1. USB0 驱动是否加载
   a，USB0 host
   cat /sys/devices/platform/soc/usbc0/usb_host

b，USB0 device
cat /sys/devices/platform/soc/usbc0/usb_device

c，获取USB0当前角色
cat /sys/devices/platform/soc/usbc0/otg_role

2. USB1驱动加载
   a，加载
   echo 1 > /sys/devices/platform/soc/5200000.ehci1-controller/ehci_enable
   echo 1 > /sys/devices/platform/soc/5200000.ohci1-controller/ohci_enable

b，卸载
echo 0 > /sys/devices/platform/soc/5200000.ehci1-controller/ehci_enable
echo 0 > /sys/devices/platform/soc/5200000.ohci1-controller/ohci_enable

3. USB做mass storage
   dd if=/dev/zero of=/dev/a.bin bs=1M count=100
   mount -t configfs none /sys/kernel/config
   mkdir /sys/kernel/config/usb_gadget/g1
   echo “0x18d1” > /sys/kernel/config/usb_gadget/g1/idVendor
   echo “0x0001” > /sys/kernel/config/usb_gadget/g1/idProduct
   mkdir /sys/kernel/config/usb_gadget/g1/strings/0x409
   mkdir /sys/kernel/config/usb_gadget/g1/functions/mass_storage.usb0
   echo /dev/a.bin > /sys/kernel/config/usb_gadget/g1/functions/mass_sto
   rage.usb0/lun.0/file
   mkdir /sys/kernel/config/usb_gadget/g1/configs/c.1
   echo 0xc0 > /sys/kernel/config/usb_gadget/g1/configs/c.1/bmAttributes
   echo 500 > /sys/kernel/config/usb_gadget/g1/configs/c.1/MaxPower
   mkdir /sys/kernel/config/usb_gadget/g1/configs/c.1/strings/0x409
   ln -s /sys/kernel/config/usb_gadget/g1/functions/mass_storage.usb0/ /sys/kernel/config/usb_gadget/g1/configs/c.1/
   ls /sys/class/udc/ |xargs echo > /sys/kernel/config/usb_gadget/g1/UDC

4. USB做CDROM