include/linux/device/bus.h

Source file repositories/reference/linux-study-clean/include/linux/device/bus.h

File Facts

System
Linux kernel
Corpus path
include/linux/device/bus.h
Extension
.h
Size
11393 bytes
Lines
296
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct device_driver;
struct fwnode_handle;

/**
 * struct bus_type - The bus type of the device
 *
 * @name:	The name of the bus.
 * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
 * @bus_groups:	Default attributes of the bus.
 * @dev_groups:	Default attributes of the devices on the bus.
 * @drv_groups: Default attributes of the device drivers on the bus.
 * @match:	Called, perhaps multiple times, whenever a new device or driver
 *		is added for this bus. It should return a positive value if the
 *		given device can be handled by the given driver and zero
 *		otherwise. It may also return error code if determining that
 *		the driver supports the device is not possible. In case of
 *		-EPROBE_DEFER it will queue the device for deferred probing.
 *		Note: This callback may be invoked with or without the device
 *		lock held.
 * @uevent:	Called when a device is added, removed, or a few other things
 *		that generate uevents to add the environment variables.
 * @probe:	Called when a new device or driver add to this bus, and callback
 *		the specific driver's probe to initial the matched device.
 * @sync_state:	Called to sync device state to software state after all the
 *		state tracking consumers linked to this device (present at
 *		the time of late_initcall) have successfully bound to a
 *		driver. If the device has no consumers, this function will
 *		be called at late_initcall_sync level. If the device has
 *		consumers that are never bound to a driver, this function
 *		will never get called until they do.
 * @remove:	Called when a device removed from this bus.
 * @shutdown:	Called at shut-down time to quiesce the device.
 * @irq_get_affinity:	Get IRQ affinity mask for the device on this bus.
 *
 * @online:	Called to put the device back online (after offlining it).
 * @offline:	Called to put the device offline for hot-removal. May fail.
 *
 * @suspend:	Called when a device on this bus wants to go to sleep mode.
 * @resume:	Called to bring a device on this bus out of sleep mode.
 * @num_vf:	Called to find out how many virtual functions a device on this
 *		bus supports.
 * @dma_configure:	Called to setup DMA configuration on a device on
 *			this bus.
 * @dma_cleanup:	Called to cleanup DMA configuration on a device on
 *			this bus.
 * @pm:		Power management operations of this bus, callback the specific
 *		device driver's pm-ops.
 * @driver_override:	Set to true if this bus supports the driver_override
 *			mechanism, which allows userspace to force a specific
 *			driver to bind to a device via a sysfs attribute.
 * @need_parent_lock:	When probing or removing a device on this bus, the
 *			device core should lock the device's parent.
 *
 * A bus is a channel between the processor and one or more devices. For the
 * purposes of the device model, all devices are connected via a bus, even if
 * it is an internal, virtual, "platform" bus. Buses can plug into each other.
 * A USB controller is usually a PCI device, for example. The device model
 * represents the actual connections between buses and the devices they control.
 * A bus is represented by the bus_type structure. It contains the name, the
 * default attributes, the bus' methods, PM operations, and the driver core's
 * private data.
 */
struct bus_type {
	const char		*name;
	const char		*dev_name;
	const struct attribute_group *const *bus_groups;
	const struct attribute_group *const *dev_groups;
	const struct attribute_group *const *drv_groups;

	int (*match)(struct device *dev, const struct device_driver *drv);
	int (*uevent)(const struct device *dev, struct kobj_uevent_env *env);
	int (*probe)(struct device *dev);
	void (*sync_state)(struct device *dev);
	void (*remove)(struct device *dev);
	void (*shutdown)(struct device *dev);
	const struct cpumask *(*irq_get_affinity)(struct device *dev,
			unsigned int irq_vec);

	int (*online)(struct device *dev);
	int (*offline)(struct device *dev);

	int (*suspend)(struct device *dev, pm_message_t state);
	int (*resume)(struct device *dev);

	int (*num_vf)(struct device *dev);

	int (*dma_configure)(struct device *dev);
	void (*dma_cleanup)(struct device *dev);

	const struct dev_pm_ops *pm;

Annotation

Implementation Notes