From: Uwe Kleine-König <uwe@xxxxxxxxxxxxxxxxx>
BCM2711-based Raspberry Pi boards (4B, CM4 and 400) multiplex the I2C0
controller over two sets of pins, GPIO0+1 and GPIO44+45. The former is
exposed on the 40-pin header, while the latter is used for the CSI and
DSI connectors.
Add a pinctrl-based I2C bus multiplexer to bcm2711-rpi.dtsi to model
this multiplexing. The two child buses are named i2c0_0 and i2c0_1.
Note that if you modified the dts before to add devices to the i2c bus
appearing on pins gpio0 + gpio1 (either directly in the dts or using an
overlay), you have to put these into the i2c0_0 node introduced here
now.
Signed-off-by: Uwe Kleine-König <uwe@xxxxxxxxxxxxxxxxx>
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
Changes since v3:
- Split addition of the RTC to a separate patch
- Move the mux to bcm2711-rpi.dtsi
---
arch/arm/boot/dts/bcm2711-rpi.dtsi | 31 ++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/arch/arm/boot/dts/bcm2711-rpi.dtsi b/arch/arm/boot/dts/bcm2711-rpi.dtsi
index 5e95e2321218..7eb9f131cfd1 100644
--- a/arch/arm/boot/dts/bcm2711-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2711-rpi.dtsi
@@ -16,6 +16,32 @@ aliases {
pcie0 = &pcie0;
blconfig = &blconfig;
};
+
+ i2c0mux: i2c0mux {
+ compatible = "i2c-mux-pinctrl";
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c-parent = <&i2c0>;
+
+ pinctrl-names = "i2c0", "i2c0-vc";
+ pinctrl-0 = <&i2c0_gpio0>;
+ pinctrl-1 = <&i2c0_gpio44>;
+
+ status = "disabled";
+
+ i2c0_0: i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ i2c0_1: i2c@1 {
+ reg = <1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+ };
};
&firmware {
@@ -48,6 +74,11 @@ &hvs {
clocks = <&firmware_clocks 4>;
};
+&i2c0 {
+ /delete-property/ pinctrl-names;
+ /delete-property/ pinctrl-0;
+};
+
&rmem {
/*
* RPi4's co-processor will copy the board's bootloader configuration
--
Regards,
Laurent Pinchart
