Sample driver

Jeff Mock jeff at mock.com
Thu Feb 21 02:13:15 EST 2008


Josh Boyer wrote:
>> Does anyone have sample drivers in Linux for the EBC interface for PPC405Ex?
>> I would be thankful if someone could put in a sample code here. 
> 
> Linux typically doesn't touch the EBC itself.  That is normally set up
> by firmware such as U-Boot and Linux uses it as-is.
> 

True, but there's always a lot of ways to do it.  Here's an example that 
might help you get started configuring the EBC from Linux.  Here's a 
device driver directory from a recent 440GX project:
 
http://www.mock.com/wsvn/listing.php?repname=mock.pdev&path=%2Ftrunk%2Fsw%2Fdriver%2F#_trunk_sw_driver_

You might look at pdev-gxctl.c.  It is a simple module that sets up the 
EBC address space for two sets of address ranges with 16-bit data paths. 
  These are for simple register read/writes to control some FPGAs. 
Pdev-gxctl provides an mmap() interface to /dev/xxx so user code can 
easily access the FPGA registers mapped onto the EBC.  The difference 
for the 405Ex should be pretty small.

jeff



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