From 7fd195f01ae52871b04b752447f865e1a6661487 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Leonard=20G=C3=B6hrs?= <l.goehrs@pengutronix.de>
Date: Mon, 29 Jan 2024 12:46:49 +0100
Subject: [PATCH] ARM: dts: stm32: lxa-tac: reduce RGMII interface drive
strength
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit
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 <l.goehrs@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
---
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 7e835a7cf64a5..cfaf8adde319f 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 @@ baseboard_eeprom: &sip_eeprom {
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>;
--
2.30.2