cpld.c

linux 485欻串口编程示例

/*
 * Copyright (C) 2004 Gexin TECH 
 *                     <[e-mail]>
 *
	 This file just for GX-ARM9-2410EP  

   Sat Feb 7 2004 Huo Ran <[e-mail]>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/interrupt.h>	/* for in_interrupt */
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/delay.h>	/* for udelay */
#include <linux/modversions.h>
#include <linux/version.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware.h>

#include "OURS_DEF.h"


#define CPLD_MAJOR	99


static int CPLD_CTL_ADDR;
static int CPLD_ID_ADDR;
static int XGPIO_IN_ADDR;
static int XGPIO_OUT_ADDR;
	

devfs_handle_t  dev_handle;     /* register handle to store device fs */
int CPLD_temp_count=0;
static long ioremap_addr;

ssize_t CPLD_read (struct file * file ,char * buf, size_t count, loff_t * f_ops)
{

	printk("s3c2410: device file-read operation!\n");	

	return count;
}	

/*=========== SimpleD  Write =======================*/
ssize_t CPLD_write (struct file * file ,const char * buf, size_t count, loff_t * f_ops)
{

	printk("s3c2410: device file-write operation!\n");		
	return count;
}	



/*=========== SimpleD Ioctl =======================*/
ssize_t CPLD_ioctl (struct inode * inode ,struct file * file,
	       	   unsigned int cmd, long data)
{
	//printk("s3c2410: device ioctl operation!\n");	
	switch (cmd)
	{
		 case READ_XGPIO_IN :
			return inw(XGPIO_IN_ADDR);
		 case READ_XGPIO_OUT :
			return inw(XGPIO_OUT_ADDR);
		 case WRITE_XGPIO_OUT :
			outw(data, XGPIO_OUT_ADDR);
			return 0;
		 case READ_CPLD_CTL :
			return inw(CPLD_CTL_ADDR);
		 case WRITE_CPLD_CTL :
			outw(data, CPLD_CTL_ADDR);
			return 0;
		 case READ_CPLD_ID :
			return inw(CPLD_ID_ADDR);
		 default :
			return 0;
	}
	
}

/*============ SimpleD device open ==============*/ 
ssize_t CPLD_open (struct inode * inode ,struct file * file)
{
	return 0;
}	

/*============ SimpleD device close =============*/
ssize_t CPLD_release (struct inode  * inode ,struct file * file)
{
	printk("s3c2410: device release operation!\n");
	return 0;
}

struct file_operations CPLD_ops ={
	
	open:		CPLD_open,
	
	read:		CPLD_read,
	
	write:		CPLD_write,
	
	ioctl:		CPLD_ioctl,
	
	release:	CPLD_release,
};


static int __init HW_CPLD_init(void)
{
    int ret = -ENODEV;
    int delay,i ;
	
	ret = devfs_register_chrdev(CPLD_MAJOR, "CPLD", &CPLD_ops);  		

	if( ret < 0 ){
		printk (" s3c2410: init_module failed with %d\n", ret);	
		return ret;
	}
	else
		{
		printk(KERN_INFO" S3c2410 CPLD register success!!!\n");
		;
		}

	dev_handle = devfs_register( NULL, "CPLD", DEVFS_FL_DEFAULT,
                        CPLD_MAJOR, 0, S_IFCHR, &CPLD_ops, NULL);

//*************************************************************************************

	//remap the address of the registers	

	CPLD_CTL_ADDR = ioremap(0x21000000,0x0f);
	CPLD_ID_ADDR = ioremap(0x22400000,0x0f);
	XGPIO_IN_ADDR = ioremap(0x21800000,0x0f);
	XGPIO_OUT_ADDR = ioremap(0x21400000,0x0f);	

	printk(" CPLD_ID is %x\n", inb(CPLD_ID_ADDR));	//read the ID of CPLD

	//!!!!!!!!!!!!!!
     

    return ret;
}


int __init s3c2410_CPLD_init(void) {
    int  ret = -ENODEV;

    ret = HW_CPLD_init();
    if (ret)
      return ret;
    return 0;
}
int init_module()
{
	s3c2410_CPLD_init();
}
void cleanup_module()
{

	devfs_unregister_chrdev(CPLD_MAJOR, "CPLD" );
        devfs_unregister( dev_handle );
}