From dc5f13949ec415f594abc5ed7a51ad845a090fb7 Mon Sep 17 00:00:00 2001
From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date: Sat, 29 Mar 2025 19:58:53 +0100
Subject: [PATCH 13/50] FROMGIT(6.16): 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 <martin.blumenstingl@googlemail.com>
---
 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 4b75b4d07901..0b6f13f8911b 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 @@ mux {
 							groups = "uart_a_tx",
 								 "uart_a_rx";
 							function = "uart_a";
-							bias-disable;
+							bias-pull-up;
 						};
 					};
 
@@ -1521,7 +1521,7 @@ mux {
 							groups = "uart_b_tx",
 								 "uart_b_rx";
 							function = "uart_b";
-							bias-disable;
+							bias-pull-up;
 						};
 					};
 
@@ -1918,7 +1918,7 @@ mux {
 						groups = "uart_ao_a_tx",
 							 "uart_ao_a_rx";
 						function = "uart_ao_a";
-						bias-disable;
+						bias-pull-up;
 					};
 				};
 
@@ -1936,7 +1936,7 @@ mux {
 						groups = "uart_ao_b_tx_2",
 							 "uart_ao_b_rx_3";
 						function = "uart_ao_b";
-						bias-disable;
+						bias-pull-up;
 					};
 				};
 
@@ -1945,7 +1945,7 @@ mux {
 						groups = "uart_ao_b_tx_8",
 							 "uart_ao_b_rx_9";
 						function = "uart_ao_b";
-						bias-disable;
+						bias-pull-up;
 					};
 				};
 
-- 
2.34.1

