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 Maciej W. Rozycki <macro@ds2.pg.gda.pl>
  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 #ifdef CONFIG_SERIAL_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/bitops.h>
  67 #include <asm/uaccess.h>
  68 #include <asm/wbflush.h>
  69 #include <asm/bootinfo.h>
  70 #ifdef CONFIG_DECSTATION
  71 #include <asm/dec/interrupts.h>
  72 #include <asm/dec/machtype.h>
  73 #include <asm/dec/tc.h>
  74 #include <asm/dec/ioasic_addrs.h>
  75 #endif
  76 #ifdef CONFIG_BAGET_MIPS
  77 #include <asm/baget/baget.h>
  78 unsigned long system_base;
  79 #endif
  80 #ifdef CONFIG_KGDB
  81 #include <asm/kgdb.h>
  82 #endif
  83 #ifdef CONFIG_MAGIC_SYSRQ
  84 #include <linux/sysrq.h>
  85 #endif
  86
  87 #include "zs.h"
  88
  89 /*
  90  * It would be nice to dynamically allocate everything that
  91  * depends on NUM_SERIAL, so we could support any number of
  92  * Z8530s, but for now...
  93  */
  94 #define NUM_SERIAL      2               /* Max number of ZS chips supported */
  95 #define NUM_CHANNELS    (NUM_SERIAL * 2)        /* 2 channels per chip */
  96 #define CHANNEL_A_NR  (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
  97                                         /* Number of channel A in the chip */
  98 #define ZS_CHAN_IO_SIZE 8
  99 #define ZS_CLOCK        7372800         /* Z8530 RTxC input clock rate */
 100
 101 #define RECOVERY_DELAY  udelay(2)
 102
 103 struct zs_parms {
 104         unsigned long scc0;
 105         unsigned long scc1;
 106         int channel_a_offset;
 107         int channel_b_offset;
 108         int irq;
 109         int clock;
 110 };
 111
 112 static struct zs_parms *zs_parms;
 113
 114 #ifdef CONFIG_DECSTATION
 115 static struct zs_parms ds_parms = {
 116         scc0 : SCC0,
 117         scc1 : SCC1,
 118         channel_a_offset : 1,
 119         channel_b_offset : 9,
 120         irq : SERIAL,
 121         clock : ZS_CLOCK
 122 };
 123 #endif
 124 #ifdef CONFIG_BAGET_MIPS
 125 static struct zs_parms baget_parms = {
 126         scc0 : UNI_SCC0,
 127         scc1 : UNI_SCC1,
 128         channel_a_offset : 9,
 129         channel_b_offset : 1,
 130         irq : BAGET_SCC_IRQ,
 131         clock : 14745000
 132 };
 133 #endif
 134
 135 #ifdef CONFIG_DECSTATION
 136 #define DS_BUS_PRESENT (IOASIC)
 137 #else
 138 #define DS_BUS_PRESENT 0
 139 #endif
 140
 141 #ifdef CONFIG_BAGET_MIPS
 142 #define BAGET_BUS_PRESENT (mips_machtype == MACH_BAGET202)
 143 #else
 144 #define BAGET_BUS_PRESENT 0
 145 #endif
 146
 147 #define BUS_PRESENT (DS_BUS_PRESENT || BAGET_BUS_PRESENT)
 148
 149 struct dec_zschannel zs_channels[NUM_CHANNELS];
 150 struct dec_serial zs_soft[NUM_CHANNELS];
 151 int zs_channels_found;
 152 struct dec_serial *zs_chain;    /* list of all channels */
 153
 154 struct tty_struct zs_ttys[NUM_CHANNELS];
 155
 156 #ifdef CONFIG_SERIAL_CONSOLE
 157 static struct console sercons;
 158 #endif
 159 #if defined(CONFIG_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) \
 160     && !defined(MODULE)
 161 static unsigned long break_pressed; /* break, really ... */
 162 #endif
 163
 164 static unsigned char zs_init_regs[16] __initdata = {
 165         0,                           /* write 0 */
 166         0,                           /* write 1 */
 167         0xf0,                        /* write 2 */
 168         (Rx8),                       /* write 3 */
 169         (X16CLK | SB1),              /* write 4 */
 170         (Tx8),                       /* write 5 */
 171         0, 0, 0,                     /* write 6, 7, 8 */
 172         (VIS),                       /* write 9 */
 173         (NRZ),                       /* write 10 */
 174         (TCBR | RCBR),               /* write 11 */
 175         0, 0,                        /* BRG time constant, write 12 + 13 */
 176         (BRSRC | BRENABL),           /* write 14 */
 177         0                            /* write 15 */
 178 };
 179
 180 DECLARE_TASK_QUEUE(tq_zs_serial);
 181
 182 static struct tty_driver *serial_driver;
 183
 184 /* serial subtype definitions */
 185 #define SERIAL_TYPE_NORMAL      1
 186
 187 /* number of characters left in xmit buffer before we ask for more */
 188 #define WAKEUP_CHARS 256
 189
 190 /*
 191  * Debugging.
 192  */
 193 #undef SERIAL_DEBUG_INTR
 194 #undef SERIAL_DEBUG_OPEN
 195 #undef SERIAL_DEBUG_FLOW
 196 #undef SERIAL_DEBUG_THROTTLE
 197 #undef SERIAL_PARANOIA_CHECK
 198
 199 #undef ZS_DEBUG_REGS
 200
 201 #ifdef SERIAL_DEBUG_THROTTLE
 202 #define _tty_name(tty,buf) tty_name(tty,buf)
 203 #endif
 204
 205 #define RS_STROBE_TIME 10
 206 #define RS_ISR_PASS_LIMIT 256
 207
 208 #define _INLINE_ inline
 209
 210 static void probe_sccs(void);
 211 static void change_speed(struct dec_serial *info);
 212 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 213
 214 #ifndef MIN
 215 #define MIN(a,b)        ((a) < (b) ? (a) : (b))
 216 #endif
 217
 218 /*
 219  * tmp_buf is used as a temporary buffer by serial_write.  We need to
 220  * lock it in case the copy_from_user blocks while swapping in a page,
 221  * and some other program tries to do a serial write at the same time.
 222  * Since the lock will only come under contention when the system is
 223  * swapping and available memory is low, it makes sense to share one
 224  * buffer across all the serial ports, since it significantly saves
 225  * memory if large numbers of serial ports are open.
 226  */
 227 static unsigned char tmp_buf[4096]; /* This is cheating */
 228 static DECLARE_MUTEX(tmp_buf_sem);
 229
 230 static inline int serial_paranoia_check(struct dec_serial *info,
 231                                         char *name, const char *routine)
 232 {
 233 #ifdef SERIAL_PARANOIA_CHECK
 234         static const char *badmagic =
 235                 "Warning: bad magic number for serial struct %s in %s\n";
 236         static const char *badinfo =
 237                 "Warning: null mac_serial for %s in %s\n";
 238
 239         if (!info) {
 240                 printk(badinfo, name, routine);
 241                 return 1;
 242         }
 243         if (info->magic != SERIAL_MAGIC) {
 244                 printk(badmagic, name, routine);
 245                 return 1;
 246         }
 247 #endif
 248         return 0;
 249 }
 250
 251 /*
 252  * This is used to figure out the divisor speeds and the timeouts
 253  */
 254 static int baud_table[] = {
 255         0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
 256         9600, 19200, 38400, 57600, 115200, 0 };
 257
 258 /*
 259  * Reading and writing Z8530 registers.
 260  */
 261 static inline unsigned char read_zsreg(struct dec_zschannel *channel,
 262                                        unsigned char reg)
 263 {
 264         unsigned char retval;
 265
 266         if (reg != 0) {
 267                 *channel->control = reg & 0xf;
 268                 wbflush(); RECOVERY_DELAY;
 269         }
 270         retval = *channel->control;
 271         RECOVERY_DELAY;
 272         return retval;
 273 }
 274
 275 static inline void write_zsreg(struct dec_zschannel *channel,
 276                                unsigned char reg, unsigned char value)
 277 {
 278         if (reg != 0) {
 279                 *channel->control = reg & 0xf;
 280                 wbflush(); RECOVERY_DELAY;
 281         }
 282         *channel->control = value;
 283         wbflush(); RECOVERY_DELAY;
 284         return;
 285 }
 286
 287 static inline unsigned char read_zsdata(struct dec_zschannel *channel)
 288 {
 289         unsigned char retval;
 290
 291         retval = *channel->data;
 292         RECOVERY_DELAY;
 293         return retval;
 294 }
 295
 296 static inline void write_zsdata(struct dec_zschannel *channel,
 297                                 unsigned char value)
 298 {
 299         *channel->data = value;
 300         wbflush(); RECOVERY_DELAY;
 301         return;
 302 }
 303
 304 static inline void load_zsregs(struct dec_zschannel *channel,
 305                                unsigned char *regs)
 306 {
 307 /*      ZS_CLEARERR(channel);
 308         ZS_CLEARFIFO(channel); */
 309         /* Load 'em up */
 310         write_zsreg(channel, R4, regs[R4]);
 311         write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
 312         write_zsreg(channel, R5, regs[R5] & ~TxENAB);
 313         write_zsreg(channel, R9, regs[R9]);
 314         write_zsreg(channel, R1, regs[R1]);
 315         write_zsreg(channel, R2, regs[R2]);
 316         write_zsreg(channel, R10, regs[R10]);
 317         write_zsreg(channel, R11, regs[R11]);
 318         write_zsreg(channel, R12, regs[R12]);
 319         write_zsreg(channel, R13, regs[R13]);
 320         write_zsreg(channel, R14, regs[R14]);
 321         write_zsreg(channel, R15, regs[R15]);
 322         write_zsreg(channel, R3, regs[R3]);
 323         write_zsreg(channel, R5, regs[R5]);
 324         return;
 325 }
 326
 327 /* Sets or clears DTR/RTS on the requested line */
 328 static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
 329 {
 330         unsigned long flags;
 331
 332
 333         save_flags(flags); cli();
 334         if (info->zs_channel != info->zs_chan_a) {
 335                 if (set) {
 336                         info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
 337                 } else {
 338                         info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
 339                 }
 340                 write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
 341         }
 342         restore_flags(flags);
 343 }
 344
 345 /* Utility routines for the Zilog */
 346 static inline int get_zsbaud(struct dec_serial *ss)
 347 {
 348         struct dec_zschannel *channel = ss->zs_channel;
 349         int brg;
 350
 351         /* The baud rate is split up between two 8-bit registers in
 352          * what is termed 'BRG time constant' format in my docs for
 353          * the chip, it is a function of the clk rate the chip is
 354          * receiving which happens to be constant.
 355          */
 356         brg = (read_zsreg(channel, 13) << 8);
 357         brg |= read_zsreg(channel, 12);
 358         return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
 359 }
 360
 361 /* On receive, this clears errors and the receiver interrupts */
 362 static inline void rs_recv_clear(struct dec_zschannel *zsc)
 363 {
 364         write_zsreg(zsc, 0, ERR_RES);
 365         write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
 366 }
 367
 368 /*
 369  * ----------------------------------------------------------------------
 370  *
 371  * Here starts the interrupt handling routines.  All of the following
 372  * subroutines are declared as inline and are folded into
 373  * rs_interrupt().  They were separated out for readability's sake.
 374  *
 375  *                              - Ted Ts'o (tytso@mit.edu), 7-Mar-93
 376  * -----------------------------------------------------------------------
 377  */
 378
 379 static int tty_break;   /* Set whenever BREAK condition is detected.  */
 380
 381 /*
 382  * This routine is used by the interrupt handler to schedule
 383  * processing in the software interrupt portion of the driver.
 384  */
 385 static _INLINE_ void rs_sched_event(struct dec_serial *info,
 386                                   int event)
 387 {
 388         info->event |= 1 << event;
 389         queue_task(&info->tqueue, &tq_zs_serial);
 390         mark_bh(SERIAL_BH);
 391 }
 392
 393 static _INLINE_ void receive_chars(struct dec_serial *info,
 394                                    struct pt_regs *regs)
 395 {
 396         struct tty_struct *tty = info->tty;
 397         unsigned char ch, stat, flag;
 398
 399         while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
 400
 401                 stat = read_zsreg(info->zs_channel, R1);
 402                 ch = read_zsdata(info->zs_channel);
 403
 404                 if (!tty && !info->hook && !info->hook->rx_char)
 405                         continue;
 406
 407                 if (tty_break) {
 408                         tty_break = 0;
 409 #if defined(CONFIG_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && !defined(MODULE)
 410                         if (info->line == sercons.index) {
 411                                 if (!break_pressed) {
 412                                         break_pressed = jiffies;
 413                                         goto ignore_char;
 414                                 }
 415                                 break_pressed = 0;
 416                         }
 417 #endif
 418                         flag = TTY_BREAK;
 419                         if (info->flags & ZILOG_SAK)
 420                                 do_SAK(tty);
 421                 } else {
 422                         if (stat & Rx_OVR) {
 423                                 flag = TTY_OVERRUN;
 424                         } else if (stat & FRM_ERR) {
 425                                 flag = TTY_FRAME;
 426                         } else if (stat & PAR_ERR) {
 427                                 flag = TTY_PARITY;
 428                         } else
 429                                 flag = 0;
 430                         if (flag)
 431                                 /* reset the error indication */
 432                                 write_zsreg(info->zs_channel, R0, ERR_RES);
 433                 }
 434
 435 #if defined(CONFIG_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && !defined(MODULE)
 436                 if (break_pressed && info->line == sercons.index) {
 437                         if (ch != 0 &&
 438                             time_before(jiffies, break_pressed + HZ*5)) {
 439                                 handle_sysrq(ch, regs, NULL);
 440                                 break_pressed = 0;
 441                                 goto ignore_char;
 442                         }
 443                         break_pressed = 0;
 444                 }
 445 #endif
 446
 447                 if (info->hook && info->hook->rx_char) {
 448                         (*info->hook->rx_char)(ch, flag);
 449                         return;
 450                 }
 451
 452                 if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
 453                         static int flip_buf_ovf;
 454                         ++flip_buf_ovf;
 455                         continue;
 456                 }
 457                 tty->flip.count++;
 458                 {
 459                         static int flip_max_cnt;
 460                         if (flip_max_cnt < tty->flip.count)
 461                                 flip_max_cnt = tty->flip.count;
 462                 }
 463
 464                 *tty->flip.flag_buf_ptr++ = flag;
 465                 *tty->flip.char_buf_ptr++ = ch;
 466         ignore_char:
 467         }
 468         if (tty)
 469                 tty_flip_buffer_push(tty);
 470 }
 471
 472 static void transmit_chars(struct dec_serial *info)
 473 {
 474         if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
 475                 return;
 476         info->tx_active = 0;
 477
 478         if (info->x_char) {
 479                 /* Send next char */
 480                 write_zsdata(info->zs_channel, info->x_char);
 481                 info->x_char = 0;
 482                 info->tx_active = 1;
 483                 return;
 484         }
 485
 486         if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
 487             || info->tx_stopped) {
 488                 write_zsreg(info->zs_channel, R0, RES_Tx_P);
 489                 return;
 490         }
 491         /* Send char */
 492         write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
 493         info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 494         info->xmit_cnt--;
 495         info->tx_active = 1;
 496
 497         if (info->xmit_cnt < WAKEUP_CHARS)
 498                 rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
 499 }
 500
 501 static _INLINE_ void status_handle(struct dec_serial *info)
 502 {
 503         unsigned char stat;
 504
 505         /* Get status from Read Register 0 */
 506         stat = read_zsreg(info->zs_channel, R0);
 507
 508         if (stat & BRK_ABRT) {
 509 #ifdef SERIAL_DEBUG_INTR
 510                 printk("handling break....");
 511 #endif
 512                 tty_break = 1;
 513         }
 514
 515         if (info->zs_channel != info->zs_chan_a) {
 516
 517                 /* FIXEM: Check for DCD transitions */
 518                 if (((stat ^ info->read_reg_zero) & DCD) != 0
 519                     && info->tty && !C_CLOCAL(info->tty)) {
 520                         if (stat & DCD) {
 521                                 wake_up_interruptible(&info->open_wait);
 522                         } else {
 523                                 tty_hangup(info->tty);
 524                         }
 525                 }
 526
 527                 /* Check for CTS transitions */
 528                 if (info->tty && C_CRTSCTS(info->tty)) {
 529                         if ((stat & CTS) != 0) {
 530                                 if (info->tx_stopped) {
 531                                         info->tx_stopped = 0;
 532                                         if (!info->tx_active)
 533                                                 transmit_chars(info);
 534                                 }
 535                         } else {
 536                                 info->tx_stopped = 1;
 537                         }
 538                 }
 539
 540         }
 541
 542         /* Clear status condition... */
 543         write_zsreg(info->zs_channel, R0, RES_EXT_INT);
 544         info->read_reg_zero = stat;
 545 }
 546
 547 /*
 548  * This is the serial driver's generic interrupt routine
 549  */
 550 void rs_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 551 {
 552         struct dec_serial *info = (struct dec_serial *) dev_id;
 553         unsigned char zs_intreg;
 554         int shift;
 555
 556         /* NOTE: The read register 3, which holds the irq status,
 557          *       does so for both channels on each chip.  Although
 558          *       the status value itself must be read from the A
 559          *       channel and is only valid when read from channel A.
 560          *       Yes... broken hardware...
 561          */
 562 #define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
 563
 564         if (info->zs_chan_a == info->zs_channel)
 565                 shift = 3;      /* Channel A */
 566         else
 567                 shift = 0;      /* Channel B */
 568
 569         for (;;) {
 570                 zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
 571                 if ((zs_intreg & CHAN_IRQMASK) == 0)
 572                         break;
 573
 574                 if (zs_intreg & CHBRxIP) {
 575                         receive_chars(info, regs);
 576                 }
 577                 if (zs_intreg & CHBTxIP) {
 578                         transmit_chars(info);
 579                 }
 580                 if (zs_intreg & CHBEXT) {
 581                         status_handle(info);
 582                 }
 583         }
 584
 585         /* Why do we need this ? */
 586         write_zsreg(info->zs_channel, 0, RES_H_IUS);
 587 }
 588
 589 #ifdef ZS_DEBUG_REGS
 590 void zs_dump (void) {
 591         int i, j;
 592         for (i = 0; i < zs_channels_found; i++) {
 593                 struct dec_zschannel *ch = &zs_channels[i];
 594                 if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
 595                         for (j = 0; j < 15; j++) {
 596                                 printk("W%d = 0x%x\t",
 597                                        j, (int)ch->curregs[j]);
 598                         }
 599                         for (j = 0; j < 15; j++) {
 600                                 printk("R%d = 0x%x\t",
 601                                        j, (int)read_zsreg(ch,j));
 602                         }
 603                         printk("\n\n");
 604                 }
 605         }
 606 }
 607 #endif
 608
 609 /*
 610  * -------------------------------------------------------------------
 611  * Here ends the serial interrupt routines.
 612  * -------------------------------------------------------------------
 613  */
 614
 615 /*
 616  * ------------------------------------------------------------
 617  * rs_stop() and rs_start()
 618  *
 619  * This routines are called before setting or resetting tty->stopped.
 620  * ------------------------------------------------------------
 621  */
 622 static void rs_stop(struct tty_struct *tty)
 623 {
 624         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 625         unsigned long flags;
 626
 627         if (serial_paranoia_check(info, tty->name, "rs_stop"))
 628                 return;
 629
 630 #if 1
 631         save_flags(flags); cli();
 632         if (info->zs_channel->curregs[5] & TxENAB) {
 633                 info->zs_channel->curregs[5] &= ~TxENAB;
 634                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 635         }
 636         restore_flags(flags);
 637 #endif
 638 }
 639
 640 static void rs_start(struct tty_struct *tty)
 641 {
 642         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 643         unsigned long flags;
 644
 645         if (serial_paranoia_check(info, tty->name, "rs_start"))
 646                 return;
 647
 648         save_flags(flags); cli();
 649 #if 1
 650         if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
 651                 info->zs_channel->curregs[5] |= TxENAB;
 652                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 653         }
 654 #else
 655         if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
 656                 transmit_chars(info);
 657         }
 658 #endif
 659         restore_flags(flags);
 660 }
 661
 662 /*
 663  * This routine is used to handle the "bottom half" processing for the
 664  * serial driver, known also the "software interrupt" processing.
 665  * This processing is done at the kernel interrupt level, after the
 666  * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
 667  * is where time-consuming activities which can not be done in the
 668  * interrupt driver proper are done; the interrupt driver schedules
 669  * them using rs_sched_event(), and they get done here.
 670  */
 671 static void do_serial_bh(void)
 672 {
 673         run_task_queue(&tq_zs_serial);
 674 }
 675
 676 static void do_softint(void *private_)
 677 {
 678         struct dec_serial       *info = (struct dec_serial *) private_;
 679         struct tty_struct       *tty;
 680
 681         tty = info->tty;
 682         if (!tty)
 683                 return;
 684
 685         if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
 686                 if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 687                     tty->ldisc.write_wakeup)
 688                         (tty->ldisc.write_wakeup)(tty);
 689                 wake_up_interruptible(&tty->write_wait);
 690         }
 691 }
 692
 693 int zs_startup(struct dec_serial * info)
 694 {
 695         unsigned long flags;
 696
 697         if (info->flags & ZILOG_INITIALIZED)
 698                 return 0;
 699
 700         if (!info->xmit_buf) {
 701                 info->xmit_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
 702                 if (!info->xmit_buf)
 703                         return -ENOMEM;
 704         }
 705
 706         save_flags(flags); cli();
 707
 708 #ifdef SERIAL_DEBUG_OPEN
 709         printk("starting up ttyS%02d (irq %d)...", info->line, info->irq);
 710 #endif
 711
 712         /*
 713          * Clear the receive FIFO.
 714          */
 715         ZS_CLEARFIFO(info->zs_channel);
 716         info->xmit_fifo_size = 1;
 717
 718         /*
 719          * Clear the interrupt registers.
 720          */
 721         write_zsreg(info->zs_channel, 0, ERR_RES);
 722         write_zsreg(info->zs_channel, 0, RES_H_IUS);
 723
 724         /*
 725          * Turn on RTS and DTR.
 726          */
 727         zs_rtsdtr(info, RTS | DTR, 1);
 728
 729         /*
 730          * Finally, enable sequencing and interrupts
 731          */
 732         info->zs_channel->curregs[1] = (info->zs_channel->curregs[1] & ~0x18) | (EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB);
 733         info->zs_channel->curregs[3] |= (RxENABLE | Rx8);
 734         info->zs_channel->curregs[5] |= (TxENAB | Tx8);
 735         info->zs_channel->curregs[15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
 736         info->zs_channel->curregs[9] |= (VIS | MIE);
 737         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
 738         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
 739         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 740         write_zsreg(info->zs_channel, 15, info->zs_channel->curregs[15]);
 741         write_zsreg(info->zs_channel, 9, info->zs_channel->curregs[9]);
 742
 743         /*
 744          * And clear the interrupt registers again for luck.
 745          */
 746         write_zsreg(info->zs_channel, 0, ERR_RES);
 747         write_zsreg(info->zs_channel, 0, RES_H_IUS);
 748
 749         if (info->tty)
 750                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
 751         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 752
 753         /*
 754          * Set the speed of the serial port
 755          */
 756         change_speed(info);
 757
 758         /* Save the current value of RR0 */
 759         info->read_reg_zero = read_zsreg(info->zs_channel, 0);
 760
 761         info->flags |= ZILOG_INITIALIZED;
 762         restore_flags(flags);
 763         return 0;
 764 }
 765
 766 /*
 767  * This routine will shutdown a serial port; interrupts are disabled, and
 768  * DTR is dropped if the hangup on close termio flag is on.
 769  */
 770 static void shutdown(struct dec_serial * info)
 771 {
 772         unsigned long   flags;
 773
 774         if (!(info->flags & ZILOG_INITIALIZED))
 775                 return;
 776
 777 #ifdef SERIAL_DEBUG_OPEN
 778         printk("Shutting down serial port %d (irq %d)....", info->line,
 779                info->irq);
 780 #endif
 781
 782         save_flags(flags); cli(); /* Disable interrupts */
 783
 784         if (info->xmit_buf) {
 785                 free_page((unsigned long) info->xmit_buf);
 786                 info->xmit_buf = 0;
 787         }
 788
 789         info->zs_channel->curregs[1] = 0;
 790         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]); /* no interrupts */
 791
 792         info->zs_channel->curregs[3] &= ~RxENABLE;
 793         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
 794
 795         info->zs_channel->curregs[5] &= ~TxENAB;
 796         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 797         if (!info->tty || C_HUPCL(info->tty)) {
 798                 zs_rtsdtr(info, RTS | DTR, 0);
 799         }
 800
 801         if (info->tty)
 802                 set_bit(TTY_IO_ERROR, &info->tty->flags);
 803
 804         info->flags &= ~ZILOG_INITIALIZED;
 805         restore_flags(flags);
 806 }
 807
 808 /*
 809  * This routine is called to set the UART divisor registers to match
 810  * the specified baud rate for a serial port.
 811  */
 812 static void change_speed(struct dec_serial *info)
 813 {
 814         unsigned cflag;
 815         int     i;
 816         int     brg, bits;
 817         unsigned long flags;
 818
 819         if (!info->hook) {
 820                 if (!info->tty || !info->tty->termios)
 821                         return;
 822                 cflag = info->tty->termios->c_cflag;
 823                 if (!info->port)
 824                         return;
 825         } else {
 826                 cflag = info->hook->cflags;
 827         }
 828
 829         i = cflag & CBAUD;
 830         if (i & CBAUDEX) {
 831                 i &= ~CBAUDEX;
 832                 if (i < 1 || i > 2) {
 833                         if (!info->hook)
 834                                 info->tty->termios->c_cflag &= ~CBAUDEX;
 835                         else
 836                                 info->hook->cflags &= ~CBAUDEX;
 837                 } else
 838                         i += 15;
 839         }
 840
 841         save_flags(flags); cli();
 842         info->zs_baud = baud_table[i];
 843         info->clk_divisor = 16;
 844         if (info->zs_baud) {
 845                 info->zs_channel->curregs[4] = X16CLK;
 846                 brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
 847                 info->zs_channel->curregs[12] = (brg & 255);
 848                 info->zs_channel->curregs[13] = ((brg >> 8) & 255);
 849                 zs_rtsdtr(info, DTR, 1);
 850         } else {
 851                 zs_rtsdtr(info, RTS | DTR, 0);
 852                 return;
 853         }
 854
 855         /* byte size and parity */
 856         info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
 857         info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
 858         switch (cflag & CSIZE) {
 859         case CS5:
 860                 bits = 7;
 861                 info->zs_channel->curregs[3] |= Rx5;
 862                 info->zs_channel->curregs[5] |= Tx5;
 863                 break;
 864         case CS6:
 865                 bits = 8;
 866                 info->zs_channel->curregs[3] |= Rx6;
 867                 info->zs_channel->curregs[5] |= Tx6;
 868                 break;
 869         case CS7:
 870                 bits = 9;
 871                 info->zs_channel->curregs[3] |= Rx7;
 872                 info->zs_channel->curregs[5] |= Tx7;
 873                 break;
 874         case CS8:
 875         default: /* defaults to 8 bits */
 876                 bits = 10;
 877                 info->zs_channel->curregs[3] |= Rx8;
 878                 info->zs_channel->curregs[5] |= Tx8;
 879                 break;
 880         }
 881
 882         info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
 883         info->timeout += HZ/50;         /* Add .02 seconds of slop */
 884
 885         info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
 886         if (cflag & CSTOPB) {
 887                 info->zs_channel->curregs[4] |= SB2;
 888         } else {
 889                 info->zs_channel->curregs[4] |= SB1;
 890         }
 891         if (cflag & PARENB) {
 892                 info->zs_channel->curregs[4] |= PAR_ENA;
 893         }
 894         if (!(cflag & PARODD)) {
 895                 info->zs_channel->curregs[4] |= PAR_EVEN;
 896         }
 897
 898         if (!(cflag & CLOCAL)) {
 899                 if (!(info->zs_channel->curregs[15] & DCDIE))
 900                         info->read_reg_zero = read_zsreg(info->zs_channel, 0);
 901                 info->zs_channel->curregs[15] |= DCDIE;
 902         } else
 903                 info->zs_channel->curregs[15] &= ~DCDIE;
 904         if (cflag & CRTSCTS) {
 905                 info->zs_channel->curregs[15] |= CTSIE;
 906                 if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
 907                         info->tx_stopped = 1;
 908         } else {
 909                 info->zs_channel->curregs[15] &= ~CTSIE;
 910                 info->tx_stopped = 0;
 911         }
 912
 913         /* Load up the new values */
 914         load_zsregs(info->zs_channel, info->zs_channel->curregs);
 915
 916         restore_flags(flags);
 917 }
 918
 919 static void rs_flush_chars(struct tty_struct *tty)
 920 {
 921         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 922         unsigned long flags;
 923
 924         if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
 925                 return;
 926
 927         if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
 928             !info->xmit_buf)
 929                 return;
 930
 931         /* Enable transmitter */
 932         save_flags(flags); cli();
 933         transmit_chars(info);
 934         restore_flags(flags);
 935 }
 936
 937 static int rs_write(struct tty_struct * tty, int from_user,
 938                     const unsigned char *buf, int count)
 939 {
 940         int     c, total = 0;
 941         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 942         unsigned long flags;
 943
 944         if (serial_paranoia_check(info, tty->name, "rs_write"))
 945                 return 0;
 946
 947         if (!tty || !info->xmit_buf)
 948                 return 0;
 949
 950         save_flags(flags);
 951         while (1) {
 952                 cli();
 953                 c = MIN(count, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 954                                    SERIAL_XMIT_SIZE - info->xmit_head));
 955                 if (c <= 0)
 956                         break;
 957
 958                 if (from_user) {
 959                         down(&tmp_buf_sem);
 960                         copy_from_user(tmp_buf, buf, c);
 961                         c = MIN(c, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 962                                        SERIAL_XMIT_SIZE - info->xmit_head));
 963                         memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
 964                         up(&tmp_buf_sem);
 965                 } else
 966                         memcpy(info->xmit_buf + info->xmit_head, buf, c);
 967                 info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
 968                 info->xmit_cnt += c;
 969                 restore_flags(flags);
 970                 buf += c;
 971                 count -= c;
 972                 total += c;
 973         }
 974
 975         if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
 976             && !info->tx_active)
 977                 transmit_chars(info);
 978         restore_flags(flags);
 979         return total;
 980 }
 981
 982 static int rs_write_room(struct tty_struct *tty)
 983 {
 984         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 985         int     ret;
 986
 987         if (serial_paranoia_check(info, tty->name, "rs_write_room"))
 988                 return 0;
 989         ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
 990         if (ret < 0)
 991                 ret = 0;
 992         return ret;
 993 }
 994
 995 static int rs_chars_in_buffer(struct tty_struct *tty)
 996 {
 997         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 998
 999         if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
1000                 return 0;
1001         return info->xmit_cnt;
1002 }
1003
1004 static void rs_flush_buffer(struct tty_struct *tty)
1005 {
1006         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1007
1008         if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
1009                 return;
1010         cli();
1011         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
1012         sti();
1013         wake_up_interruptible(&tty->write_wait);
1014         if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
1015             tty->ldisc.write_wakeup)
1016                 (tty->ldisc.write_wakeup)(tty);
1017 }
1018
1019 /*
1020  * ------------------------------------------------------------
1021  * rs_throttle()
1022  *
1023  * This routine is called by the upper-layer tty layer to signal that
1024  * incoming characters should be throttled.
1025  * ------------------------------------------------------------
1026  */
1027 static void rs_throttle(struct tty_struct * tty)
1028 {
1029         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1030         unsigned long flags;
1031
1032 #ifdef SERIAL_DEBUG_THROTTLE
1033         char    buf[64];
1034
1035         printk("throttle %s: %d....\n", _tty_name(tty, buf),
1036                tty->ldisc.chars_in_buffer(tty));
1037 #endif
1038
1039         if (serial_paranoia_check(info, tty->name, "rs_throttle"))
1040                 return;
1041
1042         if (I_IXOFF(tty)) {
1043                 save_flags(flags); cli();
1044                 info->x_char = STOP_CHAR(tty);
1045                 if (!info->tx_active)
1046                         transmit_chars(info);
1047                 restore_flags(flags);
1048         }
1049
1050         if (C_CRTSCTS(tty)) {
1051                 zs_rtsdtr(info, RTS, 0);
1052         }
1053 }
1054
1055 static void rs_unthrottle(struct tty_struct * tty)
1056 {
1057         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1058         unsigned long flags;
1059
1060 #ifdef SERIAL_DEBUG_THROTTLE
1061         char    buf[64];
1062
1063         printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
1064                tty->ldisc.chars_in_buffer(tty));
1065 #endif
1066
1067         if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
1068                 return;
1069
1070         if (I_IXOFF(tty)) {
1071                 save_flags(flags); cli();
1072                 if (info->x_char)
1073                         info->x_char = 0;
1074                 else {
1075                         info->x_char = START_CHAR(tty);
1076                         if (!info->tx_active)
1077                                 transmit_chars(info);
1078                 }
1079                 restore_flags(flags);
1080         }
1081
1082         if (C_CRTSCTS(tty)) {
1083                 zs_rtsdtr(info, RTS, 1);
1084         }
1085 }
1086
1087 /*
1088  * ------------------------------------------------------------
1089  * rs_ioctl() and friends
1090  * ------------------------------------------------------------
1091  */
1092
1093 static int get_serial_info(struct dec_serial * info,
1094                            struct serial_struct * retinfo)
1095 {
1096         struct serial_struct tmp;
1097
1098         if (!retinfo)
1099                 return -EFAULT;
1100         memset(&tmp, 0, sizeof(tmp));
1101         tmp.type = info->type;
1102         tmp.line = info->line;
1103         tmp.port = info->port;
1104         tmp.irq = info->irq;
1105         tmp.flags = info->flags;
1106         tmp.baud_base = info->baud_base;
1107         tmp.close_delay = info->close_delay;
1108         tmp.closing_wait = info->closing_wait;
1109         tmp.custom_divisor = info->custom_divisor;
1110         return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
1111 }
1112
1113 static int set_serial_info(struct dec_serial * info,
1114                            struct serial_struct * new_info)
1115 {
1116         struct serial_struct new_serial;
1117         struct dec_serial old_info;
1118         int                     retval = 0;
1119
1120         if (!new_info)
1121                 return -EFAULT;
1122         copy_from_user(&new_serial,new_info,sizeof(new_serial));
1123         old_info = *info;
1124
1125         if (!capable(CAP_SYS_ADMIN)) {
1126                 if ((new_serial.baud_base != info->baud_base) ||
1127                     (new_serial.type != info->type) ||
1128                     (new_serial.close_delay != info->close_delay) ||
1129                     ((new_serial.flags & ~ZILOG_USR_MASK) !=
1130                      (info->flags & ~ZILOG_USR_MASK)))
1131                         return -EPERM;
1132                 info->flags = ((info->flags & ~ZILOG_USR_MASK) |
1133                                (new_serial.flags & ZILOG_USR_MASK));
1134                 info->custom_divisor = new_serial.custom_divisor;
1135                 goto check_and_exit;
1136         }
1137
1138         if (info->count > 1)
1139                 return -EBUSY;
1140
1141         /*
1142          * OK, past this point, all the error checking has been done.
1143          * At this point, we start making changes.....
1144          */
1145
1146         info->baud_base = new_serial.baud_base;
1147         info->flags = ((info->flags & ~ZILOG_FLAGS) |
1148                         (new_serial.flags & ZILOG_FLAGS));
1149         info->type = new_serial.type;
1150         info->close_delay = new_serial.close_delay;
1151         info->closing_wait = new_serial.closing_wait;
1152
1153 check_and_exit:
1154         retval = zs_startup(info);
1155         return retval;
1156 }
1157
1158 /*
1159  * get_lsr_info - get line status register info
1160  *
1161  * Purpose: Let user call ioctl() to get info when the UART physically
1162  *          is emptied.  On bus types like RS485, the transmitter must
1163  *          release the bus after transmitting. This must be done when
1164  *          the transmit shift register is empty, not be done when the
1165  *          transmit holding register is empty.  This functionality
1166  *          allows an RS485 driver to be written in user space.
1167  */
1168 static int get_lsr_info(struct dec_serial * info, unsigned int *value)
1169 {
1170         unsigned char status;
1171
1172         cli();
1173         status = read_zsreg(info->zs_channel, 0);
1174         sti();
1175         put_user(status,value);
1176         return 0;
1177 }
1178
1179 static int rs_tiocmget(struct tty_struct *tty, struct file *file)
1180 {
1181         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1182         unsigned char control, status_a, status_b;
1183         unsigned int result;
1184
1185         if (info->hook)
1186                 return -ENODEV;
1187
1188         if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1189                 return -ENODEV;
1190
1191         if (tty->flags & (1 << TTY_IO_ERROR))
1192                 return -EIO;
1193
1194         if (info->zs_channel == info->zs_chan_a)
1195                 result = 0;
1196         else {
1197                 cli();
1198                 control = info->zs_chan_a->curregs[5];
1199                 status_a = read_zsreg(info->zs_chan_a, 0);
1200                 status_b = read_zsreg(info->zs_channel, 0);
1201                 sti();
1202                 result =  ((control  & RTS) ? TIOCM_RTS: 0)
1203                         | ((control  & DTR) ? TIOCM_DTR: 0)
1204                         | ((status_b & DCD) ? TIOCM_CAR: 0)
1205                         | ((status_a & DCD) ? TIOCM_RNG: 0)
1206                         | ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
1207                         | ((status_b & CTS) ? TIOCM_CTS: 0);
1208         }
1209         return result;
1210 }
1211
1212 static int rs_tiocmset(struct tty_struct *tty, struct file *file,
1213                        unsigned int set, unsigned int clear)
1214 {
1215         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1216         int error;
1217         unsigned int arg, bits;
1218
1219         if (info->hook)
1220                 return -ENODEV;
1221
1222         if (serial_paranoia_check(info, tty->name, __FUNCTION__))
1223                 return -ENODEV;
1224
1225         if (tty->flags & (1 << TTY_IO_ERROR))
1226                 return -EIO;
1227
1228         if (info->zs_channel == info->zs_chan_a)
1229                 return 0;
1230
1231         cli();
1232         if (set & TIOCM_RTS)
1233                 info->zs_chan_a->curregs[5] |= RTS;
1234         if (set & TIOCM_DTR)
1235                 info->zs_chan_a->curregs[5] |= DTR;
1236         if (clear & TIOCM_RTS)
1237                 info->zs_chan_a->curregs[5] &= ~RTS;
1238         if (clear & TIOCM_DTR)
1239                 info->zs_chan_a->curregs[5] &= ~DTR;
1240         write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
1241         sti();
1242         return 0;
1243 }
1244
1245 /*
1246  * rs_break - turn transmit break condition on/off
1247  */
1248 static void rs_break(struct tty_struct *tty, int break_state)
1249 {
1250         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1251         unsigned long flags;
1252
1253         if (serial_paranoia_check(info, tty->name, "rs_break"))
1254                 return;
1255         if (!info->port)
1256                 return;
1257
1258         save_flags(flags); cli();
1259         if (break_state == -1)
1260                 info->zs_channel->curregs[5] |= SND_BRK;
1261         else
1262                 info->zs_channel->curregs[5] &= ~SND_BRK;
1263         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
1264         restore_flags(flags);
1265 }
1266
1267 static int rs_ioctl(struct tty_struct *tty, struct file * file,
1268                     unsigned int cmd, unsigned long arg)
1269 {
1270         int error;
1271         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1272
1273         if (info->hook)
1274                 return -ENODEV;
1275
1276         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1277                 return -ENODEV;
1278
1279         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1280             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
1281             (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
1282                 if (tty->flags & (1 << TTY_IO_ERROR))
1283                     return -EIO;
1284         }
1285
1286         switch (cmd) {
1287                 case TIOCGSERIAL:
1288                         error = verify_area(VERIFY_WRITE, (void *) arg,
1289                                                 sizeof(struct serial_struct));
1290                         if (error)
1291                                 return error;
1292                         return get_serial_info(info,
1293                                                (struct serial_struct *) arg);
1294                 case TIOCSSERIAL:
1295                         return set_serial_info(info,
1296                                                (struct serial_struct *) arg);
1297                 case TIOCSERGETLSR: /* Get line status register */
1298                         error = verify_area(VERIFY_WRITE, (void *) arg,
1299                                 sizeof(unsigned int));
1300                         if (error)
1301                                 return error;
1302                         else
1303                             return get_lsr_info(info, (unsigned int *) arg);
1304
1305                 case TIOCSERGSTRUCT:
1306                         error = verify_area(VERIFY_WRITE, (void *) arg,
1307                                                 sizeof(struct dec_serial));
1308                         if (error)
1309                                 return error;
1310                         copy_from_user((struct dec_serial *) arg,
1311                                        info, sizeof(struct dec_serial));
1312                         return 0;
1313
1314                 default:
1315                         return -ENOIOCTLCMD;
1316                 }
1317         return 0;
1318 }
1319
1320 static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
1321 {
1322         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1323         int was_stopped;
1324
1325         if (tty->termios->c_cflag == old_termios->c_cflag)
1326                 return;
1327         was_stopped = info->tx_stopped;
1328
1329         change_speed(info);
1330
1331         if (was_stopped && !info->tx_stopped)
1332                 rs_start(tty);
1333 }
1334
1335 /*
1336  * ------------------------------------------------------------
1337  * rs_close()
1338  *
1339  * This routine is called when the serial port gets closed.
1340  * Wait for the last remaining data to be sent.
1341  * ------------------------------------------------------------
1342  */
1343 static void rs_close(struct tty_struct *tty, struct file * filp)
1344 {
1345         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1346         unsigned long flags;
1347
1348         if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
1349                 return;
1350
1351         save_flags(flags); cli();
1352
1353         if (tty_hung_up_p(filp)) {
1354                 restore_flags(flags);
1355                 return;
1356         }
1357
1358 #ifdef SERIAL_DEBUG_OPEN
1359         printk("rs_close ttyS%02d, count = %d\n", info->line, info->count);
1360 #endif
1361         if ((tty->count == 1) && (info->count != 1)) {
1362                 /*
1363                  * Uh, oh.  tty->count is 1, which means that the tty
1364                  * structure will be freed.  Info->count should always
1365                  * be one in these conditions.  If it's greater than
1366                  * one, we've got real problems, since it means the
1367                  * serial port won't be shutdown.
1368                  */
1369                 printk("rs_close: bad serial port count; tty->count is 1, "
1370                        "info->count is %d\n", info->count);
1371                 info->count = 1;
1372         }
1373         if (--info->count < 0) {
1374                 printk("rs_close: bad serial port count for ttyS%02d: %d\n",
1375                        info->line, info->count);
1376                 info->count = 0;
1377         }
1378         if (info->count) {
1379                 restore_flags(flags);
1380                 return;
1381         }
1382         info->flags |= ZILOG_CLOSING;
1383         /*
1384          * Now we wait for the transmit buffer to clear; and we notify
1385          * the line discipline to only process XON/XOFF characters.
1386          */
1387         tty->closing = 1;
1388         if (info->closing_wait != ZILOG_CLOSING_WAIT_NONE)
1389                 tty_wait_until_sent(tty, info->closing_wait);
1390         /*
1391          * At this point we stop accepting input.  To do this, we
1392          * disable the receiver and receive interrupts.
1393          */
1394         info->zs_channel->curregs[3] &= ~RxENABLE;
1395         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
1396         info->zs_channel->curregs[1] = 0;       /* disable any rx ints */
1397         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
1398         ZS_CLEARFIFO(info->zs_channel);
1399         if (info->flags & ZILOG_INITIALIZED) {
1400                 /*
1401                  * Before we drop DTR, make sure the SCC transmitter
1402                  * has completely drained.
1403                  */
1404                 rs_wait_until_sent(tty, info->timeout);
1405         }
1406
1407         shutdown(info);
1408         if (tty->driver->flush_buffer)
1409                 tty->driver->flush_buffer(tty);
1410         if (tty->ldisc.flush_buffer)
1411                 tty->ldisc.flush_buffer(tty);
1412         tty->closing = 0;
1413         info->event = 0;
1414         info->tty = 0;
1415         if (info->blocked_open) {
1416                 if (info->close_delay) {
1417                         current->state = TASK_INTERRUPTIBLE;
1418                         schedule_timeout(info->close_delay);
1419                 }
1420                 wake_up_interruptible(&info->open_wait);
1421         }
1422         info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CLOSING);
1423         wake_up_interruptible(&info->close_wait);
1424         restore_flags(flags);
1425 }
1426
1427 /*
1428  * rs_wait_until_sent() --- wait until the transmitter is empty
1429  */
1430 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1431 {
1432         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1433         unsigned long orig_jiffies, char_time;
1434
1435         if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1436                 return;
1437
1438         orig_jiffies = jiffies;
1439         /*
1440          * Set the check interval to be 1/5 of the estimated time to
1441          * send a single character, and make it at least 1.  The check
1442          * interval should also be less than the timeout.
1443          */
1444         char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1445         char_time = char_time / 5;
1446         if (char_time == 0)
1447                 char_time = 1;
1448         if (timeout)
1449                 char_time = MIN(char_time, timeout);
1450         while ((read_zsreg(info->zs_channel, 1) & Tx_BUF_EMP) == 0) {
1451                 current->state = TASK_INTERRUPTIBLE;
1452                 schedule_timeout(char_time);
1453                 if (signal_pending(current))
1454                         break;
1455                 if (timeout && time_after(jiffies, orig_jiffies + timeout))
1456                         break;
1457         }
1458         current->state = TASK_RUNNING;
1459 }
1460
1461 /*
1462  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1463  */
1464 void rs_hangup(struct tty_struct *tty)
1465 {
1466         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1467
1468         if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1469                 return;
1470
1471         rs_flush_buffer(tty);
1472         shutdown(info);
1473         info->event = 0;
1474         info->count = 0;
1475         info->flags &= ~ZILOG_NORMAL_ACTIVE;
1476         info->tty = 0;
1477         wake_up_interruptible(&info->open_wait);
1478 }
1479
1480 /*
1481  * ------------------------------------------------------------
1482  * rs_open() and friends
1483  * ------------------------------------------------------------
1484  */
1485 static int block_til_ready(struct tty_struct *tty, struct file * filp,
1486                            struct dec_serial *info)
1487 {
1488         DECLARE_WAITQUEUE(wait, current);
1489         int             retval;
1490         int             do_clocal = 0;
1491
1492         /*
1493          * If the device is in the middle of being closed, then block
1494          * until it's done, and then try again.
1495          */
1496         if (info->flags & ZILOG_CLOSING) {
1497                 interruptible_sleep_on(&info->close_wait);
1498 #ifdef SERIAL_DO_RESTART
1499                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1500                         -EAGAIN : -ERESTARTSYS);
1501 #else
1502                 return -EAGAIN;
1503 #endif
1504         }
1505
1506         /*
1507          * If this is a callout device, then just make sure the normal
1508          * device isn't being used.
1509          */
1510
1511         /*
1512          * If non-blocking mode is set, or the port is not enabled,
1513          * then make the check up front and then exit.
1514          */
1515         if ((filp->f_flags & O_NONBLOCK) ||
1516             (tty->flags & (1 << TTY_IO_ERROR))) {
1517                 info->flags |= ZILOG_NORMAL_ACTIVE;
1518                 return 0;
1519         }
1520
1521         if (tty->termios->c_cflag & CLOCAL)
1522                 do_clocal = 1;
1523
1524         /*
1525          * Block waiting for the carrier detect and the line to become
1526          * free (i.e., not in use by the callout).  While we are in
1527          * this loop, info->count is dropped by one, so that
1528          * rs_close() knows when to free things.  We restore it upon
1529          * exit, either normal or abnormal.
1530          */
1531         retval = 0;
1532         add_wait_queue(&info->open_wait, &wait);
1533 #ifdef SERIAL_DEBUG_OPEN
1534         printk("block_til_ready before block: ttyS%02d, count = %d\n",
1535                info->line, info->count);
1536 #endif
1537         cli();
1538         if (!tty_hung_up_p(filp))
1539                 info->count--;
1540         sti();
1541         info->blocked_open++;
1542         while (1) {
1543                 cli();
1544                 if (tty->termios->c_cflag & CBAUD)
1545                         zs_rtsdtr(info, RTS | DTR, 1);
1546                 sti();
1547                 set_current_state(TASK_INTERRUPTIBLE);
1548                 if (tty_hung_up_p(filp) ||
1549                     !(info->flags & ZILOG_INITIALIZED)) {
1550 #ifdef SERIAL_DO_RESTART
1551                         if (info->flags & ZILOG_HUP_NOTIFY)
1552                                 retval = -EAGAIN;
1553                         else
1554                                 retval = -ERESTARTSYS;
1555 #else
1556                         retval = -EAGAIN;
1557 #endif
1558                         break;
1559                 }
1560                 if (!(info->flags & ZILOG_CLOSING) &&
1561                     (do_clocal || (read_zsreg(info->zs_channel, 0) & DCD)))
1562                         break;
1563                 if (signal_pending(current)) {
1564                         retval = -ERESTARTSYS;
1565                         break;
1566                 }
1567 #ifdef SERIAL_DEBUG_OPEN
1568                 printk("block_til_ready blocking: ttyS%02d, count = %d\n",
1569                        info->line, info->count);
1570 #endif
1571                 schedule();
1572         }
1573         current->state = TASK_RUNNING;
1574         remove_wait_queue(&info->open_wait, &wait);
1575         if (!tty_hung_up_p(filp))
1576                 info->count++;
1577         info->blocked_open--;
1578 #ifdef SERIAL_DEBUG_OPEN
1579         printk("block_til_ready after blocking: ttyS%02d, count = %d\n",
1580                info->line, info->count);
1581 #endif
1582         if (retval)
1583                 return retval;
1584         info->flags |= ZILOG_NORMAL_ACTIVE;
1585         return 0;
1586 }
1587
1588 /*
1589  * This routine is called whenever a serial port is opened.  It
1590  * enables interrupts for a serial port, linking in its ZILOG structure into
1591  * the IRQ chain.   It also performs the serial-specific
1592  * initialization for the tty structure.
1593  */
1594 int rs_open(struct tty_struct *tty, struct file * filp)
1595 {
1596         struct dec_serial       *info;
1597         int                     retval, line;
1598
1599         line = tty->index;
1600         if ((line < 0) || (line >= zs_channels_found))
1601                 return -ENODEV;
1602         info = zs_soft + line;
1603
1604         if (info->hook)
1605                 return -ENODEV;
1606
1607         if (serial_paranoia_check(info, tty->name, "rs_open"))
1608                 return -ENODEV;
1609 #ifdef SERIAL_DEBUG_OPEN
1610         printk("rs_open %s, count = %d\n", tty->name, info->count);
1611 #endif
1612
1613         info->count++;
1614         tty->driver_data = info;
1615         info->tty = tty;
1616
1617         /*
1618          * If the port is the middle of closing, bail out now
1619          */
1620         if (tty_hung_up_p(filp) ||
1621             (info->flags & ZILOG_CLOSING)) {
1622                 if (info->flags & ZILOG_CLOSING)
1623                         interruptible_sleep_on(&info->close_wait);
1624 #ifdef SERIAL_DO_RESTART
1625                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1626                         -EAGAIN : -ERESTARTSYS);
1627 #else
1628                 return -EAGAIN;
1629 #endif
1630         }
1631
1632         /*
1633          * Start up serial port
1634          */
1635         retval = zs_startup(info);
1636         if (retval)
1637                 return retval;
1638
1639         retval = block_til_ready(tty, filp, info);
1640         if (retval) {
1641 #ifdef SERIAL_DEBUG_OPEN
1642                 printk("rs_open returning after block_til_ready with %d\n",
1643                        retval);
1644 #endif
1645                 return retval;
1646         }
1647
1648 #ifdef CONFIG_SERIAL_CONSOLE
1649         if (sercons.cflag && sercons.index == line) {
1650                 tty->termios->c_cflag = sercons.cflag;
1651                 sercons.cflag = 0;
1652                 change_speed(info);
1653         }
1654 #endif
1655
1656 #ifdef SERIAL_DEBUG_OPEN
1657         printk("rs_open %s successful...", tty->name);
1658 #endif
1659 /* tty->low_latency = 1; */
1660         return 0;
1661 }
1662
1663 /* Finally, routines used to initialize the serial driver. */
1664
1665 static void __init show_serial_version(void)
1666 {
1667         printk("DECstation Z8530 serial driver version 0.05\n");
1668 }
1669
1670 /*  Initialize Z8530s zs_channels
1671  */
1672
1673 static void __init probe_sccs(void)
1674 {
1675         struct dec_serial **pp;
1676         int i, n, n_chips = 0, n_channels, chip, channel;
1677
1678         /*
1679          * did we get here by accident?
1680          */
1681         if(!BUS_PRESENT) {
1682                 printk("Not on JUNKIO machine, skipping probe_sccs\n");
1683                 return;
1684         }
1685
1686         /*
1687          * When serial console is activated, tc_init has not been called yet
1688          * and system_base is undefined. Unfortunately we have to hardcode
1689          * system_base for this case :-(. HK
1690          */
1691         switch(mips_machtype) {
1692 #ifdef CONFIG_DECSTATION
1693         case MACH_DS5000_2X0:
1694                 system_base = 0xbf800000;
1695                 n_chips = 2;
1696                 zs_parms = &ds_parms;
1697                 break;
1698         case MACH_DS5000_1XX:
1699                 system_base = 0xbc000000;
1700                 n_chips = 2;
1701                 zs_parms = &ds_parms;
1702                 break;
1703         case MACH_DS5000_XX:
1704                 system_base = 0xbc000000;
1705                 n_chips = 1;
1706                 zs_parms = &ds_parms;
1707                 break;
1708 #endif
1709 #ifdef CONFIG_BAGET_MIPS
1710         case MACH_BAGET202:
1711                 system_base = UNI_IO_BASE;
1712                 n_chips = 2;
1713                 zs_parms = &baget_parms;
1714                 zs_init_regs[2] = 0x8;
1715                 break;
1716 #endif
1717         default:
1718                 panic("zs: unsupported bus");
1719         }
1720         if (!zs_parms)
1721                 panic("zs: uninitialized parms");
1722
1723         pp = &zs_chain;
1724
1725         n_channels = 0;
1726
1727         for (chip = 0; chip < n_chips; chip++) {
1728                 for (channel = 0; channel <= 1; channel++) {
1729                         /*
1730                          * The sccs reside on the high byte of the 16 bit IOBUS
1731                          */
1732                         zs_channels[n_channels].control =
1733                                 (volatile unsigned char *)system_base +
1734                           (0 == chip ? zs_parms->scc0 : zs_parms->scc1) +
1735                           (0 == channel ? zs_parms->channel_a_offset :
1736                                           zs_parms->channel_b_offset);
1737                         zs_channels[n_channels].data =
1738                                 zs_channels[n_channels].control + 4;
1739
1740 #ifndef CONFIG_SERIAL_CONSOLE
1741                         /*
1742                          * We're called early and memory managment isn't up, yet.
1743                          * Thus check_region would fail.
1744                          */
1745                         if (check_region((unsigned long)
1746                                          zs_channels[n_channels].control,
1747                                          ZS_CHAN_IO_SIZE) < 0) {
1748                                 panic("SCC I/O region is not free");
1749                         }
1750                         request_region((unsigned long)
1751                                        zs_channels[n_channels].control,
1752                                        ZS_CHAN_IO_SIZE, "SCC");
1753 #endif
1754                         zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
1755                         zs_soft[n_channels].irq = zs_parms->irq;
1756
1757                         /*
1758                          *  Identification of channel A. Location of channel A
1759                          *  inside chip depends on mapping of internal address
1760                          *  the chip decodes channels by.
1761                          *  CHANNEL_A_NR returns either 0 (in case of
1762                          *  DECstations) or 1 (in case of Baget).
1763                          */
1764                         if (CHANNEL_A_NR == channel)
1765                                 zs_soft[n_channels].zs_chan_a =
1766                                     &zs_channels[n_channels+1-2*CHANNEL_A_NR];
1767                         else
1768                                 zs_soft[n_channels].zs_chan_a =
1769                                     &zs_channels[n_channels];
1770
1771                         *pp = &zs_soft[n_channels];
1772                         pp = &zs_soft[n_channels].zs_next;
1773                         n_channels++;
1774                 }
1775         }
1776
1777         *pp = 0;
1778         zs_channels_found = n_channels;
1779
1780         for (n = 0; n < zs_channels_found; n++) {
1781                 for (i = 0; i < 16; i++) {
1782                         zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
1783                 }
1784         }
1785
1786 /*      save_and_cli(flags);
1787         for (n = 0; n < zs_channels_found; n++) {
1788                 if (((int)zs_channels[n].control & 0xf) == 1) {
1789                         write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
1790                         mdelay(10);
1791                         write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
1792                 }
1793                 load_zsregs(zs_soft[n].zs_channel, zs_soft[n].zs_channel->curregs);
1794         }
1795         restore_flags(flags); */
1796 }
1797
1798 static struct tty_operations serial_ops = {
1799         .open = rs_open,
1800         .close = rs_close,
1801         .write = rs_write,
1802         .flush_chars = rs_flush_chars,
1803         .write_room = rs_write_room,
1804         .chars_in_buffer = rs_chars_in_buffer,
1805         .flush_buffer = rs_flush_buffer,
1806         .ioctl = rs_ioctl,
1807         .throttle = rs_throttle,
1808         .unthrottle = rs_unthrottle,
1809         .set_termios = rs_set_termios,
1810         .stop = rs_stop,
1811         .start = rs_start,
1812         .hangup = rs_hangup,
1813         .break_ctl = rs_break,
1814         .wait_until_sent = rs_wait_until_sent,
1815         .tiocmget = rs_tiocmget,
1816         .tiocmset = rs_tiocmset,
1817 };
1818
1819 /* zs_init inits the driver */
1820 int __init zs_init(void)
1821 {
1822         int channel, i;
1823         unsigned long flags;
1824         struct dec_serial *info;
1825
1826         if(!BUS_PRESENT)
1827                 return -ENODEV;
1828
1829         /* Setup base handler, and timer table. */
1830         init_bh(SERIAL_BH, do_serial_bh);
1831
1832         /* Find out how many Z8530 SCCs we have */
1833         if (zs_chain == 0)
1834                 probe_sccs();
1835
1836         serial_driver = alloc_tty_driver(zs_channels_found);
1837         if (!serial_driver)
1838                 return -ENOMEM;
1839
1840         show_serial_version();
1841
1842         /* Initialize the tty_driver structure */
1843         /* Not all of this is exactly right for us. */
1844
1845         serial_driver->owner = THIS_MODULE;
1846         serial_driver->devfs_name = "tts/";
1847         serial_driver->name = "ttyS";
1848         serial_driver->major = TTY_MAJOR;
1849         serial_driver->minor_start = 64;
1850         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1851         serial_driver->subtype = SERIAL_TYPE_NORMAL;
1852         serial_driver->init_termios = tty_std_termios;
1853         serial_driver->init_termios.c_cflag =
1854                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1855         serial_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
1856         tty_set_operations(serial_driver, &serial_ops);
1857
1858         if (tty_register_driver(serial_driver))
1859                 panic("Couldn't register serial driver\n");
1860
1861         save_flags(flags); cli();
1862
1863         for (channel = 0; channel < zs_channels_found; ++channel) {
1864                 if (zs_soft[channel].hook &&
1865                     zs_soft[channel].hook->init_channel)
1866                         (*zs_soft[channel].hook->init_channel)
1867                                 (&zs_soft[channel]);
1868
1869                 zs_soft[channel].clk_divisor = 16;
1870                 zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);
1871
1872                 if (request_irq(zs_parms->irq, rs_interrupt, SA_SHIRQ,
1873                                 "SCC", &zs_soft[channel]))
1874                         printk(KERN_ERR "decserial: can't get irq %d\n",
1875                                zs_parms->irq);
1876         }
1877
1878         for (info = zs_chain, i = 0; info; info = info->zs_next, i++)
1879         {
1880                 if (info->hook && info->hook->init_info) {
1881                         (*info->hook->init_info)(info);
1882                         continue;
1883                 }
1884                 info->magic = SERIAL_MAGIC;
1885                 info->port = (int) info->zs_channel->control;
1886                 info->line = i;
1887                 info->tty = 0;
1888                 info->custom_divisor = 16;
1889                 info->close_delay = 50;
1890                 info->closing_wait = 3000;
1891                 info->x_char = 0;
1892                 info->event = 0;
1893                 info->count = 0;
1894                 info->blocked_open = 0;
1895                 info->tqueue.routine = do_softint;
1896                 info->tqueue.data = info;
1897                 init_waitqueue_head(&info->open_wait);
1898                 init_waitqueue_head(&info->close_wait);
1899                 printk("ttyS%02d at 0x%08x (irq = %d)", info->line,
1900                        info->port, info->irq);
1901                 printk(" is a Z85C30 SCC\n");
1902                 tty_register_device(serial_driver, info->line, NULL);
1903         }
1904
1905         restore_flags(flags);
1906
1907         return 0;
1908 }
1909
1910 /*
1911  * register_serial and unregister_serial allows for serial ports to be
1912  * configured at run-time, to support PCMCIA modems.
1913  */
1914 /* PowerMac: Unused at this time, just here to make things link. */
1915 int register_serial(struct serial_struct *req)
1916 {
1917         return -1;
1918 }
1919
1920 void unregister_serial(int line)
1921 {
1922         return;
1923 }
1924
1925 /*
1926  * polling I/O routines
1927  */
1928 static int
1929 zs_poll_tx_char(struct dec_serial *info, unsigned char ch)
1930 {
1931         struct dec_zschannel *chan = info->zs_channel;
1932         int    ret;
1933
1934         if(chan) {
1935                 int loops = 10000;
1936 //              int nine = read_zsreg(chan, R9);
1937
1938                 RECOVERY_DELAY;
1939 //              write_zsreg(chan, R9, nine & ~MIE);
1940                 wbflush();
1941                 RECOVERY_DELAY;
1942
1943                 while (!(*(chan->control) & Tx_BUF_EMP) && --loops)
1944                         RECOVERY_DELAY;
1945
1946                 if (loops) {
1947                         ret = 0;
1948                         *(chan->data) = ch;
1949                         wbflush();
1950                         RECOVERY_DELAY;
1951                 } else
1952                         ret = -EAGAIN;
1953
1954 //              write_zsreg(chan, R9, nine);
1955                 wbflush();
1956                 RECOVERY_DELAY;
1957
1958                 return ret;
1959         }
1960
1961         return -ENODEV;
1962 }
1963
1964 static int
1965 zs_poll_rx_char(struct dec_serial *info)
1966 {
1967         struct dec_zschannel *chan = info->zs_channel;
1968         int    ret;
1969
1970         if(chan) {
1971                 int loops = 10000;
1972
1973                 while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
1974                         loops--;
1975
1976                 if (loops)
1977                         ret = read_zsdata(chan);
1978                 else
1979                         ret = -EAGAIN;
1980
1981                 return ret;
1982         } else
1983                 return -ENODEV;
1984 }
1985
1986 unsigned int register_zs_hook(unsigned int channel, struct zs_hook *hook)
1987 {
1988         struct dec_serial *info = &zs_soft[channel];
1989
1990         if (info->hook) {
1991                 printk("%s: line %d has already a hook registered\n",
1992                        __FUNCTION__, channel);
1993
1994                 return 0;
1995         } else {
1996                 info->hook = hook;
1997
1998                 if (zs_chain == 0)
1999                         probe_sccs();
2000
2001                 if (!(info->flags & ZILOG_INITIALIZED))
2002                         zs_startup(info);
2003
2004                 hook->poll_rx_char = zs_poll_rx_char;
2005                 hook->poll_tx_char = zs_poll_tx_char;
2006
2007                 return 1;
2008         }
2009 }
2010
2011 unsigned int unregister_zs_hook(unsigned int channel)
2012 {
2013         struct dec_serial *info = &zs_soft[channel];
2014
2015         if (info->hook) {
2016                 info->hook = NULL;
2017                 return 1;
2018         } else {
2019                 printk("%s: trying to unregister hook on line %d,"
2020                        " but none is registered\n", __FUNCTION__, channel);
2021                 return 0;
2022         }
2023 }
2024
2025 /*
2026  * ------------------------------------------------------------
2027  * Serial console driver
2028  * ------------------------------------------------------------
2029  */
2030 #ifdef CONFIG_SERIAL_CONSOLE
2031
2032
2033 /*
2034  *      Print a string to the serial port trying not to disturb
2035  *      any possible real use of the port...
2036  */
2037 static void serial_console_write(struct console *co, const char *s,
2038                                  unsigned count)
2039 {
2040         struct dec_serial *info;
2041         int i;
2042
2043         info = zs_soft + co->index;
2044
2045         for (i = 0; i < count; i++, s++) {
2046                 if(*s == '\n')
2047                         zs_poll_tx_char(info, '\r');
2048                 zs_poll_tx_char(info, *s);
2049         }
2050 }
2051
2052 static struct tty_driver *serial_console_device(struct console *c, int *index)
2053 {
2054         *index = c->index;
2055         return serial_driver;
2056 }
2057
2058 /*
2059  *      Setup initial baud/bits/parity. We do two things here:
2060  *      - construct a cflag setting for the first rs_open()
2061  *      - initialize the serial port
2062  *      Return non-zero if we didn't find a serial port.
2063  */
2064 static int __init serial_console_setup(struct console *co, char *options)
2065 {
2066         struct dec_serial *info;
2067         int     baud = 9600;
2068         int     bits = 8;
2069         int     parity = 'n';
2070         int     cflag = CREAD | HUPCL | CLOCAL;
2071         char    *s;
2072         unsigned long flags;
2073
2074         if(!BUS_PRESENT)
2075                 return -ENODEV;
2076
2077         info = zs_soft + co->index;
2078
2079         if (zs_chain == 0)
2080                 probe_sccs();
2081
2082         info->is_cons = 1;
2083
2084         if (options) {
2085                 baud = simple_strtoul(options, NULL, 10);
2086                 s = options;
2087                 while(*s >= '0' && *s <= '9')
2088                         s++;
2089                 if (*s)
2090                         parity = *s++;
2091                 if (*s)
2092                         bits   = *s - '0';
2093         }
2094
2095         /*
2096          *      Now construct a cflag setting.
2097          */
2098         switch(baud) {
2099         case 1200:
2100                 cflag |= B1200;
2101                 break;
2102         case 2400:
2103                 cflag |= B2400;
2104                 break;
2105         case 4800:
2106                 cflag |= B4800;
2107                 break;
2108         case 19200:
2109                 cflag |= B19200;
2110                 break;
2111         case 38400:
2112                 cflag |= B38400;
2113                 break;
2114         case 57600:
2115                 cflag |= B57600;
2116                 break;
2117         case 115200:
2118                 cflag |= B115200;
2119                 break;
2120         case 9600:
2121         default:
2122                 cflag |= B9600;
2123                 break;
2124         }
2125         switch(bits) {
2126         case 7:
2127                 cflag |= CS7;
2128                 break;
2129         default:
2130         case 8:
2131                 cflag |= CS8;
2132                 break;
2133         }
2134         switch(parity) {
2135         case 'o': case 'O':
2136                 cflag |= PARODD;
2137                 break;
2138         case 'e': case 'E':
2139                 cflag |= PARENB;
2140                 break;
2141         }
2142         co->cflag = cflag;
2143 #if 1
2144         save_and_cli(flags);
2145
2146         /*
2147          * Turn on RTS and DTR.
2148          */
2149         zs_rtsdtr(info, RTS | DTR, 1);
2150
2151         /*
2152          * Finally, enable sequencing
2153          */
2154         info->zs_channel->curregs[3] |= (RxENABLE | Rx8);
2155         info->zs_channel->curregs[5] |= (TxENAB | Tx8);
2156         info->zs_channel->curregs[9] |= (VIS);
2157         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
2158         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
2159         write_zsreg(info->zs_channel, 9, info->zs_channel->curregs[9]);
2160
2161         /*
2162          * Clear the interrupt registers.
2163          */
2164         write_zsreg(info->zs_channel, 0, ERR_RES);
2165         write_zsreg(info->zs_channel, 0, RES_H_IUS);
2166
2167         /*
2168          * Set the speed of the serial port
2169          */
2170         change_speed(info);
2171
2172         /* Save the current value of RR0 */
2173         info->read_reg_zero = read_zsreg(info->zs_channel, 0);
2174
2175         zs_soft[co->index].clk_divisor = 16;
2176         zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);
2177
2178         restore_flags(flags);
2179 #endif
2180         return 0;
2181 }
2182
2183 static struct console sercons = {
2184         .name           = "ttyS",
2185         .write          = serial_console_write,
2186         .device         = serial_console_device,
2187         .setup          = serial_console_setup,
2188         .flags          = CON_PRINTBUFFER,
2189         .index          = -1,
2190 };
2191
2192 /*
2193  *      Register console.
2194  */
2195 void __init zs_serial_console_init(void)
2196 {
2197         register_console(&sercons);
2198 }
2199 #endif /* ifdef CONFIG_SERIAL_CONSOLE */
2200
2201 #ifdef CONFIG_KGDB
2202 struct dec_zschannel *zs_kgdbchan;
2203 static unsigned char scc_inittab[] = {
2204         9,  0x80,       /* reset A side (CHRA) */
2205         13, 0,          /* set baud rate divisor */
2206         12, 1,
2207         14, 1,          /* baud rate gen enable, src=rtxc (BRENABL) */
2208         11, 0x50,       /* clocks = br gen (RCBR | TCBR) */
2209         5,  0x6a,       /* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
2210         4,  0x44,       /* x16 clock, 1 stop (SB1 | X16CLK)*/
2211         3,  0xc1,       /* rx enable, 8 bits (RxENABLE | Rx8)*/
2212 };
2213
2214 /* These are for receiving and sending characters under the kgdb
2215  * source level kernel debugger.
2216  */
2217 void putDebugChar(char kgdb_char)
2218 {
2219         struct dec_zschannel *chan = zs_kgdbchan;
2220         while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
2221                 RECOVERY_DELAY;
2222         write_zsdata(chan, kgdb_char);
2223 }
2224 char getDebugChar(void)
2225 {
2226         struct dec_zschannel *chan = zs_kgdbchan;
2227         while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
2228                 eieio(); /*barrier();*/
2229         return read_zsdata(chan);
2230 }
2231 void kgdb_interruptible(int yes)
2232 {
2233         struct dec_zschannel *chan = zs_kgdbchan;
2234         int one, nine;
2235         nine = read_zsreg(chan, 9);
2236         if (yes == 1) {
2237                 one = EXT_INT_ENAB|INT_ALL_Rx;
2238                 nine |= MIE;
2239                 printk("turning serial ints on\n");
2240         } else {
2241                 one = RxINT_DISAB;
2242                 nine &= ~MIE;
2243                 printk("turning serial ints off\n");
2244         }
2245         write_zsreg(chan, 1, one);
2246         write_zsreg(chan, 9, nine);
2247 }
2248
2249 static int kgdbhook_init_channel(struct dec_serial* info)
2250 {
2251         return 0;
2252 }
2253
2254 static void kgdbhook_init_info(struct dec_serial* info)
2255 {
2256 }
2257
2258 static void kgdbhook_rx_char(struct dec_serial* info,
2259                              unsigned char ch, unsigned char stat)
2260 {
2261         if (ch == 0x03 || ch == '$')
2262                 breakpoint();
2263         if (stat & (Rx_OVR|FRM_ERR|PAR_ERR))
2264                 write_zsreg(info->zs_channel, 0, ERR_RES);
2265 }
2266
2267 /* This sets up the serial port we're using, and turns on
2268  * interrupts for that channel, so kgdb is usable once we're done.
2269  */
2270 static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
2271 {
2272         int brg;
2273         int i, x;
2274         volatile char *sccc = ms->control;
2275         brg = BPS_TO_BRG(bps, zs_parms->clock/16);
2276         printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
2277         for (i = 20000; i != 0; --i) {
2278                 x = *sccc; eieio();
2279         }
2280         for (i = 0; i < sizeof(scc_inittab); ++i) {
2281                 write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
2282                 i++;
2283         }
2284 }
2285 /* This is called at boot time to prime the kgdb serial debugging
2286  * serial line.  The 'tty_num' argument is 0 for /dev/ttya and 1
2287  * for /dev/ttyb which is determined in setup_arch() from the
2288  * boot command line flags.
2289  */
2290 struct zs_hook zs_kgdbhook = {
2291         init_channel : kgdbhook_init_channel,
2292         init_info    : kgdbhook_init_info,
2293         cflags       : B38400|CS8|CLOCAL,
2294         rx_char      : kgdbhook_rx_char,
2295 }
2296
2297 void __init zs_kgdb_hook(int tty_num)
2298 {
2299         /* Find out how many Z8530 SCCs we have */
2300         if (zs_chain == 0)
2301                 probe_sccs();
2302         zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
2303         zs_kgdbchan = zs_soft[tty_num].zs_channel;
2304         zs_soft[tty_num].change_needed = 0;
2305         zs_soft[tty_num].clk_divisor = 16;
2306         zs_soft[tty_num].zs_baud = 38400;
2307         zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
2308         /* Turn on transmitter/receiver at 8-bits/char */
2309         kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
2310         printk("KGDB: on channel %d initialized\n", tty_num);
2311         set_debug_traps(); /* init stub */
2312 }
2313 #endif /* ifdef CONFIG_KGDB */
2314
2315