All of mmc controllers include SDMMC, SDIO0, SDIO1, and EMMC on RK3288 are limited to 150Mhz. It was mainly caused by two reasons: - RK3288's IO pad(except DDR IO pad) is generic, which can only support the max of 150Mhz. - Mmc controller was designed at 150Mhz, and the pressure test by IC team was based on this freequency point. Signed-off-by: Addy Ke <addy.ke@xxxxxxxxxxxxxx> --- 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 acb6a2f..9c35a1d 100644 --- a/arch/arm/boot/dts/rk3288.dtsi +++ b/arch/arm/boot/dts/rk3288.dtsi @@ -149,6 +149,7 @@ sdmmc: dwmmc@ff0c0000 { compatible = "rockchip,rk3288-dw-mshc"; + clock-freq-min-max = <400000 150000000>; clocks = <&cru HCLK_SDMMC>, <&cru SCLK_SDMMC>; clock-names = "biu", "ciu"; fifo-depth = <0x100>; @@ -159,6 +160,7 @@ sdio0: dwmmc@ff0d0000 { compatible = "rockchip,rk3288-dw-mshc"; + clock-freq-min-max = <400000 150000000>; clocks = <&cru HCLK_SDIO0>, <&cru SCLK_SDIO0>; clock-names = "biu", "ciu"; fifo-depth = <0x100>; @@ -169,6 +171,7 @@ sdio1: dwmmc@ff0e0000 { compatible = "rockchip,rk3288-dw-mshc"; + clock-freq-min-max = <400000 150000000>; clocks = <&cru HCLK_SDIO1>, <&cru SCLK_SDIO1>; clock-names = "biu", "ciu"; fifo-depth = <0x100>; @@ -179,6 +182,7 @@ emmc: dwmmc@ff0f0000 { compatible = "rockchip,rk3288-dw-mshc"; + clock-freq-min-max = <400000 150000000>; clocks = <&cru HCLK_EMMC>, <&cru SCLK_EMMC>; clock-names = "biu", "ciu"; fifo-depth = <0x100>; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html