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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Retu watchdog driver
4 *
5 * Copyright (C) 2004, 2005 Nokia Corporation
6 *
7 * Based on code written by Amit Kucheria and Michael Buesch.
8 * Rewritten by Aaro Koskinen.
9 */
10
11#include <linux/devm-helpers.h>
12#include <linux/slab.h>
13#include <linux/errno.h>
14#include <linux/device.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/mfd/retu.h>
18#include <linux/watchdog.h>
19#include <linux/platform_device.h>
20
21/* Watchdog timer values in seconds */
22#define RETU_WDT_MAX_TIMER 63
23
24struct retu_wdt_dev {
25 struct retu_dev *rdev;
26 struct device *dev;
27 struct delayed_work ping_work;
28};
29
30/*
31 * Since Retu watchdog cannot be disabled in hardware, we must kick it
32 * with a timer until userspace watchdog software takes over. If
33 * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.
34 */
35static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)
36{
37 retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
38 schedule_delayed_work(&wdev->ping_work,
39 round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));
40}
41
42static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)
43{
44 retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
45 cancel_delayed_work_sync(&wdev->ping_work);
46}
47
48static void retu_wdt_ping_work(struct work_struct *work)
49{
50 struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),
51 struct retu_wdt_dev, ping_work);
52 retu_wdt_ping_enable(wdev);
53}
54
55static int retu_wdt_start(struct watchdog_device *wdog)
56{
57 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
58
59 retu_wdt_ping_disable(wdev);
60
61 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
62}
63
64static int retu_wdt_stop(struct watchdog_device *wdog)
65{
66 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
67
68 retu_wdt_ping_enable(wdev);
69
70 return 0;
71}
72
73static int retu_wdt_ping(struct watchdog_device *wdog)
74{
75 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
76
77 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
78}
79
80static int retu_wdt_set_timeout(struct watchdog_device *wdog,
81 unsigned int timeout)
82{
83 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
84
85 wdog->timeout = timeout;
86 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
87}
88
89static const struct watchdog_info retu_wdt_info = {
90 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
91 .identity = "Retu watchdog",
92};
93
94static const struct watchdog_ops retu_wdt_ops = {
95 .owner = THIS_MODULE,
96 .start = retu_wdt_start,
97 .stop = retu_wdt_stop,
98 .ping = retu_wdt_ping,
99 .set_timeout = retu_wdt_set_timeout,
100};
101
102static int retu_wdt_probe(struct platform_device *pdev)
103{
104 struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
105 bool nowayout = WATCHDOG_NOWAYOUT;
106 struct watchdog_device *retu_wdt;
107 struct retu_wdt_dev *wdev;
108 int ret;
109
110 retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL);
111 if (!retu_wdt)
112 return -ENOMEM;
113
114 wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
115 if (!wdev)
116 return -ENOMEM;
117
118 retu_wdt->info = &retu_wdt_info;
119 retu_wdt->ops = &retu_wdt_ops;
120 retu_wdt->timeout = RETU_WDT_MAX_TIMER;
121 retu_wdt->min_timeout = 0;
122 retu_wdt->max_timeout = RETU_WDT_MAX_TIMER;
123 retu_wdt->parent = &pdev->dev;
124
125 watchdog_set_drvdata(retu_wdt, wdev);
126 watchdog_set_nowayout(retu_wdt, nowayout);
127
128 wdev->rdev = rdev;
129 wdev->dev = &pdev->dev;
130
131 ret = devm_delayed_work_autocancel(&pdev->dev, &wdev->ping_work,
132 retu_wdt_ping_work);
133 if (ret)
134 return ret;
135
136 ret = devm_watchdog_register_device(&pdev->dev, retu_wdt);
137 if (ret < 0)
138 return ret;
139
140 if (nowayout)
141 retu_wdt_ping(retu_wdt);
142 else
143 retu_wdt_ping_enable(wdev);
144
145 return 0;
146}
147
148static struct platform_driver retu_wdt_driver = {
149 .probe = retu_wdt_probe,
150 .driver = {
151 .name = "retu-wdt",
152 },
153};
154module_platform_driver(retu_wdt_driver);
155
156MODULE_ALIAS("platform:retu-wdt");
157MODULE_DESCRIPTION("Retu watchdog");
158MODULE_AUTHOR("Amit Kucheria");
159MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
160MODULE_LICENSE("GPL");
1/*
2 * Retu watchdog driver
3 *
4 * Copyright (C) 2004, 2005 Nokia Corporation
5 *
6 * Based on code written by Amit Kucheria and Michael Buesch.
7 * Rewritten by Aaro Koskinen.
8 *
9 * This file is subject to the terms and conditions of the GNU General
10 * Public License. See the file "COPYING" in the main directory of this
11 * archive for more details.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/slab.h>
20#include <linux/errno.h>
21#include <linux/device.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/mfd/retu.h>
25#include <linux/watchdog.h>
26#include <linux/platform_device.h>
27
28/* Watchdog timer values in seconds */
29#define RETU_WDT_MAX_TIMER 63
30
31struct retu_wdt_dev {
32 struct retu_dev *rdev;
33 struct device *dev;
34 struct delayed_work ping_work;
35};
36
37/*
38 * Since Retu watchdog cannot be disabled in hardware, we must kick it
39 * with a timer until userspace watchdog software takes over. If
40 * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.
41 */
42static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)
43{
44 retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
45 schedule_delayed_work(&wdev->ping_work,
46 round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));
47}
48
49static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)
50{
51 retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
52 cancel_delayed_work_sync(&wdev->ping_work);
53}
54
55static void retu_wdt_ping_work(struct work_struct *work)
56{
57 struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),
58 struct retu_wdt_dev, ping_work);
59 retu_wdt_ping_enable(wdev);
60}
61
62static int retu_wdt_start(struct watchdog_device *wdog)
63{
64 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
65
66 retu_wdt_ping_disable(wdev);
67
68 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
69}
70
71static int retu_wdt_stop(struct watchdog_device *wdog)
72{
73 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
74
75 retu_wdt_ping_enable(wdev);
76
77 return 0;
78}
79
80static int retu_wdt_ping(struct watchdog_device *wdog)
81{
82 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
83
84 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
85}
86
87static int retu_wdt_set_timeout(struct watchdog_device *wdog,
88 unsigned int timeout)
89{
90 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
91
92 wdog->timeout = timeout;
93 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
94}
95
96static const struct watchdog_info retu_wdt_info = {
97 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
98 .identity = "Retu watchdog",
99};
100
101static const struct watchdog_ops retu_wdt_ops = {
102 .owner = THIS_MODULE,
103 .start = retu_wdt_start,
104 .stop = retu_wdt_stop,
105 .ping = retu_wdt_ping,
106 .set_timeout = retu_wdt_set_timeout,
107};
108
109static int retu_wdt_probe(struct platform_device *pdev)
110{
111 struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
112 bool nowayout = WATCHDOG_NOWAYOUT;
113 struct watchdog_device *retu_wdt;
114 struct retu_wdt_dev *wdev;
115 int ret;
116
117 retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL);
118 if (!retu_wdt)
119 return -ENOMEM;
120
121 wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
122 if (!wdev)
123 return -ENOMEM;
124
125 retu_wdt->info = &retu_wdt_info;
126 retu_wdt->ops = &retu_wdt_ops;
127 retu_wdt->timeout = RETU_WDT_MAX_TIMER;
128 retu_wdt->min_timeout = 0;
129 retu_wdt->max_timeout = RETU_WDT_MAX_TIMER;
130 retu_wdt->parent = &pdev->dev;
131
132 watchdog_set_drvdata(retu_wdt, wdev);
133 watchdog_set_nowayout(retu_wdt, nowayout);
134
135 wdev->rdev = rdev;
136 wdev->dev = &pdev->dev;
137
138 INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work);
139
140 ret = watchdog_register_device(retu_wdt);
141 if (ret < 0)
142 return ret;
143
144 if (nowayout)
145 retu_wdt_ping(retu_wdt);
146 else
147 retu_wdt_ping_enable(wdev);
148
149 platform_set_drvdata(pdev, retu_wdt);
150
151 return 0;
152}
153
154static int retu_wdt_remove(struct platform_device *pdev)
155{
156 struct watchdog_device *wdog = platform_get_drvdata(pdev);
157 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
158
159 watchdog_unregister_device(wdog);
160 cancel_delayed_work_sync(&wdev->ping_work);
161
162 return 0;
163}
164
165static struct platform_driver retu_wdt_driver = {
166 .probe = retu_wdt_probe,
167 .remove = retu_wdt_remove,
168 .driver = {
169 .name = "retu-wdt",
170 },
171};
172module_platform_driver(retu_wdt_driver);
173
174MODULE_ALIAS("platform:retu-wdt");
175MODULE_DESCRIPTION("Retu watchdog");
176MODULE_AUTHOR("Amit Kucheria");
177MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
178MODULE_LICENSE("GPL");