sam: atsamc21: enable CAN module in c21 board

Configure pinmux pins at samc21 xpro board. Boards has
hard-configured pins for CAN0 and CAN1 module.

Signed-off-by: Kamil Serwus <[email protected]>

Author: benys

boards/arm/atsamc21n_xpro/atsamc21n_xpro-pinctrl.dtsi

@@ -25,6 +25,20 @@
 		};
 	};
 
+	can0_default: can0_default {
+		group1 {
+			pinmux = <PA25G_CAN0_RX>,
+				 <PA24G_CAN0_TX>;
+		};
+	};
+
+	can1_default: can1_default {
+		group1 {
+			pinmux = <PB15G_CAN1_RX>,
+				 <PB14G_CAN1_TX>;
+		};
+	};
+
 	sercom0_uart_default: sercom0_uart_default {
 		group1 {
 			pinmux = <PB25C_SERCOM0_PAD1>,

boards/arm/atsamc21n_xpro/atsamc21n_xpro.dts

@@ -18,6 +18,7 @@
 		zephyr,shell-uart = &sercom4;
 		zephyr,sram = &sram0;
 		zephyr,flash = &flash0;
+		zephyr,canbus = &can0;
 	};
 
 	/* These aliases are provided for compatibility with samples */
@@ -151,3 +152,29 @@
 		};
 	};
 };
+
+&can0 {
+	status = "okay";
+
+	pinctrl-0 = <&can0_default>;
+	pinctrl-names = "default";
+
+	bus-speed = <125000>;
+	bus-speed-data = <1000000>;
+
+	can-transceiver {
+		max-bitrate = <5000000>;
+	};
+};
+
+&can1 {
+	pinctrl-0 = <&can1_default>;
+	pinctrl-names = "default";
+
+	bus-speed = <125000>;
+	bus-speed-data = <1000000>;
+
+	can-transceiver {
+		max-bitrate = <5000000>;
+	};
+};

boards/arm/atsamc21n_xpro/atsamc21n_xpro.yaml

@@ -17,3 +17,4 @@ supported:
   - i2c
   - pwm
   - spi
+  - can

boards/arm/atsamc21n_xpro/doc/index.rst

@@ -71,6 +71,9 @@ features:
     * - SPI
       - on-chip
       - Serial Peripheral Interface ports
+    * - CAN
+      - on-chip
+      - CAN ports
 
 Other hardware features are not currently supported by Zephyr.
 
@@ -90,6 +93,10 @@ Default Zephyr Peripheral Mapping:
 ----------------------------------
 - ADC0             : PB09
 - ADC1             : PA08
+- CAN0 TX          : PA24
+- CAN0 RX          : PA25
+- CAN1 TX          : PB14
+- CAN1 RX          : PB15
 - SERCOM0 USART TX : PB24
 - SERCOM0 USART RX : PB25
 - SERCOM1 I2C SDA  : PA16