/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Media device
*
* Copyright (C) 2010 Nokia Corporation
*
* Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
* Sakari Ailus <sakari.ailus@iki.fi>
*/
#ifndef _MEDIA_DEVICE_H
#define _MEDIA_DEVICE_H
#include <linux/list.h>
#include <linux/mutex.h>
#include <media/media-devnode.h>
#include <media/media-entity.h>
struct ida;
struct device;
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 list_head list;
void *notify_data;
void (*notify)(struct media_entity *entity, void *notify_data);
};
/**
* 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 {
int (*link_notify)(struct media_link *link, u32 flags,
unsigned int notification);
struct media_request *(*req_alloc)(struct media_device *mdev);
void (*req_free)(struct media_request *req);
int (*req_validate)(struct media_request *req);
void (*req_queue)(struct media_request *req);
};
/**
* 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
* 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 {
/* dev->driver_data points to this struct. */
struct device *dev;
struct media_devnode *devnode;
char model[32];
char driver_name[32];
char serial[40];
char bus_info[32];
u32 hw_revision;
u64 topology_version;
u32 id;
struct ida entity_internal_idx;
int entity_internal_idx_max;
struct list_head entities;
struct list_head interfaces;
struct list_head pads;
struct list_head links;
/* notify callback list invoked when a new entity is registered */
struct list_head entity_notify;
/* Serializes graph operations. */
struct mutex graph_mutex;
struct media_graph pm_count_walk;
void *source_priv;
int (*enable_source)(struct media_entity *entity,
struct media_pipeline *pipe);
void (*disable_source)(struct media_entity *entity);
const struct media_device_ops *ops;
struct mutex req_queue_mutex;
atomic_t request_id;
};
/* We don't need to include pci.h or usb.h here */
struct pci_dev;
struct usb_device;
#ifdef CONFIG_MEDIA_CONTROLLER
/* Supported link_notify @notification values. */
#define MEDIA_DEV_NOTIFY_PRE_LINK_CH 0
#define MEDIA_DEV_NOTIFY_POST_LINK_CH 1
/**
* media_entity_enum_init - Initialise an entity enumeration
*
* @ent_enum: Entity enumeration to be initialised
* @mdev: The related media device
*
* Return: zero on success or a negative error code.
*/
static inline __must_check int media_entity_enum_init(
struct media_entity_enum *ent_enum, struct media_device *mdev)
{
return __media_entity_enum_init(ent_enum,
mdev->entity_internal_idx_max + 1);
}
/**
* 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.
*/
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_entity.dev must point to the parent device (usually a &pci_dev,
* &usb_interface or &platform_device instance).
*
* - &media_entity.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_entity.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_entity.bus_info represents the location of the device in the
* system as a NUL-terminated ASCII string. For PCI/PCIe devices
* &media_entity.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_entity.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_register(mdev, THIS_MODULE)
/**
* 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.
*/
int __must_check 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) \
list_for_each_entry(entity, &(mdev)->entities, graph_obj.list)
/* Iterate over all interfaces. */
#define media_device_for_each_intf(intf, mdev) \
list_for_each_entry(intf, &(mdev)->interfaces, graph_obj.list)
/* Iterate over all pads. */
#define media_device_for_each_pad(pad, mdev) \
list_for_each_entry(pad, &(mdev)->pads, graph_obj.list)
/* Iterate over all links. */
#define media_device_for_each_link(link, mdev) \
list_for_each_entry(link, &(mdev)->links, graph_obj.list)
/**
* 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 int media_device_register(struct media_device *mdev)
{
return 0;
}
static inline void media_device_unregister(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 int media_device_register_entity_notify(
struct media_device *mdev,
struct media_entity_notify *nptr)
{
return 0;
}
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_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
#endif
