 433 * each element at &struct v4l2_subdev_ops. 434 * @args...: arguments for @f. 435 * 436 * Ignore any errors. 437 * 438 * Note: subdevs cannot be added or deleted while walking 439 * the subdevs list. 440 */ 441 #define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \ 442 do { \ 443 struct v4l2_subdev *__sd; \ 444 \ 445 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 446 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 447 ##args); \ 448 } while (0) 449 450 /** 451 * v4l2_device_mask_call_until_err - Calls the specified operation for 452 * all subdevices where a group ID matches a specified bitmask. 453 * 454 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 455 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 456 * group ID to be matched. Use 0 to match them all. 457 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 458 * Each element there groups a set of operations functions. 459 * @f: operation function that will be called if @cond matches. 460 * The operation functions are defined in groups, according to 461 * each element at &struct v4l2_subdev_ops. 462 * @args...: arguments for @f. 463 * 464 * Return: 465 * 466 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 467 * for any subdevice, then abort and return with that error code, 468 * zero otherwise. 469 * 470 * Note: subdevs cannot be added or deleted while walking 471 * the subdevs list. 472 */ 473 #define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \ 474 ({ \ 475 struct v4l2_subdev *__sd; \ 476 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 477 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 478 ##args); \ 479 }) 480 481 482 /** 483 * v4l2_device_has_op - checks if any subdev with matching grpid has a 484 * given ops. 485 * 486 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 487 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 488 * Use 0 to match them all. 489 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 490 * Each element there groups a set of operations functions. 491 * @f: operation function that will be called if @cond matches. 492 * The operation functions are defined in groups, according to 493 * each element at &struct v4l2_subdev_ops. 494 */ 495 #define v4l2_device_has_op(v4l2_dev, grpid, o, f) \ 496 ({ \ 497 struct v4l2_subdev *__sd; \ 498 bool __result = false; \ 499 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 500 if ((grpid) && __sd->grp_id != (grpid)) \ 501 continue; \ 502 if (v4l2_subdev_has_op(__sd, o, f)) { \ 503 __result = true; \ 504 break; \ 505 } \ 506 } \ 507 __result; \ 508 }) 509 510 /** 511 * v4l2_device_mask_has_op - checks if any subdev with matching group 512 * mask has a given ops. 513 * 514 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 515 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 516 * group ID to be matched. Use 0 to match them all. 517 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 518 * Each element there groups a set of operations functions. 519 * @f: operation function that will be called if @cond matches. 520 * The operation functions are defined in groups, according to 521 * each element at &struct v4l2_subdev_ops. 522 */ 523 #define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \ 524 ({ \ 525 struct v4l2_subdev *__sd; \ 526 bool __result = false; \ 527 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 528 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \ 529 continue; \ 530 if (v4l2_subdev_has_op(__sd, o, f)) { \ 531 __result = true; \ 532 break; \ 533 } \ 534 } \ 535 __result; \ 536 }) 537 538 #endif 539