This patch adds ethernet PHY reset GPIO config for Beaglebone Black
series boards with revision C3. This fixes a random phy startup failure
bug discussed at [1]. The GPIO pin used for reset is not used on older
revisions, so it is ok to apply to all board revisions. The reset timing
was discussed and tested at [2].
[1] https://forum.digikey.com/t/ethernet-device-is-not-detecting-on-ubuntu-20-04-lts-on-bbg/19948
[2] https://forum.beagleboard.org/t/recognizing-a-beaglebone-black-rev-c3-board/31249/
Signed-off-by: Robert Nelson <[email protected]>
Signed-off-by: Shengyu Qu <[email protected]>
---
arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi b/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi
index 7b784a87efc6..943d40fe2272 100644
--- a/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi
+++ b/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi
@@ -145,6 +145,8 @@ davinci_mdio_default: davinci-mdio-default-pins {
/* MDIO */
AM33XX_PADCONF(AM335X_PIN_MDIO, PIN_INPUT_PULLUP | SLEWCTRL_FAST, MUX_MODE0)
AM33XX_PADCONF(AM335X_PIN_MDC, PIN_OUTPUT_PULLUP, MUX_MODE0)
+ /* added to support GPIO controlled PHY reset */
+ AM33XX_PADCONF(AM335X_PIN_UART0_CTSN, PIN_OUTPUT_PULLUP, MUX_MODE7)
>;
};
@@ -153,6 +155,8 @@ davinci_mdio_sleep: davinci-mdio-sleep-pins {
/* MDIO reset value */
AM33XX_PADCONF(AM335X_PIN_MDIO, PIN_INPUT_PULLDOWN, MUX_MODE7)
AM33XX_PADCONF(AM335X_PIN_MDC, PIN_INPUT_PULLDOWN, MUX_MODE7)
+ /* added to support GPIO controlled PHY reset */
+ AM33XX_PADCONF(AM335X_PIN_UART0_CTSN, PIN_INPUT_PULLDOWN, MUX_MODE7)
>;
};
@@ -378,6 +382,10 @@ &davinci_mdio_sw {
ethphy0: ethernet-phy@0 {
reg = <0>;
+ // Support GPIO Reset on Rev C3 boards
+ reset-gpios = <&gpio1 8 GPIO_ACTIVE_LOW>;
+ reset-assert-us = <300>;
+ reset-deassert-us = <6500>;
};
};
--
2.41.0