// SPDX-License-Identifier: GPL-2.0+
/*
* Watchdog driver for DA9063 PMICs.
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mfd/da9063/registers.h>
#include <linux/mfd/da9063/core.h>
#include <linux/regmap.h>
/*
* Watchdog selector to timeout in seconds.
* 0: WDT disabled;
* others: timeout = 2048 ms * 2^(TWDSCALE-1).
*/
static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
#define DA9063_TWDSCALE_DISABLE 0
#define DA9063_TWDSCALE_MIN 1
#define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
#define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN]
#define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX]
#define DA9063_WDG_TIMEOUT wdt_timeout[3]
#define DA9063_RESET_PROTECTION_MS 256
static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
{
unsigned int i;
for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
if (wdt_timeout[i] >= secs)
return i;
}
return DA9063_TWDSCALE_MAX;
}
/*
* Return 0 if watchdog is disabled, else non zero.
*/
static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
{
unsigned int val;
regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
return val & DA9063_TWDSCALE_MASK;
}
static int da9063_wdt_disable_timer(struct da9063 *da9063)
{
return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
DA9063_TWDSCALE_MASK,
DA9063_TWDSCALE_DISABLE);
}
static int
da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout)
{
unsigned int regval;
int ret;
/*
* The watchdog triggers a reboot if a timeout value is already
* programmed because the timeout value combines two functions
* in one: indicating the counter limit and starting the watchdog.
* The watchdog must be disabled to be able to change the timeout
* value if the watchdog is already running. Then we can set the
* new timeout value which enables the watchdog again.
*/
ret = da9063_wdt_disable_timer(da9063);
if (ret)
return ret;
usleep_range(150, 300);
regval = da9063_wdt_timeout_to_sel(timeout);
return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
DA9063_TWDSCALE_MASK, regval);
}
static int da9063_wdt_start(struct watchdog_device *wdd)
{
struct da9063 *da9063 = watchdog_get_drvdata(wdd);
int ret;
ret = da9063_wdt_update_timeout(da9063, wdd->timeout);
if (ret)
dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
ret);
return ret;
}
static int da9063_wdt_stop(struct watchdog_device *wdd)
{
struct da9063 *da9063 = watchdog_get_drvdata(wdd);
int ret;
ret = da9063_wdt_disable_timer(da9063);
if (ret)
dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
ret);
return ret;
}
static int da9063_wdt_ping(struct watchdog_device *wdd)
{
struct da9063 *da9063 = watchdog_get_drvdata(wdd);
int ret;
ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
DA9063_WATCHDOG);
if (ret)
dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
ret);
return ret;
}
static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct da9063 *da9063 = watchdog_get_drvdata(wdd);
int ret = 0;
/*
* There are two cases when a set_timeout() will be called:
* 1. The watchdog is off and someone wants to set the timeout for the
* further use.
* 2. The watchdog is already running and a new timeout value should be
* set.
*
* The watchdog can't store a timeout value not equal zero without
* enabling the watchdog, so the timeout must be buffered by the driver.
*/
if (watchdog_active(wdd))
ret = da9063_wdt_update_timeout(da9063, timeout);
if (ret)
dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
ret);
else
wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)];
return ret;
}
static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
void *data)
{
struct da9063 *da9063 = watchdog_get_drvdata(wdd);
int ret;
ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
DA9063_SHUTDOWN);
if (ret)
dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
ret);
return ret;
}
static const struct watchdog_info da9063_watchdog_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "DA9063 Watchdog",
};
static const struct watchdog_ops da9063_watchdog_ops = {
.owner = THIS_MODULE,
.start = da9063_wdt_start,
.stop = da9063_wdt_stop,
.ping = da9063_wdt_ping,
.set_timeout = da9063_wdt_set_timeout,
.restart = da9063_wdt_restart,
};
static int da9063_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct da9063 *da9063;
struct watchdog_device *wdd;
if (!dev->parent)
return -EINVAL;
da9063 = dev_get_drvdata(dev->parent);
if (!da9063)
return -EINVAL;
wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL);
if (!wdd)
return -ENOMEM;
wdd->info = &da9063_watchdog_info;
wdd->ops = &da9063_watchdog_ops;
wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
wdd->parent = dev;
wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
watchdog_set_restart_priority(wdd, 128);
watchdog_set_drvdata(wdd, da9063);
/* Set default timeout, maybe override it with DT value, scale it */
wdd->timeout = DA9063_WDG_TIMEOUT;
watchdog_init_timeout(wdd, 0, dev);
da9063_wdt_set_timeout(wdd, wdd->timeout);
/* Change the timeout to the default value if the watchdog is running */
if (da9063_wdt_is_running(da9063)) {
da9063_wdt_update_timeout(da9063, wdd->timeout);
set_bit(WDOG_HW_RUNNING, &wdd->status);
}
return devm_watchdog_register_device(dev, wdd);
}
static struct platform_driver da9063_wdt_driver = {
.probe = da9063_wdt_probe,
.driver = {
.name = DA9063_DRVNAME_WATCHDOG,
},
};
module_platform_driver(da9063_wdt_driver);
MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);
