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// SPDX-License-Identifier: GPL-2.0+
/*
* Watchdog device driver for DA9062 and DA9061 PMICs
* Copyright (C) 2015 Dialog Semiconductor Ltd.
*
*/
#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/i2c.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9062/registers.h>
#include <linux/mfd/da9062/core.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/of.h>
static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
#define DA9062_TWDSCALE_DISABLE 0
#define DA9062_TWDSCALE_MIN 1
#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
#define DA9062_RESET_PROTECTION_MS 300
struct da9062_watchdog {
struct da9062 *hw;
struct watchdog_device wdtdev;
bool use_sw_pm;
};
static unsigned int da9062_wdt_read_timeout(struct da9062_watchdog *wdt)
{
unsigned int val;
regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val);
return wdt_timeout[val & DA9062AA_TWDSCALE_MASK];
}
static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
{
unsigned int i;
for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
if (wdt_timeout[i] >= secs)
return i;
}
return DA9062_TWDSCALE_MAX;
}
static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
{
return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
DA9062AA_WATCHDOG_MASK,
DA9062AA_WATCHDOG_MASK);
}
static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
unsigned int regval)
{
struct da9062 *chip = wdt->hw;
regmap_update_bits(chip->regmap,
DA9062AA_CONTROL_D,
DA9062AA_TWDSCALE_MASK,
DA9062_TWDSCALE_DISABLE);
usleep_range(150, 300);
return regmap_update_bits(chip->regmap,
DA9062AA_CONTROL_D,
DA9062AA_TWDSCALE_MASK,
regval);
}
static int da9062_wdt_start(struct watchdog_device *wdd)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
unsigned int selector;
int ret;
selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
ret = da9062_wdt_update_timeout_register(wdt, selector);
if (ret)
dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
ret);
return ret;
}
static int da9062_wdt_stop(struct watchdog_device *wdd)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
int ret;
ret = regmap_update_bits(wdt->hw->regmap,
DA9062AA_CONTROL_D,
DA9062AA_TWDSCALE_MASK,
DA9062_TWDSCALE_DISABLE);
if (ret)
dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
ret);
return ret;
}
static int da9062_wdt_ping(struct watchdog_device *wdd)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
int ret;
/*
* Prevent pings from occurring late in system poweroff/reboot sequence
* and possibly locking out restart handler from accessing i2c bus.
*/
if (system_state > SYSTEM_RUNNING)
return 0;
ret = da9062_reset_watchdog_timer(wdt);
if (ret)
dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
ret);
return ret;
}
static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
unsigned int selector;
int ret;
selector = da9062_wdt_timeout_to_sel(timeout);
ret = da9062_wdt_update_timeout_register(wdt, selector);
if (ret)
dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
ret);
else
wdd->timeout = wdt_timeout[selector];
return ret;
}
static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
void *data)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
struct i2c_client *client = to_i2c_client(wdt->hw->dev);
union i2c_smbus_data msg;
int ret;
/*
* Don't use regmap because it is not atomic safe. Additionally, use
* unlocked flavor of i2c_smbus_xfer to avoid scenario where i2c bus
* might be previously locked by some process unable to release the
* lock due to interrupts already being disabled at this late stage.
*/
msg.byte = DA9062AA_SHUTDOWN_MASK;
ret = __i2c_smbus_xfer(client->adapter, client->addr, client->flags,
I2C_SMBUS_WRITE, DA9062AA_CONTROL_F,
I2C_SMBUS_BYTE_DATA, &msg);
if (ret < 0)
dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
ret);
/* wait for reset to assert... */
mdelay(500);
return ret;
}
static const struct watchdog_info da9062_watchdog_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "DA9062 WDT",
};
static const struct watchdog_ops da9062_watchdog_ops = {
.owner = THIS_MODULE,
.start = da9062_wdt_start,
.stop = da9062_wdt_stop,
.ping = da9062_wdt_ping,
.set_timeout = da9062_wdt_set_timeout,
.restart = da9062_wdt_restart,
};
static const struct of_device_id da9062_compatible_id_table[] = {
{ .compatible = "dlg,da9062-watchdog", },
{ },
};
MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
static int da9062_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
unsigned int timeout;
struct da9062 *chip;
struct da9062_watchdog *wdt;
chip = dev_get_drvdata(dev->parent);
if (!chip)
return -EINVAL;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
wdt->hw = chip;
wdt->wdtdev.info = &da9062_watchdog_info;
wdt->wdtdev.ops = &da9062_watchdog_ops;
wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
wdt->wdtdev.parent = dev;
watchdog_set_restart_priority(&wdt->wdtdev, 128);
watchdog_set_drvdata(&wdt->wdtdev, wdt);
dev_set_drvdata(dev, &wdt->wdtdev);
timeout = da9062_wdt_read_timeout(wdt);
if (timeout)
wdt->wdtdev.timeout = timeout;
/* Set timeout from DT value if available */
watchdog_init_timeout(&wdt->wdtdev, 0, dev);
if (timeout) {
da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
}
return devm_watchdog_register_device(dev, &wdt->wdtdev);
}
static int __maybe_unused da9062_wdt_suspend(struct device *dev)
{
struct watchdog_device *wdd = dev_get_drvdata(dev);
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
if (!wdt->use_sw_pm)
return 0;
if (watchdog_active(wdd))
return da9062_wdt_stop(wdd);
return 0;
}
static int __maybe_unused da9062_wdt_resume(struct device *dev)
{
struct watchdog_device *wdd = dev_get_drvdata(dev);
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
if (!wdt->use_sw_pm)
return 0;
if (watchdog_active(wdd))
return da9062_wdt_start(wdd);
return 0;
}
static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
da9062_wdt_suspend, da9062_wdt_resume);
static struct platform_driver da9062_wdt_driver = {
.probe = da9062_wdt_probe,
.driver = {
.name = "da9062-watchdog",
.pm = &da9062_wdt_pm_ops,
.of_match_table = da9062_compatible_id_table,
},
};
module_platform_driver(da9062_wdt_driver);
MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9062-watchdog");
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