[PATCH v3 09/11] power: supply: bq24190_charger: Get input_current_limit from our supplier

From: Hans de Goede
Date: Wed Aug 30 2017 - 05:48:56 EST


On some devices the USB Type-C port power (USB PD 2.0) negotiation is
done by a separate port-controller IC, while the current limit is
controlled through another (charger) IC.

It has been decided to model this by modelling the external Type-C
power brick (adapter/charger) as a power-supply class device which
supplies the charger-IC, with its voltage-now and current-max representing
the negotiated voltage and max current draw.

This commit adds support for this to the bq24190_charger driver by adding
an external_power_changed callback and calling
power_supply_set_input_current_limit_from_supplier from this callback.
This callback will only get called if the bq24190 has a parent-supply.

Note this replaces the functionality to get the current-limit from an
extcon device, which will be removed in a follow-up commit.

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v2:
-Wait a bit before applying current-max from our supplier as input-current-limit
the bq24190 may still be in its power-good wait-state while our supplier is
done negotating current-max and if we apply the limit to early then the
input-current-limit will be reset to 0.5A by the bq24190 after its
power-good wait is done.

Changes in v3:
-Drop the input-current-limit-from-supplier device-property, simply always
sync the input-current-limit with the parent-supply if a parent-supply is
present
---
drivers/power/supply/bq24190_charger.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/power/supply/bq24190_charger.c b/drivers/power/supply/bq24190_charger.c
index e606a078b0dd..35ff406aca48 100644
--- a/drivers/power/supply/bq24190_charger.c
+++ b/drivers/power/supply/bq24190_charger.c
@@ -165,6 +165,7 @@ struct bq24190_dev_info {
struct extcon_dev *extcon;
struct notifier_block extcon_nb;
struct delayed_work extcon_work;
+ struct delayed_work input_current_limit_work;
char model_name[I2C_NAME_SIZE];
bool initialized;
bool irq_event;
@@ -1210,6 +1211,32 @@ static int bq24190_charger_property_is_writeable(struct power_supply *psy,
return ret;
}

+static void bq24190_input_current_limit_work(struct work_struct *work)
+{
+ struct bq24190_dev_info *bdi =
+ container_of(work, struct bq24190_dev_info,
+ input_current_limit_work.work);
+
+ power_supply_set_input_current_limit_from_supplier(bdi->charger);
+}
+
+/* Sync the input-current-limit with our parent supply (if we have one) */
+static void bq24190_charger_external_power_changed(struct power_supply *psy)
+{
+ struct bq24190_dev_info *bdi = power_supply_get_drvdata(psy);
+
+ /*
+ * The Power-Good detection may take up to 220ms, sometimes
+ * the external charger detection is quicker, and the bq24190 will
+ * reset to iinlim based on its own charger detection (which is not
+ * hooked up when using external charger detection) resulting in a
+ * too low default 500mA iinlim. Delay setting the input-current-limit
+ * for 300ms to avoid this.
+ */
+ queue_delayed_work(system_wq, &bdi->input_current_limit_work,
+ msecs_to_jiffies(300));
+}
+
static enum power_supply_property bq24190_charger_properties[] = {
POWER_SUPPLY_PROP_CHARGE_TYPE,
POWER_SUPPLY_PROP_HEALTH,
@@ -1240,6 +1267,7 @@ static const struct power_supply_desc bq24190_charger_desc = {
.get_property = bq24190_charger_get_property,
.set_property = bq24190_charger_set_property,
.property_is_writeable = bq24190_charger_property_is_writeable,
+ .external_power_changed = bq24190_charger_external_power_changed,
};

/* Battery power supply property routines */
@@ -1758,6 +1786,8 @@ static int bq24190_probe(struct i2c_client *client,
mutex_init(&bdi->f_reg_lock);
bdi->f_reg = 0;
bdi->ss_reg = BQ24190_REG_SS_VBUS_STAT_MASK; /* impossible state */
+ INIT_DELAYED_WORK(&bdi->input_current_limit_work,
+ bq24190_input_current_limit_work);

i2c_set_clientdata(client, bdi);

--
2.13.4