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
|
/*
* MOXA ART SoCs watchdog driver.
*
* Copyright (C) 2013 Jonas Jensen
*
* Jonas Jensen <jonas.jensen@gmail.com>
*
* 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.
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
#include <linux/moduleparam.h>
#define REG_COUNT 0x4
#define REG_MODE 0x8
#define REG_ENABLE 0xC
struct moxart_wdt_dev {
struct watchdog_device dev;
void __iomem *base;
unsigned int clock_frequency;
struct notifier_block restart_handler;
};
static int heartbeat;
static int moxart_restart_handle(struct notifier_block *this,
unsigned long mode, void *cmd)
{
struct moxart_wdt_dev *moxart_wdt = container_of(this,
struct moxart_wdt_dev,
restart_handler);
writel(1, moxart_wdt->base + REG_COUNT);
writel(0x5ab9, moxart_wdt->base + REG_MODE);
writel(0x03, moxart_wdt->base + REG_ENABLE);
return NOTIFY_DONE;
}
static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
{
struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
writel(0, moxart_wdt->base + REG_ENABLE);
return 0;
}
static int moxart_wdt_start(struct watchdog_device *wdt_dev)
{
struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
writel(moxart_wdt->clock_frequency * wdt_dev->timeout,
moxart_wdt->base + REG_COUNT);
writel(0x5ab9, moxart_wdt->base + REG_MODE);
writel(0x03, moxart_wdt->base + REG_ENABLE);
return 0;
}
static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
wdt_dev->timeout = timeout;
return 0;
}
static const struct watchdog_info moxart_wdt_info = {
.identity = "moxart-wdt",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops moxart_wdt_ops = {
.owner = THIS_MODULE,
.start = moxart_wdt_start,
.stop = moxart_wdt_stop,
.set_timeout = moxart_wdt_set_timeout,
};
static int moxart_wdt_probe(struct platform_device *pdev)
{
struct moxart_wdt_dev *moxart_wdt;
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node;
struct resource *res;
struct clk *clk;
int err;
unsigned int max_timeout;
bool nowayout = WATCHDOG_NOWAYOUT;
moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL);
if (!moxart_wdt)
return -ENOMEM;
platform_set_drvdata(pdev, moxart_wdt);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
moxart_wdt->base = devm_ioremap_resource(dev, res);
if (IS_ERR(moxart_wdt->base))
return PTR_ERR(moxart_wdt->base);
clk = of_clk_get(node, 0);
if (IS_ERR(clk)) {
pr_err("%s: of_clk_get failed\n", __func__);
return PTR_ERR(clk);
}
moxart_wdt->clock_frequency = clk_get_rate(clk);
if (moxart_wdt->clock_frequency == 0) {
pr_err("%s: incorrect clock frequency\n", __func__);
return -EINVAL;
}
max_timeout = UINT_MAX / moxart_wdt->clock_frequency;
moxart_wdt->dev.info = &moxart_wdt_info;
moxart_wdt->dev.ops = &moxart_wdt_ops;
moxart_wdt->dev.timeout = max_timeout;
moxart_wdt->dev.min_timeout = 1;
moxart_wdt->dev.max_timeout = max_timeout;
moxart_wdt->dev.parent = dev;
watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
err = watchdog_register_device(&moxart_wdt->dev);
if (err)
return err;
moxart_wdt->restart_handler.notifier_call = moxart_restart_handle;
moxart_wdt->restart_handler.priority = 128;
err = register_restart_handler(&moxart_wdt->restart_handler);
if (err)
dev_err(dev, "cannot register restart notifier (err=%d)\n",
err);
dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
moxart_wdt->dev.timeout, nowayout);
return 0;
}
static int moxart_wdt_remove(struct platform_device *pdev)
{
struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
unregister_restart_handler(&moxart_wdt->restart_handler);
moxart_wdt_stop(&moxart_wdt->dev);
return 0;
}
static const struct of_device_id moxart_watchdog_match[] = {
{ .compatible = "moxa,moxart-watchdog" },
{ },
};
MODULE_DEVICE_TABLE(of, moxart_watchdog_match);
static struct platform_driver moxart_wdt_driver = {
.probe = moxart_wdt_probe,
.remove = moxart_wdt_remove,
.driver = {
.name = "moxart-watchdog",
.of_match_table = moxart_watchdog_match,
},
};
module_platform_driver(moxart_wdt_driver);
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
MODULE_DESCRIPTION("MOXART watchdog driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
|
