中断方式按键驱动.doc

中断方式按键驱动

实验器材:ok6410开发板
RedHat5.0
实验目的:利用中断方式来测试按键驱动
实验原理:

从上图可以得出:
<1>当按键没有按下时,为高电平;当按下时,为低电平
<2>S[2-7]按键分别对应的是外部中断XEINT[0-5]

驱动程序:
#include<plat/regs-gpio.h>
#include<plat/gpio-bank-n.h>
#include<linux/device.h>
#include<linux/kernel.h>
#include<linux/module.h>
#include<linux/init.h>
#include<linux/fs.h>
#include<linux/errno.h>
#include<linux/poll.h>
#include<linux/interrupt.h>
#include<linux/irq.h>
#include<asm/irq.h>
#include<asm/io.h>
#include<mach/hardware.h>
#include<linux/miscdevice.h>

#defineGPNCON0x7F008830
#defineGPNDAT0x7F008834

volatileunsignedlong*s3c6410_GPNCON;
volatileunsignedlong*s3c6410_GPNDAT;

staticstructclass*mysecond_key_class;
staticstructdevice*mysecond_key_class_dev;

staticDECLARE_WAIT_QUEUE_HEAD(key_waitq);//定义一个等待队列头

/*中断事件标志，中断服务程序将它置１，ｒｅａｄ函数将它置０ */
staticvolatileintev_press=0;

/*键值:按下时,0x01,0x02,0x03,0x04,0x05,0x06*/
/*键值:松开时,0x81,0x82,0x83,0x84,0x85,0x86*/

staticunsignedintkeyvals;

structmysecond_key
{
unsignedintirq_no;//中断号
unsignedintkey_val;//键值
unsignedintnum;//按键数
char*name;//按键名字
};

staticstructmysecond_keysecond_keys[6]=
{
{IRQ_EINT(0),0x01,0,"KEY1"},
{IRQ_EINT(1),0x02,1,"KEY2"},
{IRQ_EINT(2),0x03,2,"KEY3"},
{IRQ_EINT(3),0x04,3,"KEY4"},
{IRQ_EINT(4),0x05,4,"KEY5"},
{IRQ_EINT(5),0x06,5,"KEY6"},
};

staticirqreturn_tmykey_handle(intirq,void*dev_id)
{

intnum;
unsignedinttmp;
unsignedintpinval;

structmysecond_key*pindesc=(structmysecond_key*)dev_id;

num=pindesc->num;
tmp=readl(S3C64XX_GPNDAT);//读出GPNDAT的值
pinval=(tmp&(1<<num));

if(pinval)//松开
{
keyvals=pindesc->key_val|0x80;
}
else//按下
{
keyvals=pindesc->key_val;
}

ev_press=1;//将按键标识符置1
wake_up_interruptible(&key_waitq);//唤醒睡眠

returnIRQ_RETVAL(IRQ_HANDLED);
}

staticintmysecond_key_open(structinode*inode,structfile*file)
{
/*配置GPN[0-5]为中断引脚*/
inti=0;
interr;

for(i=0;i<sizeof(second_keys)/sizeof(second_keys[0]);i++)
{
err=request_irq(second_keys[i].irq_no,mykey_handle,IRQ_TYPE_EDGE_BOTH,
second_k