LF-311 ARM: dts: imx6sx: add tuning step and tuning start tap for usdhc

If usdhc want to support SDR104/HS200, it need to do tuning, so need
to config the tuning step and tuning start tap. Otherwise some card may
meet tuning issue as the following log show:

mmc2: Tuning failed, falling back to fixed sampling clock

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>

diff --git a/arch/arm/boot/dts/imx6sx.dtsi b/arch/arm/boot/dts/imx6sx.dtsi
index 480ae0b..2d41482 100644 (file)
--- a/arch/arm/boot/dts/imx6sx.dtsi
+++ b/arch/arm/boot/dts/imx6sx.dtsi
@@ -1095,6 +1095,8 @@
                                         <&clks IMX6SX_CLK_USDHC1>;
                                clock-names = "ipg", "ahb", "per";
                                bus-width = <4>;
+                               fsl,tuning-start-tap = <20>;
+                               fsl,tuning-step= <2>;
                                status = "disabled";
                        };
 
@@ -1107,6 +1109,8 @@
                                         <&clks IMX6SX_CLK_USDHC2>;
                                clock-names = "ipg", "ahb", "per";
                                bus-width = <4>;
+                               fsl,tuning-start-tap = <20>;
+                               fsl,tuning-step= <2>;
                                status = "disabled";
                        };
 
@@ -1119,6 +1123,8 @@
                                         <&clks IMX6SX_CLK_USDHC3>;
                                clock-names = "ipg", "ahb", "per";
                                bus-width = <4>;
+                               fsl,tuning-start-tap = <20>;
+                               fsl,tuning-step= <2>;
                                status = "disabled";
                        };
 
@@ -1131,6 +1137,8 @@
                                         <&clks IMX6SX_CLK_USDHC4>;
                                clock-names = "ipg", "ahb", "per";
                                bus-width = <4>;
+                               fsl,tuning-start-tap = <20>;
+                               fsl,tuning-step= <2>;
                                status = "disabled";
                        };