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 35static int timeout = WDT_DEFAULT_TIME; 36static bool nowayout = WATCHDOG_NOWAYOUT; 37 38module_param(timeout, int, 0); 39MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default=" 40 __MODULE_STRING(WDT_DEFAULT_TIME) ")"); 41 42module_param(nowayout, bool, 0); 43MODULE_PARM_DESC(nowayout, 44 "Watchdog cannot be stopped once started (default=" 45 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 46 47static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd) 48{ 49 return container_of(wdd, struct bcm47xx_wdt, wdd); 50} 51 52static 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 61static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd) 62{ 63 return 0; 64} 65 66static 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 75static 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 91static 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 99static 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 112static 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 121static 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 131static 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 141static 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 154static const struct watchdog_info bcm47xx_wdt_info = { 155 .identity = DRV_NAME, 156 .options = WDIOF_SETTIMEOUT | 157 WDIOF_KEEPALIVEPING | 158 WDIOF_MAGICCLOSE, 159}; 160 161static 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 172static 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 183static 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 191static 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 wdt->wdd.parent = &pdev->dev; 213 ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout); 214 if (ret) 215 goto err_timer; 216 watchdog_set_nowayout(&wdt->wdd, nowayout); 217 218 wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys; 219 220 ret = register_reboot_notifier(&wdt->notifier); 221 if (ret) 222 goto err_timer; 223 224 wdt->restart_handler.notifier_call = &bcm47xx_wdt_restart; 225 wdt->restart_handler.priority = 64; 226 ret = register_restart_handler(&wdt->restart_handler); 227 if (ret) 228 goto err_notifier; 229 230 ret = watchdog_register_device(&wdt->wdd); 231 if (ret) 232 goto err_handler; 233 234 dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n", 235 timeout, nowayout ? ", nowayout" : "", 236 soft ? ", Software Timer" : ""); 237 return 0; 238 239err_handler: 240 unregister_restart_handler(&wdt->restart_handler); 241err_notifier: 242 unregister_reboot_notifier(&wdt->notifier); 243err_timer: 244 if (soft) 245 del_timer_sync(&wdt->soft_timer); 246 247 return ret; 248} 249 250static int bcm47xx_wdt_remove(struct platform_device *pdev) 251{ 252 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 253 254 if (!wdt) 255 return -ENXIO; 256 257 watchdog_unregister_device(&wdt->wdd); 258 unregister_reboot_notifier(&wdt->notifier); 259 260 return 0; 261} 262 263static struct platform_driver bcm47xx_wdt_driver = { 264 .driver = { 265 .name = "bcm47xx-wdt", 266 }, 267 .probe = bcm47xx_wdt_probe, 268 .remove = bcm47xx_wdt_remove, 269}; 270 271module_platform_driver(bcm47xx_wdt_driver); 272 273MODULE_AUTHOR("Aleksandar Radovanovic"); 274MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>"); 275MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); 276MODULE_LICENSE("GPL"); 277