PM / sleep: Asynchronous threads for suspend_noirq

[linux/fpc-iii.git] / drivers / extcon / extcon-max14577.c

/*
 * extcon-max14577.c - MAX14577 extcon driver to support MAX14577 MUIC
 *
 * Copyright (C) 2013 Samsung Electrnoics
 * 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.
 *
 * 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/interrupt.h>
#include <linux/platform_device.h>
#include <linux/mfd/max14577.h>
#include <linux/mfd/max14577-private.h>
#include <linux/extcon.h>

#define DEV_NAME                        "max14577-muic"
#define DELAY_MS_DEFAULT                17000           /* unit: millisecond */

enum max14577_muic_adc_debounce_time {
        ADC_DEBOUNCE_TIME_5MS = 0,
        ADC_DEBOUNCE_TIME_10MS,
        ADC_DEBOUNCE_TIME_25MS,
        ADC_DEBOUNCE_TIME_38_62MS,
};

enum max14577_muic_status {
        MAX14577_MUIC_STATUS1 = 0,
        MAX14577_MUIC_STATUS2 = 1,
        MAX14577_MUIC_STATUS_END,
};

struct max14577_muic_info {
        struct device *dev;
        struct max14577 *max14577;
        struct extcon_dev *edev;
        int prev_cable_type;
        int prev_chg_type;
        u8 status[MAX14577_MUIC_STATUS_END];

        bool irq_adc;
        bool irq_chg;
        struct work_struct irq_work;
        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 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;
};

enum max14577_muic_cable_group {
        MAX14577_CABLE_GROUP_ADC = 0,
        MAX14577_CABLE_GROUP_CHG,
};

/**
 * struct max14577_muic_irq
 * @irq: the index of irq list of MUIC device.
 * @name: the name of irq.
 * @virq: the virtual irq to use irq domain
 */
struct max14577_muic_irq {
        unsigned int irq;
        const char *name;
        unsigned int virq;
};

static struct max14577_muic_irq muic_irqs[] = {
        { MAX14577_IRQ_INT1_ADC,        "muic-ADC" },
        { MAX14577_IRQ_INT1_ADCLOW,     "muic-ADCLOW" },
        { MAX14577_IRQ_INT1_ADCERR,     "muic-ADCError" },
        { MAX14577_IRQ_INT2_CHGTYP,     "muic-CHGTYP" },
        { MAX14577_IRQ_INT2_CHGDETRUN,  "muic-CHGDETRUN" },
        { MAX14577_IRQ_INT2_DCDTMR,     "muic-DCDTMR" },
        { MAX14577_IRQ_INT2_DBCHG,      "muic-DBCHG" },
        { MAX14577_IRQ_INT2_VBVOLT,     "muic-VBVOLT" },
};

/* Define supported accessory type */
enum max14577_muic_acc_type {
        MAX14577_MUIC_ADC_GROUND = 0x0,
        MAX14577_MUIC_ADC_SEND_END_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S1_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S2_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S3_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S4_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S5_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S6_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S7_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S8_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S9_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S10_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S11_BUTTON,
        MAX14577_MUIC_ADC_REMOTE_S12_BUTTON,
        MAX14577_MUIC_ADC_RESERVED_ACC_1,
        MAX14577_MUIC_ADC_RESERVED_ACC_2,
        MAX14577_MUIC_ADC_RESERVED_ACC_3,
        MAX14577_MUIC_ADC_RESERVED_ACC_4,
        MAX14577_MUIC_ADC_RESERVED_ACC_5,
        MAX14577_MUIC_ADC_AUDIO_DEVICE_TYPE2,
        MAX14577_MUIC_ADC_PHONE_POWERED_DEV,
        MAX14577_MUIC_ADC_TTY_CONVERTER,
        MAX14577_MUIC_ADC_UART_CABLE,
        MAX14577_MUIC_ADC_CEA936A_TYPE1_CHG,
        MAX14577_MUIC_ADC_FACTORY_MODE_USB_OFF,
        MAX14577_MUIC_ADC_FACTORY_MODE_USB_ON,
        MAX14577_MUIC_ADC_AV_CABLE_NOLOAD,
        MAX14577_MUIC_ADC_CEA936A_TYPE2_CHG,
        MAX14577_MUIC_ADC_FACTORY_MODE_UART_OFF,
        MAX14577_MUIC_ADC_FACTORY_MODE_UART_ON,
        MAX14577_MUIC_ADC_AUDIO_DEVICE_TYPE1, /* with Remote and Simple Ctrl */
        MAX14577_MUIC_ADC_OPEN,
};

/* max14577 MUIC device support below list of accessories(external connector) */
enum {
        EXTCON_CABLE_USB = 0,
        EXTCON_CABLE_TA,
        EXTCON_CABLE_FAST_CHARGER,
        EXTCON_CABLE_SLOW_CHARGER,
        EXTCON_CABLE_CHARGE_DOWNSTREAM,
        EXTCON_CABLE_JIG_USB_ON,
        EXTCON_CABLE_JIG_USB_OFF,
        EXTCON_CABLE_JIG_UART_OFF,
        EXTCON_CABLE_JIG_UART_ON,

        _EXTCON_CABLE_NUM,
};

static const char *max14577_extcon_cable[] = {
        [EXTCON_CABLE_USB]                      = "USB",
        [EXTCON_CABLE_TA]                       = "TA",
        [EXTCON_CABLE_FAST_CHARGER]             = "Fast-charger",
        [EXTCON_CABLE_SLOW_CHARGER]             = "Slow-charger",
        [EXTCON_CABLE_CHARGE_DOWNSTREAM]        = "Charge-downstream",
        [EXTCON_CABLE_JIG_USB_ON]               = "JIG-USB-ON",
        [EXTCON_CABLE_JIG_USB_OFF]              = "JIG-USB-OFF",
        [EXTCON_CABLE_JIG_UART_OFF]             = "JIG-UART-OFF",
        [EXTCON_CABLE_JIG_UART_ON]              = "JIG-UART-ON",

        NULL,
};

/*
 * max14577_muic_set_debounce_time - Set the debounce time of ADC
 * @info: the instance including private data of max14577 MUIC
 * @time: the debounce time of ADC
 */
static int max14577_muic_set_debounce_time(struct max14577_muic_info *info,
                enum max14577_muic_adc_debounce_time time)
{
        u8 ret;

        switch (time) {
        case ADC_DEBOUNCE_TIME_5MS:
        case ADC_DEBOUNCE_TIME_10MS:
        case ADC_DEBOUNCE_TIME_25MS:
        case ADC_DEBOUNCE_TIME_38_62MS:
                ret = max14577_update_reg(info->max14577->regmap,
                                          MAX14577_MUIC_REG_CONTROL3,
                                          CTRL3_ADCDBSET_MASK,
                                          time << CTRL3_ADCDBSET_SHIFT);
                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;
};

/*
 * max14577_muic_set_path - Set hardware line according to attached cable
 * @info: the instance including private data of max14577 MUIC
 * @value: the path according to attached cable
 * @attached: the state of cable (true:attached, false:detached)
 *
 * The max14577 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 max14577_muic_set_path(struct max14577_muic_info *info,
                u8 val, bool attached)
{
        int ret = 0;
        u8 ctrl1, ctrl2 = 0;

        /* Set open state to path before changing hw path */
        ret = max14577_update_reg(info->max14577->regmap,
                                MAX14577_MUIC_REG_CONTROL1,
                                CLEAR_IDBEN_MICEN_MASK, CTRL1_SW_OPEN);
        if (ret < 0) {
                dev_err(info->dev, "failed to update MUIC register\n");
                return ret;
        }

        if (attached)
                ctrl1 = val;
        else
                ctrl1 = CTRL1_SW_OPEN;

        ret = max14577_update_reg(info->max14577->regmap,
                                MAX14577_MUIC_REG_CONTROL1,
                                CLEAR_IDBEN_MICEN_MASK, ctrl1);
        if (ret < 0) {
                dev_err(info->dev, "failed to update MUIC register\n");
                return ret;
        }

        if (attached)
                ctrl2 |= CTRL2_CPEN_MASK;       /* LowPwr=0, CPEn=1 */
        else
                ctrl2 |= CTRL2_LOWPWR_MASK;     /* LowPwr=1, CPEn=0 */

        ret = max14577_update_reg(info->max14577->regmap,
                        MAX14577_REG_CONTROL2,
                        CTRL2_LOWPWR_MASK | CTRL2_CPEN_MASK, ctrl2);
        if (ret < 0) {
                dev_err(info->dev, "failed to update MUIC register\n");
                return ret;
        }

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

        return 0;
}

/*
 * max14577_muic_get_cable_type - Return cable type and check cable state
 * @info: the instance including private data of max14577 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.
 *      - max14577_CABLE_GROUP_ADC
 *      - max14577_CABLE_GROUP_CHG
 */
static int max14577_muic_get_cable_type(struct max14577_muic_info *info,
                enum max14577_muic_cable_group group, bool *attached)
{
        int cable_type = 0;
        int adc;
        int chg_type;

        switch (group) {
        case MAX14577_CABLE_GROUP_ADC:
                /*
                 * Read ADC value to check cable type and decide cable state
                 * according to cable type
                 */
                adc = info->status[MAX14577_MUIC_STATUS1] & 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 == MAX14577_MUIC_ADC_OPEN) {
                        *attached = false;

                        cable_type = info->prev_cable_type;
                        info->prev_cable_type = MAX14577_MUIC_ADC_OPEN;
                } else {
                        *attached = true;

                        cable_type = info->prev_cable_type = adc;
                }
                break;
        case MAX14577_CABLE_GROUP_CHG:
                /*
                 * Read charger type to check cable type and decide cable state
                 * according to type of charger cable.
                 */
                chg_type = info->status[MAX14577_MUIC_STATUS2] &
                        STATUS2_CHGTYP_MASK;
                chg_type >>= STATUS2_CHGTYP_SHIFT;

                if (chg_type == MAX14577_CHARGER_TYPE_NONE) {
                        *attached = false;

                        cable_type = info->prev_chg_type;
                        info->prev_chg_type = MAX14577_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 max14577_muic_jig_handler(struct max14577_muic_info *info,
                int cable_type, bool attached)
{
        char cable_name[32];
        int ret = 0;
        u8 path = CTRL1_SW_OPEN;

        dev_dbg(info->dev,
                "external connector is %s (adc:0x%02x)\n",
                attached ? "attached" : "detached", cable_type);

        switch (cable_type) {
        case MAX14577_MUIC_ADC_FACTORY_MODE_USB_OFF:    /* ADC_JIG_USB_OFF */
                /* PATH:AP_USB */
                strcpy(cable_name, "JIG-USB-OFF");
                path = CTRL1_SW_USB;
                break;
        case MAX14577_MUIC_ADC_FACTORY_MODE_USB_ON:     /* ADC_JIG_USB_ON */
                /* PATH:AP_USB */
                strcpy(cable_name, "JIG-USB-ON");
                path = CTRL1_SW_USB;
                break;
        case MAX14577_MUIC_ADC_FACTORY_MODE_UART_OFF:   /* ADC_JIG_UART_OFF */
                /* PATH:AP_UART */
                strcpy(cable_name, "JIG-UART-OFF");
                path = CTRL1_SW_UART;
                break;
        default:
                dev_err(info->dev, "failed to detect %s jig cable\n",
                        attached ? "attached" : "detached");
                return -EINVAL;
        }

        ret = max14577_muic_set_path(info, path, attached);
        if (ret < 0)
                return ret;

        extcon_set_cable_state(info->edev, cable_name, attached);

        return 0;
}

static int max14577_muic_adc_handler(struct max14577_muic_info *info)
{
        int cable_type;
        bool attached;
        int ret = 0;

        /* Check accessory state which is either detached or attached */
        cable_type = max14577_muic_get_cable_type(info,
                                MAX14577_CABLE_GROUP_ADC, &attached);

        dev_dbg(info->dev,
                "external connector is %s (adc:0x%02x, prev_adc:0x%x)\n",
                attached ? "attached" : "detached", cable_type,
                info->prev_cable_type);

        switch (cable_type) {
        case MAX14577_MUIC_ADC_FACTORY_MODE_USB_OFF:
        case MAX14577_MUIC_ADC_FACTORY_MODE_USB_ON:
        case MAX14577_MUIC_ADC_FACTORY_MODE_UART_OFF:
                /* JIG */
                ret = max14577_muic_jig_handler(info, cable_type, attached);
                if (ret < 0)
                        return ret;
                break;
        case MAX14577_MUIC_ADC_GROUND:
        case MAX14577_MUIC_ADC_SEND_END_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S1_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S2_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S3_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S4_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S5_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S6_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S7_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S8_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S9_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S10_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S11_BUTTON:
        case MAX14577_MUIC_ADC_REMOTE_S12_BUTTON:
        case MAX14577_MUIC_ADC_RESERVED_ACC_1:
        case MAX14577_MUIC_ADC_RESERVED_ACC_2:
        case MAX14577_MUIC_ADC_RESERVED_ACC_3:
        case MAX14577_MUIC_ADC_RESERVED_ACC_4:
        case MAX14577_MUIC_ADC_RESERVED_ACC_5:
        case MAX14577_MUIC_ADC_AUDIO_DEVICE_TYPE2:
        case MAX14577_MUIC_ADC_PHONE_POWERED_DEV:
        case MAX14577_MUIC_ADC_TTY_CONVERTER:
        case MAX14577_MUIC_ADC_UART_CABLE:
        case MAX14577_MUIC_ADC_CEA936A_TYPE1_CHG:
        case MAX14577_MUIC_ADC_AV_CABLE_NOLOAD:
        case MAX14577_MUIC_ADC_CEA936A_TYPE2_CHG:
        case MAX14577_MUIC_ADC_FACTORY_MODE_UART_ON:
        case MAX14577_MUIC_ADC_AUDIO_DEVICE_TYPE1:
                /*
                 * This accessory isn't used in general case if it is specially
                 * needed to detect additional accessory, should implement
                 * proper operation when this accessory is attached/detached.
                 */
                dev_info(info->dev,
                        "accessory is %s but it isn't used (adc:0x%x)\n",
                        attached ? "attached" : "detached", cable_type);
                return -EAGAIN;
        default:
                dev_err(info->dev,
                        "failed to detect %s accessory (adc:0x%x)\n",
                        attached ? "attached" : "detached", cable_type);
                return -EINVAL;
        }

        return 0;
}

static int max14577_muic_chg_handler(struct max14577_muic_info *info)
{
        int chg_type;
        bool attached;
        int ret = 0;

        chg_type = max14577_muic_get_cable_type(info,
                                MAX14577_CABLE_GROUP_CHG, &attached);

        dev_dbg(info->dev,
                "external connector is %s(chg_type:0x%x, prev_chg_type:0x%x)\n",
                        attached ? "attached" : "detached",
                        chg_type, info->prev_chg_type);

        switch (chg_type) {
        case MAX14577_CHARGER_TYPE_USB:
                /* PATH:AP_USB */
                ret = max14577_muic_set_path(info, info->path_usb, attached);
                if (ret < 0)
                        return ret;

                extcon_set_cable_state(info->edev, "USB", attached);
                break;
        case MAX14577_CHARGER_TYPE_DEDICATED_CHG:
                extcon_set_cable_state(info->edev, "TA", attached);
                break;
        case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
                extcon_set_cable_state(info->edev,
                                "Charge-downstream", attached);
                break;
        case MAX14577_CHARGER_TYPE_SPECIAL_500MA:
                extcon_set_cable_state(info->edev, "Slow-charger", attached);
                break;
        case MAX14577_CHARGER_TYPE_SPECIAL_1A:
                extcon_set_cable_state(info->edev, "Fast-charger", attached);
                break;
        case MAX14577_CHARGER_TYPE_NONE:
        case MAX14577_CHARGER_TYPE_DEAD_BATTERY:
                break;
        default:
                dev_err(info->dev,
                        "failed to detect %s accessory (chg_type:0x%x)\n",
                        attached ? "attached" : "detached", chg_type);
                return -EINVAL;
        }

        return 0;
}

static void max14577_muic_irq_work(struct work_struct *work)
{
        struct max14577_muic_info *info = container_of(work,
                        struct max14577_muic_info, irq_work);
        int ret = 0;

        if (!info->edev)
                return;

        mutex_lock(&info->mutex);

        ret = max14577_bulk_read(info->max14577->regmap,
                        MAX14577_MUIC_REG_STATUS1, info->status, 2);
        if (ret) {
                dev_err(info->dev, "failed to read MUIC register\n");
                mutex_unlock(&info->mutex);
                return;
        }

        if (info->irq_adc) {
                ret = max14577_muic_adc_handler(info);
                info->irq_adc = false;
        }
        if (info->irq_chg) {
                ret = max14577_muic_chg_handler(info);
                info->irq_chg = false;
        }

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

        mutex_unlock(&info->mutex);

        return;
}

static irqreturn_t max14577_muic_irq_handler(int irq, void *data)
{
        struct max14577_muic_info *info = data;
        int i, irq_type = -1;

        /*
         * We may be called multiple times for different nested IRQ-s.
         * Including changes in INT1_ADC and INT2_CGHTYP at once.
         * However we only need to know whether it was ADC, charger
         * or both interrupts so decode IRQ and turn on proper flags.
         */
        for (i = 0; i < ARRAY_SIZE(muic_irqs); i++)
                if (irq == muic_irqs[i].virq)
                        irq_type = muic_irqs[i].irq;

        switch (irq_type) {
        case MAX14577_IRQ_INT1_ADC:
        case MAX14577_IRQ_INT1_ADCLOW:
        case MAX14577_IRQ_INT1_ADCERR:
                /* Handle all of accessory except for
                   type of charger accessory */
                info->irq_adc = true;
                break;
        case MAX14577_IRQ_INT2_CHGTYP:
        case MAX14577_IRQ_INT2_CHGDETRUN:
        case MAX14577_IRQ_INT2_DCDTMR:
        case MAX14577_IRQ_INT2_DBCHG:
        case MAX14577_IRQ_INT2_VBVOLT:
                /* Handle charger accessory */
                info->irq_chg = true;
                break;
        default:
                dev_err(info->dev, "muic interrupt: irq %d occurred, skipped\n",
                                irq_type);
                return IRQ_HANDLED;
        }
        schedule_work(&info->irq_work);

        return IRQ_HANDLED;
}

static int max14577_muic_detect_accessory(struct max14577_muic_info *info)
{
        int ret = 0;
        int adc;
        int chg_type;
        bool attached;

        mutex_lock(&info->mutex);

        /* Read STATUSx register to detect accessory */
        ret = max14577_bulk_read(info->max14577->regmap,
                        MAX14577_MUIC_REG_STATUS1, info->status, 2);
        if (ret) {
                dev_err(info->dev, "failed to read MUIC register\n");
                mutex_unlock(&info->mutex);
                return ret;
        }

        adc = max14577_muic_get_cable_type(info, MAX14577_CABLE_GROUP_ADC,
                                        &attached);
        if (attached && adc != MAX14577_MUIC_ADC_OPEN) {
                ret = max14577_muic_adc_handler(info);
                if (ret < 0) {
                        dev_err(info->dev, "Cannot detect accessory\n");
                        mutex_unlock(&info->mutex);
                        return ret;
                }
        }

        chg_type = max14577_muic_get_cable_type(info, MAX14577_CABLE_GROUP_CHG,
                                        &attached);
        if (attached && chg_type != MAX14577_CHARGER_TYPE_NONE) {
                ret = max14577_muic_chg_handler(info);
                if (ret < 0) {
                        dev_err(info->dev, "Cannot detect charger accessory\n");
                        mutex_unlock(&info->mutex);
                        return ret;
                }
        }

        mutex_unlock(&info->mutex);

        return 0;
}

static void max14577_muic_detect_cable_wq(struct work_struct *work)
{
        struct max14577_muic_info *info = container_of(to_delayed_work(work),
                                struct max14577_muic_info, wq_detcable);

        max14577_muic_detect_accessory(info);
}

static int max14577_muic_probe(struct platform_device *pdev)
{
        struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
        struct max14577_muic_info *info;
        int delay_jiffies;
        int ret;
        int i;
        u8 id;

        info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
        if (!info) {
                dev_err(&pdev->dev, "failed to allocate memory\n");
                return -ENOMEM;
        }
        info->dev = &pdev->dev;
        info->max14577 = max14577;

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

        INIT_WORK(&info->irq_work, max14577_muic_irq_work);

        /* Support irq domain for max14577 MUIC device */
        for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
                struct max14577_muic_irq *muic_irq = &muic_irqs[i];
                unsigned int virq = 0;

                virq = regmap_irq_get_virq(max14577->irq_data, muic_irq->irq);
                if (!virq)
                        return -EINVAL;
                muic_irq->virq = virq;

                ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
                                max14577_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);
                        return ret;
                }
        }

        /* Initialize extcon device */
        info->edev = devm_kzalloc(&pdev->dev, sizeof(*info->edev), GFP_KERNEL);
        if (!info->edev) {
                dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
                return -ENOMEM;
        }
        info->edev->name = DEV_NAME;
        info->edev->supported_cable = max14577_extcon_cable;
        ret = extcon_dev_register(info->edev);
        if (ret) {
                dev_err(&pdev->dev, "failed to register extcon device\n");
                return ret;
        }

        /* Default h/w line path */
        info->path_usb = CTRL1_SW_USB;
        info->path_uart = CTRL1_SW_UART;
        delay_jiffies = msecs_to_jiffies(DELAY_MS_DEFAULT);

        /* Set initial path for UART */
        max14577_muic_set_path(info, info->path_uart, true);

        /* Check revision number of MUIC device*/
        ret = max14577_read_reg(info->max14577->regmap,
                        MAX14577_REG_DEVICEID, &id);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to read revision number\n");
                goto err_extcon;
        }
        dev_info(info->dev, "device ID : 0x%x\n", id);

        /* Set ADC debounce time */
        max14577_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, max14577_muic_detect_cable_wq);
        ret = queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
                        delay_jiffies);
        if (ret < 0) {
                dev_err(&pdev->dev,
                        "failed to schedule delayed work for cable detect\n");
                goto err_extcon;
        }

        return ret;

err_extcon:
        extcon_dev_unregister(info->edev);
        return ret;
}

static int max14577_muic_remove(struct platform_device *pdev)
{
        struct max14577_muic_info *info = platform_get_drvdata(pdev);

        cancel_work_sync(&info->irq_work);
        extcon_dev_unregister(info->edev);

        return 0;
}

static struct platform_driver max14577_muic_driver = {
        .driver         = {
                .name   = DEV_NAME,
                .owner  = THIS_MODULE,
        },
        .probe          = max14577_muic_probe,
        .remove         = max14577_muic_remove,
};

module_platform_driver(max14577_muic_driver);

MODULE_DESCRIPTION("MAXIM 14577 Extcon driver");
MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:extcon-max14577");