feat(eppp): Add support for transport via Ethernet EMAC-2-EMAC

components/eppp_link/Kconfig

@@ -87,4 +87,34 @@ menu "eppp_link"
         default "06:00:00:00:00:02"
         depends on EPPP_LINK_DEVICE_ETH
 
+    config EPPP_LINK_ETHERNET_USE_DUMMY_PHY
+        bool "Use dummy phy (emac2emac)"
+        default n
+        depends on EPPP_LINK_DEVICE_ETH
+
+    choice EPPP_LINK_ETHERNET_CLK_ROLE
+        prompt "RMII CLK Role"
+        default EPPP_LINK_ETHERNET_CLK_SOURCE
+        depends on EPPP_LINK_ETHERNET_USE_DUMMY_PHY
+        help
+            Configure device type. ESP32 device which is RMII CLK source needs to wait
+            with its Ethernet initialization for the "RMII CLK Sink Device" since
+            the RMII CLK input pin (GPIO0) is also used as a boot strap pin. If
+            the "RMII CLK Source Device" didn't wait, the "RMII CLK Sink Device"
+            could boot into incorrect mode.
+
+        config EPPP_LINK_ETHERNET_CLK_SOURCE
+            bool "RMII CLK Source Device"
+        config EPPP_LINK_ETHERNET_CLK_SINK
+            bool "RMII CLK Sink Device"
+    endchoice
+
+    config EPPP_LINK_ETHERNET_SINK_READY_GPIO
+        int "RMII CLK Sink Device is ready GPIO"
+        default 4
+        depends on EPPP_LINK_ETHERNET_USE_DUMMY_PHY
+        help
+            GPIO number at which the "RMII CLK Sink Device" is ready and so the "RMII
+            CLK Source Device" can continue in its Ethernet initialization.
+
 endmenu

components/eppp_link/eppp_eth.c

@@ -16,6 +16,8 @@
 #include "esp_eth_driver.h"
 #include "ethernet_init.h"
 #include "esp_eth_spec.h"
+#include "driver/gpio.h"
+#include "esp_eth_phy_dummy.h"
 
 typedef struct header {
     uint8_t dst[ETH_ADDR_LEN];
@@ -65,30 +67,23 @@ static esp_err_t receive(esp_eth_handle_t h, uint8_t *buffer, uint32_t len, void
     return ESP_FAIL;
 }
 
+static esp_err_t eth_init(void);
+
 esp_err_t eppp_transport_init(eppp_config_t *config, esp_netif_t *esp_netif)
 {
-    uint8_t eth_port_cnt = 0;
-    ESP_ERROR_CHECK(ethernet_init_all(&s_eth_handles, &eth_port_cnt));
-    if (eth_port_cnt > 1) {
-        ESP_LOGW(TAG, "multiple Ethernet devices detected, the first initialized is to be used!");
-    }
-    ESP_ERROR_CHECK(esp_eth_update_input_path(s_eth_handles[0], receive, esp_netif));
+    ESP_RETURN_ON_ERROR(eth_init(), TAG, "Failed to initialize Ethernet driver");
+    ESP_RETURN_ON_ERROR(esp_eth_update_input_path(s_eth_handles[0], receive, esp_netif), TAG, "Failed to set Ethernet Rx callback");
     sscanf(CONFIG_EPPP_LINK_ETHERNET_OUR_ADDRESS, "%2" PRIu8 ":%2" PRIu8 ":%2" PRIi8 ":%2" PRIu8 ":%2" PRIu8 ":%2" PRIu8,
            &s_our_mac[0], &s_our_mac[1], &s_our_mac[2], &s_our_mac[3], &s_our_mac[4], &s_our_mac[5]);
 
     sscanf(CONFIG_EPPP_LINK_ETHERNET_THEIR_ADDRESS, "%2" PRIu8 ":%2" PRIu8 ":%2" PRIi8 ":%2" PRIu8 ":%2" PRIu8 ":%2" PRIu8,
            &s_their_mac[0], &s_their_mac[1], &s_their_mac[2], &s_their_mac[3], &s_their_mac[4], &s_their_mac[5]);
     esp_eth_ioctl(s_eth_handles[0], ETH_CMD_S_MAC_ADDR, s_our_mac);
-    ESP_ERROR_CHECK(esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, event_handler, NULL));
-    ESP_ERROR_CHECK(esp_eth_start(s_eth_handles[0]));
+    ESP_RETURN_ON_ERROR(esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, event_handler, NULL), TAG, "Failed to register Ethernet handlers");
+    ESP_RETURN_ON_ERROR(esp_eth_start(s_eth_handles[0]), TAG, "Failed to start Ethernet driver");
     return ESP_OK;
 }
 
-void eppp_transport_deinit(void)
-{
-    ethernet_deinit_all(s_eth_handles);
-}
-
 esp_err_t eppp_transport_tx(void *h, void *buffer, size_t len)
 {
     if (!s_is_connected) {
@@ -107,3 +102,148 @@ esp_err_t eppp_transport_tx(void *h, void *buffer, size_t len)
     memcpy(s_out_buffer + ETH_HEADER_LEN, buffer, len);
     return esp_eth_transmit(s_eth_handles[0], s_out_buffer, frame_payload_len + ETH_HEADER_LEN);
 }
+
+#ifdef CONFIG_EPPP_LINK_ETHERNET_USE_DUMMY_PHY
+
+static esp_eth_mac_t *s_mac = NULL;
+static esp_eth_phy_t *s_phy = NULL;
+
+#if CONFIG_EPPP_LINK_ETHERNET_CLK_SOURCE
+IRAM_ATTR static void gpio_isr_handler(void *arg)
+{
+    BaseType_t high_task_wakeup = pdFALSE;
+    TaskHandle_t task_handle = (TaskHandle_t)arg;
+
+    vTaskNotifyGiveFromISR(task_handle, &high_task_wakeup);
+    if (high_task_wakeup != pdFALSE) {
+        portYIELD_FROM_ISR();
+    }
+}
+#else
+#define STARTUP_DELAY_MS 500
+#endif
+
+static esp_err_t eth_init(void)
+{
+#if CONFIG_EPPP_LINK_ETHERNET_CLK_SOURCE
+    esp_rom_gpio_pad_select_gpio(EMAC_CLK_OUT_180_GPIO);
+    gpio_set_pull_mode(EMAC_CLK_OUT_180_GPIO, GPIO_FLOATING); // to not affect GPIO0 (so the Sink Device could be flashed)
+    gpio_install_isr_service(0);
+    gpio_config_t gpio_source_cfg = {
+        .pin_bit_mask = (1ULL << CONFIG_EPPP_LINK_ETHERNET_SINK_READY_GPIO),
+        .mode = GPIO_MODE_INPUT,
+        .pull_up_en = GPIO_PULLUP_DISABLE,
+        .pull_down_en = GPIO_PULLDOWN_ENABLE,
+        .intr_type = GPIO_INTR_ANYEDGE
+    };
+    gpio_config(&gpio_source_cfg);
+    TaskHandle_t task_handle = xTaskGetHandle(pcTaskGetName(NULL));
+    gpio_isr_handler_add(CONFIG_EPPP_LINK_ETHERNET_SINK_READY_GPIO, gpio_isr_handler, task_handle);
+    ESP_LOGW(TAG, "waiting for RMII CLK sink device interrupt");
+    ESP_LOGW(TAG, "if RMII CLK sink device is already running, reset it by `EN` button");
+    while (1) {
+        ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
+        if (gpio_get_level(CONFIG_EPPP_LINK_ETHERNET_SINK_READY_GPIO) == 1) {
+            break;
+        }
+    }
+    ESP_LOGI(TAG, "starting Ethernet initialization");
+#else
+    gpio_config_t gpio_sink_cfg = {
+        .pin_bit_mask = (1ULL << CONFIG_EPPP_LINK_ETHERNET_SINK_READY_GPIO),
+        .mode = GPIO_MODE_OUTPUT,
+        .pull_up_en = GPIO_PULLUP_DISABLE,
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
+        .intr_type = GPIO_INTR_DISABLE
+    };
+    gpio_config(&gpio_sink_cfg);
+    gpio_set_level(CONFIG_EPPP_LINK_ETHERNET_SINK_READY_GPIO, 0);
+    vTaskDelay(pdMS_TO_TICKS(STARTUP_DELAY_MS));
+    gpio_set_level(CONFIG_EPPP_LINK_ETHERNET_SINK_READY_GPIO, 1);
+#endif // CONFIG_EPPP_LINK_ETHERNET_CLK_SOURCE
+
+    // --- Initialize Ethernet driver ---
+    // Init common MAC and PHY configs to default
+    eth_mac_config_t mac_config = ETH_MAC_DEFAULT_CONFIG();
+    eth_phy_config_t phy_config = ETH_PHY_DEFAULT_CONFIG();
+
+    // Update PHY config based on board specific configuration
+    phy_config.reset_gpio_num = -1; // no HW reset
+
+    // Init vendor specific MAC config to default
+    eth_esp32_emac_config_t esp32_emac_config = ETH_ESP32_EMAC_DEFAULT_CONFIG();
+    // Update vendor specific MAC config based on board configuration
+    // No SMI, speed/duplex must be statically configured the same in both devices
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 3, 0)
+    esp32_emac_config.smi_gpio.mdc_num = -1;
+    esp32_emac_config.smi_gpio.mdio_num = -1;
+#else
+    esp32_emac_config.smi_mdc_gpio_num = -1;
+    esp32_emac_config.smi_mdio_gpio_num = -1;
+#endif
+#if CONFIG_EPPP_LINK_ETHERNET_CLK_SOURCE
+    esp32_emac_config.clock_config.rmii.clock_mode = EMAC_CLK_OUT;
+    esp32_emac_config.clock_config.rmii.clock_gpio = EMAC_CLK_OUT_180_GPIO;
+#else
+    esp32_emac_config.clock_config.rmii.clock_mode = EMAC_CLK_EXT_IN;
+    esp32_emac_config.clock_config.rmii.clock_gpio = EMAC_CLK_IN_GPIO;
+#endif // CONFIG_EPPP_LINK_ETHERNET_CLK_SOURCE
+
+    // Create new ESP32 Ethernet MAC instance
+    s_mac = esp_eth_mac_new_esp32(&esp32_emac_config, &mac_config);
+    // Create dummy PHY instance
+    s_phy = esp_eth_phy_new_dummy(&phy_config);
+
+    // Init Ethernet driver to default and install it
+    s_eth_handles = malloc(sizeof(esp_eth_handle_t));
+    ESP_RETURN_ON_FALSE(s_eth_handles, ESP_ERR_NO_MEM, TAG, "Our of memory");
+    esp_eth_config_t config = ETH_DEFAULT_CONFIG(s_mac, s_phy);
+#if CONFIG_EPPP_LINK_ETHERNET_CLK_SINK
+    // REF RMII CLK sink device performs multiple EMAC init attempts since RMII CLK source device may not be ready yet
+    int i;
+    for (i = 1; i <= 5; i++) {
+        ESP_LOGI(TAG, "Ethernet driver install attempt: %i", i);
+        if (esp_eth_driver_install(&config, &s_eth_handles[0]) == ESP_OK) {
+            break;
+        }
+        vTaskDelay(pdMS_TO_TICKS(100));
+    }
+    ESP_RETURN_ON_FALSE(i <= 5, ESP_FAIL, TAG, "Ethernet driver install failed");
+#else
+    ESP_RETURN_ON_ERROR(esp_eth_driver_install(&config, &s_eth_handles[0]), TAG, "Ethernet driver install failed");
+#endif // CONFIG_EPPP_LINK_ETHERNET_CLK_SINK
+    return ESP_OK;
+}
+
+void eppp_transport_deinit(void)
+{
+    if (esp_eth_driver_uninstall(&s_eth_handles[0]) != ESP_OK) {
+        ESP_LOGE(TAG, "Unable to deinitialize ethernet handle");
+    }
+    if (s_mac) {
+        s_mac->del(s_mac);
+        s_mac = NULL;
+    }
+    if (s_phy) {
+        s_phy->del(s_phy);
+        s_phy = NULL;
+    }
+    free(s_eth_handles);
+    s_eth_handles = NULL;
+}
+
+#else
+static esp_err_t eth_init(void)
+{
+    uint8_t eth_port_cnt = 0;
+    ESP_RETURN_ON_ERROR(ethernet_init_all(&s_eth_handles, &eth_port_cnt), TAG, "Failed to init common eth drivers");
+    ESP_RETURN_ON_FALSE(eth_port_cnt > 1, ESP_ERR_INVALID_ARG, TAG, "multiple Ethernet devices detected, please init only one");
+    return ESP_OK;
+}
+
+void eppp_transport_deinit(void)
+{
+    ethernet_deinit_all(s_eth_handles);
+}
+
+#endif // CONFIG_EPPP_LINK_ETHERNET_USE_DUMMY_PHY

components/eppp_link/examples/host/sdkconfig.ci.emac2emac

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_EPPP_LINK_DEVICE_ETH=y
+CONFIG_EPPP_LINK_ETHERNET_USE_DUMMY_PHY=y
+CONFIG_EPPP_LINK_ETHERNET_CLK_SOURCE=y

components/eppp_link/examples/slave/sdkconfig.ci.emac2emac

@@ -0,0 +1,6 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_EPPP_LINK_DEVICE_ETH=y
+CONFIG_EPPP_LINK_ETHERNET_OUR_ADDRESS="06:00:00:00:00:02"
+CONFIG_EPPP_LINK_ETHERNET_THEIR_ADDRESS="06:00:00:00:00:01"
+CONFIG_EPPP_LINK_ETHERNET_USE_DUMMY_PHY=y
+CONFIG_EPPP_LINK_ETHERNET_CLK_SINK=y

components/eppp_link/idf_component.yml

@@ -5,3 +5,4 @@ dependencies:
   idf: '>=5.2'
   espressif/esp_serial_slave_link: "^1.1.0"
   espressif/ethernet_init: '>=0.0.7'
+  espressif/eth_dummy_phy: '*'