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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/atomic.h>
15#include <linux/list.h>
16#include <linux/mutex.h>
17#include <linux/pci.h>
18#include <linux/platform_device.h>
19
20#include <media/media-devnode.h>
21#include <media/media-entity.h>
22
23struct ida;
24struct media_device;
25
26/**
27 * struct media_entity_notify - Media Entity Notify
28 *
29 * @list: List head
30 * @notify_data: Input data to invoke the callback
31 * @notify: Callback function pointer
32 *
33 * Drivers may register a callback to take action when new entities get
34 * registered with the media device. This handler is intended for creating
35 * links between existing entities and should not create entities and register
36 * them.
37 */
38struct media_entity_notify {
39 struct list_head list;
40 void *notify_data;
41 void (*notify)(struct media_entity *entity, void *notify_data);
42};
43
44/**
45 * struct media_device_ops - Media device operations
46 * @link_notify: Link state change notification callback. This callback is
47 * called with the graph_mutex held.
48 * @req_alloc: Allocate a request. Set this if you need to allocate a struct
49 * larger then struct media_request. @req_alloc and @req_free must
50 * either both be set or both be NULL.
51 * @req_free: Free a request. Set this if @req_alloc was set as well, leave
52 * to NULL otherwise.
53 * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex
54 * lock is held when this op is called.
55 * @req_queue: Queue a validated request, cannot fail. If something goes
56 * wrong when queueing this request then it should be marked
57 * as such internally in the driver and any related buffers
58 * must eventually return to vb2 with state VB2_BUF_STATE_ERROR.
59 * The req_queue_mutex lock is held when this op is called.
60 * It is important that vb2 buffer objects are queued last after
61 * all other object types are queued: queueing a buffer kickstarts
62 * the request processing, so all other objects related to the
63 * request (and thus the buffer) must be available to the driver.
64 * And once a buffer is queued, then the driver can complete
65 * or delete objects from the request before req_queue exits.
66 */
67struct media_device_ops {
68 int (*link_notify)(struct media_link *link, u32 flags,
69 unsigned int notification);
70 struct media_request *(*req_alloc)(struct media_device *mdev);
71 void (*req_free)(struct media_request *req);
72 int (*req_validate)(struct media_request *req);
73 void (*req_queue)(struct media_request *req);
74};
75
76/**
77 * struct media_device - Media device
78 * @dev: Parent device
79 * @devnode: Media device node
80 * @driver_name: Optional device driver name. If not set, calls to
81 * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``.
82 * This is needed for USB drivers for example, as otherwise
83 * they'll all appear as if the driver name was "usb".
84 * @model: Device model name
85 * @serial: Device serial number (optional)
86 * @bus_info: Unique and stable device location identifier
87 * @hw_revision: Hardware device revision
88 * @topology_version: Monotonic counter for storing the version of the graph
89 * topology. Should be incremented each time the topology changes.
90 * @id: Unique ID used on the last registered graph object
91 * @entity_internal_idx: Unique internal entity ID used by the graph traversal
92 * algorithms
93 * @entity_internal_idx_max: Allocated internal entity indices
94 * @entities: List of registered entities
95 * @interfaces: List of registered interfaces
96 * @pads: List of registered pads
97 * @links: List of registered links
98 * @entity_notify: List of registered entity_notify callbacks
99 * @graph_mutex: Protects access to struct media_device data
100 * @pm_count_walk: Graph walk for power state walk. Access serialised using
101 * graph_mutex.
102 *
103 * @source_priv: Driver Private data for enable/disable source handlers
104 * @enable_source: Enable Source Handler function pointer
105 * @disable_source: Disable Source Handler function pointer
106 *
107 * @ops: Operation handler callbacks
108 * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
109 * other operations that stop or start streaming.
110 * @num_requests: number of associated requests
111 * @num_request_objects: number of associated request objects
112 * @media_dir: DebugFS media directory
113 * @request_id: Used to generate unique request IDs
114 *
115 * This structure represents an abstract high-level media device. It allows easy
116 * access to entities and provides basic media device-level support. The
117 * structure can be allocated directly or embedded in a larger structure.
118 *
119 * The parent @dev is a physical device. It must be set before registering the
120 * media device.
121 *
122 * @model is a descriptive model name exported through sysfs. It doesn't have to
123 * be unique.
124 *
125 * @enable_source is a handler to find source entity for the
126 * sink entity and activate the link between them if source
127 * entity is free. Drivers should call this handler before
128 * accessing the source.
129 *
130 * @disable_source is a handler to find source entity for the
131 * sink entity and deactivate the link between them. Drivers
132 * should call this handler to release the source.
133 *
134 * Use-case: find tuner entity connected to the decoder
135 * entity and check if it is available, and activate the
136 * link between them from @enable_source and deactivate
137 * from @disable_source.
138 *
139 * .. note::
140 *
141 * Bridge driver is expected to implement and set the
142 * handler when &media_device is registered or when
143 * bridge driver finds the media_device during probe.
144 * Bridge driver sets source_priv with information
145 * necessary to run @enable_source and @disable_source handlers.
146 * Callers should hold graph_mutex to access and call @enable_source
147 * and @disable_source handlers.
148 */
149struct media_device {
150 /* dev->driver_data points to this struct. */
151 struct device *dev;
152 struct media_devnode *devnode;
153
154 char model[32];
155 char driver_name[32];
156 char serial[40];
157 char bus_info[32];
158 u32 hw_revision;
159
160 u64 topology_version;
161
162 u32 id;
163 struct ida entity_internal_idx;
164 int entity_internal_idx_max;
165
166 struct list_head entities;
167 struct list_head interfaces;
168 struct list_head pads;
169 struct list_head links;
170
171 /* notify callback list invoked when a new entity is registered */
172 struct list_head entity_notify;
173
174 /* Serializes graph operations. */
175 struct mutex graph_mutex;
176 struct media_graph pm_count_walk;
177
178 void *source_priv;
179 int (*enable_source)(struct media_entity *entity,
180 struct media_pipeline *pipe);
181 void (*disable_source)(struct media_entity *entity);
182
183 const struct media_device_ops *ops;
184
185 struct mutex req_queue_mutex;
186 atomic_t num_requests;
187 atomic_t num_request_objects;
188
189 /* debugfs */
190 struct dentry *media_dir;
191 atomic_t request_id;
192};
193
194/* We don't need to include usb.h here */
195struct usb_device;
196
197#ifdef CONFIG_MEDIA_CONTROLLER
198
199/* Supported link_notify @notification values. */
200#define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0
201#define MEDIA_DEV_NOTIFY_POST_LINK_CH 1
202
203/**
204 * media_device_init() - Initializes a media device element
205 *
206 * @mdev: pointer to struct &media_device
207 *
208 * This function initializes the media device prior to its registration.
209 * The media device initialization and registration is split in two functions
210 * to avoid race conditions and make the media device available to user-space
211 * before the media graph has been completed.
212 *
213 * So drivers need to first initialize the media device, register any entity
214 * within the media device, create pad to pad links and then finally register
215 * the media device by calling media_device_register() as a final step.
216 *
217 * The caller is responsible for initializing the media device before
218 * registration. The following fields must be set:
219 *
220 * - dev must point to the parent device
221 * - model must be filled with the device model name
222 *
223 * The bus_info field is set by media_device_init() for PCI and platform devices
224 * if the field begins with '\0'.
225 */
226void media_device_init(struct media_device *mdev);
227
228/**
229 * media_device_cleanup() - Cleanups a media device element
230 *
231 * @mdev: pointer to struct &media_device
232 *
233 * This function that will destroy the graph_mutex that is
234 * initialized in media_device_init().
235 */
236void media_device_cleanup(struct media_device *mdev);
237
238/**
239 * __media_device_register() - Registers a media device element
240 *
241 * @mdev: pointer to struct &media_device
242 * @owner: should be filled with %THIS_MODULE
243 *
244 * Users, should, instead, call the media_device_register() macro.
245 *
246 * The caller is responsible for initializing the &media_device structure
247 * before registration. The following fields of &media_device must be set:
248 *
249 * - &media_device.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_device.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_device.bus_info represents the location of the device in the
261 * system as a NUL-terminated ASCII string. For PCI/PCIe devices
262 * &media_device.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_device.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 */
279int __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 */
301void 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 */
339int __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 */
361void 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
376void 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 */
387void 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 */
415void 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 */
435void __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
441static inline void media_device_init(struct media_device *mdev)
442{
443}
444static inline int media_device_register(struct media_device *mdev)
445{
446 return 0;
447}
448static inline void media_device_unregister(struct media_device *mdev)
449{
450}
451static inline void media_device_cleanup(struct media_device *mdev)
452{
453}
454static inline int media_device_register_entity(struct media_device *mdev,
455 struct media_entity *entity)
456{
457 return 0;
458}
459static inline void media_device_unregister_entity(struct media_entity *entity)
460{
461}
462static inline void media_device_register_entity_notify(
463 struct media_device *mdev,
464 struct media_entity_notify *nptr)
465{
466}
467static inline void media_device_unregister_entity_notify(
468 struct media_device *mdev,
469 struct media_entity_notify *nptr)
470{
471}
472
473static inline void media_device_pci_init(struct media_device *mdev,
474 struct pci_dev *pci_dev,
475 char *name)
476{
477}
478
479static inline void __media_device_usb_init(struct media_device *mdev,
480 struct usb_device *udev,
481 char *board_name,
482 char *driver_name)
483{
484}
485
486#endif /* CONFIG_MEDIA_CONTROLLER */
487
488/**
489 * media_device_usb_init() - create and initialize a
490 * struct &media_device from a PCI device.
491 *
492 * @mdev: pointer to struct &media_device
493 * @udev: pointer to struct usb_device
494 * @name: media device name. If %NULL, the routine will use the usb
495 * product name, if available.
496 *
497 * This macro calls media_device_usb_init() passing the
498 * media_device_usb_init() **driver_name** parameter filled with
499 * %KBUILD_MODNAME.
500 */
501#define media_device_usb_init(mdev, udev, name) \
502 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
503
504/**
505 * media_set_bus_info() - Set bus_info field
506 *
507 * @bus_info: Variable where to write the bus info (char array)
508 * @bus_info_size: Length of the bus_info
509 * @dev: Related struct device
510 *
511 * Sets bus information based on &dev. This is currently done for PCI and
512 * platform devices. dev is required to be non-NULL for this to happen.
513 *
514 * This function is not meant to be called from drivers.
515 */
516static inline void
517media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev)
518{
519 if (!dev)
520 strscpy(bus_info, "no bus info", bus_info_size);
521 else if (dev_is_platform(dev))
522 snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev));
523 else if (dev_is_pci(dev))
524 snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev));
525}
526
527#endif