/*
   * 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 */
  static const unsigned int rt8973a_extcon_cable[] = {
  	EXTCON_USB,
  	EXTCON_USB_HOST,
  	EXTCON_CHG_USB_DCP,
  	EXTCON_JIG,
  	EXTCON_NONE,
  };
  
  /* 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
  ");
  			return ret;
  		}
  		break;
  	default:
  		dev_err(info->dev, "Unknown DM_CON/DP_CON switch type (%d)
  ",
  				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
  ");
  		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
  ");
  		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;
  	unsigned int con_sw = DM_DP_SWITCH_UART;
  	int ret, cable_type;
  	unsigned int id;
  	bool attached = false;
  
  	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
  ",
  			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)
  ", event);
  		return -EINVAL;
  	}
  	prev_cable_type = cable_type;
  
  	switch (cable_type) {
  	case RT8973A_MUIC_ADC_OTG:
  		id = EXTCON_USB_HOST;
  		con_sw = DM_DP_SWITCH_USB;
  		break;
  	case RT8973A_MUIC_ADC_TA:
  		id = EXTCON_CHG_USB_DCP;
  		con_sw = DM_DP_SWITCH_OPEN;
  		break;
  	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_OFF_USB:
  	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_ON_USB:
  		id = EXTCON_JIG;
  		con_sw = DM_DP_SWITCH_USB;
  		break;
  	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_OFF_UART:
  	case RT8973A_MUIC_ADC_FACTORY_MODE_BOOT_ON_UART:
  		id = EXTCON_JIG;
  		con_sw = DM_DP_SWITCH_UART;
  		break;
  	case RT8973A_MUIC_ADC_USB:
  		id = EXTCON_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)
  ", 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)
  ", 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)
  ",
  			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, id, 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
  ");
  
  	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)
  ", 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
  ");
  }
  
  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
  ", 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
  ",
  			    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
  ", 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
  ");
  	}
  }
  
  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)
  		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
  ",
  				   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)
  ",
  				    info->irq, ret);
  		return ret;
  	}
  
  	for (i = 0; i < info->num_muic_irqs; i++) {
  		struct muic_irq *muic_irq = &info->muic_irqs[i];
  		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)
  ",
  				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
  ");
  		return -ENOMEM;
  	}
  
  	/* Register extcon device */
  	ret = devm_extcon_dev_register(info->dev, info->edev);
  	if (ret) {
  		dev_err(info->dev, "failed to register extcon device
  ");
  		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 const struct of_device_id rt8973a_dt_match[] = {
  	{ .compatible = "richtek,rt8973a-muic" },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, rt8973a_dt_match);
  
  #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",
  		.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");