From: David Bauer <mail@david-bauer.net>
Date: Tue, 6 May 2025 16:23:50 +0000 (+0200)
Subject: ramips: use i2c-gpio driver for EX400
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f828be4d10d795e2bd74ea77ea12dec285107974;p=thirdparty%2Fopenwrt.git

ramips: use i2c-gpio driver for EX400

Configure the i2c pins as GPIO outputs and use the i2c-gpio driver to
control the Semtech SX9512 touch controller.

This fixes spurious errors in i2c transactions even at 1kHz with the
native i2c driver.

leds green:wan: Setting an LED's brightness failed (-6)

Signed-off-by: David Bauer <mail@david-bauer.net>
---

diff --git a/target/linux/ramips/dts/mt7621_genexis_pulse-ex400-common.dtsi b/target/linux/ramips/dts/mt7621_genexis_pulse-ex400-common.dtsi
index a3bc70e8cef..ebcf558359b 100644
--- a/target/linux/ramips/dts/mt7621_genexis_pulse-ex400-common.dtsi
+++ b/target/linux/ramips/dts/mt7621_genexis_pulse-ex400-common.dtsi
@@ -41,6 +41,18 @@
 			gpios = <&gpio 11 GPIO_ACTIVE_HIGH>;
 		};
 	};
+
+	i2c_gpio: i2c-gpio {
+		compatible = "i2c-gpio";
+
+		sda-gpios = <&gpio 3 GPIO_ACTIVE_HIGH>;
+		scl-gpios = <&gpio 4 GPIO_ACTIVE_HIGH>;
+
+		i2c-gpio,delay-us = <50>;
+		i2c-gpio,timeout-ms = <100>;
+
+		/* Semtech SX9512 */
+	};
 };
 
 &pcie {
@@ -92,7 +104,8 @@
 };
 
 &i2c {
-	status = "okay";
+	/* Uses i2c-gpio */
+	status = "disabled";
 };
 
 &ethphy0 {
@@ -101,7 +114,7 @@
 
 &state_default {
 	gpio {
-		groups = "uart2", "uart3";
+		groups = "i2c", "uart2", "uart3";
 		function = "gpio";
 	};
 };
diff --git a/target/linux/ramips/dts/mt7621_genexis_pulse-ex400.dts b/target/linux/ramips/dts/mt7621_genexis_pulse-ex400.dts
index 61b3e869d7e..ad8a22ad79d 100644
--- a/target/linux/ramips/dts/mt7621_genexis_pulse-ex400.dts
+++ b/target/linux/ramips/dts/mt7621_genexis_pulse-ex400.dts
@@ -22,9 +22,7 @@
 	};
 };
 
-&i2c {
-	clock-frequency = <1000>;
-
+&i2c_gpio {
 	touch@2b {
 		compatible = "semtech,sx9512";