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 (serial_t scb, const char *name);
 234 static void dos_raw (serial_t scb);
 235 static int dos_readchar (serial_t scb, int timeout);
 236 static int dos_setbaudrate (serial_t scb, int rate);
 237 static int dos_write (serial_t scb, const char *str, int len);
 238 static void dos_close (serial_t scb);
 239 static serial_ttystate dos_get_tty_state (serial_t scb);
 240 static int dos_set_tty_state (serial_t scb, serial_ttystate state);
 241 static int dos_baudconv (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 (volatile struct dos_ttystate *port)
 251 {
 252   int c;
 253
 254   if (port->count == 0)
 255     return -1;
 256
 257   c = port->cbuf[port->first];
 258   disable ();
 259   port->first = (port->first + 1) & (CBSIZE - 1);
 260   port->count--;
 261   enable ();
 262   return c;
 263 }
 264
 265
 266 static int
 267 dos_putc (int c, struct dos_ttystate *port)
 268 {
 269   if (port->count >= CBSIZE - 1)
 270     return -1;
 271   port->cbuf[(port->first + port->count) & (CBSIZE - 1)] = c;
 272   port->count++;
 273   return 0;
 274 }
 275 \f
 276
 277
 278 static void
 279 dos_comisr (int irq)
 280 {
 281   struct dos_ttystate *port;
 282   unsigned char iir, lsr, c;
 283
 284   disable ();                   /* Paranoia */
 285   outportb (ICU_OCW2, 0x20);    /* End-Of-Interrupt */
 286 #ifdef DOS_STATS
 287   ++intrcnt;
 288 #endif
 289
 290   port = intrupts[irq].port;
 291   if (!port)
 292     {
 293       COUNT (CNT_STRAY);
 294       return;                   /* not open */
 295     }
 296
 297   while (1)
 298     {
 299       iir = inb (port, com_iir) & IIR_IMASK;
 300       switch (iir)
 301         {
 302
 303         case IIR_RLS:
 304           lsr = inb (port, com_lsr);
 305           goto rx;
 306
 307         case IIR_RXTOUT:
 308         case IIR_RXRDY:
 309           lsr = 0;
 310
 311         rx:
 312           do
 313             {
 314               c = inb (port, com_data);
 315               if (lsr & (LSR_BI | LSR_FE | LSR_PE | LSR_OE))
 316                 {
 317                   if (lsr & (LSR_BI | LSR_FE))
 318                     port->ferr++;
 319                   else if (lsr & LSR_PE)
 320                     port->perr++;
 321                   if (lsr & LSR_OE)
 322                     port->oflo++;
 323                 }
 324
 325               if (dos_putc (c, port) < 0)
 326                 {
 327                   COUNT (CNT_ORUN);
 328                 }
 329               else
 330                 {
 331                   COUNT (CNT_RX);
 332                 }
 333             }
 334           while ((lsr = inb (port, com_lsr)) & LSR_RXRDY);
 335           break;
 336
 337         case IIR_MLSC:
 338           /* could be used to flowcontrol Tx */
 339           port->msr = inb (port, com_msr);
 340           break;
 341
 342         case IIR_TXRDY:
 343           port->txbusy = 0;
 344           break;
 345
 346         case IIR_NOPEND:
 347           /* no more pending interrupts, all done */
 348           return;
 349
 350         default:
 351           /* unexpected interrupt, ignore */
 352           break;
 353         }
 354       COUNT (iir);
 355     }
 356 }
 357
 358 #define ISRNAME(x) dos_comisr##x
 359 #define ISR(x) static void ISRNAME(x)() {dos_comisr(x);}
 360
 361 ISR (0) ISR (1) ISR (2) ISR (3)
 362 ISR (4) ISR (5) ISR (6) ISR (7)
 363
 364      typedef void (*isr_t) ();
 365
 366      static isr_t isrs[NINTR] =
 367      {
 368        ISRNAME (0), ISRNAME (1), ISRNAME (2), ISRNAME (3),
 369        ISRNAME (4), ISRNAME (5), ISRNAME (6), ISRNAME (7)
 370 };
 371 \f
 372
 373
 374      static struct intrupt *
 375        dos_hookirq (irq)
 376      unsigned int irq;
 377 {
 378   struct intrupt *intr;
 379   unsigned int vec;
 380   isr_t isr;
 381
 382   if (irq >= NINTR)
 383     return 0;
 384
 385   intr = &intrupts[irq];
 386   if (intr->inuse)
 387     return 0;
 388
 389   vec = 0x08 + irq;
 390   isr = isrs[irq];
 391
 392   /* setup real mode handler */
 393   _go32_dpmi_get_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 394
 395   intr->new_rmhandler.pm_selector = _go32_my_cs ();
 396   intr->new_rmhandler.pm_offset = (u_long) isr;
 397   if (_go32_dpmi_allocate_real_mode_callback_iret (&intr->new_rmhandler,
 398                                                    &intr->regs))
 399     {
 400       return 0;
 401     }
 402
 403   if (_go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->new_rmhandler))
 404     {
 405       return 0;
 406     }
 407
 408   /* setup protected mode handler */
 409   _go32_dpmi_get_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 410
 411   intr->new_pmhandler.pm_selector = _go32_my_cs ();
 412   intr->new_pmhandler.pm_offset = (u_long) isr;
 413   _go32_dpmi_allocate_iret_wrapper (&intr->new_pmhandler);
 414
 415   if (_go32_dpmi_set_protected_mode_interrupt_vector (vec, &intr->new_pmhandler))
 416     {
 417       return 0;
 418     }
 419
 420   /* setup interrupt controller mask */
 421   disable ();
 422   outportb (ICU_MASK, inportb (ICU_MASK) & ~(1 << irq));
 423   enable ();
 424
 425   intr->inuse = 1;
 426   return intr;
 427 }
 428
 429
 430 static void
 431 dos_unhookirq (struct intrupt *intr)
 432 {
 433   unsigned int irq, vec;
 434   unsigned char mask;
 435
 436   irq = intr - intrupts;
 437   vec = 0x08 + irq;
 438
 439   /* restore old interrupt mask bit */
 440   mask = 1 << irq;
 441   disable ();
 442   outportb (ICU_MASK, inportb (ICU_MASK) | (mask & icu_oldmask));
 443   enable ();
 444
 445   /* remove real mode handler */
 446   _go32_dpmi_set_real_mode_interrupt_vector (vec, &intr->old_rmhandler);
 447   _go32_dpmi_free_real_mode_callback (&intr->new_rmhandler);
 448
 449   /* remove protected mode handler */
 450   _go32_dpmi_set_protected_mode_interrupt_vector (vec, &intr->old_pmhandler);
 451   _go32_dpmi_free_iret_wrapper (&intr->new_pmhandler);
 452   intr->inuse = 0;
 453 }
 454 \f
 455
 456
 457 static int
 458 dos_open (serial_t scb, const char *name)
 459 {
 460   struct dos_ttystate *port;
 461   int fd, i;
 462
 463   if (strncasecmp (name, "/dev/", 5) == 0)
 464     name += 5;
 465   else if (strncasecmp (name, "\\dev\\", 5) == 0)
 466     name += 5;
 467
 468   if (strlen (name) != 4 || strncasecmp (name, "com", 3) != 0)
 469     {
 470       errno = ENOENT;
 471       return -1;
 472     }
 473
 474   if (name[3] < '1' || name[3] > '4')
 475     {
 476       errno = ENOENT;
 477       return -1;
 478     }
 479
 480   /* FIXME: this is a Bad Idea (tm)!  One should *never* invent file
 481      handles, since they might be already used by other files/devices.
 482      The Right Way to do this is to create a real handle by dup()'ing
 483      some existing one.  */
 484   fd = name[3] - '1';
 485   port = &ports[fd];
 486   if (port->refcnt++ > 0)
 487     {
 488       /* Device already opened another user.  Just point at it. */
 489       scb->fd = fd;
 490       return 0;
 491     }
 492
 493   /* force access to ID reg */
 494   outb (port, com_cfcr, 0);
 495   outb (port, com_iir, 0);
 496   for (i = 0; i < 17; i++)
 497     {
 498       if ((inb (port, com_iir) & 0x38) == 0)
 499         goto ok;
 500       (void) inb (port, com_data);      /* clear recv */
 501     }
 502   errno = ENODEV;
 503   return -1;
 504
 505 ok:
 506   /* disable all interrupts in chip */
 507   outb (port, com_ier, 0);
 508
 509   /* tentatively enable 16550 fifo, and see if it responds */
 510   outb (port, com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER);
 511   sleep (1);
 512   port->fifo = ((inb (port, com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK);
 513
 514   /* clear pending status reports. */
 515   (void) inb (port, com_lsr);
 516   (void) inb (port, com_msr);
 517
 518   /* enable external interrupt gate (to avoid floating IRQ) */
 519   outb (port, com_mcr, MCR_IENABLE);
 520
 521   /* hook up interrupt handler and initialise icu */
 522   port->intrupt = dos_hookirq (port->irq);
 523   if (!port->intrupt)
 524     {
 525       outb (port, com_mcr, 0);
 526       outb (port, com_fifo, 0);
 527       errno = ENODEV;
 528       return -1;
 529     }
 530
 531   disable ();
 532
 533   /* record port */
 534   port->intrupt->port = port;
 535   scb->fd = fd;
 536
 537   /* clear rx buffer, tx busy flag and overflow count */
 538   port->first = port->count = 0;
 539   port->txbusy = 0;
 540   port->oflo = 0;
 541
 542   /* set default baud rate and mode: 9600,8,n,1 */
 543   i = dos_baudconv (port->baudrate = 9600);
 544   outb (port, com_cfcr, CFCR_DLAB);
 545   outb (port, com_dlbl, i & 0xff);
 546   outb (port, com_dlbh, i >> 8);
 547   outb (port, com_cfcr, CFCR_8BITS);
 548
 549   /* enable all interrupts */
 550   outb (port, com_ier, IER_ETXRDY | IER_ERXRDY | IER_ERLS | IER_EMSC);
 551
 552   /* enable DTR & RTS */
 553   outb (port, com_mcr, MCR_DTR | MCR_RTS | MCR_IENABLE);
 554
 555   enable ();
 556
 557   return 0;
 558 }
 559
 560
 561 static void
 562 dos_close (serial_t scb)
 563 {
 564   struct dos_ttystate *port;
 565   struct intrupt *intrupt;
 566
 567   if (!scb)
 568     return;
 569
 570   port = &ports[scb->fd];
 571
 572   if (port->refcnt-- > 1)
 573     return;
 574
 575   if (!(intrupt = port->intrupt))
 576     return;
 577
 578   /* disable interrupts, fifo, flow control */
 579   disable ();
 580   port->intrupt = 0;
 581   intrupt->port = 0;
 582   outb (port, com_fifo, 0);
 583   outb (port, com_ier, 0);
 584   enable ();
 585
 586   /* unhook handler, and disable interrupt gate */
 587   dos_unhookirq (intrupt);
 588   outb (port, com_mcr, 0);
 589
 590   /* Check for overflow errors */
 591   if (port->oflo)
 592     {
 593       fprintf_unfiltered (gdb_stderr,
 594                           "Serial input overruns occurred.\n");
 595       fprintf_unfiltered (gdb_stderr, "This system %s handle %d baud.\n",
 596                           port->fifo ? "cannot" : "needs a 16550 to",
 597                           port->baudrate);
 598     }
 599 }
 600 \f
 601
 602
 603 static int
 604 dos_noop (serial_t scb ATTRIBUTE_UNUSED)
 605 {
 606   return 0;
 607 }
 608
 609 static void
 610 dos_raw (serial_t scb ATTRIBUTE_UNUSED)
 611 {
 612   /* Always in raw mode */
 613 }
 614
 615 static int
 616 dos_readchar (serial_t scb, int timeout)
 617 {
 618   struct dos_ttystate *port = &ports[scb->fd];
 619   long then;
 620   int c;
 621
 622   then = rawclock () + (timeout * RAWHZ);
 623   while ((c = dos_getc (port)) < 0)
 624     {
 625       if (timeout >= 0 && (rawclock () - then) >= 0)
 626         return SERIAL_TIMEOUT;
 627       notice_quit ();
 628     }
 629
 630   return c;
 631 }
 632
 633
 634 static serial_ttystate
 635 dos_get_tty_state (serial_t scb)
 636 {
 637   struct dos_ttystate *port = &ports[scb->fd];
 638   struct dos_ttystate *state;
 639
 640   /* Are they asking about a port we opened?  */
 641   if (port->refcnt <= 0)
 642     {
 643       /* We've never heard about this port.  We should fail this call,
 644          unless they are asking about one of the 3 standard handles,
 645          in which case we pretend the handle was open by us if it is
 646          connected to a terminal device.  This is beacuse Unix
 647          terminals use the serial interface, so GDB expects the
 648          standard handles to go through here.  */
 649       if (scb->fd >= 3 || !isatty (scb->fd))
 650         return NULL;
 651     }
 652
 653   state = (struct dos_ttystate *) xmalloc (sizeof *state);
 654   *state = *port;
 655   return (serial_ttystate) state;
 656 }
 657
 658 static int
 659 dos_set_tty_state (serial_t scb, serial_ttystate ttystate)
 660 {
 661   struct dos_ttystate *state;
 662
 663   state = (struct dos_ttystate *) ttystate;
 664   dos_setbaudrate (scb, state->baudrate);
 665   return 0;
 666 }
 667
 668 static int
 669 dos_noflush_set_tty_state (serial_t scb, serial_ttystate new_ttystate,
 670                            serial_ttystate old_ttystate ATTRIBUTE_UNUSED)
 671 {
 672   struct dos_ttystate *state;
 673
 674   state = (struct dos_ttystate *) new_ttystate;
 675   dos_setbaudrate (scb, state->baudrate);
 676   return 0;
 677 }
 678
 679 static int
 680 dos_flush_input (serial_t scb)
 681 {
 682   struct dos_ttystate *port = &ports[scb->fd];
 683   disable ();
 684   port->first = port->count = 0;
 685   if (port->fifo)
 686     outb (port, com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_TRIGGER);
 687   enable ();
 688   return 0;
 689 }
 690
 691 static void
 692 dos_print_tty_state (serial_t scb ATTRIBUTE_UNUSED,
 693                      serial_ttystate ttystate ATTRIBUTE_UNUSED,
 694                      struct ui_file *stream ATTRIBUTE_UNUSED)
 695 {
 696   /* Nothing to print */
 697   return;
 698 }
 699
 700 static int
 701 dos_baudconv (int rate)
 702 {
 703   long x, err;
 704
 705   if (rate <= 0)
 706     return -1;
 707
 708 #define divrnd(n, q)    (((n) * 2 / (q) + 1) / 2)       /* divide and round off */
 709   x = divrnd (COMTICK, rate);
 710   if (x <= 0)
 711     return -1;
 712
 713   err = divrnd (1000 * COMTICK, x * rate) - 1000;
 714   if (err < 0)
 715     err = -err;
 716   if (err > SPEED_TOLERANCE)
 717     return -1;
 718 #undef divrnd
 719   return x;
 720 }
 721
 722
 723 static int
 724 dos_setbaudrate (serial_t scb, int rate)
 725 {
 726   struct dos_ttystate *port = &ports[scb->fd];
 727
 728   if (port->baudrate != rate)
 729     {
 730       int x;
 731       unsigned char cfcr;
 732
 733       x = dos_baudconv (rate);
 734       if (x <= 0)
 735         {
 736           fprintf_unfiltered (gdb_stderr, "%d: impossible baudrate\n", rate);
 737           errno = EINVAL;
 738           return -1;
 739         }
 740
 741       disable ();
 742       cfcr = inb (port, com_cfcr);
 743
 744       outb (port, com_cfcr, CFCR_DLAB);
 745       outb (port, com_dlbl, x & 0xff);
 746       outb (port, com_dlbh, x >> 8);
 747       outb (port, com_cfcr, cfcr);
 748       port->baudrate = rate;
 749       enable ();
 750     }
 751
 752   return 0;
 753 }
 754
 755 static int
 756 dos_setstopbits (serial_t scb, int num)
 757 {
 758   struct dos_ttystate *port = &ports[scb->fd];
 759   unsigned char cfcr;
 760
 761   disable ();
 762   cfcr = inb (port, com_cfcr);
 763
 764   switch (num)
 765     {
 766     case SERIAL_1_STOPBITS:
 767       outb (port, com_cfcr, cfcr & ~CFCR_STOPB);
 768       break;
 769     case SERIAL_1_AND_A_HALF_STOPBITS:
 770     case SERIAL_2_STOPBITS:
 771       outb (port, com_cfcr, cfcr | CFCR_STOPB);
 772       break;
 773     default:
 774       enable ();
 775       return 1;
 776     }
 777   enable ();
 778
 779   return 0;
 780 }
 781
 782 static int
 783 dos_write (serial_t scb, const char *str, int len)
 784 {
 785   volatile struct dos_ttystate *port = &ports[scb->fd];
 786   int fifosize = port->fifo ? 16 : 1;
 787   long then;
 788   int cnt;
 789
 790   while (len > 0)
 791     {
 792       /* send the data, fifosize bytes at a time */
 793       cnt = fifosize > len ? len : fifosize;
 794       port->txbusy = 1;
 795       /* Francisco Pastor <fpastor.etra-id@etra.es> says OUTSB messes
 796          up the communications with UARTs with FIFOs.  */
 797 #ifdef UART_FIFO_WORKS
 798       outportsb (port->base + com_data, str, cnt);
 799       str += cnt;
 800       len -= cnt;
 801 #else
 802       for ( ; cnt > 0; cnt--, len--)
 803         outportb (port->base + com_data, *str++);
 804 #endif
 805 #ifdef DOS_STATS
 806       cnts[CNT_TX] += cnt;
 807 #endif
 808       /* wait for transmission to complete (max 1 sec) */
 809       then = rawclock () + RAWHZ;
 810       while (port->txbusy)
 811         {
 812           if ((rawclock () - then) >= 0)
 813             {
 814               errno = EIO;
 815               return SERIAL_ERROR;
 816             }
 817         }
 818     }
 819   return 0;
 820 }
 821
 822
 823 static int
 824 dos_sendbreak (serial_t scb)
 825 {
 826   volatile struct dos_ttystate *port = &ports[scb->fd];
 827   unsigned char cfcr;
 828   long then;
 829
 830   cfcr = inb (port, com_cfcr);
 831   outb (port, com_cfcr, cfcr | CFCR_SBREAK);
 832
 833   /* 0.25 sec delay */
 834   then = rawclock () + RAWHZ / 4;
 835   while ((rawclock () - then) < 0)
 836     continue;
 837
 838   outb (port, com_cfcr, cfcr);
 839   return 0;
 840 }
 841
 842
 843 static struct serial_ops dos_ops =
 844 {
 845   "hardwire",
 846   0,
 847   dos_open,
 848   dos_close,
 849   dos_readchar,
 850   dos_write,
 851   dos_noop,                     /* flush output */
 852   dos_flush_input,
 853   dos_sendbreak,
 854   dos_raw,
 855   dos_get_tty_state,
 856   dos_set_tty_state,
 857   dos_print_tty_state,
 858   dos_noflush_set_tty_state,
 859   dos_setbaudrate,
 860   dos_setstopbits,
 861   dos_noop,                     /* wait for output to drain */
 862   (void (*)(serial_t, int))NULL /* change into async mode */
 863 };
 864
 865
 866 static void
 867 dos_info (char *arg ATTRIBUTE_UNUSED, int from_tty ATTRIBUTE_UNUSED)
 868 {
 869   struct dos_ttystate *port;
 870 #ifdef DOS_STATS
 871   int i;
 872 #endif
 873
 874   for (port = ports; port < &ports[4]; port++)
 875     {
 876       if (port->baudrate == 0)
 877         continue;
 878       printf_filtered ("Port:\tCOM%ld (%sactive)\n", (long)(port - ports) + 1,
 879                        port->intrupt ? "" : "not ");
 880       printf_filtered ("Addr:\t0x%03x (irq %d)\n", port->base, port->irq);
 881       printf_filtered ("16550:\t%s\n", port->fifo ? "yes" : "no");
 882       printf_filtered ("Speed:\t%d baud\n", port->baudrate);
 883       printf_filtered ("Errs:\tframing %d parity %d overflow %d\n\n",
 884                        port->ferr, port->perr, port->oflo);
 885     }
 886
 887 #ifdef DOS_STATS
 888   printf_filtered ("\nTotal interrupts: %d\n", intrcnt);
 889   for (i = 0; i < NCNT; i++)
 890     if (cnts[i])
 891       printf_filtered ("%s:\t%d\n", cntnames[i], cnts[i]);
 892 #endif
 893 }
 894
 895
 896 void
 897 _initialize_ser_dos (void)
 898 {
 899   serial_add_interface (&dos_ops);
 900
 901   /* Save original interrupt mask register. */
 902   icu_oldmask = inportb (ICU_MASK);
 903
 904   /* Mark fixed motherboard irqs as inuse. */
 905   intrupts[0].inuse =           /* timer tick */
 906     intrupts[1].inuse =         /* keyboard */
 907     intrupts[2].inuse = 1;      /* slave icu */
 908
 909   add_show_from_set (
 910                       add_set_cmd ("com1base", class_obscure, var_zinteger,
 911                                    (char *) &ports[0].base,
 912                                    "Set COM1 base i/o port address.",
 913                                    &setlist),
 914                       &showlist);
 915
 916   add_show_from_set (
 917                       add_set_cmd ("com1irq", class_obscure, var_zinteger,
 918                                    (char *) &ports[0].irq,
 919                                    "Set COM1 interrupt request.",
 920                                    &setlist),
 921                       &showlist);
 922
 923   add_show_from_set (
 924                       add_set_cmd ("com2base", class_obscure, var_zinteger,
 925                                    (char *) &ports[1].base,
 926                                    "Set COM2 base i/o port address.",
 927                                    &setlist),
 928                       &showlist);
 929
 930   add_show_from_set (
 931                       add_set_cmd ("com2irq", class_obscure, var_zinteger,
 932                                    (char *) &ports[1].irq,
 933                                    "Set COM2 interrupt request.",
 934                                    &setlist),
 935                       &showlist);
 936
 937   add_show_from_set (
 938                       add_set_cmd ("com3base", class_obscure, var_zinteger,
 939                                    (char *) &ports[2].base,
 940                                    "Set COM3 base i/o port address.",
 941                                    &setlist),
 942                       &showlist);
 943
 944   add_show_from_set (
 945                       add_set_cmd ("com3irq", class_obscure, var_zinteger,
 946                                    (char *) &ports[2].irq,
 947                                    "Set COM3 interrupt request.",
 948                                    &setlist),
 949                       &showlist);
 950
 951   add_show_from_set (
 952                       add_set_cmd ("com4base", class_obscure, var_zinteger,
 953                                    (char *) &ports[3].base,
 954                                    "Set COM4 base i/o port address.",
 955                                    &setlist),
 956                       &showlist);
 957
 958   add_show_from_set (
 959                       add_set_cmd ("com4irq", class_obscure, var_zinteger,
 960                                    (char *) &ports[3].irq,
 961                                    "Set COM4 interrupt request.",
 962                                    &setlist),
 963                       &showlist);
 964
 965   add_info ("serial", dos_info,
 966             "Print DOS serial port status.");
 967 }