From b6a41f36279a7fbe3db2ef420a9909035a537e38 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sat, 29 Mar 2025 19:58:53 +0100 Subject: [PATCH] arm64: dts: amlogic: g12: enable UART RX and TX pull up by default Some boards have noise on the UART RX line when the UART pins are not connected to another device (such as an USB UART adapter). This can be addressed by using a pull up resistor. Not all boards may provide such a pull up resistor on the PCB so enable the SoC's pull-up on the UART RX and TX pads by default. This matches the default (from u-boot or SoC hardware) state for the pinmux configuration on these pads. Signed-off-by: Martin Blumenstingl Reviewed-by: Neil Armstrong Link: https://lore.kernel.org/r/20250329185855.854186-6-martin.blumenstingl@googlemail.com Signed-off-by: Neil Armstrong --- arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi b/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi index ab2b3f15ef194..12e8daaa1c9b8 100644 --- a/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi @@ -1503,7 +1503,7 @@ groups = "uart_a_tx", "uart_a_rx"; function = "uart_a"; - bias-disable; + bias-pull-up; }; }; @@ -1521,7 +1521,7 @@ groups = "uart_b_tx", "uart_b_rx"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; @@ -1918,7 +1918,7 @@ groups = "uart_ao_a_tx", "uart_ao_a_rx"; function = "uart_ao_a"; - bias-disable; + bias-pull-up; }; }; @@ -1936,7 +1936,7 @@ groups = "uart_ao_b_tx_2", "uart_ao_b_rx_3"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; }; @@ -1945,7 +1945,7 @@ groups = "uart_ao_b_tx_8", "uart_ao_b_rx_9"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; }; -- 2.51.0