Re: [PATCH v1 1/5] dt-bindings: cpufreq: Add binding for NVIDIA Tegra20/30

Dmitry Osipenko
2018-10-17T12:37:38Z

On 10/17/18 11:40 AM, Jon Hunter wrote:
>
> On 30/08/2018 20:43, Dmitry Osipenko wrote:
>> Add device-tree binding that describes CPU frequency-scaling hardware
>> found on NVIDIA Tegra20/30 SoC's.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>> .../cpufreq/nvidia,tegra20-cpufreq.txt | 38 +++++++++++++++++++
>> 1 file changed, 38 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
>>
>> diff --git a/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt b/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
>> new file mode 100644
>> index 000000000000..2c51f676e958
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
>> @@ -0,0 +1,38 @@
>> +Binding for NVIDIA Tegra20 CPUFreq
>> +==================================
>> +
>> +Required properties:
>> +- clocks: Must contain an entry for each entry in clock-names.
>> + See ../clocks/clock-bindings.txt for details.
>> +- clock-names: Must include the following entries:
>> + - pll_x: main-parent for CPU clock, must be the first entry
>> + - backup: intermediate-parent for CPU clock
>> + - cpu: the CPU clock
>
> Is it likely that 'backup' will be anything other that pll_p? If not why
> not just call it pll_p? Personally, I don't 'backup' to descriptive even
> though I can see what you mean.
>
> I can see that you want to make this flexible, but if the likelihood is
> that we will just use pll_p then I am not sure it is warranted at this
> point.

That won't describe HW, but software. And device tree should describe HW.