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1 : : /* SPDX-License-Identifier: GPL-2.0-only */
2 : : /*
3 : : * Media device
4 : : *
5 : : * Copyright (C) 2010 Nokia Corporation
6 : : *
7 : : * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8 : : * Sakari Ailus <sakari.ailus@iki.fi>
9 : : */
10 : :
11 : : #ifndef _MEDIA_DEVICE_H
12 : : #define _MEDIA_DEVICE_H
13 : :
14 : : #include <linux/list.h>
15 : : #include <linux/mutex.h>
16 : :
17 : : #include <media/media-devnode.h>
18 : : #include <media/media-entity.h>
19 : :
20 : : struct ida;
21 : : struct device;
22 : : struct media_device;
23 : :
24 : : /**
25 : : * struct media_entity_notify - Media Entity Notify
26 : : *
27 : : * @list: List head
28 : : * @notify_data: Input data to invoke the callback
29 : : * @notify: Callback function pointer
30 : : *
31 : : * Drivers may register a callback to take action when new entities get
32 : : * registered with the media device. This handler is intended for creating
33 : : * links between existing entities and should not create entities and register
34 : : * them.
35 : : */
36 : : struct media_entity_notify {
37 : : struct list_head list;
38 : : void *notify_data;
39 : : void (*notify)(struct media_entity *entity, void *notify_data);
40 : : };
41 : :
42 : : /**
43 : : * struct media_device_ops - Media device operations
44 : : * @link_notify: Link state change notification callback. This callback is
45 : : * called with the graph_mutex held.
46 : : * @req_alloc: Allocate a request. Set this if you need to allocate a struct
47 : : * larger then struct media_request. @req_alloc and @req_free must
48 : : * either both be set or both be NULL.
49 : : * @req_free: Free a request. Set this if @req_alloc was set as well, leave
50 : : * to NULL otherwise.
51 : : * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex
52 : : * lock is held when this op is called.
53 : : * @req_queue: Queue a validated request, cannot fail. If something goes
54 : : * wrong when queueing this request then it should be marked
55 : : * as such internally in the driver and any related buffers
56 : : * must eventually return to vb2 with state VB2_BUF_STATE_ERROR.
57 : : * The req_queue_mutex lock is held when this op is called.
58 : : * It is important that vb2 buffer objects are queued last after
59 : : * all other object types are queued: queueing a buffer kickstarts
60 : : * the request processing, so all other objects related to the
61 : : * request (and thus the buffer) must be available to the driver.
62 : : * And once a buffer is queued, then the driver can complete
63 : : * or delete objects from the request before req_queue exits.
64 : : */
65 : : struct media_device_ops {
66 : : int (*link_notify)(struct media_link *link, u32 flags,
67 : : unsigned int notification);
68 : : struct media_request *(*req_alloc)(struct media_device *mdev);
69 : : void (*req_free)(struct media_request *req);
70 : : int (*req_validate)(struct media_request *req);
71 : : void (*req_queue)(struct media_request *req);
72 : : };
73 : :
74 : : /**
75 : : * struct media_device - Media device
76 : : * @dev: Parent device
77 : : * @devnode: Media device node
78 : : * @driver_name: Optional device driver name. If not set, calls to
79 : : * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``.
80 : : * This is needed for USB drivers for example, as otherwise
81 : : * they'll all appear as if the driver name was "usb".
82 : : * @model: Device model name
83 : : * @serial: Device serial number (optional)
84 : : * @bus_info: Unique and stable device location identifier
85 : : * @hw_revision: Hardware device revision
86 : : * @topology_version: Monotonic counter for storing the version of the graph
87 : : * topology. Should be incremented each time the topology changes.
88 : : * @id: Unique ID used on the last registered graph object
89 : : * @entity_internal_idx: Unique internal entity ID used by the graph traversal
90 : : * algorithms
91 : : * @entity_internal_idx_max: Allocated internal entity indices
92 : : * @entities: List of registered entities
93 : : * @interfaces: List of registered interfaces
94 : : * @pads: List of registered pads
95 : : * @links: List of registered links
96 : : * @entity_notify: List of registered entity_notify callbacks
97 : : * @graph_mutex: Protects access to struct media_device data
98 : : * @pm_count_walk: Graph walk for power state walk. Access serialised using
99 : : * graph_mutex.
100 : : *
101 : : * @source_priv: Driver Private data for enable/disable source handlers
102 : : * @enable_source: Enable Source Handler function pointer
103 : : * @disable_source: Disable Source Handler function pointer
104 : : *
105 : : * @ops: Operation handler callbacks
106 : : * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
107 : : * other operations that stop or start streaming.
108 : : * @request_id: Used to generate unique request IDs
109 : : *
110 : : * This structure represents an abstract high-level media device. It allows easy
111 : : * access to entities and provides basic media device-level support. The
112 : : * structure can be allocated directly or embedded in a larger structure.
113 : : *
114 : : * The parent @dev is a physical device. It must be set before registering the
115 : : * media device.
116 : : *
117 : : * @model is a descriptive model name exported through sysfs. It doesn't have to
118 : : * be unique.
119 : : *
120 : : * @enable_source is a handler to find source entity for the
121 : : * sink entity and activate the link between them if source
122 : : * entity is free. Drivers should call this handler before
123 : : * accessing the source.
124 : : *
125 : : * @disable_source is a handler to find source entity for the
126 : : * sink entity and deactivate the link between them. Drivers
127 : : * should call this handler to release the source.
128 : : *
129 : : * Use-case: find tuner entity connected to the decoder
130 : : * entity and check if it is available, and activate the
131 : : * the link between them from @enable_source and deactivate
132 : : * from @disable_source.
133 : : *
134 : : * .. note::
135 : : *
136 : : * Bridge driver is expected to implement and set the
137 : : * handler when &media_device is registered or when
138 : : * bridge driver finds the media_device during probe.
139 : : * Bridge driver sets source_priv with information
140 : : * necessary to run @enable_source and @disable_source handlers.
141 : : * Callers should hold graph_mutex to access and call @enable_source
142 : : * and @disable_source handlers.
143 : : */
144 : : struct media_device {
145 : : /* dev->driver_data points to this struct. */
146 : : struct device *dev;
147 : : struct media_devnode *devnode;
148 : :
149 : : char model[32];
150 : : char driver_name[32];
151 : : char serial[40];
152 : : char bus_info[32];
153 : : u32 hw_revision;
154 : :
155 : : u64 topology_version;
156 : :
157 : : u32 id;
158 : : struct ida entity_internal_idx;
159 : : int entity_internal_idx_max;
160 : :
161 : : struct list_head entities;
162 : : struct list_head interfaces;
163 : : struct list_head pads;
164 : : struct list_head links;
165 : :
166 : : /* notify callback list invoked when a new entity is registered */
167 : : struct list_head entity_notify;
168 : :
169 : : /* Serializes graph operations. */
170 : : struct mutex graph_mutex;
171 : : struct media_graph pm_count_walk;
172 : :
173 : : void *source_priv;
174 : : int (*enable_source)(struct media_entity *entity,
175 : : struct media_pipeline *pipe);
176 : : void (*disable_source)(struct media_entity *entity);
177 : :
178 : : const struct media_device_ops *ops;
179 : :
180 : : struct mutex req_queue_mutex;
181 : : atomic_t request_id;
182 : : };
183 : :
184 : : /* We don't need to include pci.h or usb.h here */
185 : : struct pci_dev;
186 : : struct usb_device;
187 : :
188 : : #ifdef CONFIG_MEDIA_CONTROLLER
189 : :
190 : : /* Supported link_notify @notification values. */
191 : : #define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0
192 : : #define MEDIA_DEV_NOTIFY_POST_LINK_CH 1
193 : :
194 : : /**
195 : : * media_entity_enum_init - Initialise an entity enumeration
196 : : *
197 : : * @ent_enum: Entity enumeration to be initialised
198 : : * @mdev: The related media device
199 : : *
200 : : * Return: zero on success or a negative error code.
201 : : */
202 : : static inline __must_check int media_entity_enum_init(
203 : : struct media_entity_enum *ent_enum, struct media_device *mdev)
204 : : {
205 : 414 : return __media_entity_enum_init(ent_enum,
206 : 414 : mdev->entity_internal_idx_max + 1);
207 : : }
208 : :
209 : : /**
210 : : * media_device_init() - Initializes a media device element
211 : : *
212 : : * @mdev: pointer to struct &media_device
213 : : *
214 : : * This function initializes the media device prior to its registration.
215 : : * The media device initialization and registration is split in two functions
216 : : * to avoid race conditions and make the media device available to user-space
217 : : * before the media graph has been completed.
218 : : *
219 : : * So drivers need to first initialize the media device, register any entity
220 : : * within the media device, create pad to pad links and then finally register
221 : : * the media device by calling media_device_register() as a final step.
222 : : */
223 : : void media_device_init(struct media_device *mdev);
224 : :
225 : : /**
226 : : * media_device_cleanup() - Cleanups a media device element
227 : : *
228 : : * @mdev: pointer to struct &media_device
229 : : *
230 : : * This function that will destroy the graph_mutex that is
231 : : * initialized in media_device_init().
232 : : */
233 : : void media_device_cleanup(struct media_device *mdev);
234 : :
235 : : /**
236 : : * __media_device_register() - Registers a media device element
237 : : *
238 : : * @mdev: pointer to struct &media_device
239 : : * @owner: should be filled with %THIS_MODULE
240 : : *
241 : : * Users, should, instead, call the media_device_register() macro.
242 : : *
243 : : * The caller is responsible for initializing the &media_device structure
244 : : * before registration. The following fields of &media_device must be set:
245 : : *
246 : : * - &media_entity.dev must point to the parent device (usually a &pci_dev,
247 : : * &usb_interface or &platform_device instance).
248 : : *
249 : : * - &media_entity.model must be filled with the device model name as a
250 : : * NUL-terminated UTF-8 string. The device/model revision must not be
251 : : * stored in this field.
252 : : *
253 : : * The following fields are optional:
254 : : *
255 : : * - &media_entity.serial is a unique serial number stored as a
256 : : * NUL-terminated ASCII string. The field is big enough to store a GUID
257 : : * in text form. If the hardware doesn't provide a unique serial number
258 : : * this field must be left empty.
259 : : *
260 : : * - &media_entity.bus_info represents the location of the device in the
261 : : * system as a NUL-terminated ASCII string. For PCI/PCIe devices
262 : : * &media_entity.bus_info must be set to "PCI:" (or "PCIe:") followed by
263 : : * the value of pci_name(). For USB devices,the usb_make_path() function
264 : : * must be used. This field is used by applications to distinguish between
265 : : * otherwise identical devices that don't provide a serial number.
266 : : *
267 : : * - &media_entity.hw_revision is the hardware device revision in a
268 : : * driver-specific format. When possible the revision should be formatted
269 : : * with the KERNEL_VERSION() macro.
270 : : *
271 : : * .. note::
272 : : *
273 : : * #) Upon successful registration a character device named media[0-9]+ is created. The device major and minor numbers are dynamic. The model name is exported as a sysfs attribute.
274 : : *
275 : : * #) Unregistering a media device that hasn't been registered is **NOT** safe.
276 : : *
277 : : * Return: returns zero on success or a negative error code.
278 : : */
279 : : int __must_check __media_device_register(struct media_device *mdev,
280 : : struct module *owner);
281 : :
282 : :
283 : : /**
284 : : * media_device_register() - Registers a media device element
285 : : *
286 : : * @mdev: pointer to struct &media_device
287 : : *
288 : : * This macro calls __media_device_register() passing %THIS_MODULE as
289 : : * the __media_device_register() second argument (**owner**).
290 : : */
291 : : #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
292 : :
293 : : /**
294 : : * media_device_unregister() - Unregisters a media device element
295 : : *
296 : : * @mdev: pointer to struct &media_device
297 : : *
298 : : * It is safe to call this function on an unregistered (but initialised)
299 : : * media device.
300 : : */
301 : : void media_device_unregister(struct media_device *mdev);
302 : :
303 : : /**
304 : : * media_device_register_entity() - registers a media entity inside a
305 : : * previously registered media device.
306 : : *
307 : : * @mdev: pointer to struct &media_device
308 : : * @entity: pointer to struct &media_entity to be registered
309 : : *
310 : : * Entities are identified by a unique positive integer ID. The media
311 : : * controller framework will such ID automatically. IDs are not guaranteed
312 : : * to be contiguous, and the ID number can change on newer Kernel versions.
313 : : * So, neither the driver nor userspace should hardcode ID numbers to refer
314 : : * to the entities, but, instead, use the framework to find the ID, when
315 : : * needed.
316 : : *
317 : : * The media_entity name, type and flags fields should be initialized before
318 : : * calling media_device_register_entity(). Entities embedded in higher-level
319 : : * standard structures can have some of those fields set by the higher-level
320 : : * framework.
321 : : *
322 : : * If the device has pads, media_entity_pads_init() should be called before
323 : : * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads
324 : : * should be zeroed before calling this function.
325 : : *
326 : : * Entities have flags that describe the entity capabilities and state:
327 : : *
328 : : * %MEDIA_ENT_FL_DEFAULT
329 : : * indicates the default entity for a given type.
330 : : * This can be used to report the default audio and video devices or the
331 : : * default camera sensor.
332 : : *
333 : : * .. note::
334 : : *
335 : : * Drivers should set the entity function before calling this function.
336 : : * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and
337 : : * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers.
338 : : */
339 : : int __must_check media_device_register_entity(struct media_device *mdev,
340 : : struct media_entity *entity);
341 : :
342 : : /**
343 : : * media_device_unregister_entity() - unregisters a media entity.
344 : : *
345 : : * @entity: pointer to struct &media_entity to be unregistered
346 : : *
347 : : * All links associated with the entity and all PADs are automatically
348 : : * unregistered from the media_device when this function is called.
349 : : *
350 : : * Unregistering an entity will not change the IDs of the other entities and
351 : : * the previoully used ID will never be reused for a newly registered entities.
352 : : *
353 : : * When a media device is unregistered, all its entities are unregistered
354 : : * automatically. No manual entities unregistration is then required.
355 : : *
356 : : * .. note::
357 : : *
358 : : * The media_entity instance itself must be freed explicitly by
359 : : * the driver if required.
360 : : */
361 : : void media_device_unregister_entity(struct media_entity *entity);
362 : :
363 : : /**
364 : : * media_device_register_entity_notify() - Registers a media entity_notify
365 : : * callback
366 : : *
367 : : * @mdev: The media device
368 : : * @nptr: The media_entity_notify
369 : : *
370 : : * .. note::
371 : : *
372 : : * When a new entity is registered, all the registered
373 : : * media_entity_notify callbacks are invoked.
374 : : */
375 : :
376 : : int __must_check media_device_register_entity_notify(struct media_device *mdev,
377 : : struct media_entity_notify *nptr);
378 : :
379 : : /**
380 : : * media_device_unregister_entity_notify() - Unregister a media entity notify
381 : : * callback
382 : : *
383 : : * @mdev: The media device
384 : : * @nptr: The media_entity_notify
385 : : *
386 : : */
387 : : void media_device_unregister_entity_notify(struct media_device *mdev,
388 : : struct media_entity_notify *nptr);
389 : :
390 : : /* Iterate over all entities. */
391 : : #define media_device_for_each_entity(entity, mdev) \
392 : : list_for_each_entry(entity, &(mdev)->entities, graph_obj.list)
393 : :
394 : : /* Iterate over all interfaces. */
395 : : #define media_device_for_each_intf(intf, mdev) \
396 : : list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list)
397 : :
398 : : /* Iterate over all pads. */
399 : : #define media_device_for_each_pad(pad, mdev) \
400 : : list_for_each_entry(pad, &(mdev)->pads, graph_obj.list)
401 : :
402 : : /* Iterate over all links. */
403 : : #define media_device_for_each_link(link, mdev) \
404 : : list_for_each_entry(link, &(mdev)->links, graph_obj.list)
405 : :
406 : : /**
407 : : * media_device_pci_init() - create and initialize a
408 : : * struct &media_device from a PCI device.
409 : : *
410 : : * @mdev: pointer to struct &media_device
411 : : * @pci_dev: pointer to struct pci_dev
412 : : * @name: media device name. If %NULL, the routine will use the default
413 : : * name for the pci device, given by pci_name() macro.
414 : : */
415 : : void media_device_pci_init(struct media_device *mdev,
416 : : struct pci_dev *pci_dev,
417 : : const char *name);
418 : : /**
419 : : * __media_device_usb_init() - create and initialize a
420 : : * struct &media_device from a PCI device.
421 : : *
422 : : * @mdev: pointer to struct &media_device
423 : : * @udev: pointer to struct usb_device
424 : : * @board_name: media device name. If %NULL, the routine will use the usb
425 : : * product name, if available.
426 : : * @driver_name: name of the driver. if %NULL, the routine will use the name
427 : : * given by ``udev->dev->driver->name``, with is usually the wrong
428 : : * thing to do.
429 : : *
430 : : * .. note::
431 : : *
432 : : * It is better to call media_device_usb_init() instead, as
433 : : * such macro fills driver_name with %KBUILD_MODNAME.
434 : : */
435 : : void __media_device_usb_init(struct media_device *mdev,
436 : : struct usb_device *udev,
437 : : const char *board_name,
438 : : const char *driver_name);
439 : :
440 : : #else
441 : : static inline int media_device_register(struct media_device *mdev)
442 : : {
443 : : return 0;
444 : : }
445 : : static inline void media_device_unregister(struct media_device *mdev)
446 : : {
447 : : }
448 : : static inline int media_device_register_entity(struct media_device *mdev,
449 : : struct media_entity *entity)
450 : : {
451 : : return 0;
452 : : }
453 : : static inline void media_device_unregister_entity(struct media_entity *entity)
454 : : {
455 : : }
456 : : static inline int media_device_register_entity_notify(
457 : : struct media_device *mdev,
458 : : struct media_entity_notify *nptr)
459 : : {
460 : : return 0;
461 : : }
462 : : static inline void media_device_unregister_entity_notify(
463 : : struct media_device *mdev,
464 : : struct media_entity_notify *nptr)
465 : : {
466 : : }
467 : :
468 : : static inline void media_device_pci_init(struct media_device *mdev,
469 : : struct pci_dev *pci_dev,
470 : : char *name)
471 : : {
472 : : }
473 : :
474 : : static inline void __media_device_usb_init(struct media_device *mdev,
475 : : struct usb_device *udev,
476 : : char *board_name,
477 : : char *driver_name)
478 : : {
479 : : }
480 : :
481 : : #endif /* CONFIG_MEDIA_CONTROLLER */
482 : :
483 : : /**
484 : : * media_device_usb_init() - create and initialize a
485 : : * struct &media_device from a PCI device.
486 : : *
487 : : * @mdev: pointer to struct &media_device
488 : : * @udev: pointer to struct usb_device
489 : : * @name: media device name. If %NULL, the routine will use the usb
490 : : * product name, if available.
491 : : *
492 : : * This macro calls media_device_usb_init() passing the
493 : : * media_device_usb_init() **driver_name** parameter filled with
494 : : * %KBUILD_MODNAME.
495 : : */
496 : : #define media_device_usb_init(mdev, udev, name) \
497 : : __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
498 : :
499 : : #endif
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