From: Primoz Fiser <primoz.fiser@norik.com>
Date: Thu, 7 May 2026 06:20:56 +0000 (+0200)
Subject: arm64: dts: freescale: imx{91,93}-phycore-som: Set BUCK5 in FPWM mode
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5601ee1b64da17d2df2e657a7f1582ad468ed4d2;p=thirdparty%2Flinux.git

arm64: dts: freescale: imx{91,93}-phycore-som: Set BUCK5 in FPWM mode

Set PMIC BUCK5 mode to forced PWM (Pulse Width Modulation) mode instead
of the default automatic PFM and PWM transition mode. FPWM mode produces
less ripple on the output voltage rail under light load conditions. And
since BUCK5 supplies SoC internal ADC reference voltage we need to keep
voltage ripple to a minimum. This solves issues with the occasional ADC
calibration procedure failures on phyCORE-i.MX91/93 SoM based boards.

Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

diff --git a/arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi b/arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi
index b9a453f6b290..95a6a0b1dd75 100644
--- a/arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi
@@ -8,6 +8,7 @@
  */
 
 #include <dt-bindings/leds/common.h>
+#include <dt-bindings/regulator/nxp,pca9450-regulator.h>
 
 #include "imx91.dtsi"
 
@@ -160,6 +161,7 @@
 				regulator-min-microvolt = <1800000>;
 				regulator-boot-on;
 				regulator-always-on;
+				regulator-initial-mode = <PCA9450_BUCK_MODE_FORCE_PWM>;
 			};
 
 			buck6: BUCK6 {
diff --git a/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi b/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi
index 94eb04ace96e..d59a89254623 100644
--- a/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi
@@ -9,6 +9,7 @@
  */
 
 #include <dt-bindings/leds/common.h>
+#include <dt-bindings/regulator/nxp,pca9450-regulator.h>
 
 #include "imx93.dtsi"
 
@@ -162,6 +163,7 @@
 				regulator-max-microvolt = <1800000>;
 				regulator-boot-on;
 				regulator-always-on;
+				regulator-initial-mode = <PCA9450_BUCK_MODE_FORCE_PWM>;
 			};
 
 			buck6: BUCK6 {