From patchwork Wed Apr 26 14:44:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fei Shao X-Patchwork-Id: 677933 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 87B1CC77B7C for ; Wed, 26 Apr 2023 14:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241480AbjDZOov (ORCPT ); Wed, 26 Apr 2023 10:44:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241484AbjDZOon (ORCPT ); Wed, 26 Apr 2023 10:44:43 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C056872B4 for ; Wed, 26 Apr 2023 07:44:41 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-63b5465fb99so5995679b3a.1 for ; Wed, 26 Apr 2023 07:44:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1682520281; x=1685112281; 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=LMx52XrqJI/lkSS1akmRczc5aEbg1BtnIjYD6cH52u8=; b=F91dapaZh/JVWjuQtDJodQztlL98yiEx4kYIDCxP4Mk0I/lkQ2G5L4dBr6bLELESx/ vvHmStLQPZXLg8Ifj2mb3/SVQJ5Y/ZlwxynDVlrhes5pGa97XuaU5Lw8uQ71dccoS4YT SB5JXG7eTFanP0Dzp+JpYeLIwiaFta1xOhPAk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682520281; x=1685112281; 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=LMx52XrqJI/lkSS1akmRczc5aEbg1BtnIjYD6cH52u8=; b=k7RgVrZEk+WRUanhiLQJqp5BQLZiiR+hPp+v4EmnjEbABstkdZMMYda61Ie24h1Y1p qGVo2mBA25uJUPtDlXamrxXjJ/0Xpf61Mbhl3b6ha6JJSeU+Tto41ZXN15uaWZj4pzhK bCMU3iiN7IpB6wFOO9jWDJT5znuCEFwvoUy3cYKvwt3OaVbZ9acPTvXtxvkKcbmS3fDK j2Ya6Z1dAC5nXiUXcIblMOvD+me/twyyAVpgEYZtl/YiZll5PGGyBrADOGBwB+ZVVdlt mGLf4lP2A0w1WsJ7dH9x/3GcojqLkUAJVam1a8lIBtFGAklszUTpaGCwZ6C0ZSfDXSSD yttg== X-Gm-Message-State: AAQBX9cune4De/1oQkPzEBzkjrXeu7GqMNuLO87t2JrSRQkCaXrLnsDE 5ppXzAdc5RiiO6DdP8FY1r9sag== X-Google-Smtp-Source: AKy350YHKPdB0cD+iLdEEgdjKOEmIZB2krvhGetLkbFmx30LTATpiGYRXuiXoO70s1nsDAjFe3+khA== X-Received: by 2002:a05:6a21:6d96:b0:f4:3934:96b0 with SMTP id wl22-20020a056a216d9600b000f4393496b0mr15771936pzb.37.1682520281201; Wed, 26 Apr 2023 07:44:41 -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 f17-20020a631011000000b00502f20aa4desm8750495pgl.70.2023.04.26.07.44.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Apr 2023 07:44:40 -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 v3 1/2] dt-bindings: input: goodix: Add "goodix,no-reset-during-suspend" property Date: Wed, 26 Apr 2023 22:44:21 +0800 Message-ID: <20230426144423.2820826-2-fshao@chromium.org> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog In-Reply-To: <20230426144423.2820826-1-fshao@chromium.org> References: <20230426144423.2820826-1-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 --- (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 From patchwork Wed Apr 26 14:44:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fei Shao X-Patchwork-Id: 677415 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 F2502C7EE20 for ; Wed, 26 Apr 2023 14:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241495AbjDZOov (ORCPT ); Wed, 26 Apr 2023 10:44:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241506AbjDZOor (ORCPT ); Wed, 26 Apr 2023 10:44:47 -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 B5D1976AD for ; Wed, 26 Apr 2023 07:44:45 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id d2e1a72fcca58-63b4e5fdb1eso8501509b3a.1 for ; Wed, 26 Apr 2023 07:44:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1682520285; x=1685112285; 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=unoMmmw4ERQhjIti7rAorCXdA4tzC1K8iFsMEZhavZ0=; b=XaZLVrt1MAcN0Beh1WTI5sVwkDsA+97s0BzKfnIKBZXqCwILv939LL07A9EKds4tZq 8FCdjSIFw0HB45f41bM8shTO1Ui1nC9PjiOX/W1dXmAkhtzf3ayfCNRpOsPX6bFWLOEK A2WO/vb+Yy50KEqx2a6Hj18+F0UfUnYqAMzas= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682520285; x=1685112285; 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=unoMmmw4ERQhjIti7rAorCXdA4tzC1K8iFsMEZhavZ0=; b=lrss0xe2/WF+fsedJ47VDyLsUtJtxqRifhz5NgYr119J8FIEZjULOFiQdcTndCB8ff qmoC4nVb1ru7xajmnhkNfQ2OSBTzyqeEgbXJd/WCeG89cBA5dBtjSNcqASrDwHJ1LDQc ETfBtNYiKnZrW9w4SbmxJFgiZF+INEXYhL1lRMjSUMdp9e97JtDoRWqmXUr441MPWzW+ C2BI/ELJz8asW+kU3OCppHA97H9EMcjZ0NEjpr5Y0e2dNJbZkuoUb7Pyz4cH6pnEXDrh m/GcJN5V5hJS1wBKxQQusFxfhRjakpFsS0suahOR/dpkh/wVvFbxXEOK5002HeEOu7D7 SxaA== X-Gm-Message-State: AAQBX9cKUVTHyw6NFHyO1ordK9QM8myp5wi1Hg/Ci6JO6yXMjbENcmYR RbYP0ACeGS1X3mURC5h+fXn7TQ== X-Google-Smtp-Source: AKy350anOfPnTjWBVxV9V8oS46CcuV5wDlXlWJitrGClrfTDhJe52dFeq38OdC4o4ASuG2TpDuywjQ== X-Received: by 2002:a05:6a00:1305:b0:63d:a0d:6fa1 with SMTP id j5-20020a056a00130500b0063d0a0d6fa1mr24917705pfu.21.1682520285002; Wed, 26 Apr 2023 07:44:45 -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 f17-20020a631011000000b00502f20aa4desm8750495pgl.70.2023.04.26.07.44.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Apr 2023 07:44:44 -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 v3 2/2] HID: i2c-hid: goodix: Add support for "goodix,no-reset-during-suspend" property Date: Wed, 26 Apr 2023 22:44:22 +0800 Message-ID: <20230426144423.2820826-3-fshao@chromium.org> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog In-Reply-To: <20230426144423.2820826-1-fshao@chromium.org> References: <20230426144423.2820826-1-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 disables regulators normally. This is for the two-regulator and shared-regulator designs. Signed-off-by: Fei Shao Reviewed-by: Douglas Anderson --- Changes in v3: - In power-down, only skip the GPIO but not the regulator calls if the flag is set Changes in v2: - Do not change the regulator_enable logic during power-up. drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c index 0060e3dcd775..3ed365b50432 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 +38,14 @@ 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) { + /* + * We assert reset GPIO 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. + */ + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + } ret = regulator_enable(ihid_goodix->vdd); if (ret) return ret; @@ -60,7 +69,9 @@ 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); - gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + if (!ihid_goodix->no_reset_during_suspend) + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + regulator_disable(ihid_goodix->vddio); regulator_disable(ihid_goodix->vdd); } @@ -91,6 +102,9 @@ 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);