text: /****************************************************************************
   * configs/stm32f4discovery/src/stm32_pm_buttons.c
   *
   *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
   *   Authors: Gregory Nutt <gnutt@nuttx.org>
   *            Diego Sanchez <dsanchez@nx-engineering.com>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <arch/board/board.h>
  #include <nuttx/config.h>
  
  #include <nuttx/power/pm.h>
  #include <arch/irq.h>
  #include <stdbool.h>
  #include <debug.h>
  
  #include "up_arch.h"
  #include "nvic.h"
  #include "stm32_pwr.h"
  #include "stm32_pm.h"
  #include "stm32f4discovery.h"
  
  #if defined(CONFIG_PM) && defined(CONFIG_ARCH_IDLE_CUSTOM) && defined(CONFIG_PM_BUTTONS)
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  /* Configuration ************************************************************/
  
  #ifndef CONFIG_ARCH_BUTTONS
  #  error "CONFIG_ARCH_BUTTONS is not defined in the configuration"
  #endif
  
  #ifndef CONFIG_ARCH_IRQBUTTONS
  #  warning "CONFIG_ARCH_IRQBUTTONS is not defined in the configuration"
  #endif
  
  #ifndef CONFIG_PM_BUTTON_ACTIVITY
  #  define CONFIG_PM_BUTTON_ACTIVITY 10
  #endif
  
  /****************************************************************************
   * Private Types
   ****************************************************************************/
  
  /****************************************************************************
   * Private Function Prototypes
   ****************************************************************************/
  
  #ifdef CONFIG_ARCH_IRQBUTTONS
  static int button_handler(int irq, FAR void *context);
  #endif /* CONFIG_ARCH_IRQBUTTONS */
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: button_handler
   *
   * Description:
   *   Handle a button wake-up interrupt
   *
   ****************************************************************************/
  
  #ifdef CONFIG_ARCH_IRQBUTTONS
  static int button_handler(int irq, FAR void *context)
  {
    /* At this point the MCU should have already awakened.  The state
     * change will be handled in the IDLE loop when the system is re-awakened
     * The button interrupt handler should be totally ignorant of the PM
     * activities and should report button activity as if nothing
     * special happened.
     */
  
    pm_activity(CONFIG_PM_BUTTON_ACTIVITY);
    return OK;
  }
  #endif /* CONFIG_ARCH_IRQBUTTONS */
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: stm32_pm_buttons
   *
   * Description:
   *   Configure the user button of the STM32f4discovery board as EXTI,
   *   so it is able to wakeup the MCU from the PM_STANDBY mode
   *
   ****************************************************************************/
  
  void stm32_pm_buttons(void)
  {
    /* Initialize the button GPIOs */
  
    board_button_initialize();
  
  #ifdef CONFIG_ARCH_IRQBUTTONS
        xcpt_t oldhandler = board_button_irq(0, button_handler);
  
        if (oldhandler != NULL)
          {
            lowsyslog("WARNING: oldhandler:%p is not NULL!  "
                          "Button events may be lost or aliased!\n",
                          oldhandler);
          }
  #endif
  }
  
  #endif /* CONFIG_PM && CONFIG_ARCH_IDLE_CUSTOM && CONFIG_PM_BUTTONS)*/
  