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/*
* duart.c
*
* This code is a modified version of what you will find at the
* end of the IDP User's manual. The original code is copyrighted
* by Motorola and Motorola Semiconductor Products as well as
* Motorola Software products group.
*
* Modifications to the original IDP code by Doug McBride, Colorado
* Space Grant College. Modifications include a means of accessing
* port B of the duart as well as port A as well as modifications for
* buffering and RTEMS support. Modifications are provided
* as is and may not be correct.
*
* Rob Savoye provided the format for the mc68681 header file
*
* Joel Sherrill provided inspiration for recoding my original assembly
* for this file into C (a good idea)
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
* Copyright assigned to U.S. Government, 1994.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id: duart.c
*/
#define MC68681_OFFSET_MULTIPLIER 8
#include <motorola/mc68681.h>
#include <bsp.h>
#include <ringbuf.h>
rtems_isr console_isr (rtems_vector_number vector);
Ring_buffer_t TX_Buffer[2];
Ring_buffer_t RX_Buffer[2];
/*PAGE
*
* init_mc88681
*
* volatile routine to initialize duart
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* Return Values: NONE
*/
volatile void init_mc88681()
{
/*
* Initialize Ring buffers
*/
Ring_buffer_Initialize( &RX_Buffer[ 0 ] );
Ring_buffer_Initialize( &RX_Buffer[ 1 ] );
Ring_buffer_Initialize( &TX_Buffer[ 0 ] );
Ring_buffer_Initialize( &TX_Buffer[ 1 ] );
}
/*PAGE
*
* console_isr
*
* interrupt handler for receive of character from duart on ports A & B
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* Return Values: NONE
*/
rtems_isr console_isr (rtems_vector_number vector)
{
/*
* Fill me in later ...
*/
}
/*PAGE
*
* console_outbyte_polled
*
* This routine transmits a character out.
*
* Input parameters:
* port - port to transmit character to
* ch - character to be transmitted
*
* Output parameters: NONE
*
* Return values: NONE
*/
void console_outbyte_polled(
int port,
char ch
)
{
unsigned char status;
unsigned char data;
unsigned char t = 0;
if (port == MC68681_PORT_A) {
status = MC68681_STATUS_REG_A;
data = MC68681_TRANSMIT_BUFFER_A;
} else {
status = MC68681_STATUS_REG_B;
data = MC68681_TRANSMIT_BUFFER_B;
}
while ( !(MC68681_READ(DUART_ADDR, status) & MC68681_TX_READY) ){
if (t == 0) {
Debug_Entry( 0x8000 );
t++;
}
}
Debug_Entry( 0x9000 );
MC68681_WRITE(DUART_ADDR, data, ch);
}
/*PAGE
*
* console_inbyte_nonblocking
*
* This routine reads a character from the UART.
*
* Input parameters:
* port - port to read character from
*
* Output parameters: NONE
*
* Return values:
* character read from UART
*/
#define MC68681_RECEIVE_ERRORS \
(MC68681_OVERRUN_ERROR | MC68681_PARITY_ERROR | MC68681_FRAMING_ERROR)
int console_inbyte_nonblocking( int port )
{
char status;
char data;
char cmd;
unsigned char status_info;
/*
* Set Port A or B unique variables.
*/
if (port == MC68681_PORT_A) {
status = MC68681_STATUS_REG_A;
data = MC68681_RECEIVE_BUFFER_A;
cmd = MC68681_COMMAND_REG_A;
} else {
status = MC68681_STATUS_REG_B;
data = MC68681_RECEIVE_BUFFER_B;
cmd = MC68681_COMMAND_REG_B;
}
/* Wait for the Ready bit and Clear any errors */
for ( ; ; ) {
status_info = MC68681_READ(DUART_ADDR, status);
if ( status_info & MC68681_RX_READY )
break;
if ( status_info & MC68681_RECEIVE_ERRORS )
MC68681_WRITE( DUART_ADDR, cmd, MC68681_MODE_REG_RESET_ERROR );
}
return MC68681_READ(DUART_ADDR, data);
}
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