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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
/* Loongson 1 Watchdog Register Definitions */
#define WDT_EN 0x0
#define WDT_TIMER 0x4
#define WDT_SET 0x8
#define DEFAULT_HEARTBEAT 30
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);
static unsigned int heartbeat;
module_param(heartbeat, uint, 0444);
struct ls1x_wdt_drvdata {
void __iomem *base;
struct clk *clk;
unsigned long clk_rate;
struct watchdog_device wdt;
};
static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x1, drvdata->base + WDT_SET);
return 0;
}
static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
unsigned int counts;
wdt_dev->timeout = timeout;
counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
writel(counts, drvdata->base + WDT_TIMER);
return 0;
}
static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x1, drvdata->base + WDT_EN);
return 0;
}
static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x0, drvdata->base + WDT_EN);
return 0;
}
static int ls1x_wdt_restart(struct watchdog_device *wdt_dev,
unsigned long action, void *data)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x1, drvdata->base + WDT_EN);
writel(0x1, drvdata->base + WDT_TIMER);
writel(0x1, drvdata->base + WDT_SET);
return 0;
}
static const struct watchdog_info ls1x_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Loongson1 Watchdog",
};
static const struct watchdog_ops ls1x_wdt_ops = {
.owner = THIS_MODULE,
.start = ls1x_wdt_start,
.stop = ls1x_wdt_stop,
.ping = ls1x_wdt_ping,
.set_timeout = ls1x_wdt_set_timeout,
.restart = ls1x_wdt_restart,
};
static int ls1x_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ls1x_wdt_drvdata *drvdata;
struct watchdog_device *ls1x_wdt;
unsigned long clk_rate;
int err;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(drvdata->base))
return PTR_ERR(drvdata->base);
drvdata->clk = devm_clk_get_enabled(dev, pdev->name);
if (IS_ERR(drvdata->clk))
return PTR_ERR(drvdata->clk);
clk_rate = clk_get_rate(drvdata->clk);
if (!clk_rate)
return -EINVAL;
drvdata->clk_rate = clk_rate;
ls1x_wdt = &drvdata->wdt;
ls1x_wdt->info = &ls1x_wdt_info;
ls1x_wdt->ops = &ls1x_wdt_ops;
ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
ls1x_wdt->min_timeout = 1;
ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
ls1x_wdt->parent = dev;
watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
watchdog_set_nowayout(ls1x_wdt, nowayout);
watchdog_set_drvdata(ls1x_wdt, drvdata);
err = devm_watchdog_register_device(dev, &drvdata->wdt);
if (err)
return err;
platform_set_drvdata(pdev, drvdata);
dev_info(dev, "Loongson1 Watchdog driver registered\n");
return 0;
}
static struct platform_driver ls1x_wdt_driver = {
.probe = ls1x_wdt_probe,
.driver = {
.name = "ls1x-wdt",
},
};
module_platform_driver(ls1x_wdt_driver);
MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
MODULE_LICENSE("GPL");
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