drivers/watchdog/pm8916_wdt.c - linux - Git at Google

 // 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");
	// 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");