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/config.h>
  43 #include <linux/errno.h>
  44 #include <linux/signal.h>
  45 #include <linux/sched.h>
  46 #include <linux/timer.h>
  47 #include <linux/interrupt.h>
  48 #include <linux/tty.h>
  49 #include <linux/tty_flip.h>
  50 #include <linux/major.h>
  51 #include <linux/string.h>
  52 #include <linux/fcntl.h>
  53 #include <linux/mm.h>
  54 #include <linux/kernel.h>
  55 #include <linux/delay.h>
  56 #include <linux/init.h>
  57 #include <linux/ioport.h>
  58 #include <linux/spinlock.h>
  59 #ifdef CONFIG_SERIAL_DEC_CONSOLE
  60 #include <linux/console.h>
  61 #endif
  62
  63 #include <asm/io.h>
  64 #include <asm/pgtable.h>
  65 #include <asm/irq.h>
  66 #include <asm/system.h>
  67 #include <asm/bootinfo.h>
  68
  69 #include <asm/dec/interrupts.h>
  70 #include <asm/dec/ioasic_addrs.h>
  71 #include <asm/dec/machtype.h>
  72 #include <asm/dec/serial.h>
  73 #include <asm/dec/system.h>
  74 #include <asm/dec/tc.h>
  75
  76 #ifdef CONFIG_KGDB
  77 #include <asm/kgdb.h>
  78 #endif
  79 #ifdef CONFIG_MAGIC_SYSRQ
  80 #include <linux/sysrq.h>
  81 #endif
  82
  83 #include "zs.h"
  84
  85 /*
  86  * It would be nice to dynamically allocate everything that
  87  * depends on NUM_SERIAL, so we could support any number of
  88  * Z8530s, but for now...
  89  */
  90 #define NUM_SERIAL      2               /* Max number of ZS chips supported */
  91 #define NUM_CHANNELS    (NUM_SERIAL * 2)        /* 2 channels per chip */
  92 #define CHANNEL_A_NR  (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
  93                                         /* Number of channel A in the chip */
  94 #define ZS_CHAN_IO_SIZE 8
  95 #define ZS_CLOCK        7372800         /* Z8530 RTxC input clock rate */
  96
  97 #define RECOVERY_DELAY  udelay(2)
  98
  99 struct zs_parms {
 100         unsigned long scc0;
 101         unsigned long scc1;
 102         int channel_a_offset;
 103         int channel_b_offset;
 104         int irq0;
 105         int irq1;
 106         int clock;
 107 };
 108
 109 static struct zs_parms *zs_parms;
 110
 111 #ifdef CONFIG_MACH_DECSTATION
 112 static struct zs_parms ds_parms = {
 113         scc0 : IOASIC_SCC0,
 114         scc1 : IOASIC_SCC1,
 115         channel_a_offset : 1,
 116         channel_b_offset : 9,
 117         irq0 : -1,
 118         irq1 : -1,
 119         clock : ZS_CLOCK
 120 };
 121 #endif
 122
 123 #ifdef CONFIG_MACH_DECSTATION
 124 #define DS_BUS_PRESENT (IOASIC)
 125 #else
 126 #define DS_BUS_PRESENT 0
 127 #endif
 128
 129 #define BUS_PRESENT (DS_BUS_PRESENT)
 130
 131 DEFINE_SPINLOCK(zs_lock);
 132
 133 struct dec_zschannel zs_channels[NUM_CHANNELS];
 134 struct dec_serial zs_soft[NUM_CHANNELS];
 135 int zs_channels_found;
 136 struct dec_serial *zs_chain;    /* list of all channels */
 137
 138 struct tty_struct zs_ttys[NUM_CHANNELS];
 139
 140 #ifdef CONFIG_SERIAL_DEC_CONSOLE
 141 static struct console sercons;
 142 #endif
 143 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
 144    !defined(MODULE)
 145 static unsigned long break_pressed; /* break, really ... */
 146 #endif
 147
 148 static unsigned char zs_init_regs[16] __initdata = {
 149         0,                              /* write 0 */
 150         0,                              /* write 1 */
 151         0,                              /* write 2 */
 152         0,                              /* write 3 */
 153         (X16CLK),                       /* write 4 */
 154         0,                              /* write 5 */
 155         0, 0, 0,                        /* write 6, 7, 8 */
 156         (MIE | DLC | NV),               /* write 9 */
 157         (NRZ),                          /* write 10 */
 158         (TCBR | RCBR),                  /* write 11 */
 159         0, 0,                           /* BRG time constant, write 12 + 13 */
 160         (BRSRC | BRENABL),              /* write 14 */
 161         0                               /* write 15 */
 162 };
 163
 164 static struct tty_driver *serial_driver;
 165
 166 /* serial subtype definitions */
 167 #define SERIAL_TYPE_NORMAL      1
 168
 169 /* number of characters left in xmit buffer before we ask for more */
 170 #define WAKEUP_CHARS 256
 171
 172 /*
 173  * Debugging.
 174  */
 175 #undef SERIAL_DEBUG_OPEN
 176 #undef SERIAL_DEBUG_FLOW
 177 #undef SERIAL_DEBUG_THROTTLE
 178 #undef SERIAL_PARANOIA_CHECK
 179
 180 #undef ZS_DEBUG_REGS
 181
 182 #ifdef SERIAL_DEBUG_THROTTLE
 183 #define _tty_name(tty,buf) tty_name(tty,buf)
 184 #endif
 185
 186 #define RS_STROBE_TIME 10
 187 #define RS_ISR_PASS_LIMIT 256
 188
 189 static void probe_sccs(void);
 190 static void change_speed(struct dec_serial *info);
 191 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 192
 193 static inline int serial_paranoia_check(struct dec_serial *info,
 194                                         char *name, const char *routine)
 195 {
 196 #ifdef SERIAL_PARANOIA_CHECK
 197         static const char *badmagic =
 198                 "Warning: bad magic number for serial struct %s in %s\n";
 199         static const char *badinfo =
 200                 "Warning: null mac_serial for %s in %s\n";
 201
 202         if (!info) {
 203                 printk(badinfo, name, routine);
 204                 return 1;
 205         }
 206         if (info->magic != SERIAL_MAGIC) {
 207                 printk(badmagic, name, routine);
 208                 return 1;
 209         }
 210 #endif
 211         return 0;
 212 }
 213
 214 /*
 215  * This is used to figure out the divisor speeds and the timeouts
 216  */
 217 static int baud_table[] = {
 218         0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
 219         9600, 19200, 38400, 57600, 115200, 0 };
 220
 221 /*
 222  * Reading and writing Z8530 registers.
 223  */
 224 static inline unsigned char read_zsreg(struct dec_zschannel *channel,
 225                                        unsigned char reg)
 226 {
 227         unsigned char retval;
 228
 229         if (reg != 0) {
 230                 *channel->control = reg & 0xf;
 231                 fast_iob(); RECOVERY_DELAY;
 232         }
 233         retval = *channel->control;
 234         RECOVERY_DELAY;
 235         return retval;
 236 }
 237
 238 static inline void write_zsreg(struct dec_zschannel *channel,
 239                                unsigned char reg, unsigned char value)
 240 {
 241         if (reg != 0) {
 242                 *channel->control = reg & 0xf;
 243                 fast_iob(); RECOVERY_DELAY;
 244         }
 245         *channel->control = value;
 246         fast_iob(); RECOVERY_DELAY;
 247         return;
 248 }
 249
 250 static inline unsigned char read_zsdata(struct dec_zschannel *channel)
 251 {
 252         unsigned char retval;
 253
 254         retval = *channel->data;
 255         RECOVERY_DELAY;
 256         return retval;
 257 }
 258
 259 static inline void write_zsdata(struct dec_zschannel *channel,
 260                                 unsigned char value)
 261 {
 262         *channel->data = value;
 263         fast_iob(); RECOVERY_DELAY;
 264         return;
 265 }
 266
 267 static inline void load_zsregs(struct dec_zschannel *channel,
 268                                unsigned char *regs)
 269 {
 270 /*      ZS_CLEARERR(channel);
 271         ZS_CLEARFIFO(channel); */
 272         /* Load 'em up */
 273         write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
 274         write_zsreg(channel, R5, regs[R5] & ~TxENAB);
 275         write_zsreg(channel, R4, regs[R4]);
 276         write_zsreg(channel, R9, regs[R9]);
 277         write_zsreg(channel, R1, regs[R1]);
 278         write_zsreg(channel, R2, regs[R2]);
 279         write_zsreg(channel, R10, regs[R10]);
 280         write_zsreg(channel, R11, regs[R11]);
 281         write_zsreg(channel, R12, regs[R12]);
 282         write_zsreg(channel, R13, regs[R13]);
 283         write_zsreg(channel, R14, regs[R14]);
 284         write_zsreg(channel, R15, regs[R15]);
 285         write_zsreg(channel, R3, regs[R3]);
 286         write_zsreg(channel, R5, regs[R5]);
 287         return;
 288 }
 289
 290 /* Sets or clears DTR/RTS on the requested line */
 291 static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
 292 {
 293         unsigned long flags;
 294
 295         spin_lock_irqsave(&zs_lock, flags);
 296         if (info->zs_channel != info->zs_chan_a) {
 297                 if (set) {
 298                         info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
 299                 } else {
 300                         info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
 301                 }
 302                 write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
 303         }
 304         spin_unlock_irqrestore(&zs_lock, flags);
 305 }
 306
 307 /* Utility routines for the Zilog */
 308 static inline int get_zsbaud(struct dec_serial *ss)
 309 {
 310         struct dec_zschannel *channel = ss->zs_channel;
 311         int brg;
 312
 313         /* The baud rate is split up between two 8-bit registers in
 314          * what is termed 'BRG time constant' format in my docs for
 315          * the chip, it is a function of the clk rate the chip is
 316          * receiving which happens to be constant.
 317          */
 318         brg = (read_zsreg(channel, 13) << 8);
 319         brg |= read_zsreg(channel, 12);
 320         return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
 321 }
 322
 323 /* On receive, this clears errors and the receiver interrupts */
 324 static inline void rs_recv_clear(struct dec_zschannel *zsc)
 325 {
 326         write_zsreg(zsc, 0, ERR_RES);
 327         write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
 328 }
 329
 330 /*
 331  * ----------------------------------------------------------------------
 332  *
 333  * Here starts the interrupt handling routines.  All of the following
 334  * subroutines are declared as inline and are folded into
 335  * rs_interrupt().  They were separated out for readability's sake.
 336  *
 337  *                              - Ted Ts'o (tytso@mit.edu), 7-Mar-93
 338  * -----------------------------------------------------------------------
 339  */
 340
 341 /*
 342  * This routine is used by the interrupt handler to schedule
 343  * processing in the software interrupt portion of the driver.
 344  */
 345 static void rs_sched_event(struct dec_serial *info, int event)
 346 {
 347         info->event |= 1 << event;
 348         tasklet_schedule(&info->tlet);
 349 }
 350
 351 static void receive_chars(struct dec_serial *info, struct pt_regs *regs)
 352 {
 353         struct tty_struct *tty = info->tty;
 354         unsigned char ch, stat, flag;
 355
 356         while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
 357
 358                 stat = read_zsreg(info->zs_channel, R1);
 359                 ch = read_zsdata(info->zs_channel);
 360
 361                 if (!tty && (!info->hook || !info->hook->rx_char))
 362                         continue;
 363
 364                 flag = TTY_NORMAL;
 365                 if (info->tty_break) {
 366                         info->tty_break = 0;
 367                         flag = TTY_BREAK;
 368                         if (info->flags & ZILOG_SAK)
 369                                 do_SAK(tty);
 370                         /* Ignore the null char got when BREAK is removed.  */
 371                         if (ch == 0)
 372                                 continue;
 373                 } else {
 374                         if (stat & Rx_OVR) {
 375                                 flag = TTY_OVERRUN;
 376                         } else if (stat & FRM_ERR) {
 377                                 flag = TTY_FRAME;
 378                         } else if (stat & PAR_ERR) {
 379                                 flag = TTY_PARITY;
 380                         }
 381                         if (flag != TTY_NORMAL)
 382                                 /* reset the error indication */
 383                                 write_zsreg(info->zs_channel, R0, ERR_RES);
 384                 }
 385
 386 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
 387    !defined(MODULE)
 388                 if (break_pressed && info->line == sercons.index) {
 389                         /* Ignore the null char got when BREAK is removed.  */
 390                         if (ch == 0)
 391                                 continue;
 392                         if (time_before(jiffies, break_pressed + HZ * 5)) {
 393                                 handle_sysrq(ch, regs, NULL);
 394                                 break_pressed = 0;
 395                                 continue;
 396                         }
 397                         break_pressed = 0;
 398                 }
 399 #endif
 400
 401                 if (info->hook && info->hook->rx_char) {
 402                         (*info->hook->rx_char)(ch, flag);
 403                         return;
 404                 }
 405
 406                 tty_insert_flip_char(tty, ch, flag);
 407         }
 408         if (tty)
 409                 tty_flip_buffer_push(tty);
 410 }
 411
 412 static void transmit_chars(struct dec_serial *info)
 413 {
 414         if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
 415                 return;
 416         info->tx_active = 0;
 417
 418         if (info->x_char) {
 419                 /* Send next char */
 420                 write_zsdata(info->zs_channel, info->x_char);
 421                 info->x_char = 0;
 422                 info->tx_active = 1;
 423                 return;
 424         }
 425
 426         if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
 427             || info->tx_stopped) {
 428                 write_zsreg(info->zs_channel, R0, RES_Tx_P);
 429                 return;
 430         }
 431         /* Send char */
 432         write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
 433         info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 434         info->xmit_cnt--;
 435         info->tx_active = 1;
 436
 437         if (info->xmit_cnt < WAKEUP_CHARS)
 438                 rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
 439 }
 440
 441 static void status_handle(struct dec_serial *info)
 442 {
 443         unsigned char stat;
 444
 445         /* Get status from Read Register 0 */
 446         stat = read_zsreg(info->zs_channel, R0);
 447
 448         if ((stat & BRK_ABRT) && !(info->read_reg_zero & BRK_ABRT)) {
 449 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
 450    !defined(MODULE)
 451                 if (info->line == sercons.index) {
 452                         if (!break_pressed)
 453                                 break_pressed = jiffies;
 454                 } else
 455 #endif
 456                         info->tty_break = 1;
 457         }
 458
 459         if (info->zs_channel != info->zs_chan_a) {
 460
 461                 /* Check for DCD transitions */
 462                 if (info->tty && !C_CLOCAL(info->tty) &&
 463                     ((stat ^ info->read_reg_zero) & DCD) != 0 ) {
 464                         if (stat & DCD) {
 465                                 wake_up_interruptible(&info->open_wait);
 466                         } else {
 467                                 tty_hangup(info->tty);
 468                         }
 469                 }
 470
 471                 /* Check for CTS transitions */
 472                 if (info->tty && C_CRTSCTS(info->tty)) {
 473                         if ((stat & CTS) != 0) {
 474                                 if (info->tx_stopped) {
 475                                         info->tx_stopped = 0;
 476                                         if (!info->tx_active)
 477                                                 transmit_chars(info);
 478                                 }
 479                         } else {
 480                                 info->tx_stopped = 1;
 481                         }
 482                 }
 483
 484         }
 485
 486         /* Clear status condition... */
 487         write_zsreg(info->zs_channel, R0, RES_EXT_INT);
 488         info->read_reg_zero = stat;
 489 }
 490
 491 /*
 492  * This is the serial driver's generic interrupt routine
 493  */
 494 static irqreturn_t rs_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 495 {
 496         struct dec_serial *info = (struct dec_serial *) dev_id;
 497         irqreturn_t status = IRQ_NONE;
 498         unsigned char zs_intreg;
 499         int shift;
 500
 501         /* NOTE: The read register 3, which holds the irq status,
 502          *       does so for both channels on each chip.  Although
 503          *       the status value itself must be read from the A
 504          *       channel and is only valid when read from channel A.
 505          *       Yes... broken hardware...
 506          */
 507 #define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
 508
 509         if (info->zs_chan_a == info->zs_channel)
 510                 shift = 3;      /* Channel A */
 511         else
 512                 shift = 0;      /* Channel B */
 513
 514         for (;;) {
 515                 zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
 516                 if ((zs_intreg & CHAN_IRQMASK) == 0)
 517                         break;
 518
 519                 status = IRQ_HANDLED;
 520
 521                 if (zs_intreg & CHBRxIP) {
 522                         receive_chars(info, regs);
 523                 }
 524                 if (zs_intreg & CHBTxIP) {
 525                         transmit_chars(info);
 526                 }
 527                 if (zs_intreg & CHBEXT) {
 528                         status_handle(info);
 529                 }
 530         }
 531
 532         /* Why do we need this ? */
 533         write_zsreg(info->zs_channel, 0, RES_H_IUS);
 534
 535         return status;
 536 }
 537
 538 #ifdef ZS_DEBUG_REGS
 539 void zs_dump (void) {
 540         int i, j;
 541         for (i = 0; i < zs_channels_found; i++) {
 542                 struct dec_zschannel *ch = &zs_channels[i];
 543                 if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
 544                         for (j = 0; j < 15; j++) {
 545                                 printk("W%d = 0x%x\t",
 546                                        j, (int)ch->curregs[j]);
 547                         }
 548                         for (j = 0; j < 15; j++) {
 549                                 printk("R%d = 0x%x\t",
 550                                        j, (int)read_zsreg(ch,j));
 551                         }
 552                         printk("\n\n");
 553                 }
 554         }
 555 }
 556 #endif
 557
 558 /*
 559  * -------------------------------------------------------------------
 560  * Here ends the serial interrupt routines.
 561  * -------------------------------------------------------------------
 562  */
 563
 564 /*
 565  * ------------------------------------------------------------
 566  * rs_stop() and rs_start()
 567  *
 568  * This routines are called before setting or resetting tty->stopped.
 569  * ------------------------------------------------------------
 570  */
 571 static void rs_stop(struct tty_struct *tty)
 572 {
 573         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 574         unsigned long flags;
 575
 576         if (serial_paranoia_check(info, tty->name, "rs_stop"))
 577                 return;
 578
 579 #if 1
 580         spin_lock_irqsave(&zs_lock, flags);
 581         if (info->zs_channel->curregs[5] & TxENAB) {
 582                 info->zs_channel->curregs[5] &= ~TxENAB;
 583                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 584         }
 585         spin_unlock_irqrestore(&zs_lock, flags);
 586 #endif
 587 }
 588
 589 static void rs_start(struct tty_struct *tty)
 590 {
 591         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 592         unsigned long flags;
 593
 594         if (serial_paranoia_check(info, tty->name, "rs_start"))
 595                 return;
 596
 597         spin_lock_irqsave(&zs_lock, flags);
 598 #if 1
 599         if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
 600                 info->zs_channel->curregs[5] |= TxENAB;
 601                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 602         }
 603 #else
 604         if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
 605                 transmit_chars(info);
 606         }
 607 #endif
 608         spin_unlock_irqrestore(&zs_lock, flags);
 609 }
 610
 611 /*
 612  * This routine is used to handle the "bottom half" processing for the
 613  * serial driver, known also the "software interrupt" processing.
 614  * This processing is done at the kernel interrupt level, after the
 615  * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
 616  * is where time-consuming activities which can not be done in the
 617  * interrupt driver proper are done; the interrupt driver schedules
 618  * them using rs_sched_event(), and they get done here.
 619  */
 620
 621 static void do_softint(unsigned long private_)
 622 {
 623         struct dec_serial       *info = (struct dec_serial *) private_;
 624         struct tty_struct       *tty;
 625
 626         tty = info->tty;
 627         if (!tty)
 628                 return;
 629
 630         if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
 631                 tty_wakeup(tty);
 632                 wake_up_interruptible(&tty->write_wait);
 633         }
 634 }
 635
 636 static int zs_startup(struct dec_serial * info)
 637 {
 638         unsigned long flags;
 639
 640         if (info->flags & ZILOG_INITIALIZED)
 641                 return 0;
 642
 643         if (!info->xmit_buf) {
 644                 info->xmit_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
 645                 if (!info->xmit_buf)
 646                         return -ENOMEM;
 647         }
 648
 649         spin_lock_irqsave(&zs_lock, flags);
 650
 651 #ifdef SERIAL_DEBUG_OPEN
 652         printk("starting up ttyS%d (irq %d)...", info->line, info->irq);
 653 #endif
 654
 655         /*
 656          * Clear the receive FIFO.
 657          */
 658         ZS_CLEARFIFO(info->zs_channel);
 659         info->xmit_fifo_size = 1;
 660
 661         /*
 662          * Clear the interrupt registers.
 663          */
 664         write_zsreg(info->zs_channel, R0, ERR_RES);
 665         write_zsreg(info->zs_channel, R0, RES_H_IUS);
 666
 667         /*
 668          * Set the speed of the serial port
 669          */
 670         change_speed(info);
 671
 672         /*
 673          * Turn on RTS and DTR.
 674          */
 675         zs_rtsdtr(info, RTS | DTR, 1);
 676
 677         /*
 678          * Finally, enable sequencing and interrupts
 679          */
 680         info->zs_channel->curregs[R1] &= ~RxINT_MASK;
 681         info->zs_channel->curregs[R1] |= (RxINT_ALL | TxINT_ENAB |
 682                                           EXT_INT_ENAB);
 683         info->zs_channel->curregs[R3] |= RxENABLE;
 684         info->zs_channel->curregs[R5] |= TxENAB;
 685         info->zs_channel->curregs[R15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
 686         write_zsreg(info->zs_channel, R1, info->zs_channel->curregs[R1]);
 687         write_zsreg(info->zs_channel, R3, info->zs_channel->curregs[R3]);
 688         write_zsreg(info->zs_channel, R5, info->zs_channel->curregs[R5]);
 689         write_zsreg(info->zs_channel, R15, info->zs_channel->curregs[R15]);
 690
 691         /*
 692          * And clear the interrupt registers again for luck.
 693          */
 694         write_zsreg(info->zs_channel, R0, ERR_RES);
 695         write_zsreg(info->zs_channel, R0, RES_H_IUS);
 696
 697         /* Save the current value of RR0 */
 698         info->read_reg_zero = read_zsreg(info->zs_channel, R0);
 699
 700         if (info->tty)
 701                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
 702         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 703
 704         info->flags |= ZILOG_INITIALIZED;
 705         spin_unlock_irqrestore(&zs_lock, flags);
 706         return 0;
 707 }
 708
 709 /*
 710  * This routine will shutdown a serial port; interrupts are disabled, and
 711  * DTR is dropped if the hangup on close termio flag is on.
 712  */
 713 static void shutdown(struct dec_serial * info)
 714 {
 715         unsigned long   flags;
 716
 717         if (!(info->flags & ZILOG_INITIALIZED))
 718                 return;
 719
 720 #ifdef SERIAL_DEBUG_OPEN
 721         printk("Shutting down serial port %d (irq %d)....", info->line,
 722                info->irq);
 723 #endif
 724
 725         spin_lock_irqsave(&zs_lock, flags);
 726
 727         if (info->xmit_buf) {
 728                 free_page((unsigned long) info->xmit_buf);
 729                 info->xmit_buf = 0;
 730         }
 731
 732         info->zs_channel->curregs[1] = 0;
 733         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]); /* no interrupts */
 734
 735         info->zs_channel->curregs[3] &= ~RxENABLE;
 736         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
 737
 738         info->zs_channel->curregs[5] &= ~TxENAB;
 739         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 740         if (!info->tty || C_HUPCL(info->tty)) {
 741                 zs_rtsdtr(info, RTS | DTR, 0);
 742         }
 743
 744         if (info->tty)
 745                 set_bit(TTY_IO_ERROR, &info->tty->flags);
 746
 747         info->flags &= ~ZILOG_INITIALIZED;
 748         spin_unlock_irqrestore(&zs_lock, flags);
 749 }
 750
 751 /*
 752  * This routine is called to set the UART divisor registers to match
 753  * the specified baud rate for a serial port.
 754  */
 755 static void change_speed(struct dec_serial *info)
 756 {
 757         unsigned cflag;
 758         int     i;
 759         int     brg, bits;
 760         unsigned long flags;
 761
 762         if (!info->hook) {
 763                 if (!info->tty || !info->tty->termios)
 764                         return;
 765                 cflag = info->tty->termios->c_cflag;
 766                 if (!info->port)
 767                         return;
 768         } else {
 769                 cflag = info->hook->cflags;
 770         }
 771
 772         i = cflag & CBAUD;
 773         if (i & CBAUDEX) {
 774                 i &= ~CBAUDEX;
 775                 if (i < 1 || i > 2) {
 776                         if (!info->hook)
 777                                 info->tty->termios->c_cflag &= ~CBAUDEX;
 778                         else
 779                                 info->hook->cflags &= ~CBAUDEX;
 780                 } else
 781                         i += 15;
 782         }
 783
 784         spin_lock_irqsave(&zs_lock, flags);
 785         info->zs_baud = baud_table[i];
 786         if (info->zs_baud) {
 787                 brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
 788                 info->zs_channel->curregs[12] = (brg & 255);
 789                 info->zs_channel->curregs[13] = ((brg >> 8) & 255);
 790                 zs_rtsdtr(info, DTR, 1);
 791         } else {
 792                 zs_rtsdtr(info, RTS | DTR, 0);
 793                 return;
 794         }
 795
 796         /* byte size and parity */
 797         info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
 798         info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
 799         switch (cflag & CSIZE) {
 800         case CS5:
 801                 bits = 7;
 802                 info->zs_channel->curregs[3] |= Rx5;
 803                 info->zs_channel->curregs[5] |= Tx5;
 804                 break;
 805         case CS6:
 806                 bits = 8;
 807                 info->zs_channel->curregs[3] |= Rx6;
 808                 info->zs_channel->curregs[5] |= Tx6;
 809                 break;
 810         case CS7:
 811                 bits = 9;
 812                 info->zs_channel->curregs[3] |= Rx7;
 813                 info->zs_channel->curregs[5] |= Tx7;
 814                 break;
 815         case CS8:
 816         default: /* defaults to 8 bits */
 817                 bits = 10;
 818                 info->zs_channel->curregs[3] |= Rx8;
 819                 info->zs_channel->curregs[5] |= Tx8;
 820                 break;
 821         }
 822
 823         info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
 824         info->timeout += HZ/50;         /* Add .02 seconds of slop */
 825
 826         info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
 827         if (cflag & CSTOPB) {
 828                 info->zs_channel->curregs[4] |= SB2;
 829         } else {
 830                 info->zs_channel->curregs[4] |= SB1;
 831         }
 832         if (cflag & PARENB) {
 833                 info->zs_channel->curregs[4] |= PAR_ENA;
 834         }
 835         if (!(cflag & PARODD)) {
 836                 info->zs_channel->curregs[4] |= PAR_EVEN;
 837         }
 838
 839         if (!(cflag & CLOCAL)) {
 840                 if (!(info->zs_channel->curregs[15] & DCDIE))
 841                         info->read_reg_zero = read_zsreg(info->zs_channel, 0);
 842                 info->zs_channel->curregs[15] |= DCDIE;
 843         } else
 844                 info->zs_channel->curregs[15] &= ~DCDIE;
 845         if (cflag & CRTSCTS) {
 846                 info->zs_channel->curregs[15] |= CTSIE;
 847                 if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
 848                         info->tx_stopped = 1;
 849         } else {
 850                 info->zs_channel->curregs[15] &= ~CTSIE;
 851                 info->tx_stopped = 0;
 852         }
 853
 854         /* Load up the new values */
 855         load_zsregs(info->zs_channel, info->zs_channel->curregs);
 856
 857         spin_unlock_irqrestore(&zs_lock, flags);
 858 }
 859
 860 static void rs_flush_chars(struct tty_struct *tty)
 861 {
 862         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 863         unsigned long flags;
 864
 865         if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
 866                 return;
 867
 868         if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
 869             !info->xmit_buf)
 870                 return;
 871
 872         /* Enable transmitter */
 873         spin_lock_irqsave(&zs_lock, flags);
 874         transmit_chars(info);
 875         spin_unlock_irqrestore(&zs_lock, flags);
 876 }
 877
 878 static int rs_write(struct tty_struct * tty,
 879                     const unsigned char *buf, int count)
 880 {
 881         int     c, total = 0;
 882         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 883         unsigned long flags;
 884
 885         if (serial_paranoia_check(info, tty->name, "rs_write"))
 886                 return 0;
 887
 888         if (!tty || !info->xmit_buf)
 889                 return 0;
 890
 891         while (1) {
 892                 spin_lock_irqsave(&zs_lock, flags);
 893                 c = min(count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 894                                    SERIAL_XMIT_SIZE - info->xmit_head));
 895                 if (c <= 0)
 896                         break;
 897
 898                 memcpy(info->xmit_buf + info->xmit_head, buf, c);
 899                 info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
 900                 info->xmit_cnt += c;
 901                 spin_unlock_irqrestore(&zs_lock, flags);
 902                 buf += c;
 903                 count -= c;
 904                 total += c;
 905         }
 906
 907         if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
 908             && !info->tx_active)
 909                 transmit_chars(info);
 910         spin_unlock_irqrestore(&zs_lock, flags);
 911         return total;
 912 }
 913
 914 static int rs_write_room(struct tty_struct *tty)
 915 {
 916         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 917         int     ret;
 918
 919         if (serial_paranoia_check(info, tty->name, "rs_write_room"))
 920                 return 0;
 921         ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
 922         if (ret < 0)
 923                 ret = 0;
 924         return ret;
 925 }
 926
 927 static int rs_chars_in_buffer(struct tty_struct *tty)
 928 {
 929         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 930
 931         if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
 932                 return 0;
 933         return info->xmit_cnt;
 934 }
 935
 936 static void rs_flush_buffer(struct tty_struct *tty)
 937 {
 938         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 939
 940         if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
 941                 return;
 942         spin_lock_irq(&zs_lock);
 943         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 944         spin_unlock_irq(&zs_lock);
 945         tty_wakeup(tty);
 946 }
 947
 948 /*
 949  * ------------------------------------------------------------
 950  * rs_throttle()
 951  *
 952  * This routine is called by the upper-layer tty layer to signal that
 953  * incoming characters should be throttled.
 954  * ------------------------------------------------------------
 955  */
 956 static void rs_throttle(struct tty_struct * tty)
 957 {
 958         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 959         unsigned long flags;
 960
 961 #ifdef SERIAL_DEBUG_THROTTLE
 962         char    buf[64];
 963
 964         printk("throttle %s: %d....\n", _tty_name(tty, buf),
 965                tty->ldisc.chars_in_buffer(tty));
 966 #endif
 967
 968         if (serial_paranoia_check(info, tty->name, "rs_throttle"))
 969                 return;
 970
 971         if (I_IXOFF(tty)) {
 972                 spin_lock_irqsave(&zs_lock, flags);
 973                 info->x_char = STOP_CHAR(tty);
 974                 if (!info->tx_active)
 975                         transmit_chars(info);
 976                 spin_unlock_irqrestore(&zs_lock, flags);
 977         }
 978
 979         if (C_CRTSCTS(tty)) {
 980                 zs_rtsdtr(info, RTS, 0);
 981         }
 982 }
 983
 984 static void rs_unthrottle(struct tty_struct * tty)
 985 {
 986         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 987         unsigned long flags;
 988
 989 #ifdef SERIAL_DEBUG_THROTTLE
 990         char    buf[64];
 991
 992         printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
 993                tty->ldisc.chars_in_buffer(tty));
 994 #endif
 995
 996         if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
 997                 return;
 998
 999         if (I_IXOFF(tty)) {
1000                 spin_lock_irqsave(&zs_lock, flags);
1001                 if (info->x_char)
1002                         info->x_char = 0;
1003                 else {
1004                         info->x_char = START_CHAR(tty);
1005                         if (!info->tx_active)
1006                                 transmit_chars(info);
1007                 }
1008                 spin_unlock_irqrestore(&zs_lock, flags);
1009         }
1010
1011         if (C_CRTSCTS(tty)) {
1012                 zs_rtsdtr(info, RTS, 1);
1013         }
1014 }
1015
1016 /*
1017  * ------------------------------------------------------------
1018  * rs_ioctl() and friends
1019  * ------------------------------------------------------------
1020  */
1021
1022 static int get_serial_info(struct dec_serial * info,
1023                            struct serial_struct * retinfo)
1024 {
1025         struct serial_struct tmp;
1026
1027         if (!retinfo)
1028                 return -EFAULT;
1029         memset(&tmp, 0, sizeof(tmp));
1030         tmp.type = info->type;
1031         tmp.line = info->line;
1032         tmp.port = info->port;
1033         tmp.irq = info->irq;
1034         tmp.flags = info->flags;
1035         tmp.baud_base = info->baud_base;
1036         tmp.close_delay = info->close_delay;
1037         tmp.closing_wait = info->closing_wait;
1038         tmp.custom_divisor = info->custom_divisor;
1039         return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
1040 }
1041
1042 static int set_serial_info(struct dec_serial * info,
1043                            struct serial_struct * new_info)
1044 {
1045         struct serial_struct new_serial;
1046         struct dec_serial old_info;
1047         int                     retval = 0;
1048
1049         if (!new_info)
1050                 return -EFAULT;
1051         copy_from_user(&new_serial,new_info,sizeof(new_serial));
1052         old_info = *info;
1053
1054         if (!capable(CAP_SYS_ADMIN)) {
1055                 if ((new_serial.baud_base != info->baud_base) ||
1056                     (new_serial.type != info->type) ||
1057                     (new_serial.close_delay != info->close_delay) ||
1058                     ((new_serial.flags & ~ZILOG_USR_MASK) !=
1059                      (info->flags & ~ZILOG_USR_MASK)))
1060                         return -EPERM;
1061                 info->flags = ((info->flags & ~ZILOG_USR_MASK) |
1062                                (new_serial.flags & ZILOG_USR_MASK));
1063                 info->custom_divisor = new_serial.custom_divisor;
1064                 goto check_and_exit;
1065         }
1066
1067         if (info->count > 1)
1068                 return -EBUSY;
1069
1070         /*
1071          * OK, past this point, all the error checking has been done.
1072          * At this point, we start making changes.....
1073          */
1074
1075         info->baud_base = new_serial.baud_base;
1076         info->flags = ((info->flags & ~ZILOG_FLAGS) |
1077                         (new_serial.flags & ZILOG_FLAGS));
1078         info->type = new_serial.type;
1079         info->close_delay = new_serial.close_delay;
1080         info->closing_wait = new_serial.closing_wait;
1081
1082 check_and_exit:
1083         retval = zs_startup(info);
1084         return retval;
1085 }
1086
1087 /*
1088  * get_lsr_info - get line status register info
1089  *
1090  * Purpose: Let user call ioctl() to get info when the UART physically
1091  *          is emptied.  On bus types like RS485, the transmitter must
1092  *          release the bus after transmitting. This must be done when
1093  *          the transmit shift register is empty, not be done when the
1094  *          transmit holding register is empty.  This functionality
1095  *          allows an RS485 driver to be written in user space.
1096  */
1097 static int get_lsr_info(struct dec_serial * info, unsigned int *value)
1098 {
1099         unsigned char status;
1100
1101         spin_lock(&zs_lock);
1102         status = read_zsreg(info->zs_channel, 0);
1103         spin_unlock_irq(&zs_lock);
1104         put_user(status,value);
1105         return 0;
1106 }
1107
1108 static int rs_tiocmget(struct tty_struct *tty, struct file *file)
1109 {
1110         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1111         unsigned char control, status_a, status_b;
1112         unsigned int result;
1113
1114         if (info->hook)
1115                 return -ENODEV;
1116
1117         if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1118                 return -ENODEV;
1119
1120         if (tty->flags & (1 << TTY_IO_ERROR))
1121                 return -EIO;
1122
1123         if (info->zs_channel == info->zs_chan_a)
1124                 result = 0;
1125         else {
1126                 spin_lock(&zs_lock);
1127                 control = info->zs_chan_a->curregs[5];
1128                 status_a = read_zsreg(info->zs_chan_a, 0);
1129                 status_b = read_zsreg(info->zs_channel, 0);
1130                 spin_unlock_irq(&zs_lock);
1131                 result =  ((control  & RTS) ? TIOCM_RTS: 0)
1132                         | ((control  & DTR) ? TIOCM_DTR: 0)
1133                         | ((status_b & DCD) ? TIOCM_CAR: 0)
1134                         | ((status_a & DCD) ? TIOCM_RNG: 0)
1135                         | ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
1136                         | ((status_b & CTS) ? TIOCM_CTS: 0);
1137         }
1138         return result;
1139 }
1140
1141 static int rs_tiocmset(struct tty_struct *tty, struct file *file,
1142                        unsigned int set, unsigned int clear)
1143 {
1144         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1145
1146         if (info->hook)
1147                 return -ENODEV;
1148
1149         if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1150                 return -ENODEV;
1151
1152         if (tty->flags & (1 << TTY_IO_ERROR))
1153                 return -EIO;
1154
1155         if (info->zs_channel == info->zs_chan_a)
1156                 return 0;
1157
1158         spin_lock(&zs_lock);
1159         if (set & TIOCM_RTS)
1160                 info->zs_chan_a->curregs[5] |= RTS;
1161         if (set & TIOCM_DTR)
1162                 info->zs_chan_a->curregs[5] |= DTR;
1163         if (clear & TIOCM_RTS)
1164                 info->zs_chan_a->curregs[5] &= ~RTS;
1165         if (clear & TIOCM_DTR)
1166                 info->zs_chan_a->curregs[5] &= ~DTR;
1167         write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
1168         spin_unlock_irq(&zs_lock);
1169         return 0;
1170 }
1171
1172 /*
1173  * rs_break - turn transmit break condition on/off
1174  */
1175 static void rs_break(struct tty_struct *tty, int break_state)
1176 {
1177         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1178         unsigned long flags;
1179
1180         if (serial_paranoia_check(info, tty->name, "rs_break"))
1181                 return;
1182         if (!info->port)
1183                 return;
1184
1185         spin_lock_irqsave(&zs_lock, flags);
1186         if (break_state == -1)
1187                 info->zs_channel->curregs[5] |= SND_BRK;
1188         else
1189                 info->zs_channel->curregs[5] &= ~SND_BRK;
1190         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
1191         spin_unlock_irqrestore(&zs_lock, flags);
1192 }
1193
1194 static int rs_ioctl(struct tty_struct *tty, struct file * file,
1195                     unsigned int cmd, unsigned long arg)
1196 {
1197         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1198
1199         if (info->hook)
1200                 return -ENODEV;
1201
1202         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1203                 return -ENODEV;
1204
1205         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1206             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
1207             (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
1208                 if (tty->flags & (1 << TTY_IO_ERROR))
1209                     return -EIO;
1210         }
1211
1212         switch (cmd) {
1213         case TIOCGSERIAL:
1214                 if (!access_ok(VERIFY_WRITE, (void *)arg,
1215                                sizeof(struct serial_struct)))
1216                         return -EFAULT;
1217                 return get_serial_info(info, (struct serial_struct *)arg);
1218
1219         case TIOCSSERIAL:
1220                 return set_serial_info(info, (struct serial_struct *)arg);
1221
1222         case TIOCSERGETLSR:                     /* Get line status register */
1223                 if (!access_ok(VERIFY_WRITE, (void *)arg,
1224                                sizeof(unsigned int)))
1225                         return -EFAULT;
1226                 return get_lsr_info(info, (unsigned int *)arg);
1227
1228         case TIOCSERGSTRUCT:
1229                 if (!access_ok(VERIFY_WRITE, (void *)arg,
1230                                sizeof(struct dec_serial)))
1231                         return -EFAULT;
1232                 copy_from_user((struct dec_serial *)arg, info,
1233                                sizeof(struct dec_serial));
1234                 return 0;
1235
1236         default:
1237                 return -ENOIOCTLCMD;
1238         }
1239         return 0;
1240 }
1241
1242 static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
1243 {
1244         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1245         int was_stopped;
1246
1247         if (tty->termios->c_cflag == old_termios->c_cflag)
1248                 return;
1249         was_stopped = info->tx_stopped;
1250
1251         change_speed(info);
1252
1253         if (was_stopped && !info->tx_stopped)
1254                 rs_start(tty);
1255 }
1256
1257 /*
1258  * ------------------------------------------------------------
1259  * rs_close()
1260  *
1261  * This routine is called when the serial port gets closed.
1262  * Wait for the last remaining data to be sent.
1263  * ------------------------------------------------------------
1264  */
1265 static void rs_close(struct tty_struct *tty, struct file * filp)
1266 {
1267         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1268         unsigned long flags;
1269
1270         if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
1271                 return;
1272
1273         spin_lock_irqsave(&zs_lock, flags);
1274
1275         if (tty_hung_up_p(filp)) {
1276                 spin_unlock_irqrestore(&zs_lock, flags);
1277                 return;
1278         }
1279
1280 #ifdef SERIAL_DEBUG_OPEN
1281         printk("rs_close ttyS%d, count = %d\n", info->line, info->count);
1282 #endif
1283         if ((tty->count == 1) && (info->count != 1)) {
1284                 /*
1285                  * Uh, oh.  tty->count is 1, which means that the tty
1286                  * structure will be freed.  Info->count should always
1287                  * be one in these conditions.  If it's greater than
1288                  * one, we've got real problems, since it means the
1289                  * serial port won't be shutdown.
1290                  */
1291                 printk("rs_close: bad serial port count; tty->count is 1, "
1292                        "info->count is %d\n", info->count);
1293                 info->count = 1;
1294         }
1295         if (--info->count < 0) {
1296                 printk("rs_close: bad serial port count for ttyS%d: %d\n",
1297                        info->line, info->count);
1298                 info->count = 0;
1299         }
1300         if (info->count) {
1301                 spin_unlock_irqrestore(&zs_lock, flags);
1302                 return;
1303         }
1304         info->flags |= ZILOG_CLOSING;
1305         /*
1306          * Now we wait for the transmit buffer to clear; and we notify
1307          * the line discipline to only process XON/XOFF characters.
1308          */
1309         tty->closing = 1;
1310         if (info->closing_wait != ZILOG_CLOSING_WAIT_NONE)
1311                 tty_wait_until_sent(tty, info->closing_wait);
1312         /*
1313          * At this point we stop accepting input.  To do this, we
1314          * disable the receiver and receive interrupts.
1315          */
1316         info->zs_channel->curregs[3] &= ~RxENABLE;
1317         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
1318         info->zs_channel->curregs[1] = 0;       /* disable any rx ints */
1319         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
1320         ZS_CLEARFIFO(info->zs_channel);
1321         if (info->flags & ZILOG_INITIALIZED) {
1322                 /*
1323                  * Before we drop DTR, make sure the SCC transmitter
1324                  * has completely drained.
1325                  */
1326                 rs_wait_until_sent(tty, info->timeout);
1327         }
1328
1329         shutdown(info);
1330         if (tty->driver->flush_buffer)
1331                 tty->driver->flush_buffer(tty);
1332         tty_ldisc_flush(tty);
1333         tty->closing = 0;
1334         info->event = 0;
1335         info->tty = 0;
1336         if (info->blocked_open) {
1337                 if (info->close_delay) {
1338                         msleep_interruptible(jiffies_to_msecs(info->close_delay));
1339                 }
1340                 wake_up_interruptible(&info->open_wait);
1341         }
1342         info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CLOSING);
1343         wake_up_interruptible(&info->close_wait);
1344         spin_unlock_irqrestore(&zs_lock, flags);
1345 }
1346
1347 /*
1348  * rs_wait_until_sent() --- wait until the transmitter is empty
1349  */
1350 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1351 {
1352         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1353         unsigned long orig_jiffies;
1354         int char_time;
1355
1356         if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1357                 return;
1358
1359         orig_jiffies = jiffies;
1360         /*
1361          * Set the check interval to be 1/5 of the estimated time to
1362          * send a single character, and make it at least 1.  The check
1363          * interval should also be less than the timeout.
1364          */
1365         char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1366         char_time = char_time / 5;
1367         if (char_time == 0)
1368                 char_time = 1;
1369         if (timeout)
1370                 char_time = min(char_time, timeout);
1371         while ((read_zsreg(info->zs_channel, 1) & Tx_BUF_EMP) == 0) {
1372                 msleep_interruptible(jiffies_to_msecs(char_time));
1373                 if (signal_pending(current))
1374                         break;
1375                 if (timeout && time_after(jiffies, orig_jiffies + timeout))
1376                         break;
1377         }
1378         current->state = TASK_RUNNING;
1379 }
1380
1381 /*
1382  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1383  */
1384 static void rs_hangup(struct tty_struct *tty)
1385 {
1386         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1387
1388         if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1389                 return;
1390
1391         rs_flush_buffer(tty);
1392         shutdown(info);
1393         info->event = 0;
1394         info->count = 0;
1395         info->flags &= ~ZILOG_NORMAL_ACTIVE;
1396         info->tty = 0;
1397         wake_up_interruptible(&info->open_wait);
1398 }
1399
1400 /*
1401  * ------------------------------------------------------------
1402  * rs_open() and friends
1403  * ------------------------------------------------------------
1404  */
1405 static int block_til_ready(struct tty_struct *tty, struct file * filp,
1406                            struct dec_serial *info)
1407 {
1408         DECLARE_WAITQUEUE(wait, current);
1409         int             retval;
1410         int             do_clocal = 0;
1411
1412         /*
1413          * If the device is in the middle of being closed, then block
1414          * until it's done, and then try again.
1415          */
1416         if (info->flags & ZILOG_CLOSING) {
1417                 interruptible_sleep_on(&info->close_wait);
1418 #ifdef SERIAL_DO_RESTART
1419                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1420                         -EAGAIN : -ERESTARTSYS);
1421 #else
1422                 return -EAGAIN;
1423 #endif
1424         }
1425
1426         /*
1427          * If non-blocking mode is set, or the port is not enabled,
1428          * then make the check up front and then exit.
1429          */
1430         if ((filp->f_flags & O_NONBLOCK) ||
1431             (tty->flags & (1 << TTY_IO_ERROR))) {
1432                 info->flags |= ZILOG_NORMAL_ACTIVE;
1433                 return 0;
1434         }
1435
1436         if (tty->termios->c_cflag & CLOCAL)
1437                 do_clocal = 1;
1438
1439         /*
1440          * Block waiting for the carrier detect and the line to become
1441          * free (i.e., not in use by the callout).  While we are in
1442          * this loop, info->count is dropped by one, so that
1443          * rs_close() knows when to free things.  We restore it upon
1444          * exit, either normal or abnormal.
1445          */
1446         retval = 0;
1447         add_wait_queue(&info->open_wait, &wait);
1448 #ifdef SERIAL_DEBUG_OPEN
1449         printk("block_til_ready before block: ttyS%d, count = %d\n",
1450                info->line, info->count);
1451 #endif
1452         spin_lock(&zs_lock);
1453         if (!tty_hung_up_p(filp))
1454                 info->count--;
1455         spin_unlock_irq(&zs_lock);
1456         info->blocked_open++;
1457         while (1) {
1458                 spin_lock(&zs_lock);
1459                 if (tty->termios->c_cflag & CBAUD)
1460                         zs_rtsdtr(info, RTS | DTR, 1);
1461                 spin_unlock_irq(&zs_lock);
1462                 set_current_state(TASK_INTERRUPTIBLE);
1463                 if (tty_hung_up_p(filp) ||
1464                     !(info->flags & ZILOG_INITIALIZED)) {
1465 #ifdef SERIAL_DO_RESTART
1466                         if (info->flags & ZILOG_HUP_NOTIFY)
1467                                 retval = -EAGAIN;
1468                         else
1469                                 retval = -ERESTARTSYS;
1470 #else
1471                         retval = -EAGAIN;
1472 #endif
1473                         break;
1474                 }
1475                 if (!(info->flags & ZILOG_CLOSING) &&
1476                     (do_clocal || (read_zsreg(info->zs_channel, 0) & DCD)))
1477                         break;
1478                 if (signal_pending(current)) {
1479                         retval = -ERESTARTSYS;
1480                         break;
1481                 }
1482 #ifdef SERIAL_DEBUG_OPEN
1483                 printk("block_til_ready blocking: ttyS%d, count = %d\n",
1484                        info->line, info->count);
1485 #endif
1486                 schedule();
1487         }
1488         current->state = TASK_RUNNING;
1489         remove_wait_queue(&info->open_wait, &wait);
1490         if (!tty_hung_up_p(filp))
1491                 info->count++;
1492         info->blocked_open--;
1493 #ifdef SERIAL_DEBUG_OPEN
1494         printk("block_til_ready after blocking: ttyS%d, count = %d\n",
1495                info->line, info->count);
1496 #endif
1497         if (retval)
1498                 return retval;
1499         info->flags |= ZILOG_NORMAL_ACTIVE;
1500         return 0;
1501 }
1502
1503 /*
1504  * This routine is called whenever a serial port is opened.  It
1505  * enables interrupts for a serial port, linking in its ZILOG structure into
1506  * the IRQ chain.   It also performs the serial-specific
1507  * initialization for the tty structure.
1508  */
1509 static int rs_open(struct tty_struct *tty, struct file * filp)
1510 {
1511         struct dec_serial       *info;
1512         int                     retval, line;
1513
1514         line = tty->index;
1515         if ((line < 0) || (line >= zs_channels_found))
1516                 return -ENODEV;
1517         info = zs_soft + line;
1518
1519         if (info->hook)
1520                 return -ENODEV;
1521
1522         if (serial_paranoia_check(info, tty->name, "rs_open"))
1523                 return -ENODEV;
1524 #ifdef SERIAL_DEBUG_OPEN
1525         printk("rs_open %s, count = %d\n", tty->name, info->count);
1526 #endif
1527
1528         info->count++;
1529         tty->driver_data = info;
1530         info->tty = tty;
1531
1532         /*
1533          * If the port is the middle of closing, bail out now
1534          */
1535         if (tty_hung_up_p(filp) ||
1536             (info->flags & ZILOG_CLOSING)) {
1537                 if (info->flags & ZILOG_CLOSING)
1538                         interruptible_sleep_on(&info->close_wait);
1539 #ifdef SERIAL_DO_RESTART
1540                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1541                         -EAGAIN : -ERESTARTSYS);
1542 #else
1543                 return -EAGAIN;
1544 #endif
1545         }
1546
1547         /*
1548          * Start up serial port
1549          */
1550         retval = zs_startup(info);
1551         if (retval)
1552                 return retval;
1553
1554         retval = block_til_ready(tty, filp, info);
1555         if (retval) {
1556 #ifdef SERIAL_DEBUG_OPEN
1557                 printk("rs_open returning after block_til_ready with %d\n",
1558                        retval);
1559 #endif
1560                 return retval;
1561         }
1562
1563 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1564         if (sercons.cflag && sercons.index == line) {
1565                 tty->termios->c_cflag = sercons.cflag;
1566                 sercons.cflag = 0;
1567                 change_speed(info);
1568         }
1569 #endif
1570
1571 #ifdef SERIAL_DEBUG_OPEN
1572         printk("rs_open %s successful...", tty->name);
1573 #endif
1574 /* tty->low_latency = 1; */
1575         return 0;
1576 }
1577
1578 /* Finally, routines used to initialize the serial driver. */
1579
1580 static void __init show_serial_version(void)
1581 {
1582         printk("DECstation Z8530 serial driver version 0.09\n");
1583 }
1584
1585 /*  Initialize Z8530s zs_channels
1586  */
1587
1588 static void __init probe_sccs(void)
1589 {
1590         struct dec_serial **pp;
1591         int i, n, n_chips = 0, n_channels, chip, channel;
1592         unsigned long flags;
1593
1594         /*
1595          * did we get here by accident?
1596          */
1597         if(!BUS_PRESENT) {
1598                 printk("Not on JUNKIO machine, skipping probe_sccs\n");
1599                 return;
1600         }
1601
1602         switch(mips_machtype) {
1603 #ifdef CONFIG_MACH_DECSTATION
1604         case MACH_DS5000_2X0:
1605         case MACH_DS5900:
1606                 n_chips = 2;
1607                 zs_parms = &ds_parms;
1608                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1609                 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1610                 break;
1611         case MACH_DS5000_1XX:
1612                 n_chips = 2;
1613                 zs_parms = &ds_parms;
1614                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1615                 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1616                 break;
1617         case MACH_DS5000_XX:
1618                 n_chips = 1;
1619                 zs_parms = &ds_parms;
1620                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1621                 break;
1622 #endif
1623         default:
1624                 panic("zs: unsupported bus");
1625         }
1626         if (!zs_parms)
1627                 panic("zs: uninitialized parms");
1628
1629         pp = &zs_chain;
1630
1631         n_channels = 0;
1632
1633         for (chip = 0; chip < n_chips; chip++) {
1634                 for (channel = 0; channel <= 1; channel++) {
1635                         /*
1636                          * The sccs reside on the high byte of the 16 bit IOBUS
1637                          */
1638                         zs_channels[n_channels].control =
1639                                 (volatile void *)CKSEG1ADDR(dec_kn_slot_base +
1640                           (0 == chip ? zs_parms->scc0 : zs_parms->scc1) +
1641                           (0 == channel ? zs_parms->channel_a_offset :
1642                                           zs_parms->channel_b_offset));
1643                         zs_channels[n_channels].data =
1644                                 zs_channels[n_channels].control + 4;
1645
1646 #ifndef CONFIG_SERIAL_DEC_CONSOLE
1647                         /*
1648                          * We're called early and memory managment isn't up, yet.
1649                          * Thus request_region would fail.
1650                          */
1651                         if (!request_region((unsigned long)
1652                                          zs_channels[n_channels].control,
1653                                          ZS_CHAN_IO_SIZE, "SCC"))
1654                                 panic("SCC I/O region is not free");
1655 #endif
1656                         zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
1657                         /* HACK alert! */
1658                         if (!(chip & 1))
1659                                 zs_soft[n_channels].irq = zs_parms->irq0;
1660                         else
1661                                 zs_soft[n_channels].irq = zs_parms->irq1;
1662
1663                         /*
1664                          *  Identification of channel A. Location of channel A
1665                          *  inside chip depends on mapping of internal address
1666                          *  the chip decodes channels by.
1667                          *  CHANNEL_A_NR returns either 0 (in case of
1668                          *  DECstations) or 1 (in case of Baget).
1669                          */
1670                         if (CHANNEL_A_NR == channel)
1671                                 zs_soft[n_channels].zs_chan_a =
1672                                     &zs_channels[n_channels+1-2*CHANNEL_A_NR];
1673                         else
1674                                 zs_soft[n_channels].zs_chan_a =
1675                                     &zs_channels[n_channels];
1676
1677                         *pp = &zs_soft[n_channels];
1678                         pp = &zs_soft[n_channels].zs_next;
1679                         n_channels++;
1680                 }
1681         }
1682
1683         *pp = 0;
1684         zs_channels_found = n_channels;
1685
1686         for (n = 0; n < zs_channels_found; n++) {
1687                 for (i = 0; i < 16; i++) {
1688                         zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
1689                 }
1690         }
1691
1692         spin_lock_irqsave(&zs_lock, flags);
1693         for (n = 0; n < zs_channels_found; n++) {
1694                 if (n % 2 == 0) {
1695                         write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
1696                         udelay(10);
1697                         write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
1698                 }
1699                 load_zsregs(zs_soft[n].zs_channel,
1700                             zs_soft[n].zs_channel->curregs);
1701         }
1702         spin_unlock_irqrestore(&zs_lock, flags);
1703 }
1704
1705 static struct tty_operations serial_ops = {
1706         .open = rs_open,
1707         .close = rs_close,
1708         .write = rs_write,
1709         .flush_chars = rs_flush_chars,
1710         .write_room = rs_write_room,
1711         .chars_in_buffer = rs_chars_in_buffer,
1712         .flush_buffer = rs_flush_buffer,
1713         .ioctl = rs_ioctl,
1714         .throttle = rs_throttle,
1715         .unthrottle = rs_unthrottle,
1716         .set_termios = rs_set_termios,
1717         .stop = rs_stop,
1718         .start = rs_start,
1719         .hangup = rs_hangup,
1720         .break_ctl = rs_break,
1721         .wait_until_sent = rs_wait_until_sent,
1722         .tiocmget = rs_tiocmget,
1723         .tiocmset = rs_tiocmset,
1724 };
1725
1726 /* zs_init inits the driver */
1727 int __init zs_init(void)
1728 {
1729         int channel, i;
1730         struct dec_serial *info;
1731
1732         if(!BUS_PRESENT)
1733                 return -ENODEV;
1734
1735         /* Find out how many Z8530 SCCs we have */
1736         if (zs_chain == 0)
1737                 probe_sccs();
1738         serial_driver = alloc_tty_driver(zs_channels_found);
1739         if (!serial_driver)
1740                 return -ENOMEM;
1741
1742         show_serial_version();
1743
1744         /* Initialize the tty_driver structure */
1745         /* Not all of this is exactly right for us. */
1746
1747         serial_driver->owner = THIS_MODULE;
1748         serial_driver->name = "ttyS";
1749         serial_driver->major = TTY_MAJOR;
1750         serial_driver->minor_start = 64;
1751         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1752         serial_driver->subtype = SERIAL_TYPE_NORMAL;
1753         serial_driver->init_termios = tty_std_termios;
1754         serial_driver->init_termios.c_cflag =
1755                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1756         serial_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1757         tty_set_operations(serial_driver, &serial_ops);
1758
1759         if (tty_register_driver(serial_driver))
1760                 panic("Couldn't register serial driver");
1761
1762         for (info = zs_chain, i = 0; info; info = info->zs_next, i++) {
1763
1764                 /* Needed before interrupts are enabled. */
1765                 info->tty = 0;
1766                 info->x_char = 0;
1767
1768                 if (info->hook && info->hook->init_info) {
1769                         (*info->hook->init_info)(info);
1770                         continue;
1771                 }
1772
1773                 info->magic = SERIAL_MAGIC;
1774                 info->port = (int) info->zs_channel->control;
1775                 info->line = i;
1776                 info->custom_divisor = 16;
1777                 info->close_delay = 50;
1778                 info->closing_wait = 3000;
1779                 info->event = 0;
1780                 info->count = 0;
1781                 info->blocked_open = 0;
1782                 tasklet_init(&info->tlet, do_softint, (unsigned long)info);
1783                 init_waitqueue_head(&info->open_wait);
1784                 init_waitqueue_head(&info->close_wait);
1785                 printk("ttyS%02d at 0x%08x (irq = %d) is a Z85C30 SCC\n",
1786                        info->line, info->port, info->irq);
1787                 tty_register_device(serial_driver, info->line, NULL);
1788
1789         }
1790
1791         for (channel = 0; channel < zs_channels_found; ++channel) {
1792                 zs_soft[channel].clk_divisor = 16;
1793                 zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);
1794
1795                 if (request_irq(zs_soft[channel].irq, rs_interrupt, SA_SHIRQ,
1796                                 "scc", &zs_soft[channel]))
1797                         printk(KERN_ERR "decserial: can't get irq %d\n",
1798                                zs_soft[channel].irq);
1799
1800                 if (zs_soft[channel].hook) {
1801                         zs_startup(&zs_soft[channel]);
1802                         if (zs_soft[channel].hook->init_channel)
1803                                 (*zs_soft[channel].hook->init_channel)
1804                                         (&zs_soft[channel]);
1805                 }
1806         }
1807
1808         return 0;
1809 }
1810
1811 /*
1812  * polling I/O routines
1813  */
1814 static int zs_poll_tx_char(void *handle, unsigned char ch)
1815 {
1816         struct dec_serial *info = handle;
1817         struct dec_zschannel *chan = info->zs_channel;
1818         int    ret;
1819
1820         if(chan) {
1821                 int loops = 10000;
1822
1823                 while (loops && !(read_zsreg(chan, 0) & Tx_BUF_EMP))
1824                         loops--;
1825
1826                 if (loops) {
1827                         write_zsdata(chan, ch);
1828                         ret = 0;
1829                 } else
1830                         ret = -EAGAIN;
1831
1832                 return ret;
1833         } else
1834                 return -ENODEV;
1835 }
1836
1837 static int zs_poll_rx_char(void *handle)
1838 {
1839         struct dec_serial *info = handle;
1840         struct dec_zschannel *chan = info->zs_channel;
1841         int    ret;
1842
1843         if(chan) {
1844                 int loops = 10000;
1845
1846                 while (loops && !(read_zsreg(chan, 0) & Rx_CH_AV))
1847                         loops--;
1848
1849                 if (loops)
1850                         ret = read_zsdata(chan);
1851                 else
1852                         ret = -EAGAIN;
1853
1854                 return ret;
1855         } else
1856                 return -ENODEV;
1857 }
1858
1859 int register_zs_hook(unsigned int channel, struct dec_serial_hook *hook)
1860 {
1861         struct dec_serial *info = &zs_soft[channel];
1862
1863         if (info->hook) {
1864                 printk("%s: line %d has already a hook registered\n",
1865                        __FUNCTION__, channel);
1866
1867                 return 0;
1868         } else {
1869                 hook->poll_rx_char = zs_poll_rx_char;
1870                 hook->poll_tx_char = zs_poll_tx_char;
1871                 info->hook = hook;
1872
1873                 return 1;
1874         }
1875 }
1876
1877 int unregister_zs_hook(unsigned int channel)
1878 {
1879         struct dec_serial *info = &zs_soft[channel];
1880
1881         if (info->hook) {
1882                 info->hook = NULL;
1883                 return 1;
1884         } else {
1885                 printk("%s: trying to unregister hook on line %d,"
1886                        " but none is registered\n", __FUNCTION__, channel);
1887                 return 0;
1888         }
1889 }
1890
1891 /*
1892  * ------------------------------------------------------------
1893  * Serial console driver
1894  * ------------------------------------------------------------
1895  */
1896 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1897
1898
1899 /*
1900  *      Print a string to the serial port trying not to disturb
1901  *      any possible real use of the port...
1902  */
1903 static void serial_console_write(struct console *co, const char *s,
1904                                  unsigned count)
1905 {
1906         struct dec_serial *info;
1907         int i;
1908
1909         info = zs_soft + co->index;
1910
1911         for (i = 0; i < count; i++, s++) {
1912                 if(*s == '\n')
1913                         zs_poll_tx_char(info, '\r');
1914                 zs_poll_tx_char(info, *s);
1915         }
1916 }
1917
1918 static struct tty_driver *serial_console_device(struct console *c, int *index)
1919 {
1920         *index = c->index;
1921         return serial_driver;
1922 }
1923
1924 /*
1925  *      Setup initial baud/bits/parity. We do two things here:
1926  *      - construct a cflag setting for the first rs_open()
1927  *      - initialize the serial port
1928  *      Return non-zero if we didn't find a serial port.
1929  */
1930 static int __init serial_console_setup(struct console *co, char *options)
1931 {
1932         struct dec_serial *info;
1933         int baud = 9600;
1934         int bits = 8;
1935         int parity = 'n';
1936         int cflag = CREAD | HUPCL | CLOCAL;
1937         int clk_divisor = 16;
1938         int brg;
1939         char *s;
1940         unsigned long flags;
1941
1942         if(!BUS_PRESENT)
1943                 return -ENODEV;
1944
1945         info = zs_soft + co->index;
1946
1947         if (zs_chain == 0)
1948                 probe_sccs();
1949
1950         info->is_cons = 1;
1951
1952         if (options) {
1953                 baud = simple_strtoul(options, NULL, 10);
1954                 s = options;
1955                 while(*s >= '0' && *s <= '9')
1956                         s++;
1957                 if (*s)
1958                         parity = *s++;
1959                 if (*s)
1960                         bits   = *s - '0';
1961         }
1962
1963         /*
1964          *      Now construct a cflag setting.
1965          */
1966         switch(baud) {
1967         case 1200:
1968                 cflag |= B1200;
1969                 break;
1970         case 2400:
1971                 cflag |= B2400;
1972                 break;
1973         case 4800:
1974                 cflag |= B4800;
1975                 break;
1976         case 19200:
1977                 cflag |= B19200;
1978                 break;
1979         case 38400:
1980                 cflag |= B38400;
1981                 break;
1982         case 57600:
1983                 cflag |= B57600;
1984                 break;
1985         case 115200:
1986                 cflag |= B115200;
1987                 break;
1988         case 9600:
1989         default:
1990                 cflag |= B9600;
1991                 /*
1992                  * Set this to a sane value to prevent a divide error.
1993                  */
1994                 baud  = 9600;
1995                 break;
1996         }
1997         switch(bits) {
1998         case 7:
1999                 cflag |= CS7;
2000                 break;
2001         default:
2002         case 8:
2003                 cflag |= CS8;
2004                 break;
2005         }
2006         switch(parity) {
2007         case 'o': case 'O':
2008                 cflag |= PARODD;
2009                 break;
2010         case 'e': case 'E':
2011                 cflag |= PARENB;
2012                 break;
2013         }
2014         co->cflag = cflag;
2015
2016         spin_lock_irqsave(&zs_lock, flags);
2017
2018         /*
2019          * Set up the baud rate generator.
2020          */
2021         brg = BPS_TO_BRG(baud, zs_parms->clock / clk_divisor);
2022         info->zs_channel->curregs[R12] = (brg & 255);
2023         info->zs_channel->curregs[R13] = ((brg >> 8) & 255);
2024
2025         /*
2026          * Set byte size and parity.
2027          */
2028         if (bits == 7) {
2029                 info->zs_channel->curregs[R3] |= Rx7;
2030                 info->zs_channel->curregs[R5] |= Tx7;
2031         } else {
2032                 info->zs_channel->curregs[R3] |= Rx8;
2033                 info->zs_channel->curregs[R5] |= Tx8;
2034         }
2035         if (cflag & PARENB) {
2036                 info->zs_channel->curregs[R4] |= PAR_ENA;
2037         }
2038         if (!(cflag & PARODD)) {
2039                 info->zs_channel->curregs[R4] |= PAR_EVEN;
2040         }
2041         info->zs_channel->curregs[R4] |= SB1;
2042
2043         /*
2044          * Turn on RTS and DTR.
2045          */
2046         zs_rtsdtr(info, RTS | DTR, 1);
2047
2048         /*
2049          * Finally, enable sequencing.
2050          */
2051         info->zs_channel->curregs[R3] |= RxENABLE;
2052         info->zs_channel->curregs[R5] |= TxENAB;
2053
2054         /*
2055          * Clear the interrupt registers.
2056          */
2057         write_zsreg(info->zs_channel, R0, ERR_RES);
2058         write_zsreg(info->zs_channel, R0, RES_H_IUS);
2059
2060         /*
2061          * Load up the new values.
2062          */
2063         load_zsregs(info->zs_channel, info->zs_channel->curregs);
2064
2065         /* Save the current value of RR0 */
2066         info->read_reg_zero = read_zsreg(info->zs_channel, R0);
2067
2068         zs_soft[co->index].clk_divisor = clk_divisor;
2069         zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);
2070
2071         spin_unlock_irqrestore(&zs_lock, flags);
2072
2073         return 0;
2074 }
2075
2076 static struct console sercons = {
2077         .name           = "ttyS",
2078         .write          = serial_console_write,
2079         .device         = serial_console_device,
2080         .setup          = serial_console_setup,
2081         .flags          = CON_PRINTBUFFER,
2082         .index          = -1,
2083 };
2084
2085 /*
2086  *      Register console.
2087  */
2088 void __init zs_serial_console_init(void)
2089 {
2090         register_console(&sercons);
2091 }
2092 #endif /* ifdef CONFIG_SERIAL_DEC_CONSOLE */
2093
2094 #ifdef CONFIG_KGDB
2095 struct dec_zschannel *zs_kgdbchan;
2096 static unsigned char scc_inittab[] = {
2097         9,  0x80,       /* reset A side (CHRA) */
2098         13, 0,          /* set baud rate divisor */
2099         12, 1,
2100         14, 1,          /* baud rate gen enable, src=rtxc (BRENABL) */
2101         11, 0x50,       /* clocks = br gen (RCBR | TCBR) */
2102         5,  0x6a,       /* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
2103         4,  0x44,       /* x16 clock, 1 stop (SB1 | X16CLK)*/
2104         3,  0xc1,       /* rx enable, 8 bits (RxENABLE | Rx8)*/
2105 };
2106
2107 /* These are for receiving and sending characters under the kgdb
2108  * source level kernel debugger.
2109  */
2110 void putDebugChar(char kgdb_char)
2111 {
2112         struct dec_zschannel *chan = zs_kgdbchan;
2113         while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
2114                 RECOVERY_DELAY;
2115         write_zsdata(chan, kgdb_char);
2116 }
2117 char getDebugChar(void)
2118 {
2119         struct dec_zschannel *chan = zs_kgdbchan;
2120         while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
2121                 eieio(); /*barrier();*/
2122         return read_zsdata(chan);
2123 }
2124 void kgdb_interruptible(int yes)
2125 {
2126         struct dec_zschannel *chan = zs_kgdbchan;
2127         int one, nine;
2128         nine = read_zsreg(chan, 9);
2129         if (yes == 1) {
2130                 one = EXT_INT_ENAB|RxINT_ALL;
2131                 nine |= MIE;
2132                 printk("turning serial ints on\n");
2133         } else {
2134                 one = RxINT_DISAB;
2135                 nine &= ~MIE;
2136                 printk("turning serial ints off\n");
2137         }
2138         write_zsreg(chan, 1, one);
2139         write_zsreg(chan, 9, nine);
2140 }
2141
2142 static int kgdbhook_init_channel(void *handle)
2143 {
2144         return 0;
2145 }
2146
2147 static void kgdbhook_init_info(void *handle)
2148 {
2149 }
2150
2151 static void kgdbhook_rx_char(void *handle, unsigned char ch, unsigned char fl)
2152 {
2153         struct dec_serial *info = handle;
2154
2155         if (fl != TTY_NORMAL)
2156                 return;
2157         if (ch == 0x03 || ch == '$')
2158                 breakpoint();
2159 }
2160
2161 /* This sets up the serial port we're using, and turns on
2162  * interrupts for that channel, so kgdb is usable once we're done.
2163  */
2164 static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
2165 {
2166         int brg;
2167         int i, x;
2168         volatile char *sccc = ms->control;
2169         brg = BPS_TO_BRG(bps, zs_parms->clock/16);
2170         printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
2171         for (i = 20000; i != 0; --i) {
2172                 x = *sccc; eieio();
2173         }
2174         for (i = 0; i < sizeof(scc_inittab); ++i) {
2175                 write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
2176                 i++;
2177         }
2178 }
2179 /* This is called at boot time to prime the kgdb serial debugging
2180  * serial line.  The 'tty_num' argument is 0 for /dev/ttya and 1
2181  * for /dev/ttyb which is determined in setup_arch() from the
2182  * boot command line flags.
2183  */
2184 struct dec_serial_hook zs_kgdbhook = {
2185         .init_channel   = kgdbhook_init_channel,
2186         .init_info      = kgdbhook_init_info,
2187         .rx_char        = kgdbhook_rx_char,
2188         .cflags         = B38400 | CS8 | CLOCAL,
2189 }
2190
2191 void __init zs_kgdb_hook(int tty_num)
2192 {
2193         /* Find out how many Z8530 SCCs we have */
2194         if (zs_chain == 0)
2195                 probe_sccs();
2196         zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
2197         zs_kgdbchan = zs_soft[tty_num].zs_channel;
2198         zs_soft[tty_num].change_needed = 0;
2199         zs_soft[tty_num].clk_divisor = 16;
2200         zs_soft[tty_num].zs_baud = 38400;
2201         zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
2202         /* Turn on transmitter/receiver at 8-bits/char */
2203         kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
2204         printk("KGDB: on channel %d initialized\n", tty_num);
2205         set_debug_traps(); /* init stub */
2206 }
2207 #endif /* ifdef CONFIG_KGDB */