xref: /linux/drivers/pnp/isapnp/proc.c (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
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 
35 	lock_kernel();
36 	switch (whence) {
37 	case 0:
38 		new = off;
39 		break;
40 	case 1:
41 		new = file->f_pos + off;
42 		break;
43 	case 2:
44 		new = 256 + off;
45 		break;
46 	}
47 	if (new < 0 || new > 256) {
48 		unlock_kernel();
49 		return -EINVAL;
50 	}
51 	unlock_kernel();
52 	return (file->f_pos = new);
53 }
54 
55 static ssize_t isapnp_proc_bus_read(struct file *file, char __user * buf,
56 				    size_t nbytes, loff_t * ppos)
57 {
58 	struct inode *ino = file->f_path.dentry->d_inode;
59 	struct proc_dir_entry *dp = PDE(ino);
60 	struct pnp_dev *dev = dp->data;
61 	int pos = *ppos;
62 	int cnt, size = 256;
63 
64 	if (pos >= size)
65 		return 0;
66 	if (nbytes >= size)
67 		nbytes = size;
68 	if (pos + nbytes > size)
69 		nbytes = size - pos;
70 	cnt = nbytes;
71 
72 	if (!access_ok(VERIFY_WRITE, buf, cnt))
73 		return -EINVAL;
74 
75 	isapnp_cfg_begin(dev->card->number, dev->number);
76 	for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
77 		unsigned char val;
78 		val = isapnp_read_byte(pos);
79 		__put_user(val, buf);
80 	}
81 	isapnp_cfg_end();
82 
83 	*ppos = pos;
84 	return nbytes;
85 }
86 
87 static const struct file_operations isapnp_proc_bus_file_operations = {
88 	.owner	= THIS_MODULE,
89 	.llseek = isapnp_proc_bus_lseek,
90 	.read = isapnp_proc_bus_read,
91 };
92 
93 static int isapnp_proc_attach_device(struct pnp_dev *dev)
94 {
95 	struct pnp_card *bus = dev->card;
96 	struct proc_dir_entry *de, *e;
97 	char name[16];
98 
99 	if (!(de = bus->procdir)) {
100 		sprintf(name, "%02x", bus->number);
101 		de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
102 		if (!de)
103 			return -ENOMEM;
104 	}
105 	sprintf(name, "%02x", dev->number);
106 	e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
107 			&isapnp_proc_bus_file_operations, dev);
108 	if (!e)
109 		return -ENOMEM;
110 	e->size = 256;
111 	return 0;
112 }
113 
114 int __init isapnp_proc_init(void)
115 {
116 	struct pnp_dev *dev;
117 
118 	isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
119 	protocol_for_each_dev(&isapnp_protocol, dev) {
120 		isapnp_proc_attach_device(dev);
121 	}
122 	return 0;
123 }
124