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path: root/drivers/power/ds2760_battery.c
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Diffstat (limited to 'drivers/power/ds2760_battery.c')
-rw-r--r--drivers/power/ds2760_battery.c147
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);