git.oblomov.eu Git - linux-2.6/blob - 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/init.h>
  20 #include <linux/errno.h>
  21 #include <linux/sched.h>
  22 #include <linux/tty.h>
  23 #include <linux/tty_flip.h>
  24 #include <linux/major.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/mm.h>
  27 #include <linux/slab.h>
  28 #include <linux/capability.h>
  29 #include <linux/console.h>
  30 #include <linux/module.h>
  31 #include <linux/serial.h>
  32 #include <linux/serialP.h>
  33 #include <linux/sysrq.h>
  34
  35 #include <asm/irq.h>
  36 #include <asm/hw_irq.h>
  37 #include <asm/uaccess.h>
  38
  39 #ifdef CONFIG_KDB
  40 # include <linux/kdb.h>
  41 #endif
  42
  43 #undef SIMSERIAL_DEBUG  /* define this to get some debug information */
  44
  45 #define KEYBOARD_INTR   3       /* must match with simulator! */
  46
  47 #define NR_PORTS        1       /* only one port for now */
  48
  49 #define IRQ_T(info) ((info->flags & ASYNC_SHARE_IRQ) ? IRQF_SHARED : IRQF_DISABLED)
  50
  51 #define SSC_GETCHAR     21
  52
  53 extern long ia64_ssc (long, long, long, long, int);
  54 extern void ia64_ssc_connect_irq (long intr, long irq);
  55
  56 static char *serial_name = "SimSerial driver";
  57 static char *serial_version = "0.6";
  58
  59 /*
  60  * This has been extracted from asm/serial.h. We need one eventually but
  61  * I don't know exactly what we're going to put in it so just fake one
  62  * for now.
  63  */
  64 #define BASE_BAUD ( 1843200 / 16 )
  65
  66 #define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
  67
  68 /*
  69  * Most of the values here are meaningless to this particular driver.
  70  * However some values must be preserved for the code (leveraged from serial.c
  71  * to work correctly).
  72  * port must not be 0
  73  * type must not be UNKNOWN
  74  * So I picked arbitrary (guess from where?) values instead
  75  */
  76 static struct serial_state rs_table[NR_PORTS]={
  77   /* UART CLK   PORT IRQ     FLAGS        */
  78   { 0, BASE_BAUD, 0x3F8, 0, STD_COM_FLAGS,0,PORT_16550 }  /* ttyS0 */
  79 };
  80
  81 /*
  82  * Just for the fun of it !
  83  */
  84 static struct serial_uart_config uart_config[] = {
  85         { "unknown", 1, 0 },
  86         { "8250", 1, 0 },
  87         { "16450", 1, 0 },
  88         { "16550", 1, 0 },
  89         { "16550A", 16, UART_CLEAR_FIFO | UART_USE_FIFO },
  90         { "cirrus", 1, 0 },
  91         { "ST16650", 1, UART_CLEAR_FIFO | UART_STARTECH },
  92         { "ST16650V2", 32, UART_CLEAR_FIFO | UART_USE_FIFO |
  93                   UART_STARTECH },
  94         { "TI16750", 64, UART_CLEAR_FIFO | UART_USE_FIFO},
  95         { 0, 0}
  96 };
  97
  98 struct tty_driver *hp_simserial_driver;
  99
 100 static struct async_struct *IRQ_ports[NR_IRQS];
 101
 102 static struct console *console;
 103
 104 static unsigned char *tmp_buf;
 105
 106 extern struct console *console_drivers; /* from kernel/printk.c */
 107
 108 /*
 109  * ------------------------------------------------------------
 110  * rs_stop() and rs_start()
 111  *
 112  * This routines are called before setting or resetting tty->stopped.
 113  * They enable or disable transmitter interrupts, as necessary.
 114  * ------------------------------------------------------------
 115  */
 116 static void rs_stop(struct tty_struct *tty)
 117 {
 118 #ifdef SIMSERIAL_DEBUG
 119         printk("rs_stop: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
 120                 tty->stopped, tty->hw_stopped, tty->flow_stopped);
 121 #endif
 122
 123 }
 124
 125 static void rs_start(struct tty_struct *tty)
 126 {
 127 #ifdef SIMSERIAL_DEBUG
 128         printk("rs_start: 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 static  void receive_chars(struct tty_struct *tty, struct pt_regs *regs)
 134 {
 135         unsigned char ch;
 136         static unsigned char seen_esc = 0;
 137
 138         while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
 139                 if ( ch == 27 && seen_esc == 0 ) {
 140                         seen_esc = 1;
 141                         continue;
 142                 } else {
 143                         if ( seen_esc==1 && ch == 'O' ) {
 144                                 seen_esc = 2;
 145                                 continue;
 146                         } else if ( seen_esc == 2 ) {
 147                                 if ( ch == 'P' ) /* F1 */
 148                                         show_state();
 149 #ifdef CONFIG_MAGIC_SYSRQ
 150                                 if ( ch == 'S' ) { /* F4 */
 151                                         do
 152                                                 ch = ia64_ssc(0, 0, 0, 0,
 153                                                               SSC_GETCHAR);
 154                                         while (!ch);
 155                                         handle_sysrq(ch, regs, NULL);
 156                                 }
 157 #endif
 158                                 seen_esc = 0;
 159                                 continue;
 160                         }
 161                 }
 162                 seen_esc = 0;
 163
 164                 if (tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0)
 165                         break;
 166         }
 167         tty_flip_buffer_push(tty);
 168 }
 169
 170 /*
 171  * This is the serial driver's interrupt routine for a single port
 172  */
 173 static irqreturn_t rs_interrupt_single(int irq, void *dev_id, struct pt_regs * regs)
 174 {
 175         struct async_struct * info;
 176
 177         /*
 178          * I don't know exactly why they don't use the dev_id opaque data
 179          * pointer instead of this extra lookup table
 180          */
 181         info = IRQ_ports[irq];
 182         if (!info || !info->tty) {
 183                 printk(KERN_INFO "simrs_interrupt_single: info|tty=0 info=%p problem\n", info);
 184                 return IRQ_NONE;
 185         }
 186         /*
 187          * pretty simple in our case, because we only get interrupts
 188          * on inbound traffic
 189          */
 190         receive_chars(info->tty, regs);
 191         return IRQ_HANDLED;
 192 }
 193
 194 /*
 195  * -------------------------------------------------------------------
 196  * Here ends the serial interrupt routines.
 197  * -------------------------------------------------------------------
 198  */
 199
 200 #if 0
 201 /*
 202  * not really used in our situation so keep them commented out for now
 203  */
 204 static DECLARE_TASK_QUEUE(tq_serial); /* used to be at the top of the file */
 205 static void do_serial_bh(void)
 206 {
 207         run_task_queue(&tq_serial);
 208         printk(KERN_ERR "do_serial_bh: called\n");
 209 }
 210 #endif
 211
 212 static void do_softint(void *private_)
 213 {
 214         printk(KERN_ERR "simserial: do_softint called\n");
 215 }
 216
 217 static void rs_put_char(struct tty_struct *tty, unsigned char ch)
 218 {
 219         struct async_struct *info = (struct async_struct *)tty->driver_data;
 220         unsigned long flags;
 221
 222         if (!tty || !info->xmit.buf) return;
 223
 224         local_irq_save(flags);
 225         if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
 226                 local_irq_restore(flags);
 227                 return;
 228         }
 229         info->xmit.buf[info->xmit.head] = ch;
 230         info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
 231         local_irq_restore(flags);
 232 }
 233
 234 static void transmit_chars(struct async_struct *info, int *intr_done)
 235 {
 236         int count;
 237         unsigned long flags;
 238
 239
 240         local_irq_save(flags);
 241
 242         if (info->x_char) {
 243                 char c = info->x_char;
 244
 245                 console->write(console, &c, 1);
 246
 247                 info->state->icount.tx++;
 248                 info->x_char = 0;
 249
 250                 goto out;
 251         }
 252
 253         if (info->xmit.head == info->xmit.tail || info->tty->stopped || info->tty->hw_stopped) {
 254 #ifdef SIMSERIAL_DEBUG
 255                 printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
 256                        info->xmit.head, info->xmit.tail, info->tty->stopped);
 257 #endif
 258                 goto out;
 259         }
 260         /*
 261          * We removed the loop and try to do it in to chunks. We need
 262          * 2 operations maximum because it's a ring buffer.
 263          *
 264          * First from current to tail if possible.
 265          * Then from the beginning of the buffer until necessary
 266          */
 267
 268         count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
 269                     SERIAL_XMIT_SIZE - info->xmit.tail);
 270         console->write(console, info->xmit.buf+info->xmit.tail, count);
 271
 272         info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);
 273
 274         /*
 275          * We have more at the beginning of the buffer
 276          */
 277         count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 278         if (count) {
 279                 console->write(console, info->xmit.buf, count);
 280                 info->xmit.tail += count;
 281         }
 282 out:
 283         local_irq_restore(flags);
 284 }
 285
 286 static void rs_flush_chars(struct tty_struct *tty)
 287 {
 288         struct async_struct *info = (struct async_struct *)tty->driver_data;
 289
 290         if (info->xmit.head == info->xmit.tail || tty->stopped || tty->hw_stopped ||
 291             !info->xmit.buf)
 292                 return;
 293
 294         transmit_chars(info, NULL);
 295 }
 296
 297
 298 static int rs_write(struct tty_struct * tty,
 299                     const unsigned char *buf, int count)
 300 {
 301         int     c, ret = 0;
 302         struct async_struct *info = (struct async_struct *)tty->driver_data;
 303         unsigned long flags;
 304
 305         if (!tty || !info->xmit.buf || !tmp_buf) return 0;
 306
 307         local_irq_save(flags);
 308         while (1) {
 309                 c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 310                 if (count < c)
 311                         c = count;
 312                 if (c <= 0) {
 313                         break;
 314                 }
 315                 memcpy(info->xmit.buf + info->xmit.head, buf, c);
 316                 info->xmit.head = ((info->xmit.head + c) &
 317                                    (SERIAL_XMIT_SIZE-1));
 318                 buf += c;
 319                 count -= c;
 320                 ret += c;
 321         }
 322         local_irq_restore(flags);
 323         /*
 324          * Hey, we transmit directly from here in our case
 325          */
 326         if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE)
 327             && !tty->stopped && !tty->hw_stopped) {
 328                 transmit_chars(info, NULL);
 329         }
 330         return ret;
 331 }
 332
 333 static int rs_write_room(struct tty_struct *tty)
 334 {
 335         struct async_struct *info = (struct async_struct *)tty->driver_data;
 336
 337         return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 338 }
 339
 340 static int rs_chars_in_buffer(struct tty_struct *tty)
 341 {
 342         struct async_struct *info = (struct async_struct *)tty->driver_data;
 343
 344         return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 345 }
 346
 347 static void rs_flush_buffer(struct tty_struct *tty)
 348 {
 349         struct async_struct *info = (struct async_struct *)tty->driver_data;
 350         unsigned long flags;
 351
 352         local_irq_save(flags);
 353         info->xmit.head = info->xmit.tail = 0;
 354         local_irq_restore(flags);
 355
 356         wake_up_interruptible(&tty->write_wait);
 357
 358         if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 359             tty->ldisc.write_wakeup)
 360                 (tty->ldisc.write_wakeup)(tty);
 361 }
 362
 363 /*
 364  * This function is used to send a high-priority XON/XOFF character to
 365  * the device
 366  */
 367 static void rs_send_xchar(struct tty_struct *tty, char ch)
 368 {
 369         struct async_struct *info = (struct async_struct *)tty->driver_data;
 370
 371         info->x_char = ch;
 372         if (ch) {
 373                 /*
 374                  * I guess we could call console->write() directly but
 375                  * let's do that for now.
 376                  */
 377                 transmit_chars(info, NULL);
 378         }
 379 }
 380
 381 /*
 382  * ------------------------------------------------------------
 383  * rs_throttle()
 384  *
 385  * This routine is called by the upper-layer tty layer to signal that
 386  * incoming characters should be throttled.
 387  * ------------------------------------------------------------
 388  */
 389 static void rs_throttle(struct tty_struct * tty)
 390 {
 391         if (I_IXOFF(tty)) rs_send_xchar(tty, STOP_CHAR(tty));
 392
 393         printk(KERN_INFO "simrs_throttle called\n");
 394 }
 395
 396 static void rs_unthrottle(struct tty_struct * tty)
 397 {
 398         struct async_struct *info = (struct async_struct *)tty->driver_data;
 399
 400         if (I_IXOFF(tty)) {
 401                 if (info->x_char)
 402                         info->x_char = 0;
 403                 else
 404                         rs_send_xchar(tty, START_CHAR(tty));
 405         }
 406         printk(KERN_INFO "simrs_unthrottle called\n");
 407 }
 408
 409 /*
 410  * rs_break() --- routine which turns the break handling on or off
 411  */
 412 static void rs_break(struct tty_struct *tty, int break_state)
 413 {
 414 }
 415
 416 static int rs_ioctl(struct tty_struct *tty, struct file * file,
 417                     unsigned int cmd, unsigned long arg)
 418 {
 419         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
 420             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
 421             (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
 422                 if (tty->flags & (1 << TTY_IO_ERROR))
 423                     return -EIO;
 424         }
 425
 426         switch (cmd) {
 427                 case TIOCMGET:
 428                         printk(KERN_INFO "rs_ioctl: TIOCMGET called\n");
 429                         return -EINVAL;
 430                 case TIOCMBIS:
 431                 case TIOCMBIC:
 432                 case TIOCMSET:
 433                         printk(KERN_INFO "rs_ioctl: TIOCMBIS/BIC/SET called\n");
 434                         return -EINVAL;
 435                 case TIOCGSERIAL:
 436                         printk(KERN_INFO "simrs_ioctl TIOCGSERIAL called\n");
 437                         return 0;
 438                 case TIOCSSERIAL:
 439                         printk(KERN_INFO "simrs_ioctl TIOCSSERIAL called\n");
 440                         return 0;
 441                 case TIOCSERCONFIG:
 442                         printk(KERN_INFO "rs_ioctl: TIOCSERCONFIG called\n");
 443                         return -EINVAL;
 444
 445                 case TIOCSERGETLSR: /* Get line status register */
 446                         printk(KERN_INFO "rs_ioctl: TIOCSERGETLSR called\n");
 447                         return  -EINVAL;
 448
 449                 case TIOCSERGSTRUCT:
 450                         printk(KERN_INFO "rs_ioctl: TIOCSERGSTRUCT called\n");
 451 #if 0
 452                         if (copy_to_user((struct async_struct *) arg,
 453                                          info, sizeof(struct async_struct)))
 454                                 return -EFAULT;
 455 #endif
 456                         return 0;
 457
 458                 /*
 459                  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
 460                  * - mask passed in arg for lines of interest
 461                  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
 462                  * Caller should use TIOCGICOUNT to see which one it was
 463                  */
 464                 case TIOCMIWAIT:
 465                         printk(KERN_INFO "rs_ioctl: TIOCMIWAIT: called\n");
 466                         return 0;
 467                 /*
 468                  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
 469                  * Return: write counters to the user passed counter struct
 470                  * NB: both 1->0 and 0->1 transitions are counted except for
 471                  *     RI where only 0->1 is counted.
 472                  */
 473                 case TIOCGICOUNT:
 474                         printk(KERN_INFO "rs_ioctl: TIOCGICOUNT called\n");
 475                         return 0;
 476
 477                 case TIOCSERGWILD:
 478                 case TIOCSERSWILD:
 479                         /* "setserial -W" is called in Debian boot */
 480                         printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
 481                         return 0;
 482
 483                 default:
 484                         return -ENOIOCTLCMD;
 485                 }
 486         return 0;
 487 }
 488
 489 #define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
 490
 491 static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
 492 {
 493         unsigned int cflag = tty->termios->c_cflag;
 494
 495         if (   (cflag == old_termios->c_cflag)
 496             && (   RELEVANT_IFLAG(tty->termios->c_iflag)
 497                 == RELEVANT_IFLAG(old_termios->c_iflag)))
 498           return;
 499
 500
 501         /* Handle turning off CRTSCTS */
 502         if ((old_termios->c_cflag & CRTSCTS) &&
 503             !(tty->termios->c_cflag & CRTSCTS)) {
 504                 tty->hw_stopped = 0;
 505                 rs_start(tty);
 506         }
 507 }
 508 /*
 509  * This routine will shutdown a serial port; interrupts are disabled, and
 510  * DTR is dropped if the hangup on close termio flag is on.
 511  */
 512 static void shutdown(struct async_struct * info)
 513 {
 514         unsigned long   flags;
 515         struct serial_state *state;
 516         int             retval;
 517
 518         if (!(info->flags & ASYNC_INITIALIZED)) return;
 519
 520         state = info->state;
 521
 522 #ifdef SIMSERIAL_DEBUG
 523         printk("Shutting down serial port %d (irq %d)....", info->line,
 524                state->irq);
 525 #endif
 526
 527         local_irq_save(flags);
 528         {
 529                 /*
 530                  * First unlink the serial port from the IRQ chain...
 531                  */
 532                 if (info->next_port)
 533                         info->next_port->prev_port = info->prev_port;
 534                 if (info->prev_port)
 535                         info->prev_port->next_port = info->next_port;
 536                 else
 537                         IRQ_ports[state->irq] = info->next_port;
 538
 539                 /*
 540                  * Free the IRQ, if necessary
 541                  */
 542                 if (state->irq && (!IRQ_ports[state->irq] ||
 543                                    !IRQ_ports[state->irq]->next_port)) {
 544                         if (IRQ_ports[state->irq]) {
 545                                 free_irq(state->irq, NULL);
 546                                 retval = request_irq(state->irq, rs_interrupt_single,
 547                                                      IRQ_T(info), "serial", NULL);
 548
 549                                 if (retval)
 550                                         printk(KERN_ERR "serial shutdown: request_irq: error %d"
 551                                                "  Couldn't reacquire IRQ.\n", retval);
 552                         } else
 553                                 free_irq(state->irq, NULL);
 554                 }
 555
 556                 if (info->xmit.buf) {
 557                         free_page((unsigned long) info->xmit.buf);
 558                         info->xmit.buf = 0;
 559                 }
 560
 561                 if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags);
 562
 563                 info->flags &= ~ASYNC_INITIALIZED;
 564         }
 565         local_irq_restore(flags);
 566 }
 567
 568 /*
 569  * ------------------------------------------------------------
 570  * rs_close()
 571  *
 572  * This routine is called when the serial port gets closed.  First, we
 573  * wait for the last remaining data to be sent.  Then, we unlink its
 574  * async structure from the interrupt chain if necessary, and we free
 575  * that IRQ if nothing is left in the chain.
 576  * ------------------------------------------------------------
 577  */
 578 static void rs_close(struct tty_struct *tty, struct file * filp)
 579 {
 580         struct async_struct * info = (struct async_struct *)tty->driver_data;
 581         struct serial_state *state;
 582         unsigned long flags;
 583
 584         if (!info ) return;
 585
 586         state = info->state;
 587
 588         local_irq_save(flags);
 589         if (tty_hung_up_p(filp)) {
 590 #ifdef SIMSERIAL_DEBUG
 591                 printk("rs_close: hung_up\n");
 592 #endif
 593                 local_irq_restore(flags);
 594                 return;
 595         }
 596 #ifdef SIMSERIAL_DEBUG
 597         printk("rs_close ttys%d, count = %d\n", info->line, state->count);
 598 #endif
 599         if ((tty->count == 1) && (state->count != 1)) {
 600                 /*
 601                  * Uh, oh.  tty->count is 1, which means that the tty
 602                  * structure will be freed.  state->count should always
 603                  * be one in these conditions.  If it's greater than
 604                  * one, we've got real problems, since it means the
 605                  * serial port won't be shutdown.
 606                  */
 607                 printk(KERN_ERR "rs_close: bad serial port count; tty->count is 1, "
 608                        "state->count is %d\n", state->count);
 609                 state->count = 1;
 610         }
 611         if (--state->count < 0) {
 612                 printk(KERN_ERR "rs_close: bad serial port count for ttys%d: %d\n",
 613                        info->line, state->count);
 614                 state->count = 0;
 615         }
 616         if (state->count) {
 617                 local_irq_restore(flags);
 618                 return;
 619         }
 620         info->flags |= ASYNC_CLOSING;
 621         local_irq_restore(flags);
 622
 623         /*
 624          * Now we wait for the transmit buffer to clear; and we notify
 625          * the line discipline to only process XON/XOFF characters.
 626          */
 627         shutdown(info);
 628         if (tty->driver->flush_buffer) tty->driver->flush_buffer(tty);
 629         if (tty->ldisc.flush_buffer) tty->ldisc.flush_buffer(tty);
 630         info->event = 0;
 631         info->tty = 0;
 632         if (info->blocked_open) {
 633                 if (info->close_delay)
 634                         schedule_timeout_interruptible(info->close_delay);
 635                 wake_up_interruptible(&info->open_wait);
 636         }
 637         info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
 638         wake_up_interruptible(&info->close_wait);
 639 }
 640
 641 /*
 642  * rs_wait_until_sent() --- wait until the transmitter is empty
 643  */
 644 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 645 {
 646 }
 647
 648
 649 /*
 650  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 651  */
 652 static void rs_hangup(struct tty_struct *tty)
 653 {
 654         struct async_struct * info = (struct async_struct *)tty->driver_data;
 655         struct serial_state *state = info->state;
 656
 657 #ifdef SIMSERIAL_DEBUG
 658         printk("rs_hangup: called\n");
 659 #endif
 660
 661         state = info->state;
 662
 663         rs_flush_buffer(tty);
 664         if (info->flags & ASYNC_CLOSING)
 665                 return;
 666         shutdown(info);
 667
 668         info->event = 0;
 669         state->count = 0;
 670         info->flags &= ~ASYNC_NORMAL_ACTIVE;
 671         info->tty = 0;
 672         wake_up_interruptible(&info->open_wait);
 673 }
 674
 675
 676 static int get_async_struct(int line, struct async_struct **ret_info)
 677 {
 678         struct async_struct *info;
 679         struct serial_state *sstate;
 680
 681         sstate = rs_table + line;
 682         sstate->count++;
 683         if (sstate->info) {
 684                 *ret_info = sstate->info;
 685                 return 0;
 686         }
 687         info = kmalloc(sizeof(struct async_struct), GFP_KERNEL);
 688         if (!info) {
 689                 sstate->count--;
 690                 return -ENOMEM;
 691         }
 692         memset(info, 0, sizeof(struct async_struct));
 693         init_waitqueue_head(&info->open_wait);
 694         init_waitqueue_head(&info->close_wait);
 695         init_waitqueue_head(&info->delta_msr_wait);
 696         info->magic = SERIAL_MAGIC;
 697         info->port = sstate->port;
 698         info->flags = sstate->flags;
 699         info->xmit_fifo_size = sstate->xmit_fifo_size;
 700         info->line = line;
 701         INIT_WORK(&info->work, do_softint, info);
 702         info->state = sstate;
 703         if (sstate->info) {
 704                 kfree(info);
 705                 *ret_info = sstate->info;
 706                 return 0;
 707         }
 708         *ret_info = sstate->info = info;
 709         return 0;
 710 }
 711
 712 static int
 713 startup(struct async_struct *info)
 714 {
 715         unsigned long flags;
 716         int     retval=0;
 717         irqreturn_t (*handler)(int, void *, struct pt_regs *);
 718         struct serial_state *state= info->state;
 719         unsigned long page;
 720
 721         page = get_zeroed_page(GFP_KERNEL);
 722         if (!page)
 723                 return -ENOMEM;
 724
 725         local_irq_save(flags);
 726
 727         if (info->flags & ASYNC_INITIALIZED) {
 728                 free_page(page);
 729                 goto errout;
 730         }
 731
 732         if (!state->port || !state->type) {
 733                 if (info->tty) set_bit(TTY_IO_ERROR, &info->tty->flags);
 734                 free_page(page);
 735                 goto errout;
 736         }
 737         if (info->xmit.buf)
 738                 free_page(page);
 739         else
 740                 info->xmit.buf = (unsigned char *) page;
 741
 742 #ifdef SIMSERIAL_DEBUG
 743         printk("startup: ttys%d (irq %d)...", info->line, state->irq);
 744 #endif
 745
 746         /*
 747          * Allocate the IRQ if necessary
 748          */
 749         if (state->irq && (!IRQ_ports[state->irq] ||
 750                           !IRQ_ports[state->irq]->next_port)) {
 751                 if (IRQ_ports[state->irq]) {
 752                         retval = -EBUSY;
 753                         goto errout;
 754                 } else
 755                         handler = rs_interrupt_single;
 756
 757                 retval = request_irq(state->irq, handler, IRQ_T(info), "simserial", NULL);
 758                 if (retval) {
 759                         if (capable(CAP_SYS_ADMIN)) {
 760                                 if (info->tty)
 761                                         set_bit(TTY_IO_ERROR,
 762                                                 &info->tty->flags);
 763                                 retval = 0;
 764                         }
 765                         goto errout;
 766                 }
 767         }
 768
 769         /*
 770          * Insert serial port into IRQ chain.
 771          */
 772         info->prev_port = 0;
 773         info->next_port = IRQ_ports[state->irq];
 774         if (info->next_port)
 775                 info->next_port->prev_port = info;
 776         IRQ_ports[state->irq] = info;
 777
 778         if (info->tty) clear_bit(TTY_IO_ERROR, &info->tty->flags);
 779
 780         info->xmit.head = info->xmit.tail = 0;
 781
 782 #if 0
 783         /*
 784          * Set up serial timers...
 785          */
 786         timer_table[RS_TIMER].expires = jiffies + 2*HZ/100;
 787         timer_active |= 1 << RS_TIMER;
 788 #endif
 789
 790         /*
 791          * Set up the tty->alt_speed kludge
 792          */
 793         if (info->tty) {
 794                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
 795                         info->tty->alt_speed = 57600;
 796                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
 797                         info->tty->alt_speed = 115200;
 798                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
 799                         info->tty->alt_speed = 230400;
 800                 if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
 801                         info->tty->alt_speed = 460800;
 802         }
 803
 804         info->flags |= ASYNC_INITIALIZED;
 805         local_irq_restore(flags);
 806         return 0;
 807
 808 errout:
 809         local_irq_restore(flags);
 810         return retval;
 811 }
 812
 813
 814 /*
 815  * This routine is called whenever a serial port is opened.  It
 816  * enables interrupts for a serial port, linking in its async structure into
 817  * the IRQ chain.   It also performs the serial-specific
 818  * initialization for the tty structure.
 819  */
 820 static int rs_open(struct tty_struct *tty, struct file * filp)
 821 {
 822         struct async_struct     *info;
 823         int                     retval, line;
 824         unsigned long           page;
 825
 826         line = tty->index;
 827         if ((line < 0) || (line >= NR_PORTS))
 828                 return -ENODEV;
 829         retval = get_async_struct(line, &info);
 830         if (retval)
 831                 return retval;
 832         tty->driver_data = info;
 833         info->tty = tty;
 834
 835 #ifdef SIMSERIAL_DEBUG
 836         printk("rs_open %s, count = %d\n", tty->name, info->state->count);
 837 #endif
 838         info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 839
 840         if (!tmp_buf) {
 841                 page = get_zeroed_page(GFP_KERNEL);
 842                 if (!page)
 843                         return -ENOMEM;
 844                 if (tmp_buf)
 845                         free_page(page);
 846                 else
 847                         tmp_buf = (unsigned char *) page;
 848         }
 849
 850         /*
 851          * If the port is the middle of closing, bail out now
 852          */
 853         if (tty_hung_up_p(filp) ||
 854             (info->flags & ASYNC_CLOSING)) {
 855                 if (info->flags & ASYNC_CLOSING)
 856                         interruptible_sleep_on(&info->close_wait);
 857 #ifdef SERIAL_DO_RESTART
 858                 return ((info->flags & ASYNC_HUP_NOTIFY) ?
 859                         -EAGAIN : -ERESTARTSYS);
 860 #else
 861                 return -EAGAIN;
 862 #endif
 863         }
 864
 865         /*
 866          * Start up serial port
 867          */
 868         retval = startup(info);
 869         if (retval) {
 870                 return retval;
 871         }
 872
 873         /*
 874          * figure out which console to use (should be one already)
 875          */
 876         console = console_drivers;
 877         while (console) {
 878                 if ((console->flags & CON_ENABLED) && console->write) break;
 879                 console = console->next;
 880         }
 881
 882 #ifdef SIMSERIAL_DEBUG
 883         printk("rs_open ttys%d successful\n", info->line);
 884 #endif
 885         return 0;
 886 }
 887
 888 /*
 889  * /proc fs routines....
 890  */
 891
 892 static inline int line_info(char *buf, struct serial_state *state)
 893 {
 894         return sprintf(buf, "%d: uart:%s port:%lX irq:%d\n",
 895                        state->line, uart_config[state->type].name,
 896                        state->port, state->irq);
 897 }
 898
 899 static int rs_read_proc(char *page, char **start, off_t off, int count,
 900                  int *eof, void *data)
 901 {
 902         int i, len = 0, l;
 903         off_t   begin = 0;
 904
 905         len += sprintf(page, "simserinfo:1.0 driver:%s\n", serial_version);
 906         for (i = 0; i < NR_PORTS && len < 4000; i++) {
 907                 l = line_info(page + len, &rs_table[i]);
 908                 len += l;
 909                 if (len+begin > off+count)
 910                         goto done;
 911                 if (len+begin < off) {
 912                         begin += len;
 913                         len = 0;
 914                 }
 915         }
 916         *eof = 1;
 917 done:
 918         if (off >= len+begin)
 919                 return 0;
 920         *start = page + (begin-off);
 921         return ((count < begin+len-off) ? count : begin+len-off);
 922 }
 923
 924 /*
 925  * ---------------------------------------------------------------------
 926  * rs_init() and friends
 927  *
 928  * rs_init() is called at boot-time to initialize the serial driver.
 929  * ---------------------------------------------------------------------
 930  */
 931
 932 /*
 933  * This routine prints out the appropriate serial driver version
 934  * number, and identifies which options were configured into this
 935  * driver.
 936  */
 937 static inline void show_serial_version(void)
 938 {
 939         printk(KERN_INFO "%s version %s with", serial_name, serial_version);
 940         printk(KERN_INFO " no serial options enabled\n");
 941 }
 942
 943 static struct tty_operations hp_ops = {
 944         .open = rs_open,
 945         .close = rs_close,
 946         .write = rs_write,
 947         .put_char = rs_put_char,
 948         .flush_chars = rs_flush_chars,
 949         .write_room = rs_write_room,
 950         .chars_in_buffer = rs_chars_in_buffer,
 951         .flush_buffer = rs_flush_buffer,
 952         .ioctl = rs_ioctl,
 953         .throttle = rs_throttle,
 954         .unthrottle = rs_unthrottle,
 955         .send_xchar = rs_send_xchar,
 956         .set_termios = rs_set_termios,
 957         .stop = rs_stop,
 958         .start = rs_start,
 959         .hangup = rs_hangup,
 960         .break_ctl = rs_break,
 961         .wait_until_sent = rs_wait_until_sent,
 962         .read_proc = rs_read_proc,
 963 };
 964
 965 /*
 966  * The serial driver boot-time initialization code!
 967  */
 968 static int __init
 969 simrs_init (void)
 970 {
 971         int                     i, rc;
 972         struct serial_state     *state;
 973
 974         if (!ia64_platform_is("hpsim"))
 975                 return -ENODEV;
 976
 977         hp_simserial_driver = alloc_tty_driver(1);
 978         if (!hp_simserial_driver)
 979                 return -ENOMEM;
 980
 981         show_serial_version();
 982
 983         /* Initialize the tty_driver structure */
 984
 985         hp_simserial_driver->owner = THIS_MODULE;
 986         hp_simserial_driver->driver_name = "simserial";
 987         hp_simserial_driver->name = "ttyS";
 988         hp_simserial_driver->major = TTY_MAJOR;
 989         hp_simserial_driver->minor_start = 64;
 990         hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
 991         hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
 992         hp_simserial_driver->init_termios = tty_std_termios;
 993         hp_simserial_driver->init_termios.c_cflag =
 994                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 995         hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
 996         tty_set_operations(hp_simserial_driver, &hp_ops);
 997
 998         /*
 999          * Let's have a little bit of fun !
1000          */
1001         for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {
1002
1003                 if (state->type == PORT_UNKNOWN) continue;
1004
1005                 if (!state->irq) {
1006                         if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0)
1007                                 panic("%s: out of interrupt vectors!\n",
1008                                       __FUNCTION__);
1009                         state->irq = rc;
1010                         ia64_ssc_connect_irq(KEYBOARD_INTR, state->irq);
1011                 }
1012
1013                 printk(KERN_INFO "ttyS%d at 0x%04lx (irq = %d) is a %s\n",
1014                        state->line,
1015                        state->port, state->irq,
1016                        uart_config[state->type].name);
1017         }
1018
1019         if (tty_register_driver(hp_simserial_driver))
1020                 panic("Couldn't register simserial driver\n");
1021
1022         return 0;
1023 }
1024
1025 #ifndef MODULE
1026 __initcall(simrs_init);
1027 #endif