linux-kernel - Re: [PATCH v5 3/3] cpufreq: qcom-hw: Add CPU clock provider support

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Message-ID: <20221108155717.srlnabls5ze2resx@bogus>
Date:   Tue, 8 Nov 2022 15:57:17 +0000
From:   Sudeep Holla <sudeep.holla@....com>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Cc:     andersson@...nel.org, viresh.kumar@...aro.org,
        krzysztof.kozlowski+dt@...aro.org, rafael@...nel.org,
        robh+dt@...nel.org, johan@...nel.org, devicetree@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v5 3/3] cpufreq: qcom-hw: Add CPU clock provider support

On Tue, Nov 08, 2022 at 09:10:37PM +0530, Manivannan Sadhasivam wrote:
> Qcom CPUFreq hardware (EPSS/OSM) controls clock and voltage to the CPU
> cores. But this relationship is not represented with the clk framework
> so far.
> 
> So, let's make the qcom-cpufreq-hw driver a clock provider. This makes the
> clock producer/consumer relationship cleaner and is also useful for CPU
> related frameworks like OPP to know the frequency at which the CPUs are
> running.
> 
> The clock frequency provided by the driver is for each frequency domain.
> We cannot get the frequency of each CPU core because, not all platforms
> support per-core DCVS feature.
> 
> Also the frequency supplied by the driver is the actual frequency that
> comes out of the EPSS/OSM block after the DCVS operation. This frequency is
> not same as what the CPUFreq framework has set but it is the one that gets
> supplied to the CPUs after throttling by LMh.
>

OK now I see more info here. How different is this value from the one
returned by qcom_cpufreq_hw_get() ?

-- 
Regards,
Sudeep