[PATCH] arm64: dts: meson: sm1: add Ethernet PHY reset line for ODROID-C4/HC4

[Dongjin Kim]

This patch is to fix an issue that the ethernet link doesn't come up
when using ip link set down/up:
   [   11.428114] meson8b-dwmac ff3f0000.ethernet eth0: Link is Down
   [   14.428595] meson8b-dwmac ff3f0000.ethernet eth0: PHY [0.0:00] driver [RTL8211F Gigabit Ethernet] (irq=31)
   [   14.428610] meson8b-dwmac ff3f0000.ethernet: Failed to reset the dma
   [   14.428974] meson8b-dwmac ff3f0000.ethernet eth0: stmmac_hw_setup: DMA engine initialization failed
   [   14.711185] meson8b-dwmac ff3f0000.ethernet eth0: stmmac_open: Hw setup failed

This fix has been referred two commits applied for ODROID-N2 (G12B).
    commit 658e4129bb81 ("arm64: dts: meson: g12b: odroid-n2: add the Ethernet PHY reset line")
    commit 1c7412530d5d0 ("arm64: dts: meson: g12b: odroid-n2: fix PHY deassert timing requirements")

Signed-off-by: Dongjin Kim <tobetter at gmail.com>
---
 arch/arm64/boot/dts/amlogic/meson-sm1-odroid.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1-odroid.dtsi b/arch/arm64/boot/dts/amlogic/meson-sm1-odroid.dtsi
index d14716b3d0f1..1230beba04aa 100644
--- a/arch/arm64/boot/dts/amlogic/meson-sm1-odroid.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-sm1-odroid.dtsi
@@ -256,6 +256,10 @@ external_phy: ethernet-phy at 0 {
 		reg = <0>;
 		max-speed = <1000>;
 
+		reset-assert-us = <10000>;
+		reset-deassert-us = <80000>;
+		reset-gpios = <&gpio GPIOZ_15 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+
 		interrupt-parent = <&gpio_intc>;
 		/* MAC_INTR on GPIOZ_14 */
 		interrupts = <26 IRQ_TYPE_LEVEL_LOW>;
-- 
2.30.2