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2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
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2 | /* |
3 | * Watchdog driver for the wm8350 | |
4 | * | |
5 | * Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com> | |
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6 | */ |
7 | ||
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8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
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10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/kernel.h> | |
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14 | #include <linux/platform_device.h> |
15 | #include <linux/watchdog.h> | |
16 | #include <linux/uaccess.h> | |
17 | #include <linux/mfd/wm8350/core.h> | |
18 | ||
86a1e189 WVS |
19 | static bool nowayout = WATCHDOG_NOWAYOUT; |
20 | module_param(nowayout, bool, 0); | |
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21 | MODULE_PARM_DESC(nowayout, |
22 | "Watchdog cannot be stopped once started (default=" | |
23 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
24 | ||
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25 | static DEFINE_MUTEX(wdt_mutex); |
26 | ||
27 | static struct { | |
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28 | unsigned int time; /* Seconds */ |
29 | u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */ | |
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30 | } wm8350_wdt_cfgs[] = { |
31 | { 1, 0x02 }, | |
32 | { 2, 0x04 }, | |
33 | { 4, 0x05 }, | |
34 | }; | |
35 | ||
2e51d90f AL |
36 | static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev, |
37 | unsigned int timeout) | |
006948ba | 38 | { |
2e51d90f AL |
39 | struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); |
40 | int ret, i; | |
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41 | u16 reg; |
42 | ||
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43 | for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++) |
44 | if (wm8350_wdt_cfgs[i].time == timeout) | |
45 | break; | |
46 | if (i == ARRAY_SIZE(wm8350_wdt_cfgs)) | |
47 | return -EINVAL; | |
48 | ||
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49 | mutex_lock(&wdt_mutex); |
50 | wm8350_reg_unlock(wm8350); | |
51 | ||
52 | reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); | |
53 | reg &= ~WM8350_WDOG_TO_MASK; | |
2e51d90f | 54 | reg |= wm8350_wdt_cfgs[i].val; |
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55 | ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); |
56 | ||
57 | wm8350_reg_lock(wm8350); | |
58 | mutex_unlock(&wdt_mutex); | |
59 | ||
0197c1c4 | 60 | wdt_dev->timeout = timeout; |
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61 | return ret; |
62 | } | |
63 | ||
2e51d90f | 64 | static int wm8350_wdt_start(struct watchdog_device *wdt_dev) |
006948ba | 65 | { |
2e51d90f | 66 | struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); |
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67 | int ret; |
68 | u16 reg; | |
69 | ||
70 | mutex_lock(&wdt_mutex); | |
71 | wm8350_reg_unlock(wm8350); | |
72 | ||
73 | reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); | |
74 | reg &= ~WM8350_WDOG_MODE_MASK; | |
75 | reg |= 0x20; | |
76 | ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); | |
77 | ||
78 | wm8350_reg_lock(wm8350); | |
79 | mutex_unlock(&wdt_mutex); | |
80 | ||
81 | return ret; | |
82 | } | |
83 | ||
2e51d90f | 84 | static int wm8350_wdt_stop(struct watchdog_device *wdt_dev) |
006948ba | 85 | { |
2e51d90f | 86 | struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); |
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87 | int ret; |
88 | u16 reg; | |
89 | ||
90 | mutex_lock(&wdt_mutex); | |
91 | wm8350_reg_unlock(wm8350); | |
92 | ||
93 | reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); | |
94 | reg &= ~WM8350_WDOG_MODE_MASK; | |
95 | ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); | |
96 | ||
97 | wm8350_reg_lock(wm8350); | |
98 | mutex_unlock(&wdt_mutex); | |
99 | ||
100 | return ret; | |
101 | } | |
102 | ||
2e51d90f | 103 | static int wm8350_wdt_ping(struct watchdog_device *wdt_dev) |
006948ba | 104 | { |
2e51d90f | 105 | struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev); |
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106 | int ret; |
107 | u16 reg; | |
108 | ||
109 | mutex_lock(&wdt_mutex); | |
110 | ||
111 | reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); | |
112 | ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); | |
113 | ||
114 | mutex_unlock(&wdt_mutex); | |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
2e51d90f | 119 | static const struct watchdog_info wm8350_wdt_info = { |
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120 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
121 | .identity = "WM8350 Watchdog", | |
122 | }; | |
123 | ||
2e51d90f | 124 | static const struct watchdog_ops wm8350_wdt_ops = { |
006948ba | 125 | .owner = THIS_MODULE, |
2e51d90f AL |
126 | .start = wm8350_wdt_start, |
127 | .stop = wm8350_wdt_stop, | |
128 | .ping = wm8350_wdt_ping, | |
129 | .set_timeout = wm8350_wdt_set_timeout, | |
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130 | }; |
131 | ||
2e51d90f AL |
132 | static struct watchdog_device wm8350_wdt = { |
133 | .info = &wm8350_wdt_info, | |
134 | .ops = &wm8350_wdt_ops, | |
135 | .timeout = 4, | |
136 | .min_timeout = 1, | |
137 | .max_timeout = 4, | |
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138 | }; |
139 | ||
2d991a16 | 140 | static int wm8350_wdt_probe(struct platform_device *pdev) |
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141 | { |
142 | struct wm8350 *wm8350 = platform_get_drvdata(pdev); | |
143 | ||
144 | if (!wm8350) { | |
cfca31ce | 145 | pr_err("No driver data supplied\n"); |
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146 | return -ENODEV; |
147 | } | |
148 | ||
2e51d90f AL |
149 | watchdog_set_nowayout(&wm8350_wdt, nowayout); |
150 | watchdog_set_drvdata(&wm8350_wdt, wm8350); | |
6551881c | 151 | wm8350_wdt.parent = &pdev->dev; |
006948ba | 152 | |
2e51d90f AL |
153 | /* Default to 4s timeout */ |
154 | wm8350_wdt_set_timeout(&wm8350_wdt, 4); | |
006948ba | 155 | |
2e51d90f | 156 | return watchdog_register_device(&wm8350_wdt); |
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157 | } |
158 | ||
4b12b896 | 159 | static int wm8350_wdt_remove(struct platform_device *pdev) |
006948ba | 160 | { |
2e51d90f | 161 | watchdog_unregister_device(&wm8350_wdt); |
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162 | return 0; |
163 | } | |
164 | ||
165 | static struct platform_driver wm8350_wdt_driver = { | |
166 | .probe = wm8350_wdt_probe, | |
82268714 | 167 | .remove = wm8350_wdt_remove, |
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168 | .driver = { |
169 | .name = "wm8350-wdt", | |
170 | }, | |
171 | }; | |
172 | ||
216f3ad9 | 173 | module_platform_driver(wm8350_wdt_driver); |
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174 | |
175 | MODULE_AUTHOR("Mark Brown"); | |
176 | MODULE_DESCRIPTION("WM8350 Watchdog"); | |
177 | MODULE_LICENSE("GPL"); | |
178 | MODULE_ALIAS("platform:wm8350-wdt"); |