diff --git a/arch/arm/soc/st_stm32/stm32f1/soc_gpio.c b/arch/arm/soc/st_stm32/stm32f1/soc_gpio.c
index 303528b9499..c9e461e8ac2 100644
--- a/arch/arm/soc/st_stm32/stm32f1/soc_gpio.c
+++ b/arch/arm/soc/st_stm32/stm32f1/soc_gpio.c
@@ -87,8 +87,10 @@ int stm32_gpio_flags_to_conf(int flags, int *pincfg)
 	}
 
 	if (direction == GPIO_DIR_OUT) {
+		/* Pin is configured as an output */
 		*pincfg = STM32F10X_PIN_CONFIG_DRIVE_PUSH_PULL;
-	} else if (direction == GPIO_DIR_IN) {
+	} else {
+		/* Pin is configured as an input */
 		int pud = flags & GPIO_PUD_MASK;
 
 		/* pull-{up,down} maybe? */
@@ -100,8 +102,6 @@ int stm32_gpio_flags_to_conf(int flags, int *pincfg)
 			/* floating */
 			*pincfg = STM32F10X_PIN_CONFIG_BIAS_HIGH_IMPEDANCE;
 		}
-	} else {
-		return -ENOTSUP;
 	}
 
 	return 0;