power: supply: cpcap-battery: Fix handling of lowered charger voltage

With cpcap-charger now using 4.2V instead of 4.35V, we never reach
POWER_SUPPLY_CAPACITY_LEVEL_FULL unless we handle the lowered charge
voltage.

Let's do this by implementing POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
and assume anything at that level or higher is a full battery.

Let's also make it configurable for users who may still want to
reconfigure it, and notify the charger if supported by the charger.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
index 00a96e4..1640c39 100644 (file)
--- a/drivers/power/supply/cpcap-battery.c
+++ b/drivers/power/supply/cpcap-battery.c
@@ -79,6 +79,7 @@ struct cpcap_battery_config {
        int ccm;
        int cd_factor;
        struct power_supply_info info;
+       struct power_supply_battery_info bat;
 };
 
 struct cpcap_coulomb_counter_data {
@@ -369,8 +370,8 @@ static bool cpcap_battery_full(struct cpcap_battery_ddata *ddata)
 {
        struct cpcap_battery_state_data *state = cpcap_battery_latest(ddata);
 
-       /* Basically anything that measures above 4347000 is full */
-       if (state->voltage >= (ddata->config.info.voltage_max_design - 4000))
+       if (state->voltage >=
+           (ddata->config.bat.constant_charge_voltage_max_uv - 18000))
                return true;
 
        return false;
@@ -417,6 +418,7 @@ static enum power_supply_property cpcap_battery_props[] = {
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
        POWER_SUPPLY_PROP_CURRENT_AVG,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
@@ -475,6 +477,9 @@ static int cpcap_battery_get_property(struct power_supply *psy,
        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
                val->intval = ddata->config.info.voltage_min_design;
                break;
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+               val->intval = ddata->config.bat.constant_charge_voltage_max_uv;
+               break;
        case POWER_SUPPLY_PROP_CURRENT_AVG:
                sample = latest->cc.sample - previous->cc.sample;
                if (!sample) {
@@ -540,6 +545,69 @@ static int cpcap_battery_get_property(struct power_supply *psy,
        return 0;
 }
 
+static int cpcap_battery_update_charger(struct cpcap_battery_ddata *ddata,
+                                       int const_charge_voltage)
+{
+       union power_supply_propval prop;
+       union power_supply_propval val;
+       struct power_supply *charger;
+       int error;
+
+       charger = power_supply_get_by_name("usb");
+       if (!charger)
+               return -ENODEV;
+
+       error = power_supply_get_property(charger,
+                               POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
+                               &prop);
+       if (error)
+               return error;
+
+       /* Allow charger const voltage lower than battery const voltage */
+       if (const_charge_voltage > prop.intval)
+               return 0;
+
+       val.intval = const_charge_voltage;
+
+       return power_supply_set_property(charger,
+                       POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
+                       &val);
+}
+
+static int cpcap_battery_set_property(struct power_supply *psy,
+                                     enum power_supply_property psp,
+                                     const union power_supply_propval *val)
+{
+       struct cpcap_battery_ddata *ddata = power_supply_get_drvdata(psy);
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+               if (val->intval < ddata->config.info.voltage_min_design)
+                       return -EINVAL;
+               if (val->intval > ddata->config.info.voltage_max_design)
+                       return -EINVAL;
+
+               ddata->config.bat.constant_charge_voltage_max_uv = val->intval;
+
+               return cpcap_battery_update_charger(ddata, val->intval);
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int cpcap_battery_property_is_writeable(struct power_supply *psy,
+                                              enum power_supply_property psp)
+{
+       switch (psp) {
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+               return 1;
+       default:
+               return 0;
+       }
+}
+
 static irqreturn_t cpcap_battery_irq_thread(int irq, void *data)
 {
        struct cpcap_battery_ddata *ddata = data;
@@ -695,6 +763,7 @@ static const struct cpcap_battery_config cpcap_battery_default_data = {
        .info.voltage_max_design = 4351000,
        .info.voltage_min_design = 3100000,
        .info.charge_full_design = 1740000,
+       .bat.constant_charge_voltage_max_uv = 4200000,
 };
 
 #ifdef CONFIG_OF
@@ -762,11 +831,13 @@ static int cpcap_battery_probe(struct platform_device *pdev)
        if (!psy_desc)
                return -ENOMEM;
 
-       psy_desc->name = "battery",
-       psy_desc->type = POWER_SUPPLY_TYPE_BATTERY,
-       psy_desc->properties = cpcap_battery_props,
-       psy_desc->num_properties = ARRAY_SIZE(cpcap_battery_props),
-       psy_desc->get_property = cpcap_battery_get_property,
+       psy_desc->name = "battery";
+       psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
+       psy_desc->properties = cpcap_battery_props;
+       psy_desc->num_properties = ARRAY_SIZE(cpcap_battery_props);
+       psy_desc->get_property = cpcap_battery_get_property;
+       psy_desc->set_property = cpcap_battery_set_property;
+       psy_desc->property_is_writeable = cpcap_battery_property_is_writeable;
 
        psy_cfg.of_node = pdev->dev.of_node;
        psy_cfg.drv_data = ddata;