[PATCH v2] ARM: dts: imx: Set default tuning step for imx7d usdhc

[Xiaolei Wang <xiaolei.wang@windriver.com>]

If the tuning step is not set, the tuning step is set to 1.
For some sd cards, the following Tuning timeout will occur,
so set the default tuning step. This refers to the NXP vendor's
commit below:

https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/
arch/arm/boot/dts/imx7s.dtsi#L1216-L1217

Fixes: 1e336aa0c025 ("mmc: sdhci-esdhc-imx: correct the tuning start tap and step setting")
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>

v2:
  * Refer to https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm/boot/dts/imx7s.dtsi#L1216-L1217
    and add the following attributes for all usdhc of imx7:
      fsl,tuning-step = <2>;
      fsl,tuning-start-tap = <20>;

---
 arch/arm/boot/dts/nxp/imx/imx7s.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/nxp/imx/imx7s.dtsi b/arch/arm/boot/dts/nxp/imx/imx7s.dtsi
index 54026c2c93fa..6ffb428dc939 100644
--- a/arch/arm/boot/dts/nxp/imx/imx7s.dtsi
+++ b/arch/arm/boot/dts/nxp/imx/imx7s.dtsi
@@ -1184,6 +1184,8 @@ usdhc1: mmc@30b40000 {
 					<&clks IMX7D_USDHC1_ROOT_CLK>;
 				clock-names = "ipg", "ahb", "per";
 				bus-width = <4>;
+				fsl,tuning-step = <2>;
+				fsl,tuning-start-tap = <20>;
 				status = "disabled";
 			};
 
@@ -1196,6 +1198,8 @@ usdhc2: mmc@30b50000 {
 					<&clks IMX7D_USDHC2_ROOT_CLK>;
 				clock-names = "ipg", "ahb", "per";
 				bus-width = <4>;
+				fsl,tuning-step = <2>;
+				fsl,tuning-start-tap = <20>;
 				status = "disabled";
 			};
 
@@ -1208,6 +1212,8 @@ usdhc3: mmc@30b60000 {
 					<&clks IMX7D_USDHC3_ROOT_CLK>;
 				clock-names = "ipg", "ahb", "per";
 				bus-width = <4>;
+				fsl,tuning-step = <2>;
+				fsl,tuning-start-tap = <20>;
 				status = "disabled";
 			};
 
-- 
2.25.1