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

From: Taniya Das <tdas@codeaurora.org>
To: Sudeep Holla <sudeep.holla@arm.com>,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	Stephen Boyd <sboyd@kernel.org>,
	robh@kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	Amit Nischal <anischal@codeaurora.org>,
	devicetree@vger.kernel.org, skannan@codeaurora.org,
	amit.kucheria@linaro.org
Subject: Re: [PATCH v2 1/2] dt-bindings: cpufreq: Introduce QCOM CPUFREQ FW bindings
Date: Thu, 24 May 2018 11:16:06 +0530	[thread overview]
Message-ID: <05796839-2584-a011-127f-ce193b0ae7c3@codeaurora.org> (raw)
In-Reply-To: <34b510f5-fd0b-2e28-45b0-f200f9f8d2c5@arm.com>

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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