Re: [PATCH v7 05/16] clk: tegra: Add DFLL DVCO reset control for Tegra124

Peter De Schrijver
2015-02-16T09:40:01Z

On Fri, Feb 13, 2015 at 12:39:03PM +0200, Mikko Perttunen wrote:
> On 02/12/2015 04:19 PM, Peter De Schrijver wrote:
> >On Thu, Jan 08, 2015 at 03:22:08PM +0200, Mikko Perttunen wrote:
> >>From: Paul Walmsley <pwalmsley@nvidia.com>
> >>
> >>The DVCO present in the DFLL IP block has a separate reset line,
> >>exposed via the CAR IP block. This reset line is asserted upon SoC
> >>reset. Unless something (such as the DFLL driver) deasserts this
> >>line, the DVCO will not oscillate, although reads and writes to the
> >>DFLL IP block will complete.
> >>
> >>Thanks to Aleksandr Frid <afrid@nvidia.com> for identifying this and
> >>saving hours of debugging time.
> >>
> >
> >Should this be done as a reset driver?
>
> Probably through the already existing CAR reset driver. This reset
> doesn't fit well with the existing numbering scheme there, though.
> Perhaps a magic high-valued constant that represents it.
>

Indeed. Just like only the lower part of the clock IDs map have a realtion
with the hardware registers. The rest is just arbitrary numbers.

Cheers,

Peter.