drivers/parisc/eisa_eeprom.c

   1 /*
   2  *    EISA "eeprom" support routines
   3  *
   4  *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/miscdevice.h>
  26 #include <linux/slab.h>
  27 #include <linux/fs.h>
  28 #include <asm/io.h>
  29 #include <linux/uaccess.h>
  30 #include <asm/eisa_eeprom.h>
  31
  32 #define         EISA_EEPROM_MINOR 241
  33
  34 static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin)
  35 {
  36         return fixed_size_llseek(file, offset, origin, HPEE_MAX_LENGTH);
  37 }
  38
  39 static ssize_t eisa_eeprom_read(struct file * file,
  40                               char __user *buf, size_t count, loff_t *ppos )
  41 {
  42         unsigned char *tmp;
  43         ssize_t ret;
  44         int i;
  45
  46         if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
  47                 return 0;
  48
  49         count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
  50         tmp = kmalloc(count, GFP_KERNEL);
  51         if (tmp) {
  52                 for (i = 0; i < count; i++)
  53                         tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);
  54
  55                 if (copy_to_user (buf, tmp, count))
  56                         ret = -EFAULT;
  57                 else
  58                         ret = count;
  59                 kfree (tmp);
  60         } else
  61                 ret = -ENOMEM;
  62
  63         return ret;
  64 }
  65
  66 static int eisa_eeprom_open(struct inode *inode, struct file *file)
  67 {
  68         if (file->f_mode & FMODE_WRITE)
  69                 return -EINVAL;
  70
  71         return 0;
  72 }
  73
  74 static int eisa_eeprom_release(struct inode *inode, struct file *file)
  75 {
  76         return 0;
  77 }
  78
  79 /*
  80  *      The various file operations we support.
  81  */
  82 static const struct file_operations eisa_eeprom_fops = {
  83         .owner =        THIS_MODULE,
  84         .llseek =       eisa_eeprom_llseek,
  85         .read =         eisa_eeprom_read,
  86         .open =         eisa_eeprom_open,
  87         .release =      eisa_eeprom_release,
  88 };
  89
  90 static struct miscdevice eisa_eeprom_dev = {
  91         EISA_EEPROM_MINOR,
  92         "eisa_eeprom",
  93         &eisa_eeprom_fops
  94 };
  95
  96 static int __init eisa_eeprom_init(void)
  97 {
  98         int retval;
  99
 100         if (!eisa_eeprom_addr)
 101                 return -ENODEV;
 102
 103         retval = misc_register(&eisa_eeprom_dev);
 104         if (retval < 0) {
 105                 printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
 106                 return retval;
 107         }
 108
 109         printk(KERN_INFO "EISA EEPROM at 0x%p\n", eisa_eeprom_addr);
 110         return 0;
 111 }
 112
 113 MODULE_LICENSE("GPL");
 114
 115 module_init(eisa_eeprom_init);