[PATCH] [RFC] arm: add documentation describing Marvell families of SoC

[thomas.petazzoni@free-electrons.com (Thomas Petazzoni)]

Le Wed, 18 Jul 2012 02:01:51 +0800,
Eric Miao <eric.y.miao@gmail.com> a ?crit :

> This is so useful to Marvell processor new comers, thanks everyone to
> compile this.

You're welcome. Glad to see that this is seen as a useful thing.

> The PXA side might need a bit modification though, so for historical reason
> there is PXA series as originated back from Intel. So there are really those
> legacy ones:
> 
>   PXA21x/PXA25x/PXA27x/PXA3xx/PXA93x
> 
> The new ones developed after Marvell acquired Intel's XScale biz are:
> 
>   PXA95x/PXA168/PXA910/MMP2
> 
> And among these, they are actually categorized into two flavors:
> 
>   AP with CP: PXA93x/PXA95X/PXA910
>   AP only without CP: the rest of them
> 
> And the ARM cores used are also a bit different:
> 
>   XScale (Intel's ARMv5te compatible): PXA21x/PXA25x/PXA27x/PXA3xx/PXA93x
>   Marvell's PJ1 (Marvell's ARMv5te compatible): PXA168/PXA910
>   Marvell's PJ4 (Marvell's ARMv7 compatible): PXA95x/MMP2
> 
> So these are really a bit complicated, by the end of the day, we would still
> go the way as Arnd suggested, that to collapse PXA and MMP series into one,
> so that will be simpler and easier to understand.
> 
> Considering the complications here, I would suggest to simply have a single
> processor line as: PXA/MMP processor line, and list all the processor flavors
> under, whether it's an AP or a AP+CP could be individually indicated.

Ok, thanks, I'll try to take this into account in the next spin.
However, I'm not sure about putting them into a single family, because
what I tried to do until now is to map mach-* directories to the
families, even if down the road there is a wish to merge some of them.

Maybe you could share some insights on why in the first place mach-pxa
and mach-mmp were both created? I guess at some point in time there was
a vision that there were two SoC families with enough differences so
that it required two mach-* directories. I'd like to document this if
possible.

Also, do you have more public datasheet links available for those SoCs?
I think I've gathered all the ones I could find on the Marvell website,
but there are a lot of missing datasheets.

Thanks,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com