text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2016 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 <stdio.h>
  #include <stdint.h>
  #include <string.h>
  
  #include "ets_sys.h"
  #include "user_interface.h"
  #include "uart.h"
  
  #include "py/runtime.h"
  #include "py/stream.h"
  #include "py/mperrno.h"
  #include "py/mphal.h"
  #include "modmachine.h"
  
  // UartDev is defined and initialized in rom code.
  extern UartDevice UartDev;
  
  typedef struct _pyb_uart_obj_t {
      mp_obj_base_t base;
      uint8_t uart_id;
      uint8_t bits;
      uint8_t parity;
      uint8_t stop;
      uint32_t baudrate;
      uint16_t timeout;       // timeout waiting for first char (in ms)
      uint16_t timeout_char;  // timeout waiting between chars (in ms)
  } pyb_uart_obj_t;
  
  STATIC const char *_parity_name[] = {"None", "1", "0"};
  
  /******************************************************************************/
  // MicroPython bindings for UART
  
  STATIC void pyb_uart_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
      pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
      mp_printf(print, "UART(%u, baudrate=%u, bits=%u, parity=%s, stop=%u, rxbuf=%u, timeout=%u, timeout_char=%u)",
          self->uart_id, self->baudrate, self->bits, _parity_name[self->parity],
          self->stop, uart0_get_rxbuf_len() - 1, self->timeout, self->timeout_char);
  }
  
  STATIC void pyb_uart_init_helper(pyb_uart_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_baudrate, ARG_bits, ARG_parity, ARG_stop, ARG_tx, ARG_rx, ARG_rxbuf, ARG_timeout, ARG_timeout_char };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_baudrate, MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_bits, MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_parity, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_stop, MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_tx, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_rx, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_rxbuf, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_timeout_char, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
      };
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      // set baudrate
      if (args[ARG_baudrate].u_int > 0) {
          self->baudrate = args[ARG_baudrate].u_int;
          UartDev.baut_rate = self->baudrate; // Sic!
      }
  
      // set data bits
      switch (args[ARG_bits].u_int) {
          case 0:
              break;
          case 5:
              UartDev.data_bits = UART_FIVE_BITS;
              self->bits = 5;
              break;
          case 6:
              UartDev.data_bits = UART_SIX_BITS;
              self->bits = 6;
              break;
          case 7:
              UartDev.data_bits = UART_SEVEN_BITS;
              self->bits = 7;
              break;
          case 8:
              UartDev.data_bits = UART_EIGHT_BITS;
              self->bits = 8;
              break;
          default:
              mp_raise_ValueError(MP_ERROR_TEXT("invalid data bits"));
              break;
      }
  
      // set parity
      if (args[ARG_parity].u_obj != MP_OBJ_NULL) {
          if (args[ARG_parity].u_obj == mp_const_none) {
              UartDev.parity = UART_NONE_BITS;
              UartDev.exist_parity = UART_STICK_PARITY_DIS;
              self->parity = 0;
          } else {
              mp_int_t parity = mp_obj_get_int(args[ARG_parity].u_obj);
              UartDev.exist_parity = UART_STICK_PARITY_EN;
              if (parity & 1) {
                  UartDev.parity = UART_ODD_BITS;
                  self->parity = 1;
              } else {
                  UartDev.parity = UART_EVEN_BITS;
                  self->parity = 2;
              }
          }
      }
  
      // set tx/rx pins
      mp_hal_pin_obj_t tx = 1, rx = 3;
      if (args[ARG_tx].u_obj != MP_OBJ_NULL) {
          tx = mp_hal_get_pin_obj(args[ARG_tx].u_obj);
      }
      if (args[ARG_rx].u_obj != MP_OBJ_NULL) {
          rx = mp_hal_get_pin_obj(args[ARG_rx].u_obj);
      }
      if (tx == 1 && rx == 3) {
          system_uart_de_swap();
      } else if (tx == 15 && rx == 13) {
          system_uart_swap();
      } else {
          mp_raise_ValueError(MP_ERROR_TEXT("invalid tx/rx"));
      }
  
      // set stop bits
      switch (args[ARG_stop].u_int) {
          case 0:
              break;
          case 1:
              UartDev.stop_bits = UART_ONE_STOP_BIT;
              self->stop = 1;
              break;
          case 2:
              UartDev.stop_bits = UART_TWO_STOP_BIT;
              self->stop = 2;
              break;
          default:
              mp_raise_ValueError(MP_ERROR_TEXT("invalid stop bits"));
              break;
      }
  
      // set rx ring buffer
      if (args[ARG_rxbuf].u_int > 0) {
          uint16_t len = args[ARG_rxbuf].u_int + 1; // account for usable items in ringbuf
          byte *buf;
          if (len <= UART0_STATIC_RXBUF_LEN) {
              buf = uart_ringbuf_array;
              MP_STATE_PORT(uart0_rxbuf) = NULL; // clear any old pointer
          } else {
              buf = m_new(byte, len);
              MP_STATE_PORT(uart0_rxbuf) = buf; // retain root pointer
          }
          uart0_set_rxbuf(buf, len);
      }
  
      // set timeout
      self->timeout = args[ARG_timeout].u_int;
  
      // set timeout_char
      // make sure it is at least as long as a whole character (13 bits to be safe)
      self->timeout_char = args[ARG_timeout_char].u_int;
      uint32_t min_timeout_char = 13000 / self->baudrate + 1;
      if (self->timeout_char < min_timeout_char) {
          self->timeout_char = min_timeout_char;
      }
  
      // setup
      uart_setup(self->uart_id);
  }
  
  STATIC mp_obj_t pyb_uart_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
  
      // get uart id
      mp_int_t uart_id = mp_obj_get_int(args[0]);
      if (uart_id != 0 && uart_id != 1) {
          mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("UART(%d) does not exist"), uart_id);
      }
  
      // create instance
      pyb_uart_obj_t *self = mp_obj_malloc(pyb_uart_obj_t, &pyb_uart_type);
      self->uart_id = uart_id;
      self->baudrate = 115200;
      self->bits = 8;
      self->parity = 0;
      self->stop = 1;
      self->timeout = 0;
      self->timeout_char = 0;
  
      // init the peripheral
      mp_map_t kw_args;
      mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
      pyb_uart_init_helper(self, n_args - 1, args + 1, &kw_args);
  
      return MP_OBJ_FROM_PTR(self);
  }
  
  STATIC mp_obj_t pyb_uart_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
      pyb_uart_init_helper(args[0], n_args - 1, args + 1, kw_args);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(pyb_uart_init_obj, 1, pyb_uart_init);
  
  STATIC mp_obj_t pyb_uart_any(mp_obj_t self_in) {
      pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
      return MP_OBJ_NEW_SMALL_INT(uart_rx_any(self->uart_id));
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_any_obj, pyb_uart_any);
  
  STATIC const mp_rom_map_elem_t pyb_uart_locals_dict_table[] = {
      { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_uart_init_obj) },
  
      { MP_ROM_QSTR(MP_QSTR_any), MP_ROM_PTR(&pyb_uart_any_obj) },
      { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
      { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
      { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
      { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
  };
  
  STATIC MP_DEFINE_CONST_DICT(pyb_uart_locals_dict, pyb_uart_locals_dict_table);
  
  STATIC mp_uint_t pyb_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
      pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
  
      if (self->uart_id == 1) {
          mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("UART(1) can't read"));
      }
  
      // make sure we want at least 1 char
      if (size == 0) {
          return 0;
      }
  
      // wait for first char to become available
      if (!uart_rx_wait(self->timeout * 1000)) {
          *errcode = MP_EAGAIN;
          return MP_STREAM_ERROR;
      }
  
      // read the data
      uint8_t *buf = buf_in;
      for (;;) {
          *buf++ = uart_rx_char();
          if (--size == 0 || !uart_rx_wait(self->timeout_char * 1000)) {
              // return number of bytes read
              return buf - (uint8_t *)buf_in;
          }
      }
  }
  
  STATIC mp_uint_t pyb_uart_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {
      pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
      const byte *buf = buf_in;
  
      /* TODO implement non-blocking
      // wait to be able to write the first character
      if (!uart_tx_wait(self, timeout)) {
          *errcode = EAGAIN;
          return MP_STREAM_ERROR;
      }
      */
  
      // write the data
      for (size_t i = 0; i < size; ++i) {
          uart_tx_one_char(self->uart_id, *buf++);
      }
  
      // return number of bytes written
      return size;
  }
  
  STATIC mp_uint_t pyb_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint_t arg, int *errcode) {
      pyb_uart_obj_t *self = self_in;
      mp_uint_t ret;
      if (request == MP_STREAM_POLL) {
          mp_uint_t flags = arg;
          ret = 0;
          if ((flags & MP_STREAM_POLL_RD) && uart_rx_any(self->uart_id)) {
              ret |= MP_STREAM_POLL_RD;
          }
          if ((flags & MP_STREAM_POLL_WR) && uart_tx_any_room(self->uart_id)) {
              ret |= MP_STREAM_POLL_WR;
          }
      } else {
          *errcode = MP_EINVAL;
          ret = MP_STREAM_ERROR;
      }
      return ret;
  }
  
  STATIC const mp_stream_p_t uart_stream_p = {
      .read = pyb_uart_read,
      .write = pyb_uart_write,
      .ioctl = pyb_uart_ioctl,
      .is_text = false,
  };
  
  const mp_obj_type_t pyb_uart_type = {
      { &mp_type_type },
      .name = MP_QSTR_UART,
      .print = pyb_uart_print,
      .make_new = pyb_uart_make_new,
      .getiter = mp_identity_getiter,
      .iternext = mp_stream_unbuffered_iter,
      .protocol = &uart_stream_p,
      .locals_dict = (mp_obj_dict_t *)&pyb_uart_locals_dict,
  };
  