[Glastonbury] Drivers

[Graham Oxley]

On Monday 12 July 2004 12:24 am, you wrote:
> Does anyone know of any good resources for creating Linux drivers for
> hardware (in particular gamepads). I have a gamepad that I can't get a
> Linux driver for, so I thought it would be the perfect opportunity to
> learn.

there is a book in Shepton Mallet library called LINUX DEVICE DRIVERS.
I know because I got them to get it.

It's quite new, deals with the 2.4 kernel, and tells you quite a lot about 
how linux works, using INSMOD, how interrupts work (fast ints, slow ints, top 
halves, bottom halves etc.) and how to deal with the hardware.

Well worth checking out.

Regarding game pads, the hardware is pretty simple. I had cause to decode a 
joystick once. There are only two I/O ports used, in pre-pci days they lived 
at address 0x200 and 0x201. I belive (though I'm not certain) that you write 
a value into one port (to select which analogue input you want to read, there 
are four of them I seem to remember) and read an 8-bit value from the ADC at 
the other port. There are NO interrupts from the game port - it has to be 
polled. I'll have a look to see if I still have the info. 

Good luck...

Graham