From: Fei Shao <fshao@chromium.org> To: Jeff LaBundy <jeff@labundy.com>, Douglas Anderson <dianders@chromium.org>, Benjamin Tissoires <benjamin.tissoires@redhat.com>, Rob Herring <robh+dt@kernel.org> Cc: linux-mediatek <linux-mediatek@lists.infradead.org>, Fei Shao <fshao@chromium.org>, Matthias Brugger <matthias.bgg@gmail.com>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, devicetree@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/2] dt-bindings: input: goodix: Add "goodix,no-reset-during-suspend" property Date: Thu, 27 Apr 2023 11:56:55 +0800 [thread overview] Message-ID: <20230427035656.1962698-2-fshao@chromium.org> (raw) In-Reply-To: <20230427035656.1962698-1-fshao@chromium.org> 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
WARNING: multiple messages have this Message-ID (diff)
From: Fei Shao <fshao@chromium.org> To: Jeff LaBundy <jeff@labundy.com>, Douglas Anderson <dianders@chromium.org>, Benjamin Tissoires <benjamin.tissoires@redhat.com>, Rob Herring <robh+dt@kernel.org> Cc: devicetree@vger.kernel.org, Dmitry Torokhov <dmitry.torokhov@gmail.com>, linux-kernel@vger.kernel.org, linux-mediatek <linux-mediatek@lists.infradead.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, linux-input@vger.kernel.org, Matthias Brugger <matthias.bgg@gmail.com> Subject: [PATCH v4 1/2] dt-bindings: input: goodix: Add "goodix,no-reset-during-suspend" property Date: Thu, 27 Apr 2023 11:56:55 +0800 [thread overview] Message-ID: <20230427035656.1962698-2-fshao@chromium.org> (raw) In-Reply-To: <20230427035656.1962698-1-fshao@chromium.org> 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
next prev parent reply other threads:[~2023-04-27 3:57 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-04-27 3:56 [PATCH v4 0/2] Fix Goodix touchscreen power leakage for MT8186 boards Fei Shao 2023-04-27 3:56 ` Fei Shao 2023-04-27 3:56 ` Fei Shao [this message] 2023-04-27 3:56 ` [PATCH v4 1/2] dt-bindings: input: goodix: Add "goodix,no-reset-during-suspend" property Fei Shao 2023-04-27 17:35 ` Rob Herring 2023-04-27 3:56 ` [PATCH v4 2/2] HID: i2c-hid: goodix: Add support for " Fei Shao 2023-04-27 3:56 ` Fei Shao 2023-05-19 14:08 ` [PATCH v4 0/2] Fix Goodix touchscreen power leakage for MT8186 boards Doug Anderson 2023-05-23 13:11 ` Jiri Kosina 2023-05-23 13:11 ` Jiri Kosina 2023-05-23 13:32 ` Doug Anderson 2023-05-23 13:32 ` Doug Anderson 2023-05-23 15:29 ` Fei Shao
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