@@ -331,24 +331,12 @@ struct ab8500_maxim_parameters {
* struct ab8500_battery_type - different batteries supported
* @resis_high: battery upper resistance limit
* @resis_low: battery lower resistance limit
- * @maint_a_cur_lvl: charger current in maintenance A state in mA
- * @maint_a_vol_lvl: charger voltage in maintenance A state in mV
- * @maint_a_chg_timer_h: charge time in maintenance A state
- * @maint_b_cur_lvl: charger current in maintenance B state in mA
- * @maint_b_vol_lvl: charger voltage in maintenance B state in mV
- * @maint_b_chg_timer_h: charge time in maintenance B state
* @low_high_cur_lvl: charger current in temp low/high state in mA
* @low_high_vol_lvl: charger voltage in temp low/high state in mV'
*/
struct ab8500_battery_type {
int resis_high;
int resis_low;
- int maint_a_cur_lvl;
- int maint_a_vol_lvl;
- int maint_a_chg_timer_h;
- int maint_b_cur_lvl;
- int maint_b_vol_lvl;
- int maint_b_chg_timer_h;
int low_high_cur_lvl;
int low_high_vol_lvl;
};
@@ -393,7 +381,6 @@ struct ab8500_bm_charger_parameters {
* @usb_safety_tmr_h safety timer for usb charger
* @bkup_bat_v voltage which we charge the backup battery with
* @bkup_bat_i current which we charge the backup battery with
- * @no_maintenance indicates that maintenance charging is disabled
* @capacity_scaling indicates whether capacity scaling is to be used
* @chg_unknown_bat flag to enable charging of unknown batteries
* @enable_overshoot flag to enable VBAT overshoot control
@@ -417,7 +404,6 @@ struct ab8500_bm_data {
int usb_safety_tmr_h;
int bkup_bat_v;
int bkup_bat_i;
- bool no_maintenance;
bool capacity_scaling;
bool chg_unknown_bat;
bool enable_overshoot;
@@ -58,16 +58,25 @@ static struct power_supply_resistance_temp_table temp_to_batres_tbl_thermistor[]
{ .temp = -20, .resistance = 198 /* 595 mOhm */ },
};
+static struct power_supply_maintenance_charge_table ab8500_maint_charg_table[] = {
+ {
+ /* Maintenance charging phase A, 60 hours */
+ .charge_current_max_ua = 400000,
+ .charge_voltage_max_uv = 4050000,
+ .charge_safety_timer_minutes = 60*60,
+ },
+ {
+ /* Maintenance charging phase B, 200 hours */
+ .charge_current_max_ua = 400000,
+ .charge_voltage_max_uv = 4000000,
+ .charge_safety_timer_minutes = 200*60,
+ }
+};
+
/* Default battery type for reference designs is the unknown type */
static struct ab8500_battery_type bat_type_thermistor_unknown = {
.resis_high = 0,
.resis_low = 0,
- .maint_a_cur_lvl = 400,
- .maint_a_vol_lvl = 4050,
- .maint_a_chg_timer_h = 60,
- .maint_b_cur_lvl = 400,
- .maint_b_vol_lvl = 4000,
- .maint_b_chg_timer_h = 200,
.low_high_cur_lvl = 300,
.low_high_vol_lvl = 4000,
};
@@ -124,7 +133,6 @@ struct ab8500_bm_data ab8500_bm_data = {
.usb_safety_tmr_h = 4,
.bkup_bat_v = BUP_VCH_SEL_2P6V,
.bkup_bat_i = BUP_ICH_SEL_150UA,
- .no_maintenance = false,
.capacity_scaling = false,
.chg_unknown_bat = false,
.enable_overshoot = false,
@@ -179,6 +187,11 @@ int ab8500_bm_of_probe(struct power_supply *psy,
/* Charging stops when we drop below this current */
bi->charge_term_current_ua = 200000;
+ if (!bi->maintenance_charge || !bi->maintenance_charge_size) {
+ bi->maintenance_charge = ab8500_maint_charg_table;
+ bi->maintenance_charge_size = ARRAY_SIZE(ab8500_maint_charg_table);
+ }
+
/*
* Internal resistance and factory resistance are tightly coupled
* so both MUST be defined or we fall back to defaults.
@@ -430,7 +430,7 @@ static void ab8500_chargalg_stop_safety_timer(struct ab8500_chargalg *di)
/**
* ab8500_chargalg_start_maintenance_timer() - Start charging maintenance timer
* @di: pointer to the ab8500_chargalg structure
- * @duration: duration of ther maintenance timer in hours
+ * @duration: duration of ther maintenance timer in minutes
*
* The maintenance timer is used to maintain the charge in the battery once
* the battery is considered full. These timers are chosen to match the
@@ -439,9 +439,10 @@ static void ab8500_chargalg_stop_safety_timer(struct ab8500_chargalg *di)
static void ab8500_chargalg_start_maintenance_timer(struct ab8500_chargalg *di,
int duration)
{
+ /* Set a timer in minutes with a 30 second range */
hrtimer_set_expires_range(&di->maintenance_timer,
- ktime_set(duration * ONE_HOUR_IN_SECONDS, 0),
- ktime_set(FIVE_MINUTES_IN_SECONDS, 0));
+ ktime_set(duration * 60, 0),
+ ktime_set(30, 0));
di->events.maintenance_timer_expired = false;
hrtimer_start_expires(&di->maintenance_timer, HRTIMER_MODE_REL);
}
@@ -1223,6 +1224,7 @@ static void ab8500_chargalg_external_power_changed(struct power_supply *psy)
static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di)
{
struct power_supply_battery_info *bi = di->bm->bi;
+ struct power_supply_maintenance_charge_table *mt;
int charger_status;
int ret;
@@ -1433,7 +1435,12 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di)
handle_maxim_chg_curr(di);
if (di->charge_status == POWER_SUPPLY_STATUS_FULL &&
di->maintenance_chg) {
- if (di->bm->no_maintenance)
+ /*
+ * The battery is fully charged, check if we support
+ * maintenance charging else go back to waiting for
+ * the recharge voltage limit.
+ */
+ if (!power_supply_supports_maintenance_charging(bi))
ab8500_chargalg_state_to(di,
STATE_WAIT_FOR_RECHARGE_INIT);
else
@@ -1454,12 +1461,19 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di)
break;
case STATE_MAINTENANCE_A_INIT:
+ mt = power_supply_get_maintenance_charging_setting(bi, 0);
+ if (!mt) {
+ /* No maintenance A state, go back to normal */
+ ab8500_chargalg_state_to(di, STATE_NORMAL_INIT);
+ power_supply_changed(di->chargalg_psy);
+ break;
+ }
ab8500_chargalg_stop_safety_timer(di);
ab8500_chargalg_start_maintenance_timer(di,
- di->bm->bat_type->maint_a_chg_timer_h);
+ mt->charge_safety_timer_minutes);
ab8500_chargalg_start_charging(di,
- di->bm->bat_type->maint_a_vol_lvl,
- di->bm->bat_type->maint_a_cur_lvl);
+ mt->charge_voltage_max_uv,
+ mt->charge_current_max_ua);
ab8500_chargalg_state_to(di, STATE_MAINTENANCE_A);
power_supply_changed(di->chargalg_psy);
fallthrough;
@@ -1472,11 +1486,18 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di)
break;
case STATE_MAINTENANCE_B_INIT:
+ mt = power_supply_get_maintenance_charging_setting(bi, 1);
+ if (!mt) {
+ /* No maintenance B state, go back to normal */
+ ab8500_chargalg_state_to(di, STATE_NORMAL_INIT);
+ power_supply_changed(di->chargalg_psy);
+ break;
+ }
ab8500_chargalg_start_maintenance_timer(di,
- di->bm->bat_type->maint_b_chg_timer_h);
+ mt->charge_safety_timer_minutes);
ab8500_chargalg_start_charging(di,
- di->bm->bat_type->maint_b_vol_lvl,
- di->bm->bat_type->maint_b_cur_lvl);
+ mt->charge_voltage_max_uv,
+ mt->charge_current_max_ua);
ab8500_chargalg_state_to(di, STATE_MAINTENANCE_B);
power_supply_changed(di->chargalg_psy);
fallthrough;
@@ -595,6 +595,7 @@ int power_supply_get_battery_info(struct power_supply *psy,
info->precharge_voltage_max_uv = -EINVAL;
info->charge_restart_voltage_uv = -EINVAL;
info->overvoltage_limit_uv = -EINVAL;
+ info->maintenance_charge = NULL;
info->temp_ambient_alert_min = INT_MIN;
info->temp_ambient_alert_max = INT_MAX;
info->temp_alert_min = INT_MIN;
@@ -844,6 +845,16 @@ int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *t
}
EXPORT_SYMBOL_GPL(power_supply_temp2resist_simple);
+struct power_supply_maintenance_charge_table *
+power_supply_get_maintenance_charging_setting(struct power_supply_battery_info *info,
+ int index)
+{
+ if (index >= info->maintenance_charge_size)
+ return NULL;
+ return &info->maintenance_charge[index];
+}
+EXPORT_SYMBOL_GPL(power_supply_get_maintenance_charging_setting);
+
/**
* power_supply_ocv2cap_simple() - find the battery capacity
* @table: Pointer to battery OCV lookup table
@@ -349,6 +349,52 @@ struct power_supply_resistance_temp_table {
int resistance; /* internal resistance percent */
};
+/**
+ * struct power_supply_maintenance_charge_table - setting for maintenace charging
+ * @charge_current_max_ua: maintenance charging current that is used to keep
+ * the charge of the battery full as current is consumed after full charging.
+ * The corresponding charge_voltage_max_uv is used as a safeguard: when we
+ * reach this voltage the maintenance charging current is turned off. It is
+ * turned back on if we fall below this voltage.
+ * @charge_voltage_max_uv: maintenance charging voltage that is usually a bit
+ * lower than the constant_charge_voltage_max_uv. We can apply this settings
+ * charge_current_max_ua until we get back up to this voltage.
+ * @safety_timer_minutes: maintenance charging safety timer, with an expiry
+ * time in minutes. We will only use maintenance charging in this setting
+ * for a certain amount of time, then we will first move to the next
+ * maintenance charge current and voltage pair in respective array and wait
+ * for the next safety timer timeout, or, if we reached the last maintencance
+ * charging setting, disable charging until we reach
+ * charge_restart_voltage_uv and restart ordinary CC/CV charging from there.
+ * These timers should be chosen to align with the typical discharge curve
+ * for the battery.
+ *
+ * When the main CC/CV charging is complete the battery can optionally be
+ * maintenance charged at the voltages from this table: a table of settings is
+ * traversed using a slightly lower current and voltage than what is used for
+ * CC/CV charging. The maintenance charging will for safety reasons not go on
+ * indefinately: we lower the current and voltage with successive maintenance
+ * settings, then disable charging completely after we reach the last one,
+ * and after that we do not restart charging until we reach
+ * charge_restart_voltage_uv (see struct power_supply_battery_info) and restart
+ * ordinary CC/CV charging from there.
+ *
+ * As an example, a Samsung EB425161LA Lithium-Ion battery is CC/CV charged
+ * at 900mA to 4340mV, then maintenance charged at 600mA and 4150mV for
+ * 60 hours, then maintenance charged at 600mA and 4100mV for 200 hours.
+ * After this the charge cycle is restarted waiting for
+ * charge_restart_voltage_uv.
+ *
+ * For most mobile electronics this type of maintenance charging is enough for
+ * the user to disconnect the device and make use of it before both maintenance
+ * charging cycles are complete.
+ */
+struct power_supply_maintenance_charge_table {
+ int charge_current_max_ua;
+ int charge_voltage_max_uv;
+ int charge_safety_timer_minutes;
+};
+
#define POWER_SUPPLY_OCV_TEMP_MAX 20
/**
@@ -394,6 +440,10 @@ struct power_supply_resistance_temp_table {
* @constant_charge_voltage_max_uv: voltage in microvolts signifying the end of
* the CC (constant current) charging phase and the beginning of the CV
* (constant voltage) charging phase.
+ * @maintenance_charge: an array of maintenance charging settings to be used
+ * after the main CC/CV charging phase is complete.
+ * @maintenance_charge_size: the number of maintenance charging settings in
+ * maintenance_charge.
* @factory_internal_resistance_uohm: the internal resistance of the battery
* at fabrication time, expressed in microohms. This resistance will vary
* depending on the lifetime and charge of the battery, so this is just a
@@ -543,6 +593,8 @@ struct power_supply_battery_info {
int overvoltage_limit_uv;
int constant_charge_current_max_ua;
int constant_charge_voltage_max_uv;
+ struct power_supply_maintenance_charge_table *maintenance_charge;
+ int maintenance_charge_size;
int factory_internal_resistance_uohm;
int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX];
int temp_ambient_alert_min;
@@ -596,6 +648,8 @@ extern int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info,
extern int
power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table,
int table_len, int temp);
+extern struct power_supply_maintenance_charge_table *
+power_supply_get_maintenance_charging_setting(struct power_supply_battery_info *info, int index);
extern void power_supply_changed(struct power_supply *psy);
extern int power_supply_am_i_supplied(struct power_supply *psy);
int power_supply_get_property_from_supplier(struct power_supply *psy,
@@ -603,6 +657,16 @@ int power_supply_get_property_from_supplier(struct power_supply *psy,
union power_supply_propval *val);
extern int power_supply_set_battery_charged(struct power_supply *psy);
+static inline bool
+power_supply_supports_maintenance_charging(struct power_supply_battery_info *info)
+{
+ struct power_supply_maintenance_charge_table *mt;
+
+ mt = power_supply_get_maintenance_charging_setting(info, 0);
+
+ return (mt != NULL);
+}
+
#ifdef CONFIG_POWER_SUPPLY
extern int power_supply_is_system_supplied(void);
#else