memory map in fdt was: Re: orion/kirkwood and device tree

Jason linux_arm at lakedaemon.net
Fri Nov 4 05:15:25 EST 2011


Michael,

I've added the devicetree ml to the CC:.  Hopefully someone there can
provide some insight...

On Wed, Nov 02, 2011 at 11:03:04PM +0100, Michael Walle wrote:
> Am Dienstag 01 November 2011, 07:25:23 schrieben Andrew:
> > 
> > We could maybe put this table into DT?
> 
> I don't know if these informations belong to the DT or to generic kirkwood 
> arch support (eg. mach-kirkwood/board-dt.c).
> 
> In both cases there needs to be some functions to retrieve these properties 
> (instead of passing a pointer to some structure around). But i don't know if 
> this fits the linux device drivers concept, eg. to be independent from any 
> architecture.
> 
> So if any kernel hacker is reading this, i'm happy for every hint :) The 
> problem is that most kirkwood/orion SoC devices needs a memory map to set up 
> its internal memory windows for DMA access. Actually it only uses one window, 
> which addresses the main memory. The arch-{kirkwood,orion} code stores the 
> needed informations within a static *_mbus_dram_info variable, which is then 
> passed as a pointer within platform_data to the device driver.
> 
> Is there a best practice for doing such things with device tree aware drivers?

thx,

Jason.


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