Re: [PATCH 10/15] power: supply: bq24190_charger: Use extcon to determine ilimit, 5v boost

[Hans de Goede]

Hi,

On 17-03-17 18:33, Andy Shevchenko wrote:
> On Fri, 2017-03-17 at 10:55 +0100, Hans de Goede wrote:
> > Add support for monitoring an extcon device with SDP/CDP/DCP and HOST
> > cables and adjust ilimit and enable/disable the 5v boost converter
> > accordingly. This is necessary on systems where the PSEL pin is
> > hardwired
> > high and ILIM needs to be set by software based on the detected
> > charger
> > type.
>
> >  config CHARGER_BQ24190
> >  	tristate "TI BQ24190 battery charger driver"
> >  	depends on I2C
>
> > +	depends on EXTCON
>
> I dunno what is preferred here, but if we would like to keep
> compatibility with previous configurations "select" should be used over
> "depends on".

select really should only be used for hidden options,
using select in other scenarios leads to all sort of
problems (hard to debug Kconfig dependency loops).

> > +static void bq24190_extcon_work(struct work_struct *work)
> > +{
> > +	struct bq24190_dev_info *bdi =
> > +		container_of(work, struct bq24190_dev_info,
> > extcon_work);
> > +	int ret, iinlim = 0;
> > +
> > +	if (extcon_get_state(bdi->extcon, EXTCON_CHG_USB_SDP) == 1)
> > +		iinlim = 500000;
> > +	else if (extcon_get_state(bdi->extcon, EXTCON_CHG_USB_CDP) ==
> > 1 ||
> > +		 extcon_get_state(bdi->extcon, EXTCON_CHG_USB_ACA) ==
> > 1)
> > +		iinlim = 1500000;
> > +	else if (extcon_get_state(bdi->extcon, EXTCON_CHG_USB_DCP) ==
> > 1)
> > +		iinlim = 2000000;
> > +
>
> > +	if (iinlim) {
>
> Could be possible to call below unconditionally here (use 0)?

If there is no Vbus setting iinlim is not useful, the charger
will reset it to a default as soon as Vbus comes up and i2c
transactions are not free.

> > +		ret = bq24190_set_field_val(bdi, BQ24190_REG_ISC,
> > +				BQ24190_REG_ISC_IINLIM_MASK,
> > +				BQ24190_REG_ISC_IINLIM_SHIFT,
> > +				bq24190_iinlim_values,
> > +				ARRAY_SIZE(bq24190_iinlim_values),
> > +				iinlim);
> > +		if (ret)
> > +			dev_err(bdi->dev, "Can't set IINLIM: %d\n",
> > ret);
> > +	}
>
> Perhaps make above as a helper?
>
> In that case no need for "if (iinlim)" and perhaps switch-case might be
> used instead of if-else-if (latter is up to you).

I prefer to keep this as is.

Thanks & Regards,

Hans