How USB/pci device driver invokes char/block/network layer in kernel?
 

Hi,

While writing device driver for USB/PCI where do we pass the information that the device is of char/block/network type so that the driver invokes the correct layer ie)char or block or network layer?

When will the device driver register/unregister function specific for char/block/network drivers used if there is separate register/unregister functions available for USB,PCI,Bluetooth,tty interfaces?

Do the char/block/network driver register/unregister functions are invoked subsequently by USB/PCI/tty driver register/unregister functions internally, for example when an USB with char device type is used, will the USB register/unregister function invokes char driver register /unregister function?

Please reply!