eisa_eeprom.c

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/* 
 *    EISA "eeprom" support routines
 *
 *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/eisa_eeprom.h>

#define     EISA_EEPROM_MINOR 241

static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin )
{
    switch (origin) {
      case 0:
        /* nothing to do */
        break;
      case 1:
        offset += file->f_pos;
        break;
      case 2:
        offset += HPEE_MAX_LENGTH;
        break;
    }
    return (offset >= 0 && offset < HPEE_MAX_LENGTH) ? (file->f_pos = offset) : -EINVAL;
}

static ssize_t eisa_eeprom_read(struct file * file,
                  char __user *buf, size_t count, loff_t *ppos )
{
    unsigned char *tmp;
    ssize_t ret;
    int i;
    
    if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
        return 0;
    
    count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
    tmp = kmalloc(count, GFP_KERNEL);
    if (tmp) {
        for (i = 0; i < count; i++)
            tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);

        if (copy_to_user (buf, tmp, count))
            ret = -EFAULT;
        else
            ret = count;
        kfree (tmp);
    } else
        ret = -ENOMEM;
    
    return ret;
}

static int eisa_eeprom_open(struct inode *inode, struct file *file)
{
    if (file->f_mode & FMODE_WRITE)
        return -EINVAL;
   
    return 0;
}

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

/*
 *  The various file operations we support.
 */
static const struct file_operations eisa_eeprom_fops = {
    .owner =    THIS_MODULE,
    .llseek =   eisa_eeprom_llseek,
    .read =     eisa_eeprom_read,
    .open =     eisa_eeprom_open,
    .release =  eisa_eeprom_release,
};

static struct miscdevice eisa_eeprom_dev = {
    EISA_EEPROM_MINOR,
    "eisa_eeprom",
    &eisa_eeprom_fops
};

static int __init eisa_eeprom_init(void)
{
    int retval;

    if (!eisa_eeprom_addr)
        return -ENODEV;

    retval = misc_register(&eisa_eeprom_dev);
    if (retval < 0) {
        printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
        return retval;
    }

    printk(KERN_INFO "EISA EEPROM at 0x%p\n", eisa_eeprom_addr);
    return 0;
}

MODULE_LICENSE("GPL");

module_init(eisa_eeprom_init);