WhyCan Forum(哇酷开发者社区)

#include <linux/major.h>
#include <linux/slab.h>
#include <asm/fb.h>
#include <linux/uaccess.h> 


#define DEVICE "myKey"
#define PB3_GPIO 35 //PB3 35=32*1+3
#define GPIO_INT_NAME  "PB3_int"

#define GPIO_HIGH gpio_get_value(PB3_GPIO)
#define GPIO_LOW (gpio_get_value(PB3_GPIO) == 0)
short int irq_any_gpio    = 0;
int count =0;

struct class *key_dev_class = NULL;
struct class_device *key_dev_class_dev = NULL;



enum { falling, rising } type; 
static irqreturn_t r_irq_handler(int irq, void *dev_id)
 {
    count++;
    printk(KERN_DEBUG "interrupt received (irq: %d)\n", irq);
	if (irq == gpio_to_irq(PB3_GPIO)) 
    {

        type = GPIO_LOW ? falling : rising;

        if(type == falling)
        {
            printk("gpio pin is low\n");    
        }
        else
            printk("gpio pin is high\n");

    }

    return IRQ_HANDLED;
}
int led_open(struct inode *inode, struct file *filp)
{
   int ret;
	int err;
   if (gpio_request(PB3_GPIO, GPIO_INT_NAME )) 
   {
      printk("PB3_GPIO request failure: %s\n", GPIO_INT_NAME );
      return -1;
   }

   if ( (irq_any_gpio = gpio_to_irq(PB3_GPIO)) < 0 ) {
      printk("PB3_GPIO to IRQ mapping failure %s\n",GPIO_INT_NAME );
      return -1;
   }

   printk(KERN_NOTICE "Mapped int %d\n", irq_any_gpio);
 
   if (request_irq(irq_any_gpio,(irq_handler_t ) r_irq_handler, IRQF_TRIGGER_FALLING , GPIO_INT_NAME, NULL)) 
   {
      printk("Irq Request failure\n");
      return -1;
   }
	printk("led_open == ok\n");
 	return 0;
} 
static int key_dev_read(struct file *filp, char __user *buff, size_t count, loff_t *offp)
{
	unsigned long err ;
	printk("Enter key_dev_read == %d\n",type);
	buff[0] = type;
	
	//err = copy_to_user(buff,&type,1,1);
	printk("copy_to_user == %d\n",buff[0]);
	//return err ? -EFAULT : 0;
	return 0;
}

int r_int_release(struct inode *inode, struct 
 free_irq(gpio_to_irq(PB3_GPIO), NULL);
   gpio_free(PB3_GPIO);
   return 0;
}

struct file_operations led_fops ={
		.owner		= THIS_MODULE,
		.open		= led_open,
		.release	= r_int_release,
		.read		= key_dev_read
};

struct miscdevice led_dev ={
		.minor		= MISC_DYNAMIC_MINOR,//minor是这个混杂设备的次设备号，由系统自动配置，
		.name		= DEVICE,			//.name 设备名
		.fops		= &led_fops
};

void r_int_config(void) 
{

   int ret;
   ret = misc_register(&led_dev);//注册驱动程序时采用misc_register函数注册，此函数中会自动创建设备节点，即设备文件
   if(ret)
   {		
			printk("error: cannot register misc.\n");
			return ret;
   }
   return 0;
}

static void __exit Key_exit(void)
{
		misc_deregister(&led_dev);//杂项设备的注销过程，其实就是注册过程的逆向过程
		printk("mise-deregister %s\n", DEVICE);
}

int init_module(void)
{
        printk("<1>Hello World\n"); 
    r_int_config();
        return 0;
}

module_init(init_module);    // Do some better naming
module_exit(Key_exit);

MODULE_AUTHOR("ysc201995");             	// 驱动程序的作者
MODULE_DESCRIPTION("Key")