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 return __media_entity_enum_init(ent_enum,
206 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