/* SPDX-License-Identifier: GPL-2.0-only */ /* * Media device * * Copyright (C) 2010 Nokia Corporation * * Contacts: Laurent Pinchart <[email protected]> * Sakari Ailus <[email protected]> */ #ifndef _MEDIA_DEVICE_H #define _MEDIA_DEVICE_H #include <linux/list.h> #include <linux/mutex.h> #include <linux/pci.h> #include <linux/platform_device.h> #include <media/media-devnode.h> #include <media/media-entity.h> struct ida; struct media_device; /** * struct media_entity_notify - Media Entity Notify * * @list: List head * @notify_data: Input data to invoke the callback * @notify: Callback function pointer * * Drivers may register a callback to take action when new entities get * registered with the media device. This handler is intended for creating * links between existing entities and should not create entities and register * them. */ struct media_entity_notify { … }; /** * struct media_device_ops - Media device operations * @link_notify: Link state change notification callback. This callback is * called with the graph_mutex held. * @req_alloc: Allocate a request. Set this if you need to allocate a struct * larger then struct media_request. @req_alloc and @req_free must * either both be set or both be NULL. * @req_free: Free a request. Set this if @req_alloc was set as well, leave * to NULL otherwise. * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex * lock is held when this op is called. * @req_queue: Queue a validated request, cannot fail. If something goes * wrong when queueing this request then it should be marked * as such internally in the driver and any related buffers * must eventually return to vb2 with state VB2_BUF_STATE_ERROR. * The req_queue_mutex lock is held when this op is called. * It is important that vb2 buffer objects are queued last after * all other object types are queued: queueing a buffer kickstarts * the request processing, so all other objects related to the * request (and thus the buffer) must be available to the driver. * And once a buffer is queued, then the driver can complete * or delete objects from the request before req_queue exits. */ struct media_device_ops { … }; /** * struct media_device - Media device * @dev: Parent device * @devnode: Media device node * @driver_name: Optional device driver name. If not set, calls to * %MEDIA_IOC_DEVICE_INFO will return ``dev->driver->name``. * This is needed for USB drivers for example, as otherwise * they'll all appear as if the driver name was "usb". * @model: Device model name * @serial: Device serial number (optional) * @bus_info: Unique and stable device location identifier * @hw_revision: Hardware device revision * @topology_version: Monotonic counter for storing the version of the graph * topology. Should be incremented each time the topology changes. * @id: Unique ID used on the last registered graph object * @entity_internal_idx: Unique internal entity ID used by the graph traversal * algorithms * @entity_internal_idx_max: Allocated internal entity indices * @entities: List of registered entities * @interfaces: List of registered interfaces * @pads: List of registered pads * @links: List of registered links * @entity_notify: List of registered entity_notify callbacks * @graph_mutex: Protects access to struct media_device data * @pm_count_walk: Graph walk for power state walk. Access serialised using * graph_mutex. * * @source_priv: Driver Private data for enable/disable source handlers * @enable_source: Enable Source Handler function pointer * @disable_source: Disable Source Handler function pointer * * @ops: Operation handler callbacks * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. * other operations that stop or start streaming. * @request_id: Used to generate unique request IDs * * This structure represents an abstract high-level media device. It allows easy * access to entities and provides basic media device-level support. The * structure can be allocated directly or embedded in a larger structure. * * The parent @dev is a physical device. It must be set before registering the * media device. * * @model is a descriptive model name exported through sysfs. It doesn't have to * be unique. * * @enable_source is a handler to find source entity for the * sink entity and activate the link between them if source * entity is free. Drivers should call this handler before * accessing the source. * * @disable_source is a handler to find source entity for the * sink entity and deactivate the link between them. Drivers * should call this handler to release the source. * * Use-case: find tuner entity connected to the decoder * entity and check if it is available, and activate the * link between them from @enable_source and deactivate * from @disable_source. * * .. note:: * * Bridge driver is expected to implement and set the * handler when &media_device is registered or when * bridge driver finds the media_device during probe. * Bridge driver sets source_priv with information * necessary to run @enable_source and @disable_source handlers. * Callers should hold graph_mutex to access and call @enable_source * and @disable_source handlers. */ struct media_device { … }; /* We don't need to include usb.h here */ struct usb_device; #ifdef CONFIG_MEDIA_CONTROLLER /* Supported link_notify @notification values. */ #define MEDIA_DEV_NOTIFY_PRE_LINK_CH … #define MEDIA_DEV_NOTIFY_POST_LINK_CH … /** * media_device_init() - Initializes a media device element * * @mdev: pointer to struct &media_device * * This function initializes the media device prior to its registration. * The media device initialization and registration is split in two functions * to avoid race conditions and make the media device available to user-space * before the media graph has been completed. * * So drivers need to first initialize the media device, register any entity * within the media device, create pad to pad links and then finally register * the media device by calling media_device_register() as a final step. * * The caller is responsible for initializing the media device before * registration. The following fields must be set: * * - dev must point to the parent device * - model must be filled with the device model name * * The bus_info field is set by media_device_init() for PCI and platform devices * if the field begins with '\0'. */ void media_device_init(struct media_device *mdev); /** * media_device_cleanup() - Cleanups a media device element * * @mdev: pointer to struct &media_device * * This function that will destroy the graph_mutex that is * initialized in media_device_init(). */ void media_device_cleanup(struct media_device *mdev); /** * __media_device_register() - Registers a media device element * * @mdev: pointer to struct &media_device * @owner: should be filled with %THIS_MODULE * * Users, should, instead, call the media_device_register() macro. * * The caller is responsible for initializing the &media_device structure * before registration. The following fields of &media_device must be set: * * - &media_device.model must be filled with the device model name as a * NUL-terminated UTF-8 string. The device/model revision must not be * stored in this field. * * The following fields are optional: * * - &media_device.serial is a unique serial number stored as a * NUL-terminated ASCII string. The field is big enough to store a GUID * in text form. If the hardware doesn't provide a unique serial number * this field must be left empty. * * - &media_device.bus_info represents the location of the device in the * system as a NUL-terminated ASCII string. For PCI/PCIe devices * &media_device.bus_info must be set to "PCI:" (or "PCIe:") followed by * the value of pci_name(). For USB devices,the usb_make_path() function * must be used. This field is used by applications to distinguish between * otherwise identical devices that don't provide a serial number. * * - &media_device.hw_revision is the hardware device revision in a * driver-specific format. When possible the revision should be formatted * with the KERNEL_VERSION() macro. * * .. note:: * * #) 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. * * #) Unregistering a media device that hasn't been registered is **NOT** safe. * * Return: returns zero on success or a negative error code. */ int __must_check __media_device_register(struct media_device *mdev, struct module *owner); /** * media_device_register() - Registers a media device element * * @mdev: pointer to struct &media_device * * This macro calls __media_device_register() passing %THIS_MODULE as * the __media_device_register() second argument (**owner**). */ #define media_device_register(mdev) … /** * media_device_unregister() - Unregisters a media device element * * @mdev: pointer to struct &media_device * * It is safe to call this function on an unregistered (but initialised) * media device. */ void media_device_unregister(struct media_device *mdev); /** * media_device_register_entity() - registers a media entity inside a * previously registered media device. * * @mdev: pointer to struct &media_device * @entity: pointer to struct &media_entity to be registered * * Entities are identified by a unique positive integer ID. The media * controller framework will such ID automatically. IDs are not guaranteed * to be contiguous, and the ID number can change on newer Kernel versions. * So, neither the driver nor userspace should hardcode ID numbers to refer * to the entities, but, instead, use the framework to find the ID, when * needed. * * The media_entity name, type and flags fields should be initialized before * calling media_device_register_entity(). Entities embedded in higher-level * standard structures can have some of those fields set by the higher-level * framework. * * If the device has pads, media_entity_pads_init() should be called before * this function. Otherwise, the &media_entity.pad and &media_entity.num_pads * should be zeroed before calling this function. * * Entities have flags that describe the entity capabilities and state: * * %MEDIA_ENT_FL_DEFAULT * indicates the default entity for a given type. * This can be used to report the default audio and video devices or the * default camera sensor. * * .. note:: * * Drivers should set the entity function before calling this function. * Please notice that the values %MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN and * %MEDIA_ENT_F_UNKNOWN should not be used by the drivers. */ int __must_check media_device_register_entity(struct media_device *mdev, struct media_entity *entity); /** * media_device_unregister_entity() - unregisters a media entity. * * @entity: pointer to struct &media_entity to be unregistered * * All links associated with the entity and all PADs are automatically * unregistered from the media_device when this function is called. * * Unregistering an entity will not change the IDs of the other entities and * the previoully used ID will never be reused for a newly registered entities. * * When a media device is unregistered, all its entities are unregistered * automatically. No manual entities unregistration is then required. * * .. note:: * * The media_entity instance itself must be freed explicitly by * the driver if required. */ void media_device_unregister_entity(struct media_entity *entity); /** * media_device_register_entity_notify() - Registers a media entity_notify * callback * * @mdev: The media device * @nptr: The media_entity_notify * * .. note:: * * When a new entity is registered, all the registered * media_entity_notify callbacks are invoked. */ void media_device_register_entity_notify(struct media_device *mdev, struct media_entity_notify *nptr); /** * media_device_unregister_entity_notify() - Unregister a media entity notify * callback * * @mdev: The media device * @nptr: The media_entity_notify * */ void media_device_unregister_entity_notify(struct media_device *mdev, struct media_entity_notify *nptr); /* Iterate over all entities. */ #define media_device_for_each_entity(entity, mdev) … /* Iterate over all interfaces. */ #define media_device_for_each_intf(intf, mdev) … /* Iterate over all pads. */ #define media_device_for_each_pad(pad, mdev) … /* Iterate over all links. */ #define media_device_for_each_link(link, mdev) … /** * media_device_pci_init() - create and initialize a * struct &media_device from a PCI device. * * @mdev: pointer to struct &media_device * @pci_dev: pointer to struct pci_dev * @name: media device name. If %NULL, the routine will use the default * name for the pci device, given by pci_name() macro. */ void media_device_pci_init(struct media_device *mdev, struct pci_dev *pci_dev, const char *name); /** * __media_device_usb_init() - create and initialize a * struct &media_device from a PCI device. * * @mdev: pointer to struct &media_device * @udev: pointer to struct usb_device * @board_name: media device name. If %NULL, the routine will use the usb * product name, if available. * @driver_name: name of the driver. if %NULL, the routine will use the name * given by ``udev->dev->driver->name``, with is usually the wrong * thing to do. * * .. note:: * * It is better to call media_device_usb_init() instead, as * such macro fills driver_name with %KBUILD_MODNAME. */ void __media_device_usb_init(struct media_device *mdev, struct usb_device *udev, const char *board_name, const char *driver_name); #else static inline void media_device_init(struct media_device *mdev) { } static inline int media_device_register(struct media_device *mdev) { return 0; } static inline void media_device_unregister(struct media_device *mdev) { } static inline void media_device_cleanup(struct media_device *mdev) { } static inline int media_device_register_entity(struct media_device *mdev, struct media_entity *entity) { return 0; } static inline void media_device_unregister_entity(struct media_entity *entity) { } static inline void media_device_register_entity_notify( struct media_device *mdev, struct media_entity_notify *nptr) { } static inline void media_device_unregister_entity_notify( struct media_device *mdev, struct media_entity_notify *nptr) { } static inline void media_device_pci_init(struct media_device *mdev, struct pci_dev *pci_dev, char *name) { } static inline void __media_device_usb_init(struct media_device *mdev, struct usb_device *udev, char *board_name, char *driver_name) { } #endif /* CONFIG_MEDIA_CONTROLLER */ /** * media_device_usb_init() - create and initialize a * struct &media_device from a PCI device. * * @mdev: pointer to struct &media_device * @udev: pointer to struct usb_device * @name: media device name. If %NULL, the routine will use the usb * product name, if available. * * This macro calls media_device_usb_init() passing the * media_device_usb_init() **driver_name** parameter filled with * %KBUILD_MODNAME. */ #define media_device_usb_init(mdev, udev, name) … /** * media_set_bus_info() - Set bus_info field * * @bus_info: Variable where to write the bus info (char array) * @bus_info_size: Length of the bus_info * @dev: Related struct device * * Sets bus information based on &dev. This is currently done for PCI and * platform devices. dev is required to be non-NULL for this to happen. * * This function is not meant to be called from drivers. */ static inline void media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev) { … } #endif
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