dts: i2c: introduce gd32 i2c interface

Add gd32 i2c interface support.

Signed-off-by: HaiLong Yang <[email protected]>

Author: cameled

dts/arm/gigadevice/gd32f4xx/gd32f4xx.dtsi

@@ -6,6 +6,7 @@
 
 #include <arm/armv7-m.dtsi>
 #include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/i2c/i2c.h>
 
 #include <dt-bindings/pwm/pwm.h>
 
@@ -131,6 +132,45 @@
 			#io-channel-cells = <1>;
 		};
 
+		i2c0: i2c@40005400 {
+			compatible = "gd,gd32-i2c";
+			reg = <0x40005400 0x400>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			clock-frequency = <I2C_BITRATE_STANDARD>;
+			interrupts = <31 0>, <32 0>;
+			interrupt-names = "event", "error";
+			rcu-periph-clock = <0x1015>;
+			status = "disabled";
+			label = "I2C_0";
+		};
+
+		i2c1: i2c@40005800 {
+			compatible = "gd,gd32-i2c";
+			reg = <0x40005800 0x400>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			clock-frequency = <I2C_BITRATE_STANDARD>;
+			interrupts = <33 0>, <34 0>;
+			interrupt-names = "event", "error";
+			rcu-periph-clock = <0x1016>;
+			status = "disabled";
+			label = "I2C_1";
+		};
+
+		i2c2: i2c@40005c00 {
+			compatible = "gd,gd32-i2c";
+			reg = <0x40005c00 0x400>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			clock-frequency = <I2C_BITRATE_STANDARD>;
+			interrupts = <72 0>, <73 0>;
+			interrupt-names = "event", "error";
+			rcu-periph-clock = <0x1017>;
+			status = "disabled";
+			label = "I2C_2";
+		};
+
 		syscfg: syscfg@40013800 {
 			compatible = "gd,gd32-syscfg";
 			reg = <0x40013800 0x400>;

dts/bindings/i2c/gd,gd32-i2c.yaml

@@ -0,0 +1,26 @@
+# Copyright (c) 2021 BrainCo Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+description: GigiDevice GD32 I2C
+
+compatible: "gd,gd32-i2c"
+
+include: [i2c-controller.yaml, pinctrl-device.yaml]
+
+properties:
+  reg:
+    required: true
+
+  interrupts:
+    required: true
+
+  rcu-periph-clock:
+    type: int
+    description: Reset Control Unit Peripheral Clock ID
+    required: true
+
+  pinctrl-0:
+    required: true
+
+  pinctrl-names:
+    required: true

dts/riscv/gigadevice/gd32vf103.dtsi

@@ -6,6 +6,7 @@
 
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/timer/riscv-machine-timer.h>
+#include <dt-bindings/i2c/i2c.h>
 
 #include <dt-bindings/pwm/pwm.h>
 
@@ -108,6 +109,20 @@
 			#io-channel-cells = <1>;
 		};
 
+		i2c0: i2c@40005400 {
+			compatible = "gd,gd32-i2c";
+			reg = <0x40005400 0x400>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			clock-frequency = <I2C_BITRATE_STANDARD>;
+			interrupts = <50 0>, <51 0>;
+			interrupt-names = "event", "error";
+			interrupt-parent = <&eclic>;
+			rcu-periph-clock = <0x715>;
+			status = "disabled";
+			label = "I2C_0";
+		};
+
 		afio: afio@40010000 {
 			compatible = "gd,gd32-afio";
 			reg = <0x40010000 0x400>;