在Linux内核中经常看到如下的打印信息：
[ 1.468817] dwc2 13500000.otg: Configuration mismatch. Forcing host mode
[ 1.475870] dwc2 13500000.otg: OTG CLK 47493fc4
[ 1.481146] dwc2 13500000.otg: OPCR CLK 701580
[ 1.598530] dwc2 13500000.otg: DWC OTG Controller
[ 1.603444] dwc2 13500000.otg: new USB bus registered, assigned bus number 1
[ 1.610775] dwc2 13500000.otg: irq 9, io mem 0x00000000
dwc2就是usb2.0的一个控制器，dw是DesignWare是一个IP核设计公司。
DesignWare Hi-Speed USB 2.0 On-the-Go Controller
The DesignWare® Hi-Speed USB 2.0 On-The-Go (HS OTG) Controller provides designers with high-quality USB IP for the most demanding USB 2.0 peripherals. The controller performs as a standard Hi-Speed Dual-Role Device (DRD), operating as either a USB 2.0 Hi-Speed peripheral, or Hi-Speed USB 2.0 Host. Based on Synopsys' success in building and deploying Hi-Speed USB 2.0 Host, Device and PHY designs, the DesignWare USB 2.0 HS OTG Controller incorporates Synopsys expertise in Reuse Methodology, Constrained Random Verification, and USB PHY interoperability to deliver flexible, quality IP in Verilog source. The controller is optimized for area- and power-sensitive markets such as Internet of Things (IoT)
