PowerPC/Linux device driver question

PowerPC/Linux device driver question

[Madhu Saravana Sibi Govindan]

Hello all,

I'm trying to write a device driver in linux on a PowerPC processor.
The device has been allocated a range of addresses in the physical
address space of the processor (IBM 440GP) - from 0x100000000 -
0x13fffffff. (FYI, the 440GP is a 32 bit processor using 36 physical
addresses, the processor's MMU appends the extra 4 bits to get a
36-bit physical address).

I'm not sure how to request this range of physical memory from the
kernel. I thought I could use ioremap to map this range into the
virtual space, but ioremap takes only an unsigned long as an argument,
which is only 32 bits on 440GP. I don't think I can represent the range of =
my
device with 32 bits.

Could someone tell me how to solve the problem? I want this range of
physical addresses to be associated with my device driver and how do I
do that?

Thanks in advance,
G.Sibi

Re: PowerPC/Linux device driver question

[Matt Porter]

On Thu, Oct 20, 2005 at 02:56:21PM -0500, Madhu Saravana Sibi Govindan wrote:
> I'm not sure how to request this range of physical memory from the
> kernel. I thought I could use ioremap to map this range into the
> virtual space, but ioremap takes only an unsigned long as an argument,
> which is only 32 bits on 440GP. I don't think I can represent the range of my
> device with 32 bits.
> 
> Could someone tell me how to solve the problem? I want this range of
> physical addresses to be associated with my device driver and how do I
> do that?

Use the ppc-specific ioremap64() call. 

-Matt