Re: [PATCH] platform/x86: x86-android-tablets: Add Lenovo Yoga Tab 3 (YT3-X90F) charger + fuel-gauge data

[Andy Shevchenko <andy@kernel.org>]

On Mon, Nov 28, 2022 at 11:44:36AM +0100, Hans de Goede wrote:
> On 11/28/22 11:20, Andy Shevchenko wrote:
> > On Sun, Nov 27, 2022 at 07:24:58PM +0100, Hans de Goede wrote:

...

> >> +	/*
> >> +	 * The "bq25892_0" charger IC has its /CE (Charge-Enable) and OTG pins
> >> +	 * connected to GPIOs, rather then having them hardwired to the correct
> >> +	 * values as is normally done.
> >> +	 *
> >> +	 * The bq25890_charger driver controls these through I2C, but this only
> >> +	 * works if not overridden by the pins. Set these pins here:
> >> +	 * 1. Set /CE to 0 to allow charging.
> > 
> > If I read this correctly then the /CE is an active low pin and setting to 0
> > means active state
> 
> Correct.
> 
> > which...
> > 
> >> +	 * 2. Set OTG to 0 disable V5 boost output since the 5V boost output of
> >> +	 *    the main "bq25892_1" charger is used when necessary.
> >> +	 */
> >> +
> >> +	/* /CE pin */
> >> +	ret = x86_android_tablet_get_gpiod("INT33FF:02", 22, &gpiod);
> >> +	if (ret < 0)
> >> +		return ret;
> > 
> >> +	gpiod_set_value(gpiod, 0);
> > 
> > ...contradicts with the virtual state here. Perhaps you missed the
> > corresponding flag to enable negation?
> 
> x86_android_tablet_get_gpiod() gets the GPIO directly from
> the gpio-chip using gpiochip_get_desc() since these GPIOs are
> not described in ACPI. There is no option to pass a gpio_lookup_flags
> flag like GPIO_ACTIVE_LOW this way since we are not doing an actual lookup.

gpiod_toggle_active_low() is your friend, no?

> >> +	ret = x86_android_tablet_get_gpiod("INT33FF:03", 19, &gpiod);
> >> +	if (ret < 0)
> >> +		return ret;
> >> +
> >> +	gpiod_set_value(gpiod, 0);

-- 
With Best Regards,
Andy Shevchenko