nucleo-g431rb: add button support

boards/arm/stm32/nucleo-g431rb/src/stm32_bringup.c

@@ -33,6 +33,10 @@
 #  include <nuttx/leds/userled.h>
 #endif
 
+#ifdef CONFIG_INPUT_BUTTONS
+#  include <nuttx/input/buttons.h>
+#endif
+
 #include "nucleo-g431rb.h"
 
 /****************************************************************************
@@ -67,6 +71,16 @@ int stm32_bringup(void)
 {
   int ret;
 
+#ifdef CONFIG_INPUT_BUTTONS
+  /* Register the BUTTON driver */
+
+  ret = btn_lower_initialize("/dev/buttons");
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: btn_lower_initialize() failed: %d\n", ret);
+    }
+#endif
+
 #ifdef HAVE_LEDS
   /* Register the LED driver */
 

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

@@ -0,0 +1,111 @@
+/****************************************************************************
+ * boards/arm/stm32/nucleo-g431rb/src/stm32_buttons.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <errno.h>
+
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+#include "stm32.h"
+#include "nucleo-g431rb.h"
+
+#ifdef CONFIG_ARCH_BUTTONS
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_button_initialize
+ *
+ * Description:
+ *   board_button_initialize() must be called to initialize button
+ *   resources.  After that, board_buttons() may be called to collect the
+ *   current state of all buttons or board_button_irq() may be called to
+ *   register button interrupt handlers.
+ *
+ ****************************************************************************/
+
+uint32_t board_button_initialize(void)
+{
+  /* Configure the single button as an input.  NOTE that EXTI interrupts are
+   * also configured for the pin.
+   */
+
+  stm32_configgpio(GPIO_BTN_USER);
+  return NUM_BUTTONS;
+}
+
+/****************************************************************************
+ * Name: board_buttons
+ *
+ * Description:
+ *   After board_button_initialize() has been called, board_buttons() may be
+ *   called to collect the state of all buttons.  board_buttons() returns an
+ *   32-bit unsigned integer with each bit associated with a button.  See the
+ *   BUTTON_*_BIT definitions in board.h for the meaning of each bit.
+ *
+ ****************************************************************************/
+
+uint32_t board_buttons(void)
+{
+  /* Check the state of the USER button.  A LOW value means that the key is
+   * pressed.
+   */
+
+  return stm32_gpioread(GPIO_BTN_USER) ? 0 : BUTTON_USER_BIT;
+}
+
+/****************************************************************************
+ * Name: board_button_irq
+ *
+ * Description:
+ *   board_button_irq() may be called to register an interrupt handler that
+ *   will be called when a button is depressed or released.  The ID value is
+ *   a button enumeration value that uniquely identifies a button resource.
+ *   See the BUTTON_* definitions in board.h for the meaning of the
+ *   enumeration value.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_ARCH_IRQBUTTONS
+int board_button_irq(int id, xcpt_t irqhandler, FAR void *arg)
+{
+  int ret = -EINVAL;
+
+  if (id == BUTTON_USER)
+    {
+      ret = stm32_gpiosetevent(GPIO_BTN_USER, true, true, true, irqhandler,
+                               arg);
+    }
+
+  return ret;
+}
+#endif
+
+#endif /* CONFIG_ARCH_BUTTONS */