From mboxrd@z Thu Jan 1 00:00:00 1970 From: Caesar Wang Subject: [PATCH] arm64: dts: rockchip: update dynamic-power-coefficient for rk3399 Date: Tue, 25 Jul 2017 17:22:55 +0800 Message-ID: <1500974575-2244-1-git-send-email-wxt@rock-chips.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Heiko Stuebner Cc: linux-rockchip@lists.infradead.org, Caesar Wang , Douglas Anderson , William wu , Elaine Zhang , Kever Yang , Brian Norris , linux-kernel@vger.kernel.org, Shawn Lin , devicetree@vger.kernel.org, Rob Herring , linux-arm-kernel@lists.infradead.org, Will Deacon , Mark Rutland , Catalin Marinas , Roger Chen List-Id: devicetree@vger.kernel.org This patch updates the dynamic-power-coefficient for big cluster on rk3399 SoCs. The dynamic power consumption of the CPU is proportional to the square of the Voltage (V) and the clock frequency (f). The coefficient is used to calculate the dynamic power as below - Pdyn = dynamic-power-coefficient * V^2 * f Where Voltage is in uV, frequency is in MHz. As the following is the tested data on rk3399's big cluster. frequency(MHz) Voltage(V) Current(mA) Dynamic-power-coefficient 24 0.8 15 48 0.8 23 ~417 96 0.8 40 ~443 216 0.8 82 ~438 312 0.8 115 ~430 408 0.8 150 ~455 So the dynamic-power-coefficient average value is about 436. Signed-off-by: Caesar Wang --- arch/arm64/boot/dts/rockchip/rk3399.dtsi | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index 9d02006..5d54a06 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi @@ -150,7 +150,7 @@ enable-method = "psci"; #cooling-cells = <2>; /* min followed by max */ clocks = <&cru ARMCLKB>; - dynamic-power-coefficient = <100>; + dynamic-power-coefficient = <436>; }; cpu_b1: cpu@101 { @@ -159,7 +159,7 @@ reg = <0x0 0x101>; enable-method = "psci"; clocks = <&cru ARMCLKB>; - dynamic-power-coefficient = <100>; + dynamic-power-coefficient = <436>; }; }; -- 2.7.4