twl4030_wdt.c
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/*
* Copyright (C) Nokia Corporation
*
* Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
*
* 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.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/i2c/twl.h>
#define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int twl4030_wdt_write(unsigned char val)
{
return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val,
TWL4030_WATCHDOG_CFG_REG_OFFS);
}
static int twl4030_wdt_start(struct watchdog_device *wdt)
{
return twl4030_wdt_write(wdt->timeout + 1);
}
static int twl4030_wdt_stop(struct watchdog_device *wdt)
{
return twl4030_wdt_write(0);
}
static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
unsigned int timeout)
{
wdt->timeout = timeout;
return 0;
}
static const struct watchdog_info twl4030_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "TWL4030 Watchdog",
};
static const struct watchdog_ops twl4030_wdt_ops = {
.owner = THIS_MODULE,
.start = twl4030_wdt_start,
.stop = twl4030_wdt_stop,
.set_timeout = twl4030_wdt_set_timeout,
};
static int twl4030_wdt_probe(struct platform_device *pdev)
{
int ret = 0;
struct watchdog_device *wdt;
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->info = &twl4030_wdt_info;
wdt->ops = &twl4030_wdt_ops;
wdt->status = 0;
wdt->timeout = 30;
wdt->min_timeout = 1;
wdt->max_timeout = 30;
watchdog_set_nowayout(wdt, nowayout);
platform_set_drvdata(pdev, wdt);
twl4030_wdt_stop(wdt);
ret = watchdog_register_device(wdt);
if (ret)
return ret;
return 0;
}
static int twl4030_wdt_remove(struct platform_device *pdev)
{
struct watchdog_device *wdt = platform_get_drvdata(pdev);
watchdog_unregister_device(wdt);
return 0;
}
#ifdef CONFIG_PM
static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
struct watchdog_device *wdt = platform_get_drvdata(pdev);
if (watchdog_active(wdt))
return twl4030_wdt_stop(wdt);
return 0;
}
static int twl4030_wdt_resume(struct platform_device *pdev)
{
struct watchdog_device *wdt = platform_get_drvdata(pdev);
if (watchdog_active(wdt))
return twl4030_wdt_start(wdt);
return 0;
}
#else
#define twl4030_wdt_suspend NULL
#define twl4030_wdt_resume NULL
#endif
static const struct of_device_id twl_wdt_of_match[] = {
{ .compatible = "ti,twl4030-wdt", },
{ },
};
MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
static struct platform_driver twl4030_wdt_driver = {
.probe = twl4030_wdt_probe,
.remove = twl4030_wdt_remove,
.suspend = twl4030_wdt_suspend,
.resume = twl4030_wdt_resume,
.driver = {
.owner = THIS_MODULE,
.name = "twl4030_wdt",
.of_match_table = twl_wdt_of_match,
},
};
module_platform_driver(twl4030_wdt_driver);
MODULE_AUTHOR("Nokia Corporation");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:twl4030_wdt");