Re: [linux-sunxi] [PATCH 10/10] ARM: dts: sun8i: Add SY8106A regulator to Orange Pi PC

icenowy
2017-07-26T07:36:30Z

在 2017-07-26 15:30，Chen-Yu Tsai 写道：
> On Wed, Jul 26, 2017 at 3:16 PM, Icenowy Zheng <icenowy@aosc.io> wrote:
>>
>>
>> 于 2017年7月26日 GMT+08:00 下午3:08:06, Chen-Yu Tsai <wens@csie.org> 写到:
>>> On Sun, Jul 23, 2017 at 6:27 PM, Icenowy Zheng <icenowy@aosc.io>
>>> wrote:
>>>> From: Ondrej Jirman <megous@megous.com>
>>>>
>>>> Add SY8106A regulator to r_i2c bus and enable the r_i2c bus on
>>>> Orange Pi PC, then set the power supply of the ARM cores to this
>>>> regulator, in order to enable DVFS.
>>>>
>>>> Signed-off-by: Ondrej Jirman <megous@megous.com>
>>>> [Icenowy: Enable DVFS in this patch, slight changes and change
>>>> commit
>>>> message]
>>>> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
>>>> ---
>>>> arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts | 19 +++++++++++++++++++
>>>> 1 file changed, 19 insertions(+)
>>>>
>>>> diff --git a/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
>>> b/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
>>>> index 998b60f8d295..d855f8b6254e 100644
>>>> --- a/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
>>>> +++ b/arch/arm/boot/dts/sun8i-h3-orangepi-pc.dts
>>>> @@ -98,6 +98,10 @@
>>>> status = "okay";
>>>> };
>>>>
>>>> +&cpu0 {
>>>> + cpu-supply = <&reg_sy8106a>;
>>>> +};
>>>> +
>>>> &ehci0 {
>>>> status = "okay";
>>>> };
>>>> @@ -160,6 +164,21 @@
>>>> };
>>>> };
>>>>
>>>> +&r_i2c {
>>>> + status = "okay";
>>>> +
>>>> + reg_sy8106a: regulator@65 {
>>>> + compatible = "silergy,sy8106a";
>>>> + reg = <0x65>;
>>>> + regulator-name = "vdd-cpux";
>>>> + regulator-min-microvolt = <1000000>;
>>>
>>> According to the H3 datasheet, the minimum voltage is 1.1V, not 1V.
>>
>> But the Armbian OPP table for H3 contains several
>> OPP under 1.1V...
>
> Can you provide a link?
>
> If Armbian users have actually field tested this (a big if),
> then I would like to see some evidence of the SoC running
> stably at those OPPs with those lower voltages under full load.

See [1].

[1]
https://github.com/armbian/build/blob/master/config/fex/orangepipc.fex#L736

>
> Even then you should still leave a note describing why we allow
> voltages below the recommended range.
>
> ChenYu
>
>>
>>>
>>> Otherwse
>>>
>>>> + regulator-max-microvolt = <1400000>;
>>>> + regulator-ramp-delay = <200>;
>>>
>>> Is this an actual constraint of the SoC? Or is it a characteristic
>>> of the regulator? If it is the latter, it belongs in the driver.
>>> AFAIK the regulator supports varying the ramp delay (slew rate).

I don't know...

Maybe I should ask Ondrej?

>>>
>>> ChenYu
>>>
>>>> + regulator-boot-on;
>>>> + regulator-always-on;
>>>> + };
>>>> +};
>>>> +
>>>> &r_pio {
>>>> leds_r_opc: led_pins@0 {
>>>> pins = "PL10";
>>>> --
>>>> 2.13.0
>>>>