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/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");