#include "project.h"

#define BUFFER_SIZE 256
#define BIG_BUFFER_SIZE 600

volatile ring_t rx6_ring;
static uint8_t rx6_ring_buf[BUFFER_SIZE];

volatile ring_t tx6_ring;
static uint8_t tx6_ring_buf[BUFFER_SIZE];


#define TX6   GPIO6
#define TX6_PORT  GPIOC

#define RX6   GPIO7
#define RX6_PORT  GPIOC


void usart6_isr (void)
{
  uint8_t data;

  /* Check if we were called because of RXNE. */
  if (((USART_CR1 (USART6) & USART_CR1_RXNEIE) != 0) &&
      ((USART_SR (USART6) & USART_SR_RXNE) != 0)) {

    /* Retrieve the data from the peripheral. */
    data = usart_recv (USART6);

    ring_write_byte (&rx6_ring, data);
  }

  /* Check if we were called because of TXE. */
  if (((USART_CR1 (USART6) & USART_CR1_TXEIE) != 0) &&
      ((USART_SR (USART6) & USART_SR_TXE) != 0)) {

    if (ring_read_byte (&tx6_ring, &data)) {
      /*No more data, Disable the TXE interrupt, it's no longer needed. */
      usart_disable_tx_interrupt (USART6);
    } else
      usart_send_blocking (USART6, data);
  }

}

void
usart6_queue (uint8_t d)
{
  ring_write_byte (&tx6_ring, d);
  usart_enable_tx_interrupt (USART6);
}

void
usart6_drain (void)
{
  while (!ring_empty (&tx6_ring));
}


int
usart6_write (char *ptr, int len, int blocking)
{
  int ret;

  ret = ring_write (&tx6_ring, (uint8_t *) ptr, len, blocking);
  usart_enable_tx_interrupt (USART6);
  return ret;
}


void
usart_init (void)
{

  ring_init (&rx6_ring, rx6_ring_buf, sizeof (rx6_ring_buf));
  ring_init (&tx6_ring, tx6_ring_buf, sizeof (tx6_ring_buf));

  /* Map pins, and set usart2 to have pull ups */

  MAP_AF (TX6, GPIO_AF8);
  MAP_AF_PU (RX6, GPIO_AF8);

  usart_set_baudrate (USART6, 38400);
  usart_set_databits (USART6, 8);
  usart_set_stopbits (USART6, USART_STOPBITS_1);
  usart_set_parity (USART6, USART_PARITY_NONE);
  usart_set_flow_control (USART6, USART_FLOWCONTROL_NONE);
  usart_set_mode (USART6, USART_MODE_TX_RX);


  usart_enable_rx_interrupt (USART6);

  /* Finally enable the USARTs. */
  usart_enable (USART6);

  nvic_enable_irq (NVIC_USART6_IRQ);


}