aboutsummaryrefslogtreecommitdiff
path: root/drivers/watchdog/ux500_wdt.c
blob: 5aed9d7ad47e6ee81e96b4f16b15aa653a6a9482 (plain)
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
/*
 * Copyright (C) ST-Ericsson SA 2011-2013
 *
 * License Terms: GNU General Public License v2
 *
 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/platform_data/ux500_wdt.h>

#include <linux/mfd/dbx500-prcmu.h>

#define WATCHDOG_TIMEOUT 600 /* 10 minutes */

#define WATCHDOG_MIN	0
#define WATCHDOG_MAX28	268435  /* 28 bit resolution in ms == 268435.455 s */
#define WATCHDOG_MAX32	4294967 /* 32 bit resolution in ms == 4294967.295 s */

static unsigned int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. default="
				__MODULE_STRING(WATCHDOG_TIMEOUT) ".");

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 int ux500_wdt_start(struct watchdog_device *wdd)
{
	return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
}

static int ux500_wdt_stop(struct watchdog_device *wdd)
{
	return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
}

static int ux500_wdt_keepalive(struct watchdog_device *wdd)
{
	return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
}

static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
				 unsigned int timeout)
{
	ux500_wdt_stop(wdd);
	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
	ux500_wdt_start(wdd);

	return 0;
}

static const struct watchdog_info ux500_wdt_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
	.identity = "Ux500 WDT",
	.firmware_version = 1,
};

static const struct watchdog_ops ux500_wdt_ops = {
	.owner = THIS_MODULE,
	.start = ux500_wdt_start,
	.stop  = ux500_wdt_stop,
	.ping  = ux500_wdt_keepalive,
	.set_timeout = ux500_wdt_set_timeout,
};

static struct watchdog_device ux500_wdt = {
	.info = &ux500_wdt_info,
	.ops = &ux500_wdt_ops,
	.min_timeout = WATCHDOG_MIN,
	.max_timeout = WATCHDOG_MAX32,
};

static int ux500_wdt_probe(struct platform_device *pdev)
{
	int ret;
	struct ux500_wdt_data *pdata = dev_get_platdata(&pdev->dev);

	if (pdata) {
		if (pdata->timeout > 0)
			timeout = pdata->timeout;
		if (pdata->has_28_bits_resolution)
			ux500_wdt.max_timeout = WATCHDOG_MAX28;
	}

	watchdog_set_nowayout(&ux500_wdt, nowayout);

	/* disable auto off on sleep */
	prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);

	/* set HW initial value */
	prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);

	ret = watchdog_register_device(&ux500_wdt);
	if (ret)
		return ret;

	dev_info(&pdev->dev, "initialized\n");

	return 0;
}

static int ux500_wdt_remove(struct platform_device *dev)
{
	watchdog_unregister_device(&ux500_wdt);

	return 0;
}

#ifdef CONFIG_PM
static int ux500_wdt_suspend(struct platform_device *pdev,
			     pm_message_t state)
{
	if (watchdog_active(&ux500_wdt)) {
		ux500_wdt_stop(&ux500_wdt);
		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);

		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
		ux500_wdt_start(&ux500_wdt);
	}
	return 0;
}

static int ux500_wdt_resume(struct platform_device *pdev)
{
	if (watchdog_active(&ux500_wdt)) {
		ux500_wdt_stop(&ux500_wdt);
		prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);

		prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
		ux500_wdt_start(&ux500_wdt);
	}
	return 0;
}
#else
#define ux500_wdt_suspend NULL
#define ux500_wdt_resume NULL
#endif

static struct platform_driver ux500_wdt_driver = {
	.probe		= ux500_wdt_probe,
	.remove		= ux500_wdt_remove,
	.suspend	= ux500_wdt_suspend,
	.resume		= ux500_wdt_resume,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "ux500_wdt",
	},
};

module_platform_driver(ux500_wdt_driver);

MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
MODULE_DESCRIPTION("Ux500 Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ux500_wdt");