/*
 * Driver for batteries with DS2760 chips inside.
 *
 * Copyright © 2007 Anton Vorontsov
 *             2004-2007 Matt Reimer
 *             2004 Szabolcs Gyurko
 *
 * Use consistent with the GNU GPL is permitted,
 * provided that this copyright notice is
 * preserved in its entirety in all copies and derived works.
 *
 * Author:  Anton Vorontsov <cbou@mail.ru>
 *          February 2007
 *
 *          Matt Reimer <mreimer@vpop.net>
 *          April 2004, 2005, 2007
 *
 *          Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
 *          September 2004
 */

#include <linux/module.h>
#include <linux/param.h>
#include <linux/jiffies.h>
#include <linux/workqueue.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/suspend.h>
#include <linux/w1.h>
#include <linux/of.h>

static unsigned int cache_time = 1000;
module_param(cache_time, uint, 0644);
MODULE_PARM_DESC(cache_time, "cache time in milliseconds");

static bool pmod_enabled;
module_param(pmod_enabled, bool, 0644);
MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");

static unsigned int rated_capacity;
module_param(rated_capacity, uint, 0644);
MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");

static unsigned int current_accum;
module_param(current_accum, uint, 0644);
MODULE_PARM_DESC(current_accum, "current accumulator value");

#define W1_FAMILY_DS2760                0x30

/* Known commands to the DS2760 chip */
#define W1_DS2760_SWAP                  0xAA
#define W1_DS2760_READ_DATA             0x69
#define W1_DS2760_WRITE_DATA            0x6C
#define W1_DS2760_COPY_DATA             0x48
#define W1_DS2760_RECALL_DATA           0xB8
#define W1_DS2760_LOCK                  0x6A

/* Number of valid register addresses */
#define DS2760_DATA_SIZE                0x40

#define DS2760_PROTECTION_REG           0x00

#define DS2760_STATUS_REG               0x01
#define DS2760_STATUS_IE                (1 << 2)
#define DS2760_STATUS_SWEN              (1 << 3)
#define DS2760_STATUS_RNAOP             (1 << 4)
#define DS2760_STATUS_PMOD              (1 << 5)

#define DS2760_EEPROM_REG               0x07
#define DS2760_SPECIAL_FEATURE_REG      0x08
#define DS2760_VOLTAGE_MSB              0x0c
#define DS2760_VOLTAGE_LSB              0x0d
#define DS2760_CURRENT_MSB              0x0e
#define DS2760_CURRENT_LSB              0x0f
#define DS2760_CURRENT_ACCUM_MSB        0x10
#define DS2760_CURRENT_ACCUM_LSB        0x11
#define DS2760_TEMP_MSB                 0x18
#define DS2760_TEMP_LSB                 0x19
#define DS2760_EEPROM_BLOCK0            0x20
#define DS2760_ACTIVE_FULL              0x20
#define DS2760_EEPROM_BLOCK1            0x30
#define DS2760_STATUS_WRITE_REG         0x31
#define DS2760_RATED_CAPACITY           0x32
#define DS2760_CURRENT_OFFSET_BIAS      0x33
#define DS2760_ACTIVE_EMPTY             0x3b

struct ds2760_device_info {
        struct device *dev;

        /* DS2760 data, valid after calling ds2760_battery_read_status() */
        unsigned long update_time;      /* jiffies when data read */
        char raw[DS2760_DATA_SIZE];     /* raw DS2760 data */
        int voltage_raw;                /* units of 4.88 mV */
        int voltage_uV;                 /* units of µV */
        int current_raw;                /* units of 0.625 mA */
        int current_uA;                 /* units of µA */
        int accum_current_raw;          /* units of 0.25 mAh */
        int accum_current_uAh;          /* units of µAh */
        int temp_raw;                   /* units of 0.125 °C */
        int temp_C;                     /* units of 0.1 °C */
        int rated_capacity;             /* units of µAh */
        int rem_capacity;               /* percentage */
        int full_active_uAh;            /* units of µAh */
        int empty_uAh;                  /* units of µAh */
        int life_sec;                   /* units of seconds */
        int charge_status;              /* POWER_SUPPLY_STATUS_* */

        int full_counter;
        struct power_supply *bat;
        struct power_supply_desc bat_desc;
        struct workqueue_struct *monitor_wqueue;
        struct delayed_work monitor_work;
        struct notifier_block pm_notifier;
};

static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
                        int io)
{
        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

        if (!dev)
                return 0;

        mutex_lock(&sl->master->bus_mutex);

        if (addr > DS2760_DATA_SIZE || addr < 0) {
                count = 0;
                goto out;
        }
        if (addr + count > DS2760_DATA_SIZE)
                count = DS2760_DATA_SIZE - addr;

        if (!w1_reset_select_slave(sl)) {
                if (!io) {
                        w1_write_8(sl->master, W1_DS2760_READ_DATA);
                        w1_write_8(sl->master, addr);
                        count = w1_read_block(sl->master, buf, count);
                } else {
                        w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
                        w1_write_8(sl->master, addr);
                        w1_write_block(sl->master, buf, count);
                        /* XXX w1_write_block returns void, not n_written */
                }
        }

out:
        mutex_unlock(&sl->master->bus_mutex);

        return count;
}

static int w1_ds2760_read(struct device *dev,
                          char *buf, int addr,
                          size_t count)
{
        return w1_ds2760_io(dev, buf, addr, count, 0);
}

static int w1_ds2760_write(struct device *dev,
                           char *buf,
                           int addr, size_t count)
{
        return w1_ds2760_io(dev, buf, addr, count, 1);
}

static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
{
        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

        if (!dev)
                return -EINVAL;

        mutex_lock(&sl->master->bus_mutex);

        if (w1_reset_select_slave(sl) == 0) {
                w1_write_8(sl->master, cmd);
                w1_write_8(sl->master, addr);
        }

        mutex_unlock(&sl->master->bus_mutex);
        return 0;
}

static int w1_ds2760_store_eeprom(struct device *dev, int addr)
{
        return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
}

static int w1_ds2760_recall_eeprom(struct device *dev, int addr)
{
        return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
}

static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
                             const struct bin_attribute *bin_attr, char *buf,
                             loff_t off, size_t count)
{
        struct device *dev = kobj_to_dev(kobj);
        return w1_ds2760_read(dev, buf, off, count);
}

static const BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);

static const struct bin_attribute *const w1_ds2760_bin_attrs[] = {
        &bin_attr_w1_slave,
        NULL,
};

static const struct attribute_group w1_ds2760_group = {
        .bin_attrs = w1_ds2760_bin_attrs,
};

static const struct attribute_group *w1_ds2760_groups[] = {
        &w1_ds2760_group,
        NULL,
};
/* Some batteries have their rated capacity stored a N * 10 mAh, while
 * others use an index into this table. */
static int rated_capacities[] = {
        0,
        920,    /* Samsung */
        920,    /* BYD */
        920,    /* Lishen */
        920,    /* NEC */
        1440,   /* Samsung */
        1440,   /* BYD */
        1440,   /* Lishen */
        1440,   /* NEC */
        2880,   /* Samsung */
        2880,   /* BYD */
        2880,   /* Lishen */
        2880,   /* NEC */
};

/* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
 * temp is in Celsius */
static int battery_interpolate(int array[], int temp)
{
        int index, dt;

        if (temp <= 0)
                return array[0];
        if (temp >= 40)
                return array[4];

        index = temp / 10;
        dt    = temp % 10;

        return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
}

static int ds2760_battery_read_status(struct ds2760_device_info *di)
{
        int ret, i, start, count, scale[5];

        if (di->update_time && time_before(jiffies, di->update_time +
                                           msecs_to_jiffies(cache_time)))
                return 0;

        /* The first time we read the entire contents of SRAM/EEPROM,
         * but after that we just read the interesting bits that change. */
        if (di->update_time == 0) {
                start = 0;
                count = DS2760_DATA_SIZE;
        } else {
                start = DS2760_VOLTAGE_MSB;
                count = DS2760_TEMP_LSB - start + 1;
        }

        ret = w1_ds2760_read(di->dev, di->raw + start, start, count);
        if (ret != count) {
                dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
                         di->dev);
                return 1;
        }

        di->update_time = jiffies;

        /* DS2760 reports voltage in units of 4.88mV, but the battery class
         * reports in units of uV, so convert by multiplying by 4880. */
        di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
                          (di->raw[DS2760_VOLTAGE_LSB] >> 5);
        di->voltage_uV = di->voltage_raw * 4880;

        /* DS2760 reports current in signed units of 0.625mA, but the battery
         * class reports in units of µA, so convert by multiplying by 625. */
        di->current_raw =
            (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
                          (di->raw[DS2760_CURRENT_LSB] >> 3);
        di->current_uA = di->current_raw * 625;

        /* DS2760 reports accumulated current in signed units of 0.25mAh. */
        di->accum_current_raw =
            (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
                           di->raw[DS2760_CURRENT_ACCUM_LSB];
        di->accum_current_uAh = di->accum_current_raw * 250;

        /* DS2760 reports temperature in signed units of 0.125°C, but the
         * battery class reports in units of 1/10 °C, so we convert by
         * multiplying by .125 * 10 = 1.25. */
        di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
                                     (di->raw[DS2760_TEMP_LSB] >> 5);
        di->temp_C = di->temp_raw + (di->temp_raw / 4);

        /* At least some battery monitors (e.g. HP iPAQ) store the battery's
         * maximum rated capacity. */
        if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
                di->rated_capacity = rated_capacities[
                        (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
        else
                di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;

        di->rated_capacity *= 1000; /* convert to µAh */

        /* Calculate the full level at the present temperature. */
        di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
                              di->raw[DS2760_ACTIVE_FULL + 1];

        /* If the full_active_uAh value is not given, fall back to the rated
         * capacity. This is likely to happen when chips are not part of the
         * battery pack and is therefore not bootstrapped. */
        if (di->full_active_uAh == 0)
                di->full_active_uAh = di->rated_capacity / 1000L;

        scale[0] = di->full_active_uAh;
        for (i = 1; i < 5; i++)
                scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];

        di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
        di->full_active_uAh *= 1000; /* convert to µAh */

        /* Calculate the empty level at the present temperature. */
        scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
        for (i = 3; i >= 0; i--)
                scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];

        di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
        di->empty_uAh *= 1000; /* convert to µAh */

        if (di->full_active_uAh == di->empty_uAh)
                di->rem_capacity = 0;
        else
                /* From Maxim Application Note 131: remaining capacity =
                 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
                di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
                                    (di->full_active_uAh - di->empty_uAh);

        if (di->rem_capacity < 0)
                di->rem_capacity = 0;
        if (di->rem_capacity > 100)
                di->rem_capacity = 100;

        if (di->current_uA < -100L)
                di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
                                        / (di->current_uA / 100L);
        else
                di->life_sec = 0;

        return 0;
}

static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
                                             unsigned int acr_val)
{
        unsigned char acr[2];

        /* acr is in units of 0.25 mAh */
        acr_val *= 4L;
        acr_val /= 1000;

        acr[0] = acr_val >> 8;
        acr[1] = acr_val & 0xff;

        if (w1_ds2760_write(di->dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
                dev_warn(di->dev, "ACR write failed\n");
}

static void ds2760_battery_update_status(struct ds2760_device_info *di)
{
        int old_charge_status = di->charge_status;

        ds2760_battery_read_status(di);

        if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
                di->full_counter = 0;

        if (power_supply_am_i_supplied(di->bat)) {
                if (di->current_uA > 10000) {
                        di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
                        di->full_counter = 0;
                } else if (di->current_uA < -5000) {
                        if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
                                dev_notice(di->dev, "not enough power to "
                                           "charge\n");
                        di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
                        di->full_counter = 0;
                } else if (di->current_uA < 10000 &&
                            di->charge_status != POWER_SUPPLY_STATUS_FULL) {

                        /* Don't consider the battery to be full unless
                         * we've seen the current < 10 mA at least two
                         * consecutive times. */

                        di->full_counter++;

                        if (di->full_counter < 2) {
                                di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
                        } else {
                                di->charge_status = POWER_SUPPLY_STATUS_FULL;
                                ds2760_battery_set_current_accum(di,
                                                di->full_active_uAh);
                        }
                }
        } else {
                di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
                di->full_counter = 0;
        }

        if (di->charge_status != old_charge_status)
                power_supply_changed(di->bat);
}

static void ds2760_battery_write_status(struct ds2760_device_info *di,
                                        char status)
{
        if (status == di->raw[DS2760_STATUS_REG])
                return;

        w1_ds2760_write(di->dev, &status, DS2760_STATUS_WRITE_REG, 1);
        w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
        w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
}

static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
                                                unsigned char rated_capacity)
{
        if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
                return;

        w1_ds2760_write(di->dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
        w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
        w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
}

static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
                                             int active_full)
{
        unsigned char tmp[2] = {
                active_full >> 8,
                active_full & 0xff
        };

        if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
            tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
                return;

        w1_ds2760_write(di->dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
        w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
        w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK0);

        /* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
         * values won't be read back by ds2760_battery_read_status() */
        di->raw[DS2760_ACTIVE_FULL] = tmp[0];
        di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
}

static void ds2760_battery_work(struct work_struct *work)
{
        struct ds2760_device_info *di = container_of(work,
                struct ds2760_device_info, monitor_work.work);
        const int interval = HZ * 60;

        dev_dbg(di->dev, "%s\n", __func__);

        ds2760_battery_update_status(di);
        queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
}

static void ds2760_battery_external_power_changed(struct power_supply *psy)
{
        struct ds2760_device_info *di = power_supply_get_drvdata(psy);

        dev_dbg(di->dev, "%s\n", __func__);

        mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
}


static int ds2760_battery_get_property(struct power_supply *psy,
                                       enum power_supply_property psp,
                                       union power_supply_propval *val)
{
        struct ds2760_device_info *di = power_supply_get_drvdata(psy);

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = di->charge_status;
                return 0;
        default:
                break;
        }

        ds2760_battery_read_status(di);

        switch (psp) {
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = di->voltage_uV;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                val->intval = di->current_uA;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
                val->intval = di->rated_capacity;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL:
                val->intval = di->full_active_uAh;
                break;
        case POWER_SUPPLY_PROP_CHARGE_EMPTY:
                val->intval = di->empty_uAh;
                break;
        case POWER_SUPPLY_PROP_CHARGE_NOW:
                val->intval = di->accum_current_uAh;
                break;
        case POWER_SUPPLY_PROP_TEMP:
                val->intval = di->temp_C;
                break;
        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
                val->intval = di->life_sec;
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                val->intval = di->rem_capacity;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int ds2760_battery_set_property(struct power_supply *psy,
                                       enum power_supply_property psp,
                                       const union power_supply_propval *val)
{
        struct ds2760_device_info *di = power_supply_get_drvdata(psy);

        switch (psp) {
        case POWER_SUPPLY_PROP_CHARGE_FULL:
                /* the interface counts in uAh, convert the value */
                ds2760_battery_write_active_full(di, val->intval / 1000L);
                break;

        case POWER_SUPPLY_PROP_CHARGE_NOW:
                /* ds2760_battery_set_current_accum() does the conversion */
                ds2760_battery_set_current_accum(di, val->intval);
                break;

        default:
                return -EPERM;
        }

        return 0;
}

static int ds2760_battery_property_is_writeable(struct power_supply *psy,
                                                enum power_supply_property psp)
{
        switch (psp) {
        case POWER_SUPPLY_PROP_CHARGE_FULL:
        case POWER_SUPPLY_PROP_CHARGE_NOW:
                return 1;

        default:
                break;
        }

        return 0;
}

static enum power_supply_property ds2760_battery_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
        POWER_SUPPLY_PROP_CHARGE_FULL,
        POWER_SUPPLY_PROP_CHARGE_EMPTY,
        POWER_SUPPLY_PROP_CHARGE_NOW,
        POWER_SUPPLY_PROP_TEMP,
        POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
        POWER_SUPPLY_PROP_CAPACITY,
};

static int ds2760_pm_notifier(struct notifier_block *notifier,
                              unsigned long pm_event,
                              void *unused)
{
        struct ds2760_device_info *di =
                container_of(notifier, struct ds2760_device_info, pm_notifier);

        switch (pm_event) {
        case PM_HIBERNATION_PREPARE:
        case PM_SUSPEND_PREPARE:
                di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
                break;

        case PM_POST_RESTORE:
        case PM_POST_HIBERNATION:
        case PM_POST_SUSPEND:
                di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
                power_supply_changed(di->bat);
                mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);

                break;

        case PM_RESTORE_PREPARE:
        default:
                break;
        }

        return NOTIFY_DONE;
}

static int w1_ds2760_add_slave(struct w1_slave *sl)
{
        struct power_supply_config psy_cfg = {};
        struct ds2760_device_info *di;
        struct device *dev = &sl->dev;
        int retval = 0;
        char name[32];
        char status;

        di = devm_kzalloc(dev, sizeof(*di), GFP_KERNEL);
        if (!di) {
                retval = -ENOMEM;
                goto di_alloc_failed;
        }

        snprintf(name, sizeof(name), "ds2760-battery.%d", dev->id);

        di->dev                         = dev;
        di->bat_desc.name               = name;
        di->bat_desc.type               = POWER_SUPPLY_TYPE_BATTERY;
        di->bat_desc.properties         = ds2760_battery_props;
        di->bat_desc.num_properties     = ARRAY_SIZE(ds2760_battery_props);
        di->bat_desc.get_property       = ds2760_battery_get_property;
        di->bat_desc.set_property       = ds2760_battery_set_property;
        di->bat_desc.property_is_writeable =
                                  ds2760_battery_property_is_writeable;
        di->bat_desc.external_power_changed =
                                  ds2760_battery_external_power_changed;

        psy_cfg.drv_data = di;
        psy_cfg.fwnode = dev_fwnode(dev);

        if (dev->of_node) {
                u32 tmp;

                if (!of_property_read_bool(dev->of_node, "maxim,pmod-enabled"))
                        pmod_enabled = true;

                if (!of_property_read_u32(dev->of_node,
                                          "maxim,cache-time-ms", &tmp))
                        cache_time = tmp;

                if (!of_property_read_u32(dev->of_node,
                                          "rated-capacity-microamp-hours",
                                          &tmp))
                        rated_capacity = tmp / 10; /* property is in mAh */
        }

        di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;

        sl->family_data = di;

        /* enable sleep mode feature */
        ds2760_battery_read_status(di);
        status = di->raw[DS2760_STATUS_REG];
        if (pmod_enabled)
                status |= DS2760_STATUS_PMOD;
        else
                status &= ~DS2760_STATUS_PMOD;

        ds2760_battery_write_status(di, status);

        /* set rated capacity from module param or device tree */
        if (rated_capacity)
                ds2760_battery_write_rated_capacity(di, rated_capacity);

        /* set current accumulator if given as parameter.
         * this should only be done for bootstrapping the value */
        if (current_accum)
                ds2760_battery_set_current_accum(di, current_accum);

        di->bat = devm_power_supply_register(dev, &di->bat_desc, &psy_cfg);
        if (IS_ERR(di->bat)) {
                dev_err(di->dev, "failed to register battery\n");
                retval = PTR_ERR(di->bat);
                goto batt_failed;
        }

        INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
        di->monitor_wqueue = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
        if (!di->monitor_wqueue) {
                retval = -ESRCH;
                goto workqueue_failed;
        }
        queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);

        di->pm_notifier.notifier_call = ds2760_pm_notifier;
        register_pm_notifier(&di->pm_notifier);

        goto success;

workqueue_failed:
batt_failed:
di_alloc_failed:
success:
        return retval;
}

static void w1_ds2760_remove_slave(struct w1_slave *sl)
{
        struct ds2760_device_info *di = sl->family_data;

        unregister_pm_notifier(&di->pm_notifier);
        cancel_delayed_work_sync(&di->monitor_work);
        destroy_workqueue(di->monitor_wqueue);
}

#ifdef CONFIG_OF
static const struct of_device_id w1_ds2760_of_ids[] = {
        { .compatible = "maxim,ds2760" },
        {}
};
#endif

static const struct w1_family_ops w1_ds2760_fops = {
        .add_slave      = w1_ds2760_add_slave,
        .remove_slave   = w1_ds2760_remove_slave,
        .groups         = w1_ds2760_groups,
};

static struct w1_family w1_ds2760_family = {
        .fid            = W1_FAMILY_DS2760,
        .fops           = &w1_ds2760_fops,
        .of_match_table = of_match_ptr(w1_ds2760_of_ids),
};
module_w1_family(w1_ds2760_family);

MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
              "Matt Reimer <mreimer@vpop.net>, "
              "Anton Vorontsov <cbou@mail.ru>");
MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));