Cypress USB device from Windows to Linux

[Michael Torrie]

Dave Smith wrote:
> I've got a Cypress-based USB device that has been solely used with Windows in 
> the past. Now I want to make that device work under Linux. I imagine this 
> means I'll have to do some hacking to create a driver (but maybe not). This is 
> not a "standard" device like a keyboard, hard drive, or webcam. It has its 
> own, in-house-developed command set for interacting with the device. When I 
> connect the device to my Arch box, this appears in /var/log/messages.log:
> 
>   kernel: usb 1-1: new high speed USB device using ehci_hcd and address 2
>   kernel: usb 1-1: config 1 interface 0 altsetting 0 bulk endpoint 0x81 has 
> invalid maxpacket 64
>   kernel: usb 1-1: configuration #1 chosen from 1 choice
> 
> I don't really know where to get started. Can anyone recommend a starting 
> point? Books? Other resources? General advice?

It may be possible to do everything you want without writing a driver.
Linux has some pretty advanced user space methods for interacting with
USB devices.  This article is an introduction to libusb and friends:

http://www.linuxjournal.com/article/7466