overlays: Factor out the common i2c bus selection

Create an i2c-buses.dtsi to hold all of the common I2C bus selection logic, and refactor existing overlays to use it. This patch should have no functional change overall except to increase the range of options for some overlays. There is a slightly ugly mechanism for overriding the default bus, where the mux nodes may or may not need to be enabled. Signed-off-by: Phil Elwell <[email protected]>
raspberrypi · Jan 29, 2025 · 8aba331 · 8aba331
1 parent 9196579
commit 8aba331
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diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
diff --git a/arch/arm/boot/dts/overlays/ads1115-overlay.dts b/arch/arm/boot/dts/overlays/ads1115-overlay.dts
@@ -5,6 +5,8 @@
 /dts-v1/;
 /plugin/;
 
+#include "i2c-buses.dtsi"
+
 / {
 	compatible = "brcm,bcm2835";
 
@@ -81,27 +83,6 @@
 		};
 	};
 
-	frag100: fragment@100 {
-		target = <&i2c1>;
-		i2cbus: __overlay__ {
-			status = "okay";
-		};
-	};
-
-	fragment@101 {
-		target = <&i2c0if>;
-		__dormant__ {
-			status = "okay";
-		};
-	};
-
-	fragment@102 {
-		target = <&i2c0mux>;
-		__dormant__ {
-			status = "okay";
-		};
-	};
-
 	__overrides__ {
 		addr =            <&ads1115>,"reg:0";
 		cha_enable =      <0>,"=0";
@@ -120,21 +101,5 @@
 		chd_cfg =         <&channel_d>,"reg:0";
 		chd_gain =        <&channel_d>,"ti,gain:0";
 		chd_datarate =    <&channel_d>,"ti,datarate:0";
-		i2c0 = <&frag100>, "target:0=",<&i2c0>,
-			      <0>,"+101+102";
-		i2c_csi_dsi = <&frag100>, "target:0=",<&i2c_csi_dsi>,
-			      <0>,"+101+102";
-		i2c_csi_dsi0 = <&frag100>, "target:0=",<&i2c_csi_dsi0>,
-			      <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";
-		i2c-path = <&frag100>, "target?=0",
-		       <&frag100>, "target-path";
 	};
 };
diff --git a/arch/arm/boot/dts/overlays/edt-ft5406-overlay.dts b/arch/arm/boot/dts/overlays/edt-ft5406-overlay.dts
@@ -7,43 +7,16 @@
 /dts-v1/;
 /plugin/;
 
+#define ENABLE_I2C0_MUX
+#include "i2c-buses.dtsi"
 #include "edt-ft5406.dtsi"
 
-/ {
-	fragment@0 {
-		target = <&i2c0if>;
-		__overlay__ {
-			status = "okay";
-		};
-	};
-
-	fragment@1 {
-		target = <&i2c0mux>;
-		__overlay__ {
-			status = "okay";
-		};
-	};
+&busfrag {
+	target = <&i2c_csi_dsi>;
+};
 
+/ {
 	__overrides__ {
-		i2c0 = <&ts_i2c_frag>,"target:0=",<&i2c0>;
-		i2c1 = <&ts_i2c_frag>, "target?=0",
-		       <&ts_i2c_frag>, "target-path=i2c1",
-		       <0>,"-0-1";
-		i2c3 = <&ts_i2c_frag>, "target?=0",
-		       <&ts_i2c_frag>, "target-path=i2c3",
-		       <0>,"-0-1";
-		i2c4 = <&ts_i2c_frag>, "target?=0",
-		       <&ts_i2c_frag>, "target-path=i2c4",
-		       <0>,"-0-1";
-		i2c5 = <&ts_i2c_frag>, "target?=0",
-		       <&ts_i2c_frag>, "target-path=i2c5",
-		       <0>,"-0-1";
-		i2c6 = <&ts_i2c_frag>, "target?=0",
-		       <&ts_i2c_frag>, "target-path=i2c6",
-		       <0>,"-0-1";
-		i2c-path = <&ts_i2c_frag>, "target?=0",
-		       <&ts_i2c_frag>, "target-path",
-		       <0>,"-0-1";
 		addr = <&ft5406>,"reg:0";
 	};
 };
diff --git a/arch/arm/boot/dts/overlays/edt-ft5406.dtsi b/arch/arm/boot/dts/overlays/edt-ft5406.dtsi
@@ -22,12 +22,11 @@
 		};
 	};
 
-	ts_i2c_frag: fragment@12 {
-		target = <&i2c_csi_dsi>;
+	fragment@12 {
+		target = <&i2cbus>;
 		__overlay__ {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			status = "okay";
 
 			ft5406: ts@38 {
 				compatible = "edt,edt-ft5506";

diff --git a/arch/arm/boot/dts/overlays/i2c-buses.dtsi b/arch/arm/boot/dts/overlays/i2c-buses.dtsi
@@ -0,0 +1,67 @@
+// Common i2c buses, and dtparams to select them
+
+/ {
+	compatible = "brcm,bcm2835";
+
+	busfrag: fragment@100 {
+		target = <&i2c_arm>;
+		i2cbus: __overlay__ {
+			status = "okay";
+		};
+	};
+
+	fragment@101 {
+		target = <&i2c0if>;
+#ifdef ENABLE_I2C0_MUX
+		__overlay__ {
+#else
+		__dormant__ {
+#endif
+			status = "okay";
+		};
+	};
+
+	fragment@102 {
+		target = <&i2c0mux>;
+#ifdef ENABLE_I2C0_MUX
+		__overlay__ {
+#else
+		__dormant__ {
+#endif
+			status = "okay";
+		};
+	};
+
+	__overrides__ {
+		i2c0 = <&busfrag>,"target:0=",<&i2c0>,
+			      <&busfrag>, "target-path?=0",
+			      <0>,"+101+102";
+		i2c_csi_dsi = <&busfrag>,"target:0=",<&i2c_csi_dsi>,
+			      <&busfrag>, "target-path?=0",
+			      <0>,"+101+102";
+		i2c_csi_dsi0 = <&busfrag>, "target:0=",<&i2c_csi_dsi0>,
+			       <&busfrag>, "target-path?=0",
+			       <0>,"+101+102";
+		i2c1 = <&busfrag>,"target:0=",<&i2c1>,
+		       <&busfrag>, "target-path?=0",
+		       <0>,"-101-102";
+		i2c2 = <&busfrag>, "target?=0",
+		       <&busfrag>, "target-path=i2c2",
+		       <0>,"-101-102";
+		i2c3 = <&busfrag>, "target?=0",
+		       <&busfrag>, "target-path=i2c3",
+		       <0>,"-101-102";
+		i2c4 = <&busfrag>, "target?=0",
+		       <&busfrag>, "target-path=i2c4",
+		       <0>,"-101-102";
+		i2c5 = <&busfrag>, "target?=0",
+		       <&busfrag>, "target-path=i2c5",
+		       <0>,"-101-102";
+		i2c6 = <&busfrag>, "target?=0",
+		       <&busfrag>, "target-path=i2c6",
+		       <0>,"-101-102";
+		i2c-path = <&busfrag>, "target?=0",
+			   <&busfrag>, "target-path",
+			   <0>,"-101-102";
+	};
+};
diff --git a/arch/arm/boot/dts/overlays/i2c-fan-overlay.dts b/arch/arm/boot/dts/overlays/i2c-fan-overlay.dts
@@ -4,6 +4,8 @@
 
 #include <dt-bindings/thermal/thermal.h>
 
+#include "i2c-buses.dtsi"
+
 / {
 	compatible = "brcm,bcm2835";
 
@@ -22,35 +24,14 @@
 		};
 	};
 
-	frag100: fragment@100 {
-		target = <&i2c_arm>;
-		i2cbus: __overlay__ {
-			status = "okay";
-		};
-	};
-
-	fragment@101 {
-		target = <&i2c0if>;
-		__dormant__ {
-			status = "okay";
-		};
-	};
-
-	fragment@102 {
-		target = <&i2c0mux>;
-		__dormant__ {
-			status = "okay";
-		};
-	};
-
-	fragment@103 {
+	fragment@1 {
 		target = <&cpu_thermal>;
 		__overlay__ {
 			polling-delay = <2000>; /* milliseconds */
 		};
 	};
 
-	fragment@104 {
+	fragment@2 {
 		target = <&thermal_trips>;
 		__overlay__ {
 			fanmid0: fanmid0 {
@@ -66,7 +47,7 @@
 		};
 	};
 
-	fragment@105 {
+	fragment@3 {
 		target = <&cooling_maps>;
 		__overlay__ {
 			map0: map0 {
@@ -81,22 +62,6 @@
 	};
 
 	__overrides__ {
-		i2c0 =		<&frag100>,"target:0=",<&i2c0>,
-				<0>,"+101+102";
-		i2c_csi_dsi =	<&frag100>,"target:0=",<&i2c_csi_dsi>,
-				<0>,"+101+102";
-		i2c_csi_dsi0 = <&frag100>, "target:0=",<&i2c_csi_dsi0>,
-			      <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";
-		i2c-path = <&frag100>, "target?=0",
-			   <&frag100>, "target-path";
 		addr =		<&emc2301>,"reg:0";
 		minpwm =	<&emc2301>,"emc2305,pwm-min.0";
 		maxpwm =	<&emc2301>,"emc2305,pwm-max.0";

diff --git a/arch/arm/boot/dts/overlays/i2c-mux-overlay.dts b/arch/arm/boot/dts/overlays/i2c-mux-overlay.dts
@@ -5,6 +5,8 @@
 
 #include <dt-bindings/mux/mux.h>
 
+#include "i2c-buses.dtsi"
+
 /{
 	compatible = "brcm,bcm2835";
 
@@ -13,7 +15,6 @@
 		__dormant__ {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			status = "okay";
 
 			pca9542: mux@70 {
 				compatible = "nxp,pca9542";
@@ -40,7 +41,6 @@
 		__dormant__ {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			status = "okay";
 
 			pca9545: mux@70 {
 				compatible = "nxp,pca9545";
@@ -77,7 +77,6 @@
 		__dormant__ {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			status = "okay";
 
 			pca9548: mux@70 {
 				compatible = "nxp,pca9548";
@@ -129,27 +128,6 @@
 		};
 	};
 
-	frag100: fragment@100 {
-		target = <&i2c_arm>;
-		i2cbus: __overlay__ {
-			status = "okay";
-		};
-	};
-
-	fragment@101 {
-		target = <&i2c0if>;
-		__dormant__ {
-			status = "okay";
-		};
-	};
-
-	fragment@102 {
-		target = <&i2c0mux>;
-		__dormant__ {
-			status = "okay";
-		};
-	};
-
 	__overrides__ {
 		pca9542 = <0>, "+0";
 		pca9545 = <0>, "+1";
@@ -163,22 +141,6 @@
 			<&pca9545>,"base-nr:0",
 			<&pca9548>,"base-nr:0";
 
-		i2c0 = <&frag100>, "target:0=",<&i2c0>,
-			      <0>,"+101+102";
-		i2c_csi_dsi = <&frag100>, "target:0=",<&i2c_csi_dsi>,
-			      <0>,"+101+102";
-		i2c_csi_dsi0 = <&frag100>, "target:0=",<&i2c_csi_dsi0>,
-			      <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";
-		i2c-path = <&frag100>, "target?=0",
-			   <&frag100>, "target-path";
 		disconnect_on_idle =
 			<&pca9542>,"idle-state:0=", <MUX_IDLE_DISCONNECT>,
 			<&pca9545>,"idle-state:0=", <MUX_IDLE_DISCONNECT>,