xref: /openbmc/linux/drivers/pnp/isapnp/proc.c (revision 65417d9f)
1 /*
2  *  ISA Plug & Play support
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *   This program is free software; you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *   GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program; if not, write to the Free Software
17  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  */
19 
20 #include <linux/module.h>
21 #include <linux/isapnp.h>
22 #include <linux/proc_fs.h>
23 #include <linux/init.h>
24 #include <linux/uaccess.h>
25 
26 extern struct pnp_protocol isapnp_protocol;
27 
28 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
29 
30 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
31 {
32 	return fixed_size_llseek(file, off, whence, 256);
33 }
34 
35 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
36 				    size_t nbytes, loff_t * ppos)
37 {
38 	struct pnp_dev *dev = PDE_DATA(file_inode(file));
39 	int pos = *ppos;
40 	int cnt, size = 256;
41 
42 	if (pos >= size)
43 		return 0;
44 	if (nbytes >= size)
45 		nbytes = size;
46 	if (pos + nbytes > size)
47 		nbytes = size - pos;
48 	cnt = nbytes;
49 
50 	if (!access_ok(VERIFY_WRITE, buf, cnt))
51 		return -EINVAL;
52 
53 	isapnp_cfg_begin(dev->card->number, dev->number);
54 	for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
55 		unsigned char val;
56 		val = isapnp_read_byte(pos);
57 		__put_user(val, buf);
58 	}
59 	isapnp_cfg_end();
60 
61 	*ppos = pos;
62 	return nbytes;
63 }
64 
65 static const struct file_operations isapnp_proc_bus_file_operations = {
66 	.owner	= THIS_MODULE,
67 	.llseek = isapnp_proc_bus_lseek,
68 	.read = isapnp_proc_bus_read,
69 };
70 
71 static int isapnp_proc_attach_device(struct pnp_dev *dev)
72 {
73 	struct pnp_card *bus = dev->card;
74 	struct proc_dir_entry *de, *e;
75 	char name[16];
76 
77 	if (!(de = bus->procdir)) {
78 		sprintf(name, "%02x", bus->number);
79 		de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
80 		if (!de)
81 			return -ENOMEM;
82 	}
83 	sprintf(name, "%02x", dev->number);
84 	e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
85 			&isapnp_proc_bus_file_operations, dev);
86 	if (!e)
87 		return -ENOMEM;
88 	proc_set_size(e, 256);
89 	return 0;
90 }
91 
92 int __init isapnp_proc_init(void)
93 {
94 	struct pnp_dev *dev;
95 
96 	isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
97 	protocol_for_each_dev(&isapnp_protocol, dev) {
98 		isapnp_proc_attach_device(dev);
99 	}
100 	return 0;
101 }
102