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/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 /* seconds */ 31 #define WDT_SOFTTIMER_MAX 255 /* seconds */ 32 #define WDT_SOFTTIMER_THRESHOLD 60 /* seconds */ 33 34 static int timeout = WDT_DEFAULT_TIME; 35 static bool nowayout = WATCHDOG_NOWAYOUT; 36 37 module_param(timeout, int, 0); 38 MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default=" 39 __MODULE_STRING(WDT_DEFAULT_TIME) ")"); 40 41 module_param(nowayout, bool, 0); 42 MODULE_PARM_DESC(nowayout, 43 "Watchdog cannot be stopped once started (default=" 44 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 45 46 static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd) 47 { 48 return container_of(wdd, struct bcm47xx_wdt, wdd); 49 } 50 51 static 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 60 static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd) 61 { 62 return 0; 63 } 64 65 static 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 74 static 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 90 static int bcm47xx_wdt_restart(struct watchdog_device *wdd) 91 { 92 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 93 94 wdt->timer_set(wdt, 1); 95 96 return 0; 97 } 98 99 static struct watchdog_ops bcm47xx_wdt_hard_ops = { 100 .owner = THIS_MODULE, 101 .start = bcm47xx_wdt_hard_start, 102 .stop = bcm47xx_wdt_hard_stop, 103 .ping = bcm47xx_wdt_hard_keepalive, 104 .set_timeout = bcm47xx_wdt_hard_set_timeout, 105 .restart = bcm47xx_wdt_restart, 106 }; 107 108 static void bcm47xx_wdt_soft_timer_tick(unsigned long data) 109 { 110 struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data; 111 u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms); 112 113 if (!atomic_dec_and_test(&wdt->soft_ticks)) { 114 wdt->timer_set_ms(wdt, next_tick); 115 mod_timer(&wdt->soft_timer, jiffies + HZ); 116 } else { 117 pr_crit("Watchdog will fire soon!!!\n"); 118 } 119 } 120 121 static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd) 122 { 123 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 124 125 atomic_set(&wdt->soft_ticks, wdd->timeout); 126 127 return 0; 128 } 129 130 static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd) 131 { 132 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 133 134 bcm47xx_wdt_soft_keepalive(wdd); 135 bcm47xx_wdt_soft_timer_tick((unsigned long)wdt); 136 137 return 0; 138 } 139 140 static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd) 141 { 142 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 143 144 del_timer_sync(&wdt->soft_timer); 145 wdt->timer_set(wdt, 0); 146 147 return 0; 148 } 149 150 static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd, 151 unsigned int new_time) 152 { 153 if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) { 154 pr_warn("timeout value must be 1<=x<=%d, using %d\n", 155 WDT_SOFTTIMER_MAX, new_time); 156 return -EINVAL; 157 } 158 159 wdd->timeout = new_time; 160 return 0; 161 } 162 163 static const struct watchdog_info bcm47xx_wdt_info = { 164 .identity = DRV_NAME, 165 .options = WDIOF_SETTIMEOUT | 166 WDIOF_KEEPALIVEPING | 167 WDIOF_MAGICCLOSE, 168 }; 169 170 static struct watchdog_ops bcm47xx_wdt_soft_ops = { 171 .owner = THIS_MODULE, 172 .start = bcm47xx_wdt_soft_start, 173 .stop = bcm47xx_wdt_soft_stop, 174 .ping = bcm47xx_wdt_soft_keepalive, 175 .set_timeout = bcm47xx_wdt_soft_set_timeout, 176 .restart = bcm47xx_wdt_restart, 177 }; 178 179 static int bcm47xx_wdt_probe(struct platform_device *pdev) 180 { 181 int ret; 182 bool soft; 183 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 184 185 if (!wdt) 186 return -ENXIO; 187 188 soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000; 189 190 if (soft) { 191 wdt->wdd.ops = &bcm47xx_wdt_soft_ops; 192 setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick, 193 (long unsigned int)wdt); 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; 216 217 err_timer: 218 if (soft) 219 del_timer_sync(&wdt->soft_timer); 220 221 return ret; 222 } 223 224 static int bcm47xx_wdt_remove(struct platform_device *pdev) 225 { 226 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 227 228 if (!wdt) 229 return -ENXIO; 230 231 watchdog_unregister_device(&wdt->wdd); 232 233 return 0; 234 } 235 236 static struct platform_driver bcm47xx_wdt_driver = { 237 .driver = { 238 .name = "bcm47xx-wdt", 239 }, 240 .probe = bcm47xx_wdt_probe, 241 .remove = bcm47xx_wdt_remove, 242 }; 243 244 module_platform_driver(bcm47xx_wdt_driver); 245 246 MODULE_AUTHOR("Aleksandar Radovanovic"); 247 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>"); 248 MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); 249 MODULE_LICENSE("GPL"); 250