text: /*-----------------------------------------------------------------------------
   * Name:    Buttons_32F4Discovery.c
   * Purpose: Buttons interface for STM32F4 Discovery Kit
   * Rev.:    1.00
   *----------------------------------------------------------------------------*/
  
  /* Copyright (c) 2013 - 2014 ARM LIMITED
  
     All rights reserved.
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are met:
     - Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
     - 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.
     - Neither the name of ARM 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 COPYRIGHT HOLDERS AND 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.
     ---------------------------------------------------------------------------*/
  
  #include "stm32f4xx_hal.h"
  #include "Board_Buttons.h"
  
  /* Buttons for STM32F4 Discovery */
  #define BUTTONS_COUNT                  (1)
  #define BUTTONS_USER_MASK              (1<<0)
  #define BUTTONS_USER_PORT               GPIOA
  #define BUTTONS_USER_PIN                GPIO_PIN_0
  
  
  /**
    \fn          int32_t Buttons_Initialize (void)
    \brief       Initialize buttons
    \returns
     - \b  0: function succeeded
     - \b -1: function failed
  */
  int32_t Buttons_Initialize (void) {
    GPIO_InitTypeDef GPIO_InitStruct;
  
    /* GPIO Ports Clock Enable */
    __GPIOA_CLK_ENABLE();
  
    /* Configure GPIO pin: PA0 (USER) */
    GPIO_InitStruct.Pin = GPIO_PIN_0;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  
    return 0;
  }
  
  /**
    \fn          int32_t Buttons_Uninitialize (void)
    \brief       De-initialize buttons
    \returns
     - \b  0: function succeeded
     - \b -1: function failed
  */
  int32_t Buttons_Uninitialize (void) {
  
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_0);
  
    return 0;
  }
  
  /**
    \fn          uint32_t Buttons_GetState (void)
    \brief       Get buttons state
    \returns     Buttons state
  */
  uint32_t Buttons_GetState (void) {
    uint32_t val = 0;
  
    if (HAL_GPIO_ReadPin(BUTTONS_USER_PORT, BUTTONS_USER_PIN) == GPIO_PIN_SET) {
      val |= BUTTONS_USER_MASK;
    }
  
    return val;
  }
  
  /**
    \fn          uint32_t Buttons_GetCount (void)
    \brief       Get number of available buttons
    \return      Number of available buttons
  */
  uint32_t Buttons_GetCount (void) {
    return BUTTONS_COUNT;
  }
  