Hardware access from linux

Access to hardware peripherals in a Linux environment requires the use of Linux kernel drivers.

The available kernel drivers for the AM1808 are found at the following site which represents the Linux Platform Support Package.

Ok so I'm kinda screwed since there is only a spi Flash driver and it looks like there's no support for PWM, interrupt handling ang GPIO...

If I want to access that, I'll need to write my own kernel drivers I guess... If it's not made, is it because it's impossible or just not a priority?

Thanks!

The unavailability of a driver is more of a priority of implementation issue that capability.

Simon,

It is also possible to program the ARM9 without using Linux.  You can write a bare-bone C program using CCS instead.  There are example programs available in the UBL (in the Linux package) and the AM1808 BSL (board support library that you can download from LogicPD website). 

--Christina

Yeah I know this option is always available but let's say it's more a fallback than my first option...

If I go through kernel drivers, is it still possible to obtain some real-time access to interrupts, timers and other hardware peripherals like that?

Thanks!

I'm also interested in this.

What is the problem with mmap() the register directly?  I tried it, and it seems to not be very stable.  That's how you usually get around driver writing. 

For example, mmap'ing to control the SPI, does that make the SPI tx/rx flags unstable for some reason, or is it possible with proper setup of the control registers?

I would recommend posting this to the Linux forum.  The folks there will have better knowledge on how to directly access the registers through Linux.

--Christina