feat(esp_eth): added HW Time Stamping support for ESP32P4

Added mechanism to L2 TAP to retreive time stamp

Added PTP time synchronization example

examples/ethernet/ptp/main/ptp_main.c

@@ -0,0 +1,150 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <string.h>
+#include "sdkconfig.h"
+#include "esp_log.h"
+#include "esp_event.h"
+#include "esp_eth.h"
+#include "esp_netif.h"
+#include "ethernet_init.h"
+#include "esp_vfs_l2tap.h"
+#include "driver/gpio.h"
+#include "ptpd.h"
+
+#include "esp_eth_time.h"
+
+static const char *TAG = "ptp_example";
+
+static struct timespec s_next_time;
+static bool s_gpio_level;
+
+void init_ethernet_and_netif(void)
+{
+    uint8_t eth_port_cnt;
+    esp_eth_handle_t *eth_handles;
+
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    ESP_ERROR_CHECK(example_eth_init(&eth_handles, &eth_port_cnt));
+
+    ESP_ERROR_CHECK(esp_netif_init());
+
+    ESP_ERROR_CHECK(esp_vfs_l2tap_intf_register(NULL));
+
+    esp_netif_inherent_config_t esp_netif_base_config = ESP_NETIF_INHERENT_DEFAULT_ETH();
+    esp_netif_config_t esp_netif_config = {
+        .base = &esp_netif_base_config,
+        .stack = ESP_NETIF_NETSTACK_DEFAULT_ETH
+    };
+    char if_key_str[10];
+    char if_desc_str[10];
+    char num_str[3];
+    for (int i = 0; i < eth_port_cnt; i++) {
+        itoa(i, num_str, 10);
+        strcat(strcpy(if_key_str, "ETH_"), num_str);
+        strcat(strcpy(if_desc_str, "eth"), num_str);
+        esp_netif_base_config.if_key = if_key_str;
+        esp_netif_base_config.if_desc = if_desc_str;
+        esp_netif_base_config.route_prio -= i*5;
+        esp_netif_t *eth_netif = esp_netif_new(&esp_netif_config);
+
+        // attach Ethernet driver to TCP/IP stack
+        ESP_ERROR_CHECK(esp_netif_attach(eth_netif, esp_eth_new_netif_glue(eth_handles[i])));
+    }
+
+    for (int i = 0; i < eth_port_cnt; i++) {
+        ESP_ERROR_CHECK(esp_eth_start(eth_handles[i]));
+    }
+}
+
+IRAM_ATTR bool ts_callback(esp_eth_mediator_t *eth, void *user_args)
+{
+    gpio_set_level(CONFIG_EXAMPLE_PTP_PULSE_GPIO, s_gpio_level ^= 1);
+
+    // Set the next target time
+    struct timespec interval = {
+        .tv_sec = 0,
+        .tv_nsec = CONFIG_EXAMPLE_PTP_PULSE_WIDTH_NS
+    };
+    timespecadd(&s_next_time, &interval, &s_next_time);
+
+    struct timespec curr_time;
+    esp_eth_clock_gettime(CLOCK_PTP_SYSTEM, &curr_time);
+    // check the next time is in the future
+    if (timespeccmp(&s_next_time, &curr_time, >)) {
+        esp_eth_clock_set_target_time(CLOCK_PTP_SYSTEM, &s_next_time);
+    }
+
+    return false;
+}
+
+void app_main(void)
+{
+    init_ethernet_and_netif();
+
+    int pid = ptpd_start("ETH_0");
+
+    struct timespec cur_time;
+    // wait for the clock to be available
+    while (esp_eth_clock_gettime(CLOCK_PTP_SYSTEM, &cur_time) == -1) {
+        vTaskDelay(pdMS_TO_TICKS(500));
+    }
+    // register callback function which will toggle output pin
+    esp_eth_clock_register_target_cb(CLOCK_PTP_SYSTEM, ts_callback);
+
+    // initialize output pin
+    gpio_config_t gpio_out_cfg = {
+        .pin_bit_mask = (1ULL << CONFIG_EXAMPLE_PTP_PULSE_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_out_cfg);
+    gpio_set_level(CONFIG_EXAMPLE_PTP_PULSE_GPIO, 0);
+
+    bool first_pass = true;
+    bool clock_source_valid = false;
+    bool clock_source_valid_last = false;
+    int32_t clock_source_valid_cnt = 0;
+    while (1) {
+        struct ptpd_status_s ptp_status;
+        // if valid PTP status
+        if (ptpd_status(pid, &ptp_status) == 0) {
+            if (ptp_status.clock_source_valid) {
+                clock_source_valid_cnt++;
+            } else {
+                clock_source_valid_cnt = 0;
+            }
+        } else {
+            clock_source_valid_cnt = 0;
+        }
+        // consider the source valid only after n consequent intervals to be sure clock was synced
+        if (clock_source_valid_cnt > 2) {
+            clock_source_valid = true;
+        } else {
+            clock_source_valid = false;
+        }
+        // source validity changed => resync the pulse for ptp slave OR when the first pass to PTP master
+        // starts generating its pulses
+        if ((clock_source_valid == true && clock_source_valid_last == false) || first_pass) {
+            first_pass = false;
+            // get the most recent (now synced) time
+            esp_eth_clock_gettime(CLOCK_PTP_SYSTEM, &cur_time);
+            // compute the next target time
+            s_next_time.tv_sec = 1;
+            timespecadd(&s_next_time, &cur_time, &s_next_time);
+            s_next_time.tv_nsec = CONFIG_EXAMPLE_PTP_PULSE_WIDTH_NS;
+            ESP_LOGI(TAG, "Starting Pulse train");
+            ESP_LOGI(TAG, "curr time: %llu.%09lu", cur_time.tv_sec, cur_time.tv_nsec);
+            ESP_LOGI(TAG, "next time: %llu.%09lu", s_next_time.tv_sec, s_next_time.tv_nsec);
+            s_gpio_level = 0;
+            gpio_set_level(CONFIG_EXAMPLE_PTP_PULSE_GPIO, s_gpio_level);
+            esp_eth_clock_set_target_time(CLOCK_PTP_SYSTEM, &s_next_time);
+        }
+        clock_source_valid_last = clock_source_valid;
+    }
+}