gdb/ser-go32.c

   1 /* Remote serial interface for local (hardwired) serial ports for GO32.
   2    Copyright 1992, 1993, 2000 Free Software Foundation, Inc.
   3
   4    Contributed by Nigel Stephens, Algorithmics Ltd. (nigel@algor.co.uk).
   5
   6    This version uses DPMI interrupts to handle buffered i/o
   7    without the separate "asynctsr" program.
   8
   9    This file is part of GDB.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 59 Temple Place - Suite 330,
  24    Boston, MA 02111-1307, USA.  */
  25
  26 #include "defs.h"
  27 #include "gdbcmd.h"
  28 #include "serial.h"
  29
  30
  31 /*
  32  * NS16550 UART registers
  33  */
  34
  35 #define COM1ADDR        0x3f8
  36 #define COM2ADDR        0x2f8
  37 #define COM3ADDR        0x3e8
  38 #define COM4ADDR        0x3e0
  39
  40 #define com_data        0       /* data register (R/W) */
  41 #define com_dlbl        0       /* divisor latch low (W) */
  42 #define com_ier         1       /* interrupt enable (W) */
  43 #define com_dlbh        1       /* divisor latch high (W) */
  44 #define com_iir         2       /* interrupt identification (R) */
  45 #define com_fifo        2       /* FIFO control (W) */
  46 #define com_lctl        3       /* line control register (R/W) */
  47 #define com_cfcr        3       /* line control register (R/W) */
  48 #define com_mcr         4       /* modem control register (R/W) */
  49 #define com_lsr         5       /* line status register (R/W) */
  50 #define com_msr         6       /* modem status register (R/W) */
  51
  52 /*
  53  * Constants for computing 16 bit baud rate divisor (lower byte
  54  * in com_dlbl, upper in com_dlbh) from 1.8432MHz crystal.  Divisor is
  55  * 1.8432 MHz / (16 * X) for X bps.  If the baud rate can't be set
  56  * to within +- (desired_rate*SPEED_TOLERANCE/1000) bps, we fail.
  57  */
  58 #define COMTICK         (1843200/16)
  59 #define SPEED_TOLERANCE 30      /* thousandths; real == desired +- 3.0% */
  60
  61 /* interrupt enable register */
  62 #define IER_ERXRDY      0x1     /* int on rx ready */
  63 #define IER_ETXRDY      0x2     /* int on tx ready */
  64 #define IER_ERLS        0x4     /* int on line status change */
  65 #define IER_EMSC        0x8     /* int on modem status change */
  66
  67 /* interrupt identification register */
  68 #define IIR_FIFO_MASK   0xc0    /* set if FIFOs are enabled */
  69 #define IIR_IMASK       0xf     /* interrupt cause mask */
  70 #define IIR_NOPEND      0x1     /* nothing pending */
  71 #define IIR_RLS         0x6     /* receive line status */
  72 #define IIR_RXRDY       0x4     /* receive ready */
  73 #define IIR_RXTOUT      0xc     /* receive timeout */
  74 #define IIR_TXRDY       0x2     /* transmit ready */
  75 #define IIR_MLSC        0x0     /* modem status */
  76
  77
  78 /* fifo control register */
  79 #define FIFO_ENABLE     0x01    /* enable fifo */
  80 #define FIFO_RCV_RST    0x02    /* reset receive fifo */
  81 #define FIFO_XMT_RST    0x04    /* reset transmit fifo */
  82 #define FIFO_DMA_MODE   0x08    /* enable dma mode */
  83 #define FIFO_TRIGGER_1  0x00    /* trigger at 1 char */
  84 #define FIFO_TRIGGER_4  0x40    /* trigger at 4 chars */
  85 #define FIFO_TRIGGER_8  0x80    /* trigger at 8 chars */
  86 #define FIFO_TRIGGER_14 0xc0    /* trigger at 14 chars */
  87
  88 /* character format control register */
  89 #define CFCR_DLAB       0x80    /* divisor latch */
  90 #define CFCR_SBREAK     0x40    /* send break */
  91 #define CFCR_PZERO      0x30    /* zero parity */
  92 #define CFCR_PONE       0x20    /* one parity */
  93 #define CFCR_PEVEN      0x10    /* even parity */
  94 #define CFCR_PODD       0x00    /* odd parity */
  95 #define CFCR_PENAB      0x08    /* parity enable */
  96 #define CFCR_STOPB      0x04    /* 2 stop bits */
  97 #define CFCR_8BITS      0x03    /* 8 data bits */
  98 #define CFCR_7BITS      0x02    /* 7 data bits */
  99 #define CFCR_6BITS      0x01    /* 6 data bits */
 100 #define CFCR_5BITS      0x00    /* 5 data bits */
 101
 102 /* modem control register */
 103 #define MCR_LOOPBACK    0x10    /* loopback */
 104 #define MCR_IENABLE     0x08    /* output 2 = int enable */
 105 #define MCR_DRS         0x04    /* output 1 = xxx */
 106 #define MCR_RTS         0x02    /* enable RTS */
 107 #define MCR_DTR         0x01    /* enable DTR */
 108
 109 /* line status register */
 110 #define LSR_RCV_FIFO    0x80    /* error in receive fifo */
 111 #define LSR_TSRE        0x40    /* transmitter empty */
 112 #define LSR_TXRDY       0x20    /* transmitter ready */
 113 #define LSR_BI          0x10    /* break detected */
 114 #define LSR_FE          0x08    /* framing error */
 115 #define LSR_PE          0x04    /* parity error */
 116 #define LSR_OE          0x02    /* overrun error */
 117 #define LSR_RXRDY       0x01    /* receiver ready */
 118 #define LSR_RCV_MASK    0x1f
 119
 120 /* modem status register */
 121 #define MSR_DCD         0x80
 122 #define MSR_RI          0x40
 123 #define MSR_DSR         0x20
 124 #define MSR_CTS         0x10
 125 #define MSR_DDCD        0x08
 126 #define MSR_TERI        0x04
 127 #define MSR_DDSR        0x02
 128 #define MSR_DCTS        0x01
 129
 130 #include <string.h>
 131 #include <dos.h>
 132 #include <go32.h>
 133 #include <dpmi.h>
 134 typedef unsigned long u_long;
 135
 136 /* 16550 rx fifo trigger point */
 137 #define FIFO_TRIGGER    FIFO_TRIGGER_4
 138
 139 /* input buffer size */
 140 #define CBSIZE  4096
 141
 142 /* return raw 18Hz clock count */
 143 extern long rawclock (void);
 144
 145 #define RAWHZ   18
 146
 147 #ifdef DOS_STATS
 148 #define CNT_RX          16
 149 #define CNT_TX          17
 150 #define CNT_STRAY       18
 151 #define CNT_ORUN        19
 152 #define NCNT            20
 153
 154 static int intrcnt;
 155 static int cnts[NCNT];
 156 static char *cntnames[NCNT] =
 157 {
 158   /* h/w interrupt counts. */
 159   "mlsc", "nopend", "txrdy", "?3",
 160   "rxrdy", "?5", "rls", "?7",
 161   "?8", "?9", "?a", "?b",
 162   "rxtout", "?d", "?e", "?f",
 163   /* s/w counts. */
 164   "rxcnt", "txcnt", "stray", "swoflo"
 165 };
 166
 167 #define COUNT(x) cnts[x]++
 168 #else
 169 #define COUNT(x)
 170 #endif
 171
 172 /* Main interrupt controller port addresses. */
 173 #define ICU_BASE        0x20
 174 #define ICU_OCW2        (ICU_BASE + 0)
 175 #define ICU_MASK        (ICU_BASE + 1)
 176
 177 /* Original interrupt controller mask register. */
 178 unsigned char icu_oldmask;
 179
 180 /* Maximum of 8 interrupts (we don't handle the slave icu yet). */
 181 #define NINTR   8
 182
 183 static struct intrupt
 184   {
 185     char inuse;
 186     struct dos_ttystate *port;
 187     _go32_dpmi_seginfo old_rmhandler;
 188     _go32_dpmi_seginfo old_pmhandler;
 189     _go32_dpmi_seginfo new_rmhandler;
 190     _go32_dpmi_seginfo new_pmhandler;
 191     _go32_dpmi_registers regs;
 192   }
 193 intrupts[NINTR];
 194
 195
 196 static struct dos_ttystate
 197   {
 198     int base;
 199     int irq;
 200     int refcnt;
 201     struct intrupt *intrupt;
 202     int fifo;
 203     int baudrate;
 204     unsigned char cbuf[CBSIZE];
 205     unsigned int first;
 206     unsigned int count;
 207     int txbusy;
 208     unsigned char old_mcr;
 209     int ferr;
 210     int perr;
 211     int oflo;
 212     int msr;
 213   }
 214 ports[4] =
 215 {
 216   {
 217     COM1ADDR, 4, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 218   }
 219   ,
 220   {
 221     COM2ADDR, 3, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 222   }
 223   ,
 224   {
 225     COM3ADDR, 4, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 226   }
 227   ,
 228   {
 229     COM4ADDR, 3, 0, NULL, 0, 0, "", 0, 0, 0, 0, 0, 0, 0, 0
 230   }
 231 };
 232
 233 static int dos_open PARAMS ((serial_t scb, const char *name));
 234 static void dos_raw PARAMS ((serial_t scb));
 235 static int dos_readchar PARAMS ((serial_t scb, int timeout));
 236 static int dos_setbaudrate PARAMS ((serial_t scb, int rate));
 237 static int dos_write PARAMS ((serial_t scb, const char *str, int len));
 238 static void dos_close PARAMS ((serial_t scb));
 239 static serial_ttystate dos_get_tty_state PARAMS ((serial_t scb));
 240 static int dos_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
 241 static int dos_baudconv PARAMS ((int rate));
 242
 243 #define inb(p,a)        inportb((p)->base + (a))
 244 #define outb(p,a,v)     outportb((p)->base + (a), (v))
 245 #define disable()       asm volatile ("cli");
 246 #define enable()        asm volatile ("sti");
 247
 248
 249 static int
 250 dos_getc (port)
 251      volatile struct dos_ttystate *port;
 252 {
 253   int c;
 254
 255   if (port->count == 0)
 256     return -1;
 257
 258   c = port->cbuf[port->first];
 259   disable ();
 260   port->first = (port->first + 1) & (CBSIZE - 1);
 261   port->count--;
 262   enable ();
 263   return c;
 264 }
 265
 266
 267 static int
 268 dos_putc (c, port)
 269      int c;
 270      struct dos_ttystate *port;
 271 {
 272   if (port->count >= CBSIZE - 1)
 273     return -1;
 274   port->cbuf[(port->first + port->count) & (CBSIZE - 1)] = c;
 275   port->count++;
 276   return 0;
 277 }
 278 \f
 279
 280
 281 static void
 282 dos_comisr (irq)
 283      int irq;
 284 {
 285   struct dos_ttystate *port;
 286   unsigned char iir, lsr, c;
 287
 288   disable ();                   /* Paranoia */
 289   outportb (ICU_OCW2, 0x20);    /* End-Of-Interrupt */
 290 #ifdef DOS_STATS
 291   ++intrcnt;
 292 #endif
 293
 294   port = intrupts[irq].port;
 295   if (!port)
 296     {
 297       COUNT (CNT_STRAY);
 298       return;                   /* not open */
 299     }
 300
 301   while (1)
 302     {
 303       iir = inb (port, com_iir) & IIR_IMASK;
 304       switch (iir)
 305         {
 306
 307         case IIR_RLS:
 308           lsr = inb (port, com_lsr);
 309           goto rx;
 310
 311         case IIR_RXTOUT:
 312         case IIR_RXRDY:
 313           lsr = 0;
 314
 315         rx:
 316           do
 317             {
 318               c = inb (port, com_data);
 319               if (lsr & (LSR_BI | LSR_FE | LSR_PE | LSR_OE))
 320                 {
 321                   if (lsr & (LSR_BI | LSR_FE))
 322                     port->ferr++;
 323                   else if (lsr & LSR_PE)
 324                     port->perr++;
 325                   if (lsr & LSR_OE)
 326                     port->oflo++;
 327                 }
 328
 329               if (dos_putc (c, port) < 0)
 330                 {
 331                   COUNT (CNT_ORUN);
 332                 }
 333               else
 334                 {
 335                   COUNT (CNT_RX);
 336                 }
 337             }
 338           while ((lsr = inb (port, com_lsr)) & LSR_RXRDY);
 339           break;
 340
 341         case IIR_MLSC:
 342           /* could be used to flowcontrol Tx */
 343           port->msr = inb (port, com_msr);
 344           break;
 345
 346         case IIR_TXRDY:
 347           port->txbusy = 0;
 348           break;
 349
 350         case IIR_NOPEND:
 351           /* no more pending interrupts, all done */
 352           return;
 353
 354         default:
 355           /* unexpected interrupt, ignore */
 356           break;
 357         }
 358       COUNT (iir);
 359     }
 360 }
 361
 362 #ifdef __STDC__
 363 #define ISRNAME(x) dos_comisr##x
 364 #else
 365 #define ISRNAME(x) dos_comisr/**/x
 366 #endif
 367 #define ISR(x) static void ISRNAME(x)() {dos_comisr(x);}
 368
 369 ISR (0) ISR (1) ISR (2) ISR (3)
 370 ISR (4) ISR (5) ISR (6) ISR (7)
 371
 372      typedef void (*isr_t) ();
 373
 374      static isr_t isrs[NINTR] =
 375      {
 376        ISRNAME (0), ISRNAME (1), ISRNAME (2), ISRNAME (3),
 377        ISRNAME (4), ISRNAME (5), ISRNAME (6), ISRNAME (7)
 378 };
 379 \f
 380
 381
 382      static struct intrupt *
 383        dos_hookirq (irq)
 384      unsigned int irq;
 385 {
 386   struct intrupt *intr;
 387   unsigned int vec;
 388   isr_t isr;
 389
 390   if (irq >= NINTR)
 391     return 0;
 392
 393   intr = &intrupts[irq];
 394   if (intr->inuse)
 395     return 0;
 396
 397   vec = 0x08 + irq;
 398   isr = isrs[irq];
 399
 400   /* setup real mode handler */
 401   _go32_dpmi_get_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 402
 403   intr->new_rmhandler.pm_selector = _go32_my_cs ();
 404   intr->new_rmhandler.pm_offset = (u_long) isr;
 405   if (_go32_dpmi_allocate_real_mode_callback_iret (&intr->new_rmhandler,
 406                                                    &intr->regs))
 407     {
 408       return 0;
 409     }
 410
 411   if (_go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->new_rmhandler))
 412     {
 413       return 0;
 414     }
 415
 416   /* setup protected mode handler */
 417   _go32_dpmi_get_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 418
 419   intr->new_pmhandler.pm_selector = _go32_my_cs ();
 420   intr->new_pmhandler.pm_offset = (u_long) isr;
 421   _go32_dpmi_allocate_iret_wrapper (&intr->new_pmhandler);
 422
 423   if (_go32_dpmi_set_protected_mode_interrupt_vector (vec, &intr->new_pmhandler))
 424     {
 425       return 0;
 426     }
 427
 428   /* setup interrupt controller mask */
 429   disable ();
 430   outportb (ICU_MASK, inportb (ICU_MASK) & ~(1 << irq));
 431   enable ();
 432
 433   intr->inuse = 1;
 434   return intr;
 435 }
 436
 437
 438 static void
 439 dos_unhookirq (intr)
 440      struct intrupt *intr;
 441 {
 442   unsigned int irq, vec;
 443   unsigned char mask;
 444
 445   irq = intr - intrupts;
 446   vec = 0x08 + irq;
 447
 448   /* restore old interrupt mask bit */
 449   mask = 1 << irq;
 450   disable ();
 451   outportb (ICU_MASK, inportb (ICU_MASK) | (mask & icu_oldmask));
 452   enable ();
 453
 454   /* remove real mode handler */
 455   _go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 456   _go32_dpmi_free_real_mode_callback (&intr->new_rmhandler);
 457
 458   /* remove protected mode handler */
 459   _go32_dpmi_set_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 460   _go32_dpmi_free_iret_wrapper (&intr->new_pmhandler);
 461   intr->inuse = 0;
 462 }
 463 \f
 464
 465
 466 static int
 467 dos_open (scb, name)
 468      serial_t scb;
 469      const char *name;
 470 {
 471   struct dos_ttystate *port;
 472   int fd, i;
 473
 474   if (strncasecmp (name, "/dev/", 5) == 0)
 475     name += 5;
 476   else if (strncasecmp (name, "\\dev\\", 5) == 0)
 477     name += 5;
 478
 479   if (strlen (name) != 4 || strncasecmp (name, "com", 3) != 0)
 480     {
 481       errno = ENOENT;
 482       return -1;
 483     }
 484
 485   if (name[3] < '1' || name[3] > '4')
 486     {
 487       errno = ENOENT;
 488       return -1;
 489     }
 490
 491   /* FIXME: this is a Bad Idea (tm)!  One should *never* invent file
 492      handles, since they might be already used by other files/devices.
 493      The Right Way to do this is to create a real handle by dup()'ing
 494      some existing one.  */
 495   fd = name[3] - '1';
 496   port = &ports[fd];
 497   if (port->refcnt++ > 0)
 498     {
 499       /* Device already opened another user.  Just point at it. */
 500       scb->fd = fd;
 501       return 0;
 502     }
 503
 504   /* force access to ID reg */
 505   outb (port, com_cfcr, 0);
 506   outb (port, com_iir, 0);
 507   for (i = 0; i < 17; i++)
 508     {
 509       if ((inb (port, com_iir) & 0x38) == 0)
 510         goto ok;
 511       (void) inb (port, com_data);      /* clear recv */
 512     }
 513   errno = ENODEV;
 514   return -1;
 515
 516 ok:
 517   /* disable all interrupts in chip */
 518   outb (port, com_ier, 0);
 519
 520   /* tentatively enable 16550 fifo, and see if it responds */
 521   outb (port, com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER);
 522   sleep (1);
 523   port->fifo = ((inb (port, com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK);
 524
 525   /* clear pending status reports. */
 526   (void) inb (port, com_lsr);
 527   (void) inb (port, com_msr);
 528
 529   /* enable external interrupt gate (to avoid floating IRQ) */
 530   outb (port, com_mcr, MCR_IENABLE);
 531
 532   /* hook up interrupt handler and initialise icu */
 533   port->intrupt = dos_hookirq (port->irq);
 534   if (!port->intrupt)
 535     {
 536       outb (port, com_mcr, 0);
 537       outb (port, com_fifo, 0);
 538       errno = ENODEV;
 539       return -1;
 540     }
 541
 542   disable ();
 543
 544   /* record port */
 545   port->intrupt->port = port;
 546   scb->fd = fd;
 547
 548   /* clear rx buffer, tx busy flag and overflow count */
 549   port->first = port->count = 0;
 550   port->txbusy = 0;
 551   port->oflo = 0;
 552
 553   /* set default baud rate and mode: 9600,8,n,1 */
 554   i = dos_baudconv (port->baudrate = 9600);
 555   outb (port, com_cfcr, CFCR_DLAB);
 556   outb (port, com_dlbl, i & 0xff);
 557   outb (port, com_dlbh, i >> 8);
 558   outb (port, com_cfcr, CFCR_8BITS);
 559
 560   /* enable all interrupts */
 561   outb (port, com_ier, IER_ETXRDY | IER_ERXRDY | IER_ERLS | IER_EMSC);
 562
 563   /* enable DTR & RTS */
 564   outb (port, com_mcr, MCR_DTR | MCR_RTS | MCR_IENABLE);
 565
 566   enable ();
 567
 568   return 0;
 569 }
 570
 571
 572 static void
 573 dos_close (scb)
 574      serial_t scb;
 575 {
 576   struct dos_ttystate *port;
 577   struct intrupt *intrupt;
 578
 579   if (!scb)
 580     return;
 581
 582   port = &ports[scb->fd];
 583
 584   if (port->refcnt-- > 1)
 585     return;
 586
 587   if (!(intrupt = port->intrupt))
 588     return;
 589
 590   /* disable interrupts, fifo, flow control */
 591   disable ();
 592   port->intrupt = 0;
 593   intrupt->port = 0;
 594   outb (port, com_fifo, 0);
 595   outb (port, com_ier, 0);
 596   enable ();
 597
 598   /* unhook handler, and disable interrupt gate */
 599   dos_unhookirq (intrupt);
 600   outb (port, com_mcr, 0);
 601
 602   /* Check for overflow errors */
 603   if (port->oflo)
 604     {
 605       fprintf_unfiltered (gdb_stderr,
 606                           "Serial input overruns occurred.\n");
 607       fprintf_unfiltered (gdb_stderr, "This system %s handle %d baud.\n",
 608                           port->fifo ? "cannot" : "needs a 16550 to",
 609                           port->baudrate);
 610     }
 611 }
 612 \f
 613
 614
 615 static int
 616 dos_noop (serial_t scb ATTRIBUTE_UNUSED)
 617 {
 618   return 0;
 619 }
 620
 621 static void
 622 dos_raw (serial_t scb ATTRIBUTE_UNUSED)
 623 {
 624   /* Always in raw mode */
 625 }
 626
 627 static int
 628 dos_readchar (scb, timeout)
 629      serial_t scb;
 630      int timeout;
 631 {
 632   struct dos_ttystate *port = &ports[scb->fd];
 633   long then;
 634   int c;
 635
 636   then = rawclock () + (timeout * RAWHZ);
 637   while ((c = dos_getc (port)) < 0)
 638     {
 639       if (timeout >= 0 && (rawclock () - then) >= 0)
 640         return SERIAL_TIMEOUT;
 641       notice_quit ();
 642     }
 643
 644   return c;
 645 }
 646
 647
 648 static serial_ttystate
 649 dos_get_tty_state (scb)
 650      serial_t scb;
 651 {
 652   struct dos_ttystate *port = &ports[scb->fd];
 653   struct dos_ttystate *state;
 654
 655   /* Are they asking about a port we opened?  */
 656   if (port->refcnt <= 0)
 657     {
 658       /* We've never heard about this port.  We should fail this call,
 659          unless they are asking about one of the 3 standard handles,
 660          in which case we pretend the handle was open by us if it is
 661          connected to a terminal device.  This is beacuse Unix
 662          terminals use the serial interface, so GDB expects the
 663          standard handles to go through here.  */
 664       if (scb->fd >= 3 || !isatty (scb->fd))
 665         return NULL;
 666     }
 667
 668   state = (struct dos_ttystate *) xmalloc (sizeof *state);
 669   *state = *port;
 670   return (serial_ttystate) state;
 671 }
 672
 673 static int
 674 dos_set_tty_state (scb, ttystate)
 675      serial_t scb;
 676      serial_ttystate ttystate;
 677 {
 678   struct dos_ttystate *state;
 679
 680   state = (struct dos_ttystate *) ttystate;
 681   dos_setbaudrate (scb, state->baudrate);
 682   return 0;
 683 }
 684
 685 static int
 686 dos_noflush_set_tty_state (serial_t scb, serial_ttystate new_ttystate,
 687                            serial_ttystate old_ttystate ATTRIBUTE_UNUSED)
 688 {
 689   struct dos_ttystate *state;
 690
 691   state = (struct dos_ttystate *) new_ttystate;
 692   dos_setbaudrate (scb, state->baudrate);
 693   return 0;
 694 }
 695
 696 static int
 697 dos_flush_input (scb)
 698      serial_t scb;
 699 {
 700   struct dos_ttystate *port = &ports[scb->fd];
 701   disable ();
 702   port->first = port->count = 0;
 703   if (port->fifo)
 704     outb (port, com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_TRIGGER);
 705   enable ();
 706   return 0;
 707 }
 708
 709 static void
 710 dos_print_tty_state (serial_t scb ATTRIBUTE_UNUSED,
 711                      serial_ttystate ttystate ATTRIBUTE_UNUSED,
 712                      struct ui_file *stream ATTRIBUTE_UNUSED)
 713 {
 714   /* Nothing to print */
 715   return;
 716 }
 717
 718 static int
 719 dos_baudconv (rate)
 720      int rate;
 721 {
 722   long x, err;
 723
 724   if (rate <= 0)
 725     return -1;
 726
 727 #define divrnd(n, q)    (((n) * 2 / (q) + 1) / 2)       /* divide and round off */
 728   x = divrnd (COMTICK, rate);
 729   if (x <= 0)
 730     return -1;
 731
 732   err = divrnd (1000 * COMTICK, x * rate) - 1000;
 733   if (err < 0)
 734     err = -err;
 735   if (err > SPEED_TOLERANCE)
 736     return -1;
 737 #undef divrnd
 738   return x;
 739 }
 740
 741
 742 static int
 743 dos_setbaudrate (scb, rate)
 744      serial_t scb;
 745      int rate;
 746 {
 747   struct dos_ttystate *port = &ports[scb->fd];
 748
 749   if (port->baudrate != rate)
 750     {
 751       int x;
 752       unsigned char cfcr;
 753
 754       x = dos_baudconv (rate);
 755       if (x <= 0)
 756         {
 757           fprintf_unfiltered (gdb_stderr, "%d: impossible baudrate\n", rate);
 758           errno = EINVAL;
 759           return -1;
 760         }
 761
 762       disable ();
 763       cfcr = inb (port, com_cfcr);
 764
 765       outb (port, com_cfcr, CFCR_DLAB);
 766       outb (port, com_dlbl, x & 0xff);
 767       outb (port, com_dlbh, x >> 8);
 768       outb (port, com_cfcr, cfcr);
 769       port->baudrate = rate;
 770       enable ();
 771     }
 772
 773   return 0;
 774 }
 775
 776 static int
 777 dos_setstopbits (scb, num)
 778      serial_t scb;
 779      int num;
 780 {
 781   struct dos_ttystate *port = &ports[scb->fd];
 782   unsigned char cfcr;
 783
 784   disable ();
 785   cfcr = inb (port, com_cfcr);
 786
 787   switch (num)
 788     {
 789     case SERIAL_1_STOPBITS:
 790       outb (port, com_cfcr, cfcr & ~CFCR_STOPB);
 791       break;
 792     case SERIAL_1_AND_A_HALF_STOPBITS:
 793     case SERIAL_2_STOPBITS:
 794       outb (port, com_cfcr, cfcr | CFCR_STOPB);
 795       break;
 796     default:
 797       enable ();
 798       return 1;
 799     }
 800   enable ();
 801
 802   return 0;
 803 }
 804
 805 static int
 806 dos_write (scb, str, len)
 807      serial_t scb;
 808      const char *str;
 809      int len;
 810 {
 811   volatile struct dos_ttystate *port = &ports[scb->fd];
 812   int fifosize = port->fifo ? 16 : 1;
 813   long then;
 814   int cnt;
 815
 816   while (len > 0)
 817     {
 818       /* send the data, fifosize bytes at a time */
 819       cnt = fifosize > len ? len : fifosize;
 820       port->txbusy = 1;
 821       outportsb (port->base + com_data, str, cnt);
 822       str += cnt;
 823       len -= cnt;
 824 #ifdef DOS_STATS
 825       cnts[CNT_TX] += cnt;
 826 #endif
 827       /* wait for transmission to complete (max 1 sec) */
 828       then = rawclock () + RAWHZ;
 829       while (port->txbusy)
 830         {
 831           if ((rawclock () - then) >= 0)
 832             {
 833               errno = EIO;
 834               return SERIAL_ERROR;
 835             }
 836         }
 837     }
 838   return 0;
 839 }
 840
 841
 842 static int
 843 dos_sendbreak (scb)
 844      serial_t scb;
 845 {
 846   volatile struct dos_ttystate *port = &ports[scb->fd];
 847   unsigned char cfcr;
 848   long then;
 849
 850   cfcr = inb (port, com_cfcr);
 851   outb (port, com_cfcr, cfcr | CFCR_SBREAK);
 852
 853   /* 0.25 sec delay */
 854   then = rawclock () + RAWHZ / 4;
 855   while ((rawclock () - then) < 0)
 856     continue;
 857
 858   outb (port, com_cfcr, cfcr);
 859   return 0;
 860 }
 861
 862
 863 static struct serial_ops dos_ops =
 864 {
 865   "hardwire",
 866   0,
 867   dos_open,
 868   dos_close,
 869   dos_readchar,
 870   dos_write,
 871   dos_noop,                     /* flush output */
 872   dos_flush_input,
 873   dos_sendbreak,
 874   dos_raw,
 875   dos_get_tty_state,
 876   dos_set_tty_state,
 877   dos_print_tty_state,
 878   dos_noflush_set_tty_state,
 879   dos_setbaudrate,
 880   dos_setstopbits,
 881   dos_noop,                     /* wait for output to drain */
 882   (void (*)(serial_t, int))NULL /* change into async mode */
 883 };
 884
 885
 886 static void
 887 dos_info (char *arg ATTRIBUTE_UNUSED, int from_tty ATTRIBUTE_UNUSED)
 888 {
 889   struct dos_ttystate *port;
 890 #ifdef DOS_STATS
 891   int i;
 892 #endif
 893
 894   for (port = ports; port < &ports[4]; port++)
 895     {
 896       if (port->baudrate == 0)
 897         continue;
 898       printf_filtered ("Port:\tCOM%ld (%sactive)\n", (long)(port - ports) + 1,
 899                        port->intrupt ? "" : "not ");
 900       printf_filtered ("Addr:\t0x%03x (irq %d)\n", port->base, port->irq);
 901       printf_filtered ("16550:\t%s\n", port->fifo ? "yes" : "no");
 902       printf_filtered ("Speed:\t%d baud\n", port->baudrate);
 903       printf_filtered ("Errs:\tframing %d parity %d overflow %d\n\n",
 904                        port->ferr, port->perr, port->oflo);
 905     }
 906
 907 #ifdef DOS_STATS
 908   printf_filtered ("\nTotal interrupts: %d\n", intrcnt);
 909   for (i = 0; i < NCNT; i++)
 910     if (cnts[i])
 911       printf_filtered ("%s:\t%d\n", cntnames[i], cnts[i]);
 912 #endif
 913 }
 914
 915
 916 void
 917 _initialize_ser_dos ()
 918 {
 919   serial_add_interface (&dos_ops);
 920
 921   /* Save original interrupt mask register. */
 922   icu_oldmask = inportb (ICU_MASK);
 923
 924   /* Mark fixed motherboard irqs as inuse. */
 925   intrupts[0].inuse =           /* timer tick */
 926     intrupts[1].inuse =         /* keyboard */
 927     intrupts[2].inuse = 1;      /* slave icu */
 928
 929   add_show_from_set (
 930                       add_set_cmd ("com1base", class_obscure, var_zinteger,
 931                                    (char *) &ports[0].base,
 932                                    "Set COM1 base i/o port address.",
 933                                    &setlist),
 934                       &showlist);
 935
 936   add_show_from_set (
 937                       add_set_cmd ("com1irq", class_obscure, var_zinteger,
 938                                    (char *) &ports[0].irq,
 939                                    "Set COM1 interrupt request.",
 940                                    &setlist),
 941                       &showlist);
 942
 943   add_show_from_set (
 944                       add_set_cmd ("com2base", class_obscure, var_zinteger,
 945                                    (char *) &ports[1].base,
 946                                    "Set COM2 base i/o port address.",
 947                                    &setlist),
 948                       &showlist);
 949
 950   add_show_from_set (
 951                       add_set_cmd ("com2irq", class_obscure, var_zinteger,
 952                                    (char *) &ports[1].irq,
 953                                    "Set COM2 interrupt request.",
 954                                    &setlist),
 955                       &showlist);
 956
 957   add_show_from_set (
 958                       add_set_cmd ("com3base", class_obscure, var_zinteger,
 959                                    (char *) &ports[2].base,
 960                                    "Set COM3 base i/o port address.",
 961                                    &setlist),
 962                       &showlist);
 963
 964   add_show_from_set (
 965                       add_set_cmd ("com3irq", class_obscure, var_zinteger,
 966                                    (char *) &ports[2].irq,
 967                                    "Set COM3 interrupt request.",
 968                                    &setlist),
 969                       &showlist);
 970
 971   add_show_from_set (
 972                       add_set_cmd ("com4base", class_obscure, var_zinteger,
 973                                    (char *) &ports[3].base,
 974                                    "Set COM4 base i/o port address.",
 975                                    &setlist),
 976                       &showlist);
 977
 978   add_show_from_set (
 979                       add_set_cmd ("com4irq", class_obscure, var_zinteger,
 980                                    (char *) &ports[3].irq,
 981                                    "Set COM4 interrupt request.",
 982                                    &setlist),
 983                       &showlist);
 984
 985   add_info ("serial", dos_info,
 986             "Print DOS serial port status.");
 987 }