[PATCH v3 9/9] ARM: dts: aspeed: anacapa: evt2: add shunt resistor values for HSC monitors

From: Colin Huang via B4 Relay

Date: Tue Jun 02 2026 - 09:25:34 EST


From: Peter Shen <peter.shen@xxxxxxx>

Add shunt resistor configuration for LTC4287 hot-swap controllers on
Anacapa EVT2 platform.

The resistor values are required for accurate current and power
measurement by the driver. These settings reflect the actual BOM used
on EVT2, where different sense resistor values (150 uOhm and 250 uOhm)
are populated across rails.

Without this configuration, the reported readings would be incorrect.

Signed-off-by: Peter Shen <peter.shen@xxxxxxx>
---
.../aspeed/aspeed-bmc-facebook-anacapa-evt2.dts | 50 ++++++++++++++++++++++
1 file changed, 50 insertions(+)

diff --git a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-anacapa-evt2.dts b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-anacapa-evt2.dts
index 4a6ae7c6cbf8..59875e9d84fd 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-anacapa-evt2.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-anacapa-evt2.dts
@@ -8,6 +8,56 @@ / {
compatible = "facebook,anacapa-bmc-evt2", "aspeed,ast2600";
};

+// MB - PDB
+&i2c8 {
+
+ i2c-mux@72 {
+
+ i2c8mux0ch0: i2c@0 {
+
+ power-monitor@42 {
+ compatible = "lltc,ltc4287";
+ reg = <0x42>;
+ shunt-resistor-micro-ohms = <150>;
+ };
+ power-monitor@43 {
+ compatible = "lltc,ltc4287";
+ reg = <0x43>;
+ shunt-resistor-micro-ohms = <150>;
+ };
+ power-monitor@44 {
+ compatible = "lltc,ltc4287";
+ reg = <0x44>;
+ shunt-resistor-micro-ohms = <250>;
+ };
+ power-monitor@45 {
+ compatible = "lltc,ltc4287";
+ reg = <0x45>;
+ shunt-resistor-micro-ohms = <250>;
+ };
+ };
+
+ i2c8mux0ch1: i2c@1 {
+
+ power-monitor@40 {
+ compatible = "lltc,ltc4287";
+ reg = <0x40>;
+ shunt-resistor-micro-ohms = <150>;
+ };
+ power-monitor@41 {
+ compatible = "lltc,ltc4287";
+ reg = <0x41>;
+ shunt-resistor-micro-ohms = <150>;
+ };
+ power-monitor@45 {
+ compatible = "lltc,ltc4287";
+ reg = <0x45>;
+ shunt-resistor-micro-ohms = <250>;
+ };
+ };
+ };
+};
+
&sgpiom0 {
ngpios = <128>;
bus-frequency = <2000000>;

--
2.34.1