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 | |
20 | static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin) |
21 | { |
22 | return fixed_size_llseek(file, offset, whence: origin, size: HPEE_MAX_LENGTH); |
23 | } |
24 | |
25 | static 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(size: count, GFP_KERNEL); |
37 | if (tmp) { |
38 | for (i = 0; i < count; i++) |
39 | tmp[i] = readb(addr: eisa_eeprom_addr+(*ppos)++); |
40 | |
41 | if (copy_to_user (to: buf, from: tmp, n: count)) |
42 | ret = -EFAULT; |
43 | else |
44 | ret = count; |
45 | kfree (objp: tmp); |
46 | } else |
47 | ret = -ENOMEM; |
48 | |
49 | return ret; |
50 | } |
51 | |
52 | static 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 | |
60 | static 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 | */ |
68 | static 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 | |
76 | static struct miscdevice eisa_eeprom_dev = { |
77 | EISA_EEPROM_MINOR, |
78 | "eisa_eeprom" , |
79 | &eisa_eeprom_fops |
80 | }; |
81 | |
82 | static int __init eisa_eeprom_init(void) |
83 | { |
84 | int retval; |
85 | |
86 | if (!eisa_eeprom_addr) |
87 | return -ENODEV; |
88 | |
89 | retval = misc_register(misc: &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 | |
99 | MODULE_LICENSE("GPL" ); |
100 | |
101 | module_init(eisa_eeprom_init); |
102 | |