Add sc16is7xx kernel drivers to allow use of RS485 equipment

Feature Requests
1

I have a use case where i am setting up an IoT gateway with LTE 4G (using a raspi 64bit) to talk to Modbus equipment as well as doubling as a router and having these drivers built into the kernel would be a big help.

My specific use case is using a board from waveshare.
https://www.waveshare.com/wiki/RS485_CAN_HAT_(B)

Thanks!

2

Does your IoT gateway have an i2c bus exposed (software-wise) where this module could attach to? Or do you run a customized firmware where you can expose the i2c bus?

That said, here is the documentation on how to add kernel modules.

3

After more and more digging, I eventually found that the driver I was after is in the base kernel but not enabled. After enabling "SPI" and then the "sc16is7xx" driver in the kernel_menuconfig and building my own image i got it to work.

Would be great if these options were enabled in the kernel by default then selectable in the menuconfig.

4

Yes, that's exactly what the link I posted above talks about - how to package kernel modules. You can create the package and once everything works, create a PR.