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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) STMicroelectronics 2018
// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics.
#include <linux/kernel.h>
#include <linux/mfd/stpmic1.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/watchdog.h>
/* WATCHDOG CONTROL REGISTER bit */
#define WDT_START BIT(0)
#define WDT_PING BIT(1)
#define WDT_START_MASK BIT(0)
#define WDT_PING_MASK BIT(1)
#define WDT_STOP 0
#define PMIC_WDT_MIN_TIMEOUT 1
#define PMIC_WDT_MAX_TIMEOUT 256
#define PMIC_WDT_DEFAULT_TIMEOUT 30
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) ")");
struct stpmic1_wdt {
struct stpmic1 *pmic;
struct watchdog_device wdtdev;
};
static int pmic_wdt_start(struct watchdog_device *wdd)
{
struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
return regmap_update_bits(wdt->pmic->regmap,
WCHDG_CR, WDT_START_MASK, WDT_START);
}
static int pmic_wdt_stop(struct watchdog_device *wdd)
{
struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
return regmap_update_bits(wdt->pmic->regmap,
WCHDG_CR, WDT_START_MASK, WDT_STOP);
}
static int pmic_wdt_ping(struct watchdog_device *wdd)
{
struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
return regmap_update_bits(wdt->pmic->regmap,
WCHDG_CR, WDT_PING_MASK, WDT_PING);
}
static int pmic_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
wdd->timeout = timeout;
/* timeout is equal to register value + 1 */
return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1);
}
static const struct watchdog_info pmic_watchdog_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "STPMIC1 PMIC Watchdog",
};
static const struct watchdog_ops pmic_watchdog_ops = {
.owner = THIS_MODULE,
.start = pmic_wdt_start,
.stop = pmic_wdt_stop,
.ping = pmic_wdt_ping,
.set_timeout = pmic_wdt_set_timeout,
};
static int pmic_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int ret;
struct stpmic1 *pmic;
struct stpmic1_wdt *wdt;
if (!dev->parent)
return -EINVAL;
pmic = dev_get_drvdata(dev->parent);
if (!pmic)
return -EINVAL;
wdt = devm_kzalloc(dev, sizeof(struct stpmic1_wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->pmic = pmic;
wdt->wdtdev.info = &pmic_watchdog_info;
wdt->wdtdev.ops = &pmic_watchdog_ops;
wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT;
wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT;
wdt->wdtdev.parent = dev;
wdt->wdtdev.timeout = PMIC_WDT_DEFAULT_TIMEOUT;
watchdog_init_timeout(&wdt->wdtdev, 0, dev);
watchdog_set_nowayout(&wdt->wdtdev, nowayout);
watchdog_set_drvdata(&wdt->wdtdev, wdt);
ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
if (ret)
return ret;
dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n");
return 0;
}
static const struct of_device_id of_pmic_wdt_match[] = {
{ .compatible = "st,stpmic1-wdt" },
{ },
};
MODULE_DEVICE_TABLE(of, of_pmic_wdt_match);
static struct platform_driver stpmic1_wdt_driver = {
.probe = pmic_wdt_probe,
.driver = {
.name = "stpmic1-wdt",
.of_match_table = of_pmic_wdt_match,
},
};
module_platform_driver(stpmic1_wdt_driver);
MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device");
MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");
MODULE_LICENSE("GPL v2");