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 <robertcnelson@xxxxxxxxx> Signed-off-by: Shengyu Qu <wiagn233@xxxxxxxxxxx> --- Changes since v1: - Using /**/ rather than // to comment --- 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..96451c8a815c 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 revision C3 boards */ + reset-gpios = <&gpio1 8 GPIO_ACTIVE_LOW>; + reset-assert-us = <300>; + reset-deassert-us = <6500>; }; }; -- 2.41.0
