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

Chen-Yu Tsai
2017-07-26T07:30:40Z

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.

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