Re: [PATCH 15/15] metag: tz1090: add TZ1090 clocks to device tree

From: James Hogan
Date: Fri Nov 21 2014 - 05:06:58 EST


On Thu, Nov 20, 2014 at 01:56:24PM +0100, Heiko StÃbner wrote:
> Hi James,
>
> interestingly I only got the cover-letter, so had to find the other patches
> through my list-archive :-) .

Hmm, sorry about that. I copy cover letter Cc list from the Ccs of the
patches, so not sure what happened there.

>
>
> Am Mittwoch, 19. November 2014, 23:15:43 schrieb James Hogan:
> > Enable the common clock framework for the TZ1090 SoC, add a tz1090_clk
> > device tree file describing the clocks, and connect the Meta core clock
> > so that the rate of the Meta timer can be determined.
> >
> > Most of the clock tree is described apart from some AFE clocks which
> > aren't usually of much interest to Linux. These are represented with
> > placeholder clocks.
> >
> > Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
> > Cc: Mike Turquette <mturquette@xxxxxxxxxx>
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: Pawel Moll <pawel.moll@xxxxxxx>
> > Cc: Mark Rutland <mark.rutland@xxxxxxx>
> > Cc: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>
> > Cc: Kumar Gala <galak@xxxxxxxxxxxxxx>
> > Cc: linux-metag@xxxxxxxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx
> > ---
>
>
> I don't know enough about your clock structure, but it looks quite a bit like
> Mike's mail from May [0] may apply here too.
>
> The register layout also suggests that it is indeed one clock ip-block:
>
> 0x02005908 0x4 CR_TOP_CLKSWITCH
> 0x0200590c 0x4 CR_TOP_CLKENAB
> 0x02005950 0x4 CR_TOP_SYSPLL_CTL0
> 0x02005954 0x4 CR_TOP_SYSPLL_CTL1
> 0x02005988 0x4 CR_TOP_CLKSWITCH2
> 0x0200598c 0x4 CR_TOP_CLKENAB2
> ...
>
>
> [0] https://lkml.org/lkml/2014/5/14/715

Thanks, that does make sense. It's probably more like 4 memory regions
("top" level, "perip" peripheral registers, "hep" high end peripheral
registers, and "pdc" powerdown controller registers), but it could
certainly still have a single binding with multiple memory regions to
simplify the clock specifiers.

I'll take a look at doing it that way.

Cheers
James

Attachment: signature.asc
Description: Digital signature