cp210x-cfg

CLI utility for programming CP210x USB<->UART bridges

Intended as a scriptable alternative to the official Silicon Labs CP21xx Customization Utility.

Tested with CP2102, CP2105 and the newer CP2102n chips.

Supported fields that can be programmed:

• Vendor ID
• Product ID
• Product Name string
• Serial string
• Buffer flush bitmap
• SCI/ECI gpio/modem mode

Additionally for the CP2102n:

• Manufacturer string
• Toggle between internal and external serial number

CAUTION

This applies to the older CP210x chips (not the CP2102n) Programming a CP210x config field is a write-once operation. It's perfectly possible to write bad values. The consequences are yours, and yours alone.

Suffice to say that I've got a couple of modules which have a VID/PID of 0000:0000. Don't do that. If you happen to screw up the VID/PID anyway, in Linux you can sort-of work around it by registering the new VID/PID combo with the cp210x driver like so:

echo 0000 0000 | sudo tee /sys/bus/usb-serial/drivers/cp210x/new_id

Consider yourself forewarned, and forearmed.

Newer chips like the CP2102n can be reprogrammed indefinitely.

Examples

####Showing the built-in help message (may differ from below)

$ ./cp210x-cfg -h
Syntax:
cp210x-cfg [-h ] |
           [-m vid:pid] [-d bus:dev]
           [ -l | [-V vid] [-P pid] [-F flush] [-M mode] [-N name] [-S serial]]

  -h            This help
  -m vid:pid    Find and use first device with vid:pid
  -d bus:dev    Find and use device at bus:dev
  -l            List all CP210x devices connected
  -V vid        Program the given Vendor ID
  -P pid        Program the given Product ID
  -F flush      Program the given buffer flush bitmap (CP2105 only)
  -M mode       Program the given SCI/ECI mode (CP2105 only)
  -N name       Program the given product name string
  -C manufact.  Program the given manufacturer name (CP2101n only)\n
  -S serial     Program the given serial string
  -t 0/1        Toggle between internal and user specified serial (CP2101n only)\n"

Unless the -d option is used, the first found CP210x device is used.
If no programming options are used, the current values are printed.

Switching a CP2105 into modem mode

$ sudo ./cp210x-cfg -d 4.113 -M 0
ID 10c4:ea70 @ bus 004, dev 113: CP2105 Dual USB to UART Bridge Controller
Model: CP2105
Vendor ID: 10c4
Product ID: ea70
Name: CP2105 Dual USB to UART Bridge Controller
Serial: 007079CC
Flush buffers: 33
SCI/ECI mode: 0000