Re: What is OCP_FUNC_OPB ??

[Eugene Surovegin <ebs@ebshome.net>]

On Thu, Oct 13, 2005 at 01:05:20PM -0700, Roland Dreier wrote:
> While merging Ruslan Sushko's fix for GPIO and IIC addresses into my
> 440SPe tree, I noticed that ocp_core[] has an entry for a function
> OCP_FUNC_OPB.  I'd like to get this correct for the 440SPe port, but I
> don't see any users in the tree.
> 
> Is this field just used to create an entry in sysfs -- if so what does
> userspace use it for??  Or is it just completely obsolete?  What is
> the .paddr member supposed to represent?  Is it just the base address
> of the whole OPB region?
> 
> Is it worth applying the patch below (according to the 440SP manual,
> the OPB region starts at 0x1 f000 0000), or should we just get rid of
> these entries entirely?
> 
> Thanks,
>   Roland
> 
> [PPC32] Correct OPB base address for PowerPC 440SP
> 
> Signed-off-by: Roland Dreier <rolandd@cisco.com>
> 
> ---
> 
> diff --git a/arch/ppc/platforms/4xx/ibm440sp.c b/arch/ppc/platforms/4xx/ibm440sp.c
> index feb17e4..0b7e462 100644
> --- a/arch/ppc/platforms/4xx/ibm440sp.c
> +++ b/arch/ppc/platforms/4xx/ibm440sp.c
> @@ -60,7 +60,7 @@ struct ocp_def core_ocp[] = {
>  	{ .vendor	= OCP_VENDOR_IBM,
>  	  .function	= OCP_FUNC_OPB,
>  	  .index	= 0,
> -	  .paddr	= 0x0000000140000000ULL,
> +	  .paddr	= 0x00000001f0000000ULL,
>  	  .irq		= OCP_IRQ_NA,
>  	  .pm		= OCP_CPM_NA,
>  	},


I think this is useless stuff. IIRC Ben added these fields when 
converting from Armin's OCP, I have no idea what he had in mind at 
the time (probably some "bus" object owning all "peripheral" objects).

I doubt anything in user/kernel-space uses it. IMHO we can safely 
remove these entries from all 4xx platform files.

-- 
Eugene