diff options
Diffstat (limited to 'drivers/watchdog/retu_wdt.c')
| -rw-r--r-- | drivers/watchdog/retu_wdt.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/watchdog/retu_wdt.c b/drivers/watchdog/retu_wdt.c new file mode 100644 index 00000000000..a7a0695971e --- /dev/null +++ b/drivers/watchdog/retu_wdt.c @@ -0,0 +1,177 @@ +/* + * Retu watchdog driver + * + * Copyright (C) 2004, 2005 Nokia Corporation + * + * Based on code written by Amit Kucheria and Michael Buesch. + * Rewritten by Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mfd/retu.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> + +/* Watchdog timer values in seconds */ +#define RETU_WDT_MAX_TIMER 63 + +struct retu_wdt_dev { + struct retu_dev *rdev; + struct device *dev; + struct delayed_work ping_work; +}; + +/* + * Since Retu watchdog cannot be disabled in hardware, we must kick it + * with a timer until userspace watchdog software takes over. If + * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding. + */ +static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev) +{ + retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); + schedule_delayed_work(&wdev->ping_work, + round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2)); +} + +static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev) +{ + retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); + cancel_delayed_work_sync(&wdev->ping_work); +} + +static void retu_wdt_ping_work(struct work_struct *work) +{ + struct retu_wdt_dev *wdev = container_of(to_delayed_work(work), + struct retu_wdt_dev, ping_work); + retu_wdt_ping_enable(wdev); +} + +static int retu_wdt_start(struct watchdog_device *wdog) +{ + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); + + retu_wdt_ping_disable(wdev); + + return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); +} + +static int retu_wdt_stop(struct watchdog_device *wdog) +{ + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); + + retu_wdt_ping_enable(wdev); + + return 0; +} + +static int retu_wdt_ping(struct watchdog_device *wdog) +{ + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); + + return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); +} + +static int retu_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int timeout) +{ + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); + + wdog->timeout = timeout; + return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); +} + +static const struct watchdog_info retu_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "Retu watchdog", +}; + +static const struct watchdog_ops retu_wdt_ops = { + .owner = THIS_MODULE, + .start = retu_wdt_start, + .stop = retu_wdt_stop, + .ping = retu_wdt_ping, + .set_timeout = retu_wdt_set_timeout, +}; + +static int retu_wdt_probe(struct platform_device *pdev) +{ + struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); + bool nowayout = WATCHDOG_NOWAYOUT; + struct watchdog_device *retu_wdt; + struct retu_wdt_dev *wdev; + int ret; + + retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL); + if (!retu_wdt) + return -ENOMEM; + + wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); + if (!wdev) + return -ENOMEM; + + retu_wdt->info = &retu_wdt_info; + retu_wdt->ops = &retu_wdt_ops; + retu_wdt->timeout = RETU_WDT_MAX_TIMER; + retu_wdt->min_timeout = 0; + retu_wdt->max_timeout = RETU_WDT_MAX_TIMER; + + watchdog_set_drvdata(retu_wdt, wdev); + watchdog_set_nowayout(retu_wdt, nowayout); + + wdev->rdev = rdev; + wdev->dev = &pdev->dev; + + INIT_DELAYED_WORK(&wdev->ping_work, retu_wdt_ping_work); + + ret = watchdog_register_device(retu_wdt); + if (ret < 0) + return ret; + + if (nowayout) + retu_wdt_ping(retu_wdt); + else + retu_wdt_ping_enable(wdev); + + platform_set_drvdata(pdev, retu_wdt); + + return 0; +} + +static int retu_wdt_remove(struct platform_device *pdev) +{ + struct watchdog_device *wdog = platform_get_drvdata(pdev); + struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); + + watchdog_unregister_device(wdog); + cancel_delayed_work_sync(&wdev->ping_work); + + return 0; +} + +static struct platform_driver retu_wdt_driver = { + .probe = retu_wdt_probe, + .remove = retu_wdt_remove, + .driver = { + .name = "retu-wdt", + }, +}; +module_platform_driver(retu_wdt_driver); + +MODULE_ALIAS("platform:retu-wdt"); +MODULE_DESCRIPTION("Retu watchdog"); +MODULE_AUTHOR("Amit Kucheria"); +MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>"); +MODULE_LICENSE("GPL"); |