nucleo-g431rb: fixes for button

boards/arm/stm32/nucleo-g431rb/src/Make.defs

@@ -29,6 +29,10 @@ else
 CSRCS += stm32_userleds.c
 endif
 
+ifeq ($(CONFIG_ARCH_BUTTONS),y)
+CSRCS += stm32_buttons.c
+endif
+
 ifeq ($(CONFIG_LIB_BOARDCTL),y)
 CSRCS += stm32_appinit.c
 endif

boards/arm/stm32/nucleo-g431rb/src/nucleo-g431rb.h

@@ -57,6 +57,24 @@
 
 #define LED_DRIVER_PATH                "/dev/userleds"
 
+/* Button definitions *******************************************************/
+
+/* The Nucleo G431RB supports two buttons; only one button is controllable
+ * by software:
+ *
+ *   B1 USER:  user button connected to the I/O PC13 of the STM32G431RB.
+ *   B2 RESET: push button connected to NRST is used to RESET the
+ *             STM32G431R.
+ *
+ * NOTE that EXTI interrupts are configured.
+ */
+
+#define MIN_IRQBUTTON  BUTTON_USER
+#define MAX_IRQBUTTON  BUTTON_USER
+#define NUM_IRQBUTTONS 1
+
+#define GPIO_BTN_USER  (GPIO_INPUT|GPIO_FLOAT|GPIO_EXTI|GPIO_PORTC|GPIO_PIN13)
+
 /* PWM */
 
 #define NUCLEOG431RB_PWMTIMER   1

boards/arm/stm32/nucleo-g431rb/src/stm32_buttons.c

@@ -74,11 +74,11 @@ uint32_t board_button_initialize(void)
 
 uint32_t board_buttons(void)
 {
-  /* Check the state of the USER button.  A LOW value means that the key is
+  /* Check the state of the USER button.  A HIGH value means that the key is
    * pressed.
    */
 
-  return stm32_gpioread(GPIO_BTN_USER) ? 0 : BUTTON_USER_BIT;
+  return stm32_gpioread(GPIO_BTN_USER) ? BUTTON_USER_BIT : 0;
 }
 
 /****************************************************************************