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

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 16-08-17 22:28, Liam Breck wrote:
> Hi Hans,
> 
> On Tue, Aug 15, 2017 at 1:04 PM, Hans de Goede <hdegoede@redhat.com> 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@redhat.com>
>> ---
>> 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?
>     }

Done, except for making the flag a field in input_current_limit_work,
input_current_limit_work is of type struct delayed_work so I cannot just
add a field.

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

Also done for v3 of this patch.

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

I've cherry-picked v3 of the patch adding the dt-binding-doc to my tree so
that I could add the documentation for the property on top. I will make sure
to rebase on top of the rest once the rest is merged by Sebastian (otherwise
I need to rebase after each revision of the patch-set).

Regards,

Hans