[PATCH v1 10/24] ARM: dts: imx7-colibri: add delay for on-module phy supply

From: Marcel Ziswiler
Date: Fri May 06 2022 - 11:30:03 EST


From: Oleksandr Suvorov <oleksandr.suvorov@xxxxxxxxxxx>

There is a significant time required for PHY Micrel KSZ8041 to power up.
Add a delay on start-up/wake-up before the FEC starts communicating with
the PHY.

LDO1 takes 6 ms, R39 + C44 takes ~100ms, the KSZ8041 datasheet asks for
~11 ms before starting any programming on the MIIM.

Counting that, add a 200 ms delay to be sure the PHY is ready for
programming. Also, add the same off delay time to give the capacitor
time to discharge in order to properly reset.

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@xxxxxxxxxxx>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
---

arch/arm/boot/dts/imx7-colibri.dtsi | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/imx7-colibri.dtsi b/arch/arm/boot/dts/imx7-colibri.dtsi
index 329638985db6..09dbd262dad1 100644
--- a/arch/arm/boot/dts/imx7-colibri.dtsi
+++ b/arch/arm/boot/dts/imx7-colibri.dtsi
@@ -94,6 +94,17 @@ reg_module_3v3_avdd: regulator-module-3v3-avdd {
regulator-name = "+V3.3_AVDD_AUDIO";
};

+ reg_module_3v3_eth: regulator-module-3v3-eth {
+ compatible = "regulator-fixed";
+ off-on-delay-us = <200000>;
+ regulator-name = "+V3.3_ETH";
+ regulator-min-microvolt = <3300000>;
+ regulator-max-microvolt = <3300000>;
+ regulator-boot-on;
+ startup-delay-us = <200000>;
+ vin-supply = <&reg_LDO1>;
+ };
+
reg_usbh_vbus: regulator-usbh-vbus {
compatible = "regulator-fixed";
gpio = <&gpio4 7 GPIO_ACTIVE_LOW>; /* SODIMM 129 / USBH_PEN */
@@ -153,7 +164,7 @@ &fec1 {
fsl,magic-packet;
phy-handle = <&ethphy0>;
phy-mode = "rmii";
- phy-supply = <&reg_LDO1>;
+ phy-supply = <&reg_module_3v3_eth>;
pinctrl-names = "default", "sleep";
pinctrl-0 = <&pinctrl_enet1>;
pinctrl-1 = <&pinctrl_enet1_sleep>;
@@ -440,7 +451,7 @@ reg_DCDC4: DCDC4 { /* V1.35_DRAM */
};

reg_LDO1: LDO1 { /* PWR_EN_+V3.3_ETH */
- regulator-min-microvolt = <1800000>;
+ regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-boot-on;
};
--
2.35.1