text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2020-2021 Damien P. George
   *
   * 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 "py/runtime.h"
  #include "py/ringbuf.h"
  #include "py/mphal.h"
  #include "uart.h"
  
  #include "hardware/uart.h"
  #include "hardware/irq.h"
  #include "hardware/regs/uart.h"
  
  #if MICROPY_HW_ENABLE_UART_REPL
  
  void uart_irq(void) {
      uart_get_hw(uart_default)->icr = UART_UARTICR_BITS; // clear interrupt flags
      if (uart_is_readable(uart_default)) {
          int c = uart_getc(uart_default);
          #if MICROPY_KBD_EXCEPTION
          if (c == mp_interrupt_char) {
              mp_keyboard_interrupt();
              return;
          }
          #endif
          ringbuf_put(&stdin_ringbuf, c);
      }
  }
  
  void mp_uart_init(void) {
      uart_get_hw(uart_default)->imsc = UART_UARTIMSC_BITS; // enable mask
      uint irq_num = uart_get_index(uart_default) ? UART1_IRQ : UART0_IRQ;
      irq_set_exclusive_handler(irq_num, uart_irq);
      irq_set_enabled(irq_num, true); // enable irq
  }
  
  void mp_uart_write_strn(const char *str, size_t len) {
      uart_write_blocking(uart_default, (const uint8_t *)str, len);
  }
  
  #endif
  