[PATCH for next 05/15] ARM: dts: imx6: phyboards: reduce clock speed for usdhc3

[Stefan Christ]

Due to hardware issues the usdhc3 interface on phyBOARD-ALCOR i.MX6 and
phyBOARD-SUBRA i.MX6 doesn't work reliable at 50Mhz.  You get
communication errors like

    barebox at Phytec phyBOARD SUBRA:/ ls /mnt/mmc/
    mmc2: detected SD card version 2.0
    mmc2: registered mmc2
    imx-esdhc 2198000.usdhc: timeout 2
    mmc2: Cannot read MBR/partition table

Therefore reduce the maximum clock speed to avoid these problems.

Signed-off-by: Stefan Christ <s.christ at phytec.de>
---
 arch/arm/dts/imx6q-phytec-phyboard-alcor.dts    | 1 +
 arch/arm/dts/imx6qdl-phytec-phyboard-subra.dtsi | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/arm/dts/imx6q-phytec-phyboard-alcor.dts b/arch/arm/dts/imx6q-phytec-phyboard-alcor.dts
index a60fc18..1c4a785 100644
--- a/arch/arm/dts/imx6q-phytec-phyboard-alcor.dts
+++ b/arch/arm/dts/imx6q-phytec-phyboard-alcor.dts
@@ -35,4 +35,5 @@
 
 &usdhc3 {
 	status = "okay";
+	max-frequency = <25000000>; /* 25 Mhz */
 };
diff --git a/arch/arm/dts/imx6qdl-phytec-phyboard-subra.dtsi b/arch/arm/dts/imx6qdl-phytec-phyboard-subra.dtsi
index 1efc632..a38765b 100644
--- a/arch/arm/dts/imx6qdl-phytec-phyboard-subra.dtsi
+++ b/arch/arm/dts/imx6qdl-phytec-phyboard-subra.dtsi
@@ -26,4 +26,5 @@
 
 &usdhc3 {
 	status = "okay";
+	max-frequency = <25000000>; /* 25 Mhz */
 };
-- 
1.9.1