From patchwork Sat Mar 29 18:58:54 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Blumenstingl X-Patchwork-Id: 14032783 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0C2E0C36008 for ; Sat, 29 Mar 2025 19:11:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=nM1iEKnX8goZJjbBqk+vEAeC/fnWWVRUcl0seopOhvI=; b=HKaJly4YhtkWrGVkdLJdyRVtPz /LgWBfkE3jG7YbWfTwyxBdn/ySv1zzpAgoj8qidHviE5fX8zr+Ic606C1B4I0TK7/YY1BUMqn57FO R56WrlxpaLdjPfJe50zLTMvJboUdC/OtcGxDd8uyWShin1UN89hS1lnOFxEzLCzbkzajsI27YITyk kCjgOlugz7ak9kApRmGqRKKA3kjKRDNni2d2L6o+NYRT7tyVKBbVYLFCuaS9Qo1TyUkpBQsW2xKkf WWZ73WtdJiQwLkfw9tFpTHpkpZJdjA9pUs7EY0DvNIctC3rzUe77QuEcwCow6wBsfJpDG+IxmiLII 36rQJLaQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tybao-0000000FRWO-2ehw; Sat, 29 Mar 2025 19:11:42 +0000 Received: from mail-ej1-x633.google.com ([2a00:1450:4864:20::633]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tybP2-0000000FQ27-26b8; Sat, 29 Mar 2025 18:59:33 +0000 Received: by mail-ej1-x633.google.com with SMTP id a640c23a62f3a-ac345bd8e13so537467066b.0; Sat, 29 Mar 2025 11:59:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20230601; t=1743274770; x=1743879570; darn=lists.infradead.org; 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=nM1iEKnX8goZJjbBqk+vEAeC/fnWWVRUcl0seopOhvI=; b=cJYzMc9i4Ha583/Y5gLtppwCNwtCA8id69N20hf1SFWiUSloC4dgknZwezkSCVlw2s uUpBpXWvc4t6PxzBqUcs/xI3ayVE+vM4b1dcBfmMxPMS2YGKJjiGMPrEr4e9AoIjyP36 ++k6wYygtss77+V9dJT1eidrrHPw/9txGmn+/qkZlKXD7c+YXbqBB5p86GkICfBqp/iI fqnSX0qzUU6QH+PaG3Np+RXTpCUndQSrBI+a5+ukBXNAbJ5n4CxgulbrHTa9UE40MxQN zfGyq/tKjN2Y0UxdXUpNeQaBgxIgifQ4rFRYKbOprccAeLI58qtOSnWoPmTNttrxlUMm vOhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743274770; x=1743879570; 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=nM1iEKnX8goZJjbBqk+vEAeC/fnWWVRUcl0seopOhvI=; b=ZtXcoCP4jYwabiwWXW+IVgmqiVgJSjuQGR2YlMFr3cLOxORF5LgXSsAk+87ySLl6xD 8e3+3jCv8eh7Jap3aG1SlPMLWw1jKbNY5JUUv+BuNMkNzH7hQJbezvttttKK3ia/ODXZ 8OlQzn80tkDt3LgWfH3kFPDLF+ZnbK26Mu66Z5YFG0Iiz81yXJhK9p7Bm6i1R6IhZaX4 bMGo1OgA3YXUZwN40CqUoCWH08KptYwGuLHoNiVb7RIcQ0EGk29n8FOc2xyRy57Ac3TN 4dxFO2VArXR1byQ5SPQrOsYqORxWAGKDls6UVpxlb8sReo9hlj0H66erqzDPWTceZOb6 pqqQ== X-Gm-Message-State: AOJu0YzODxNlboDFHJszx05Q/hzuuG0MBkZ0OgslF/60EiI+jznT2U+4 mloj6GSgc+aThY89Bgltne1jAM3hbN3M3on9D/3p3356UcdxQke9i17bOQ== X-Gm-Gg: ASbGnctEoNEHVUpXGnHX18dTiHOa1gwzQ0XVLTQjJ1+WBEYxDOc2XpiKZdpMvbRZPG0 QrhG6B+6W2coab9+LYttMmSIDlmGlNP03nDXQb2MokyNqsR/L2/NL4ruQaU4uBO9ZyQ42lA+T5V ZNwR88OeaP+3ZeM13Rdp+AoBGEeNNijOkk7evzYtCFBAY5To9gdCh6/YuiI47pRlCkfbham78wd DlD7H08Ep1bWgVid2BmE7jF+dDE4bwMN/04KYKxhZXCXOrnHpL1SjMIxvUEoDpap93UP1IzP/DK +MOX5ocPmk9kTD0ST39aeXs94vbQ0y08ZsjyIxnrylBM01WJQ6FEdKrnpS3DDblwvEj/1HOw8/x fDYxnD3yArRR/fGa16IUJuJuQPk39TUzY1egIAcqNFj4olkAwx0+qQlM6jJERcftctN754o3Eyl o68wpU X-Google-Smtp-Source: AGHT+IEz7v5Ljt9ZJRFv32Hw0OIPcmVi+flrUYAm3zPFqUuBjHYjrY6pgvKN0F18tzS38DfxADncyg== X-Received: by 2002:a17:907:869e:b0:ac1:ea6e:ad64 with SMTP id a640c23a62f3a-ac738a3f376mr380847966b.28.1743274770291; Sat, 29 Mar 2025 11:59:30 -0700 (PDT) Received: from localhost.localdomain (dynamic-2a02-3100-ad73-6800-0000-0000-0000-0e63.310.pool.telefonica.de. [2a02:3100:ad73:6800::e63]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-ac7196dd46asm364497866b.160.2025.03.29.11.59.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:28 -0700 (PDT) From: Martin Blumenstingl To: linux-amlogic@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, jbrunet@baylibre.com, khilman@baylibre.com, neil.armstrong@linaro.org, christianshewitt@gmail.com, Martin Blumenstingl Subject: [PATCH 6/7] arm64: dts: amlogic: axg: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:54 +0100 Message-ID: <20250329185855.854186-7-martin.blumenstingl@googlemail.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250329185855.854186-1-martin.blumenstingl@googlemail.com> References: <20250329185855.854186-1-martin.blumenstingl@googlemail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250329_115932_538360_2BAB45C3 X-CRM114-Status: GOOD ( 12.67 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Some boards have noise on the UART RX line when the UART pins are not connected to another device (such as an USB UART adapter). This can be addressed by using a pull up resistor. Not all boards may provide such a pull up resistor on the PCB so enable the SoC's pull-up on the UART RX and TX pads by default. This matches the default (from u-boot or SoC hardware) state for the pinmux configuration on these pads. Signed-off-by: Martin Blumenstingl --- arch/arm64/boot/dts/amlogic/meson-axg.dtsi | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi index a6924d246bb1..2df143aa77ce 100644 --- a/arch/arm64/boot/dts/amlogic/meson-axg.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-axg.dtsi @@ -1164,7 +1164,7 @@ mux { groups = "uart_tx_a", "uart_rx_a"; function = "uart_a"; - bias-disable; + bias-pull-up; }; }; @@ -1182,7 +1182,7 @@ mux { groups = "uart_tx_b_x", "uart_rx_b_x"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; @@ -1200,7 +1200,7 @@ mux { groups = "uart_tx_b_z", "uart_rx_b_z"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; @@ -1218,7 +1218,7 @@ mux { groups = "uart_ao_tx_b_z", "uart_ao_rx_b_z"; function = "uart_ao_b_z"; - bias-disable; + bias-pull-up; }; }; @@ -1654,7 +1654,7 @@ mux { groups = "uart_ao_tx_a", "uart_ao_rx_a"; function = "uart_ao_a"; - bias-disable; + bias-pull-up; }; }; @@ -1672,7 +1672,7 @@ mux { groups = "uart_ao_tx_b", "uart_ao_rx_b"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; };