1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Watchdog driver for Broadcom BCM47XX |
4 | * |
5 | * Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs> |
6 | * Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr> |
7 | * Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de> |
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 /* seconds */ |
28 | #define WDT_SOFTTIMER_MAX 255 /* seconds */ |
29 | #define WDT_SOFTTIMER_THRESHOLD 60 /* seconds */ |
30 | |
31 | static int timeout = WDT_DEFAULT_TIME; |
32 | static bool nowayout = WATCHDOG_NOWAYOUT; |
33 | |
34 | module_param(timeout, int, 0); |
35 | MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default=" |
36 | __MODULE_STRING(WDT_DEFAULT_TIME) ")" ); |
37 | |
38 | module_param(nowayout, bool, 0); |
39 | MODULE_PARM_DESC(nowayout, |
40 | "Watchdog cannot be stopped once started (default=" |
41 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")" ); |
42 | |
43 | static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd) |
44 | { |
45 | return container_of(wdd, struct bcm47xx_wdt, wdd); |
46 | } |
47 | |
48 | static 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 | |
57 | static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd) |
58 | { |
59 | return 0; |
60 | } |
61 | |
62 | static 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 | |
71 | static 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 | |
87 | static 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 | |
97 | static 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 | |
106 | static 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(v: &wdt->soft_ticks)) { |
112 | wdt->timer_set_ms(wdt, next_tick); |
113 | mod_timer(timer: &wdt->soft_timer, expires: jiffies + HZ); |
114 | } else { |
115 | pr_crit("Watchdog will fire soon!!!\n" ); |
116 | } |
117 | } |
118 | |
119 | static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd) |
120 | { |
121 | struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); |
122 | |
123 | atomic_set(v: &wdt->soft_ticks, i: wdd->timeout); |
124 | |
125 | return 0; |
126 | } |
127 | |
128 | static 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(t: &wdt->soft_timer); |
134 | |
135 | return 0; |
136 | } |
137 | |
138 | static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd) |
139 | { |
140 | struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); |
141 | |
142 | del_timer_sync(timer: &wdt->soft_timer); |
143 | wdt->timer_set(wdt, 0); |
144 | |
145 | return 0; |
146 | } |
147 | |
148 | static 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 | |
161 | static const struct watchdog_info bcm47xx_wdt_info = { |
162 | .identity = DRV_NAME, |
163 | .options = WDIOF_SETTIMEOUT | |
164 | WDIOF_KEEPALIVEPING | |
165 | WDIOF_MAGICCLOSE, |
166 | }; |
167 | |
168 | static 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 | |
177 | static int bcm47xx_wdt_probe(struct platform_device *pdev) |
178 | { |
179 | int ret; |
180 | bool soft; |
181 | struct bcm47xx_wdt *wdt = dev_get_platdata(dev: &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(wdd: &wdt->wdd, nowayout); |
202 | watchdog_set_restart_priority(wdd: &wdt->wdd, priority: 64); |
203 | watchdog_stop_on_reboot(wdd: &wdt->wdd); |
204 | |
205 | ret = devm_watchdog_register_device(dev: &pdev->dev, &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 | |
214 | err_timer: |
215 | if (soft) |
216 | del_timer_sync(timer: &wdt->soft_timer); |
217 | |
218 | return ret; |
219 | } |
220 | |
221 | static struct platform_driver bcm47xx_wdt_driver = { |
222 | .driver = { |
223 | .name = "bcm47xx-wdt" , |
224 | }, |
225 | .probe = bcm47xx_wdt_probe, |
226 | }; |
227 | |
228 | module_platform_driver(bcm47xx_wdt_driver); |
229 | |
230 | MODULE_AUTHOR("Aleksandar Radovanovic" ); |
231 | MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>" ); |
232 | MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx" ); |
233 | MODULE_LICENSE("GPL" ); |
234 | |