stm32l1xx_gpio.c

STM32+Grlib

/**
  ******************************************************************************
  * @file    stm32l1xx_gpio.c
  * @author  MCD Application Team
  * @version V1.0.0
  * @date    31-December-2010
  * @brief   This file provides firmware functions to manage the following 
  *          functionalities of the GPIO peripheral:           
  *           - Initialization and Configuration
  *           - GPIO Read and Write
  *           - GPIO Alternate functions configuration
  * 
  *  @verbatim
  *
  *          ===================================================================
  *                                 How to use this driver
  *          ===================================================================       
  *           1. Enable the GPIO AHB clock using RCC_AHBPeriphClockCmd()
  *             
  *           2. 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: Very Low, Low,
  *                  Medium 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.
  * 
  *          3- 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
  *                 - 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
  *        
  *          4. To get the level of a pin configured in input mode use GPIO_ReadInputDataBit()
  *          
  *          5. To set/reset the level of a pin configured in output mode use
  *             GPIO_SetBits()/GPIO_ResetBits()
  *               
  *          6. During and just after reset, the alternate functions are not 
  *             active and the GPIO pins are configured in input floating mode
  *             (except JTAG pins).
  *
  *          7. 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.
  *
  *          8. The HSE oscillator pins OSC_IN/OSC_OUT can be used as 
  *             general-purpose PH0 and PH1, respectively, when the HSE 
  *             oscillator is off. The HSE has priority over the GPIO function.
  *             
  *  @endverbatim        
  *
  ******************************************************************************
  * @attention
  *
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  *
  * <h2><center>&copy; COPYRIGHT 2010 STMicroelectronics</center></h2>
  ******************************************************************************  
  */ 

/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_gpio.h"
#include "stm32l1xx_rcc.h"

/** @addtogroup STM32L1xx_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.
  *         By default, The GPIO pins are configured in input floating mode
  *         (except JTAG pins).
  * @param  GPIOx: where x can be (A, B, C, D, E or H) 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 == GPIOE)
  {
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOE, ENABLE);
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOE, DISABLE);
  }
  else
  {
    if(GPIOx == GPIOH)
    {
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOH, ENABLE);
      RCC_AHBPeriphResetCmd(RCC_AHBPeriph_GPIOH, 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, E or H) to select the GPIO peripheral.
  * @param  GPIO_InitStruct: pointer to a GPIO_InitTypeDef structure that 
  *         contains the configuration information for the specified GPIO
  *         peripheral.
  *         GPIO_Pin: selects the pin to be configured: GPIO_Pin_0 -> GPIO_Pin_15
  *         GPIO_Mode: selects the mode of the pin: 
  *                      - Input mode: GPIO_Mode_IN
  *                      - Output mode: GPIO_Mode_OUT
  *                      - Alternate Function mode: GPIO_Mode_AF
  *                      - Analog mode: GPIO_Mode_AN
  *         GPIO_Speed: selects the speed of the pin if configured in Output:
  *                      - Very Low: GPIO_Speed_400KHz
  *                      - Low: GPIO_Speed_2MHz
  *                      - Medium: GPIO_Speed_10MHz
  *                      - High: GPIO_Speed_40MHz
  *         GPIO_OType: selects the Output type (if the selected mode is output):
  *                      - Push-pull: GPIO_OType_PP
  *                      - Open Drain: GPIO_OType_OD
  *         GPIO_PuPd: configures the Pull-up/Pull-down resistor on the pin:
  *                      - pull-up: GPIO_PuPd_UP
  *                      - pull-down: GPIO_PuPd_DOWN
  *                      - Neither pull-up nor Pull-down: GPIO_PuPd_NOPULL
  * @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)
    {
      GPIOx->MODER  &= ~(GPIO_MODER_MODER0 << (pinpos * 2));

      GPIOx->MODER |= (((uint32_t)GPIO_InitStruct->GPIO_Mode) << (pinpos * 2));

      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));
      }

      /* 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_400KHz;
  GPIO_InitStruct->GPIO_OType = GPIO_OType_PP;
  GPIO_InitStruct->GPIO_PuPd = GPIO_PuPd_NOPULL;
}

/**
  * @brief  Locks GPIO Pins configuration registers.
  *         The locked registers are GPIOx_MODER, GPIOx_OTYPER, GPIOx_OSPEEDR,