Re: [PATCH v2 11/14] power: supply: bq24190_charger: Get input_current_limit from our supplier

[Liam Breck]

Hi Hans,

On Tue, Aug 15, 2017 at 1:04 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> 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 calling
> power_supply_set_input_current_limit_from_supplier helper if the
> "input-current-limit-from-supplier" device-property is set.
>
> 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.
> ---
>  drivers/power/supply/bq24190_charger.c | 35 ++++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
>
> diff --git a/drivers/power/supply/bq24190_charger.c b/drivers/power/supply/bq24190_charger.c
> index f13f892..6f75c8e 100644
> --- a/drivers/power/supply/bq24190_charger.c
> +++ b/drivers/power/supply/bq24190_charger.c
> @@ -159,9 +159,11 @@ 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;
> +       bool                            input_current_limit_from_supplier;
>         struct mutex                    f_reg_lock;
>         u8                              f_reg;
>         u8                              ss_reg;
> @@ -1142,6 +1144,32 @@ 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);
> +}
> +
> +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.
> +        */
> +       if (bdi->input_current_limit_from_supplier)
> +               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,
> @@ -1170,6 +1198,7 @@ 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 */
> @@ -1651,6 +1680,8 @@ 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);
>
> @@ -1659,6 +1690,10 @@ static int bq24190_probe(struct i2c_client *client,
>                 return -EINVAL;
>         }
>
> +       bdi->input_current_limit_from_supplier =
> +               device_property_read_bool(dev,
> +                                         "input-current-limit-from-supplier");
> +

Maybe
  if (device_property_read_bool(dev,
"linux,input-current-limit-from-supplier")) {
       INIT_DELAYED_WORK(&bdi->input_current_limit_work,
                         bq24190_input_current_limit_work);
      bdi->input_current_limit_from_supplier = true; // or use a field
in bdi->input_current_limit_work as the flag?
   }

Also should document property for DT use assuming Sebastian is ok with
new power_supply method.

And can you rebase to my pending series in next pass? There's nothing
controversial in it :-)