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 unsigned long action, void *data) 92 { 93 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 94 95 wdt->timer_set(wdt, 1); 96 97 return 0; 98 } 99 100 static struct watchdog_ops bcm47xx_wdt_hard_ops = { 101 .owner = THIS_MODULE, 102 .start = bcm47xx_wdt_hard_start, 103 .stop = bcm47xx_wdt_hard_stop, 104 .ping = bcm47xx_wdt_hard_keepalive, 105 .set_timeout = bcm47xx_wdt_hard_set_timeout, 106 .restart = bcm47xx_wdt_restart, 107 }; 108 109 static void bcm47xx_wdt_soft_timer_tick(unsigned long data) 110 { 111 struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data; 112 u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms); 113 114 if (!atomic_dec_and_test(&wdt->soft_ticks)) { 115 wdt->timer_set_ms(wdt, next_tick); 116 mod_timer(&wdt->soft_timer, jiffies + HZ); 117 } else { 118 pr_crit("Watchdog will fire soon!!!\n"); 119 } 120 } 121 122 static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd) 123 { 124 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 125 126 atomic_set(&wdt->soft_ticks, wdd->timeout); 127 128 return 0; 129 } 130 131 static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd) 132 { 133 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 134 135 bcm47xx_wdt_soft_keepalive(wdd); 136 bcm47xx_wdt_soft_timer_tick((unsigned long)wdt); 137 138 return 0; 139 } 140 141 static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd) 142 { 143 struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd); 144 145 del_timer_sync(&wdt->soft_timer); 146 wdt->timer_set(wdt, 0); 147 148 return 0; 149 } 150 151 static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd, 152 unsigned int new_time) 153 { 154 if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) { 155 pr_warn("timeout value must be 1<=x<=%d, using %d\n", 156 WDT_SOFTTIMER_MAX, new_time); 157 return -EINVAL; 158 } 159 160 wdd->timeout = new_time; 161 return 0; 162 } 163 164 static const struct watchdog_info bcm47xx_wdt_info = { 165 .identity = DRV_NAME, 166 .options = WDIOF_SETTIMEOUT | 167 WDIOF_KEEPALIVEPING | 168 WDIOF_MAGICCLOSE, 169 }; 170 171 static struct watchdog_ops bcm47xx_wdt_soft_ops = { 172 .owner = THIS_MODULE, 173 .start = bcm47xx_wdt_soft_start, 174 .stop = bcm47xx_wdt_soft_stop, 175 .ping = bcm47xx_wdt_soft_keepalive, 176 .set_timeout = bcm47xx_wdt_soft_set_timeout, 177 .restart = bcm47xx_wdt_restart, 178 }; 179 180 static int bcm47xx_wdt_probe(struct platform_device *pdev) 181 { 182 int ret; 183 bool soft; 184 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 185 186 if (!wdt) 187 return -ENXIO; 188 189 soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000; 190 191 if (soft) { 192 wdt->wdd.ops = &bcm47xx_wdt_soft_ops; 193 setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick, 194 (long unsigned int)wdt); 195 } else { 196 wdt->wdd.ops = &bcm47xx_wdt_hard_ops; 197 } 198 199 wdt->wdd.info = &bcm47xx_wdt_info; 200 wdt->wdd.timeout = WDT_DEFAULT_TIME; 201 wdt->wdd.parent = &pdev->dev; 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 watchdog_set_restart_priority(&wdt->wdd, 64); 207 watchdog_stop_on_reboot(&wdt->wdd); 208 209 ret = watchdog_register_device(&wdt->wdd); 210 if (ret) 211 goto err_timer; 212 213 dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n", 214 timeout, nowayout ? ", nowayout" : "", 215 soft ? ", Software Timer" : ""); 216 return 0; 217 218 err_timer: 219 if (soft) 220 del_timer_sync(&wdt->soft_timer); 221 222 return ret; 223 } 224 225 static int bcm47xx_wdt_remove(struct platform_device *pdev) 226 { 227 struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev); 228 229 if (!wdt) 230 return -ENXIO; 231 232 watchdog_unregister_device(&wdt->wdd); 233 234 return 0; 235 } 236 237 static struct platform_driver bcm47xx_wdt_driver = { 238 .driver = { 239 .name = "bcm47xx-wdt", 240 }, 241 .probe = bcm47xx_wdt_probe, 242 .remove = bcm47xx_wdt_remove, 243 }; 244 245 module_platform_driver(bcm47xx_wdt_driver); 246 247 MODULE_AUTHOR("Aleksandar Radovanovic"); 248 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>"); 249 MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); 250 MODULE_LICENSE("GPL"); 251