power: supply: ab8500: Standardize alert mode charging

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071846
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
 support in the kernel for NXP i.MX8 platforms.  This set updates the
 power subsystem.  This set has been tested via simple boot tests and
 the CI loop.

Conflicts:
    drivers/power/supply/ab8500-bm.h
    drivers/power/supply/ab8500_bmdata.c
    drivers/power/supply/abx500_chargalg.c

    This is not a supported device so these portions of the
    patch have been dropped.

commit 0e8b903
Author: Linus Walleij <linus.walleij@linaro.org>
Date:   Sat Feb 26 00:27:56 2022 +0100

    power: supply: ab8500: Standardize alert mode charging

    The AB8500 code is using a special current and voltage setting
    when the battery is in "alert mode", i.e. when it is starting
    to go outside normal operating conditions so it is too
    cold or too hot. This makes sense as a way for the charging
    algorithm to deal with hostile environments.

    Add the needed members to the struct power_supply_battery_info,
    and switch the AB8500 charging code over to using this.

    Reviewed-by: Matti Vaittineen <matti.vaittinen@fi.rohmeurope.com>
    Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
    Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
    (cherry picked from commit 0e8b903)

Signed-off-by: Al Stone <ahs3@redhat.com>

Author: Al Stone

drivers/power/supply/ab8500_bmdata.c

@@ -246,7 +246,6 @@ static struct abx500_battery_type bat_type_thermistor[] = {
 		.v_to_cap_tbl = cap_tbl_a_thermistor,
 		.n_batres_tbl_elements = ARRAY_SIZE(temp_to_batres_tbl_thermistor),
 		.batres_tbl = temp_to_batres_tbl_thermistor,
-
 	},
 	{
 		.name = POWER_SUPPLY_TECHNOLOGY_LIPO,
@@ -281,8 +280,8 @@ static struct abx500_battery_type bat_type_ext_thermistor[] = {
 	[BATTERY_UNKNOWN] = {
 		/* First element always represent the UNKNOWN battery */
 		.name = POWER_SUPPLY_TECHNOLOGY_UNKNOWN,
-		.resis_high = 0,
-		.resis_low = 0,
+	.resis_high = 0,
+	.resis_low = 0,
 		.battery_resistance = 300,
 		.charge_full_design = 612,
 		.nominal_voltage = 3700,
@@ -297,8 +296,8 @@ static struct abx500_battery_type bat_type_ext_thermistor[] = {
 		.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,
+	.low_high_cur_lvl = 300,
+	.low_high_vol_lvl = 4000,
 		.n_temp_tbl_elements = ARRAY_SIZE(temp_tbl),
 		.r_to_t_tbl = temp_tbl,
 		.n_v_cap_tbl_elements = ARRAY_SIZE(cap_tbl),

drivers/power/supply/abx500_chargalg.c

@@ -731,12 +731,12 @@ static void abx500_chargalg_check_temp(struct abx500_chargalg *di)
 		di->t_hyst_norm = 0;
 		di->t_hyst_lowhigh = 0;
 	} else {
-		if (((di->batt_data.temp >= di->bm->temp_high) &&
+		if (((di->batt_data.temp >= bi->temp_alert_max) &&
 			(di->batt_data.temp <
-				(di->bm->temp_over - di->t_hyst_lowhigh))) ||
+				(bi->temp_max - di->t_hyst_lowhigh))) ||
 			((di->batt_data.temp >
-				(di->bm->temp_under + di->t_hyst_lowhigh)) &&
-			(di->batt_data.temp <= di->bm->temp_low))) {
+				(bi->temp_min + di->t_hyst_lowhigh)) &&
+			(di->batt_data.temp <= bi->temp_alert_min))) {
 			/* TEMP minor!!!!! */
 			di->events.btemp_underover = false;
 			di->events.btemp_lowhigh = true;
@@ -1589,12 +1589,10 @@ static void abx500_chargalg_algorithm(struct abx500_chargalg *di)
 		break;
 
 	case STATE_TEMP_LOWHIGH_INIT:
-		abx500_chargalg_start_charging(di,
-			di->bm->bat_type[
-				di->bm->batt_id].low_high_vol_lvl,
-			di->bm->bat_type[
-				di->bm->batt_id].low_high_cur_lvl);
-		abx500_chargalg_stop_maintenance_timer(di);
+		ab8500_chargalg_start_charging(di,
+			di->bm->bat_type->low_high_vol_lvl,
+			di->bm->bat_type->low_high_cur_lvl);
+		ab8500_chargalg_stop_maintenance_timer(di);
 		di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
 		abx500_chargalg_state_to(di, STATE_TEMP_LOWHIGH);
 		power_supply_changed(di->chargalg_psy);

drivers/power/supply/power_supply_core.c

@@ -596,6 +596,10 @@ int power_supply_get_battery_info(struct power_supply *psy,
 	info->charge_restart_voltage_uv      = -EINVAL;
 	info->overvoltage_limit_uv           = -EINVAL;
 	info->maintenance_charge             = NULL;
+	info->alert_low_temp_charge_current_ua = -EINVAL;
+	info->alert_low_temp_charge_voltage_uv = -EINVAL;
+	info->alert_high_temp_charge_current_ua = -EINVAL;
+	info->alert_high_temp_charge_voltage_uv = -EINVAL;
 	info->temp_ambient_alert_min         = INT_MIN;
 	info->temp_ambient_alert_max         = INT_MAX;
 	info->temp_alert_min                 = INT_MIN;

include/linux/power_supply.h

@@ -444,6 +444,19 @@ struct power_supply_maintenance_charge_table {
  *   after the main CC/CV charging phase is complete.
  * @maintenance_charge_size: the number of maintenance charging settings in
  *   maintenance_charge.
+ * @alert_low_temp_charge_current_ua: The charging current to use if the battery
+ *   enters low alert temperature, i.e. if the internal temperature is between
+ *   temp_alert_min and temp_min. No matter the charging phase, this
+ *   and alert_high_temp_charge_voltage_uv will be applied.
+ * @alert_low_temp_charge_voltage_uv: Same as alert_low_temp_charge_current_ua,
+ *   but for the charging voltage.
+ * @alert_high_temp_charge_current_ua: The charging current to use if the
+ *   battery enters high alert temperature, i.e. if the internal temperature is
+ *   between temp_alert_max and temp_max. No matter the charging phase, this
+ *   and alert_high_temp_charge_voltage_uv will be applied, usually lowering
+ *   the charging current as an evasive manouver.
+ * @alert_high_temp_charge_voltage_uv: Same as
+ *   alert_high_temp_charge_current_ua, but for the charging voltage.
  * @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
@@ -595,6 +608,10 @@ struct power_supply_battery_info {
 	int constant_charge_voltage_max_uv;
 	struct power_supply_maintenance_charge_table *maintenance_charge;
 	int maintenance_charge_size;
+	int alert_low_temp_charge_current_ua;
+	int alert_low_temp_charge_voltage_uv;
+	int alert_high_temp_charge_current_ua;
+	int alert_high_temp_charge_voltage_uv;
 	int factory_internal_resistance_uohm;
 	int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX];
 	int temp_ambient_alert_min;