在实际的项目开发过程中，常常会遇到硬件电路的修改，然后修改的部分就需要修改驱动程序。想这样需求该来该去是程序员们最烦闷的事情（重复劳动痛不欲生啊~）。为了避免或减少重复劳动，就需要在程序的架构上下功夫。接下来以最常见的KEY驱动程序为例，进行程序结构设计。

1，开发环境

     1，固件库：STM32F4xx_DSP_StdPeriph_Lib_V1.8.0

     2，编译器：ARMCC V5.06

     3，IDE：Keil uVision5

     4，操作系统：Windows 10 专业版

2，程序源码

      KEY.h文件

/** 

  ****************************************************************************** 

  * @file    KEY.h 

  * @author  XinLi 

  * @version v1.0 

  * @date    24-October-2017 

  * @brief   Header file for KEY.c module. 

  ****************************************************************************** 

  * @attention 

  * 

  *

Copyright © 2017 XinLi

  * 

  * This program is free software: you can redistribute it and/or modify 

  * it under the terms of the GNU General Public License as published by 

  * the Free Software Foundation, either version 3 of the License, or 

  * (at your option) any later version. 

  * 

  * This program is distributed in the hope that it will be useful, 

  * but WITHOUT ANY WARRANTY; without even the implied warranty of 

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 

  * GNU General Public License for more details. 

  * 

  * You should have received a copy of the GNU General Public License 

  * along with this program.  If not, see . 

  * 

  ****************************************************************************** 

  */  

#ifndef __KEY_H  

#define __KEY_H  

#ifdef __cplusplus  

extern "C" {  

#endif  

/* Header includes -----------------------------------------------------------*/  

#include "stm32f4xx.h"  

/* Macro definitions ---------------------------------------------------------*/  

#define KEYn                            (3)  

#define KEY1_RCC_AHB1Periph_GPIO        RCC_AHB1Periph_GPIOC  

#define KEY1_GPIO                       GPIOC  

#define KEY1_GPIO_Pin                   GPIO_Pin_2  

#define KEY2_RCC_AHB1Periph_GPIO        RCC_AHB1Periph_GPIOC  

#define KEY2_GPIO                       GPIOC  

#define KEY2_GPIO_Pin                   GPIO_Pin_3  

#define KEY3_RCC_AHB1Periph_GPIO        RCC_AHB1Periph_GPIOC  

#define KEY3_GPIO                       GPIOC  

#define KEY3_GPIO_Pin                   GPIO_Pin_4  

#define KEY_RCC_APB1Periph_TIM          RCC_APB1Periph_TIM2  

#define KEY_TIM                         TIM2  

#define KEY_TIM_Prescaler               (83)   /*!< Clock divided to 1MHz. */  

#define KEY_TIM_Period                  (4999) /*!< 5ms timer interrupt. */  

#define KEY_TIM_IRQn                    TIM2_IRQn  

#define KEY_TIM_IRQHandler              TIM2_IRQHandler  

#define KEY_TIM_IRQ_PreemptionPriority  (0)  

#define KEY_TIM_IRQ_SubPriority         (0)  

#define KEY_PRESS_STATUS                Bit_SET  

/* Type definitions ----------------------------------------------------------*/  

typedef enum  

{  

  KEY_Pin1 = 0,  

  KEY_Pin2 = 1,  

  KEY_Pin3 = 2  

}KEY_Pin;  

typedef enum  

{  

  KEY_NoPress    = 0,  

  KEY_ShortPress = 1,  

  KEY_LongPress  = 2  

}KEY_Status;  

/* Variable declarations -----------------------------------------------------*/  

/* Variable definitions ------------------------------------------------------*/  

/* Function declarations -----------------------------------------------------*/  

void KEY_Init(void);  

void KEY_DeInit(void);  

KEY_Status KEY_GetStatus(KEY_Pin pin);  

void KEY_SetShortPressCallback(KEY_Pin pin, void (*fun)(void));  

void KEY_SetLongPressCallback(KEY_Pin pin, void (*fun)(void));  

void KEY_ClearShortPressCallback(KEY_Pin pin);  

void KEY_ClearLongPressCallback(KEY_Pin pin);  

/* Function definitions ------------------------------------------------------*/  

#ifdef __cplusplus  

}  

#endif  

#endif /* __KEY_H */  

      KEY.c文件

/** 

  ****************************************************************************** 

  * @file    KEY.c 

  * @author  XinLi 

  * @version v1.0 

  * @date    24-October-2017 

  * @brief   KEY module driver. 

  ****************************************************************************** 

  * @attention 

  * 

  *

Copyright © 2017 XinLi

  * 

  * This program is free software: you can redistribute it and/or modify 

  * it under the terms of the GNU General Public License as published by 

  * the Free Software Foundation, either version 3 of the License, or 

  * (at your option) any later version. 

  * 

  * This program is distributed in the hope that it will be useful, 

  * but WITHOUT ANY WARRANTY; without even the implied warranty of 

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 

  * GNU General Public License for more details. 

  * 

  * You should have received a copy of the GNU General Public License 

  * along with this program.  If not, see . 

  * 

  ****************************************************************************** 

  */  

/* Header includes -----------------------------------------------------------*/  

#include "KEY.h"  

#include  

/* Macro definitions ---------------------------------------------------------*/  

/* Type definitions ----------------------------------------------------------*/  

/* Variable declarations -----------------------------------------------------*/  

/* Variable definitions ------------------------------------------------------*/  

static      GPIO_TypeDef *KEY_GPIO[KEYn]                     = {KEY1_GPIO, KEY2_GPIO, KEY3_GPIO};  

static      uint16_t      KEY_GPIO_Pin[KEYn]                 = {KEY1_GPIO_Pin, KEY2_GPIO_Pin, KEY3_GPIO_Pin};  

static      uint32_t      KEY_RCC_AHB1Periph_GPIO[KEYn]      = {KEY1_RCC_AHB1Periph_GPIO, KEY2_RCC_AHB1Periph_GPIO, KEY3_RCC_AHB1Periph_GPIO};  

static __IO int           keyInputHighCount[KEYn]            = {0};  

static __IO int           keyInputLowCount[KEYn]             = {0};  

static __IO KEY_Status    keyStatus[KEYn]                    = {KEY_NoPress, KEY_NoPress, KEY_NoPress};  

static __IO KEY_Status    keyGetStatus[KEYn]                 = {KEY_NoPress, KEY_NoPress, KEY_NoPress};  

static __IO void        (*keyShortPressCallback[KEYn])(void) = {NULL};  

static __IO void        (*keyLongPressCallback[KEYn])(void)  = {NULL};  

/* Function declarations -----------------------------------------------------*/  

/* Function definitions ------------------------------------------------------*/  

/** 

  * @brief  Key initializes. 

  * @param  None. 

  * @return None. 

  */  

void KEY_Init(void)  

{  

  for(int i = 0; i < KEYn; i++)  

  {  

    GPIO_InitTypeDef GPIO_InitStructure = {0};  

    RCC_AHB1PeriphClockCmd(KEY_RCC_AHB1Periph_GPIO[i], ENABLE);  

    GPIO_InitStructure.GPIO_Pin   = KEY_GPIO_Pin[i];  

    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_IN;  

    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  

    GPIO_Init(KEY_GPIO[i], &GPIO_InitStructure);  

    keyInputHighCount[i]     = 0;  

    keyInputLowCount[i]      = 0;  

    keyStatus[i]             = KEY_NoPress;  

    keyGetStatus[i]          = KEY_NoPress;  

    keyShortPressCallback[i] = NULL;  

    keyLongPressCallback[i]  = NULL;  

  }  

  TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure = {0};  

  RCC_APB1PeriphClockCmd(KEY_RCC_APB1Periph_TIM, ENABLE);  

  TIM_TimeBaseInitStructure.TIM_Prescaler     = KEY_TIM_Prescaler;  

  TIM_TimeBaseInitStructure.TIM_CounterMode   = TIM_CounterMode_Up;  

  TIM_TimeBaseInitStructure.TIM_Period        = KEY_TIM_Period;  

  TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;  

  TIM_TimeBaseInit(KEY_TIM, &TIM_TimeBaseInitStructure);  

  TIM_ClearFlag(KEY_TIM, TIM_FLAG_Update);  

  TIM_ITConfig(KEY_TIM, TIM_IT_Update, ENABLE);  

  TIM_Cmd(KEY_TIM, ENABLE);  

  NVIC_InitTypeDef NVIC_InitStructure = {0};  

  NVIC_InitStructure.NVIC_IRQChannel                   = KEY_TIM_IRQn;  

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = KEY_TIM_IRQ_PreemptionPriority;  

  NVIC_InitStructure.NVIC_IRQChannelSubPriority        = KEY_TIM_IRQ_SubPriority;  

  NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;  

  NVIC_Init(&NVIC_InitStructure);  

}  

/** 

  * @brief  Key de-initializes. 

  * @param  None. 

  * @return None. 

  */  

void KEY_DeInit(void)  

{  

  for(int i = 0; i < KEYn; i++)  

  {  

    keyInputHighCount[i]     = 0;  

    keyInputLowCount[i]      = 0;  

    keyStatus[i]             = KEY_NoPress;  

    keyGetStatus[i]          = KEY_NoPress;  

    keyShortPressCallback[i] = NULL;  

    keyLongPressCallback[i]  = NULL;  

  }  

  TIM_DeInit(KEY_TIM);  

  RCC_APB1PeriphClockCmd(KEY_RCC_APB1Periph_TIM, DISABLE);  

  NVIC_InitTypeDef NVIC_InitStructure = {0};  

  NVIC_InitStructure.NVIC_IRQChannel                   = KEY_TIM_IRQn;  

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = KEY_TIM_IRQ_PreemptionPriority;  

  NVIC_InitStructure.NVIC_IRQChannelSubPriority        = KEY_TIM_IRQ_SubPriority;  

  NVIC_InitStructure.NVIC_IRQChannelCmd                = DISABLE;  

  NVIC_Init(&NVIC_InitStructure);  

}  

/** 

  * @brief  Get key status. 

  * @param  [in] pin: That key. 

  * @return Key status. 

  */  

KEY_Status KEY_GetStatus(KEY_Pin pin)  

{  

  KEY_Status status = KEY_NoPress;  

  if(keyGetStatus[pin] != KEY_NoPress)  

  {  

    status            = keyGetStatus[pin];  

    keyGetStatus[pin] = KEY_NoPress;  

  }  

  return status;  

}  

/** 

  * @brief  Set key short press callback. 

  * @param  [in] pin: That key. 

  * @param  [in] fun: Function pointer. 

  * @return None. 

  */  

void KEY_SetShortPressCallback(KEY_Pin pin, void (*fun)(void))  

{  

  keyShortPressCallback[pin] = (__IO void (*)(void))fun;  

}  

/** 

  * @brief  Set key long press callback. 

  * @param  [in] pin: That key. 

  * @param  [in] fun: Function pointer. 

  * @return None. 

  */  

void KEY_SetLongPressCallback(KEY_Pin pin, void (*fun)(void))  

{  

  keyLongPressCallback[pin] = (__IO void (*)(void))fun;  

}  

/** 

  * @brief  Clear key short press callback. 

  * @param  [in] pin: That key. 

  * @param  [in] fun: Function pointer. 

  * @return None. 

  */  

void KEY_ClearShortPressCallback(KEY_Pin pin)  

{  

  keyShortPressCallback[pin] = NULL;  

}  

/** 

  * @brief  Clear key long press callback. 

  * @param  [in] pin: That key. 

  * @param  [in] fun: Function pointer. 

  * @return None. 

  */  

void KEY_ClearLongPressCallback(KEY_Pin pin)  

{  

  keyLongPressCallback[pin] = NULL;  

}  

/** 

  * @brief  This function handles TIM Handler. 

  * @param  None. 

  * @return None. 

  */  

void KEY_TIM_IRQHandler(void)  

{  

  if(TIM_GetITStatus(KEY_TIM, TIM_IT_Update) != RESET)  

  {  

    TIM_ClearITPendingBit(KEY_TIM, TIM_IT_Update);  

    for(int i = 0; i < KEYn; i++)  

    {  

      if(GPIO_ReadInputDataBit(KEY_GPIO[i], KEY_GPIO_Pin[i]) == KEY_PRESS_STATUS)  

      {  

        keyInputLowCount[i]++;  

        if(keyInputLowCount[i] > 1)  

        {  

          keyInputHighCount[i] = 0;  

        }  

        if(keyInputLowCount[i] > 100)  

        {  

          keyInputLowCount[i] = 0;  

          keyStatus[i]        = KEY_LongPress;  

          keyGetStatus[i]     = KEY_LongPress;  

          if(keyLongPressCallback[i] != NULL)  

          {  

            keyLongPressCallback[i]();  

          }  

        }  

      }  

      else  

      {  

        keyInputHighCount[i]++;  

        if(keyInputHighCount[i] > 1)  

        {  

          if((keyStatus[i] == KEY_NoPress) && (keyInputLowCount[i] > 1))  

          {  

            keyInputHighCount[i] = 0;  

            keyInputLowCount[i]  = 0;  

            keyStatus[i]         = KEY_ShortPress;  

            keyGetStatus[i]      = KEY_ShortPress;  

            if(keyShortPressCallback[i] != NULL)  

            {  

              keyShortPressCallback[i]();  

            }  

          }  

          else  

          {  

            keyInputHighCount[i] = 0;  

            keyInputLowCount[i]  = 0;  

            keyStatus[i]         = KEY_NoPress;  

          }  

        }  

      }  

    }  

  }  

}  

      main.c文件

/** 

  ****************************************************************************** 

  * @file    main.c 

  * @author  XinLi 

  * @version v1.0 

  * @date    24-October-2017 

  * @brief   Main program body. 

  ****************************************************************************** 

  * @attention 

  * 

  *

Copyright © 2017 XinLi

  * 

  * This program is free software: you can redistribute it and/or modify 

  * it under the terms of the GNU General Public License as published by 

  * the Free Software Foundation, either version 3 of the License, or 

  * (at your option) any later version. 

  * 

  * This program is distributed in the hope that it will be useful, 

  * but WITHOUT ANY WARRANTY; without even the implied warranty of 

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 

  * GNU General Public License for more details. 

  * 

  * You should have received a copy of the GNU General Public License 

  * along with this program.  If not, see . 

  * 

  ****************************************************************************** 

  */  

/* Header includes -----------------------------------------------------------*/  

#include "main.h"  

#include "KEY.h"  

/* Macro definitions ---------------------------------------------------------*/  

/* Type definitions ----------------------------------------------------------*/  

/* Variable declarations -----------------------------------------------------*/  

/* Variable definitions ------------------------------------------------------*/  

static __IO int key1ShortPressCount = 0;  

static __IO int key1LongPressCount  = 0;  

static __IO int key2ShortPressCount = 0;  

static __IO int key2LongPressCount  = 0;  

/* Function declarations -----------------------------------------------------*/  

static void key1ShortPressCallback(void);  

static void key1LongPressCallback(void);  

/* Function definitions ------------------------------------------------------*/  

/** 

  * @brief  Main program. 

  * @param  None. 

  * @return None. 

  */  

int main(void)  

{  

  KEY_Init();  

  KEY_SetShortPressCallback(KEY_Pin1, key1ShortPressCallback);  

  KEY_SetLongPressCallback(KEY_Pin1, key1LongPressCallback);  

  for(;;)  

  {  

    KEY_Status status = KEY_GetStatus(KEY_Pin2);  

    if(status != KEY_NoPress)  

    {  

      if(status == KEY_ShortPress)  

      {  

        key2ShortPressCount++;  

      }  

      else  

      {  

        key2LongPressCount++;  

      }  

    }  

  }  

}  

/** 

  * @brief  Key 1 short press callback. 

  * @param  None. 

  * @return None. 

  */  

static void key1ShortPressCallback(void)  

{  

  key1ShortPressCount++;  

}  

/** 

  * @brief  Key 1 long press callback. 

  * @param  None. 

  * @return None. 

  */  

static void key1LongPressCallback(void)  

{  

  key1LongPressCount++;  

}  

3，注意

       修改接口需要注意，按键的检测电平、使用的TIM和增减按键的个数。对应修改KEY_PRESS_STATUS宏、TIM时钟配置函数和源文件的变量定义。