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linux/drivers/watchdog/bcm47xx_wdt.c
Hauke Mehrtens e3e83d0001 watchdog: bcm47xx_wdt.c: add hard timer 
The more recent devices have a watchdog timer which could be configured
for over 2 hours and not just 2 seconds like the first generation
devices. For those devices do not use the extra software timer, but
directly program the time into the register. This will automatically be
used if the timer supports more than a minute.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-03-01 12:47:31 +01:00

259 lines
6.2 KiB
C
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/*
* 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/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/reboot.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 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,
};
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 int bcm47xx_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
struct bcm47xx_wdt *wdt;
wdt = container_of(this, struct bcm47xx_wdt, notifier);
if (code == SYS_DOWN || code == SYS_HALT)
wdt->wdd.ops->stop(&wdt->wdd);
return NOTIFY_DONE;
}
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,
};
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;
ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
if (ret)
goto err_timer;
watchdog_set_nowayout(&wdt->wdd, nowayout);
wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;
ret = register_reboot_notifier(&wdt->notifier);
if (ret)
goto err_timer;
ret = watchdog_register_device(&wdt->wdd);
if (ret)
goto err_notifier;
dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
timeout, nowayout ? ", nowayout" : "",
soft ? ", Software Timer" : "");
return 0;
err_notifier:
unregister_reboot_notifier(&wdt->notifier);
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);
if (!wdt)
return -ENXIO;
watchdog_unregister_device(&wdt->wdd);
unregister_reboot_notifier(&wdt->notifier);
return 0;
}
static struct platform_driver bcm47xx_wdt_driver = {
.driver = {
.owner = THIS_MODULE,
.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");
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