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