//-----------------------------------------------------------------------------
// F34x_MSD_UART0.c
//-----------------------------------------------------------------------------
// Copyright 2006 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// File contains initialization functions for UART interface.
//
//
//
// How To Test:    See Readme.txt
//
//
// FID:            34X000057
// Target:         C8051F34x
// Tool chain:     Keil
// Command Line:   See Readme.txt
// Project Name:   F34x_USB_MSD
//
// Release 1.1
//    -All changes by PKC
//    -09 JUN 2006
//    -Replaced SFR definitions file "c8051f320.h" with "c8051f340.h"
//
// Release 1.0
//    -Initial Release
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------

#include <stdio.h>

#include "main.h"
#include "f34x_uart0.h"
#include "fifo.h"

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

#define CRITICAL_UART0(func) \
{\
  ES0 = 0;\
  func;\
  ES0 = 1;\
}


/**
 * FIFO
 */
xdata fifo_char_t fifo_tx0;
xdata fifo_char_t fifo_rx0;
static __xdata __at (0x100) 
  char buffer_tx0[UART0_TX_BUFFER_SIZE];
static __xdata __at (0x100 + UART0_TX_BUFFER_SIZE) 
  char buffer_rx0[UART0_RX_BUFFER_SIZE];

void uart0_bauding(unsigned long baudrate){
  unsigned long selector1 = SYSCLK/baudrate/2;
  unsigned long selector2 = selector1 / 256;
  
  TR1 = 0;
  
  if (selector2 < 1){
    TH1 = 0x0ff & (-selector1);
    CKCON |=  0x08;                  // T1M = 1; SCA1:0 = xx
  }else if (selector2 < 4){
    TH1 = 0x0ff & (-(selector1/4));
    CKCON &= ~0x0B;                  
    CKCON |=  0x01;                  // T1M = 0; SCA1:0 = 01
  }else if (selector2 < 12){
    TH1 = 0x0ff & (-(selector1/12));
    CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 00
  }else{
    TH1 = 0x0ff & (-(selector1/48));
    CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 10
    CKCON |=  0x02;
  }
  
  TL1 = TH1;        // init Timer1
  TMOD &= ~0xf0;    // TMOD: timer 1 in 8-bit autoreload
  TMOD |=  0x20;
  TR1 = 1;
}


//----------------------------------------------------------------------------
// uart0_init
//----------------------------------------------------------------------------
//
// This function initializes UART 0 interface.
//
// Parameters   :
// Return Value :
//----------------------------------------------------------------------------
void uart0_init(void) {
  SCON0 = 0x10;     // SCON0: 8-bit variable bit rate
                    //        level of STOP bit is ignored
                    //        RX enabled
                    //        ninth bits are zeros
                    //        clear RI0 and TI0 bits
  fifo_char_init(&fifo_tx0, buffer_tx0, UART0_TX_BUFFER_SIZE); 
  fifo_char_init(&fifo_rx0, buffer_rx0, UART0_RX_BUFFER_SIZE); 

  uart0_bauding(DEFAULT_BAUDRATE);

  TB80 = 0;         // TB80は書込み中フラグは0(書込みしていない)
  ES0 = 1;          // 割り込み有効
  //PS0 = 1;          // 優先度1
}

/**
 * key_available
 * 
 * @return TRUE if RI0 flag is set and FALSE if not.
 */
unsigned char key_available() {
  return (uart0_rx_size() > 0);
}

/**
 * Regist sending data via UART0
 * 
 * @param data pointer to data
 * @param size size of data
 * @return (FIFO_SIZE_T) the size of registed data to buffer
 */
FIFO_SIZE_T uart0_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_tx0, buf, size);
    CRITICAL_UART0(
      if(!(SCON0 & 0x0A)){ // !TB80 && !TI0
        TI0 = 1;
        //interrupt_uart0(); // 手動で割込みをかける
      }
    );
  }
  return size;
}

/**
 * Return the size of untransimitted data via UART0
 * 
 * @return (FIFO_SIZE_T) the size
 */
FIFO_SIZE_T uart0_tx_size(){
  return fifo_char_size(&fifo_tx0);
}

/**
 * Return the size of empty
 * 
 * @return (FIFO_SIZE_T) the size
 */
FIFO_SIZE_T uart0_tx_margin(){
  return fifo_char_margin(&fifo_tx0);
}

/**
 * Get the recieved data via UART0
 * 
 * @param buf buffer
 * @param size the size of buffer
 * @return (FIFO_SIZE_T) the real size of grabbed data
 */
FIFO_SIZE_T uart0_read(char *buf, FIFO_SIZE_T size){
  return fifo_char_read(&fifo_rx0, buf, size);
}

/**
 * Return the size of ungrabbed data via UART0
 * 
 * @return (FIFO_SIZE_T) the size
 */
FIFO_SIZE_T uart0_rx_size(){
  return fifo_char_size(&fifo_rx0);
}

/**
 * Return the size of empty
 * 
 * @return (FIFO_SIZE_T) the size
 */
FIFO_SIZE_T uart0_rx_margin(){
  return fifo_char_margin(&fifo_rx0);
}

/**
 * stdio.h support
 * 
 */

/**
 * putchar - No blocking
 */
void putchar (char c){
  while(uart0_write(&c, 1) == 0);
}

/**
 * getchar - blocking
 */
char getchar (void){
  char c;
  while(uart0_read(&c, sizeof(c)) == 0);
  return c;
}