diff options
Diffstat (limited to 'trs_uart.c')
| -rw-r--r-- | trs_uart.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/trs_uart.c b/trs_uart.c new file mode 100644 index 0000000..c8ac193 --- /dev/null +++ b/trs_uart.c @@ -0,0 +1,421 @@ +/* Copyright (c) 2000, Timothy Mann */ + +/* This software may be copied, modified, and used for any purpose + * without fee, provided that (1) the above copyright notice is + * retained, and (2) modified versions are clearly marked as having + * been modified, with the modifier's name and the date included. */ + +/* Last modified on Thu May 18 00:42:46 PDT 2000 by mann */ + +/* + * Emulation of the Radio Shack TRS-80 Model I/III/4/4P serial port. + */ + +#include <errno.h> +#include <termios.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/file.h> +#include <fcntl.h> +#include <string.h> +#include <signal.h> +#include "trs.h" +#include "trs_uart.h" + +#ifndef FNONBLOCK +#define FNONBLOCK O_NONBLOCK +#endif + +#define BUFSIZE 256 +/*#define UARTDEBUG 1*/ +/*#define UARTDEBUG2 1*/ + +#if __linux +char *trs_uart_name = "/dev/ttyS0"; +#else +char *trs_uart_name = "/dev/tty00"; +#endif +int trs_uart_switches = + 0x7 | TRS_UART_NOPAR | TRS_UART_WORD8; /* Default: 9600 8N1 */ + +static int initialized = 0; + +static struct { + int modem; + int switches; + int baud; + int status; + int control; + int idata; + int odata; + + Uchar buf[BUFSIZE]; + Uchar* bufp; + int bufleft; + int tstates; + + int fd; + int fdflags; + struct termios t; +} uart; + +static int trs_uart_wordbits[] = TRS_UART_WORDBITS_TABLE; +static float trs_uart_baud[] = TRS_UART_BAUD_TABLE; + +static int +xlate_baud(int trs_baud) +{ + switch (trs_baud) { + case TRS_UART_50: + return B50; + case TRS_UART_75: + return B75; + case TRS_UART_110: + return B110; + case TRS_UART_134: + return B134; + case TRS_UART_150: + return B150; + case TRS_UART_300: + return B300; + case TRS_UART_600: + return B600; + case TRS_UART_1200: + return B1200; + case TRS_UART_1800: + return B1800; + case TRS_UART_2000: + error("unix does not support 2000 baud, using 38400"); + return B38400; + case TRS_UART_2400: + return B2400; + case TRS_UART_3600: +#ifdef B57600 + error("unix does not support 3600 baud, using 57600"); + return B57600; +#else + error("unix does not support 3600 baud"); + return B0; +#endif + case TRS_UART_4800: + return B4800; + case TRS_UART_7200: +#ifdef B115200 + error("unix does not support 7200 baud, using 115200"); + return B115200; +#else + error("unix does not support 7200 baud"); + return B0; +#endif + case TRS_UART_9600: + return B9600; + case TRS_UART_19200: + return B19200; + } + return B0; /* not reached */ +} + +void +trs_uart_init(int reset_button) +{ + int err; +#if UARTDEBUG + debug("trs_uart_init\n"); +#endif + if (initialized == 1 && uart.fd != -1) close(uart.fd); + if (trs_uart_name == NULL || trs_uart_name[0] == '\000') { + /* Emulate having no serial port */ + initialized = -1; + return; + } + initialized = 1; + uart.fd = open(trs_uart_name, O_RDWR|O_NOCTTY|O_NONBLOCK); + if (uart.fd == -1) { + error("can't open %s: %s", trs_uart_name, strerror(errno)); + } else { + uart.fdflags = FNONBLOCK; +#if HAVE_SIGIO + if (trs_model > 1) { + uart.fdflags |= FASYNC; + fcntl(uart.fd, F_SETOWN, getpid()); /* is this needed? */ + fcntl(uart.fd, F_SETFL, uart.fdflags); + } +#endif + err = tcgetattr(uart.fd, &uart.t); + if (err < 0) { + error("can't get attributes of %s: %s", trs_uart_name, strerror(errno)); + } + } + + uart.t.c_iflag = 0; + uart.t.c_oflag = 0; + uart.t.c_lflag = 0; + memset(uart.t.c_cc, 0, sizeof(uart.t.c_cc)); + + /* Not readable from a user process on unix */ + uart.modem = TRS_UART_CTS | TRS_UART_DSR | TRS_UART_CD; + + uart.switches = (trs_model == 1) ? trs_uart_switches : 0xff; + + /* arbitrary default */ + uart.baud = -1; + trs_uart_baud_out((TRS_UART_9600 << 4) + TRS_UART_9600); + + /* arbitrary default */ + uart.control = -1; + trs_uart_control_out(TRS_UART_NOPAR | TRS_UART_WORD8 | TRS_UART_NOTBREAK | + TRS_UART_DTR | TRS_UART_RTS); + + uart.status = TRS_UART_SENT; + trs_uart_snd_interrupt(1); + + uart.bufp = uart.buf; + uart.bufleft = 0; +} + +int +trs_uart_modem_in() +{ + /* should poll hardware here, if we could */ + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return 0xff; +#if UARTDEBUG2 + debug("trs_uart_modem_in returns 0x%02x\n", uart.modem); +#endif + return uart.modem; +} + +void +trs_uart_reset_out(int value) +{ +#if UARTDEBUG + debug("trs_uart_reset_out\n"); +#endif + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) { + error("serial port emulation is not enabled"); + return; + } +} + +int +trs_uart_switches_in() +{ + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return 0xff; +#if UARTDEBUG + debug("trs_uart_switches_in returns 0x%02x\n", uart.switches); +#endif + return uart.switches; +} + +void +trs_uart_baud_out(int value) +{ + int err; + int bits; +#if UARTDEBUG + debug("trs_uart_baud_out 0x%02x\n", value); +#endif + + if (initialized == 1 && uart.baud == value) return; + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return; + uart.baud = value; + + cfsetispeed(&uart.t, xlate_baud(TRS_UART_RCVBAUD(value))); + cfsetospeed(&uart.t, xlate_baud(TRS_UART_SNDBAUD(value))); + + bits = 1 + trs_uart_wordbits[TRS_UART_WORDBITS(uart.control)] + + ((uart.control & TRS_UART_NOPAR) ? 0 : 1) + + ((uart.control & TRS_UART_STOP2) ? 2 : 1); + uart.tstates = (z80_state.clockMHz * 1000000.0 * bits) + / trs_uart_baud[TRS_UART_SNDBAUD(value)]; +#if UARTDEBUG + debug("total bits %d; tstates per word %d\n", bits, uart.tstates); +#endif + + if (uart.fd != -1) { + err = tcsetattr(uart.fd, TCSADRAIN, &uart.t); + if (err == -1) { + error("can't set attributes of %s: %s", trs_uart_name, strerror(errno)); + } + } +} + +void +trs_uart_set_avail(int dummy) +{ + uart.status |= TRS_UART_RCVD; + trs_uart_rcv_interrupt(1); +} + +void +trs_uart_set_empty(int dummy) +{ + uart.status |= TRS_UART_SENT; + trs_uart_snd_interrupt(1); +} + +int +trs_uart_check_avail() +{ + if (initialized == 1 && uart.bufleft == 0 && uart.fd != -1) { + /* check for data available */ + int rc; + if (!(uart.fdflags & FNONBLOCK)) { +#if UARTDEBUG + debug("trs_uart nonblocking\n"); +#endif + uart.fdflags |= FNONBLOCK; + fcntl(uart.fd, F_SETFL, uart.fdflags); + } + do { + rc = read(uart.fd, uart.buf, BUFSIZE); + } while (rc < 0 && errno == EINTR); +#if UARTDEBUG +#if !UARTDEBUG2 + if (rc >= 0 || errno != EAGAIN) +#endif + debug("trs_uart read returns %d, errno %d\n", rc, errno); +#endif + if (rc < 0) { + if (errno != EAGAIN) { + error("can't read from %s: %s", trs_uart_name, strerror(errno)); + } + rc = 0; + } + uart.bufp = uart.buf; + uart.bufleft = rc; + if (rc > 0) { + /* be sure events don't happen too fast */ + trs_schedule_event(trs_uart_set_avail, 1, uart.tstates); + } + } +#if UARTDEBUG2 + debug("trs_uart_check_avail returns %d\n", uart.bufleft); +#endif + return uart.bufleft; +} + +int +trs_uart_status_in() +{ +#if UARTDEBUG + static int oldstatus = -1; +#endif + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return 0xff; + trs_uart_check_avail(); +#if UARTDEBUG + if (uart.status != oldstatus) { + debug("trs_uart_status_in returns 0x%02x\n", uart.status); + oldstatus = uart.status; + } +#endif + return uart.status; +} + +void +trs_uart_control_out(int value) +{ + int err; + int cflag = HUPCL|CREAD|CLOCAL; +#if UARTDEBUG + debug("trs_uart_control_out 0x%02x\n", value); +#endif + if (initialized == 1 && uart.control == value) return; + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return; + uart.control = value; + if (!(value & TRS_UART_EVENPAR)) cflag |= PARODD; + switch (value & TRS_UART_WORDMASK) { + case TRS_UART_WORD5: + cflag |= CS5; + break; + case TRS_UART_WORD6: + cflag |= CS6; + break; + case TRS_UART_WORD7: + cflag |= CS7; + break; + case TRS_UART_WORD8: + cflag |= CS8; + break; + } + if (value & TRS_UART_STOP2) cflag |= CSTOPB; + if (!(value & TRS_UART_NOPAR)) cflag |= PARENB; + uart.t.c_cflag = cflag; + if (uart.fd != -1) { + err = tcsetattr(uart.fd, TCSADRAIN, &uart.t); + if (err == -1) { + error("can't set attributes of %s: %s", trs_uart_name, strerror(errno)); + } + } + + if (!(value & TRS_UART_NOTBREAK) && uart.fd != -1) { + sigset_t set, oldset; + sigemptyset(&set); + sigaddset(&set, SIGALRM); + sigaddset(&set, SIGIO); + sigprocmask(SIG_BLOCK, &set, &oldset); + err = tcsendbreak(uart.fd, 0); + sigprocmask(SIG_SETMASK, &oldset, NULL); + if (err == -1) { + error("can't send break on %s: %s", trs_uart_name, strerror(errno)); + } + } +} + +int +trs_uart_data_in() +{ + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return 0xff; + trs_uart_check_avail(); + if (uart.status & TRS_UART_RCVD) { + uart.status &= ~TRS_UART_RCVD; + trs_uart_rcv_interrupt(0); + uart.bufleft--; + uart.idata = *uart.bufp++; + if (uart.bufleft) { + trs_schedule_event(trs_uart_set_avail, 1, uart.tstates); + } + } +#if UARTDEBUG + debug("trs_uart_data_in returns 0x%02x\n", uart.idata); +#endif + return uart.idata; +} + +void +trs_uart_data_out(int value) +{ + int err; + +#if UARTDEBUG + debug("trs_uart_data_out 0x%02x\n", value); +#endif + if (initialized == 0) trs_uart_init(0); + if (initialized == -1) return; + uart.odata = value; + if (uart.fd != -1) { + for (;;) { + err = write(uart.fd, &uart.odata, 1); + if (err >= 0) return; + if (errno != EAGAIN) { + error("can't read from %s: %s", trs_uart_name, strerror(errno)); + return; + } + /* Oops, here we didn't really want nonblocking i/o */ +#if UARTDEBUG + debug("trs_uart blocking\n"); +#endif + uart.fdflags &= ~FNONBLOCK; + fcntl(uart.fd, F_SETFL, uart.fdflags); + } + trs_uart_snd_interrupt(0); + trs_schedule_event(trs_uart_set_empty, 1, uart.tstates); + } +} |