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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> | |
23 | #include <linux/regmap.h> | |
24 | ||
25 | /* | |
26 | * Watchdog selector to timeout in seconds. | |
27 | * 0: WDT disabled; | |
28 | * others: timeout = 2048 ms * 2^(TWDSCALE-1). | |
29 | */ | |
30 | static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; | |
31 | #define DA9063_TWDSCALE_DISABLE 0 | |
32 | #define DA9063_TWDSCALE_MIN 1 | |
33 | #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) | |
34 | #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] | |
35 | #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] | |
36 | #define DA9063_WDG_TIMEOUT wdt_timeout[3] | |
37 | ||
38 | struct da9063_watchdog { | |
39 | struct da9063 *da9063; | |
40 | struct watchdog_device wdtdev; | |
41 | }; | |
42 | ||
43 | static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) | |
44 | { | |
45 | unsigned int i; | |
46 | ||
47 | for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { | |
48 | if (wdt_timeout[i] >= secs) | |
49 | return i; | |
50 | } | |
51 | ||
52 | return DA9063_TWDSCALE_MAX; | |
53 | } | |
54 | ||
55 | static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) | |
56 | { | |
57 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, | |
58 | DA9063_TWDSCALE_MASK, regval); | |
59 | } | |
60 | ||
61 | static int da9063_wdt_start(struct watchdog_device *wdd) | |
62 | { | |
63 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
64 | unsigned int selector; | |
65 | int ret; | |
66 | ||
67 | selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); | |
68 | ret = _da9063_wdt_set_timeout(wdt->da9063, selector); | |
69 | if (ret) | |
70 | dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", | |
71 | ret); | |
72 | ||
73 | return ret; | |
74 | } | |
75 | ||
76 | static int da9063_wdt_stop(struct watchdog_device *wdd) | |
77 | { | |
78 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
79 | int ret; | |
80 | ||
81 | ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, | |
82 | DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); | |
83 | if (ret) | |
84 | dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", | |
85 | ret); | |
86 | ||
87 | return ret; | |
88 | } | |
89 | ||
90 | static int da9063_wdt_ping(struct watchdog_device *wdd) | |
91 | { | |
92 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
93 | int ret; | |
94 | ||
95 | ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, | |
96 | DA9063_WATCHDOG); | |
97 | if (ret) | |
98 | dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", | |
99 | ret); | |
100 | ||
101 | return ret; | |
102 | } | |
103 | ||
104 | static int da9063_wdt_set_timeout(struct watchdog_device *wdd, | |
105 | unsigned int timeout) | |
106 | { | |
107 | struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); | |
108 | unsigned int selector; | |
109 | int ret; | |
110 | ||
111 | selector = da9063_wdt_timeout_to_sel(timeout); | |
112 | ret = _da9063_wdt_set_timeout(wdt->da9063, selector); | |
113 | if (ret) | |
114 | dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", | |
115 | ret); | |
116 | else | |
117 | wdd->timeout = wdt_timeout[selector]; | |
118 | ||
119 | return ret; | |
120 | } | |
121 | ||
122 | static const struct watchdog_info da9063_watchdog_info = { | |
123 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
124 | .identity = "DA9063 Watchdog", | |
125 | }; | |
126 | ||
127 | static const struct watchdog_ops da9063_watchdog_ops = { | |
128 | .owner = THIS_MODULE, | |
129 | .start = da9063_wdt_start, | |
130 | .stop = da9063_wdt_stop, | |
131 | .ping = da9063_wdt_ping, | |
132 | .set_timeout = da9063_wdt_set_timeout, | |
133 | }; | |
134 | ||
135 | static int da9063_wdt_probe(struct platform_device *pdev) | |
136 | { | |
137 | int ret; | |
138 | struct da9063 *da9063; | |
139 | struct da9063_watchdog *wdt; | |
140 | ||
141 | if (!pdev->dev.parent) | |
142 | return -EINVAL; | |
143 | ||
144 | da9063 = dev_get_drvdata(pdev->dev.parent); | |
145 | if (!da9063) | |
146 | return -EINVAL; | |
147 | ||
148 | wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); | |
149 | if (!wdt) | |
150 | return -ENOMEM; | |
151 | ||
152 | wdt->da9063 = da9063; | |
153 | ||
154 | wdt->wdtdev.info = &da9063_watchdog_info; | |
155 | wdt->wdtdev.ops = &da9063_watchdog_ops; | |
156 | wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; | |
157 | wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; | |
158 | wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; | |
159 | ||
160 | wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; | |
161 | ||
162 | watchdog_set_drvdata(&wdt->wdtdev, wdt); | |
163 | dev_set_drvdata(&pdev->dev, wdt); | |
164 | ||
165 | ret = watchdog_register_device(&wdt->wdtdev); | |
166 | ||
167 | return ret; | |
168 | } | |
169 | ||
170 | static int da9063_wdt_remove(struct platform_device *pdev) | |
171 | { | |
172 | struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); | |
173 | ||
174 | watchdog_unregister_device(&wdt->wdtdev); | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | static struct platform_driver da9063_wdt_driver = { | |
180 | .probe = da9063_wdt_probe, | |
181 | .remove = da9063_wdt_remove, | |
182 | .driver = { | |
183 | .name = DA9063_DRVNAME_WATCHDOG, | |
184 | }, | |
185 | }; | |
186 | module_platform_driver(da9063_wdt_driver); | |
187 | ||
188 | MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); | |
189 | MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); | |
190 | MODULE_LICENSE("GPL"); | |
191 | MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); |