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Date:   Sat, 22 Oct 2022 13:12:22 +0200
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Subject: Re: [PATCH 1/2] thermal: rockchip: Support RK3588 SoC in the thermal
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To:     Nicolas Frattaroli <frattaroli.nicolas@gmail.com>,
        Sebastian Reichel <sebastian.reichel@collabora.com>,
        Heiko Stuebner <heiko@sntech.de>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        linux-rockchip@lists.infradead.org
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Finley Xiao <finley.xiao@rock-chips.com>, kernel@collabora.com
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From:   Daniel Lezcano <daniel.lezcano@linaro.org>
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On 22/10/2022 10:43, Nicolas Frattaroli wrote:

[ ... ]

>> What is TOP and CENTER ?
>>
>> There are 4 Bigs on this platform but two sensors ?
> 
> As far as I know, the four big cores in the SoC are arranged in two
> clusters of two cores each, so one temperature sensor for each
> cluster. As far as I can tell each CPU in a cluster shares its voltage
> with its partner CPU core in its cluster.

Ok, I found some more details on the datasheet, page 7-8.

So it is a big "Cluster" with the 4 Big cores. They share the same cache.

There is one power domain per core (cpuidle)

There are two performance domains (cpufreq x 2)

So it makes sense to have one sensor per performance domain to mitigate 
the temperature.

> If you have access to the TRM, it contains the following line in
> part 1 on page 1372:

Unfortunately no, I don't have access to the TRM. But I'll be happy if I 
can ;)

> 	Support to 7 channel TS-ADC (near chip center, A76_0/1, A76_2/3,
> 	DSU and A55_0/1/2/3, PD_CENTER, NPU, GPU)
> 
> I assume one of "TOP" and "CENTER" is "near chip center", the other is
> PD_CENTER, whatever that means (PD = power domain maybe?)

Yes certainly.

I take the opportunity to let you know there is a new tool in the linux 
tools directory called 'thermometer'. You can capture the temperature 
and use the data to create graphics.

> I agree these could be named more descriptively.
> 


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