Commit a06d4fde authored by Dmitry Rokosov's avatar Dmitry Rokosov Committed by Neil Armstrong

arm64: dts: amlogic: axg: initialize default SoC capacitance

The capacitance value is required for the usage of the cpufreq cooling
device and power_allocator thermal governor in the appropriate energy
model.

It helps to compute the power estimated by the SoC at the appropriate
frequency. If it is the frequency of an existing OPP, or at the
frequency of the first OPP above the requested value otherwise.

The power is estimated as P = C * V^2 * f, with C being the SoC's
capacitance and V and f respectively representing the voltage and
frequency of the OPP.

Since AXG SoC doesn't have SCMI protocol support, we need to initialize
capacitance using the 'dynamic-power-coefficient' DT entry. Its value is
retrieved from the vendor kernel, and it gives us the following
freq2power mapping:
    +-----------+--------+
    | frequency,| power, |
    |    MHz    |   uW   |
    +-----------+--------+
    |     100   |  10354 |
    +-----------+--------+
    |     250   |  27104 |
    +-----------+--------+
    |     500   |  55447 |
    +-----------+--------+
    |     667   |  77327 |
    +-----------+--------+
    |    1000   | 129024 |
    +-----------+--------+
    |    1200   | 164656 |
    +-----------+--------+
    |    1296   | 192489 |
    +-----------+--------+
    |    1416   | 239870 |
    +-----------+--------+
Signed-off-by: default avatarDmitry Rokosov <ddrokosov@salutedevices.com>
Reviewed-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240209212816.11187-3-ddrokosov@salutedevices.comSigned-off-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
parent 7c3215fe
......@@ -74,6 +74,7 @@ cpu0: cpu@0 {
enable-method = "psci";
next-level-cache = <&l2>;
clocks = <&scpi_dvfs 0>;
dynamic-power-coefficient = <140>;
#cooling-cells = <2>;
};
......@@ -84,6 +85,7 @@ cpu1: cpu@1 {
enable-method = "psci";
next-level-cache = <&l2>;
clocks = <&scpi_dvfs 0>;
dynamic-power-coefficient = <140>;
#cooling-cells = <2>;
};
......@@ -94,6 +96,7 @@ cpu2: cpu@2 {
enable-method = "psci";
next-level-cache = <&l2>;
clocks = <&scpi_dvfs 0>;
dynamic-power-coefficient = <140>;
#cooling-cells = <2>;
};
......@@ -104,6 +107,7 @@ cpu3: cpu@3 {
enable-method = "psci";
next-level-cache = <&l2>;
clocks = <&scpi_dvfs 0>;
dynamic-power-coefficient = <140>;
#cooling-cells = <2>;
};
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment