drivers/tc/zs.c

   1 /*
   2  * decserial.c: Serial port driver for IOASIC DECstations.
   3  *
   4  * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras.
   5  * Derived from drivers/macintosh/macserial.c by Harald Koerfgen.
   6  *
   7  * DECstation changes
   8  * Copyright (C) 1998-2000 Harald Koerfgen
   9  * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005  Maciej W. Rozycki
  10  *
  11  * For the rest of the code the original Copyright applies:
  12  * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
  13  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  14  *
  15  *
  16  * Note: for IOASIC systems the wiring is as follows:
  17  *
  18  * mouse/keyboard:
  19  * DIN-7 MJ-4  signal        SCC
  20  * 2     1     TxD       <-  A.TxD
  21  * 3     4     RxD       ->  A.RxD
  22  *
  23  * EIA-232/EIA-423:
  24  * DB-25 MMJ-6 signal        SCC
  25  * 2     2     TxD       <-  B.TxD
  26  * 3     5     RxD       ->  B.RxD
  27  * 4           RTS       <- ~A.RTS
  28  * 5           CTS       -> ~B.CTS
  29  * 6     6     DSR       -> ~A.SYNC
  30  * 8           CD        -> ~B.DCD
  31  * 12          DSRS(DCE) -> ~A.CTS  (*)
  32  * 15          TxC       ->  B.TxC
  33  * 17          RxC       ->  B.RxC
  34  * 20    1     DTR       <- ~A.DTR
  35  * 22          RI        -> ~A.DCD
  36  * 23          DSRS(DTE) <- ~B.RTS
  37  *
  38  * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE)
  39  *     is shared with DSRS(DTE) at pin 23.
  40  */
  41
  42 #include <linux/errno.h>
  43 #include <linux/signal.h>
  44 #include <linux/sched.h>
  45 #include <linux/timer.h>
  46 #include <linux/interrupt.h>
  47 #include <linux/tty.h>
  48 #include <linux/tty_flip.h>
  49 #include <linux/major.h>
  50 #include <linux/string.h>
  51 #include <linux/fcntl.h>
  52 #include <linux/mm.h>
  53 #include <linux/kernel.h>
  54 #include <linux/delay.h>
  55 #include <linux/init.h>
  56 #include <linux/ioport.h>
  57 #include <linux/spinlock.h>
  58 #ifdef CONFIG_SERIAL_DEC_CONSOLE
  59 #include <linux/console.h>
  60 #endif
  61
  62 #include <asm/io.h>
  63 #include <asm/pgtable.h>
  64 #include <asm/irq.h>
  65 #include <asm/system.h>
  66 #include <asm/bootinfo.h>
  67
  68 #include <asm/dec/interrupts.h>
  69 #include <asm/dec/ioasic_addrs.h>
  70 #include <asm/dec/machtype.h>
  71 #include <asm/dec/serial.h>
  72 #include <asm/dec/system.h>
  73
  74 #ifdef CONFIG_KGDB
  75 #include <asm/kgdb.h>
  76 #endif
  77 #ifdef CONFIG_MAGIC_SYSRQ
  78 #include <linux/sysrq.h>
  79 #endif
  80
  81 #include "zs.h"
  82
  83 /*
  84  * It would be nice to dynamically allocate everything that
  85  * depends on NUM_SERIAL, so we could support any number of
  86  * Z8530s, but for now...
  87  */
  88 #define NUM_SERIAL      2               /* Max number of ZS chips supported */
  89 #define NUM_CHANNELS    (NUM_SERIAL * 2)        /* 2 channels per chip */
  90 #define CHANNEL_A_NR  (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
  91                                         /* Number of channel A in the chip */
  92 #define ZS_CHAN_IO_SIZE 8
  93 #define ZS_CLOCK        7372800         /* Z8530 RTxC input clock rate */
  94
  95 #define RECOVERY_DELAY  udelay(2)
  96
  97 struct zs_parms {
  98         unsigned long scc0;
  99         unsigned long scc1;
 100         int channel_a_offset;
 101         int channel_b_offset;
 102         int irq0;
 103         int irq1;
 104         int clock;
 105 };
 106
 107 static struct zs_parms *zs_parms;
 108
 109 #ifdef CONFIG_MACH_DECSTATION
 110 static struct zs_parms ds_parms = {
 111         scc0 : IOASIC_SCC0,
 112         scc1 : IOASIC_SCC1,
 113         channel_a_offset : 1,
 114         channel_b_offset : 9,
 115         irq0 : -1,
 116         irq1 : -1,
 117         clock : ZS_CLOCK
 118 };
 119 #endif
 120
 121 #ifdef CONFIG_MACH_DECSTATION
 122 #define DS_BUS_PRESENT (IOASIC)
 123 #else
 124 #define DS_BUS_PRESENT 0
 125 #endif
 126
 127 #define BUS_PRESENT (DS_BUS_PRESENT)
 128
 129 DEFINE_SPINLOCK(zs_lock);
 130
 131 struct dec_zschannel zs_channels[NUM_CHANNELS];
 132 struct dec_serial zs_soft[NUM_CHANNELS];
 133 int zs_channels_found;
 134 struct dec_serial *zs_chain;    /* list of all channels */
 135
 136 struct tty_struct zs_ttys[NUM_CHANNELS];
 137
 138 #ifdef CONFIG_SERIAL_DEC_CONSOLE
 139 static struct console zs_console;
 140 #endif
 141 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
 142    !defined(MODULE)
 143 static unsigned long break_pressed; /* break, really ... */
 144 #endif
 145
 146 static unsigned char zs_init_regs[16] __initdata = {
 147         0,                              /* write 0 */
 148         0,                              /* write 1 */
 149         0,                              /* write 2 */
 150         0,                              /* write 3 */
 151         (X16CLK),                       /* write 4 */
 152         0,                              /* write 5 */
 153         0, 0, 0,                        /* write 6, 7, 8 */
 154         (MIE | DLC | NV),               /* write 9 */
 155         (NRZ),                          /* write 10 */
 156         (TCBR | RCBR),                  /* write 11 */
 157         0, 0,                           /* BRG time constant, write 12 + 13 */
 158         (BRSRC | BRENABL),              /* write 14 */
 159         0                               /* write 15 */
 160 };
 161
 162 static struct tty_driver *serial_driver;
 163
 164 /* serial subtype definitions */
 165 #define SERIAL_TYPE_NORMAL      1
 166
 167 /* number of characters left in xmit buffer before we ask for more */
 168 #define WAKEUP_CHARS 256
 169
 170 /*
 171  * Debugging.
 172  */
 173 #undef SERIAL_DEBUG_OPEN
 174 #undef SERIAL_DEBUG_FLOW
 175 #undef SERIAL_DEBUG_THROTTLE
 176 #undef SERIAL_PARANOIA_CHECK
 177
 178 #undef ZS_DEBUG_REGS
 179
 180 #ifdef SERIAL_DEBUG_THROTTLE
 181 #define _tty_name(tty,buf) tty_name(tty,buf)
 182 #endif
 183
 184 #define RS_STROBE_TIME 10
 185 #define RS_ISR_PASS_LIMIT 256
 186
 187 static void probe_sccs(void);
 188 static void change_speed(struct dec_serial *info);
 189 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 190
 191 static inline int serial_paranoia_check(struct dec_serial *info,
 192                                         char *name, const char *routine)
 193 {
 194 #ifdef SERIAL_PARANOIA_CHECK
 195         static const char *badmagic =
 196                 "Warning: bad magic number for serial struct %s in %s\n";
 197         static const char *badinfo =
 198                 "Warning: null mac_serial for %s in %s\n";
 199
 200         if (!info) {
 201                 printk(badinfo, name, routine);
 202                 return 1;
 203         }
 204         if (info->magic != SERIAL_MAGIC) {
 205                 printk(badmagic, name, routine);
 206                 return 1;
 207         }
 208 #endif
 209         return 0;
 210 }
 211
 212 /*
 213  * This is used to figure out the divisor speeds and the timeouts
 214  */
 215 static int baud_table[] = {
 216         0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
 217         9600, 19200, 38400, 57600, 115200, 0 };
 218
 219 /*
 220  * Reading and writing Z8530 registers.
 221  */
 222 static inline unsigned char read_zsreg(struct dec_zschannel *channel,
 223                                        unsigned char reg)
 224 {
 225         unsigned char retval;
 226
 227         if (reg != 0) {
 228                 *channel->control = reg & 0xf;
 229                 fast_iob(); RECOVERY_DELAY;
 230         }
 231         retval = *channel->control;
 232         RECOVERY_DELAY;
 233         return retval;
 234 }
 235
 236 static inline void write_zsreg(struct dec_zschannel *channel,
 237                                unsigned char reg, unsigned char value)
 238 {
 239         if (reg != 0) {
 240                 *channel->control = reg & 0xf;
 241                 fast_iob(); RECOVERY_DELAY;
 242         }
 243         *channel->control = value;
 244         fast_iob(); RECOVERY_DELAY;
 245         return;
 246 }
 247
 248 static inline unsigned char read_zsdata(struct dec_zschannel *channel)
 249 {
 250         unsigned char retval;
 251
 252         retval = *channel->data;
 253         RECOVERY_DELAY;
 254         return retval;
 255 }
 256
 257 static inline void write_zsdata(struct dec_zschannel *channel,
 258                                 unsigned char value)
 259 {
 260         *channel->data = value;
 261         fast_iob(); RECOVERY_DELAY;
 262         return;
 263 }
 264
 265 static inline void load_zsregs(struct dec_zschannel *channel,
 266                                unsigned char *regs)
 267 {
 268 /*      ZS_CLEARERR(channel);
 269         ZS_CLEARFIFO(channel); */
 270         /* Load 'em up */
 271         write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
 272         write_zsreg(channel, R5, regs[R5] & ~TxENAB);
 273         write_zsreg(channel, R4, regs[R4]);
 274         write_zsreg(channel, R9, regs[R9]);
 275         write_zsreg(channel, R1, regs[R1]);
 276         write_zsreg(channel, R2, regs[R2]);
 277         write_zsreg(channel, R10, regs[R10]);
 278         write_zsreg(channel, R11, regs[R11]);
 279         write_zsreg(channel, R12, regs[R12]);
 280         write_zsreg(channel, R13, regs[R13]);
 281         write_zsreg(channel, R14, regs[R14]);
 282         write_zsreg(channel, R15, regs[R15]);
 283         write_zsreg(channel, R3, regs[R3]);
 284         write_zsreg(channel, R5, regs[R5]);
 285         return;
 286 }
 287
 288 /* Sets or clears DTR/RTS on the requested line */
 289 static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
 290 {
 291         unsigned long flags;
 292
 293         spin_lock_irqsave(&zs_lock, flags);
 294         if (info->zs_channel != info->zs_chan_a) {
 295                 if (set) {
 296                         info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
 297                 } else {
 298                         info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
 299                 }
 300                 write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
 301         }
 302         spin_unlock_irqrestore(&zs_lock, flags);
 303 }
 304
 305 /* Utility routines for the Zilog */
 306 static inline int get_zsbaud(struct dec_serial *ss)
 307 {
 308         struct dec_zschannel *channel = ss->zs_channel;
 309         int brg;
 310
 311         /* The baud rate is split up between two 8-bit registers in
 312          * what is termed 'BRG time constant' format in my docs for
 313          * the chip, it is a function of the clk rate the chip is
 314          * receiving which happens to be constant.
 315          */
 316         brg = (read_zsreg(channel, 13) << 8);
 317         brg |= read_zsreg(channel, 12);
 318         return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
 319 }
 320
 321 /* On receive, this clears errors and the receiver interrupts */
 322 static inline void rs_recv_clear(struct dec_zschannel *zsc)
 323 {
 324         write_zsreg(zsc, 0, ERR_RES);
 325         write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
 326 }
 327
 328 /*
 329  * ----------------------------------------------------------------------
 330  *
 331  * Here starts the interrupt handling routines.  All of the following
 332  * subroutines are declared as inline and are folded into
 333  * rs_interrupt().  They were separated out for readability's sake.
 334  *
 335  *                              - Ted Ts'o (tytso@mit.edu), 7-Mar-93
 336  * -----------------------------------------------------------------------
 337  */
 338
 339 /*
 340  * This routine is used by the interrupt handler to schedule
 341  * processing in the software interrupt portion of the driver.
 342  */
 343 static void rs_sched_event(struct dec_serial *info, int event)
 344 {
 345         info->event |= 1 << event;
 346         tasklet_schedule(&info->tlet);
 347 }
 348
 349 static void receive_chars(struct dec_serial *info)
 350 {
 351         struct tty_struct *tty = info->tty;
 352         unsigned char ch, stat, flag;
 353
 354         while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
 355
 356                 stat = read_zsreg(info->zs_channel, R1);
 357                 ch = read_zsdata(info->zs_channel);
 358
 359                 if (!tty && (!info->hook || !info->hook->rx_char))
 360                         continue;
 361
 362                 flag = TTY_NORMAL;
 363                 if (info->tty_break) {
 364                         info->tty_break = 0;
 365                         flag = TTY_BREAK;
 366                         if (info->flags & ZILOG_SAK)
 367                                 do_SAK(tty);
 368                         /* Ignore the null char got when BREAK is removed.  */
 369                         if (ch == 0)
 370                                 continue;
 371                 } else {
 372                         if (stat & Rx_OVR) {
 373                                 flag = TTY_OVERRUN;
 374                         } else if (stat & FRM_ERR) {
 375                                 flag = TTY_FRAME;
 376                         } else if (stat & PAR_ERR) {
 377                                 flag = TTY_PARITY;
 378                         }
 379                         if (flag != TTY_NORMAL)
 380                                 /* reset the error indication */
 381                                 write_zsreg(info->zs_channel, R0, ERR_RES);
 382                 }
 383
 384 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
 385    !defined(MODULE)
 386                 if (break_pressed && info->line == zs_console.index) {
 387                         /* Ignore the null char got when BREAK is removed.  */
 388                         if (ch == 0)
 389                                 continue;
 390                         if (time_before(jiffies, break_pressed + HZ * 5)) {
 391                                 handle_sysrq(ch, NULL);
 392                                 break_pressed = 0;
 393                                 continue;
 394                         }
 395                         break_pressed = 0;
 396                 }
 397 #endif
 398
 399                 if (info->hook && info->hook->rx_char) {
 400                         (*info->hook->rx_char)(ch, flag);
 401                         return;
 402                 }
 403
 404                 tty_insert_flip_char(tty, ch, flag);
 405         }
 406         if (tty)
 407                 tty_flip_buffer_push(tty);
 408 }
 409
 410 static void transmit_chars(struct dec_serial *info)
 411 {
 412         if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
 413                 return;
 414         info->tx_active = 0;
 415
 416         if (info->x_char) {
 417                 /* Send next char */
 418                 write_zsdata(info->zs_channel, info->x_char);
 419                 info->x_char = 0;
 420                 info->tx_active = 1;
 421                 return;
 422         }
 423
 424         if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
 425             || info->tx_stopped) {
 426                 write_zsreg(info->zs_channel, R0, RES_Tx_P);
 427                 return;
 428         }
 429         /* Send char */
 430         write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
 431         info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 432         info->xmit_cnt--;
 433         info->tx_active = 1;
 434
 435         if (info->xmit_cnt < WAKEUP_CHARS)
 436                 rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
 437 }
 438
 439 static void status_handle(struct dec_serial *info)
 440 {
 441         unsigned char stat;
 442
 443         /* Get status from Read Register 0 */
 444         stat = read_zsreg(info->zs_channel, R0);
 445
 446         if ((stat & BRK_ABRT) && !(info->read_reg_zero & BRK_ABRT)) {
 447 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
 448    !defined(MODULE)
 449                 if (info->line == zs_console.index) {
 450                         if (!break_pressed)
 451                                 break_pressed = jiffies;
 452                 } else
 453 #endif
 454                         info->tty_break = 1;
 455         }
 456
 457         if (info->zs_channel != info->zs_chan_a) {
 458
 459                 /* Check for DCD transitions */
 460                 if (info->tty && !C_CLOCAL(info->tty) &&
 461                     ((stat ^ info->read_reg_zero) & DCD) != 0 ) {
 462                         if (stat & DCD) {
 463                                 wake_up_interruptible(&info->open_wait);
 464                         } else {
 465                                 tty_hangup(info->tty);
 466                         }
 467                 }
 468
 469                 /* Check for CTS transitions */
 470                 if (info->tty && C_CRTSCTS(info->tty)) {
 471                         if ((stat & CTS) != 0) {
 472                                 if (info->tx_stopped) {
 473                                         info->tx_stopped = 0;
 474                                         if (!info->tx_active)
 475                                                 transmit_chars(info);
 476                                 }
 477                         } else {
 478                                 info->tx_stopped = 1;
 479                         }
 480                 }
 481
 482         }
 483
 484         /* Clear status condition... */
 485         write_zsreg(info->zs_channel, R0, RES_EXT_INT);
 486         info->read_reg_zero = stat;
 487 }
 488
 489 /*
 490  * This is the serial driver's generic interrupt routine
 491  */
 492 static irqreturn_t rs_interrupt(int irq, void *dev_id)
 493 {
 494         struct dec_serial *info = (struct dec_serial *) dev_id;
 495         irqreturn_t status = IRQ_NONE;
 496         unsigned char zs_intreg;
 497         int shift;
 498
 499         /* NOTE: The read register 3, which holds the irq status,
 500          *       does so for both channels on each chip.  Although
 501          *       the status value itself must be read from the A
 502          *       channel and is only valid when read from channel A.
 503          *       Yes... broken hardware...
 504          */
 505 #define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
 506
 507         if (info->zs_chan_a == info->zs_channel)
 508                 shift = 3;      /* Channel A */
 509         else
 510                 shift = 0;      /* Channel B */
 511
 512         for (;;) {
 513                 zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
 514                 if ((zs_intreg & CHAN_IRQMASK) == 0)
 515                         break;
 516
 517                 status = IRQ_HANDLED;
 518
 519                 if (zs_intreg & CHBRxIP) {
 520                         receive_chars(info);
 521                 }
 522                 if (zs_intreg & CHBTxIP) {
 523                         transmit_chars(info);
 524                 }
 525                 if (zs_intreg & CHBEXT) {
 526                         status_handle(info);
 527                 }
 528         }
 529
 530         /* Why do we need this ? */
 531         write_zsreg(info->zs_channel, 0, RES_H_IUS);
 532
 533         return status;
 534 }
 535
 536 #ifdef ZS_DEBUG_REGS
 537 void zs_dump (void) {
 538         int i, j;
 539         for (i = 0; i < zs_channels_found; i++) {
 540                 struct dec_zschannel *ch = &zs_channels[i];
 541                 if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
 542                         for (j = 0; j < 15; j++) {
 543                                 printk("W%d = 0x%x\t",
 544                                        j, (int)ch->curregs[j]);
 545                         }
 546                         for (j = 0; j < 15; j++) {
 547                                 printk("R%d = 0x%x\t",
 548                                        j, (int)read_zsreg(ch,j));
 549                         }
 550                         printk("\n\n");
 551                 }
 552         }
 553 }
 554 #endif
 555
 556 /*
 557  * -------------------------------------------------------------------
 558  * Here ends the serial interrupt routines.
 559  * -------------------------------------------------------------------
 560  */
 561
 562 /*
 563  * ------------------------------------------------------------
 564  * rs_stop() and rs_start()
 565  *
 566  * This routines are called before setting or resetting tty->stopped.
 567  * ------------------------------------------------------------
 568  */
 569 static void rs_stop(struct tty_struct *tty)
 570 {
 571         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 572         unsigned long flags;
 573
 574         if (serial_paranoia_check(info, tty->name, "rs_stop"))
 575                 return;
 576
 577 #if 1
 578         spin_lock_irqsave(&zs_lock, flags);
 579         if (info->zs_channel->curregs[5] & TxENAB) {
 580                 info->zs_channel->curregs[5] &= ~TxENAB;
 581                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 582         }
 583         spin_unlock_irqrestore(&zs_lock, flags);
 584 #endif
 585 }
 586
 587 static void rs_start(struct tty_struct *tty)
 588 {
 589         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 590         unsigned long flags;
 591
 592         if (serial_paranoia_check(info, tty->name, "rs_start"))
 593                 return;
 594
 595         spin_lock_irqsave(&zs_lock, flags);
 596 #if 1
 597         if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
 598                 info->zs_channel->curregs[5] |= TxENAB;
 599                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 600         }
 601 #else
 602         if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
 603                 transmit_chars(info);
 604         }
 605 #endif
 606         spin_unlock_irqrestore(&zs_lock, flags);
 607 }
 608
 609 /*
 610  * This routine is used to handle the "bottom half" processing for the
 611  * serial driver, known also the "software interrupt" processing.
 612  * This processing is done at the kernel interrupt level, after the
 613  * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
 614  * is where time-consuming activities which can not be done in the
 615  * interrupt driver proper are done; the interrupt driver schedules
 616  * them using rs_sched_event(), and they get done here.
 617  */
 618
 619 static void do_softint(unsigned long private_)
 620 {
 621         struct dec_serial       *info = (struct dec_serial *) private_;
 622         struct tty_struct       *tty;
 623
 624         tty = info->tty;
 625         if (!tty)
 626                 return;
 627
 628         if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event))
 629                 tty_wakeup(tty);
 630 }
 631
 632 static int zs_startup(struct dec_serial * info)
 633 {
 634         unsigned long flags;
 635
 636         if (info->flags & ZILOG_INITIALIZED)
 637                 return 0;
 638
 639         if (!info->xmit_buf) {
 640                 info->xmit_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
 641                 if (!info->xmit_buf)
 642                         return -ENOMEM;
 643         }
 644
 645         spin_lock_irqsave(&zs_lock, flags);
 646
 647 #ifdef SERIAL_DEBUG_OPEN
 648         printk("starting up ttyS%d (irq %d)...", info->line, info->irq);
 649 #endif
 650
 651         /*
 652          * Clear the receive FIFO.
 653          */
 654         ZS_CLEARFIFO(info->zs_channel);
 655         info->xmit_fifo_size = 1;
 656
 657         /*
 658          * Clear the interrupt registers.
 659          */
 660         write_zsreg(info->zs_channel, R0, ERR_RES);
 661         write_zsreg(info->zs_channel, R0, RES_H_IUS);
 662
 663         /*
 664          * Set the speed of the serial port
 665          */
 666         change_speed(info);
 667
 668         /*
 669          * Turn on RTS and DTR.
 670          */
 671         zs_rtsdtr(info, RTS | DTR, 1);
 672
 673         /*
 674          * Finally, enable sequencing and interrupts
 675          */
 676         info->zs_channel->curregs[R1] &= ~RxINT_MASK;
 677         info->zs_channel->curregs[R1] |= (RxINT_ALL | TxINT_ENAB |
 678                                           EXT_INT_ENAB);
 679         info->zs_channel->curregs[R3] |= RxENABLE;
 680         info->zs_channel->curregs[R5] |= TxENAB;
 681         info->zs_channel->curregs[R15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
 682         write_zsreg(info->zs_channel, R1, info->zs_channel->curregs[R1]);
 683         write_zsreg(info->zs_channel, R3, info->zs_channel->curregs[R3]);
 684         write_zsreg(info->zs_channel, R5, info->zs_channel->curregs[R5]);
 685         write_zsreg(info->zs_channel, R15, info->zs_channel->curregs[R15]);
 686
 687         /*
 688          * And clear the interrupt registers again for luck.
 689          */
 690         write_zsreg(info->zs_channel, R0, ERR_RES);
 691         write_zsreg(info->zs_channel, R0, RES_H_IUS);
 692
 693         /* Save the current value of RR0 */
 694         info->read_reg_zero = read_zsreg(info->zs_channel, R0);
 695
 696         if (info->tty)
 697                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
 698         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 699
 700         info->flags |= ZILOG_INITIALIZED;
 701         spin_unlock_irqrestore(&zs_lock, flags);
 702         return 0;
 703 }
 704
 705 /*
 706  * This routine will shutdown a serial port; interrupts are disabled, and
 707  * DTR is dropped if the hangup on close termio flag is on.
 708  */
 709 static void shutdown(struct dec_serial * info)
 710 {
 711         unsigned long   flags;
 712
 713         if (!(info->flags & ZILOG_INITIALIZED))
 714                 return;
 715
 716 #ifdef SERIAL_DEBUG_OPEN
 717         printk("Shutting down serial port %d (irq %d)....", info->line,
 718                info->irq);
 719 #endif
 720
 721         spin_lock_irqsave(&zs_lock, flags);
 722
 723         if (info->xmit_buf) {
 724                 free_page((unsigned long) info->xmit_buf);
 725                 info->xmit_buf = 0;
 726         }
 727
 728         info->zs_channel->curregs[1] = 0;
 729         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]); /* no interrupts */
 730
 731         info->zs_channel->curregs[3] &= ~RxENABLE;
 732         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
 733
 734         info->zs_channel->curregs[5] &= ~TxENAB;
 735         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 736         if (!info->tty || C_HUPCL(info->tty)) {
 737                 zs_rtsdtr(info, RTS | DTR, 0);
 738         }
 739
 740         if (info->tty)
 741                 set_bit(TTY_IO_ERROR, &info->tty->flags);
 742
 743         info->flags &= ~ZILOG_INITIALIZED;
 744         spin_unlock_irqrestore(&zs_lock, flags);
 745 }
 746
 747 /*
 748  * This routine is called to set the UART divisor registers to match
 749  * the specified baud rate for a serial port.
 750  */
 751 static void change_speed(struct dec_serial *info)
 752 {
 753         unsigned cflag;
 754         int     i;
 755         int     brg, bits;
 756         unsigned long flags;
 757
 758         if (!info->hook) {
 759                 if (!info->tty || !info->tty->termios)
 760                         return;
 761                 cflag = info->tty->termios->c_cflag;
 762                 if (!info->port)
 763                         return;
 764         } else {
 765                 cflag = info->hook->cflags;
 766         }
 767
 768         i = cflag & CBAUD;
 769         if (i & CBAUDEX) {
 770                 i &= ~CBAUDEX;
 771                 if (i < 1 || i > 2) {
 772                         if (!info->hook)
 773                                 info->tty->termios->c_cflag &= ~CBAUDEX;
 774                         else
 775                                 info->hook->cflags &= ~CBAUDEX;
 776                 } else
 777                         i += 15;
 778         }
 779
 780         spin_lock_irqsave(&zs_lock, flags);
 781         info->zs_baud = baud_table[i];
 782         if (info->zs_baud) {
 783                 brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
 784                 info->zs_channel->curregs[12] = (brg & 255);
 785                 info->zs_channel->curregs[13] = ((brg >> 8) & 255);
 786                 zs_rtsdtr(info, DTR, 1);
 787         } else {
 788                 zs_rtsdtr(info, RTS | DTR, 0);
 789                 return;
 790         }
 791
 792         /* byte size and parity */
 793         info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
 794         info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
 795         switch (cflag & CSIZE) {
 796         case CS5:
 797                 bits = 7;
 798                 info->zs_channel->curregs[3] |= Rx5;
 799                 info->zs_channel->curregs[5] |= Tx5;
 800                 break;
 801         case CS6:
 802                 bits = 8;
 803                 info->zs_channel->curregs[3] |= Rx6;
 804                 info->zs_channel->curregs[5] |= Tx6;
 805                 break;
 806         case CS7:
 807                 bits = 9;
 808                 info->zs_channel->curregs[3] |= Rx7;
 809                 info->zs_channel->curregs[5] |= Tx7;
 810                 break;
 811         case CS8:
 812         default: /* defaults to 8 bits */
 813                 bits = 10;
 814                 info->zs_channel->curregs[3] |= Rx8;
 815                 info->zs_channel->curregs[5] |= Tx8;
 816                 break;
 817         }
 818
 819         info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
 820         info->timeout += HZ/50;         /* Add .02 seconds of slop */
 821
 822         info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
 823         if (cflag & CSTOPB) {
 824                 info->zs_channel->curregs[4] |= SB2;
 825         } else {
 826                 info->zs_channel->curregs[4] |= SB1;
 827         }
 828         if (cflag & PARENB) {
 829                 info->zs_channel->curregs[4] |= PAR_ENA;
 830         }
 831         if (!(cflag & PARODD)) {
 832                 info->zs_channel->curregs[4] |= PAR_EVEN;
 833         }
 834
 835         if (!(cflag & CLOCAL)) {
 836                 if (!(info->zs_channel->curregs[15] & DCDIE))
 837                         info->read_reg_zero = read_zsreg(info->zs_channel, 0);
 838                 info->zs_channel->curregs[15] |= DCDIE;
 839         } else
 840                 info->zs_channel->curregs[15] &= ~DCDIE;
 841         if (cflag & CRTSCTS) {
 842                 info->zs_channel->curregs[15] |= CTSIE;
 843                 if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
 844                         info->tx_stopped = 1;
 845         } else {
 846                 info->zs_channel->curregs[15] &= ~CTSIE;
 847                 info->tx_stopped = 0;
 848         }
 849
 850         /* Load up the new values */
 851         load_zsregs(info->zs_channel, info->zs_channel->curregs);
 852
 853         spin_unlock_irqrestore(&zs_lock, flags);
 854 }
 855
 856 static void rs_flush_chars(struct tty_struct *tty)
 857 {
 858         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 859         unsigned long flags;
 860
 861         if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
 862                 return;
 863
 864         if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
 865             !info->xmit_buf)
 866                 return;
 867
 868         /* Enable transmitter */
 869         spin_lock_irqsave(&zs_lock, flags);
 870         transmit_chars(info);
 871         spin_unlock_irqrestore(&zs_lock, flags);
 872 }
 873
 874 static int rs_write(struct tty_struct * tty,
 875                     const unsigned char *buf, int count)
 876 {
 877         int     c, total = 0;
 878         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 879         unsigned long flags;
 880
 881         if (serial_paranoia_check(info, tty->name, "rs_write"))
 882                 return 0;
 883
 884         if (!tty || !info->xmit_buf)
 885                 return 0;
 886
 887         while (1) {
 888                 spin_lock_irqsave(&zs_lock, flags);
 889                 c = min(count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 890                                    SERIAL_XMIT_SIZE - info->xmit_head));
 891                 if (c <= 0)
 892                         break;
 893
 894                 memcpy(info->xmit_buf + info->xmit_head, buf, c);
 895                 info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
 896                 info->xmit_cnt += c;
 897                 spin_unlock_irqrestore(&zs_lock, flags);
 898                 buf += c;
 899                 count -= c;
 900                 total += c;
 901         }
 902
 903         if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
 904             && !info->tx_active)
 905                 transmit_chars(info);
 906         spin_unlock_irqrestore(&zs_lock, flags);
 907         return total;
 908 }
 909
 910 static int rs_write_room(struct tty_struct *tty)
 911 {
 912         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 913         int     ret;
 914
 915         if (serial_paranoia_check(info, tty->name, "rs_write_room"))
 916                 return 0;
 917         ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
 918         if (ret < 0)
 919                 ret = 0;
 920         return ret;
 921 }
 922
 923 static int rs_chars_in_buffer(struct tty_struct *tty)
 924 {
 925         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 926
 927         if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
 928                 return 0;
 929         return info->xmit_cnt;
 930 }
 931
 932 static void rs_flush_buffer(struct tty_struct *tty)
 933 {
 934         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 935
 936         if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
 937                 return;
 938         spin_lock_irq(&zs_lock);
 939         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 940         spin_unlock_irq(&zs_lock);
 941         tty_wakeup(tty);
 942 }
 943
 944 /*
 945  * ------------------------------------------------------------
 946  * rs_throttle()
 947  *
 948  * This routine is called by the upper-layer tty layer to signal that
 949  * incoming characters should be throttled.
 950  * ------------------------------------------------------------
 951  */
 952 static void rs_throttle(struct tty_struct * tty)
 953 {
 954         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 955         unsigned long flags;
 956
 957 #ifdef SERIAL_DEBUG_THROTTLE
 958         char    buf[64];
 959
 960         printk("throttle %s: %d....\n", _tty_name(tty, buf),
 961                tty->ldisc.chars_in_buffer(tty));
 962 #endif
 963
 964         if (serial_paranoia_check(info, tty->name, "rs_throttle"))
 965                 return;
 966
 967         if (I_IXOFF(tty)) {
 968                 spin_lock_irqsave(&zs_lock, flags);
 969                 info->x_char = STOP_CHAR(tty);
 970                 if (!info->tx_active)
 971                         transmit_chars(info);
 972                 spin_unlock_irqrestore(&zs_lock, flags);
 973         }
 974
 975         if (C_CRTSCTS(tty)) {
 976                 zs_rtsdtr(info, RTS, 0);
 977         }
 978 }
 979
 980 static void rs_unthrottle(struct tty_struct * tty)
 981 {
 982         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 983         unsigned long flags;
 984
 985 #ifdef SERIAL_DEBUG_THROTTLE
 986         char    buf[64];
 987
 988         printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
 989                tty->ldisc.chars_in_buffer(tty));
 990 #endif
 991
 992         if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
 993                 return;
 994
 995         if (I_IXOFF(tty)) {
 996                 spin_lock_irqsave(&zs_lock, flags);
 997                 if (info->x_char)
 998                         info->x_char = 0;
 999                 else {
1000                         info->x_char = START_CHAR(tty);
1001                         if (!info->tx_active)
1002                                 transmit_chars(info);
1003                 }
1004                 spin_unlock_irqrestore(&zs_lock, flags);
1005         }
1006
1007         if (C_CRTSCTS(tty)) {
1008                 zs_rtsdtr(info, RTS, 1);
1009         }
1010 }
1011
1012 /*
1013  * ------------------------------------------------------------
1014  * rs_ioctl() and friends
1015  * ------------------------------------------------------------
1016  */
1017
1018 static int get_serial_info(struct dec_serial * info,
1019                            struct serial_struct * retinfo)
1020 {
1021         struct serial_struct tmp;
1022
1023         if (!retinfo)
1024                 return -EFAULT;
1025         memset(&tmp, 0, sizeof(tmp));
1026         tmp.type = info->type;
1027         tmp.line = info->line;
1028         tmp.port = info->port;
1029         tmp.irq = info->irq;
1030         tmp.flags = info->flags;
1031         tmp.baud_base = info->baud_base;
1032         tmp.close_delay = info->close_delay;
1033         tmp.closing_wait = info->closing_wait;
1034         tmp.custom_divisor = info->custom_divisor;
1035         return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
1036 }
1037
1038 static int set_serial_info(struct dec_serial * info,
1039                            struct serial_struct * new_info)
1040 {
1041         struct serial_struct new_serial;
1042         struct dec_serial old_info;
1043         int                     retval = 0;
1044
1045         if (!new_info)
1046                 return -EFAULT;
1047         copy_from_user(&new_serial,new_info,sizeof(new_serial));
1048         old_info = *info;
1049
1050         if (!capable(CAP_SYS_ADMIN)) {
1051                 if ((new_serial.baud_base != info->baud_base) ||
1052                     (new_serial.type != info->type) ||
1053                     (new_serial.close_delay != info->close_delay) ||
1054                     ((new_serial.flags & ~ZILOG_USR_MASK) !=
1055                      (info->flags & ~ZILOG_USR_MASK)))
1056                         return -EPERM;
1057                 info->flags = ((info->flags & ~ZILOG_USR_MASK) |
1058                                (new_serial.flags & ZILOG_USR_MASK));
1059                 info->custom_divisor = new_serial.custom_divisor;
1060                 goto check_and_exit;
1061         }
1062
1063         if (info->count > 1)
1064                 return -EBUSY;
1065
1066         /*
1067          * OK, past this point, all the error checking has been done.
1068          * At this point, we start making changes.....
1069          */
1070
1071         info->baud_base = new_serial.baud_base;
1072         info->flags = ((info->flags & ~ZILOG_FLAGS) |
1073                         (new_serial.flags & ZILOG_FLAGS));
1074         info->type = new_serial.type;
1075         info->close_delay = new_serial.close_delay;
1076         info->closing_wait = new_serial.closing_wait;
1077
1078 check_and_exit:
1079         retval = zs_startup(info);
1080         return retval;
1081 }
1082
1083 /*
1084  * get_lsr_info - get line status register info
1085  *
1086  * Purpose: Let user call ioctl() to get info when the UART physically
1087  *          is emptied.  On bus types like RS485, the transmitter must
1088  *          release the bus after transmitting. This must be done when
1089  *          the transmit shift register is empty, not be done when the
1090  *          transmit holding register is empty.  This functionality
1091  *          allows an RS485 driver to be written in user space.
1092  */
1093 static int get_lsr_info(struct dec_serial * info, unsigned int *value)
1094 {
1095         unsigned char status;
1096
1097         spin_lock(&zs_lock);
1098         status = read_zsreg(info->zs_channel, 0);
1099         spin_unlock_irq(&zs_lock);
1100         put_user(status,value);
1101         return 0;
1102 }
1103
1104 static int rs_tiocmget(struct tty_struct *tty, struct file *file)
1105 {
1106         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1107         unsigned char control, status_a, status_b;
1108         unsigned int result;
1109
1110         if (info->hook)
1111                 return -ENODEV;
1112
1113         if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1114                 return -ENODEV;
1115
1116         if (tty->flags & (1 << TTY_IO_ERROR))
1117                 return -EIO;
1118
1119         if (info->zs_channel == info->zs_chan_a)
1120                 result = 0;
1121         else {
1122                 spin_lock(&zs_lock);
1123                 control = info->zs_chan_a->curregs[5];
1124                 status_a = read_zsreg(info->zs_chan_a, 0);
1125                 status_b = read_zsreg(info->zs_channel, 0);
1126                 spin_unlock_irq(&zs_lock);
1127                 result =  ((control  & RTS) ? TIOCM_RTS: 0)
1128                         | ((control  & DTR) ? TIOCM_DTR: 0)
1129                         | ((status_b & DCD) ? TIOCM_CAR: 0)
1130                         | ((status_a & DCD) ? TIOCM_RNG: 0)
1131                         | ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
1132                         | ((status_b & CTS) ? TIOCM_CTS: 0);
1133         }
1134         return result;
1135 }
1136
1137 static int rs_tiocmset(struct tty_struct *tty, struct file *file,
1138                        unsigned int set, unsigned int clear)
1139 {
1140         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1141
1142         if (info->hook)
1143                 return -ENODEV;
1144
1145         if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1146                 return -ENODEV;
1147
1148         if (tty->flags & (1 << TTY_IO_ERROR))
1149                 return -EIO;
1150
1151         if (info->zs_channel == info->zs_chan_a)
1152                 return 0;
1153
1154         spin_lock(&zs_lock);
1155         if (set & TIOCM_RTS)
1156                 info->zs_chan_a->curregs[5] |= RTS;
1157         if (set & TIOCM_DTR)
1158                 info->zs_chan_a->curregs[5] |= DTR;
1159         if (clear & TIOCM_RTS)
1160                 info->zs_chan_a->curregs[5] &= ~RTS;
1161         if (clear & TIOCM_DTR)
1162                 info->zs_chan_a->curregs[5] &= ~DTR;
1163         write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
1164         spin_unlock_irq(&zs_lock);
1165         return 0;
1166 }
1167
1168 /*
1169  * rs_break - turn transmit break condition on/off
1170  */
1171 static void rs_break(struct tty_struct *tty, int break_state)
1172 {
1173         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1174         unsigned long flags;
1175
1176         if (serial_paranoia_check(info, tty->name, "rs_break"))
1177                 return;
1178         if (!info->port)
1179                 return;
1180
1181         spin_lock_irqsave(&zs_lock, flags);
1182         if (break_state == -1)
1183                 info->zs_channel->curregs[5] |= SND_BRK;
1184         else
1185                 info->zs_channel->curregs[5] &= ~SND_BRK;
1186         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
1187         spin_unlock_irqrestore(&zs_lock, flags);
1188 }
1189
1190 static int rs_ioctl(struct tty_struct *tty, struct file * file,
1191                     unsigned int cmd, unsigned long arg)
1192 {
1193         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1194
1195         if (info->hook)
1196                 return -ENODEV;
1197
1198         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1199                 return -ENODEV;
1200
1201         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1202             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
1203             (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
1204                 if (tty->flags & (1 << TTY_IO_ERROR))
1205                     return -EIO;
1206         }
1207
1208         switch (cmd) {
1209         case TIOCGSERIAL:
1210                 if (!access_ok(VERIFY_WRITE, (void *)arg,
1211                                sizeof(struct serial_struct)))
1212                         return -EFAULT;
1213                 return get_serial_info(info, (struct serial_struct *)arg);
1214
1215         case TIOCSSERIAL:
1216                 return set_serial_info(info, (struct serial_struct *)arg);
1217
1218         case TIOCSERGETLSR:                     /* Get line status register */
1219                 if (!access_ok(VERIFY_WRITE, (void *)arg,
1220                                sizeof(unsigned int)))
1221                         return -EFAULT;
1222                 return get_lsr_info(info, (unsigned int *)arg);
1223
1224         case TIOCSERGSTRUCT:
1225                 if (!access_ok(VERIFY_WRITE, (void *)arg,
1226                                sizeof(struct dec_serial)))
1227                         return -EFAULT;
1228                 copy_from_user((struct dec_serial *)arg, info,
1229                                sizeof(struct dec_serial));
1230                 return 0;
1231
1232         default:
1233                 return -ENOIOCTLCMD;
1234         }
1235         return 0;
1236 }
1237
1238 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1239 {
1240         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1241         int was_stopped;
1242
1243         if (tty->termios->c_cflag == old_termios->c_cflag)
1244                 return;
1245         was_stopped = info->tx_stopped;
1246
1247         change_speed(info);
1248
1249         if (was_stopped && !info->tx_stopped)
1250                 rs_start(tty);
1251 }
1252
1253 /*
1254  * ------------------------------------------------------------
1255  * rs_close()
1256  *
1257  * This routine is called when the serial port gets closed.
1258  * Wait for the last remaining data to be sent.
1259  * ------------------------------------------------------------
1260  */
1261 static void rs_close(struct tty_struct *tty, struct file * filp)
1262 {
1263         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1264         unsigned long flags;
1265
1266         if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
1267                 return;
1268
1269         spin_lock_irqsave(&zs_lock, flags);
1270
1271         if (tty_hung_up_p(filp)) {
1272                 spin_unlock_irqrestore(&zs_lock, flags);
1273                 return;
1274         }
1275
1276 #ifdef SERIAL_DEBUG_OPEN
1277         printk("rs_close ttyS%d, count = %d\n", info->line, info->count);
1278 #endif
1279         if ((tty->count == 1) && (info->count != 1)) {
1280                 /*
1281                  * Uh, oh.  tty->count is 1, which means that the tty
1282                  * structure will be freed.  Info->count should always
1283                  * be one in these conditions.  If it's greater than
1284                  * one, we've got real problems, since it means the
1285                  * serial port won't be shutdown.
1286                  */
1287                 printk("rs_close: bad serial port count; tty->count is 1, "
1288                        "info->count is %d\n", info->count);
1289                 info->count = 1;
1290         }
1291         if (--info->count < 0) {
1292                 printk("rs_close: bad serial port count for ttyS%d: %d\n",
1293                        info->line, info->count);
1294                 info->count = 0;
1295         }
1296         if (info->count) {
1297                 spin_unlock_irqrestore(&zs_lock, flags);
1298                 return;
1299         }
1300         info->flags |= ZILOG_CLOSING;
1301         /*
1302          * Now we wait for the transmit buffer to clear; and we notify
1303          * the line discipline to only process XON/XOFF characters.
1304          */
1305         tty->closing = 1;
1306         if (info->closing_wait != ZILOG_CLOSING_WAIT_NONE)
1307                 tty_wait_until_sent(tty, info->closing_wait);
1308         /*
1309          * At this point we stop accepting input.  To do this, we
1310          * disable the receiver and receive interrupts.
1311          */
1312         info->zs_channel->curregs[3] &= ~RxENABLE;
1313         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
1314         info->zs_channel->curregs[1] = 0;       /* disable any rx ints */
1315         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
1316         ZS_CLEARFIFO(info->zs_channel);
1317         if (info->flags & ZILOG_INITIALIZED) {
1318                 /*
1319                  * Before we drop DTR, make sure the SCC transmitter
1320                  * has completely drained.
1321                  */
1322                 rs_wait_until_sent(tty, info->timeout);
1323         }
1324
1325         shutdown(info);
1326         if (tty->driver->flush_buffer)
1327                 tty->driver->flush_buffer(tty);
1328         tty_ldisc_flush(tty);
1329         tty->closing = 0;
1330         info->event = 0;
1331         info->tty = 0;
1332         if (info->blocked_open) {
1333                 if (info->close_delay) {
1334                         msleep_interruptible(jiffies_to_msecs(info->close_delay));
1335                 }
1336                 wake_up_interruptible(&info->open_wait);
1337         }
1338         info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CLOSING);
1339         wake_up_interruptible(&info->close_wait);
1340         spin_unlock_irqrestore(&zs_lock, flags);
1341 }
1342
1343 /*
1344  * rs_wait_until_sent() --- wait until the transmitter is empty
1345  */
1346 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1347 {
1348         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1349         unsigned long orig_jiffies;
1350         int char_time;
1351
1352         if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1353                 return;
1354
1355         orig_jiffies = jiffies;
1356         /*
1357          * Set the check interval to be 1/5 of the estimated time to
1358          * send a single character, and make it at least 1.  The check
1359          * interval should also be less than the timeout.
1360          */
1361         char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1362         char_time = char_time / 5;
1363         if (char_time == 0)
1364                 char_time = 1;
1365         if (timeout)
1366                 char_time = min(char_time, timeout);
1367         while ((read_zsreg(info->zs_channel, 1) & Tx_BUF_EMP) == 0) {
1368                 msleep_interruptible(jiffies_to_msecs(char_time));
1369                 if (signal_pending(current))
1370                         break;
1371                 if (timeout && time_after(jiffies, orig_jiffies + timeout))
1372                         break;
1373         }
1374         current->state = TASK_RUNNING;
1375 }
1376
1377 /*
1378  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1379  */
1380 static void rs_hangup(struct tty_struct *tty)
1381 {
1382         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1383
1384         if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1385                 return;
1386
1387         rs_flush_buffer(tty);
1388         shutdown(info);
1389         info->event = 0;
1390         info->count = 0;
1391         info->flags &= ~ZILOG_NORMAL_ACTIVE;
1392         info->tty = 0;
1393         wake_up_interruptible(&info->open_wait);
1394 }
1395
1396 /*
1397  * ------------------------------------------------------------
1398  * rs_open() and friends
1399  * ------------------------------------------------------------
1400  */
1401 static int block_til_ready(struct tty_struct *tty, struct file * filp,
1402                            struct dec_serial *info)
1403 {
1404         DECLARE_WAITQUEUE(wait, current);
1405         int             retval;
1406         int             do_clocal = 0;
1407
1408         /*
1409          * If the device is in the middle of being closed, then block
1410          * until it's done, and then try again.
1411          */
1412         if (info->flags & ZILOG_CLOSING) {
1413                 interruptible_sleep_on(&info->close_wait);
1414 #ifdef SERIAL_DO_RESTART
1415                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1416                         -EAGAIN : -ERESTARTSYS);
1417 #else
1418                 return -EAGAIN;
1419 #endif
1420         }
1421
1422         /*
1423          * If non-blocking mode is set, or the port is not enabled,
1424          * then make the check up front and then exit.
1425          */
1426         if ((filp->f_flags & O_NONBLOCK) ||
1427             (tty->flags & (1 << TTY_IO_ERROR))) {
1428                 info->flags |= ZILOG_NORMAL_ACTIVE;
1429                 return 0;
1430         }
1431
1432         if (tty->termios->c_cflag & CLOCAL)
1433                 do_clocal = 1;
1434
1435         /*
1436          * Block waiting for the carrier detect and the line to become
1437          * free (i.e., not in use by the callout).  While we are in
1438          * this loop, info->count is dropped by one, so that
1439          * rs_close() knows when to free things.  We restore it upon
1440          * exit, either normal or abnormal.
1441          */
1442         retval = 0;
1443         add_wait_queue(&info->open_wait, &wait);
1444 #ifdef SERIAL_DEBUG_OPEN
1445         printk("block_til_ready before block: ttyS%d, count = %d\n",
1446                info->line, info->count);
1447 #endif
1448         spin_lock(&zs_lock);
1449         if (!tty_hung_up_p(filp))
1450                 info->count--;
1451         spin_unlock_irq(&zs_lock);
1452         info->blocked_open++;
1453         while (1) {
1454                 spin_lock(&zs_lock);
1455                 if (tty->termios->c_cflag & CBAUD)
1456                         zs_rtsdtr(info, RTS | DTR, 1);
1457                 spin_unlock_irq(&zs_lock);
1458                 set_current_state(TASK_INTERRUPTIBLE);
1459                 if (tty_hung_up_p(filp) ||
1460                     !(info->flags & ZILOG_INITIALIZED)) {
1461 #ifdef SERIAL_DO_RESTART
1462                         if (info->flags & ZILOG_HUP_NOTIFY)
1463                                 retval = -EAGAIN;
1464                         else
1465                                 retval = -ERESTARTSYS;
1466 #else
1467                         retval = -EAGAIN;
1468 #endif
1469                         break;
1470                 }
1471                 if (!(info->flags & ZILOG_CLOSING) &&
1472                     (do_clocal || (read_zsreg(info->zs_channel, 0) & DCD)))
1473                         break;
1474                 if (signal_pending(current)) {
1475                         retval = -ERESTARTSYS;
1476                         break;
1477                 }
1478 #ifdef SERIAL_DEBUG_OPEN
1479                 printk("block_til_ready blocking: ttyS%d, count = %d\n",
1480                        info->line, info->count);
1481 #endif
1482                 schedule();
1483         }
1484         current->state = TASK_RUNNING;
1485         remove_wait_queue(&info->open_wait, &wait);
1486         if (!tty_hung_up_p(filp))
1487                 info->count++;
1488         info->blocked_open--;
1489 #ifdef SERIAL_DEBUG_OPEN
1490         printk("block_til_ready after blocking: ttyS%d, count = %d\n",
1491                info->line, info->count);
1492 #endif
1493         if (retval)
1494                 return retval;
1495         info->flags |= ZILOG_NORMAL_ACTIVE;
1496         return 0;
1497 }
1498
1499 /*
1500  * This routine is called whenever a serial port is opened.  It
1501  * enables interrupts for a serial port, linking in its ZILOG structure into
1502  * the IRQ chain.   It also performs the serial-specific
1503  * initialization for the tty structure.
1504  */
1505 static int rs_open(struct tty_struct *tty, struct file * filp)
1506 {
1507         struct dec_serial       *info;
1508         int                     retval, line;
1509
1510         line = tty->index;
1511         if ((line < 0) || (line >= zs_channels_found))
1512                 return -ENODEV;
1513         info = zs_soft + line;
1514
1515         if (info->hook)
1516                 return -ENODEV;
1517
1518         if (serial_paranoia_check(info, tty->name, "rs_open"))
1519                 return -ENODEV;
1520 #ifdef SERIAL_DEBUG_OPEN
1521         printk("rs_open %s, count = %d\n", tty->name, info->count);
1522 #endif
1523
1524         info->count++;
1525         tty->driver_data = info;
1526         info->tty = tty;
1527
1528         /*
1529          * If the port is the middle of closing, bail out now
1530          */
1531         if (tty_hung_up_p(filp) ||
1532             (info->flags & ZILOG_CLOSING)) {
1533                 if (info->flags & ZILOG_CLOSING)
1534                         interruptible_sleep_on(&info->close_wait);
1535 #ifdef SERIAL_DO_RESTART
1536                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1537                         -EAGAIN : -ERESTARTSYS);
1538 #else
1539                 return -EAGAIN;
1540 #endif
1541         }
1542
1543         /*
1544          * Start up serial port
1545          */
1546         retval = zs_startup(info);
1547         if (retval)
1548                 return retval;
1549
1550         retval = block_til_ready(tty, filp, info);
1551         if (retval) {
1552 #ifdef SERIAL_DEBUG_OPEN
1553                 printk("rs_open returning after block_til_ready with %d\n",
1554                        retval);
1555 #endif
1556                 return retval;
1557         }
1558
1559 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1560         if (zs_console.cflag && zs_console.index == line) {
1561                 tty->termios->c_cflag = zs_console.cflag;
1562                 zs_console.cflag = 0;
1563                 change_speed(info);
1564         }
1565 #endif
1566
1567 #ifdef SERIAL_DEBUG_OPEN
1568         printk("rs_open %s successful...", tty->name);
1569 #endif
1570 /* tty->low_latency = 1; */
1571         return 0;
1572 }
1573
1574 /* Finally, routines used to initialize the serial driver. */
1575
1576 static void __init show_serial_version(void)
1577 {
1578         printk("DECstation Z8530 serial driver version 0.09\n");
1579 }
1580
1581 /*  Initialize Z8530s zs_channels
1582  */
1583
1584 static void __init probe_sccs(void)
1585 {
1586         struct dec_serial **pp;
1587         int i, n, n_chips = 0, n_channels, chip, channel;
1588         unsigned long flags;
1589
1590         /*
1591          * did we get here by accident?
1592          */
1593         if(!BUS_PRESENT) {
1594                 printk("Not on JUNKIO machine, skipping probe_sccs\n");
1595                 return;
1596         }
1597
1598         switch(mips_machtype) {
1599 #ifdef CONFIG_MACH_DECSTATION
1600         case MACH_DS5000_2X0:
1601         case MACH_DS5900:
1602                 n_chips = 2;
1603                 zs_parms = &ds_parms;
1604                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1605                 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1606                 break;
1607         case MACH_DS5000_1XX:
1608                 n_chips = 2;
1609                 zs_parms = &ds_parms;
1610                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1611                 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1612                 break;
1613         case MACH_DS5000_XX:
1614                 n_chips = 1;
1615                 zs_parms = &ds_parms;
1616                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1617                 break;
1618 #endif
1619         default:
1620                 panic("zs: unsupported bus");
1621         }
1622         if (!zs_parms)
1623                 panic("zs: uninitialized parms");
1624
1625         pp = &zs_chain;
1626
1627         n_channels = 0;
1628
1629         for (chip = 0; chip < n_chips; chip++) {
1630                 for (channel = 0; channel <= 1; channel++) {
1631                         /*
1632                          * The sccs reside on the high byte of the 16 bit IOBUS
1633                          */
1634                         zs_channels[n_channels].control =
1635                                 (volatile void *)CKSEG1ADDR(dec_kn_slot_base +
1636                           (0 == chip ? zs_parms->scc0 : zs_parms->scc1) +
1637                           (0 == channel ? zs_parms->channel_a_offset :
1638                                           zs_parms->channel_b_offset));
1639                         zs_channels[n_channels].data =
1640                                 zs_channels[n_channels].control + 4;
1641
1642 #ifndef CONFIG_SERIAL_DEC_CONSOLE
1643                         /*
1644                          * We're called early and memory managment isn't up, yet.
1645                          * Thus request_region would fail.
1646                          */
1647                         if (!request_region((unsigned long)
1648                                          zs_channels[n_channels].control,
1649                                          ZS_CHAN_IO_SIZE, "SCC"))
1650                                 panic("SCC I/O region is not free");
1651 #endif
1652                         zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
1653                         /* HACK alert! */
1654                         if (!(chip & 1))
1655                                 zs_soft[n_channels].irq = zs_parms->irq0;
1656                         else
1657                                 zs_soft[n_channels].irq = zs_parms->irq1;
1658
1659                         /*
1660                          *  Identification of channel A. Location of channel A
1661                          *  inside chip depends on mapping of internal address
1662                          *  the chip decodes channels by.
1663                          *  CHANNEL_A_NR returns either 0 (in case of
1664                          *  DECstations) or 1 (in case of Baget).
1665                          */
1666                         if (CHANNEL_A_NR == channel)
1667                                 zs_soft[n_channels].zs_chan_a =
1668                                     &zs_channels[n_channels+1-2*CHANNEL_A_NR];
1669                         else
1670                                 zs_soft[n_channels].zs_chan_a =
1671                                     &zs_channels[n_channels];
1672
1673                         *pp = &zs_soft[n_channels];
1674                         pp = &zs_soft[n_channels].zs_next;
1675                         n_channels++;
1676                 }
1677         }
1678
1679         *pp = 0;
1680         zs_channels_found = n_channels;
1681
1682         for (n = 0; n < zs_channels_found; n++) {
1683                 for (i = 0; i < 16; i++) {
1684                         zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
1685                 }
1686         }
1687
1688         spin_lock_irqsave(&zs_lock, flags);
1689         for (n = 0; n < zs_channels_found; n++) {
1690                 if (n % 2 == 0) {
1691                         write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
1692                         udelay(10);
1693                         write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
1694                 }
1695                 load_zsregs(zs_soft[n].zs_channel,
1696                             zs_soft[n].zs_channel->curregs);
1697         }
1698         spin_unlock_irqrestore(&zs_lock, flags);
1699 }
1700
1701 static const struct tty_operations serial_ops = {
1702         .open = rs_open,
1703         .close = rs_close,
1704         .write = rs_write,
1705         .flush_chars = rs_flush_chars,
1706         .write_room = rs_write_room,
1707         .chars_in_buffer = rs_chars_in_buffer,
1708         .flush_buffer = rs_flush_buffer,
1709         .ioctl = rs_ioctl,
1710         .throttle = rs_throttle,
1711         .unthrottle = rs_unthrottle,
1712         .set_termios = rs_set_termios,
1713         .stop = rs_stop,
1714         .start = rs_start,
1715         .hangup = rs_hangup,
1716         .break_ctl = rs_break,
1717         .wait_until_sent = rs_wait_until_sent,
1718         .tiocmget = rs_tiocmget,
1719         .tiocmset = rs_tiocmset,
1720 };
1721
1722 /* zs_init inits the driver */
1723 int __init zs_init(void)
1724 {
1725         int channel, i;
1726         struct dec_serial *info;
1727
1728         if(!BUS_PRESENT)
1729                 return -ENODEV;
1730
1731         /* Find out how many Z8530 SCCs we have */
1732         if (zs_chain == 0)
1733                 probe_sccs();
1734         serial_driver = alloc_tty_driver(zs_channels_found);
1735         if (!serial_driver)
1736                 return -ENOMEM;
1737
1738         show_serial_version();
1739
1740         /* Initialize the tty_driver structure */
1741         /* Not all of this is exactly right for us. */
1742
1743         serial_driver->owner = THIS_MODULE;
1744         serial_driver->name = "ttyS";
1745         serial_driver->major = TTY_MAJOR;
1746         serial_driver->minor_start = 64;
1747         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1748         serial_driver->subtype = SERIAL_TYPE_NORMAL;
1749         serial_driver->init_termios = tty_std_termios;
1750         serial_driver->init_termios.c_cflag =
1751                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1752         serial_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1753         tty_set_operations(serial_driver, &serial_ops);
1754
1755         if (tty_register_driver(serial_driver))
1756                 panic("Couldn't register serial driver");
1757
1758         for (info = zs_chain, i = 0; info; info = info->zs_next, i++) {
1759
1760                 /* Needed before interrupts are enabled. */
1761                 info->tty = 0;
1762                 info->x_char = 0;
1763
1764                 if (info->hook && info->hook->init_info) {
1765                         (*info->hook->init_info)(info);
1766                         continue;
1767                 }
1768
1769                 info->magic = SERIAL_MAGIC;
1770                 info->port = (int) info->zs_channel->control;
1771                 info->line = i;
1772                 info->custom_divisor = 16;
1773                 info->close_delay = 50;
1774                 info->closing_wait = 3000;
1775                 info->event = 0;
1776                 info->count = 0;
1777                 info->blocked_open = 0;
1778                 tasklet_init(&info->tlet, do_softint, (unsigned long)info);
1779                 init_waitqueue_head(&info->open_wait);
1780                 init_waitqueue_head(&info->close_wait);
1781                 printk("ttyS%02d at 0x%08x (irq = %d) is a Z85C30 SCC\n",
1782                        info->line, info->port, info->irq);
1783                 tty_register_device(serial_driver, info->line, NULL);
1784
1785         }
1786
1787         for (channel = 0; channel < zs_channels_found; ++channel) {
1788                 zs_soft[channel].clk_divisor = 16;
1789                 zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);
1790
1791                 if (request_irq(zs_soft[channel].irq, rs_interrupt, IRQF_SHARED,
1792                                 "scc", &zs_soft[channel]))
1793                         printk(KERN_ERR "decserial: can't get irq %d\n",
1794                                zs_soft[channel].irq);
1795
1796                 if (zs_soft[channel].hook) {
1797                         zs_startup(&zs_soft[channel]);
1798                         if (zs_soft[channel].hook->init_channel)
1799                                 (*zs_soft[channel].hook->init_channel)
1800                                         (&zs_soft[channel]);
1801                 }
1802         }
1803
1804         return 0;
1805 }
1806
1807 /*
1808  * polling I/O routines
1809  */
1810 static int zs_poll_tx_char(void *handle, unsigned char ch)
1811 {
1812         struct dec_serial *info = handle;
1813         struct dec_zschannel *chan = info->zs_channel;
1814         int    ret;
1815
1816         if(chan) {
1817                 int loops = 10000;
1818
1819                 while (loops && !(read_zsreg(chan, 0) & Tx_BUF_EMP))
1820                         loops--;
1821
1822                 if (loops) {
1823                         write_zsdata(chan, ch);
1824                         ret = 0;
1825                 } else
1826                         ret = -EAGAIN;
1827
1828                 return ret;
1829         } else
1830                 return -ENODEV;
1831 }
1832
1833 static int zs_poll_rx_char(void *handle)
1834 {
1835         struct dec_serial *info = handle;
1836         struct dec_zschannel *chan = info->zs_channel;
1837         int    ret;
1838
1839         if(chan) {
1840                 int loops = 10000;
1841
1842                 while (loops && !(read_zsreg(chan, 0) & Rx_CH_AV))
1843                         loops--;
1844
1845                 if (loops)
1846                         ret = read_zsdata(chan);
1847                 else
1848                         ret = -EAGAIN;
1849
1850                 return ret;
1851         } else
1852                 return -ENODEV;
1853 }
1854
1855 int register_zs_hook(unsigned int channel, struct dec_serial_hook *hook)
1856 {
1857         struct dec_serial *info = &zs_soft[channel];
1858
1859         if (info->hook) {
1860                 printk("%s: line %d has already a hook registered\n",
1861                        __FUNCTION__, channel);
1862
1863                 return 0;
1864         } else {
1865                 hook->poll_rx_char = zs_poll_rx_char;
1866                 hook->poll_tx_char = zs_poll_tx_char;
1867                 info->hook = hook;
1868
1869                 return 1;
1870         }
1871 }
1872
1873 int unregister_zs_hook(unsigned int channel)
1874 {
1875         struct dec_serial *info = &zs_soft[channel];
1876
1877         if (info->hook) {
1878                 info->hook = NULL;
1879                 return 1;
1880         } else {
1881                 printk("%s: trying to unregister hook on line %d,"
1882                        " but none is registered\n", __FUNCTION__, channel);
1883                 return 0;
1884         }
1885 }
1886
1887 /*
1888  * ------------------------------------------------------------
1889  * Serial console driver
1890  * ------------------------------------------------------------
1891  */
1892 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1893
1894
1895 /*
1896  *      Print a string to the serial port trying not to disturb
1897  *      any possible real use of the port...
1898  */
1899 static void serial_console_write(struct console *co, const char *s,
1900                                  unsigned count)
1901 {
1902         struct dec_serial *info;
1903         int i;
1904
1905         info = zs_soft + co->index;
1906
1907         for (i = 0; i < count; i++, s++) {
1908                 if(*s == '\n')
1909                         zs_poll_tx_char(info, '\r');
1910                 zs_poll_tx_char(info, *s);
1911         }
1912 }
1913
1914 static struct tty_driver *serial_console_device(struct console *c, int *index)
1915 {
1916         *index = c->index;
1917         return serial_driver;
1918 }
1919
1920 /*
1921  *      Setup initial baud/bits/parity. We do two things here:
1922  *      - construct a cflag setting for the first rs_open()
1923  *      - initialize the serial port
1924  *      Return non-zero if we didn't find a serial port.
1925  */
1926 static int __init serial_console_setup(struct console *co, char *options)
1927 {
1928         struct dec_serial *info;
1929         int baud = 9600;
1930         int bits = 8;
1931         int parity = 'n';
1932         int cflag = CREAD | HUPCL | CLOCAL;
1933         int clk_divisor = 16;
1934         int brg;
1935         char *s;
1936         unsigned long flags;
1937
1938         if(!BUS_PRESENT)
1939                 return -ENODEV;
1940
1941         info = zs_soft + co->index;
1942
1943         if (zs_chain == 0)
1944                 probe_sccs();
1945
1946         info->is_cons = 1;
1947
1948         if (options) {
1949                 baud = simple_strtoul(options, NULL, 10);
1950                 s = options;
1951                 while(*s >= '0' && *s <= '9')
1952                         s++;
1953                 if (*s)
1954                         parity = *s++;
1955                 if (*s)
1956                         bits   = *s - '0';
1957         }
1958
1959         /*
1960          *      Now construct a cflag setting.
1961          */
1962         switch(baud) {
1963         case 1200:
1964                 cflag |= B1200;
1965                 break;
1966         case 2400:
1967                 cflag |= B2400;
1968                 break;
1969         case 4800:
1970                 cflag |= B4800;
1971                 break;
1972         case 19200:
1973                 cflag |= B19200;
1974                 break;
1975         case 38400:
1976                 cflag |= B38400;
1977                 break;
1978         case 57600:
1979                 cflag |= B57600;
1980                 break;
1981         case 115200:
1982                 cflag |= B115200;
1983                 break;
1984         case 9600:
1985         default:
1986                 cflag |= B9600;
1987                 /*
1988                  * Set this to a sane value to prevent a divide error.
1989                  */
1990                 baud  = 9600;
1991                 break;
1992         }
1993         switch(bits) {
1994         case 7:
1995                 cflag |= CS7;
1996                 break;
1997         default:
1998         case 8:
1999                 cflag |= CS8;
2000                 break;
2001         }
2002         switch(parity) {
2003         case 'o': case 'O':
2004                 cflag |= PARODD;
2005                 break;
2006         case 'e': case 'E':
2007                 cflag |= PARENB;
2008                 break;
2009         }
2010         co->cflag = cflag;
2011
2012         spin_lock_irqsave(&zs_lock, flags);
2013
2014         /*
2015          * Set up the baud rate generator.
2016          */
2017         brg = BPS_TO_BRG(baud, zs_parms->clock / clk_divisor);
2018         info->zs_channel->curregs[R12] = (brg & 255);
2019         info->zs_channel->curregs[R13] = ((brg >> 8) & 255);
2020
2021         /*
2022          * Set byte size and parity.
2023          */
2024         if (bits == 7) {
2025                 info->zs_channel->curregs[R3] |= Rx7;
2026                 info->zs_channel->curregs[R5] |= Tx7;
2027         } else {
2028                 info->zs_channel->curregs[R3] |= Rx8;
2029                 info->zs_channel->curregs[R5] |= Tx8;
2030         }
2031         if (cflag & PARENB) {
2032                 info->zs_channel->curregs[R4] |= PAR_ENA;
2033         }
2034         if (!(cflag & PARODD)) {
2035                 info->zs_channel->curregs[R4] |= PAR_EVEN;
2036         }
2037         info->zs_channel->curregs[R4] |= SB1;
2038
2039         /*
2040          * Turn on RTS and DTR.
2041          */
2042         zs_rtsdtr(info, RTS | DTR, 1);
2043
2044         /*
2045          * Finally, enable sequencing.
2046          */
2047         info->zs_channel->curregs[R3] |= RxENABLE;
2048         info->zs_channel->curregs[R5] |= TxENAB;
2049
2050         /*
2051          * Clear the interrupt registers.
2052          */
2053         write_zsreg(info->zs_channel, R0, ERR_RES);
2054         write_zsreg(info->zs_channel, R0, RES_H_IUS);
2055
2056         /*
2057          * Load up the new values.
2058          */
2059         load_zsregs(info->zs_channel, info->zs_channel->curregs);
2060
2061         /* Save the current value of RR0 */
2062         info->read_reg_zero = read_zsreg(info->zs_channel, R0);
2063
2064         zs_soft[co->index].clk_divisor = clk_divisor;
2065         zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);
2066
2067         spin_unlock_irqrestore(&zs_lock, flags);
2068
2069         return 0;
2070 }
2071
2072 static struct console zs_console = {
2073         .name           = "ttyS",
2074         .write          = serial_console_write,
2075         .device         = serial_console_device,
2076         .setup          = serial_console_setup,
2077         .flags          = CON_PRINTBUFFER,
2078         .index          = -1,
2079 };
2080
2081 /*
2082  *      Register console.
2083  */
2084 void __init zs_serial_console_init(void)
2085 {
2086         register_console(&zs_console);
2087 }
2088 #endif /* ifdef CONFIG_SERIAL_DEC_CONSOLE */
2089
2090 #ifdef CONFIG_KGDB
2091 struct dec_zschannel *zs_kgdbchan;
2092 static unsigned char scc_inittab[] = {
2093         9,  0x80,       /* reset A side (CHRA) */
2094         13, 0,          /* set baud rate divisor */
2095         12, 1,
2096         14, 1,          /* baud rate gen enable, src=rtxc (BRENABL) */
2097         11, 0x50,       /* clocks = br gen (RCBR | TCBR) */
2098         5,  0x6a,       /* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
2099         4,  0x44,       /* x16 clock, 1 stop (SB1 | X16CLK)*/
2100         3,  0xc1,       /* rx enable, 8 bits (RxENABLE | Rx8)*/
2101 };
2102
2103 /* These are for receiving and sending characters under the kgdb
2104  * source level kernel debugger.
2105  */
2106 void putDebugChar(char kgdb_char)
2107 {
2108         struct dec_zschannel *chan = zs_kgdbchan;
2109         while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
2110                 RECOVERY_DELAY;
2111         write_zsdata(chan, kgdb_char);
2112 }
2113 char getDebugChar(void)
2114 {
2115         struct dec_zschannel *chan = zs_kgdbchan;
2116         while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
2117                 eieio(); /*barrier();*/
2118         return read_zsdata(chan);
2119 }
2120 void kgdb_interruptible(int yes)
2121 {
2122         struct dec_zschannel *chan = zs_kgdbchan;
2123         int one, nine;
2124         nine = read_zsreg(chan, 9);
2125         if (yes == 1) {
2126                 one = EXT_INT_ENAB|RxINT_ALL;
2127                 nine |= MIE;
2128                 printk("turning serial ints on\n");
2129         } else {
2130                 one = RxINT_DISAB;
2131                 nine &= ~MIE;
2132                 printk("turning serial ints off\n");
2133         }
2134         write_zsreg(chan, 1, one);
2135         write_zsreg(chan, 9, nine);
2136 }
2137
2138 static int kgdbhook_init_channel(void *handle)
2139 {
2140         return 0;
2141 }
2142
2143 static void kgdbhook_init_info(void *handle)
2144 {
2145 }
2146
2147 static void kgdbhook_rx_char(void *handle, unsigned char ch, unsigned char fl)
2148 {
2149         struct dec_serial *info = handle;
2150
2151         if (fl != TTY_NORMAL)
2152                 return;
2153         if (ch == 0x03 || ch == '$')
2154                 breakpoint();
2155 }
2156
2157 /* This sets up the serial port we're using, and turns on
2158  * interrupts for that channel, so kgdb is usable once we're done.
2159  */
2160 static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
2161 {
2162         int brg;
2163         int i, x;
2164         volatile char *sccc = ms->control;
2165         brg = BPS_TO_BRG(bps, zs_parms->clock/16);
2166         printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
2167         for (i = 20000; i != 0; --i) {
2168                 x = *sccc; eieio();
2169         }
2170         for (i = 0; i < sizeof(scc_inittab); ++i) {
2171                 write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
2172                 i++;
2173         }
2174 }
2175 /* This is called at boot time to prime the kgdb serial debugging
2176  * serial line.  The 'tty_num' argument is 0 for /dev/ttya and 1
2177  * for /dev/ttyb which is determined in setup_arch() from the
2178  * boot command line flags.
2179  */
2180 struct dec_serial_hook zs_kgdbhook = {
2181         .init_channel   = kgdbhook_init_channel,
2182         .init_info      = kgdbhook_init_info,
2183         .rx_char        = kgdbhook_rx_char,
2184         .cflags         = B38400 | CS8 | CLOCAL,
2185 };
2186
2187 void __init zs_kgdb_hook(int tty_num)
2188 {
2189         /* Find out how many Z8530 SCCs we have */
2190         if (zs_chain == 0)
2191                 probe_sccs();
2192         zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
2193         zs_kgdbchan = zs_soft[tty_num].zs_channel;
2194         zs_soft[tty_num].change_needed = 0;
2195         zs_soft[tty_num].clk_divisor = 16;
2196         zs_soft[tty_num].zs_baud = 38400;
2197         zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
2198         /* Turn on transmitter/receiver at 8-bits/char */
2199         kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
2200         printk("KGDB: on channel %d initialized\n", tty_num);
2201         set_debug_traps(); /* init stub */
2202 }
2203 #endif /* ifdef CONFIG_KGDB */