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

2017-07-26 Thread 'Ondřej Jirman' via linux-sunxi 
Maxime Ripard píše v St 26. 07. 2017 v 13:44 +0200:
> Hi,
> 
> On Wed, Jul 26, 2017 at 12:23:48PM +0200, Ondřej Jirman wrote:
> > Hi,
> > 
> > icen...@aosc.io píše v St 26. 07. 2017 v 15:36 +0800:
> > > 
> > > > > > 
> > > > > > Otherwse
> > > > > > 
> > > > > > > +   regulator-max-microvolt = <140>;
> > > > > > > +   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?
> > 
> > It is probably neither.
> > 
> > It is used to calculate a delay inserted by the kernel between setting
> > a new target voltage over I2C and changing the frequency of the CPU.
> > The actual delay is calculated by the difference between previous and
> > the new voltage.
> > 
> > I don't remember seeing anything in the datasheet of the regulator.
> > This is just some low value that works.
> > 
> > It would probably be dependent on the capacitance on the output of the
> > regulator, actual load (which varies), etc. So it is a board specific
> > value. One could measure it with an oscilloscope if there's a need to
> > optimize this.
> 
> If this is a reasonable default, then this should be in the
> driver. You can't expect anyone to properly calculate a ramp delay and
> have access to both a scope and the CPU power lines.

It translates to 1ms per 0.2V which is highly conservative. The real
times will be in 1-10us range. So I guess this could be a default in
the driver.

regards,
  o.

> Maxime
> 
> -- 
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com
> 

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

2017-07-26 Thread icenowy 

在 2017-07-26 19:44，Maxime Ripard 写道：

Hi,

On Wed, Jul 26, 2017 at 12:23:48PM +0200, Ondřej Jirman wrote:

Hi,

icen...@aosc.io píše v St 26. 07. 2017 v 15:36 +0800:
>
> > > >
> > > > Otherwse
> > > >
> > > > > +   regulator-max-microvolt = <140>;
> > > > > +   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?

It is probably neither.

It is used to calculate a delay inserted by the kernel between setting
a new target voltage over I2C and changing the frequency of the CPU.
The actual delay is calculated by the difference between previous and
the new voltage.

I don't remember seeing anything in the datasheet of the regulator.
This is just some low value that works.

It would probably be dependent on the capacitance on the output of the
regulator, actual load (which varies), etc. So it is a board specific
value. One could measure it with an oscilloscope if there's a need to
optimize this.


If this is a reasonable default, then this should be in the
driver. You can't expect anyone to properly calculate a ramp delay and
have access to both a scope and the CPU power lines.


It seems that in regulator_desc structure a default value of ramp delay
can be set, and the ones specified in dt can override it.

So just add .ramp_delay = 200 in the driver's regulator_desc part?

Should a comment be added that explains it's only an experienced value
on Allwinner H3/H5 boards VDD-CPUX usage?



Maxime

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

2017-07-26 Thread Maxime Ripard 
Hi,

On Wed, Jul 26, 2017 at 12:23:48PM +0200, Ondřej Jirman wrote:
> Hi,
> 
> icen...@aosc.io píše v St 26. 07. 2017 v 15:36 +0800:
> > 
> > > > > 
> > > > > Otherwse
> > > > > 
> > > > > > +   regulator-max-microvolt = <140>;
> > > > > > +   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?
> 
> It is probably neither.
> 
> It is used to calculate a delay inserted by the kernel between setting
> a new target voltage over I2C and changing the frequency of the CPU.
> The actual delay is calculated by the difference between previous and
> the new voltage.
> 
> I don't remember seeing anything in the datasheet of the regulator.
> This is just some low value that works.
> 
> It would probably be dependent on the capacitance on the output of the
> regulator, actual load (which varies), etc. So it is a board specific
> value. One could measure it with an oscilloscope if there's a need to
> optimize this.

If this is a reasonable default, then this should be in the
driver. You can't expect anyone to properly calculate a ramp delay and
have access to both a scope and the CPU power lines.

Maxime

-- 
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Embedded Linux and Kernel engineering
http://free-electrons.com

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

2017-07-26 Thread 'Ondřej Jirman' via linux-sunxi 
Hi,

icen...@aosc.io píše v St 26. 07. 2017 v 15:36 +0800:
> 
> > > > 
> > > > Otherwse
> > > > 
> > > > > +   regulator-max-microvolt = <140>;
> > > > > +   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?

It is probably neither.

It is used to calculate a delay inserted by the kernel between setting
a new target voltage over I2C and changing the frequency of the CPU.
The actual delay is calculated by the difference between previous and
the new voltage.

I don't remember seeing anything in the datasheet of the regulator.
This is just some low value that works.

It would probably be dependent on the capacitance on the output of the
regulator, actual load (which varies), etc. So it is a board specific
value. One could measure it with an oscilloscope if there's a need to
optimize this.

regards,
  o.

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

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

2017-07-26 Thread icenowy 

在 2017-07-26 15:30，Chen-Yu Tsai 写道：

On Wed, Jul 26, 2017 at 3:16 PM, Icenowy Zheng  wrote:



于 2017年7月26日 GMT+08:00 下午3:08:06, Chen-Yu Tsai  写到:
On Sun, Jul 23, 2017 at 6:27 PM, Icenowy Zheng  
wrote:

From: Ondrej Jirman 

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 
[Icenowy: Enable DVFS in this patch, slight changes and change 
commit

 message]
Signed-off-by: Icenowy Zheng 
---
 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";
 };

+ {
+   cpu-supply = <_sy8106a>;
+};
+
  {
status = "okay";
 };
@@ -160,6 +164,21 @@
};
 };

+_i2c {
+   status = "okay";
+
+   reg_sy8106a: regulator@65 {
+   compatible = "silergy,sy8106a";
+   reg = <0x65>;
+   regulator-name = "vdd-cpux";
+   regulator-min-microvolt = <100>;


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 = <140>;
+   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;
+   };
+};
+
 _pio {
leds_r_opc: led_pins@0 {
pins = "PL10";
--
2.13.0



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

2017-07-26 Thread Chen-Yu Tsai 
On Wed, Jul 26, 2017 at 3:16 PM, Icenowy Zheng  wrote:
>
>
> 于 2017年7月26日 GMT+08:00 下午3:08:06, Chen-Yu Tsai  写到:
>>On Sun, Jul 23, 2017 at 6:27 PM, Icenowy Zheng  wrote:
>>> From: Ondrej Jirman 
>>>
>>> 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 
>>> [Icenowy: Enable DVFS in this patch, slight changes and change commit
>>>  message]
>>> Signed-off-by: Icenowy Zheng 
>>> ---
>>>  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";
>>>  };
>>>
>>> + {
>>> +   cpu-supply = <_sy8106a>;
>>> +};
>>> +
>>>   {
>>> status = "okay";
>>>  };
>>> @@ -160,6 +164,21 @@
>>> };
>>>  };
>>>
>>> +_i2c {
>>> +   status = "okay";
>>> +
>>> +   reg_sy8106a: regulator@65 {
>>> +   compatible = "silergy,sy8106a";
>>> +   reg = <0x65>;
>>> +   regulator-name = "vdd-cpux";
>>> +   regulator-min-microvolt = <100>;
>>
>>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 = <140>;
>>> +   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;
>>> +   };
>>> +};
>>> +
>>>  _pio {
>>> leds_r_opc: led_pins@0 {
>>> pins = "PL10";
>>> --
>>> 2.13.0
>>>

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

2017-07-26 Thread Icenowy Zheng 


于 2017年7月26日 GMT+08:00 下午3:08:06, Chen-Yu Tsai  写到:
>On Sun, Jul 23, 2017 at 6:27 PM, Icenowy Zheng  wrote:
>> From: Ondrej Jirman 
>>
>> 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 
>> [Icenowy: Enable DVFS in this patch, slight changes and change commit
>>  message]
>> Signed-off-by: Icenowy Zheng 
>> ---
>>  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";
>>  };
>>
>> + {
>> +   cpu-supply = <_sy8106a>;
>> +};
>> +
>>   {
>> status = "okay";
>>  };
>> @@ -160,6 +164,21 @@
>> };
>>  };
>>
>> +_i2c {
>> +   status = "okay";
>> +
>> +   reg_sy8106a: regulator@65 {
>> +   compatible = "silergy,sy8106a";
>> +   reg = <0x65>;
>> +   regulator-name = "vdd-cpux";
>> +   regulator-min-microvolt = <100>;
>
>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...

>
>Otherwse
>
>> +   regulator-max-microvolt = <140>;
>> +   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;
>> +   };
>> +};
>> +
>>  _pio {
>> leds_r_opc: led_pins@0 {
>> pins = "PL10";
>> --
>> 2.13.0
>>
>> --
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Re: [linux-sunxi] [PATCH 10/10] ARM: dts: sun8i: Add SY8106A regulator to Orange Pi PC

2017-07-26 Thread Chen-Yu Tsai 
On Sun, Jul 23, 2017 at 6:27 PM, Icenowy Zheng  wrote:
> From: Ondrej Jirman 
>
> 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 
> [Icenowy: Enable DVFS in this patch, slight changes and change commit
>  message]
> Signed-off-by: Icenowy Zheng 
> ---
>  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";
>  };
>
> + {
> +   cpu-supply = <_sy8106a>;
> +};
> +
>   {
> status = "okay";
>  };
> @@ -160,6 +164,21 @@
> };
>  };
>
> +_i2c {
> +   status = "okay";
> +
> +   reg_sy8106a: regulator@65 {
> +   compatible = "silergy,sy8106a";
> +   reg = <0x65>;
> +   regulator-name = "vdd-cpux";
> +   regulator-min-microvolt = <100>;

According to the H3 datasheet, the minimum voltage is 1.1V, not 1V.

Otherwse

> +   regulator-max-microvolt = <140>;
> +   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;
> +   };
> +};
> +
>  _pio {
> leds_r_opc: led_pins@0 {
> pins = "PL10";
> --
> 2.13.0
>
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[linux-sunxi] [PATCH 10/10] ARM: dts: sun8i: Add SY8106A regulator to Orange Pi PC

2017-07-23 Thread Icenowy Zheng 
From: Ondrej Jirman 

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 
[Icenowy: Enable DVFS in this patch, slight changes and change commit
 message]
Signed-off-by: Icenowy Zheng 
---
 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";
 };
 
+ {
+   cpu-supply = <_sy8106a>;
+};
+
  {
status = "okay";
 };
@@ -160,6 +164,21 @@
};
 };
 
+_i2c {
+   status = "okay";
+
+   reg_sy8106a: regulator@65 {
+   compatible = "silergy,sy8106a";
+   reg = <0x65>;
+   regulator-name = "vdd-cpux";
+   regulator-min-microvolt = <100>;
+   regulator-max-microvolt = <140>;
+   regulator-ramp-delay = <200>;
+   regulator-boot-on;
+   regulator-always-on;
+   };
+};
+
 _pio {
leds_r_opc: led_pins@0 {
pins = "PL10";
-- 
2.13.0

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