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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
16struct 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 */
45struct 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 */
67static 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 */
80int 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 */
94int __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 */
124int 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 */
138void 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 */
146void 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)
161int __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 */
175void 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 */
187int __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 */
200static inline int __must_check
201v4l2_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 */
219static inline int __must_check
220v4l2_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 */
238static 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 */
250static 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
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/* Each instance of a V4L2 device should create the v4l2_device struct,
29 either stand-alone or embedded in a larger struct.
30
31 It allows easy access to sub-devices (see v4l2-subdev.h) and provides
32 basic V4L2 device-level support.
33 */
34
35#define V4L2_DEVICE_NAME_SIZE (20 + 16)
36
37struct v4l2_ctrl_handler;
38
39struct v4l2_device {
40 /* dev->driver_data points to this struct.
41 Note: dev might be NULL if there is no parent device
42 as is the case with e.g. ISA devices. */
43 struct device *dev;
44#if defined(CONFIG_MEDIA_CONTROLLER)
45 struct media_device *mdev;
46#endif
47 /* used to keep track of the registered subdevs */
48 struct list_head subdevs;
49 /* lock this struct; can be used by the driver as well if this
50 struct is embedded into a larger struct. */
51 spinlock_t lock;
52 /* unique device name, by default the driver name + bus ID */
53 char name[V4L2_DEVICE_NAME_SIZE];
54 /* notify callback called by some sub-devices. */
55 void (*notify)(struct v4l2_subdev *sd,
56 unsigned int notification, void *arg);
57 /* The control handler. May be NULL. */
58 struct v4l2_ctrl_handler *ctrl_handler;
59 /* Device's priority state */
60 struct v4l2_prio_state prio;
61 /* BKL replacement mutex. Temporary solution only. */
62 struct mutex ioctl_lock;
63 /* Keep track of the references to this struct. */
64 struct kref ref;
65 /* Release function that is called when the ref count goes to 0. */
66 void (*release)(struct v4l2_device *v4l2_dev);
67};
68
69static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
70{
71 kref_get(&v4l2_dev->ref);
72}
73
74int v4l2_device_put(struct v4l2_device *v4l2_dev);
75
76/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
77 dev may be NULL in rare cases (ISA devices). In that case you
78 must fill in the v4l2_dev->name field before calling this function. */
79int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
80
81/* Optional function to initialize the name field of struct v4l2_device using
82 the driver name and a driver-global atomic_t instance.
83 This function will increment the instance counter and returns the instance
84 value used in the name.
85
86 Example:
87
88 static atomic_t drv_instance = ATOMIC_INIT(0);
89
90 ...
91
92 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance);
93
94 The first time this is called the name field will be set to foo0 and
95 this function returns 0. If the name ends with a digit (e.g. cx18),
96 then the name will be set to cx18-0 since cx180 looks really odd. */
97int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
98 atomic_t *instance);
99
100/* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects.
101 Since the parent disappears this ensures that v4l2_dev doesn't have an
102 invalid parent pointer. */
103void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
104
105/* Unregister all sub-devices and any other resources related to v4l2_dev. */
106void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
107
108/* Register a subdev with a v4l2 device. While registered the subdev module
109 is marked as in-use. An error is returned if the module is no longer
110 loaded when you attempt to register it. */
111int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
112 struct v4l2_subdev *sd);
113/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
114 wasn't registered. In that case it will do nothing. */
115void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
116
117/* Register device nodes for all subdev of the v4l2 device that are marked with
118 * the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
119 */
120int __must_check
121v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
122
123/* Iterate over all subdevs. */
124#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
125 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
126
127/* Call the specified callback for all subdevs matching the condition.
128 Ignore any errors. Note that you cannot add or delete a subdev
129 while walking the subdevs list. */
130#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
131 do { \
132 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
133 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
134 (sd)->ops->o->f((sd) , ##args); \
135 } while (0)
136
137#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
138 do { \
139 struct v4l2_subdev *__sd; \
140 \
141 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
142 f , ##args); \
143 } while (0)
144
145/* Call the specified callback for all subdevs matching the condition.
146 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
147 return with that error code. Note that you cannot add or delete a
148 subdev while walking the subdevs list. */
149#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
150({ \
151 long __err = 0; \
152 \
153 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
154 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
155 __err = (sd)->ops->o->f((sd) , ##args); \
156 if (__err && __err != -ENOIOCTLCMD) \
157 break; \
158 } \
159 (__err == -ENOIOCTLCMD) ? 0 : __err; \
160})
161
162#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
163({ \
164 struct v4l2_subdev *__sd; \
165 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
166 f , ##args); \
167})
168
169/* Call the specified callback for all subdevs matching grp_id (if 0, then
170 match them all). Ignore any errors. Note that you cannot add or delete
171 a subdev while walking the subdevs list. */
172#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
173 do { \
174 struct v4l2_subdev *__sd; \
175 \
176 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
177 !(grpid) || __sd->grp_id == (grpid), o, f , \
178 ##args); \
179 } while (0)
180
181/* Call the specified callback for all subdevs matching grp_id (if 0, then
182 match them all). If the callback returns an error other than 0 or
183 -ENOIOCTLCMD, then return with that error code. Note that you cannot
184 add or delete a subdev while walking the subdevs list. */
185#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
186({ \
187 struct v4l2_subdev *__sd; \
188 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
189 !(grpid) || __sd->grp_id == (grpid), o, f , \
190 ##args); \
191})
192
193#define v4l2_device_has_op(v4l2_dev, o, f) \
194({ \
195 struct v4l2_subdev *__sd; \
196 bool __result = false; \
197 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
198 if (v4l2_subdev_has_op(__sd, o, f)) { \
199 __result = true; \
200 break; \
201 } \
202 } \
203 __result; \
204})
205
206#endif