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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 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#ifndef _MEDIA_DEVICE_H
24#define _MEDIA_DEVICE_H
25
26#include <linux/list.h>
27#include <linux/mutex.h>
28#include <linux/spinlock.h>
29
30#include <media/media-devnode.h>
31#include <media/media-entity.h>
32
33/**
34 * DOC: Media Controller
35 *
36 * The media controller userspace API is documented in DocBook format in
37 * Documentation/DocBook/media/v4l/media-controller.xml. This document focus
38 * on the kernel-side implementation of the media framework.
39 *
40 * * Abstract media device model:
41 *
42 * Discovering a device internal topology, and configuring it at runtime, is one
43 * of the goals of the media framework. To achieve this, hardware devices are
44 * modelled as an oriented graph of building blocks called entities connected
45 * through pads.
46 *
47 * An entity is a basic media hardware building block. It can correspond to
48 * a large variety of logical blocks such as physical hardware devices
49 * (CMOS sensor for instance), logical hardware devices (a building block
50 * in a System-on-Chip image processing pipeline), DMA channels or physical
51 * connectors.
52 *
53 * A pad is a connection endpoint through which an entity can interact with
54 * other entities. Data (not restricted to video) produced by an entity
55 * flows from the entity's output to one or more entity inputs. Pads should
56 * not be confused with physical pins at chip boundaries.
57 *
58 * A link is a point-to-point oriented connection between two pads, either
59 * on the same entity or on different entities. Data flows from a source
60 * pad to a sink pad.
61 *
62 *
63 * * Media device:
64 *
65 * A media device is represented by a struct &media_device instance, defined in
66 * include/media/media-device.h. Allocation of the structure is handled by the
67 * media device driver, usually by embedding the &media_device instance in a
68 * larger driver-specific structure.
69 *
70 * Drivers register media device instances by calling
71 * __media_device_register() via the macro media_device_register()
72 * and unregistered by calling
73 * media_device_unregister().
74 *
75 * * Entities, pads and links:
76 *
77 * - Entities
78 *
79 * Entities are represented by a struct &media_entity instance, defined in
80 * include/media/media-entity.h. The structure is usually embedded into a
81 * higher-level structure, such as a v4l2_subdev or video_device instance,
82 * although drivers can allocate entities directly.
83 *
84 * Drivers initialize entity pads by calling
85 * media_entity_pads_init().
86 *
87 * Drivers register entities with a media device by calling
88 * media_device_register_entity()
89 * and unregistred by calling
90 * media_device_unregister_entity().
91 *
92 * - Interfaces
93 *
94 * Interfaces are represented by a struct &media_interface instance, defined in
95 * include/media/media-entity.h. Currently, only one type of interface is
96 * defined: a device node. Such interfaces are represented by a struct
97 * &media_intf_devnode.
98 *
99 * Drivers initialize and create device node interfaces by calling
100 * media_devnode_create()
101 * and remove them by calling:
102 * media_devnode_remove().
103 *
104 * - Pads
105 *
106 * Pads are represented by a struct &media_pad instance, defined in
107 * include/media/media-entity.h. Each entity stores its pads in a pads array
108 * managed by the entity driver. Drivers usually embed the array in a
109 * driver-specific structure.
110 *
111 * Pads are identified by their entity and their 0-based index in the pads
112 * array.
113 * Both information are stored in the &media_pad structure, making the
114 * &media_pad pointer the canonical way to store and pass link references.
115 *
116 * Pads have flags that describe the pad capabilities and state.
117 *
118 * %MEDIA_PAD_FL_SINK indicates that the pad supports sinking data.
119 * %MEDIA_PAD_FL_SOURCE indicates that the pad supports sourcing data.
120 *
121 * NOTE: One and only one of %MEDIA_PAD_FL_SINK and %MEDIA_PAD_FL_SOURCE must
122 * be set for each pad.
123 *
124 * - Links
125 *
126 * Links are represented by a struct &media_link instance, defined in
127 * include/media/media-entity.h. There are two types of links:
128 *
129 * 1. pad to pad links:
130 *
131 * Associate two entities via their PADs. Each entity has a list that points
132 * to all links originating at or targeting any of its pads.
133 * A given link is thus stored twice, once in the source entity and once in
134 * the target entity.
135 *
136 * Drivers create pad to pad links by calling:
137 * media_create_pad_link() and remove with media_entity_remove_links().
138 *
139 * 2. interface to entity links:
140 *
141 * Associate one interface to a Link.
142 *
143 * Drivers create interface to entity links by calling:
144 * media_create_intf_link() and remove with media_remove_intf_links().
145 *
146 * NOTE:
147 *
148 * Links can only be created after having both ends already created.
149 *
150 * Links have flags that describe the link capabilities and state. The
151 * valid values are described at media_create_pad_link() and
152 * media_create_intf_link().
153 *
154 * Graph traversal:
155 *
156 * The media framework provides APIs to iterate over entities in a graph.
157 *
158 * To iterate over all entities belonging to a media device, drivers can use
159 * the media_device_for_each_entity macro, defined in
160 * include/media/media-device.h.
161 *
162 * struct media_entity *entity;
163 *
164 * media_device_for_each_entity(entity, mdev) {
165 * // entity will point to each entity in turn
166 * ...
167 * }
168 *
169 * Drivers might also need to iterate over all entities in a graph that can be
170 * reached only through enabled links starting at a given entity. The media
171 * framework provides a depth-first graph traversal API for that purpose.
172 *
173 * Note that graphs with cycles (whether directed or undirected) are *NOT*
174 * supported by the graph traversal API. To prevent infinite loops, the graph
175 * traversal code limits the maximum depth to MEDIA_ENTITY_ENUM_MAX_DEPTH,
176 * currently defined as 16.
177 *
178 * Drivers initiate a graph traversal by calling
179 * media_entity_graph_walk_start()
180 *
181 * The graph structure, provided by the caller, is initialized to start graph
182 * traversal at the given entity.
183 *
184 * Drivers can then retrieve the next entity by calling
185 * media_entity_graph_walk_next()
186 *
187 * When the graph traversal is complete the function will return NULL.
188 *
189 * Graph traversal can be interrupted at any moment. No cleanup function call
190 * is required and the graph structure can be freed normally.
191 *
192 * Helper functions can be used to find a link between two given pads, or a pad
193 * connected to another pad through an enabled link
194 * media_entity_find_link() and media_entity_remote_pad()
195 *
196 * Use count and power handling:
197 *
198 * Due to the wide differences between drivers regarding power management
199 * needs, the media controller does not implement power management. However,
200 * the &media_entity structure includes a use_count field that media drivers
201 * can use to track the number of users of every entity for power management
202 * needs.
203 *
204 * The &media_entity.@use_count field is owned by media drivers and must not be
205 * touched by entity drivers. Access to the field must be protected by the
206 * &media_device.@graph_mutex lock.
207 *
208 * Links setup:
209 *
210 * Link properties can be modified at runtime by calling
211 * media_entity_setup_link()
212 *
213 * Pipelines and media streams:
214 *
215 * When starting streaming, drivers must notify all entities in the pipeline to
216 * prevent link states from being modified during streaming by calling
217 * media_entity_pipeline_start().
218 *
219 * The function will mark all entities connected to the given entity through
220 * enabled links, either directly or indirectly, as streaming.
221 *
222 * The &media_pipeline instance pointed to by the pipe argument will be stored
223 * in every entity in the pipeline. Drivers should embed the &media_pipeline
224 * structure in higher-level pipeline structures and can then access the
225 * pipeline through the &media_entity pipe field.
226 *
227 * Calls to media_entity_pipeline_start() can be nested. The pipeline pointer
228 * must be identical for all nested calls to the function.
229 *
230 * media_entity_pipeline_start() may return an error. In that case, it will
231 * clean up any of the changes it did by itself.
232 *
233 * When stopping the stream, drivers must notify the entities with
234 * media_entity_pipeline_stop().
235 *
236 * If multiple calls to media_entity_pipeline_start() have been made the same
237 * number of media_entity_pipeline_stop() calls are required to stop streaming.
238 * The &media_entity pipe field is reset to NULL on the last nested stop call.
239 *
240 * Link configuration will fail with -%EBUSY by default if either end of the
241 * link is a streaming entity. Links that can be modified while streaming must
242 * be marked with the %MEDIA_LNK_FL_DYNAMIC flag.
243 *
244 * If other operations need to be disallowed on streaming entities (such as
245 * changing entities configuration parameters) drivers can explicitly check the
246 * media_entity stream_count field to find out if an entity is streaming. This
247 * operation must be done with the media_device graph_mutex held.
248 *
249 * Link validation:
250 *
251 * Link validation is performed by media_entity_pipeline_start() for any
252 * entity which has sink pads in the pipeline. The
253 * &media_entity.@link_validate() callback is used for that purpose. In
254 * @link_validate() callback, entity driver should check that the properties of
255 * the source pad of the connected entity and its own sink pad match. It is up
256 * to the type of the entity (and in the end, the properties of the hardware)
257 * what matching actually means.
258 *
259 * Subsystems should facilitate link validation by providing subsystem specific
260 * helper functions to provide easy access for commonly needed information, and
261 * in the end provide a way to use driver-specific callbacks.
262 */
263
264struct ida;
265struct device;
266
267/**
268 * struct media_entity_notify - Media Entity Notify
269 *
270 * @list: List head
271 * @notify_data: Input data to invoke the callback
272 * @notify: Callback function pointer
273 *
274 * Drivers may register a callback to take action when
275 * new entities get registered with the media device.
276 */
277struct media_entity_notify {
278 struct list_head list;
279 void *notify_data;
280 void (*notify)(struct media_entity *entity, void *notify_data);
281};
282
283/**
284 * struct media_device - Media device
285 * @dev: Parent device
286 * @devnode: Media device node
287 * @driver_name: Optional device driver name. If not set, calls to
288 * %MEDIA_IOC_DEVICE_INFO will return dev->driver->name.
289 * This is needed for USB drivers for example, as otherwise
290 * they'll all appear as if the driver name was "usb".
291 * @model: Device model name
292 * @serial: Device serial number (optional)
293 * @bus_info: Unique and stable device location identifier
294 * @hw_revision: Hardware device revision
295 * @driver_version: Device driver version
296 * @topology_version: Monotonic counter for storing the version of the graph
297 * topology. Should be incremented each time the topology changes.
298 * @id: Unique ID used on the last registered graph object
299 * @entity_internal_idx: Unique internal entity ID used by the graph traversal
300 * algorithms
301 * @entity_internal_idx_max: Allocated internal entity indices
302 * @entities: List of registered entities
303 * @interfaces: List of registered interfaces
304 * @pads: List of registered pads
305 * @links: List of registered links
306 * @entity_notify: List of registered entity_notify callbacks
307 * @lock: Entities list lock
308 * @graph_mutex: Entities graph operation lock
309 * @pm_count_walk: Graph walk for power state walk. Access serialised using
310 * graph_mutex.
311 *
312 * @source_priv: Driver Private data for enable/disable source handlers
313 * @enable_source: Enable Source Handler function pointer
314 * @disable_source: Disable Source Handler function pointer
315 *
316 * @link_notify: Link state change notification callback
317 *
318 * This structure represents an abstract high-level media device. It allows easy
319 * access to entities and provides basic media device-level support. The
320 * structure can be allocated directly or embedded in a larger structure.
321 *
322 * The parent @dev is a physical device. It must be set before registering the
323 * media device.
324 *
325 * @model is a descriptive model name exported through sysfs. It doesn't have to
326 * be unique.
327 *
328 * @enable_source is a handler to find source entity for the
329 * sink entity and activate the link between them if source
330 * entity is free. Drivers should call this handler before
331 * accessing the source.
332 *
333 * @disable_source is a handler to find source entity for the
334 * sink entity and deactivate the link between them. Drivers
335 * should call this handler to release the source.
336 *
337 * Note: Bridge driver is expected to implement and set the
338 * handler when media_device is registered or when
339 * bridge driver finds the media_device during probe.
340 * Bridge driver sets source_priv with information
341 * necessary to run enable/disable source handlers.
342 *
343 * Use-case: find tuner entity connected to the decoder
344 * entity and check if it is available, and activate the
345 * the link between them from enable_source and deactivate
346 * from disable_source.
347 */
348struct media_device {
349 /* dev->driver_data points to this struct. */
350 struct device *dev;
351 struct media_devnode devnode;
352
353 char model[32];
354 char driver_name[32];
355 char serial[40];
356 char bus_info[32];
357 u32 hw_revision;
358 u32 driver_version;
359
360 u32 topology_version;
361
362 u32 id;
363 struct ida entity_internal_idx;
364 int entity_internal_idx_max;
365
366 struct list_head entities;
367 struct list_head interfaces;
368 struct list_head pads;
369 struct list_head links;
370
371 /* notify callback list invoked when a new entity is registered */
372 struct list_head entity_notify;
373
374 /* Protects the graph objects creation/removal */
375 spinlock_t lock;
376 /* Serializes graph operations. */
377 struct mutex graph_mutex;
378 struct media_entity_graph pm_count_walk;
379
380 void *source_priv;
381 int (*enable_source)(struct media_entity *entity,
382 struct media_pipeline *pipe);
383 void (*disable_source)(struct media_entity *entity);
384
385 int (*link_notify)(struct media_link *link, u32 flags,
386 unsigned int notification);
387};
388
389/* We don't need to include pci.h or usb.h here */
390struct pci_dev;
391struct usb_device;
392
393#ifdef CONFIG_MEDIA_CONTROLLER
394
395/* Supported link_notify @notification values. */
396#define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0
397#define MEDIA_DEV_NOTIFY_POST_LINK_CH 1
398
399/* media_devnode to media_device */
400#define to_media_device(node) container_of(node, struct media_device, devnode)
401
402/**
403 * media_entity_enum_init - Initialise an entity enumeration
404 *
405 * @ent_enum: Entity enumeration to be initialised
406 * @mdev: The related media device
407 *
408 * Returns zero on success or a negative error code.
409 */
410static inline __must_check int media_entity_enum_init(
411 struct media_entity_enum *ent_enum, struct media_device *mdev)
412{
413 return __media_entity_enum_init(ent_enum,
414 mdev->entity_internal_idx_max + 1);
415}
416
417/**
418 * media_device_init() - Initializes a media device element
419 *
420 * @mdev: pointer to struct &media_device
421 *
422 * This function initializes the media device prior to its registration.
423 * The media device initialization and registration is split in two functions
424 * to avoid race conditions and make the media device available to user-space
425 * before the media graph has been completed.
426 *
427 * So drivers need to first initialize the media device, register any entity
428 * within the media device, create pad to pad links and then finally register
429 * the media device by calling media_device_register() as a final step.
430 */
431void media_device_init(struct media_device *mdev);
432
433/**
434 * media_device_cleanup() - Cleanups a media device element
435 *
436 * @mdev: pointer to struct &media_device
437 *
438 * This function that will destroy the graph_mutex that is
439 * initialized in media_device_init().
440 */
441void media_device_cleanup(struct media_device *mdev);
442
443/**
444 * __media_device_register() - Registers a media device element
445 *
446 * @mdev: pointer to struct &media_device
447 * @owner: should be filled with %THIS_MODULE
448 *
449 * Users, should, instead, call the media_device_register() macro.
450 *
451 * The caller is responsible for initializing the media_device structure before
452 * registration. The following fields must be set:
453 *
454 * - dev must point to the parent device (usually a &pci_dev, &usb_interface or
455 * &platform_device instance).
456 *
457 * - model must be filled with the device model name as a NUL-terminated UTF-8
458 * string. The device/model revision must not be stored in this field.
459 *
460 * The following fields are optional:
461 *
462 * - serial is a unique serial number stored as a NUL-terminated ASCII string.
463 * The field is big enough to store a GUID in text form. If the hardware
464 * doesn't provide a unique serial number this field must be left empty.
465 *
466 * - bus_info represents the location of the device in the system as a
467 * NUL-terminated ASCII string. For PCI/PCIe devices bus_info must be set to
468 * "PCI:" (or "PCIe:") followed by the value of pci_name(). For USB devices,
469 * the usb_make_path() function must be used. This field is used by
470 * applications to distinguish between otherwise identical devices that don't
471 * provide a serial number.
472 *
473 * - hw_revision is the hardware device revision in a driver-specific format.
474 * When possible the revision should be formatted with the KERNEL_VERSION
475 * macro.
476 *
477 * - driver_version is formatted with the KERNEL_VERSION macro. The version
478 * minor must be incremented when new features are added to the userspace API
479 * without breaking binary compatibility. The version major must be
480 * incremented when binary compatibility is broken.
481 *
482 * Notes:
483 *
484 * Upon successful registration a character device named media[0-9]+ is created.
485 * The device major and minor numbers are dynamic. The model name is exported as
486 * a sysfs attribute.
487 *
488 * Unregistering a media device that hasn't been registered is *NOT* safe.
489 *
490 * Return: returns zero on success or a negative error code.
491 */
492int __must_check __media_device_register(struct media_device *mdev,
493 struct module *owner);
494#define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
495
496/**
497 * __media_device_unregister() - Unegisters a media device element
498 *
499 * @mdev: pointer to struct &media_device
500 *
501 *
502 * It is safe to call this function on an unregistered (but initialised)
503 * media device.
504 */
505void media_device_unregister(struct media_device *mdev);
506
507/**
508 * media_device_register_entity() - registers a media entity inside a
509 * previously registered media device.
510 *
511 * @mdev: pointer to struct &media_device
512 * @entity: pointer to struct &media_entity to be registered
513 *
514 * Entities are identified by a unique positive integer ID. The media
515 * controller framework will such ID automatically. IDs are not guaranteed
516 * to be contiguous, and the ID number can change on newer Kernel versions.
517 * So, neither the driver nor userspace should hardcode ID numbers to refer
518 * to the entities, but, instead, use the framework to find the ID, when
519 * needed.
520 *
521 * The media_entity name, type and flags fields should be initialized before
522 * calling media_device_register_entity(). Entities embedded in higher-level
523 * standard structures can have some of those fields set by the higher-level
524 * framework.
525 *
526 * If the device has pads, media_entity_pads_init() should be called before
527 * this function. Otherwise, the &media_entity.@pad and &media_entity.@num_pads
528 * should be zeroed before calling this function.
529 *
530 * Entities have flags that describe the entity capabilities and state:
531 *
532 * %MEDIA_ENT_FL_DEFAULT indicates the default entity for a given type.
533 * This can be used to report the default audio and video devices or the
534 * default camera sensor.
535 *
536 * NOTE: Drivers should set the entity function before calling this function.
537 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and
538 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers.
539 */
540int __must_check media_device_register_entity(struct media_device *mdev,
541 struct media_entity *entity);
542
543/*
544 * media_device_unregister_entity() - unregisters a media entity.
545 *
546 * @entity: pointer to struct &media_entity to be unregistered
547 *
548 * All links associated with the entity and all PADs are automatically
549 * unregistered from the media_device when this function is called.
550 *
551 * Unregistering an entity will not change the IDs of the other entities and
552 * the previoully used ID will never be reused for a newly registered entities.
553 *
554 * When a media device is unregistered, all its entities are unregistered
555 * automatically. No manual entities unregistration is then required.
556 *
557 * Note: the media_entity instance itself must be freed explicitly by
558 * the driver if required.
559 */
560void media_device_unregister_entity(struct media_entity *entity);
561
562/**
563 * media_device_register_entity_notify() - Registers a media entity_notify
564 * callback
565 *
566 * @mdev: The media device
567 * @nptr: The media_entity_notify
568 *
569 * Note: When a new entity is registered, all the registered
570 * media_entity_notify callbacks are invoked.
571 */
572
573int __must_check media_device_register_entity_notify(struct media_device *mdev,
574 struct media_entity_notify *nptr);
575
576/**
577 * media_device_unregister_entity_notify() - Unregister a media entity notify
578 * callback
579 *
580 * @mdev: The media device
581 * @nptr: The media_entity_notify
582 *
583 */
584void media_device_unregister_entity_notify(struct media_device *mdev,
585 struct media_entity_notify *nptr);
586
587/**
588 * media_device_get_devres() - get media device as device resource
589 * creates if one doesn't exist
590 *
591 * @dev: pointer to struct &device.
592 *
593 * Sometimes, the media controller &media_device needs to be shared by more
594 * than one driver. This function adds support for that, by dynamically
595 * allocating the &media_device and allowing it to be obtained from the
596 * struct &device associated with the common device where all sub-device
597 * components belong. So, for example, on an USB device with multiple
598 * interfaces, each interface may be handled by a separate per-interface
599 * drivers. While each interface have its own &device, they all share a
600 * common &device associated with the hole USB device.
601 */
602struct media_device *media_device_get_devres(struct device *dev);
603
604/**
605 * media_device_find_devres() - find media device as device resource
606 *
607 * @dev: pointer to struct &device.
608 */
609struct media_device *media_device_find_devres(struct device *dev);
610
611/* Iterate over all entities. */
612#define media_device_for_each_entity(entity, mdev) \
613 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list)
614
615/* Iterate over all interfaces. */
616#define media_device_for_each_intf(intf, mdev) \
617 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list)
618
619/* Iterate over all pads. */
620#define media_device_for_each_pad(pad, mdev) \
621 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list)
622
623/* Iterate over all links. */
624#define media_device_for_each_link(link, mdev) \
625 list_for_each_entry(link, &(mdev)->links, graph_obj.list)
626
627/**
628 * media_device_pci_init() - create and initialize a
629 * struct &media_device from a PCI device.
630 *
631 * @mdev: pointer to struct &media_device
632 * @pci_dev: pointer to struct pci_dev
633 * @name: media device name. If %NULL, the routine will use the default
634 * name for the pci device, given by pci_name() macro.
635 */
636void media_device_pci_init(struct media_device *mdev,
637 struct pci_dev *pci_dev,
638 const char *name);
639/**
640 * __media_device_usb_init() - create and initialize a
641 * struct &media_device from a PCI device.
642 *
643 * @mdev: pointer to struct &media_device
644 * @udev: pointer to struct usb_device
645 * @board_name: media device name. If %NULL, the routine will use the usb
646 * product name, if available.
647 * @driver_name: name of the driver. if %NULL, the routine will use the name
648 * given by udev->dev->driver->name, with is usually the wrong
649 * thing to do.
650 *
651 * NOTE: It is better to call media_device_usb_init() instead, as
652 * such macro fills driver_name with %KBUILD_MODNAME.
653 */
654void __media_device_usb_init(struct media_device *mdev,
655 struct usb_device *udev,
656 const char *board_name,
657 const char *driver_name);
658
659#else
660static inline int media_device_register(struct media_device *mdev)
661{
662 return 0;
663}
664static inline void media_device_unregister(struct media_device *mdev)
665{
666}
667static inline int media_device_register_entity(struct media_device *mdev,
668 struct media_entity *entity)
669{
670 return 0;
671}
672static inline void media_device_unregister_entity(struct media_entity *entity)
673{
674}
675static inline int media_device_register_entity_notify(
676 struct media_device *mdev,
677 struct media_entity_notify *nptr)
678{
679 return 0;
680}
681static inline void media_device_unregister_entity_notify(
682 struct media_device *mdev,
683 struct media_entity_notify *nptr)
684{
685}
686static inline struct media_device *media_device_get_devres(struct device *dev)
687{
688 return NULL;
689}
690static inline struct media_device *media_device_find_devres(struct device *dev)
691{
692 return NULL;
693}
694
695static inline void media_device_pci_init(struct media_device *mdev,
696 struct pci_dev *pci_dev,
697 char *name)
698{
699}
700
701static inline void __media_device_usb_init(struct media_device *mdev,
702 struct usb_device *udev,
703 char *board_name,
704 char *driver_name)
705{
706}
707
708#endif /* CONFIG_MEDIA_CONTROLLER */
709
710#define media_device_usb_init(mdev, udev, name) \
711 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
712
713#endif
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
20struct ida;
21struct device;
22struct 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 */
36struct 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 */
65struct 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 * 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 */
144struct 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 */
185struct pci_dev;
186struct 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 */
202static 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 */
223void 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 */
233void 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 */
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
376int __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 */
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 int media_device_register(struct media_device *mdev)
442{
443 return 0;
444}
445static inline void media_device_unregister(struct media_device *mdev)
446{
447}
448static inline int media_device_register_entity(struct media_device *mdev,
449 struct media_entity *entity)
450{
451 return 0;
452}
453static inline void media_device_unregister_entity(struct media_entity *entity)
454{
455}
456static inline int media_device_register_entity_notify(
457 struct media_device *mdev,
458 struct media_entity_notify *nptr)
459{
460 return 0;
461}
462static inline void media_device_unregister_entity_notify(
463 struct media_device *mdev,
464 struct media_entity_notify *nptr)
465{
466}
467
468static inline void media_device_pci_init(struct media_device *mdev,
469 struct pci_dev *pci_dev,
470 char *name)
471{
472}
473
474static 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