xref: /openbmc/linux/drivers/parisc/eisa_eeprom.c (revision aac5987a)
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);
116