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
|
/*
* Watchdog timer for PowerPC Book-E systems
*
* Author: Matthew McClintock
* Maintainer: Kumar Gala <galak@kernel.crashing.org>
*
* Copyright 2005, 2008 Freescale Semiconductor Inc.
*
* 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.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/miscdevice.h>
#include <linux/notifier.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <asm/reg_booke.h>
#include <asm/system.h>
/* If the kernel parameter wdt=1, the watchdog will be enabled at boot.
* Also, the wdt_period sets the watchdog timer period timeout.
* For E500 cpus the wdt_period sets which bit changing from 0->1 will
* trigger a watchog timeout. This watchdog timeout will occur 3 times, the
* first time nothing will happen, the second time a watchdog exception will
* occur, and the final time the board will reset.
*/
#ifdef CONFIG_FSL_BOOKE
#define WDT_PERIOD_DEFAULT 63 /* Ex. wdt_period=28 bus=333Mhz,reset=~40sec */
#else
#define WDT_PERIOD_DEFAULT 3 /* Refer to the PPC40x and PPC4xx manuals */
#endif /* for timing information */
u32 booke_wdt_enabled;
u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
#ifdef CONFIG_FSL_BOOKE
#define WDTP(x) ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
#else
#define WDTP(x) (TCR_WP(x))
#endif
static DEFINE_SPINLOCK(booke_wdt_lock);
static void __booke_wdt_ping(void *data)
{
mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
}
static void booke_wdt_ping(void)
{
on_each_cpu(__booke_wdt_ping, NULL, 0);
}
static void __booke_wdt_enable(void *data)
{
u32 val;
/* clear status before enabling watchdog */
__booke_wdt_ping(NULL);
val = mfspr(SPRN_TCR);
val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
mtspr(SPRN_TCR, val);
}
static ssize_t booke_wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
booke_wdt_ping();
return count;
}
static struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "PowerPC Book-E Watchdog",
};
static long booke_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
u32 tmp = 0;
u32 __user *p = (u32 __user *)arg;
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(arg, &ident, sizeof(struct watchdog_info)))
return -EFAULT;
case WDIOC_GETSTATUS:
return put_user(ident.options, p);
case WDIOC_GETBOOTSTATUS:
/* XXX: something is clearing TSR */
tmp = mfspr(SPRN_TSR) & TSR_WRS(3);
/* returns 1 if last reset was caused by the WDT */
return (tmp ? 1 : 0);
case WDIOC_KEEPALIVE:
booke_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(booke_wdt_period, p))
return -EFAULT;
mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP(0)) |
WDTP(booke_wdt_period));
return 0;
case WDIOC_GETTIMEOUT:
return put_user(booke_wdt_period, p);
case WDIOC_SETOPTIONS:
if (get_user(tmp, p))
return -EINVAL;
if (tmp == WDIOS_ENABLECARD) {
booke_wdt_ping();
break;
} else
return -EINVAL;
return 0;
default:
return -ENOTTY;
}
return 0;
}
static int booke_wdt_open(struct inode *inode, struct file *file)
{
spin_lock(&booke_wdt_lock);
if (booke_wdt_enabled == 0) {
booke_wdt_enabled = 1;
on_each_cpu(__booke_wdt_enable, NULL, 0);
printk(KERN_INFO
"PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
booke_wdt_period);
}
spin_unlock(&booke_wdt_lock);
return nonseekable_open(inode, file);
}
static const struct file_operations booke_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = booke_wdt_write,
.unlocked_ioctl = booke_wdt_ioctl,
.open = booke_wdt_open,
};
static struct miscdevice booke_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &booke_wdt_fops,
};
static void __exit booke_wdt_exit(void)
{
misc_deregister(&booke_wdt_miscdev);
}
static int __init booke_wdt_init(void)
{
int ret = 0;
printk(KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n");
ident.firmware_version = cur_cpu_spec->pvr_value;
ret = misc_register(&booke_wdt_miscdev);
if (ret) {
printk(KERN_CRIT "Cannot register miscdev on minor=%d: %d\n",
WATCHDOG_MINOR, ret);
return ret;
}
spin_lock(&booke_wdt_lock);
if (booke_wdt_enabled == 1) {
printk(KERN_INFO
"PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
booke_wdt_period);
on_each_cpu(__booke_wdt_enable, NULL, 0);
}
spin_unlock(&booke_wdt_lock);
return ret;
}
device_initcall(booke_wdt_init);
|
