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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
31#define WDT_SOFTTIMER_MAX 255
32#define WDT_SOFTTIMER_THRESHOLD 60
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 const 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(struct timer_list *t)
110{
111 struct bcm47xx_wdt *wdt = from_timer(wdt, t, soft_timer);
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(&wdt->soft_timer);
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 const 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 timer_setup(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick, 0);
194 } else {
195 wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
196 }
197
198 wdt->wdd.info = &bcm47xx_wdt_info;
199 wdt->wdd.timeout = WDT_DEFAULT_TIME;
200 wdt->wdd.parent = &pdev->dev;
201 ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
202 if (ret)
203 goto err_timer;
204 watchdog_set_nowayout(&wdt->wdd, nowayout);
205 watchdog_set_restart_priority(&wdt->wdd, 64);
206 watchdog_stop_on_reboot(&wdt->wdd);
207
208 ret = watchdog_register_device(&wdt->wdd);
209 if (ret)
210 goto err_timer;
211
212 dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
213 timeout, nowayout ? ", nowayout" : "",
214 soft ? ", Software Timer" : "");
215 return 0;
216
217err_timer:
218 if (soft)
219 del_timer_sync(&wdt->soft_timer);
220
221 return ret;
222}
223
224static int bcm47xx_wdt_remove(struct platform_device *pdev)
225{
226 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
227
228 watchdog_unregister_device(&wdt->wdd);
229
230 return 0;
231}
232
233static struct platform_driver bcm47xx_wdt_driver = {
234 .driver = {
235 .name = "bcm47xx-wdt",
236 },
237 .probe = bcm47xx_wdt_probe,
238 .remove = bcm47xx_wdt_remove,
239};
240
241module_platform_driver(bcm47xx_wdt_driver);
242
243MODULE_AUTHOR("Aleksandar Radovanovic");
244MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
245MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
246MODULE_LICENSE("GPL");
247
