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de6303ab WS |
1 | /* |
2 | * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28 | |
3 | * | |
4 | * Author: Wolfram Sang <w.sang@pengutronix.de> | |
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 | */ | |
12 | #include <linux/init.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/miscdevice.h> | |
16 | #include <linux/watchdog.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/stmp3xxx_rtc_wdt.h> | |
19 | ||
20 | #define WDOG_TICK_RATE 1000 /* 1 kHz clock */ | |
21 | #define STMP3XXX_DEFAULT_TIMEOUT 19 | |
22 | #define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE) | |
23 | ||
24 | static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT; | |
25 | module_param(heartbeat, uint, 0); | |
26 | MODULE_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 | ||
30 | static int wdt_start(struct watchdog_device *wdd) | |
31 | { | |
32 | struct device *dev = watchdog_get_drvdata(wdd); | |
33 | struct stmp3xxx_wdt_pdata *pdata = dev->platform_data; | |
34 | ||
35 | pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE); | |
36 | return 0; | |
37 | } | |
38 | ||
39 | static int wdt_stop(struct watchdog_device *wdd) | |
40 | { | |
41 | struct device *dev = watchdog_get_drvdata(wdd); | |
42 | struct stmp3xxx_wdt_pdata *pdata = dev->platform_data; | |
43 | ||
44 | pdata->wdt_set_timeout(dev->parent, 0); | |
45 | return 0; | |
46 | } | |
47 | ||
48 | static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout) | |
49 | { | |
50 | wdd->timeout = new_timeout; | |
51 | return wdt_start(wdd); | |
52 | } | |
53 | ||
54 | static const struct watchdog_info stmp3xxx_wdt_ident = { | |
55 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
56 | .identity = "STMP3XXX RTC Watchdog", | |
57 | }; | |
58 | ||
59 | static 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 | ||
66 | static 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 | ||
74 | static int stmp3xxx_wdt_probe(struct platform_device *pdev) | |
75 | { | |
76 | int ret; | |
77 | ||
78 | watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev); | |
79 | ||
80 | stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT); | |
81 | ||
82 | ret = watchdog_register_device(&stmp3xxx_wdd); | |
83 | if (ret < 0) { | |
84 | dev_err(&pdev->dev, "cannot register watchdog device\n"); | |
85 | return ret; | |
86 | } | |
87 | ||
88 | dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n", | |
89 | stmp3xxx_wdd.timeout); | |
90 | return 0; | |
91 | } | |
92 | ||
93 | static int stmp3xxx_wdt_remove(struct platform_device *pdev) | |
94 | { | |
95 | watchdog_unregister_device(&stmp3xxx_wdd); | |
96 | return 0; | |
97 | } | |
98 | ||
99 | static struct platform_driver stmp3xxx_wdt_driver = { | |
100 | .driver = { | |
101 | .name = "stmp3xxx_rtc_wdt", | |
102 | }, | |
103 | .probe = stmp3xxx_wdt_probe, | |
104 | .remove = stmp3xxx_wdt_remove, | |
105 | }; | |
106 | module_platform_driver(stmp3xxx_wdt_driver); | |
107 | ||
108 | MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver"); | |
109 | MODULE_LICENSE("GPL v2"); | |
110 | MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>"); | |
111 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |