s3c2440使用中断方式读取按键终端

傷城~ 2022-08-21 14:39 56阅读 0赞

/\*功能:使用中断方式读取按键终端  
2016年5月4日22:54:53  
\*/  
\#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 <linux/irq.h>  
\#include <asm/io.h>  
\#include <asm/arch/regs-gpio.h>  
\#include <asm/hardware.h>  
  
  
  
  
static struct class \*thirddrv\_class;  
static struct class\_device \*thirddrv\_class\_devs\[4\];  
  
  
volatile unsigned long \* gpfcon;  
volatile unsigned long \* gpfdat;  
  
  
volatile unsigned long \* gpgcon;  
volatile unsigned long \* gpgdat;  
  
  
  
  
//serial21285\_tx\_chars  
  
  
  
  
static irqreturn\_t buttons\_irq(int irq, void \*dev\_id)  
\{  
printk("irq = %d\\n",irq);  
  
  
return IRQ\_HANDLED;  
\}  
  
  
static int third\_drv\_open(struct inode \* inode, struct file \* file)  
\{  
/\*配置GPF0,2  位输入引脚 \*/  
/\*配置GPG3,11为输入引脚 \*/  
/\*  
IRQ\_EINT0是在irqs.h中定义的  
IRQT\_BOTHEDGE是在s3c\_irqext\_type函数中找到，在irq.h中定义  
  
  
  
  
\*/  
//向内核注册中断处理函数  
request\_irq(IRQ\_EINT0,buttons\_irq,IRQT\_BOTHEDGE,"s2",1);  
request\_irq(IRQ\_EINT2,buttons\_irq,IRQT\_BOTHEDGE,"s3",1);  
request\_irq(IRQ\_EINT11,buttons\_irq,IRQT\_BOTHEDGE,"s4",1);  
request\_irq(IRQ\_EINT19,buttons\_irq,IRQT\_BOTHEDGE,"s5",1);  
  
  
  
  
  
return 0;  
\}  
  
  
  
  
  
  
  
  
  
  
/\*函数的参数是用户空间的函数的参数\*/  
static ssize\_t third\_drv\_read(struct file \*file, const \_\_user char \*buffer,size\_t count, loff\_t \*ppos)  
\{  
if(count != sizeof(key\_vals)  
return -EINVAL;//返回错误值  
  
/\*返回四个引脚的电平状态\*/  
unsigned char key\_vals\[4\];  
int regval;  
/\*读GPF0,2引脚\*/  
regval = \*gpfdat;  
key\_vals\[0\] = (regval & (1<<0)) ? 1 : 0;  
key\_vals\[1\] = (regval & (1<<2)) ? 1 : 0;  
  
  
/\*读GPG3,11引脚\*/  
regval = \*gpgdat;  
key\_vals\[2\] = (regval & (1<<3)) ? 1 : 0;  
key\_vals\[3\] = (regval & (1<<11)) ? 1 : 0;  
  
  
/\*用户空间和内核空间之间是通过参数来传递的,  
static ssize\_t third\_drv\_read(struct file \*file, const \_\_user char \*buffer,size\_t count, loff\_t \*ppos)  
函数的参数是用户空间的，内核空间的参数是我们自己定义的，他们之间传递参数都是用指针来实现的  
\*/  
copy\_to\_user(buffer ,key\_vals,sizeof(key\_vals));  
return sizeof(key\_vals);  
  
  
  
  
  
\}  
  
  
  
  
/\*入口函数\*/  
int major;  
static int third\_drv\_init (void)  
\{  
major = register\_chrdev(0,"secod\_drv",&third\_drv\_fops);  
  
  
thirddrv\_class = class\_create(THIS\_MODULE, "secod\_drv");//创建个类  
  
thirddrv\_class\_devs = class\_device\_create(thirddrv\_class, NULL, MKDEV(major, 0), NULL, "buttons"); /\* /dev/buttons \*/  
  
  
  
gpfcon = (volatile unsigned long \*)ioremap(0x56000050,16);  
gpfdat = gpfcon + 1;//指向0x56000054  
  
  
gpgcon = (volatile unsigned long \*)ioremap(0x56000060,16);  
gpgdat = gpgcon + 1;//指向0x56000064  
  
  
return 0;  
  
  
\}  
  
  
  
  
  
  
/\*出口函数\*/  
int major;  
static int third\_drv\_exit (void)  
\{  
unregister\_chrdev(major,"secod\_drv");  
  
class\_device\_unregister(thirddrv\_class\_devs);  
   
class\_destroy(thirddrv\_class);  
  
  
  
iounmap(gpfcon);   
iounmap(gpgcon);  
return 0;  
  
  
\}  
  
  
int third\_drv\_close (struct inode \* inode, struct file \* file)  
\{  
free\_irq(IRQ\_EINT0,1);  
free\_irq(IRQ\_EINT2,1);  
free\_irq(IRQ\_EINT11,1);  
free\_irq(IRQ\_EINT19,1);  
return 0;  
  
  
\}  
  
  
  
  
static struct file\_operations third\_drv\_fops = \{  
    .owner  =   THIS\_MODULE,    /\* 这是一个宏，推向编译模块时自动创建的\_\_this\_module变量 \*/  
    .open   =   third\_drv\_open,    //表示将first\_drv\_open函数的地址赋给file\_operations结构体中open函数，  
.read = third\_drv\_read, //以后执行 first\_drv\_open函数时会自动调用file\_operations结构体中的open函数  
.close =    third\_drv\_close,//关闭设备的时候，释放open函数中配置的irq  
\};  
  
  
/\*修饰\*/  
modules\_init(third\_drv\_init);  
modules\_exit(third\_drv\_exit);  
  
  
MODULE\_LICENSE("GPL");