#include <linux/init.h>

 #include <linux/module.h>

 #include <linux/input.h>

 #include <linux/irq.h>

 #include <linux/interrupt.h>

 #include <asm/gpio.h>

 #include <plat/gpio-cfg.h>

 //定义按键硬件私有数据结构

 struct btn_resource {

     char *name; //名称

     int irq;    //中断号

     int gpio;   //GPIO编号

     int code;   //键值

 };

 //初始化开发板按键信息

 static struct btn_resource btn_info[] = {

     [] = {

         .name = "KEY_L",

         .irq = IRQ_EINT(),

         .gpio = S5PV210_GPH0(),

         .code = KEY_L

     },

     [] = {

         .name = "KEY_S",

         .irq = IRQ_EINT(),

         .gpio = S5PV210_GPH0(),

         .code = KEY_S

     },

     [] = {

         .name = "KEY_ENTER",

         .irq = IRQ_EINT(),

         .gpio = S5PV210_GPH0(),

         .code = KEY_ENTER

     },

 };

 //定义input_dev指针

 static struct input_dev *btn_dev;

 //分配定时器

 static struct timer_list btn_timer;

 static struct btn_resource *pdata; 

 //定时器的处理函数

 static void btn_timer_func(unsigned long data)

 {

     unsigned int pinstate;

     //2.获取按键的状态

     pinstate = gpio_get_value(pdata->gpio);

     //3.上报按键信息给核心层然后唤醒休眠的进程

     if (pinstate == ) { //松开

         //EV_KEY:上报按键类事件

         //pdata->code:具体键值

         //0:松开

         input_event(btn_dev, EV_KEY, pdata->code, );

         input_sync(btn_dev); //上报同步类事件

     } else {    //按下

         //EV_KEY:上报按键类事件

         //pdata->code:具体键值

         //1:按下

         input_event(btn_dev, EV_KEY, pdata->code, );

         input_sync(btn_dev);//上报同步类事件

     }

 }

 //中断处理函数

 static irqreturn_t button_isr(int irq, void *dev_id)

 {

     //1.获取按键对应的数据项

     pdata = (struct btn_resource *)dev_id;

     //2.启动定时器，设置定时器的超时时间为10ms

     mod_timer(&btn_timer, jiffies + msecs_to_jiffies());

     return IRQ_HANDLED;

 }

 static int btn_init(void)

 {

     int i;

     //1.分配input_dev

     btn_dev = input_allocate_device();

     //2.初始化input_dev

     btn_dev->name = "wf_button";

     //2.1设置上报按键类事件

     set_bit(EV_KEY, btn_dev->evbit);

     //2.2设置上报重复类事件

     set_bit(EV_REP, btn_dev->evbit);

     //2.3设置上报按键类事件中的哪些键值

     for(i = ; i < ARRAY_SIZE(btn_info); i++)

             set_bit(btn_info[i].code, btn_dev->keybit);

     //3.注册input_dev

     input_register_device(btn_dev);

     //4.申请GPIO资源

     //5.注册中断处理函数

     for (i = ; i < ARRAY_SIZE(btn_info); i++) {

         gpio_request(btn_info[i].gpio, btn_info[i].name);

         request_irq(btn_info[i].irq, button_isr/*中断处理函数*/,

                 IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,/*下降沿和上升沿触发*/

                 btn_info[i].name, &btn_info[i]/*给中断处理函数传递的参数*/);

     }

     //6.初始化定时器 处理按键的毛刺

     init_timer(&btn_timer);

     //6.1指定定时器的处理函数

     btn_timer.function = btn_timer_func;

     add_timer(&btn_timer);//将定时器添加到内核中

     return ;

 }

 static void btn_exit(void)

 {

     int i;

     //1.释放中断，释放GPIO资源

     for (i = ; i < ARRAY_SIZE(btn_info); i++) {

         gpio_free(btn_info[i].gpio);

         free_irq(btn_info[i].irq, &btn_info[i]);

     }

     //2.卸载input_dev

     input_unregister_device(btn_dev);

     //3.释放input_dev内存

     input_free_device(btn_dev);

     //4.删除定时器

     del_timer(&btn_timer);

 }

 module_init(btn_init);

 module_exit(btn_exit);

 MODULE_LICENSE("GPL");

 #include <stdio.h>

 #include <sys/types.h>

 #include <sys/stat.h>

 #include <fcntl.h>

 #include <linux/input.h> //input_event,标准键值等

 int main(int argc, char *argv[])

 {

     int fd;

     struct input_event button;

     fd = open(argv[], O_RDWR); //./btn_test /dev/input/event3

     if (fd < ) {

         printf("open button failed.\n");

         return -;

     }

     while() {

         read(fd, &button, sizeof(button));

         printf("type = %#x, code = %#x, value = %#x\n",

                     button.type, button.code, button.value);

     }

     close(fd);

     return ;

 }