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 #define V4L2_DEVICE_NAME_SIZE (20 + 16)
17
18 struct v4l2_ctrl_handler;
19
20 /**
21 * struct v4l2_device - main struct to for V4L2 device drivers
22 *
23 * @dev: pointer to struct device.
24 * @mdev: pointer to struct media_device, may be NULL.
25 * @subdevs: used to keep track of the registered subdevs
26 * @lock: lock this struct; can be used by the driver as well
27 * if this struct is embedded into a larger struct.
28 * @name: unique device name, by default the driver name + bus ID
29 * @notify: notify operation called by some sub-devices.
30 * @ctrl_handler: The control handler. May be %NULL.
31 * @prio: Device's priority state
32 * @ref: Keep track of the references to this struct.
33 * @release: Release function that is called when the ref count
34 * goes to 0.
35 *
36 * Each instance of a V4L2 device should create the v4l2_device struct,
37 * either stand-alone or embedded in a larger struct.
38 *
39 * It allows easy access to sub-devices (see v4l2-subdev.h) and provides
40 * basic V4L2 device-level support.
41 *
42 * .. note::
43 *
44 * #) @dev->driver_data points to this struct.
45 * #) @dev might be %NULL if there is no parent device
46 */
47 struct v4l2_device {
48 struct device *dev;
49 struct media_device *mdev;
50 struct list_head subdevs;
51 spinlock_t lock;
52 char name[V4L2_DEVICE_NAME_SIZE];
53 void (*notify)(struct v4l2_subdev *sd,
54 unsigned int notification, void *arg);
55 struct v4l2_ctrl_handler *ctrl_handler;
56 struct v4l2_prio_state prio;
57 struct kref ref;
58 void (*release)(struct v4l2_device *v4l2_dev);
59 };
60
61 /**
62 * v4l2_device_get - gets a V4L2 device reference
63 *
64 * @v4l2_dev: pointer to struct &v4l2_device
65 *
66 * This is an ancillary routine meant to increment the usage for the
67 * struct &v4l2_device pointed by @v4l2_dev.
68 */
v4l2_device_get(struct v4l2_device * v4l2_dev)69 static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
70 {
71 kref_get(&v4l2_dev->ref);
72 }
73
74 /**
75 * v4l2_device_put - puts a V4L2 device reference
76 *
77 * @v4l2_dev: pointer to struct &v4l2_device
78 *
79 * This is an ancillary routine meant to decrement the usage for the
80 * struct &v4l2_device pointed by @v4l2_dev.
81 */
82 int v4l2_device_put(struct v4l2_device *v4l2_dev);
83
84 /**
85 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data
86 * point to @v4l2_dev.
87 *
88 * @dev: pointer to struct &device
89 * @v4l2_dev: pointer to struct &v4l2_device
90 *
91 * .. note::
92 * @dev may be %NULL in rare cases (ISA devices).
93 * In such case the caller must fill in the @v4l2_dev->name field
94 * before calling this function.
95 */
96 int __must_check v4l2_device_register(struct device *dev,
97 struct v4l2_device *v4l2_dev);
98
99 /**
100 * v4l2_device_set_name - Optional function to initialize the
101 * name field of struct &v4l2_device
102 *
103 * @v4l2_dev: pointer to struct &v4l2_device
104 * @basename: base name for the device name
105 * @instance: pointer to a static atomic_t var with the instance usage for
106 * the device driver.
107 *
108 * v4l2_device_set_name() initializes the name field of struct &v4l2_device
109 * using the driver name and a driver-global atomic_t instance.
110 *
111 * This function will increment the instance counter and returns the
112 * instance value used in the name.
113 *
114 * Example:
115 *
116 * static atomic_t drv_instance = ATOMIC_INIT(0);
117 *
118 * ...
119 *
120 * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance);
121 *
122 * The first time this is called the name field will be set to foo0 and
123 * this function returns 0. If the name ends with a digit (e.g. cx18),
124 * then the name will be set to cx18-0 since cx180 would look really odd.
125 */
126 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
127 atomic_t *instance);
128
129 /**
130 * v4l2_device_disconnect - Change V4L2 device state to disconnected.
131 *
132 * @v4l2_dev: pointer to struct v4l2_device
133 *
134 * Should be called when the USB parent disconnects.
135 * Since the parent disappears, this ensures that @v4l2_dev doesn't have
136 * an invalid parent pointer.
137 *
138 * .. note:: This function sets @v4l2_dev->dev to NULL.
139 */
140 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
141
142 /**
143 * v4l2_device_unregister - Unregister all sub-devices and any other
144 * resources related to @v4l2_dev.
145 *
146 * @v4l2_dev: pointer to struct v4l2_device
147 */
148 void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
149
150 /**
151 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device.
152 *
153 * @v4l2_dev: pointer to struct &v4l2_device
154 * @sd: pointer to &struct v4l2_subdev
155 *
156 * While registered, the subdev module is marked as in-use.
157 *
158 * An error is returned if the module is no longer loaded on any attempts
159 * to register it.
160 */
161 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
162 struct v4l2_subdev *sd);
163
164 /**
165 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device.
166 *
167 * @sd: pointer to &struct v4l2_subdev
168 *
169 * .. note ::
170 *
171 * Can also be called if the subdev wasn't registered. In such
172 * case, it will do nothing.
173 */
174 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
175
176 /**
177 * __v4l2_device_register_ro_subdev_nodes - Registers device nodes for
178 * all subdevs of the v4l2 device that are marked with the
179 * %V4L2_SUBDEV_FL_HAS_DEVNODE flag.
180 *
181 * @v4l2_dev: pointer to struct v4l2_device
182 * @read_only: subdevices read-only flag. True to register the subdevices
183 * device nodes in read-only mode, false to allow full access to the
184 * subdevice userspace API.
185 */
186 int __must_check
187 __v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev,
188 bool read_only);
189
190 /**
191 * v4l2_device_register_subdev_nodes - Registers subdevices device nodes with
192 * unrestricted access to the subdevice userspace operations
193 *
194 * Internally calls __v4l2_device_register_subdev_nodes(). See its documentation
195 * for more details.
196 *
197 * @v4l2_dev: pointer to struct v4l2_device
198 */
199 static inline int __must_check
v4l2_device_register_subdev_nodes(struct v4l2_device * v4l2_dev)200 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
201 {
202 #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
203 return __v4l2_device_register_subdev_nodes(v4l2_dev, false);
204 #else
205 return 0;
206 #endif
207 }
208
209 /**
210 * v4l2_device_register_ro_subdev_nodes - Registers subdevices device nodes
211 * in read-only mode
212 *
213 * Internally calls __v4l2_device_register_subdev_nodes(). See its documentation
214 * for more details.
215 *
216 * @v4l2_dev: pointer to struct v4l2_device
217 */
218 static inline int __must_check
v4l2_device_register_ro_subdev_nodes(struct v4l2_device * v4l2_dev)219 v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev)
220 {
221 #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
222 return __v4l2_device_register_subdev_nodes(v4l2_dev, true);
223 #else
224 return 0;
225 #endif
226 }
227
228 /**
229 * v4l2_subdev_notify - Sends a notification to v4l2_device.
230 *
231 * @sd: pointer to &struct v4l2_subdev
232 * @notification: type of notification. Please notice that the notification
233 * type is driver-specific.
234 * @arg: arguments for the notification. Those are specific to each
235 * notification type.
236 */
v4l2_subdev_notify(struct v4l2_subdev * sd,unsigned int notification,void * arg)237 static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
238 unsigned int notification, void *arg)
239 {
240 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify)
241 sd->v4l2_dev->notify(sd, notification, arg);
242 }
243
244 /**
245 * v4l2_device_supports_requests - Test if requests are supported.
246 *
247 * @v4l2_dev: pointer to struct v4l2_device
248 */
v4l2_device_supports_requests(struct v4l2_device * v4l2_dev)249 static inline bool v4l2_device_supports_requests(struct v4l2_device *v4l2_dev)
250 {
251 return v4l2_dev->mdev && v4l2_dev->mdev->ops &&
252 v4l2_dev->mdev->ops->req_queue;
253 }
254
255 /* Helper macros to iterate over all subdevs. */
256
257 /**
258 * v4l2_device_for_each_subdev - Helper macro that interates over all
259 * sub-devices of a given &v4l2_device.
260 *
261 * @sd: pointer that will be filled by the macro with all
262 * &struct v4l2_subdev pointer used as an iterator by the loop.
263 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
264 *
265 * This macro iterates over all sub-devices owned by the @v4l2_dev device.
266 * It acts as a for loop iterator and executes the next statement with
267 * the @sd variable pointing to each sub-device in turn.
268 */
269 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \
270 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
271
272 /**
273 * __v4l2_device_call_subdevs_p - Calls the specified operation for
274 * all subdevs matching the condition.
275 *
276 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
277 * @sd: pointer that will be filled by the macro with all
278 * &struct v4l2_subdev pointer used as an iterator by the loop.
279 * @cond: condition to be match
280 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
281 * Each element there groups a set of operations functions.
282 * @f: operation function that will be called if @cond matches.
283 * The operation functions are defined in groups, according to
284 * each element at &struct v4l2_subdev_ops.
285 * @args: arguments for @f.
286 *
287 * Ignore any errors.
288 *
289 * Note: subdevs cannot be added or deleted while walking
290 * the subdevs list.
291 */
292 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
293 do { \
294 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
295 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
296 (sd)->ops->o->f((sd) , ##args); \
297 } while (0)
298
299 /**
300 * __v4l2_device_call_subdevs - Calls the specified operation for
301 * all subdevs matching the condition.
302 *
303 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
304 * @cond: condition to be match
305 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
306 * Each element there groups a set of operations functions.
307 * @f: operation function that will be called if @cond matches.
308 * The operation functions are defined in groups, according to
309 * each element at &struct v4l2_subdev_ops.
310 * @args: arguments for @f.
311 *
312 * Ignore any errors.
313 *
314 * Note: subdevs cannot be added or deleted while walking
315 * the subdevs list.
316 */
317 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
318 do { \
319 struct v4l2_subdev *__sd; \
320 \
321 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
322 f , ##args); \
323 } while (0)
324
325 /**
326 * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for
327 * all subdevs matching the condition.
328 *
329 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
330 * @sd: pointer that will be filled by the macro with all
331 * &struct v4l2_subdev sub-devices associated with @v4l2_dev.
332 * @cond: condition to be match
333 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
334 * Each element there groups a set of operations functions.
335 * @f: operation function that will be called if @cond matches.
336 * The operation functions are defined in groups, according to
337 * each element at &struct v4l2_subdev_ops.
338 * @args: arguments for @f.
339 *
340 * Return:
341 *
342 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
343 * for any subdevice, then abort and return with that error code, zero
344 * otherwise.
345 *
346 * Note: subdevs cannot be added or deleted while walking
347 * the subdevs list.
348 */
349 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
350 ({ \
351 long __err = 0; \
352 \
353 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
354 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
355 __err = (sd)->ops->o->f((sd) , ##args); \
356 if (__err && __err != -ENOIOCTLCMD) \
357 break; \
358 } \
359 (__err == -ENOIOCTLCMD) ? 0 : __err; \
360 })
361
362 /**
363 * __v4l2_device_call_subdevs_until_err - Calls the specified operation for
364 * all subdevs matching the condition.
365 *
366 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
367 * @cond: condition to be match
368 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
369 * Each element there groups a set of operations functions.
370 * @f: operation function that will be called if @cond matches.
371 * The operation functions are defined in groups, according to
372 * each element at &struct v4l2_subdev_ops.
373 * @args: arguments for @f.
374 *
375 * Return:
376 *
377 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
378 * for any subdevice, then abort and return with that error code,
379 * zero otherwise.
380 *
381 * Note: subdevs cannot be added or deleted while walking
382 * the subdevs list.
383 */
384 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
385 ({ \
386 struct v4l2_subdev *__sd; \
387 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
388 f , ##args); \
389 })
390
391 /**
392 * v4l2_device_call_all - Calls the specified operation for
393 * all subdevs matching the &v4l2_subdev.grp_id, as assigned
394 * by the bridge driver.
395 *
396 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
397 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
398 * Use 0 to match them all.
399 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
400 * Each element there groups a set of operations functions.
401 * @f: operation function that will be called if @cond matches.
402 * The operation functions are defined in groups, according to
403 * each element at &struct v4l2_subdev_ops.
404 * @args: arguments for @f.
405 *
406 * Ignore any errors.
407 *
408 * Note: subdevs cannot be added or deleted while walking
409 * the subdevs list.
410 */
411 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
412 do { \
413 struct v4l2_subdev *__sd; \
414 \
415 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
416 (grpid) == 0 || __sd->grp_id == (grpid), o, f , \
417 ##args); \
418 } while (0)
419
420 /**
421 * v4l2_device_call_until_err - Calls the specified operation for
422 * all subdevs matching the &v4l2_subdev.grp_id, as assigned
423 * by the bridge driver, until an error occurs.
424 *
425 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
426 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
427 * Use 0 to match them all.
428 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
429 * Each element there groups a set of operations functions.
430 * @f: operation function that will be called if @cond matches.
431 * The operation functions are defined in groups, according to
432 * each element at &struct v4l2_subdev_ops.
433 * @args: arguments for @f.
434 *
435 * Return:
436 *
437 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
438 * for any subdevice, then abort and return with that error code,
439 * zero otherwise.
440 *
441 * Note: subdevs cannot be added or deleted while walking
442 * the subdevs list.
443 */
444 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
445 ({ \
446 struct v4l2_subdev *__sd; \
447 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
448 (grpid) == 0 || __sd->grp_id == (grpid), o, f , \
449 ##args); \
450 })
451
452 /**
453 * v4l2_device_mask_call_all - Calls the specified operation for
454 * all subdevices where a group ID matches a specified bitmask.
455 *
456 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
457 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
458 * group ID to be matched. Use 0 to match them all.
459 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
460 * Each element there groups a set of operations functions.
461 * @f: operation function that will be called if @cond matches.
462 * The operation functions are defined in groups, according to
463 * each element at &struct v4l2_subdev_ops.
464 * @args: arguments for @f.
465 *
466 * Ignore any errors.
467 *
468 * Note: subdevs cannot be added or deleted while walking
469 * the subdevs list.
470 */
471 #define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \
472 do { \
473 struct v4l2_subdev *__sd; \
474 \
475 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
476 (grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \
477 f , ##args); \
478 } while (0)
479
480 /**
481 * v4l2_device_mask_call_until_err - Calls the specified operation for
482 * all subdevices where a group ID matches a specified bitmask.
483 *
484 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
485 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
486 * group ID to be matched. Use 0 to match them all.
487 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
488 * Each element there groups a set of operations functions.
489 * @f: operation function that will be called if @cond matches.
490 * The operation functions are defined in groups, according to
491 * each element at &struct v4l2_subdev_ops.
492 * @args: arguments for @f.
493 *
494 * Return:
495 *
496 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
497 * for any subdevice, then abort and return with that error code,
498 * zero otherwise.
499 *
500 * Note: subdevs cannot be added or deleted while walking
501 * the subdevs list.
502 */
503 #define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \
504 ({ \
505 struct v4l2_subdev *__sd; \
506 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
507 (grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \
508 f , ##args); \
509 })
510
511
512 /**
513 * v4l2_device_has_op - checks if any subdev with matching grpid has a
514 * given ops.
515 *
516 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
517 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
518 * Use 0 to match them all.
519 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
520 * Each element there groups a set of operations functions.
521 * @f: operation function that will be called if @cond matches.
522 * The operation functions are defined in groups, according to
523 * each element at &struct v4l2_subdev_ops.
524 */
525 #define v4l2_device_has_op(v4l2_dev, grpid, o, f) \
526 ({ \
527 struct v4l2_subdev *__sd; \
528 bool __result = false; \
529 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
530 if ((grpid) && __sd->grp_id != (grpid)) \
531 continue; \
532 if (v4l2_subdev_has_op(__sd, o, f)) { \
533 __result = true; \
534 break; \
535 } \
536 } \
537 __result; \
538 })
539
540 /**
541 * v4l2_device_mask_has_op - checks if any subdev with matching group
542 * mask has a given ops.
543 *
544 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
545 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
546 * group ID to be matched. Use 0 to match them all.
547 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
548 * Each element there groups a set of operations functions.
549 * @f: operation function that will be called if @cond matches.
550 * The operation functions are defined in groups, according to
551 * each element at &struct v4l2_subdev_ops.
552 */
553 #define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \
554 ({ \
555 struct v4l2_subdev *__sd; \
556 bool __result = false; \
557 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
558 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \
559 continue; \
560 if (v4l2_subdev_has_op(__sd, o, f)) { \
561 __result = true; \
562 break; \
563 } \
564 } \
565 __result; \
566 })
567
568 #endif
569