summaryrefslogtreecommitdiff
path: root/include/media/v4l2-device.h
blob: e0b8f2602670de71f3c35d9b863f731adc2e10c9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
    V4L2 device support header.

    Copyright (C) 2008  Hans Verkuil <hverkuil@xs4all.nl>

 */

#ifndef _V4L2_DEVICE_H
#define _V4L2_DEVICE_H

#include <media/media-device.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-dev.h>

#define V4L2_DEVICE_NAME_SIZE (20 + 16)

struct v4l2_ctrl_handler;

/**
 * struct v4l2_device - main struct to for V4L2 device drivers
 *
 * @dev: pointer to struct device.
 * @mdev: pointer to struct media_device, may be NULL.
 * @subdevs: used to keep track of the registered subdevs
 * @lock: lock this struct; can be used by the driver as well
 *	if this struct is embedded into a larger struct.
 * @name: unique device name, by default the driver name + bus ID
 * @notify: notify operation called by some sub-devices.
 * @ctrl_handler: The control handler. May be %NULL.
 * @prio: Device's priority state
 * @ref: Keep track of the references to this struct.
 * @release: Release function that is called when the ref count
 *	goes to 0.
 *
 * Each instance of a V4L2 device should create the v4l2_device struct,
 * either stand-alone or embedded in a larger struct.
 *
 * It allows easy access to sub-devices (see v4l2-subdev.h) and provides
 * basic V4L2 device-level support.
 *
 * .. note::
 *
 *    #) @dev->driver_data points to this struct.
 *    #) @dev might be %NULL if there is no parent device
 */
struct v4l2_device {
	struct device *dev;
	struct media_device *mdev;
	struct list_head subdevs;
	spinlock_t lock;
	char name[V4L2_DEVICE_NAME_SIZE];
	void (*notify)(struct v4l2_subdev *sd,
			unsigned int notification, void *arg);
	struct v4l2_ctrl_handler *ctrl_handler;
	struct v4l2_prio_state prio;
	struct kref ref;
	void (*release)(struct v4l2_device *v4l2_dev);
};

/**
 * v4l2_device_get - gets a V4L2 device reference
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 *
 * This is an ancillary routine meant to increment the usage for the
 * struct &v4l2_device pointed by @v4l2_dev.
 */
static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
{
	kref_get(&v4l2_dev->ref);
}

/**
 * v4l2_device_put - putss a V4L2 device reference
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 *
 * This is an ancillary routine meant to decrement the usage for the
 * struct &v4l2_device pointed by @v4l2_dev.
 */
int v4l2_device_put(struct v4l2_device *v4l2_dev);

/**
 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data
 *	point to @v4l2_dev.
 *
 * @dev: pointer to struct &device
 * @v4l2_dev: pointer to struct &v4l2_device
 *
 * .. note::
 *	@dev may be %NULL in rare cases (ISA devices).
 *	In such case the caller must fill in the @v4l2_dev->name field
 *	before calling this function.
 */
int __must_check v4l2_device_register(struct device *dev,
				      struct v4l2_device *v4l2_dev);

/**
 * v4l2_device_set_name - Optional function to initialize the
 *	name field of struct &v4l2_device
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 * @basename: base name for the device name
 * @instance: pointer to a static atomic_t var with the instance usage for
 *	the device driver.
 *
 * v4l2_device_set_name() initializes the name field of struct &v4l2_device
 * using the driver name and a driver-global atomic_t instance.
 *
 * This function will increment the instance counter and returns the
 * instance value used in the name.
 *
 * Example:
 *
 *   static atomic_t drv_instance = ATOMIC_INIT(0);
 *
 *   ...
 *
 *   instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance);
 *
 * The first time this is called the name field will be set to foo0 and
 * this function returns 0. If the name ends with a digit (e.g. cx18),
 * then the name will be set to cx18-0 since cx180 would look really odd.
 */
int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
			 atomic_t *instance);

/**
 * v4l2_device_disconnect - Change V4L2 device state to disconnected.
 *
 * @v4l2_dev: pointer to struct v4l2_device
 *
 * Should be called when the USB parent disconnects.
 * Since the parent disappears, this ensures that @v4l2_dev doesn't have
 * an invalid parent pointer.
 *
 * .. note:: This function sets @v4l2_dev->dev to NULL.
 */
void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);

/**
 *  v4l2_device_unregister - Unregister all sub-devices and any other
 *	 resources related to @v4l2_dev.
 *
 * @v4l2_dev: pointer to struct v4l2_device
 */
void v4l2_device_unregister(struct v4l2_device *v4l2_dev);

/**
 * v4l2_device_register_subdev - Registers a subdev with a v4l2 device.
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 * @sd: pointer to &struct v4l2_subdev
 *
 * While registered, the subdev module is marked as in-use.
 *
 * An error is returned if the module is no longer loaded on any attempts
 * to register it.
 */
int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
					     struct v4l2_subdev *sd);

/**
 * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device.
 *
 * @sd: pointer to &struct v4l2_subdev
 *
 * .. note ::
 *
 *	Can also be called if the subdev wasn't registered. In such
 *	case, it will do nothing.
 */
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);

/**
 * v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs
 *	of the v4l2 device that are marked with
 *	the %V4L2_SUBDEV_FL_HAS_DEVNODE flag.
 *
 * @v4l2_dev: pointer to struct v4l2_device
 */
int __must_check
v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);

/**
 * v4l2_subdev_notify - Sends a notification to v4l2_device.
 *
 * @sd: pointer to &struct v4l2_subdev
 * @notification: type of notification. Please notice that the notification
 *	type is driver-specific.
 * @arg: arguments for the notification. Those are specific to each
 *	notification type.
 */
static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
				      unsigned int notification, void *arg)
{
	if (sd && sd->v4l2_dev && sd->v4l2_dev->notify)
		sd->v4l2_dev->notify(sd, notification, arg);
}

/**
 * v4l2_device_supports_requests - Test if requests are supported.
 *
 * @v4l2_dev: pointer to struct v4l2_device
 */
static inline bool v4l2_device_supports_requests(struct v4l2_device *v4l2_dev)
{
	return v4l2_dev->mdev && v4l2_dev->mdev->ops &&
	       v4l2_dev->mdev->ops->req_queue;
}

/* Helper macros to iterate over all subdevs. */

/**
 * v4l2_device_for_each_subdev - Helper macro that interates over all
 *	sub-devices of a given &v4l2_device.
 *
 * @sd: pointer that will be filled by the macro with all
 *	&struct v4l2_subdev pointer used as an iterator by the loop.
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 *
 * This macro iterates over all sub-devices owned by the @v4l2_dev device.
 * It acts as a for loop iterator and executes the next statement with
 * the @sd variable pointing to each sub-device in turn.
 */
#define v4l2_device_for_each_subdev(sd, v4l2_dev)			\
	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)

/**
 * __v4l2_device_call_subdevs_p - Calls the specified operation for
 *	all subdevs matching the condition.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @sd: pointer that will be filled by the macro with all
 *	&struct v4l2_subdev pointer used as an iterator by the loop.
 * @cond: condition to be match
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Ignore any errors.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...)	\
	do {								\
		list_for_each_entry((sd), &(v4l2_dev)->subdevs, list)	\
			if ((cond) && (sd)->ops->o && (sd)->ops->o->f)	\
				(sd)->ops->o->f((sd) , ##args);		\
	} while (0)

/**
 * __v4l2_device_call_subdevs - Calls the specified operation for
 *	all subdevs matching the condition.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @cond: condition to be match
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Ignore any errors.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...)	\
	do {								\
		struct v4l2_subdev *__sd;				\
									\
		__v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o,	\
						f , ##args);		\
	} while (0)

/**
 * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for
 *	all subdevs matching the condition.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @sd: pointer that will be filled by the macro with all
 *	&struct v4l2_subdev sub-devices associated with @v4l2_dev.
 * @cond: condition to be match
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Return:
 *
 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
 * for any subdevice, then abort and return with that error code, zero
 * otherwise.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
({									\
	long __err = 0;							\
									\
	list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) {		\
		if ((cond) && (sd)->ops->o && (sd)->ops->o->f)		\
			__err = (sd)->ops->o->f((sd) , ##args);		\
		if (__err && __err != -ENOIOCTLCMD)			\
			break;						\
	}								\
	(__err == -ENOIOCTLCMD) ? 0 : __err;				\
})

/**
 * __v4l2_device_call_subdevs_until_err - Calls the specified operation for
 *	all subdevs matching the condition.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @cond: condition to be match
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Return:
 *
 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
 * for any subdevice, then abort and return with that error code,
 * zero otherwise.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
({									\
	struct v4l2_subdev *__sd;					\
	__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o,	\
						f , ##args);		\
})

/**
 * v4l2_device_call_all - Calls the specified operation for
 *	all subdevs matching the &v4l2_subdev.grp_id, as assigned
 *	by the bridge driver.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
 *	    Use 0 to match them all.
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Ignore any errors.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...)		\
	do {								\
		struct v4l2_subdev *__sd;				\
									\
		__v4l2_device_call_subdevs_p(v4l2_dev, __sd,		\
			!(grpid) || __sd->grp_id == (grpid), o, f ,	\
			##args);					\
	} while (0)

/**
 * v4l2_device_call_until_err - Calls the specified operation for
 *	all subdevs matching the &v4l2_subdev.grp_id, as assigned
 *	by the bridge driver, until an error occurs.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
 *	   Use 0 to match them all.
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Return:
 *
 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
 * for any subdevice, then abort and return with that error code,
 * zero otherwise.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...)	\
({									\
	struct v4l2_subdev *__sd;					\
	__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd,		\
			!(grpid) || __sd->grp_id == (grpid), o, f ,	\
			##args);					\
})

/**
 * v4l2_device_mask_call_all - Calls the specified operation for
 *	all subdevices where a group ID matches a specified bitmask.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
 *	    group ID to be matched. Use 0 to match them all.
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Ignore any errors.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...)	\
	do {								\
		struct v4l2_subdev *__sd;				\
									\
		__v4l2_device_call_subdevs_p(v4l2_dev, __sd,		\
			!(grpmsk) || (__sd->grp_id & (grpmsk)), o, f ,	\
			##args);					\
	} while (0)

/**
 * v4l2_device_mask_call_until_err - Calls the specified operation for
 *	all subdevices where a group ID matches a specified bitmask.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
 *	    group ID to be matched. Use 0 to match them all.
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 * @args...: arguments for @f.
 *
 * Return:
 *
 * If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
 * for any subdevice, then abort and return with that error code,
 * zero otherwise.
 *
 * Note: subdevs cannot be added or deleted while walking
 * the subdevs list.
 */
#define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \
({									\
	struct v4l2_subdev *__sd;					\
	__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd,		\
			!(grpmsk) || (__sd->grp_id & (grpmsk)), o, f ,	\
			##args);					\
})


/**
 * v4l2_device_has_op - checks if any subdev with matching grpid has a
 *	given ops.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @grpid: &struct v4l2_subdev->grp_id group ID to match.
 *	   Use 0 to match them all.
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 */
#define v4l2_device_has_op(v4l2_dev, grpid, o, f)			\
({									\
	struct v4l2_subdev *__sd;					\
	bool __result = false;						\
	list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) {		\
		if ((grpid) && __sd->grp_id != (grpid))			\
			continue;					\
		if (v4l2_subdev_has_op(__sd, o, f)) {			\
			__result = true;				\
			break;						\
		}							\
	}								\
	__result;							\
})

/**
 * v4l2_device_mask_has_op - checks if any subdev with matching group
 *	mask has a given ops.
 *
 * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
 * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
 *	    group ID to be matched. Use 0 to match them all.
 * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
 *     Each element there groups a set of operations functions.
 * @f: operation function that will be called if @cond matches.
 *	The operation functions are defined in groups, according to
 *	each element at &struct v4l2_subdev_ops.
 */
#define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f)			\
({									\
	struct v4l2_subdev *__sd;					\
	bool __result = false;						\
	list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) {		\
		if ((grpmsk) && !(__sd->grp_id & (grpmsk)))		\
			continue;					\
		if (v4l2_subdev_has_op(__sd, o, f)) {			\
			__result = true;				\
			break;						\
		}							\
	}								\
	__result;							\
})

#endif