[PATCH 5.9 099/252] ARM: dts: vf610-zii-dev-rev-b: Fix MDIO over clocking

[Greg Kroah-Hartman]

From: Andrew Lunn <andrew@xxxxxxx>

[ Upstream commit f8b5a33707c9a19ec905d2826be0acd151997a09 ]

The ZII devel B board has two generations of Marvell Switches.  The
mv88e6352 supports an MDIO clock of 12MHz. However the older 88e6185
does not like 12MHz, and often fails to probe.

Reduce the clock speed to 5MHz, which seems to work reliably.

Cc: Chris Healy <cphealy@xxxxxxxxx>
Fixes: b955387667ec ("ARM: dts: ZII: update MDIO speed and preamble")
Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
Reviewed-by: Chris Healy <cphealy@xxxxxxxxx>
Signed-off-by: Shawn Guo <shawnguo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/arm/boot/dts/vf610-zii-dev-rev-b.dts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/boot/dts/vf610-zii-dev-rev-b.dts b/arch/arm/boot/dts/vf610-zii-dev-rev-b.dts
index e500911ce0a59..6f1e0f0d4f0ae 100644
--- a/arch/arm/boot/dts/vf610-zii-dev-rev-b.dts
+++ b/arch/arm/boot/dts/vf610-zii-dev-rev-b.dts
@@ -406,6 +406,9 @@
 	};
 };
 
+&mdio1 {
+	clock-frequency = <5000000>;
+};
 
 &iomuxc {
 	pinctrl_gpio_e6185_eeprom_sel: pinctrl-gpio-e6185-eeprom-spi0 {
-- 
2.27.0