| Message ID | 20230426144423.2820826-2-fshao@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix Goodix touchscreen power leakage for MT8186 boards | expand |
Hi Fei, On Wed, Apr 26, 2023 at 10:44:21PM +0800, Fei Shao wrote: > We observed that on Chromebook device Steelix, if Goodix GT7375P > touchscreen is powered in suspend (because, for example, it connects to > an always-on regulator) and with the reset GPIO asserted, it will > introduce about 14mW power leakage. > > To address that, we add this property to skip reset during suspend. > If it's set, the driver will stop asserting the reset GPIO during > power-down. Refer to the comments in the driver for details. > > Signed-off-by: Fei Shao <fshao@chromium.org> > Reviewed-by: Douglas Anderson <dianders@chromium.org> > Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> > --- Reviewed-by: Jeff LaBundy <jeff@labundy.com> > > (no changes since v2) > > Changes in v2: > - Use a more accurate property name and with "goodix," prefix. > > .../devicetree/bindings/input/goodix,gt7375p.yaml | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml b/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml > index ce18d7dadae2..1edad1da1196 100644 > --- a/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml > +++ b/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml > @@ -43,6 +43,15 @@ properties: > itself as long as it allows the main board to make signals compatible > with what the touchscreen is expecting for its IO rails. > > + goodix,no-reset-during-suspend: > + description: > + Set this to true to enforce the driver to not assert the reset GPIO > + during suspend. > + Due to potential touchscreen hardware flaw, back-powering could happen in > + suspend if the power supply is on and with active-low reset GPIO asserted. > + This property is used to avoid the back-powering issue. > + type: boolean > + > required: > - compatible > - reg > -- > 2.40.1.495.gc816e09b53d-goog > Many thanks to you and Doug for the informative discussion. Kind regards, Jeff LaBundy
diff --git a/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml b/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml index ce18d7dadae2..1edad1da1196 100644 --- a/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml +++ b/Documentation/devicetree/bindings/input/goodix,gt7375p.yaml @@ -43,6 +43,15 @@ properties: itself as long as it allows the main board to make signals compatible with what the touchscreen is expecting for its IO rails. + goodix,no-reset-during-suspend: + description: + Set this to true to enforce the driver to not assert the reset GPIO + during suspend. + Due to potential touchscreen hardware flaw, back-powering could happen in + suspend if the power supply is on and with active-low reset GPIO asserted. + This property is used to avoid the back-powering issue. + type: boolean + required: - compatible - reg