text: /**
    ******************************************************************************
    * @file    stm32f0xx_gpio.c
    * @author  MCD Application Team
    * @version V1.0.1
    * @date    20-April-2012
    * @brief   This file provides firmware functions to manage the following 
    *          functionalities of the GPIO peripheral:
    *           + Initialization and Configuration functions
    *           + GPIO Read and Write functions
    *           + GPIO Alternate functions configuration functions
    *
    *  @verbatim
    *
    *
      ===========================================================================
                           ##### How to use this driver #####
      ===========================================================================
        [..]
        (#) Enable the GPIO AHB clock using RCC_AHBPeriphClockCmd()
        (#) Configure the GPIO pin(s) using GPIO_Init()
            Four possible configuration are available for each pin:
           (++) Input: Floating, Pull-up, Pull-down.
           (++) Output: Push-Pull (Pull-up, Pull-down or no Pull)
                        Open Drain (Pull-up, Pull-down or no Pull).
                In output mode, the speed is configurable: Low, Medium, Fast or High.
           (++) Alternate Function: Push-Pull (Pull-up, Pull-down or no Pull)
                                    Open Drain (Pull-up, Pull-down or no Pull).
           (++) Analog: required mode when a pin is to be used as ADC channel,
                DAC output or comparator input.
        (#) Peripherals alternate function:
           (++) For ADC, DAC and comparators, configure the desired pin in analog 
                mode using GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AN
           (++) For other peripherals (TIM, USART...):
                (+++) Connect the pin to the desired peripherals' Alternate 
                      Function (AF) using GPIO_PinAFConfig() function. For PortC, 
                      PortD and PortF, no configuration is needed.
                (+++) Configure the desired pin in alternate function mode using
                      GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AF
                (+++) Select the type, pull-up/pull-down and output speed via 
                      GPIO_PuPd, GPIO_OType and GPIO_Speed members
                (+++) Call GPIO_Init() function
        (#) To get the level of a pin configured in input mode use GPIO_ReadInputDataBit()
        (#) To set/reset the level of a pin configured in output mode use
            GPIO_SetBits()/GPIO_ResetBits()
        (#) During and just after reset, the alternate functions are not active and 
            the GPIO pins are configured in input floating mode (except JTAG pins).
        (#) The LSE oscillator pins OSC32_IN and OSC32_OUT can be used as 
            general-purpose (PC14 and PC15, respectively) when the LSE oscillator 
            is off. The LSE has priority over the GPIO function.
        (#) The HSE oscillator pins OSC_IN/OSC_OUT can be used as general-purpose 
            PD0 and PD1, respectively, when the HSE oscillator is off. The HSE has 
            priority over the GPIO function.
      @endverbatim
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
    *
    * Licensed under MCD-ST Liberty SW License Agreement V2, (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.st.com/software_license_agreement_liberty_v2
    *
    * 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.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "stm32f0xx_gpio.h"
  #include "stm32f0xx_rcc.h"
  
  /** @addtogroup STM32F0xx_StdPeriph_Driver
    * @{
    */
  
  /** @defgroup GPIO 
    * @brief GPIO driver modules
    * @{
    */
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Private function prototypes -----------------------------------------------*/
  /* Private functions ---------------------------------------------------------*/
  
  /** @defgroup GPIO_Private_Functions 
    * @{
    */
  
  /** @defgroup GPIO_Group1 Initialization and Configuration
   *  @brief   Initialization and Configuration
   *
  @verbatim
   ===============================================================================
                      ##### Initialization and Configuration #####
   ===============================================================================
  
  @endverbatim
    * @{
    */
  
  /**
    * @brief  Deinitializes the GPIOx peripheral registers to their default reset 
    *         values.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @retval None
    */
  void GPIO_DeInit(GPIO_TypeDef* GPIOx)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
  
    if(GPIOx == GPIOA)
    {
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOA, ENABLE);
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOA, DISABLE);
    }
    else if(GPIOx == GPIOB)
    {
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOB, ENABLE);
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOB, DISABLE);
    }
    else if(GPIOx == GPIOC)
    {
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOC, ENABLE);
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOC, DISABLE);
    }
    else if(GPIOx == GPIOD)
    {
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOD, ENABLE);
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOD, DISABLE);
    }
    else
    {
      if(GPIOx == GPIOF)
      {
        RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOF, ENABLE);
        RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOF, DISABLE);
      }
    }
  }
  
  /**
    * @brief  Initializes the GPIOx peripheral according to the specified 
    *         parameters in the GPIO_InitStruct.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  GPIO_InitStruct: pointer to a GPIO_InitTypeDef structure that contains
    *         the configuration information for the specified GPIO peripheral.
    * @note   The configured pins can be: GPIO_Pin_0 to GPIO_Pin_15 for GPIOA, GPIOB and GPIOC,
    *         GPIO_Pin_0 to GPIO_Pin_2 for GPIOD, GPIO_Pin_0 to GPIO_Pin_3 for GPIOF.
    * @retval None
    */
  void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_InitTypeDef* GPIO_InitStruct)
  {
    uint32_t pinpos = 0x00, pos = 0x00 , currentpin = 0x00;
  
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
    assert_param(IS_GPIO_PIN(GPIO_InitStruct->GPIO_Pin));
    assert_param(IS_GPIO_MODE(GPIO_InitStruct->GPIO_Mode));
    assert_param(IS_GPIO_PUPD(GPIO_InitStruct->GPIO_PuPd));
  
    /*-------------------------- Configure the port pins -----------------------*/
    /*-- GPIO Mode Configuration --*/
    for (pinpos = 0x00; pinpos < 0x10; pinpos++)
    {
      pos = ((uint32_t)0x01) << pinpos;
  
      /* Get the port pins position */
      currentpin = (GPIO_InitStruct->GPIO_Pin) & pos;
  
      if (currentpin == pos)
      {
        if ((GPIO_InitStruct->GPIO_Mode == GPIO_Mode_OUT) || (GPIO_InitStruct->GPIO_Mode == GPIO_Mode_AF))
        {
          /* Check Speed mode parameters */
          assert_param(IS_GPIO_SPEED(GPIO_InitStruct->GPIO_Speed));
  
          /* Speed mode configuration */
          GPIOx->OSPEEDR &= ~(GPIO_OSPEEDER_OSPEEDR0 << (pinpos * 2));
          GPIOx->OSPEEDR |= ((uint32_t)(GPIO_InitStruct->GPIO_Speed) << (pinpos * 2));
  
          /* Check Output mode parameters */
          assert_param(IS_GPIO_OTYPE(GPIO_InitStruct->GPIO_OType));
  
          /* Output mode configuration */
          GPIOx->OTYPER &= ~((GPIO_OTYPER_OT_0) << ((uint16_t)pinpos));
          GPIOx->OTYPER |= (uint16_t)(((uint16_t)GPIO_InitStruct->GPIO_OType) << ((uint16_t)pinpos));
        }
  
        GPIOx->MODER  &= ~(GPIO_MODER_MODER0 << (pinpos * 2));
  
        GPIOx->MODER |= (((uint32_t)GPIO_InitStruct->GPIO_Mode) << (pinpos * 2));
  
        /* Pull-up Pull down resistor configuration */
        GPIOx->PUPDR &= ~(GPIO_PUPDR_PUPDR0 << ((uint16_t)pinpos * 2));
        GPIOx->PUPDR |= (((uint32_t)GPIO_InitStruct->GPIO_PuPd) << (pinpos * 2));
      }
    }
  }
  
  /**
    * @brief  Fills each GPIO_InitStruct member with its default value.
    * @param  GPIO_InitStruct: pointer to a GPIO_InitTypeDef structure which will 
    *         be initialized.
    * @retval None
    */
  void GPIO_StructInit(GPIO_InitTypeDef* GPIO_InitStruct)
  {
    /* Reset GPIO init structure parameters values */
    GPIO_InitStruct->GPIO_Pin  = GPIO_Pin_All;
    GPIO_InitStruct->GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStruct->GPIO_Speed = GPIO_Speed_Level_2;
    GPIO_InitStruct->GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct->GPIO_PuPd = GPIO_PuPd_NOPULL;
  }
  
  /**
    * @brief  Locks GPIO Pins configuration registers.
    * @note   The locked registers are GPIOx_MODER, GPIOx_OTYPER, GPIOx_OSPEEDR,
    *         GPIOx_PUPDR, GPIOx_AFRL and GPIOx_AFRH.
    * @note   The configuration of the locked GPIO pins can no longer be modified
    *         until the next device reset.
    * @param  GPIOx: where x can be (A or B) to select the GPIO peripheral.
    * @param  GPIO_Pin: specifies the port bit to be written.
    *          This parameter can be any combination of GPIO_Pin_x where x can be (0..15).
    * @retval None
    */
  void GPIO_PinLockConfig(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
  {
    __IO uint32_t tmp = 0x00010000;
  
    /* Check the parameters */
    assert_param(IS_GPIO_LIST_PERIPH(GPIOx));
    assert_param(IS_GPIO_PIN(GPIO_Pin));
  
    tmp |= GPIO_Pin;
    /* Set LCKK bit */
    GPIOx->LCKR = tmp;
    /* Reset LCKK bit */
    GPIOx->LCKR =  GPIO_Pin;
    /* Set LCKK bit */
    GPIOx->LCKR = tmp;
    /* Read LCKK bit */
    tmp = GPIOx->LCKR;
    /* Read LCKK bit */
    tmp = GPIOx->LCKR;
  }
  
  /**
    * @}
    */
  
  /** @defgroup GPIO_Group2 GPIO Read and Write
   *  @brief   GPIO Read and Write
   *
  @verbatim   
   ===============================================================================
                        ##### GPIO Read and Write #####
   ===============================================================================  
  
  @endverbatim
    * @{
    */
  
  /**
    * @brief  Reads the specified input port pin.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  GPIO_Pin: specifies the port bit to read.
    * @note   This parameter can be GPIO_Pin_x where x can be:(0..15) for GPIOA, 
    *         GPIOB or GPIOC,(0..2) for GPIOD and(0..3) for GPIOF.
    * @retval The input port pin value.
    */
  uint8_t GPIO_ReadInputDataBit(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
  {
    uint8_t bitstatus = 0x00;
  
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
    assert_param(IS_GET_GPIO_PIN(GPIO_Pin));
  
    if ((GPIOx->IDR & GPIO_Pin) != (uint32_t)Bit_RESET)
    {
      bitstatus = (uint8_t)Bit_SET;
    }
    else
    {
      bitstatus = (uint8_t)Bit_RESET;
    }
    return bitstatus;
  }
  
  /**
    * @brief  Reads the specified input port pin.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @retval The input port pin value.
    */
  uint16_t GPIO_ReadInputData(GPIO_TypeDef* GPIOx)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
  
    return ((uint16_t)GPIOx->IDR);
  }
  
  /**
    * @brief  Reads the specified output data port bit.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  GPIO_Pin: Specifies the port bit to read.
    * @note   This parameter can be GPIO_Pin_x where x can be:(0..15) for GPIOA, 
    *         GPIOB or GPIOC,(0..2) for GPIOD and(0..3) for GPIOF.
    * @retval The output port pin value.
    */
  uint8_t GPIO_ReadOutputDataBit(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
  {
    uint8_t bitstatus = 0x00;
  
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
    assert_param(IS_GET_GPIO_PIN(GPIO_Pin));
  
    if ((GPIOx->ODR & GPIO_Pin) != (uint32_t)Bit_RESET)
    {
      bitstatus = (uint8_t)Bit_SET;
    }
    else
    {
      bitstatus = (uint8_t)Bit_RESET;
    }
    return bitstatus;
  }
  
  /**
    * @brief  Reads the specified GPIO output data port.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @retval GPIO output data port value.
    */
  uint16_t GPIO_ReadOutputData(GPIO_TypeDef* GPIOx)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
  
    return ((uint16_t)GPIOx->ODR);
  }
  
  /**
    * @brief  Sets the selected data port bits.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  GPIO_Pin: specifies the port bits to be written.
    * @note   This parameter can be GPIO_Pin_x where x can be:(0..15) for GPIOA, 
    *         GPIOB or GPIOC,(0..2) for GPIOD and(0..3) for GPIOF.
    * @retval None
    */
  void GPIO_SetBits(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
    assert_param(IS_GPIO_PIN(GPIO_Pin));
  
    GPIOx->BSRR = GPIO_Pin;
  }
  
  /**
    * @brief  Clears the selected data port bits.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  GPIO_Pin: specifies the port bits to be written.
    * @note   This parameter can be GPIO_Pin_x where x can be: (0..15) for GPIOA, 
    *         GPIOB or GPIOC,(0..2) for GPIOD and(0..3) for GPIOF.
    * @retval None
    */
  void GPIO_ResetBits(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
    assert_param(IS_GPIO_PIN(GPIO_Pin));
  
    GPIOx->BRR = GPIO_Pin;
  }
  
  /**
    * @brief  Sets or clears the selected data port bit.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  GPIO_Pin: specifies the port bit to be written.
    * @param  BitVal: specifies the value to be written to the selected bit.
    *          This parameter can be one of the BitAction enumeration values:
    *            @arg Bit_RESET: to clear the port pin
    *            @arg Bit_SET: to set the port pin
    * @note   The GPIO_Pin parameter can be GPIO_Pin_x where x can be: (0..15) for GPIOA, 
    *         GPIOB or GPIOC,(0..2) for GPIOD and(0..3) for GPIOF.  
    * @retval None
    */
  void GPIO_WriteBit(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin, BitAction BitVal)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
    assert_param(IS_GET_GPIO_PIN(GPIO_Pin));
    assert_param(IS_GPIO_BIT_ACTION(BitVal));
  
    if (BitVal != Bit_RESET)
    {
      GPIOx->BSRR = GPIO_Pin;
    }
    else
    {
      GPIOx->BRR = GPIO_Pin ;
    }
  }
  
  /**
    * @brief  Writes data to the specified GPIO data port.
    * @param  GPIOx: where x can be (A, B, C, D or F) to select the GPIO peripheral.
    * @param  PortVal: specifies the value to be written to the port output data register.
    * @retval None
    */
  void GPIO_Write(GPIO_TypeDef* GPIOx, uint16_t PortVal)
  {
    /* Check the parameters */
    assert_param(IS_GPIO_ALL_PERIPH(GPIOx));
  
    GPIOx->ODR = PortVal;
  }
  
  /**
    * @}
    */
  
  /** @defgroup GPIO_Group3 GPIO Alternate functions configuration functions
   *  @brief   GPIO Alternate functions configuration functions
   *
  @verbatim   
   ===============================================================================
            ##### GPIO Alternate functions configuration functions #####
   ===============================================================================  
  
  @endverbatim
    * @{
    */
  
  /**
    * @brief  Writes data to the specified GPIO data port.
    * @param  GPIOx: where x can be (A or B) to select the GPIO peripheral.
    * @param  GPIO_PinSource: specifies the pin for the Alternate function.
    *          This parameter can be GPIO_PinSourcex where x can be (0..15).
    * @param  GPIO_AF: selects the pin to used as Alternate function.
    *          This parameter can be one of the following value:
    *            @arg GPIO_AF_0: WKUP, EVENTOUT, TIM15, SPI1, TIM17,MCO, SWDAT, SWCLK, TIM14,
    *                            BOOT,USART1, CEC, IR_OUT, SPI2 
    *            @arg GPIO_AF_1: USART2, CEC, Tim3, USART1, USART2,EVENTOUT, I2C1, I2C2, TIM15 
    *            @arg GPIO_AF_2: TIM2, TIM1, EVENTOUT, TIM16, TIM17
    *            @arg GPIO_AF_3: TS, I2C1, TIM15, EVENTOUT 
    *            @arg GPIO_AF_4: TIM14
    *            @arg GPIO_AF_5: TIM16, TIM17
    *            @arg GPIO_AF_6: EVENTOUT
    *            @arg GPIO_AF_7: COMP1 OUT, COMP2 OUT 
    * @note   The pin should already been configured in Alternate Function mode(AF)
    *         using GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AF
    * @note   Refer to the Alternate function mapping table in the device datasheet 
    *         for the detailed mapping of the system and peripherals'alternate 
    *         function I/O pins.
    * @retval None
    */
  void GPIO_PinAFConfig(GPIO_TypeDef* GPIOx, uint16_t GPIO_PinSource, uint8_t GPIO_AF)
  {
    uint32_t temp = 0x00;
    uint32_t temp_2 = 0x00;
  
    /* Check the parameters */
    assert_param(IS_GPIO_LIST_PERIPH(GPIOx));
    assert_param(IS_GPIO_PIN_SOURCE(GPIO_PinSource));
    assert_param(IS_GPIO_AF(GPIO_AF));
  
    temp = ((uint32_t)(GPIO_AF) << ((uint32_t)((uint32_t)GPIO_PinSource & (uint32_t)0x07) * 4));
    GPIOx->AFR[GPIO_PinSource >> 0x03] &= ~((uint32_t)0xF << ((uint32_t)((uint32_t)GPIO_PinSource & (uint32_t)0x07) * 4));
    temp_2 = GPIOx->AFR[GPIO_PinSource >> 0x03] | temp;
    GPIOx->AFR[GPIO_PinSource >> 0x03] = temp_2;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  