ebc-c384_wdt.c
3.99 KB
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
/*
* Watchdog timer driver for the WinSystems EBC-C384
* Copyright (C) 2016 William Breathitt Gray
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/isa.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define MODULE_NAME "ebc-c384_wdt"
#define WATCHDOG_TIMEOUT 60
/*
* The timeout value in minutes must fit in a single byte when sent to the
* watchdog timer; the maximum timeout possible is 15300 (255 * 60) seconds.
*/
#define WATCHDOG_MAX_TIMEOUT 15300
#define BASE_ADDR 0x564
#define ADDR_EXTENT 5
#define CFG_ADDR (BASE_ADDR + 1)
#define PET_ADDR (BASE_ADDR + 2)
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static unsigned timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
static int ebc_c384_wdt_start(struct watchdog_device *wdev)
{
unsigned t = wdev->timeout;
/* resolution is in minutes for timeouts greater than 255 seconds */
if (t > 255)
t = DIV_ROUND_UP(t, 60);
outb(t, PET_ADDR);
return 0;
}
static int ebc_c384_wdt_stop(struct watchdog_device *wdev)
{
outb(0x00, PET_ADDR);
return 0;
}
static int ebc_c384_wdt_set_timeout(struct watchdog_device *wdev, unsigned t)
{
/* resolution is in minutes for timeouts greater than 255 seconds */
if (t > 255) {
/* round second resolution up to minute granularity */
wdev->timeout = roundup(t, 60);
/* set watchdog timer for minutes */
outb(0x00, CFG_ADDR);
} else {
wdev->timeout = t;
/* set watchdog timer for seconds */
outb(0x80, CFG_ADDR);
}
return 0;
}
static const struct watchdog_ops ebc_c384_wdt_ops = {
.start = ebc_c384_wdt_start,
.stop = ebc_c384_wdt_stop,
.set_timeout = ebc_c384_wdt_set_timeout
};
static const struct watchdog_info ebc_c384_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT,
.identity = MODULE_NAME
};
static int ebc_c384_wdt_probe(struct device *dev, unsigned int id)
{
struct watchdog_device *wdd;
if (!devm_request_region(dev, BASE_ADDR, ADDR_EXTENT, dev_name(dev))) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
BASE_ADDR, BASE_ADDR + ADDR_EXTENT);
return -EBUSY;
}
wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL);
if (!wdd)
return -ENOMEM;
wdd->info = &ebc_c384_wdt_info;
wdd->ops = &ebc_c384_wdt_ops;
wdd->timeout = WATCHDOG_TIMEOUT;
wdd->min_timeout = 1;
wdd->max_timeout = WATCHDOG_MAX_TIMEOUT;
watchdog_set_nowayout(wdd, nowayout);
if (watchdog_init_timeout(wdd, timeout, dev))
dev_warn(dev, "Invalid timeout (%u seconds), using default (%u seconds)\n",
timeout, WATCHDOG_TIMEOUT);
return devm_watchdog_register_device(dev, wdd);
}
static struct isa_driver ebc_c384_wdt_driver = {
.probe = ebc_c384_wdt_probe,
.driver = {
.name = MODULE_NAME
},
};
static int __init ebc_c384_wdt_init(void)
{
if (!dmi_match(DMI_BOARD_NAME, "EBC-C384 SBC"))
return -ENODEV;
return isa_register_driver(&ebc_c384_wdt_driver, 1);
}
static void __exit ebc_c384_wdt_exit(void)
{
isa_unregister_driver(&ebc_c384_wdt_driver);
}
module_init(ebc_c384_wdt_init);
module_exit(ebc_c384_wdt_exit);
MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
MODULE_DESCRIPTION("WinSystems EBC-C384 watchdog timer driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("isa:" MODULE_NAME);