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12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/watchdog.h>
15#include <linux/platform_device.h>
16#include <linux/stmp3xxx_rtc_wdt.h>
17#include <linux/notifier.h>
18#include <linux/reboot.h>
19
20#define WDOG_TICK_RATE 1000
21#define STMP3XXX_DEFAULT_TIMEOUT 19
22#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
23
24static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
25module_param(heartbeat, uint, 0);
26MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
27 __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
28 __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
29
30static int wdt_start(struct watchdog_device *wdd)
31{
32 struct device *dev = watchdog_get_drvdata(wdd);
33 struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
34
35 pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
36 return 0;
37}
38
39static int wdt_stop(struct watchdog_device *wdd)
40{
41 struct device *dev = watchdog_get_drvdata(wdd);
42 struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
43
44 pdata->wdt_set_timeout(dev->parent, 0);
45 return 0;
46}
47
48static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
49{
50 wdd->timeout = new_timeout;
51 return wdt_start(wdd);
52}
53
54static const struct watchdog_info stmp3xxx_wdt_ident = {
55 .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
56 .identity = "STMP3XXX RTC Watchdog",
57};
58
59static const struct watchdog_ops stmp3xxx_wdt_ops = {
60 .owner = THIS_MODULE,
61 .start = wdt_start,
62 .stop = wdt_stop,
63 .set_timeout = wdt_set_timeout,
64};
65
66static struct watchdog_device stmp3xxx_wdd = {
67 .info = &stmp3xxx_wdt_ident,
68 .ops = &stmp3xxx_wdt_ops,
69 .min_timeout = 1,
70 .max_timeout = STMP3XXX_MAX_TIMEOUT,
71 .status = WATCHDOG_NOWAYOUT_INIT_STATUS,
72};
73
74static int wdt_notify_sys(struct notifier_block *nb, unsigned long code,
75 void *unused)
76{
77 switch (code) {
78 case SYS_DOWN:
79 break;
80 case SYS_HALT:
81 case SYS_POWER_OFF:
82 wdt_stop(&stmp3xxx_wdd);
83 break;
84 }
85
86 return NOTIFY_DONE;
87}
88
89static struct notifier_block wdt_notifier = {
90 .notifier_call = wdt_notify_sys,
91};
92
93static int stmp3xxx_wdt_probe(struct platform_device *pdev)
94{
95 int ret;
96
97 watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);
98
99 stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
100 stmp3xxx_wdd.parent = &pdev->dev;
101
102 ret = watchdog_register_device(&stmp3xxx_wdd);
103 if (ret < 0) {
104 dev_err(&pdev->dev, "cannot register watchdog device\n");
105 return ret;
106 }
107
108 if (register_reboot_notifier(&wdt_notifier))
109 dev_warn(&pdev->dev, "cannot register reboot notifier\n");
110
111 dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
112 stmp3xxx_wdd.timeout);
113 return 0;
114}
115
116static int stmp3xxx_wdt_remove(struct platform_device *pdev)
117{
118 unregister_reboot_notifier(&wdt_notifier);
119 watchdog_unregister_device(&stmp3xxx_wdd);
120 return 0;
121}
122
123static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
124{
125 struct watchdog_device *wdd = &stmp3xxx_wdd;
126
127 if (watchdog_active(wdd))
128 return wdt_stop(wdd);
129
130 return 0;
131}
132
133static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
134{
135 struct watchdog_device *wdd = &stmp3xxx_wdd;
136
137 if (watchdog_active(wdd))
138 return wdt_start(wdd);
139
140 return 0;
141}
142
143static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
144 stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
145
146static struct platform_driver stmp3xxx_wdt_driver = {
147 .driver = {
148 .name = "stmp3xxx_rtc_wdt",
149 .pm = &stmp3xxx_wdt_pm_ops,
150 },
151 .probe = stmp3xxx_wdt_probe,
152 .remove = stmp3xxx_wdt_remove,
153};
154module_platform_driver(stmp3xxx_wdt_driver);
155
156MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
157MODULE_LICENSE("GPL v2");
158MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
159
