From e93cac0aa36ed009dc30486ac12806cf4648932d Mon Sep 17 00:00:00 2001
From: Janis Streib <janis+github@dogcraft.de>
Date: Sun, 15 Oct 2023 21:08:40 +0200
Subject: [PATCH] overlays: mcp23017: allow specification of the i2c bus

Analogous to i2c-rtc-overlay.dts

See: https://github.com/raspberrypi/linux/pull/5650
---
 arch/arm/boot/dts/overlays/README               | 10 ++++
 arch/arm/boot/dts/overlays/mcp23017-overlay.dts | 68 ++++++++++++++++++-------
 2 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
index 7f5fda9..73a5a34 100644
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -2810,6 +2810,16 @@ Params: gpiopin                 Gpio pin connected to the INTA output of the
 
         mcp23008                Configure an MCP23008 instead.
         noints                  Disable the interrupt GPIO line.
+        i2c0                    Choose the I2C0 bus on GPIOs 0&1
+        i2c_csi_dsi             Choose the I2C0 bus on GPIOs 44&45
+        i2c3                    Choose the I2C3 bus (configure with the i2c3
+                                overlay - BCM2711 only)
+        i2c4                    Choose the I2C4 bus (configure with the i2c4
+                                overlay - BCM2711 only)
+        i2c5                    Choose the I2C5 bus (configure with the i2c5
+                                overlay - BCM2711 only)
+        i2c6                    Choose the I2C6 bus (configure with the i2c6
+                                overlay - BCM2711 only)
 
 
 Name:   mcp23s17
diff --git a/arch/arm/boot/dts/overlays/mcp23017-overlay.dts b/arch/arm/boot/dts/overlays/mcp23017-overlay.dts
index c546d8b..d77690b 100644
--- a/arch/arm/boot/dts/overlays/mcp23017-overlay.dts
+++ b/arch/arm/boot/dts/overlays/mcp23017-overlay.dts
@@ -7,7 +7,7 @@
 	compatible = "brcm,bcm2835";
 
 	fragment@0 {
-		target = <&i2c1>;
+		target = <&i2cbus>;
 		__overlay__ {
 			status = "okay";
 		};
@@ -24,13 +24,33 @@
 	};
 
 	fragment@2 {
-		target = <&i2c1>;
+		target = <&mcp23017>;
+		__dormant__ {
+			compatible = "microchip,mcp23008";
+		};
+	};
+
+	fragment@3 {
+		target = <&mcp23017>;
+		mcp23017_irq: __overlay__ {
+			#interrupt-cells=<2>;
+			interrupt-parent = <&gpio>;
+			interrupts = <4 2>;
+			interrupt-controller;
+			microchip,irq-mirror;
+		};
+	};
+
+	fragment@4 {
+		target = <&i2cbus>;
 		__overlay__ {
 			#address-cells = <1>;
 			#size-cells = <0>;
 
 			mcp23017: mcp@20 {
 				compatible = "microchip,mcp23017";
+				pinctrl-name = "default";
+				pinctrl-0 = <&mcp23017_pins>;
 				reg = <0x20>;
 				gpio-controller;
 				#gpio-cells = <2>;
@@ -40,30 +60,44 @@
 		};
 	};
 
-	fragment@3 {
-		target = <&mcp23017>;
-		__dormant__ {
-			compatible = "microchip,mcp23008";
+	frag100: fragment@100 {
+		target = <&i2c1>;
+		i2cbus: __overlay__ {
+			status = "okay";
 		};
 	};
 
-	fragment@4 {
-		target = <&mcp23017>;
-		mcp23017_irq: __overlay__ {
-			#interrupt-cells=<2>;
-			interrupt-parent = <&gpio>;
-			interrupts = <4 2>;
-			interrupt-controller;
-			microchip,irq-mirror;
-		};
+	fragment@101 { 
+		target = <&i2c0if>; 
+		__dormant__ { 
+			status = "okay"; 
+		}; 
+	};
+
+	fragment@102 { 
+		target = <&i2c0mux>; 
+		__dormant__ { 
+			status = "okay"; 
+		}; 
 	};
 
 	__overrides__ {
 		gpiopin = <&mcp23017_pins>,"brcm,pins:0",
 				<&mcp23017_irq>,"interrupts:0";
 		addr = <&mcp23017>,"reg:0", <&mcp23017_pins>,"reg:0";
-		mcp23008 = <0>,"=3";
-		noints = <0>,"!1!4";
+		mcp23008 = <0>,"=2";
+		noints = <0>,"!1!3";
+		i2c0 = <&frag100>, "target:0=",<&i2c0>;
+		i2c_csi_dsi = <&frag100>, "target:0=",<&i2c_csi_dsi>,
+			      <0>,"+101+102";
+		i2c3 = <&frag100>, "target?=0",
+		       <&frag100>, "target-path=i2c3";
+		i2c4 = <&frag100>, "target?=0",
+		       <&frag100>, "target-path=i2c4";
+		i2c5 = <&frag100>, "target?=0",
+		       <&frag100>, "target-path=i2c5";
+		i2c6 = <&frag100>, "target?=0",
+		       <&frag100>, "target-path=i2c6";
 	};
 };
 
-- 
2.7.4