System Setup; Linux Usb Drivers Structure - Quectel UC20 User Manual

3

System Setup

Linux OS includes a generic USB to serial driver for modem. You can make the UC20 module available in
the Embedded Linux OS by adding some kernel configuration items and adding the information (VID/PID)
in Linux kernel.
The first part of this chapter is to describe the structure of Linux USB Driver and the rest is to explain how
to build the USB driver for UC20 module.
3.1. Linux USB Driver Structure
USB is a kind of hierarchical bus structure. The data transmission between USB devices and Host is
achieved by USB Controller. The following picture illustrates the architecture of USB Driver. Linux USB
Host driver includes three parts: USB Host Controller driver, USB core and USB device drivers.
URB
URB
UC20_Embedded_Linux_USB_Driver_User_Guide
Applicantions
USB Device Drivers
USB Core
USB Host Controller Driver
( OHCI/EHCI/UHCI )
USB Controllers ( OHCI/EHCI/UHCI )
Figure 1: USB Driver Structure
UC20 Embedded Linux USB Driver User Guide
Linux Host
USBD
Interface
HCD
Interface
Confidential / Released
UMTS/HSPA Module
UC20 Module
Software
UC20 Module
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