Root/target/linux/ifxmips/files-2.6.33/drivers/watchdog/ifxmips.c

1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15 *
16 * Copyright (C) 2008 John Crispin <blogic@openwrt.org>
17 * Based on EP93xx wdt driver
18 */
19
20#include <linux/module.h>
21#include <linux/fs.h>
22#include <linux/miscdevice.h>
23#include <linux/miscdevice.h>
24#include <linux/watchdog.h>
25#include <linux/platform_device.h>
26#include <linux/uaccess.h>
27
28#include <ifxmips.h>
29#include <ifxmips_cgu.h>
30
31#define IFXMIPS_WDT_PW1 0x00BE0000
32#define IFXMIPS_WDT_PW2 0x00DC0000
33
34#ifndef CONFIG_WATCHDOG_NOWAYOUT
35static int wdt_ok_to_close;
36#endif
37
38static int wdt_timeout = 30;
39
40int ifxmips_wdt_enable(unsigned int timeout)
41{
42    u32 fpi;
43    fpi = cgu_get_io_region_clock();
44    ifxmips_w32(IFXMIPS_WDT_PW1, IFXMIPS_BIU_WDT_CR);
45    ifxmips_w32(IFXMIPS_WDT_PW2 |
46        (0x3 << 26) | /* PWL */
47        (0x3 << 24) | /* CLKDIV */
48        (0x1 << 31) | /* enable */
49        ((timeout * (fpi / 0x40000)) + 0x1000), /* reload */
50        IFXMIPS_BIU_WDT_CR);
51    return 0;
52}
53
54void ifxmips_wdt_disable(void)
55{
56#ifndef CONFIG_WATCHDOG_NOWAYOUT
57    wdt_ok_to_close = 0;
58#endif
59    ifxmips_w32(IFXMIPS_WDT_PW1, IFXMIPS_BIU_WDT_CR);
60    ifxmips_w32(IFXMIPS_WDT_PW2, IFXMIPS_BIU_WDT_CR);
61}
62
63static ssize_t ifxmips_wdt_write(struct file *file, const char __user *data,
64        size_t len, loff_t *ppos)
65{
66    size_t i;
67
68    if (!len)
69        return 0;
70
71#ifndef CONFIG_WATCHDOG_NOWAYOUT
72    for (i = 0; i != len; i++) {
73        char c;
74        if (get_user(c, data + i))
75            return -EFAULT;
76        if (c == 'V')
77            wdt_ok_to_close = 1;
78    }
79#endif
80    ifxmips_wdt_enable(wdt_timeout);
81    return len;
82}
83
84static struct watchdog_info ident = {
85    .options = WDIOF_MAGICCLOSE,
86    .identity = "ifxmips Watchdog",
87};
88
89static int ifxmips_wdt_ioctl(struct inode *inode, struct file *file,
90        unsigned int cmd, unsigned long arg)
91{
92    int ret = -ENOTTY;
93
94    switch (cmd) {
95    case WDIOC_GETSUPPORT:
96        ret = copy_to_user((struct watchdog_info __user *)arg, &ident,
97                sizeof(ident)) ? -EFAULT : 0;
98        break;
99
100    case WDIOC_GETTIMEOUT:
101        ret = put_user(wdt_timeout, (int __user *)arg);
102        break;
103
104    case WDIOC_SETTIMEOUT:
105        ret = get_user(wdt_timeout, (int __user *)arg);
106        break;
107
108    case WDIOC_KEEPALIVE:
109        ifxmips_wdt_enable(wdt_timeout);
110        ret = 0;
111        break;
112    }
113    return ret;
114}
115
116static int ifxmips_wdt_open(struct inode *inode, struct file *file)
117{
118    ifxmips_wdt_enable(wdt_timeout);
119    return nonseekable_open(inode, file);
120}
121
122static int ifxmips_wdt_release(struct inode *inode, struct file *file)
123{
124#ifndef CONFIG_WATCHDOG_NOWAYOUT
125    if (wdt_ok_to_close)
126        ifxmips_wdt_disable();
127    else
128#endif
129        printk(KERN_ERR "ifxmips_wdt: watchdog closed without warning,"
130            " rebooting system\n");
131    return 0;
132}
133
134static const struct file_operations ifxmips_wdt_fops = {
135    .owner = THIS_MODULE,
136    .write = ifxmips_wdt_write,
137    .ioctl = ifxmips_wdt_ioctl,
138    .open = ifxmips_wdt_open,
139    .release = ifxmips_wdt_release,
140};
141
142static struct miscdevice ifxmips_wdt_miscdev = {
143    .minor = WATCHDOG_MINOR,
144    .name = "watchdog",
145    .fops = &ifxmips_wdt_fops,
146};
147
148static int ifxmips_wdt_probe(struct platform_device *dev)
149{
150    int err;
151    err = misc_register(&ifxmips_wdt_miscdev);
152    if (err)
153        printk(KERN_INFO "ifxmips_wdt: error creating device\n");
154    else
155        printk(KERN_INFO "ifxmips_wdt: loaded\n");
156    return err;
157}
158
159static int ifxmips_wdt_remove(struct platform_device *dev)
160{
161    ifxmips_wdt_disable();
162    misc_deregister(&ifxmips_wdt_miscdev);
163    return 0;
164}
165
166
167static struct platform_driver ifxmips_wdt_driver = {
168    .probe = ifxmips_wdt_probe,
169    .remove = ifxmips_wdt_remove,
170    .driver = {
171        .name = "ifxmips_wdt",
172        .owner = THIS_MODULE,
173    },
174};
175
176static int __init init_ifxmips_wdt(void)
177{
178    int ret = platform_driver_register(&ifxmips_wdt_driver);
179    if (ret)
180        printk(KERN_INFO "ifxmips_wdt: error registering platfom driver!");
181    return ret;
182}
183
184static void __exit exit_ifxmips_wdt(void)
185{
186    platform_driver_unregister(&ifxmips_wdt_driver);
187}
188
189module_init(init_ifxmips_wdt);
190module_exit(exit_ifxmips_wdt);
191
192MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
193MODULE_DESCRIPTION("ifxmips Watchdog");
194MODULE_LICENSE("GPL");
195MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
196

Archive Download this file

Branches:
backfire
history
master
release_2010-11-17
release_2010-12-14
release_2011-02-23
release_2011-05-28
release_2011-08-27
release_2011-11-13
release_2012-03-18
release_2012-04-09
release_2012-10-11
uclibc_nptl



interactive