From patchwork Mon Jan 29 11:46:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 13535421 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 AA0BBC47422 for ; Mon, 29 Jan 2024 11:47:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=IJ/IzjKc449eX+m7LZHKPpOPm5N5oS5Z9egSxRyMPjo=; b=QEuWs0KwBrUNxm Ta/3VMSr+N+oNuPUotCqax3G8UoJSNBlZEZ6pqYy33hZuqSoNGevAY96RT90FHrvhu2qp1jV4XK9E QsFBLwrwgIp19d080dCqQsrZhHhdjQdj1yQo6R4gCc4C4jbx8mb6MiZPGir5GLWEfujbg/+BN50WC 1zIdNMepuTcrU6r5Q/Eyj0i2oaYTV+pvCXOZ3wxxnty3qnjp2NgoBWfk2rXUweSmJ5nUnL1NHF3mV pI1zvhN3FGX0OlykTCb5tJ+AyJx+f/D0Kqcet0G+ICWqMFClaW7Izy+necVkBycM03Lg3eVOz7e/l Y384TcrhSZTQ5qC698YA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUQ6V-0000000CRtd-1Qvj; Mon, 29 Jan 2024 11:47:07 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUQ6O-0000000CRpy-0Eao for linux-arm-kernel@lists.infradead.org; Mon, 29 Jan 2024 11:47:01 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rUQ6H-0007AJ-UJ; Mon, 29 Jan 2024 12:46:53 +0100 Received: from [2a0a:edc0:0:900:1d::77] (helo=ptz.office.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1rUQ6G-0039yH-9z; Mon, 29 Jan 2024 12:46:52 +0100 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1rUQ6G-00AsMQ-0i; Mon, 29 Jan 2024 12:46:52 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue Cc: =?utf-8?q?Leonard_G=C3=B6hrs?= , devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de Subject: [PATCH] ARM: dts: stm32: lxa-tac: reduce RGMII interface drive strength Date: Mon, 29 Jan 2024 12:46:49 +0100 Message-ID: <20240129114649.2458468-2-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=978; i=u.kleine-koenig@pengutronix.de; h=from:subject; bh=w+TUJeocBu4MMweRw8tgYLEmSQuNkXHs+pH1aqUe1wQ=; b=owEBbQGS/pANAwAKAY+A+1h9Ev5OAcsmYgBlt5ApRWpQOr/HHLFho90eiPiFHmcdiFtup9Fto Zjfr+PQQX2JATMEAAEKAB0WIQQ/gaxpOnoeWYmt/tOPgPtYfRL+TgUCZbeQKQAKCRCPgPtYfRL+ TtrUCACPEt3J6ytRV2Ghf98LrqiuTr7dzOZ8ewYTkSVm4W71RPtEJ9aUtBuaYc+l5QkvyJdSSin 2h05pGiRPFROrYBEZulTdOH1ptW2wmWX6myUubT9dhCFm7ESv0FDAJv4W1ZR7cSWalS4j00umPL LSSM+noHFkfj7TmOW5HY1Uxr66IwZZrrYrgTQoWgGWrwT1hanEL44aamLxJWPAFz+MgK8Aypdhe C58PQS8TCkO1CC0e3jhpP0w2RAcjFNsaDwRpNIZOPITXgIn/G5vEBkjt8okOM+ZTjudf/A3wPxo B/f7TrxUzr0AMWGS/sP2HsB9H+i3g/6G7IvhonZEdWmSKAy1 X-Developer-Key: i=u.kleine-koenig@pengutronix.de; a=openpgp; fpr=0D2511F322BFAB1C1580266BE2DCDD9132669BD6 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240129_034700_123928_0433289C X-CRM114-Status: GOOD ( 10.28 ) 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 From: Leonard Göhrs This results in an improvement of EMI performance by reducing the 125MHz emission and its harmonics caused by the RGMII clock line. Signed-off-by: Leonard Göhrs Signed-off-by: Uwe Kleine-König --- arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi b/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi index 7e835a7cf64a..cfaf8adde319 100644 --- a/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi +++ b/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi @@ -471,6 +471,10 @@ switch: switch@0 { interrupt-parent = <&gpioa>; interrupts = <6 IRQ_TYPE_EDGE_RISING>; + /* Reduce RGMII EMI emissions by reducing drive strength */ + microchip,hi-drive-strength-microamp = <2000>; + microchip,lo-drive-strength-microamp = <8000>; + ports { #address-cells = <1>; #size-cells = <0>;