drivers/input/misc/pmic8xxx-pwrkey.c - arm/linux - Git at Google

 /* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/log2.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

 #define PON_CNTL_1 0x1C
 #define PON_CNTL_PULL_UP BIT(7)
 #define PON_CNTL_TRIG_DELAY_MASK (0x7)
 #define PON_CNTL_1_PULL_UP_EN			0xe0
 #define PON_CNTL_1_USB_PWR_EN			0x10
 #define PON_CNTL_1_WD_EN_RESET			0x08

 #define PM8058_SLEEP_CTRL			0x02b
 #define PM8921_SLEEP_CTRL			0x10a

 #define SLEEP_CTRL_SMPL_EN_RESET		0x04

 /* Regulator master enable addresses */
 #define REG_PM8058_VREG_EN_MSM			0x018
 #define REG_PM8058_VREG_EN_GRP_5_4		0x1c8

 /* Regulator control registers for shutdown/reset */
 #define PM8058_S0_CTRL				0x004
 #define PM8058_S1_CTRL				0x005
 #define PM8058_S3_CTRL				0x111
 #define PM8058_L21_CTRL				0x120
 #define PM8058_L22_CTRL				0x121

 #define PM8058_REGULATOR_ENABLE_MASK		0x80
 #define PM8058_REGULATOR_ENABLE			0x80
 #define PM8058_REGULATOR_DISABLE		0x00
 #define PM8058_REGULATOR_PULL_DOWN_MASK		0x40
 #define PM8058_REGULATOR_PULL_DOWN_EN		0x40

 /* Buck CTRL register */
 #define PM8058_SMPS_LEGACY_VREF_SEL		0x20
 #define PM8058_SMPS_LEGACY_VPROG_MASK		0x1f
 #define PM8058_SMPS_ADVANCED_BAND_MASK		0xC0
 #define PM8058_SMPS_ADVANCED_BAND_SHIFT		6
 #define PM8058_SMPS_ADVANCED_VPROG_MASK		0x3f

 /* Buck TEST2 registers for shutdown/reset */
 #define PM8058_S0_TEST2				0x084
 #define PM8058_S1_TEST2				0x085
 #define PM8058_S3_TEST2				0x11a

 #define PM8058_REGULATOR_BANK_WRITE		0x80
 #define PM8058_REGULATOR_BANK_MASK		0x70
 #define PM8058_REGULATOR_BANK_SHIFT		4
 #define PM8058_REGULATOR_BANK_SEL(n)	((n) << PM8058_REGULATOR_BANK_SHIFT)

 /* Buck TEST2 register bank 1 */
 #define PM8058_SMPS_LEGACY_VLOW_SEL		0x01

 /* Buck TEST2 register bank 7 */
 #define PM8058_SMPS_ADVANCED_MODE_MASK		0x02
 #define PM8058_SMPS_ADVANCED_MODE		0x02
 #define PM8058_SMPS_LEGACY_MODE			0x00

 /**
  * struct pmic8xxx_pwrkey - pmic8xxx pwrkey information
  * @key_press_irq: key press irq number
  * @regmap: device regmap
  * @shutdown_fn: shutdown configuration function
  */
 struct pmic8xxx_pwrkey {
 	int key_press_irq;
 	struct regmap *regmap;
 	int (*shutdown_fn)(struct pmic8xxx_pwrkey *, bool);
 };

 static irqreturn_t pwrkey_press_irq(int irq, void *_pwr)
 {
 	struct input_dev *pwr = _pwr;

 	input_report_key(pwr, KEY_POWER, 1);
 	input_sync(pwr);

 	return IRQ_HANDLED;
 }

 static irqreturn_t pwrkey_release_irq(int irq, void *_pwr)
 {
 	struct input_dev *pwr = _pwr;

 	input_report_key(pwr, KEY_POWER, 0);
 	input_sync(pwr);

 	return IRQ_HANDLED;
 }

 static int __maybe_unused pmic8xxx_pwrkey_suspend(struct device *dev)
 {
 	struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

 	if (device_may_wakeup(dev))
 		enable_irq_wake(pwrkey->key_press_irq);

 	return 0;
 }

 static int __maybe_unused pmic8xxx_pwrkey_resume(struct device *dev)
 {
 	struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

 	if (device_may_wakeup(dev))
 		disable_irq_wake(pwrkey->key_press_irq);

 	return 0;
 }

 static SIMPLE_DEV_PM_OPS(pm8xxx_pwr_key_pm_ops,
 		pmic8xxx_pwrkey_suspend, pmic8xxx_pwrkey_resume);

 static void pmic8xxx_pwrkey_shutdown(struct platform_device *pdev)
 {
 	struct pmic8xxx_pwrkey *pwrkey = platform_get_drvdata(pdev);
 	int error;
 	u8 mask, val;
 	bool reset = system_state == SYSTEM_RESTART;

 	if (pwrkey->shutdown_fn) {
 		error = pwrkey->shutdown_fn(pwrkey, reset);
 		if (error)
 			return;
 	}

 	/*
 	 * Select action to perform (reset or shutdown) when PS_HOLD goes low.
 	 * Also ensure that KPD, CBL0, and CBL1 pull ups are enabled and that
 	 * USB charging is enabled.
 	 */
 	mask = PON_CNTL_1_PULL_UP_EN | PON_CNTL_1_USB_PWR_EN;
 	mask |= PON_CNTL_1_WD_EN_RESET;
 	val = mask;
 	if (!reset)
 		val &= ~PON_CNTL_1_WD_EN_RESET;

 	regmap_update_bits(pwrkey->regmap, PON_CNTL_1, mask, val);
 }

 /*
  * Set an SMPS regulator to be disabled in its CTRL register, but enabled
  * in the master enable register.  Also set it's pull down enable bit.
  * Take care to make sure that the output voltage doesn't change if switching
  * from advanced mode to legacy mode.
  */
 static int pm8058_disable_smps_locally_set_pull_down(struct regmap *regmap,
 	u16 ctrl_addr, u16 test2_addr, u16 master_enable_addr,
 	u8 master_enable_bit)
 {
 	int error;
 	u8 vref_sel, vlow_sel, band, vprog, bank;
 	unsigned int reg;

 	bank = PM8058_REGULATOR_BANK_SEL(7);
 	error = regmap_write(regmap, test2_addr, bank);
 	if (error)
 		return error;

 	error = regmap_read(regmap, test2_addr, &reg);
 	if (error)
 		return error;

 	reg &= PM8058_SMPS_ADVANCED_MODE_MASK;
 	/* Check if in advanced mode. */
 	if (reg == PM8058_SMPS_ADVANCED_MODE) {
 		/* Determine current output voltage. */
 		error = regmap_read(regmap, ctrl_addr, &reg);
 		if (error)
 			return error;

 		band = reg & PM8058_SMPS_ADVANCED_BAND_MASK;
 		band >>= PM8058_SMPS_ADVANCED_BAND_SHIFT;
 		switch (band) {
 		case 3:
 			vref_sel = 0;
 			vlow_sel = 0;
 			break;
 		case 2:
 			vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
 			vlow_sel = 0;
 			break;
 		case 1:
 			vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
 			vlow_sel = PM8058_SMPS_LEGACY_VLOW_SEL;
 			break;
 		default:
 			pr_err("%s: regulator already disabled\n", __func__);
 			return -EPERM;
 		}
 		vprog = reg & PM8058_SMPS_ADVANCED_VPROG_MASK;
 		/* Round up if fine step is in use. */
 		vprog = (vprog + 1) >> 1;
 		if (vprog > PM8058_SMPS_LEGACY_VPROG_MASK)
 			vprog = PM8058_SMPS_LEGACY_VPROG_MASK;

 		/* Set VLOW_SEL bit. */
 		bank = PM8058_REGULATOR_BANK_SEL(1);
 		error = regmap_write(regmap, test2_addr, bank);
 		if (error)
 			return error;

 		error = regmap_update_bits(regmap, test2_addr,
 			PM8058_REGULATOR_BANK_WRITE | PM8058_REGULATOR_BANK_MASK
 				| PM8058_SMPS_LEGACY_VLOW_SEL,
 			PM8058_REGULATOR_BANK_WRITE |
 			PM8058_REGULATOR_BANK_SEL(1) | vlow_sel);
 		if (error)
 			return error;

 		/* Switch to legacy mode */
 		bank = PM8058_REGULATOR_BANK_SEL(7);
 		error = regmap_write(regmap, test2_addr, bank);
 		if (error)
 			return error;

 		error = regmap_update_bits(regmap, test2_addr,
 				PM8058_REGULATOR_BANK_WRITE |
 				PM8058_REGULATOR_BANK_MASK |
 				PM8058_SMPS_ADVANCED_MODE_MASK,
 				PM8058_REGULATOR_BANK_WRITE |
 				PM8058_REGULATOR_BANK_SEL(7) |
 				PM8058_SMPS_LEGACY_MODE);
 		if (error)
 			return error;

 		/* Enable locally, enable pull down, keep voltage the same. */
 		error = regmap_update_bits(regmap, ctrl_addr,
 			PM8058_REGULATOR_ENABLE_MASK |
 			PM8058_REGULATOR_PULL_DOWN_MASK |
 			PM8058_SMPS_LEGACY_VREF_SEL |
 			PM8058_SMPS_LEGACY_VPROG_MASK,
 			PM8058_REGULATOR_ENABLE | PM8058_REGULATOR_PULL_DOWN_EN
 				| vref_sel | vprog);
 		if (error)
 			return error;
 	}

 	/* Enable in master control register. */
 	error = regmap_update_bits(regmap, master_enable_addr,
 			master_enable_bit, master_enable_bit);
 	if (error)
 		return error;

 	/* Disable locally and enable pull down. */
 	return regmap_update_bits(regmap, ctrl_addr,
 		PM8058_REGULATOR_ENABLE_MASK | PM8058_REGULATOR_PULL_DOWN_MASK,
 		PM8058_REGULATOR_DISABLE | PM8058_REGULATOR_PULL_DOWN_EN);
 }

 static int pm8058_disable_ldo_locally_set_pull_down(struct regmap *regmap,
 		u16 ctrl_addr, u16 master_enable_addr, u8 master_enable_bit)
 {
 	int error;

 	/* Enable LDO in master control register. */
 	error = regmap_update_bits(regmap, master_enable_addr,
 			master_enable_bit, master_enable_bit);
 	if (error)
 		return error;

 	/* Disable LDO in CTRL register and set pull down */
 	return regmap_update_bits(regmap, ctrl_addr,
 		PM8058_REGULATOR_ENABLE_MASK | PM8058_REGULATOR_PULL_DOWN_MASK,
 		PM8058_REGULATOR_DISABLE | PM8058_REGULATOR_PULL_DOWN_EN);
 }

 static int pm8058_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
 {
 	int error;
 	struct regmap *regmap = pwrkey->regmap;
 	u8 mask, val;

 	/* When shutting down, enable active pulldowns on important rails. */
 	if (!reset) {
 		/* Disable SMPS's 0,1,3 locally and set pulldown enable bits. */
 		pm8058_disable_smps_locally_set_pull_down(regmap,
 			PM8058_S0_CTRL, PM8058_S0_TEST2,
 			REG_PM8058_VREG_EN_MSM, BIT(7));
 		pm8058_disable_smps_locally_set_pull_down(regmap,
 			PM8058_S1_CTRL, PM8058_S1_TEST2,
 			REG_PM8058_VREG_EN_MSM, BIT(6));
 		pm8058_disable_smps_locally_set_pull_down(regmap,
 			PM8058_S3_CTRL, PM8058_S3_TEST2,
 			REG_PM8058_VREG_EN_GRP_5_4, BIT(7) | BIT(4));
 		/* Disable LDO 21 locally and set pulldown enable bit. */
 		pm8058_disable_ldo_locally_set_pull_down(regmap,
 			PM8058_L21_CTRL, REG_PM8058_VREG_EN_GRP_5_4,
 			BIT(1));
 	}

 	/*
 	 * Fix-up: Set regulator LDO22 to 1.225 V in high power mode. Leave its
 	 * pull-down state intact. This ensures a safe shutdown.
 	 */
 	error = regmap_update_bits(regmap, PM8058_L22_CTRL, 0xbf, 0x93);
 	if (error)
 		return error;

 	/* Enable SMPL if resetting is desired */
 	mask = SLEEP_CTRL_SMPL_EN_RESET;
 	val = 0;
 	if (reset)
 		val = mask;
 	return regmap_update_bits(regmap, PM8058_SLEEP_CTRL, mask, val);
 }

 static int pm8921_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
 {
 	struct regmap *regmap = pwrkey->regmap;
 	u8 mask = SLEEP_CTRL_SMPL_EN_RESET;
 	u8 val = 0;

 	/* Enable SMPL if resetting is desired */
 	if (reset)
 		val = mask;
 	return regmap_update_bits(regmap, PM8921_SLEEP_CTRL, mask, val);
 }

 static int pmic8xxx_pwrkey_probe(struct platform_device *pdev)
 {
 	struct input_dev *pwr;
 	int key_release_irq = platform_get_irq(pdev, 0);
 	int key_press_irq = platform_get_irq(pdev, 1);
 	int err;
 	unsigned int delay;
 	unsigned int pon_cntl;
 	struct regmap *regmap;
 	struct pmic8xxx_pwrkey *pwrkey;
 	u32 kpd_delay;
 	bool pull_up;

 	if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay))
 		kpd_delay = 15625;

 	/* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */
 	if (kpd_delay > USEC_PER_SEC * 2 || kpd_delay < USEC_PER_SEC / 64) {
 		dev_err(&pdev->dev, "invalid power key trigger delay\n");
 		return -EINVAL;
 	}

 	pull_up = of_property_read_bool(pdev->dev.of_node, "pull-up");

 	regmap = dev_get_regmap(pdev->dev.parent, NULL);
 	if (!regmap) {
 		dev_err(&pdev->dev, "failed to locate regmap for the device\n");
 		return -ENODEV;
 	}

 	pwrkey = devm_kzalloc(&pdev->dev, sizeof(*pwrkey), GFP_KERNEL);
 	if (!pwrkey)
 		return -ENOMEM;

 	pwrkey->shutdown_fn = of_device_get_match_data(&pdev->dev);
 	pwrkey->regmap = regmap;
 	pwrkey->key_press_irq = key_press_irq;

 	pwr = devm_input_allocate_device(&pdev->dev);
 	if (!pwr) {
 		dev_dbg(&pdev->dev, "Can't allocate power button\n");
 		return -ENOMEM;
 	}

 	input_set_capability(pwr, EV_KEY, KEY_POWER);

 	pwr->name = "pmic8xxx_pwrkey";
 	pwr->phys = "pmic8xxx_pwrkey/input0";

 	delay = (kpd_delay << 6) / USEC_PER_SEC;
 	delay = ilog2(delay);

 	err = regmap_read(regmap, PON_CNTL_1, &pon_cntl);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed reading PON_CNTL_1 err=%d\n", err);
 		return err;
 	}

 	pon_cntl &= ~PON_CNTL_TRIG_DELAY_MASK;
 	pon_cntl |= (delay & PON_CNTL_TRIG_DELAY_MASK);
 	if (pull_up)
 		pon_cntl |= PON_CNTL_PULL_UP;
 	else
 		pon_cntl &= ~PON_CNTL_PULL_UP;

 	err = regmap_write(regmap, PON_CNTL_1, pon_cntl);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed writing PON_CNTL_1 err=%d\n", err);
 		return err;
 	}

 	err = devm_request_irq(&pdev->dev, key_press_irq, pwrkey_press_irq,
 			       IRQF_TRIGGER_RISING,
 			       "pmic8xxx_pwrkey_press", pwr);
 	if (err) {
 		dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
 			key_press_irq, err);
 		return err;
 	}

 	err = devm_request_irq(&pdev->dev, key_release_irq, pwrkey_release_irq,
 			       IRQF_TRIGGER_RISING,
 			       "pmic8xxx_pwrkey_release", pwr);
 	if (err) {
 		dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
 			key_release_irq, err);
 		return err;
 	}

 	err = input_register_device(pwr);
 	if (err) {
 		dev_err(&pdev->dev, "Can't register power key: %d\n", err);
 		return err;
 	}

 	platform_set_drvdata(pdev, pwrkey);
 	device_init_wakeup(&pdev->dev, 1);

 	return 0;
 }

 static int pmic8xxx_pwrkey_remove(struct platform_device *pdev)
 {
 	device_init_wakeup(&pdev->dev, 0);

 	return 0;
 }

 static const struct of_device_id pm8xxx_pwr_key_id_table[] = {
 	{ .compatible = "qcom,pm8058-pwrkey", .data = &pm8058_pwrkey_shutdown },
 	{ .compatible = "qcom,pm8921-pwrkey", .data = &pm8921_pwrkey_shutdown },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, pm8xxx_pwr_key_id_table);

 static struct platform_driver pmic8xxx_pwrkey_driver = {
 	.probe		= pmic8xxx_pwrkey_probe,
 	.remove		= pmic8xxx_pwrkey_remove,
 	.shutdown	= pmic8xxx_pwrkey_shutdown,
 	.driver		= {
 		.name	= "pm8xxx-pwrkey",
 		.pm	= &pm8xxx_pwr_key_pm_ops,
 		.of_match_table = pm8xxx_pwr_key_id_table,
 	},
 };
 module_platform_driver(pmic8xxx_pwrkey_driver);

 MODULE_ALIAS("platform:pmic8xxx_pwrkey");
 MODULE_DESCRIPTION("PMIC8XXX Power Key driver");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");
	/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/interrupt.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/log2.h>
	#include <linux/of.h>
	#include <linux/of_device.h>

	#define PON_CNTL_1 0x1C
	#define PON_CNTL_PULL_UP BIT(7)
	#define PON_CNTL_TRIG_DELAY_MASK (0x7)
	#define PON_CNTL_1_PULL_UP_EN 0xe0
	#define PON_CNTL_1_USB_PWR_EN 0x10
	#define PON_CNTL_1_WD_EN_RESET 0x08

	#define PM8058_SLEEP_CTRL 0x02b
	#define PM8921_SLEEP_CTRL 0x10a

	#define SLEEP_CTRL_SMPL_EN_RESET 0x04

	/* Regulator master enable addresses */
	#define REG_PM8058_VREG_EN_MSM 0x018
	#define REG_PM8058_VREG_EN_GRP_5_4 0x1c8

	/* Regulator control registers for shutdown/reset */
	#define PM8058_S0_CTRL 0x004
	#define PM8058_S1_CTRL 0x005
	#define PM8058_S3_CTRL 0x111
	#define PM8058_L21_CTRL 0x120
	#define PM8058_L22_CTRL 0x121

	#define PM8058_REGULATOR_ENABLE_MASK 0x80
	#define PM8058_REGULATOR_ENABLE 0x80
	#define PM8058_REGULATOR_DISABLE 0x00
	#define PM8058_REGULATOR_PULL_DOWN_MASK 0x40
	#define PM8058_REGULATOR_PULL_DOWN_EN 0x40

	/* Buck CTRL register */
	#define PM8058_SMPS_LEGACY_VREF_SEL 0x20
	#define PM8058_SMPS_LEGACY_VPROG_MASK 0x1f
	#define PM8058_SMPS_ADVANCED_BAND_MASK 0xC0
	#define PM8058_SMPS_ADVANCED_BAND_SHIFT 6
	#define PM8058_SMPS_ADVANCED_VPROG_MASK 0x3f

	/* Buck TEST2 registers for shutdown/reset */
	#define PM8058_S0_TEST2 0x084
	#define PM8058_S1_TEST2 0x085
	#define PM8058_S3_TEST2 0x11a

	#define PM8058_REGULATOR_BANK_WRITE 0x80
	#define PM8058_REGULATOR_BANK_MASK 0x70
	#define PM8058_REGULATOR_BANK_SHIFT 4
	#define PM8058_REGULATOR_BANK_SEL(n) ((n) << PM8058_REGULATOR_BANK_SHIFT)

	/* Buck TEST2 register bank 1 */
	#define PM8058_SMPS_LEGACY_VLOW_SEL 0x01

	/* Buck TEST2 register bank 7 */
	#define PM8058_SMPS_ADVANCED_MODE_MASK 0x02
	#define PM8058_SMPS_ADVANCED_MODE 0x02
	#define PM8058_SMPS_LEGACY_MODE 0x00

	/**
	* struct pmic8xxx_pwrkey - pmic8xxx pwrkey information
	* @key_press_irq: key press irq number
	* @regmap: device regmap
	* @shutdown_fn: shutdown configuration function
	*/
	struct pmic8xxx_pwrkey {
	int key_press_irq;
	struct regmap *regmap;
	int (shutdown_fn)(struct pmic8xxx_pwrkey , bool);
	};

	static irqreturn_t pwrkey_press_irq(int irq, void *_pwr)
	{
	struct input_dev *pwr = _pwr;

	input_report_key(pwr, KEY_POWER, 1);
	input_sync(pwr);

	return IRQ_HANDLED;
	}

	static irqreturn_t pwrkey_release_irq(int irq, void *_pwr)
	{
	struct input_dev *pwr = _pwr;

	input_report_key(pwr, KEY_POWER, 0);
	input_sync(pwr);

	return IRQ_HANDLED;
	}

	static int __maybe_unused pmic8xxx_pwrkey_suspend(struct device *dev)
	{
	struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
	enable_irq_wake(pwrkey->key_press_irq);

	return 0;
	}

	static int __maybe_unused pmic8xxx_pwrkey_resume(struct device *dev)
	{
	struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
	disable_irq_wake(pwrkey->key_press_irq);

	return 0;
	}

	static SIMPLE_DEV_PM_OPS(pm8xxx_pwr_key_pm_ops,
	pmic8xxx_pwrkey_suspend, pmic8xxx_pwrkey_resume);

	static void pmic8xxx_pwrkey_shutdown(struct platform_device *pdev)
	{
	struct pmic8xxx_pwrkey *pwrkey = platform_get_drvdata(pdev);
	int error;
	u8 mask, val;
	bool reset = system_state == SYSTEM_RESTART;

	if (pwrkey->shutdown_fn) {
	error = pwrkey->shutdown_fn(pwrkey, reset);
	if (error)
	return;
	}

	/*
	* Select action to perform (reset or shutdown) when PS_HOLD goes low.
	* Also ensure that KPD, CBL0, and CBL1 pull ups are enabled and that
	* USB charging is enabled.
	*/
	mask = PON_CNTL_1_PULL_UP_EN \| PON_CNTL_1_USB_PWR_EN;
	mask \|= PON_CNTL_1_WD_EN_RESET;
	val = mask;
	if (!reset)
	val &= ~PON_CNTL_1_WD_EN_RESET;

	regmap_update_bits(pwrkey->regmap, PON_CNTL_1, mask, val);
	}

	/*
	* Set an SMPS regulator to be disabled in its CTRL register, but enabled
	* in the master enable register. Also set it's pull down enable bit.
	* Take care to make sure that the output voltage doesn't change if switching
	* from advanced mode to legacy mode.
	*/
	static int pm8058_disable_smps_locally_set_pull_down(struct regmap *regmap,
	u16 ctrl_addr, u16 test2_addr, u16 master_enable_addr,
	u8 master_enable_bit)
	{
	int error;
	u8 vref_sel, vlow_sel, band, vprog, bank;
	unsigned int reg;

	bank = PM8058_REGULATOR_BANK_SEL(7);
	error = regmap_write(regmap, test2_addr, bank);
	if (error)
	return error;

	error = regmap_read(regmap, test2_addr, &reg);
	if (error)
	return error;

	reg &= PM8058_SMPS_ADVANCED_MODE_MASK;
	/* Check if in advanced mode. */
	if (reg == PM8058_SMPS_ADVANCED_MODE) {
	/* Determine current output voltage. */
	error = regmap_read(regmap, ctrl_addr, &reg);
	if (error)
	return error;

	band = reg & PM8058_SMPS_ADVANCED_BAND_MASK;
	band >>= PM8058_SMPS_ADVANCED_BAND_SHIFT;
	switch (band) {
	case 3:
	vref_sel = 0;
	vlow_sel = 0;
	break;
	case 2:
	vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
	vlow_sel = 0;
	break;
	case 1:
	vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
	vlow_sel = PM8058_SMPS_LEGACY_VLOW_SEL;
	break;
	default:
	pr_err("%s: regulator already disabled\n", __func__);
	return -EPERM;
	}
	vprog = reg & PM8058_SMPS_ADVANCED_VPROG_MASK;
	/* Round up if fine step is in use. */
	vprog = (vprog + 1) >> 1;
	if (vprog > PM8058_SMPS_LEGACY_VPROG_MASK)
	vprog = PM8058_SMPS_LEGACY_VPROG_MASK;

	/* Set VLOW_SEL bit. */
	bank = PM8058_REGULATOR_BANK_SEL(1);
	error = regmap_write(regmap, test2_addr, bank);
	if (error)
	return error;

	error = regmap_update_bits(regmap, test2_addr,
	PM8058_REGULATOR_BANK_WRITE \| PM8058_REGULATOR_BANK_MASK
	\| PM8058_SMPS_LEGACY_VLOW_SEL,
	PM8058_REGULATOR_BANK_WRITE \|
	PM8058_REGULATOR_BANK_SEL(1) \| vlow_sel);
	if (error)
	return error;

	/* Switch to legacy mode */
	bank = PM8058_REGULATOR_BANK_SEL(7);
	error = regmap_write(regmap, test2_addr, bank);
	if (error)
	return error;

	error = regmap_update_bits(regmap, test2_addr,
	PM8058_REGULATOR_BANK_WRITE \|
	PM8058_REGULATOR_BANK_MASK \|
	PM8058_SMPS_ADVANCED_MODE_MASK,
	PM8058_REGULATOR_BANK_WRITE \|
	PM8058_REGULATOR_BANK_SEL(7) \|
	PM8058_SMPS_LEGACY_MODE);
	if (error)
	return error;

	/* Enable locally, enable pull down, keep voltage the same. */
	error = regmap_update_bits(regmap, ctrl_addr,
	PM8058_REGULATOR_ENABLE_MASK \|
	PM8058_REGULATOR_PULL_DOWN_MASK \|
	PM8058_SMPS_LEGACY_VREF_SEL \|
	PM8058_SMPS_LEGACY_VPROG_MASK,
	PM8058_REGULATOR_ENABLE \| PM8058_REGULATOR_PULL_DOWN_EN
	\| vref_sel \| vprog);
	if (error)
	return error;
	}

	/* Enable in master control register. */
	error = regmap_update_bits(regmap, master_enable_addr,
	master_enable_bit, master_enable_bit);
	if (error)
	return error;

	/* Disable locally and enable pull down. */
	return regmap_update_bits(regmap, ctrl_addr,
	PM8058_REGULATOR_ENABLE_MASK \| PM8058_REGULATOR_PULL_DOWN_MASK,
	PM8058_REGULATOR_DISABLE \| PM8058_REGULATOR_PULL_DOWN_EN);
	}

	static int pm8058_disable_ldo_locally_set_pull_down(struct regmap *regmap,
	u16 ctrl_addr, u16 master_enable_addr, u8 master_enable_bit)
	{
	int error;

	/* Enable LDO in master control register. */
	error = regmap_update_bits(regmap, master_enable_addr,
	master_enable_bit, master_enable_bit);
	if (error)
	return error;

	/* Disable LDO in CTRL register and set pull down */
	return regmap_update_bits(regmap, ctrl_addr,
	PM8058_REGULATOR_ENABLE_MASK \| PM8058_REGULATOR_PULL_DOWN_MASK,
	PM8058_REGULATOR_DISABLE \| PM8058_REGULATOR_PULL_DOWN_EN);
	}

	static int pm8058_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
	{
	int error;
	struct regmap *regmap = pwrkey->regmap;
	u8 mask, val;

	/* When shutting down, enable active pulldowns on important rails. */
	if (!reset) {
	/* Disable SMPS's 0,1,3 locally and set pulldown enable bits. */
	pm8058_disable_smps_locally_set_pull_down(regmap,
	PM8058_S0_CTRL, PM8058_S0_TEST2,
	REG_PM8058_VREG_EN_MSM, BIT(7));
	pm8058_disable_smps_locally_set_pull_down(regmap,
	PM8058_S1_CTRL, PM8058_S1_TEST2,
	REG_PM8058_VREG_EN_MSM, BIT(6));
	pm8058_disable_smps_locally_set_pull_down(regmap,
	PM8058_S3_CTRL, PM8058_S3_TEST2,
	REG_PM8058_VREG_EN_GRP_5_4, BIT(7) \| BIT(4));
	/* Disable LDO 21 locally and set pulldown enable bit. */
	pm8058_disable_ldo_locally_set_pull_down(regmap,
	PM8058_L21_CTRL, REG_PM8058_VREG_EN_GRP_5_4,
	BIT(1));
	}

	/*
	* Fix-up: Set regulator LDO22 to 1.225 V in high power mode. Leave its
	* pull-down state intact. This ensures a safe shutdown.
	*/
	error = regmap_update_bits(regmap, PM8058_L22_CTRL, 0xbf, 0x93);
	if (error)
	return error;

	/* Enable SMPL if resetting is desired */
	mask = SLEEP_CTRL_SMPL_EN_RESET;
	val = 0;
	if (reset)
	val = mask;
	return regmap_update_bits(regmap, PM8058_SLEEP_CTRL, mask, val);
	}

	static int pm8921_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
	{
	struct regmap *regmap = pwrkey->regmap;
	u8 mask = SLEEP_CTRL_SMPL_EN_RESET;
	u8 val = 0;

	/* Enable SMPL if resetting is desired */
	if (reset)
	val = mask;
	return regmap_update_bits(regmap, PM8921_SLEEP_CTRL, mask, val);
	}

	static int pmic8xxx_pwrkey_probe(struct platform_device *pdev)
	{
	struct input_dev *pwr;
	int key_release_irq = platform_get_irq(pdev, 0);
	int key_press_irq = platform_get_irq(pdev, 1);
	int err;
	unsigned int delay;
	unsigned int pon_cntl;
	struct regmap *regmap;
	struct pmic8xxx_pwrkey *pwrkey;
	u32 kpd_delay;
	bool pull_up;

	if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay))
	kpd_delay = 15625;

	/* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */
	if (kpd_delay > USEC_PER_SEC * 2 \|\| kpd_delay < USEC_PER_SEC / 64) {
	dev_err(&pdev->dev, "invalid power key trigger delay\n");
	return -EINVAL;
	}

	pull_up = of_property_read_bool(pdev->dev.of_node, "pull-up");

	regmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!regmap) {
	dev_err(&pdev->dev, "failed to locate regmap for the device\n");
	return -ENODEV;
	}

	pwrkey = devm_kzalloc(&pdev->dev, sizeof(*pwrkey), GFP_KERNEL);
	if (!pwrkey)
	return -ENOMEM;

	pwrkey->shutdown_fn = of_device_get_match_data(&pdev->dev);
	pwrkey->regmap = regmap;
	pwrkey->key_press_irq = key_press_irq;

	pwr = devm_input_allocate_device(&pdev->dev);
	if (!pwr) {
	dev_dbg(&pdev->dev, "Can't allocate power button\n");
	return -ENOMEM;
	}

	input_set_capability(pwr, EV_KEY, KEY_POWER);

	pwr->name = "pmic8xxx_pwrkey";
	pwr->phys = "pmic8xxx_pwrkey/input0";

	delay = (kpd_delay << 6) / USEC_PER_SEC;
	delay = ilog2(delay);

	err = regmap_read(regmap, PON_CNTL_1, &pon_cntl);
	if (err < 0) {
	dev_err(&pdev->dev, "failed reading PON_CNTL_1 err=%d\n", err);
	return err;
	}

	pon_cntl &= ~PON_CNTL_TRIG_DELAY_MASK;
	pon_cntl \|= (delay & PON_CNTL_TRIG_DELAY_MASK);
	if (pull_up)
	pon_cntl \|= PON_CNTL_PULL_UP;
	else
	pon_cntl &= ~PON_CNTL_PULL_UP;

	err = regmap_write(regmap, PON_CNTL_1, pon_cntl);
	if (err < 0) {
	dev_err(&pdev->dev, "failed writing PON_CNTL_1 err=%d\n", err);
	return err;
	}

	err = devm_request_irq(&pdev->dev, key_press_irq, pwrkey_press_irq,
	IRQF_TRIGGER_RISING,
	"pmic8xxx_pwrkey_press", pwr);
	if (err) {
	dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
	key_press_irq, err);
	return err;
	}

	err = devm_request_irq(&pdev->dev, key_release_irq, pwrkey_release_irq,
	IRQF_TRIGGER_RISING,
	"pmic8xxx_pwrkey_release", pwr);
	if (err) {
	dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
	key_release_irq, err);
	return err;
	}

	err = input_register_device(pwr);
	if (err) {
	dev_err(&pdev->dev, "Can't register power key: %d\n", err);
	return err;
	}

	platform_set_drvdata(pdev, pwrkey);
	device_init_wakeup(&pdev->dev, 1);

	return 0;
	}

	static int pmic8xxx_pwrkey_remove(struct platform_device *pdev)
	{
	device_init_wakeup(&pdev->dev, 0);

	return 0;
	}

	static const struct of_device_id pm8xxx_pwr_key_id_table[] = {
	{ .compatible = "qcom,pm8058-pwrkey", .data = &pm8058_pwrkey_shutdown },
	{ .compatible = "qcom,pm8921-pwrkey", .data = &pm8921_pwrkey_shutdown },
	{ }
	};
	MODULE_DEVICE_TABLE(of, pm8xxx_pwr_key_id_table);

	static struct platform_driver pmic8xxx_pwrkey_driver = {
	.probe = pmic8xxx_pwrkey_probe,
	.remove = pmic8xxx_pwrkey_remove,
	.shutdown = pmic8xxx_pwrkey_shutdown,
	.driver = {
	.name = "pm8xxx-pwrkey",
	.pm = &pm8xxx_pwr_key_pm_ops,
	.of_match_table = pm8xxx_pwr_key_id_table,
	},
	};
	module_platform_driver(pmic8xxx_pwrkey_driver);

	MODULE_ALIAS("platform:pmic8xxx_pwrkey");
	MODULE_DESCRIPTION("PMIC8XXX Power Key driver");
	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");