struct_class (9)

struct class {
  const char * name;
  struct module * owner;
  struct class_attribute * class_attrs;
  const struct attribute_group ** dev_groups;
  struct kobject * dev_kobj;
  int (* dev_uevent) (struct device *dev, struct kobj_uevent_env *env);
  char *(* devnode) (struct device *dev, umode_t *mode);
  void (* class_release) (struct class *class);
  void (* dev_release) (struct device *dev);
  int (* suspend) (struct device *dev, pm_message_t state);
  int (* resume) (struct device *dev);
  const struct kobj_ns_type_operations * ns_type;
  const void *(* namespace) (struct device *dev);
  const struct dev_pm_ops * pm;
  struct subsys_private * p;
};

name

Name of the class.

owner

The module owner.

class_attrs

Default attributes of this class.

dev_groups

Default attributes of the devices that belong to the class.

dev_kobj

The kobject that represents this class and links it into the hierarchy.

dev_uevent

Called when a device is added, removed from this class, or a few other things that generate uevents to add the environment variables.

devnode

Callback to provide the devtmpfs.

class_release

Called to release this class.

dev_release

Called to release the device.

suspend

Used to put the device to sleep mode, usually to a low power state.

resume

Used to bring the device from the sleep mode.

ns_type

Callbacks so sysfs can detemine namespaces.

namespace

Namespace of the device belongs to this class.

pm

The default device power management operations of this class.

p

The private data of the driver core, no one other than the driver core can touch this.

A class is a higher-level view of a device that abstracts out low-level implementation details. Drivers may see a SCSI disk or an ATA disk, but, at the class level, they are all simply disks. Classes allow user space to work with devices based on what they do, rather than how they are connected or how they work.