tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/init.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
23#include <linux/platform_device.h>
24#include <linux/reboot.h>
25#include <linux/types.h>
26#include <linux/watchdog.h>
27#include <linux/timer.h>
28#include <linux/jiffies.h>
29
30#define DRV_NAME "bcm47xx_wdt"
31
32#define WDT_DEFAULT_TIME 30 /* seconds */
33#define WDT_SOFTTIMER_MAX 255 /* seconds */
34#define WDT_SOFTTIMER_THRESHOLD 60 /* seconds */
35
36static int timeout = WDT_DEFAULT_TIME;
37static bool nowayout = WATCHDOG_NOWAYOUT;
38
39module_param(timeout, int, 0);
40MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
41 __MODULE_STRING(WDT_DEFAULT_TIME) ")");
42
43module_param(nowayout, bool, 0);
44MODULE_PARM_DESC(nowayout,
45 "Watchdog cannot be stopped once started (default="
46 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
47
48static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
49{
50 return container_of(wdd, struct bcm47xx_wdt, wdd);
51}
52
53static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
54{
55 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
56
57 wdt->timer_set_ms(wdt, wdd->timeout * 1000);
58
59 return 0;
60}
61
62static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
63{
64 return 0;
65}
66
67static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
68{
69 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
70
71 wdt->timer_set(wdt, 0);
72
73 return 0;
74}
75
76static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
77 unsigned int new_time)
78{
79 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
80 u32 max_timer = wdt->max_timer_ms;
81
82 if (new_time < 1 || new_time > max_timer / 1000) {
83 pr_warn("timeout value must be 1<=x<=%d, using %d\n",
84 max_timer / 1000, new_time);
85 return -EINVAL;
86 }
87
88 wdd->timeout = new_time;
89 return 0;
90}
91
92static struct watchdog_ops bcm47xx_wdt_hard_ops = {
93 .owner = THIS_MODULE,
94 .start = bcm47xx_wdt_hard_start,
95 .stop = bcm47xx_wdt_hard_stop,
96 .ping = bcm47xx_wdt_hard_keepalive,
97 .set_timeout = bcm47xx_wdt_hard_set_timeout,
98};
99
100static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
101{
102 struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data;
103 u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);
104
105 if (!atomic_dec_and_test(&wdt->soft_ticks)) {
106 wdt->timer_set_ms(wdt, next_tick);
107 mod_timer(&wdt->soft_timer, jiffies + HZ);
108 } else {
109 pr_crit("Watchdog will fire soon!!!\n");
110 }
111}
112
113static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
114{
115 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
116
117 atomic_set(&wdt->soft_ticks, wdd->timeout);
118
119 return 0;
120}
121
122static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
123{
124 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
125
126 bcm47xx_wdt_soft_keepalive(wdd);
127 bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);
128
129 return 0;
130}
131
132static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
133{
134 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
135
136 del_timer_sync(&wdt->soft_timer);
137 wdt->timer_set(wdt, 0);
138
139 return 0;
140}
141
142static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
143 unsigned int new_time)
144{
145 if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
146 pr_warn("timeout value must be 1<=x<=%d, using %d\n",
147 WDT_SOFTTIMER_MAX, new_time);
148 return -EINVAL;
149 }
150
151 wdd->timeout = new_time;
152 return 0;
153}
154
155static const struct watchdog_info bcm47xx_wdt_info = {
156 .identity = DRV_NAME,
157 .options = WDIOF_SETTIMEOUT |
158 WDIOF_KEEPALIVEPING |
159 WDIOF_MAGICCLOSE,
160};
161
162static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
163 unsigned long code, void *unused)
164{
165 struct bcm47xx_wdt *wdt;
166
167 wdt = container_of(this, struct bcm47xx_wdt, notifier);
168 if (code == SYS_DOWN || code == SYS_HALT)
169 wdt->wdd.ops->stop(&wdt->wdd);
170 return NOTIFY_DONE;
171}
172
173static struct watchdog_ops bcm47xx_wdt_soft_ops = {
174 .owner = THIS_MODULE,
175 .start = bcm47xx_wdt_soft_start,
176 .stop = bcm47xx_wdt_soft_stop,
177 .ping = bcm47xx_wdt_soft_keepalive,
178 .set_timeout = bcm47xx_wdt_soft_set_timeout,
179};
180
181static int bcm47xx_wdt_probe(struct platform_device *pdev)
182{
183 int ret;
184 bool soft;
185 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
186
187 if (!wdt)
188 return -ENXIO;
189
190 soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;
191
192 if (soft) {
193 wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
194 setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
195 (long unsigned int)wdt);
196 } else {
197 wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
198 }
199
200 wdt->wdd.info = &bcm47xx_wdt_info;
201 wdt->wdd.timeout = WDT_DEFAULT_TIME;
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
207 wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;
208
209 ret = register_reboot_notifier(&wdt->notifier);
210 if (ret)
211 goto err_timer;
212
213 ret = watchdog_register_device(&wdt->wdd);
214 if (ret)
215 goto err_notifier;
216
217 dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
218 timeout, nowayout ? ", nowayout" : "",
219 soft ? ", Software Timer" : "");
220 return 0;
221
222err_notifier:
223 unregister_reboot_notifier(&wdt->notifier);
224err_timer:
225 if (soft)
226 del_timer_sync(&wdt->soft_timer);
227
228 return ret;
229}
230
231static int bcm47xx_wdt_remove(struct platform_device *pdev)
232{
233 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
234
235 if (!wdt)
236 return -ENXIO;
237
238 watchdog_unregister_device(&wdt->wdd);
239 unregister_reboot_notifier(&wdt->notifier);
240
241 return 0;
242}
243
244static struct platform_driver bcm47xx_wdt_driver = {
245 .driver = {
246 .owner = THIS_MODULE,
247 .name = "bcm47xx-wdt",
248 },
249 .probe = bcm47xx_wdt_probe,
250 .remove = bcm47xx_wdt_remove,
251};
252
253module_platform_driver(bcm47xx_wdt_driver);
254
255MODULE_AUTHOR("Aleksandar Radovanovic");
256MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
257MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
258MODULE_LICENSE("GPL");