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