linux/drivers/watchdog/ux500_wdt.c

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/*
* Copyright (C) ST-Ericsson SA 2011-2013
*
* License Terms: GNU General Public License v2
*
* Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
* Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/platform_data/ux500_wdt.h>
#include <linux/mfd/dbx500-prcmu.h>
#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
#define WATCHDOG_MIN 0
#define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */
#define WATCHDOG_MAX32 4294967 /* 32 bit resolution in ms == 4294967.295 s */
static unsigned int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
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 ux500_wdt_start(struct watchdog_device *wdd)
{
return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
}
static int ux500_wdt_stop(struct watchdog_device *wdd)
{
return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
}
static int ux500_wdt_keepalive(struct watchdog_device *wdd)
{
return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
}
static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
ux500_wdt_stop(wdd);
prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
ux500_wdt_start(wdd);
return 0;
}
static const struct watchdog_info ux500_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Ux500 WDT",
.firmware_version = 1,
};
static const struct watchdog_ops ux500_wdt_ops = {
.owner = THIS_MODULE,
.start = ux500_wdt_start,
.stop = ux500_wdt_stop,
.ping = ux500_wdt_keepalive,
.set_timeout = ux500_wdt_set_timeout,
};
static struct watchdog_device ux500_wdt = {
.info = &ux500_wdt_info,
.ops = &ux500_wdt_ops,
.min_timeout = WATCHDOG_MIN,
.max_timeout = WATCHDOG_MAX32,
};
static int ux500_wdt_probe(struct platform_device *pdev)
{
int ret;
struct ux500_wdt_data *pdata = dev_get_platdata(&pdev->dev);
if (pdata) {
if (pdata->timeout > 0)
timeout = pdata->timeout;
if (pdata->has_28_bits_resolution)
ux500_wdt.max_timeout = WATCHDOG_MAX28;
}
watchdog_set_nowayout(&ux500_wdt, nowayout);
/* disable auto off on sleep */
prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
/* set HW initial value */
prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
ret = watchdog_register_device(&ux500_wdt);
if (ret)
return ret;
dev_info(&pdev->dev, "initialized\n");
return 0;
}
static int ux500_wdt_remove(struct platform_device *dev)
{
watchdog_unregister_device(&ux500_wdt);
return 0;
}
#ifdef CONFIG_PM
static int ux500_wdt_suspend(struct platform_device *pdev,
pm_message_t state)
{
if (watchdog_active(&ux500_wdt)) {
ux500_wdt_stop(&ux500_wdt);
prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
ux500_wdt_start(&ux500_wdt);
}
return 0;
}
static int ux500_wdt_resume(struct platform_device *pdev)
{
if (watchdog_active(&ux500_wdt)) {
ux500_wdt_stop(&ux500_wdt);
prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
ux500_wdt_start(&ux500_wdt);
}
return 0;
}
#else
#define ux500_wdt_suspend NULL
#define ux500_wdt_resume NULL
#endif
static struct platform_driver ux500_wdt_driver = {
.probe = ux500_wdt_probe,
.remove = ux500_wdt_remove,
.suspend = ux500_wdt_suspend,
.resume = ux500_wdt_resume,
.driver = {
.name = "ux500_wdt",
},
};
module_platform_driver(ux500_wdt_driver);
MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
MODULE_DESCRIPTION("Ux500 Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ux500_wdt");