xref: /linux/drivers/pnp/isapnp/proc.c (revision 092e0e7e520a1fca03e13c9f2d157432a8657ff2)
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/smp_lock.h>
25 #include <asm/uaccess.h>
26 
27 extern struct pnp_protocol isapnp_protocol;
28 
29 static struct proc_dir_entry *isapnp_proc_bus_dir = NULL;
30 
31 static loff_t isapnp_proc_bus_lseek(struct file *file, loff_t off, int whence)
32 {
33 	loff_t new = -1;
34 	struct inode *inode = file->f_path.dentry->d_inode;
35 
36 	mutex_lock(&inode->i_mutex);
37 	switch (whence) {
38 	case 0:
39 		new = off;
40 		break;
41 	case 1:
42 		new = file->f_pos + off;
43 		break;
44 	case 2:
45 		new = 256 + off;
46 		break;
47 	}
48 	if (new < 0 || new > 256)
49 		new = -EINVAL;
50 	else
51 		file->f_pos = new;
52 	mutex_unlock(&inode->i_mutex);
53 	return new;
54 }
55 
56 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
57 				    size_t nbytes, loff_t * ppos)
58 {
59 	struct inode *ino = file->f_path.dentry->d_inode;
60 	struct proc_dir_entry *dp = PDE(ino);
61 	struct pnp_dev *dev = dp->data;
62 	int pos = *ppos;
63 	int cnt, size = 256;
64 
65 	if (pos >= size)
66 		return 0;
67 	if (nbytes >= size)
68 		nbytes = size;
69 	if (pos + nbytes > size)
70 		nbytes = size - pos;
71 	cnt = nbytes;
72 
73 	if (!access_ok(VERIFY_WRITE, buf, cnt))
74 		return -EINVAL;
75 
76 	isapnp_cfg_begin(dev->card->number, dev->number);
77 	for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
78 		unsigned char val;
79 		val = isapnp_read_byte(pos);
80 		__put_user(val, buf);
81 	}
82 	isapnp_cfg_end();
83 
84 	*ppos = pos;
85 	return nbytes;
86 }
87 
88 static const struct file_operations isapnp_proc_bus_file_operations = {
89 	.owner	= THIS_MODULE,
90 	.llseek = isapnp_proc_bus_lseek,
91 	.read = isapnp_proc_bus_read,
92 };
93 
94 static int isapnp_proc_attach_device(struct pnp_dev *dev)
95 {
96 	struct pnp_card *bus = dev->card;
97 	struct proc_dir_entry *de, *e;
98 	char name[16];
99 
100 	if (!(de = bus->procdir)) {
101 		sprintf(name, "%02x", bus->number);
102 		de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
103 		if (!de)
104 			return -ENOMEM;
105 	}
106 	sprintf(name, "%02x", dev->number);
107 	e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
108 			&isapnp_proc_bus_file_operations, dev);
109 	if (!e)
110 		return -ENOMEM;
111 	e->size = 256;
112 	return 0;
113 }
114 
115 int __init isapnp_proc_init(void)
116 {
117 	struct pnp_dev *dev;
118 
119 	isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
120 	protocol_for_each_dev(&isapnp_protocol, dev) {
121 		isapnp_proc_attach_device(dev);
122 	}
123 	return 0;
124 }
125