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
  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 void bcm47xx_wdt_soft_timer_tick(unsigned long data)
  53 {
  54         struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data;
  55         u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);
  56
  57         if (!atomic_dec_and_test(&wdt->soft_ticks)) {
  58                 wdt->timer_set_ms(wdt, next_tick);
  59                 mod_timer(&wdt->soft_timer, jiffies + HZ);
  60         } else {
  61                 pr_crit("Watchdog will fire soon!!!\n");
  62         }
  63 }
  64
  65 static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
  66 {
  67         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  68
  69         atomic_set(&wdt->soft_ticks, wdd->timeout);
  70
  71         return 0;
  72 }
  73
  74 static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
  75 {
  76         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  77
  78         bcm47xx_wdt_soft_keepalive(wdd);
  79         bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);
  80
  81         return 0;
  82 }
  83
  84 static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
  85 {
  86         struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  87
  88         del_timer_sync(&wdt->soft_timer);
  89         wdt->timer_set(wdt, 0);
  90
  91         return 0;
  92 }
  93
  94 static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
  95                                         unsigned int new_time)
  96 {
  97         if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
  98                 pr_warn("timeout value must be 1<=x<=%d, using %d\n",
  99                         WDT_SOFTTIMER_MAX, new_time);
 100                 return -EINVAL;
 101         }
 102
 103         wdd->timeout = new_time;
 104         return 0;
 105 }
 106
 107 static const struct watchdog_info bcm47xx_wdt_info = {
 108         .identity       = DRV_NAME,
 109         .options        = WDIOF_SETTIMEOUT |
 110                                 WDIOF_KEEPALIVEPING |
 111                                 WDIOF_MAGICCLOSE,
 112 };
 113
 114 static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
 115                                   unsigned long code, void *unused)
 116 {
 117         struct bcm47xx_wdt *wdt;
 118
 119         wdt = container_of(this, struct bcm47xx_wdt, notifier);
 120         if (code == SYS_DOWN || code == SYS_HALT)
 121                 wdt->wdd.ops->stop(&wdt->wdd);
 122         return NOTIFY_DONE;
 123 }
 124
 125 static struct watchdog_ops bcm47xx_wdt_soft_ops = {
 126         .owner          = THIS_MODULE,
 127         .start          = bcm47xx_wdt_soft_start,
 128         .stop           = bcm47xx_wdt_soft_stop,
 129         .ping           = bcm47xx_wdt_soft_keepalive,
 130         .set_timeout    = bcm47xx_wdt_soft_set_timeout,
 131 };
 132
 133 static int bcm47xx_wdt_probe(struct platform_device *pdev)
 134 {
 135         int ret;
 136         struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
 137
 138         if (!wdt)
 139                 return -ENXIO;
 140
 141         setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
 142                     (long unsigned int)wdt);
 143
 144         wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
 145         wdt->wdd.info = &bcm47xx_wdt_info;
 146         wdt->wdd.timeout = WDT_DEFAULT_TIME;
 147         ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
 148         if (ret)
 149                 goto err_timer;
 150         watchdog_set_nowayout(&wdt->wdd, nowayout);
 151
 152         wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;
 153
 154         ret = register_reboot_notifier(&wdt->notifier);
 155         if (ret)
 156                 goto err_timer;
 157
 158         ret = watchdog_register_device(&wdt->wdd);
 159         if (ret)
 160                 goto err_notifier;
 161
 162         pr_info("BCM47xx Watchdog Timer enabled (%d seconds%s)\n",
 163                 timeout, nowayout ? ", nowayout" : "");
 164         return 0;
 165
 166 err_notifier:
 167         unregister_reboot_notifier(&wdt->notifier);
 168 err_timer:
 169         del_timer_sync(&wdt->soft_timer);
 170
 171         return ret;
 172 }
 173
 174 static int bcm47xx_wdt_remove(struct platform_device *pdev)
 175 {
 176         struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
 177
 178         if (!wdt)
 179                 return -ENXIO;
 180
 181         watchdog_unregister_device(&wdt->wdd);
 182         unregister_reboot_notifier(&wdt->notifier);
 183
 184         return 0;
 185 }
 186
 187 static struct platform_driver bcm47xx_wdt_driver = {
 188         .driver         = {
 189                 .owner  = THIS_MODULE,
 190                 .name   = "bcm47xx-wdt",
 191         },
 192         .probe          = bcm47xx_wdt_probe,
 193         .remove         = bcm47xx_wdt_remove,
 194 };
 195
 196 module_platform_driver(bcm47xx_wdt_driver);
 197
 198 MODULE_AUTHOR("Aleksandar Radovanovic");
 199 MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
 200 MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
 201 MODULE_LICENSE("GPL");