drivers/watchdog/bcm47xx_wdt.c

   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");