diff --git a/boards/arm/disco_l475_iot1/disco_l475_iot1.dts b/boards/arm/disco_l475_iot1/disco_l475_iot1.dts
index dd847f3a66bef..8b42ddbb3abbd 100644
--- a/boards/arm/disco_l475_iot1/disco_l475_iot1.dts
+++ b/boards/arm/disco_l475_iot1/disco_l475_iot1.dts
@@ -7,7 +7,7 @@
 /dts-v1/;
 #include <st/l4/stm32l475Xg.dtsi>
 #include "arduino_r3_connector.dtsi"
-
+#include <dt-bindings/pinctrl/stm32l4-pins.h>
 
 / {
 	model = "STMicroelectronics B-L475E-IOT01Ax board";
@@ -49,13 +49,74 @@
 	};
 };
 
+&pinctrl {
+	usart1_pins_default: pinmux_usart1_pins {
+		pinmux = <STM32_PINMUX('A', 9, AF7)>, <STM32_PINMUX('A', 10, AF7)>;
+		bias-disable;
+	};
+
+	usart2_pins_default: pinmux_usart2_pins {
+		pinmux = <STM32_PINMUX('A', 2, AF7)>, <STM32_PINMUX('A', 3, AF7)>;
+		bias-disable;
+	};
+};
+
+&pinctrl {
+	usart1_pins_default: pinmux_usart1_pins {
+		rx {
+			pinmux = <STM32_PINMUX('A', 10, AF7)>;
+			bias-disable;
+		};
+		tx {
+			pinmux = <STM32_PINMUX('A', 9, AF7)>;
+			bias-pull-up;
+		};
+	};
+
+	usart2_pins_default: pinmux_usart2_pins {
+		rx {
+			pinmux = <STM32_PINMUX('A', 3, AF7)>;
+			bias-disable;
+		};
+		tx {
+			pinmux = <STM32_PINMUX('A', 2, AF7)>;
+			bias-pull-up;
+		};
+	};
+};
+
+&pinctrl {
+	usart1_rx_pins_default: pinmux_usart1_rx_pins {
+		pinmux = <STM32_PINMUX('A', 10, AF7)>;
+		bias-disable;
+	};
+
+	usart1_tx_pins_default: pinmux_usart1_tx_pins {
+		pinmux = <STM32_PINMUX('A', 9, AF7)>;
+		bias-pull-up;
+	};
+
+	usart2_rx_pins_default: pinmux_usart2_rx_pins {
+		pinmux = <PIN_PA3_UART2_RX>;
+		bias-disable;
+	};
+
+	usart2_tx_pins_default: pinmux_usart2_tx_pins {
+		pinmux = <PIN_PA2_UART2_TX STM32_PUSHPULL_PULLUP>;
+	};
+};
+
 &usart1 {
 	current-speed = <115200>;
+	pinctrl-0 = <&usart1_pins_default>;
+	pinctrl-names = "default";
 	status = "okay";
 };
 
 &usart2 {
 	current-speed = <115200>;
+	pinctrl-0 = <&usart2_rx_pins_default &usart2_tx_pins_default>;
+	pinctrl-names = "default";
 	status = "okay";
 };
 
diff --git a/dts/bindings/pinctrl/st,stm32-pinmux.yaml b/dts/bindings/pinctrl/st,stm32-pinmux.yaml
index face232eb7480..564c0ab48e106 100644
--- a/dts/bindings/pinctrl/st,stm32-pinmux.yaml
+++ b/dts/bindings/pinctrl/st,stm32-pinmux.yaml
@@ -11,6 +11,50 @@ properties:
     reg:
       required: true
 
-pinmux-cells:
-  - pin
-  - function
+child-binding:
+    title: STM32 PIN configurations
+
+    description: |
+        This binding gives a base representation of the STM32 pins configration
+
+    properties:
+        pinmux:
+          required: false
+          type: int
+
+        bias-disable:
+          required: false
+          type: boolean
+
+        bias-pull-down:
+          required: false
+          type: boolean
+
+        bias-pull-up:
+          required: false
+          type: boolean
+
+        drive-push-pull:
+          required: false
+          type: boolean
+
+        drive-open-drain:
+          required: false
+          type: boolean
+
+        output-low:
+          required: false
+          type: boolean
+
+        output-high:
+          required: false
+          type: boolean
+
+        slew-rate:
+          type: int
+          default: 2
+          enum:
+          - 0
+          - 1
+          - 2
+          - 3
diff --git a/include/dt-bindings/pinctrl/stm32-pinctrl-common.h b/include/dt-bindings/pinctrl/stm32-pinctrl-common.h
index c58e91f32f7da..98f928db3deab 100644
--- a/include/dt-bindings/pinctrl/stm32-pinctrl-common.h
+++ b/include/dt-bindings/pinctrl/stm32-pinctrl-common.h
@@ -7,6 +7,31 @@
 #ifndef ZEPHYR_STM32_PINCTRL_COMMON_H_
 #define ZEPHYR_STM32_PINCTRL_COMMON_H_
 
+/* Extracted from Linux: include/dt-bindings/pinctrl/stm32-pinfunc.h */
+/*  define PIN modes */
+#define GPIO	0x0
+#define AF0	0x1
+#define AF1	0x2
+#define AF2	0x3
+#define AF3	0x4
+#define AF4	0x5
+#define AF5	0x6
+#define AF6	0x7
+#define AF7	0x8
+#define AF8	0x9
+#define AF9	0xa
+#define AF10	0xb
+#define AF11	0xc
+#define AF12	0xd
+#define AF13	0xe
+#define AF14	0xf
+#define AF15	0x10
+#define ANALOG	0x11
+
+/* define Pins number*/
+#define PIN_NO(port, line)	(((port) - 'A') * 0x10 + (line))
+
+#define STM32_PINMUX(port, line, mode) (((PIN_NO(port, line)) << 8) | (mode))
 
 /**
  * @brief numerical IDs for IO ports
diff --git a/include/dt-bindings/pinctrl/stm32l4-pins.h b/include/dt-bindings/pinctrl/stm32l4-pins.h
new file mode 100644
index 0000000000000..d9c59dbd1feff
--- /dev/null
+++ b/include/dt-bindings/pinctrl/stm32l4-pins.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef INCLUDE_DT_BINDINGS_PINCTRL_STM32L4_PINCTRL_H_
+#define INCLUDE_DT_BINDINGS_PINCTRL_STM32L4_PINCTRL_H_
+
+#include "stm32-pinctrl.h"
+
+#define PIN_PA3_UART2_RX            STM32_PINMUX('A', 3, AF7)
+#define PIN_PA2_UART2_TX            STM32_PINMUX('A', 2, AF7)
+
+
+#endif /* INCLUDE_DT_BINDINGS_PINCTRL_STM32L4_PINCTRL_H_ */