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
18#define 	EISA_EEPROM_MINOR 241
19
20static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin)
21{
22	return fixed_size_llseek(file, offset, origin, HPEE_MAX_LENGTH);
23}
24
25static ssize_t eisa_eeprom_read(struct file * file,
26			      char __user *buf, size_t count, loff_t *ppos )
27{
28	unsigned char *tmp;
29	ssize_t ret;
30	int i;
31
32	if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
33		return 0;
34
35	count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
36	tmp = kmalloc(count, GFP_KERNEL);
37	if (tmp) {
38		for (i = 0; i < count; i++)
39			tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);
40
41		if (copy_to_user (buf, tmp, count))
42			ret = -EFAULT;
43		else
44			ret = count;
45		kfree (tmp);
46	} else
47		ret = -ENOMEM;
48
49	return ret;
50}
51
52static int eisa_eeprom_open(struct inode *inode, struct file *file)
53{
54	if (file->f_mode & FMODE_WRITE)
55		return -EINVAL;
56
57	return 0;
58}
59
60static int eisa_eeprom_release(struct inode *inode, struct file *file)
61{
62	return 0;
63}
64
65/*
66 *	The various file operations we support.
67 */
68static const struct file_operations eisa_eeprom_fops = {
69	.owner =	THIS_MODULE,
70	.llseek =	eisa_eeprom_llseek,
71	.read =		eisa_eeprom_read,
72	.open =		eisa_eeprom_open,
73	.release =	eisa_eeprom_release,
74};
75
76static struct miscdevice eisa_eeprom_dev = {
77	EISA_EEPROM_MINOR,
78	"eisa_eeprom",
79	&eisa_eeprom_fops
80};
81
82static int __init eisa_eeprom_init(void)
83{
84	int retval;
85
86	if (!eisa_eeprom_addr)
87		return -ENODEV;
88
89	retval = misc_register(&eisa_eeprom_dev);
90	if (retval < 0) {
91		printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
92		return retval;
93	}
94
95	printk(KERN_INFO "EISA EEPROM at 0x%px\n", eisa_eeprom_addr);
96	return 0;
97}
98
99MODULE_LICENSE("GPL");
100
101module_init(eisa_eeprom_init);
102