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de6303ab WS |
1 | /* |
2 | * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28 | |
3 | * | |
cf82f52d | 4 | * Author: Wolfram Sang <kernel@pengutronix.de> |
de6303ab WS |
5 | * |
6 | * Copyright (C) 2011-12 Wolfram Sang, Pengutronix | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License version 2 as published by | |
10 | * the Free Software Foundation. | |
11 | */ | |
de6303ab WS |
12 | #include <linux/kernel.h> |
13 | #include <linux/module.h> | |
de6303ab WS |
14 | #include <linux/watchdog.h> |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/stmp3xxx_rtc_wdt.h> | |
17 | ||
18 | #define WDOG_TICK_RATE 1000 /* 1 kHz clock */ | |
19 | #define STMP3XXX_DEFAULT_TIMEOUT 19 | |
20 | #define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE) | |
21 | ||
22 | static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT; | |
23 | module_param(heartbeat, uint, 0); | |
24 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to " | |
25 | __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default " | |
26 | __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT)); | |
27 | ||
28 | static int wdt_start(struct watchdog_device *wdd) | |
29 | { | |
30 | struct device *dev = watchdog_get_drvdata(wdd); | |
bc8fdfbe | 31 | struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev); |
de6303ab WS |
32 | |
33 | pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE); | |
34 | return 0; | |
35 | } | |
36 | ||
37 | static int wdt_stop(struct watchdog_device *wdd) | |
38 | { | |
39 | struct device *dev = watchdog_get_drvdata(wdd); | |
bc8fdfbe | 40 | struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev); |
de6303ab WS |
41 | |
42 | pdata->wdt_set_timeout(dev->parent, 0); | |
43 | return 0; | |
44 | } | |
45 | ||
46 | static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout) | |
47 | { | |
48 | wdd->timeout = new_timeout; | |
49 | return wdt_start(wdd); | |
50 | } | |
51 | ||
52 | static const struct watchdog_info stmp3xxx_wdt_ident = { | |
53 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
54 | .identity = "STMP3XXX RTC Watchdog", | |
55 | }; | |
56 | ||
57 | static const struct watchdog_ops stmp3xxx_wdt_ops = { | |
58 | .owner = THIS_MODULE, | |
59 | .start = wdt_start, | |
60 | .stop = wdt_stop, | |
61 | .set_timeout = wdt_set_timeout, | |
62 | }; | |
63 | ||
64 | static struct watchdog_device stmp3xxx_wdd = { | |
65 | .info = &stmp3xxx_wdt_ident, | |
66 | .ops = &stmp3xxx_wdt_ops, | |
67 | .min_timeout = 1, | |
68 | .max_timeout = STMP3XXX_MAX_TIMEOUT, | |
69 | .status = WATCHDOG_NOWAYOUT_INIT_STATUS, | |
70 | }; | |
71 | ||
72 | static int stmp3xxx_wdt_probe(struct platform_device *pdev) | |
73 | { | |
74 | int ret; | |
75 | ||
76 | watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev); | |
77 | ||
78 | stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT); | |
6551881c | 79 | stmp3xxx_wdd.parent = &pdev->dev; |
de6303ab WS |
80 | |
81 | ret = watchdog_register_device(&stmp3xxx_wdd); | |
82 | if (ret < 0) { | |
83 | dev_err(&pdev->dev, "cannot register watchdog device\n"); | |
84 | return ret; | |
85 | } | |
86 | ||
87 | dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n", | |
88 | stmp3xxx_wdd.timeout); | |
89 | return 0; | |
90 | } | |
91 | ||
92 | static int stmp3xxx_wdt_remove(struct platform_device *pdev) | |
93 | { | |
94 | watchdog_unregister_device(&stmp3xxx_wdd); | |
95 | return 0; | |
96 | } | |
97 | ||
3281b85c JU |
98 | static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev) |
99 | { | |
100 | struct watchdog_device *wdd = &stmp3xxx_wdd; | |
101 | ||
102 | if (watchdog_active(wdd)) | |
103 | return wdt_stop(wdd); | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
108 | static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev) | |
109 | { | |
110 | struct watchdog_device *wdd = &stmp3xxx_wdd; | |
111 | ||
112 | if (watchdog_active(wdd)) | |
113 | return wdt_start(wdd); | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops, | |
119 | stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume); | |
120 | ||
de6303ab WS |
121 | static struct platform_driver stmp3xxx_wdt_driver = { |
122 | .driver = { | |
123 | .name = "stmp3xxx_rtc_wdt", | |
3281b85c | 124 | .pm = &stmp3xxx_wdt_pm_ops, |
de6303ab WS |
125 | }, |
126 | .probe = stmp3xxx_wdt_probe, | |
127 | .remove = stmp3xxx_wdt_remove, | |
128 | }; | |
129 | module_platform_driver(stmp3xxx_wdt_driver); | |
130 | ||
131 | MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver"); | |
132 | MODULE_LICENSE("GPL v2"); | |
cf82f52d | 133 | MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); |