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#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/hardware.h>
#define DEVICE_NAME "utukey"
#define KEY_TIME_DELAY (HZ/5)//200ms
#define KEY_TIME_DELAY1 (HZ/250)//4ms
#define KEYSTATUS_DOWNX 0 //刚被按下
#define KEYSTATUS_DOWN 1 //一直被按着hold
#define KEYSTATUS_UP 2 //按键抬起了
static void utu2440button_timer_callback(unsigned long data);//时间软中断定时器处理函数
static irqreturn_t utu2440_isr_kbd(int irq, void *dev_id, struct pt_regs *reg);//按键中断处理函数
static int utukey_open(struct inode *inode, struct file *filp);
static int utukey_release(struct inode *inode, struct file *filp);
void my_tasklet_func(unsigned long t);
int tasklet_time;
DECLARE_TASKLET(my_tasklet,my_tasklet_func,&tasklet_time);
static dev_t utukey_major=252;//主设备号自设定
unsigned int keynumber=6;//只是作为标记所用
struct utukey_dev_t
{
struct cdev cdev;
unsigned int keyStatus;
};
struct utukey_dev_t utukey_dev;
struct timer_list key_timer;
static const struct file_operations utukey_fops =
{
.owner = THIS_MODULE,
.open = utukey_open,
.release = utukey_release,
};
/*打开函数*/
static int utukey_open(struct inode *inode, struct file *filp)
{
filp->private_data = &utukey_dev;
printk(KERN_NOTICE "utukey opened\n");
return 0;
}
/*释放函数*/
static int utukey_release(struct inode *inode, struct file *filp)
{
printk(KERN_NOTICE "utukey released\n");
return 0;
}
/*中断服务程序*/
static irqreturn_t utu2440_isr_kbd(int irq, void *dev_id, struct pt_regs *reg)
{
// int *key = (int*)dev_id;
// printk(KERN_NOTICE "utukey interrupt key number is %d\n",*key);//传进了keynumber
printk(KERN_NOTICE "utukey interrupt key number is %d\n",keynumber);
if ( irq)
{
printk(KERN_NOTICE"bad irq %d in button\n", irq);
return IRQ_NONE;
}
disable_irq(IRQ_EINT19);//先屏蔽此中断
utukey_dev.keyStatus= KEYSTATUS_DOWNX; //表示刚被按下
key_timer.expires = jiffies + KEY_TIME_DELAY1;//通过这个来实现去抖,并判断是否一直被按下，百分之一秒
add_timer(&key_timer); //开始计时
// tasklet_schedule(&my_tasklet);
return IRQ_HANDLED;//表示处理好了 和 IRQ_NONE对应
}
/*timer 延时处理函数data参数来自于定时器结构中的data变量*/
static void utu2440button_timer_callback(unsigned long data)
{
if (s3c2410_gpio_getpin(S3C2410_GPG11) == 0)
{
if (utukey_dev.keyStatus== KEYSTATUS_DOWNX)//从中断进入
{
printk(KERN_NOTICE "utukey is down\n");
utukey_dev.keyStatus= KEYSTATUS_DOWN;//从中断进入的，证明按键已经被按下expires时间了，一直在被按着
key_timer.expires = jiffies + KEY_TIME_DELAY; //判断是否还被按着，五分之一秒
add_timer(&key_timer);
}
else //不是第一次进入定时器，表示按键一直被按着
{
printk(KERN_NOTICE "utukey is hold\n");
key_timer.expires = jiffies + KEY_TIME_DELAY;//HOLD key,每隔200MS发送一次
add_timer(&key_timer);
}
}
else
{
utukey_dev.keyStatus= KEYSTATUS_UP;
printk(KERN_NOTICE "utukey is up\n");
enable_irq(IRQ_EINT19);//按键抬起的时候，重新开中断
}
}
//中断下半部tasklet
void my_tasklet_func(unsigned long t)
{
int data=*(int*)t;
printk("tasklet is executing %d\n",data);
(*(int*)t)++;
}
//insmod
static int __init utukey_init(void)
{
int result,ret;
dev_t devno = MKDEV(utukey_major,0);
if (utukey_major)
{
result = register_chrdev_region(devno, 1, DEVICE_NAME);
/*int register_chrdev_region(dev_t first, unsigned int count, char *name)
First :要分配的设备编号范围的初始值(次设备号常设为0);
Count:连续编号范围.（被使用只是一个要请求的范围，最终只能分配给你一个号码）
Name:编号相关联的设备名称. (/proc/devices);
*/
}
else
{
result = alloc_chrdev_region(&devno, 0, 1, DEVICE_NAME);
/*Int alloc_chrdev_region(dev_t *dev,unsigned int firstminor,unsigned int count,char *name);动态分配
Firstminor : 通常为0;
*dev:存放返回的设备号;
*/
utukey_major = MAJOR(devno);
}
if (result < 0)
{
return result;
}
cdev_init(&utukey_dev.cdev,&utukey_fops);//字符设备初始化
utukey_dev.cdev.owner = THIS_MODULE;
utukey_dev.cdev.ops = &utukey_fops;
utukey_dev.keyStatus = KEYSTATUS_UP;//按键初始状态为抬起
ret = cdev_add(&utukey_dev.cdev, devno, 1);
if (ret)
{
printk(KERN_NOTICE "Error %d adding utukey",ret);
}
s3c2410_gpio_cfgpin(S3C2410_GPG11, S3C2410_GPG11_EINT19);//申请中断
set_irq_type(IRQ_EINT19, IRQT_FALLING);//设置为下降沿触发
if (ret=request_irq(IRQ_EINT19, utu2440_isr_kbd, SA_INTERRUPT, DEVICE_NAME, NULL))//注册的中断号,中断服务程序,快速中断,设备名,传递的参数
{
printk(KERN_NOTICE"request irq in button failed key is %d,return is %d\n",keynumber,ret);
return -1;
}
printk(KERN_NOTICE"request irq in button,successed\n");
/*timer结构初始化*/
key_timer.function = utu2440button_timer_callback;//timer的调用函数
key_timer.data =keynumber;
init_timer(&key_timer);
return 0;
}
//rmmod
static void __exit utukey_exit(void)
{
cdev_del(&utukey_dev.cdev);
del_timer(&key_timer);
free_irq(IRQ_EINT19,NULL);//释放irq中断void free_irq(unsigned int irq,void *dev_id); dev_id用于多个设备的中断共享
unregister_chrdev_region(MKDEV(utukey_major,0),1);
/*
释放:
Void unregist_chrdev_region(dev_t first,unsigned int count);
*/
}
MODULE_AUTHOR("lwcheng");
MODULE_LICENSE("Dual BSD/GPL");
module_init(utukey_init);
module_exit(utukey_exit)
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