irqtest_kernel.c

用gpio9作中断

/*This irqtest device is used to test the interrupt using gpio9 as the interrupt source and 
using the interrupt to light gpio10.*/

#include<linux/module.h>
#include<linux/config.h>
#include<linux/kernel.h>
#include<linux/init.h>
#include<asm/uaccess.h>
#include<asm/mach-au1x00/au1000.h>
#include<asm/io.h>
#include<linux/types.h>
#include<linux/miscdevice.h>
#include<asm/ioctl.h>
#include<linux/fs.h>
#include<linux/stat.h>
#include<linux/sched.h>
#include<linux/interrupt.h>
#include<linux/mm.h>

#define DEBUG

#ifdef DEBUG
# define PRITNTK(format,args...) printk(KERN_DEBUG "irqtest:"format,##args)
#else 
# define PRITNTK(format,args...) 
#endif

#define IRQTEST_MINOR	137 
#define IRQTEST_IS_OPEN 0x1	
static spinlock_t irqtest_lock;             //spinlock_t变量名
static unsigned long irqtest_status = 0;

#define IRQTEST_IOC_MAGIC 'F'
#define START_IRQTEST               _IO(IRQTEST_IOC_MAGIC,0)
#define STOP_IRQTEST                _IO(IRQTEST_IOC_MAGIC,1)

void irqtest_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{  PRINTK("------irqtest_interrupt------");
   int i;
   for(i=1;i<=10;i++)
   	{
    au_writel(0x00000400, SYS_OUTPUTSET);
	mdelay(500);
	au_writel(0x00000400, SYS_OUTPUTCLR);
	mdelay(500);
   	}
}

static int irqtest_open(struct inode *inode, struct file *filp)    //static定义内部函数
{   
	PRINTK("irqtest_open\n");
	spin_lock_irq(&irqtest_lock);
	if (irqtest_status & IRQTEST_IS_OPEN)         // if(0)
	{
	spin_unlock_irq(&irqtest_lock);
	return -EBUSY;
	}

	irqtest_status |= IRQTEST_IS_OPEN;           //gpio17_lcd_status=1
	spin_unlock_irq(&irqtest_lock);
	return 0;
}
static int irqtest_release(struct inode *inode, struct file *filp)
{
    PRINTK("------irqtest_release------\n");
	spin_lock_irq(&irqtest_lock);
	irqtest_status &= ~IRQTEST_IS_OPEN;           //gpio17_lcd_status=0
	spin_unlock_irq(&irqtest_lock);
	return 0;
}

static int irqtest_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{   PRITNTK("------irqtest_ioctl------");
	int result=0;
	switch (cmd)          //switch语句中的return和break都可跳出
	{
	case START_IRQTEST:
		result=request_irq(AU1000_GPIO_9,irqtest_interrupt,SA_INTERRUPT,"irqtest",NULL);
		if(result)
		{
		 printk(KERN_INFO "can't get request irq AU1000_GPIO_9\n");
	    }
	break;
	case STOP_IRQTEST: 
		free_irq(AU1000_GPIO_9,NULL);
	break;	
	
	default:
	return -EINVAL;
	}
return 0;
}

static struct file_operations irqtest_fops=		
{
 	    .owner=  THIS_MODULE,		
        .ioctl=  irqtest_ioctl,             
        .open=   irqtest_open,             
        .release=  irqtest_release,	         
};
	
static struct miscdevice irqtest_dev = 	
{
	IRQTEST_MINOR,
	"irqtest_dev",
	&irqtest_fops,
};

static int __init irqtest_init()                
{ 	PRINTK("------irqtest_init()------\n");
	u32 pin_func;
	pin_func = au_readl(SYS_PINFUNC) & (~((u32)(1<<7)));	//Configure pins GPIO[9,10,13,14] as GPIO
	au_writel(pin_func, SYS_PINFUNC);
	au_writel(0x00000200, SYS_PININPUTEN); 
	misc_register(&irqtest_dev);
}

static void __exit au1200_gpio9_lcd_exit(void)
{   
	PRINTK("------irq_exit------\n");			
	misc_deregister(&irq_dev);
}


MODULE_AUTHOR("kwj");
MODULE_LICENSE("GPL");
module_init(irqtest_init);
module_exit(irttest_exit);