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[karo-tx-linux.git] / drivers / watchdog / bcm47xx_wdt.c
1 /*
2  *  Watchdog driver for Broadcom BCM47XX
3  *
4  *  Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
5  *  Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
6  *  Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de>
7  *
8  *  This program is free software; you can redistribute it and/or
9  *  modify it under the terms of the GNU General Public License
10  *  as published by the Free Software Foundation; either version
11  *  2 of the License, or (at your option) any later version.
12  */
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/bcm47xx_wdt.h>
17 #include <linux/bitops.h>
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/platform_device.h>
23 #include <linux/types.h>
24 #include <linux/watchdog.h>
25 #include <linux/timer.h>
26 #include <linux/jiffies.h>
27
28 #define DRV_NAME                "bcm47xx_wdt"
29
30 #define WDT_DEFAULT_TIME        30      /* seconds */
31 #define WDT_SOFTTIMER_MAX       255     /* seconds */
32 #define WDT_SOFTTIMER_THRESHOLD 60      /* seconds */
33
34 static int timeout = WDT_DEFAULT_TIME;
35 static bool nowayout = WATCHDOG_NOWAYOUT;
36
37 module_param(timeout, int, 0);
38 MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
39                                 __MODULE_STRING(WDT_DEFAULT_TIME) ")");
40
41 module_param(nowayout, bool, 0);
42 MODULE_PARM_DESC(nowayout,
43                 "Watchdog cannot be stopped once started (default="
44                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
45
46 static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
47 {
48         return container_of(wdd, struct bcm47xx_wdt, wdd);
49 }
50
51 static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
52 {
53         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
54
55         wdt->timer_set_ms(wdt, wdd->timeout * 1000);
56
57         return 0;
58 }
59
60 static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
61 {
62         return 0;
63 }
64
65 static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
66 {
67         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
68
69         wdt->timer_set(wdt, 0);
70
71         return 0;
72 }
73
74 static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
75                                         unsigned int new_time)
76 {
77         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
78         u32 max_timer = wdt->max_timer_ms;
79
80         if (new_time < 1 || new_time > max_timer / 1000) {
81                 pr_warn("timeout value must be 1<=x<=%d, using %d\n",
82                         max_timer / 1000, new_time);
83                 return -EINVAL;
84         }
85
86         wdd->timeout = new_time;
87         return 0;
88 }
89
90 static int bcm47xx_wdt_restart(struct watchdog_device *wdd,
91                                unsigned long action, void *data)
92 {
93         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
94
95         wdt->timer_set(wdt, 1);
96
97         return 0;
98 }
99
100 static struct watchdog_ops bcm47xx_wdt_hard_ops = {
101         .owner          = THIS_MODULE,
102         .start          = bcm47xx_wdt_hard_start,
103         .stop           = bcm47xx_wdt_hard_stop,
104         .ping           = bcm47xx_wdt_hard_keepalive,
105         .set_timeout    = bcm47xx_wdt_hard_set_timeout,
106         .restart        = bcm47xx_wdt_restart,
107 };
108
109 static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
110 {
111         struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data;
112         u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);
113
114         if (!atomic_dec_and_test(&wdt->soft_ticks)) {
115                 wdt->timer_set_ms(wdt, next_tick);
116                 mod_timer(&wdt->soft_timer, jiffies + HZ);
117         } else {
118                 pr_crit("Watchdog will fire soon!!!\n");
119         }
120 }
121
122 static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
123 {
124         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
125
126         atomic_set(&wdt->soft_ticks, wdd->timeout);
127
128         return 0;
129 }
130
131 static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
132 {
133         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
134
135         bcm47xx_wdt_soft_keepalive(wdd);
136         bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);
137
138         return 0;
139 }
140
141 static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
142 {
143         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
144
145         del_timer_sync(&wdt->soft_timer);
146         wdt->timer_set(wdt, 0);
147
148         return 0;
149 }
150
151 static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
152                                         unsigned int new_time)
153 {
154         if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
155                 pr_warn("timeout value must be 1<=x<=%d, using %d\n",
156                         WDT_SOFTTIMER_MAX, new_time);
157                 return -EINVAL;
158         }
159
160         wdd->timeout = new_time;
161         return 0;
162 }
163
164 static const struct watchdog_info bcm47xx_wdt_info = {
165         .identity       = DRV_NAME,
166         .options        = WDIOF_SETTIMEOUT |
167                                 WDIOF_KEEPALIVEPING |
168                                 WDIOF_MAGICCLOSE,
169 };
170
171 static struct watchdog_ops bcm47xx_wdt_soft_ops = {
172         .owner          = THIS_MODULE,
173         .start          = bcm47xx_wdt_soft_start,
174         .stop           = bcm47xx_wdt_soft_stop,
175         .ping           = bcm47xx_wdt_soft_keepalive,
176         .set_timeout    = bcm47xx_wdt_soft_set_timeout,
177         .restart        = bcm47xx_wdt_restart,
178 };
179
180 static int bcm47xx_wdt_probe(struct platform_device *pdev)
181 {
182         int ret;
183         bool soft;
184         struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
185
186         if (!wdt)
187                 return -ENXIO;
188
189         soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;
190
191         if (soft) {
192                 wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
193                 setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
194                             (long unsigned int)wdt);
195         } else {
196                 wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
197         }
198
199         wdt->wdd.info = &bcm47xx_wdt_info;
200         wdt->wdd.timeout = WDT_DEFAULT_TIME;
201         wdt->wdd.parent = &pdev->dev;
202         ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
203         if (ret)
204                 goto err_timer;
205         watchdog_set_nowayout(&wdt->wdd, nowayout);
206         watchdog_set_restart_priority(&wdt->wdd, 64);
207         watchdog_stop_on_reboot(&wdt->wdd);
208
209         ret = watchdog_register_device(&wdt->wdd);
210         if (ret)
211                 goto err_timer;
212
213         dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
214                 timeout, nowayout ? ", nowayout" : "",
215                 soft ? ", Software Timer" : "");
216         return 0;
217
218 err_timer:
219         if (soft)
220                 del_timer_sync(&wdt->soft_timer);
221
222         return ret;
223 }
224
225 static int bcm47xx_wdt_remove(struct platform_device *pdev)
226 {
227         struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
228
229         if (!wdt)
230                 return -ENXIO;
231
232         watchdog_unregister_device(&wdt->wdd);
233
234         return 0;
235 }
236
237 static struct platform_driver bcm47xx_wdt_driver = {
238         .driver         = {
239                 .name   = "bcm47xx-wdt",
240         },
241         .probe          = bcm47xx_wdt_probe,
242         .remove         = bcm47xx_wdt_remove,
243 };
244
245 module_platform_driver(bcm47xx_wdt_driver);
246
247 MODULE_AUTHOR("Aleksandar Radovanovic");
248 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
249 MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
250 MODULE_LICENSE("GPL");