arch/ia64/hp/sim/simserial.c

   1 /*
   2  * Simulated Serial Driver (fake serial)
   3  *
   4  * This driver is mostly used for bringup purposes and will go away.
   5  * It has a strong dependency on the system console. All outputs
   6  * are rerouted to the same facility as the one used by printk which, in our
   7  * case means sys_sim.c console (goes via the simulator). The code hereafter
   8  * is completely leveraged from the serial.c driver.
   9  *
  10  * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
  11  *      Stephane Eranian <eranian@hpl.hp.com>
  12  *      David Mosberger-Tang <davidm@hpl.hp.com>
  13  *
  14  * 02/04/00 D. Mosberger        Merged in serial.c bug fixes in rs_close().
  15  * 02/25/00 D. Mosberger        Synced up with 2.3.99pre-5 version of serial.c.
  16  * 07/30/02 D. Mosberger        Replace sti()/cli() with explicit spinlocks & local irq masking
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/init.h>
  21 #include <linux/errno.h>
  22 #include <linux/sched.h>
  23 #include <linux/tty.h>
  24 #include <linux/tty_flip.h>
  25 #include <linux/major.h>
  26 #include <linux/fcntl.h>
  27 #include <linux/mm.h>
  28 #include <linux/slab.h>
  29 #include <linux/console.h>
  30 #include <linux/module.h>
  31 #include <linux/serial.h>
  32 #include <linux/serialP.h>
  33
  34 #include <asm/irq.h>
  35 #include <asm/hw_irq.h>
  36 #include <asm/uaccess.h>
  37
  38 #ifdef CONFIG_KDB
  39 # include <linux/kdb.h>
  40 #endif
  41
  42 #undef SIMSERIAL_DEBUG  /* define this to get some debug information */
  43
  44 #define KEYBOARD_INTR   3       /* must match with simulator! */
  45
  46 #define NR_PORTS        1       /* only one port for now */
  47 #define SERIAL_INLINE   1
  48
  49 #ifdef SERIAL_INLINE
  50 #define _INLINE_ inline
  51 #endif
  52
  53 #ifndef MIN
  54 #define MIN(a,b)        ((a) < (b) ? (a) : (b))
  55 #endif
  56
  57 #define IRQ_T(info) ((info->flags & ASYNC_SHARE_IRQ) ? SA_SHIRQ : SA_INTERRUPT)
  58
  59 #define SSC_GETCHAR     21
  60
  61 extern long ia64_ssc (long, long, long, long, int);
  62 extern void ia64_ssc_connect_irq (long intr, long irq);
  63
  64 static char *serial_name = "SimSerial driver";
  65 static char *serial_version = "0.6";
  66
  67 /*
  68  * This has been extracted from asm/serial.h. We need one eventually but
  69  * I don't know exactly what we're going to put in it so just fake one
  70  * for now.
  71  */
  72 #define BASE_BAUD ( 1843200 / 16 )
  73
  74 #define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
  75
  76 /*
  77  * Most of the values here are meaningless to this particular driver.
  78  * However some values must be preserved for the code (leveraged from serial.c
  79  * to work correctly).
  80  * port must not be 0
  81  * type must not be UNKNOWN
  82  * So I picked arbitrary (guess from where?) values instead
  83  */
  84 static struct serial_state rs_table[NR_PORTS]={
  85   /* UART CLK   PORT IRQ     FLAGS        */
  86   { 0, BASE_BAUD, 0x3F8, 0, STD_COM_FLAGS,0,PORT_16550 }  /* ttyS0 */
  87 };
  88
  89 /*
  90  * Just for the fun of it !
  91  */
  92 static struct serial_uart_config uart_config[] = {
  93         { "unknown", 1, 0 },
  94         { "8250", 1, 0 },
  95         { "16450", 1, 0 },
  96         { "16550", 1, 0 },
  97         { "16550A", 16, UART_CLEAR_FIFO | UART_USE_FIFO },
  98         { "cirrus", 1, 0 },
  99         { "ST16650", 1, UART_CLEAR_FIFO | UART_STARTECH },
 100         { "ST16650V2", 32, UART_CLEAR_FIFO | UART_USE_FIFO |
 101                   UART_STARTECH },
 102         { "TI16750", 64, UART_CLEAR_FIFO | UART_USE_FIFO},
 103         { 0, 0}
 104 };
 105
 106 struct tty_driver *hp_simserial_driver;
 107
 108 static struct async_struct *IRQ_ports[NR_IRQS];
 109
 110 static struct console *console;
 111
 112 static unsigned char *tmp_buf;
 113 static DECLARE_MUTEX(tmp_buf_sem);
 114
 115 extern struct console *console_drivers; /* from kernel/printk.c */
 116
 117 /*
 118  * ------------------------------------------------------------
 119  * rs_stop() and rs_start()
 120  *
 121  * This routines are called before setting or resetting tty->stopped.
 122  * They enable or disable transmitter interrupts, as necessary.
 123  * ------------------------------------------------------------
 124  */
 125 static void rs_stop(struct tty_struct *tty)
 126 {
 127 #ifdef SIMSERIAL_DEBUG
 128         printk("rs_stop: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
 129                 tty->stopped, tty->hw_stopped, tty->flow_stopped);
 130 #endif
 131
 132 }
 133
 134 static void rs_start(struct tty_struct *tty)
 135 {
 136 #if SIMSERIAL_DEBUG
 137         printk("rs_start: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
 138                 tty->stopped, tty->hw_stopped, tty->flow_stopped);
 139 #endif
 140 }
 141
 142 static  void receive_chars(struct tty_struct *tty, struct pt_regs *regs)
 143 {
 144         unsigned char ch;
 145         static unsigned char seen_esc = 0;
 146
 147         while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
 148                 if ( ch == 27 && seen_esc == 0 ) {
 149                         seen_esc = 1;
 150                         continue;
 151                 } else {
 152                         if ( seen_esc==1 && ch == 'O' ) {
 153                                 seen_esc = 2;
 154                                 continue;
 155                         } else if ( seen_esc == 2 ) {
 156                                 if ( ch == 'P' ) show_state();          /* F1 key */
 157 #ifdef CONFIG_KDB
 158                                 if ( ch == 'S' )
 159                                         kdb(KDB_REASON_KEYBOARD, 0, (kdb_eframe_t) regs);
 160 #endif
 161
 162                                 seen_esc = 0;
 163                                 continue;
 164                         }
 165                 }
 166                 seen_esc = 0;
 167                 if (tty->flip.count >= TTY_FLIPBUF_SIZE) break;
 168
 169                 *tty->flip.char_buf_ptr = ch;
 170
 171                 *tty->flip.flag_buf_ptr = 0;
 172
 173                 tty->flip.flag_buf_ptr++;
 174                 tty->flip.char_buf_ptr++;
 175                 tty->flip.count++;
 176         }
 177         tty_flip_buffer_push(tty);
 178 }
 179
 180 /*
 181  * This is the serial driver's interrupt routine for a single port
 182  */
 183 static irqreturn_t rs_interrupt_single(int irq, void *dev_id, struct pt_regs * regs)
 184 {
 185         struct async_struct * info;
 186
 187         /*
 188          * I don't know exactly why they don't use the dev_id opaque data
 189          * pointer instead of this extra lookup table
 190          */
 191         info = IRQ_ports[irq];
 192         if (!info || !info->tty) {
 193                 printk(KERN_INFO "simrs_interrupt_single: info|tty=0 info=%p problem\n", info);
 194                 return IRQ_NONE;
 195         }
 196         /*
 197          * pretty simple in our case, because we only get interrupts
 198          * on inbound traffic
 199          */
 200         receive_chars(info->tty, regs);
 201         return IRQ_HANDLED;
 202 }
 203
 204 /*
 205  * -------------------------------------------------------------------
 206  * Here ends the serial interrupt routines.
 207  * -------------------------------------------------------------------
 208  */
 209
 210 #if 0
 211 /*
 212  * not really used in our situation so keep them commented out for now
 213  */
 214 static DECLARE_TASK_QUEUE(tq_serial); /* used to be at the top of the file */
 215 static void do_serial_bh(void)
 216 {
 217         run_task_queue(&tq_serial);
 218         printk(KERN_ERR "do_serial_bh: called\n");
 219 }
 220 #endif
 221
 222 static void do_softint(void *private_)
 223 {
 224         printk(KERN_ERR "simserial: do_softint called\n");
 225 }
 226
 227 static void rs_put_char(struct tty_struct *tty, unsigned char ch)
 228 {
 229         struct async_struct *info = (struct async_struct *)tty->driver_data;
 230         unsigned long flags;
 231
 232         if (!tty || !info->xmit.buf) return;
 233
 234         local_irq_save(flags);
 235         if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
 236                 local_irq_restore(flags);
 237                 return;
 238         }
 239         info->xmit.buf[info->xmit.head] = ch;
 240         info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
 241         local_irq_restore(flags);
 242 }
 243
 244 static _INLINE_ void transmit_chars(struct async_struct *info, int *intr_done)
 245 {
 246         int count;
 247         unsigned long flags;
 248
 249
 250         local_irq_save(flags);
 251
 252         if (info->x_char) {
 253                 char c = info->x_char;
 254
 255                 console->write(console, &c, 1);
 256
 257                 info->state->icount.tx++;
 258                 info->x_char = 0;
 259
 260                 goto out;
 261         }
 262
 263         if (info->xmit.head == info->xmit.tail || info->tty->stopped || info->tty->hw_stopped) {
 264 #ifdef SIMSERIAL_DEBUG
 265                 printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
 266                        info->xmit.head, info->xmit.tail, info->tty->stopped);
 267 #endif
 268                 goto out;
 269         }
 270         /*
 271          * We removed the loop and try to do it in to chunks. We need
 272          * 2 operations maximum because it's a ring buffer.
 273          *
 274          * First from current to tail if possible.
 275          * Then from the beginning of the buffer until necessary
 276          */
 277
 278         count = MIN(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
 279                     SERIAL_XMIT_SIZE - info->xmit.tail);
 280         console->write(console, info->xmit.buf+info->xmit.tail, count);
 281
 282         info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);
 283
 284         /*
 285          * We have more at the beginning of the buffer
 286          */
 287         count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 288         if (count) {
 289                 console->write(console, info->xmit.buf, count);
 290                 info->xmit.tail += count;
 291         }
 292 out:
 293         local_irq_restore(flags);
 294 }
 295
 296 static void rs_flush_chars(struct tty_struct *tty)
 297 {
 298         struct async_struct *info = (struct async_struct *)tty->driver_data;
 299
 300         if (info->xmit.head == info->xmit.tail || tty->stopped || tty->hw_stopped ||
 301             !info->xmit.buf)
 302                 return;
 303
 304         transmit_chars(info, NULL);
 305 }
 306
 307
 308 static int rs_write(struct tty_struct * tty, int from_user,
 309                     const unsigned char *buf, int count)
 310 {
 311         int     c, ret = 0;
 312         struct async_struct *info = (struct async_struct *)tty->driver_data;
 313         unsigned long flags;
 314
 315         if (!tty || !info->xmit.buf || !tmp_buf) return 0;
 316
 317         if (from_user) {
 318                 down(&tmp_buf_sem);
 319                 while (1) {
 320                         int c1;
 321                         c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 322                         if (count < c)
 323                                 c = count;
 324                         if (c <= 0)
 325                                 break;
 326
 327                         c -= copy_from_user(tmp_buf, buf, c);
 328                         if (!c) {
 329                                 if (!ret)
 330                                         ret = -EFAULT;
 331                                 break;
 332                         }
 333
 334                         local_irq_save(flags);
 335                         {
 336                                 c1 = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail,
 337                                                        SERIAL_XMIT_SIZE);
 338                                 if (c1 < c)
 339                                         c = c1;
 340                                 memcpy(info->xmit.buf + info->xmit.head, tmp_buf, c);
 341                                 info->xmit.head = ((info->xmit.head + c) &
 342                                                    (SERIAL_XMIT_SIZE-1));
 343                         }
 344                         local_irq_restore(flags);
 345
 346                         buf += c;
 347                         count -= c;
 348                         ret += c;
 349                 }
 350                 up(&tmp_buf_sem);
 351         } else {
 352                 local_irq_save(flags);
 353                 while (1) {
 354                         c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 355                         if (count < c)
 356                                 c = count;
 357                         if (c <= 0) {
 358                                 break;
 359                         }
 360                         memcpy(info->xmit.buf + info->xmit.head, buf, c);
 361                         info->xmit.head = ((info->xmit.head + c) &
 362                                            (SERIAL_XMIT_SIZE-1));
 363                         buf += c;
 364                         count -= c;
 365                         ret += c;
 366                 }
 367                 local_irq_restore(flags);
 368         }
 369         /*
 370          * Hey, we transmit directly from here in our case
 371          */
 372         if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE)
 373             && !tty->stopped && !tty->hw_stopped) {
 374                 transmit_chars(info, NULL);
 375         }
 376         return ret;
 377 }
 378
 379 static int rs_write_room(struct tty_struct *tty)
 380 {
 381         struct async_struct *info = (struct async_struct *)tty->driver_data;
 382
 383         return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 384 }
 385
 386 static int rs_chars_in_buffer(struct tty_struct *tty)
 387 {
 388         struct async_struct *info = (struct async_struct *)tty->driver_data;
 389
 390         return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 391 }
 392
 393 static void rs_flush_buffer(struct tty_struct *tty)
 394 {
 395         struct async_struct *info = (struct async_struct *)tty->driver_data;
 396         unsigned long flags;
 397
 398         local_irq_save(flags);
 399         info->xmit.head = info->xmit.tail = 0;
 400         local_irq_restore(flags);
 401
 402         wake_up_interruptible(&tty->write_wait);
 403
 404         if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 405             tty->ldisc.write_wakeup)
 406                 (tty->ldisc.write_wakeup)(tty);
 407 }
 408
 409 /*
 410  * This function is used to send a high-priority XON/XOFF character to
 411  * the device
 412  */
 413 static void rs_send_xchar(struct tty_struct *tty, char ch)
 414 {
 415         struct async_struct *info = (struct async_struct *)tty->driver_data;
 416
 417         info->x_char = ch;
 418         if (ch) {
 419                 /*
 420                  * I guess we could call console->write() directly but
 421                  * let's do that for now.
 422                  */
 423                 transmit_chars(info, NULL);
 424         }
 425 }
 426
 427 /*
 428  * ------------------------------------------------------------
 429  * rs_throttle()
 430  *
 431  * This routine is called by the upper-layer tty layer to signal that
 432  * incoming characters should be throttled.
 433  * ------------------------------------------------------------
 434  */
 435 static void rs_throttle(struct tty_struct * tty)
 436 {
 437         if (I_IXOFF(tty)) rs_send_xchar(tty, STOP_CHAR(tty));
 438
 439         printk(KERN_INFO "simrs_throttle called\n");
 440 }
 441
 442 static void rs_unthrottle(struct tty_struct * tty)
 443 {
 444         struct async_struct *info = (struct async_struct *)tty->driver_data;
 445
 446         if (I_IXOFF(tty)) {
 447                 if (info->x_char)
 448                         info->x_char = 0;
 449                 else
 450                         rs_send_xchar(tty, START_CHAR(tty));
 451         }
 452         printk(KERN_INFO "simrs_unthrottle called\n");
 453 }
 454
 455 /*
 456  * rs_break() --- routine which turns the break handling on or off
 457  */
 458 static void rs_break(struct tty_struct *tty, int break_state)
 459 {
 460 }
 461
 462 static int rs_ioctl(struct tty_struct *tty, struct file * file,
 463                     unsigned int cmd, unsigned long arg)
 464 {
 465         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
 466             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
 467             (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
 468                 if (tty->flags & (1 << TTY_IO_ERROR))
 469                     return -EIO;
 470         }
 471
 472         switch (cmd) {
 473                 case TIOCMGET:
 474                         printk(KERN_INFO "rs_ioctl: TIOCMGET called\n");
 475                         return -EINVAL;
 476                 case TIOCMBIS:
 477                 case TIOCMBIC:
 478                 case TIOCMSET:
 479                         printk(KERN_INFO "rs_ioctl: TIOCMBIS/BIC/SET called\n");
 480                         return -EINVAL;
 481                 case TIOCGSERIAL:
 482                         printk(KERN_INFO "simrs_ioctl TIOCGSERIAL called\n");
 483                         return 0;
 484                 case TIOCSSERIAL:
 485                         printk(KERN_INFO "simrs_ioctl TIOCSSERIAL called\n");
 486                         return 0;
 487                 case TIOCSERCONFIG:
 488                         printk(KERN_INFO "rs_ioctl: TIOCSERCONFIG called\n");
 489                         return -EINVAL;
 490
 491                 case TIOCSERGETLSR: /* Get line status register */
 492                         printk(KERN_INFO "rs_ioctl: TIOCSERGETLSR called\n");
 493                         return  -EINVAL;
 494
 495                 case TIOCSERGSTRUCT:
 496                         printk(KERN_INFO "rs_ioctl: TIOCSERGSTRUCT called\n");
 497 #if 0
 498                         if (copy_to_user((struct async_struct *) arg,
 499                                          info, sizeof(struct async_struct)))
 500                                 return -EFAULT;
 501 #endif
 502                         return 0;
 503
 504                 /*
 505                  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
 506                  * - mask passed in arg for lines of interest
 507                  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
 508                  * Caller should use TIOCGICOUNT to see which one it was
 509                  */
 510                 case TIOCMIWAIT:
 511                         printk(KERN_INFO "rs_ioctl: TIOCMIWAIT: called\n");
 512                         return 0;
 513                 /*
 514                  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
 515                  * Return: write counters to the user passed counter struct
 516                  * NB: both 1->0 and 0->1 transitions are counted except for
 517                  *     RI where only 0->1 is counted.
 518                  */
 519                 case TIOCGICOUNT:
 520                         printk(KERN_INFO "rs_ioctl: TIOCGICOUNT called\n");
 521                         return 0;
 522
 523                 case TIOCSERGWILD:
 524                 case TIOCSERSWILD:
 525                         /* "setserial -W" is called in Debian boot */
 526                         printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
 527                         return 0;
 528
 529                 default:
 530                         return -ENOIOCTLCMD;
 531                 }
 532         return 0;
 533 }
 534
 535 #define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
 536
 537 static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
 538 {
 539         unsigned int cflag = tty->termios->c_cflag;
 540
 541         if (   (cflag == old_termios->c_cflag)
 542             && (   RELEVANT_IFLAG(tty->termios->c_iflag)
 543                 == RELEVANT_IFLAG(old_termios->c_iflag)))
 544           return;
 545
 546
 547         /* Handle turning off CRTSCTS */
 548         if ((old_termios->c_cflag & CRTSCTS) &&
 549             !(tty->termios->c_cflag & CRTSCTS)) {
 550                 tty->hw_stopped = 0;
 551                 rs_start(tty);
 552         }
 553 }
 554 /*
 555  * This routine will shutdown a serial port; interrupts are disabled, and
 556  * DTR is dropped if the hangup on close termio flag is on.
 557  */
 558 static void shutdown(struct async_struct * info)
 559 {
 560         unsigned long   flags;
 561         struct serial_state *state;
 562         int             retval;
 563
 564         if (!(info->flags & ASYNC_INITIALIZED)) return;
 565
 566         state = info->state;
 567
 568 #ifdef SIMSERIAL_DEBUG
 569         printk("Shutting down serial port %d (irq %d)....", info->line,
 570                state->irq);
 571 #endif
 572
 573         local_irq_save(flags);
 574         {
 575                 /*
 576                  * First unlink the serial port from the IRQ chain...
 577                  */
 578                 if (info->next_port)
 579                         info->next_port->prev_port = info->prev_port;
 580                 if (info->prev_port)
 581                         info->prev_port->next_port = info->next_port;
 582                 else
 583                         IRQ_ports[state->irq] = info->next_port;
 584
 585                 /*
 586                  * Free the IRQ, if necessary
 587                  */
 588                 if (state->irq && (!IRQ_ports[state->irq] ||
 589                                    !IRQ_ports[state->irq]->next_port)) {
 590                         if (IRQ_ports[state->irq]) {
 591                                 free_irq(state->irq, NULL);
 592                                 retval = request_irq(state->irq, rs_interrupt_single,
 593                                                      IRQ_T(info), "serial", NULL);
 594
 595                                 if (retval)
 596                                         printk(KERN_ERR "serial shutdown: request_irq: error %d"
 597                                                "  Couldn't reacquire IRQ.\n", retval);
 598                         } else
 599                                 free_irq(state->irq, NULL);
 600                 }
 601
 602                 if (info->xmit.buf) {
 603                         free_page((unsigned long) info->xmit.buf);
 604                         info->xmit.buf = 0;
 605                 }
 606
 607                 if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags);
 608
 609                 info->flags &= ~ASYNC_INITIALIZED;
 610         }
 611         local_irq_restore(flags);
 612 }
 613
 614 /*
 615  * ------------------------------------------------------------
 616  * rs_close()
 617  *
 618  * This routine is called when the serial port gets closed.  First, we
 619  * wait for the last remaining data to be sent.  Then, we unlink its
 620  * async structure from the interrupt chain if necessary, and we free
 621  * that IRQ if nothing is left in the chain.
 622  * ------------------------------------------------------------
 623  */
 624 static void rs_close(struct tty_struct *tty, struct file * filp)
 625 {
 626         struct async_struct * info = (struct async_struct *)tty->driver_data;
 627         struct serial_state *state;
 628         unsigned long flags;
 629
 630         if (!info ) return;
 631
 632         state = info->state;
 633
 634         local_irq_save(flags);
 635         if (tty_hung_up_p(filp)) {
 636 #ifdef SIMSERIAL_DEBUG
 637                 printk("rs_close: hung_up\n");
 638 #endif
 639                 local_irq_restore(flags);
 640                 return;
 641         }
 642 #ifdef SIMSERIAL_DEBUG
 643         printk("rs_close ttys%d, count = %d\n", info->line, state->count);
 644 #endif
 645         if ((tty->count == 1) && (state->count != 1)) {
 646                 /*
 647                  * Uh, oh.  tty->count is 1, which means that the tty
 648                  * structure will be freed.  state->count should always
 649                  * be one in these conditions.  If it's greater than
 650                  * one, we've got real problems, since it means the
 651                  * serial port won't be shutdown.
 652                  */
 653                 printk(KERN_ERR "rs_close: bad serial port count; tty->count is 1, "
 654                        "state->count is %d\n", state->count);
 655                 state->count = 1;
 656         }
 657         if (--state->count < 0) {
 658                 printk(KERN_ERR "rs_close: bad serial port count for ttys%d: %d\n",
 659                        info->line, state->count);
 660                 state->count = 0;
 661         }
 662         if (state->count) {
 663                 local_irq_restore(flags);
 664                 return;
 665         }
 666         info->flags |= ASYNC_CLOSING;
 667         local_irq_restore(flags);
 668
 669         /*
 670          * Now we wait for the transmit buffer to clear; and we notify
 671          * the line discipline to only process XON/XOFF characters.
 672          */
 673         shutdown(info);
 674         if (tty->driver->flush_buffer) tty->driver->flush_buffer(tty);
 675         if (tty->ldisc.flush_buffer) tty->ldisc.flush_buffer(tty);
 676         info->event = 0;
 677         info->tty = 0;
 678         if (info->blocked_open) {
 679                 if (info->close_delay) {
 680                         current->state = TASK_INTERRUPTIBLE;
 681                         schedule_timeout(info->close_delay);
 682                 }
 683                 wake_up_interruptible(&info->open_wait);
 684         }
 685         info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
 686         wake_up_interruptible(&info->close_wait);
 687 }
 688
 689 /*
 690  * rs_wait_until_sent() --- wait until the transmitter is empty
 691  */
 692 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 693 {
 694 }
 695
 696
 697 /*
 698  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 699  */
 700 static void rs_hangup(struct tty_struct *tty)
 701 {
 702         struct async_struct * info = (struct async_struct *)tty->driver_data;
 703         struct serial_state *state = info->state;
 704
 705 #ifdef SIMSERIAL_DEBUG
 706         printk("rs_hangup: called\n");
 707 #endif
 708
 709         state = info->state;
 710
 711         rs_flush_buffer(tty);
 712         if (info->flags & ASYNC_CLOSING)
 713                 return;
 714         shutdown(info);
 715
 716         info->event = 0;
 717         state->count = 0;
 718         info->flags &= ~ASYNC_NORMAL_ACTIVE;
 719         info->tty = 0;
 720         wake_up_interruptible(&info->open_wait);
 721 }
 722
 723
 724 static int get_async_struct(int line, struct async_struct **ret_info)
 725 {
 726         struct async_struct *info;
 727         struct serial_state *sstate;
 728
 729         sstate = rs_table + line;
 730         sstate->count++;
 731         if (sstate->info) {
 732                 *ret_info = sstate->info;
 733                 return 0;
 734         }
 735         info = kmalloc(sizeof(struct async_struct), GFP_KERNEL);
 736         if (!info) {
 737                 sstate->count--;
 738                 return -ENOMEM;
 739         }
 740         memset(info, 0, sizeof(struct async_struct));
 741         init_waitqueue_head(&info->open_wait);
 742         init_waitqueue_head(&info->close_wait);
 743         init_waitqueue_head(&info->delta_msr_wait);
 744         info->magic = SERIAL_MAGIC;
 745         info->port = sstate->port;
 746         info->flags = sstate->flags;
 747         info->xmit_fifo_size = sstate->xmit_fifo_size;
 748         info->line = line;
 749         INIT_WORK(&info->work, do_softint, info);
 750         info->state = sstate;
 751         if (sstate->info) {
 752                 kfree(info);
 753                 *ret_info = sstate->info;
 754                 return 0;
 755         }
 756         *ret_info = sstate->info = info;
 757         return 0;
 758 }
 759
 760 static int
 761 startup(struct async_struct *info)
 762 {
 763         unsigned long flags;
 764         int     retval=0;
 765         irqreturn_t (*handler)(int, void *, struct pt_regs *);
 766         struct serial_state *state= info->state;
 767         unsigned long page;
 768
 769         page = get_zeroed_page(GFP_KERNEL);
 770         if (!page)
 771                 return -ENOMEM;
 772
 773         local_irq_save(flags);
 774
 775         if (info->flags & ASYNC_INITIALIZED) {
 776                 free_page(page);
 777                 goto errout;
 778         }
 779
 780         if (!state->port || !state->type) {
 781                 if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags);
 782                 free_page(page);
 783                 goto errout;
 784         }
 785         if (info->xmit.buf)
 786                 free_page(page);
 787         else
 788                 info->xmit.buf = (unsigned char *) page;
 789
 790 #ifdef SIMSERIAL_DEBUG
 791         printk("startup: ttys%d (irq %d)...", info->line, state->irq);
 792 #endif
 793
 794         /*
 795          * Allocate the IRQ if necessary
 796          */
 797         if (state->irq && (!IRQ_ports[state->irq] ||
 798                           !IRQ_ports[state->irq]->next_port)) {
 799                 if (IRQ_ports[state->irq]) {
 800                         retval = -EBUSY;
 801                         goto errout;
 802                 } else
 803                         handler = rs_interrupt_single;
 804
 805                 retval = request_irq(state->irq, handler, IRQ_T(info), "simserial", NULL);
 806                 if (retval) {
 807                         if (capable(CAP_SYS_ADMIN)) {
 808                                 if (info->tty)
 809                                         set_bit(TTY_IO_ERROR,
 810                                                 &info->tty->flags);
 811                                 retval = 0;
 812                         }
 813                         goto errout;
 814                 }
 815         }
 816
 817         /*
 818          * Insert serial port into IRQ chain.
 819          */
 820         info->prev_port = 0;
 821         info->next_port = IRQ_ports[state->irq];
 822         if (info->next_port)
 823                 info->next_port->prev_port = info;
 824         IRQ_ports[state->irq] = info;
 825
 826         if (info->tty) clear_bit(TTY_IO_ERROR, &info->tty->flags);
 827
 828         info->xmit.head = info->xmit.tail = 0;
 829
 830 #if 0
 831         /*
 832          * Set up serial timers...
 833          */
 834         timer_table[RS_TIMER].expires = jiffies + 2*HZ/100;
 835         timer_active |= 1 << RS_TIMER;
 836 #endif
 837
 838         /*
 839          * Set up the tty->alt_speed kludge
 840          */
 841         if (info->tty) {
 842                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
 843                         info->tty->alt_speed = 57600;
 844                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
 845                         info->tty->alt_speed = 115200;
 846                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
 847                         info->tty->alt_speed = 230400;
 848                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
 849                         info->tty->alt_speed = 460800;
 850         }
 851
 852         info->flags |= ASYNC_INITIALIZED;
 853         local_irq_restore(flags);
 854         return 0;
 855
 856 errout:
 857         local_irq_restore(flags);
 858         return retval;
 859 }
 860
 861
 862 /*
 863  * This routine is called whenever a serial port is opened.  It
 864  * enables interrupts for a serial port, linking in its async structure into
 865  * the IRQ chain.   It also performs the serial-specific
 866  * initialization for the tty structure.
 867  */
 868 static int rs_open(struct tty_struct *tty, struct file * filp)
 869 {
 870         struct async_struct     *info;
 871         int                     retval, line;
 872         unsigned long           page;
 873
 874         line = tty->index;
 875         if ((line < 0) || (line >= NR_PORTS))
 876                 return -ENODEV;
 877         retval = get_async_struct(line, &info);
 878         if (retval)
 879                 return retval;
 880         tty->driver_data = info;
 881         info->tty = tty;
 882
 883 #ifdef SIMSERIAL_DEBUG
 884         printk("rs_open %s, count = %d\n", tty->name, info->state->count);
 885 #endif
 886         info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 887
 888         if (!tmp_buf) {
 889                 page = get_zeroed_page(GFP_KERNEL);
 890                 if (!page)
 891                         return -ENOMEM;
 892                 if (tmp_buf)
 893                         free_page(page);
 894                 else
 895                         tmp_buf = (unsigned char *) page;
 896         }
 897
 898         /*
 899          * If the port is the middle of closing, bail out now
 900          */
 901         if (tty_hung_up_p(filp) ||
 902             (info->flags & ASYNC_CLOSING)) {
 903                 if (info->flags & ASYNC_CLOSING)
 904                         interruptible_sleep_on(&info->close_wait);
 905 #ifdef SERIAL_DO_RESTART
 906                 return ((info->flags & ASYNC_HUP_NOTIFY) ?
 907                         -EAGAIN : -ERESTARTSYS);
 908 #else
 909                 return -EAGAIN;
 910 #endif
 911         }
 912
 913         /*
 914          * Start up serial port
 915          */
 916         retval = startup(info);
 917         if (retval) {
 918                 return retval;
 919         }
 920
 921         /*
 922          * figure out which console to use (should be one already)
 923          */
 924         console = console_drivers;
 925         while (console) {
 926                 if ((console->flags & CON_ENABLED) && console->write) break;
 927                 console = console->next;
 928         }
 929
 930 #ifdef SIMSERIAL_DEBUG
 931         printk("rs_open ttys%d successful\n", info->line);
 932 #endif
 933         return 0;
 934 }
 935
 936 /*
 937  * /proc fs routines....
 938  */
 939
 940 static inline int line_info(char *buf, struct serial_state *state)
 941 {
 942         return sprintf(buf, "%d: uart:%s port:%lX irq:%d\n",
 943                        state->line, uart_config[state->type].name,
 944                        state->port, state->irq);
 945 }
 946
 947 static int rs_read_proc(char *page, char **start, off_t off, int count,
 948                  int *eof, void *data)
 949 {
 950         int i, len = 0, l;
 951         off_t   begin = 0;
 952
 953         len += sprintf(page, "simserinfo:1.0 driver:%s\n", serial_version);
 954         for (i = 0; i < NR_PORTS && len < 4000; i++) {
 955                 l = line_info(page + len, &rs_table[i]);
 956                 len += l;
 957                 if (len+begin > off+count)
 958                         goto done;
 959                 if (len+begin < off) {
 960                         begin += len;
 961                         len = 0;
 962                 }
 963         }
 964         *eof = 1;
 965 done:
 966         if (off >= len+begin)
 967                 return 0;
 968         *start = page + (begin-off);
 969         return ((count < begin+len-off) ? count : begin+len-off);
 970 }
 971
 972 /*
 973  * ---------------------------------------------------------------------
 974  * rs_init() and friends
 975  *
 976  * rs_init() is called at boot-time to initialize the serial driver.
 977  * ---------------------------------------------------------------------
 978  */
 979
 980 /*
 981  * This routine prints out the appropriate serial driver version
 982  * number, and identifies which options were configured into this
 983  * driver.
 984  */
 985 static inline void show_serial_version(void)
 986 {
 987         printk(KERN_INFO "%s version %s with", serial_name, serial_version);
 988         printk(KERN_INFO " no serial options enabled\n");
 989 }
 990
 991 static struct tty_operations hp_ops = {
 992         .open = rs_open,
 993         .close = rs_close,
 994         .write = rs_write,
 995         .put_char = rs_put_char,
 996         .flush_chars = rs_flush_chars,
 997         .write_room = rs_write_room,
 998         .chars_in_buffer = rs_chars_in_buffer,
 999         .flush_buffer = rs_flush_buffer,
1000         .ioctl = rs_ioctl,
1001         .throttle = rs_throttle,
1002         .unthrottle = rs_unthrottle,
1003         .send_xchar = rs_send_xchar,
1004         .set_termios = rs_set_termios,
1005         .stop = rs_stop,
1006         .start = rs_start,
1007         .hangup = rs_hangup,
1008         .break_ctl = rs_break,
1009         .wait_until_sent = rs_wait_until_sent,
1010         .read_proc = rs_read_proc,
1011 };
1012
1013 /*
1014  * The serial driver boot-time initialization code!
1015  */
1016 static int __init
1017 simrs_init (void)
1018 {
1019         int                     i;
1020         struct serial_state     *state;
1021
1022         if (!ia64_platform_is("hpsim"))
1023                 return -ENODEV;
1024
1025         hp_simserial_driver = alloc_tty_driver(1);
1026         if (!hp_simserial_driver)
1027                 return -ENOMEM;
1028
1029         show_serial_version();
1030
1031         /* Initialize the tty_driver structure */
1032
1033         hp_simserial_driver->owner = THIS_MODULE;
1034         hp_simserial_driver->driver_name = "simserial";
1035         hp_simserial_driver->name = "ttyS";
1036         hp_simserial_driver->major = TTY_MAJOR;
1037         hp_simserial_driver->minor_start = 64;
1038         hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1039         hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
1040         hp_simserial_driver->init_termios = tty_std_termios;
1041         hp_simserial_driver->init_termios.c_cflag =
1042                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1043         hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
1044         tty_set_operations(hp_simserial_driver, &hp_ops);
1045
1046         /*
1047          * Let's have a little bit of fun !
1048          */
1049         for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {
1050
1051                 if (state->type == PORT_UNKNOWN) continue;
1052
1053                 if (!state->irq) {
1054                         state->irq = assign_irq_vector(AUTO_ASSIGN);
1055                         ia64_ssc_connect_irq(KEYBOARD_INTR, state->irq);
1056                 }
1057
1058                 printk(KERN_INFO "ttyS%02d at 0x%04lx (irq = %d) is a %s\n",
1059                        state->line,
1060                        state->port, state->irq,
1061                        uart_config[state->type].name);
1062         }
1063
1064         if (tty_register_driver(hp_simserial_driver))
1065                 panic("Couldn't register simserial driver\n");
1066
1067         return 0;
1068 }
1069
1070 #ifndef MODULE
1071 __initcall(simrs_init);
1072 #endif