eepromdriver.c

eeprom驱动

#ifndef __KERNEL__
#define __KERNEL__
#endif

#ifndef MODULE
#define MODULE
#endif


#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <asm/irq.h>   //disable && enable irq
#include <asm/uaccess.h>//copy_from_user | to_user
#include <linux/ioctl.h>

#include <linux/fs.h>       /* everything... */
#include <asm/io.h>
#include <linux/ioport.h>//ioremap
#include <linux/sched.h>//wait_queue
#include <linux/wait.h>

#include <linux/mm.h>
#include <linux/slab.h> //kmalloc
#include <linux/interrupt.h>

#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/time.h>
#define DRIVER_VERSION "v1.0"

MODULE_LICENSE("Dual BSD/GPL");

#define INT8U	unsigned char
#define INT32U	unsigned int
#define INT32	signed int

#define SMBUS_BASE       0x56fffff0

volatile unsigned char *smbase_addr = NULL;

#define SMBus_CLH		(*((volatile INT8U *) smbase_addr+1))
#define SMBus_CLL		(*((volatile INT8U *) smbase_addr))
#define SMBus_CON		(*((volatile INT8U *) smbase_addr+2))
#define SMBus_CMD		(*((volatile INT8U *) smbase_addr+4))
#define SMBus_TXR		(*((volatile INT8U *) smbase_addr+3))
#define SMBus_RXR		(*((volatile INT8U *) smbase_addr+3))
#define SMBus_STS		(*((volatile INT8U *) smbase_addr+4))

#define READ			0
#define WRITE			1

int eeprom_major = -1;

struct eeprom_addr_string
{
	INT32U addr;
	INT32U num;					//每一条目包含的字符数
	char string[20];            //eeprom芯片AT24C02，256Byte。前16Byte用于存放mac
								//后240byte用于存放固件的ascii码
								//固件版本每16byte作为一个条目，最多支持15个条目
								//每个条目最大16个字符
};


void SMBus_Init(INT8U CLH,INT8U CLL);
INT8U SMBus_SendStr(INT8U sla, INT8U suba, INT8U *s, INT8U no);
INT8U SMBus_RecvStr(INT8U sla, INT8U suba, INT8U *s, INT8U no);


void SMBus_Init(INT8U CLH,INT8U CLL)
{
	SMBus_CLH = CLH;
	SMBus_CLL = CLL;
	SMBus_CON = 0xc0;				// Enable SMBus and Interrupt Output
}


static int eeprom_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long argv)
{
	struct eeprom_addr_string ras,was;

	memset (&ras,0,sizeof(struct eeprom_addr_string));
	memset (&was,0,sizeof(struct eeprom_addr_string));

	switch ( cmd )			//每次调用读写一个条目，最大16Byte
	{
		case WRITE:
			copy_from_user(&was,(void *)argv,sizeof(struct eeprom_addr_string));
			printk("WRITE:addr:%x,num:%x,string:%s\n",was.addr,was.num,was.string);
			if ( was.num <= 8 )
				SMBus_SendStr(0xa0, was.addr, was.string, was.num);
			else if ( 8 < was.num && was.num <= 16 )
			{
//				printk("KERN:was.num:%d\n",was.num);
				SMBus_SendStr(0xa0, was.addr, &was.string[0], 8);
				mdelay(100);
				SMBus_SendStr(0xa0, was.addr+8, &was.string[8], was.num-8);
			}
			else
			{
				printk("Error:was.num=%d\n",was.num);
				return -1;
			}
			break;
		case READ:
			copy_from_user(&ras,(void *)argv,sizeof(struct eeprom_addr_string));
			printk("READ:addr:%x,num:%x,string:%s\n",ras.addr,ras.num,ras.string);
			if ( ras.num <= 8 )
				SMBus_RecvStr(0xa0, ras.addr, ras.string, ras.num);
			else if ( 8 < ras.num && ras.num <= 16 )
			{
//				printk("KERN:ras.num:%d\n",ras.num);
				SMBus_RecvStr(0xa0, ras.addr, &ras.string[0], 8);
				mdelay(100);
				SMBus_RecvStr(0xa0, ras.addr+8, &ras.string[8], ras.num-8);
			}
			else
			{
				printk("Error:ras.num=%d\n",ras.num);
				return -1;
			}
//			printk("KERN:string:%s\n",ras.string);
			copy_to_user((void *)argv,&ras,sizeof(struct eeprom_addr_string));
			break;
		default:
			printk("cmd error\n");
			return -1;
	}
	return 0;

}


INT8U SMBus_SendStr(INT8U sla, INT8U suba, INT8U *s, INT8U no)
{
    INT8U sla_ack, i;

    SMBus_TXR = sla;
    SMBus_CMD = 0x90;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    sla_ack = SMBus_STS & 0x80;
    if (sla_ack != 0x00)
    {
        return 0;
    }

    SMBus_TXR = suba;
    SMBus_CMD = 0x10;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    sla_ack = SMBus_STS & 0x80;
    if (sla_ack != 0x00)
    {
        return 0;
    }

    for (i = 0; i < no - 1; i++)
    {
        SMBus_TXR = *s;
        SMBus_CMD = 0x10;
        while ((SMBus_STS & 0x01) != 0x01);
        SMBus_CMD = 0x01;
        sla_ack = SMBus_STS & 0x80;
        if (sla_ack != 0x00)
        {
            return 0;
        }
        s++;
    }

    SMBus_TXR = *s;
    SMBus_CMD = 0x50;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    sla_ack = SMBus_STS & 0x80;
    if (sla_ack != 0x00)
    {
        return 0;
    }
    return 1;
}

INT8U SMBus_RecvStr(INT8U sla, INT8U suba, INT8U *s, INT8U no)
{
    INT8U sla_ack, i;

    SMBus_TXR = sla;
    SMBus_CMD = 0x90;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    sla_ack = SMBus_STS & 0x80;
    if (sla_ack != 0x00)
    {
        return 0;
    }

    SMBus_TXR = suba;
    SMBus_CMD = 0x10;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    sla_ack = SMBus_STS & 0x80;
    if (sla_ack != 0x00)
    {
        return 0;
    }

    SMBus_TXR = sla + 1;
    SMBus_CMD = 0x90;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    sla_ack = SMBus_STS & 0x80;
    if (sla_ack != 0x00)
    {
        return 0;
    }

    for (i = 0; i < no - 1; i++)
    {
        SMBus_CMD = 0x20;
        while ((SMBus_STS & 0x01) != 0x01);
        SMBus_CMD = 0x01;
        if (sla_ack != 0x00)
        {
            return 0;
        }
        *s = SMBus_RXR;
        s++;
    }

    SMBus_CMD = 0x68;
    while ((SMBus_STS & 0x01) != 0x01);
    SMBus_CMD = 0x01;
    *s = SMBus_RXR;

    return(1);
}



struct file_operations eeprom_fops = {
	.owner =    THIS_MODULE,
	.ioctl =    eeprom_ioctl,
};

static int __init eeprom_init(void)
{

	smbase_addr=(volatile unsigned char *)ioremap_nocache(SMBUS_BASE,5);

	eeprom_major = register_chrdev(231, "eeprom", &eeprom_fops);
	printk("eeprom_major:%d\n",eeprom_major);
	SMBus_Init(0x01, 0x00);

	printk("Hello EEPROM!\n");
	return 0;
}

static void __exit eeprom_exit(void)
{
	unregister_chrdev(eeprom_major, "eeprom");
	iounmap((void *)smbase_addr);

	printk("Bye EEPROM.\n");

}

module_init(eeprom_init);
module_exit(eeprom_exit);