text: /*
   *  Watchdog driver for Broadcom BCM47XX
   *
   *  Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
   *  Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
   *  Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de>
   *
   *  This program is free software; you can redistribute it and/or
   *  modify it under the terms of the GNU General Public License
   *  as published by the Free Software Foundation; either version
   *  2 of the License, or (at your option) any later version.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/bcm47xx_wdt.h>
  #include <linux/bitops.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/platform_device.h>
  #include <linux/types.h>
  #include <linux/watchdog.h>
  #include <linux/timer.h>
  #include <linux/jiffies.h>
  
  #define DRV_NAME		"bcm47xx_wdt"
  
  #define WDT_DEFAULT_TIME	30	/* seconds */
  #define WDT_SOFTTIMER_MAX	255	/* seconds */
  #define WDT_SOFTTIMER_THRESHOLD	60	/* seconds */
  
  static int timeout = WDT_DEFAULT_TIME;
  static bool nowayout = WATCHDOG_NOWAYOUT;
  
  module_param(timeout, int, 0);
  MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
  				__MODULE_STRING(WDT_DEFAULT_TIME) ")");
  
  module_param(nowayout, bool, 0);
  MODULE_PARM_DESC(nowayout,
  		"Watchdog cannot be stopped once started (default="
  				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  
  static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
  {
  	return container_of(wdd, struct bcm47xx_wdt, wdd);
  }
  
  static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  
  	wdt->timer_set_ms(wdt, wdd->timeout * 1000);
  
  	return 0;
  }
  
  static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
  {
  	return 0;
  }
  
  static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  
  	wdt->timer_set(wdt, 0);
  
  	return 0;
  }
  
  static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
  					unsigned int new_time)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  	u32 max_timer = wdt->max_timer_ms;
  
  	if (new_time < 1 || new_time > max_timer / 1000) {
  		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
  			max_timer / 1000, new_time);
  		return -EINVAL;
  	}
  
  	wdd->timeout = new_time;
  	return 0;
  }
  
  static int bcm47xx_wdt_restart(struct watchdog_device *wdd,
  			       unsigned long action, void *data)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  
  	wdt->timer_set(wdt, 1);
  
  	return 0;
  }
  
  static struct watchdog_ops bcm47xx_wdt_hard_ops = {
  	.owner		= THIS_MODULE,
  	.start		= bcm47xx_wdt_hard_start,
  	.stop		= bcm47xx_wdt_hard_stop,
  	.ping		= bcm47xx_wdt_hard_keepalive,
  	.set_timeout	= bcm47xx_wdt_hard_set_timeout,
  	.restart        = bcm47xx_wdt_restart,
  };
  
  static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
  {
  	struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data;
  	u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);
  
  	if (!atomic_dec_and_test(&wdt->soft_ticks)) {
  		wdt->timer_set_ms(wdt, next_tick);
  		mod_timer(&wdt->soft_timer, jiffies + HZ);
  	} else {
  		pr_crit("Watchdog will fire soon!!!\n");
  	}
  }
  
  static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  
  	atomic_set(&wdt->soft_ticks, wdd->timeout);
  
  	return 0;
  }
  
  static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  
  	bcm47xx_wdt_soft_keepalive(wdd);
  	bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);
  
  	return 0;
  }
  
  static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
  {
  	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
  
  	del_timer_sync(&wdt->soft_timer);
  	wdt->timer_set(wdt, 0);
  
  	return 0;
  }
  
  static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
  					unsigned int new_time)
  {
  	if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
  		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
  			WDT_SOFTTIMER_MAX, new_time);
  		return -EINVAL;
  	}
  
  	wdd->timeout = new_time;
  	return 0;
  }
  
  static const struct watchdog_info bcm47xx_wdt_info = {
  	.identity	= DRV_NAME,
  	.options	= WDIOF_SETTIMEOUT |
  				WDIOF_KEEPALIVEPING |
  				WDIOF_MAGICCLOSE,
  };
  
  static struct watchdog_ops bcm47xx_wdt_soft_ops = {
  	.owner		= THIS_MODULE,
  	.start		= bcm47xx_wdt_soft_start,
  	.stop		= bcm47xx_wdt_soft_stop,
  	.ping		= bcm47xx_wdt_soft_keepalive,
  	.set_timeout	= bcm47xx_wdt_soft_set_timeout,
  	.restart        = bcm47xx_wdt_restart,
  };
  
  static int bcm47xx_wdt_probe(struct platform_device *pdev)
  {
  	int ret;
  	bool soft;
  	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
  
  	if (!wdt)
  		return -ENXIO;
  
  	soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;
  
  	if (soft) {
  		wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
  		setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
  			    (long unsigned int)wdt);
  	} else {
  		wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
  	}
  
  	wdt->wdd.info = &bcm47xx_wdt_info;
  	wdt->wdd.timeout = WDT_DEFAULT_TIME;
  	wdt->wdd.parent = &pdev->dev;
  	ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
  	if (ret)
  		goto err_timer;
  	watchdog_set_nowayout(&wdt->wdd, nowayout);
  	watchdog_set_restart_priority(&wdt->wdd, 64);
  	watchdog_stop_on_reboot(&wdt->wdd);
  
  	ret = watchdog_register_device(&wdt->wdd);
  	if (ret)
  		goto err_timer;
  
  	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
  		timeout, nowayout ? ", nowayout" : "",
  		soft ? ", Software Timer" : "");
  	return 0;
  
  err_timer:
  	if (soft)
  		del_timer_sync(&wdt->soft_timer);
  
  	return ret;
  }
  
  static int bcm47xx_wdt_remove(struct platform_device *pdev)
  {
  	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
  
  	watchdog_unregister_device(&wdt->wdd);
  
  	return 0;
  }
  
  static struct platform_driver bcm47xx_wdt_driver = {
  	.driver		= {
  		.name	= "bcm47xx-wdt",
  	},
  	.probe		= bcm47xx_wdt_probe,
  	.remove		= bcm47xx_wdt_remove,
  };
  
  module_platform_driver(bcm47xx_wdt_driver);
  
  MODULE_AUTHOR("Aleksandar Radovanovic");
  MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
  MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
  MODULE_LICENSE("GPL");
  