#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/device.h>//新版内核
#include <linux/gpio.h>
#include <plat/gpio-cfg.h>
static struct class *key_irq_class;
static struct class_device*key_class_irq;
volatile unsigned long *gpncon=NULL;
volatile unsigned long *gpndat=NULL;
static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
/* 中断事件标志, 中断服务程序将它置1，third_drv_read将它清0 */
static volatile int ev_press = 0;
struct key_desc{
unsigned int pin;
unsigned int key_val;
};
/*键值:按下时，0x01,0x02,0x03,0x04,0x05,0x06*/
/*键值:松开时，0x81,0x82,0x83,0x84,0x85,0x86*/
static unsigned char key_num;
struct key_desc keys_desc[6]={
{1,0x01},
{2,0x02},
{3,0x03},
{4,0x04},
{5,0x05},
{6,0x06},
};
static irqreturn_t key_irq(int irq, void *dev_id)
{
struct key_desc *pin=(struct key_desc*)dev_id;
unsigned int pinval;
pinval=gpio_get_value(S3C64XX_GPN(pin->pin));
if(pinval)
{
key_num=0x80|pin->key_val;
}
else
{
key_num=pin->key_val;
}
//printk("*********************");
//printk("key_num= %x\n",key_num);
//printk("*********************");
//ev_press=1;/*表示中断发生了*/
wake_up_interruptible(&button_waitq);/*唤醒休眠的进程*/
return IRQ_HANDLED;
}
static int key_drv_open(struct inode * inode, struct file * file)
{
request_irq(IRQ_EINT(1),key_irq,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING,"S1",&keys_desc[0]);
request_irq(IRQ_EINT(2),key_irq,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING,"S2",&keys_desc[1]);
request_irq(IRQ_EINT(3),key_irq,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING,"S3",&keys_desc[2]);
request_irq(IRQ_EINT(4),key_irq,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING,"S4",&keys_desc[3]);
request_irq(IRQ_EINT(5),key_irq,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING,"S5",&keys_desc[4]);
request_irq(IRQ_EINT(6),key_irq,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING,"S6",&keys_desc[5]);
return 0;
}
static ssize_t key_drv_write(struct inode * file, const char __user *buf, size_t count, loff_t *ppos)
{
return 0;
}
ssize_t key_drv_read (struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
//返回四个引脚的电平
if(size != 1)
return -EINVAL;
/*如果没有按键动作发生就休眠*/
wait_event_interruptible(button_waitq, ev_press);
/*如果有按键动作，返回键值*/
copy_to_user(buf,&key_num,1);
ev_press=0;
return 1;
}
int key_drv_release(struct inode * inode, struct file * file)
{
free_irq(IRQ_EINT(1),&keys_desc[0]);
free_irq(IRQ_EINT(2),&keys_desc[1]);
free_irq(IRQ_EINT(3),&keys_desc[2]);
free_irq(IRQ_EINT(4),&keys_desc[3]);
free_irq(IRQ_EINT(5),&keys_desc[4]);
free_irq(IRQ_EINT(6),&keys_desc[5]);
return 0;
}
static struct file_operations key_drv_openration ={
.owner = THIS_MODULE,
.open = key_drv_open,
.write =key_drv_write,
.read=key_drv_read,
.release=key_drv_release,
};
int major;
static int key_drv_init(void)
{
major=register_chrdev(0,"key_irq",&key_drv_openration);
key_irq_class = class_create(THIS_MODULE, "key_irq");
//自动创建设备节点
/* 新版的内核不能用class_device_create 要用device_create*/
key_class_irq = device_create(key_irq_class, NULL, MKDEV(major, 0), NULL, "key"); /* /dev/xyz */
gpncon = (volatile unsigned long*)ioremap(0x7F008830,16);
gpndat=gpncon+1;//指针的操作是按照指针指向的长度为单位?
/*本例中使用的是unsigned long类型刚好是4个字节*/
return 0;
}
static void key_drv_exit(void)
{
unregister_chrdev(major,"key_irq");
device_unregister(key_class_irq);
class_destroy(key_irq_class);
iounmap(gpncon);
return 0;
}
module_init(key_drv_init);
module_exit(key_drv_exit);
MODULE_LICENSE("GPL");
测试程序：
#include<sys/types.h>测试结果：
#include<sys/stat.h>
#include<fcntl.h>
#include<stdio.h>
int main(int argc,char **argv)
{
int fd;
unsigned char key_val;
int cnt;
fd=open("/dev/key",O_RDWR);
if(fd < 0)
{
printf("can not open!!!\n");
return 0;
}
while(1)
{
read(fd,&key_val,1);
printf("key_val = 0x%x\n", key_val);
}
return 0;
}
[root@Pillar /driver/key/key_IRQ]#./main &
[root@Pillar /driver/key/key_IRQ]#*********************key_num= 81
*********************key_val = 0x81
*********************key_num= 82
*********************key_val = 0x82
*********************key_num= 3
******************************************key_num= 3
******************************************key_num= 83
*********************key_val = 0x3