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Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +02001/*
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>
Geert Uytterhoeven396f1632015-01-29 15:26:05 +010023#include <linux/reboot.h>
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +020024#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 */
31static 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
39struct da9063_watchdog {
40 struct da9063 *da9063;
41 struct watchdog_device wdtdev;
Geert Uytterhoeven396f1632015-01-29 15:26:05 +010042 struct notifier_block restart_handler;
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +020043};
44
45static 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
57static 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
63static 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
78static 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
92static 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
106static 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
Geert Uytterhoeven396f1632015-01-29 15:26:05 +0100124static 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
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +0200141static const struct watchdog_info da9063_watchdog_info = {
142 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
143 .identity = "DA9063 Watchdog",
144};
145
146static 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
154static 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;
Pratyush Anand65518812015-08-20 14:05:01 +0530178 wdt->wdtdev.parent = &pdev->dev;
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +0200179
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);
Geert Uytterhoeven396f1632015-01-29 15:26:05 +0100186 if (ret)
187 return ret;
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +0200188
Geert Uytterhoeven396f1632015-01-29 15:26:05 +0100189 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;
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +0200197}
198
199static int da9063_wdt_remove(struct platform_device *pdev)
200{
201 struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);
202
Geert Uytterhoeven396f1632015-01-29 15:26:05 +0100203 unregister_restart_handler(&wdt->restart_handler);
204
Krystian Garbaciak5e9c16e2014-09-28 19:05:45 +0200205 watchdog_unregister_device(&wdt->wdtdev);
206
207 return 0;
208}
209
210static 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};
217module_platform_driver(da9063_wdt_driver);
218
219MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
220MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
221MODULE_LICENSE("GPL");
222MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);