drivers/extcon/extcon-max8997.c - kernel/msm-4.9 - Gitiles

 /*
  * extcon-max8997.c - MAX8997 extcon driver to support MAX8997 MUIC
  *
  *  Copyright (C) 2012 Samsung Electronics
  *  Donggeun Kim <dg77.kim@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.
  *
  * 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/kernel.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/kobject.h>
 #include <linux/mfd/max8997.h>
 #include <linux/mfd/max8997-private.h>
 #include <linux/extcon.h>
 #include <linux/irqdomain.h>

 #define	DEV_NAME			"max8997-muic"
 #define	DELAY_MS_DEFAULT		20000		/* unit: millisecond */

 enum max8997_muic_adc_debounce_time {
 	ADC_DEBOUNCE_TIME_0_5MS = 0,	/* 0.5ms */
 	ADC_DEBOUNCE_TIME_10MS,		/* 10ms */
 	ADC_DEBOUNCE_TIME_25MS,		/* 25ms */
 	ADC_DEBOUNCE_TIME_38_62MS,	/* 38.62ms */
 };

 struct max8997_muic_irq {
 	unsigned int irq;
 	const char *name;
 	unsigned int virq;
 };

 static struct max8997_muic_irq muic_irqs[] = {
 	{ MAX8997_MUICIRQ_ADCError,	"muic-ADCERROR" },
 	{ MAX8997_MUICIRQ_ADCLow,	"muic-ADCLOW" },
 	{ MAX8997_MUICIRQ_ADC,		"muic-ADC" },
 	{ MAX8997_MUICIRQ_VBVolt,	"muic-VBVOLT" },
 	{ MAX8997_MUICIRQ_DBChg,	"muic-DBCHG" },
 	{ MAX8997_MUICIRQ_DCDTmr,	"muic-DCDTMR" },
 	{ MAX8997_MUICIRQ_ChgDetRun,	"muic-CHGDETRUN" },
 	{ MAX8997_MUICIRQ_ChgTyp,	"muic-CHGTYP" },
 	{ MAX8997_MUICIRQ_OVP,		"muic-OVP" },
 };

 /* Define supported cable type */
 enum max8997_muic_acc_type {
 	MAX8997_MUIC_ADC_GROUND = 0x0,
 	MAX8997_MUIC_ADC_MHL,			/* MHL*/
 	MAX8997_MUIC_ADC_REMOTE_S1_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S2_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S3_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S4_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S5_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S6_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S7_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S8_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S9_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S10_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S11_BUTTON,
 	MAX8997_MUIC_ADC_REMOTE_S12_BUTTON,
 	MAX8997_MUIC_ADC_RESERVED_ACC_1,
 	MAX8997_MUIC_ADC_RESERVED_ACC_2,
 	MAX8997_MUIC_ADC_RESERVED_ACC_3,
 	MAX8997_MUIC_ADC_RESERVED_ACC_4,
 	MAX8997_MUIC_ADC_RESERVED_ACC_5,
 	MAX8997_MUIC_ADC_CEA936_AUDIO,
 	MAX8997_MUIC_ADC_PHONE_POWERED_DEV,
 	MAX8997_MUIC_ADC_TTY_CONVERTER,
 	MAX8997_MUIC_ADC_UART_CABLE,
 	MAX8997_MUIC_ADC_CEA936A_TYPE1_CHG,
 	MAX8997_MUIC_ADC_FACTORY_MODE_USB_OFF,	/* JIG-USB-OFF */
 	MAX8997_MUIC_ADC_FACTORY_MODE_USB_ON,	/* JIG-USB-ON */
 	MAX8997_MUIC_ADC_AV_CABLE_NOLOAD,	/* DESKDOCK */
 	MAX8997_MUIC_ADC_CEA936A_TYPE2_CHG,
 	MAX8997_MUIC_ADC_FACTORY_MODE_UART_OFF,	/* JIG-UART */
 	MAX8997_MUIC_ADC_FACTORY_MODE_UART_ON,	/* CARDOCK */
 	MAX8997_MUIC_ADC_AUDIO_MODE_REMOTE,
 	MAX8997_MUIC_ADC_OPEN,			/* OPEN */
 };

 enum max8997_muic_cable_group {
 	MAX8997_CABLE_GROUP_ADC = 0,
 	MAX8997_CABLE_GROUP_ADC_GND,
 	MAX8997_CABLE_GROUP_CHG,
 	MAX8997_CABLE_GROUP_VBVOLT,
 };

 enum max8997_muic_usb_type {
 	MAX8997_USB_HOST,
 	MAX8997_USB_DEVICE,
 };

 enum max8997_muic_charger_type {
 	MAX8997_CHARGER_TYPE_NONE = 0,
 	MAX8997_CHARGER_TYPE_USB,
 	MAX8997_CHARGER_TYPE_DOWNSTREAM_PORT,
 	MAX8997_CHARGER_TYPE_DEDICATED_CHG,
 	MAX8997_CHARGER_TYPE_500MA,
 	MAX8997_CHARGER_TYPE_1A,
 	MAX8997_CHARGER_TYPE_DEAD_BATTERY = 7,
 };

 struct max8997_muic_info {
 	struct device *dev;
 	struct i2c_client *muic;
 	struct extcon_dev *edev;
 	int prev_cable_type;
 	int prev_chg_type;
 	u8 status[2];

 	int irq;
 	struct work_struct irq_work;
 	struct mutex mutex;

 	struct max8997_muic_platform_data *muic_pdata;
 	enum max8997_muic_charger_type pre_charger_type;

 	/*
 	 * 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 usb/uart path whether UART/USB or AUX_UART/AUX_USB
 	 * h/w path of COMP2/COMN1 on CONTROL1 register.
 	 */
 	int path_usb;
 	int path_uart;
 };

 static const unsigned int max8997_extcon_cable[] = {
 	EXTCON_USB,
 	EXTCON_USB_HOST,
 	EXTCON_CHG_USB_SDP,
 	EXTCON_CHG_USB_DCP,
 	EXTCON_CHG_USB_FAST,
 	EXTCON_CHG_USB_SLOW,
 	EXTCON_CHG_USB_CDP,
 	EXTCON_DISP_MHL,
 	EXTCON_DOCK,
 	EXTCON_JIG,
 	EXTCON_NONE,
 };

 /*
  * max8997_muic_set_debounce_time - Set the debounce time of ADC
  * @info: the instance including private data of max8997 MUIC
  * @time: the debounce time of ADC
  */
 static int max8997_muic_set_debounce_time(struct max8997_muic_info *info,
 		enum max8997_muic_adc_debounce_time time)
 {
 	int ret;

 	switch (time) {
 	case ADC_DEBOUNCE_TIME_0_5MS:
 	case ADC_DEBOUNCE_TIME_10MS:
 	case ADC_DEBOUNCE_TIME_25MS:
 	case ADC_DEBOUNCE_TIME_38_62MS:
 		ret = max8997_update_reg(info->muic,
 					  MAX8997_MUIC_REG_CONTROL3,
 					  time << CONTROL3_ADCDBSET_SHIFT,
 					  CONTROL3_ADCDBSET_MASK);
 		if (ret) {
 			dev_err(info->dev, "failed to set ADC debounce time\n");
 			return ret;
 		}
 		break;
 	default:
 		dev_err(info->dev, "invalid ADC debounce time\n");
 		return -EINVAL;
 	}

 	return 0;
 };

 /*
  * max8997_muic_set_path - Set hardware line according to attached cable
  * @info: the instance including private data of max8997 MUIC
  * @value: the path according to attached cable
  * @attached: the state of cable (true:attached, false:detached)
  *
  * The max8997 MUIC device share outside H/W line among a varity of cables,
  * so this function set internal path of H/W line according to the type of
  * attached cable.
  */
 static int max8997_muic_set_path(struct max8997_muic_info *info,
 		u8 val, bool attached)
 {
 	int ret = 0;
 	u8 ctrl1, ctrl2 = 0;

 	if (attached)
 		ctrl1 = val;
 	else
 		ctrl1 = CONTROL1_SW_OPEN;

 	ret = max8997_update_reg(info->muic,
 			MAX8997_MUIC_REG_CONTROL1, ctrl1, COMP_SW_MASK);
 	if (ret < 0) {
 		dev_err(info->dev, "failed to update MUIC register\n");
 		return ret;
 	}

 	if (attached)
 		ctrl2 |= CONTROL2_CPEN_MASK;	/* LowPwr=0, CPEn=1 */
 	else
 		ctrl2 |= CONTROL2_LOWPWR_MASK;	/* LowPwr=1, CPEn=0 */

 	ret = max8997_update_reg(info->muic,
 			MAX8997_MUIC_REG_CONTROL2, ctrl2,
 			CONTROL2_LOWPWR_MASK | CONTROL2_CPEN_MASK);
 	if (ret < 0) {
 		dev_err(info->dev, "failed to update MUIC register\n");
 		return ret;
 	}

 	dev_info(info->dev,
 		"CONTROL1 : 0x%02x, CONTROL2 : 0x%02x, state : %s\n",
 		ctrl1, ctrl2, attached ? "attached" : "detached");

 	return 0;
 }

 /*
  * max8997_muic_get_cable_type - Return cable type and check cable state
  * @info: the instance including private data of max8997 MUIC
  * @group: the path according to attached cable
  * @attached: store cable state and return
  *
  * This function check the cable state either attached or detached,
  * and then divide precise type of cable according to cable group.
  *	- MAX8997_CABLE_GROUP_ADC
  *	- MAX8997_CABLE_GROUP_CHG
  */
 static int max8997_muic_get_cable_type(struct max8997_muic_info *info,
 		enum max8997_muic_cable_group group, bool *attached)
 {
 	int cable_type = 0;
 	int adc;
 	int chg_type;

 	switch (group) {
 	case MAX8997_CABLE_GROUP_ADC:
 		/*
 		 * Read ADC value to check cable type and decide cable state
 		 * according to cable type
 		 */
 		adc = info->status[0] & STATUS1_ADC_MASK;
 		adc >>= STATUS1_ADC_SHIFT;

 		/*
 		 * Check current cable state/cable type and store cable type
 		 * (info->prev_cable_type) for handling cable when cable is
 		 * detached.
 		 */
 		if (adc == MAX8997_MUIC_ADC_OPEN) {
 			*attached = false;

 			cable_type = info->prev_cable_type;
 			info->prev_cable_type = MAX8997_MUIC_ADC_OPEN;
 		} else {
 			*attached = true;

 			cable_type = info->prev_cable_type = adc;
 		}
 		break;
 	case MAX8997_CABLE_GROUP_CHG:
 		/*
 		 * Read charger type to check cable type and decide cable state
 		 * according to type of charger cable.
 		 */
 		chg_type = info->status[1] & STATUS2_CHGTYP_MASK;
 		chg_type >>= STATUS2_CHGTYP_SHIFT;

 		if (chg_type == MAX8997_CHARGER_TYPE_NONE) {
 			*attached = false;

 			cable_type = info->prev_chg_type;
 			info->prev_chg_type = MAX8997_CHARGER_TYPE_NONE;
 		} else {
 			*attached = true;

 			/*
 			 * Check current cable state/cable type and store cable
 			 * type(info->prev_chg_type) for handling cable when
 			 * charger cable is detached.
 			 */
 			cable_type = info->prev_chg_type = chg_type;
 		}

 		break;
 	default:
 		dev_err(info->dev, "Unknown cable group (%d)\n", group);
 		cable_type = -EINVAL;
 		break;
 	}

 	return cable_type;
 }

 static int max8997_muic_handle_usb(struct max8997_muic_info *info,
 			enum max8997_muic_usb_type usb_type, bool attached)
 {
 	int ret = 0;

 	ret = max8997_muic_set_path(info, info->path_usb, attached);
 	if (ret < 0) {
 		dev_err(info->dev, "failed to update muic register\n");
 		return ret;
 	}

 	switch (usb_type) {
 	case MAX8997_USB_HOST:
 		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, attached);
 		break;
 	case MAX8997_USB_DEVICE:
 		extcon_set_state_sync(info->edev, EXTCON_USB, attached);
 		extcon_set_state_sync(info->edev, EXTCON_CHG_USB_SDP,
 					attached);
 		break;
 	default:
 		dev_err(info->dev, "failed to detect %s usb cable\n",
 			attached ? "attached" : "detached");
 		return -EINVAL;
 	}

 	return 0;
 }

 static int max8997_muic_handle_dock(struct max8997_muic_info *info,
 			int cable_type, bool attached)
 {
 	int ret = 0;

 	ret = max8997_muic_set_path(info, CONTROL1_SW_AUDIO, attached);
 	if (ret) {
 		dev_err(info->dev, "failed to update muic register\n");
 		return ret;
 	}

 	switch (cable_type) {
 	case MAX8997_MUIC_ADC_AV_CABLE_NOLOAD:
 	case MAX8997_MUIC_ADC_FACTORY_MODE_UART_ON:
 		extcon_set_state_sync(info->edev, EXTCON_DOCK, attached);
 		break;
 	default:
 		dev_err(info->dev, "failed to detect %s dock device\n",
 			attached ? "attached" : "detached");
 		return -EINVAL;
 	}

 	return 0;
 }

 static int max8997_muic_handle_jig_uart(struct max8997_muic_info *info,
 			bool attached)
 {
 	int ret = 0;

 	/* switch to UART */
 	ret = max8997_muic_set_path(info, info->path_uart, attached);
 	if (ret) {
 		dev_err(info->dev, "failed to update muic register\n");
 		return ret;
 	}

 	extcon_set_state_sync(info->edev, EXTCON_JIG, attached);

 	return 0;
 }

 static int max8997_muic_adc_handler(struct max8997_muic_info *info)
 {
 	int cable_type;
 	bool attached;
 	int ret = 0;

 	/* Check cable state which is either detached or attached */
 	cable_type = max8997_muic_get_cable_type(info,
 				MAX8997_CABLE_GROUP_ADC, &attached);

 	switch (cable_type) {
 	case MAX8997_MUIC_ADC_GROUND:
 		ret = max8997_muic_handle_usb(info, MAX8997_USB_HOST, attached);
 		if (ret < 0)
 			return ret;
 		break;
 	case MAX8997_MUIC_ADC_MHL:
 		extcon_set_state_sync(info->edev, EXTCON_DISP_MHL, attached);
 		break;
 	case MAX8997_MUIC_ADC_FACTORY_MODE_USB_OFF:
 	case MAX8997_MUIC_ADC_FACTORY_MODE_USB_ON:
 		ret = max8997_muic_handle_usb(info,
 					     MAX8997_USB_DEVICE, attached);
 		if (ret < 0)
 			return ret;
 		break;
 	case MAX8997_MUIC_ADC_AV_CABLE_NOLOAD:
 	case MAX8997_MUIC_ADC_FACTORY_MODE_UART_ON:
 		ret = max8997_muic_handle_dock(info, cable_type, attached);
 		if (ret < 0)
 			return ret;
 		break;
 	case MAX8997_MUIC_ADC_FACTORY_MODE_UART_OFF:
 		ret = max8997_muic_handle_jig_uart(info, attached);
 		break;
 	case MAX8997_MUIC_ADC_REMOTE_S1_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S2_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S3_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S4_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S5_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S6_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S7_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S8_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S9_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S10_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S11_BUTTON:
 	case MAX8997_MUIC_ADC_REMOTE_S12_BUTTON:
 	case MAX8997_MUIC_ADC_RESERVED_ACC_1:
 	case MAX8997_MUIC_ADC_RESERVED_ACC_2:
 	case MAX8997_MUIC_ADC_RESERVED_ACC_3:
 	case MAX8997_MUIC_ADC_RESERVED_ACC_4:
 	case MAX8997_MUIC_ADC_RESERVED_ACC_5:
 	case MAX8997_MUIC_ADC_CEA936_AUDIO:
 	case MAX8997_MUIC_ADC_PHONE_POWERED_DEV:
 	case MAX8997_MUIC_ADC_TTY_CONVERTER:
 	case MAX8997_MUIC_ADC_UART_CABLE:
 	case MAX8997_MUIC_ADC_CEA936A_TYPE1_CHG:
 	case MAX8997_MUIC_ADC_CEA936A_TYPE2_CHG:
 	case MAX8997_MUIC_ADC_AUDIO_MODE_REMOTE:
 		/*
 		 * This cable isn't used in general case if it is specially
 		 * needed to detect additional cable, should implement
 		 * proper operation when this cable is attached/detached.
 		 */
 		dev_info(info->dev,
 			"cable is %s but it isn't used (type:0x%x)\n",
 			attached ? "attached" : "detached", cable_type);
 		return -EAGAIN;
 	default:
 		dev_err(info->dev,
 			"failed to detect %s unknown cable (type:0x%x)\n",
 			attached ? "attached" : "detached", cable_type);
 		return -EINVAL;
 	}

 	return 0;
 }

 static int max8997_muic_chg_handler(struct max8997_muic_info *info)
 {
 	int chg_type;
 	bool attached;
 	int adc;

 	chg_type = max8997_muic_get_cable_type(info,
 				MAX8997_CABLE_GROUP_CHG, &attached);

 	switch (chg_type) {
 	case MAX8997_CHARGER_TYPE_NONE:
 		break;
 	case MAX8997_CHARGER_TYPE_USB:
 		adc = info->status[0] & STATUS1_ADC_MASK;
 		adc >>= STATUS1_ADC_SHIFT;

 		if ((adc & STATUS1_ADC_MASK) == MAX8997_MUIC_ADC_OPEN) {
 			max8997_muic_handle_usb(info,
 					MAX8997_USB_DEVICE, attached);
 		}
 		break;
 	case MAX8997_CHARGER_TYPE_DOWNSTREAM_PORT:
 		extcon_set_state_sync(info->edev, EXTCON_CHG_USB_CDP,
 					attached);
 		break;
 	case MAX8997_CHARGER_TYPE_DEDICATED_CHG:
 		extcon_set_state_sync(info->edev, EXTCON_CHG_USB_DCP,
 					attached);
 		break;
 	case MAX8997_CHARGER_TYPE_500MA:
 		extcon_set_state_sync(info->edev, EXTCON_CHG_USB_SLOW,
 					attached);
 		break;
 	case MAX8997_CHARGER_TYPE_1A:
 		extcon_set_state_sync(info->edev, EXTCON_CHG_USB_FAST,
 					attached);
 		break;
 	default:
 		dev_err(info->dev,
 			"failed to detect %s unknown chg cable (type:0x%x)\n",
 			attached ? "attached" : "detached", chg_type);
 		return -EINVAL;
 	}

 	return 0;
 }

 static void max8997_muic_irq_work(struct work_struct *work)
 {
 	struct max8997_muic_info *info = container_of(work,
 			struct max8997_muic_info, irq_work);
 	int irq_type = 0;
 	int i, ret;

 	if (!info->edev)
 		return;

 	mutex_lock(&info->mutex);

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

 	ret = max8997_bulk_read(info->muic, MAX8997_MUIC_REG_STATUS1,
 				2, info->status);
 	if (ret) {
 		dev_err(info->dev, "failed to read muic register\n");
 		mutex_unlock(&info->mutex);
 		return;
 	}

 	switch (irq_type) {
 	case MAX8997_MUICIRQ_ADCError:
 	case MAX8997_MUICIRQ_ADCLow:
 	case MAX8997_MUICIRQ_ADC:
 		/* Handle all of cable except for charger cable */
 		ret = max8997_muic_adc_handler(info);
 		break;
 	case MAX8997_MUICIRQ_VBVolt:
 	case MAX8997_MUICIRQ_DBChg:
 	case MAX8997_MUICIRQ_DCDTmr:
 	case MAX8997_MUICIRQ_ChgDetRun:
 	case MAX8997_MUICIRQ_ChgTyp:
 		/* Handle charger cable */
 		ret = max8997_muic_chg_handler(info);
 		break;
 	case MAX8997_MUICIRQ_OVP:
 		break;
 	default:
 		dev_info(info->dev, "misc interrupt: irq %d occurred\n",
 				irq_type);
 		mutex_unlock(&info->mutex);
 		return;
 	}

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

 	mutex_unlock(&info->mutex);
 }

 static irqreturn_t max8997_muic_irq_handler(int irq, void *data)
 {
 	struct max8997_muic_info *info = data;

 	dev_dbg(info->dev, "irq:%d\n", irq);
 	info->irq = irq;

 	schedule_work(&info->irq_work);

 	return IRQ_HANDLED;
 }

 static int max8997_muic_detect_dev(struct max8997_muic_info *info)
 {
 	int ret = 0;
 	int adc;
 	int chg_type;
 	bool attached;

 	mutex_lock(&info->mutex);

 	/* Read STATUSx register to detect accessory */
 	ret = max8997_bulk_read(info->muic,
 			MAX8997_MUIC_REG_STATUS1, 2, info->status);
 	if (ret) {
 		dev_err(info->dev, "failed to read MUIC register\n");
 		mutex_unlock(&info->mutex);
 		return ret;
 	}

 	adc = max8997_muic_get_cable_type(info, MAX8997_CABLE_GROUP_ADC,
 					&attached);
 	if (attached && adc != MAX8997_MUIC_ADC_OPEN) {
 		ret = max8997_muic_adc_handler(info);
 		if (ret < 0) {
 			dev_err(info->dev, "Cannot detect ADC cable\n");
 			mutex_unlock(&info->mutex);
 			return ret;
 		}
 	}

 	chg_type = max8997_muic_get_cable_type(info, MAX8997_CABLE_GROUP_CHG,
 					&attached);
 	if (attached && chg_type != MAX8997_CHARGER_TYPE_NONE) {
 		ret = max8997_muic_chg_handler(info);
 		if (ret < 0) {
 			dev_err(info->dev, "Cannot detect charger cable\n");
 			mutex_unlock(&info->mutex);
 			return ret;
 		}
 	}

 	mutex_unlock(&info->mutex);

 	return 0;
 }

 static void max8997_muic_detect_cable_wq(struct work_struct *work)
 {
 	struct max8997_muic_info *info = container_of(to_delayed_work(work),
 				struct max8997_muic_info, wq_detcable);
 	int ret;

 	ret = max8997_muic_detect_dev(info);
 	if (ret < 0)
 		dev_err(info->dev, "failed to detect cable type\n");
 }

 static int max8997_muic_probe(struct platform_device *pdev)
 {
 	struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent);
 	struct max8997_platform_data *pdata = dev_get_platdata(max8997->dev);
 	struct max8997_muic_info *info;
 	int delay_jiffies;
 	int ret, i;

 	info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_muic_info),
 			    GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;

 	info->dev = &pdev->dev;
 	info->muic = max8997->muic;

 	platform_set_drvdata(pdev, info);
 	mutex_init(&info->mutex);

 	INIT_WORK(&info->irq_work, max8997_muic_irq_work);

 	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
 		struct max8997_muic_irq *muic_irq = &muic_irqs[i];
 		unsigned int virq = 0;

 		virq = irq_create_mapping(max8997->irq_domain, muic_irq->irq);
 		if (!virq) {
 			ret = -EINVAL;
 			goto err_irq;
 		}
 		muic_irq->virq = virq;

 		ret = request_threaded_irq(virq, NULL,
 				max8997_muic_irq_handler,
 				IRQF_NO_SUSPEND,
 				muic_irq->name, info);
 		if (ret) {
 			dev_err(&pdev->dev,
 				"failed: irq request (IRQ: %d, error :%d)\n",
 				muic_irq->irq, ret);
 			goto err_irq;
 		}
 	}

 	/* External connector */
 	info->edev = devm_extcon_dev_allocate(&pdev->dev, max8997_extcon_cable);
 	if (IS_ERR(info->edev)) {
 		dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
 		ret = -ENOMEM;
 		goto err_irq;
 	}

 	ret = devm_extcon_dev_register(&pdev->dev, info->edev);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register extcon device\n");
 		goto err_irq;
 	}

 	if (pdata && pdata->muic_pdata) {
 		struct max8997_muic_platform_data *muic_pdata
 			= pdata->muic_pdata;

 		/* Initialize registers according to platform data */
 		for (i = 0; i < muic_pdata->num_init_data; i++) {
 			max8997_write_reg(info->muic,
 					muic_pdata->init_data[i].addr,
 					muic_pdata->init_data[i].data);
 		}

 		/*
 		 * Default usb/uart path whether UART/USB or AUX_UART/AUX_USB
 		 * h/w path of COMP2/COMN1 on CONTROL1 register.
 		 */
 		if (muic_pdata->path_uart)
 			info->path_uart = muic_pdata->path_uart;
 		else
 			info->path_uart = CONTROL1_SW_UART;

 		if (muic_pdata->path_usb)
 			info->path_usb = muic_pdata->path_usb;
 		else
 			info->path_usb = CONTROL1_SW_USB;

 		/*
 		 * Default delay time for detecting cable state
 		 * after certain time.
 		 */
 		if (muic_pdata->detcable_delay_ms)
 			delay_jiffies =
 				msecs_to_jiffies(muic_pdata->detcable_delay_ms);
 		else
 			delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
 	} else {
 		info->path_uart = CONTROL1_SW_UART;
 		info->path_usb = CONTROL1_SW_USB;
 		delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
 	}

 	/* Set initial path for UART */
 	 max8997_muic_set_path(info, info->path_uart, true);

 	/* Set ADC debounce time */
 	max8997_muic_set_debounce_time(info, ADC_DEBOUNCE_TIME_25MS);

 	/*
 	 * 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, max8997_muic_detect_cable_wq);
 	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
 			delay_jiffies);

 	return 0;

 err_irq:
 	while (--i >= 0)
 		free_irq(muic_irqs[i].virq, info);
 	return ret;
 }

 static int max8997_muic_remove(struct platform_device *pdev)
 {
 	struct max8997_muic_info *info = platform_get_drvdata(pdev);
 	int i;

 	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++)
 		free_irq(muic_irqs[i].virq, info);
 	cancel_work_sync(&info->irq_work);

 	return 0;
 }

 static struct platform_driver max8997_muic_driver = {
 	.driver		= {
 		.name	= DEV_NAME,
 	},
 	.probe		= max8997_muic_probe,
 	.remove		= max8997_muic_remove,
 };

 module_platform_driver(max8997_muic_driver);

 MODULE_DESCRIPTION("Maxim MAX8997 Extcon driver");
 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 MODULE_LICENSE("GPL");
	/*
	* extcon-max8997.c - MAX8997 extcon driver to support MAX8997 MUIC
	*
	* Copyright (C) 2012 Samsung Electronics
	* Donggeun Kim <dg77.kim@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.
	*
	* 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/kernel.h>
	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/slab.h>
	#include <linux/interrupt.h>
	#include <linux/err.h>
	#include <linux/platform_device.h>
	#include <linux/kobject.h>
	#include <linux/mfd/max8997.h>
	#include <linux/mfd/max8997-private.h>
	#include <linux/extcon.h>
	#include <linux/irqdomain.h>

	#define DEV_NAME "max8997-muic"
	#define DELAY_MS_DEFAULT 20000 /* unit: millisecond */

	enum max8997_muic_adc_debounce_time {
	ADC_DEBOUNCE_TIME_0_5MS = 0, /* 0.5ms */
	ADC_DEBOUNCE_TIME_10MS, /* 10ms */
	ADC_DEBOUNCE_TIME_25MS, /* 25ms */
	ADC_DEBOUNCE_TIME_38_62MS, /* 38.62ms */
	};

	struct max8997_muic_irq {
	unsigned int irq;
	const char *name;
	unsigned int virq;
	};

	static struct max8997_muic_irq muic_irqs[] = {
	{ MAX8997_MUICIRQ_ADCError, "muic-ADCERROR" },
	{ MAX8997_MUICIRQ_ADCLow, "muic-ADCLOW" },
	{ MAX8997_MUICIRQ_ADC, "muic-ADC" },
	{ MAX8997_MUICIRQ_VBVolt, "muic-VBVOLT" },
	{ MAX8997_MUICIRQ_DBChg, "muic-DBCHG" },
	{ MAX8997_MUICIRQ_DCDTmr, "muic-DCDTMR" },
	{ MAX8997_MUICIRQ_ChgDetRun, "muic-CHGDETRUN" },
	{ MAX8997_MUICIRQ_ChgTyp, "muic-CHGTYP" },
	{ MAX8997_MUICIRQ_OVP, "muic-OVP" },
	};

	/* Define supported cable type */
	enum max8997_muic_acc_type {
	MAX8997_MUIC_ADC_GROUND = 0x0,
	MAX8997_MUIC_ADC_MHL, /* MHL*/
	MAX8997_MUIC_ADC_REMOTE_S1_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S2_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S3_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S4_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S5_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S6_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S7_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S8_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S9_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S10_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S11_BUTTON,
	MAX8997_MUIC_ADC_REMOTE_S12_BUTTON,
	MAX8997_MUIC_ADC_RESERVED_ACC_1,
	MAX8997_MUIC_ADC_RESERVED_ACC_2,
	MAX8997_MUIC_ADC_RESERVED_ACC_3,
	MAX8997_MUIC_ADC_RESERVED_ACC_4,
	MAX8997_MUIC_ADC_RESERVED_ACC_5,
	MAX8997_MUIC_ADC_CEA936_AUDIO,
	MAX8997_MUIC_ADC_PHONE_POWERED_DEV,
	MAX8997_MUIC_ADC_TTY_CONVERTER,
	MAX8997_MUIC_ADC_UART_CABLE,
	MAX8997_MUIC_ADC_CEA936A_TYPE1_CHG,
	MAX8997_MUIC_ADC_FACTORY_MODE_USB_OFF, /* JIG-USB-OFF */
	MAX8997_MUIC_ADC_FACTORY_MODE_USB_ON, /* JIG-USB-ON */
	MAX8997_MUIC_ADC_AV_CABLE_NOLOAD, /* DESKDOCK */
	MAX8997_MUIC_ADC_CEA936A_TYPE2_CHG,
	MAX8997_MUIC_ADC_FACTORY_MODE_UART_OFF, /* JIG-UART */
	MAX8997_MUIC_ADC_FACTORY_MODE_UART_ON, /* CARDOCK */
	MAX8997_MUIC_ADC_AUDIO_MODE_REMOTE,
	MAX8997_MUIC_ADC_OPEN, /* OPEN */
	};

	enum max8997_muic_cable_group {
	MAX8997_CABLE_GROUP_ADC = 0,
	MAX8997_CABLE_GROUP_ADC_GND,
	MAX8997_CABLE_GROUP_CHG,
	MAX8997_CABLE_GROUP_VBVOLT,
	};

	enum max8997_muic_usb_type {
	MAX8997_USB_HOST,
	MAX8997_USB_DEVICE,
	};

	enum max8997_muic_charger_type {
	MAX8997_CHARGER_TYPE_NONE = 0,
	MAX8997_CHARGER_TYPE_USB,
	MAX8997_CHARGER_TYPE_DOWNSTREAM_PORT,
	MAX8997_CHARGER_TYPE_DEDICATED_CHG,
	MAX8997_CHARGER_TYPE_500MA,
	MAX8997_CHARGER_TYPE_1A,
	MAX8997_CHARGER_TYPE_DEAD_BATTERY = 7,
	};

	struct max8997_muic_info {
	struct device *dev;
	struct i2c_client *muic;
	struct extcon_dev *edev;
	int prev_cable_type;
	int prev_chg_type;
	u8 status[2];

	int irq;
	struct work_struct irq_work;
	struct mutex mutex;

	struct max8997_muic_platform_data *muic_pdata;
	enum max8997_muic_charger_type pre_charger_type;

	/*
	* 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 usb/uart path whether UART/USB or AUX_UART/AUX_USB
	* h/w path of COMP2/COMN1 on CONTROL1 register.
	*/
	int path_usb;
	int path_uart;
	};

	static const unsigned int max8997_extcon_cable[] = {
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_CHG_USB_SDP,
	EXTCON_CHG_USB_DCP,
	EXTCON_CHG_USB_FAST,
	EXTCON_CHG_USB_SLOW,
	EXTCON_CHG_USB_CDP,
	EXTCON_DISP_MHL,
	EXTCON_DOCK,
	EXTCON_JIG,
	EXTCON_NONE,
	};

	/*
	* max8997_muic_set_debounce_time - Set the debounce time of ADC
	* @info: the instance including private data of max8997 MUIC
	* @time: the debounce time of ADC
	*/
	static int max8997_muic_set_debounce_time(struct max8997_muic_info *info,
	enum max8997_muic_adc_debounce_time time)
	{
	int ret;

	switch (time) {
	case ADC_DEBOUNCE_TIME_0_5MS:
	case ADC_DEBOUNCE_TIME_10MS:
	case ADC_DEBOUNCE_TIME_25MS:
	case ADC_DEBOUNCE_TIME_38_62MS:
	ret = max8997_update_reg(info->muic,
	MAX8997_MUIC_REG_CONTROL3,
	time << CONTROL3_ADCDBSET_SHIFT,
	CONTROL3_ADCDBSET_MASK);
	if (ret) {
	dev_err(info->dev, "failed to set ADC debounce time\n");
	return ret;
	}
	break;
	default:
	dev_err(info->dev, "invalid ADC debounce time\n");
	return -EINVAL;
	}

	return 0;
	};

	/*
	* max8997_muic_set_path - Set hardware line according to attached cable
	* @info: the instance including private data of max8997 MUIC
	* @value: the path according to attached cable
	* @attached: the state of cable (true:attached, false:detached)
	*
	* The max8997 MUIC device share outside H/W line among a varity of cables,
	* so this function set internal path of H/W line according to the type of
	* attached cable.
	*/
	static int max8997_muic_set_path(struct max8997_muic_info *info,
	u8 val, bool attached)
	{
	int ret = 0;
	u8 ctrl1, ctrl2 = 0;

	if (attached)
	ctrl1 = val;
	else
	ctrl1 = CONTROL1_SW_OPEN;

	ret = max8997_update_reg(info->muic,
	MAX8997_MUIC_REG_CONTROL1, ctrl1, COMP_SW_MASK);
	if (ret < 0) {
	dev_err(info->dev, "failed to update MUIC register\n");
	return ret;
	}

	if (attached)
	ctrl2 \|= CONTROL2_CPEN_MASK; /* LowPwr=0, CPEn=1 */
	else
	ctrl2 \|= CONTROL2_LOWPWR_MASK; /* LowPwr=1, CPEn=0 */

	ret = max8997_update_reg(info->muic,
	MAX8997_MUIC_REG_CONTROL2, ctrl2,
	CONTROL2_LOWPWR_MASK \| CONTROL2_CPEN_MASK);
	if (ret < 0) {
	dev_err(info->dev, "failed to update MUIC register\n");
	return ret;
	}

	dev_info(info->dev,
	"CONTROL1 : 0x%02x, CONTROL2 : 0x%02x, state : %s\n",
	ctrl1, ctrl2, attached ? "attached" : "detached");

	return 0;
	}

	/*
	* max8997_muic_get_cable_type - Return cable type and check cable state
	* @info: the instance including private data of max8997 MUIC
	* @group: the path according to attached cable
	* @attached: store cable state and return
	*
	* This function check the cable state either attached or detached,
	* and then divide precise type of cable according to cable group.
	* - MAX8997_CABLE_GROUP_ADC
	* - MAX8997_CABLE_GROUP_CHG
	*/
	static int max8997_muic_get_cable_type(struct max8997_muic_info *info,
	enum max8997_muic_cable_group group, bool *attached)
	{
	int cable_type = 0;
	int adc;
	int chg_type;

	switch (group) {
	case MAX8997_CABLE_GROUP_ADC:
	/*
	* Read ADC value to check cable type and decide cable state
	* according to cable type
	*/
	adc = info->status[0] & STATUS1_ADC_MASK;
	adc >>= STATUS1_ADC_SHIFT;

	/*
	* Check current cable state/cable type and store cable type
	* (info->prev_cable_type) for handling cable when cable is
	* detached.
	*/
	if (adc == MAX8997_MUIC_ADC_OPEN) {
	*attached = false;

	cable_type = info->prev_cable_type;
	info->prev_cable_type = MAX8997_MUIC_ADC_OPEN;
	} else {
	*attached = true;

	cable_type = info->prev_cable_type = adc;
	}
	break;
	case MAX8997_CABLE_GROUP_CHG:
	/*
	* Read charger type to check cable type and decide cable state
	* according to type of charger cable.
	*/
	chg_type = info->status[1] & STATUS2_CHGTYP_MASK;
	chg_type >>= STATUS2_CHGTYP_SHIFT;

	if (chg_type == MAX8997_CHARGER_TYPE_NONE) {
	*attached = false;

	cable_type = info->prev_chg_type;
	info->prev_chg_type = MAX8997_CHARGER_TYPE_NONE;
	} else {
	*attached = true;

	/*
	* Check current cable state/cable type and store cable
	* type(info->prev_chg_type) for handling cable when
	* charger cable is detached.
	*/
	cable_type = info->prev_chg_type = chg_type;
	}

	break;
	default:
	dev_err(info->dev, "Unknown cable group (%d)\n", group);
	cable_type = -EINVAL;
	break;
	}

	return cable_type;
	}

	static int max8997_muic_handle_usb(struct max8997_muic_info *info,
	enum max8997_muic_usb_type usb_type, bool attached)
	{
	int ret = 0;

	ret = max8997_muic_set_path(info, info->path_usb, attached);
	if (ret < 0) {
	dev_err(info->dev, "failed to update muic register\n");
	return ret;
	}

	switch (usb_type) {
	case MAX8997_USB_HOST:
	extcon_set_state_sync(info->edev, EXTCON_USB_HOST, attached);
	break;
	case MAX8997_USB_DEVICE:
	extcon_set_state_sync(info->edev, EXTCON_USB, attached);
	extcon_set_state_sync(info->edev, EXTCON_CHG_USB_SDP,
	attached);
	break;
	default:
	dev_err(info->dev, "failed to detect %s usb cable\n",
	attached ? "attached" : "detached");
	return -EINVAL;
	}

	return 0;
	}

	static int max8997_muic_handle_dock(struct max8997_muic_info *info,
	int cable_type, bool attached)
	{
	int ret = 0;

	ret = max8997_muic_set_path(info, CONTROL1_SW_AUDIO, attached);
	if (ret) {
	dev_err(info->dev, "failed to update muic register\n");
	return ret;
	}

	switch (cable_type) {
	case MAX8997_MUIC_ADC_AV_CABLE_NOLOAD:
	case MAX8997_MUIC_ADC_FACTORY_MODE_UART_ON:
	extcon_set_state_sync(info->edev, EXTCON_DOCK, attached);
	break;
	default:
	dev_err(info->dev, "failed to detect %s dock device\n",
	attached ? "attached" : "detached");
	return -EINVAL;
	}

	return 0;
	}

	static int max8997_muic_handle_jig_uart(struct max8997_muic_info *info,
	bool attached)
	{
	int ret = 0;

	/* switch to UART */
	ret = max8997_muic_set_path(info, info->path_uart, attached);
	if (ret) {
	dev_err(info->dev, "failed to update muic register\n");
	return ret;
	}

	extcon_set_state_sync(info->edev, EXTCON_JIG, attached);

	return 0;
	}

	static int max8997_muic_adc_handler(struct max8997_muic_info *info)
	{
	int cable_type;
	bool attached;
	int ret = 0;

	/* Check cable state which is either detached or attached */
	cable_type = max8997_muic_get_cable_type(info,
	MAX8997_CABLE_GROUP_ADC, &attached);

	switch (cable_type) {
	case MAX8997_MUIC_ADC_GROUND:
	ret = max8997_muic_handle_usb(info, MAX8997_USB_HOST, attached);
	if (ret < 0)
	return ret;
	break;
	case MAX8997_MUIC_ADC_MHL:
	extcon_set_state_sync(info->edev, EXTCON_DISP_MHL, attached);
	break;
	case MAX8997_MUIC_ADC_FACTORY_MODE_USB_OFF:
	case MAX8997_MUIC_ADC_FACTORY_MODE_USB_ON:
	ret = max8997_muic_handle_usb(info,
	MAX8997_USB_DEVICE, attached);
	if (ret < 0)
	return ret;
	break;
	case MAX8997_MUIC_ADC_AV_CABLE_NOLOAD:
	case MAX8997_MUIC_ADC_FACTORY_MODE_UART_ON:
	ret = max8997_muic_handle_dock(info, cable_type, attached);
	if (ret < 0)
	return ret;
	break;
	case MAX8997_MUIC_ADC_FACTORY_MODE_UART_OFF:
	ret = max8997_muic_handle_jig_uart(info, attached);
	break;
	case MAX8997_MUIC_ADC_REMOTE_S1_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S2_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S3_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S4_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S5_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S6_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S7_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S8_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S9_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S10_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S11_BUTTON:
	case MAX8997_MUIC_ADC_REMOTE_S12_BUTTON:
	case MAX8997_MUIC_ADC_RESERVED_ACC_1:
	case MAX8997_MUIC_ADC_RESERVED_ACC_2:
	case MAX8997_MUIC_ADC_RESERVED_ACC_3:
	case MAX8997_MUIC_ADC_RESERVED_ACC_4:
	case MAX8997_MUIC_ADC_RESERVED_ACC_5:
	case MAX8997_MUIC_ADC_CEA936_AUDIO:
	case MAX8997_MUIC_ADC_PHONE_POWERED_DEV:
	case MAX8997_MUIC_ADC_TTY_CONVERTER:
	case MAX8997_MUIC_ADC_UART_CABLE:
	case MAX8997_MUIC_ADC_CEA936A_TYPE1_CHG:
	case MAX8997_MUIC_ADC_CEA936A_TYPE2_CHG:
	case MAX8997_MUIC_ADC_AUDIO_MODE_REMOTE:
	/*
	* This cable isn't used in general case if it is specially
	* needed to detect additional cable, should implement
	* proper operation when this cable is attached/detached.
	*/
	dev_info(info->dev,
	"cable is %s but it isn't used (type:0x%x)\n",
	attached ? "attached" : "detached", cable_type);
	return -EAGAIN;
	default:
	dev_err(info->dev,
	"failed to detect %s unknown cable (type:0x%x)\n",
	attached ? "attached" : "detached", cable_type);
	return -EINVAL;
	}

	return 0;
	}

	static int max8997_muic_chg_handler(struct max8997_muic_info *info)
	{
	int chg_type;
	bool attached;
	int adc;

	chg_type = max8997_muic_get_cable_type(info,
	MAX8997_CABLE_GROUP_CHG, &attached);

	switch (chg_type) {
	case MAX8997_CHARGER_TYPE_NONE:
	break;
	case MAX8997_CHARGER_TYPE_USB:
	adc = info->status[0] & STATUS1_ADC_MASK;
	adc >>= STATUS1_ADC_SHIFT;

	if ((adc & STATUS1_ADC_MASK) == MAX8997_MUIC_ADC_OPEN) {
	max8997_muic_handle_usb(info,
	MAX8997_USB_DEVICE, attached);
	}
	break;
	case MAX8997_CHARGER_TYPE_DOWNSTREAM_PORT:
	extcon_set_state_sync(info->edev, EXTCON_CHG_USB_CDP,
	attached);
	break;
	case MAX8997_CHARGER_TYPE_DEDICATED_CHG:
	extcon_set_state_sync(info->edev, EXTCON_CHG_USB_DCP,
	attached);
	break;
	case MAX8997_CHARGER_TYPE_500MA:
	extcon_set_state_sync(info->edev, EXTCON_CHG_USB_SLOW,
	attached);
	break;
	case MAX8997_CHARGER_TYPE_1A:
	extcon_set_state_sync(info->edev, EXTCON_CHG_USB_FAST,
	attached);
	break;
	default:
	dev_err(info->dev,
	"failed to detect %s unknown chg cable (type:0x%x)\n",
	attached ? "attached" : "detached", chg_type);
	return -EINVAL;
	}

	return 0;
	}

	static void max8997_muic_irq_work(struct work_struct *work)
	{
	struct max8997_muic_info *info = container_of(work,
	struct max8997_muic_info, irq_work);
	int irq_type = 0;
	int i, ret;

	if (!info->edev)
	return;

	mutex_lock(&info->mutex);

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

	ret = max8997_bulk_read(info->muic, MAX8997_MUIC_REG_STATUS1,
	2, info->status);
	if (ret) {
	dev_err(info->dev, "failed to read muic register\n");
	mutex_unlock(&info->mutex);
	return;
	}

	switch (irq_type) {
	case MAX8997_MUICIRQ_ADCError:
	case MAX8997_MUICIRQ_ADCLow:
	case MAX8997_MUICIRQ_ADC:
	/* Handle all of cable except for charger cable */
	ret = max8997_muic_adc_handler(info);
	break;
	case MAX8997_MUICIRQ_VBVolt:
	case MAX8997_MUICIRQ_DBChg:
	case MAX8997_MUICIRQ_DCDTmr:
	case MAX8997_MUICIRQ_ChgDetRun:
	case MAX8997_MUICIRQ_ChgTyp:
	/* Handle charger cable */
	ret = max8997_muic_chg_handler(info);
	break;
	case MAX8997_MUICIRQ_OVP:
	break;
	default:
	dev_info(info->dev, "misc interrupt: irq %d occurred\n",
	irq_type);
	mutex_unlock(&info->mutex);
	return;
	}

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

	mutex_unlock(&info->mutex);
	}

	static irqreturn_t max8997_muic_irq_handler(int irq, void *data)
	{
	struct max8997_muic_info *info = data;

	dev_dbg(info->dev, "irq:%d\n", irq);
	info->irq = irq;

	schedule_work(&info->irq_work);

	return IRQ_HANDLED;
	}

	static int max8997_muic_detect_dev(struct max8997_muic_info *info)
	{
	int ret = 0;
	int adc;
	int chg_type;
	bool attached;

	mutex_lock(&info->mutex);

	/* Read STATUSx register to detect accessory */
	ret = max8997_bulk_read(info->muic,
	MAX8997_MUIC_REG_STATUS1, 2, info->status);
	if (ret) {
	dev_err(info->dev, "failed to read MUIC register\n");
	mutex_unlock(&info->mutex);
	return ret;
	}

	adc = max8997_muic_get_cable_type(info, MAX8997_CABLE_GROUP_ADC,
	&attached);
	if (attached && adc != MAX8997_MUIC_ADC_OPEN) {
	ret = max8997_muic_adc_handler(info);
	if (ret < 0) {
	dev_err(info->dev, "Cannot detect ADC cable\n");
	mutex_unlock(&info->mutex);
	return ret;
	}
	}

	chg_type = max8997_muic_get_cable_type(info, MAX8997_CABLE_GROUP_CHG,
	&attached);
	if (attached && chg_type != MAX8997_CHARGER_TYPE_NONE) {
	ret = max8997_muic_chg_handler(info);
	if (ret < 0) {
	dev_err(info->dev, "Cannot detect charger cable\n");
	mutex_unlock(&info->mutex);
	return ret;
	}
	}

	mutex_unlock(&info->mutex);

	return 0;
	}

	static void max8997_muic_detect_cable_wq(struct work_struct *work)
	{
	struct max8997_muic_info *info = container_of(to_delayed_work(work),
	struct max8997_muic_info, wq_detcable);
	int ret;

	ret = max8997_muic_detect_dev(info);
	if (ret < 0)
	dev_err(info->dev, "failed to detect cable type\n");
	}

	static int max8997_muic_probe(struct platform_device *pdev)
	{
	struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent);
	struct max8997_platform_data *pdata = dev_get_platdata(max8997->dev);
	struct max8997_muic_info *info;
	int delay_jiffies;
	int ret, i;

	info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_muic_info),
	GFP_KERNEL);
	if (!info)
	return -ENOMEM;

	info->dev = &pdev->dev;
	info->muic = max8997->muic;

	platform_set_drvdata(pdev, info);
	mutex_init(&info->mutex);

	INIT_WORK(&info->irq_work, max8997_muic_irq_work);

	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
	struct max8997_muic_irq *muic_irq = &muic_irqs[i];
	unsigned int virq = 0;

	virq = irq_create_mapping(max8997->irq_domain, muic_irq->irq);
	if (!virq) {
	ret = -EINVAL;
	goto err_irq;
	}
	muic_irq->virq = virq;

	ret = request_threaded_irq(virq, NULL,
	max8997_muic_irq_handler,
	IRQF_NO_SUSPEND,
	muic_irq->name, info);
	if (ret) {
	dev_err(&pdev->dev,
	"failed: irq request (IRQ: %d, error :%d)\n",
	muic_irq->irq, ret);
	goto err_irq;
	}
	}

	/* External connector */
	info->edev = devm_extcon_dev_allocate(&pdev->dev, max8997_extcon_cable);
	if (IS_ERR(info->edev)) {
	dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
	ret = -ENOMEM;
	goto err_irq;
	}

	ret = devm_extcon_dev_register(&pdev->dev, info->edev);
	if (ret) {
	dev_err(&pdev->dev, "failed to register extcon device\n");
	goto err_irq;
	}

	if (pdata && pdata->muic_pdata) {
	struct max8997_muic_platform_data *muic_pdata
	= pdata->muic_pdata;

	/* Initialize registers according to platform data */
	for (i = 0; i < muic_pdata->num_init_data; i++) {
	max8997_write_reg(info->muic,
	muic_pdata->init_data[i].addr,
	muic_pdata->init_data[i].data);
	}

	/*
	* Default usb/uart path whether UART/USB or AUX_UART/AUX_USB
	* h/w path of COMP2/COMN1 on CONTROL1 register.
	*/
	if (muic_pdata->path_uart)
	info->path_uart = muic_pdata->path_uart;
	else
	info->path_uart = CONTROL1_SW_UART;

	if (muic_pdata->path_usb)
	info->path_usb = muic_pdata->path_usb;
	else
	info->path_usb = CONTROL1_SW_USB;

	/*
	* Default delay time for detecting cable state
	* after certain time.
	*/
	if (muic_pdata->detcable_delay_ms)
	delay_jiffies =
	msecs_to_jiffies(muic_pdata->detcable_delay_ms);
	else
	delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
	} else {
	info->path_uart = CONTROL1_SW_UART;
	info->path_usb = CONTROL1_SW_USB;
	delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);
	}

	/* Set initial path for UART */
	max8997_muic_set_path(info, info->path_uart, true);

	/* Set ADC debounce time */
	max8997_muic_set_debounce_time(info, ADC_DEBOUNCE_TIME_25MS);

	/*
	* 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, max8997_muic_detect_cable_wq);
	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
	delay_jiffies);

	return 0;

	err_irq:
	while (--i >= 0)
	free_irq(muic_irqs[i].virq, info);
	return ret;
	}

	static int max8997_muic_remove(struct platform_device *pdev)
	{
	struct max8997_muic_info *info = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++)
	free_irq(muic_irqs[i].virq, info);
	cancel_work_sync(&info->irq_work);

	return 0;
	}

	static struct platform_driver max8997_muic_driver = {
	.driver = {
	.name = DEV_NAME,
	},
	.probe = max8997_muic_probe,
	.remove = max8997_muic_remove,
	};

	module_platform_driver(max8997_muic_driver);

	MODULE_DESCRIPTION("Maxim MAX8997 Extcon driver");
	MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
	MODULE_LICENSE("GPL");