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[2a02:3100:ad73:6800::e63]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-ac7196dd46asm364497866b.160.2025.03.29.11.59.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:16 -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 1/7] ARM: dts: amlogic: meson8: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:49 +0100 Message-ID: <20250329185855.854186-2-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_115919_539416_1D458D08 X-CRM114-Status: GOOD ( 14.05 ) 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/arm/boot/dts/amlogic/meson8.dtsi | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/boot/dts/amlogic/meson8.dtsi b/arch/arm/boot/dts/amlogic/meson8.dtsi index 847f7b1f1e96..7fe0c7d3ee6e 100644 --- a/arch/arm/boot/dts/amlogic/meson8.dtsi +++ b/arch/arm/boot/dts/amlogic/meson8.dtsi @@ -398,7 +398,7 @@ uart_ao_a_pins: uart_ao_a { mux { groups = "uart_tx_ao_a", "uart_rx_ao_a"; function = "uart_ao"; - bias-disable; + bias-pull-up; }; }; @@ -567,7 +567,7 @@ mux { groups = "uart_tx_a1", "uart_rx_a1"; function = "uart_a"; - bias-disable; + bias-pull-up; }; }; From patchwork Sat Mar 29 18:58:50 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Blumenstingl X-Patchwork-Id: 14032777 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 1DE2FC36008 for ; Sat, 29 Mar 2025 19:04:46 +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=fnIvJ5GkQdTsudX8kCSNJ/vtno+O1kFQRgoOLI7QT+E=; b=if0qoRVVGFkEqxDaQac6IDZgIz 1fkvDdsB3uo9/z1WjLQLWZs4XN1Gf7Gx5ivyQpVV3CGLDQSu3qE4hn3Vukjm2JLXHdHWn0rcRk1vM DKf9hnj5uBf0C5co4Qb3cHWbbh7KVcd+vWEIRItn6F9mJbgWrSWLez75Simjai00DG+WlpuLPWOjk oTum0uBWHAGBuMK9SuPbV1zzIm6QbJefwvZH8Mgdvo5jVr2iqqqAirv3A3n4ihYfZE3ssnIbqhcWK tx9r2eBY31fusAfe9wFuxN+pq5XtpB8Ykto47ydjhJmFrk9AhOvOoP/hwWbcd0uMDXpAxXqGeJpsu WPIG/jkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tybTx-0000000FQpK-45Zc; Sat, 29 Mar 2025 19:04:37 +0000 Received: from mail-ej1-x635.google.com ([2a00:1450:4864:20::635]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tybOt-0000000FPyB-3IxM; Sat, 29 Mar 2025 18:59:24 +0000 Received: by mail-ej1-x635.google.com with SMTP id a640c23a62f3a-ac2dfdf3c38so581125866b.3; Sat, 29 Mar 2025 11:59:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20230601; t=1743274762; x=1743879562; 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=fnIvJ5GkQdTsudX8kCSNJ/vtno+O1kFQRgoOLI7QT+E=; b=RR+YJ1dExpwMVhPcZQohXNiBg69XC8yGvJ6BED4dLVTFbxyqwX1SyS1yVqQ7vubh+X Juyi2XcPj8DfC53AQaFdh0RZ0DWVPimb4t6LQYy0rsVBZ0JKCvkJ8m+EpNFzwS6CH/OF N1gEDyBZA4UUTZsecsuG/avf9GBdkkTRt647z88nH+LvewR2nc7tRmafB7w0RT8uW5Fz cGYx6H0LrdXb2UCWeCG9LCZ1F46pQ3kFiPPVZbYPGeKNf+Egc2IKfVRAIBg1y2MS09TA Ut59nvRrHy5+tKasuo30qD4kDoDtCHBfw5fI6nwTMRjRq+kvg7q0yklN6Y9zRO5jsZt7 vQRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743274762; x=1743879562; 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=fnIvJ5GkQdTsudX8kCSNJ/vtno+O1kFQRgoOLI7QT+E=; b=GIeakpND8T0QcQamArfPuY5FdI8HWABmoLsbMukH+XWYtCyjAe3xBmsqeiXJNlqrI6 k8bEIcUioVzkDTZM5m63NH3LtST4b63UWvh0O/0pEwbi4Q2cHnAhRO6hgOd5hQYB0d+u eUs8UOgYtJF+TAlLj5XkAhLLXWsKck+GOA3ooXT7mUUIQJHnyOqgQre9b0zmmcHsttZm U7V5oF8AaoGSmH0ByWNe/Ot0tUvy24If3hWcFsjTZggC5nq9Rps7r6NL5wbkXibeqLoa f50L5Y2AbXjqsU/8AV4vbfzFw/jAoM6zViD9D9oYmObTgMdsLdKjEmV0jJqN0BfRjFDA mXjg== X-Gm-Message-State: AOJu0YxJCI4bQcYVKMy0L4X5Pg8AZei2Up84tEogCctm05kmPRyYwjaM h+ErZFnlp53cXQMvHAK0k+h1nk7x716ZqIf6xL3IO9Au1GyKScQbF7VUTA== X-Gm-Gg: ASbGncvIxNuJx67kA/AuLXVM7LUTVf0CTVGQO2DZLA58S292K/9PqWaZq/WIqcKv/8r IEQyupwOZ32uEBwlR0Rz9ABHyvgsGuwBMKygmPw+hsUyECofRareL2QmsdzW9PigzSqVwr5qW5O /a5wnt8G1WZiL61N05fHPUYII7JYs3jnyYmy+IZxjZbnCxUesc6c88P2mpEkU9d1z9OXuofUSk5 tfiEmIiHGpNJVr/9nfiU1FKRk+6gZJ5GRsLYW+2WL4b1gc3OU1GcthyXEAinrEaK/jPhIS04Wy/ eEFXzc38QaLjTl0kEjZFD900ouE6Ml3jPINq7qlKC6EVP1Mhu3Uj4rfbphrLGkuHdP8AsE9/3aF XgIsC2KScH1AmULk0N1lovMuKFnlAcDtQI1EBzJH9+oNR5psoyCaJHC2HMGbb6uFbSEQifg== X-Google-Smtp-Source: AGHT+IFESawv1sch0Xh3dWQk//nDyTPFLIdKhU+1BsFulW/LDtgKGmqIj+1y+Hbo1pfEDL+B/1he2g== X-Received: by 2002:a17:907:868e:b0:ac3:aff6:817f with SMTP id a640c23a62f3a-ac738a5aa6fmr362758366b.13.1743274761496; Sat, 29 Mar 2025 11:59:21 -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.160.2025.03.29.11.59.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:20 -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 2/7] ARM: dts: amlogic: meson8b: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:50 +0100 Message-ID: <20250329185855.854186-3-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_115923_830395_35A263A5 X-CRM114-Status: GOOD ( 14.05 ) 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/arm/boot/dts/amlogic/meson8b.dtsi | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/boot/dts/amlogic/meson8b.dtsi b/arch/arm/boot/dts/amlogic/meson8b.dtsi index 0876611ce26a..faf09f77c605 100644 --- a/arch/arm/boot/dts/amlogic/meson8b.dtsi +++ b/arch/arm/boot/dts/amlogic/meson8b.dtsi @@ -368,7 +368,7 @@ uart_ao_a_pins: uart_ao_a { mux { groups = "uart_tx_ao_a", "uart_rx_ao_a"; function = "uart_ao"; - bias-disable; + bias-pull-up; }; }; @@ -521,7 +521,7 @@ mux { groups = "uart_tx_b0", "uart_rx_b0"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; From patchwork Sat Mar 29 18:58:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Blumenstingl X-Patchwork-Id: 14032778 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 51D99C3600C for ; Sat, 29 Mar 2025 19:06:33 +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=GKkfbO1BiF+QlXbqBxEEyljYmITDjKlUPtvMrkXYk1M=; b=Y5fzrm5soOGOyOm1XtPMSyLGsW zyFFvs/Q1i+y2er/xuf3ClD26oujnN3yWEhBDU/xf7qm9tNZe8ddwjNY8P5n5BFra3UPzPObwVQpo +Ck4SedI9bPBgfCWjn/fcavwMC9cvJoY4Ly3KrAsilMgfyM8058cmt2u6THEAAIGxsQxdFiPGiim/ 5Eo9m2XI2NIQGpU5dSh5iClgbGzyY05Fpk2FmEYUtyY8OGnBAIKtiQERj6s3QGztArR47dyY7GBrI Gqf56RzHD7Y9RbSZY1lIfLGtsF4Qj0AWXqedHfXRgA0JEu6o6Om2rK+QlhXWoMc7snE37qe+o/1pY syIhhGbA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tybVf-0000000FQyu-0tYD; Sat, 29 Mar 2025 19:06:23 +0000 Received: from mail-ej1-x62b.google.com ([2a00:1450:4864:20::62b]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tybOv-0000000FPyr-34FU; Sat, 29 Mar 2025 18:59:26 +0000 Received: by mail-ej1-x62b.google.com with SMTP id a640c23a62f3a-aaee2c5ee6eso489574966b.1; Sat, 29 Mar 2025 11:59:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20230601; t=1743274764; x=1743879564; 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=GKkfbO1BiF+QlXbqBxEEyljYmITDjKlUPtvMrkXYk1M=; b=Ti3rPXa0cNjKtf403FNHQGOa1qs+UGkbkbpus5MJv0qdacD3cD4vk/+B+I0XENoDpk HmnyLodziUmi29Unqon26kF6CNrUXwVPpyM017zmO9xPWYni/7IiGmk70FHIWm3QcNC+ 86NMqHqXPlC8QJRBB4BRiVZylSjp6iYc5DqOlXwj/pXenF4EbMVL/imuA2n7mgcKJnQd 5GnUhGcU1ecSQGwF8h1yzIiSVD2Izt3OM96zp3jVQZOQVOtKIxFSwxNeKMzjsqC4XI7B Zvso0pKLwVPBpQ0mOMEt0iC5Nkkhs1AWOYX1MmNx+xWTkRln1ztxYRjhEuEfIq+K121s lVDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743274764; x=1743879564; 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=GKkfbO1BiF+QlXbqBxEEyljYmITDjKlUPtvMrkXYk1M=; b=krPZMjSpkn68O47191nvgtUkGn0j2tNnoDPVZJ0041rIZ9wiRjJHBFdYBGlFJJySUb r7cHazi5q2foBRsYPqQV4JL029LffzLR+TPhDtCIBoe0cvQvlxhvIomnRff0x4DslbMx eSenKAKRLA+WDnJxJdXyJ5vA8vwnej0FMWG3OZ/puHu+p0ggMqttSeD6uKPK+lVpTQa0 uopZEalQ0Br8voHG5ZYpiPKiTSRF2UMmEAcnpDlhhFTBbXq/FizS9F10aZ8b9mPupShM 7rTGzqeSYAPEwTWJFfC0SQHMlW5jHcolwyc0BUCNV5wxfo1o0unChC4wrD35wBH5ge2S xPmw== X-Gm-Message-State: AOJu0Yzaka5fVow2uoJC8oWPw9Q49WCWXEDaTfq4pGEkdWNHmgeJeLHR MqdXnAu1trugVP1ABog9ZyVaFjSqRCrL4fzbOKQC3MX4teejrlGd+zGAKA== X-Gm-Gg: ASbGncusMpPEkM1mNO6HSjoDkZCDCw4Og4hmDGwIoLjp2iyS5UiMIO7U/h/AA9TqXLt cERK06CJ7f0QRQuOrg7Mv4/vXJwRD4GRh2t3l12iJ6mSV7j0+8Vzp9a5mn5zqRyOSwptsBhSRpK ffbINMXiZsbHUFAEtRWXgZuoM6rlLPPsXYJ+lt2/+Fn8WqWRd2StmWqAnEbFE1tImh7oWcFPSsw 4mFR71GnWS+S4q9dX8AtbphGRPBoCBIaAdDOqFnTWpnIm0SFpCQIzxfD67GfYlGKzr3hbMdb6NU sL2PxxnqZs1chi3NLM2CDw4Oh4aswvm0Q7vDrBzgdaOBic8ROslEDoLL71jKSGUkIvo9RY4Z/c+ 7pljNJbwwXkB3u57MSwHtFKW5pU2k0AZaXkPUO9oeGItKvOQGCrq4kY7NGml1NE+kiw21/lu0Gz Hnt8Ok X-Google-Smtp-Source: AGHT+IE5q4K7Ef6k7rcJl7ZBvAtJqJkvDsSBkJ2ZbFVfGwP8BH9jLRx/9uvMrwpU0vICOl+FUBSWnQ== X-Received: by 2002:a17:907:7d8c:b0:ac3:8790:ce75 with SMTP id a640c23a62f3a-ac7389ea3a2mr289697566b.10.1743274763406; Sat, 29 Mar 2025 11:59:23 -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.160.2025.03.29.11.59.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:22 -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 3/7] arm64: dts: amlogic: gxbb: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:51 +0100 Message-ID: <20250329185855.854186-4-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_115925_768065_3AEF88F6 X-CRM114-Status: GOOD ( 13.65 ) 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-gxbb.dtsi | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi index 8ebce7114a60..c4a9f855e5de 100644 --- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi @@ -105,7 +105,7 @@ uart_ao_a_pins: uart_ao_a { mux { groups = "uart_tx_ao_a", "uart_rx_ao_a"; function = "uart_ao"; - bias-disable; + bias-pull-up; }; }; @@ -122,7 +122,7 @@ uart_ao_b_pins: uart_ao_b { mux { groups = "uart_tx_ao_b", "uart_rx_ao_b"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; }; @@ -520,7 +520,7 @@ mux { groups = "uart_tx_a", "uart_rx_a"; function = "uart_a"; - bias-disable; + bias-pull-up; }; }; @@ -538,7 +538,7 @@ mux { groups = "uart_tx_b", "uart_rx_b"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; @@ -556,7 +556,7 @@ mux { groups = "uart_tx_c", "uart_rx_c"; 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[2a02:3100:ad73:6800::e63]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-ac7196dd46asm364497866b.160.2025.03.29.11.59.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:24 -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 4/7] arm64: dts: amlogic: gxl: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:52 +0100 Message-ID: <20250329185855.854186-5-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_115928_684625_A1F13A31 X-CRM114-Status: GOOD ( 12.85 ) 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-gxl.dtsi | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi index 2dc2fdaecf9f..460c46cfad6a 100644 --- a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi @@ -163,7 +163,7 @@ uart_ao_a_pins: uart_ao_a { mux { groups = "uart_tx_ao_a", "uart_rx_ao_a"; function = "uart_ao"; - bias-disable; + bias-pull-up; }; }; @@ -180,7 +180,7 @@ uart_ao_b_pins: uart_ao_b { mux { groups = "uart_tx_ao_b", "uart_rx_ao_b"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; }; @@ -188,7 +188,7 @@ uart_ao_b_0_1_pins: uart_ao_b_0_1 { mux { groups = "uart_tx_ao_b_0", "uart_rx_ao_b_1"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; }; @@ -522,7 +522,7 @@ mux { groups = "uart_tx_a", "uart_rx_a"; function = "uart_a"; - bias-disable; + bias-pull-up; }; }; @@ -540,7 +540,7 @@ mux { groups = "uart_tx_b", "uart_rx_b"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; @@ -558,7 +558,7 @@ mux { groups = "uart_tx_c", "uart_rx_c"; function = "uart_c"; - bias-disable; + bias-pull-up; }; }; From patchwork Sat Mar 29 18:58:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Blumenstingl X-Patchwork-Id: 14032782 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 5CFD5C36008 for ; Sat, 29 Mar 2025 19:10:06 +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; 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[2a02:3100:ad73:6800::e63]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-ac7196dd46asm364497866b.160.2025.03.29.11.59.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:27 -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 5/7] arm64: dts: amlogic: g12: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:53 +0100 Message-ID: <20250329185855.854186-6-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_115930_276834_3E0B1099 X-CRM114-Status: GOOD ( 13.38 ) 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-g12-common.dtsi | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi b/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi index ab2b3f15ef19..12e8daaa1c9b 100644 --- a/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi @@ -1503,7 +1503,7 @@ mux { groups = "uart_a_tx", "uart_a_rx"; function = "uart_a"; - bias-disable; + bias-pull-up; }; }; @@ -1521,7 +1521,7 @@ mux { groups = "uart_b_tx", "uart_b_rx"; function = "uart_b"; - bias-disable; + bias-pull-up; }; }; @@ -1918,7 +1918,7 @@ mux { groups = "uart_ao_a_tx", "uart_ao_a_rx"; function = "uart_ao_a"; - bias-disable; + bias-pull-up; }; }; @@ -1936,7 +1936,7 @@ mux { groups = "uart_ao_b_tx_2", "uart_ao_b_rx_3"; function = "uart_ao_b"; - bias-disable; + bias-pull-up; }; }; @@ -1945,7 +1945,7 @@ mux { groups = "uart_ao_b_tx_8", "uart_ao_b_rx_9"; 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[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; }; }; From patchwork Sat Mar 29 18:58:55 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Blumenstingl X-Patchwork-Id: 14032791 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 D1593C3600C for ; Sat, 29 Mar 2025 19:13:36 +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; 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[2a02:3100:ad73:6800::e63]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-ac7196dd46asm364497866b.160.2025.03.29.11.59.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 11:59:31 -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 7/7] arm64: dts: amlogic: a1: enable UART RX and TX pull up by default Date: Sat, 29 Mar 2025 19:58:55 +0100 Message-ID: <20250329185855.854186-8-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_115935_463688_DB664DC7 X-CRM114-Status: GOOD ( 12.17 ) 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-a1.dtsi | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi index 1eba0afb3fd9..f7f25a10f409 100644 --- a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi @@ -233,6 +233,7 @@ mux { groups = "uart_a_tx", "uart_a_rx"; function = "uart_a"; + bias-pull-up; }; };