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5e9c16e3 KG |
1 | /* |
2 | * Watchdog driver for DA9063 PMICs. | |
3 | * | |
4 | * Copyright(c) 2012 Dialog Semiconductor Ltd. | |
5 | * | |
6 | * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com> | |
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 as published by the | |
10 | * Free Software Foundation; either version 2 of the License, or (at your | |
11 | * option) any later version. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/watchdog.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/uaccess.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/delay.h> | |
21 | #include <linux/mfd/da9063/registers.h> | |
22 | #include <linux/mfd/da9063/core.h> | |
396f163c | 23 | #include <linux/reboot.h> |
5e9c16e3 KG |
24 | #include <linux/regmap.h> |
25 | ||
26 | /* | |
27 | * Watchdog selector to timeout in seconds. | |
28 | * 0: WDT disabled; | |
29 | * others: timeout = 2048 ms * 2^(TWDSCALE-1). | |
30 | */ | |
31 | static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; | |
32 | #define DA9063_TWDSCALE_DISABLE 0 | |
33 | #define DA9063_TWDSCALE_MIN 1 | |
34 | #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) | |
35 | #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] | |
36 | #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] | |
37 | #define DA9063_WDG_TIMEOUT wdt_timeout[3] | |
38 | ||
39 | struct da9063_watchdog { | |
40 | struct da9063 *da9063; | |
41 | struct watchdog_device wdtdev; | |
396f163c | 42 | struct notifier_block restart_handler; |
5e9c16e3 KG |
43 | }; |
44 | ||
45 | static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) | |
46 | { | |
47 | unsigned int i; | |
48 | ||
49 | for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { | |
50 | if (wdt_timeout[i] >= secs) | |
51 | return i; | |
52 | } | |
53 | ||
54 | return DA9063_TWDSCALE_MAX; | |
55 | } | |
56 | ||
57 | static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) | |
58 | { | |
59 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, | |
60 | DA9063_TWDSCALE_MASK, regval); | |
61 | } | |
62 | ||
63 | static int da9063_wdt_start(struct watchdog_device *wdd) | |
64 | { | |
65 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
66 | unsigned int selector; | |
67 | int ret; | |
68 | ||
69 | selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); | |
70 | ret = _da9063_wdt_set_timeout(wdt->da9063, selector); | |
71 | if (ret) | |
72 | dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", | |
73 | ret); | |
74 | ||
75 | return ret; | |
76 | } | |
77 | ||
78 | static int da9063_wdt_stop(struct watchdog_device *wdd) | |
79 | { | |
80 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
81 | int ret; | |
82 | ||
83 | ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, | |
84 | DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); | |
85 | if (ret) | |
86 | dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", | |
87 | ret); | |
88 | ||
89 | return ret; | |
90 | } | |
91 | ||
92 | static int da9063_wdt_ping(struct watchdog_device *wdd) | |
93 | { | |
94 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
95 | int ret; | |
96 | ||
97 | ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, | |
98 | DA9063_WATCHDOG); | |
99 | if (ret) | |
100 | dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", | |
101 | ret); | |
102 | ||
103 | return ret; | |
104 | } | |
105 | ||
106 | static int da9063_wdt_set_timeout(struct watchdog_device *wdd, | |
107 | unsigned int timeout) | |
108 | { | |
109 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
110 | unsigned int selector; | |
111 | int ret; | |
112 | ||
113 | selector = da9063_wdt_timeout_to_sel(timeout); | |
114 | ret = _da9063_wdt_set_timeout(wdt->da9063, selector); | |
115 | if (ret) | |
116 | dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", | |
117 | ret); | |
118 | else | |
119 | wdd->timeout = wdt_timeout[selector]; | |
120 | ||
121 | return ret; | |
122 | } | |
123 | ||
396f163c GU |
124 | static int da9063_wdt_restart_handler(struct notifier_block *this, |
125 | unsigned long mode, void *cmd) | |
126 | { | |
127 | struct da9063_watchdog *wdt = container_of(this, | |
128 | struct da9063_watchdog, | |
129 | restart_handler); | |
130 | int ret; | |
131 | ||
132 | ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, | |
133 | DA9063_SHUTDOWN); | |
134 | if (ret) | |
135 | dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n", | |
136 | ret); | |
137 | ||
138 | return NOTIFY_DONE; | |
139 | } | |
140 | ||
5e9c16e3 KG |
141 | static const struct watchdog_info da9063_watchdog_info = { |
142 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
143 | .identity = "DA9063 Watchdog", | |
144 | }; | |
145 | ||
146 | static const struct watchdog_ops da9063_watchdog_ops = { | |
147 | .owner = THIS_MODULE, | |
148 | .start = da9063_wdt_start, | |
149 | .stop = da9063_wdt_stop, | |
150 | .ping = da9063_wdt_ping, | |
151 | .set_timeout = da9063_wdt_set_timeout, | |
152 | }; | |
153 | ||
154 | static int da9063_wdt_probe(struct platform_device *pdev) | |
155 | { | |
156 | int ret; | |
157 | struct da9063 *da9063; | |
158 | struct da9063_watchdog *wdt; | |
159 | ||
160 | if (!pdev->dev.parent) | |
161 | return -EINVAL; | |
162 | ||
163 | da9063 = dev_get_drvdata(pdev->dev.parent); | |
164 | if (!da9063) | |
165 | return -EINVAL; | |
166 | ||
167 | wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); | |
168 | if (!wdt) | |
169 | return -ENOMEM; | |
170 | ||
171 | wdt->da9063 = da9063; | |
172 | ||
173 | wdt->wdtdev.info = &da9063_watchdog_info; | |
174 | wdt->wdtdev.ops = &da9063_watchdog_ops; | |
175 | wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; | |
176 | wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; | |
177 | wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; | |
6551881c | 178 | wdt->wdtdev.parent = &pdev->dev; |
5e9c16e3 KG |
179 | |
180 | wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; | |
181 | ||
182 | watchdog_set_drvdata(&wdt->wdtdev, wdt); | |
183 | dev_set_drvdata(&pdev->dev, wdt); | |
184 | ||
185 | ret = watchdog_register_device(&wdt->wdtdev); | |
396f163c GU |
186 | if (ret) |
187 | return ret; | |
5e9c16e3 | 188 | |
396f163c GU |
189 | wdt->restart_handler.notifier_call = da9063_wdt_restart_handler; |
190 | wdt->restart_handler.priority = 128; | |
191 | ret = register_restart_handler(&wdt->restart_handler); | |
192 | if (ret) | |
193 | dev_err(wdt->da9063->dev, | |
194 | "Failed to register restart handler (err = %d)\n", ret); | |
195 | ||
196 | return 0; | |
5e9c16e3 KG |
197 | } |
198 | ||
199 | static int da9063_wdt_remove(struct platform_device *pdev) | |
200 | { | |
201 | struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); | |
202 | ||
396f163c GU |
203 | unregister_restart_handler(&wdt->restart_handler); |
204 | ||
5e9c16e3 KG |
205 | watchdog_unregister_device(&wdt->wdtdev); |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | static struct platform_driver da9063_wdt_driver = { | |
211 | .probe = da9063_wdt_probe, | |
212 | .remove = da9063_wdt_remove, | |
213 | .driver = { | |
214 | .name = DA9063_DRVNAME_WATCHDOG, | |
215 | }, | |
216 | }; | |
217 | module_platform_driver(da9063_wdt_driver); | |
218 | ||
219 | MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); | |
220 | MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); | |
221 | MODULE_LICENSE("GPL"); | |
222 | MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); |