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

From: Liam Breck
Date: Mon Aug 28 2017 - 13:02:09 EST


Hi Hans,

On Mon, Aug 28, 2017 at 9:04 AM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> 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@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?
>> }
>
>
> 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.

What I meant was you could check an existing field in delayed_work to
see if it was init'd.

>> 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).

Sounds good.