Patchwork [v10,1/9] dt-bindings: opp: Introduce opp-level bindings

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Submitter Rajendra Nayak
Date Jan. 9, 2019, 9:04 a.m.
Message ID <20190109090420.8100-2-rnayak@codeaurora.org>
Download mbox | patch
Permalink /patch/695559/
State New
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Comments

Rajendra Nayak - Jan. 9, 2019, 9:04 a.m.
On some SoCs (especially from Qualcomm and MediaTek) an OPP
node needs to describe an additional level/corner value
that is then communicated to a remote microprocessor by the CPU, which
then takes some actions (like adjusting voltage values across variousi
rails) based on the value passed.

Add opp-level as an additional property in the OPP node and describe it
in the OPP bindings document.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
 Documentation/devicetree/bindings/opp/opp.txt | 5 +++++
 1 file changed, 5 insertions(+)
Viresh Kumar - Jan. 9, 2019, 9:09 a.m.
On 09-01-19, 14:34, Rajendra Nayak wrote:
> On some SoCs (especially from Qualcomm and MediaTek) an OPP
> node needs to describe an additional level/corner value
> that is then communicated to a remote microprocessor by the CPU, which
> then takes some actions (like adjusting voltage values across variousi
> rails) based on the value passed.
> 
> Add opp-level as an additional property in the OPP node and describe it
> in the OPP bindings document.
> 
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> ---
>  Documentation/devicetree/bindings/opp/opp.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
> index c396c4c0af92..e83fb7cbfd58 100644
> --- a/Documentation/devicetree/bindings/opp/opp.txt
> +++ b/Documentation/devicetree/bindings/opp/opp.txt
> @@ -129,6 +129,11 @@ Optional properties:
>  - opp-microamp-<name>: Named opp-microamp property. Similar to
>    opp-microvolt-<name> property, but for microamp instead.
>  
> +- opp-level: On some SoC platforms an OPP node can describe a positive value
> +  representing a corner/level that's communicated with a remote microprocessor
> +  (usually called the power manager) which then translates it into a certain
> +  voltage on a voltage rail.
> +

This binding is generic enough and doesn't have anything to do with a
remote mp and so such statements should be avoided in here. And then
Linux can use it the way it wants.

Maybe just say that it describes the performance level of the device.
That's all.

>  - clock-latency-ns: Specifies the maximum possible transition latency (in
>    nanoseconds) for switching to this OPP from any other OPP.
>  
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
Rajendra Nayak - Jan. 9, 2019, 9:20 a.m.
On 1/9/2019 2:39 PM, Viresh Kumar wrote:
> On 09-01-19, 14:34, Rajendra Nayak wrote:
>> On some SoCs (especially from Qualcomm and MediaTek) an OPP
>> node needs to describe an additional level/corner value
>> that is then communicated to a remote microprocessor by the CPU, which
>> then takes some actions (like adjusting voltage values across variousi
>> rails) based on the value passed.
>>
>> Add opp-level as an additional property in the OPP node and describe it
>> in the OPP bindings document.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>> ---
>>   Documentation/devicetree/bindings/opp/opp.txt | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
>> index c396c4c0af92..e83fb7cbfd58 100644
>> --- a/Documentation/devicetree/bindings/opp/opp.txt
>> +++ b/Documentation/devicetree/bindings/opp/opp.txt
>> @@ -129,6 +129,11 @@ Optional properties:
>>   - opp-microamp-<name>: Named opp-microamp property. Similar to
>>     opp-microvolt-<name> property, but for microamp instead.
>>   
>> +- opp-level: On some SoC platforms an OPP node can describe a positive value
>> +  representing a corner/level that's communicated with a remote microprocessor
>> +  (usually called the power manager) which then translates it into a certain
>> +  voltage on a voltage rail.
>> +
> 
> This binding is generic enough and doesn't have anything to do with a
> remote mp and so such statements should be avoided in here. And then
> Linux can use it the way it wants.
> 
> Maybe just say that it describes the performance level of the device.
> That's all.

Sure, does this seem fine?

- opp-level: A value representing the performance level of the device,
   expressed as a 32-bit big-endian integer.

I assume the changelog mentioning the motivation behind adding this is fine?

> 
>>   - clock-latency-ns: Specifies the maximum possible transition latency (in
>>     nanoseconds) for switching to this OPP from any other OPP.
>>   
>> -- 
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
>> of Code Aurora Forum, hosted by The Linux Foundation
>
Viresh Kumar - Jan. 9, 2019, 9:24 a.m.
On 09-01-19, 14:50, Rajendra Nayak wrote:
> Sure, does this seem fine?
> 
> - opp-level: A value representing the performance level of the device,
>   expressed as a 32-bit big-endian integer.

Not sure if you need to specify endian-ness here.

> I assume the changelog mentioning the motivation behind adding this is fine?

Yeah, that would be fine. Just mention that one of the users of such a
property is qcom/mtk ......

Patch

diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
index c396c4c0af92..e83fb7cbfd58 100644
--- a/Documentation/devicetree/bindings/opp/opp.txt
+++ b/Documentation/devicetree/bindings/opp/opp.txt
@@ -129,6 +129,11 @@  Optional properties:
 - opp-microamp-<name>: Named opp-microamp property. Similar to
   opp-microvolt-<name> property, but for microamp instead.
 
+- opp-level: On some SoC platforms an OPP node can describe a positive value
+  representing a corner/level that's communicated with a remote microprocessor
+  (usually called the power manager) which then translates it into a certain
+  voltage on a voltage rail.
+
 - clock-latency-ns: Specifies the maximum possible transition latency (in
   nanoseconds) for switching to this OPP from any other OPP.