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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 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/bitops.h>
14#include <linux/errno.h>
15#include <linux/fs.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/miscdevice.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/reboot.h>
22#include <linux/types.h>
23#include <linux/uaccess.h>
24#include <linux/watchdog.h>
25#include <linux/timer.h>
26#include <linux/jiffies.h>
27#include <linux/ssb/ssb_embedded.h>
28#include <asm/mach-bcm47xx/bcm47xx.h>
29
30#define DRV_NAME "bcm47xx_wdt"
31
32#define WDT_DEFAULT_TIME 30 /* seconds */
33#define WDT_MAX_TIME 255 /* seconds */
34
35static int wdt_time = WDT_DEFAULT_TIME;
36static int nowayout = WATCHDOG_NOWAYOUT;
37
38module_param(wdt_time, int, 0);
39MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
40 __MODULE_STRING(WDT_DEFAULT_TIME) ")");
41
42#ifdef CONFIG_WATCHDOG_NOWAYOUT
43module_param(nowayout, int, 0);
44MODULE_PARM_DESC(nowayout,
45 "Watchdog cannot be stopped once started (default="
46 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
47#endif
48
49static unsigned long bcm47xx_wdt_busy;
50static char expect_release;
51static struct timer_list wdt_timer;
52static atomic_t ticks;
53
54static inline void bcm47xx_wdt_hw_start(void)
55{
56 /* this is 2,5s on 100Mhz clock and 2s on 133 Mhz */
57 ssb_watchdog_timer_set(&ssb_bcm47xx, 0xfffffff);
58}
59
60static inline int bcm47xx_wdt_hw_stop(void)
61{
62 return ssb_watchdog_timer_set(&ssb_bcm47xx, 0);
63}
64
65static void bcm47xx_timer_tick(unsigned long unused)
66{
67 if (!atomic_dec_and_test(&ticks)) {
68 bcm47xx_wdt_hw_start();
69 mod_timer(&wdt_timer, jiffies + HZ);
70 } else {
71 printk(KERN_CRIT DRV_NAME "Watchdog will fire soon!!!\n");
72 }
73}
74
75static inline void bcm47xx_wdt_pet(void)
76{
77 atomic_set(&ticks, wdt_time);
78}
79
80static void bcm47xx_wdt_start(void)
81{
82 bcm47xx_wdt_pet();
83 bcm47xx_timer_tick(0);
84}
85
86static void bcm47xx_wdt_pause(void)
87{
88 del_timer_sync(&wdt_timer);
89 bcm47xx_wdt_hw_stop();
90}
91
92static void bcm47xx_wdt_stop(void)
93{
94 bcm47xx_wdt_pause();
95}
96
97static int bcm47xx_wdt_settimeout(int new_time)
98{
99 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
100 return -EINVAL;
101
102 wdt_time = new_time;
103 return 0;
104}
105
106static int bcm47xx_wdt_open(struct inode *inode, struct file *file)
107{
108 if (test_and_set_bit(0, &bcm47xx_wdt_busy))
109 return -EBUSY;
110
111 bcm47xx_wdt_start();
112 return nonseekable_open(inode, file);
113}
114
115static int bcm47xx_wdt_release(struct inode *inode, struct file *file)
116{
117 if (expect_release == 42) {
118 bcm47xx_wdt_stop();
119 } else {
120 printk(KERN_CRIT DRV_NAME
121 ": Unexpected close, not stopping watchdog!\n");
122 bcm47xx_wdt_start();
123 }
124
125 clear_bit(0, &bcm47xx_wdt_busy);
126 expect_release = 0;
127 return 0;
128}
129
130static ssize_t bcm47xx_wdt_write(struct file *file, const char __user *data,
131 size_t len, loff_t *ppos)
132{
133 if (len) {
134 if (!nowayout) {
135 size_t i;
136
137 expect_release = 0;
138
139 for (i = 0; i != len; i++) {
140 char c;
141 if (get_user(c, data + i))
142 return -EFAULT;
143 if (c == 'V')
144 expect_release = 42;
145 }
146 }
147 bcm47xx_wdt_pet();
148 }
149 return len;
150}
151
152static const struct watchdog_info bcm47xx_wdt_info = {
153 .identity = DRV_NAME,
154 .options = WDIOF_SETTIMEOUT |
155 WDIOF_KEEPALIVEPING |
156 WDIOF_MAGICCLOSE,
157};
158
159static long bcm47xx_wdt_ioctl(struct file *file,
160 unsigned int cmd, unsigned long arg)
161{
162 void __user *argp = (void __user *)arg;
163 int __user *p = argp;
164 int new_value, retval = -EINVAL;
165
166 switch (cmd) {
167 case WDIOC_GETSUPPORT:
168 return copy_to_user(argp, &bcm47xx_wdt_info,
169 sizeof(bcm47xx_wdt_info)) ? -EFAULT : 0;
170
171 case WDIOC_GETSTATUS:
172 case WDIOC_GETBOOTSTATUS:
173 return put_user(0, p);
174
175 case WDIOC_SETOPTIONS:
176 if (get_user(new_value, p))
177 return -EFAULT;
178
179 if (new_value & WDIOS_DISABLECARD) {
180 bcm47xx_wdt_stop();
181 retval = 0;
182 }
183
184 if (new_value & WDIOS_ENABLECARD) {
185 bcm47xx_wdt_start();
186 retval = 0;
187 }
188
189 return retval;
190
191 case WDIOC_KEEPALIVE:
192 bcm47xx_wdt_pet();
193 return 0;
194
195 case WDIOC_SETTIMEOUT:
196 if (get_user(new_value, p))
197 return -EFAULT;
198
199 if (bcm47xx_wdt_settimeout(new_value))
200 return -EINVAL;
201
202 bcm47xx_wdt_pet();
203
204 case WDIOC_GETTIMEOUT:
205 return put_user(wdt_time, p);
206
207 default:
208 return -ENOTTY;
209 }
210}
211
212static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
213 unsigned long code, void *unused)
214{
215 if (code == SYS_DOWN || code == SYS_HALT)
216 bcm47xx_wdt_stop();
217 return NOTIFY_DONE;
218}
219
220static const struct file_operations bcm47xx_wdt_fops = {
221 .owner = THIS_MODULE,
222 .llseek = no_llseek,
223 .unlocked_ioctl = bcm47xx_wdt_ioctl,
224 .open = bcm47xx_wdt_open,
225 .release = bcm47xx_wdt_release,
226 .write = bcm47xx_wdt_write,
227};
228
229static struct miscdevice bcm47xx_wdt_miscdev = {
230 .minor = WATCHDOG_MINOR,
231 .name = "watchdog",
232 .fops = &bcm47xx_wdt_fops,
233};
234
235static struct notifier_block bcm47xx_wdt_notifier = {
236 .notifier_call = bcm47xx_wdt_notify_sys,
237};
238
239static int __init bcm47xx_wdt_init(void)
240{
241 int ret;
242
243 if (bcm47xx_wdt_hw_stop() < 0)
244 return -ENODEV;
245
246 setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L);
247
248 if (bcm47xx_wdt_settimeout(wdt_time)) {
249 bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME);
250 printk(KERN_INFO DRV_NAME ": "
251 "wdt_time value must be 0 < wdt_time < %d, using %d\n",
252 (WDT_MAX_TIME + 1), wdt_time);
253 }
254
255 ret = register_reboot_notifier(&bcm47xx_wdt_notifier);
256 if (ret)
257 return ret;
258
259 ret = misc_register(&bcm47xx_wdt_miscdev);
260 if (ret) {
261 unregister_reboot_notifier(&bcm47xx_wdt_notifier);
262 return ret;
263 }
264
265 printk(KERN_INFO "BCM47xx Watchdog Timer enabled (%d seconds%s)\n",
266 wdt_time, nowayout ? ", nowayout" : "");
267 return 0;
268}
269
270static void __exit bcm47xx_wdt_exit(void)
271{
272 if (!nowayout)
273 bcm47xx_wdt_stop();
274
275 misc_deregister(&bcm47xx_wdt_miscdev);
276
277 unregister_reboot_notifier(&bcm47xx_wdt_notifier);
278}
279
280module_init(bcm47xx_wdt_init);
281module_exit(bcm47xx_wdt_exit);
282
283MODULE_AUTHOR("Aleksandar Radovanovic");
284MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
285MODULE_LICENSE("GPL");
286MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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
34static int timeout = WDT_DEFAULT_TIME;
35static bool nowayout = WATCHDOG_NOWAYOUT;
36
37module_param(timeout, int, 0);
38MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
39 __MODULE_STRING(WDT_DEFAULT_TIME) ")");
40
41module_param(nowayout, bool, 0);
42MODULE_PARM_DESC(nowayout,
43 "Watchdog cannot be stopped once started (default="
44 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
45
46static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
47{
48 return container_of(wdd, struct bcm47xx_wdt, wdd);
49}
50
51static 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
60static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
61{
62 return 0;
63}
64
65static 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
74static 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
90static 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
100static 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
109static 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
122static 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
131static 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
141static 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
151static 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
164static const struct watchdog_info bcm47xx_wdt_info = {
165 .identity = DRV_NAME,
166 .options = WDIOF_SETTIMEOUT |
167 WDIOF_KEEPALIVEPING |
168 WDIOF_MAGICCLOSE,
169};
170
171static 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
180static 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
218err_timer:
219 if (soft)
220 del_timer_sync(&wdt->soft_timer);
221
222 return ret;
223}
224
225static 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
237static 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
245module_platform_driver(bcm47xx_wdt_driver);
246
247MODULE_AUTHOR("Aleksandar Radovanovic");
248MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
249MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
250MODULE_LICENSE("GPL");