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// SPDX-License-Identifier: GPL-2.0
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/watchdog.h>
#define PON_POFF_REASON1 0x0c
#define PON_POFF_REASON1_PMIC_WD BIT(2)
#define PON_POFF_REASON2 0x0d
#define PON_POFF_REASON2_UVLO BIT(5)
#define PON_POFF_REASON2_OTST3 BIT(6)
#define PON_INT_RT_STS 0x10
#define PMIC_WD_BARK_STS_BIT BIT(6)
#define PON_PMIC_WD_RESET_S1_TIMER 0x54
#define PON_PMIC_WD_RESET_S2_TIMER 0x55
#define PON_PMIC_WD_RESET_S2_CTL 0x56
#define RESET_TYPE_WARM 0x01
#define RESET_TYPE_SHUTDOWN 0x04
#define RESET_TYPE_HARD 0x07
#define PON_PMIC_WD_RESET_S2_CTL2 0x57
#define S2_RESET_EN_BIT BIT(7)
#define PON_PMIC_WD_RESET_PET 0x58
#define WATCHDOG_PET_BIT BIT(0)
#define PM8916_WDT_DEFAULT_TIMEOUT 32
#define PM8916_WDT_MIN_TIMEOUT 1
#define PM8916_WDT_MAX_TIMEOUT 127
struct pm8916_wdt {
struct regmap *regmap;
struct watchdog_device wdev;
u32 baseaddr;
};
static int pm8916_wdt_start(struct watchdog_device *wdev)
{
struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
return regmap_update_bits(wdt->regmap,
wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
S2_RESET_EN_BIT, S2_RESET_EN_BIT);
}
static int pm8916_wdt_stop(struct watchdog_device *wdev)
{
struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
return regmap_update_bits(wdt->regmap,
wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
S2_RESET_EN_BIT, 0);
}
static int pm8916_wdt_ping(struct watchdog_device *wdev)
{
struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
return regmap_write(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_PET,
WATCHDOG_PET_BIT);
}
static int pm8916_wdt_configure_timers(struct watchdog_device *wdev)
{
struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
int err;
err = regmap_write(wdt->regmap,
wdt->baseaddr + PON_PMIC_WD_RESET_S1_TIMER,
wdev->timeout - wdev->pretimeout);
if (err)
return err;
return regmap_write(wdt->regmap,
wdt->baseaddr + PON_PMIC_WD_RESET_S2_TIMER,
wdev->pretimeout);
}
static int pm8916_wdt_set_timeout(struct watchdog_device *wdev,
unsigned int timeout)
{
wdev->timeout = timeout;
return pm8916_wdt_configure_timers(wdev);
}
static int pm8916_wdt_set_pretimeout(struct watchdog_device *wdev,
unsigned int pretimeout)
{
wdev->pretimeout = pretimeout;
return pm8916_wdt_configure_timers(wdev);
}
static irqreturn_t pm8916_wdt_isr(int irq, void *arg)
{
struct pm8916_wdt *wdt = arg;
int err, sts;
err = regmap_read(wdt->regmap, wdt->baseaddr + PON_INT_RT_STS, &sts);
if (err)
return IRQ_HANDLED;
if (sts & PMIC_WD_BARK_STS_BIT)
watchdog_notify_pretimeout(&wdt->wdev);
return IRQ_HANDLED;
}
static const struct watchdog_info pm8916_wdt_ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
WDIOF_OVERHEAT | WDIOF_CARDRESET | WDIOF_POWERUNDER,
.identity = "QCOM PM8916 PON WDT",
};
static const struct watchdog_info pm8916_wdt_pt_ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
WDIOF_OVERHEAT | WDIOF_CARDRESET | WDIOF_POWERUNDER |
WDIOF_PRETIMEOUT,
.identity = "QCOM PM8916 PON WDT",
};
static const struct watchdog_ops pm8916_wdt_ops = {
.owner = THIS_MODULE,
.start = pm8916_wdt_start,
.stop = pm8916_wdt_stop,
.ping = pm8916_wdt_ping,
.set_timeout = pm8916_wdt_set_timeout,
.set_pretimeout = pm8916_wdt_set_pretimeout,
};
static int pm8916_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct pm8916_wdt *wdt;
struct device *parent;
unsigned int val;
int err, irq;
u8 poff[2];
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
parent = dev->parent;
/*
* The pm8916-pon-wdt is a child of the pon device, which is a child
* of the pm8916 mfd device. We want access to the pm8916 registers.
* Retrieve regmap from pm8916 (parent->parent) and base address
* from pm8916-pon (pon).
*/
wdt->regmap = dev_get_regmap(parent->parent, NULL);
if (!wdt->regmap) {
dev_err(dev, "failed to locate regmap\n");
return -ENODEV;
}
err = device_property_read_u32(parent, "reg", &wdt->baseaddr);
if (err) {
dev_err(dev, "failed to get pm8916-pon address\n");
return err;
}
irq = platform_get_irq(pdev, 0);
if (irq > 0) {
err = devm_request_irq(dev, irq, pm8916_wdt_isr, 0,
"pm8916_wdt", wdt);
if (err)
return err;
wdt->wdev.info = &pm8916_wdt_pt_ident;
} else {
if (irq == -EPROBE_DEFER)
return -EPROBE_DEFER;
wdt->wdev.info = &pm8916_wdt_ident;
}
err = regmap_bulk_read(wdt->regmap, wdt->baseaddr + PON_POFF_REASON1,
&poff, ARRAY_SIZE(poff));
if (err) {
dev_err(dev, "failed to read POFF reason: %d\n", err);
return err;
}
dev_dbg(dev, "POFF reason: %#x %#x\n", poff[0], poff[1]);
if (poff[0] & PON_POFF_REASON1_PMIC_WD)
wdt->wdev.bootstatus |= WDIOF_CARDRESET;
if (poff[1] & PON_POFF_REASON2_UVLO)
wdt->wdev.bootstatus |= WDIOF_POWERUNDER;
if (poff[1] & PON_POFF_REASON2_OTST3)
wdt->wdev.bootstatus |= WDIOF_OVERHEAT;
err = regmap_read(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
&val);
if (err) {
dev_err(dev, "failed to check if watchdog is active: %d\n", err);
return err;
}
if (val & S2_RESET_EN_BIT)
set_bit(WDOG_HW_RUNNING, &wdt->wdev.status);
/* Configure watchdog to hard-reset mode */
err = regmap_write(wdt->regmap,
wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL,
RESET_TYPE_HARD);
if (err) {
dev_err(dev, "failed configure watchdog\n");
return err;
}
wdt->wdev.ops = &pm8916_wdt_ops,
wdt->wdev.parent = dev;
wdt->wdev.min_timeout = PM8916_WDT_MIN_TIMEOUT;
wdt->wdev.max_timeout = PM8916_WDT_MAX_TIMEOUT;
wdt->wdev.timeout = PM8916_WDT_DEFAULT_TIMEOUT;
wdt->wdev.pretimeout = 0;
watchdog_set_drvdata(&wdt->wdev, wdt);
platform_set_drvdata(pdev, wdt);
watchdog_init_timeout(&wdt->wdev, 0, dev);
pm8916_wdt_configure_timers(&wdt->wdev);
return devm_watchdog_register_device(dev, &wdt->wdev);
}
static int __maybe_unused pm8916_wdt_suspend(struct device *dev)
{
struct pm8916_wdt *wdt = dev_get_drvdata(dev);
if (watchdog_active(&wdt->wdev))
return pm8916_wdt_stop(&wdt->wdev);
return 0;
}
static int __maybe_unused pm8916_wdt_resume(struct device *dev)
{
struct pm8916_wdt *wdt = dev_get_drvdata(dev);
if (watchdog_active(&wdt->wdev))
return pm8916_wdt_start(&wdt->wdev);
return 0;
}
static SIMPLE_DEV_PM_OPS(pm8916_wdt_pm_ops, pm8916_wdt_suspend,
pm8916_wdt_resume);
static const struct of_device_id pm8916_wdt_id_table[] = {
{ .compatible = "qcom,pm8916-wdt" },
{ }
};
MODULE_DEVICE_TABLE(of, pm8916_wdt_id_table);
static struct platform_driver pm8916_wdt_driver = {
.probe = pm8916_wdt_probe,
.driver = {
.name = "pm8916-wdt",
.of_match_table = pm8916_wdt_id_table,
.pm = &pm8916_wdt_pm_ops,
},
};
module_platform_driver(pm8916_wdt_driver);
MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
MODULE_DESCRIPTION("Qualcomm pm8916 watchdog driver");
MODULE_LICENSE("GPL v2");