struct_bus_type (9)

struct bus_type {
  const char * name;
  const char * dev_name;
  struct device * dev_root;
  struct device_attribute * dev_attrs;
  const struct attribute_group ** bus_groups;
  const struct attribute_group ** dev_groups;
  const struct attribute_group ** drv_groups;
  int (* match) (struct device *dev, struct device_driver *drv);
  int (* uevent) (struct device *dev, struct kobj_uevent_env *env);
  int (* probe) (struct device *dev);
  int (* remove) (struct device *dev);
  void (* shutdown) (struct device *dev);
  int (* online) (struct device *dev);
  int (* offline) (struct device *dev);
  int (* suspend) (struct device *dev, pm_message_t state);
  int (* resume) (struct device *dev);
  const struct dev_pm_ops * pm;
  struct iommu_ops * iommu_ops;
  struct subsys_private * p;
  struct lock_class_key lock_key;
};

name

The name of the bus.

dev_name

Used for subsystems to enumerate devices like (“foou”, dev->id).

dev_root

Default device to use as the parent.

dev_attrs

Default attributes of the devices on the bus.

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 nonzero value if the given device can be handled by the given driver.

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.

remove

Called when a device removed from this bus.

shutdown

Called at shut-down time to quiesce the device.

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.

pm

Power management operations of this bus, callback the specific device driver's pm-ops.

iommu_ops

IOMMU specific operations for this bus, used to attach IOMMU driver implementations to a bus and allow the driver to do bus-specific setup

p

The private data of the driver core, only the driver core can touch this.

lock_key

Lock class key for use by the lock validator

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.