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/smp_lock.h>
  28 #include <linux/fs.h>
  29 #include <asm/io.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/eisa_eeprom.h>
  32
  33 #define         EISA_EEPROM_MINOR 241
  34
  35 static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin )
  36 {
  37         switch (origin) {
  38           case 0:
  39                 /* nothing to do */
  40                 break;
  41           case 1:
  42                 offset += file->f_pos;
  43                 break;
  44           case 2:
  45                 offset += HPEE_MAX_LENGTH;
  46                 break;
  47         }
  48         return (offset >= 0 && offset < HPEE_MAX_LENGTH) ? (file->f_pos = offset) : -EINVAL;
  49 }
  50
  51 static ssize_t eisa_eeprom_read(struct file * file,
  52                               char __user *buf, size_t count, loff_t *ppos )
  53 {
  54         unsigned char *tmp;
  55         ssize_t ret;
  56         int i;
  57
  58         if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
  59                 return 0;
  60
  61         count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
  62         tmp = kmalloc(count, GFP_KERNEL);
  63         if (tmp) {
  64                 for (i = 0; i < count; i++)
  65                         tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);
  66
  67                 if (copy_to_user (buf, tmp, count))
  68                         ret = -EFAULT;
  69                 else
  70                         ret = count;
  71                 kfree (tmp);
  72         } else
  73                 ret = -ENOMEM;
  74
  75         return ret;
  76 }
  77
  78 static int eisa_eeprom_open(struct inode *inode, struct file *file)
  79 {
  80         if (file->f_mode & FMODE_WRITE)
  81                 return -EINVAL;
  82
  83         return 0;
  84 }
  85
  86 static int eisa_eeprom_release(struct inode *inode, struct file *file)
  87 {
  88         return 0;
  89 }
  90
  91 /*
  92  *      The various file operations we support.
  93  */
  94 static const struct file_operations eisa_eeprom_fops = {
  95         .owner =        THIS_MODULE,
  96         .llseek =       eisa_eeprom_llseek,
  97         .read =         eisa_eeprom_read,
  98         .open =         eisa_eeprom_open,
  99         .release =      eisa_eeprom_release,
 100 };
 101
 102 static struct miscdevice eisa_eeprom_dev = {
 103         EISA_EEPROM_MINOR,
 104         "eisa_eeprom",
 105         &eisa_eeprom_fops
 106 };
 107
 108 static int __init eisa_eeprom_init(void)
 109 {
 110         int retval;
 111
 112         if (!eisa_eeprom_addr)
 113                 return -ENODEV;
 114
 115         retval = misc_register(&eisa_eeprom_dev);
 116         if (retval < 0) {
 117                 printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
 118                 return retval;
 119         }
 120
 121         printk(KERN_INFO "EISA EEPROM at 0x%p\n", eisa_eeprom_addr);
 122         return 0;
 123 }
 124
 125 MODULE_LICENSE("GPL");
 126
 127 module_init(eisa_eeprom_init);