diff options
Diffstat (limited to 'drivers/power/ds2760_battery.c')
-rw-r--r-- | drivers/power/ds2760_battery.c | 147 |
1 files changed, 122 insertions, 25 deletions
diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c index 520b5c49ff30..6f1dba5a519d 100644 --- a/drivers/power/ds2760_battery.c +++ b/drivers/power/ds2760_battery.c @@ -56,6 +56,7 @@ struct ds2760_device_info { struct device *w1_dev; struct workqueue_struct *monitor_wqueue; struct delayed_work monitor_work; + struct delayed_work set_charged_work; }; static unsigned int cache_time = 1000; @@ -66,6 +67,14 @@ static unsigned int 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"); + /* Some batteries have their rated capacity stored a N * 10 mAh, while * others use an index into this table. */ static int rated_capacities[] = { @@ -168,8 +177,13 @@ static int ds2760_battery_read_status(struct ds2760_device_info *di) 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]; + /* 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 + 2 + i]; @@ -197,15 +211,31 @@ static int ds2760_battery_read_status(struct ds2760_device_info *di) 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; + 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->w1_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; @@ -237,21 +267,9 @@ static void ds2760_battery_update_status(struct ds2760_device_info *di) 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; + ds2760_battery_set_current_accum(di, + di->full_active_uAh); } } } else { @@ -274,6 +292,17 @@ static void ds2760_battery_write_status(struct ds2760_device_info *di, w1_ds2760_recall_eeprom(di->w1_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->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1); + w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1); + w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1); +} + static void ds2760_battery_work(struct work_struct *work) { struct ds2760_device_info *di = container_of(work, @@ -299,6 +328,52 @@ static void ds2760_battery_external_power_changed(struct power_supply *psy) queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10); } + +static void ds2760_battery_set_charged_work(struct work_struct *work) +{ + char bias; + struct ds2760_device_info *di = container_of(work, + struct ds2760_device_info, set_charged_work.work); + + dev_dbg(di->dev, "%s\n", __func__); + + ds2760_battery_read_status(di); + + /* When we get notified by external circuitry that the battery is + * considered fully charged now, we know that there is no current + * flow any more. However, the ds2760's internal current meter is + * too inaccurate to rely on - spec say something ~15% failure. + * Hence, we use the current offset bias register to compensate + * that error. + */ + + if (!power_supply_am_i_supplied(&di->bat)) + return; + + bias = (signed char) di->current_raw + + (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS]; + + dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias); + + w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1); + w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1); + w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1); + + /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS + * value won't be read back by ds2760_battery_read_status() */ + di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias; +} + +static void ds2760_battery_set_charged(struct power_supply *psy) +{ + struct ds2760_device_info *di = to_ds2760_device_info(psy); + + /* postpone the actual work by 20 secs. This is for debouncing GPIO + * signals and to let the current value settle. See AN4188. */ + cancel_delayed_work(&di->set_charged_work); + queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20); +} + static int ds2760_battery_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) @@ -337,6 +412,12 @@ static int ds2760_battery_get_property(struct power_supply *psy, 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; } @@ -353,6 +434,8 @@ static enum power_supply_property ds2760_battery_props[] = { 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_battery_probe(struct platform_device *pdev) @@ -376,17 +459,12 @@ static int ds2760_battery_probe(struct platform_device *pdev) 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.set_charged = ds2760_battery_set_charged; 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\n"); - goto batt_failed; - } - /* enable sleep mode feature */ ds2760_battery_read_status(di); status = di->raw[DS2760_STATUS_REG]; @@ -397,7 +475,24 @@ static int ds2760_battery_probe(struct platform_device *pdev) ds2760_battery_write_status(di, status); + /* set rated capacity from module param */ + 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); + + retval = power_supply_register(&pdev->dev, &di->bat); + if (retval) { + dev_err(di->dev, "failed to register battery\n"); + goto batt_failed; + } + INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work); + INIT_DELAYED_WORK(&di->set_charged_work, + ds2760_battery_set_charged_work); di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev)); if (!di->monitor_wqueue) { retval = -ESRCH; @@ -422,6 +517,8 @@ static int ds2760_battery_remove(struct platform_device *pdev) cancel_rearming_delayed_workqueue(di->monitor_wqueue, &di->monitor_work); + cancel_rearming_delayed_workqueue(di->monitor_wqueue, + &di->set_charged_work); destroy_workqueue(di->monitor_wqueue); power_supply_unregister(&di->bat); |