/*
* $Id$
*/
/*#########################################################
#
# 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 <bsp.h>
#include <rtems/ringbuf.h>
rtems_isr C_Receive_ISR(rtems_vector_number vector);
extern Ring_buffer_t Console_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()
{
/*
* ports A & B while configuring PIT by:
*
* + disable Interrupt Mask Register
* + disable port A transmitter
* + disable port A receiver
* + disable port B transmitter
* + disable port B receiver
*/
MC68681_WRITE(DUART_ADDR, MC68681_INTERRUPT_MASK_REG, 0x00);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_A ,MC68681_MODE_REG_DISABLE_TX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_A, MC68681_MODE_REG_DISABLE_RX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_B, MC68681_MODE_REG_DISABLE_TX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_B, MC68681_MODE_REG_DISABLE_RX);
/*
* install ISR for ports A and B
*/
set_vector(C_Receive_ISR, (VECT+H3VECT), 1);
/*
* initialize pit
*
* set mode to 0 -- disable all ports
* set up pirq and piack
* all pins on port b are input
* submode 1x, h3 interrupt enabled
* setup pivr
* turn on all ports
*/
MC68230_WRITE(PGCR, 0x00);
MC68230_WRITE(PSRR, 0x18);
MC68230_WRITE(PBDDR, 0x00);
MC68230_WRITE(PBCR, 0x82);
MC68230_WRITE(PIVR, VECT);
MC68230_WRITE(PGCR, 0x20);
/*
* 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)
{
/*
* initialize the duart registers on port b
* WARNING:OPTIMIZER MAY ONLY EXECUTE THIRD STATEMENT IF NOT VOLATILE
*
* reset tx, channel b
* reset rx, channel b
* reset mr pointer, ch
*/
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_B, MC68681_MODE_REG_RESET_TX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_B, MC68681_MODE_REG_RESET_RX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_B, MC68681_MODE_REG_RESET_MR_PTR);
/*
* initialize the duart registers on port a
* WARNING:OPTIMIZER MAY ONLY EXECUTE THIRD STATEMENT IF NOT VOLATILE
*
* reset tx, channel a
* reset rx, channel a
* reset mr pointer, ch
*/
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_A, MC68681_MODE_REG_RESET_TX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_A, MC68681_MODE_REG_RESET_RX);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_A, MC68681_MODE_REG_RESET_MR_PTR);
Pit_initialized = 1;
}
/*
* Init the general registers of the duart
*
* init ivr
* init imr
* init acr
* init ctur
* init ctlr
* init opcr
* init cts
*/
MC68681_WRITE(DUART_ADDR, MC68681_INTERRUPT_VECTOR_REG,
MC68681_INTERRUPT_VECTOR_INIT);
MC68681_WRITE(DUART_ADDR, MC68681_INTERRUPT_MASK_REG,
MC68681_IR_RX_READY_A | MC68681_IR_RX_READY_B);
MC68681_WRITE(DUART_ADDR, MC68681_AUX_CTRL_REG, MC68681_CLEAR);
MC68681_WRITE(DUART_ADDR, MC68681_COUNTER_TIMER_UPPER_REG, 0x00);
MC68681_WRITE(DUART_ADDR, MC68681_COUNTER_TIMER_LOWER_REG, 0x02);
MC68681_WRITE(DUART_ADDR, MC68681_OUTPUT_PORT_CONFIG_REG, MC68681_CLEAR);
MC68681_WRITE(DUART_ADDR, MC68681_OUTPUT_PORT_SET_REG, 0x01);
/*
* init the actual serial port for port a
*
* Set Baud Rate to 9600
* Set Stop bit length of 1
* enable Transmit and receive
*/
MC68681_WRITE(DUART_ADDR, MC68681_CLOCK_SELECT_REG_A, MC68681_BAUD_RATE_MASK_9600);
MC68681_WRITE(DUART_ADDR, MC68681_MODE_REG_1A,
(MC68681_8BIT_CHARS | MC68681_NO_PARITY));
MC68681_WRITE(DUART_ADDR, MC68681_MODE_REG_2A,MC68681_STOP_BIT_LENGTH_1);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_A,
(MC68681_MODE_REG_ENABLE_TX | MC68681_MODE_REG_ENABLE_RX));
/*
* init the actual serial port for port b
* init csrb -- 9600 baud
*/
MC68681_WRITE(DUART_ADDR, MC68681_CLOCK_SELECT_REG_B, MC68681_BAUD_RATE_MASK_9600);
#define EIGHT_BITS_NO_PARITY
#ifdef EIGHT_BITS_NO_PARITY
/*
* Set 8 Bit characters with no parity
*/
MC68681_WRITE(DUART_ADDR, MC68681_MODE_REG_1B,
(MC68681_NO_PARITY | MC68681_8BIT_CHARS) );
#else
/*
* Set 7 Bit Characters with parity
*/
MC68681_WRITE(DUART_ADDR, MC68681_MODE_REG_1B,
(MC68681_WITH_PARITY | MC68681_7BIT_CHARS) );
#endif
/*
* Set Stop Bit length to 1
* Disable Recieve and transmit on B
*/
MC68681_WRITE(DUART_ADDR, MC68681_MODE_REG_2B,MC68681_STOP_BIT_LENGTH_1);
MC68681_WRITE(DUART_ADDR, MC68681_COMMAND_REG_B,
(MC68681_MODE_REG_ENABLE_TX | MC68681_MODE_REG_ENABLE_RX) );
}
/*#####################################################################
# 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;
/*
* Clear pit interrupt.
*/
_addr = (unsigned char *) (PIT_ADDR + PITSR);
*_addr = 0x04;
/*
* check port A first for input
* extract rcvrdy on port B
* set ptr to recieve buffer and read character into ring buffer
*/
_addr = (unsigned char *) (DUART_ADDR + MC68681_STATUS_REG_A);
if (*_addr & MC68681_RX_READY) /* extract rcvrdy on port A */
{
_addr = (unsigned char *) (DUART_ADDR + MC68681_RECEIVE_BUFFER_A);
Ring_buffer_Add_character( &Console_Buffer[ 0 ], *_addr );
}
/*
* If not on port A, let's check port B
* extract rcvrdy on port B
* set ptr to recieve buffer and read character into ring buffer
*/
else
{
_addr = (unsigned char *) (DUART_ADDR + MC68681_STATUS_REG_B);
if (*_addr & MC68681_RX_READY) /* extract rcvrdy on port B */
{
_addr = (unsigned char *) (DUART_ADDR + MC68681_RECEIVE_BUFFER_B);
Ring_buffer_Add_character( &Console_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 + MC68681_STATUS_REG_A);
while (!(*_addr & MC68681_TX_READY))
{
}
/*
* transmit character over port A
*/
MC68681_WRITE(DUART_ADDR, MC68681_TRANSMIT_BUFFER_A, 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 + MC68681_STATUS_REG_B);
while (!(*_addr & MC68681_TX_READY))
{
}
/*
* transmit character over port B
*/
MC68681_WRITE(DUART_ADDR, MC68681_TRANSMIT_BUFFER_B, ch);
}
