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: 13224314 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 From patchwork Wed Apr 26 09:32:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fei Shao X-Patchwork-Id: 13224315 X-Patchwork-Delegate: jikos@jikos.cz 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 E6280C77B7F for ; Wed, 26 Apr 2023 09:33:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240340AbjDZJdo (ORCPT ); Wed, 26 Apr 2023 05:33:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240289AbjDZJdm (ORCPT ); Wed, 26 Apr 2023 05:33:42 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29EE01BE4 for ; Wed, 26 Apr 2023 02:33:41 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id d2e1a72fcca58-63b7096e2e4so5714935b3a.2 for ; Wed, 26 Apr 2023 02:33:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1682501620; x=1685093620; 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=GbkTP3zHcJFJuVybS9KupjRL2tPIXD5dw4xi+AbtQaw=; b=C8LAqlu6DToCZB9Khh7AJe4KKQMWtFvMtBzAAACPvEmA1+DBreI552kDfQTb3Q2Ut2 9m+esTfiRzAeUqVB12gteiAuVqPePd+h2FTlmetMy85ujIIAEcG/uplvGHmGt/4Ql1oO IVX72xlund0sCV7s9Co3GT2hmPe6NI97Y1VZE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682501620; x=1685093620; 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=GbkTP3zHcJFJuVybS9KupjRL2tPIXD5dw4xi+AbtQaw=; b=cIxUdsQ2cHl8oOXcSzPrJe+LLaHyw3EAo8LPRGiEZBsnLSvlscp/jegtM3TgFONmzq 0sfenlm12GWPVWGXaQoL2gXnbJgh5HXJ5/3TNa8sh11EOwT80U9059jTpuMJM/dJobkx w80gRhrCnFhD/CnwML9ew4bS3FRdwNHW/3UxeecvFdfVvJeuRdD2oDMzJvT2HTU7Paca RhKY/nc/PpSdpqfUoJ0QIZy8ipwpOdXkzq8diqhmF9WiQKCiO9WofWiPgWaFnvrnPLIf yhFuVsDsblQmpW1j3phTQtCrDfNsqrGAEwWuQSqqa2JEPVEZzmU7PpcUJAAm6xu5h3wk 0RUw== X-Gm-Message-State: AAQBX9de4Tjf4v8wk7H9wjLdeLF10C6VP5yavVM7n/jKF5c1mn+1TEIa DbOxe/VTt54Vvd4K2sLAGTh7la/2UeBI78A+qYg= X-Google-Smtp-Source: AKy350YrCareTvj+eDZ+fbTN6x5p6afQ7jO7RDXDEbJX15Wm3ZZLFh0VsSVNstRbc8sSNOzhz1r+9Q== X-Received: by 2002:a05:6a00:2da7:b0:625:ea57:389b with SMTP id fb39-20020a056a002da700b00625ea57389bmr27528444pfb.5.1682501620593; Wed, 26 Apr 2023 02:33:40 -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.0.2023.04.26.02.33.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Apr 2023 02:33:40 -0700 (PDT) From: Fei Shao To: Jeff LaBundy , Douglas Anderson , Benjamin Tissoires , Rob Herring Cc: linux-mediatek , Fei Shao , Dmitry Torokhov , Jiri Kosina , Matthias Kaehlcke , Stephen Kitt , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] HID: i2c-hid: goodix: Add support for "goodix,no-reset-during-suspend" property Date: Wed, 26 Apr 2023 17:32:30 +0800 Message-ID: <20230426093231.1466984-3-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 In the beginning, commit 18eeef46d359 ("HID: i2c-hid: goodix: Tie the reset line to true state of the regulator") introduced a change to tie the reset line of the Goodix touchscreen to the state of the regulator to fix a power leakage issue in suspend. After some time, the change was deemed unnecessary and was reverted in commit 557e05fa9fdd ("HID: i2c-hid: goodix: Stop tying the reset line to the regulator") due to difficulties in managing regulator notifiers for designs like Evoker, which provides a second power rail to touchscreen. However, the revert caused a power regression on another Chromebook device Steelix in the field, which has a dedicated always-on regulator for touchscreen and was covered by the workaround in the first commit. To address both cases, this patch adds the support for the new "goodix,no-reset-during-suspend" property in the driver: - When set to true, the driver does not assert the reset GPIO during power-down. Instead, the GPIO will be asserted during power-up to ensure the touchscreen always has a clean start and consistent behavior after resuming. This is for designs with a dedicated always-on regulator. - When set to false or unset, the driver uses the original control flow and asserts GPIO and disable regulators normally. This is for the two-regulator and shared-regulator designs. Signed-off-by: Fei Shao Reviewed-by: Douglas Anderson --- Changes in v2: - Do not change the regulator_enable logic during power-up. drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 26 +++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c index 0060e3dcd775..fc4532fcadcc 100644 --- a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c +++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c @@ -28,6 +28,7 @@ struct i2c_hid_of_goodix { struct regulator *vdd; struct regulator *vddio; struct gpio_desc *reset_gpio; + bool no_reset_during_suspend; const struct goodix_i2c_hid_timing_data *timings; }; @@ -37,6 +38,20 @@ static int goodix_i2c_hid_power_up(struct i2chid_ops *ops) container_of(ops, struct i2c_hid_of_goodix, ops); int ret; + if (ihid_goodix->no_reset_during_suspend) { + /* + * This is not mandatory, but we assert reset here (instead of + * during power-down) to ensure the device will have a clean + * state after powering up, just like the normal scenarios will + * have. + * + * Note that in this case we assume the regulators should be + * (marked as) always-on, so the regulator core knows what to + * do with them in the following regulator_enable() calls + * despite regulator_disable() was not called previously. + */ + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + } ret = regulator_enable(ihid_goodix->vdd); if (ret) return ret; @@ -60,6 +75,14 @@ static void goodix_i2c_hid_power_down(struct i2chid_ops *ops) struct i2c_hid_of_goodix *ihid_goodix = container_of(ops, struct i2c_hid_of_goodix, ops); + /* + * Don't assert reset GPIO if it's set. + * Also, it's okay to skip the following regulator_disable() calls + * because the regulators should be always-on in this case. + */ + if (ihid_goodix->no_reset_during_suspend) + return; + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); regulator_disable(ihid_goodix->vddio); regulator_disable(ihid_goodix->vdd); @@ -91,6 +114,9 @@ static int i2c_hid_of_goodix_probe(struct i2c_client *client) if (IS_ERR(ihid_goodix->vddio)) return PTR_ERR(ihid_goodix->vddio); + ihid_goodix->no_reset_during_suspend = + of_property_read_bool(client->dev.of_node, "goodix,no-reset-during-suspend"); + ihid_goodix->timings = device_get_match_data(&client->dev); return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001, 0);