#include "project.h"

#define BUFFER_SIZE 256
#define BIG_BUFFER_SIZE 600

ring_t rx1_ring;
static uint8_t rx1_ring_buf[BUFFER_SIZE];

ring_t tx1_ring;
static uint8_t tx1_ring_buf[BUFFER_SIZE];

ring_t rx2_ring;
static uint8_t rx2_ring_buf[BUFFER_SIZE];

ring_t tx2_ring;
static uint8_t tx2_ring_buf[BIG_BUFFER_SIZE];

void
usart1_isr (void)
{
  uint8_t data;

  /* Check if we were called because of RXNE. */
  if (((USART_CR1 (USART1) & USART_CR1_RXNEIE) != 0) &&
      ((USART_SR (USART1) & USART_SR_RXNE) != 0))
    {

      /* Retrieve the data from the peripheral. */
      data = usart_recv (USART1);


      ring_write_byte (&rx1_ring, data);
    }

  /* Check if we were called because of TXE. */
  if (((USART_CR1 (USART1) & USART_CR1_TXEIE) != 0) &&
      ((USART_SR (USART1) & USART_SR_TXE) != 0))
    {

      if (ring_read_byte (&tx1_ring, &data))
        {
          /*No more data, Disable the TXE interrupt, it's no longer needed. */
          USART_CR1 (USART1) &= ~USART_CR1_TXEIE;
        }
      else
        {
          usart_send (USART1, data);
        }
    }

}

void
usart2_isr (void)
{
  uint8_t data;

  /* Check if we were called because of RXNE. */
  if (((USART_CR1 (USART2) & USART_CR1_RXNEIE) != 0) &&
      ((USART_SR (USART2) & USART_SR_RXNE) != 0))
    {

      /* Retrieve the data from the peripheral. */
      data = usart_recv (USART2);

      ring_write_byte (&rx2_ring, data);
    }

  /* Check if we were called because of TXE. */
  if (((USART_CR1 (USART2) & USART_CR1_TXEIE) != 0) &&
      ((USART_SR (USART2) & USART_SR_TXE) != 0))
    {

      if (ring_read_byte (&tx2_ring, &data))
        {
          /*No more data, Disable the TXE interrupt, it's no longer needed. */
          USART_CR1 (USART2) &= ~USART_CR1_TXEIE;
        }
      else
        {
          usart_send_blocking (USART2, data);
        }
    }

}

int
_write (int file, char *ptr, int len)
{
  int ret;

  if (file == 1)
    {
      ret = ring_write (&tx1_ring, (uint8_t *) ptr, len);

      if (ret < 0)
        ret = -ret;

      USART_CR1 (USART1) |= USART_CR1_TXEIE;
      return ret;
    }

  errno = EIO;
  return -1;
}

void
usart1_queue (uint8_t d)
{
  ring_write_byte (&tx1_ring, d);
  USART_CR1 (USART1) |= USART_CR1_TXEIE;
}


void
usart2_queue (uint8_t d)
{
  ring_write_byte (&tx2_ring, d);
  USART_CR1 (USART2) |= USART_CR1_TXEIE;
}

void
usart2_drain (void)
{
  while (!ring_empty (&tx2_ring));
}

void
usart1_drain (void)
{
  while (!ring_empty (&tx1_ring));
}



void
usart_init (void)
{
  rcc_periph_clock_enable (RCC_USART1);
  rcc_periph_clock_enable (RCC_USART2);
  rcc_periph_clock_enable (RCC_USART3);

  ring_init (&rx1_ring, rx1_ring_buf, sizeof (rx1_ring_buf));
  ring_init (&tx1_ring, tx1_ring_buf, sizeof (tx1_ring_buf));

  ring_init (&rx2_ring, rx2_ring_buf, sizeof (rx2_ring_buf));
  ring_init (&tx2_ring, tx2_ring_buf, sizeof (tx2_ring_buf));


  /* Enable the USART1,2 interrupt. */
  nvic_enable_irq (NVIC_USART1_IRQ);
  nvic_enable_irq (NVIC_USART2_IRQ);

  /* Map pins, and set usart2 to have pull ups */
  gpio_set_mode (GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
                 GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
  gpio_set_mode (GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT,
                 GPIO_USART1_RX);

  gpio_set_mode (GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
                 GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
  gpio_set_mode (GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN,
                 GPIO_USART2_RX);
  gpio_set (GPIOA, GPIO_USART2_RX);


  /* Setup UART1 parameters. */
  usart_set_baudrate (USART1, 38400);
  usart_set_databits (USART1, 8);
  usart_set_stopbits (USART1, USART_STOPBITS_1);
  usart_set_parity (USART1, USART_PARITY_NONE);
  usart_set_flow_control (USART1, USART_FLOWCONTROL_NONE);
  usart_set_mode (USART1, USART_MODE_TX_RX);

  /* Setup UART2 parameters. */
  usart_set_baudrate (USART2, 9600);
  usart_set_databits (USART2, 8);
  usart_set_stopbits (USART2, USART_STOPBITS_1);
  usart_set_parity (USART2, USART_PARITY_NONE);
  usart_set_flow_control (USART2, USART_FLOWCONTROL_NONE);
  usart_set_mode (USART2, USART_MODE_TX_RX);


  /* Enable USART1,2 Receive interrupt. */
  USART_CR1 (USART1) |= USART_CR1_RXNEIE;
  USART_CR1 (USART2) |= USART_CR1_RXNEIE;

  /* Finally enable the USARTs. */
  usart_enable (USART1);
  usart_enable (USART2);
}