xref: /linux/drivers/pnp/isapnp/proc.c (revision 96ac6d435100450f0565708d9b885ea2a7400e0a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  ISA Plug & Play support
4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5  */
6 
7 #include <linux/module.h>
8 #include <linux/isapnp.h>
9 #include <linux/proc_fs.h>
10 #include <linux/init.h>
11 #include <linux/uaccess.h>
12 
13 extern struct pnp_protocol isapnp_protocol;
14 
15 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
16 
17 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
18 {
19 	return fixed_size_llseek(file, off, whence, 256);
20 }
21 
22 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
23 				    size_t nbytes, loff_t * ppos)
24 {
25 	struct pnp_dev *dev = PDE_DATA(file_inode(file));
26 	int pos = *ppos;
27 	int cnt, size = 256;
28 
29 	if (pos >= size)
30 		return 0;
31 	if (nbytes >= size)
32 		nbytes = size;
33 	if (pos + nbytes > size)
34 		nbytes = size - pos;
35 	cnt = nbytes;
36 
37 	if (!access_ok(buf, cnt))
38 		return -EINVAL;
39 
40 	isapnp_cfg_begin(dev->card->number, dev->number);
41 	for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
42 		unsigned char val;
43 		val = isapnp_read_byte(pos);
44 		__put_user(val, buf);
45 	}
46 	isapnp_cfg_end();
47 
48 	*ppos = pos;
49 	return nbytes;
50 }
51 
52 static const struct file_operations isapnp_proc_bus_file_operations = {
53 	.owner	= THIS_MODULE,
54 	.llseek = isapnp_proc_bus_lseek,
55 	.read = isapnp_proc_bus_read,
56 };
57 
58 static int isapnp_proc_attach_device(struct pnp_dev *dev)
59 {
60 	struct pnp_card *bus = dev->card;
61 	struct proc_dir_entry *de, *e;
62 	char name[16];
63 
64 	if (!(de = bus->procdir)) {
65 		sprintf(name, "%02x", bus->number);
66 		de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
67 		if (!de)
68 			return -ENOMEM;
69 	}
70 	sprintf(name, "%02x", dev->number);
71 	e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
72 			&isapnp_proc_bus_file_operations, dev);
73 	if (!e)
74 		return -ENOMEM;
75 	proc_set_size(e, 256);
76 	return 0;
77 }
78 
79 int __init isapnp_proc_init(void)
80 {
81 	struct pnp_dev *dev;
82 
83 	isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
84 	protocol_for_each_dev(&isapnp_protocol, dev) {
85 		isapnp_proc_attach_device(dev);
86 	}
87 	return 0;
88 }
89