内核版本：linux2.6.22.6 硬件平台：JZ2440
驱动源码 block_ipc_poll_key_int_drv.c ：
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/arch/regs-gpio.h>
#include <asm/hardware.h>
#include <linux/poll.h> static struct class *key_int_class;
static struct class_device *key_int_class_device; volatile unsigned long *GPFCON=NULL;
volatile unsigned long *GPFDAT=NULL;
volatile unsigned long *GPGCON=NULL;
volatile unsigned long *GPGDAT=NULL; static struct fasync_struct fasync_key; //定义一个 fsync 结构体 struct pin_desc
{
unsigned int pin;
unsigned int key_val;
}; static unsigned char key_val;
static volatile int ev_press=; static struct pin_desc pin_desc_array[]={{S3C2410_GPF0,0x01},{S3C2410_GPF2,0X02},{S3C2410_GPG3,0x03},{S3C2410_GPG11,0x04}}; static DECLARE_WAIT_QUEUE_HEAD(wait_key); //定义一个信号量
static DECLARE_MUTEX(key_lock); static irqreturn_t key_handler(int irq, void *dev_id)
{
struct pin_desc *pindesc = (struct pin_desc *)dev_id;
unsigned int pinval=; pinval = s3c2410_gpio_getpin(pindesc->pin); if(pinval) key_val = 0x08 | pindesc->key_val;
else key_val = pindesc->key_val; kill_fasync(&fasync_key,SIGIO,POLL_IN); //发生中断后 向结构体里的PID进程 发送 SIGIO 信号 wake_up_interruptible(&wait_key);
ev_press = ;
return IRQ_RETVAL(IRQ_HANDLED);
} static int key_drv_open(struct inode *inode,struct file *file)
{ if(file->f_flags & O_NONBLOCK)
{
if(down_trylock(&key_lock))
return -EBUSY;
}
else
{
//获取信号量
down(&key_lock);
} request_irq(IRQ_EINT0, key_handler,IRQT_BOTHEDGE,"KEY1", &pin_desc_array[]);
request_irq(IRQ_EINT2, key_handler,IRQT_BOTHEDGE,"KEY2", &pin_desc_array[]);
request_irq(IRQ_EINT11, key_handler,IRQT_BOTHEDGE,"KEY3",&pin_desc_array[]);
request_irq(IRQ_EINT19, key_handler,IRQT_BOTHEDGE,"KEY4",&pin_desc_array[]); return ;
} ssize_t key_drv_read(struct file *file,const char __user *buf,size_t count,loff_t *ppos)
{
if (count != )
return -EINVAL; if(file->f_flags & O_NONLOCK)
{
if(!ev_press)
return -EAGAIN;
}
else
{
wait_event_interruptible(wait_key,ev_press);
}
ev_press=;
copy_to_user(buf,&key_val,); return ;
} static int key_drv_close(struct inode *inode,struct file *file)
{
free_irq(IRQ_EINT0, &pin_desc_array[]);
free_irq(IRQ_EINT2, &pin_desc_array[]);
free_irq(IRQ_EINT11, &pin_desc_array[]);
free_irq(IRQ_EINT19, &pin_desc_array[]); //释放信号量
up(&key_lock);
return ;
} unsigned int key_drv_poll(struct file *file,poll_table *wait)
{
unsigned int mask=;
poll_wait(file,&wait_key,wait); if(ev_press) mask |= POLLIN | POLLRDNORM; return mask;
} static int init_fasync(int fd,struct file *file,int on) // 初始化FASYNC 结构体
{
printk("init fasync struct...\n");
return fasync_helper(fd,file,on,&fasync_key);
} static struct file_operations key_drv_mode=
{
.owner = THIS_MODULE,
.open = key_drv_open,
.read = key_drv_read,
.release = key_drv_close,
.poll = key_drv_poll,
.fasync = init_fasync,
}; int major=;
static int key_drv_init(void)
{
major = register_chrdev(,"block_ipc_poll_key",&key_drv_mode); // /proc/devices key_int_class = class_create(THIS_MODULE,"key_int_class");
key_int_class_device = class_device_create(key_int_class,NULL,MKDEV(major,),NULL,"block_ipc_poll_key"); // /dev/key_int_drv GPFCON=(volatile unsigned long *)ioremap(0x56000050,);
GPFDAT=GPFCON+;
GPGCON=(volatile unsigned long *)ioremap(0x56000060,);
GPGDAT=GPGCON+; return ;
} static void key_drv_exit(void)
{
unregister_chrdev(major,"block_ipc_poll_key"); class_device_unregister(key_int_class_device);
class_destroy(key_int_class);
iounmap(GPFCON);
iounmap(GPGCON); } module_init(key_drv_init);
module_exit(key_drv_exit);
MODULE_LICENSE("GPL");
测试应用程序 block_ipc_poll_key_int_drv_test.c ：
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h> int fd=; int main(int argc,char **argv)
{
unsigned char key_val=;
int oflags=; int ret;
struct pollfd fds[]; fd = open("/dev/block_ipc_poll_key",O_RDWR | O_NONBLOCK); if(fd <)
{
printf("error: can't open device :/dev/block_ipc_poll_key\n");
return -;
} while()
{
ret = read(fd,&key_val,);
printf("key_val= %d ,return= %d\n",key_val,ret);
sleep();
}
return ;
}
Makefile文件:
KER_DIR=/work/systems/kernel/linux-/linux-2.6.22.6 all:
make -C $(KER_DIR) M=`pwd` modules clean:
make -C $(KER_DIR) M=`pwd` modules clean
rm -fr moudles.order obj-m +=signal_ipc_poll_key_int_drv.o