Merge branch 'bugfix/openthread_uart_vfs_register_v5_3' into 'release/v5.3'

fix(openthread): register uart vfs devices when they are not registered(v5.3)

See merge request espressif/esp-idf!31795

Author: jack0c

components/openthread/src/port/esp_openthread_uart.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -17,6 +17,7 @@
 #include "esp_openthread_common_macro.h"
 #include "esp_openthread_platform.h"
 #include "esp_openthread_types.h"
+#include "esp_vfs.h"
 #include "esp_vfs_dev.h"
 #include "common/logging.hpp"
 #include "driver/uart.h"
@@ -62,6 +63,17 @@ otError otPlatUartSend(const uint8_t *buf, uint16_t buf_length)
 
 esp_err_t esp_openthread_uart_init_port(const esp_openthread_uart_config_t *config)
 {
+#ifndef CONFIG_ESP_CONSOLE_UART
+    // If UART console is used, UART vfs devices should be registered during startup.
+    // Otherwise we need to register them here.
+    DIR *uart_dir = opendir("/dev/uart");
+    if (!uart_dir) {
+        // If UART vfs devices are registered, we will failed to open the directory
+        uart_vfs_dev_register();
+    } else {
+        closedir(uart_dir);
+    }
+#endif
     ESP_RETURN_ON_ERROR(uart_param_config(config->port, &config->uart_config), OT_PLAT_LOG_TAG,
                         "uart_param_config failed");
     ESP_RETURN_ON_ERROR(
@@ -91,7 +103,6 @@ esp_err_t esp_openthread_host_cli_usb_init(const esp_openthread_platform_config_
 
     ret = usb_serial_jtag_driver_install((usb_serial_jtag_driver_config_t *)&config->host_config.host_usb_config);
     usb_serial_jtag_vfs_use_driver();
-    uart_vfs_dev_register();
     return ret;
 }
 #endif