[PATCH v2] ARM: dts: nxp/imx: limit sk-imx53 supported frequencies

[Dmitry Baryshkov]

The SK-IMX53 board, bearing i.MX536A CPU, is not stable when running at
1.2 GHz (default iMX53 maximum). The SoC is only rated up to 800 MHz.
Disable 1.2 GHz and 1 GHz frequencies.

Fixes: 0b8576d8440a ("ARM: dts: imx: Add support for SK-iMX53 board")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---

Changes since v1:
- After additional consideration, also disable the 1 GHz frequency. The
  datasheets are clear the the SoC is not required to support this
  frequency (Fabio).

---
 arch/arm/boot/dts/nxp/imx/imx53-sk-imx53.dts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/nxp/imx/imx53-sk-imx53.dts b/arch/arm/boot/dts/nxp/imx/imx53-sk-imx53.dts
index 6ea103a49697..3d9f14f32efd 100644
--- a/arch/arm/boot/dts/nxp/imx/imx53-sk-imx53.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx53-sk-imx53.dts
@@ -77,6 +77,16 @@ &can1 {
 	status = "okay";
 };
 
+&cpu0 {
+	/* CPU rated to 800 MHz, not the default 1.2GHz. */
+	operating-points = <
+		/* kHz   uV */
+		166666  850000
+		400000  900000
+		800000  1050000
+	>;
+};
+
 &ecspi1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_ecspi1>;
-- 
2.39.2