#include "includes.h"
#include "usart.h"

#define BUFF_SIZE   512

/* ?????????????????????????????? volatile????
   ?????????????????? volatile ???? Pa082 ????????? */
#define IS_FULL(head, tail)   ((((head) + 1) % BUFF_SIZE) == (tail))
#define IS_EMPTY(head, tail)  ((head) == (tail))

/* ==================== ???????????? ==================== */

/* ????????????????????????????? */
typedef struct
{
  uint8_t  rx_buff[BUFF_SIZE];
  volatile uint16_t rx_head;
  volatile uint16_t rx_tail;

  uint8_t  tx_buff[BUFF_SIZE];
  volatile uint16_t tx_head;
  volatile uint16_t tx_tail;

  usart_type *usart;      /* ??????????????USART2 / UART4?? */
} uart_ring_t;

/* USART2 ?? UART4 ???????? */
static uart_ring_t uart2;
static uart_ring_t uart4;

/* ?????????????????????? wk_usart2_init / wk_uart4_init ????? */
void uart_ring_usart2_init(void)
{
  uart2.usart = USART2;
}

void uart_ring_uart4_init(void)
{
  uart4.usart = UART4;
}

/* ==================== ??????/???????????????? ==================== */

/* ????ISR ???????????? volatile ???????????? Pa082 */
static void ring_rx_push(uart_ring_t *rb, uint8_t c)
{
  uint16_t h = rb->rx_head;
  uint16_t t = rb->rx_tail;
  if(IS_FULL(h, t)) return;      /* ???????????????????? */
  rb->rx_buff[h] = c;
  rb->rx_head = (h + 1) % BUFF_SIZE;
}

/* ??????????????? */
static uint8_t ring_rx_pop(uart_ring_t *rb, uint8_t *c)
{
  uint16_t h = rb->rx_head;
  uint16_t t = rb->rx_tail;
  if(IS_EMPTY(h, t)) return 0;
  *c = rb->rx_buff[t];
  rb->rx_tail = (t + 1) % BUFF_SIZE;
  return 1;
}

/* ???? tx ??????????????????????? ISR ?????? */
static void ring_tx_write(uart_ring_t *rb, uint8_t *data, uint16_t len)
{
  uint16_t h = rb->tx_head;
  uint16_t t = rb->tx_tail;
  for(uint16_t i = 0; i < len; i++)
  {
    if(IS_FULL(h, t)) break;     /* ?? tx ???? */
    rb->tx_buff[h] = data[i];
    h = (h + 1) % BUFF_SIZE;
  }
  rb->tx_head = h;               /* ???????????? volatile */
}

/* ==================== ?????????????????? ==================== */

/* ?????????????? ?? ?????? ?? ?? TDBE ??????????? */
static void uart_ring_send(uart_ring_t *rb, uint8_t *data, uint16_t len)
{
  rt_base_t level = rt_hw_interrupt_disable();

  ring_tx_write(rb, data, len);
  usart_interrupt_enable(rb->usart, USART_TDBE_INT, TRUE);   /* ?????????? */

  rt_hw_interrupt_enable(level);
}

/* USART2 ?????????midi_send.c ??????? */
void USART2_SendData(uint8_t *data, uint16_t len)
{
  uart_ring_send(&uart2, data, len);
}

/* UART4 ????????? */
void USART4_SendData(uint8_t *data, uint16_t len)
{
  uart_ring_send(&uart4, data, len);
}

void USART4_WaitTxIdle(uint32_t timeout_ms)
{
  uint32_t t0 = rt_tick_get();
  while ((rt_tick_get() - t0) < rt_tick_from_millisecond(timeout_ms ? timeout_ms : 1))
  {
    uint16_t h = uart4.tx_head;
    uint16_t t = uart4.tx_tail;
    if (IS_EMPTY(h, t))
    {
      /* ����պ��ٵ���λ�Ĵ������� */
      if (usart_flag_get(uart4.usart, USART_TDC_FLAG) == SET)
        return;
    }
    rt_thread_mdelay(1);
  }
}

/* USART2 ???????????? */
uint8_t USART2_RxPop(uint8_t *c)
{
  return ring_rx_pop(&uart2, c);
}

/* UART4 ???????????? */
uint8_t UART4_RxPop(uint8_t *c)
{
  return ring_rx_pop(&uart4, c);
}

/* ==================== ???????? ==================== */

static void uart_ring_isr(uart_ring_t *rb)
{
  if(usart_flag_get(rb->usart, USART_RDBF_FLAG) == SET)
  {
    uint8_t data = usart_data_receive(rb->usart);
    ring_rx_push(rb, data);
    if(rb->usart == UART4)
    {
      rt_sem_release(UART4_sem);
    }
  }

  if(usart_flag_get(rb->usart, USART_TDBE_FLAG) == SET)
  {
    uint16_t h = rb->tx_head;
    uint16_t t = rb->tx_tail;
    if(!IS_EMPTY(h, t))
    {
      usart_data_transmit(rb->usart, rb->tx_buff[t]);
      rb->tx_tail = (t + 1) % BUFF_SIZE;
    }
    else
    {
      usart_interrupt_enable(rb->usart, USART_TDBE_INT, FALSE);
    }
  }

  if(usart_flag_get(rb->usart, USART_ROERR_FLAG) == SET)
    usart_flag_clear(rb->usart, USART_ROERR_FLAG);
}

void USART2_IRQHandler(void)
{
  rt_interrupt_enter();
  uart_ring_isr(&uart2);
  rt_interrupt_leave();
}

void UART4_IRQHandler(void)
{
  rt_interrupt_enter();
  uart_ring_isr(&uart4);
  rt_interrupt_leave();
}