Add device to device hierarchy.
int device_add(struct device * dev);
dev
device.
This is part 2 of device_register, though may be called separately _iff_ device_initialize has been called separately.
This adds dev to the kobject hierarchy via kobject_add, adds it to the global and sibling lists for the device, then adds it to the other relevant subsystems of the driver model.
Do not call this routine or device_register more than once for any device structure. The driver model core is not designed to work with devices that get unregistered and then spring back to life. (Among other things, it's very hard to guarantee that all references to the previous incarnation of dev have been dropped.) Allocate and register a fresh new struct device instead.
_Never_ directly free dev after calling this function, even if it returned an error! Always use put_device to give up your reference instead.