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/reboot.h> 24 #include <linux/types.h> 25 #include <linux/watchdog.h> 26 #include <linux/timer.h> 27 #include <linux/jiffies.h> 28 29 #define DRV_NAME "bcm47xx_wdt" 30 31 #define WDT_DEFAULT_TIME 30 /* seconds */ 32 #define WDT_SOFTTIMER_MAX 255 /* seconds */ 33 #define WDT_SOFTTIMER_THRESHOLD 60 /* seconds */ 34 35 static int timeout = WDT_DEFAULT_TIME; 36 static bool nowayout = WATCHDOG_NOWAYOUT; 37 38 module_param(timeout, int, 0); 39 MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default=" 40 __MODULE_STRING(WDT_DEFAULT_TIME) ")"); 41 42 module_param(nowayout, bool, 0); 43 MODULE_PARM_DESC(nowayout, 44 "Watchdog cannot be stopped once started (default=" 45 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 46 47 static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd) 48 { 49 return container_of(wdd, struct bcm47xx_wdt, wdd); 50 } 51 52 static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd) 53 { 54 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 55 56 wdt->timer_set_ms(wdt, wdd->timeout * 1000); 57 58 return 0; 59 } 60 61 static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd) 62 { 63 return 0; 64 } 65 66 static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd) 67 { 68 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 69 70 wdt->timer_set(wdt, 0); 71 72 return 0; 73 } 74 75 static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd, 76 unsigned int new_time) 77 { 78 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 79 u32 max_timer = wdt->max_timer_ms; 80 81 if (new_time < 1 || new_time > max_timer / 1000) { 82 pr_warn("timeout value must be 1<=x<=%d, using %d\n", 83 max_timer / 1000, new_time); 84 return -EINVAL; 85 } 86 87 wdd->timeout = new_time; 88 return 0; 89 } 90 91 static struct watchdog_ops bcm47xx_wdt_hard_ops = { 92 .owner = THIS_MODULE, 93 .start = bcm47xx_wdt_hard_start, 94 .stop = bcm47xx_wdt_hard_stop, 95 .ping = bcm47xx_wdt_hard_keepalive, 96 .set_timeout = bcm47xx_wdt_hard_set_timeout, 97 }; 98 99 static void bcm47xx_wdt_soft_timer_tick(unsigned long data) 100 { 101 struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data; 102 u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms); 103 104 if (!atomic_dec_and_test(&wdt->soft_ticks)) { 105 wdt->timer_set_ms(wdt, next_tick); 106 mod_timer(&wdt->soft_timer, jiffies + HZ); 107 } else { 108 pr_crit("Watchdog will fire soon!!!\n"); 109 } 110 } 111 112 static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd) 113 { 114 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 115 116 atomic_set(&wdt->soft_ticks, wdd->timeout); 117 118 return 0; 119 } 120 121 static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd) 122 { 123 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 124 125 bcm47xx_wdt_soft_keepalive(wdd); 126 bcm47xx_wdt_soft_timer_tick((unsigned long)wdt); 127 128 return 0; 129 } 130 131 static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd) 132 { 133 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 134 135 del_timer_sync(&wdt->soft_timer); 136 wdt->timer_set(wdt, 0); 137 138 return 0; 139 } 140 141 static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd, 142 unsigned int new_time) 143 { 144 if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) { 145 pr_warn("timeout value must be 1<=x<=%d, using %d\n", 146 WDT_SOFTTIMER_MAX, new_time); 147 return -EINVAL; 148 } 149 150 wdd->timeout = new_time; 151 return 0; 152 } 153 154 static const struct watchdog_info bcm47xx_wdt_info = { 155 .identity = DRV_NAME, 156 .options = WDIOF_SETTIMEOUT | 157 WDIOF_KEEPALIVEPING | 158 WDIOF_MAGICCLOSE, 159 }; 160 161 static int bcm47xx_wdt_notify_sys(struct notifier_block *this, 162 unsigned long code, void *unused) 163 { 164 struct bcm47xx_wdt *wdt; 165 166 wdt = container_of(this, struct bcm47xx_wdt, notifier); 167 if (code == SYS_DOWN || code == SYS_HALT) 168 wdt->wdd.ops->stop(&wdt->wdd); 169 return NOTIFY_DONE; 170 } 171 172 static int bcm47xx_wdt_restart(struct notifier_block *this, unsigned long mode, 173 void *cmd) 174 { 175 struct bcm47xx_wdt *wdt; 176 177 wdt = container_of(this, struct bcm47xx_wdt, restart_handler); 178 wdt->timer_set(wdt, 1); 179 180 return NOTIFY_DONE; 181 } 182 183 static struct watchdog_ops bcm47xx_wdt_soft_ops = { 184 .owner = THIS_MODULE, 185 .start = bcm47xx_wdt_soft_start, 186 .stop = bcm47xx_wdt_soft_stop, 187 .ping = bcm47xx_wdt_soft_keepalive, 188 .set_timeout = bcm47xx_wdt_soft_set_timeout, 189 }; 190 191 static int bcm47xx_wdt_probe(struct platform_device *pdev) 192 { 193 int ret; 194 bool soft; 195 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 196 197 if (!wdt) 198 return -ENXIO; 199 200 soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000; 201 202 if (soft) { 203 wdt->wdd.ops = &bcm47xx_wdt_soft_ops; 204 setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick, 205 (long unsigned int)wdt); 206 } else { 207 wdt->wdd.ops = &bcm47xx_wdt_hard_ops; 208 } 209 210 wdt->wdd.info = &bcm47xx_wdt_info; 211 wdt->wdd.timeout = WDT_DEFAULT_TIME; 212 ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout); 213 if (ret) 214 goto err_timer; 215 watchdog_set_nowayout(&wdt->wdd, nowayout); 216 217 wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys; 218 219 ret = register_reboot_notifier(&wdt->notifier); 220 if (ret) 221 goto err_timer; 222 223 wdt->restart_handler.notifier_call = &bcm47xx_wdt_restart; 224 wdt->restart_handler.priority = 64; 225 ret = register_restart_handler(&wdt->restart_handler); 226 if (ret) 227 goto err_notifier; 228 229 ret = watchdog_register_device(&wdt->wdd); 230 if (ret) 231 goto err_handler; 232 233 dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n", 234 timeout, nowayout ? ", nowayout" : "", 235 soft ? ", Software Timer" : ""); 236 return 0; 237 238 err_handler: 239 unregister_restart_handler(&wdt->restart_handler); 240 err_notifier: 241 unregister_reboot_notifier(&wdt->notifier); 242 err_timer: 243 if (soft) 244 del_timer_sync(&wdt->soft_timer); 245 246 return ret; 247 } 248 249 static int bcm47xx_wdt_remove(struct platform_device *pdev) 250 { 251 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 252 253 if (!wdt) 254 return -ENXIO; 255 256 watchdog_unregister_device(&wdt->wdd); 257 unregister_reboot_notifier(&wdt->notifier); 258 259 return 0; 260 } 261 262 static struct platform_driver bcm47xx_wdt_driver = { 263 .driver = { 264 .name = "bcm47xx-wdt", 265 }, 266 .probe = bcm47xx_wdt_probe, 267 .remove = bcm47xx_wdt_remove, 268 }; 269 270 module_platform_driver(bcm47xx_wdt_driver); 271 272 MODULE_AUTHOR("Aleksandar Radovanovic"); 273 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>"); 274 MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); 275 MODULE_LICENSE("GPL"); 276