#include <stdio.h>

#include "f38x_uart1.h"
#include "fifo.h"

#define DEFAULT_BAUDRATE  9600UL          // Baud rate of UART in bps

#ifdef USE_ASM_FOR_SFR_MANIP
#define CRITICAL_UART1(func) \
{\
  {__asm anl _EIE2,SHARP ~0x02 __endasm; } \
  func;\
  {__asm orl _EIE2,SHARP 0x02 __endasm; } \
}
#else
#define CRITICAL_UART1(func) \
{\
  EIE2 &= ~0x02;\
  func;\
  EIE2 |= 0x02;\
}
#endif

__xdata fifo_char_t fifo_tx1; ///< FIFO TX
__xdata fifo_char_t fifo_rx1; ///< FIFO RX
static __xdata __at (0x100) 
  char buffer_tx1[UART1_TX_BUFFER_SIZE];
static __xdata __at (0x100 + UART1_TX_BUFFER_SIZE) 
  char buffer_rx1[UART1_RX_BUFFER_SIZE];

/**
 * Change UART1 baudrate
 * 
 */
void uart1_bauding_config(u16 baudrate_register){
  SBCON1 = 0x03; // SB1PS[1:0] = 11;
  
  SBRLH1 = (u8)((baudrate_register >> 8) & 0xFF);
  SBRLL1 = (u8)(baudrate_register & 0xFF);
  
  SBCON1 |= 0x40; // SB1RUN = 1;
}


/**
 * uart1_init
 * 
 */
void uart1_init() {
  // SCON1: RX enabled
  // ninth bits are zeros
  // clear RI1 and TI1 bits
  SCON1 = 0x10;
  
  // 8-bit, no parity, 1 stop bit
  //SMOD1 = 0x0C; // default
          
  fifo_char_init(&fifo_tx1, buffer_tx1, UART1_TX_BUFFER_SIZE); 
  fifo_char_init(&fifo_rx1, buffer_rx1, UART1_RX_BUFFER_SIZE); 

  uart1_bauding(DEFAULT_BAUDRATE);

  SCON1 &= ~0x08;   // TBX1は書込み中フラグは0(書込みしていない)
  EIE2 |= 0x02;     // 割り込み有効
  //EIP2 = 0x02;      // 優先度1
}

/**
 * Register trasmitting data via UART1
 * 
 * @param data pointer to data
 * @param size size of data
 * @return (FIFO_SIZE_T) the size of registered data to buffer
 */
FIFO_SIZE_T uart1_write(char *buf, FIFO_SIZE_T size){
  // TB80は書込み中フラグとして使う
  // 0(書込みしていない)だったら手動割り込みをかける
  if(size){
    size = fifo_char_write(&fifo_tx1, buf, size);
    CRITICAL_UART1(
      if(!(SCON1 & 0x0A)){ // !TBX1 && !TI1
        SCON1 |= 0x02; // 手動で割込みをかける
      }
    );
  }
  return size;
}

/**
 * Return the size of storable data which will be transfered via UART1
 * 
 * @return (FIFO_SIZE_T) the size
 */
FIFO_SIZE_T uart1_tx_margin(){
  return fifo_char_margin(&fifo_tx1);
}

/**
 * Get the received data via UART1
 * 
 * @param buf buffer
 * @param size the size of buffer
 * @return (FIFO_SIZE_T) the real size of grabbed data
 */
FIFO_SIZE_T uart1_read(char *buf, FIFO_SIZE_T size){
  return fifo_char_read(&fifo_rx1, buf, size);
}

/**
 * Return the size of unread data which is received via UART1
 * 
 * @return (FIFO_SIZE_T) the size
 */
FIFO_SIZE_T uart1_rx_size(){
  return fifo_char_size(&fifo_rx1);
}

///< Interrupt(TI1 / RI1)
void interrupt_uart1 (void) __interrupt (INTERRUPT_UART1) {
  unsigned char res;

  if(SCON1 & 0x01){   // RI1
    SCON1 &= ~0x01;
    /* リングバッファに1バイト書き出し */
    FIFO_DIRECT_PUT(fifo_rx1, SBUF1, res);
    if(res == 0){
      // TODO: buffer overflow
    }
  }

  if(SCON1 & 0x02){   // TI1
    SCON1 &= ~0x02;
    /* 書き込むデータがあるか確認 */
    FIFO_DIRECT_GET(fifo_tx1, SBUF1, res);
    if(res > 0){
      SCON1 |= 0x08;   // TBX1は書込み中フラグとして使う、1(書込み中)に
    }else{
      SCON1 &= ~0x08;  // TBX1は書込み中フラグとして使う、0(書込みしていない)に
    }
  }
}