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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
16#define V4L2_DEVICE_NAME_SIZE (20 + 16)
17
18struct 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 */
47struct 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 */
69static 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 */
82int 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 */
96int __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 */
126int 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 */
140void 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 */
148void 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 */
161int __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 */
174void 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 */
186int __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 */
199static inline int __must_check
200v4l2_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 */
218static inline int __must_check
219v4l2_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 */
237static 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 */
249static 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
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
30struct 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
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 callback 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
60struct v4l2_device {
61 struct device *dev;
62#if defined(CONFIG_MEDIA_CONTROLLER)
63 struct media_device *mdev;
64#endif
65 struct list_head subdevs;
66 spinlock_t lock;
67 char name[V4L2_DEVICE_NAME_SIZE];
68 void (*notify)(struct v4l2_subdev *sd,
69 unsigned int notification, void *arg);
70 struct v4l2_ctrl_handler *ctrl_handler;
71 struct v4l2_prio_state prio;
72 struct kref ref;
73 void (*release)(struct v4l2_device *v4l2_dev);
74};
75
76/**
77 * v4l2_device_get - gets a V4L2 device reference
78 *
79 * @v4l2_dev: pointer to struct &v4l2_device
80 *
81 * This is an ancillary routine meant to increment the usage for the
82 * struct &v4l2_device pointed by @v4l2_dev.
83 */
84static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
85{
86 kref_get(&v4l2_dev->ref);
87}
88
89/**
90 * v4l2_device_put - putss a V4L2 device reference
91 *
92 * @v4l2_dev: pointer to struct &v4l2_device
93 *
94 * This is an ancillary routine meant to decrement the usage for the
95 * struct &v4l2_device pointed by @v4l2_dev.
96 */
97int v4l2_device_put(struct v4l2_device *v4l2_dev);
98
99/**
100 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data
101 * point to @v4l2_dev.
102 *
103 * @dev: pointer to struct &device
104 * @v4l2_dev: pointer to struct &v4l2_device
105 *
106 * .. note::
107 * @dev may be %NULL in rare cases (ISA devices).
108 * In such case the caller must fill in the @v4l2_dev->name field
109 * before calling this function.
110 */
111int __must_check v4l2_device_register(struct device *dev,
112 struct v4l2_device *v4l2_dev);
113
114/**
115 * v4l2_device_set_name - Optional function to initialize the
116 * name field of struct &v4l2_device
117 *
118 * @v4l2_dev: pointer to struct &v4l2_device
119 * @basename: base name for the device name
120 * @instance: pointer to a static atomic_t var with the instance usage for
121 * the device driver.
122 *
123 * v4l2_device_set_name() initializes the name field of struct &v4l2_device
124 * using the driver name and a driver-global atomic_t instance.
125 *
126 * This function will increment the instance counter and returns the
127 * instance value used in the name.
128 *
129 * Example:
130 *
131 * static atomic_t drv_instance = ATOMIC_INIT(0);
132 *
133 * ...
134 *
135 * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance);
136 *
137 * The first time this is called the name field will be set to foo0 and
138 * this function returns 0. If the name ends with a digit (e.g. cx18),
139 * then the name will be set to cx18-0 since cx180 would look really odd.
140 */
141int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
142 atomic_t *instance);
143
144/**
145 * v4l2_device_disconnect - Change V4L2 device state to disconnected.
146 *
147 * @v4l2_dev: pointer to struct v4l2_device
148 *
149 * Should be called when the USB parent disconnects.
150 * Since the parent disappears, this ensures that @v4l2_dev doesn't have
151 * an invalid parent pointer.
152 *
153 * .. note:: This function sets @v4l2_dev->dev to NULL.
154 */
155void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
156
157/**
158 * v4l2_device_unregister - Unregister all sub-devices and any other
159 * resources related to @v4l2_dev.
160 *
161 * @v4l2_dev: pointer to struct v4l2_device
162 */
163void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
164
165/**
166 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device.
167 *
168 * @v4l2_dev: pointer to struct &v4l2_device
169 * @sd: pointer to struct &v4l2_subdev
170 *
171 * While registered, the subdev module is marked as in-use.
172 *
173 * An error is returned if the module is no longer loaded on any attempts
174 * to register it.
175 */
176int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
177 struct v4l2_subdev *sd);
178
179/**
180 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device.
181 *
182 * @sd: pointer to struct &v4l2_subdev
183 *
184 * .. note ::
185 *
186 * Can also be called if the subdev wasn't registered. In such
187 * case, it will do nothing.
188 */
189void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
190
191/**
192 * v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs
193 * of the v4l2 device that are marked with
194 * the %V4L2_SUBDEV_FL_HAS_DEVNODE flag.
195 *
196 * @v4l2_dev: pointer to struct v4l2_device
197 */
198int __must_check
199v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
200
201/**
202 * v4l2_subdev_notify - Sends a notification to v4l2_device.
203 *
204 * @sd: pointer to struct &v4l2_subdev
205 * @notification: type of notification. Please notice that the notification
206 * type is driver-specific.
207 * @arg: arguments for the notification. Those are specific to each
208 * notification type.
209 */
210static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
211 unsigned int notification, void *arg)
212{
213 if (sd && sd->v4l2_dev && sd->v4l2_dev->notify)
214 sd->v4l2_dev->notify(sd, notification, arg);
215}
216
217/* Iterate over all subdevs. */
218#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
219 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
220
221/* Call the specified callback for all subdevs matching the condition.
222 Ignore any errors. Note that you cannot add or delete a subdev
223 while walking the subdevs list. */
224#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
225 do { \
226 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
227 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
228 (sd)->ops->o->f((sd) , ##args); \
229 } while (0)
230
231#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
232 do { \
233 struct v4l2_subdev *__sd; \
234 \
235 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
236 f , ##args); \
237 } while (0)
238
239/* Call the specified callback for all subdevs matching the condition.
240 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
241 return with that error code. Note that you cannot add or delete a
242 subdev while walking the subdevs list. */
243#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
244({ \
245 long __err = 0; \
246 \
247 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
248 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
249 __err = (sd)->ops->o->f((sd) , ##args); \
250 if (__err && __err != -ENOIOCTLCMD) \
251 break; \
252 } \
253 (__err == -ENOIOCTLCMD) ? 0 : __err; \
254})
255
256#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
257({ \
258 struct v4l2_subdev *__sd; \
259 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
260 f , ##args); \
261})
262
263/* Call the specified callback for all subdevs matching grp_id (if 0, then
264 match them all). Ignore any errors. Note that you cannot add or delete
265 a subdev while walking the subdevs list. */
266#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
267 do { \
268 struct v4l2_subdev *__sd; \
269 \
270 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
271 !(grpid) || __sd->grp_id == (grpid), o, f , \
272 ##args); \
273 } while (0)
274
275/* Call the specified callback for all subdevs matching grp_id (if 0, then
276 match them all). If the callback returns an error other than 0 or
277 -ENOIOCTLCMD, then return with that error code. Note that you cannot
278 add or delete a subdev while walking the subdevs list. */
279#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
280({ \
281 struct v4l2_subdev *__sd; \
282 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
283 !(grpid) || __sd->grp_id == (grpid), o, f , \
284 ##args); \
285})
286
287/*
288 * Call the specified callback for all subdevs where grp_id & grpmsk != 0
289 * (if grpmsk == `0, then match them all). Ignore any errors. Note that you
290 * cannot add or delete a subdev while walking the subdevs list.
291 */
292#define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \
293 do { \
294 struct v4l2_subdev *__sd; \
295 \
296 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
297 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \
298 ##args); \
299 } while (0)
300
301/*
302 * Call the specified callback for all subdevs where grp_id & grpmsk != 0
303 * (if grpmsk == 0, then match them all). If the callback returns an error
304 * other than 0 or %-ENOIOCTLCMD, then return with that error code. Note that
305 * you cannot add or delete a subdev while walking the subdevs list.
306 */
307#define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \
308({ \
309 struct v4l2_subdev *__sd; \
310 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
311 !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \
312 ##args); \
313})
314
315/*
316 * Does any subdev with matching grpid (or all if grpid == 0) has the given
317 * op?
318 */
319#define v4l2_device_has_op(v4l2_dev, grpid, o, f) \
320({ \
321 struct v4l2_subdev *__sd; \
322 bool __result = false; \
323 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
324 if ((grpid) && __sd->grp_id != (grpid)) \
325 continue; \
326 if (v4l2_subdev_has_op(__sd, o, f)) { \
327 __result = true; \
328 break; \
329 } \
330 } \
331 __result; \
332})
333
334/*
335 * Does any subdev with matching grpmsk (or all if grpmsk == 0) has the given
336 * op?
337 */
338#define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \
339({ \
340 struct v4l2_subdev *__sd; \
341 bool __result = false; \
342 list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
343 if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \
344 continue; \
345 if (v4l2_subdev_has_op(__sd, o, f)) { \
346 __result = true; \
347 break; \
348 } \
349 } \
350 __result; \
351})
352
353#endif