From 3980d5c442012d5abe9bf06268b2a370aa574bcf Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmail.com>
Date: Tue, 23 Jun 2026 11:20:39 +0200
Subject: [PATCH] Revert "GoodWe: remove non-functional wallbox phase switching
 (#30790)"

This reverts commit 3aac67bdd0f635c116c660c900ae6508e50e73e4.
---
 charger/goodwe.go                             | 40 ++++++++++++++-----
 .../definition/charger/goodwe-wallbox.yaml    |  2 +-
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/charger/goodwe.go b/charger/goodwe.go
index 06898d86d..2aa1b6ac3 100644
--- a/charger/goodwe.go
+++ b/charger/goodwe.go
@@ -46,17 +46,18 @@ type GoodWe struct {
 }
 
 const (
-	goodweRegVoltages      = 10009 // U16 ×0.1 V, 3 regs (L1/L2/L3)
-	goodweRegCurrents      = 10012 // U16 ×0.1 A, 3 regs (L1/L2/L3)
-	goodweRegActualPower   = 10015 // U16 ×0.1 kW
-	goodweRegStatus        = 10017 // U16 enum (see status mapping)
-	goodweRegMaxPower      = 10029 // U16 ×0.1 kW, raw range [14,220]
-	goodweRegChargeMode    = 10032 // U16 (0=fast, 1=PV, 2=PV+battery)
-	goodweRegPowerSpec     = 10058 // U16 (0=7kW, 1=11kW, 2=22kW)
-	goodweRegPhaseSpec     = 10059 // U16 (0=3p, 1=1p)
-	goodweRegRfid          = 10500 // 7 regs ASCII (14-byte card UID)
-	goodweRegChargeCommand = 10060 // U16 (1=stop, 2=start)
-	goodweRegTotalEnergy   = 10065 // U32 ×0.1 kWh, 2 regs
+	goodweRegVoltages       = 10009 // U16 ×0.1 V, 3 regs (L1/L2/L3)
+	goodweRegCurrents       = 10012 // U16 ×0.1 A, 3 regs (L1/L2/L3)
+	goodweRegActualPower    = 10015 // U16 ×0.1 kW
+	goodweRegStatus         = 10017 // U16 enum (see status mapping)
+	goodweRegPhaseSwEnabled = 10023 // U16 (0=Off, 1=On)
+	goodweRegMaxPower       = 10029 // U16 ×0.1 kW, raw range [14,220]
+	goodweRegChargeMode     = 10032 // U16 (0=fast, 1=PV, 2=PV+battery)
+	goodweRegPowerSpec      = 10058 // U16 (0=7kW, 1=11kW, 2=22kW)
+	goodweRegPhaseSpec      = 10059 // U16 (0=3p, 1=1p)
+	goodweRegRfid           = 10500 // 7 regs ASCII (14-byte card UID)
+	goodweRegChargeCommand  = 10060 // U16 (1=stop, 2=start)
+	goodweRegTotalEnergy    = 10065 // U32 ×0.1 kWh, 2 regs
 
 	goodweChargeStop  = 1
 	goodweChargeStart = 2
@@ -134,6 +135,18 @@ func NewGoodWe(ctx context.Context, uri string, slaveID uint8) (api.Charger, err
 		log.WARN.Printf("read hw phase count failed, defaulting to 3-phase: %v", err)
 	}
 
+	// only 3-phase hardware can do 1p/3p switching; conditionally register phase switching
+	// based on hardware capability. On read error, fall back to fixed-phase operation.
+	if wb.phases == 3 {
+		if b, err := wb.conn.ReadHoldingRegisters(goodweRegPhaseSwEnabled, 1); err == nil {
+			if binary.BigEndian.Uint16(b) == 1 {
+				implement.Has(wb, implement.PhaseSwitcher(wb.phases1p3p))
+			}
+		} else {
+			log.WARN.Printf("read phase switch config failed, disabling dynamic phase switching: %v", err)
+		}
+	}
+
 	// force "fast" charging mode so evcc fully controls power setpoint
 	if _, err := wb.conn.WriteSingleRegister(goodweRegChargeMode, goodweChargeModeFast); err != nil {
 		return nil, fmt.Errorf("set charge mode: %w", err)
@@ -255,6 +268,11 @@ func (wb *GoodWe) Voltages() (float64, float64, float64, error) {
 	return wb.phaseValues(goodweRegVoltages, 10)
 }
 
+func (wb *GoodWe) phases1p3p(phases int) error {
+	wb.phases = phases
+	return nil
+}
+
 var _ api.Identifier = (*GoodWe)(nil)
 
 // Identify implements api.Identifier (RFID UID, 14-byte NUL-padded ASCII).
diff --git a/templates/definition/charger/goodwe-wallbox.yaml b/templates/definition/charger/goodwe-wallbox.yaml
index dbd28a1d3..e9ca504b5 100644
--- a/templates/definition/charger/goodwe-wallbox.yaml
+++ b/templates/definition/charger/goodwe-wallbox.yaml
@@ -3,7 +3,7 @@ products:
   - brand: GoodWe
     description:
       generic: HCA Wallbox (Gen2)
-capabilities: ["mA", "rfid", "meter"]
+capabilities: ["mA", "rfid", "1p3p", "meter"]
 requirements:
   evcc: ["sponsorship"]
   description: