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