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