Re: [PATCH] char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)

From: Greg KH
Date: Tue Jan 05 2021 - 08:46:55 EST


On Sun, Dec 13, 2020 at 07:05:03PM +0200, eli.billauer@xxxxxxxxx wrote:
> From: Eli Billauer <eli.billauer@xxxxxxxxx>
>
> The XillyUSB driver is the USB variant for the Xillybus FPGA IP core.
> Even though it presents a nearly identical API on the FPGA and host,
> it's almost a complete rewrite of the driver: The framework for exchanging
> data on a USB bus is fundamentally different from doing the same with a
> PCIe interface, which leaves very little in common between the existing
> driver and the new one for XillyUSB.

But in this one you are talking to userspace directly through a char
node, why not use the same interface that the xillybus_core.c code uses?
Creating yet-another-class-device feels odd when you already have one
that is in use.

Try to merge them together to use the same framework, or document the
heck out of why this is somehow different, yet looks the same...

thanks,

greg k-h