[PATCH 1/3] arm64: dts: freescale: imx{91,93}-phycore-som: Set BUCK5 in FPWM mode

[Primoz Fiser]

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 at norik.com>
---
 arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi | 2 ++
 arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi b/arch/arm64/boot/dts/freescale/imx91-phycore-som.dtsi
index 29a428a052b0..19e7e84ad6f7 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"
 
@@ -138,6 +139,7 @@ buck5: BUCK5 {
 				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 ebc57841f27f..626160132e3c 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"
 
@@ -140,6 +141,7 @@ buck5: BUCK5 {
 				regulator-max-microvolt = <1800000>;
 				regulator-boot-on;
 				regulator-always-on;
+				regulator-initial-mode = <PCA9450_BUCK_MODE_FORCE_PWM>;
 			};
 
 			buck6: BUCK6 {
-- 
2.34.1