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/*
* Watchdog driver for CSR SiRFprimaII and SiRFatlasVI
*
* Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company.
*
* Licensed under GPLv2 or later.
*/
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define CLOCK_FREQ 1000000
#define SIRFSOC_TIMER_COUNTER_LO 0x0000
#define SIRFSOC_TIMER_MATCH_0 0x0008
#define SIRFSOC_TIMER_INT_EN 0x0024
#define SIRFSOC_TIMER_WATCHDOG_EN 0x0028
#define SIRFSOC_TIMER_LATCH 0x0030
#define SIRFSOC_TIMER_LATCHED_LO 0x0034
#define SIRFSOC_TIMER_WDT_INDEX 5
#define SIRFSOC_WDT_MIN_TIMEOUT 30 /* 30 secs */
#define SIRFSOC_WDT_MAX_TIMEOUT (10 * 60) /* 10 mins */
#define SIRFSOC_WDT_DEFAULT_TIMEOUT 30 /* 30 secs */
static unsigned int timeout;
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(timeout, uint, 0);
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static void __iomem *sirfsoc_wdt_base(struct watchdog_device *wdd)
{
return (void __iomem __force *)watchdog_get_drvdata(wdd);
}
static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd)
{
u32 counter, match;
void __iomem *wdt_base;
int time_left;
wdt_base = sirfsoc_wdt_base(wdd);
counter = readl(wdt_base + SIRFSOC_TIMER_COUNTER_LO);
match = readl(wdt_base +
SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
time_left = match - counter;
return time_left / CLOCK_FREQ;
}
static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd)
{
u32 counter, timeout_ticks;
void __iomem *wdt_base;
timeout_ticks = wdd->timeout * CLOCK_FREQ;
wdt_base = sirfsoc_wdt_base(wdd);
/* Enable the latch before reading the LATCH_LO register */
writel(1, wdt_base + SIRFSOC_TIMER_LATCH);
/* Set the TO value */
counter = readl(wdt_base + SIRFSOC_TIMER_LATCHED_LO);
counter += timeout_ticks;
writel(counter, wdt_base +
SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
return 0;
}
static int sirfsoc_wdt_enable(struct watchdog_device *wdd)
{
void __iomem *wdt_base = sirfsoc_wdt_base(wdd);
sirfsoc_wdt_updatetimeout(wdd);
/*
* NOTE: If interrupt is not enabled
* then WD-Reset doesn't get generated at all.
*/
writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN)
| (1 << SIRFSOC_TIMER_WDT_INDEX),
wdt_base + SIRFSOC_TIMER_INT_EN);
writel(1, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN);
return 0;
}
static int sirfsoc_wdt_disable(struct watchdog_device *wdd)
{
void __iomem *wdt_base = sirfsoc_wdt_base(wdd);
writel(0, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN);
writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN)
& (~(1 << SIRFSOC_TIMER_WDT_INDEX)),
wdt_base + SIRFSOC_TIMER_INT_EN);
return 0;
}
static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
{
wdd->timeout = to;
sirfsoc_wdt_updatetimeout(wdd);
return 0;
}
#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
static const struct watchdog_info sirfsoc_wdt_ident = {
.options = OPTIONS,
.firmware_version = 0,
.identity = "SiRFSOC Watchdog",
};
static const struct watchdog_ops sirfsoc_wdt_ops = {
.owner = THIS_MODULE,
.start = sirfsoc_wdt_enable,
.stop = sirfsoc_wdt_disable,
.get_timeleft = sirfsoc_wdt_gettimeleft,
.ping = sirfsoc_wdt_updatetimeout,
.set_timeout = sirfsoc_wdt_settimeout,
};
static struct watchdog_device sirfsoc_wdd = {
.info = &sirfsoc_wdt_ident,
.ops = &sirfsoc_wdt_ops,
.timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT,
.min_timeout = SIRFSOC_WDT_MIN_TIMEOUT,
.max_timeout = SIRFSOC_WDT_MAX_TIMEOUT,
};
static int sirfsoc_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int ret;
void __iomem *base;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
watchdog_set_drvdata(&sirfsoc_wdd, (__force void *)base);
watchdog_init_timeout(&sirfsoc_wdd, timeout, dev);
watchdog_set_nowayout(&sirfsoc_wdd, nowayout);
sirfsoc_wdd.parent = dev;
watchdog_stop_on_reboot(&sirfsoc_wdd);
watchdog_stop_on_unregister(&sirfsoc_wdd);
ret = devm_watchdog_register_device(dev, &sirfsoc_wdd);
if (ret)
return ret;
platform_set_drvdata(pdev, &sirfsoc_wdd);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int sirfsoc_wdt_suspend(struct device *dev)
{
return 0;
}
static int sirfsoc_wdt_resume(struct device *dev)
{
struct watchdog_device *wdd = dev_get_drvdata(dev);
/*
* NOTE: Since timer controller registers settings are saved
* and restored back by the timer-prima2.c, so we need not
* update WD settings except refreshing timeout.
*/
sirfsoc_wdt_updatetimeout(wdd);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(sirfsoc_wdt_pm_ops,
sirfsoc_wdt_suspend, sirfsoc_wdt_resume);
static const struct of_device_id sirfsoc_wdt_of_match[] = {
{ .compatible = "sirf,prima2-tick"},
{},
};
MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match);
static struct platform_driver sirfsoc_wdt_driver = {
.driver = {
.name = "sirfsoc-wdt",
.pm = &sirfsoc_wdt_pm_ops,
.of_match_table = sirfsoc_wdt_of_match,
},
.probe = sirfsoc_wdt_probe,
};
module_platform_driver(sirfsoc_wdt_driver);
MODULE_DESCRIPTION("SiRF SoC watchdog driver");
MODULE_AUTHOR("Xianglong Du <Xianglong.Du@csr.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:sirfsoc-wdt");
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