Re: ARM: mx28: cpufreq-cpu0 support?

[Stefan Wahren <info@lategoodbye.de>]

Hello Fabio,

Am 01.09.2014 15:33, schrieb Fabio Estevam:
> Hi Stefan,
>
> On Mon, Sep 1, 2014 at 3:31 AM, Stefan Wahren <info@lategoodbye.de> wrote:
>
>> thanks. Okay, that leads to more questions:
>>
>> How can i test a ported mxs-regulator driver, that it's really working? Is
>> there any userspace interface?
>
> After you ported the mxs regulator you can check whether it probed
> correctly and if the reported voltages in the kernel log match the
> register settings. You can also check if the voltages are really in
> the correct reported value with a scope.
>
> On mx6q we have the following:
>
> [    0.070554] vdd1p1: 800 <--> 1375 mV at 1100 mV
> [    0.071521] vdd3p0: 2800 <--> 3150 mV at 3000 mV
> [    0.072397] vdd2p5: 2000 <--> 2750 mV at 2400 mV
> [    0.073369] vddarm: 725 <--> 1450 mV at 1150 mV
> [    0.074282] vddpu: 725 <--> 1450 mV at 1150 mV
> [    0.075247] vddsoc: 725 <--> 1450 mV at 1200 mV
>
> and you should get something like that in your kernel log after you
> ported the mxs regulator driver.
>
>> Is there a good DT implementation of a similiar regulator driver, so i can
>> orientate on?
>
> You could take a look at the drivers/regulator/anatop-regulator.c
> driver, which handles the internal regulators on mx6.
>
> The dts is arch/arm/boot/dts/imx6qdl.dtsi . Search for "anatop-regulator"
>

thanks again. Now i unterstand much more, but otherwise the portation 
won't be straight forward. The old source in 
drivers/regulator/mxs-regulator.c needs a low level part located in 
arch/arm/plat-mx28/power.c . As far as i know, the low level part needs 
to move into the devicetree binding and into the mxs-regulator.c . Am i 
right?

Yesterday i had looked into the mx28 reference manual and into the low 
level part of the mxs regulator. The reference manual defines four 
voltage regulators: vddd, vdda, vddio and vddmem plus a overall current 
regulator. But the low level part make use of vddd, vdda, vddio, 
vddio_bo and the overall current.

Do i need the brown out regulator (vddio_bo) and the vddmem?

Stefan