[RFC] cpufreq-cpu0: allow OPP table supplied by platform

[Shawn Guo]

On Thu, Mar 13, 2014 at 07:44:24PM +0800, Jisheng Zhang wrote:
> > On 13 March 2014 16:25, Viresh Kumar <viresh.kumar at linaro.org> wrote:
> > > On 13 March 2014 16:18, Jisheng Zhang <jszhang at marvell.com> wrote:
> > >> Hi all,
> > >>
> > >> cpufreq-cpu0 is suitable for Marvell Berlin SoC. But there's one issue
> > >> to address. The opp is different between chips even on the same step
> > >> SoC, BG2Q for example. we can calculate the OPP table from the value of
> > >> one OTP register. We have two solutions:
> > >>
> > >> 1. bootloader reads OTP register and calculate the OPP table then change
> > >> dtb danamically
> > >>
> > >> 2. supply one driver in mach-berlin to initialize the OPP table; and
> > >> modify cpufreq-cpu0 to allow platform supply OPP table, fall back to
> > >> of_init_opp_table() if there's no OPP table.
> > >>
> > >> Which solution is better?
> > >
> > > I think we can go ahead with second option here. We can just check if opp
> > > tables are already initialized or not. In case they are, don't probe from
> > > dt..
> > >
> > > But lets see with others have to say here..

Yea, we had gone for the second option on imx6q-cpufreq driver with
commit 20b7cbe (cpufreq: imx6q: add of_init_opp_table).

Shawn