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 /* Helper macros to iterate over all subdevs. */ 215 216 /** 217 * v4l2_device_for_each_subdev - Helper macro that interates over all 218 * sub-devices of a given &v4l2_device. 219 * 220 * @sd: pointer that will be filled by the macro with all 221 * &struct v4l2_subdev pointer used as an iterator by the loop. 222 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 223 * 224 * This macro iterates over all sub-devices owned by the @v4l2_dev device. 225 * It acts as a for loop iterator and executes the next statement with 226 * the @sd variable pointing to each sub-device in turn. 227 */ 228 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ 229 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) 230 231 /** 232 * __v4l2_device_call_subdevs_p - Calls the specified operation for 233 * all subdevs matching the condition. 234 * 235 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 236 * @sd: pointer that will be filled by the macro with all 237 * &struct v4l2_subdev pointer used as an iterator by the loop. 238 * @cond: condition to be match 239 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 240 * Each element there groups a set of operations functions. 241 * @f: operation function that will be called if @cond matches. 242 * The operation functions are defined in groups, according to 243 * each element at &struct v4l2_subdev_ops. 244 * @args...: arguments for @f. 245 * 246 * Ignore any errors. 247 * 248 * Note: subdevs cannot be added or deleted while walking 249 * the subdevs list. 250 */ 251 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ 252 do { \ 253 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ 254 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 255 (sd)->ops->o->f((sd) , ##args); \ 256 } while (0) 257 258 /** 259 * __v4l2_device_call_subdevs - Calls the specified operation for 260 * all subdevs matching the condition. 261 * 262 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 263 * @cond: condition to be match 264 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 265 * Each element there groups a set of operations functions. 266 * @f: operation function that will be called if @cond matches. 267 * The operation functions are defined in groups, according to 268 * each element at &struct v4l2_subdev_ops. 269 * @args...: arguments for @f. 270 * 271 * Ignore any errors. 272 * 273 * Note: subdevs cannot be added or deleted while walking 274 * the subdevs list. 275 */ 276 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ 277 do { \ 278 struct v4l2_subdev *__sd; \ 279 \ 280 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ 281 f , ##args); \ 282 } while (0) 283 284 /** 285 * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for 286 * all subdevs matching the condition. 287 * 288 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 289 * @sd: pointer that will be filled by the macro with all 290 * &struct v4l2_subdev sub-devices associated with @v4l2_dev. 291 * @cond: condition to be match 292 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 293 * Each element there groups a set of operations functions. 294 * @f: operation function that will be called if @cond matches. 295 * The operation functions are defined in groups, according to 296 * each element at &struct v4l2_subdev_ops. 297 * @args...: arguments for @f. 298 * 299 * Return: 300 * 301 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 302 * for any subdevice, then abort and return with that error code, zero 303 * otherwise. 304 * 305 * Note: subdevs cannot be added or deleted while walking 306 * the subdevs list. 307 */ 308 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ 309 ({ \ 310 long __err = 0; \ 311 \ 312 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ 313 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ 314 __err = (sd)->ops->o->f((sd) , ##args); \ 315 if (__err && __err != -ENOIOCTLCMD) \ 316 break; \ 317 } \ 318 (__err == -ENOIOCTLCMD) ? 0 : __err; \ 319 }) 320 321 /** 322 * __v4l2_device_call_subdevs_until_err - Calls the specified operation for 323 * all subdevs matching the condition. 324 * 325 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 326 * @cond: condition to be match 327 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 328 * Each element there groups a set of operations functions. 329 * @f: operation function that will be called if @cond matches. 330 * The operation functions are defined in groups, according to 331 * each element at &struct v4l2_subdev_ops. 332 * @args...: arguments for @f. 333 * 334 * Return: 335 * 336 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 337 * for any subdevice, then abort and return with that error code, 338 * zero otherwise. 339 * 340 * Note: subdevs cannot be added or deleted while walking 341 * the subdevs list. 342 */ 343 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ 344 ({ \ 345 struct v4l2_subdev *__sd; \ 346 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ 347 f , ##args); \ 348 }) 349 350 /** 351 * v4l2_device_call_all - Calls the specified operation for 352 * all subdevs matching the &v4l2_subdev.grp_id, as assigned 353 * by the bridge driver. 354 * 355 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 356 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 357 * Use 0 to match them all. 358 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 359 * Each element there groups a set of operations functions. 360 * @f: operation function that will be called if @cond matches. 361 * The operation functions are defined in groups, according to 362 * each element at &struct v4l2_subdev_ops. 363 * @args...: arguments for @f. 364 * 365 * Ignore any errors. 366 * 367 * Note: subdevs cannot be added or deleted while walking 368 * the subdevs list. 369 */ 370 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ 371 do { \ 372 struct v4l2_subdev *__sd; \ 373 \ 374 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 375 !(grpid) || __sd->grp_id == (grpid), o, f , \ 376 ##args); \ 377 } while (0) 378 379 /** 380 * v4l2_device_call_until_err - Calls the specified operation for 381 * all subdevs matching the &v4l2_subdev.grp_id, as assigned 382 * by the bridge driver, until an error occurs. 383 * 384 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 385 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 386 * Use 0 to match them all. 387 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 388 * Each element there groups a set of operations functions. 389 * @f: operation function that will be called if @cond matches. 390 * The operation functions are defined in groups, according to 391 * each element at &struct v4l2_subdev_ops. 392 * @args...: arguments for @f. 393 * 394 * Return: 395 * 396 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 397 * for any subdevice, then abort and return with that error code, 398 * zero otherwise. 399 * 400 * Note: subdevs cannot be added or deleted while walking 401 * the subdevs list. 402 */ 403 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ 404 ({ \ 405 struct v4l2_subdev *__sd; \ 406 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 407 !(grpid) || __sd->grp_id == (grpid), o, f , \ 408 ##args); \ 409 }) 410 411 /** 412 * v4l2_device_mask_call_all - Calls the specified operation for 413 * all subdevices where a group ID matches a specified bitmask. 414 * 415 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 416 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 417 * group ID to be matched. Use 0 to match them all. 418 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 419 * Each element there groups a set of operations functions. 420 * @f: operation function that will be called if @cond matches. 421 * The operation functions are defined in groups, according to 422 * each element at &struct v4l2_subdev_ops. 423 * @args...: arguments for @f. 424 * 425 * Ignore any errors. 426 * 427 * Note: subdevs cannot be added or deleted while walking 428 * the subdevs list. 429 */ 430 #define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \ 431 do { \ 432 struct v4l2_subdev *__sd; \ 433 \ 434 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ 435 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 436 ##args); \ 437 } while (0) 438 439 /** 440 * v4l2_device_mask_call_until_err - Calls the specified operation for 441 * all subdevices where a group ID matches a specified bitmask. 442 * 443 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 444 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 445 * group ID to be matched. Use 0 to match them all. 446 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 447 * Each element there groups a set of operations functions. 448 * @f: operation function that will be called if @cond matches. 449 * The operation functions are defined in groups, according to 450 * each element at &struct v4l2_subdev_ops. 451 * @args...: arguments for @f. 452 * 453 * Return: 454 * 455 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` 456 * for any subdevice, then abort and return with that error code, 457 * zero otherwise. 458 * 459 * Note: subdevs cannot be added or deleted while walking 460 * the subdevs list. 461 */ 462 #define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \ 463 ({ \ 464 struct v4l2_subdev *__sd; \ 465 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ 466 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ 467 ##args); \ 468 }) 469 470 471 /** 472 * v4l2_device_has_op - checks if any subdev with matching grpid has a 473 * given ops. 474 * 475 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 476 * @grpid: &struct v4l2_subdev->grp_id group ID to match. 477 * Use 0 to match them all. 478 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 479 * Each element there groups a set of operations functions. 480 * @f: operation function that will be called if @cond matches. 481 * The operation functions are defined in groups, according to 482 * each element at &struct v4l2_subdev_ops. 483 */ 484 #define v4l2_device_has_op(v4l2_dev, grpid, o, f) \ 485 ({ \ 486 struct v4l2_subdev *__sd; \ 487 bool __result = false; \ 488 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 489 if ((grpid) && __sd->grp_id != (grpid)) \ 490 continue; \ 491 if (v4l2_subdev_has_op(__sd, o, f)) { \ 492 __result = true; \ 493 break; \ 494 } \ 495 } \ 496 __result; \ 497 }) 498 499 /** 500 * v4l2_device_mask_has_op - checks if any subdev with matching group 501 * mask has a given ops. 502 * 503 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. 504 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id 505 * group ID to be matched. Use 0 to match them all. 506 * @o: name of the element at &struct v4l2_subdev_ops that contains @f. 507 * Each element there groups a set of operations functions. 508 * @f: operation function that will be called if @cond matches. 509 * The operation functions are defined in groups, according to 510 * each element at &struct v4l2_subdev_ops. 511 */ 512 #define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \ 513 ({ \ 514 struct v4l2_subdev *__sd; \ 515 bool __result = false; \ 516 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ 517 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \ 518 continue; \ 519 if (v4l2_subdev_has_op(__sd, o, f)) { \ 520 __result = true; \ 521 break; \ 522 } \ 523 } \ 524 __result; \ 525 }) 526 527 #endif 528