xref: /openbmc/linux/drivers/pnp/isapnp/proc.c (revision ee89bd6b)
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 <asm/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 	loff_t new = -1;
33 	struct inode *inode = file_inode(file);
34 
35 	mutex_lock(&inode->i_mutex);
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 		new = -EINVAL;
49 	else
50 		file->f_pos = new;
51 	mutex_unlock(&inode->i_mutex);
52 	return 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 pnp_dev *dev = PDE_DATA(file_inode(file));
59 	int pos = *ppos;
60 	int cnt, size = 256;
61 
62 	if (pos >= size)
63 		return 0;
64 	if (nbytes >= size)
65 		nbytes = size;
66 	if (pos + nbytes > size)
67 		nbytes = size - pos;
68 	cnt = nbytes;
69 
70 	if (!access_ok(VERIFY_WRITE, buf, cnt))
71 		return -EINVAL;
72 
73 	isapnp_cfg_begin(dev->card->number, dev->number);
74 	for (; pos < 256 && cnt > 0; pos++, buf++, cnt--) {
75 		unsigned char val;
76 		val = isapnp_read_byte(pos);
77 		__put_user(val, buf);
78 	}
79 	isapnp_cfg_end();
80 
81 	*ppos = pos;
82 	return nbytes;
83 }
84 
85 static const struct file_operations isapnp_proc_bus_file_operations = {
86 	.owner	= THIS_MODULE,
87 	.llseek = isapnp_proc_bus_lseek,
88 	.read = isapnp_proc_bus_read,
89 };
90 
91 static int isapnp_proc_attach_device(struct pnp_dev *dev)
92 {
93 	struct pnp_card *bus = dev->card;
94 	struct proc_dir_entry *de, *e;
95 	char name[16];
96 
97 	if (!(de = bus->procdir)) {
98 		sprintf(name, "%02x", bus->number);
99 		de = bus->procdir = proc_mkdir(name, isapnp_proc_bus_dir);
100 		if (!de)
101 			return -ENOMEM;
102 	}
103 	sprintf(name, "%02x", dev->number);
104 	e = dev->procent = proc_create_data(name, S_IFREG | S_IRUGO, de,
105 			&isapnp_proc_bus_file_operations, dev);
106 	if (!e)
107 		return -ENOMEM;
108 	proc_set_size(e, 256);
109 	return 0;
110 }
111 
112 int __init isapnp_proc_init(void)
113 {
114 	struct pnp_dev *dev;
115 
116 	isapnp_proc_bus_dir = proc_mkdir("bus/isapnp", NULL);
117 	protocol_for_each_dev(&isapnp_protocol, dev) {
118 		isapnp_proc_attach_device(dev);
119 	}
120 	return 0;
121 }
122