// ******************** uart.c ***************************************
//                 Risc-Dsp runtime library
//
// Debug console input/output for MIPS microcontrollers.
// Send a byte to the UART transmitter, with interrupts disabled.
//
// (c) multicore.ru
//
// *******************************************************************
#include "mcom02.h"
#include "uart.h"

unsigned get_l3comm_freq(void)
{
       return (((SET_SPLL&0xff) + 1)*XTI_FREQ >> (DIV_SYS0_CTR&0x1)) >> (DIV_SYS1_CTR&0x1);
}

//
// @name: uart_getchar
// @description: determine uart base offset by id
unsigned long
uart_base(unsigned int idUart)
{
        unsigned long ulBase = 0;

	switch ( idUart )
	{
	case 0:
		ulBase = UART0_BASE;
		break;
	case 1:
		ulBase = UART1_BASE;
		break;
	case 2:
		ulBase = UART2_BASE;
		break;
	case 3:
		ulBase = UART3_BASE;
		break;
	}

        return  ulBase;
}


//
// @name: uart_config
// @description: Setup uart port to transfer at given speed and frequency
//
// @in unsigned int khz   - frequency
// @in unsigned long baud - data transfer speed
//
void uart_config(unsigned int idUart, unsigned long baud)
{
    unsigned long baudRatio =       0;
    unsigned long ulBase = uart_base(idUart);

    baudRatio  = get_l3comm_freq();
    baudRatio  /= 16;
    baudRatio  /= baud;

	/* Disable and program some of the baudrate */
	*UART_IIR(ulBase) = 0;
	*UART_IER(ulBase) = 0;

	*UART_LCR(ulBase) = UART_LCR_DLAB;
	*UART_DLL(ulBase) = baudRatio & 0xff;
    *UART_DLH(ulBase) = baudRatio >> 8;
	/* Program the Mode */
	*UART_LCR(ulBase) = 3;  //  8 bits, No parity, 1 stop bit.
	*UART_MSR(ulBase) = 3;

	/* Enable the Device. */
//	*UART_FCR(ulBase) = UART_FCR_FEWO;
	*UART_FCR(ulBase) = 7;
}

//
// @name: uart_putchar
// @description: Send symbol
//
// @in short c   -
//
void uart_putchar (unsigned int idUart, short c)
{
        unsigned long ulBase = uart_base(idUart);

	if ( 0 != ulBase )
	{
		while ( ( *UART_LSR(ulBase) & UART_LSR_THRE ) == 0 );
		*UART_THR(ulBase) = c;
	}
}

//
// @name: uart_getchar
// @description: Wait for the byte to be received and return it.
// @return: unsigned short - received symbol
//
unsigned short uart_getchar (unsigned int idUart)
{
    unsigned short c = 0;
    unsigned long ulBase = uart_base(idUart);

	if ( 0 != ulBase )
	{
		while ( ( *UART_LSR(ulBase) & UART_LSR_RDR ) == 0 )
                        /*  wait  */;

                c = ((unsigned short) *UART_RBR(ulBase));
        }
        return c;
}

//
// Function: vt_puts
//  put string to uart port
// 
// Parameters: 
//      const char* str - string 
//
int uart_puts(unsigned int uart_id, const char* str){
    do{
        uart_putchar(uart_id, *str);
    } while(*str++);
    return 0;
}