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/config.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/slab.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 unsigned long eeprom_addr;
  36
  37 static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin )
  38 {
  39         switch (origin) {
  40           case 0:
  41                 /* nothing to do */
  42                 break;
  43           case 1:
  44                 offset += file->f_pos;
  45                 break;
  46           case 2:
  47                 offset += HPEE_MAX_LENGTH;
  48                 break;
  49         }
  50         return (offset >= 0 && offset < HPEE_MAX_LENGTH) ? (file->f_pos = offset) : -EINVAL;
  51 }
  52
  53 static ssize_t eisa_eeprom_read(struct file * file,
  54                               char *buf, size_t count, loff_t *ppos )
  55 {
  56         unsigned char *tmp;
  57         ssize_t ret;
  58         int i;
  59
  60         if (*ppos >= HPEE_MAX_LENGTH)
  61                 return 0;
  62
  63         count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
  64         tmp = kmalloc(count, GFP_KERNEL);
  65         if (tmp) {
  66                 for (i = 0; i < count; i++)
  67                         tmp[i] = gsc_readb(eeprom_addr+(*ppos)++);
  68
  69                 if (copy_to_user (buf, tmp, count))
  70                         ret = -EFAULT;
  71                 else
  72                         ret = count;
  73                 kfree (tmp);
  74         } else
  75                 ret = -ENOMEM;
  76
  77         return ret;
  78 }
  79
  80 static int eisa_eeprom_ioctl(struct inode *inode, struct file *file,
  81                            unsigned int cmd,
  82                            unsigned long arg)
  83 {
  84         return -ENOTTY;
  85 }
  86
  87 static int eisa_eeprom_open(struct inode *inode, struct file *file)
  88 {
  89         if (file->f_mode & 2 || eeprom_addr == 0)
  90                 return -EINVAL;
  91
  92         return 0;
  93 }
  94
  95 static int eisa_eeprom_release(struct inode *inode, struct file *file)
  96 {
  97         return 0;
  98 }
  99
 100 /*
 101  *      The various file operations we support.
 102  */
 103 static struct file_operations eisa_eeprom_fops = {
 104         .owner =        THIS_MODULE,
 105         .llseek =       eisa_eeprom_llseek,
 106         .read =         eisa_eeprom_read,
 107         .ioctl =        eisa_eeprom_ioctl,
 108         .open =         eisa_eeprom_open,
 109         .release =      eisa_eeprom_release,
 110 };
 111
 112 static struct miscdevice eisa_eeprom_dev=
 113 {
 114         EISA_EEPROM_MINOR,
 115         "eisa eeprom",
 116         &eisa_eeprom_fops
 117 };
 118
 119 int __init eisa_eeprom_init(unsigned long addr)
 120 {
 121         int retval;
 122
 123         /* XXX why return success when we haven't done anything? */
 124         if (!addr)
 125                 return 0;
 126
 127         eeprom_addr = addr;
 128
 129         retval = misc_register(&eisa_eeprom_dev);
 130         if (retval < 0) {
 131                 printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
 132                 return retval;
 133         }
 134
 135         printk(KERN_INFO "EISA EEPROM at 0x%lx\n", eeprom_addr);
 136         return 0;
 137 }
 138
 139 MODULE_LICENSE("GPL");