Re: [PATCH v2 1/2] dt-bindings: cpufreq: Introduce QCOM CPUFREQ FW bindings

Taniya Das
2018-05-24T05:46:20Z

On 5/23/2018 8:43 PM, Sudeep Holla wrote:
>
>
> On 19/05/18 18:34, Taniya Das wrote:
>> Add QCOM cpufreq firmware device bindings for Qualcomm Technology Inc's
>> SoCs. This is required for managing the cpu frequency transitions which are
>> controlled by firmware.
>>
>> Signed-off-by: Taniya Das <tdas@codeaurora.org>
>> ---
>> .../bindings/cpufreq/cpufreq-qcom-fw.txt | 68 ++++++++++++++++++++++
>> 1 file changed, 68 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-fw.txt
>>
>> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-fw.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-fw.txt
>> new file mode 100644
>> index 0000000..bc912f4
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-fw.txt
>> @@ -0,0 +1,68 @@
>> +Qualcomm Technologies, Inc. CPUFREQ Bindings
>> +
>> +CPUFREQ FW is a hardware engine used by some Qualcomm Technologies, Inc. (QTI)
>> +SoCs to manage frequency in hardware. It is capable of controlling frequency
>> +for multiple clusters.
>> +
>> +Properties:
>> +- compatible
>> + Usage: required
>> + Value type: <string>
>> + Definition: must be "qcom,cpufreq-fw".
>> +
>
> If the firmware is referred with some other name, better to use that
> than cpufreq
>> +Note that #address-cells, #size-cells, and ranges shall be present to ensure
>> +the cpufreq can address a freq-domain registers.
>> +
>> +A freq-domain sub-node would be defined for the cpus with the following
>> +properties:
>> +
>> +- compatible:
>> + Usage: required
>> + Value type: <string>
>> + Definition: must be "cpufreq".
>> +
>> +- reg
>> + Usage: required
>> + Value type: <prop-encoded-array>
>> + Definition: Addresses and sizes for the memory of the perf_base
>> + , lut_base and en_base.
>
> Can you explicitly define each one of them ? Either here or in reg-names.
>

Sure will define each of them in the next series.

>> +- reg-names
>> + Usage: required
>> + Value type: <stringlist>
>> + Definition: Address names. Must be "perf_base", "lut_base",
>> + "en_base".
>> + Must be specified in the same order as the
>> + corresponding addresses are specified in the reg
>> + property.
>> +
>> +- qcom,cpulist
>> + Usage: required
>> + Value type: <phandles of CPU>
>> + Definition: List of related cpu handles which are under a cluster.
>> +
>
> As already mentioned by Rob and Viresh, better to align with OPP style
> to avoid phandle list of CPUs.
>

I have put down an example device tree node for Rob & Viresh to review.

> Also I see similar bindings for devfreq, can't they be aligned ?
> E.g. lut_base here while it's ftbl_base in devfreq.
>

It is actually the look up table, thus was the name given as "lut". Will
check with Saravana for devfreq and align accordingly.

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