[PATCH 1/2] ARM: dts: bcm2*: Demux i2c0 with a pinctrl

Detlev Casanova
2022-02-09T16:27:08Z

The i2c0 device has 2 different busses controlled by a pinctrl.
This commit separates the device node into 2 i2c devices:
* pin 0: Base i2c bus
* pin 44: DSI i2c bus

i2c0 is renamed to i2c0if so that device-trees referencing i2c0 don't
break and use the i2c0 node defined in i2c0mux node.

i2c_csi_dsi can be used to control devices via the DSI i2c bus, used for
DSI displays.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 1 +
arch/arm/boot/dts/bcm2711.dtsi | 2 +-
arch/arm/boot/dts/bcm2835-rpi.dtsi | 9 ++++---
.../boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi | 4 +++
arch/arm/boot/dts/bcm283x.dtsi | 26 ++++++++++++++++++-
5 files changed, 37 insertions(+), 5 deletions(-)
create mode 100644 arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi

diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index 4432412044de..5dcce58817e6 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -4,6 +4,7 @@
#include "bcm2711-rpi.dtsi"
#include "bcm283x-rpi-usb-peripheral.dtsi"
#include "bcm283x-rpi-wifi-bt.dtsi"
+#include "bcm283x-rpi-i2c0mux_0_44.dtsi"

/ {
compatible = "raspberrypi,4-model-b", "brcm,bcm2711";
diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
index 3b60297af7f6..bf6e8251c2c7 100644
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -1037,7 +1037,7 @@ &cma {
alloc-ranges = <0x0 0x00000000 0x40000000>;
};

-&i2c0 {
+&i2c0if {
compatible = "brcm,bcm2711-i2c", "brcm,bcm2835-i2c";
interrupts = <GIC_SPI 117 IRQ_TYPE_LEVEL_HIGH>;
};
diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
index 87ddcad76083..1e38f9f0e80e 100644
--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
@@ -49,13 +49,16 @@ alt0: alt0 {
};
};

-&i2c0 {
- pinctrl-names = "default";
- pinctrl-0 = <&i2c0_gpio0>;
+&i2c0if {
status = "okay";
clock-frequency = <100000>;
};

+&i2c0mux {
+ pinctrl-0 = <&i2c0_gpio0>;
+ status = "okay";
+};
+
&i2c1 {
pinctrl-names = "default";
pinctrl-0 = <&i2c1_gpio2>;
diff --git a/arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi b/arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi
new file mode 100644
index 000000000000..119946d878db
--- /dev/null
+++ b/arch/arm/boot/dts/bcm283x-rpi-i2c0mux_0_44.dtsi
@@ -0,0 +1,4 @@
+&i2c0mux {
+ pinctrl-0 = <&i2c0_gpio0>;
+ pinctrl-1 = <&i2c0_gpio44>;
+};
diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index a3e06b680947..06d04cde52b9 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -334,7 +334,7 @@ spi: spi@7e204000 {
status = "disabled";
};

- i2c0: i2c@7e205000 {
+ i2c0if: i2c@7e205000 {
compatible = "brcm,bcm2835-i2c";
reg = <0x7e205000 0x200>;
interrupts = <2 21>;
@@ -344,6 +344,30 @@ i2c0: i2c@7e205000 {
status = "disabled";
};

+ i2c0mux: i2c0mux {
+ compatible = "i2c-mux-pinctrl";
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c-parent = <&i2c0if>;
+
+ pinctrl-names = "i2c0", "i2c_csi_dsi";
+
+ status = "disabled";
+
+ i2c0: i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ i2c_csi_dsi: i2c@1 {
+ reg = <1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+ };
+
dpi: dpi@7e208000 {
compatible = "brcm,bcm2835-dpi";
reg = <0x7e208000 0x8c>;
--
2.35.1