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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
/*
* drivers/watchdog/m54xx_wdt.c
*
* Watchdog driver for ColdFire MCF547x & MCF548x processors
* Copyright 2010 (c) Philippe De Muyter <phdm@macqel.be>
*
* Adapted from the IXP4xx watchdog driver, which carries these notices:
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2004 (c) MontaVista, Software, Inc.
* Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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>
#include <linux/ioport.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <asm/coldfire.h>
#include <asm/m54xxsim.h>
#include <asm/m54xxgpt.h>
static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int heartbeat = 30; /* (secs) Default is 0.5 minute */
static unsigned long wdt_status;
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
static void wdt_enable(void)
{
unsigned int gms0;
/* preserve GPIO usage, if any */
gms0 = __raw_readl(MCF_GPT_GMS0);
if (gms0 & MCF_GPT_GMS_TMS_GPIO)
gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK
| MCF_GPT_GMS_OD);
else
gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD;
__raw_writel(gms0, MCF_GPT_GMS0);
__raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) |
MCF_GPT_GCIR_CNT(0xffff), MCF_GPT_GCIR0);
gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE;
__raw_writel(gms0, MCF_GPT_GMS0);
}
static void wdt_disable(void)
{
unsigned int gms0;
/* disable watchdog */
gms0 = __raw_readl(MCF_GPT_GMS0);
gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE);
__raw_writel(gms0, MCF_GPT_GMS0);
}
static void wdt_keepalive(void)
{
unsigned int gms0;
gms0 = __raw_readl(MCF_GPT_GMS0);
gms0 |= MCF_GPT_GMS_OCPW(0xA5);
__raw_writel(gms0, MCF_GPT_GMS0);
}
static int m54xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
wdt_enable();
return stream_open(inode, file);
}
static ssize_t m54xx_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
}
wdt_keepalive();
}
return len;
}
static const struct watchdog_info ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = "Coldfire M54xx Watchdog",
};
static long m54xx_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
int time;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_KEEPALIVE:
wdt_keepalive();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, (int *)arg);
if (ret)
break;
if (time <= 0 || time > 30) {
ret = -EINVAL;
break;
}
heartbeat = time;
wdt_enable();
/* Fall through */
case WDIOC_GETTIMEOUT:
ret = put_user(heartbeat, (int *)arg);
break;
}
return ret;
}
static int m54xx_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
wdt_disable();
else {
pr_crit("Device closed unexpectedly - timer will not stop\n");
wdt_keepalive();
}
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
return 0;
}
static const struct file_operations m54xx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = m54xx_wdt_write,
.unlocked_ioctl = m54xx_wdt_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = m54xx_wdt_open,
.release = m54xx_wdt_release,
};
static struct miscdevice m54xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &m54xx_wdt_fops,
};
static int __init m54xx_wdt_init(void)
{
if (!request_mem_region(MCF_GPT_GCIR0, 4, "Coldfire M54xx Watchdog")) {
pr_warn("I/O region busy\n");
return -EBUSY;
}
pr_info("driver is loaded\n");
return misc_register(&m54xx_wdt_miscdev);
}
static void __exit m54xx_wdt_exit(void)
{
misc_deregister(&m54xx_wdt_miscdev);
release_mem_region(MCF_GPT_GCIR0, 4);
}
module_init(m54xx_wdt_init);
module_exit(m54xx_wdt_exit);
MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
MODULE_DESCRIPTION("Coldfire M54xx Watchdog");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_LICENSE("GPL");
|
