#include<linux/module.h>
#include<linux/init.h>
#include<linux/miscdevice.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/io.h>
#define GPNCON 0x7f008830
irqreturn_t key_int(int irq,void *dev_id)
{
//检测是否发生了中断
//清除已经发生的中断
//打印按键值
printk("key down!\n");
return 0;
}
void key_hw_init(void)
{
unsigned int *gpio_config;
unsigned short data;
gpio_config=ioremap(GPNCON,4); //转换成虚拟地址
data=readw(gpio_config);
data &= ~0b11;
data |= 0b10;
writew(data,gpio_config);
}
int key_open(struct inode *node,struct file *filp)
{
return 0;
}
struct file_operations key_fops =
{
.open = key_open,
};
struct miscdevice key_miscdev =
{
.minor = 200,
.name = "key",
.fops = &key_fops,
};
static int button_init(void)
{
misc_register(&key_miscdev);
//按键初始化
key_hw_init();
//注册中断处理程序
request_irq(IRQ_EINT0_3,key_int,IRQF_TRIGGER_FALLING,"key",0); //IRQF_TRIGGER_FALLING按下时产生中断
return 0;
}
static void button_exit(void)
{
misc_deregister(&key_miscdev);
//注销中断
free_irq(IRQ_EINT0_3,0);
}
module_init(button_init);
module_exit(button_exit);
