1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 V4L2 device support header.
4
5 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
6
7 */
8
9 #ifndef _V4L2_DEVICE_H
10 #define _V4L2_DEVICE_H
11
12 #include <media/media-device.h>
13 #include <media/v4l2-subdev.h>
14 #include <media/v4l2-dev.h>
15
16 struct v4l2_ctrl_handler;
17
18 /**
19 * struct v4l2_device - main struct to for V4L2 device drivers
20 *
21 * @dev: pointer to struct device.
22 * @mdev: pointer to struct media_device, may be NULL.
23 * @subdevs: used to keep track of the registered subdevs
24 * @lock: lock this struct; can be used by the driver as well
25 * if this struct is embedded into a larger struct.
26 * @name: unique device name, by default the driver name + bus ID
27 * @notify: notify operation called by some sub-devices.
28 * @ctrl_handler: The control handler. May be %NULL.
29 * @prio: Device's priority state
30 * @ref: Keep track of the references to this struct.
31 * @release: Release function that is called when the ref count
32 * goes to 0.
33 *
34 * Each instance of a V4L2 device should create the v4l2_device struct,
35 * either stand-alone or embedded in a larger struct.
36 *
37 * It allows easy access to sub-devices (see v4l2-subdev.h) and provides
38 * basic V4L2 device-level support.
39 *
40 * .. note::
41 *
42 * #) @dev->driver_data points to this struct.
43 * #) @dev might be %NULL if there is no parent device
44 */
45 struct v4l2_device {
46 struct device *dev;
47 struct media_device *mdev;
48 struct list_head subdevs;
49 spinlock_t lock;
50 char name[36];
51 void (*notify)(struct v4l2_subdev *sd,
52 unsigned int notification, void *arg);
53 struct v4l2_ctrl_handler *ctrl_handler;
54 struct v4l2_prio_state prio;
55 struct kref ref;
56 void (*release)(struct v4l2_device *v4l2_dev);
57 };
58
59 /**
60 * v4l2_device_get - gets a V4L2 device reference
61 *
62 * @v4l2_dev: pointer to struct &v4l2_device
63 *
64 * This is an ancillary routine meant to increment the usage for the
65 * struct &v4l2_device pointed by @v4l2_dev.
66 */
67 static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
68 {
69 kref_get(&v4l2_dev->ref);
70 }
71
72 /**
73 * v4l2_device_put - puts a V4L2 device reference
74 *
75 * @v4l2_dev: pointer to struct &v4l2_device
76 *
77 * This is an ancillary routine meant to decrement the usage for the
78 * struct &v4l2_device pointed by @v4l2_dev.
79 */
80 int v4l2_device_put(struct v4l2_device *v4l2_dev);
81
82 /**
83 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data
84 * point to @v4l2_dev.
85 *
86 * @dev: pointer to struct &device
87 * @v4l2_dev: pointer to struct &v4l2_device
88 *
89 * .. note::
90 * @dev may be %NULL in rare cases (ISA devices).
91 * In such case the caller must fill in the @v4l2_dev->name field
92 * before calling this function.
93 */
94 int __must_check v4l2_device_register(struct device *dev,
95 struct v4l2_device *v4l2_dev);
96
97 /**
98 * v4l2_device_set_name - Optional function to initialize the
99 * name field of struct &v4l2_device
100 *
101 * @v4l2_dev: pointer to struct &v4l2_device
102 * @basename: base name for the device name
103 * @instance: pointer to a static atomic_t var with the instance usage for
104 * the device driver.
105 *
106 * v4l2_device_set_name() initializes the name field of struct &v4l2_device
107 * using the driver name and a driver-global atomic_t instance.
108 *
109 * This function will increment the instance counter and returns the
110 * instance value used in the name.
111 *
112 * Example:
113 *
114 * static atomic_t drv_instance = ATOMIC_INIT(0);
115 *
116 * ...
117 *
118 * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance);
119 *
120 * The first time this is called the name field will be set to foo0 and
121 * this function returns 0. If the name ends with a digit (e.g. cx18),
122 * then the name will be set to cx18-0 since cx180 would look really odd.
123 */
124 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
125 atomic_t *instance);
126
127 /**
128 * v4l2_device_disconnect - Change V4L2 device state to disconnected.
129 *
130 * @v4l2_dev: pointer to struct v4l2_device
131 *
132 * Should be called when the USB parent disconnects.
133 * Since the parent disappears, this ensures that @v4l2_dev doesn't have
134 * an invalid parent pointer.
135 *
136 * .. note:: This function sets @v4l2_dev->dev to NULL.
137 */
138 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
139
140 /**
141 * v4l2_device_unregister - Unregister all sub-devices and any other
142 * resources related to @v4l2_dev.
143 *
144 * @v4l2_dev: pointer to struct v4l2_device
145 */
146 void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
147
148 /**
149 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device.
150 *
151 * @v4l2_dev: pointer to struct &v4l2_device
152 * @sd: pointer to &struct v4l2_subdev
153 *
154 * While registered, the subdev module is marked as in-use.
155 *
156 * An error is returned if the module is no longer loaded on any attempts
157 * to register it.
158 */
159 #define v4l2_device_register_subdev(v4l2_dev, sd) \
160 __v4l2_device_register_subdev(v4l2_dev, sd, THIS_MODULE)
161 int __must_check __v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
162 struct v4l2_subdev *sd,
163 struct module *module);
164
165 /**
166 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device.
167 *
168 * @sd: pointer to &struct v4l2_subdev
169 *
170 * .. note ::
171 *
172 * Can also be called if the subdev wasn't registered. In such
173 * case, it will do nothing.
174 */
175 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
176
177 /**
178 * __v4l2_device_register_subdev_nodes - Registers device nodes for
179 * all subdevs of the v4l2 device that are marked with the
180 * %V4L2_SUBDEV_FL_HAS_DEVNODE flag.
181 *
182 * @v4l2_dev: pointer to struct v4l2_device
183 * @read_only: subdevices read-only flag. True to register the subdevices
184 * device nodes in read-only mode, false to allow full access to the
185 * subdevice userspace API.
186 */
187 int __must_check
188 __v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev,
189 bool read_only);
190
191 /**
192 * v4l2_device_register_subdev_nodes - Registers subdevices device nodes with
193 * unrestricted access to the subdevice userspace operations
194 *
195 * Internally calls __v4l2_device_register_subdev_nodes(). See its documentation
196 * for more details.
197 *
198 * @v4l2_dev: pointer to struct v4l2_device
199 */
200 static inline int __must_check
201 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
202 {
203 #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
204 return __v4l2_device_register_subdev_nodes(v4l2_dev, false);
205 #else
206 return 0;
207 #endif
208 }
209
210 /**
211 * v4l2_device_register_ro_subdev_nodes - Registers subdevices device nodes
212 * in read-only mode
213 *
214 * Internally calls __v4l2_device_register_subdev_nodes(). See its documentation
215 * for more details.
216 *
217 * @v4l2_dev: pointer to struct v4l2_device
218 */
219 static inline int __must_check
220 v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev)
221 {
222 #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
223 return __v4l2_device_register_subdev_nodes(v4l2_dev, true);
224 #else
225 return 0;
226 #endif
227 }
228
229 /**
230 * v4l2_subdev_notify - Sends a notification to v4l2_device.
231 *
232 * @sd: pointer to &struct v4l2_subdev
233 * @notification: type of notification. Please notice that the notification
234 * type is driver-specific.
235 * @arg: arguments for the notification. Those are specific to each
236 * notification type.
237 */
238 static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
239 unsigned int notification, void *arg)
240 {
241 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify)
242 sd->v4l2_dev->notify(sd, notification, arg);
243 }
244
245 /**
246 * v4l2_device_supports_requests - Test if requests are supported.
247 *
248 * @v4l2_dev: pointer to struct v4l2_device
249 */
250 static inline bool v4l2_device_supports_requests(struct v4l2_device *v4l2_dev)
251 {
252 return v4l2_dev->mdev && v4l2_dev->mdev->ops &&
253 v4l2_dev->mdev->ops->req_queue;
254 }
255
256 /* Helper macros to iterate over all subdevs. */
257
258 /**
259 * v4l2_device_for_each_subdev - Helper macro that interates over all
260 * sub-devices of a given &v4l2_device.
261 *
262 * @sd: pointer that will be filled by the macro with all
263 * &struct v4l2_subdev pointer used as an iterator by the loop.
264 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
265 *
266 * This macro iterates over all sub-devices owned by the @v4l2_dev device.
267 * It acts as a for loop iterator and executes the next statement with
268 * the @sd variable pointing to each sub-device in turn.
269 */
270 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \
271 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
272
273 /**
274 * __v4l2_device_call_subdevs_p - Calls the specified operation for
275 * all subdevs matching the condition.
276 *
277 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
278 * @sd: pointer that will be filled by the macro with all
279 * &struct v4l2_subdev pointer used as an iterator by the loop.
280 * @cond: condition to be match
281 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
282 * Each element there groups a set of operations functions.
283 * @f: operation function that will be called if @cond matches.
284 * The operation functions are defined in groups, according to
285 * each element at &struct v4l2_subdev_ops.
286 * @args: arguments for @f.
287 *
288 * Ignore any errors.
289 *
290 * Note: subdevs cannot be added or deleted while walking
291 * the subdevs list.
292 */
293 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
294 do { \
295 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
296 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
297 (sd)->ops->o->f((sd) , ##args); \
298 } while (0)
299
300 /**
301 * __v4l2_device_call_subdevs - Calls the specified operation for
302 * all subdevs matching the condition.
303 *
304 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
305 * @cond: condition to be match
306 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
307 * Each element there groups a set of operations functions.
308 * @f: operation function that will be called if @cond matches.
309 * The operation functions are defined in groups, according to
310 * each element at &struct v4l2_subdev_ops.
311 * @args: arguments for @f.
312 *
313 * Ignore any errors.
314 *
315 * Note: subdevs cannot be added or deleted while walking
316 * the subdevs list.
317 */
318 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
319 do { \
320 struct v4l2_subdev *__sd; \
321 \
322 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
323 f , ##args); \
324 } while (0)
325
326 /**
327 * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for
328 * all subdevs matching the condition.
329 *
330 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
331 * @sd: pointer that will be filled by the macro with all
332 * &struct v4l2_subdev sub-devices associated with @v4l2_dev.
333 * @cond: condition to be match
334 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
335 * Each element there groups a set of operations functions.
336 * @f: operation function that will be called if @cond matches.
337 * The operation functions are defined in groups, according to
338 * each element at &struct v4l2_subdev_ops.
339 * @args: arguments for @f.
340 *
341 * Return:
342 *
343 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
344 * for any subdevice, then abort and return with that error code, zero
345 * otherwise.
346 *
347 * Note: subdevs cannot be added or deleted while walking
348 * the subdevs list.
349 */
350 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
351 ({ \
352 long __err = 0; \
353 \
354 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
355 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
356 __err = (sd)->ops->o->f((sd) , ##args); \
357 if (__err && __err != -ENOIOCTLCMD) \
358 break; \
359 } \
360 (__err == -ENOIOCTLCMD) ? 0 : __err; \
361 })
362
363 /**
364 * __v4l2_device_call_subdevs_until_err - Calls the specified operation for
365 * all subdevs matching the condition.
366 *
367 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
368 * @cond: condition to be match
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 * Return:
377 *
378 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
379 * for any subdevice, then abort and return with that error code,
380 * zero otherwise.
381 *
382 * Note: subdevs cannot be added or deleted while walking
383 * the subdevs list.
384 */
385 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
386 ({ \
387 struct v4l2_subdev *__sd; \
388 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
389 f , ##args); \
390 })
391
392 /**
393 * v4l2_device_call_all - Calls the specified operation for
394 * all subdevs matching the &v4l2_subdev.grp_id, as assigned
395 * by the bridge driver.
396 *
397 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
398 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
399 * Use 0 to match them all.
400 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
401 * Each element there groups a set of operations functions.
402 * @f: operation function that will be called if @cond matches.
403 * The operation functions are defined in groups, according to
404 * each element at &struct v4l2_subdev_ops.
405 * @args: arguments for @f.
406 *
407 * Ignore any errors.
408 *
409 * Note: subdevs cannot be added or deleted while walking
410 * the subdevs list.
411 */
412 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
413 do { \
414 struct v4l2_subdev *__sd; \
415 \
416 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
417 (grpid) == 0 || __sd->grp_id == (grpid), o, f , \
418 ##args); \
419 } while (0)
420
421 /**
422 * v4l2_device_call_until_err - Calls the specified operation for
423 * all subdevs matching the &v4l2_subdev.grp_id, as assigned
424 * by the bridge driver, until an error occurs.
425 *
426 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
427 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
428 * 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 * Return:
437 *
438 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
439 * for any subdevice, then abort and return with that error code,
440 * zero otherwise.
441 *
442 * Note: subdevs cannot be added or deleted while walking
443 * the subdevs list.
444 */
445 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
446 ({ \
447 struct v4l2_subdev *__sd; \
448 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
449 (grpid) == 0 || __sd->grp_id == (grpid), o, f , \
450 ##args); \
451 })
452
453 /**
454 * v4l2_device_mask_call_all - Calls the specified operation for
455 * all subdevices where a group ID matches a specified bitmask.
456 *
457 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
458 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
459 * group ID to be matched. Use 0 to match them all.
460 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
461 * Each element there groups a set of operations functions.
462 * @f: operation function that will be called if @cond matches.
463 * The operation functions are defined in groups, according to
464 * each element at &struct v4l2_subdev_ops.
465 * @args: arguments for @f.
466 *
467 * Ignore any errors.
468 *
469 * Note: subdevs cannot be added or deleted while walking
470 * the subdevs list.
471 */
472 #define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \
473 do { \
474 struct v4l2_subdev *__sd; \
475 \
476 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
477 (grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \
478 f , ##args); \
479 } while (0)
480
481 /**
482 * v4l2_device_mask_call_until_err - Calls the specified operation for
483 * all subdevices where a group ID matches a specified bitmask.
484 *
485 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
486 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
487 * group ID to be matched. Use 0 to match them all.
488 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
489 * Each element there groups a set of operations functions.
490 * @f: operation function that will be called if @cond matches.
491 * The operation functions are defined in groups, according to
492 * each element at &struct v4l2_subdev_ops.
493 * @args: arguments for @f.
494 *
495 * Return:
496 *
497 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
498 * for any subdevice, then abort and return with that error code,
499 * zero otherwise.
500 *
501 * Note: subdevs cannot be added or deleted while walking
502 * the subdevs list.
503 */
504 #define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \
505 ({ \
506 struct v4l2_subdev *__sd; \
507 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
508 (grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \
509 f , ##args); \
510 })
511
512
513 /**
514 * v4l2_device_has_op - checks if any subdev with matching grpid has a
515 * given ops.
516 *
517 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
518 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
519 * Use 0 to match them all.
520 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
521 * Each element there groups a set of operations functions.
522 * @f: operation function that will be called if @cond matches.
523 * The operation functions are defined in groups, according to
524 * each element at &struct v4l2_subdev_ops.
525 */
526 #define v4l2_device_has_op(v4l2_dev, grpid, o, f) \
527 ({ \
528 struct v4l2_subdev *__sd; \
529 bool __result = false; \
530 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
531 if ((grpid) && __sd->grp_id != (grpid)) \
532 continue; \
533 if (v4l2_subdev_has_op(__sd, o, f)) { \
534 __result = true; \
535 break; \
536 } \
537 } \
538 __result; \
539 })
540
541 /**
542 * v4l2_device_mask_has_op - checks if any subdev with matching group
543 * mask has a given ops.
544 *
545 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
546 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
547 * group ID to be matched. Use 0 to match them all.
548 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
549 * Each element there groups a set of operations functions.
550 * @f: operation function that will be called if @cond matches.
551 * The operation functions are defined in groups, according to
552 * each element at &struct v4l2_subdev_ops.
553 */
554 #define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \
555 ({ \
556 struct v4l2_subdev *__sd; \
557 bool __result = false; \
558 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
559 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \
560 continue; \
561 if (v4l2_subdev_has_op(__sd, o, f)) { \
562 __result = true; \
563 break; \
564 } \
565 } \
566 __result; \
567 })
568
569 #endif
570
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.