text: /* mbed Microcontroller Library
   * Copyright (c) 2006-2013 ARM Limited
   *
   * Licensed 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.
   */
  #include "pinmap.h"
  #include "error.h"
  
  // Alternate-function mapping
  static const uint32_t AF_mapping[] = {
    0,                   // 0 = No AF
    GPIO_Remap_SPI1,     // 1
    GPIO_Remap_I2C1,     // 2
    GPIO_Remap_USART1,   // 3
    GPIO_Remap_USART2,   // 4
    GPIO_FullRemap_TIM2, // 5
    GPIO_FullRemap_TIM3, // 6
    GPIO_Remap_I2C1      // 7
  };
  
  /**
   * Set the pin function (input, output, alternate function or analog) + output speed + AF
   */
  void pin_function(PinName pin, int data) {
      if (pin == NC) return;
  
      // Get the pin mode and alternate-function number
      uint32_t mode  = STM_PIN_MODE(data);
      uint32_t afnum = STM_PIN_AFNUM(data);
  
      // Get GPIO structure base address
      uint32_t pin_number = (uint32_t)pin;
      uint32_t pin_index  = (pin_number & 0xF);
      uint32_t port_index = (pin_number >> 4);
      GPIO_TypeDef *gpio  = ((GPIO_TypeDef *)(GPIOA_BASE + (port_index << 10)));
  
      // Enable GPIO and AFIO clocks
      RCC_APB2PeriphClockCmd((uint32_t)(RCC_APB2Periph_GPIOA << port_index), ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
    
      // Configure GPIO
      GPIO_InitTypeDef GPIO_InitStructure;
      GPIO_InitStructure.GPIO_Pin   = (uint16_t)(1 << pin_index);
      GPIO_InitStructure.GPIO_Mode  = (GPIOMode_TypeDef)mode;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_Init(gpio, &GPIO_InitStructure);
  
      // Configure Alternate Function
      if (afnum > 0) {
          GPIO_PinRemapConfig(AF_mapping[afnum], ENABLE);
      }
      
      // Disconnect JTAG-DP + SW-DP signals.
      // Warning: Need to reconnect under reset
      if ((pin == PA_13) || (pin == PA_14)) {
          GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);
      }
      if ((pin == PA_15) || (pin == PB_3) || (pin == PB_4)) {
          GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);
      }    
  }
  
  /**
   * Set the pin mode (open-drain/push-pull + pull-up/pull-down)
   */
  void pin_mode(PinName pin, PinMode mode) {
      if (pin == NC) return;
  
      GPIO_InitTypeDef GPIO_InitStructure;
    
      // Get GPIO structure base address
      uint32_t pin_number = (uint32_t)pin;
      uint32_t pin_index  = (pin_number & 0xF);
      uint32_t port_index = (pin_number >> 4);
      GPIO_TypeDef *gpio  = ((GPIO_TypeDef *)(GPIOA_BASE + (port_index << 10)));
  
      // Enable GPIO clock
      RCC_APB2PeriphClockCmd((uint32_t)(RCC_APB2Periph_GPIOA << port_index), ENABLE);
    
      // Configure open-drain and pull-up/down
      switch (mode) {
        case PullNone:       
          return;
        case PullUp:
          GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
        break;
        case PullDown:
          GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;
        break;
        case OpenDrain:
          if (pin_index < 8) {
              if ((gpio->CRL & (0x03 << (pin_index * 4))) > 0) { // MODE bits = Output mode
                  gpio->CRL |= (0x04 << (pin_index * 4)); // Set open-drain
              }
          }
          else {
              if ((gpio->CRH & (0x03 << ((pin_index % 8) * 4))) > 0) { // MODE bits = Output mode          
                  gpio->CRH |= (0x04 << ((pin_index % 8) * 4)); // Set open-drain
              }
          }
          return;
        default:
        break;
      }
      
      // Configure GPIO
      GPIO_InitStructure.GPIO_Pin   = (uint16_t)(1 << pin_index);
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_Init(gpio, &GPIO_InitStructure);    
  }
  