[RFC 2/3] ARM: dts: Specify MSHC realistic clocks and use frequency scaling

Krzysztof Kozlowski
2015-01-12T09:26:36Z

Lower the dw_mmc host clock from 400 MHz to 100 MHz because there are a
lot of MMC errors above 100 MHz.

Enable frequency scaling to reduce energy consumption. In idle this
reduced energy consumption by 2.6% (from 119.5 mA to 116.4 mA).

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
arch/arm/boot/dts/exynos4412-trats2.dts | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/exynos4412-trats2.dts b/arch/arm/boot/dts/exynos4412-trats2.dts
index 29231b452643..21f1236ae979 100644
--- a/arch/arm/boot/dts/exynos4412-trats2.dts
+++ b/arch/arm/boot/dts/exynos4412-trats2.dts
@@ -558,7 +558,9 @@
non-removable;
card-detect-delay = <200>;
vmmc-supply = <&vemmc_reg>;
- clock-frequency = <400000000>;
+ clock-frequency = <100000000>;
+ clock-freq-min-max = <400000 100000000>;
+ frequency-scaling;
samsung,dw-mshc-ciu-div = <0>;
samsung,dw-mshc-sdr-timing = <2 3>;
samsung,dw-mshc-ddr-timing = <1 2>;
--
1.9.1