esp_eth: Add CONFIG_ETH_ENABLED flag to enable/disable ethernet at build time

Always enabled by default, as SPI/Ethernet support is enabled by default.

components/esp_eth/CMakeLists.txt

@@ -1,20 +1,30 @@
-set(esp_eth_srcs "src/esp_eth.c"
-                 "src/esp_eth_phy_dp83848.c"
-                 "src/esp_eth_phy_ip101.c"
-                 "src/esp_eth_phy_lan8720.c"
-                 "src/esp_eth_phy_rtl8201.c")
+set(srcs)  # If ethernet disabled in Kconfig, this is a config-only component
+set(include)
+set(linker)
 
-if(CONFIG_ETH_USE_ESP32_EMAC)
-    list(APPEND esp_eth_srcs "src/esp_eth_mac_esp32.c")
+if(CONFIG_ETH_ENABLED)
+    set(srcs "src/esp_eth.c")
+    set(include "include")
+    set(linker "linker.lf")
+
+    if(CONFIG_ETH_USE_ESP32_EMAC)
+        list(APPEND srcs "src/esp_eth_mac_esp32.c"
+                                 "src/esp_eth_phy_dp83848.c"
+                                 "src/esp_eth_phy_ip101.c"
+                                 "src/esp_eth_phy_lan8720.c"
+                                 "src/esp_eth_phy_rtl8201.c"
+            )
+    endif()
+
+    if(CONFIG_ETH_SPI_ETHERNET_DM9051)
+        list(APPEND srcs "src/esp_eth_mac_dm9051.c"
+                                 "src/esp_eth_phy_dm9051.c")
+    endif()
 endif()
 
-if(CONFIG_ETH_SPI_ETHERNET_DM9051)
-    list(APPEND esp_eth_srcs "src/esp_eth_mac_dm9051.c"
-                             "src/esp_eth_phy_dm9051.c")
-endif()
+idf_component_register(SRCS "${srcs}"
+    INCLUDE_DIRS ${include}
+    LDFRAGMENTS ${linker}
+    REQUIRES "esp_event"
+    PRIV_REQUIRES "tcpip_adapter" "driver" "log")
 
-idf_component_register(SRCS "${esp_eth_srcs}"
-                       INCLUDE_DIRS "include"
-                       LDFRAGMENTS "linker.lf"
-                       REQUIRES "esp_event"
-                       PRIV_REQUIRES "tcpip_adapter" "driver" "log")

components/esp_eth/Kconfig

@@ -1,9 +1,15 @@
 menu "Ethernet"
 
+     # Invisible item that is enabled if any Ethernet
+     # selection is made
+     config ETH_ENABLED
+     bool
+
     menuconfig ETH_USE_ESP32_EMAC
         depends on IDF_TARGET_ESP32
         bool "Support ESP32 internal EMAC controller"
         default y
+        select ETH_ENABLED
         help
             ESP32 integrates a 10/100M Ethernet MAC controller.
 
@@ -132,8 +138,9 @@ menu "Ethernet"
     menuconfig ETH_USE_SPI_ETHERNET
         bool "Support SPI to Ethernet Module"
         default y
+        select ETH_ENABLED
         help
-            ESP-IDF can also support some SPI-Ethernet module.
+            ESP-IDF can also support some SPI-Ethernet modules.
 
     if ETH_USE_SPI_ETHERNET
         menuconfig ETH_SPI_ETHERNET_DM9051

components/lwip/CMakeLists.txt

@@ -87,7 +87,6 @@ set(srcs
     "port/esp32/freertos/sys_arch.c"
     "port/esp32/netif/dhcp_state.c"
     "port/esp32/netif/nettestif.c"
-    "port/esp32/netif/ethernetif.c"
     "port/esp32/netif/wlanif.c")
 
 if(CONFIG_LWIP_PPP_SUPPORT)
@@ -124,6 +123,10 @@ if(CONFIG_LWIP_PPP_SUPPORT)
         "lwip/src/netif/ppp/polarssl/sha1.c")
 endif()
 
+if(CONFIG_ETH_ENABLED)
+    list(APPEND srcs "port/esp32/netif/ethernetif.c")
+endif()
+
 idf_component_register(SRCS "${srcs}"
                     INCLUDE_DIRS "${include_dirs}"
                     LDFRAGMENTS linker.lf

components/tcpip_adapter/event_handlers.c

@@ -17,7 +17,7 @@
 #include "esp_event.h"
 #include "esp_wifi.h"
 #include "esp_private/wifi.h"
-#if CONFIG_IDF_TARGET_ESP32
+#if CONFIG_ETH_ENABLED
 #include "esp_eth.h"
 #endif
 #include "esp_err.h"
@@ -43,7 +43,7 @@ static void handle_sta_stop(void *arg, esp_event_base_t base, int32_t event_id,
 static void handle_sta_connected(void *arg, esp_event_base_t base, int32_t event_id, void *data);
 static void handle_sta_disconnected(void *arg, esp_event_base_t base, int32_t event_id, void *data);
 static void handle_sta_got_ip(void *arg, esp_event_base_t base, int32_t event_id, void *data);
-#if CONFIG_IDF_TARGET_ESP32
+#if CONFIG_ETH_ENABLED
 static void handle_eth_start(void *arg, esp_event_base_t base, int32_t event_id, void *data);
 static void handle_eth_stop(void *arg, esp_event_base_t base, int32_t event_id, void *data);
 static void handle_eth_connected(void *arg, esp_event_base_t base, int32_t event_id, void *data);
@@ -266,7 +266,7 @@ esp_err_t tcpip_adapter_clear_default_wifi_handlers(void)
     return ESP_OK;
 }
 
-#if CONFIG_IDF_TARGET_ESP32
+#if CONFIG_ETH_ENABLED
 esp_err_t tcpip_adapter_set_default_eth_handlers(void)
 {
     esp_err_t err;

components/tcpip_adapter/tcpip_adapter_lwip.c

@@ -16,7 +16,6 @@
 #include <string.h>
 
 #include "tcpip_adapter_internal.h"
-
 #if CONFIG_TCPIP_LWIP
 
 #include "lwip/inet.h"
@@ -32,7 +31,9 @@
 #include "lwip/netif.h"
 #endif
 #include "netif/wlanif.h"
+#ifdef CONFIG_ETH_ENABLED
 #include "netif/ethernetif.h"
+#endif
 #include "netif/nettestif.h"
 
 #include "dhcpserver/dhcpserver.h"
@@ -227,8 +228,12 @@ static esp_err_t tcpip_adapter_start(tcpip_adapter_if_t tcpip_if, uint8_t *mac,
 
 esp_err_t tcpip_adapter_eth_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info, void *args)
 {
+#ifdef CONFIG_ETH_ENABLED
     esp_netif_init_fn[TCPIP_ADAPTER_IF_ETH] = ethernetif_init;
     return tcpip_adapter_start(TCPIP_ADAPTER_IF_ETH, mac, ip_info, args);
+#else
+    return ESP_ERR_NOT_SUPPORTED;
+#endif
 }
 
 esp_err_t tcpip_adapter_sta_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info)
@@ -1115,8 +1120,12 @@ static esp_err_t tcpip_adapter_dhcpc_stop_api(tcpip_adapter_api_msg_t *msg)
 
 esp_err_t tcpip_adapter_eth_input(void *buffer, uint16_t len, void *eb)
 {
+#ifdef CONFIG_ETH_ENABLED
     ethernetif_input(esp_netif[TCPIP_ADAPTER_IF_ETH], buffer, len);
     return ESP_OK;
+#else
+    return ESP_ERR_NOT_SUPPORTED;
+#endif
 }
 
 esp_err_t tcpip_adapter_sta_input(void *buffer, uint16_t len, void *eb)