/*
 * extcon-rt8973a.c - Richtek RT8973A extcon driver to support USB switches
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd
 * Author: Chanwoo Choi <cw00.choi@samsung.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/extcon.h>

#include "extcon-rt8973a.h"

#define	DELAY_MS_DEFAULT		20000	/* unit: millisecond */

struct muic_irq {
	unsigned int irq;
	const char *name;
	unsigned int virq;
};

struct reg_data {
	u8 reg;
	u8 mask;
	u8 val;
	bool invert;
};

struct rt8973a_muic_info {
	struct device *dev;
	struct extcon_dev *edev;

	struct i2c_client *i2c;
	struct regmap *regmap;

	struct regmap_irq_chip_data *irq_data;
	struct muic_irq *muic_irqs;
	unsigned int num_muic_irqs;
	int irq;
	bool irq_attach;
	bool irq_detach;
	bool irq_ovp;
	bool irq_otp;
	struct work_struct irq_work;

	struct reg_data *reg_data;
	unsigned int num_reg_data;
	bool auto_config;

	struct mutex mutex;

	/*
	 * Use delayed workqueue to detect cable state and then
	 * notify cable state to notifiee/platform through uevent.
	 * After completing the booting of platform, the extcon provider
	 * driver should notify cable state to upper layer.
	 */
	struct delayed_work wq_detcable;
};

/* Default value of RT8973A register to bring up MUIC device. */
static struct reg_data rt8973a_reg_data[] = {
	{
		.reg = RT8973A_REG_CONTROL1,
		.mask = RT8973A_REG_CONTROL1_ADC_EN_MASK
			| RT8973A_REG_CONTROL1_USB_CHD_EN_MASK
			| RT8973A_REG_CONTROL1_CHGTYP_MASK
			| RT8973A_REG_CONTROL1_SWITCH_OPEN_MASK
			| RT8973A_REG_CONTROL1_AUTO_CONFIG_MASK
			| RT8973A_REG_CONTROL1_INTM_MASK,
		.val = RT8973A_REG_CONTROL1_ADC_EN_MASK
			| RT8973A_REG_CONTROL1_USB_CHD_EN_MASK
			| RT8973A_REG_CONTROL1_CHGTYP_MASK,
		.invert = false,
	},
	{ /* sentinel */ }
};

/* List of detectable cables */
enum {
	EXTCON_CABLE_USB = 0,
	EXTCON_CABLE_USB_HOST,
	EXTCON_CABLE_TA,
	EXTCON_CABLE_JIG_OFF_USB,
	EXTCON_CABLE_JIG_ON_USB,
	EXTCON_CABLE_JIG_OFF_UART,
	EXTCON_CABLE_JIG_ON_UART,

	EXTCON_CABLE_END,
};

static const char *rt8973a_extcon_cable[] = {
	[EXTCON_CABLE_USB]		= "USB",
	[EXTCON_CABLE_USB_HOST]		= "USB-Host",
	[EXTCON_CABLE_TA]		= "TA",
	[EXTCON_CABLE_JIG_OFF_USB]	= "JIG-USB-OFF",
	[EXTCON_CABLE_JIG_ON_USB]	= "JIG-USB-ON",
	[EXTCON_CABLE_JIG_OFF_UART]	= "JIG-UART-OFF",
	[EXTCON_CABLE_JIG_ON_UART]	= "JIG-UART-ON",
	NULL,
};

/* Define OVP (Over Voltage Protection), OTP (Over Temperature Protection) */
enum rt8973a_event_type {
	RT8973A_EVENT_ATTACH = 1,
	RT8973A_EVENT_DETACH,
	RT8973A_EVENT_OVP,
	RT8973A_EVENT_OTP,
};

/* Define supported accessory type */
enum rt8973a_muic_acc_type {
	RT8973A_MUIC_ADC_OTG = 0x0,
	RT8973A_MUIC_ADC_AUDIO_SEND_END_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S1_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S2_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S3_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S4_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S5_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S6_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S7_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S8_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S9_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S10_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S11_BUTTON,
	RT8973A_MUIC_ADC_AUDIO_REMOTE_S12_BUTTON,
	RT8973A_MUIC_ADC_RESERVED_ACC_1,
	RT8973A_MUIC_ADC_RESERVED_ACC_2,
	RT8973A_MUIC_ADC_RESERVED_ACC_3,
	RT8973A_MUIC_ADC_RESERVED_ACC_4,
	RT8973A_MUIC_ADC_RESERVED_ACC_5,
	RT8973A_MUIC_ADC_AUDIO_TYPE2,
	RT8973A_MUIC_ADC_PHONE_POWERED_DEV,
	RT8973A_MUIC_ADC_UNKNOWN_ACC_1,
	RT8973A_MUIC_ADC_UNKNOWN_ACC_2,
	RT8973A_MUIC_ADC_TA,
	RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_OFF_USB,
	RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_ON_USB,
	RT8973A_MUIC_ADC_UNKNOWN_ACC_3,
	RT8973A_MUIC_ADC_UNKNOWN_ACC_4,
	RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_OFF_UART,
	RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_ON_UART,
	RT8973A_MUIC_ADC_UNKNOWN_ACC_5,
	RT8973A_MUIC_ADC_OPEN = 0x1f,

	/* The below accessories has same ADC value (0x1f).
	   So, Device type1 is used to separate specific accessory. */
					/* |---------|--ADC| */
					/* |    [7:5]|[4:0]| */
	RT8973A_MUIC_ADC_USB = 0x3f,	/* |      001|11111| */
};

/* List of supported interrupt for RT8973A */
static struct muic_irq rt8973a_muic_irqs[] = {
	{ RT8973A_INT1_ATTACH,		"muic-attach" },
	{ RT8973A_INT1_DETACH,		"muic-detach" },
	{ RT8973A_INT1_CHGDET,		"muic-chgdet" },
	{ RT8973A_INT1_DCD_T,		"muic-dcd-t" },
	{ RT8973A_INT1_OVP,		"muic-ovp" },
	{ RT8973A_INT1_CONNECT,		"muic-connect" },
	{ RT8973A_INT1_ADC_CHG,		"muic-adc-chg" },
	{ RT8973A_INT1_OTP,		"muic-otp" },
	{ RT8973A_INT2_UVLO,		"muic-uvlo" },
	{ RT8973A_INT2_POR,		"muic-por" },
	{ RT8973A_INT2_OTP_FET,		"muic-otp-fet" },
	{ RT8973A_INT2_OVP_FET,		"muic-ovp-fet" },
	{ RT8973A_INT2_OCP_LATCH,	"muic-ocp-latch" },
	{ RT8973A_INT2_OCP,		"muic-ocp" },
	{ RT8973A_INT2_OVP_OCP,		"muic-ovp-ocp" },
};

/* Define interrupt list of RT8973A to register regmap_irq */
static const struct regmap_irq rt8973a_irqs[] = {
	/* INT1 interrupts */
	{ .reg_offset = 0, .mask = RT8973A_INT1_ATTACH_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_DETACH_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_CHGDET_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_DCD_T_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_OVP_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_CONNECT_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_ADC_CHG_MASK, },
	{ .reg_offset = 0, .mask = RT8973A_INT1_OTP_MASK, },

	/* INT2 interrupts */
	{ .reg_offset = 1, .mask = RT8973A_INT2_UVLOT_MASK,},
	{ .reg_offset = 1, .mask = RT8973A_INT2_POR_MASK, },
	{ .reg_offset = 1, .mask = RT8973A_INT2_OTP_FET_MASK, },
	{ .reg_offset = 1, .mask = RT8973A_INT2_OVP_FET_MASK, },
	{ .reg_offset = 1, .mask = RT8973A_INT2_OCP_LATCH_MASK, },
	{ .reg_offset = 1, .mask = RT8973A_INT2_OCP_MASK, },
	{ .reg_offset = 1, .mask = RT8973A_INT2_OVP_OCP_MASK, },
};

static const struct regmap_irq_chip rt8973a_muic_irq_chip = {
	.name			= "rt8973a",
	.status_base		= RT8973A_REG_INT1,
	.mask_base		= RT8973A_REG_INTM1,
	.mask_invert		= false,
	.num_regs		= 2,
	.irqs			= rt8973a_irqs,
	.num_irqs		= ARRAY_SIZE(rt8973a_irqs),
};

/* Define regmap configuration of RT8973A for I2C communication  */
static bool rt8973a_muic_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case RT8973A_REG_INTM1:
	case RT8973A_REG_INTM2:
		return true;
	default:
		break;
	}
	return false;
}

static const struct regmap_config rt8973a_muic_regmap_config = {
	.reg_bits	= 8,
	.val_bits	= 8,
	.volatile_reg	= rt8973a_muic_volatile_reg,
	.max_register	= RT8973A_REG_END,
};

/* Change DM_CON/DP_CON/VBUSIN switch according to cable type */
static int rt8973a_muic_set_path(struct rt8973a_muic_info *info,
				unsigned int con_sw, bool attached)
{
	int ret;

	/*
	 * Don't need to set h/w path according to cable type
	 * if Auto-configuration mode of CONTROL1 register is true.
	 */
	if (info->auto_config)
		return 0;

	if (!attached)
		con_sw	= DM_DP_SWITCH_UART;

	switch (con_sw) {
	case DM_DP_SWITCH_OPEN:
	case DM_DP_SWITCH_USB:
	case DM_DP_SWITCH_UART:
		ret = regmap_update_bits(info->regmap, RT8973A_REG_MANUAL_SW1,
					RT8973A_REG_MANUAL_SW1_DP_MASK |
					RT8973A_REG_MANUAL_SW1_DM_MASK,
					con_sw);
		if (ret < 0) {
			dev_err(info->dev,
				"cannot update DM_CON/DP_CON switch\n");
			return ret;
		}
		break;
	default:
		dev_err(info->dev, "Unknown DM_CON/DP_CON switch type (%d)\n",
				con_sw);
		return -EINVAL;
	}

	return 0;
}

static int rt8973a_muic_get_cable_type(struct rt8973a_muic_info *info)
{
	unsigned int adc, dev1;
	int ret, cable_type;

	/* Read ADC value according to external cable or button */
	ret = regmap_read(info->regmap, RT8973A_REG_ADC, &adc);
	if (ret) {
		dev_err(info->dev, "failed to read ADC register\n");
		return ret;
	}
	cable_type = adc & RT8973A_REG_ADC_MASK;

	/* Read Device 1 reigster to identify correct cable type */
	ret = regmap_read(info->regmap, RT8973A_REG_DEV1, &dev1);
	if (ret) {
		dev_err(info->dev, "failed to read DEV1 register\n");
		return ret;
	}

	switch (adc) {
	case RT8973A_MUIC_ADC_OPEN:
		if (dev1 & RT8973A_REG_DEV1_USB_MASK)
			cable_type = RT8973A_MUIC_ADC_USB;
		else if (dev1 & RT8973A_REG_DEV1_DCPORT_MASK)
			cable_type = RT8973A_MUIC_ADC_TA;
		else
			cable_type = RT8973A_MUIC_ADC_OPEN;
		break;
	default:
		break;
	}

	return cable_type;
}

static int rt8973a_muic_cable_handler(struct rt8973a_muic_info *info,
					enum rt8973a_event_type event)
{
	static unsigned int prev_cable_type;
	const char **cable_names = info->edev->supported_cable;
	unsigned int con_sw = DM_DP_SWITCH_UART;
	int ret, idx = 0, cable_type;
	bool attached = false;

	if (!cable_names)
		return 0;

	switch (event) {
	case RT8973A_EVENT_ATTACH:
		cable_type = rt8973a_muic_get_cable_type(info);
		attached = true;
		break;
	case RT8973A_EVENT_DETACH:
		cable_type = prev_cable_type;
		attached = false;
		break;
	case RT8973A_EVENT_OVP:
	case RT8973A_EVENT_OTP:
		dev_warn(info->dev,
			"happen Over %s issue. Need to disconnect all cables\n",
			event == RT8973A_EVENT_OVP ? "Voltage" : "Temperature");
		cable_type = prev_cable_type;
		attached = false;
		break;
	default:
		dev_err(info->dev,
			"Cannot handle this event (event:%d)\n", event);
		return -EINVAL;
	}
	prev_cable_type = cable_type;

	switch (cable_type) {
	case RT8973A_MUIC_ADC_OTG:
		idx = EXTCON_CABLE_USB_HOST;
		con_sw = DM_DP_SWITCH_USB;
		break;
	case RT8973A_MUIC_ADC_TA:
		idx = EXTCON_CABLE_TA;
		con_sw = DM_DP_SWITCH_OPEN;
		break;
	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_OFF_USB:
		idx = EXTCON_CABLE_JIG_OFF_USB;
		con_sw = DM_DP_SWITCH_UART;
		break;
	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_ON_USB:
		idx = EXTCON_CABLE_JIG_ON_USB;
		con_sw = DM_DP_SWITCH_UART;
		break;
	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_OFF_UART:
		idx = EXTCON_CABLE_JIG_OFF_UART;
		con_sw = DM_DP_SWITCH_UART;
		break;
	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_ON_UART:
		idx = EXTCON_CABLE_JIG_ON_UART;
		con_sw = DM_DP_SWITCH_UART;
		break;
	case RT8973A_MUIC_ADC_USB:
		idx = EXTCON_CABLE_USB;
		con_sw = DM_DP_SWITCH_USB;
		break;
	case RT8973A_MUIC_ADC_OPEN:
		return 0;
	case RT8973A_MUIC_ADC_UNKNOWN_ACC_1:
	case RT8973A_MUIC_ADC_UNKNOWN_ACC_2:
	case RT8973A_MUIC_ADC_UNKNOWN_ACC_3:
	case RT8973A_MUIC_ADC_UNKNOWN_ACC_4:
	case RT8973A_MUIC_ADC_UNKNOWN_ACC_5:
		dev_warn(info->dev,
			"Unknown accessory type (adc:0x%x)\n", cable_type);
		return 0;
	case RT8973A_MUIC_ADC_AUDIO_SEND_END_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S1_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S2_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S3_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S4_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S5_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S6_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S7_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S8_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S9_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S10_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S11_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_REMOTE_S12_BUTTON:
	case RT8973A_MUIC_ADC_AUDIO_TYPE2:
		dev_warn(info->dev,
			"Audio device/button type (adc:0x%x)\n", cable_type);
		return 0;
	case RT8973A_MUIC_ADC_RESERVED_ACC_1:
	case RT8973A_MUIC_ADC_RESERVED_ACC_2:
	case RT8973A_MUIC_ADC_RESERVED_ACC_3:
	case RT8973A_MUIC_ADC_RESERVED_ACC_4:
	case RT8973A_MUIC_ADC_RESERVED_ACC_5:
	case RT8973A_MUIC_ADC_PHONE_POWERED_DEV:
		return 0;
	default:
		dev_err(info->dev,
			"Cannot handle this cable_type (adc:0x%x)\n",
			cable_type);
		return -EINVAL;
	}

	/* Change internal hardware path(DM_CON/DP_CON) */
	ret = rt8973a_muic_set_path(info, con_sw, attached);
	if (ret < 0)
		return ret;

	/* Change the state of external accessory */
	extcon_set_cable_state(info->edev, cable_names[idx], attached);

	return 0;
}

static void rt8973a_muic_irq_work(struct work_struct *work)
{
	struct rt8973a_muic_info *info = container_of(work,
			struct rt8973a_muic_info, irq_work);
	int ret = 0;

	if (!info->edev)
		return;

	mutex_lock(&info->mutex);

	/* Detect attached or detached cables */
	if (info->irq_attach) {
		ret = rt8973a_muic_cable_handler(info, RT8973A_EVENT_ATTACH);
		info->irq_attach = false;
	}

	if (info->irq_detach) {
		ret = rt8973a_muic_cable_handler(info, RT8973A_EVENT_DETACH);
		info->irq_detach = false;
	}

	if (info->irq_ovp) {
		ret = rt8973a_muic_cable_handler(info, RT8973A_EVENT_OVP);
		info->irq_ovp = false;
	}

	if (info->irq_otp) {
		ret = rt8973a_muic_cable_handler(info, RT8973A_EVENT_OTP);
		info->irq_otp = false;
	}

	if (ret < 0)
		dev_err(info->dev, "failed to handle MUIC interrupt\n");

	mutex_unlock(&info->mutex);
}

static irqreturn_t rt8973a_muic_irq_handler(int irq, void *data)
{
	struct rt8973a_muic_info *info = data;
	int i, irq_type = -1;

	for (i = 0; i < info->num_muic_irqs; i++)
		if (irq == info->muic_irqs[i].virq)
			irq_type = info->muic_irqs[i].irq;

	switch (irq_type) {
	case RT8973A_INT1_ATTACH:
		info->irq_attach = true;
		break;
	case RT8973A_INT1_DETACH:
		info->irq_detach = true;
		break;
	case RT8973A_INT1_OVP:
		info->irq_ovp = true;
		break;
	case RT8973A_INT1_OTP:
		info->irq_otp = true;
		break;
	case RT8973A_INT1_CHGDET:
	case RT8973A_INT1_DCD_T:
	case RT8973A_INT1_CONNECT:
	case RT8973A_INT1_ADC_CHG:
	case RT8973A_INT2_UVLO:
	case RT8973A_INT2_POR:
	case RT8973A_INT2_OTP_FET:
	case RT8973A_INT2_OVP_FET:
	case RT8973A_INT2_OCP_LATCH:
	case RT8973A_INT2_OCP:
	case RT8973A_INT2_OVP_OCP:
	default:
		dev_dbg(info->dev,
			"Cannot handle this interrupt (%d)\n", irq_type);
		break;
	}

	schedule_work(&info->irq_work);

	return IRQ_HANDLED;
}

static void rt8973a_muic_detect_cable_wq(struct work_struct *work)
{
	struct rt8973a_muic_info *info = container_of(to_delayed_work(work),
				struct rt8973a_muic_info, wq_detcable);
	int ret;

	/* Notify the state of connector cable or not  */
	ret = rt8973a_muic_cable_handler(info, RT8973A_EVENT_ATTACH);
	if (ret < 0)
		dev_warn(info->dev, "failed to detect cable state\n");
}

static void rt8973a_init_dev_type(struct rt8973a_muic_info *info)
{
	unsigned int data, vendor_id, version_id;
	int i, ret;

	/* To test I2C, Print version_id and vendor_id of RT8973A */
	ret = regmap_read(info->regmap, RT8973A_REG_DEVICE_ID, &data);
	if (ret) {
		dev_err(info->dev,
			"failed to read DEVICE_ID register: %d\n", ret);
		return;
	}

	vendor_id = ((data & RT8973A_REG_DEVICE_ID_VENDOR_MASK) >>
				RT8973A_REG_DEVICE_ID_VENDOR_SHIFT);
	version_id = ((data & RT8973A_REG_DEVICE_ID_VERSION_MASK) >>
				RT8973A_REG_DEVICE_ID_VERSION_SHIFT);

	dev_info(info->dev, "Device type: version: 0x%x, vendor: 0x%x\n",
			    version_id, vendor_id);

	/* Initiazle the register of RT8973A device to bring-up */
	for (i = 0; i < info->num_reg_data; i++) {
		u8 reg = info->reg_data[i].reg;
		u8 mask = info->reg_data[i].mask;
		u8 val = 0;

		if (info->reg_data[i].invert)
			val = ~info->reg_data[i].val;
		else
			val = info->reg_data[i].val;

		regmap_update_bits(info->regmap, reg, mask, val);
	}

	/* Check whether RT8973A is auto swithcing mode or not */
	ret = regmap_read(info->regmap, RT8973A_REG_CONTROL1, &data);
	if (ret) {
		dev_err(info->dev,
			"failed to read CONTROL1 register: %d\n", ret);
		return;
	}

	data &= RT8973A_REG_CONTROL1_AUTO_CONFIG_MASK;
	if (data) {
		info->auto_config = true;
		dev_info(info->dev,
			"Enable Auto-configuration for internal path\n");
	}
}

static int rt8973a_muic_i2c_probe(struct i2c_client *i2c,
				 const struct i2c_device_id *id)
{
	struct device_node *np = i2c->dev.of_node;
	struct rt8973a_muic_info *info;
	int i, ret, irq_flags;

	if (!np)
		return -EINVAL;

	info = devm_kzalloc(&i2c->dev, sizeof(*info), GFP_KERNEL);
	if (!info) {
		dev_err(&i2c->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}
	i2c_set_clientdata(i2c, info);

	info->dev = &i2c->dev;
	info->i2c = i2c;
	info->irq = i2c->irq;
	info->muic_irqs = rt8973a_muic_irqs;
	info->num_muic_irqs = ARRAY_SIZE(rt8973a_muic_irqs);
	info->reg_data = rt8973a_reg_data;
	info->num_reg_data = ARRAY_SIZE(rt8973a_reg_data);

	mutex_init(&info->mutex);

	INIT_WORK(&info->irq_work, rt8973a_muic_irq_work);

	info->regmap = devm_regmap_init_i2c(i2c, &rt8973a_muic_regmap_config);
	if (IS_ERR(info->regmap)) {
		ret = PTR_ERR(info->regmap);
		dev_err(info->dev, "failed to allocate register map: %d\n",
				   ret);
		return ret;
	}

	/* Support irq domain for RT8973A MUIC device */
	irq_flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT | IRQF_SHARED;
	ret = regmap_add_irq_chip(info->regmap, info->irq, irq_flags, 0,
				  &rt8973a_muic_irq_chip, &info->irq_data);
	if (ret != 0) {
		dev_err(info->dev, "failed to add irq_chip (irq:%d, err:%d)\n",
				    info->irq, ret);
		return ret;
	}

	for (i = 0; i < info->num_muic_irqs; i++) {
		struct muic_irq *muic_irq = &info->muic_irqs[i];
		unsigned int virq = 0;

		virq = regmap_irq_get_virq(info->irq_data, muic_irq->irq);
		if (virq <= 0)
			return -EINVAL;
		muic_irq->virq = virq;

		ret = devm_request_threaded_irq(info->dev, virq, NULL,
						rt8973a_muic_irq_handler,
						IRQF_NO_SUSPEND,
						muic_irq->name, info);
		if (ret) {
			dev_err(info->dev,
				"failed: irq request (IRQ: %d, error :%d)\n",
				muic_irq->irq, ret);
			return ret;
		}
	}

	/* Allocate extcon device */
	info->edev = devm_extcon_dev_allocate(info->dev, rt8973a_extcon_cable);
	if (IS_ERR(info->edev)) {
		dev_err(info->dev, "failed to allocate memory for extcon\n");
		return -ENOMEM;
	}
	info->edev->name = np->name;

	/* Register extcon device */
	ret = devm_extcon_dev_register(info->dev, info->edev);
	if (ret) {
		dev_err(info->dev, "failed to register extcon device\n");
		return ret;
	}

	/*
	 * Detect accessory after completing the initialization of platform
	 *
	 * - Use delayed workqueue to detect cable state and then
	 * notify cable state to notifiee/platform through uevent.
	 * After completing the booting of platform, the extcon provider
	 * driver should notify cable state to upper layer.
	 */
	INIT_DELAYED_WORK(&info->wq_detcable, rt8973a_muic_detect_cable_wq);
	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
			msecs_to_jiffies(DELAY_MS_DEFAULT));

	/* Initialize RT8973A device and print vendor id and version id */
	rt8973a_init_dev_type(info);

	return 0;
}

static int rt8973a_muic_i2c_remove(struct i2c_client *i2c)
{
	struct rt8973a_muic_info *info = i2c_get_clientdata(i2c);

	regmap_del_irq_chip(info->irq, info->irq_data);

	return 0;
}

static struct of_device_id rt8973a_dt_match[] = {
	{ .compatible = "richtek,rt8973a-muic" },
	{ },
};

#ifdef CONFIG_PM_SLEEP
static int rt8973a_muic_suspend(struct device *dev)
{
	struct i2c_client *i2c = container_of(dev, struct i2c_client, dev);
	struct rt8973a_muic_info *info = i2c_get_clientdata(i2c);

	enable_irq_wake(info->irq);

	return 0;
}

static int rt8973a_muic_resume(struct device *dev)
{
	struct i2c_client *i2c = container_of(dev, struct i2c_client, dev);
	struct rt8973a_muic_info *info = i2c_get_clientdata(i2c);

	disable_irq_wake(info->irq);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(rt8973a_muic_pm_ops,
			 rt8973a_muic_suspend, rt8973a_muic_resume);

static const struct i2c_device_id rt8973a_i2c_id[] = {
	{ "rt8973a", TYPE_RT8973A },
	{ }
};
MODULE_DEVICE_TABLE(i2c, rt8973a_i2c_id);

static struct i2c_driver rt8973a_muic_i2c_driver = {
	.driver		= {
		.name	= "rt8973a",
		.owner	= THIS_MODULE,
		.pm	= &rt8973a_muic_pm_ops,
		.of_match_table = rt8973a_dt_match,
	},
	.probe	= rt8973a_muic_i2c_probe,
	.remove	= rt8973a_muic_i2c_remove,
	.id_table = rt8973a_i2c_id,
};

static int __init rt8973a_muic_i2c_init(void)
{
	return i2c_add_driver(&rt8973a_muic_i2c_driver);
}
subsys_initcall(rt8973a_muic_i2c_init);

MODULE_DESCRIPTION("Richtek RT8973A Extcon driver");
MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
MODULE_LICENSE("GPL");