diff options
Diffstat (limited to 'drivers/power/ds2760_battery.c')
| -rw-r--r-- | drivers/power/ds2760_battery.c | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c new file mode 100644 index 00000000000..be7021ee361 --- /dev/null +++ b/drivers/power/ds2760_battery.c @@ -0,0 +1,463 @@ +/* + * 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/platform_device.h> +#include <linux/power_supply.h> + +#include "../w1/w1.h" +#include "../w1/slaves/w1_ds2760.h" + +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 device *w1_dev; + struct workqueue_struct *monitor_wqueue; + struct delayed_work monitor_work; +}; + +static unsigned int cache_time = 1000; +module_param(cache_time, uint, 0644); +MODULE_PARM_DESC(cache_time, "cache time in milliseconds"); + +/* 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->w1_dev, di->raw + start, start, count); + if (ret != count) { + dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n", + di->w1_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]; + + scale[0] = di->raw[DS2760_ACTIVE_FULL] << 8 | + di->raw[DS2760_ACTIVE_FULL + 1]; + for (i = 1; i < 5; i++) + scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 2 + 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 */ + + /* 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) + di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * + 3600L) / di->current_uA; + else + di->life_sec = 0; + + return 0; +} + +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 { + unsigned char acr[2]; + int acr_val; + + /* acr is in units of 0.25 mAh */ + acr_val = di->full_active_uAh * 4L / 1000; + + acr[0] = acr_val >> 8; + acr[1] = acr_val & 0xff; + + if (w1_ds2760_write(di->w1_dev, acr, + DS2760_CURRENT_ACCUM_MSB, 2) < 2) + dev_warn(di->dev, + "ACR reset failed\n"); + + di->charge_status = POWER_SUPPLY_STATUS_FULL; + } + } + } 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_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", __FUNCTION__); + + ds2760_battery_update_status(di); + queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval); +} + +#define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \ + bat); + +static void ds2760_battery_external_power_changed(struct power_supply *psy) +{ + struct ds2760_device_info *di = to_ds2760_device_info(psy); + + dev_dbg(di->dev, "%s\n", __FUNCTION__); + + cancel_delayed_work(&di->monitor_work); + queue_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 = to_ds2760_device_info(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; + default: + return -EINVAL; + } + + 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, +}; + +static int ds2760_battery_probe(struct platform_device *pdev) +{ + int retval = 0; + struct ds2760_device_info *di; + struct ds2760_platform_data *pdata; + + di = kzalloc(sizeof(*di), GFP_KERNEL); + if (!di) { + retval = -ENOMEM; + goto di_alloc_failed; + } + + platform_set_drvdata(pdev, di); + + pdata = pdev->dev.platform_data; + di->dev = &pdev->dev; + di->w1_dev = pdev->dev.parent; + di->bat.name = pdev->dev.bus_id; + di->bat.type = POWER_SUPPLY_TYPE_BATTERY; + di->bat.properties = ds2760_battery_props; + di->bat.num_properties = ARRAY_SIZE(ds2760_battery_props); + di->bat.get_property = ds2760_battery_get_property; + di->bat.external_power_changed = + ds2760_battery_external_power_changed; + + di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; + + retval = power_supply_register(&pdev->dev, &di->bat); + if (retval) { + dev_err(di->dev, "failed to register battery"); + goto batt_failed; + } + + INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work); + di->monitor_wqueue = create_singlethread_workqueue(pdev->dev.bus_id); + if (!di->monitor_wqueue) { + retval = -ESRCH; + goto workqueue_failed; + } + queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1); + + goto success; + +workqueue_failed: + power_supply_unregister(&di->bat); +batt_failed: + kfree(di); +di_alloc_failed: +success: + return retval; +} + +static int ds2760_battery_remove(struct platform_device *pdev) +{ + struct ds2760_device_info *di = platform_get_drvdata(pdev); + + cancel_rearming_delayed_workqueue(di->monitor_wqueue, + &di->monitor_work); + destroy_workqueue(di->monitor_wqueue); + power_supply_unregister(&di->bat); + + return 0; +} + +#ifdef CONFIG_PM + +static int ds2760_battery_suspend(struct platform_device *pdev, + pm_message_t state) +{ + struct ds2760_device_info *di = platform_get_drvdata(pdev); + + di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; + + return 0; +} + +static int ds2760_battery_resume(struct platform_device *pdev) +{ + struct ds2760_device_info *di = platform_get_drvdata(pdev); + + di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; + power_supply_changed(&di->bat); + + cancel_delayed_work(&di->monitor_work); + queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ); + + return 0; +} + +#else + +#define ds2760_battery_suspend NULL +#define ds2760_battery_resume NULL + +#endif /* CONFIG_PM */ + +static struct platform_driver ds2760_battery_driver = { + .driver = { + .name = "ds2760-battery", + }, + .probe = ds2760_battery_probe, + .remove = ds2760_battery_remove, + .suspend = ds2760_battery_suspend, + .resume = ds2760_battery_resume, +}; + +static int __init ds2760_battery_init(void) +{ + return platform_driver_register(&ds2760_battery_driver); +} + +static void __exit ds2760_battery_exit(void) +{ + platform_driver_unregister(&ds2760_battery_driver); +} + +module_init(ds2760_battery_init); +module_exit(ds2760_battery_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, " + "Matt Reimer <mreimer@vpop.net>, " + "Anton Vorontsov <cbou@mail.ru>"); +MODULE_DESCRIPTION("ds2760 battery driver"); |