From ac60c5e33df4ec2b69c7e3ebbc0ccf1557e7bd5e Mon Sep 17 00:00:00 2001 From: Matthias Kaehlcke Date: Thu, 11 Apr 2019 17:01:58 -0700 Subject: [PATCH] ARM: dts: rockchip: Add dynamic-power-coefficient for rk3288 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The value was determined with the following method: - take CPUs 1-3 offline - for each OPP - set cpufreq min and max freq to OPP freq - start dhrystone benchmark - measure CPU power consumption during 10s - calculate Cx for OPPx - Cx = (Px - P1) / (Vx²fx - V1²f1) [1] using the following units: mW / Ghz / V [2] - C = avg(C2, ..., Cn) [1] see commit 4daa001a1773 ("arm64: dts: juno: Add cpu dynamic-power-coefficient information") [2] https://patchwork.kernel.org/patch/10493615/#22158551 FTR, these are the values for the different OPPs: freq (kHz) mV Px (mW) Cx 126000 900 39 216000 900 66 370 312000 900 95 372 408000 900 122 363 600000 900 177 359 696000 950 230 363 816000 1000 297 361 1008000 1050 404 362 1200000 1100 528 362 1416000 1200 770 377 1512000 1300 984 385 1608000 1350 1156 394 Signed-off-by: Matthias Kaehlcke Signed-off-by: Heiko Stuebner --- arch/arm/boot/dts/rk3288.dtsi | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi index 23e9c52..884957d 100644 --- a/arch/arm/boot/dts/rk3288.dtsi +++ b/arch/arm/boot/dts/rk3288.dtsi @@ -64,6 +64,7 @@ #cooling-cells = <2>; /* min followed by max */ clock-latency = <40000>; clocks = <&cru ARMCLK>; + dynamic-power-coefficient = <370>; }; cpu1: cpu@501 { device_type = "cpu"; @@ -74,6 +75,7 @@ #cooling-cells = <2>; /* min followed by max */ clock-latency = <40000>; clocks = <&cru ARMCLK>; + dynamic-power-coefficient = <370>; }; cpu2: cpu@502 { device_type = "cpu"; @@ -84,6 +86,7 @@ #cooling-cells = <2>; /* min followed by max */ clock-latency = <40000>; clocks = <&cru ARMCLK>; + dynamic-power-coefficient = <370>; }; cpu3: cpu@503 { device_type = "cpu"; @@ -94,6 +97,7 @@ #cooling-cells = <2>; /* min followed by max */ clock-latency = <40000>; clocks = <&cru ARMCLK>; + dynamic-power-coefficient = <370>; }; }; -- 2.7.4