From: Martin Blumenstingl Date: Sat, 29 Mar 2025 18:58:50 +0000 (+0100) Subject: ARM: dts: amlogic: meson8b: enable UART RX and TX pull up by default X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7db1068a5eedc419347a30dc81a25e3342fbbc10;p=users%2Fwilly%2Fxarray.git ARM: dts: amlogic: meson8b: 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/20250329185855.854186-3-martin.blumenstingl@googlemail.com Signed-off-by: Neil Armstrong --- diff --git a/arch/arm/boot/dts/amlogic/meson8b.dtsi b/arch/arm/boot/dts/amlogic/meson8b.dtsi index 0876611ce26a..faf09f77c605 100644 --- a/arch/arm/boot/dts/amlogic/meson8b.dtsi +++ b/arch/arm/boot/dts/amlogic/meson8b.dtsi @@ -368,7 +368,7 @@ mux { groups = "uart_tx_ao_a", "uart_rx_ao_a"; function = "uart_ao"; - bias-disable; + bias-pull-up; }; }; @@ -521,7 +521,7 @@ groups = "uart_tx_b0", "uart_rx_b0"; function = "uart_b"; - bias-disable; + bias-pull-up; }; };