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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2018 Kalray Inc.
*/
#include <common.h>
#include <init.h>
#include <io.h>
#include <of.h>
#include <watchdog.h>
#include <linux/reset.h>
#include <linux/clk.h>
#include <linux/err.h>
#define WDT_REG_RESET_EN 0x104
#define WDT_REG_TIMEOUT 0x108
#define WDT_REG_CONTROL 0x110
#define WDT_REG_UNLOCK 0x13c
#define WDT_UNLOCK_KEY 0x378f0765
#define WDT_TICKS_PER_SEC 50000000
struct starfive_wdt {
u32 clk_rate;
struct watchdog wdd;
void __iomem *base;
bool setup;
};
static int starfive_wdt_set_timeout(struct watchdog *wdd, unsigned int timeout)
{
struct starfive_wdt *wd = container_of(wdd, struct starfive_wdt, wdd);
writel(0, wd->base + WDT_REG_CONTROL);
if (timeout > 0) {
timeout *= wd->clk_rate;
writel(timeout, wd->base + WDT_REG_TIMEOUT);
writel(1, wd->base + WDT_REG_CONTROL);
}
return 0;
}
static int starfive_wdt_drv_probe(struct device *dev)
{
struct starfive_wdt *wd;
struct resource *iores;
struct watchdog *wdd;
struct clk_bulk_data clks[] = {
{ .id = "bus" },
{ .id = "core" },
};
int ret;
ret = clk_bulk_get(dev, ARRAY_SIZE(clks), clks);
if (ret)
return ret;
ret = clk_bulk_enable(ARRAY_SIZE(clks), clks);
if (ret < 0)
return ret;
ret = device_reset_all(dev);
if (ret)
return ret;
iores = dev_request_mem_resource(dev, 0);
if (IS_ERR(iores))
return PTR_ERR(iores);
wd = xzalloc(sizeof(*wd));
wd->base = IOMEM(iores->start);
wd->clk_rate = WDT_TICKS_PER_SEC;
writel(WDT_UNLOCK_KEY, wd->base + WDT_REG_UNLOCK);
wd->base = IOMEM(iores->start);
/* reset, not interrupt, on timer expiry */
writel(1, wd->base + WDT_REG_RESET_EN);
wdd = &wd->wdd;
wdd->name = "starfive_wdt";
wdd->hwdev = dev;
wdd->set_timeout = starfive_wdt_set_timeout;
wdd->timeout_max = U32_MAX / wd->clk_rate;
wdd->running = readl(wd->base + WDT_REG_CONTROL) & 1 ?
WDOG_HW_RUNNING : WDOG_HW_NOT_RUNNING;
return watchdog_register(wdd);
}
static struct of_device_id starfive_wdt_of_match[] = {
{ .compatible = "starfive,wdt", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, starfive_wdt_of_match);
static struct driver starfive_wdt_driver = {
.name = "starfive-wdt",
.probe = starfive_wdt_drv_probe,
.of_compatible = starfive_wdt_of_match,
};
device_platform_driver(starfive_wdt_driver);
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