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
|
/*
* Watchdog driver for Cirrus Logic EP93xx family of devices.
*
* Copyright (c) 2004 Ray Lehtiniemi
* Copyright (c) 2006 Tower Technologies
* Based on ep93xx driver, bits from alim7101_wdt.c
*
* Authors: Ray Lehtiniemi <rayl@mail.com>,
* Alessandro Zummo <a.zummo@towertech.it>
*
* Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
* Convert to a platform device and use the watchdog framework API
*
* 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.
*
* This watchdog fires after 250msec, which is a too short interval
* for us to rely on the user space daemon alone. So we ping the
* wdt each ~200msec and eventually stop doing it if the user space
* daemon dies.
*
* TODO:
*
* - Test last reset from watchdog status
* - Add a few missing ioctls
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/io.h>
#define WDT_VERSION "0.4"
/* default timeout (secs) */
#define WDT_TIMEOUT 30
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
static unsigned int timeout = WDT_TIMEOUT;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (1<=timeout<=3600, default="
__MODULE_STRING(WDT_TIMEOUT) ")");
static void __iomem *mmio_base;
static struct timer_list timer;
static unsigned long next_heartbeat;
#define EP93XX_WATCHDOG 0x00
#define EP93XX_WDSTATUS 0x04
/* reset the wdt every ~200ms - the heartbeat of the device is 0.250 seconds*/
#define WDT_INTERVAL (HZ/5)
static void ep93xx_wdt_timer_ping(unsigned long data)
{
if (time_before(jiffies, next_heartbeat))
writel(0x5555, mmio_base + EP93XX_WATCHDOG);
/* Re-set the timer interval */
mod_timer(&timer, jiffies + WDT_INTERVAL);
}
static int ep93xx_wdt_start(struct watchdog_device *wdd)
{
next_heartbeat = jiffies + (timeout * HZ);
writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
mod_timer(&timer, jiffies + WDT_INTERVAL);
return 0;
}
static int ep93xx_wdt_stop(struct watchdog_device *wdd)
{
del_timer_sync(&timer);
writel(0xaa55, mmio_base + EP93XX_WATCHDOG);
return 0;
}
static int ep93xx_wdt_keepalive(struct watchdog_device *wdd)
{
/* user land ping */
next_heartbeat = jiffies + (timeout * HZ);
return 0;
}
static const struct watchdog_info ep93xx_wdt_ident = {
.options = WDIOF_CARDRESET |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.identity = "EP93xx Watchdog",
};
static struct watchdog_ops ep93xx_wdt_ops = {
.owner = THIS_MODULE,
.start = ep93xx_wdt_start,
.stop = ep93xx_wdt_stop,
.ping = ep93xx_wdt_keepalive,
};
static struct watchdog_device ep93xx_wdt_wdd = {
.info = &ep93xx_wdt_ident,
.ops = &ep93xx_wdt_ops,
};
static int ep93xx_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
unsigned long val;
int err;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mmio_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(mmio_base))
return PTR_ERR(mmio_base);
if (timeout < 1 || timeout > 3600) {
timeout = WDT_TIMEOUT;
dev_warn(&pdev->dev,
"timeout value must be 1<=x<=3600, using %d\n",
timeout);
}
val = readl(mmio_base + EP93XX_WATCHDOG);
ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
ep93xx_wdt_wdd.timeout = timeout;
watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout);
setup_timer(&timer, ep93xx_wdt_timer_ping, 1);
err = watchdog_register_device(&ep93xx_wdt_wdd);
if (err)
return err;
dev_info(&pdev->dev,
"EP93XX watchdog, driver version " WDT_VERSION "%s\n",
(val & 0x08) ? " (nCS1 disable detected)" : "");
return 0;
}
static int ep93xx_wdt_remove(struct platform_device *pdev)
{
watchdog_unregister_device(&ep93xx_wdt_wdd);
return 0;
}
static struct platform_driver ep93xx_wdt_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "ep93xx-wdt",
},
.probe = ep93xx_wdt_probe,
.remove = ep93xx_wdt_remove,
};
module_platform_driver(ep93xx_wdt_driver);
MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_DESCRIPTION("EP93xx Watchdog");
MODULE_LICENSE("GPL");
MODULE_VERSION(WDT_VERSION);
|
