#
# $Id$
#
/*#########################################################
#
# 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)
#
##########################################################*/
#include "mc68230.h"
#include "mc68681.h"
#include "ringbuf.h"
#include "rtems.h"
#include "bsp.h"
rtems_isr C_Receive_ISR(rtems_vector_number vector);
extern Ring_buffer_t Buffer[];
extern unsigned char inbuf[];
extern unsigned char inbuf_portb[];
extern unsigned tail;
extern unsigned tail_portb;
unsigned char Pit_initialized = 0;
/*#####################################################################
# The volatile routine to initialize the duart -- port a and port b
######################################################################*/
volatile void init_pit()
{
/* Disable ports A & B while configuring PIT */
MC68681_WRITE(DUART_IMR, 0x00); /* disable imr */
MC68681_WRITE(DUART_CRA, 0x08); /* disable port a transmitter */
MC68681_WRITE(DUART_CRA, 0x02); /* disable port a receiver */
MC68681_WRITE(DUART_CRB, 0x08); /* disable port b transmitter */
MC68681_WRITE(DUART_CRB, 0x02); /* disable port b receiver */
/* install ISR for ports A and B */
set_vector(C_Receive_ISR, (VECT+H3VECT), 1);
/* initialize pit */
MC68230_WRITE(PGCR, 0x00); /* set mode to 0 -- disable all ports */
MC68230_WRITE(PSRR, 0x18); /* set up pirq and piack */
MC68230_WRITE(PBDDR, 0x00); /* all pins on port b are input */
MC68230_WRITE(PBCR, 0x82); /* submode 1x, h3 interrupt enabled */
MC68230_WRITE(PIVR, VECT); /* setup pivr */
MC68230_WRITE(PGCR, 0x20); /* turn on all ports */
/* For some reason, the reset of receiver/transmitter only works for
the first time around -- it garbles the output otherwise (e.g., sp21) */
if (!Pit_initialized)
{
/* now initialize the duart registers on port b */
/* WARNING:OPTIMIZER MAY ONLY EXECUTE THIRD STATEMENT IF NOT VOLATILE */
MC68681_WRITE(DUART_CRB, 0x30); /* reset tx, channel b */
MC68681_WRITE(DUART_CRB, 0x20); /* reset rx, channel b */
MC68681_WRITE(DUART_CRB, 0x10); /* reset mr pointer, channel b */
/* now initialize the duart registers on port a */
/* WARNING:OPTIMIZER MAY ONLY EXECUTE THIRD STATEMENT IF NOT VOLATILE */
MC68681_WRITE(DUART_CRA, 0x30); /* reset tx, channel a */
MC68681_WRITE(DUART_CRA, 0x20); /* reset rx, channel a */
MC68681_WRITE(DUART_CRA, 0x10); /* reset mr pointer, channel a */
Pit_initialized = 1;
}
/* init the general registers of the duart */
MC68681_WRITE(DUART_IVR, 0x0f); /* init ivr */
MC68681_WRITE(DUART_IMR, 0x22); /* init imr */
MC68681_WRITE(DUART_ACR, 0x00); /* init acr */
MC68681_WRITE(DUART_CTUR, 0x00); /* init ctur */
MC68681_WRITE(DUART_CTLR, 0x02); /* init ctlr */
MC68681_WRITE(DUART_OPCR, 0x00); /* init opcr */
MC68681_WRITE(DUART_OPRSET, 0x01); /* init cts */
/* init the actual serial port for port a */
MC68681_WRITE(DUART_CSRA, 0xbb); /* init csra -- 9600 baud */
MC68681_WRITE(DUART_MR1A, 0x13); /* init mr1a */
MC68681_WRITE(DUART_MR2A, 0x07); /* init mr2a */
MC68681_WRITE(DUART_CRA, 0x05); /* init cra */
/* init the actual serial port for port b */
MC68681_WRITE(DUART_CSRB, 0xbb); /* init csrb -- 9600 baud */
#define EIGHT_BITS_NO_PARITY
#ifdef EIGHT_BITS_NO_PARITY
MC68681_WRITE(DUART_MR1B, 0x13); /* init mr1b */
#else /* 7 bits, even parity */
MC68681_WRITE(DUART_MR1B, 0x02); /* init mr1b */
#endif
MC68681_WRITE(DUART_MR2B, 0x07); /* init mr2b -- one stop bit */
MC68681_WRITE(DUART_CRB, 0x05); /* init crb */
}
/*#####################################################################
# interrupt handler for receive of character from duart on ports A & B
#####################################################################*/
rtems_isr C_Receive_ISR(rtems_vector_number vector)
{
volatile unsigned char *_addr;
_addr = (unsigned char *) (PIT_ADDR + PITSR);
*_addr = 0x04; /* clear pit interrupt */
/* Let's check port A first for input */
_addr = (unsigned char *) (DUART_ADDR + DUART_SRA);
if (*_addr & 0x01) /* extract rcvrdy on port A */
{
/* Read input on port A */
_addr = (unsigned char *) (DUART_ADDR + DUART_RBA);
Ring_buffer_Add_character( &Buffer[ 0 ], *_addr );
}
else /* If not on port A, let's check port B */
{
_addr = (unsigned char *) (DUART_ADDR + DUART_SRB);
if (*_addr & 0x01) /* extract rcvrdy on port B */
{
/* Read input on port B */
_addr = (unsigned char *) (DUART_ADDR + DUART_RBB);
Ring_buffer_Add_character( &Buffer[ 1 ], *_addr );
}
/* if not ready on port A or port B, must be an error */
/* if error, get out so that fifo is undisturbed */
}
}
/*#####################################################################
# This is the routine that actually transmits a character one at a time
# This routine transmits on port A of the IDP board
#####################################################################*/
void transmit_char(char ch)
{
volatile unsigned char *_addr;
/* Get SRA (extract txrdy) */
_addr = (unsigned char *) (DUART_ADDR + DUART_SRA);
while (!(*_addr & 0x04))
{
}
/* transmit character over port A */
MC68681_WRITE(DUART_TBA, ch);
}
/*#####################################################################
# This is the routine that actually transmits a character one at a time
# This routine transmits on port B of the IDP board
#####################################################################*/
void transmit_char_portb(char ch)
{
volatile unsigned char *_addr;
/* Get SRB (extract txrdy) */
_addr = (unsigned char *) (DUART_ADDR + DUART_SRB);
while (!(*_addr & 0x04))
{
}
/* transmit character over port B */
MC68681_WRITE(DUART_TBB, ch);
}
