1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 *
4 * V 4 L 2 D R I V E R H E L P E R A P I
5 *
6 * Moved from videodev2.h
7 *
8 * Some commonly needed functions for drivers (v4l2-common.o module)
9 */
10 #ifndef _V4L2_DEV_H
11 #define _V4L2_DEV_H
12
13 #include <linux/poll.h>
14 #include <linux/fs.h>
15 #include <linux/device.h>
16 #include <linux/cdev.h>
17 #include <linux/mutex.h>
18 #include <linux/videodev2.h>
19
20 #include <media/media-entity.h>
21
22 #define VIDEO_MAJOR 81
23
24 /**
25 * enum vfl_devnode_type - type of V4L2 device node
26 *
27 * @VFL_TYPE_VIDEO: for video input/output devices
28 * @VFL_TYPE_VBI: for vertical blank data (i.e. closed captions, teletext)
29 * @VFL_TYPE_RADIO: for radio tuners
30 * @VFL_TYPE_SUBDEV: for V4L2 subdevices
31 * @VFL_TYPE_SDR: for Software Defined Radio tuners
32 * @VFL_TYPE_TOUCH: for touch sensors
33 * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum
34 */
35 enum vfl_devnode_type {
36 VFL_TYPE_VIDEO,
37 VFL_TYPE_VBI,
38 VFL_TYPE_RADIO,
39 VFL_TYPE_SUBDEV,
40 VFL_TYPE_SDR,
41 VFL_TYPE_TOUCH,
42 VFL_TYPE_MAX /* Shall be the last one */
43 };
44
45 /**
46 * enum vfl_devnode_direction - Identifies if a &struct video_device
47 * corresponds to a receiver, a transmitter or a mem-to-mem device.
48 *
49 * @VFL_DIR_RX: device is a receiver.
50 * @VFL_DIR_TX: device is a transmitter.
51 * @VFL_DIR_M2M: device is a memory to memory device.
52 *
53 * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV.
54 */
55 enum vfl_devnode_direction {
56 VFL_DIR_RX,
57 VFL_DIR_TX,
58 VFL_DIR_M2M,
59 };
60
61 struct v4l2_ioctl_callbacks;
62 struct video_device;
63 struct v4l2_device;
64 struct v4l2_ctrl_handler;
65
66 /**
67 * enum v4l2_video_device_flags - Flags used by &struct video_device
68 *
69 * @V4L2_FL_REGISTERED:
70 * indicates that a &struct video_device is registered.
71 * Drivers can clear this flag if they want to block all future
72 * device access. It is cleared by video_unregister_device.
73 * @V4L2_FL_USES_V4L2_FH:
74 * indicates that file->private_data points to &struct v4l2_fh.
75 * This flag is set by the core when v4l2_fh_init() is called.
76 * All new drivers should use it.
77 * @V4L2_FL_QUIRK_INVERTED_CROP:
78 * some old M2M drivers use g/s_crop/cropcap incorrectly: crop and
79 * compose are swapped. If this flag is set, then the selection
80 * targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c.
81 * This allows those drivers to correctly implement the selection API,
82 * but the old crop API will still work as expected in order to preserve
83 * backwards compatibility.
84 * Never set this flag for new drivers.
85 * @V4L2_FL_SUBDEV_RO_DEVNODE:
86 * indicates that the video device node is registered in read-only mode.
87 * The flag only applies to device nodes registered for sub-devices, it is
88 * set by the core when the sub-devices device nodes are registered with
89 * v4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl
90 * handler to restrict access to some ioctl calls.
91 */
92 enum v4l2_video_device_flags {
93 V4L2_FL_REGISTERED = 0,
94 V4L2_FL_USES_V4L2_FH = 1,
95 V4L2_FL_QUIRK_INVERTED_CROP = 2,
96 V4L2_FL_SUBDEV_RO_DEVNODE = 3,
97 };
98
99 /* Priority helper functions */
100
101 /**
102 * struct v4l2_prio_state - stores the priority states
103 *
104 * @prios: array with elements to store the array priorities
105 *
106 *
107 * .. note::
108 * The size of @prios array matches the number of priority types defined
109 * by enum &v4l2_priority.
110 */
111 struct v4l2_prio_state {
112 atomic_t prios[4];
113 };
114
115 /**
116 * v4l2_prio_init - initializes a struct v4l2_prio_state
117 *
118 * @global: pointer to &struct v4l2_prio_state
119 */
120 void v4l2_prio_init(struct v4l2_prio_state *global);
121
122 /**
123 * v4l2_prio_change - changes the v4l2 file handler priority
124 *
125 * @global: pointer to the &struct v4l2_prio_state of the device node.
126 * @local: pointer to the desired priority, as defined by enum &v4l2_priority
127 * @new: Priority type requested, as defined by enum &v4l2_priority.
128 *
129 * .. note::
130 * This function should be used only by the V4L2 core.
131 */
132 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
133 enum v4l2_priority new);
134
135 /**
136 * v4l2_prio_open - Implements the priority logic for a file handler open
137 *
138 * @global: pointer to the &struct v4l2_prio_state of the device node.
139 * @local: pointer to the desired priority, as defined by enum &v4l2_priority
140 *
141 * .. note::
142 * This function should be used only by the V4L2 core.
143 */
144 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
145
146 /**
147 * v4l2_prio_close - Implements the priority logic for a file handler close
148 *
149 * @global: pointer to the &struct v4l2_prio_state of the device node.
150 * @local: priority to be released, as defined by enum &v4l2_priority
151 *
152 * .. note::
153 * This function should be used only by the V4L2 core.
154 */
155 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
156
157 /**
158 * v4l2_prio_max - Return the maximum priority, as stored at the @global array.
159 *
160 * @global: pointer to the &struct v4l2_prio_state of the device node.
161 *
162 * .. note::
163 * This function should be used only by the V4L2 core.
164 */
165 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
166
167 /**
168 * v4l2_prio_check - Implements the priority logic for a file handler close
169 *
170 * @global: pointer to the &struct v4l2_prio_state of the device node.
171 * @local: desired priority, as defined by enum &v4l2_priority local
172 *
173 * .. note::
174 * This function should be used only by the V4L2 core.
175 */
176 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
177
178 /**
179 * struct v4l2_file_operations - fs operations used by a V4L2 device
180 *
181 * @owner: pointer to struct module
182 * @read: operations needed to implement the read() syscall
183 * @write: operations needed to implement the write() syscall
184 * @poll: operations needed to implement the poll() syscall
185 * @unlocked_ioctl: operations needed to implement the ioctl() syscall
186 * @compat_ioctl32: operations needed to implement the ioctl() syscall for
187 * the special case where the Kernel uses 64 bits instructions, but
188 * the userspace uses 32 bits.
189 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU
190 * @mmap: operations needed to implement the mmap() syscall
191 * @open: operations needed to implement the open() syscall
192 * @release: operations needed to implement the release() syscall
193 *
194 * .. note::
195 *
196 * Those operations are used to implemente the fs struct file_operations
197 * at the V4L2 drivers. The V4L2 core overrides the fs ops with some
198 * extra logic needed by the subsystem.
199 */
200 struct v4l2_file_operations {
201 struct module *owner;
202 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
203 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
204 __poll_t (*poll) (struct file *, struct poll_table_struct *);
205 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
206 #ifdef CONFIG_COMPAT
207 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
208 #endif
209 unsigned long (*get_unmapped_area) (struct file *, unsigned long,
210 unsigned long, unsigned long, unsigned long);
211 int (*mmap) (struct file *, struct vm_area_struct *);
212 int (*open) (struct file *);
213 int (*release) (struct file *);
214 };
215
216 /*
217 * Newer version of video_device, handled by videodev2.c
218 * This version moves redundant code from video device code to
219 * the common handler
220 */
221
222 /**
223 * struct video_device - Structure used to create and manage the V4L2 device
224 * nodes.
225 *
226 * @entity: &struct media_entity
227 * @intf_devnode: pointer to &struct media_intf_devnode
228 * @pipe: &struct media_pipeline
229 * @fops: pointer to &struct v4l2_file_operations for the video device
230 * @device_caps: device capabilities as used in v4l2_capabilities
231 * @dev: &struct device for the video device
232 * @cdev: character device
233 * @v4l2_dev: pointer to &struct v4l2_device parent
234 * @dev_parent: pointer to &struct device parent
235 * @ctrl_handler: Control handler associated with this device node.
236 * May be NULL.
237 * @queue: &struct vb2_queue associated with this device node. May be NULL.
238 * @prio: pointer to &struct v4l2_prio_state with device's Priority state.
239 * If NULL, then v4l2_dev->prio will be used.
240 * @name: video device name
241 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type
242 * @vfl_dir: V4L receiver, transmitter or m2m
243 * @minor: device node 'minor'. It is set to -1 if the registration failed
244 * @num: number of the video device node
245 * @flags: video device flags. Use bitops to set/clear/test flags.
246 * Contains a set of &enum v4l2_video_device_flags.
247 * @index: attribute to differentiate multiple indices on one physical device
248 * @fh_lock: Lock for all v4l2_fhs
249 * @fh_list: List of &struct v4l2_fh
250 * @dev_debug: Internal device debug flags, not for use by drivers
251 * @tvnorms: Supported tv norms
252 *
253 * @release: video device release() callback
254 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
255 *
256 * @valid_ioctls: bitmap with the valid ioctls for this device
257 * @lock: pointer to &struct mutex serialization lock
258 *
259 * .. note::
260 * Only set @dev_parent if that can't be deduced from @v4l2_dev.
261 */
262
263 struct video_device
264 {
265 #if defined(CONFIG_MEDIA_CONTROLLER)
266 struct media_entity entity;
267 struct media_intf_devnode *intf_devnode;
268 struct media_pipeline pipe;
269 #endif
270 const struct v4l2_file_operations *fops;
271
272 u32 device_caps;
273
274 /* sysfs */
275 struct device dev;
276 struct cdev *cdev;
277
278 struct v4l2_device *v4l2_dev;
279 struct device *dev_parent;
280
281 struct v4l2_ctrl_handler *ctrl_handler;
282
283 struct vb2_queue *queue;
284
285 struct v4l2_prio_state *prio;
286
287 /* device info */
288 char name[32];
289 enum vfl_devnode_type vfl_type;
290 enum vfl_devnode_direction vfl_dir;
291 int minor;
292 u16 num;
293 unsigned long flags;
294 int index;
295
296 /* V4L2 file handles */
297 spinlock_t fh_lock;
298 struct list_head fh_list;
299
300 int dev_debug;
301
302 v4l2_std_id tvnorms;
303
304 /* callbacks */
305 void (*release)(struct video_device *vdev);
306 const struct v4l2_ioctl_ops *ioctl_ops;
307 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
308
309 struct mutex *lock;
310 };
311
312 /**
313 * media_entity_to_video_device - Returns a &struct video_device from
314 * the &struct media_entity embedded on it.
315 *
316 * @__entity: pointer to &struct media_entity
317 */
318 #define media_entity_to_video_device(__entity) \
319 container_of(__entity, struct video_device, entity)
320
321 /**
322 * to_video_device - Returns a &struct video_device from the
323 * &struct device embedded on it.
324 *
325 * @cd: pointer to &struct device
326 */
327 #define to_video_device(cd) container_of(cd, struct video_device, dev)
328
329 /**
330 * __video_register_device - register video4linux devices
331 *
332 * @vdev: struct video_device to register
333 * @type: type of device to register, as defined by &enum vfl_devnode_type
334 * @nr: which device node number is desired:
335 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
336 * @warn_if_nr_in_use: warn if the desired device node number
337 * was already in use and another number was chosen instead.
338 * @owner: module that owns the video device node
339 *
340 * The registration code assigns minor numbers and device node numbers
341 * based on the requested type and registers the new device node with
342 * the kernel.
343 *
344 * This function assumes that struct video_device was zeroed when it
345 * was allocated and does not contain any stale date.
346 *
347 * An error is returned if no free minor or device node number could be
348 * found, or if the registration of the device node failed.
349 *
350 * Returns 0 on success.
351 *
352 * .. note::
353 *
354 * This function is meant to be used only inside the V4L2 core.
355 * Drivers should use video_register_device() or
356 * video_register_device_no_warn().
357 */
358 int __must_check __video_register_device(struct video_device *vdev,
359 enum vfl_devnode_type type,
360 int nr, int warn_if_nr_in_use,
361 struct module *owner);
362
363 /**
364 * video_register_device - register video4linux devices
365 *
366 * @vdev: struct video_device to register
367 * @type: type of device to register, as defined by &enum vfl_devnode_type
368 * @nr: which device node number is desired:
369 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
370 *
371 * Internally, it calls __video_register_device(). Please see its
372 * documentation for more details.
373 *
374 * .. note::
375 * if video_register_device fails, the release() callback of
376 * &struct video_device structure is *not* called, so the caller
377 * is responsible for freeing any data. Usually that means that
378 * you video_device_release() should be called on failure.
379 */
video_register_device(struct video_device * vdev,enum vfl_devnode_type type,int nr)380 static inline int __must_check video_register_device(struct video_device *vdev,
381 enum vfl_devnode_type type,
382 int nr)
383 {
384 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
385 }
386
387 /**
388 * video_register_device_no_warn - register video4linux devices
389 *
390 * @vdev: struct video_device to register
391 * @type: type of device to register, as defined by &enum vfl_devnode_type
392 * @nr: which device node number is desired:
393 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
394 *
395 * This function is identical to video_register_device() except that no
396 * warning is issued if the desired device node number was already in use.
397 *
398 * Internally, it calls __video_register_device(). Please see its
399 * documentation for more details.
400 *
401 * .. note::
402 * if video_register_device fails, the release() callback of
403 * &struct video_device structure is *not* called, so the caller
404 * is responsible for freeing any data. Usually that means that
405 * you video_device_release() should be called on failure.
406 */
407 static inline int __must_check
video_register_device_no_warn(struct video_device * vdev,enum vfl_devnode_type type,int nr)408 video_register_device_no_warn(struct video_device *vdev,
409 enum vfl_devnode_type type, int nr)
410 {
411 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
412 }
413
414 /**
415 * video_unregister_device - Unregister video devices.
416 *
417 * @vdev: &struct video_device to register
418 *
419 * Does nothing if vdev == NULL or if video_is_registered() returns false.
420 */
421 void video_unregister_device(struct video_device *vdev);
422
423 /**
424 * video_device_alloc - helper function to alloc &struct video_device
425 *
426 * Returns NULL if %-ENOMEM or a &struct video_device on success.
427 */
428 struct video_device * __must_check video_device_alloc(void);
429
430 /**
431 * video_device_release - helper function to release &struct video_device
432 *
433 * @vdev: pointer to &struct video_device
434 *
435 * Can also be used for video_device->release\(\).
436 */
437 void video_device_release(struct video_device *vdev);
438
439 /**
440 * video_device_release_empty - helper function to implement the
441 * video_device->release\(\) callback.
442 *
443 * @vdev: pointer to &struct video_device
444 *
445 * This release function does nothing.
446 *
447 * It should be used when the video_device is a static global struct.
448 *
449 * .. note::
450 * Having a static video_device is a dubious construction at best.
451 */
452 void video_device_release_empty(struct video_device *vdev);
453
454 /**
455 * v4l2_disable_ioctl- mark that a given command isn't implemented.
456 * shouldn't use core locking
457 *
458 * @vdev: pointer to &struct video_device
459 * @cmd: ioctl command
460 *
461 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but
462 * disable ioctls based on the specific card that is actually found.
463 *
464 * .. note::
465 *
466 * This must be called before video_register_device.
467 * See also the comments for determine_valid_ioctls().
468 */
v4l2_disable_ioctl(struct video_device * vdev,unsigned int cmd)469 static inline void v4l2_disable_ioctl(struct video_device *vdev,
470 unsigned int cmd)
471 {
472 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
473 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
474 }
475
476 /**
477 * video_get_drvdata - gets private data from &struct video_device.
478 *
479 * @vdev: pointer to &struct video_device
480 *
481 * returns a pointer to the private data
482 */
video_get_drvdata(struct video_device * vdev)483 static inline void *video_get_drvdata(struct video_device *vdev)
484 {
485 return dev_get_drvdata(&vdev->dev);
486 }
487
488 /**
489 * video_set_drvdata - sets private data from &struct video_device.
490 *
491 * @vdev: pointer to &struct video_device
492 * @data: private data pointer
493 */
video_set_drvdata(struct video_device * vdev,void * data)494 static inline void video_set_drvdata(struct video_device *vdev, void *data)
495 {
496 dev_set_drvdata(&vdev->dev, data);
497 }
498
499 /**
500 * video_devdata - gets &struct video_device from struct file.
501 *
502 * @file: pointer to struct file
503 */
504 struct video_device *video_devdata(struct file *file);
505
506 /**
507 * video_drvdata - gets private data from &struct video_device using the
508 * struct file.
509 *
510 * @file: pointer to struct file
511 *
512 * This is function combines both video_get_drvdata() and video_devdata()
513 * as this is used very often.
514 */
video_drvdata(struct file * file)515 static inline void *video_drvdata(struct file *file)
516 {
517 return video_get_drvdata(video_devdata(file));
518 }
519
520 /**
521 * video_device_node_name - returns the video device name
522 *
523 * @vdev: pointer to &struct video_device
524 *
525 * Returns the device name string
526 */
video_device_node_name(struct video_device * vdev)527 static inline const char *video_device_node_name(struct video_device *vdev)
528 {
529 return dev_name(&vdev->dev);
530 }
531
532 /**
533 * video_is_registered - returns true if the &struct video_device is registered.
534 *
535 *
536 * @vdev: pointer to &struct video_device
537 */
video_is_registered(struct video_device * vdev)538 static inline int video_is_registered(struct video_device *vdev)
539 {
540 return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
541 }
542
543 #endif /* _V4L2_DEV_H */
544
