Initial commit

components/usb_api/CMakeLists.txt

@@ -0,0 +1,5 @@
+idf_component_register(
+    SRCS "usb_api.c"
+    INCLUDE_DIRS "include"
+    REQUIRES driver
+)

components/usb_api/include/usb_api.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <stdbool.h>
+
+typedef void (*usb_api_line_handler_t)(const char *line);
+
+// Initialize USB Serial/JTAG line reader; pass handler for complete lines.
+void usb_api_init(usb_api_line_handler_t handler);
+
+// Non-blocking poll; call from main loop/task.
+void usb_api_tick(void);
+
+// Send a line to host (no automatic newline added).
+void usb_api_send_line(const char *line);
+
+// Return true when host is connected over USB Serial/JTAG.
+bool usb_api_is_connected(void);

components/usb_api/usb_api.c

@@ -0,0 +1,75 @@
+#include "usb_api.h"
+#include <string.h>
+#include "esp_err.h"
+#include "esp_log.h"
+#include "driver/usb_serial_jtag.h"
+
+static const char *TAG = "usb_api";
+static usb_api_line_handler_t s_handler = NULL;
+static char s_line_buf[256];
+static size_t s_line_len = 0;
+
+void usb_api_init(usb_api_line_handler_t handler)
+{
+    s_handler = handler;
+    s_line_len = 0;
+    usb_serial_jtag_driver_config_t cfg = USB_SERIAL_JTAG_DRIVER_CONFIG_DEFAULT();
+    esp_err_t err = usb_serial_jtag_driver_install(&cfg);
+    if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
+        ESP_LOGE(TAG, "usb driver install failed: %s", esp_err_to_name(err));
+    }
+}
+
+bool usb_api_is_connected(void)
+{
+    return usb_serial_jtag_is_connected();
+}
+
+void usb_api_send_line(const char *line)
+{
+    if (!line) {
+        return;
+    }
+    size_t len = strlen(line);
+    if (len == 0) {
+        return;
+    }
+    int written = usb_serial_jtag_write_bytes((const uint8_t *)line, len, 0);
+    if (written < 0) {
+        ESP_LOGW(TAG, "usb write failed");
+    }
+}
+
+static void handle_complete_line(void)
+{
+    if (s_line_len == 0) {
+        return;
+    }
+    s_line_buf[s_line_len] = '\0';
+    if (s_handler) {
+        s_handler(s_line_buf);
+    }
+    s_line_len = 0;
+}
+
+void usb_api_tick(void)
+{
+    uint8_t buf[64];
+    int n = usb_serial_jtag_read_bytes(buf, sizeof(buf), 0);
+    if (n <= 0) {
+        return;
+    }
+    for (int i = 0; i < n; i++) {
+        char c = (char)buf[i];
+        if (c == '\r' || c == '\n') {
+            handle_complete_line();
+            continue;
+        }
+        if (s_line_len + 1 >= sizeof(s_line_buf)) {
+            // drop line on overflow
+            s_line_len = 0;
+            continue;
+        }
+        s_line_buf[s_line_len++] = c;
+    }
+}