From patchwork Wed Apr 26 09:32:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fei Shao X-Patchwork-Id: 677936 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6946BC77B60 for ; Wed, 26 Apr 2023 09:33:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240311AbjDZJdl (ORCPT ); Wed, 26 Apr 2023 05:33:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240289AbjDZJdk (ORCPT ); Wed, 26 Apr 2023 05:33:40 -0400 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B8FC1FCF for ; Wed, 26 Apr 2023 02:33:38 -0700 (PDT) Received: by mail-pg1-x536.google.com with SMTP id 41be03b00d2f7-51f1b6e8179so4916017a12.3 for ; Wed, 26 Apr 2023 02:33:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1682501618; x=1685093618; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=uvPQ+p6p7LPXccnkrXRgDzY3F78Ex853x9Swf3yMEqY=; b=UN9smnlgDaW5ESWDJZoeDD7OlyBxrsIf28fmOhRxgm4lMwF6p8cR8ZIYRXZbuDIspr YybIhG7VpOorRriLB+GvVyUHM/p1Hb6FjJ+OLjzchNz19jZmWkbZgywjgs17uqCMeIlf fA4mCMYzACCi0X1GaK4qaVvMvfnlCYLoP87mI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682501618; x=1685093618; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=uvPQ+p6p7LPXccnkrXRgDzY3F78Ex853x9Swf3yMEqY=; b=MMDkPzKr74ZdFe2ibmlQeMsjJSomyCSIYu1LDDZsyGWNKkdaQLCuhIhw4yt5fqvZa4 lK1dWXlxP5A6ttkLgi8VQe3Zi7MDbVSY2OeqvNwQduM4CXvsd5uh6heGNZLa2bsXi+oY U/PKeatZFIbxZYE/QK6t3Ky7tVqGr9wKIM0Famls8Aw0UC5EcwJ59PNstoYD2Cy/RuM2 Z1kKkDQQ99sbsRVuDjtOE6URflCeUvKgNrA3MRieuTjbejbQtVXgxnELmns7blxAMC3S xbww3mp+cqoNiSDO7OqHm+GuwoYtjtuACQw06xKFfeiKWaJmsl1PTOrvKYc5RXycNcRE e+3w== X-Gm-Message-State: AAQBX9d2BKGywhUuRSExqKliEDjOnvs/MvybZHpIpjgAhTgFUy3iMsjK KhtV37UUIMbBm7yT9iJx7R8K8g== X-Google-Smtp-Source: AKy350YjtwjO/wAtSJ0FYazTCI27tdYfzjYulYfZEnuLWJzP+p7+c5W5QWYGIc03oOV+EW2KT9YN/g== X-Received: by 2002:a05:6a20:7350:b0:f2:745a:b87e with SMTP id v16-20020a056a20735000b000f2745ab87emr22849547pzc.12.1682501617975; Wed, 26 Apr 2023 02:33:37 -0700 (PDT) Received: from fshao-glinux.tpe.corp.google.com ([2401:fa00:1:10:dcf6:797f:140d:6d]) by smtp.gmail.com with ESMTPSA id g1-20020a056a00078100b005810c4286d6sm10730075pfu.0.2023.04.26.02.33.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Apr 2023 02:33:37 -0700 (PDT) From: Fei Shao To: Jeff LaBundy , Douglas Anderson , Benjamin Tissoires , Rob Herring Cc: linux-mediatek , Fei Shao , Matthias Brugger , Dmitry Torokhov , Krzysztof Kozlowski , devicetree@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] dt-bindings: input: goodix: Add "goodix,no-reset-during-suspend" property Date: Wed, 26 Apr 2023 17:32:29 +0800 Message-ID: <20230426093231.1466984-2-fshao@chromium.org> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog In-Reply-To: <20230426093231.1466984-1-fshao@chromium.org> References: <20230426093231.1466984-1-fshao@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.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 Reviewed-by: Douglas Anderson Reviewed-by: Matthias Brugger --- 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