[ethernet] Add per-PHY compile guards to eliminate unused PHY drivers

Extend the per-PHY compile guard pattern (already used by KSZ8081 and
LAN8670) to all RMII PHY types: LAN8720, RTL8201, DP83848, IP101, and
JL1101. This allows the linker to strip unused PHY driver code, saving
~7.5 KB flash per build since only one PHY is ever used per device.

esphome/components/ethernet/__init__.py

@@ -130,11 +130,16 @@ ETHERNET_TYPES = {
 }
 
 # PHY types that need compile-time defines for conditional compilation
+# Each RMII PHY type gets a define so unused PHY drivers are excluded by the linker
 _PHY_TYPE_TO_DEFINE = {
+    "LAN8720": "USE_ETHERNET_LAN8720",
+    "RTL8201": "USE_ETHERNET_RTL8201",
+    "DP83848": "USE_ETHERNET_DP83848",
+    "IP101": "USE_ETHERNET_IP101",
+    "JL1101": "USE_ETHERNET_JL1101",
     "KSZ8081": "USE_ETHERNET_KSZ8081",
     "KSZ8081RNA": "USE_ETHERNET_KSZ8081",
     "LAN8670": "USE_ETHERNET_LAN8670",
-    # Add other PHY types here only if they need conditional compilation
 }
 
 SPI_ETHERNET_TYPES = ["W5500", "DM9051"]

esphome/components/ethernet/ethernet_component.cpp

@@ -186,31 +186,43 @@ void EthernetComponent::setup() {
     }
 #endif
 #if CONFIG_ETH_USE_ESP32_EMAC
+#ifdef USE_ETHERNET_LAN8720
     case ETHERNET_TYPE_LAN8720: {
       this->phy_ = esp_eth_phy_new_lan87xx(&phy_config);
       break;
     }
+#endif
+#ifdef USE_ETHERNET_RTL8201
     case ETHERNET_TYPE_RTL8201: {
       this->phy_ = esp_eth_phy_new_rtl8201(&phy_config);
       break;
     }
+#endif
+#ifdef USE_ETHERNET_DP83848
     case ETHERNET_TYPE_DP83848: {
       this->phy_ = esp_eth_phy_new_dp83848(&phy_config);
       break;
     }
+#endif
+#ifdef USE_ETHERNET_IP101
     case ETHERNET_TYPE_IP101: {
       this->phy_ = esp_eth_phy_new_ip101(&phy_config);
       break;
     }
+#endif
+#ifdef USE_ETHERNET_JL1101
     case ETHERNET_TYPE_JL1101: {
       this->phy_ = esp_eth_phy_new_jl1101(&phy_config);
       break;
     }
+#endif
+#ifdef USE_ETHERNET_KSZ8081
     case ETHERNET_TYPE_KSZ8081:
     case ETHERNET_TYPE_KSZ8081RNA: {
       this->phy_ = esp_eth_phy_new_ksz80xx(&phy_config);
       break;
     }
+#endif
 #ifdef USE_ETHERNET_LAN8670
     case ETHERNET_TYPE_LAN8670: {
       this->phy_ = esp_eth_phy_new_lan867x(&phy_config);
@@ -343,26 +355,32 @@ void EthernetComponent::loop() {
 void EthernetComponent::dump_config() {
   const char *eth_type;
   switch (this->type_) {
+#ifdef USE_ETHERNET_LAN8720
     case ETHERNET_TYPE_LAN8720:
       eth_type = "LAN8720";
       break;
-
+#endif
+#ifdef USE_ETHERNET_RTL8201
     case ETHERNET_TYPE_RTL8201:
       eth_type = "RTL8201";
       break;
-
+#endif
+#ifdef USE_ETHERNET_DP83848
     case ETHERNET_TYPE_DP83848:
       eth_type = "DP83848";
       break;
-
+#endif
+#ifdef USE_ETHERNET_IP101
     case ETHERNET_TYPE_IP101:
       eth_type = "IP101";
       break;
-
+#endif
+#ifdef USE_ETHERNET_JL1101
     case ETHERNET_TYPE_JL1101:
       eth_type = "JL1101";
       break;
-
+#endif
+#ifdef USE_ETHERNET_KSZ8081
     case ETHERNET_TYPE_KSZ8081:
       eth_type = "KSZ8081";
       break;
@@ -370,19 +388,22 @@ void EthernetComponent::dump_config() {
     case ETHERNET_TYPE_KSZ8081RNA:
       eth_type = "KSZ8081RNA";
       break;
-
+#endif
+#if CONFIG_ETH_SPI_ETHERNET_W5500
     case ETHERNET_TYPE_W5500:
       eth_type = "W5500";
       break;
-
-    case ETHERNET_TYPE_OPENETH:
-      eth_type = "OPENETH";
-      break;
-
+#endif
+#if CONFIG_ETH_SPI_ETHERNET_DM9051
     case ETHERNET_TYPE_DM9051:
       eth_type = "DM9051";
       break;
-
+#endif
+#ifdef USE_ETHERNET_OPENETH
+    case ETHERNET_TYPE_OPENETH:
+      eth_type = "OPENETH";
+      break;
+#endif
 #ifdef USE_ETHERNET_LAN8670
     case ETHERNET_TYPE_LAN8670:
       eth_type = "LAN8670";
@@ -837,13 +858,15 @@ void EthernetComponent::ksz8081_set_clock_reference_(esp_eth_mac_t *mac) {
 
 void EthernetComponent::write_phy_register_(esp_eth_mac_t *mac, PHYRegister register_data) {
   esp_err_t err;
-  constexpr uint8_t eth_phy_psr_reg_addr = 0x1F;
 
+#ifdef USE_ETHERNET_RTL8201
+  constexpr uint8_t eth_phy_psr_reg_addr = 0x1F;
   if (this->type_ == ETHERNET_TYPE_RTL8201 && register_data.page) {
     ESP_LOGD(TAG, "Select PHY Register Page: 0x%02" PRIX32, register_data.page);
     err = mac->write_phy_reg(mac, this->phy_addr_, eth_phy_psr_reg_addr, register_data.page);
     ESPHL_ERROR_CHECK(err, "Select PHY Register page failed");
   }
+#endif
 
   ESP_LOGD(TAG,
            "Writing to PHY Register Address: 0x%02" PRIX32 "\n"
@@ -852,11 +875,13 @@ void EthernetComponent::write_phy_register_(esp_eth_mac_t *mac, PHYRegister regi
   err = mac->write_phy_reg(mac, this->phy_addr_, register_data.address, register_data.value);
   ESPHL_ERROR_CHECK(err, "Writing PHY Register failed");
 
+#ifdef USE_ETHERNET_RTL8201
   if (this->type_ == ETHERNET_TYPE_RTL8201 && register_data.page) {
     ESP_LOGD(TAG, "Select PHY Register Page 0x00");
     err = mac->write_phy_reg(mac, this->phy_addr_, eth_phy_psr_reg_addr, 0x0);
     ESPHL_ERROR_CHECK(err, "Select PHY Register Page 0 failed");
   }
+#endif
 }
 
 #endif

esphome/core/defines.h

@@ -241,7 +241,13 @@
 #ifdef USE_ARDUINO
 #define USE_ARDUINO_VERSION_CODE VERSION_CODE(3, 3, 7)
 #define USE_ETHERNET
+#define USE_ETHERNET_LAN8720
+#define USE_ETHERNET_RTL8201
+#define USE_ETHERNET_DP83848
+#define USE_ETHERNET_IP101
+#define USE_ETHERNET_JL1101
 #define USE_ETHERNET_KSZ8081
+#define USE_ETHERNET_LAN8670
 #define USE_ETHERNET_MANUAL_IP
 #define USE_ETHERNET_IP_STATE_LISTENERS
 #define USE_ETHERNET_CONNECT_TRIGGER