[1/3] dt-bindings: power: Introduce 'assigned-performance-states' property
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Message ID 1596541616-27688-2-git-send-email-rnayak@codeaurora.org
State Changes Requested, archived
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  • Add support for assigned-performance-states
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Commit Message

Rajendra Nayak Aug. 4, 2020, 11:46 a.m. UTC
While most devices within power-domains which support performance states,
scale the performance state dynamically, some devices might want to
set a static/default performance state while the device is active.
These devices typically would also run of a fixed clock and not support
dyamically scaling the device's performance, also known as DVFS techniques.
Add a property 'assigned-performance-states' which client devices can
use to set this default performance state on their power-domains.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
 .../devicetree/bindings/power/power-domain.yaml    | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)

Comments

Stephen Boyd Aug. 5, 2020, 6:39 a.m. UTC | #1
Quoting Rajendra Nayak (2020-08-04 04:46:54)
> While most devices within power-domains which support performance states,
> scale the performance state dynamically, some devices might want to
> set a static/default performance state while the device is active.
> These devices typically would also run of a fixed clock and not support

s/of/off/

> dyamically scaling the device's performance, also known as DVFS techniques.

s/dyamically/dynamically/

> Add a property 'assigned-performance-states' which client devices can
> use to set this default performance state on their power-domains.
> 
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> ---
>  .../devicetree/bindings/power/power-domain.yaml    | 47 ++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/power/power-domain.yaml b/Documentation/devicetree/bindings/power/power-domain.yaml
> index ff5936e..48e9319 100644
> --- a/Documentation/devicetree/bindings/power/power-domain.yaml
> +++ b/Documentation/devicetree/bindings/power/power-domain.yaml
> @@ -66,6 +66,16 @@ properties:
>         by the given provider should be subdomains of the domain specified
>         by this binding.
>  
> +  assigned-performance-states:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description:
> +       Some devices might need to configure their power domains in a default
> +       performance state while the device is active. These devices typcially
> +       would also run of a fixed clock and not support dyamically scaling the

Same of and dynamically comment.

> +       device's performance, also known as DVFS techniques. The list of performance
> +       state values should correspond to the list of power domains specified as part
> +       of the power-domains property.

This is different than assigned-clock-rates. I guess that's OK because
we don't need to assign parents with more specifiers. Maybe it should be
worded more strongly to clearly state that each cell corresponds to one
power domain? And that it should match the opp-level inside any OPP
table for the power domain?

> +
>  required:
>    - "#power-domain-cells"
>  
> @@ -129,3 +139,40 @@ examples:
>              min-residency-us = <7000>;
>          };
>      };
> +
> +  - |
> +    parent4: power-controller@12340000 {
> +        compatible = "foo,power-controller";
> +        reg = <0x12340000 0x1000>;
> +        #power-domain-cells = <0>;
> +    };
> +
> +    parent5: power-controller@43210000 {
> +        compatible = "foo,power-controller";
> +        reg = <0x43210000 0x1000>;
> +        #power-domain-cells = <0>;
> +        operating-points-v2 = <&power_opp_table>;
> +
> +        power_opp_table: opp-table {
> +            compatible = "operating-points-v2";
> +
> +            power_opp_low: opp1 {
> +                opp-level = <16>;
> +            };
> +
> +            rpmpd_opp_ret: opp2 {
> +                opp-level = <64>;
> +            };
> +
> +            rpmpd_opp_svs: opp3 {
> +                opp-level = <256>;
> +            };
> +        };
> +    };
> +
> +    child4: consumer@12341000 {
> +        compatible = "foo,consumer";
> +        reg = <0x12341000 0x1000>;
> +        power-domains = <&parent4>, <&parent5>;
> +        assigned-performance-states = <0>, <256>;

I guess <0> means don't set anything?
Rajendra Nayak Aug. 5, 2020, 8:13 a.m. UTC | #2
On 8/5/2020 12:09 PM, Stephen Boyd wrote:
> Quoting Rajendra Nayak (2020-08-04 04:46:54)
>> While most devices within power-domains which support performance states,
>> scale the performance state dynamically, some devices might want to
>> set a static/default performance state while the device is active.
>> These devices typically would also run of a fixed clock and not support
> 
> s/of/off/
> 
>> dyamically scaling the device's performance, also known as DVFS techniques.
> 
> s/dyamically/dynamically/
> 
>> Add a property 'assigned-performance-states' which client devices can
>> use to set this default performance state on their power-domains.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>> ---
>>   .../devicetree/bindings/power/power-domain.yaml    | 47 ++++++++++++++++++++++
>>   1 file changed, 47 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/power/power-domain.yaml b/Documentation/devicetree/bindings/power/power-domain.yaml
>> index ff5936e..48e9319 100644
>> --- a/Documentation/devicetree/bindings/power/power-domain.yaml
>> +++ b/Documentation/devicetree/bindings/power/power-domain.yaml
>> @@ -66,6 +66,16 @@ properties:
>>          by the given provider should be subdomains of the domain specified
>>          by this binding.
>>   
>> +  assigned-performance-states:
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    description:
>> +       Some devices might need to configure their power domains in a default
>> +       performance state while the device is active. These devices typcially
>> +       would also run of a fixed clock and not support dyamically scaling the
> 
> Same of and dynamically comment.
> 
>> +       device's performance, also known as DVFS techniques. The list of performance
>> +       state values should correspond to the list of power domains specified as part
>> +       of the power-domains property.
> 
> This is different than assigned-clock-rates. I guess that's OK because
> we don't need to assign parents with more specifiers. Maybe it should be
> worded more strongly to clearly state that each cell corresponds to one
> power domain? And that it should match the opp-level inside any OPP
> table for the power domain?

Sure, I'll reword it to make it clear that we need the same number of cells
as power-domains, and as you pointed out below that 0 corresponds to not setting
anything.

For the matching of opp-level inside the OPP table of the power-domain, I don't
think from the power-domain bindings we limit providers with only OPP tables to
support performance states? It could be just a range that the provider manages
internally?

And thanks for catching all my typos :), I'll have them fixed when I re-spin.

> 
>> +
>>   required:
>>     - "#power-domain-cells"
>>   
>> @@ -129,3 +139,40 @@ examples:
>>               min-residency-us = <7000>;
>>           };
>>       };
>> +
>> +  - |
>> +    parent4: power-controller@12340000 {
>> +        compatible = "foo,power-controller";
>> +        reg = <0x12340000 0x1000>;
>> +        #power-domain-cells = <0>;
>> +    };
>> +
>> +    parent5: power-controller@43210000 {
>> +        compatible = "foo,power-controller";
>> +        reg = <0x43210000 0x1000>;
>> +        #power-domain-cells = <0>;
>> +        operating-points-v2 = <&power_opp_table>;
>> +
>> +        power_opp_table: opp-table {
>> +            compatible = "operating-points-v2";
>> +
>> +            power_opp_low: opp1 {
>> +                opp-level = <16>;
>> +            };
>> +
>> +            rpmpd_opp_ret: opp2 {
>> +                opp-level = <64>;
>> +            };
>> +
>> +            rpmpd_opp_svs: opp3 {
>> +                opp-level = <256>;
>> +            };
>> +        };
>> +    };
>> +
>> +    child4: consumer@12341000 {
>> +        compatible = "foo,consumer";
>> +        reg = <0x12341000 0x1000>;
>> +        power-domains = <&parent4>, <&parent5>;
>> +        assigned-performance-states = <0>, <256>;
> 
> I guess <0> means don't set anything?
>
Stephen Boyd Aug. 5, 2020, 11:57 p.m. UTC | #3
Quoting Rajendra Nayak (2020-08-05 01:13:06)
> 
> On 8/5/2020 12:09 PM, Stephen Boyd wrote:
> > Quoting Rajendra Nayak (2020-08-04 04:46:54)
> > 
> >> +       device's performance, also known as DVFS techniques. The list of performance
> >> +       state values should correspond to the list of power domains specified as part
> >> +       of the power-domains property.
> > 
> > This is different than assigned-clock-rates. I guess that's OK because
> > we don't need to assign parents with more specifiers. Maybe it should be
> > worded more strongly to clearly state that each cell corresponds to one
> > power domain? And that it should match the opp-level inside any OPP
> > table for the power domain?
> 
> Sure, I'll reword it to make it clear that we need the same number of cells
> as power-domains, and as you pointed out below that 0 corresponds to not setting
> anything.
> 
> For the matching of opp-level inside the OPP table of the power-domain, I don't
> think from the power-domain bindings we limit providers with only OPP tables to
> support performance states? It could be just a range that the provider manages
> internally?

Ok. The example made it match so maybe that can be clarified as well
that it doesn't need to match any OPP table performance state.

Patch
diff mbox series

diff --git a/Documentation/devicetree/bindings/power/power-domain.yaml b/Documentation/devicetree/bindings/power/power-domain.yaml
index ff5936e..48e9319 100644
--- a/Documentation/devicetree/bindings/power/power-domain.yaml
+++ b/Documentation/devicetree/bindings/power/power-domain.yaml
@@ -66,6 +66,16 @@  properties:
        by the given provider should be subdomains of the domain specified
        by this binding.
 
+  assigned-performance-states:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description:
+       Some devices might need to configure their power domains in a default
+       performance state while the device is active. These devices typcially
+       would also run of a fixed clock and not support dyamically scaling the
+       device's performance, also known as DVFS techniques. The list of performance
+       state values should correspond to the list of power domains specified as part
+       of the power-domains property.
+
 required:
   - "#power-domain-cells"
 
@@ -129,3 +139,40 @@  examples:
             min-residency-us = <7000>;
         };
     };
+
+  - |
+    parent4: power-controller@12340000 {
+        compatible = "foo,power-controller";
+        reg = <0x12340000 0x1000>;
+        #power-domain-cells = <0>;
+    };
+
+    parent5: power-controller@43210000 {
+        compatible = "foo,power-controller";
+        reg = <0x43210000 0x1000>;
+        #power-domain-cells = <0>;
+        operating-points-v2 = <&power_opp_table>;
+
+        power_opp_table: opp-table {
+            compatible = "operating-points-v2";
+
+            power_opp_low: opp1 {
+                opp-level = <16>;
+            };
+
+            rpmpd_opp_ret: opp2 {
+                opp-level = <64>;
+            };
+
+            rpmpd_opp_svs: opp3 {
+                opp-level = <256>;
+            };
+        };
+    };
+
+    child4: consumer@12341000 {
+        compatible = "foo,consumer";
+        reg = <0x12341000 0x1000>;
+        power-domains = <&parent4>, <&parent5>;
+        assigned-performance-states = <0>, <256>;
+    };