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d0173278 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
3d3a6d18 AK |
2 | /* |
3 | * Retu watchdog driver | |
4 | * | |
5 | * Copyright (C) 2004, 2005 Nokia Corporation | |
6 | * | |
7 | * Based on code written by Amit Kucheria and Michael Buesch. | |
8 | * Rewritten by Aaro Koskinen. | |
3d3a6d18 AK |
9 | */ |
10 | ||
3d3a6d18 AK |
11 | #include <linux/slab.h> |
12 | #include <linux/errno.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/mfd/retu.h> | |
17 | #include <linux/watchdog.h> | |
18 | #include <linux/platform_device.h> | |
19 | ||
20 | /* Watchdog timer values in seconds */ | |
21 | #define RETU_WDT_MAX_TIMER 63 | |
22 | ||
23 | struct retu_wdt_dev { | |
24 | struct retu_dev *rdev; | |
25 | struct device *dev; | |
26 | struct delayed_work ping_work; | |
27 | }; | |
28 | ||
29 | /* | |
30 | * Since Retu watchdog cannot be disabled in hardware, we must kick it | |
31 | * with a timer until userspace watchdog software takes over. If | |
32 | * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding. | |
33 | */ | |
34 | static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev) | |
35 | { | |
36 | retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); | |
37 | schedule_delayed_work(&wdev->ping_work, | |
38 | round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2)); | |
39 | } | |
40 | ||
41 | static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev) | |
42 | { | |
43 | retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); | |
44 | cancel_delayed_work_sync(&wdev->ping_work); | |
45 | } | |
46 | ||
47 | static void retu_wdt_ping_work(struct work_struct *work) | |
48 | { | |
49 | struct retu_wdt_dev *wdev = container_of(to_delayed_work(work), | |
50 | struct retu_wdt_dev, ping_work); | |
51 | retu_wdt_ping_enable(wdev); | |
52 | } | |
53 | ||
54 | static int retu_wdt_start(struct watchdog_device *wdog) | |
55 | { | |
56 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
57 | ||
58 | retu_wdt_ping_disable(wdev); | |
59 | ||
60 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); | |
61 | } | |
62 | ||
63 | static int retu_wdt_stop(struct watchdog_device *wdog) | |
64 | { | |
65 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
66 | ||
67 | retu_wdt_ping_enable(wdev); | |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
72 | static int retu_wdt_ping(struct watchdog_device *wdog) | |
73 | { | |
74 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
75 | ||
76 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); | |
77 | } | |
78 | ||
79 | static int retu_wdt_set_timeout(struct watchdog_device *wdog, | |
80 | unsigned int timeout) | |
81 | { | |
82 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
83 | ||
84 | wdog->timeout = timeout; | |
85 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); | |
86 | } | |
87 | ||
88 | static const struct watchdog_info retu_wdt_info = { | |
fb1cbeae | 89 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, |
3d3a6d18 AK |
90 | .identity = "Retu watchdog", |
91 | }; | |
92 | ||
93 | static const struct watchdog_ops retu_wdt_ops = { | |
94 | .owner = THIS_MODULE, | |
95 | .start = retu_wdt_start, | |
96 | .stop = retu_wdt_stop, | |
97 | .ping = retu_wdt_ping, | |
98 | .set_timeout = retu_wdt_set_timeout, | |
99 | }; | |
100 | ||
101 | static int retu_wdt_probe(struct platform_device *pdev) | |
102 | { | |
103 | struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); | |
104 | bool nowayout = WATCHDOG_NOWAYOUT; | |
105 | struct watchdog_device *retu_wdt; | |
106 | struct retu_wdt_dev *wdev; | |
107 | int ret; | |
108 | ||
109 | retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL); | |
110 | if (!retu_wdt) | |
111 | return -ENOMEM; | |
112 | ||
113 | wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); | |
114 | if (!wdev) | |
115 | return -ENOMEM; | |
116 | ||
117 | retu_wdt->info = &retu_wdt_info; | |
118 | retu_wdt->ops = &retu_wdt_ops; | |
119 | retu_wdt->timeout = RETU_WDT_MAX_TIMER; | |
120 | retu_wdt->min_timeout = 0; | |
121 | retu_wdt->max_timeout = RETU_WDT_MAX_TIMER; | |
6551881c | 122 | retu_wdt->parent = &pdev->dev; |
3d3a6d18 AK |
123 | |
124 | watchdog_set_drvdata(retu_wdt, wdev); | |
125 | watchdog_set_nowayout(retu_wdt, nowayout); | |
126 | ||
127 | wdev->rdev = rdev; | |
128 | wdev->dev = &pdev->dev; | |
129 | ||
130 | INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work); | |
131 | ||
132 | ret = watchdog_register_device(retu_wdt); | |
133 | if (ret < 0) | |
134 | return ret; | |
135 | ||
136 | if (nowayout) | |
137 | retu_wdt_ping(retu_wdt); | |
138 | else | |
139 | retu_wdt_ping_enable(wdev); | |
140 | ||
141 | platform_set_drvdata(pdev, retu_wdt); | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | static int retu_wdt_remove(struct platform_device *pdev) | |
147 | { | |
148 | struct watchdog_device *wdog = platform_get_drvdata(pdev); | |
149 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); | |
150 | ||
151 | watchdog_unregister_device(wdog); | |
152 | cancel_delayed_work_sync(&wdev->ping_work); | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
157 | static struct platform_driver retu_wdt_driver = { | |
158 | .probe = retu_wdt_probe, | |
159 | .remove = retu_wdt_remove, | |
160 | .driver = { | |
161 | .name = "retu-wdt", | |
162 | }, | |
163 | }; | |
164 | module_platform_driver(retu_wdt_driver); | |
165 | ||
166 | MODULE_ALIAS("platform:retu-wdt"); | |
167 | MODULE_DESCRIPTION("Retu watchdog"); | |
168 | MODULE_AUTHOR("Amit Kucheria"); | |
169 | MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>"); | |
170 | MODULE_LICENSE("GPL"); |