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3d3a6d18 AK |
1 | /* |
2 | * Retu watchdog driver | |
3 | * | |
4 | * Copyright (C) 2004, 2005 Nokia Corporation | |
5 | * | |
6 | * Based on code written by Amit Kucheria and Michael Buesch. | |
7 | * Rewritten by Aaro Koskinen. | |
8 | * | |
9 | * This file is subject to the terms and conditions of the GNU General | |
10 | * Public License. See the file "COPYING" in the main directory of this | |
11 | * archive for more details. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | */ | |
18 | ||
3d3a6d18 AK |
19 | #include <linux/slab.h> |
20 | #include <linux/errno.h> | |
21 | #include <linux/device.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/mfd/retu.h> | |
25 | #include <linux/watchdog.h> | |
26 | #include <linux/platform_device.h> | |
27 | ||
28 | /* Watchdog timer values in seconds */ | |
29 | #define RETU_WDT_MAX_TIMER 63 | |
30 | ||
31 | struct retu_wdt_dev { | |
32 | struct retu_dev *rdev; | |
33 | struct device *dev; | |
34 | struct delayed_work ping_work; | |
35 | }; | |
36 | ||
37 | /* | |
38 | * Since Retu watchdog cannot be disabled in hardware, we must kick it | |
39 | * with a timer until userspace watchdog software takes over. If | |
40 | * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding. | |
41 | */ | |
42 | static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev) | |
43 | { | |
44 | retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); | |
45 | schedule_delayed_work(&wdev->ping_work, | |
46 | round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2)); | |
47 | } | |
48 | ||
49 | static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev) | |
50 | { | |
51 | retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); | |
52 | cancel_delayed_work_sync(&wdev->ping_work); | |
53 | } | |
54 | ||
55 | static void retu_wdt_ping_work(struct work_struct *work) | |
56 | { | |
57 | struct retu_wdt_dev *wdev = container_of(to_delayed_work(work), | |
58 | struct retu_wdt_dev, ping_work); | |
59 | retu_wdt_ping_enable(wdev); | |
60 | } | |
61 | ||
62 | static int retu_wdt_start(struct watchdog_device *wdog) | |
63 | { | |
64 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
65 | ||
66 | retu_wdt_ping_disable(wdev); | |
67 | ||
68 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); | |
69 | } | |
70 | ||
71 | static int retu_wdt_stop(struct watchdog_device *wdog) | |
72 | { | |
73 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
74 | ||
75 | retu_wdt_ping_enable(wdev); | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static int retu_wdt_ping(struct watchdog_device *wdog) | |
81 | { | |
82 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
83 | ||
84 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); | |
85 | } | |
86 | ||
87 | static int retu_wdt_set_timeout(struct watchdog_device *wdog, | |
88 | unsigned int timeout) | |
89 | { | |
90 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
91 | ||
92 | wdog->timeout = timeout; | |
93 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); | |
94 | } | |
95 | ||
96 | static const struct watchdog_info retu_wdt_info = { | |
97 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
98 | .identity = "Retu watchdog", | |
99 | }; | |
100 | ||
101 | static const struct watchdog_ops retu_wdt_ops = { | |
102 | .owner = THIS_MODULE, | |
103 | .start = retu_wdt_start, | |
104 | .stop = retu_wdt_stop, | |
105 | .ping = retu_wdt_ping, | |
106 | .set_timeout = retu_wdt_set_timeout, | |
107 | }; | |
108 | ||
109 | static int retu_wdt_probe(struct platform_device *pdev) | |
110 | { | |
111 | struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); | |
112 | bool nowayout = WATCHDOG_NOWAYOUT; | |
113 | struct watchdog_device *retu_wdt; | |
114 | struct retu_wdt_dev *wdev; | |
115 | int ret; | |
116 | ||
117 | retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL); | |
118 | if (!retu_wdt) | |
119 | return -ENOMEM; | |
120 | ||
121 | wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); | |
122 | if (!wdev) | |
123 | return -ENOMEM; | |
124 | ||
125 | retu_wdt->info = &retu_wdt_info; | |
126 | retu_wdt->ops = &retu_wdt_ops; | |
127 | retu_wdt->timeout = RETU_WDT_MAX_TIMER; | |
128 | retu_wdt->min_timeout = 0; | |
129 | retu_wdt->max_timeout = RETU_WDT_MAX_TIMER; | |
130 | ||
131 | watchdog_set_drvdata(retu_wdt, wdev); | |
132 | watchdog_set_nowayout(retu_wdt, nowayout); | |
133 | ||
134 | wdev->rdev = rdev; | |
135 | wdev->dev = &pdev->dev; | |
136 | ||
137 | INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work); | |
138 | ||
139 | ret = watchdog_register_device(retu_wdt); | |
140 | if (ret < 0) | |
141 | return ret; | |
142 | ||
143 | if (nowayout) | |
144 | retu_wdt_ping(retu_wdt); | |
145 | else | |
146 | retu_wdt_ping_enable(wdev); | |
147 | ||
148 | platform_set_drvdata(pdev, retu_wdt); | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
153 | static int retu_wdt_remove(struct platform_device *pdev) | |
154 | { | |
155 | struct watchdog_device *wdog = platform_get_drvdata(pdev); | |
156 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
157 | ||
158 | watchdog_unregister_device(wdog); | |
159 | cancel_delayed_work_sync(&wdev->ping_work); | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
164 | static struct platform_driver retu_wdt_driver = { | |
165 | .probe = retu_wdt_probe, | |
166 | .remove = retu_wdt_remove, | |
167 | .driver = { | |
168 | .name = "retu-wdt", | |
169 | }, | |
170 | }; | |
171 | module_platform_driver(retu_wdt_driver); | |
172 | ||
173 | MODULE_ALIAS("platform:retu-wdt"); | |
174 | MODULE_DESCRIPTION("Retu watchdog"); | |
175 | MODULE_AUTHOR("Amit Kucheria"); | |
176 | MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>"); | |
177 | MODULE_LICENSE("GPL"); |