adc0809.c

嵌入式下实验的新的驱动设计源代码

#include <linux/config.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/malloc.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <asm/irq.h>

#define ADC0809_IRQ_NUM		6
#define ADC0809_MAJOR		58

static DECLARE_WAIT_QUEUE_HEAD(Adc0809Wait);

void delay(int n)
{
	int i, j;

	for(i = 0; i < 1000; i++)
		for(j = 0; j < n; j++)
			;
}


static int Adc0809Close(struct inode * inode, struct file * file)
{
        MOD_DEC_USE_COUNT;
	return 0;
}

static int Adc0809Open(struct inode * inode, struct file * file)
{
        MOD_INC_USE_COUNT;

	return 0;
}

static int Adc0809Read(struct file * file, char * buf, size_t count, loff_t *ppos)
{
	char Value;
        unsigned char *kbuf=kmalloc(16, GFP_KERNEL); 
	
	*(unsigned long *)0xfc000000 = 0x0;
	Value = *(unsigned char *)0xfc000000;
	printk("ADC0809  Value = : 0x%02x\n", Value);
	delay(2000);
	*kbuf = Value;
	copy_to_user(buf, kbuf, 1); 
	kfree(kbuf);
	
	return (0);
}
/*
 * select for mouse input
 */
static unsigned int Adc0809Select(
	struct file *file, 
	struct poll_table_struct *wait)
{
	poll_wait(file, &Adc0809Wait, wait);
	return 0;
}

static int Adc0809Ioctl(
        struct inode *inode,
        struct file *file,
        unsigned int cmd,
        unsigned long arg
)
{
        switch(cmd) {
		case 1:
		{
                     return 0;
		
		}
		case 0:
		{
		        Adc0809Read(inode, file, (char *)arg, 1);	
			return 0;
		}		
        default:
                return -EINVAL;
        }
}

struct file_operations Adc0809_fops = {
	NULL,
        NULL,	
        read:	Adc0809Read,
	poll:	Adc0809Select, 	/* select */	
	open:	Adc0809Open,
	ioctl:	Adc0809Ioctl,
	release:	Adc0809Close,
        NULL,
	NULL,
			
};


int adc0809_init(void)
{
        int     rc;

        printk("adc0809............Support\n");

	*(unsigned long *)0xff000180 |= 0x00120000;
	*(unsigned long *)0xfc000000 = 0x0;

        rc = register_chrdev(ADC0809_MAJOR, "adc0809", &Adc0809_fops);
        if (rc < 0) {
                printk(KERN_WARNING "adc0809: can't get Major %d\n",
                        ADC0809_MAJOR);
                return rc; 

        }
	
	return 0;
}


void adc0809_cleanup(void)
{

  unregister_chrdev(ADC0809_MAJOR, "adc0809");


}	

module_init(adc0809_init);
module_exit(adc0809_cleanup);