Quelle  ds2760_battery.c   Sprache: C

/*
 * 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 , "
       "Matt Reimer , "
       "Anton Vorontsov ");
MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));