1 /* SPDX-License-Identifier: GPL-2.0-only */
5 * Copyright (C) 2010 Nokia Corporation
7 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8 * Sakari Ailus <sakari.ailus@iki.fi>
11 #ifndef _MEDIA_DEVICE_H
12 #define _MEDIA_DEVICE_H
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 #include <linux/pci.h>
17 #include <linux/platform_device.h>
19 #include <media/media-devnode.h>
20 #include <media/media-entity.h>
26 * struct media_entity_notify - Media Entity Notify
29 * @notify_data: Input data to invoke the callback
30 * @notify: Callback function pointer
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
37 struct media_entity_notify {
38 struct list_head list;
40 void (*notify)(struct media_entity *entity, void *notify_data);
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
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.
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);
76 * struct media_device - Media 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
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
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
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
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.
115 * The parent @dev is a physical device. It must be set before registering the
118 * @model is a descriptive model name exported through sysfs. It doesn't have to
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.
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.
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.
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.
145 struct media_device {
146 /* dev->driver_data points to this struct. */
148 struct media_devnode *devnode;
151 char driver_name[32];
156 u64 topology_version;
159 struct ida entity_internal_idx;
160 int entity_internal_idx_max;
162 struct list_head entities;
163 struct list_head interfaces;
164 struct list_head pads;
165 struct list_head links;
167 /* notify callback list invoked when a new entity is registered */
168 struct list_head entity_notify;
170 /* Serializes graph operations. */
171 struct mutex graph_mutex;
172 struct media_graph pm_count_walk;
175 int (*enable_source)(struct media_entity *entity,
176 struct media_pipeline *pipe);
177 void (*disable_source)(struct media_entity *entity);
179 const struct media_device_ops *ops;
181 struct mutex req_queue_mutex;
185 /* We don't need to include usb.h here */
188 #ifdef CONFIG_MEDIA_CONTROLLER
190 /* Supported link_notify @notification values. */
191 #define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0
192 #define MEDIA_DEV_NOTIFY_POST_LINK_CH 1
195 * media_entity_enum_init - Initialise an entity enumeration
197 * @ent_enum: Entity enumeration to be initialised
198 * @mdev: The related media device
200 * Return: zero on success or a negative error code.
202 static inline __must_check int media_entity_enum_init(
203 struct media_entity_enum *ent_enum, struct media_device *mdev)
205 return __media_entity_enum_init(ent_enum,
206 mdev->entity_internal_idx_max + 1);
210 * media_device_init() - Initializes a media device element
212 * @mdev: pointer to struct &media_device
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.
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.
223 * The caller is responsible for initializing the media device before
224 * registration. The following fields must be set:
226 * - dev must point to the parent device
227 * - model must be filled with the device model name
229 * The bus_info field is set by media_device_init() for PCI and platform devices
230 * if the field begins with '\0'.
232 void media_device_init(struct media_device *mdev);
235 * media_device_cleanup() - Cleanups a media device element
237 * @mdev: pointer to struct &media_device
239 * This function that will destroy the graph_mutex that is
240 * initialized in media_device_init().
242 void media_device_cleanup(struct media_device *mdev);
245 * __media_device_register() - Registers a media device element
247 * @mdev: pointer to struct &media_device
248 * @owner: should be filled with %THIS_MODULE
250 * Users, should, instead, call the media_device_register() macro.
252 * The caller is responsible for initializing the &media_device structure
253 * before registration. The following fields of &media_device must be set:
255 * - &media_device.model must be filled with the device model name as a
256 * NUL-terminated UTF-8 string. The device/model revision must not be
257 * stored in this field.
259 * The following fields are optional:
261 * - &media_device.serial is a unique serial number stored as a
262 * NUL-terminated ASCII string. The field is big enough to store a GUID
263 * in text form. If the hardware doesn't provide a unique serial number
264 * this field must be left empty.
266 * - &media_device.bus_info represents the location of the device in the
267 * system as a NUL-terminated ASCII string. For PCI/PCIe devices
268 * &media_device.bus_info must be set to "PCI:" (or "PCIe:") followed by
269 * the value of pci_name(). For USB devices,the usb_make_path() function
270 * must be used. This field is used by applications to distinguish between
271 * otherwise identical devices that don't provide a serial number.
273 * - &media_device.hw_revision is the hardware device revision in a
274 * driver-specific format. When possible the revision should be formatted
275 * with the KERNEL_VERSION() macro.
279 * #) 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.
281 * #) Unregistering a media device that hasn't been registered is **NOT** safe.
283 * Return: returns zero on success or a negative error code.
285 int __must_check __media_device_register(struct media_device *mdev,
286 struct module *owner);
290 * media_device_register() - Registers a media device element
292 * @mdev: pointer to struct &media_device
294 * This macro calls __media_device_register() passing %THIS_MODULE as
295 * the __media_device_register() second argument (**owner**).
297 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
300 * media_device_unregister() - Unregisters a media device element
302 * @mdev: pointer to struct &media_device
304 * It is safe to call this function on an unregistered (but initialised)
307 void media_device_unregister(struct media_device *mdev);
310 * media_device_register_entity() - registers a media entity inside a
311 * previously registered media device.
313 * @mdev: pointer to struct &media_device
314 * @entity: pointer to struct &media_entity to be registered
316 * Entities are identified by a unique positive integer ID. The media
317 * controller framework will such ID automatically. IDs are not guaranteed
318 * to be contiguous, and the ID number can change on newer Kernel versions.
319 * So, neither the driver nor userspace should hardcode ID numbers to refer
320 * to the entities, but, instead, use the framework to find the ID, when
323 * The media_entity name, type and flags fields should be initialized before
324 * calling media_device_register_entity(). Entities embedded in higher-level
325 * standard structures can have some of those fields set by the higher-level
328 * If the device has pads, media_entity_pads_init() should be called before
329 * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads
330 * should be zeroed before calling this function.
332 * Entities have flags that describe the entity capabilities and state:
334 * %MEDIA_ENT_FL_DEFAULT
335 * indicates the default entity for a given type.
336 * This can be used to report the default audio and video devices or the
337 * default camera sensor.
341 * Drivers should set the entity function before calling this function.
342 * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and
343 * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers.
345 int __must_check media_device_register_entity(struct media_device *mdev,
346 struct media_entity *entity);
349 * media_device_unregister_entity() - unregisters a media entity.
351 * @entity: pointer to struct &media_entity to be unregistered
353 * All links associated with the entity and all PADs are automatically
354 * unregistered from the media_device when this function is called.
356 * Unregistering an entity will not change the IDs of the other entities and
357 * the previoully used ID will never be reused for a newly registered entities.
359 * When a media device is unregistered, all its entities are unregistered
360 * automatically. No manual entities unregistration is then required.
364 * The media_entity instance itself must be freed explicitly by
365 * the driver if required.
367 void media_device_unregister_entity(struct media_entity *entity);
370 * media_device_register_entity_notify() - Registers a media entity_notify
373 * @mdev: The media device
374 * @nptr: The media_entity_notify
378 * When a new entity is registered, all the registered
379 * media_entity_notify callbacks are invoked.
382 int __must_check media_device_register_entity_notify(struct media_device *mdev,
383 struct media_entity_notify *nptr);
386 * media_device_unregister_entity_notify() - Unregister a media entity notify
389 * @mdev: The media device
390 * @nptr: The media_entity_notify
393 void media_device_unregister_entity_notify(struct media_device *mdev,
394 struct media_entity_notify *nptr);
396 /* Iterate over all entities. */
397 #define media_device_for_each_entity(entity, mdev) \
398 list_for_each_entry(entity, &(mdev)->entities, graph_obj.list)
400 /* Iterate over all interfaces. */
401 #define media_device_for_each_intf(intf, mdev) \
402 list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list)
404 /* Iterate over all pads. */
405 #define media_device_for_each_pad(pad, mdev) \
406 list_for_each_entry(pad, &(mdev)->pads, graph_obj.list)
408 /* Iterate over all links. */
409 #define media_device_for_each_link(link, mdev) \
410 list_for_each_entry(link, &(mdev)->links, graph_obj.list)
413 * media_device_pci_init() - create and initialize a
414 * struct &media_device from a PCI device.
416 * @mdev: pointer to struct &media_device
417 * @pci_dev: pointer to struct pci_dev
418 * @name: media device name. If %NULL, the routine will use the default
419 * name for the pci device, given by pci_name() macro.
421 void media_device_pci_init(struct media_device *mdev,
422 struct pci_dev *pci_dev,
425 * __media_device_usb_init() - create and initialize a
426 * struct &media_device from a PCI device.
428 * @mdev: pointer to struct &media_device
429 * @udev: pointer to struct usb_device
430 * @board_name: media device name. If %NULL, the routine will use the usb
431 * product name, if available.
432 * @driver_name: name of the driver. if %NULL, the routine will use the name
433 * given by ``udev->dev->driver->name``, with is usually the wrong
438 * It is better to call media_device_usb_init() instead, as
439 * such macro fills driver_name with %KBUILD_MODNAME.
441 void __media_device_usb_init(struct media_device *mdev,
442 struct usb_device *udev,
443 const char *board_name,
444 const char *driver_name);
447 static inline int media_device_register(struct media_device *mdev)
451 static inline void media_device_unregister(struct media_device *mdev)
454 static inline int media_device_register_entity(struct media_device *mdev,
455 struct media_entity *entity)
459 static inline void media_device_unregister_entity(struct media_entity *entity)
462 static inline int media_device_register_entity_notify(
463 struct media_device *mdev,
464 struct media_entity_notify *nptr)
468 static inline void media_device_unregister_entity_notify(
469 struct media_device *mdev,
470 struct media_entity_notify *nptr)
474 static inline void media_device_pci_init(struct media_device *mdev,
475 struct pci_dev *pci_dev,
480 static inline void __media_device_usb_init(struct media_device *mdev,
481 struct usb_device *udev,
487 #endif /* CONFIG_MEDIA_CONTROLLER */
490 * media_device_usb_init() - create and initialize a
491 * struct &media_device from a PCI device.
493 * @mdev: pointer to struct &media_device
494 * @udev: pointer to struct usb_device
495 * @name: media device name. If %NULL, the routine will use the usb
496 * product name, if available.
498 * This macro calls media_device_usb_init() passing the
499 * media_device_usb_init() **driver_name** parameter filled with
502 #define media_device_usb_init(mdev, udev, name) \
503 __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
506 * media_set_bus_info() - Set bus_info field
508 * @bus_info: Variable where to write the bus info (char array)
509 * @bus_info_size: Length of the bus_info
510 * @dev: Related struct device
512 * Sets bus information based on &dev. This is currently done for PCI and
513 * platform devices. dev is required to be non-NULL for this to happen.
515 * This function is not meant to be called from drivers.
518 media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev)
521 strscpy(bus_info, "no bus info", bus_info_size);
522 else if (dev_is_platform(dev))
523 snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev));
524 else if (dev_is_pci(dev))
525 snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev));