text: /* mbed Microcontroller Library
   *******************************************************************************
   * Copyright (c) 2014, STMicroelectronics
   * All rights reserved.
   *
   * 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 of STMicroelectronics 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 HOLDER 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.
   *******************************************************************************
   */
  #include "mbed_assert.h"
  #include "gpio_api.h"
  #include "pinmap.h"
  #include "error.h"
  
  extern uint32_t Set_GPIO_Clock(uint32_t port_idx);
  
  uint32_t gpio_set(PinName pin) {
      MBED_ASSERT(pin != (PinName)NC);
  
      pin_function(pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
      return (uint32_t)(1 << ((uint32_t)pin & 0xF)); // Return the pin mask
  }
  
  void gpio_init(gpio_t *obj, PinName pin) {
      obj->pin = pin;
      if (pin == (PinName)NC)
          return;
      uint32_t port_index = STM_PORT(pin);
    
      // Enable GPIO clock
      uint32_t gpio_add = Set_GPIO_Clock(port_index);
      GPIO_TypeDef *gpio = (GPIO_TypeDef *)gpio_add;
      
      // Fill GPIO object structure for future use
      obj->mask    = gpio_set(pin);
      obj->reg_in  = &gpio->IDR;
      obj->reg_set = &gpio->BSRRL;
      obj->reg_clr = &gpio->BSRRH;
  }
  
  void gpio_mode(gpio_t *obj, PinMode mode) {
      pin_mode(obj->pin, mode);
  }
  
  void gpio_dir(gpio_t *obj, PinDirection direction) {
      MBED_ASSERT(obj->pin != (PinName)NC);
      if (direction == PIN_OUTPUT) {
          pin_function(obj->pin, STM_PIN_DATA(STM_MODE_OUTPUT_PP, GPIO_NOPULL, 0));
      } else { // PIN_INPUT
          pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
      }
  }
  