diff options
Diffstat (limited to 'c/src/lib/libbsp/m68k/idp/console/duart.c')
| -rw-r--r-- | c/src/lib/libbsp/m68k/idp/console/duart.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/idp/console/duart.c b/c/src/lib/libbsp/m68k/idp/console/duart.c new file mode 100644 index 0000000000..c3ee92b75b --- /dev/null +++ b/c/src/lib/libbsp/m68k/idp/console/duart.c @@ -0,0 +1,170 @@ +/*######################################################### +# +# 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); +} |