| Message ID | 20240905-b4-opp-dt-binding-fix-v2-1-1e3d2a06748d@ti.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] dt-bindings: opp: operating-points-v2-ti-cpu: Describe opp-supported-hw | expand |
On Thu, Sep 05, 2024 at 10:44:32AM +0530, Dhruva Gole wrote: > It seems like we missed migrating the complete information from the old > DT binding where we had described what the opp-supported-hw is supposed > to describe. Hence, bring back the description from the previous binding > to the current one along with a bit more context on what the values are > supposed to be. > > Fixes: e576a9a8603f ("dt-bindings: cpufreq: Convert ti-cpufreq to json schema") > Signed-off-by: Dhruva Gole <d-gole@ti.com> > --- > Changes in v2: > - Drop the patch where I updated Maintainers since it's already picked > by Viresh. > - Add more details of how to populate the property based on device > documents like TRM/ datasheet. > - Link to v1: https://lore.kernel.org/r/20240903-b4-opp-dt-binding-fix-v1-0-f7e186456d9f@ti.com > --- > .../bindings/opp/operating-points-v2-ti-cpu.yaml | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml b/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml > index 02d1d2c17129..fd260b20c59c 100644 > --- a/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml > +++ b/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml > @@ -45,7 +45,21 @@ patternProperties: > clock-latency-ns: true > opp-hz: true > opp-microvolt: true > - opp-supported-hw: true > + opp-supported-hw: > + description: | > + Two bitfields indicating: > + 1. Which revision of the SoC the OPP is supported by. > + This can be easily obtained from the datasheet of the > + part being ordered/used. For eg. it will be 0x01 for SR1.0 > + 2. Which eFuse bits indicate this OPP is available. > + The device datasheet has a table talking about Device Speed Grades. > + If one were to sort this table and only retain the unique elements > + of the MAXIMUM OPERATING FREQUENCY starting from the first row > + which tells the lowest OPP, to the highest. The corresponding bits > + need to be set based on N elements of speed grade the device supports. > + So, if there are 3 possible unique MAXIMUM OPERATING FREQUENCY > + in the table, then BIT(0), (1) and (2) will be set, which means > + the value shall be 0x7. I still have no clue what the bitfield layout is. Where do 0x1 and 0x7 go in the examples from above? How many 32-bit words is not defined by the common schema. You need to define that here (maxItems/minItems). Rob
diff --git a/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml b/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml index 02d1d2c17129..fd260b20c59c 100644 --- a/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml +++ b/Documentation/devicetree/bindings/opp/operating-points-v2-ti-cpu.yaml @@ -45,7 +45,21 @@ patternProperties: clock-latency-ns: true opp-hz: true opp-microvolt: true - opp-supported-hw: true + opp-supported-hw: + description: | + Two bitfields indicating: + 1. Which revision of the SoC the OPP is supported by. + This can be easily obtained from the datasheet of the + part being ordered/used. For eg. it will be 0x01 for SR1.0 + 2. Which eFuse bits indicate this OPP is available. + The device datasheet has a table talking about Device Speed Grades. + If one were to sort this table and only retain the unique elements + of the MAXIMUM OPERATING FREQUENCY starting from the first row + which tells the lowest OPP, to the highest. The corresponding bits + need to be set based on N elements of speed grade the device supports. + So, if there are 3 possible unique MAXIMUM OPERATING FREQUENCY + in the table, then BIT(0), (1) and (2) will be set, which means + the value shall be 0x7. opp-suspend: true turbo-mode: true
It seems like we missed migrating the complete information from the old DT binding where we had described what the opp-supported-hw is supposed to describe. Hence, bring back the description from the previous binding to the current one along with a bit more context on what the values are supposed to be. Fixes: e576a9a8603f ("dt-bindings: cpufreq: Convert ti-cpufreq to json schema") Signed-off-by: Dhruva Gole <d-gole@ti.com> --- Changes in v2: - Drop the patch where I updated Maintainers since it's already picked by Viresh. - Add more details of how to populate the property based on device documents like TRM/ datasheet. - Link to v1: https://lore.kernel.org/r/20240903-b4-opp-dt-binding-fix-v1-0-f7e186456d9f@ti.com --- .../bindings/opp/operating-points-v2-ti-cpu.yaml | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) --- base-commit: ecc768a84f0b8e631986f9ade3118fa37852fef0 change-id: 20240903-b4-opp-dt-binding-fix-73c6829751d2 Best regards,