From 0b061fe76dc6ef00ba884461dbf1b2e2c3ffa06d Mon Sep 17 00:00:00 2001
From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date: Sat, 29 Mar 2025 19:58:52 +0100
Subject: [PATCH 12/50] FROMGIT(6.16): arm64: dts: amlogic: gxl: 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-gxl.dtsi | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
index 19b8a39de6a0..bc52b9e954b4 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
@@ -163,7 +163,7 @@ uart_ao_a_pins: uart_ao_a {
 			mux {
 				groups = "uart_tx_ao_a", "uart_rx_ao_a";
 				function = "uart_ao";
-				bias-disable;
+				bias-pull-up;
 			};
 		};
 
@@ -180,7 +180,7 @@ uart_ao_b_pins: uart_ao_b {
 			mux {
 				groups = "uart_tx_ao_b", "uart_rx_ao_b";
 				function = "uart_ao_b";
-				bias-disable;
+				bias-pull-up;
 			};
 		};
 
@@ -188,7 +188,7 @@ uart_ao_b_0_1_pins: uart_ao_b_0_1 {
 			mux {
 				groups = "uart_tx_ao_b_0", "uart_rx_ao_b_1";
 				function = "uart_ao_b";
-				bias-disable;
+				bias-pull-up;
 			};
 		};
 
@@ -522,7 +522,7 @@ mux {
 				groups = "uart_tx_a",
 				       "uart_rx_a";
 				function = "uart_a";
-				bias-disable;
+				bias-pull-up;
 			};
 		};
 
@@ -540,7 +540,7 @@ mux {
 				groups = "uart_tx_b",
 				       "uart_rx_b";
 				function = "uart_b";
-				bias-disable;
+				bias-pull-up;
 			};
 		};
 
@@ -558,7 +558,7 @@ mux {
 				groups = "uart_tx_c",
 				       "uart_rx_c";
 				function = "uart_c";
-				bias-disable;
+				bias-pull-up;
 			};
 		};
 
-- 
2.34.1

