arm64: dts: imx8mn-beacon: Fix HS400 USDHC clock speed

aford173 · Shawn Guo · commit e16ad6c79906 · 2025-07-11T16:34:31.000+08:00
The reference manual for the i.MX8MN states the clock rate in MMC mode is 1/2 of the input clock, therefore to properly run at HS400 rates, the input clock must be 400MHz to operate at 200MHz. Currently the clock is set to 200MHz which is half the rate it should be, so the throughput is half of what it should be for HS400 operation. Fixes: 36ca3c8 ("arm64: dts: imx: Add Beacon i.MX8M Nano development kit") Signed-off-by: Adam Ford <aford173@gmail.com> Reviewed-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
diff --git a/arch/arm64/boot/dts/freescale/imx8mn-beacon-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-beacon-som.dtsi
@@ -305,6 +305,8 @@
 	pinctrl-0 = <&pinctrl_usdhc3>;
 	pinctrl-1 = <&pinctrl_usdhc3_100mhz>;
 	pinctrl-2 = <&pinctrl_usdhc3_200mhz>;
+	assigned-clocks = <&clk IMX8MN_CLK_USDHC3>;
+	assigned-clock-rates = <400000000>;
 	bus-width = <8>;
 	non-removable;
 	status = "okay";
