Re: [PATCH 4/5] ARM: dts: sun6i: Add sun6i-a31s.dtsi

[Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

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On Wed, Nov 26, 2014 at 05:39:31PM +0800, Chen-Yu Tsai wrote:
> >>> Are the gates really identical?
> >>>
> >>> As in not even stripped down?
> >>
> >>
> >> According to the user manuals, the AHB1 gates on the A31s don't have
> >> GMAC (or EMAC in the manual) and MIPI DSI listed. Though it seems
> >> a lot of A31s hardware out there actually use GMAC.
> >
> >
> > Hmm, interesting I was focussing on the ohci2 gate when comparing them as
> > the ohci2 is not listed in the pinmux.
> >
> > The GMAC clock gate definitely actually is there, as I've an A31s based
> > board
> > with a working GMAC.
> >
> > Also Allwinner has confirmed to me that the A31 and A31s are the same die,
> > so
> > there is no reason to differentiate between the 2 at this level. Either we
> > do
> > no differentiation at all, or only at the pinmux level to reflect that
> > certain
> > pins are simply just not there.
> >
> > My vote goes to differentiating at the pinmux level.
> 
> I agree. Since it is confirmed the dies are the same, the hardware
> description should be the same as well, except for the external
> differences (pinmux). Only downside is a slightly bloated DTB
> containing nodes we will never use on the a31s.

Or we can have a sun6i.dtsi that lists all the hardware, and have the
sun6i-a31.dtsi and sun6i-a31s.dtsi that only define the various
pinmuxes.

That way we would avoid duplication, especially if they are identical,
while reducing the useless bloat too.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com