// SPDX-License-Identifier: GPL-2.0
/*
 * Fuel gauge driver for CellWise 2013 / 2015
 *
 * Copyright (C) 2012, RockChip
 * Copyright (C) 2020, Tobias Schramm
 *
 * Authors: xuhuicong <xhc@rock-chips.com>
 * Authors: Tobias Schramm <t.schramm@manjaro.org>
 */

#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/power_supply.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/time.h>
#include <linux/workqueue.h>
#include <linux/devm-helpers.h>

#define CW2015_SIZE_BATINFO             64

#define CW2015_RESET_TRIES              5

#define CW2015_REG_VERSION              0x00
#define CW2015_REG_VCELL                0x02
#define CW2015_REG_SOC                  0x04
#define CW2015_REG_RRT_ALERT            0x06
#define CW2015_REG_CONFIG               0x08
#define CW2015_REG_MODE                 0x0A
#define CW2015_REG_BATINFO              0x10

#define CW2015_MODE_SLEEP_MASK          GENMASK(7, 6)
#define CW2015_MODE_SLEEP               (0x03 << 6)
#define CW2015_MODE_NORMAL              (0x00 << 6)
#define CW2015_MODE_QUICK_START         (0x03 << 4)
#define CW2015_MODE_RESTART             (0x0f << 0)

#define CW2015_CONFIG_UPDATE_FLG        (0x01 << 1)
#define CW2015_ATHD(x)                  ((x) << 3)
#define CW2015_MASK_ATHD                GENMASK(7, 3)
#define CW2015_MASK_SOC                 GENMASK(12, 0)

/* reset gauge of no valid state of charge could be polled for 40s */
#define CW2015_BAT_SOC_ERROR_MS         (40 * MSEC_PER_SEC)
/* reset gauge if state of charge stuck for half an hour during charging */
#define CW2015_BAT_CHARGING_STUCK_MS    (1800 * MSEC_PER_SEC)

/* poll interval from CellWise GPL Android driver example */
#define CW2015_DEFAULT_POLL_INTERVAL_MS         8000

#define CW2015_AVERAGING_SAMPLES                3

struct cw_battery {
        struct device *dev;
        struct workqueue_struct *battery_workqueue;
        struct delayed_work battery_delay_work;
        struct regmap *regmap;
        struct power_supply *rk_bat;
        struct power_supply_battery_info *battery;
        u8 *bat_profile;

        bool charger_attached;
        bool battery_changed;

        int soc;
        int voltage_mv;
        int status;
        int time_to_empty;
        int charge_count;

        u32 poll_interval_ms;
        u8 alert_level;

        unsigned int read_errors;
        unsigned int charge_stuck_cnt;
};

static int cw_read_word(struct cw_battery *cw_bat, u8 reg, u16 *val)
{
        __be16 value;
        int ret;

        ret = regmap_bulk_read(cw_bat->regmap, reg, &value, sizeof(value));
        if (ret)
                return ret;

        *val = be16_to_cpu(value);
        return 0;
}

static int cw_update_profile(struct cw_battery *cw_bat)
{
        int ret;
        unsigned int reg_val;
        u8 reset_val;

        /* make sure gauge is not in sleep mode */
        ret = regmap_read(cw_bat->regmap, CW2015_REG_MODE, &reg_val);
        if (ret)
                return ret;

        reset_val = reg_val;
        if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
                dev_err(cw_bat->dev,
                        "Gauge is in sleep mode, can't update battery info\n");
                return -EINVAL;
        }

        /* write new battery info */
        ret = regmap_raw_write(cw_bat->regmap, CW2015_REG_BATINFO,
                               cw_bat->bat_profile,
                               CW2015_SIZE_BATINFO);
        if (ret)
                return ret;

        /* set config update flag  */
        reg_val |= CW2015_CONFIG_UPDATE_FLG;
        reg_val &= ~CW2015_MASK_ATHD;
        reg_val |= CW2015_ATHD(cw_bat->alert_level);
        ret = regmap_write(cw_bat->regmap, CW2015_REG_CONFIG, reg_val);
        if (ret)
                return ret;

        /* reset gauge to apply new battery profile */
        reset_val &= ~CW2015_MODE_RESTART;
        reg_val = reset_val | CW2015_MODE_RESTART;
        ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
        if (ret)
                return ret;

        /* wait for gauge to reset */
        msleep(20);

        /* clear reset flag */
        ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
        if (ret)
                return ret;

        /* wait for gauge to become ready */
        ret = regmap_read_poll_timeout(cw_bat->regmap, CW2015_REG_SOC,
                                       reg_val, reg_val <= 100,
                                       10 * USEC_PER_MSEC, 10 * USEC_PER_SEC);
        if (ret)
                dev_err(cw_bat->dev,
                        "Gauge did not become ready after profile upload\n");
        else
                dev_dbg(cw_bat->dev, "Battery profile updated\n");

        return ret;
}

static int cw_init(struct cw_battery *cw_bat)
{
        int ret;
        unsigned int reg_val = CW2015_MODE_SLEEP;

        if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
                reg_val = CW2015_MODE_NORMAL;
                ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
                if (ret)
                        return ret;
        }

        ret = regmap_read(cw_bat->regmap, CW2015_REG_CONFIG, &reg_val);
        if (ret)
                return ret;

        if ((reg_val & CW2015_MASK_ATHD) != CW2015_ATHD(cw_bat->alert_level)) {
                dev_dbg(cw_bat->dev, "Setting new alert level\n");
                reg_val &= ~CW2015_MASK_ATHD;
                reg_val |= ~CW2015_ATHD(cw_bat->alert_level);
                ret = regmap_write(cw_bat->regmap, CW2015_REG_CONFIG, reg_val);
                if (ret)
                        return ret;
        }

        ret = regmap_read(cw_bat->regmap, CW2015_REG_CONFIG, &reg_val);
        if (ret)
                return ret;

        if (!(reg_val & CW2015_CONFIG_UPDATE_FLG)) {
                dev_dbg(cw_bat->dev,
                        "Battery profile not present, uploading battery profile\n");
                if (cw_bat->bat_profile) {
                        ret = cw_update_profile(cw_bat);
                        if (ret) {
                                dev_err(cw_bat->dev,
                                        "Failed to upload battery profile\n");
                                return ret;
                        }
                } else {
                        dev_warn(cw_bat->dev,
                                 "No profile specified, continuing without profile\n");
                }
        } else if (cw_bat->bat_profile) {
                u8 bat_info[CW2015_SIZE_BATINFO];

                ret = regmap_raw_read(cw_bat->regmap, CW2015_REG_BATINFO,
                                      bat_info, CW2015_SIZE_BATINFO);
                if (ret) {
                        dev_err(cw_bat->dev,
                                "Failed to read stored battery profile\n");
                        return ret;
                }

                if (memcmp(bat_info, cw_bat->bat_profile, CW2015_SIZE_BATINFO)) {
                        dev_warn(cw_bat->dev, "Replacing stored battery profile\n");
                        ret = cw_update_profile(cw_bat);
                        if (ret)
                                return ret;
                }
        } else {
                dev_warn(cw_bat->dev,
                         "Can't check current battery profile, no profile provided\n");
        }

        dev_dbg(cw_bat->dev, "Battery profile configured\n");
        return 0;
}

static int cw_power_on_reset(struct cw_battery *cw_bat)
{
        int ret;
        unsigned char reset_val;

        reset_val = CW2015_MODE_SLEEP;
        ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
        if (ret)
                return ret;

        /* wait for gauge to enter sleep */
        msleep(20);

        reset_val = CW2015_MODE_NORMAL;
        ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
        if (ret)
                return ret;

        ret = cw_init(cw_bat);
        if (ret)
                return ret;
        return 0;
}

#define HYSTERESIS(current, previous, up, down) \
        (((current) < (previous) + (up)) && ((current) > (previous) - (down)))

static int cw_get_soc(struct cw_battery *cw_bat)
{
        unsigned int soc;
        int ret;

        ret = regmap_read(cw_bat->regmap, CW2015_REG_SOC, &soc);
        if (ret)
                return ret;

        if (soc > 100) {
                int max_error_cycles =
                        CW2015_BAT_SOC_ERROR_MS / cw_bat->poll_interval_ms;

                dev_err(cw_bat->dev, "Invalid SoC %d%%\n", soc);
                cw_bat->read_errors++;
                if (cw_bat->read_errors > max_error_cycles) {
                        dev_warn(cw_bat->dev,
                                 "Too many invalid SoC reports, resetting gauge\n");
                        cw_power_on_reset(cw_bat);
                        cw_bat->read_errors = 0;
                }
                return cw_bat->soc;
        }
        cw_bat->read_errors = 0;

        /* Reset gauge if stuck while charging */
        if (cw_bat->status == POWER_SUPPLY_STATUS_CHARGING && soc == cw_bat->soc) {
                int max_stuck_cycles =
                        CW2015_BAT_CHARGING_STUCK_MS / cw_bat->poll_interval_ms;

                cw_bat->charge_stuck_cnt++;
                if (cw_bat->charge_stuck_cnt > max_stuck_cycles) {
                        dev_warn(cw_bat->dev,
                                 "SoC stuck @%u%%, resetting gauge\n", soc);
                        cw_power_on_reset(cw_bat);
                        cw_bat->charge_stuck_cnt = 0;
                }
        } else {
                cw_bat->charge_stuck_cnt = 0;
        }

        /* Ignore voltage dips during charge */
        if (cw_bat->charger_attached && HYSTERESIS(soc, cw_bat->soc, 0, 3))
                soc = cw_bat->soc;

        /* Ignore voltage spikes during discharge */
        if (!cw_bat->charger_attached && HYSTERESIS(soc, cw_bat->soc, 3, 0))
                soc = cw_bat->soc;

        return soc;
}

static int cw_get_voltage(struct cw_battery *cw_bat)
{
        int ret, i, voltage_mv;
        u16 reg_val;
        u32 avg = 0;

        for (i = 0; i < CW2015_AVERAGING_SAMPLES; i++) {
                ret = cw_read_word(cw_bat, CW2015_REG_VCELL, &reg_val);
                if (ret)
                        return ret;

                avg += reg_val;
        }
        avg /= CW2015_AVERAGING_SAMPLES;

        /*
         * 305 uV per ADC step
         * Use 312 / 1024  as efficient approximation of 305 / 1000
         * Negligible error of 0.1%
         */
        voltage_mv = avg * 312 / 1024;

        dev_dbg(cw_bat->dev, "Read voltage: %d mV, raw=0x%04x\n",
                voltage_mv, reg_val);
        return voltage_mv;
}

static int cw_get_time_to_empty(struct cw_battery *cw_bat)
{
        int ret;
        u16 value16;

        ret = cw_read_word(cw_bat, CW2015_REG_RRT_ALERT, &value16);
        if (ret)
                return ret;

        return value16 & CW2015_MASK_SOC;
}

static void cw_update_charge_status(struct cw_battery *cw_bat)
{
        int ret;

        ret = power_supply_am_i_supplied(cw_bat->rk_bat);
        if (ret < 0) {
                dev_warn(cw_bat->dev, "Failed to get supply state: %d\n", ret);
        } else {
                bool charger_attached;

                charger_attached = !!ret;
                if (cw_bat->charger_attached != charger_attached) {
                        cw_bat->battery_changed = true;
                        if (charger_attached)
                                cw_bat->charge_count++;
                }
                cw_bat->charger_attached = charger_attached;
        }
}

static void cw_update_soc(struct cw_battery *cw_bat)
{
        int soc;

        soc = cw_get_soc(cw_bat);
        if (soc < 0)
                dev_err(cw_bat->dev, "Failed to get SoC from gauge: %d\n", soc);
        else if (cw_bat->soc != soc) {
                cw_bat->soc = soc;
                cw_bat->battery_changed = true;
        }
}

static void cw_update_voltage(struct cw_battery *cw_bat)
{
        int voltage_mv;

        voltage_mv = cw_get_voltage(cw_bat);
        if (voltage_mv < 0)
                dev_err(cw_bat->dev, "Failed to get voltage from gauge: %d\n",
                        voltage_mv);
        else
                cw_bat->voltage_mv = voltage_mv;
}

static void cw_update_status(struct cw_battery *cw_bat)
{
        int status = POWER_SUPPLY_STATUS_DISCHARGING;

        if (cw_bat->charger_attached) {
                if (cw_bat->soc >= 100)
                        status = POWER_SUPPLY_STATUS_FULL;
                else
                        status = POWER_SUPPLY_STATUS_CHARGING;
        }

        if (cw_bat->status != status)
                cw_bat->battery_changed = true;
        cw_bat->status = status;
}

static void cw_update_time_to_empty(struct cw_battery *cw_bat)
{
        int time_to_empty;

        time_to_empty = cw_get_time_to_empty(cw_bat);
        if (time_to_empty < 0)
                dev_err(cw_bat->dev, "Failed to get time to empty from gauge: %d\n",
                        time_to_empty);
        else if (cw_bat->time_to_empty != time_to_empty) {
                cw_bat->time_to_empty = time_to_empty;
                cw_bat->battery_changed = true;
        }
}

static void cw_bat_work(struct work_struct *work)
{
        struct delayed_work *delay_work;
        struct cw_battery *cw_bat;
        int ret;
        unsigned int reg_val;

        delay_work = to_delayed_work(work);
        cw_bat = container_of(delay_work, struct cw_battery, battery_delay_work);
        ret = regmap_read(cw_bat->regmap, CW2015_REG_MODE, &reg_val);
        if (ret) {
                dev_err(cw_bat->dev, "Failed to read mode from gauge: %d\n", ret);
        } else {
                if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
                        int i;

                        for (i = 0; i < CW2015_RESET_TRIES; i++) {
                                if (!cw_power_on_reset(cw_bat))
                                        break;
                        }
                }
                cw_update_soc(cw_bat);
                cw_update_voltage(cw_bat);
                cw_update_charge_status(cw_bat);
                cw_update_status(cw_bat);
                cw_update_time_to_empty(cw_bat);
        }
        dev_dbg(cw_bat->dev, "charger_attached = %d\n", cw_bat->charger_attached);
        dev_dbg(cw_bat->dev, "status = %d\n", cw_bat->status);
        dev_dbg(cw_bat->dev, "soc = %d%%\n", cw_bat->soc);
        dev_dbg(cw_bat->dev, "voltage = %dmV\n", cw_bat->voltage_mv);

        if (cw_bat->battery_changed)
                power_supply_changed(cw_bat->rk_bat);
        cw_bat->battery_changed = false;

        queue_delayed_work(cw_bat->battery_workqueue,
                           &cw_bat->battery_delay_work,
                           msecs_to_jiffies(cw_bat->poll_interval_ms));
}

static bool cw_battery_valid_time_to_empty(struct cw_battery *cw_bat)
{
        return  cw_bat->time_to_empty > 0 &&
                cw_bat->time_to_empty < CW2015_MASK_SOC &&
                cw_bat->status == POWER_SUPPLY_STATUS_DISCHARGING;
}

static int cw_battery_get_property(struct power_supply *psy,
                                   enum power_supply_property psp,
                                   union power_supply_propval *val)
{
        struct cw_battery *cw_bat;

        cw_bat = power_supply_get_drvdata(psy);
        switch (psp) {
        case POWER_SUPPLY_PROP_CAPACITY:
                val->intval = cw_bat->soc;
                break;

        case POWER_SUPPLY_PROP_STATUS:
                val->intval = cw_bat->status;
                break;

        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = !!cw_bat->voltage_mv;
                break;

        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = cw_bat->voltage_mv * 1000;
                break;

        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
                if (cw_battery_valid_time_to_empty(cw_bat))
                        val->intval = cw_bat->time_to_empty * 60;
                else
                        val->intval = 0;
                break;

        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
                break;

        case POWER_SUPPLY_PROP_CHARGE_COUNTER:
                val->intval = cw_bat->charge_count;
                break;

        case POWER_SUPPLY_PROP_CHARGE_FULL:
        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
                val->intval = max(cw_bat->battery->charge_full_design_uah, 0);
                break;

        case POWER_SUPPLY_PROP_CHARGE_NOW:
                val->intval = cw_bat->battery->charge_full_design_uah;
                val->intval = val->intval * cw_bat->soc / 100;
                break;

        case POWER_SUPPLY_PROP_CURRENT_NOW:
                if (cw_battery_valid_time_to_empty(cw_bat) &&
                    cw_bat->battery->charge_full_design_uah > 0) {
                        /* calculate remaining capacity */
                        val->intval = cw_bat->battery->charge_full_design_uah;
                        val->intval = val->intval * cw_bat->soc / 100;

                        /* estimate current based on time to empty */
                        val->intval = 60 * val->intval / cw_bat->time_to_empty;
                } else {
                        val->intval = 0;
                }

                break;

        default:
                break;
        }
        return 0;
}

static enum power_supply_property cw_battery_properties[] = {
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_CHARGE_COUNTER,
        POWER_SUPPLY_PROP_CHARGE_FULL,
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
        POWER_SUPPLY_PROP_CHARGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
};

static const struct power_supply_desc cw2015_bat_desc = {
        .name           = "cw2015-battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .properties     = cw_battery_properties,
        .num_properties = ARRAY_SIZE(cw_battery_properties),
        .get_property   = cw_battery_get_property,
};

static int cw2015_parse_properties(struct cw_battery *cw_bat)
{
        struct device *dev = cw_bat->dev;
        int length;
        int ret;

        length = device_property_count_u8(dev, "cellwise,battery-profile");
        if (length < 0) {
                dev_warn(cw_bat->dev,
                         "No battery-profile found, using current flash contents\n");
        } else if (length != CW2015_SIZE_BATINFO) {
                dev_err(cw_bat->dev, "battery-profile must be %d bytes\n",
                        CW2015_SIZE_BATINFO);
                return -EINVAL;
        } else {
                cw_bat->bat_profile = devm_kzalloc(dev, length, GFP_KERNEL);
                if (!cw_bat->bat_profile)
                        return -ENOMEM;

                ret = device_property_read_u8_array(dev,
                                                "cellwise,battery-profile",
                                                cw_bat->bat_profile,
                                                length);
                if (ret)
                        return ret;
        }

        ret = device_property_read_u32(dev, "cellwise,monitor-interval-ms",
                                       &cw_bat->poll_interval_ms);
        if (ret) {
                dev_dbg(cw_bat->dev, "Using default poll interval\n");
                cw_bat->poll_interval_ms = CW2015_DEFAULT_POLL_INTERVAL_MS;
        }

        return 0;
}

static const struct regmap_range regmap_ranges_rd_yes[] = {
        regmap_reg_range(CW2015_REG_VERSION, CW2015_REG_VERSION),
        regmap_reg_range(CW2015_REG_VCELL, CW2015_REG_CONFIG),
        regmap_reg_range(CW2015_REG_MODE, CW2015_REG_MODE),
        regmap_reg_range(CW2015_REG_BATINFO,
                        CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1),
};

static const struct regmap_access_table regmap_rd_table = {
        .yes_ranges = regmap_ranges_rd_yes,
        .n_yes_ranges = 4,
};

static const struct regmap_range regmap_ranges_wr_yes[] = {
        regmap_reg_range(CW2015_REG_RRT_ALERT, CW2015_REG_CONFIG),
        regmap_reg_range(CW2015_REG_MODE, CW2015_REG_MODE),
        regmap_reg_range(CW2015_REG_BATINFO,
                        CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1),
};

static const struct regmap_access_table regmap_wr_table = {
        .yes_ranges = regmap_ranges_wr_yes,
        .n_yes_ranges = 3,
};

static const struct regmap_range regmap_ranges_vol_yes[] = {
        regmap_reg_range(CW2015_REG_VCELL, CW2015_REG_SOC + 1),
};

static const struct regmap_access_table regmap_vol_table = {
        .yes_ranges = regmap_ranges_vol_yes,
        .n_yes_ranges = 1,
};

static const struct regmap_config cw2015_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .rd_table = &regmap_rd_table,
        .wr_table = &regmap_wr_table,
        .volatile_table = &regmap_vol_table,
        .max_register = CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1,
};

static int cw_bat_probe(struct i2c_client *client)
{
        int ret;
        struct cw_battery *cw_bat;
        struct power_supply_config psy_cfg = { 0 };

        cw_bat = devm_kzalloc(&client->dev, sizeof(*cw_bat), GFP_KERNEL);
        if (!cw_bat)
                return -ENOMEM;

        i2c_set_clientdata(client, cw_bat);
        cw_bat->dev = &client->dev;
        cw_bat->soc = 1;

        ret = cw2015_parse_properties(cw_bat);
        if (ret) {
                dev_err(cw_bat->dev, "Failed to parse cw2015 properties\n");
                return ret;
        }

        cw_bat->regmap = devm_regmap_init_i2c(client, &cw2015_regmap_config);
        if (IS_ERR(cw_bat->regmap)) {
                dev_err(cw_bat->dev, "Failed to allocate regmap: %ld\n",
                        PTR_ERR(cw_bat->regmap));
                return PTR_ERR(cw_bat->regmap);
        }

        ret = cw_init(cw_bat);
        if (ret) {
                dev_err(cw_bat->dev, "Init failed: %d\n", ret);
                return ret;
        }

        psy_cfg.drv_data = cw_bat;
        psy_cfg.fwnode = dev_fwnode(cw_bat->dev);

        cw_bat->rk_bat = devm_power_supply_register(&client->dev,
                                                    &cw2015_bat_desc,
                                                    &psy_cfg);
        if (IS_ERR(cw_bat->rk_bat)) {
                /* try again if this happens */
                dev_err_probe(&client->dev, PTR_ERR(cw_bat->rk_bat),
                        "Failed to register power supply\n");
                return PTR_ERR(cw_bat->rk_bat);
        }

        ret = power_supply_get_battery_info(cw_bat->rk_bat, &cw_bat->battery);
        if (ret) {
                /* Allocate an empty battery */
                cw_bat->battery = devm_kzalloc(&client->dev,
                                               sizeof(*cw_bat->battery),
                                               GFP_KERNEL);
                if (!cw_bat->battery)
                        return -ENOMEM;
                dev_warn(cw_bat->dev,
                         "No monitored battery, some properties will be missing\n");
        }

        cw_bat->battery_workqueue = create_singlethread_workqueue("rk_battery");
        if (!cw_bat->battery_workqueue)
                return -ENOMEM;

        ret = devm_delayed_work_autocancel(&client->dev, &cw_bat->battery_delay_work, cw_bat_work);
        if (ret) {
                dev_err_probe(&client->dev, ret,
                        "Failed to register delayed work\n");
                return ret;
        }

        queue_delayed_work(cw_bat->battery_workqueue,
                           &cw_bat->battery_delay_work, msecs_to_jiffies(10));
        return 0;
}

static int __maybe_unused cw_bat_suspend(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct cw_battery *cw_bat = i2c_get_clientdata(client);

        cancel_delayed_work_sync(&cw_bat->battery_delay_work);
        return 0;
}

static int __maybe_unused cw_bat_resume(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct cw_battery *cw_bat = i2c_get_clientdata(client);

        queue_delayed_work(cw_bat->battery_workqueue,
                           &cw_bat->battery_delay_work, 0);
        return 0;
}

static SIMPLE_DEV_PM_OPS(cw_bat_pm_ops, cw_bat_suspend, cw_bat_resume);

static const struct i2c_device_id cw_bat_id_table[] = {
        { "cw2015" },
        { }
};

static const struct of_device_id cw2015_of_match[] = {
        { .compatible = "cellwise,cw2015" },
        { }
};
MODULE_DEVICE_TABLE(of, cw2015_of_match);

static struct i2c_driver cw_bat_driver = {
        .driver = {
                .name = "cw2015",
                .of_match_table = cw2015_of_match,
                .pm = &cw_bat_pm_ops,
        },
        .probe = cw_bat_probe,
        .id_table = cw_bat_id_table,
};

module_i2c_driver(cw_bat_driver);

MODULE_AUTHOR("xhc<xhc@rock-chips.com>");
MODULE_AUTHOR("Tobias Schramm <t.schramm@manjaro.org>");
MODULE_DESCRIPTION("cw2015/cw2013 battery driver");
MODULE_LICENSE("GPL");