da.c

a/d驱动实验与d/a驱动实验 基于清华大学的TEB-44B0实验平台

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/delay.h>            
#include <linux/wait.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>	/* get_user, copy_to_user */
#include <asm/segment.h>
//#include <asm/MC68VZ328.h>
#include <asm/arch/s3c44b0x.h>

#define DA_DEBUG

#define  my_get(a)		(*(volatile unsigned char*) (a))
#define  my_put(v, a)	(*(volatile unsigned char*) (a) = (v))

#define  DA_BASE 	0x04400000

int da_major = 70;              /* Select 0 for Dynamic adressing */

void da_convert(unsigned char dav)
{
	my_put(dav, DA_BASE);
	//udelay(20);
}

static int da_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	switch(cmd)
	{
		// begin convert	
		case 0:
		       {
			unsigned char val;
			val = *(unsigned char *)arg;
			//printk("\nval = :%x\n",val);
			da_convert(val);
			return 1;	
		       }
		default:
			return -EINVAL;
	}
	return 1;
}

/* Open-Function des Devices */
static int da_open(struct inode *inode, struct file *file)
{
       
#ifdef DA_DEBUG
	outl(inl(S3C44B0X_BANKCON2)&(~(0x7fff)), S3C44B0X_BANKCON2);
	outl(inl(S3C44B0X_BANKCON2)|(0x1480), S3C44B0X_BANKCON2);
	printk("\ndac0832 is open!\n");
#endif
 	return 0;
}

/* Close-Function des Devices */
static void da_close(struct inode *inode, struct file *file)
{
#ifdef DA_DEBUG
        outl(inl(S3C44B0X_BANKCON2)&(~(0x7fff)), S3C44B0X_BANKCON2);
	outl(inl(S3C44B0X_BANKCON2)|(0x14bc), S3C44B0X_BANKCON2);
   	printk("\ndac0832 is closed!\n");
#endif
}

struct file_operations da_fops =
{
        ioctl: da_ioctl,
	open: da_open,
        release: da_close,
};
                               
int insert_da(void)
{
	int rc;
	
	outl(inl(S3C44B0X_PCONB)|((0x01)<<7), S3C44B0X_PCONB); 
	
	rc = register_chrdev(da_major, "da", &da_fops);
	if(rc < 0)
	{
#ifdef DA_DEBUG
		printk("Panic! Could not register DA-Driver\n");
#endif
		return rc;
	};
	return 0;
}


int da_init(void)
{
	int rc;

	rc = insert_da();
	if(rc)
	{
#ifdef DA_DEBUG
		printk("Panic! DA-driver could not be loaded!\n");
#endif
	}
	else 
	{
#ifdef DA_DEBUG
		printk("DA-driver init OK\n");
#endif
	}
	return rc;
}