/*

MockUART.cpp - esp8266 UART HAL EMULATION

Copyright (c) 2019 Clemens Kirchgatterer. All rights reserved.

This file is part of the esp8266 core for Arduino environment.

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

*/

/*

This UART driver is directly derived from the ESP8266 UART HAL driver

Copyright (c) 2014 Ivan Grokhotkov. It provides the same API as the

original driver and was striped from all HW dependent interfaces.

UART0 writes got to stdout, while UART1 writes got to stderr. The user

is responsible for feeding the RX FIFO new data by calling uart_new_data().

*/

#include <unistd.h> // write

#include <sys/time.h> // gettimeofday

#include <time.h> // localtime

#include "Arduino.h"

#include "uart.h"

//#define UART_DISCARD_NEWEST

extern "C" {

static int s_uart_debug_nr = UART1;

static uart_t *UART[2] = { NULL, NULL };

struct uart_rx_buffer_

{

size_t size;

size_t rpos;

size_t wpos;

uint8_t * buffer;

};

struct uart_

{

int uart_nr;

int baud_rate;

bool rx_enabled;

bool tx_enabled;

bool rx_overrun;

struct uart_rx_buffer_ * rx_buffer;

};

bool serial_timestamp = false;

// write one byte to the emulated UART

static void

uart_do_write_char(const int uart_nr, char c)

{

static bool w = false;

if (uart_nr >= UART0 && uart_nr <= UART1)

{

if (serial_timestamp && (c == '\n' || c == '\r'))

{

if (w)

{

FILE* out = uart_nr == UART0? stdout: stderr;

timeval tv;

gettimeofday(&tv, nullptr);

const tm* tm = localtime(&tv.tv_sec);

fprintf(out, "\r\n%d:%02d:%02d.%06d: ", tm->tm_hour, tm->tm_min, tm->tm_sec, (int)tv.tv_usec);

fflush(out);

w = false;

}

}

else

{

write(uart_nr + 1, &c, 1);

w = true;

}

}

}

// write a new byte into the RX FIFO buffer

static void

uart_handle_data(uart_t* uart, uint8_t data)

{

struct uart_rx_buffer_ *rx_buffer = uart->rx_buffer;

size_t nextPos = (rx_buffer->wpos + 1) % rx_buffer->size;

if(nextPos == rx_buffer->rpos)

{

uart->rx_overrun = true;

#ifdef UART_DISCARD_NEWEST

return;

#else

if (++rx_buffer->rpos == rx_buffer->size)

rx_buffer->rpos = 0;

#endif

}

rx_buffer->buffer[rx_buffer->wpos] = data;

rx_buffer->wpos = nextPos;

}

// insert a new byte into the RX FIFO nuffer

void

uart_new_data(const int uart_nr, uint8_t data)

{

uart_t* uart = UART[uart_nr];

if(uart == NULL || !uart->rx_enabled) {

return;

}

uart_handle_data(uart, data);

}

static size_t

uart_rx_available_unsafe(const struct uart_rx_buffer_ * rx_buffer)

{

size_t ret = rx_buffer->wpos - rx_buffer->rpos;

if(rx_buffer->wpos < rx_buffer->rpos)

ret = (rx_buffer->wpos + rx_buffer->size) - rx_buffer->rpos;

return ret;

}

// taking data straight from fifo, only needed in uart_resize_rx_buffer()

static int

uart_read_char_unsafe(uart_t* uart)

{

if (uart_rx_available_unsafe(uart->rx_buffer))

{

// take oldest sw data

int ret = uart->rx_buffer->buffer[uart->rx_buffer->rpos];

uart->rx_buffer->rpos = (uart->rx_buffer->rpos + 1) % uart->rx_buffer->size;

return ret;

}

// unavailable

return -1;

}

/**********************************************************/

/************ UART API FUNCTIONS **************************/

/**********************************************************/

size_t

uart_rx_available(uart_t* uart)

{

if(uart == NULL || !uart->rx_enabled)

return 0;

return uart_rx_available_unsafe(uart->rx_buffer);

}

int

uart_peek_char(uart_t* uart)

{

if(uart == NULL || !uart->rx_enabled)

return -1;

if (!uart_rx_available_unsafe(uart->rx_buffer))

return -1;

return uart->rx_buffer->buffer[uart->rx_buffer->rpos];

}

int

uart_read_char(uart_t* uart)

{

uint8_t ret;

return uart_read(uart, (char*)&ret, 1) ? ret : -1;

}

size_t

uart_read(uart_t* uart, char* userbuffer, size_t usersize)

{

if(uart == NULL || !uart->rx_enabled)

return 0;

size_t ret = 0;

while (ret < usersize && uart_rx_available_unsafe(uart->rx_buffer))

{

// pour sw buffer to user's buffer

// get largest linear length from sw buffer

size_t chunk = uart->rx_buffer->rpos < uart->rx_buffer->wpos ?

uart->rx_buffer->wpos - uart->rx_buffer->rpos :

uart->rx_buffer->size - uart->rx_buffer->rpos;

if (ret + chunk > usersize)

chunk = usersize - ret;

memcpy(userbuffer + ret, uart->rx_buffer->buffer + uart->rx_buffer->rpos, chunk);

uart->rx_buffer->rpos = (uart->rx_buffer->rpos + chunk) % uart->rx_buffer->size;

ret += chunk;

}

return ret;

}

size_t

uart_resize_rx_buffer(uart_t* uart, size_t new_size)

{

if(uart == NULL || !uart->rx_enabled)

return 0;

if(uart->rx_buffer->size == new_size)

return uart->rx_buffer->size;

uint8_t * new_buf = (uint8_t*)malloc(new_size);

if(!new_buf)

return uart->rx_buffer->size;

size_t new_wpos = 0;

// if uart_rx_available_unsafe() returns non-0, uart_read_char_unsafe() can't return -1

while(uart_rx_available_unsafe(uart->rx_buffer) && new_wpos < new_size)

new_buf[new_wpos++] = uart_read_char_unsafe(uart);

if (new_wpos == new_size)

new_wpos = 0;

uint8_t * old_buf = uart->rx_buffer->buffer;

uart->rx_buffer->rpos = 0;

uart->rx_buffer->wpos = new_wpos;

uart->rx_buffer->size = new_size;

uart->rx_buffer->buffer = new_buf;

free(old_buf);

return uart->rx_buffer->size;

}

size_t

uart_get_rx_buffer_size(uart_t* uart)

{

return uart && uart->rx_enabled ? uart->rx_buffer->size : 0;

}

size_t

uart_write_char(uart_t* uart, char c)

{

if(uart == NULL || !uart->tx_enabled)

return 0;

uart_do_write_char(uart->uart_nr, c);

return 1;

}

size_t

uart_write(uart_t* uart, const char* buf, size_t size)

{

if(uart == NULL || !uart->tx_enabled)

return 0;

size_t ret = size;

const int uart_nr = uart->uart_nr;

while (size--)

uart_do_write_char(uart_nr, *buf++);

return ret;

}

size_t

uart_tx_free(uart_t* uart)

{

if(uart == NULL || !uart->tx_enabled)

return 0;

return UART_TX_FIFO_SIZE;

}

void

uart_wait_tx_empty(uart_t* uart)

{

(void) uart;

}

void

uart_flush(uart_t* uart)

{

if(uart == NULL)

return;

if(uart->rx_enabled)

{

uart->rx_buffer->rpos = 0;

uart->rx_buffer->wpos = 0;

}

}

void

uart_set_baudrate(uart_t* uart, int baud_rate)

{

if(uart == NULL)

return;

uart->baud_rate = baud_rate;

}

int

uart_get_baudrate(uart_t* uart)

{

if(uart == NULL)

return 0;

return uart->baud_rate;

}

uint8_t

uart_get_bit_length(const int uart_nr)

{

uint8_t width = ((uart_nr % 16) >> 2) + 5;

uint8_t parity = (uart_nr >> 5) + 1;

uint8_t stop = uart_nr % 4;

return (width + parity + stop + 1);

}

uart_t*

uart_init(int uart_nr, int baudrate, int config, int mode, int tx_pin, size_t rx_size)

{

(void) config;

(void) tx_pin;

uart_t* uart = (uart_t*) malloc(sizeof(uart_t));

if(uart == NULL)

return NULL;

uart->uart_nr = uart_nr;

uart->rx_overrun = false;

switch(uart->uart_nr)

{

case UART0:

uart->rx_enabled = (mode != UART_TX_ONLY);

uart->tx_enabled = (mode != UART_RX_ONLY);

if(uart->rx_enabled)

{

struct uart_rx_buffer_ * rx_buffer = (struct uart_rx_buffer_ *)malloc(sizeof(struct uart_rx_buffer_));

if(rx_buffer == NULL)

{

free(uart);

return NULL;

}

rx_buffer->size = rx_size;//var this

rx_buffer->rpos = 0;

rx_buffer->wpos = 0;

rx_buffer->buffer = (uint8_t *)malloc(rx_buffer->size);

if(rx_buffer->buffer == NULL)

{

free(rx_buffer);

free(uart);

return NULL;

}

uart->rx_buffer = rx_buffer;

}

break;

case UART1:

// Note: uart_interrupt_handler does not support RX on UART 1.

uart->rx_enabled = false;

uart->tx_enabled = (mode != UART_RX_ONLY);

break;

case UART_NO:

default:

// big fail!

free(uart);

return NULL;

}

uart_set_baudrate(uart, baudrate);

UART[uart_nr] = uart;

return uart;

}

void

uart_uninit(uart_t* uart)

{

if(uart == NULL)

return;

if(uart->rx_enabled) {

free(uart->rx_buffer->buffer);

free(uart->rx_buffer);

}

free(uart);

}

void

uart_swap(uart_t* uart, int tx_pin)

{

(void) uart;

(void) tx_pin;

}

void

uart_set_tx(uart_t* uart, int tx_pin)

{

(void) uart;

(void) tx_pin;

}

void

uart_set_pins(uart_t* uart, int tx, int rx)

{

(void) uart;

(void) tx;

(void) rx;

}

bool

uart_tx_enabled(uart_t* uart)

{

if(uart == NULL)

return false;

return uart->tx_enabled;

}

bool

uart_rx_enabled(uart_t* uart)

{

if(uart == NULL)

return false;

return uart->rx_enabled;

}

bool

uart_has_overrun(uart_t* uart)

{

if(uart == NULL || !uart->rx_overrun)

return false;

// clear flag

uart->rx_overrun = false;

return true;

}

bool

uart_has_rx_error(uart_t* uart)

{

(void) uart;

return false;

}

void

uart_set_debug(int uart_nr)

{

(void)uart_nr;

}

int

uart_get_debug()

{

return s_uart_debug_nr;

}

void

uart_start_detect_baudrate(int uart_nr)

{

(void) uart_nr;

}

int

uart_detect_baudrate(int uart_nr)

{

(void) uart_nr;

return 115200;

}

};