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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 | #define DA9063_RESET_PROTECTION_MS 256 | |
38 | ||
39 | static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) | |
40 | { | |
41 | unsigned int i; | |
42 | ||
43 | for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { | |
44 | if (wdt_timeout[i] >= secs) | |
45 | return i; | |
46 | } | |
47 | ||
48 | return DA9063_TWDSCALE_MAX; | |
49 | } | |
50 | ||
51 | static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) | |
52 | { | |
53 | return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, | |
54 | DA9063_TWDSCALE_MASK, regval); | |
55 | } | |
56 | ||
57 | static int da9063_wdt_start(struct watchdog_device *wdd) | |
58 | { | |
59 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); | |
60 | unsigned int selector; | |
61 | int ret; | |
62 | ||
63 | selector = da9063_wdt_timeout_to_sel(wdd->timeout); | |
64 | ret = _da9063_wdt_set_timeout(da9063, selector); | |
65 | if (ret) | |
66 | dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n", | |
67 | ret); | |
68 | ||
69 | return ret; | |
70 | } | |
71 | ||
72 | static int da9063_wdt_stop(struct watchdog_device *wdd) | |
73 | { | |
74 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); | |
75 | int ret; | |
76 | ||
77 | ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, | |
78 | DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); | |
79 | if (ret) | |
80 | dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n", | |
81 | ret); | |
82 | ||
83 | return ret; | |
84 | } | |
85 | ||
86 | static int da9063_wdt_ping(struct watchdog_device *wdd) | |
87 | { | |
88 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); | |
89 | int ret; | |
90 | ||
91 | ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, | |
92 | DA9063_WATCHDOG); | |
93 | if (ret) | |
94 | dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n", | |
95 | ret); | |
96 | ||
97 | return ret; | |
98 | } | |
99 | ||
100 | static int da9063_wdt_set_timeout(struct watchdog_device *wdd, | |
101 | unsigned int timeout) | |
102 | { | |
103 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); | |
104 | unsigned int selector; | |
105 | int ret = 0; | |
106 | ||
107 | selector = da9063_wdt_timeout_to_sel(timeout); | |
108 | ||
109 | /* | |
110 | * There are two cases when a set_timeout() will be called: | |
111 | * 1. The watchdog is off and someone wants to set the timeout for the | |
112 | * further use. | |
113 | * 2. The watchdog is already running and a new timeout value should be | |
114 | * set. | |
115 | * | |
116 | * The watchdog can't store a timeout value not equal zero without | |
117 | * enabling the watchdog, so the timeout must be buffered by the driver. | |
118 | */ | |
119 | if (watchdog_active(wdd)) | |
120 | ret = _da9063_wdt_set_timeout(da9063, selector); | |
121 | ||
122 | if (ret) | |
123 | dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", | |
124 | ret); | |
125 | else | |
126 | wdd->timeout = wdt_timeout[selector]; | |
127 | ||
128 | return ret; | |
129 | } | |
130 | ||
131 | static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, | |
132 | void *data) | |
133 | { | |
134 | struct da9063 *da9063 = watchdog_get_drvdata(wdd); | |
135 | int ret; | |
136 | ||
137 | ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, | |
138 | DA9063_SHUTDOWN); | |
139 | if (ret) | |
140 | dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n", | |
141 | ret); | |
142 | ||
143 | return ret; | |
144 | } | |
145 | ||
146 | static const struct watchdog_info da9063_watchdog_info = { | |
147 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
148 | .identity = "DA9063 Watchdog", | |
149 | }; | |
150 | ||
151 | static const struct watchdog_ops da9063_watchdog_ops = { | |
152 | .owner = THIS_MODULE, | |
153 | .start = da9063_wdt_start, | |
154 | .stop = da9063_wdt_stop, | |
155 | .ping = da9063_wdt_ping, | |
156 | .set_timeout = da9063_wdt_set_timeout, | |
157 | .restart = da9063_wdt_restart, | |
158 | }; | |
159 | ||
160 | static int da9063_wdt_probe(struct platform_device *pdev) | |
161 | { | |
162 | struct da9063 *da9063; | |
163 | struct watchdog_device *wdd; | |
164 | ||
165 | if (!pdev->dev.parent) | |
166 | return -EINVAL; | |
167 | ||
168 | da9063 = dev_get_drvdata(pdev->dev.parent); | |
169 | if (!da9063) | |
170 | return -EINVAL; | |
171 | ||
172 | wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL); | |
173 | if (!wdd) | |
174 | return -ENOMEM; | |
175 | ||
176 | wdd->info = &da9063_watchdog_info; | |
177 | wdd->ops = &da9063_watchdog_ops; | |
178 | wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT; | |
179 | wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT; | |
180 | wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; | |
181 | wdd->timeout = DA9063_WDG_TIMEOUT; | |
182 | wdd->parent = &pdev->dev; | |
183 | ||
184 | wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS; | |
185 | ||
186 | watchdog_set_restart_priority(wdd, 128); | |
187 | ||
188 | watchdog_set_drvdata(wdd, da9063); | |
189 | ||
190 | return devm_watchdog_register_device(&pdev->dev, wdd); | |
191 | } | |
192 | ||
193 | static struct platform_driver da9063_wdt_driver = { | |
194 | .probe = da9063_wdt_probe, | |
195 | .driver = { | |
196 | .name = DA9063_DRVNAME_WATCHDOG, | |
197 | }, | |
198 | }; | |
199 | module_platform_driver(da9063_wdt_driver); | |
200 | ||
201 | MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); | |
202 | MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); | |
203 | MODULE_LICENSE("GPL"); | |
204 | MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); |