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

From: Jon Hunter <jonathanh@nvidia.com>
To: Dmitry Osipenko <digetx@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Rob Herring <robh+dt@kernel.org>
Cc: linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/5] dt-bindings: cpufreq: Add binding for NVIDIA Tegra20/30
Date: Wed, 17 Oct 2018 13:59:53 +0100	[thread overview]
Message-ID: <a9b6e683-3802-896c-27ad-9c49853c231f@nvidia.com> (raw)
In-Reply-To: <1448e619-35c9-0195-c68a-604d10f4dc8b@gmail.com>

On 17/10/2018 13:37, Dmitry Osipenko wrote:
> 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.

Hmm ... well that's my point exactly. So why call it 'backup'? Sounds
like a software description to me.

Jon

-- 
nvpublic