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 driver for Broadcom BCM2835
*
* "bcm2708_wdog" driver written by Luke Diamand that was obtained from
* branch "rpi-3.6.y" of git://github.com/raspberrypi/linux.git was used
* as a hardware reference for the Broadcom BCM2835 watchdog timer.
*
* Copyright (C) 2013 Lubomir Rintel <lkundrak@v3.sk>
*
* 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/types.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/miscdevice.h>
#define PM_RSTC 0x1c
#define PM_WDOG 0x24
#define PM_PASSWORD 0x5a000000
#define PM_WDOG_TIME_SET 0x000fffff
#define PM_RSTC_WRCFG_CLR 0xffffffcf
#define PM_RSTC_WRCFG_SET 0x00000030
#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
#define PM_RSTC_RESET 0x00000102
#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
struct bcm2835_wdt {
void __iomem *base;
spinlock_t lock;
};
static unsigned int heartbeat;
static bool nowayout = WATCHDOG_NOWAYOUT;
static int bcm2835_wdt_start(struct watchdog_device *wdog)
{
struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
uint32_t cur;
unsigned long flags;
spin_lock_irqsave(&wdt->lock, flags);
writel_relaxed(PM_PASSWORD | (SECS_TO_WDOG_TICKS(wdog->timeout) &
PM_WDOG_TIME_SET), wdt->base + PM_WDOG);
cur = readl_relaxed(wdt->base + PM_RSTC);
writel_relaxed(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) |
PM_RSTC_WRCFG_FULL_RESET, wdt->base + PM_RSTC);
spin_unlock_irqrestore(&wdt->lock, flags);
return 0;
}
static int bcm2835_wdt_stop(struct watchdog_device *wdog)
{
struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC);
dev_info(wdog->dev, "Watchdog timer stopped");
return 0;
}
static int bcm2835_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t)
{
wdog->timeout = t;
return 0;
}
static unsigned int bcm2835_wdt_get_timeleft(struct watchdog_device *wdog)
{
struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
uint32_t ret = readl_relaxed(wdt->base + PM_WDOG);
return WDOG_TICKS_TO_SECS(ret & PM_WDOG_TIME_SET);
}
static struct watchdog_ops bcm2835_wdt_ops = {
.owner = THIS_MODULE,
.start = bcm2835_wdt_start,
.stop = bcm2835_wdt_stop,
.set_timeout = bcm2835_wdt_set_timeout,
.get_timeleft = bcm2835_wdt_get_timeleft,
};
static struct watchdog_info bcm2835_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.identity = "Broadcom BCM2835 Watchdog timer",
};
static struct watchdog_device bcm2835_wdt_wdd = {
.info = &bcm2835_wdt_info,
.ops = &bcm2835_wdt_ops,
.min_timeout = 1,
.max_timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
.timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
};
static int bcm2835_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct bcm2835_wdt *wdt;
int err;
wdt = devm_kzalloc(dev, sizeof(struct bcm2835_wdt), GFP_KERNEL);
if (!wdt) {
dev_err(dev, "Failed to allocate memory for watchdog device");
return -ENOMEM;
}
platform_set_drvdata(pdev, wdt);
spin_lock_init(&wdt->lock);
wdt->base = of_iomap(np, 0);
if (!wdt->base) {
dev_err(dev, "Failed to remap watchdog regs");
return -ENODEV;
}
watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);
watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev);
watchdog_set_nowayout(&bcm2835_wdt_wdd, nowayout);
err = watchdog_register_device(&bcm2835_wdt_wdd);
if (err) {
dev_err(dev, "Failed to register watchdog device");
iounmap(wdt->base);
return err;
}
dev_info(dev, "Broadcom BCM2835 watchdog timer");
return 0;
}
static int bcm2835_wdt_remove(struct platform_device *pdev)
{
struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
watchdog_unregister_device(&bcm2835_wdt_wdd);
iounmap(wdt->base);
return 0;
}
static void bcm2835_wdt_shutdown(struct platform_device *pdev)
{
bcm2835_wdt_stop(&bcm2835_wdt_wdd);
}
static const struct of_device_id bcm2835_wdt_of_match[] = {
{ .compatible = "brcm,bcm2835-pm-wdt", },
{},
};
MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match);
static struct platform_driver bcm2835_wdt_driver = {
.probe = bcm2835_wdt_probe,
.remove = bcm2835_wdt_remove,
.shutdown = bcm2835_wdt_shutdown,
.driver = {
.name = "bcm2835-wdt",
.owner = THIS_MODULE,
.of_match_table = bcm2835_wdt_of_match,
},
};
module_platform_driver(bcm2835_wdt_driver);
module_param(heartbeat, uint, 0);
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer");
MODULE_LICENSE("GPL");
|
