/*
 * TI BQ24257 charger driver
 *
 * Copyright (C) 2015 Intel Corporation
 *
 * 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.
 *
 * Datasheets:
 * http://www.ti.com/product/bq24250
 * http://www.ti.com/product/bq24251
 * http://www.ti.com/product/bq24257
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>
#include <linux/types.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/delay.h>

#include <linux/acpi.h>
#include <linux/of.h>

#define BQ24257_REG_1                   0x00
#define BQ24257_REG_2                   0x01
#define BQ24257_REG_3                   0x02
#define BQ24257_REG_4                   0x03
#define BQ24257_REG_5                   0x04
#define BQ24257_REG_6                   0x05
#define BQ24257_REG_7                   0x06

#define BQ24257_MANUFACTURER            "Texas Instruments"
#define BQ24257_PG_GPIO                 "pg"

#define BQ24257_ILIM_SET_DELAY          1000    /* msec */

/*
 * When adding support for new devices make sure that enum bq2425x_chip and
 * bq2425x_chip_name[] always stay in sync!
 */
enum bq2425x_chip {
        BQ24250,
        BQ24251,
        BQ24257,
};

static const char *const bq2425x_chip_name[] = {
        "bq24250",
        "bq24251",
        "bq24257",
};

enum bq24257_fields {
        F_WD_FAULT, F_WD_EN, F_STAT, F_FAULT,                       /* REG 1 */
        F_RESET, F_IILIMIT, F_EN_STAT, F_EN_TERM, F_CE, F_HZ_MODE,  /* REG 2 */
        F_VBAT, F_USB_DET,                                          /* REG 3 */
        F_ICHG, F_ITERM,                                            /* REG 4 */
        F_LOOP_STATUS, F_LOW_CHG, F_DPDM_EN, F_CE_STATUS, F_VINDPM, /* REG 5 */
        F_X2_TMR_EN, F_TMR, F_SYSOFF, F_TS_EN, F_TS_STAT,           /* REG 6 */
        F_VOVP, F_CLR_VDP, F_FORCE_BATDET, F_FORCE_PTM,             /* REG 7 */

        F_MAX_FIELDS
};

/* initial field values, converted from uV/uA */
struct bq24257_init_data {
        u8 ichg;        /* charge current      */
        u8 vbat;        /* regulation voltage  */
        u8 iterm;       /* termination current */
        u8 iilimit;     /* input current limit */
        u8 vovp;        /* over voltage protection voltage */
        u8 vindpm;      /* VDMP input threshold voltage */
};

struct bq24257_state {
        u8 status;
        u8 fault;
        bool power_good;
};

struct bq24257_device {
        struct i2c_client *client;
        struct device *dev;
        struct power_supply *charger;

        enum bq2425x_chip chip;

        struct regmap *rmap;
        struct regmap_field *rmap_fields[F_MAX_FIELDS];

        struct gpio_desc *pg;

        struct delayed_work iilimit_setup_work;

        struct bq24257_init_data init_data;
        struct bq24257_state state;

        struct mutex lock; /* protect state data */

        bool iilimit_autoset_enable;
};

static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case BQ24257_REG_2:
        case BQ24257_REG_4:
                return false;

        default:
                return true;
        }
}

static const struct regmap_config bq24257_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,

        .max_register = BQ24257_REG_7,
        .cache_type = REGCACHE_RBTREE,

        .volatile_reg = bq24257_is_volatile_reg,
};

static const struct reg_field bq24257_reg_fields[] = {
        /* REG 1 */
        [F_WD_FAULT]            = REG_FIELD(BQ24257_REG_1, 7, 7),
        [F_WD_EN]               = REG_FIELD(BQ24257_REG_1, 6, 6),
        [F_STAT]                = REG_FIELD(BQ24257_REG_1, 4, 5),
        [F_FAULT]               = REG_FIELD(BQ24257_REG_1, 0, 3),
        /* REG 2 */
        [F_RESET]               = REG_FIELD(BQ24257_REG_2, 7, 7),
        [F_IILIMIT]             = REG_FIELD(BQ24257_REG_2, 4, 6),
        [F_EN_STAT]             = REG_FIELD(BQ24257_REG_2, 3, 3),
        [F_EN_TERM]             = REG_FIELD(BQ24257_REG_2, 2, 2),
        [F_CE]                  = REG_FIELD(BQ24257_REG_2, 1, 1),
        [F_HZ_MODE]             = REG_FIELD(BQ24257_REG_2, 0, 0),
        /* REG 3 */
        [F_VBAT]                = REG_FIELD(BQ24257_REG_3, 2, 7),
        [F_USB_DET]             = REG_FIELD(BQ24257_REG_3, 0, 1),
        /* REG 4 */
        [F_ICHG]                = REG_FIELD(BQ24257_REG_4, 3, 7),
        [F_ITERM]               = REG_FIELD(BQ24257_REG_4, 0, 2),
        /* REG 5 */
        [F_LOOP_STATUS]         = REG_FIELD(BQ24257_REG_5, 6, 7),
        [F_LOW_CHG]             = REG_FIELD(BQ24257_REG_5, 5, 5),
        [F_DPDM_EN]             = REG_FIELD(BQ24257_REG_5, 4, 4),
        [F_CE_STATUS]           = REG_FIELD(BQ24257_REG_5, 3, 3),
        [F_VINDPM]              = REG_FIELD(BQ24257_REG_5, 0, 2),
        /* REG 6 */
        [F_X2_TMR_EN]           = REG_FIELD(BQ24257_REG_6, 7, 7),
        [F_TMR]                 = REG_FIELD(BQ24257_REG_6, 5, 6),
        [F_SYSOFF]              = REG_FIELD(BQ24257_REG_6, 4, 4),
        [F_TS_EN]               = REG_FIELD(BQ24257_REG_6, 3, 3),
        [F_TS_STAT]             = REG_FIELD(BQ24257_REG_6, 0, 2),
        /* REG 7 */
        [F_VOVP]                = REG_FIELD(BQ24257_REG_7, 5, 7),
        [F_CLR_VDP]             = REG_FIELD(BQ24257_REG_7, 4, 4),
        [F_FORCE_BATDET]        = REG_FIELD(BQ24257_REG_7, 3, 3),
        [F_FORCE_PTM]           = REG_FIELD(BQ24257_REG_7, 2, 2)
};

static const u32 bq24257_vbat_map[] = {
        3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
        3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
        3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
        3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
        4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
        4300000, 4320000, 4340000, 4360000, 4380000, 4400000, 4420000, 4440000
};

#define BQ24257_VBAT_MAP_SIZE           ARRAY_SIZE(bq24257_vbat_map)

static const u32 bq24257_ichg_map[] = {
        500000, 550000, 600000, 650000, 700000, 750000, 800000, 850000, 900000,
        950000, 1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000,
        1350000, 1400000, 1450000, 1500000, 1550000, 1600000, 1650000, 1700000,
        1750000, 1800000, 1850000, 1900000, 1950000, 2000000
};

#define BQ24257_ICHG_MAP_SIZE           ARRAY_SIZE(bq24257_ichg_map)

static const u32 bq24257_iterm_map[] = {
        50000, 75000, 100000, 125000, 150000, 175000, 200000, 225000
};

#define BQ24257_ITERM_MAP_SIZE          ARRAY_SIZE(bq24257_iterm_map)

static const u32 bq24257_iilimit_map[] = {
        100000, 150000, 500000, 900000, 1500000, 2000000
};

#define BQ24257_IILIMIT_MAP_SIZE        ARRAY_SIZE(bq24257_iilimit_map)

static const u32 bq24257_vovp_map[] = {
        6000000, 6500000, 7000000, 8000000, 9000000, 9500000, 10000000,
        10500000
};

#define BQ24257_VOVP_MAP_SIZE           ARRAY_SIZE(bq24257_vovp_map)

static const u32 bq24257_vindpm_map[] = {
        4200000, 4280000, 4360000, 4440000, 4520000, 4600000, 4680000,
        4760000
};

#define BQ24257_VINDPM_MAP_SIZE         ARRAY_SIZE(bq24257_vindpm_map)

static int bq24257_field_read(struct bq24257_device *bq,
                              enum bq24257_fields field_id)
{
        int ret;
        int val;

        ret = regmap_field_read(bq->rmap_fields[field_id], &val);
        if (ret < 0)
                return ret;

        return val;
}

static int bq24257_field_write(struct bq24257_device *bq,
                               enum bq24257_fields field_id, u8 val)
{
        return regmap_field_write(bq->rmap_fields[field_id], val);
}

static u8 bq24257_find_idx(u32 value, const u32 *map, u8 map_size)
{
        u8 idx;

        for (idx = 1; idx < map_size; idx++)
                if (value < map[idx])
                        break;

        return idx - 1;
}

enum bq24257_status {
        STATUS_READY,
        STATUS_CHARGE_IN_PROGRESS,
        STATUS_CHARGE_DONE,
        STATUS_FAULT,
};

enum bq24257_fault {
        FAULT_NORMAL,
        FAULT_INPUT_OVP,
        FAULT_INPUT_UVLO,
        FAULT_SLEEP,
        FAULT_BAT_TS,
        FAULT_BAT_OVP,
        FAULT_TS,
        FAULT_TIMER,
        FAULT_NO_BAT,
        FAULT_ISET,
        FAULT_INPUT_LDO_LOW,
};

static int bq24257_get_input_current_limit(struct bq24257_device *bq,
                                           union power_supply_propval *val)
{
        int ret;

        ret = bq24257_field_read(bq, F_IILIMIT);
        if (ret < 0)
                return ret;

        /*
         * The "External ILIM" and "Production & Test" modes are not exposed
         * through this driver and not being covered by the lookup table.
         * Should such a mode have become active let's return an error rather
         * than exceeding the bounds of the lookup table and returning
         * garbage.
         */
        if (ret >= BQ24257_IILIMIT_MAP_SIZE)
                return -ENODATA;

        val->intval = bq24257_iilimit_map[ret];

        return 0;
}

static int bq24257_set_input_current_limit(struct bq24257_device *bq,
                                        const union power_supply_propval *val)
{
        /*
         * Address the case where the user manually sets an input current limit
         * while the charger auto-detection mechanism is is active. In this
         * case we want to abort and go straight to the user-specified value.
         */
        if (bq->iilimit_autoset_enable)
                cancel_delayed_work_sync(&bq->iilimit_setup_work);

        return bq24257_field_write(bq, F_IILIMIT,
                                   bq24257_find_idx(val->intval,
                                                    bq24257_iilimit_map,
                                                    BQ24257_IILIMIT_MAP_SIZE));
}

static int bq24257_power_supply_get_property(struct power_supply *psy,
                                             enum power_supply_property psp,
                                             union power_supply_propval *val)
{
        struct bq24257_device *bq = power_supply_get_drvdata(psy);
        struct bq24257_state state;

        mutex_lock(&bq->lock);
        state = bq->state;
        mutex_unlock(&bq->lock);

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                if (!state.power_good)
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                else if (state.status == STATUS_READY)
                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
                else if (state.status == STATUS_CHARGE_IN_PROGRESS)
                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
                else if (state.status == STATUS_CHARGE_DONE)
                        val->intval = POWER_SUPPLY_STATUS_FULL;
                else
                        val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
                break;

        case POWER_SUPPLY_PROP_MANUFACTURER:
                val->strval = BQ24257_MANUFACTURER;
                break;

        case POWER_SUPPLY_PROP_MODEL_NAME:
                val->strval = bq2425x_chip_name[bq->chip];
                break;

        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = state.power_good;
                break;

        case POWER_SUPPLY_PROP_HEALTH:
                switch (state.fault) {
                case FAULT_NORMAL:
                        val->intval = POWER_SUPPLY_HEALTH_GOOD;
                        break;

                case FAULT_INPUT_OVP:
                case FAULT_BAT_OVP:
                        val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
                        break;

                case FAULT_TS:
                case FAULT_BAT_TS:
                        val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
                        break;

                case FAULT_TIMER:
                        val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
                        break;

                default:
                        val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
                        break;
                }

                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
                val->intval = bq24257_ichg_map[bq->init_data.ichg];
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
                val->intval = bq24257_ichg_map[BQ24257_ICHG_MAP_SIZE - 1];
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
                val->intval = bq24257_vbat_map[bq->init_data.vbat];
                break;

        case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
                val->intval = bq24257_vbat_map[BQ24257_VBAT_MAP_SIZE - 1];
                break;

        case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
                val->intval = bq24257_iterm_map[bq->init_data.iterm];
                break;

        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                return bq24257_get_input_current_limit(bq, val);

        default:
                return -EINVAL;
        }

        return 0;
}

static int bq24257_power_supply_set_property(struct power_supply *psy,
                                        enum power_supply_property prop,
                                        const union power_supply_propval *val)
{
        struct bq24257_device *bq = power_supply_get_drvdata(psy);

        switch (prop) {
        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                return bq24257_set_input_current_limit(bq, val);
        default:
                return -EINVAL;
        }
}

static int bq24257_power_supply_property_is_writeable(struct power_supply *psy,
                                        enum power_supply_property psp)
{
        switch (psp) {
        case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
                return true;
        default:
                return false;
        }
}

static int bq24257_get_chip_state(struct bq24257_device *bq,
                                  struct bq24257_state *state)
{
        int ret;

        ret = bq24257_field_read(bq, F_STAT);
        if (ret < 0)
                return ret;

        state->status = ret;

        ret = bq24257_field_read(bq, F_FAULT);
        if (ret < 0)
                return ret;

        state->fault = ret;

        if (bq->pg)
                state->power_good = !gpiod_get_value_cansleep(bq->pg);
        else
                /*
                 * If we have a chip without a dedicated power-good GPIO or
                 * some other explicit bit that would provide this information
                 * assume the power is good if there is no supply related
                 * fault - and not good otherwise. There is a possibility for
                 * other errors to mask that power in fact is not good but this
                 * is probably the best we can do here.
                 */
                switch (state->fault) {
                case FAULT_INPUT_OVP:
                case FAULT_INPUT_UVLO:
                case FAULT_INPUT_LDO_LOW:
                        state->power_good = false;
                        break;
                default:
                        state->power_good = true;
                }

        return 0;
}

static bool bq24257_state_changed(struct bq24257_device *bq,
                                  struct bq24257_state *new_state)
{
        int ret;

        mutex_lock(&bq->lock);
        ret = (bq->state.status != new_state->status ||
               bq->state.fault != new_state->fault ||
               bq->state.power_good != new_state->power_good);
        mutex_unlock(&bq->lock);

        return ret;
}

enum bq24257_loop_status {
        LOOP_STATUS_NONE,
        LOOP_STATUS_IN_DPM,
        LOOP_STATUS_IN_CURRENT_LIMIT,
        LOOP_STATUS_THERMAL,
};

enum bq24257_in_ilimit {
        IILIMIT_100,
        IILIMIT_150,
        IILIMIT_500,
        IILIMIT_900,
        IILIMIT_1500,
        IILIMIT_2000,
        IILIMIT_EXT,
        IILIMIT_NONE,
};

enum bq24257_vovp {
        VOVP_6000,
        VOVP_6500,
        VOVP_7000,
        VOVP_8000,
        VOVP_9000,
        VOVP_9500,
        VOVP_10000,
        VOVP_10500
};

enum bq24257_vindpm {
        VINDPM_4200,
        VINDPM_4280,
        VINDPM_4360,
        VINDPM_4440,
        VINDPM_4520,
        VINDPM_4600,
        VINDPM_4680,
        VINDPM_4760
};

enum bq24257_port_type {
        PORT_TYPE_DCP,          /* Dedicated Charging Port */
        PORT_TYPE_CDP,          /* Charging Downstream Port */
        PORT_TYPE_SDP,          /* Standard Downstream Port */
        PORT_TYPE_NON_STANDARD,
};

enum bq24257_safety_timer {
        SAFETY_TIMER_45,
        SAFETY_TIMER_360,
        SAFETY_TIMER_540,
        SAFETY_TIMER_NONE,
};

static int bq24257_iilimit_autoset(struct bq24257_device *bq)
{
        int loop_status;
        int iilimit;
        int port_type;
        int ret;
        const u8 new_iilimit[] = {
                [PORT_TYPE_DCP] = IILIMIT_2000,
                [PORT_TYPE_CDP] = IILIMIT_2000,
                [PORT_TYPE_SDP] = IILIMIT_500,
                [PORT_TYPE_NON_STANDARD] = IILIMIT_500
        };

        ret = bq24257_field_read(bq, F_LOOP_STATUS);
        if (ret < 0)
                goto error;

        loop_status = ret;

        ret = bq24257_field_read(bq, F_IILIMIT);
        if (ret < 0)
                goto error;

        iilimit = ret;

        /*
         * All USB ports should be able to handle 500mA. If not, DPM will lower
         * the charging current to accommodate the power source. No need to set
         * a lower IILIMIT value.
         */
        if (loop_status == LOOP_STATUS_IN_DPM && iilimit == IILIMIT_500)
                return 0;

        ret = bq24257_field_read(bq, F_USB_DET);
        if (ret < 0)
                goto error;

        port_type = ret;

        ret = bq24257_field_write(bq, F_IILIMIT, new_iilimit[port_type]);
        if (ret < 0)
                goto error;

        ret = bq24257_field_write(bq, F_TMR, SAFETY_TIMER_360);
        if (ret < 0)
                goto error;

        ret = bq24257_field_write(bq, F_CLR_VDP, 1);
        if (ret < 0)
                goto error;

        dev_dbg(bq->dev, "port/loop = %d/%d -> iilimit = %d\n",
                port_type, loop_status, new_iilimit[port_type]);

        return 0;

error:
        dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
        return ret;
}

static void bq24257_iilimit_setup_work(struct work_struct *work)
{
        struct bq24257_device *bq = container_of(work, struct bq24257_device,
                                                 iilimit_setup_work.work);

        bq24257_iilimit_autoset(bq);
}

static void bq24257_handle_state_change(struct bq24257_device *bq,
                                        struct bq24257_state *new_state)
{
        int ret;
        struct bq24257_state old_state;

        mutex_lock(&bq->lock);
        old_state = bq->state;
        mutex_unlock(&bq->lock);

        /*
         * Handle BQ2425x state changes observing whether the D+/D- based input
         * current limit autoset functionality is enabled.
         */
        if (!new_state->power_good) {
                dev_dbg(bq->dev, "Power removed\n");
                if (bq->iilimit_autoset_enable) {
                        cancel_delayed_work_sync(&bq->iilimit_setup_work);

                        /* activate D+/D- port detection algorithm */
                        ret = bq24257_field_write(bq, F_DPDM_EN, 1);
                        if (ret < 0)
                                goto error;
                }
                /*
                 * When power is removed always return to the default input
                 * current limit as configured during probe.
                 */
                ret = bq24257_field_write(bq, F_IILIMIT, bq->init_data.iilimit);
                if (ret < 0)
                        goto error;
        } else if (!old_state.power_good) {
                dev_dbg(bq->dev, "Power inserted\n");

                if (bq->iilimit_autoset_enable)
                        /* configure input current limit */
                        schedule_delayed_work(&bq->iilimit_setup_work,
                                      msecs_to_jiffies(BQ24257_ILIM_SET_DELAY));
        } else if (new_state->fault == FAULT_NO_BAT) {
                dev_warn(bq->dev, "Battery removed\n");
        } else if (new_state->fault == FAULT_TIMER) {
                dev_err(bq->dev, "Safety timer expired! Battery dead?\n");
        }

        return;

error:
        dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
}

static irqreturn_t bq24257_irq_handler_thread(int irq, void *private)
{
        int ret;
        struct bq24257_device *bq = private;
        struct bq24257_state state;

        ret = bq24257_get_chip_state(bq, &state);
        if (ret < 0)
                return IRQ_HANDLED;

        if (!bq24257_state_changed(bq, &state))
                return IRQ_HANDLED;

        dev_dbg(bq->dev, "irq(state changed): status/fault/pg = %d/%d/%d\n",
                state.status, state.fault, state.power_good);

        bq24257_handle_state_change(bq, &state);

        mutex_lock(&bq->lock);
        bq->state = state;
        mutex_unlock(&bq->lock);

        power_supply_changed(bq->charger);

        return IRQ_HANDLED;
}

static int bq24257_hw_init(struct bq24257_device *bq)
{
        int ret;
        int i;
        struct bq24257_state state;

        const struct {
                int field;
                u32 value;
        } init_data[] = {
                {F_ICHG, bq->init_data.ichg},
                {F_VBAT, bq->init_data.vbat},
                {F_ITERM, bq->init_data.iterm},
                {F_VOVP, bq->init_data.vovp},
                {F_VINDPM, bq->init_data.vindpm},
        };

        /*
         * Disable the watchdog timer to prevent the IC from going back to
         * default settings after 50 seconds of I2C inactivity.
         */
        ret = bq24257_field_write(bq, F_WD_EN, 0);
        if (ret < 0)
                return ret;

        /* configure the charge currents and voltages */
        for (i = 0; i < ARRAY_SIZE(init_data); i++) {
                ret = bq24257_field_write(bq, init_data[i].field,
                                          init_data[i].value);
                if (ret < 0)
                        return ret;
        }

        ret = bq24257_get_chip_state(bq, &state);
        if (ret < 0)
                return ret;

        mutex_lock(&bq->lock);
        bq->state = state;
        mutex_unlock(&bq->lock);

        if (!bq->iilimit_autoset_enable) {
                dev_dbg(bq->dev, "manually setting iilimit = %u\n",
                        bq->init_data.iilimit);

                /* program fixed input current limit */
                ret = bq24257_field_write(bq, F_IILIMIT,
                                          bq->init_data.iilimit);
                if (ret < 0)
                        return ret;
        } else if (!state.power_good)
                /* activate D+/D- detection algorithm */
                ret = bq24257_field_write(bq, F_DPDM_EN, 1);
        else if (state.fault != FAULT_NO_BAT)
                ret = bq24257_iilimit_autoset(bq);

        return ret;
}

static enum power_supply_property bq24257_power_supply_props[] = {
        POWER_SUPPLY_PROP_MANUFACTURER,
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
        POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
        POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
};

static char *bq24257_charger_supplied_to[] = {
        "main-battery",
};

static const struct power_supply_desc bq24257_power_supply_desc = {
        .name = "bq24257-charger",
        .type = POWER_SUPPLY_TYPE_USB,
        .properties = bq24257_power_supply_props,
        .num_properties = ARRAY_SIZE(bq24257_power_supply_props),
        .get_property = bq24257_power_supply_get_property,
        .set_property = bq24257_power_supply_set_property,
        .property_is_writeable = bq24257_power_supply_property_is_writeable,
};

static ssize_t bq24257_show_ovp_voltage(struct device *dev,
                                        struct device_attribute *attr,
                                        char *buf)
{
        struct power_supply *psy = dev_get_drvdata(dev);
        struct bq24257_device *bq = power_supply_get_drvdata(psy);

        return scnprintf(buf, PAGE_SIZE, "%u\n",
                         bq24257_vovp_map[bq->init_data.vovp]);
}

static ssize_t bq24257_show_in_dpm_voltage(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct power_supply *psy = dev_get_drvdata(dev);
        struct bq24257_device *bq = power_supply_get_drvdata(psy);

        return scnprintf(buf, PAGE_SIZE, "%u\n",
                         bq24257_vindpm_map[bq->init_data.vindpm]);
}

static ssize_t bq24257_sysfs_show_enable(struct device *dev,
                                         struct device_attribute *attr,
                                         char *buf)
{
        struct power_supply *psy = dev_get_drvdata(dev);
        struct bq24257_device *bq = power_supply_get_drvdata(psy);
        int ret;

        if (strcmp(attr->attr.name, "high_impedance_enable") == 0)
                ret = bq24257_field_read(bq, F_HZ_MODE);
        else if (strcmp(attr->attr.name, "sysoff_enable") == 0)
                ret = bq24257_field_read(bq, F_SYSOFF);
        else
                return -EINVAL;

        if (ret < 0)
                return ret;

        return scnprintf(buf, PAGE_SIZE, "%d\n", ret);
}

static ssize_t bq24257_sysfs_set_enable(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf,
                                        size_t count)
{
        struct power_supply *psy = dev_get_drvdata(dev);
        struct bq24257_device *bq = power_supply_get_drvdata(psy);
        long val;
        int ret;

        if (kstrtol(buf, 10, &val) < 0)
                return -EINVAL;

        if (strcmp(attr->attr.name, "high_impedance_enable") == 0)
                ret = bq24257_field_write(bq, F_HZ_MODE, (bool)val);
        else if (strcmp(attr->attr.name, "sysoff_enable") == 0)
                ret = bq24257_field_write(bq, F_SYSOFF, (bool)val);
        else
                return -EINVAL;

        if (ret < 0)
                return ret;

        return count;
}

static DEVICE_ATTR(ovp_voltage, S_IRUGO, bq24257_show_ovp_voltage, NULL);
static DEVICE_ATTR(in_dpm_voltage, S_IRUGO, bq24257_show_in_dpm_voltage, NULL);
static DEVICE_ATTR(high_impedance_enable, S_IWUSR | S_IRUGO,
                   bq24257_sysfs_show_enable, bq24257_sysfs_set_enable);
static DEVICE_ATTR(sysoff_enable, S_IWUSR | S_IRUGO,
                   bq24257_sysfs_show_enable, bq24257_sysfs_set_enable);

static struct attribute *bq24257_charger_attr[] = {
        &dev_attr_ovp_voltage.attr,
        &dev_attr_in_dpm_voltage.attr,
        &dev_attr_high_impedance_enable.attr,
        &dev_attr_sysoff_enable.attr,
        NULL,
};

static const struct attribute_group bq24257_attr_group = {
        .attrs = bq24257_charger_attr,
};

static int bq24257_power_supply_init(struct bq24257_device *bq)
{
        struct power_supply_config psy_cfg = { .drv_data = bq, };

        psy_cfg.supplied_to = bq24257_charger_supplied_to;
        psy_cfg.num_supplicants = ARRAY_SIZE(bq24257_charger_supplied_to);

        bq->charger = devm_power_supply_register(bq->dev,
                                                 &bq24257_power_supply_desc,
                                                 &psy_cfg);

        return PTR_ERR_OR_ZERO(bq->charger);
}

static void bq24257_pg_gpio_probe(struct bq24257_device *bq)
{
        bq->pg = devm_gpiod_get_optional(bq->dev, BQ24257_PG_GPIO, GPIOD_IN);

        if (PTR_ERR(bq->pg) == -EPROBE_DEFER) {
                dev_info(bq->dev, "probe retry requested for PG pin\n");
                return;
        } else if (IS_ERR(bq->pg)) {
                dev_err(bq->dev, "error probing PG pin\n");
                bq->pg = NULL;
                return;
        }

        if (bq->pg)
                dev_dbg(bq->dev, "probed PG pin = %d\n", desc_to_gpio(bq->pg));
}

static int bq24257_fw_probe(struct bq24257_device *bq)
{
        int ret;
        u32 property;

        /* Required properties */
        ret = device_property_read_u32(bq->dev, "ti,charge-current", &property);
        if (ret < 0)
                return ret;

        bq->init_data.ichg = bq24257_find_idx(property, bq24257_ichg_map,
                                              BQ24257_ICHG_MAP_SIZE);

        ret = device_property_read_u32(bq->dev, "ti,battery-regulation-voltage",
                                       &property);
        if (ret < 0)
                return ret;

        bq->init_data.vbat = bq24257_find_idx(property, bq24257_vbat_map,
                                              BQ24257_VBAT_MAP_SIZE);

        ret = device_property_read_u32(bq->dev, "ti,termination-current",
                                       &property);
        if (ret < 0)
                return ret;

        bq->init_data.iterm = bq24257_find_idx(property, bq24257_iterm_map,
                                               BQ24257_ITERM_MAP_SIZE);

        /* Optional properties. If not provided use reasonable default. */
        ret = device_property_read_u32(bq->dev, "ti,current-limit",
                                       &property);
        if (ret < 0) {
                bq->iilimit_autoset_enable = true;

                /*
                 * Explicitly set a default value which will be needed for
                 * devices that don't support the automatic setting of the input
                 * current limit through the charger type detection mechanism.
                 */
                bq->init_data.iilimit = IILIMIT_500;
        } else
                bq->init_data.iilimit =
                                bq24257_find_idx(property,
                                                 bq24257_iilimit_map,
                                                 BQ24257_IILIMIT_MAP_SIZE);

        ret = device_property_read_u32(bq->dev, "ti,ovp-voltage",
                                       &property);
        if (ret < 0)
                bq->init_data.vovp = VOVP_6500;
        else
                bq->init_data.vovp = bq24257_find_idx(property,
                                                      bq24257_vovp_map,
                                                      BQ24257_VOVP_MAP_SIZE);

        ret = device_property_read_u32(bq->dev, "ti,in-dpm-voltage",
                                       &property);
        if (ret < 0)
                bq->init_data.vindpm = VINDPM_4360;
        else
                bq->init_data.vindpm =
                                bq24257_find_idx(property,
                                                 bq24257_vindpm_map,
                                                 BQ24257_VINDPM_MAP_SIZE);

        return 0;
}

static int bq24257_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
{
        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
        struct device *dev = &client->dev;
        const struct acpi_device_id *acpi_id;
        struct bq24257_device *bq;
        int ret;
        int i;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
                dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
                return -ENODEV;
        }

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

        bq->client = client;
        bq->dev = dev;

        if (ACPI_HANDLE(dev)) {
                acpi_id = acpi_match_device(dev->driver->acpi_match_table,
                                            &client->dev);
                if (!acpi_id) {
                        dev_err(dev, "Failed to match ACPI device\n");
                        return -ENODEV;
                }
                bq->chip = (enum bq2425x_chip)acpi_id->driver_data;
        } else {
                bq->chip = (enum bq2425x_chip)id->driver_data;
        }

        mutex_init(&bq->lock);

        bq->rmap = devm_regmap_init_i2c(client, &bq24257_regmap_config);
        if (IS_ERR(bq->rmap)) {
                dev_err(dev, "failed to allocate register map\n");
                return PTR_ERR(bq->rmap);
        }

        for (i = 0; i < ARRAY_SIZE(bq24257_reg_fields); i++) {
                const struct reg_field *reg_fields = bq24257_reg_fields;

                bq->rmap_fields[i] = devm_regmap_field_alloc(dev, bq->rmap,
                                                             reg_fields[i]);
                if (IS_ERR(bq->rmap_fields[i])) {
                        dev_err(dev, "cannot allocate regmap field\n");
                        return PTR_ERR(bq->rmap_fields[i]);
                }
        }

        i2c_set_clientdata(client, bq);

        if (!dev->platform_data) {
                ret = bq24257_fw_probe(bq);
                if (ret < 0) {
                        dev_err(dev, "Cannot read device properties.\n");
                        return ret;
                }
        } else {
                return -ENODEV;
        }

        /*
         * The BQ24250 doesn't support the D+/D- based charger type detection
         * used for the automatic setting of the input current limit setting so
         * explicitly disable that feature.
         */
        if (bq->chip == BQ24250)
                bq->iilimit_autoset_enable = false;

        if (bq->iilimit_autoset_enable)
                INIT_DELAYED_WORK(&bq->iilimit_setup_work,
                                  bq24257_iilimit_setup_work);

        /*
         * The BQ24250 doesn't have a dedicated Power Good (PG) pin so let's
         * not probe for it and instead use a SW-based approach to determine
         * the PG state. We also use a SW-based approach for all other devices
         * if the PG pin is either not defined or can't be probed.
         */
        if (bq->chip != BQ24250)
                bq24257_pg_gpio_probe(bq);

        if (PTR_ERR(bq->pg) == -EPROBE_DEFER)
                return PTR_ERR(bq->pg);
        else if (!bq->pg)
                dev_info(bq->dev, "using SW-based power-good detection\n");

        /* reset all registers to defaults */
        ret = bq24257_field_write(bq, F_RESET, 1);
        if (ret < 0)
                return ret;

        /*
         * Put the RESET bit back to 0, in cache. For some reason the HW always
         * returns 1 on this bit, so this is the only way to avoid resetting the
         * chip every time we update another field in this register.
         */
        ret = bq24257_field_write(bq, F_RESET, 0);
        if (ret < 0)
                return ret;

        ret = bq24257_hw_init(bq);
        if (ret < 0) {
                dev_err(dev, "Cannot initialize the chip.\n");
                return ret;
        }

        ret = bq24257_power_supply_init(bq);
        if (ret < 0) {
                dev_err(dev, "Failed to register power supply\n");
                return ret;
        }

        ret = devm_request_threaded_irq(dev, client->irq, NULL,
                                        bq24257_irq_handler_thread,
                                        IRQF_TRIGGER_FALLING |
                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                                        bq2425x_chip_name[bq->chip], bq);
        if (ret) {
                dev_err(dev, "Failed to request IRQ #%d\n", client->irq);
                return ret;
        }

        ret = sysfs_create_group(&bq->charger->dev.kobj, &bq24257_attr_group);
        if (ret < 0) {
                dev_err(dev, "Can't create sysfs entries\n");
                return ret;
        }

        return 0;
}

static int bq24257_remove(struct i2c_client *client)
{
        struct bq24257_device *bq = i2c_get_clientdata(client);

        if (bq->iilimit_autoset_enable)
                cancel_delayed_work_sync(&bq->iilimit_setup_work);

        sysfs_remove_group(&bq->charger->dev.kobj, &bq24257_attr_group);

        bq24257_field_write(bq, F_RESET, 1); /* reset to defaults */

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int bq24257_suspend(struct device *dev)
{
        struct bq24257_device *bq = dev_get_drvdata(dev);
        int ret = 0;

        if (bq->iilimit_autoset_enable)
                cancel_delayed_work_sync(&bq->iilimit_setup_work);

        /* reset all registers to default (and activate standalone mode) */
        ret = bq24257_field_write(bq, F_RESET, 1);
        if (ret < 0)
                dev_err(bq->dev, "Cannot reset chip to standalone mode.\n");

        return ret;
}

static int bq24257_resume(struct device *dev)
{
        int ret;
        struct bq24257_device *bq = dev_get_drvdata(dev);

        ret = regcache_drop_region(bq->rmap, BQ24257_REG_1, BQ24257_REG_7);
        if (ret < 0)
                return ret;

        ret = bq24257_field_write(bq, F_RESET, 0);
        if (ret < 0)
                return ret;

        ret = bq24257_hw_init(bq);
        if (ret < 0) {
                dev_err(bq->dev, "Cannot init chip after resume.\n");
                return ret;
        }

        /* signal userspace, maybe state changed while suspended */
        power_supply_changed(bq->charger);

        return 0;
}
#endif

static const struct dev_pm_ops bq24257_pm = {
        SET_SYSTEM_SLEEP_PM_OPS(bq24257_suspend, bq24257_resume)
};

static const struct i2c_device_id bq24257_i2c_ids[] = {
        { "bq24250", BQ24250 },
        { "bq24251", BQ24251 },
        { "bq24257", BQ24257 },
        {},
};
MODULE_DEVICE_TABLE(i2c, bq24257_i2c_ids);

static const struct of_device_id bq24257_of_match[] = {
        { .compatible = "ti,bq24250", },
        { .compatible = "ti,bq24251", },
        { .compatible = "ti,bq24257", },
        { },
};
MODULE_DEVICE_TABLE(of, bq24257_of_match);

static const struct acpi_device_id bq24257_acpi_match[] = {
        { "BQ242500", BQ24250 },
        { "BQ242510", BQ24251 },
        { "BQ242570", BQ24257 },
        {},
};
MODULE_DEVICE_TABLE(acpi, bq24257_acpi_match);

static struct i2c_driver bq24257_driver = {
        .driver = {
                .name = "bq24257-charger",
                .of_match_table = of_match_ptr(bq24257_of_match),
                .acpi_match_table = ACPI_PTR(bq24257_acpi_match),
                .pm = &bq24257_pm,
        },
        .probe = bq24257_probe,
        .remove = bq24257_remove,
        .id_table = bq24257_i2c_ids,
};
module_i2c_driver(bq24257_driver);

MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
MODULE_DESCRIPTION("bq24257 charger driver");
MODULE_LICENSE("GPL");