Use FDTI usb serial driver with custom Vendor/Product ID

For Developers
1

Hi Forum,

first of all: I'm new here and I did not yet do very much about building OpenWRT, but I'm looking into it.

My question is about kmod-usb-serial-ftdi to be used with a FTDI chip where vendor and product ID have been changed (professional scale):

Can I somehow add the vendor/product ID to the ftdi module as described here: https://ftdichip.com/faq/how-do-i-add-a-custom-pid-to-the-ftdi_sio-linux-com-port-driver ? This didn't work for the driver in OpenWRT as far as I can tell.

Or do I need to rebuild the module and add it? Any hints or links are welcome.

Christian

2

If the FTDI chip is compatible with the driver, and only the VID:PID is different, it should work. If not, you should see a clear error in dmesg when you have add the VID:PID to /sys/bus/usb-serial/drivers/ftdi_sio/new_id, and then plugin the USB device.
It is possible to change the programming of the chip to incompatible with the driver. Here you can find more info.

3

Hey Mijzelf,

thanks a lot for your reply. I tried what you described, but it didn't help. Is that new_id method supported by the ftdi module on openWRT?

4

If the virtual file /sys/bus/usb-serial/drivers/ftdi_sio/new_id exists then it's supported. I suppose that is always the case, but maybe it can be disabled at build.