1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * EISA "eeprom" support routines
4 *
5 * Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
6 */
7
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/miscdevice.h>
12 #include <linux/slab.h>
13 #include <linux/fs.h>
14 #include <asm/io.h>
15 #include <linux/uaccess.h>
16 #include <asm/eisa_eeprom.h>
17
eisa_eeprom_llseek(struct file * file,loff_t offset,int origin)18 static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin)
19 {
20 return fixed_size_llseek(file, offset, origin, HPEE_MAX_LENGTH);
21 }
22
eisa_eeprom_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)23 static ssize_t eisa_eeprom_read(struct file * file,
24 char __user *buf, size_t count, loff_t *ppos )
25 {
26 unsigned char *tmp;
27 ssize_t ret;
28 int i;
29
30 if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
31 return 0;
32
33 count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
34 tmp = kmalloc(count, GFP_KERNEL);
35 if (tmp) {
36 for (i = 0; i < count; i++)
37 tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);
38
39 if (copy_to_user (buf, tmp, count))
40 ret = -EFAULT;
41 else
42 ret = count;
43 kfree (tmp);
44 } else
45 ret = -ENOMEM;
46
47 return ret;
48 }
49
eisa_eeprom_open(struct inode * inode,struct file * file)50 static int eisa_eeprom_open(struct inode *inode, struct file *file)
51 {
52 if (file->f_mode & FMODE_WRITE)
53 return -EINVAL;
54
55 return 0;
56 }
57
eisa_eeprom_release(struct inode * inode,struct file * file)58 static int eisa_eeprom_release(struct inode *inode, struct file *file)
59 {
60 return 0;
61 }
62
63 /*
64 * The various file operations we support.
65 */
66 static const struct file_operations eisa_eeprom_fops = {
67 .owner = THIS_MODULE,
68 .llseek = eisa_eeprom_llseek,
69 .read = eisa_eeprom_read,
70 .open = eisa_eeprom_open,
71 .release = eisa_eeprom_release,
72 };
73
74 static struct miscdevice eisa_eeprom_dev = {
75 EISA_EEPROM_MINOR,
76 "eisa_eeprom",
77 &eisa_eeprom_fops
78 };
79
eisa_eeprom_init(void)80 static int __init eisa_eeprom_init(void)
81 {
82 int retval;
83
84 if (!eisa_eeprom_addr)
85 return -ENODEV;
86
87 retval = misc_register(&eisa_eeprom_dev);
88 if (retval < 0) {
89 printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
90 return retval;
91 }
92
93 printk(KERN_INFO "EISA EEPROM at 0x%px\n", eisa_eeprom_addr);
94 return 0;
95 }
96
97 MODULE_LICENSE("GPL");
98
99 module_init(eisa_eeprom_init);
100