Linux kernel and device drivers for NXP i.MX platforms
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From: Tim Harvey <tharvey@gateworks.com>
To: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>
Cc: devicetree@vger.kernel.org, imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Tim Harvey <tharvey@gateworks.com>
Subject: [PATCH v2 4/7] arm64: dts: imx8mm-venice-gw700x: reduce RGMII CLK drive strength
Date: Thu, 18 Sep 2025 08:44:48 -0700	[thread overview]
Message-ID: <20250918154451.2531802-5-tharvey@gateworks.com> (raw)
In-Reply-To: <20250918154451.2531802-1-tharvey@gateworks.com>

The i.MX8M Mini FEC RGMII tracelength is less than 1in and does not
require a x6 drive strength. Reduce the CLK drive strength to x1 for
lower emissions. Additionally since TXC is not a high frequency clock,
use slow slew rate (FSEL=0) for lower emmissions and improved signal
quality.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
v2: add FSEL detail to log (Peng)
---
 arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi
index baf46fe28133..dca213c85cc3 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi
@@ -446,7 +446,7 @@ MX8MM_IOMUXC_ENET_RD3_ENET1_RGMII_RD3		0x91
 			MX8MM_IOMUXC_ENET_RD2_ENET1_RGMII_RD2		0x91
 			MX8MM_IOMUXC_ENET_RD1_ENET1_RGMII_RD1		0x91
 			MX8MM_IOMUXC_ENET_RD0_ENET1_RGMII_RD0		0x91
-			MX8MM_IOMUXC_ENET_TXC_ENET1_RGMII_TXC		0x1f
+			MX8MM_IOMUXC_ENET_TXC_ENET1_RGMII_TXC		0x0
 			MX8MM_IOMUXC_ENET_RXC_ENET1_RGMII_RXC		0x91
 			MX8MM_IOMUXC_ENET_RX_CTL_ENET1_RGMII_RX_CTL	0x91
 			MX8MM_IOMUXC_ENET_TX_CTL_ENET1_RGMII_TX_CTL	0x1f
-- 
2.25.1


  parent reply	other threads:[~2025-09-18 15:45 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-18 15:44 [PATCH v2 0/7] various imx8m*-venice dt fixes Tim Harvey
2025-09-18 15:44 ` [PATCH v2 1/7] arm64: dts: freescale: imx8mp-venice-gw7905-2x: remove duplicate usdhc1 props Tim Harvey
2025-09-18 15:44 ` [PATCH v2 2/7] arm64: dts: imx8m{m,n,p}-venice: disable unused clk output for TI PHY Tim Harvey
2025-09-18 15:44 ` [PATCH v2 3/7] arm64: dts: imx8mp-venice-gw702x: reduce RGMII CLK drive strength Tim Harvey
2025-09-19  4:46   ` Peng Fan
2025-09-18 15:44 ` Tim Harvey [this message]
2025-09-19  4:46   ` [PATCH v2 4/7] arm64: dts: imx8mm-venice-gw700x: " Peng Fan
2025-09-18 15:44 ` [PATCH v2 5/7] arm64: dts: imx8mm-venice-gw72xx: remove unused sdhc1 pinctrl Tim Harvey
2025-09-18 15:44 ` [PATCH v2 6/7] arm64: dts: imx8mp-venice-gw702x: remove off-board uart Tim Harvey
2025-09-18 15:44 ` [PATCH v2 7/7] arm64: dts: imx8mp-venice-gw702x: remove off-board sdhc1 Tim Harvey
2025-09-19  4:45   ` Peng Fan
2025-10-21  8:30 ` [PATCH v2 0/7] various imx8m*-venice dt fixes Shawn Guo

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