drivers/gpio/gpio-wcove.c - kernel/msm-4.19 - Gitiles

 /*
  * Intel Whiskey Cove PMIC GPIO Driver
  *
  * This driver is written based on gpio-crystalcove.c
  *
  * Copyright (C) 2016 Intel Corporation. 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 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/bitops.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/gpio/driver.h>
 #include <linux/mfd/intel_soc_pmic.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/seq_file.h>

 /*
  * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
  * Bank 0: Pin 0 - 6
  * Bank 1: Pin 7 - 10
  * Bank 2: Pin 11 -12
  * Each pin has one output control register and one input control register.
  */
 #define BANK0_NR_PINS		7
 #define BANK1_NR_PINS		4
 #define BANK2_NR_PINS		2
 #define WCOVE_GPIO_NUM		(BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
 #define WCOVE_VGPIO_NUM		94
 /* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
 #define GPIO_OUT_CTRL_BASE	0x4e44
 /* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
 #define GPIO_IN_CTRL_BASE	0x4e51

 /*
  * GPIO interrupts are organized in two groups:
  * Group 0: Bank 0 pins (Pin 0 - 6)
  * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
  * Each group has two registers (one bit per pin): status and mask.
  */
 #define GROUP0_NR_IRQS		7
 #define GROUP1_NR_IRQS		6
 #define IRQ_MASK_BASE		0x4e19
 #define IRQ_STATUS_BASE		0x4e0b
 #define UPDATE_IRQ_TYPE		BIT(0)
 #define UPDATE_IRQ_MASK		BIT(1)

 #define CTLI_INTCNT_DIS		(0 << 1)
 #define CTLI_INTCNT_NE		(1 << 1)
 #define CTLI_INTCNT_PE		(2 << 1)
 #define CTLI_INTCNT_BE		(3 << 1)

 #define CTLO_DIR_IN		(0 << 5)
 #define CTLO_DIR_OUT		(1 << 5)

 #define CTLO_DRV_MASK		(1 << 4)
 #define CTLO_DRV_OD		(0 << 4)
 #define CTLO_DRV_CMOS		(1 << 4)

 #define CTLO_DRV_REN		(1 << 3)

 #define CTLO_RVAL_2KDOWN	(0 << 1)
 #define CTLO_RVAL_2KUP		(1 << 1)
 #define CTLO_RVAL_50KDOWN	(2 << 1)
 #define CTLO_RVAL_50KUP		(3 << 1)

 #define CTLO_INPUT_SET	(CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
 #define CTLO_OUTPUT_SET	(CTLO_DIR_OUT | CTLO_INPUT_SET)

 enum ctrl_register {
 	CTRL_IN,
 	CTRL_OUT,
 };

 /*
  * struct wcove_gpio - Whiskey Cove GPIO controller
  * @buslock: for bus lock/sync and unlock.
  * @chip: the abstract gpio_chip structure.
  * @dev: the gpio device
  * @regmap: the regmap from the parent device.
  * @regmap_irq_chip: the regmap of the gpio irq chip.
  * @update: pending IRQ setting update, to be written to the chip upon unlock.
  * @intcnt: the Interrupt Detect value to be written.
  * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
  */
 struct wcove_gpio {
 	struct mutex buslock;
 	struct gpio_chip chip;
 	struct device *dev;
 	struct regmap *regmap;
 	struct regmap_irq_chip_data *regmap_irq_chip;
 	int update;
 	int intcnt;
 	bool set_irq_mask;
 };

 static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
 {
 	unsigned int reg;
 	int bank;

 	if (gpio < BANK0_NR_PINS)
 		bank = 0;
 	else if (gpio < BANK0_NR_PINS + BANK1_NR_PINS)
 		bank = 1;
 	else
 		bank = 2;

 	if (reg_type == CTRL_IN)
 		reg = GPIO_IN_CTRL_BASE + bank;
 	else
 		reg = GPIO_OUT_CTRL_BASE + bank;

 	return reg;
 }

 static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
 {
 	unsigned int reg, mask;

 	if (gpio < GROUP0_NR_IRQS) {
 		reg = IRQ_MASK_BASE;
 		mask = BIT(gpio % GROUP0_NR_IRQS);
 	} else {
 		reg = IRQ_MASK_BASE + 1;
 		mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
 	}

 	if (wg->set_irq_mask)
 		regmap_update_bits(wg->regmap, reg, mask, mask);
 	else
 		regmap_update_bits(wg->regmap, reg, mask, 0);
 }

 static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
 {
 	unsigned int reg = to_reg(gpio, CTRL_IN);

 	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
 }

 static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
 {
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
 			    CTLO_INPUT_SET);
 }

 static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
 				    int value)
 {
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
 			    CTLO_OUTPUT_SET | value);
 }

 static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
 {
 	struct wcove_gpio *wg = gpiochip_get_data(chip);
 	unsigned int val;
 	int ret;

 	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &val);
 	if (ret)
 		return ret;

 	return !(val & CTLO_DIR_OUT);
 }

 static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
 {
 	struct wcove_gpio *wg = gpiochip_get_data(chip);
 	unsigned int val;
 	int ret;

 	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &val);
 	if (ret)
 		return ret;

 	return val & 0x1;
 }

 static void wcove_gpio_set(struct gpio_chip *chip,
 				 unsigned int gpio, int value)
 {
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	if (value)
 		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
 	else
 		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
 }

 static int wcove_gpio_set_single_ended(struct gpio_chip *chip,
 					unsigned int gpio,
 					enum single_ended_mode mode)
 {
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	switch (mode) {
 	case LINE_MODE_OPEN_DRAIN:
 		return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
 						CTLO_DRV_MASK, CTLO_DRV_OD);
 	case LINE_MODE_PUSH_PULL:
 		return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
 						CTLO_DRV_MASK, CTLO_DRV_CMOS);
 	default:
 		break;
 	}

 	return -ENOTSUPP;
 }

 static int wcove_irq_type(struct irq_data *data, unsigned int type)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	switch (type) {
 	case IRQ_TYPE_NONE:
 		wg->intcnt = CTLI_INTCNT_DIS;
 		break;
 	case IRQ_TYPE_EDGE_BOTH:
 		wg->intcnt = CTLI_INTCNT_BE;
 		break;
 	case IRQ_TYPE_EDGE_RISING:
 		wg->intcnt = CTLI_INTCNT_PE;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		wg->intcnt = CTLI_INTCNT_NE;
 		break;
 	default:
 		return -EINVAL;
 	}

 	wg->update |= UPDATE_IRQ_TYPE;

 	return 0;
 }

 static void wcove_bus_lock(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	mutex_lock(&wg->buslock);
 }

 static void wcove_bus_sync_unlock(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct wcove_gpio *wg = gpiochip_get_data(chip);
 	int gpio = data->hwirq;

 	if (wg->update & UPDATE_IRQ_TYPE)
 		wcove_update_irq_ctrl(wg, gpio);
 	if (wg->update & UPDATE_IRQ_MASK)
 		wcove_update_irq_mask(wg, gpio);
 	wg->update = 0;

 	mutex_unlock(&wg->buslock);
 }

 static void wcove_irq_unmask(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	wg->set_irq_mask = false;
 	wg->update |= UPDATE_IRQ_MASK;
 }

 static void wcove_irq_mask(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct wcove_gpio *wg = gpiochip_get_data(chip);

 	wg->set_irq_mask = true;
 	wg->update |= UPDATE_IRQ_MASK;
 }

 static struct irq_chip wcove_irqchip = {
 	.name			= "Whiskey Cove",
 	.irq_mask		= wcove_irq_mask,
 	.irq_unmask		= wcove_irq_unmask,
 	.irq_set_type		= wcove_irq_type,
 	.irq_bus_lock		= wcove_bus_lock,
 	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
 };

 static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
 {
 	struct wcove_gpio *wg = (struct wcove_gpio *)data;
 	unsigned int pending, virq, gpio, mask, offset;
 	u8 p[2];

 	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 		dev_err(wg->dev, "Failed to read irq status register\n");
 		return IRQ_NONE;
 	}

 	pending = p[0] | (p[1] << 8);
 	if (!pending)
 		return IRQ_NONE;

 	/* Iterate until no interrupt is pending */
 	while (pending) {
 		/* One iteration is for all pending bits */
 		for_each_set_bit(gpio, (const unsigned long *)&pending,
 						 GROUP0_NR_IRQS) {
 			offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
 			mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
 								BIT(gpio);
 			virq = irq_find_mapping(wg->chip.irqdomain, gpio);
 			handle_nested_irq(virq);
 			regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
 								mask, mask);
 		}

 		/* Next iteration */
 		if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 			dev_err(wg->dev, "Failed to read irq status\n");
 			break;
 		}

 		pending = p[0] | (p[1] << 8);
 	}

 	return IRQ_HANDLED;
 }

 static void wcove_gpio_dbg_show(struct seq_file *s,
 				      struct gpio_chip *chip)
 {
 	unsigned int ctlo, ctli, irq_mask, irq_status;
 	struct wcove_gpio *wg = gpiochip_get_data(chip);
 	int gpio, offset, group, ret = 0;

 	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
 		group = gpio < GROUP0_NR_IRQS ? 0 : 1;
 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
 		ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
 							&irq_mask);
 		ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
 							&irq_status);
 		if (ret) {
 			pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
 			break;
 		}

 		offset = gpio % 8;
 		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
 			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
 			   ctli & 0x1 ? "hi" : "lo",
 			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
 			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
 			   ctlo,
 			   irq_mask & BIT(offset) ? "mask  " : "unmask",
 			   irq_status & BIT(offset) ? "pending" : "       ");
 	}
 }

 static int wcove_gpio_probe(struct platform_device *pdev)
 {
 	struct intel_soc_pmic *pmic;
 	struct wcove_gpio *wg;
 	int virq, ret, irq;
 	struct device *dev;

 	/*
 	 * This gpio platform device is created by a mfd device (see
 	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
 	 * shared by all sub-devices created by the mfd device, the regmap
 	 * pointer for instance, is stored as driver data of the mfd device
 	 * driver.
 	 */
 	pmic = dev_get_drvdata(pdev->dev.parent);
 	if (!pmic)
 		return -ENODEV;

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	dev = &pdev->dev;

 	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
 	if (!wg)
 		return -ENOMEM;

 	wg->regmap_irq_chip = pmic->irq_chip_data_level2;

 	platform_set_drvdata(pdev, wg);

 	mutex_init(&wg->buslock);
 	wg->chip.label = KBUILD_MODNAME;
 	wg->chip.direction_input = wcove_gpio_dir_in;
 	wg->chip.direction_output = wcove_gpio_dir_out;
 	wg->chip.get_direction = wcove_gpio_get_direction;
 	wg->chip.get = wcove_gpio_get;
 	wg->chip.set = wcove_gpio_set;
 	wg->chip.set_single_ended = wcove_gpio_set_single_ended,
 	wg->chip.base = -1;
 	wg->chip.ngpio = WCOVE_VGPIO_NUM;
 	wg->chip.can_sleep = true;
 	wg->chip.parent = pdev->dev.parent;
 	wg->chip.dbg_show = wcove_gpio_dbg_show;
 	wg->dev = dev;
 	wg->regmap = pmic->regmap;

 	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
 	if (ret) {
 		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
 		return ret;
 	}

 	ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
 					  handle_simple_irq, IRQ_TYPE_NONE);
 	if (ret) {
 		dev_err(dev, "Failed to add irqchip: %d\n", ret);
 		return ret;
 	}

 	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
 	if (virq < 0) {
 		dev_err(dev, "Failed to get virq by irq %d\n", irq);
 		return virq;
 	}

 	ret = devm_request_threaded_irq(dev, virq, NULL,
 		wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
 	if (ret) {
 		dev_err(dev, "Failed to request irq %d\n", virq);
 		return ret;
 	}

 	gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);

 	return 0;
 }

 /*
  * Whiskey Cove PMIC itself is a analog device(but with digital control
  * interface) providing power management support for other devices in
  * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
  */
 static struct platform_driver wcove_gpio_driver = {
 	.driver = {
 		.name = "bxt_wcove_gpio",
 	},
 	.probe = wcove_gpio_probe,
 };

 module_platform_driver(wcove_gpio_driver);

 MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
 MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
 MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:bxt_wcove_gpio");
	/*
	* Intel Whiskey Cove PMIC GPIO Driver
	*
	* This driver is written based on gpio-crystalcove.c
	*
	* Copyright (C) 2016 Intel Corporation. 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 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/bitops.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/gpio/driver.h>
	#include <linux/mfd/intel_soc_pmic.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/seq_file.h>

	/*
	* Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
	* Bank 0: Pin 0 - 6
	* Bank 1: Pin 7 - 10
	* Bank 2: Pin 11 -12
	* Each pin has one output control register and one input control register.
	*/
	#define BANK0_NR_PINS 7
	#define BANK1_NR_PINS 4
	#define BANK2_NR_PINS 2
	#define WCOVE_GPIO_NUM (BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
	#define WCOVE_VGPIO_NUM 94
	/* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
	#define GPIO_OUT_CTRL_BASE 0x4e44
	/* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
	#define GPIO_IN_CTRL_BASE 0x4e51

	/*
	* GPIO interrupts are organized in two groups:
	* Group 0: Bank 0 pins (Pin 0 - 6)
	* Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
	* Each group has two registers (one bit per pin): status and mask.
	*/
	#define GROUP0_NR_IRQS 7
	#define GROUP1_NR_IRQS 6
	#define IRQ_MASK_BASE 0x4e19
	#define IRQ_STATUS_BASE 0x4e0b
	#define UPDATE_IRQ_TYPE BIT(0)
	#define UPDATE_IRQ_MASK BIT(1)

	#define CTLI_INTCNT_DIS (0 << 1)
	#define CTLI_INTCNT_NE (1 << 1)
	#define CTLI_INTCNT_PE (2 << 1)
	#define CTLI_INTCNT_BE (3 << 1)

	#define CTLO_DIR_IN (0 << 5)
	#define CTLO_DIR_OUT (1 << 5)

	#define CTLO_DRV_MASK (1 << 4)
	#define CTLO_DRV_OD (0 << 4)
	#define CTLO_DRV_CMOS (1 << 4)

	#define CTLO_DRV_REN (1 << 3)

	#define CTLO_RVAL_2KDOWN (0 << 1)
	#define CTLO_RVAL_2KUP (1 << 1)
	#define CTLO_RVAL_50KDOWN (2 << 1)
	#define CTLO_RVAL_50KUP (3 << 1)

	#define CTLO_INPUT_SET (CTLO_DRV_CMOS \| CTLO_DRV_REN \| CTLO_RVAL_2KUP)
	#define CTLO_OUTPUT_SET (CTLO_DIR_OUT \| CTLO_INPUT_SET)

	enum ctrl_register {
	CTRL_IN,
	CTRL_OUT,
	};

	/*
	* struct wcove_gpio - Whiskey Cove GPIO controller
	* @buslock: for bus lock/sync and unlock.
	* @chip: the abstract gpio_chip structure.
	* @dev: the gpio device
	* @regmap: the regmap from the parent device.
	* @regmap_irq_chip: the regmap of the gpio irq chip.
	* @update: pending IRQ setting update, to be written to the chip upon unlock.
	* @intcnt: the Interrupt Detect value to be written.
	* @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
	*/
	struct wcove_gpio {
	struct mutex buslock;
	struct gpio_chip chip;
	struct device *dev;
	struct regmap *regmap;
	struct regmap_irq_chip_data *regmap_irq_chip;
	int update;
	int intcnt;
	bool set_irq_mask;
	};

	static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
	{
	unsigned int reg;
	int bank;

	if (gpio < BANK0_NR_PINS)
	bank = 0;
	else if (gpio < BANK0_NR_PINS + BANK1_NR_PINS)
	bank = 1;
	else
	bank = 2;

	if (reg_type == CTRL_IN)
	reg = GPIO_IN_CTRL_BASE + bank;
	else
	reg = GPIO_OUT_CTRL_BASE + bank;

	return reg;
	}

	static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
	{
	unsigned int reg, mask;

	if (gpio < GROUP0_NR_IRQS) {
	reg = IRQ_MASK_BASE;
	mask = BIT(gpio % GROUP0_NR_IRQS);
	} else {
	reg = IRQ_MASK_BASE + 1;
	mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
	}

	if (wg->set_irq_mask)
	regmap_update_bits(wg->regmap, reg, mask, mask);
	else
	regmap_update_bits(wg->regmap, reg, mask, 0);
	}

	static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
	{
	unsigned int reg = to_reg(gpio, CTRL_IN);

	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
	}

	static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
	{
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
	CTLO_INPUT_SET);
	}

	static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
	int value)
	{
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
	CTLO_OUTPUT_SET \| value);
	}

	static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
	{
	struct wcove_gpio *wg = gpiochip_get_data(chip);
	unsigned int val;
	int ret;

	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &val);
	if (ret)
	return ret;

	return !(val & CTLO_DIR_OUT);
	}

	static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
	{
	struct wcove_gpio *wg = gpiochip_get_data(chip);
	unsigned int val;
	int ret;

	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &val);
	if (ret)
	return ret;

	return val & 0x1;
	}

	static void wcove_gpio_set(struct gpio_chip *chip,
	unsigned int gpio, int value)
	{
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	if (value)
	regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
	else
	regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
	}

	static int wcove_gpio_set_single_ended(struct gpio_chip *chip,
	unsigned int gpio,
	enum single_ended_mode mode)
	{
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	switch (mode) {
	case LINE_MODE_OPEN_DRAIN:
	return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
	CTLO_DRV_MASK, CTLO_DRV_OD);
	case LINE_MODE_PUSH_PULL:
	return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
	CTLO_DRV_MASK, CTLO_DRV_CMOS);
	default:
	break;
	}

	return -ENOTSUPP;
	}

	static int wcove_irq_type(struct irq_data *data, unsigned int type)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	switch (type) {
	case IRQ_TYPE_NONE:
	wg->intcnt = CTLI_INTCNT_DIS;
	break;
	case IRQ_TYPE_EDGE_BOTH:
	wg->intcnt = CTLI_INTCNT_BE;
	break;
	case IRQ_TYPE_EDGE_RISING:
	wg->intcnt = CTLI_INTCNT_PE;
	break;
	case IRQ_TYPE_EDGE_FALLING:
	wg->intcnt = CTLI_INTCNT_NE;
	break;
	default:
	return -EINVAL;
	}

	wg->update \|= UPDATE_IRQ_TYPE;

	return 0;
	}

	static void wcove_bus_lock(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	mutex_lock(&wg->buslock);
	}

	static void wcove_bus_sync_unlock(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct wcove_gpio *wg = gpiochip_get_data(chip);
	int gpio = data->hwirq;

	if (wg->update & UPDATE_IRQ_TYPE)
	wcove_update_irq_ctrl(wg, gpio);
	if (wg->update & UPDATE_IRQ_MASK)
	wcove_update_irq_mask(wg, gpio);
	wg->update = 0;

	mutex_unlock(&wg->buslock);
	}

	static void wcove_irq_unmask(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	wg->set_irq_mask = false;
	wg->update \|= UPDATE_IRQ_MASK;
	}

	static void wcove_irq_mask(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct wcove_gpio *wg = gpiochip_get_data(chip);

	wg->set_irq_mask = true;
	wg->update \|= UPDATE_IRQ_MASK;
	}

	static struct irq_chip wcove_irqchip = {
	.name = "Whiskey Cove",
	.irq_mask = wcove_irq_mask,
	.irq_unmask = wcove_irq_unmask,
	.irq_set_type = wcove_irq_type,
	.irq_bus_lock = wcove_bus_lock,
	.irq_bus_sync_unlock = wcove_bus_sync_unlock,
	};

	static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
	{
	struct wcove_gpio wg = (struct wcove_gpio )data;
	unsigned int pending, virq, gpio, mask, offset;
	u8 p[2];

	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
	dev_err(wg->dev, "Failed to read irq status register\n");
	return IRQ_NONE;
	}

	pending = p[0] \| (p[1] << 8);
	if (!pending)
	return IRQ_NONE;

	/* Iterate until no interrupt is pending */
	while (pending) {
	/* One iteration is for all pending bits */
	for_each_set_bit(gpio, (const unsigned long *)&pending,
	GROUP0_NR_IRQS) {
	offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
	mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
	BIT(gpio);
	virq = irq_find_mapping(wg->chip.irqdomain, gpio);
	handle_nested_irq(virq);
	regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
	mask, mask);
	}

	/* Next iteration */
	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
	dev_err(wg->dev, "Failed to read irq status\n");
	break;
	}

	pending = p[0] \| (p[1] << 8);
	}

	return IRQ_HANDLED;
	}

	static void wcove_gpio_dbg_show(struct seq_file *s,
	struct gpio_chip *chip)
	{
	unsigned int ctlo, ctli, irq_mask, irq_status;
	struct wcove_gpio *wg = gpiochip_get_data(chip);
	int gpio, offset, group, ret = 0;

	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
	group = gpio < GROUP0_NR_IRQS ? 0 : 1;
	ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
	ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
	ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
	&irq_mask);
	ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
	&irq_status);
	if (ret) {
	pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
	break;
	}

	offset = gpio % 8;
	seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
	gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
	ctli & 0x1 ? "hi" : "lo",
	ctli & CTLI_INTCNT_NE ? "fall" : " ",
	ctli & CTLI_INTCNT_PE ? "rise" : " ",
	ctlo,
	irq_mask & BIT(offset) ? "mask " : "unmask",
	irq_status & BIT(offset) ? "pending" : " ");
	}
	}

	static int wcove_gpio_probe(struct platform_device *pdev)
	{
	struct intel_soc_pmic *pmic;
	struct wcove_gpio *wg;
	int virq, ret, irq;
	struct device *dev;

	/*
	* This gpio platform device is created by a mfd device (see
	* drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
	* shared by all sub-devices created by the mfd device, the regmap
	* pointer for instance, is stored as driver data of the mfd device
	* driver.
	*/
	pmic = dev_get_drvdata(pdev->dev.parent);
	if (!pmic)
	return -ENODEV;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	dev = &pdev->dev;

	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
	if (!wg)
	return -ENOMEM;

	wg->regmap_irq_chip = pmic->irq_chip_data_level2;

	platform_set_drvdata(pdev, wg);

	mutex_init(&wg->buslock);
	wg->chip.label = KBUILD_MODNAME;
	wg->chip.direction_input = wcove_gpio_dir_in;
	wg->chip.direction_output = wcove_gpio_dir_out;
	wg->chip.get_direction = wcove_gpio_get_direction;
	wg->chip.get = wcove_gpio_get;
	wg->chip.set = wcove_gpio_set;
	wg->chip.set_single_ended = wcove_gpio_set_single_ended,
	wg->chip.base = -1;
	wg->chip.ngpio = WCOVE_VGPIO_NUM;
	wg->chip.can_sleep = true;
	wg->chip.parent = pdev->dev.parent;
	wg->chip.dbg_show = wcove_gpio_dbg_show;
	wg->dev = dev;
	wg->regmap = pmic->regmap;

	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
	if (ret) {
	dev_err(dev, "Failed to add gpiochip: %d\n", ret);
	return ret;
	}

	ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
	handle_simple_irq, IRQ_TYPE_NONE);
	if (ret) {
	dev_err(dev, "Failed to add irqchip: %d\n", ret);
	return ret;
	}

	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
	if (virq < 0) {
	dev_err(dev, "Failed to get virq by irq %d\n", irq);
	return virq;
	}

	ret = devm_request_threaded_irq(dev, virq, NULL,
	wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
	if (ret) {
	dev_err(dev, "Failed to request irq %d\n", virq);
	return ret;
	}

	gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);

	return 0;
	}

	/*
	* Whiskey Cove PMIC itself is a analog device(but with digital control
	* interface) providing power management support for other devices in
	* the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
	*/
	static struct platform_driver wcove_gpio_driver = {
	.driver = {
	.name = "bxt_wcove_gpio",
	},
	.probe = wcove_gpio_probe,
	};

	module_platform_driver(wcove_gpio_driver);

	MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
	MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
	MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:bxt_wcove_gpio");