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 #include <linux/pci.h>
17 #include <linux/platform_device.h>
18
19 #include <media/media-devnode.h>
20 #include <media/media-entity.h>
21
22 struct ida;
23 struct media_device;
24
25 /**
26 * struct media_entity_notify - Media Entity Notify
27 *
28 * @list: List head
29 * @notify_data: Input data to invoke the callback
30 * @notify: Callback function pointer
31 *
32 * Drivers may register a callback to take action when new entities get
33 * registered with the media device. This handler is intended for creating
34 * links between existing entities and should not create entities and register
35 * them.
36 */
37 struct media_entity_notify {
38 struct list_head list;
39 void *notify_data;
40 void (*notify)(struct media_entity *entity, void *notify_data);
41 };
42
43 /**
44 * struct media_device_ops - Media device operations
45 * @link_notify: Link state change notification callback. This callback is
46 * called with the graph_mutex held.
47 * @req_alloc: Allocate a request. Set this if you need to allocate a struct
48 * larger then struct media_request. @req_alloc and @req_free must
49 * either both be set or both be NULL.
50 * @req_free: Free a request. Set this if @req_alloc was set as well, leave
51 * to NULL otherwise.
52 * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex
53 * lock is held when this op is called.
54 * @req_queue: Queue a validated request, cannot fail. If something goes
55 * wrong when queueing this request then it should be marked
56 * as such internally in the driver and any related buffers
57 * must eventually return to vb2 with state VB2_BUF_STATE_ERROR.
58 * The req_queue_mutex lock is held when this op is called.
59 * It is important that vb2 buffer objects are queued last after
60 * all other object types are queued: queueing a buffer kickstarts
61 * the request processing, so all other objects related to the
62 * request (and thus the buffer) must be available to the driver.
63 * And once a buffer is queued, then the driver can complete
64 * or delete objects from the request before req_queue exits.
65 */
66 struct media_device_ops {
67 int (*link_notify)(struct media_link *link, u32 flags,
68 unsigned int notification);
69 struct media_request *(*req_alloc)(struct media_device *mdev);
70 void (*req_free)(struct media_request *req);
71 int (*req_validate)(struct media_request *req);
72 void (*req_queue)(struct media_request *req);
73 };
74
75 /**
76 * struct media_device - Media device
77 * @dev: Parent device
78 * @devnode: Media device node
79 * @driver_name: Optional device driver name. If not set, calls to
80 * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``.
81 * This is needed for USB drivers for example, as otherwise
82 * they'll all appear as if the driver name was "usb".
83 * @model: Device model name
84 * @serial: Device serial number (optional)
85 * @bus_info: Unique and stable device location identifier
86 * @hw_revision: Hardware device revision
87 * @topology_version: Monotonic counter for storing the version of the graph
88 * topology. Should be incremented each time the topology changes.
89 * @id: Unique ID used on the last registered graph object
90 * @entity_internal_idx: Unique internal entity ID used by the graph traversal
91 * algorithms
92 * @entity_internal_idx_max: Allocated internal entity indices
93 * @entities: List of registered entities
94 * @interfaces: List of registered interfaces
95 * @pads: List of registered pads
96 * @links: List of registered links
97 * @entity_notify: List of registered entity_notify callbacks
98 * @graph_mutex: Protects access to struct media_device data
99 * @pm_count_walk: Graph walk for power state walk. Access serialised using
100 * graph_mutex.
101 *
102 * @source_priv: Driver Private data for enable/disable source handlers
103 * @enable_source: Enable Source Handler function pointer
104 * @disable_source: Disable Source Handler function pointer
105 *
106 * @ops: Operation handler callbacks
107 * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
108 * other operations that stop or start streaming.
109 * @request_id: Used to generate unique request IDs
110 *
111 * This structure represents an abstract high-level media device. It allows easy
112 * access to entities and provides basic media device-level support. The
113 * structure can be allocated directly or embedded in a larger structure.
114 *
115 * The parent @dev is a physical device. It must be set before registering the
116 * media device.
117 *
118 * @model is a descriptive model name exported through sysfs. It doesn't have to
119 * be unique.
120 *
121 * @enable_source is a handler to find source entity for the
122 * sink entity and activate the link between them if source
123 * entity is free. Drivers should call this handler before
124 * accessing the source.
125 *
126 * @disable_source is a handler to find source entity for the
127 * sink entity and deactivate the link between them. Drivers
128 * should call this handler to release the source.
129 *
130 * Use-case: find tuner entity connected to the decoder
131 * entity and check if it is available, and activate the
132 * link between them from @enable_source and deactivate
133 * from @disable_source.
134 *
135 * .. note::
136 *
137 * Bridge driver is expected to implement and set the
138 * handler when &media_device is registered or when
139 * bridge driver finds the media_device during probe.
140 * Bridge driver sets source_priv with information
141 * necessary to run @enable_source and @disable_source handlers.
142 * Callers should hold graph_mutex to access and call @enable_source
143 * and @disable_source handlers.
144 */
145 struct media_device {
146 /* dev->driver_data points to this struct. */
147 struct device *dev;
148 struct media_devnode *devnode;
149
150 char model[32];
151 char driver_name[32];
152 char serial[40];
153 char bus_info[32];
154 u32 hw_revision;
155
156 u64 topology_version;
157
158 u32 id;
159 struct ida entity_internal_idx;
160 int entity_internal_idx_max;
161
162 struct list_head entities;
163 struct list_head interfaces;
164 struct list_head pads;
165 struct list_head links;
166
167 /* notify callback list invoked when a new entity is registered */
168 struct list_head entity_notify;
169
170 /* Serializes graph operations. */
171 struct mutex graph_mutex;
172 struct media_graph pm_count_walk;
173
174 void *source_priv;
175 int (*enable_source)(struct media_entity *entity,
176 struct media_pipeline *pipe);
177 void (*disable_source)(struct media_entity *entity);
178
179 const struct media_device_ops *ops;
180
181 struct mutex req_queue_mutex;
182 atomic_t request_id;
183 };
184
185 /* We don't need to include usb.h here */
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_device_init() - Initializes a media device element
196 *
197 * @mdev: pointer to struct &media_device
198 *
199 * This function initializes the media device prior to its registration.
200 * The media device initialization and registration is split in two functions
201 * to avoid race conditions and make the media device available to user-space
202 * before the media graph has been completed.
203 *
204 * So drivers need to first initialize the media device, register any entity
205 * within the media device, create pad to pad links and then finally register
206 * the media device by calling media_device_register() as a final step.
207 *
208 * The caller is responsible for initializing the media device before
209 * registration. The following fields must be set:
210 *
211 * - dev must point to the parent device
212 * - model must be filled with the device model name
213 *
214 * The bus_info field is set by media_device_init() for PCI and platform devices
215 * if the field begins with '\0'.
216 */
217 void media_device_init(struct media_device *mdev);
218
219 /**
220 * media_device_cleanup() - Cleanups a media device element
221 *
222 * @mdev: pointer to struct &media_device
223 *
224 * This function that will destroy the graph_mutex that is
225 * initialized in media_device_init().
226 */
227 void media_device_cleanup(struct media_device *mdev);
228
229 /**
230 * __media_device_register() - Registers a media device element
231 *
232 * @mdev: pointer to struct &media_device
233 * @owner: should be filled with %THIS_MODULE
234 *
235 * Users, should, instead, call the media_device_register() macro.
236 *
237 * The caller is responsible for initializing the &media_device structure
238 * before registration. The following fields of &media_device must be set:
239 *
240 * - &media_device.model must be filled with the device model name as a
241 * NUL-terminated UTF-8 string. The device/model revision must not be
242 * stored in this field.
243 *
244 * The following fields are optional:
245 *
246 * - &media_device.serial is a unique serial number stored as a
247 * NUL-terminated ASCII string. The field is big enough to store a GUID
248 * in text form. If the hardware doesn't provide a unique serial number
249 * this field must be left empty.
250 *
251 * - &media_device.bus_info represents the location of the device in the
252 * system as a NUL-terminated ASCII string. For PCI/PCIe devices
253 * &media_device.bus_info must be set to "PCI:" (or "PCIe:") followed by
254 * the value of pci_name(). For USB devices,the usb_make_path() function
255 * must be used. This field is used by applications to distinguish between
256 * otherwise identical devices that don't provide a serial number.
257 *
258 * - &media_device.hw_revision is the hardware device revision in a
259 * driver-specific format. When possible the revision should be formatted
260 * with the KERNEL_VERSION() macro.
261 *
262 * .. note::
263 *
264 * #) 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.
265 *
266 * #) Unregistering a media device that hasn't been registered is **NOT** safe.
267 *
268 * Return: returns zero on success or a negative error code.
269 */
270 int __must_check __media_device_register(struct media_device *mdev,
271 struct module *owner);
272
273
274 /**
275 * media_device_register() - Registers a media device element
276 *
277 * @mdev: pointer to struct &media_device
278 *
279 * This macro calls __media_device_register() passing %THIS_MODULE as
280 * the __media_device_register() second argument (**owner**).
281 */
282 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
283
284 /**
285 * media_device_unregister() - Unregisters a media device element
286 *
287 * @mdev: pointer to struct &media_device
288 *
289 * It is safe to call this function on an unregistered (but initialised)
290 * media device.
291 */
292 void media_device_unregister(struct media_device *mdev);
293
294 /**
295 * media_device_register_entity() - registers a media entity inside a
296 * previously registered media device.
297 *
298 * @mdev: pointer to struct &media_device
299 * @entity: pointer to struct &media_entity to be registered
300 *
301 * Entities are identified by a unique positive integer ID. The media
302 * controller framework will such ID automatically. IDs are not guaranteed
303 * to be contiguous, and the ID number can change on newer Kernel versions.
304 * So, neither the driver nor userspace should hardcode ID numbers to refer
305 * to the entities, but, instead, use the framework to find the ID, when
306 * needed.
307 *
308 * The media_entity name, type and flags fields should be initialized before
309 * calling media_device_register_entity(). Entities embedded in higher-level
310 * standard structures can have some of those fields set by the higher-level
311 * framework.
312 *
313 * If the device has pads, media_entity_pads_init() should be called before
314 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads
315 * should be zeroed before calling this function.
316 *
317 * Entities have flags that describe the entity capabilities and state:
318 *
319 * %MEDIA_ENT_FL_DEFAULT
320 * indicates the default entity for a given type.
321 * This can be used to report the default audio and video devices or the
322 * default camera sensor.
323 *
324 * .. note::
325 *
326 * Drivers should set the entity function before calling this function.
327 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and
328 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers.
329 */
330 int __must_check media_device_register_entity(struct media_device *mdev,
331 struct media_entity *entity);
332
333 /**
334 * media_device_unregister_entity() - unregisters a media entity.
335 *
336 * @entity: pointer to struct &media_entity to be unregistered
337 *
338 * All links associated with the entity and all PADs are automatically
339 * unregistered from the media_device when this function is called.
340 *
341 * Unregistering an entity will not change the IDs of the other entities and
342 * the previoully used ID will never be reused for a newly registered entities.
343 *
344 * When a media device is unregistered, all its entities are unregistered
345 * automatically. No manual entities unregistration is then required.
346 *
347 * .. note::
348 *
349 * The media_entity instance itself must be freed explicitly by
350 * the driver if required.
351 */
352 void media_device_unregister_entity(struct media_entity *entity);
353
354 /**
355 * media_device_register_entity_notify() - Registers a media entity_notify
356 * callback
357 *
358 * @mdev: The media device
359 * @nptr: The media_entity_notify
360 *
361 * .. note::
362 *
363 * When a new entity is registered, all the registered
364 * media_entity_notify callbacks are invoked.
365 */
366
367 void media_device_register_entity_notify(struct media_device *mdev,
368 struct media_entity_notify *nptr);
369
370 /**
371 * media_device_unregister_entity_notify() - Unregister a media entity notify
372 * callback
373 *
374 * @mdev: The media device
375 * @nptr: The media_entity_notify
376 *
377 */
378 void media_device_unregister_entity_notify(struct media_device *mdev,
379 struct media_entity_notify *nptr);
380
381 /* Iterate over all entities. */
382 #define media_device_for_each_entity(entity, mdev) \
383 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list)
384
385 /* Iterate over all interfaces. */
386 #define media_device_for_each_intf(intf, mdev) \
387 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list)
388
389 /* Iterate over all pads. */
390 #define media_device_for_each_pad(pad, mdev) \
391 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list)
392
393 /* Iterate over all links. */
394 #define media_device_for_each_link(link, mdev) \
395 list_for_each_entry(link, &(mdev)->links, graph_obj.list)
396
397 /**
398 * media_device_pci_init() - create and initialize a
399 * struct &media_device from a PCI device.
400 *
401 * @mdev: pointer to struct &media_device
402 * @pci_dev: pointer to struct pci_dev
403 * @name: media device name. If %NULL, the routine will use the default
404 * name for the pci device, given by pci_name() macro.
405 */
406 void media_device_pci_init(struct media_device *mdev,
407 struct pci_dev *pci_dev,
408 const char *name);
409 /**
410 * __media_device_usb_init() - create and initialize a
411 * struct &media_device from a PCI device.
412 *
413 * @mdev: pointer to struct &media_device
414 * @udev: pointer to struct usb_device
415 * @board_name: media device name. If %NULL, the routine will use the usb
416 * product name, if available.
417 * @driver_name: name of the driver. if %NULL, the routine will use the name
418 * given by ``udev->dev->driver->name``, with is usually the wrong
419 * thing to do.
420 *
421 * .. note::
422 *
423 * It is better to call media_device_usb_init() instead, as
424 * such macro fills driver_name with %KBUILD_MODNAME.
425 */
426 void __media_device_usb_init(struct media_device *mdev,
427 struct usb_device *udev,
428 const char *board_name,
429 const char *driver_name);
430
431 #else
media_device_init(struct media_device * mdev)432 static inline void media_device_init(struct media_device *mdev)
433 {
434 }
media_device_register(struct media_device * mdev)435 static inline int media_device_register(struct media_device *mdev)
436 {
437 return 0;
438 }
media_device_unregister(struct media_device * mdev)439 static inline void media_device_unregister(struct media_device *mdev)
440 {
441 }
media_device_cleanup(struct media_device * mdev)442 static inline void media_device_cleanup(struct media_device *mdev)
443 {
444 }
media_device_register_entity(struct media_device * mdev,struct media_entity * entity)445 static inline int media_device_register_entity(struct media_device *mdev,
446 struct media_entity *entity)
447 {
448 return 0;
449 }
media_device_unregister_entity(struct media_entity * entity)450 static inline void media_device_unregister_entity(struct media_entity *entity)
451 {
452 }
media_device_register_entity_notify(struct media_device * mdev,struct media_entity_notify * nptr)453 static inline void media_device_register_entity_notify(
454 struct media_device *mdev,
455 struct media_entity_notify *nptr)
456 {
457 }
media_device_unregister_entity_notify(struct media_device * mdev,struct media_entity_notify * nptr)458 static inline void media_device_unregister_entity_notify(
459 struct media_device *mdev,
460 struct media_entity_notify *nptr)
461 {
462 }
463
media_device_pci_init(struct media_device * mdev,struct pci_dev * pci_dev,char * name)464 static inline void media_device_pci_init(struct media_device *mdev,
465 struct pci_dev *pci_dev,
466 char *name)
467 {
468 }
469
__media_device_usb_init(struct media_device * mdev,struct usb_device * udev,char * board_name,char * driver_name)470 static inline void __media_device_usb_init(struct media_device *mdev,
471 struct usb_device *udev,
472 char *board_name,
473 char *driver_name)
474 {
475 }
476
477 #endif /* CONFIG_MEDIA_CONTROLLER */
478
479 /**
480 * media_device_usb_init() - create and initialize a
481 * struct &media_device from a PCI device.
482 *
483 * @mdev: pointer to struct &media_device
484 * @udev: pointer to struct usb_device
485 * @name: media device name. If %NULL, the routine will use the usb
486 * product name, if available.
487 *
488 * This macro calls media_device_usb_init() passing the
489 * media_device_usb_init() **driver_name** parameter filled with
490 * %KBUILD_MODNAME.
491 */
492 #define media_device_usb_init(mdev, udev, name) \
493 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
494
495 /**
496 * media_set_bus_info() - Set bus_info field
497 *
498 * @bus_info: Variable where to write the bus info (char array)
499 * @bus_info_size: Length of the bus_info
500 * @dev: Related struct device
501 *
502 * Sets bus information based on &dev. This is currently done for PCI and
503 * platform devices. dev is required to be non-NULL for this to happen.
504 *
505 * This function is not meant to be called from drivers.
506 */
507 static inline void
media_set_bus_info(char * bus_info,size_t bus_info_size,struct device * dev)508 media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev)
509 {
510 if (!dev)
511 strscpy(bus_info, "no bus info", bus_info_size);
512 else if (dev_is_platform(dev))
513 snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev));
514 else if (dev_is_pci(dev))
515 snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev));
516 }
517
518 #endif
519