CP210x GPIO control

A patch to the CP210x USB to UART Bridges driver that adds GPIO pins control by implementing ioctl function and a python script to program devices.

Tested OS

• Kubuntu Linux 13.04 (kernel 3.8)
• Kubuntu Linux 16.04 (kernel 4.15)

Tested devices

• CP2103
• CP2104

Install

1. Build:

    ./build_driver
   

2. Reload driver (from the built directory):

    sudo rmmod cp210x
    sudo insmod cp210x.ko
   

Program GPIO_MAS

1. Examples:

   • Set all 1's:

       sudo ./cp210x_gpio.py -d /dev/ttyUSB0 -m 0xff 0xff
     

   • Set GPIO[3]=1, others - 0:

       sudo ./cp210x_gpio.py -d /dev/ttyUSB1 -m 0xff 0x08
     

Changes in the driver

• Changes in the driver cp210x.c are based on the patch found here
• GPIO_VALUE=arg[23:16], GPIO_MASK=arg[7:0]

Unresolved questions

• Silabs drivers in 2.6.x and 3.x.x for GPIOs differ:
  • 2.6.x: GPIO_VALUE=arg[23:16], GPIO_MASK=arg[7:0] - this matches the patch
  • 3.x.x: GPIO_VALUE=arg[15: 8], GPIO_MASK=arg[7:0]

Links

• Silabs CP210x USB to UART Bridge VCP Drivers - supported kernels 2.6.x, 3.x.x, 4.x.x..
• cp210x: Add ioctl for GPIO support - patch