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 36 static int timeout = WDT_DEFAULT_TIME; 37 static bool nowayout = WATCHDOG_NOWAYOUT; 38 39 module_param(timeout, int, 0); 40 MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default=" 41 __MODULE_STRING(WDT_DEFAULT_TIME) ")"); 42 43 module_param(nowayout, bool, 0); 44 MODULE_PARM_DESC(nowayout, 45 "Watchdog cannot be stopped once started (default=" 46 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 47 48 static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd) 49 { 50 return container_of(wdd, struct bcm47xx_wdt, wdd); 51 } 52 53 static 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 62 static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd) 63 { 64 return 0; 65 } 66 67 static 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 76 static 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 92 static 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 }; 99 100 static 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 } 112 113 static 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 } 121 122 static 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 } 131 132 static 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 } 141 142 static 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 } 154 155 static const struct watchdog_info bcm47xx_wdt_info = { 156 .identity = DRV_NAME, 157 .options = WDIOF_SETTIMEOUT | 158 WDIOF_KEEPALIVEPING | 159 WDIOF_MAGICCLOSE, 160 }; 161 162 static 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 } 172 173 static 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 }; 180 181 static 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; 221 222 err_notifier: 223 unregister_reboot_notifier(&wdt->notifier); 224 err_timer: 225 if (soft) 226 del_timer_sync(&wdt->soft_timer); 227 228 return ret; 229 } 230 231 static 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 } 243 244 static 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 }; 252 253 module_platform_driver(bcm47xx_wdt_driver); 254 255 MODULE_AUTHOR("Aleksandar Radovanovic"); 256 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>"); 257 MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); 258 MODULE_LICENSE("GPL"); 259