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| author | Hans de Goede <hdegoede@redhat.com> | 2017-08-15 22:04:56 +0200 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.co.uk> | 2017-08-29 12:24:52 +0200 |
| commit | c3142dd8bedb8b78ee13c885dd92093fc8a50277 (patch) | |
| tree | 81a9b0594e82eb018aaa598d4484a6a8aa3a0bcf /drivers/power | |
| parent | power: supply: max17042_battery: Fix compiler warning (diff) | |
| download | linux-c3142dd8bedb8b78ee13c885dd92093fc8a50277.tar.xz linux-c3142dd8bedb8b78ee13c885dd92093fc8a50277.zip | |
power: supply: Add power_supply_set_input_current_limit_from_supplier helper
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 a power_supply_set_input_current_limit_from_supplier
helper function which charger power-supply drivers can call to get
the max-current from their supplier and have this applied
through their set_property call-back to their input-current-limit.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Diffstat (limited to 'drivers/power')
| -rw-r--r-- | drivers/power/supply/power_supply_core.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index df5374afd214..02c6340ae36f 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -371,6 +371,47 @@ int power_supply_is_system_supplied(void) } EXPORT_SYMBOL_GPL(power_supply_is_system_supplied); +static int __power_supply_get_supplier_max_current(struct device *dev, + void *data) +{ + union power_supply_propval ret = {0,}; + struct power_supply *epsy = dev_get_drvdata(dev); + struct power_supply *psy = data; + + if (__power_supply_is_supplied_by(epsy, psy)) + if (!epsy->desc->get_property(epsy, + POWER_SUPPLY_PROP_CURRENT_MAX, + &ret)) + return ret.intval; + + return 0; +} + +int power_supply_set_input_current_limit_from_supplier(struct power_supply *psy) +{ + union power_supply_propval val = {0,}; + int curr; + + if (!psy->desc->set_property) + return -EINVAL; + + /* + * This function is not intended for use with a supply with multiple + * suppliers, we simply pick the first supply to report a non 0 + * max-current. + */ + curr = class_for_each_device(power_supply_class, NULL, psy, + __power_supply_get_supplier_max_current); + if (curr <= 0) + return (curr == 0) ? -ENODEV : curr; + + val.intval = curr; + + return psy->desc->set_property(psy, + POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, &val); +} +EXPORT_SYMBOL_GPL(power_supply_set_input_current_limit_from_supplier); + int power_supply_set_battery_charged(struct power_supply *psy) { if (atomic_read(&psy->use_cnt) >= 0 && |