text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2016 Linaro Limited
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  #include <unistd.h>
  #include "py/mpconfig.h"
  #include "src/zephyr_getchar.h"
  // Zephyr headers
  #include <drivers/uart.h>
  #include <console/console.h>
  
  /*
   * Core UART functions to implement for a port
   */
  
  // Receive single character
  int mp_hal_stdin_rx_chr(void) {
      #ifdef CONFIG_CONSOLE_SUBSYS
      return console_getchar();
      #else
      return zephyr_getchar();
      #endif
  }
  
  // Send string of given length
  void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
      #ifdef CONFIG_CONSOLE_SUBSYS
      while (len--) {
          char c = *str++;
          while (console_putchar(c) == -1) {
              k_msleep(1);
          }
      }
      #else
      static const struct device *uart_console_dev;
      if (uart_console_dev == NULL) {
          uart_console_dev = device_get_binding(CONFIG_UART_CONSOLE_ON_DEV_NAME);
      }
  
      while (len--) {
          uart_poll_out(uart_console_dev, *str++);
      }
      #endif
  }
  