1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/*
* Watchdog driver for the SA11x0/PXA2xx
*
* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
* Based on SoftDog driver by Alan Cox <alan@redhat.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
*
* 27/11/2000 Initial release
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/bitops.h>
#ifdef CONFIG_ARCH_PXA
#include <asm/arch/pxa-regs.h>
#endif
#include <asm/hardware.h>
#include <asm/uaccess.h>
#define OSCR_FREQ CLOCK_TICK_RATE
static unsigned long sa1100wdt_users;
static int pre_margin;
static int boot_status;
/*
* Allow only one person to hold it open
*/
static int sa1100dog_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(1,&sa1100wdt_users))
return -EBUSY;
/* Activate SA1100 Watchdog timer */
OSMR3 = OSCR + pre_margin;
OSSR = OSSR_M3;
OWER = OWER_WME;
OIER |= OIER_E3;
return nonseekable_open(inode, file);
}
/*
* The watchdog cannot be disabled.
*
* Previous comments suggested that turning off the interrupt by
* clearing OIER[E3] would prevent the watchdog timing out but this
* does not appear to be true (at least on the PXA255).
*/
static int sa1100dog_release(struct inode *inode, struct file *file)
{
printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
clear_bit(1, &sa1100wdt_users);
return 0;
}
static ssize_t sa1100dog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
{
if (len)
/* Refresh OSMR3 timer. */
OSMR3 = OSCR + pre_margin;
return len;
}
static struct watchdog_info ident = {
.options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "SA1100/PXA255 Watchdog",
};
static int sa1100dog_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int ret = -ENOTTY;
int time;
void __user *argp = (void __user *)arg;
int __user *p = argp;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user(argp, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, p);
break;
case WDIOC_GETBOOTSTATUS:
ret = put_user(boot_status, p);
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, p);
if (ret)
break;
if (time <= 0 || time > 255) {
ret = -EINVAL;
break;
}
pre_margin = OSCR_FREQ * time;
OSMR3 = OSCR + pre_margin;
/*fall through*/
case WDIOC_GETTIMEOUT:
ret = put_user(pre_margin / OSCR_FREQ, p);
break;
case WDIOC_KEEPALIVE:
OSMR3 = OSCR + pre_margin;
ret = 0;
break;
}
return ret;
}
static const struct file_operations sa1100dog_fops =
{
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = sa1100dog_write,
.ioctl = sa1100dog_ioctl,
.open = sa1100dog_open,
.release = sa1100dog_release,
};
static struct miscdevice sa1100dog_miscdev =
{
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &sa1100dog_fops,
};
static int margin __initdata = 60; /* (secs) Default is 1 minute */
static int __init sa1100dog_init(void)
{
int ret;
/*
* Read the reset status, and save it for later. If
* we suspend, RCSR will be cleared, and the watchdog
* reset reason will be lost.
*/
boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0;
pre_margin = OSCR_FREQ * margin;
ret = misc_register(&sa1100dog_miscdev);
if (ret == 0)
printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
margin);
return ret;
}
static void __exit sa1100dog_exit(void)
{
misc_deregister(&sa1100dog_miscdev);
}
module_init(sa1100dog_init);
module_exit(sa1100dog_exit);
MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
