按键驱动程序

request_irq
free_irq
IRQ_EINT

1.添加request_irq、free_irq以及中断处理函数

2记得去掉GPIO_BUTTON以及添加平台文件

3疑问，如何把datasheet中中断9 和IRQ_EINT（9）对应的

4疑问，app应用程序如何知道按键被按下了

通过命令： cat /proc/interrupts查看中断

#include <linux/init.h>
#include <linux/module.h>

#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/device.h>

/*Linux中申请GPIO的头文件*/
#include <linux/gpio.h>
/*三星平台的GPIO配置函数头文件*/
/*三星平台EXYNOS系列平台，GPIO配置参数宏定义头文件*/
#include <plat/gpio-cfg.h>
/*三星平台4412平台，GPIO宏定义头文件*/
#include <mach/gpio-exynos4.h>
#include <linux/platform_device.h>

#include <linux/miscdevice.h>
#include <linux/irq.h>
#include <linux/interrupt.h>

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("kerwin");


#define DRIVER_NAME   "irq_key"
#define DEVICE_NAME  "key_irq_device"


#define LED EXYNOS4_GPL2(0)
unsigned int maj=0,min=0;
dev_t dev_num;


int leds_open(struct inode *inode,struct file *filp)
{
    
    return 0;
}

int leds_release(struct inode *inode,struct file *filp)
{

    return 0;
}



long leds_ioctl(struct file *filp,unsigned int cmd,unsigned long arg)
{



    return 0;
}

static struct file_operations led_ops = {
    .owner  = THIS_MODULE,
    .open   = leds_open,
    .release= leds_release,
    .unlocked_ioctl     = leds_ioctl,
};


struct miscdevice  m_misc={
    .minor=MISC_DYNAMIC_MINOR,
    .name =DRIVER_NAME,
    .fops=&led_ops,

};

irqreturn_t key_irq_handler_t (int irq, void *dev_id)
{
    
    printk(KERN_EMERG"press:%d\n",irq); 
        return IRQ_HANDLED;
}

int key_probe(struct platform_device *pd)
{
    misc_register(&m_misc);
    if(request_irq(IRQ_EINT(9),key_irq_handler_t,IRQ_TYPE_EDGE_FALLING,"key_irq",pd)<0)
    {
        printk(KERN_EMERG"request_irq err1\n");
    }else
    {
        printk(KERN_EMERG"request_irq success1\n");
    }
    return 0;
}
int key_remove(struct platform_device *pd)
{
    misc_deregister(&m_misc);
    free_irq(IRQ_EINT(9),pd);
    return 0;
}
void key_shutdown(struct platform_device *pd)
{
    

}
int key_suspend(struct platform_device *pd, pm_message_t state)
{
    
    return 0;
}
int key_resume(struct platform_device *pd)
{
    
    return 0;
}
static struct platform_driver key_driver = {
    .driver = {
        .name = DRIVER_NAME,
        .owner = THIS_MODULE,
    },
    .probe=key_probe,
    .remove=key_remove,
    .shutdown=key_shutdown,
    .suspend=key_suspend,
    .resume=key_resume,

    
};
int irq_key_init(void)
{
    
    int ret;
    printk(KERN_EMERG"module_init call \n");

    platform_driver_register(&key_driver);
    return 0;
}


void irq_key_exit(void)
{
     printk(KERN_EMERG"module_exit call \n");
       platform_driver_unregister(&key_driver);
     
    
}

module_init(irq_key_init);
module_exit(irq_key_exit);