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  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/version.h>
  44 #include <linux/errno.h>
  45 #include <linux/signal.h>
  46 #include <linux/sched.h>
  47 #include <linux/timer.h>
  48 #include <linux/interrupt.h>
  49 #include <linux/tty.h>
  50 #include <linux/tty_flip.h>
  51 #include <linux/major.h>
  52 #include <linux/string.h>
  53 #include <linux/fcntl.h>
  54 #include <linux/mm.h>
  55 #include <linux/kernel.h>
  56 #include <linux/delay.h>
  57 #include <linux/init.h>
  58 #include <linux/ioport.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/segment.h>
  68 #include <asm/bitops.h>
  69 #include <asm/uaccess.h>
  70 #include <asm/bootinfo.h>
  71 #ifdef CONFIG_DECSTATION
  72 #include <asm/dec/interrupts.h>
  73 #include <asm/dec/machtype.h>
  74 #include <asm/dec/tc.h>
  75 #include <asm/dec/ioasic_addrs.h>
  76 #endif
  77 #ifdef CONFIG_BAGET_MIPS
  78 #include <asm/baget/baget.h>
  79 unsigned long system_base;
  80 #endif
  81 #ifdef CONFIG_KGDB
  82 #include <asm/kgdb.h>
  83 #endif
  84 #ifdef CONFIG_MAGIC_SYSRQ
  85 #include <linux/sysrq.h>
  86 #endif
  87
  88 #include "zs.h"
  89
  90 /*
  91  * It would be nice to dynamically allocate everything that
  92  * depends on NUM_SERIAL, so we could support any number of
  93  * Z8530s, but for now...
  94  */
  95 #define NUM_SERIAL      2               /* Max number of ZS chips supported */
  96 #define NUM_CHANNELS    (NUM_SERIAL * 2)        /* 2 channels per chip */
  97 #define CHANNEL_A_NR  (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
  98                                         /* Number of channel A in the chip */
  99 #define ZS_CHAN_IO_SIZE 8
 100 #define ZS_CLOCK        7372800         /* Z8530 RTxC input clock rate */
 101
 102 #define RECOVERY_DELAY  udelay(2)
 103
 104 struct zs_parms {
 105         unsigned long scc0;
 106         unsigned long scc1;
 107         int channel_a_offset;
 108         int channel_b_offset;
 109         int irq0;
 110         int irq1;
 111         int clock;
 112 };
 113
 114 static struct zs_parms *zs_parms;
 115
 116 #ifdef CONFIG_DECSTATION
 117 static struct zs_parms ds_parms = {
 118         scc0 : IOASIC_SCC0,
 119         scc1 : IOASIC_SCC1,
 120         channel_a_offset : 1,
 121         channel_b_offset : 9,
 122         irq0 : -1,
 123         irq1 : -1,
 124         clock : ZS_CLOCK
 125 };
 126 #endif
 127 #ifdef CONFIG_BAGET_MIPS
 128 static struct zs_parms baget_parms = {
 129         scc0 : UNI_SCC0,
 130         scc1 : UNI_SCC1,
 131         channel_a_offset : 9,
 132         channel_b_offset : 1,
 133         irq0 : BAGET_SCC_IRQ,
 134         irq1 : BAGET_SCC_IRQ,
 135         clock : 14745000
 136 };
 137 #endif
 138
 139 #ifdef CONFIG_DECSTATION
 140 #define DS_BUS_PRESENT (IOASIC)
 141 #else
 142 #define DS_BUS_PRESENT 0
 143 #endif
 144
 145 #ifdef CONFIG_BAGET_MIPS
 146 #define BAGET_BUS_PRESENT (mips_machtype == MACH_BAGET202)
 147 #else
 148 #define BAGET_BUS_PRESENT 0
 149 #endif
 150
 151 #define BUS_PRESENT (DS_BUS_PRESENT || BAGET_BUS_PRESENT)
 152
 153 struct dec_zschannel zs_channels[NUM_CHANNELS];
 154 struct dec_serial zs_soft[NUM_CHANNELS];
 155 int zs_channels_found;
 156 struct dec_serial *zs_chain;    /* list of all channels */
 157
 158 struct tty_struct zs_ttys[NUM_CHANNELS];
 159
 160 #ifdef CONFIG_SERIAL_DEC_CONSOLE
 161 static struct console sercons;
 162 #endif
 163 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) \
 164     && !defined(MODULE)
 165 static unsigned long break_pressed; /* break, really ... */
 166 #endif
 167
 168 static unsigned char zs_init_regs[16] __initdata = {
 169         0,                              /* write 0 */
 170         0,                              /* write 1 */
 171         0,                              /* write 2 */
 172         0,                              /* write 3 */
 173         (X16CLK),                       /* write 4 */
 174         0,                              /* write 5 */
 175         0, 0, 0,                        /* write 6, 7, 8 */
 176         (MIE | DLC | NV),               /* write 9 */
 177         (NRZ),                          /* write 10 */
 178         (TCBR | RCBR),                  /* write 11 */
 179         0, 0,                           /* BRG time constant, write 12 + 13 */
 180         (BRSRC | BRENABL),              /* write 14 */
 181         0                               /* write 15 */
 182 };
 183
 184 DECLARE_TASK_QUEUE(tq_zs_serial);
 185
 186 struct tty_driver serial_driver, callout_driver;
 187 static int serial_refcount;
 188
 189 /* serial subtype definitions */
 190 #define SERIAL_TYPE_NORMAL      1
 191 #define SERIAL_TYPE_CALLOUT     2
 192
 193 /* number of characters left in xmit buffer before we ask for more */
 194 #define WAKEUP_CHARS 256
 195
 196 /*
 197  * Debugging.
 198  */
 199 #undef SERIAL_DEBUG_INTR
 200 #undef SERIAL_DEBUG_OPEN
 201 #undef SERIAL_DEBUG_FLOW
 202 #undef SERIAL_DEBUG_THROTTLE
 203 #undef SERIAL_PARANOIA_CHECK
 204
 205 #undef ZS_DEBUG_REGS
 206
 207 #ifdef SERIAL_DEBUG_THROTTLE
 208 #define _tty_name(tty,buf) tty_name(tty,buf)
 209 #endif
 210
 211 #define RS_STROBE_TIME 10
 212 #define RS_ISR_PASS_LIMIT 256
 213
 214 #define _INLINE_ inline
 215
 216 static void probe_sccs(void);
 217 static void change_speed(struct dec_serial *info);
 218 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 219
 220 static struct tty_struct *serial_table[NUM_CHANNELS];
 221 static struct termios *serial_termios[NUM_CHANNELS];
 222 static struct termios *serial_termios_locked[NUM_CHANNELS];
 223
 224 #ifndef MIN
 225 #define MIN(a,b)        ((a) < (b) ? (a) : (b))
 226 #endif
 227
 228 /*
 229  * tmp_buf is used as a temporary buffer by serial_write.  We need to
 230  * lock it in case the copy_from_user blocks while swapping in a page,
 231  * and some other program tries to do a serial write at the same time.
 232  * Since the lock will only come under contention when the system is
 233  * swapping and available memory is low, it makes sense to share one
 234  * buffer across all the serial ports, since it significantly saves
 235  * memory if large numbers of serial ports are open.
 236  */
 237 static unsigned char tmp_buf[4096]; /* This is cheating */
 238 static DECLARE_MUTEX(tmp_buf_sem);
 239
 240 static inline int serial_paranoia_check(struct dec_serial *info,
 241                                         dev_t device, const char *routine)
 242 {
 243 #ifdef SERIAL_PARANOIA_CHECK
 244         static const char *badmagic =
 245                 "Warning: bad magic number for serial struct (%d, %d) in %s\n";
 246         static const char *badinfo =
 247                 "Warning: null mac_serial for (%d, %d) in %s\n";
 248
 249         if (!info) {
 250                 printk(badinfo, MAJOR(device), MINOR(device), routine);
 251                 return 1;
 252         }
 253         if (info->magic != SERIAL_MAGIC) {
 254                 printk(badmagic, MAJOR(device), MINOR(device), routine);
 255                 return 1;
 256         }
 257 #endif
 258         return 0;
 259 }
 260
 261 /*
 262  * This is used to figure out the divisor speeds and the timeouts
 263  */
 264 static int baud_table[] = {
 265         0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
 266         9600, 19200, 38400, 57600, 115200, 0 };
 267
 268 /*
 269  * Reading and writing Z8530 registers.
 270  */
 271 static inline unsigned char read_zsreg(struct dec_zschannel *channel,
 272                                        unsigned char reg)
 273 {
 274         unsigned char retval;
 275
 276         if (reg != 0) {
 277                 *channel->control = reg & 0xf;
 278                 fast_iob(); RECOVERY_DELAY;
 279         }
 280         retval = *channel->control;
 281         RECOVERY_DELAY;
 282         return retval;
 283 }
 284
 285 static inline void write_zsreg(struct dec_zschannel *channel,
 286                                unsigned char reg, unsigned char value)
 287 {
 288         if (reg != 0) {
 289                 *channel->control = reg & 0xf;
 290                 fast_iob(); RECOVERY_DELAY;
 291         }
 292         *channel->control = value;
 293         fast_iob(); RECOVERY_DELAY;
 294         return;
 295 }
 296
 297 static inline unsigned char read_zsdata(struct dec_zschannel *channel)
 298 {
 299         unsigned char retval;
 300
 301         retval = *channel->data;
 302         RECOVERY_DELAY;
 303         return retval;
 304 }
 305
 306 static inline void write_zsdata(struct dec_zschannel *channel,
 307                                 unsigned char value)
 308 {
 309         *channel->data = value;
 310         fast_iob(); RECOVERY_DELAY;
 311         return;
 312 }
 313
 314 static inline void load_zsregs(struct dec_zschannel *channel,
 315                                unsigned char *regs)
 316 {
 317 /*      ZS_CLEARERR(channel);
 318         ZS_CLEARFIFO(channel); */
 319         /* Load 'em up */
 320         write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
 321         write_zsreg(channel, R5, regs[R5] & ~TxENAB);
 322         write_zsreg(channel, R4, regs[R4]);
 323         write_zsreg(channel, R9, regs[R9]);
 324         write_zsreg(channel, R1, regs[R1]);
 325         write_zsreg(channel, R2, regs[R2]);
 326         write_zsreg(channel, R10, regs[R10]);
 327         write_zsreg(channel, R11, regs[R11]);
 328         write_zsreg(channel, R12, regs[R12]);
 329         write_zsreg(channel, R13, regs[R13]);
 330         write_zsreg(channel, R14, regs[R14]);
 331         write_zsreg(channel, R15, regs[R15]);
 332         write_zsreg(channel, R3, regs[R3]);
 333         write_zsreg(channel, R5, regs[R5]);
 334         return;
 335 }
 336
 337 /* Sets or clears DTR/RTS on the requested line */
 338 static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
 339 {
 340         unsigned long flags;
 341
 342
 343         save_flags(flags); cli();
 344         if (info->zs_channel != info->zs_chan_a) {
 345                 if (set) {
 346                         info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
 347                 } else {
 348                         info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
 349                 }
 350                 write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
 351         }
 352         restore_flags(flags);
 353 }
 354
 355 /* Utility routines for the Zilog */
 356 static inline int get_zsbaud(struct dec_serial *ss)
 357 {
 358         struct dec_zschannel *channel = ss->zs_channel;
 359         int brg;
 360
 361         /* The baud rate is split up between two 8-bit registers in
 362          * what is termed 'BRG time constant' format in my docs for
 363          * the chip, it is a function of the clk rate the chip is
 364          * receiving which happens to be constant.
 365          */
 366         brg = (read_zsreg(channel, 13) << 8);
 367         brg |= read_zsreg(channel, 12);
 368         return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
 369 }
 370
 371 /* On receive, this clears errors and the receiver interrupts */
 372 static inline void rs_recv_clear(struct dec_zschannel *zsc)
 373 {
 374         write_zsreg(zsc, 0, ERR_RES);
 375         write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
 376 }
 377
 378 /*
 379  * ----------------------------------------------------------------------
 380  *
 381  * Here starts the interrupt handling routines.  All of the following
 382  * subroutines are declared as inline and are folded into
 383  * rs_interrupt().  They were separated out for readability's sake.
 384  *
 385  *                              - Ted Ts'o (tytso@mit.edu), 7-Mar-93
 386  * -----------------------------------------------------------------------
 387  */
 388
 389 static int tty_break;   /* Set whenever BREAK condition is detected.  */
 390
 391 /*
 392  * This routine is used by the interrupt handler to schedule
 393  * processing in the software interrupt portion of the driver.
 394  */
 395 static _INLINE_ void rs_sched_event(struct dec_serial *info,
 396                                   int event)
 397 {
 398         info->event |= 1 << event;
 399         queue_task(&info->tqueue, &tq_zs_serial);
 400         mark_bh(SERIAL_BH);
 401 }
 402
 403 static _INLINE_ void receive_chars(struct dec_serial *info,
 404                                    struct pt_regs *regs)
 405 {
 406         struct tty_struct *tty = info->tty;
 407         unsigned char ch, stat, flag;
 408
 409         while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
 410
 411                 stat = read_zsreg(info->zs_channel, R1);
 412                 ch = read_zsdata(info->zs_channel);
 413
 414                 if (!tty && (!info->hook || !info->hook->rx_char))
 415                         continue;
 416
 417                 if (tty_break) {
 418                         tty_break = 0;
 419 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && !defined(MODULE)
 420                         if (info->line == sercons.index) {
 421                                 if (!break_pressed) {
 422                                         break_pressed = jiffies;
 423                                         goto ignore_char;
 424                                 }
 425                                 break_pressed = 0;
 426                         }
 427 #endif
 428                         flag = TTY_BREAK;
 429                         if (info->flags & ZILOG_SAK)
 430                                 do_SAK(tty);
 431                 } else {
 432                         if (stat & Rx_OVR) {
 433                                 flag = TTY_OVERRUN;
 434                         } else if (stat & FRM_ERR) {
 435                                 flag = TTY_FRAME;
 436                         } else if (stat & PAR_ERR) {
 437                                 flag = TTY_PARITY;
 438                         } else
 439                                 flag = 0;
 440                         if (flag)
 441                                 /* reset the error indication */
 442                                 write_zsreg(info->zs_channel, R0, ERR_RES);
 443                 }
 444
 445 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && !defined(MODULE)
 446                 if (break_pressed && info->line == sercons.index) {
 447                         if (ch != 0 &&
 448                             time_before(jiffies, break_pressed + HZ*5)) {
 449                                 handle_sysrq(ch, regs, NULL, NULL);
 450                                 break_pressed = 0;
 451                                 goto ignore_char;
 452                         }
 453                         break_pressed = 0;
 454                 }
 455 #endif
 456
 457                 if (info->hook && info->hook->rx_char) {
 458                         (*info->hook->rx_char)(ch, flag);
 459                         return;
 460                 }
 461
 462                 if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
 463                         static int flip_buf_ovf;
 464                         ++flip_buf_ovf;
 465                         continue;
 466                 }
 467                 tty->flip.count++;
 468                 {
 469                         static int flip_max_cnt;
 470                         if (flip_max_cnt < tty->flip.count)
 471                                 flip_max_cnt = tty->flip.count;
 472                 }
 473
 474                 *tty->flip.flag_buf_ptr++ = flag;
 475                 *tty->flip.char_buf_ptr++ = ch;
 476 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && !defined(MODULE)
 477         ignore_char:
 478 #endif
 479         }
 480         if (tty)
 481                 tty_flip_buffer_push(tty);
 482 }
 483
 484 static void transmit_chars(struct dec_serial *info)
 485 {
 486         if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
 487                 return;
 488         info->tx_active = 0;
 489
 490         if (info->x_char) {
 491                 /* Send next char */
 492                 write_zsdata(info->zs_channel, info->x_char);
 493                 info->x_char = 0;
 494                 info->tx_active = 1;
 495                 return;
 496         }
 497
 498         if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
 499             || info->tx_stopped) {
 500                 write_zsreg(info->zs_channel, R0, RES_Tx_P);
 501                 return;
 502         }
 503         /* Send char */
 504         write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
 505         info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 506         info->xmit_cnt--;
 507         info->tx_active = 1;
 508
 509         if (info->xmit_cnt < WAKEUP_CHARS)
 510                 rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
 511 }
 512
 513 static _INLINE_ void status_handle(struct dec_serial *info)
 514 {
 515         unsigned char stat;
 516
 517         /* Get status from Read Register 0 */
 518         stat = read_zsreg(info->zs_channel, R0);
 519
 520         if (stat & BRK_ABRT) {
 521 #ifdef SERIAL_DEBUG_INTR
 522                 printk("handling break....");
 523 #endif
 524                 tty_break = 1;
 525         }
 526
 527         if (info->zs_channel != info->zs_chan_a) {
 528
 529                 /* Check for DCD transitions */
 530                 if (info->tty && !C_CLOCAL(info->tty) &&
 531                     ((stat ^ info->read_reg_zero) & DCD) != 0 ) {
 532                         if (stat & DCD) {
 533                                 wake_up_interruptible(&info->open_wait);
 534                         } else if (!(info->flags & ZILOG_CALLOUT_ACTIVE)) {
 535                                 tty_hangup(info->tty);
 536                         }
 537                 }
 538
 539                 /* Check for CTS transitions */
 540                 if (info->tty && C_CRTSCTS(info->tty)) {
 541                         if ((stat & CTS) != 0) {
 542                                 if (info->tx_stopped) {
 543                                         info->tx_stopped = 0;
 544                                         if (!info->tx_active)
 545                                                 transmit_chars(info);
 546                                 }
 547                         } else {
 548                                 info->tx_stopped = 1;
 549                         }
 550                 }
 551
 552         }
 553
 554         /* Clear status condition... */
 555         write_zsreg(info->zs_channel, R0, RES_EXT_INT);
 556         info->read_reg_zero = stat;
 557 }
 558
 559 /*
 560  * This is the serial driver's generic interrupt routine
 561  */
 562 void rs_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 563 {
 564         struct dec_serial *info = (struct dec_serial *) dev_id;
 565         unsigned char zs_intreg;
 566         int shift;
 567
 568         /* NOTE: The read register 3, which holds the irq status,
 569          *       does so for both channels on each chip.  Although
 570          *       the status value itself must be read from the A
 571          *       channel and is only valid when read from channel A.
 572          *       Yes... broken hardware...
 573          */
 574 #define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
 575
 576         if (info->zs_chan_a == info->zs_channel)
 577                 shift = 3;      /* Channel A */
 578         else
 579                 shift = 0;      /* Channel B */
 580
 581         for (;;) {
 582                 zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
 583                 if ((zs_intreg & CHAN_IRQMASK) == 0)
 584                         break;
 585
 586                 if (zs_intreg & CHBRxIP) {
 587                         receive_chars(info, regs);
 588                 }
 589                 if (zs_intreg & CHBTxIP) {
 590                         transmit_chars(info);
 591                 }
 592                 if (zs_intreg & CHBEXT) {
 593                         status_handle(info);
 594                 }
 595         }
 596
 597         /* Why do we need this ? */
 598         write_zsreg(info->zs_channel, 0, RES_H_IUS);
 599 }
 600
 601 #ifdef ZS_DEBUG_REGS
 602 void zs_dump (void) {
 603         int i, j;
 604         for (i = 0; i < zs_channels_found; i++) {
 605                 struct dec_zschannel *ch = &zs_channels[i];
 606                 if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
 607                         for (j = 0; j < 15; j++) {
 608                                 printk("W%d = 0x%x\t",
 609                                        j, (int)ch->curregs[j]);
 610                         }
 611                         for (j = 0; j < 15; j++) {
 612                                 printk("R%d = 0x%x\t",
 613                                        j, (int)read_zsreg(ch,j));
 614                         }
 615                         printk("\n\n");
 616                 }
 617         }
 618 }
 619 #endif
 620
 621 /*
 622  * -------------------------------------------------------------------
 623  * Here ends the serial interrupt routines.
 624  * -------------------------------------------------------------------
 625  */
 626
 627 /*
 628  * ------------------------------------------------------------
 629  * rs_stop() and rs_start()
 630  *
 631  * This routines are called before setting or resetting tty->stopped.
 632  * ------------------------------------------------------------
 633  */
 634 static void rs_stop(struct tty_struct *tty)
 635 {
 636         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 637         unsigned long flags;
 638
 639         if (serial_paranoia_check(info, tty->device, "rs_stop"))
 640                 return;
 641
 642 #if 1
 643         save_flags(flags); cli();
 644         if (info->zs_channel->curregs[5] & TxENAB) {
 645                 info->zs_channel->curregs[5] &= ~TxENAB;
 646                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 647         }
 648         restore_flags(flags);
 649 #endif
 650 }
 651
 652 static void rs_start(struct tty_struct *tty)
 653 {
 654         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 655         unsigned long flags;
 656
 657         if (serial_paranoia_check(info, tty->device, "rs_start"))
 658                 return;
 659
 660         save_flags(flags); cli();
 661 #if 1
 662         if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
 663                 info->zs_channel->curregs[5] |= TxENAB;
 664                 write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 665         }
 666 #else
 667         if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
 668                 transmit_chars(info);
 669         }
 670 #endif
 671         restore_flags(flags);
 672 }
 673
 674 /*
 675  * This routine is used to handle the "bottom half" processing for the
 676  * serial driver, known also the "software interrupt" processing.
 677  * This processing is done at the kernel interrupt level, after the
 678  * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
 679  * is where time-consuming activities which can not be done in the
 680  * interrupt driver proper are done; the interrupt driver schedules
 681  * them using rs_sched_event(), and they get done here.
 682  */
 683 static void do_serial_bh(void)
 684 {
 685         run_task_queue(&tq_zs_serial);
 686 }
 687
 688 static void do_softint(void *private_)
 689 {
 690         struct dec_serial       *info = (struct dec_serial *) private_;
 691         struct tty_struct       *tty;
 692
 693         tty = info->tty;
 694         if (!tty)
 695                 return;
 696
 697         if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
 698                 tty_wakeup(tty);
 699         }
 700 }
 701
 702 int zs_startup(struct dec_serial * info)
 703 {
 704         unsigned long flags;
 705
 706         if (info->flags & ZILOG_INITIALIZED)
 707                 return 0;
 708
 709         if (!info->xmit_buf) {
 710                 info->xmit_buf = (unsigned char *) get_free_page(GFP_KERNEL);
 711                 if (!info->xmit_buf)
 712                         return -ENOMEM;
 713         }
 714
 715         save_flags(flags); cli();
 716
 717 #ifdef SERIAL_DEBUG_OPEN
 718         printk("starting up ttyS%02d (irq %d)...", info->line, info->irq);
 719 #endif
 720
 721         /*
 722          * Clear the receive FIFO.
 723          */
 724         ZS_CLEARFIFO(info->zs_channel);
 725         info->xmit_fifo_size = 1;
 726
 727         /*
 728          * Clear the interrupt registers.
 729          */
 730         write_zsreg(info->zs_channel, R0, ERR_RES);
 731         write_zsreg(info->zs_channel, R0, RES_H_IUS);
 732
 733         /*
 734          * Set the speed of the serial port
 735          */
 736         change_speed(info);
 737
 738         /*
 739          * Turn on RTS and DTR.
 740          */
 741         zs_rtsdtr(info, RTS | DTR, 1);
 742
 743         /*
 744          * Finally, enable sequencing and interrupts
 745          */
 746         info->zs_channel->curregs[R1] &= ~RxINT_MASK;
 747         info->zs_channel->curregs[R1] |= (RxINT_ALL | TxINT_ENAB |
 748                                           EXT_INT_ENAB);
 749         info->zs_channel->curregs[R3] |= RxENABLE;
 750         info->zs_channel->curregs[R5] |= TxENAB;
 751         info->zs_channel->curregs[R15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
 752         write_zsreg(info->zs_channel, R1, info->zs_channel->curregs[R1]);
 753         write_zsreg(info->zs_channel, R3, info->zs_channel->curregs[R3]);
 754         write_zsreg(info->zs_channel, R5, info->zs_channel->curregs[R5]);
 755         write_zsreg(info->zs_channel, R15, info->zs_channel->curregs[R15]);
 756
 757         /*
 758          * And clear the interrupt registers again for luck.
 759          */
 760         write_zsreg(info->zs_channel, R0, ERR_RES);
 761         write_zsreg(info->zs_channel, R0, RES_H_IUS);
 762
 763         /* Save the current value of RR0 */
 764         info->read_reg_zero = read_zsreg(info->zs_channel, R0);
 765
 766         if (info->tty)
 767                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
 768         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 769
 770         info->flags |= ZILOG_INITIALIZED;
 771         restore_flags(flags);
 772         return 0;
 773 }
 774
 775 /*
 776  * This routine will shutdown a serial port; interrupts are disabled, and
 777  * DTR is dropped if the hangup on close termio flag is on.
 778  */
 779 static void shutdown(struct dec_serial * info)
 780 {
 781         unsigned long   flags;
 782
 783         if (!(info->flags & ZILOG_INITIALIZED))
 784                 return;
 785
 786 #ifdef SERIAL_DEBUG_OPEN
 787         printk("Shutting down serial port %d (irq %d)....", info->line,
 788                info->irq);
 789 #endif
 790
 791         save_flags(flags); cli(); /* Disable interrupts */
 792
 793         if (info->xmit_buf) {
 794                 free_page((unsigned long) info->xmit_buf);
 795                 info->xmit_buf = 0;
 796         }
 797
 798         info->zs_channel->curregs[1] = 0;
 799         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]); /* no interrupts */
 800
 801         info->zs_channel->curregs[3] &= ~RxENABLE;
 802         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
 803
 804         info->zs_channel->curregs[5] &= ~TxENAB;
 805         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
 806         if (!info->tty || C_HUPCL(info->tty)) {
 807                 zs_rtsdtr(info, RTS | DTR, 0);
 808         }
 809
 810         if (info->tty)
 811                 set_bit(TTY_IO_ERROR, &info->tty->flags);
 812
 813         info->flags &= ~ZILOG_INITIALIZED;
 814         restore_flags(flags);
 815 }
 816
 817 /*
 818  * This routine is called to set the UART divisor registers to match
 819  * the specified baud rate for a serial port.
 820  */
 821 static void change_speed(struct dec_serial *info)
 822 {
 823         unsigned cflag;
 824         int     i;
 825         int     brg, bits;
 826         unsigned long flags;
 827
 828         if (!info->hook) {
 829                 if (!info->tty || !info->tty->termios)
 830                         return;
 831                 cflag = info->tty->termios->c_cflag;
 832                 if (!info->port)
 833                         return;
 834         } else {
 835                 cflag = info->hook->cflags;
 836         }
 837
 838         i = cflag & CBAUD;
 839         if (i & CBAUDEX) {
 840                 i &= ~CBAUDEX;
 841                 if (i < 1 || i > 2) {
 842                         if (!info->hook)
 843                                 info->tty->termios->c_cflag &= ~CBAUDEX;
 844                         else
 845                                 info->hook->cflags &= ~CBAUDEX;
 846                 } else
 847                         i += 15;
 848         }
 849
 850         save_flags(flags); cli();
 851         info->zs_baud = baud_table[i];
 852         if (info->zs_baud) {
 853                 brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
 854                 info->zs_channel->curregs[12] = (brg & 255);
 855                 info->zs_channel->curregs[13] = ((brg >> 8) & 255);
 856                 zs_rtsdtr(info, DTR, 1);
 857         } else {
 858                 zs_rtsdtr(info, RTS | DTR, 0);
 859                 return;
 860         }
 861
 862         /* byte size and parity */
 863         info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
 864         info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
 865         switch (cflag & CSIZE) {
 866         case CS5:
 867                 bits = 7;
 868                 info->zs_channel->curregs[3] |= Rx5;
 869                 info->zs_channel->curregs[5] |= Tx5;
 870                 break;
 871         case CS6:
 872                 bits = 8;
 873                 info->zs_channel->curregs[3] |= Rx6;
 874                 info->zs_channel->curregs[5] |= Tx6;
 875                 break;
 876         case CS7:
 877                 bits = 9;
 878                 info->zs_channel->curregs[3] |= Rx7;
 879                 info->zs_channel->curregs[5] |= Tx7;
 880                 break;
 881         case CS8:
 882         default: /* defaults to 8 bits */
 883                 bits = 10;
 884                 info->zs_channel->curregs[3] |= Rx8;
 885                 info->zs_channel->curregs[5] |= Tx8;
 886                 break;
 887         }
 888
 889         info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
 890         info->timeout += HZ/50;         /* Add .02 seconds of slop */
 891
 892         info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
 893         if (cflag & CSTOPB) {
 894                 info->zs_channel->curregs[4] |= SB2;
 895         } else {
 896                 info->zs_channel->curregs[4] |= SB1;
 897         }
 898         if (cflag & PARENB) {
 899                 info->zs_channel->curregs[4] |= PAR_ENA;
 900         }
 901         if (!(cflag & PARODD)) {
 902                 info->zs_channel->curregs[4] |= PAR_EVEN;
 903         }
 904
 905         if (!(cflag & CLOCAL)) {
 906                 if (!(info->zs_channel->curregs[15] & DCDIE))
 907                         info->read_reg_zero = read_zsreg(info->zs_channel, 0);
 908                 info->zs_channel->curregs[15] |= DCDIE;
 909         } else
 910                 info->zs_channel->curregs[15] &= ~DCDIE;
 911         if (cflag & CRTSCTS) {
 912                 info->zs_channel->curregs[15] |= CTSIE;
 913                 if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
 914                         info->tx_stopped = 1;
 915         } else {
 916                 info->zs_channel->curregs[15] &= ~CTSIE;
 917                 info->tx_stopped = 0;
 918         }
 919
 920         /* Load up the new values */
 921         load_zsregs(info->zs_channel, info->zs_channel->curregs);
 922
 923         restore_flags(flags);
 924 }
 925
 926 static void rs_flush_chars(struct tty_struct *tty)
 927 {
 928         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 929         unsigned long flags;
 930
 931         if (serial_paranoia_check(info, tty->device, "rs_flush_chars"))
 932                 return;
 933
 934         if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
 935             !info->xmit_buf)
 936                 return;
 937
 938         /* Enable transmitter */
 939         save_flags(flags); cli();
 940         transmit_chars(info);
 941         restore_flags(flags);
 942 }
 943
 944 static int rs_write(struct tty_struct * tty, int from_user,
 945                     const unsigned char *buf, int count)
 946 {
 947         int     c, total = 0;
 948         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 949         unsigned long flags;
 950
 951         if (serial_paranoia_check(info, tty->device, "rs_write"))
 952                 return 0;
 953
 954         if (!tty || !info->xmit_buf)
 955                 return 0;
 956
 957         save_flags(flags);
 958         while (1) {
 959                 cli();
 960                 c = MIN(count, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 961                                    SERIAL_XMIT_SIZE - info->xmit_head));
 962                 if (c <= 0)
 963                         break;
 964
 965                 if (from_user) {
 966                         down(&tmp_buf_sem);
 967                         copy_from_user(tmp_buf, buf, c);
 968                         c = MIN(c, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 969                                        SERIAL_XMIT_SIZE - info->xmit_head));
 970                         memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
 971                         up(&tmp_buf_sem);
 972                 } else
 973                         memcpy(info->xmit_buf + info->xmit_head, buf, c);
 974                 info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
 975                 info->xmit_cnt += c;
 976                 restore_flags(flags);
 977                 buf += c;
 978                 count -= c;
 979                 total += c;
 980         }
 981
 982         if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
 983             && !info->tx_active)
 984                 transmit_chars(info);
 985         restore_flags(flags);
 986         return total;
 987 }
 988
 989 static int rs_write_room(struct tty_struct *tty)
 990 {
 991         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
 992         int     ret;
 993
 994         if (serial_paranoia_check(info, tty->device, "rs_write_room"))
 995                 return 0;
 996         ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
 997         if (ret < 0)
 998                 ret = 0;
 999         return ret;
1000 }
1001
1002 static int rs_chars_in_buffer(struct tty_struct *tty)
1003 {
1004         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1005
1006         if (serial_paranoia_check(info, tty->device, "rs_chars_in_buffer"))
1007                 return 0;
1008         return info->xmit_cnt;
1009 }
1010
1011 static void rs_flush_buffer(struct tty_struct *tty)
1012 {
1013         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1014
1015         if (serial_paranoia_check(info, tty->device, "rs_flush_buffer"))
1016                 return;
1017         cli();
1018         info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
1019         sti();
1020         tty_wakeup(tty);
1021 }
1022
1023 /*
1024  * ------------------------------------------------------------
1025  * rs_throttle()
1026  *
1027  * This routine is called by the upper-layer tty layer to signal that
1028  * incoming characters should be throttled.
1029  * ------------------------------------------------------------
1030  */
1031 static void rs_throttle(struct tty_struct * tty)
1032 {
1033         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1034         unsigned long flags;
1035
1036 #ifdef SERIAL_DEBUG_THROTTLE
1037         char    buf[64];
1038
1039         printk("throttle %s: %d....\n", _tty_name(tty, buf),
1040                tty->ldisc.chars_in_buffer(tty));
1041 #endif
1042
1043         if (serial_paranoia_check(info, tty->device, "rs_throttle"))
1044                 return;
1045
1046         if (I_IXOFF(tty)) {
1047                 save_flags(flags); cli();
1048                 info->x_char = STOP_CHAR(tty);
1049                 if (!info->tx_active)
1050                         transmit_chars(info);
1051                 restore_flags(flags);
1052         }
1053
1054         if (C_CRTSCTS(tty)) {
1055                 zs_rtsdtr(info, RTS, 0);
1056         }
1057 }
1058
1059 static void rs_unthrottle(struct tty_struct * tty)
1060 {
1061         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1062         unsigned long flags;
1063
1064 #ifdef SERIAL_DEBUG_THROTTLE
1065         char    buf[64];
1066
1067         printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
1068                tty->ldisc.chars_in_buffer(tty));
1069 #endif
1070
1071         if (serial_paranoia_check(info, tty->device, "rs_unthrottle"))
1072                 return;
1073
1074         if (I_IXOFF(tty)) {
1075                 save_flags(flags); cli();
1076                 if (info->x_char)
1077                         info->x_char = 0;
1078                 else {
1079                         info->x_char = START_CHAR(tty);
1080                         if (!info->tx_active)
1081                                 transmit_chars(info);
1082                 }
1083                 restore_flags(flags);
1084         }
1085
1086         if (C_CRTSCTS(tty)) {
1087                 zs_rtsdtr(info, RTS, 1);
1088         }
1089 }
1090
1091 /*
1092  * ------------------------------------------------------------
1093  * rs_ioctl() and friends
1094  * ------------------------------------------------------------
1095  */
1096
1097 static int get_serial_info(struct dec_serial * info,
1098                            struct serial_struct * retinfo)
1099 {
1100         struct serial_struct tmp;
1101
1102         if (!retinfo)
1103                 return -EFAULT;
1104         memset(&tmp, 0, sizeof(tmp));
1105         tmp.type = info->type;
1106         tmp.line = info->line;
1107         tmp.port = info->port;
1108         tmp.irq = info->irq;
1109         tmp.flags = info->flags;
1110         tmp.baud_base = info->baud_base;
1111         tmp.close_delay = info->close_delay;
1112         tmp.closing_wait = info->closing_wait;
1113         tmp.custom_divisor = info->custom_divisor;
1114         return copy_to_user(retinfo,&tmp,sizeof(*retinfo));
1115 }
1116
1117 static int set_serial_info(struct dec_serial * info,
1118                            struct serial_struct * new_info)
1119 {
1120         struct serial_struct new_serial;
1121         struct dec_serial old_info;
1122         int                     retval = 0;
1123
1124         if (!new_info)
1125                 return -EFAULT;
1126         copy_from_user(&new_serial,new_info,sizeof(new_serial));
1127         old_info = *info;
1128
1129         if (!capable(CAP_SYS_ADMIN)) {
1130                 if ((new_serial.baud_base != info->baud_base) ||
1131                     (new_serial.type != info->type) ||
1132                     (new_serial.close_delay != info->close_delay) ||
1133                     ((new_serial.flags & ~ZILOG_USR_MASK) !=
1134                      (info->flags & ~ZILOG_USR_MASK)))
1135                         return -EPERM;
1136                 info->flags = ((info->flags & ~ZILOG_USR_MASK) |
1137                                (new_serial.flags & ZILOG_USR_MASK));
1138                 info->custom_divisor = new_serial.custom_divisor;
1139                 goto check_and_exit;
1140         }
1141
1142         if (info->count > 1)
1143                 return -EBUSY;
1144
1145         /*
1146          * OK, past this point, all the error checking has been done.
1147          * At this point, we start making changes.....
1148          */
1149
1150         info->baud_base = new_serial.baud_base;
1151         info->flags = ((info->flags & ~ZILOG_FLAGS) |
1152                         (new_serial.flags & ZILOG_FLAGS));
1153         info->type = new_serial.type;
1154         info->close_delay = new_serial.close_delay;
1155         info->closing_wait = new_serial.closing_wait;
1156
1157 check_and_exit:
1158         retval = zs_startup(info);
1159         return retval;
1160 }
1161
1162 /*
1163  * get_lsr_info - get line status register info
1164  *
1165  * Purpose: Let user call ioctl() to get info when the UART physically
1166  *          is emptied.  On bus types like RS485, the transmitter must
1167  *          release the bus after transmitting. This must be done when
1168  *          the transmit shift register is empty, not be done when the
1169  *          transmit holding register is empty.  This functionality
1170  *          allows an RS485 driver to be written in user space.
1171  */
1172 static int get_lsr_info(struct dec_serial * info, unsigned int *value)
1173 {
1174         unsigned char status;
1175
1176         cli();
1177         status = read_zsreg(info->zs_channel, 0);
1178         sti();
1179         put_user(status,value);
1180         return 0;
1181 }
1182
1183 static int get_modem_info(struct dec_serial *info, unsigned int *value)
1184 {
1185         unsigned char control, status_a, status_b;
1186         unsigned int result;
1187
1188         if (info->zs_channel == info->zs_chan_a)
1189                 result = 0;
1190         else {
1191                 cli();
1192                 control = info->zs_chan_a->curregs[5];
1193                 status_a = read_zsreg(info->zs_chan_a, 0);
1194                 status_b = read_zsreg(info->zs_channel, 0);
1195                 sti();
1196                 result =  ((control  & RTS) ? TIOCM_RTS: 0)
1197                         | ((control  & DTR) ? TIOCM_DTR: 0)
1198                         | ((status_b & DCD) ? TIOCM_CAR: 0)
1199                         | ((status_a & DCD) ? TIOCM_RNG: 0)
1200                         | ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
1201                         | ((status_b & CTS) ? TIOCM_CTS: 0);
1202         }
1203         put_user(result, value);
1204         return 0;
1205 }
1206
1207 static int set_modem_info(struct dec_serial *info, unsigned int cmd,
1208                           unsigned int *value)
1209 {
1210         int error;
1211         unsigned int arg, bits;
1212
1213         error = verify_area(VERIFY_READ, value, sizeof(int));
1214         if (error)
1215                 return error;
1216
1217         if (info->zs_channel == info->zs_chan_a)
1218                 return 0;
1219
1220         get_user(arg, value);
1221         bits = (arg & TIOCM_RTS? RTS: 0) + (arg & TIOCM_DTR? DTR: 0);
1222         cli();
1223         switch (cmd) {
1224         case TIOCMBIS:
1225                 info->zs_chan_a->curregs[5] |= bits;
1226                 break;
1227         case TIOCMBIC:
1228                 info->zs_chan_a->curregs[5] &= ~bits;
1229                 break;
1230         case TIOCMSET:
1231                 info->zs_chan_a->curregs[5] =
1232                         (info->zs_chan_a->curregs[5] & ~(DTR | RTS)) | bits;
1233                 break;
1234         default:
1235                 sti();
1236                 return -EINVAL;
1237         }
1238         write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
1239         sti();
1240         return 0;
1241 }
1242
1243 /*
1244  * rs_break - turn transmit break condition on/off
1245  */
1246 static void rs_break(struct tty_struct *tty, int break_state)
1247 {
1248         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1249         unsigned long flags;
1250
1251         if (serial_paranoia_check(info, tty->device, "rs_break"))
1252                 return;
1253         if (!info->port)
1254                 return;
1255
1256         save_flags(flags); cli();
1257         if (break_state == -1)
1258                 info->zs_channel->curregs[5] |= SND_BRK;
1259         else
1260                 info->zs_channel->curregs[5] &= ~SND_BRK;
1261         write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
1262         restore_flags(flags);
1263 }
1264
1265 static int rs_ioctl(struct tty_struct *tty, struct file * file,
1266                     unsigned int cmd, unsigned long arg)
1267 {
1268         int error;
1269         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1270
1271         if (info->hook)
1272                 return -ENODEV;
1273
1274         if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
1275                 return -ENODEV;
1276
1277         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1278             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
1279             (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
1280                 if (tty->flags & (1 << TTY_IO_ERROR))
1281                     return -EIO;
1282         }
1283
1284         switch (cmd) {
1285                 case TIOCMGET:
1286                         error = verify_area(VERIFY_WRITE, (void *) arg,
1287                                 sizeof(unsigned int));
1288                         if (error)
1289                                 return error;
1290                         return get_modem_info(info, (unsigned int *) arg);
1291                 case TIOCMBIS:
1292                 case TIOCMBIC:
1293                 case TIOCMSET:
1294                         return set_modem_info(info, cmd, (unsigned int *) arg);
1295                 case TIOCGSERIAL:
1296                         error = verify_area(VERIFY_WRITE, (void *) arg,
1297                                                 sizeof(struct serial_struct));
1298                         if (error)
1299                                 return error;
1300                         return get_serial_info(info,
1301                                                (struct serial_struct *) arg);
1302                 case TIOCSSERIAL:
1303                         return set_serial_info(info,
1304                                                (struct serial_struct *) arg);
1305                 case TIOCSERGETLSR: /* Get line status register */
1306                         error = verify_area(VERIFY_WRITE, (void *) arg,
1307                                 sizeof(unsigned int));
1308                         if (error)
1309                                 return error;
1310                         else
1311                             return get_lsr_info(info, (unsigned int *) arg);
1312
1313                 case TIOCSERGSTRUCT:
1314                         error = verify_area(VERIFY_WRITE, (void *) arg,
1315                                                 sizeof(struct dec_serial));
1316                         if (error)
1317                                 return error;
1318                         copy_from_user((struct dec_serial *) arg,
1319                                        info, sizeof(struct dec_serial));
1320                         return 0;
1321
1322                 default:
1323                         return -ENOIOCTLCMD;
1324                 }
1325         return 0;
1326 }
1327
1328 static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
1329 {
1330         struct dec_serial *info = (struct dec_serial *)tty->driver_data;
1331         int was_stopped;
1332
1333         if (tty->termios->c_cflag == old_termios->c_cflag)
1334                 return;
1335         was_stopped = info->tx_stopped;
1336
1337         change_speed(info);
1338
1339         if (was_stopped && !info->tx_stopped)
1340                 rs_start(tty);
1341 }
1342
1343 /*
1344  * ------------------------------------------------------------
1345  * rs_close()
1346  *
1347  * This routine is called when the serial port gets closed.
1348  * Wait for the last remaining data to be sent.
1349  * ------------------------------------------------------------
1350  */
1351 static void rs_close(struct tty_struct *tty, struct file * filp)
1352 {
1353         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1354         unsigned long flags;
1355
1356         if (!info || serial_paranoia_check(info, tty->device, "rs_close"))
1357                 return;
1358
1359         save_flags(flags); cli();
1360
1361         if (tty_hung_up_p(filp)) {
1362                 restore_flags(flags);
1363                 return;
1364         }
1365
1366 #ifdef SERIAL_DEBUG_OPEN
1367         printk("rs_close ttyS%02d, count = %d\n", info->line, info->count);
1368 #endif
1369         if ((tty->count == 1) && (info->count != 1)) {
1370                 /*
1371                  * Uh, oh.  tty->count is 1, which means that the tty
1372                  * structure will be freed.  Info->count should always
1373                  * be one in these conditions.  If it's greater than
1374                  * one, we've got real problems, since it means the
1375                  * serial port won't be shutdown.
1376                  */
1377                 printk("rs_close: bad serial port count; tty->count is 1, "
1378                        "info->count is %d\n", info->count);
1379                 info->count = 1;
1380         }
1381         if (--info->count < 0) {
1382                 printk("rs_close: bad serial port count for ttyS%02d: %d\n",
1383                        info->line, info->count);
1384                 info->count = 0;
1385         }
1386         if (info->count) {
1387                 restore_flags(flags);
1388                 return;
1389         }
1390         info->flags |= ZILOG_CLOSING;
1391         /*
1392          * Save the termios structure, since this port may have
1393          * separate termios for callout and dialin.
1394          */
1395         if (info->flags & ZILOG_NORMAL_ACTIVE)
1396                 info->normal_termios = *tty->termios;
1397         if (info->flags & ZILOG_CALLOUT_ACTIVE)
1398                 info->callout_termios = *tty->termios;
1399         /*
1400          * Now we wait for the transmit buffer to clear; and we notify
1401          * the line discipline to only process XON/XOFF characters.
1402          */
1403         tty->closing = 1;
1404         if (info->closing_wait != ZILOG_CLOSING_WAIT_NONE)
1405                 tty_wait_until_sent(tty, info->closing_wait);
1406         /*
1407          * At this point we stop accepting input.  To do this, we
1408          * disable the receiver and receive interrupts.
1409          */
1410         info->zs_channel->curregs[3] &= ~RxENABLE;
1411         write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
1412         info->zs_channel->curregs[1] = 0;       /* disable any rx ints */
1413         write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
1414         ZS_CLEARFIFO(info->zs_channel);
1415         if (info->flags & ZILOG_INITIALIZED) {
1416                 /*
1417                  * Before we drop DTR, make sure the SCC transmitter
1418                  * has completely drained.
1419                  */
1420                 rs_wait_until_sent(tty, info->timeout);
1421         }
1422
1423         shutdown(info);
1424         if (tty->driver.flush_buffer)
1425                 tty->driver.flush_buffer(tty);
1426         tty_ldisc_flush(tty);
1427         tty->closing = 0;
1428         info->event = 0;
1429         info->tty = 0;
1430         if (info->blocked_open) {
1431                 if (info->close_delay) {
1432                         current->state = TASK_INTERRUPTIBLE;
1433                         schedule_timeout(info->close_delay);
1434                 }
1435                 wake_up_interruptible(&info->open_wait);
1436         }
1437         info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CALLOUT_ACTIVE|
1438                          ZILOG_CLOSING);
1439         wake_up_interruptible(&info->close_wait);
1440         restore_flags(flags);
1441 }
1442
1443 /*
1444  * rs_wait_until_sent() --- wait until the transmitter is empty
1445  */
1446 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1447 {
1448         struct dec_serial *info = (struct dec_serial *) tty->driver_data;
1449         unsigned long orig_jiffies, char_time;
1450
1451         if (serial_paranoia_check(info, tty->device, "rs_wait_until_sent"))
1452                 return;
1453
1454         orig_jiffies = jiffies;
1455         /*
1456          * Set the check interval to be 1/5 of the estimated time to
1457          * send a single character, and make it at least 1.  The check
1458          * interval should also be less than the timeout.
1459          */
1460         char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1461         char_time = char_time / 5;
1462         if (char_time == 0)
1463                 char_time = 1;
1464         if (timeout)
1465                 char_time = MIN(char_time, timeout);
1466         while ((read_zsreg(info->zs_channel, 1) & Tx_BUF_EMP) == 0) {
1467                 current->state = TASK_INTERRUPTIBLE;
1468                 schedule_timeout(char_time);
1469                 if (signal_pending(current))
1470                         break;
1471                 if (timeout && time_after(jiffies, orig_jiffies + timeout))
1472                         break;
1473         }
1474         current->state = TASK_RUNNING;
1475 }
1476
1477 /*
1478  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1479  */
1480 void rs_hangup(struct tty_struct *tty)
1481 {
1482         struct dec_serial * info = (struct dec_serial *)tty->driver_data;
1483
1484         if (serial_paranoia_check(info, tty->device, "rs_hangup"))
1485                 return;
1486
1487         rs_flush_buffer(tty);
1488         shutdown(info);
1489         info->event = 0;
1490         info->count = 0;
1491         info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CALLOUT_ACTIVE);
1492         info->tty = 0;
1493         wake_up_interruptible(&info->open_wait);
1494 }
1495
1496 /*
1497  * ------------------------------------------------------------
1498  * rs_open() and friends
1499  * ------------------------------------------------------------
1500  */
1501 static int block_til_ready(struct tty_struct *tty, struct file * filp,
1502                            struct dec_serial *info)
1503 {
1504         DECLARE_WAITQUEUE(wait, current);
1505         int             retval;
1506         int             do_clocal = 0;
1507
1508         /*
1509          * If the device is in the middle of being closed, then block
1510          * until it's done, and then try again.
1511          */
1512         if (info->flags & ZILOG_CLOSING) {
1513                 interruptible_sleep_on(&info->close_wait);
1514 #ifdef SERIAL_DO_RESTART
1515                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1516                         -EAGAIN : -ERESTARTSYS);
1517 #else
1518                 return -EAGAIN;
1519 #endif
1520         }
1521
1522         /*
1523          * If this is a callout device, then just make sure the normal
1524          * device isn't being used.
1525          */
1526         if (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
1527                 if (info->flags & ZILOG_NORMAL_ACTIVE)
1528                         return -EBUSY;
1529                 if ((info->flags & ZILOG_CALLOUT_ACTIVE) &&
1530                     (info->flags & ZILOG_SESSION_LOCKOUT) &&
1531                     (info->session != current->session))
1532                     return -EBUSY;
1533                 if ((info->flags & ZILOG_CALLOUT_ACTIVE) &&
1534                     (info->flags & ZILOG_PGRP_LOCKOUT) &&
1535                     (info->pgrp != current->pgrp))
1536                     return -EBUSY;
1537                 info->flags |= ZILOG_CALLOUT_ACTIVE;
1538                 return 0;
1539         }
1540
1541         /*
1542          * If non-blocking mode is set, or the port is not enabled,
1543          * then make the check up front and then exit.
1544          */
1545         if ((filp->f_flags & O_NONBLOCK) ||
1546             (tty->flags & (1 << TTY_IO_ERROR))) {
1547                 if (info->flags & ZILOG_CALLOUT_ACTIVE)
1548                         return -EBUSY;
1549                 info->flags |= ZILOG_NORMAL_ACTIVE;
1550                 return 0;
1551         }
1552
1553         if (info->flags & ZILOG_CALLOUT_ACTIVE) {
1554                 if (info->normal_termios.c_cflag & CLOCAL)
1555                         do_clocal = 1;
1556         } else {
1557                 if (tty->termios->c_cflag & CLOCAL)
1558                         do_clocal = 1;
1559         }
1560
1561         /*
1562          * Block waiting for the carrier detect and the line to become
1563          * free (i.e., not in use by the callout).  While we are in
1564          * this loop, info->count is dropped by one, so that
1565          * rs_close() knows when to free things.  We restore it upon
1566          * exit, either normal or abnormal.
1567          */
1568         retval = 0;
1569         add_wait_queue(&info->open_wait, &wait);
1570 #ifdef SERIAL_DEBUG_OPEN
1571         printk("block_til_ready before block: ttyS%02d, count = %d\n",
1572                info->line, info->count);
1573 #endif
1574         cli();
1575         if (!tty_hung_up_p(filp))
1576                 info->count--;
1577         sti();
1578         info->blocked_open++;
1579         while (1) {
1580                 cli();
1581                 if (!(info->flags & ZILOG_CALLOUT_ACTIVE) &&
1582                     (tty->termios->c_cflag & CBAUD))
1583                         zs_rtsdtr(info, RTS | DTR, 1);
1584                 sti();
1585                 set_current_state(TASK_INTERRUPTIBLE);
1586                 if (tty_hung_up_p(filp) ||
1587                     !(info->flags & ZILOG_INITIALIZED)) {
1588 #ifdef SERIAL_DO_RESTART
1589                         if (info->flags & ZILOG_HUP_NOTIFY)
1590                                 retval = -EAGAIN;
1591                         else
1592                                 retval = -ERESTARTSYS;
1593 #else
1594                         retval = -EAGAIN;
1595 #endif
1596                         break;
1597                 }
1598                 if (!(info->flags & ZILOG_CALLOUT_ACTIVE) &&
1599                     !(info->flags & ZILOG_CLOSING) &&
1600                     (do_clocal || (read_zsreg(info->zs_channel, 0) & DCD)))
1601                         break;
1602                 if (signal_pending(current)) {
1603                         retval = -ERESTARTSYS;
1604                         break;
1605                 }
1606 #ifdef SERIAL_DEBUG_OPEN
1607                 printk("block_til_ready blocking: ttyS%02d, count = %d\n",
1608                        info->line, info->count);
1609 #endif
1610                 schedule();
1611         }
1612         current->state = TASK_RUNNING;
1613         remove_wait_queue(&info->open_wait, &wait);
1614         if (!tty_hung_up_p(filp))
1615                 info->count++;
1616         info->blocked_open--;
1617 #ifdef SERIAL_DEBUG_OPEN
1618         printk("block_til_ready after blocking: ttyS%02d, count = %d\n",
1619                info->line, info->count);
1620 #endif
1621         if (retval)
1622                 return retval;
1623         info->flags |= ZILOG_NORMAL_ACTIVE;
1624         return 0;
1625 }
1626
1627 /*
1628  * This routine is called whenever a serial port is opened.  It
1629  * enables interrupts for a serial port, linking in its ZILOG structure into
1630  * the IRQ chain.   It also performs the serial-specific
1631  * initialization for the tty structure.
1632  */
1633 int rs_open(struct tty_struct *tty, struct file * filp)
1634 {
1635         struct dec_serial       *info;
1636         int                     retval, line;
1637
1638         line = MINOR(tty->device) - tty->driver.minor_start;
1639         if ((line < 0) || (line >= zs_channels_found))
1640                 return -ENODEV;
1641         info = zs_soft + line;
1642
1643         if (info->hook)
1644                 return -ENODEV;
1645
1646         if (serial_paranoia_check(info, tty->device, "rs_open"))
1647                 return -ENODEV;
1648 #ifdef SERIAL_DEBUG_OPEN
1649         printk("rs_open %s%d, count = %d\n", tty->driver.name, info->line,
1650                info->count);
1651 #endif
1652
1653         info->count++;
1654         tty->driver_data = info;
1655         info->tty = tty;
1656
1657         /*
1658          * If the port is the middle of closing, bail out now
1659          */
1660         if (tty_hung_up_p(filp) ||
1661             (info->flags & ZILOG_CLOSING)) {
1662                 if (info->flags & ZILOG_CLOSING)
1663                         interruptible_sleep_on(&info->close_wait);
1664 #ifdef SERIAL_DO_RESTART
1665                 return ((info->flags & ZILOG_HUP_NOTIFY) ?
1666                         -EAGAIN : -ERESTARTSYS);
1667 #else
1668                 return -EAGAIN;
1669 #endif
1670         }
1671
1672         /*
1673          * Start up serial port
1674          */
1675         retval = zs_startup(info);
1676         if (retval)
1677                 return retval;
1678
1679         retval = block_til_ready(tty, filp, info);
1680         if (retval) {
1681 #ifdef SERIAL_DEBUG_OPEN
1682                 printk("rs_open returning after block_til_ready with %d\n",
1683                        retval);
1684 #endif
1685                 return retval;
1686         }
1687
1688         if ((info->count == 1) && (info->flags & ZILOG_SPLIT_TERMIOS)) {
1689                 if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
1690                         *tty->termios = info->normal_termios;
1691                 else
1692                         *tty->termios = info->callout_termios;
1693                 change_speed(info);
1694         }
1695 #ifdef CONFIG_SERIAL_DEC_CONSOLE
1696         if (sercons.cflag && sercons.index == line) {
1697                 tty->termios->c_cflag = sercons.cflag;
1698                 sercons.cflag = 0;
1699                 change_speed(info);
1700         }
1701 #endif
1702
1703         info->session = current->session;
1704         info->pgrp = current->pgrp;
1705
1706 #ifdef SERIAL_DEBUG_OPEN
1707         printk("rs_open ttyS%02d successful...", info->line);
1708 #endif
1709 /* tty->low_latency = 1; */
1710         return 0;
1711 }
1712
1713 /* Finally, routines used to initialize the serial driver. */
1714
1715 static void __init show_serial_version(void)
1716 {
1717         printk("DECstation Z8530 serial driver version 0.08\n");
1718 }
1719
1720 /*  Initialize Z8530s zs_channels
1721  */
1722
1723 static void __init probe_sccs(void)
1724 {
1725         struct dec_serial **pp;
1726         int i, n, n_chips = 0, n_channels, chip, channel;
1727         unsigned long flags;
1728
1729         /*
1730          * did we get here by accident?
1731          */
1732         if(!BUS_PRESENT) {
1733                 printk("Not on JUNKIO machine, skipping probe_sccs\n");
1734                 return;
1735         }
1736
1737         /*
1738          * When serial console is activated, tc_init has not been called yet
1739          * and system_base is undefined. Unfortunately we have to hardcode
1740          * system_base for this case :-(. HK
1741          */
1742         switch(mips_machtype) {
1743 #ifdef CONFIG_DECSTATION
1744         case MACH_DS5000_2X0:
1745         case MACH_DS5900:
1746                 system_base = KSEG1ADDR(0x1f800000);
1747                 n_chips = 2;
1748                 zs_parms = &ds_parms;
1749                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1750                 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1751                 break;
1752         case MACH_DS5000_1XX:
1753                 system_base = KSEG1ADDR(0x1c000000);
1754                 n_chips = 2;
1755                 zs_parms = &ds_parms;
1756                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1757                 zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
1758                 break;
1759         case MACH_DS5000_XX:
1760                 system_base = KSEG1ADDR(0x1c000000);
1761                 n_chips = 1;
1762                 zs_parms = &ds_parms;
1763                 zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
1764                 break;
1765 #endif
1766 #ifdef CONFIG_BAGET_MIPS
1767         case MACH_BAGET202:
1768                 system_base = UNI_IO_BASE;
1769                 n_chips = 2;
1770                 zs_parms = &baget_parms;
1771                 zs_init_regs[2] = 0x8;
1772                 break;
1773 #endif
1774         default:
1775                 panic("zs: unsupported bus");
1776         }
1777         if (!zs_parms)
1778                 panic("zs: uninitialized parms");
1779
1780         pp = &zs_chain;
1781
1782         n_channels = 0;
1783
1784         for (chip = 0; chip < n_chips; chip++) {
1785                 for (channel = 0; channel <= 1; channel++) {
1786                         /*
1787                          * The sccs reside on the high byte of the 16 bit IOBUS
1788                          */
1789                         zs_channels[n_channels].control =
1790                                 (volatile unsigned char *)system_base +
1791                           (0 == chip ? zs_parms->scc0 : zs_parms->scc1) +
1792                           (0 == channel ? zs_parms->channel_a_offset :
1793                                           zs_parms->channel_b_offset);
1794                         zs_channels[n_channels].data =
1795                                 zs_channels[n_channels].control + 4;
1796
1797 #ifndef CONFIG_SERIAL_DEC_CONSOLE
1798                         /*
1799                          * We're called early and memory managment isn't up, yet.
1800                          * Thus check_region would fail.
1801                          */
1802                         if (check_region((unsigned long)
1803                                          zs_channels[n_channels].control,
1804                                          ZS_CHAN_IO_SIZE) < 0) {
1805                                 panic("SCC I/O region is not free");
1806                         }
1807                         request_region((unsigned long)
1808                                        zs_channels[n_channels].control,
1809                                        ZS_CHAN_IO_SIZE, "SCC");
1810 #endif
1811                         zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
1812                         /* HACK alert! */
1813                         if (!(chip & 1))
1814                                 zs_soft[n_channels].irq = zs_parms->irq0;
1815                         else
1816                                 zs_soft[n_channels].irq = zs_parms->irq1;
1817
1818                         /*
1819                          *  Identification of channel A. Location of channel A
1820                          *  inside chip depends on mapping of internal address
1821                          *  the chip decodes channels by.
1822                          *  CHANNEL_A_NR returns either 0 (in case of
1823                          *  DECstations) or 1 (in case of Baget).
1824                          */
1825                         if (CHANNEL_A_NR == channel)
1826                                 zs_soft[n_channels].zs_chan_a =
1827                                     &zs_channels[n_channels+1-2*CHANNEL_A_NR];
1828                         else
1829                                 zs_soft[n_channels].zs_chan_a =
1830                                     &zs_channels[n_channels];
1831
1832                         *pp = &zs_soft[n_channels];
1833                         pp = &zs_soft[n_channels].zs_next;
1834                         n_channels++;
1835                 }
1836         }
1837
1838         *pp = 0;
1839         zs_channels_found = n_channels;
1840
1841         for (n = 0; n < zs_channels_found; n++) {
1842                 for (i = 0; i < 16; i++) {
1843                         zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
1844                 }
1845         }
1846
1847         save_and_cli(flags);
1848         for (n = 0; n < zs_channels_found; n++) {
1849                 if (n % 2 == 0) {
1850                         write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
1851                         udelay(10);
1852                         write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
1853                 }
1854                 load_zsregs(zs_soft[n].zs_channel,
1855                             zs_soft[n].zs_channel->curregs);
1856         }
1857         restore_flags(flags);
1858 }
1859
1860 /* zs_init inits the driver */
1861 int __init zs_init(void)
1862 {
1863         int channel, i;
1864         struct dec_serial *info;
1865
1866         if(!BUS_PRESENT)
1867                 return -ENODEV;
1868
1869         /* Setup base handler, and timer table. */
1870         init_bh(SERIAL_BH, do_serial_bh);
1871
1872         /* Find out how many Z8530 SCCs we have */
1873         if (zs_chain == 0)
1874                 probe_sccs();
1875
1876         show_serial_version();
1877
1878         /* Initialize the tty_driver structure */
1879         /* Not all of this is exactly right for us. */
1880
1881         memset(&serial_driver, 0, sizeof(struct tty_driver));
1882         serial_driver.magic = TTY_DRIVER_MAGIC;
1883 #if (LINUX_VERSION_CODE > 0x2032D && defined(CONFIG_DEVFS_FS))
1884         serial_driver.name = "tts/%d";
1885 #else
1886         serial_driver.name = "ttyS";
1887 #endif
1888         serial_driver.major = TTY_MAJOR;
1889         serial_driver.minor_start = 64;
1890         serial_driver.num = zs_channels_found;
1891         serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
1892         serial_driver.subtype = SERIAL_TYPE_NORMAL;
1893         serial_driver.init_termios = tty_std_termios;
1894
1895         serial_driver.init_termios.c_cflag =
1896                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1897         serial_driver.flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
1898         serial_driver.refcount = &serial_refcount;
1899         serial_driver.table = serial_table;
1900         serial_driver.termios = serial_termios;
1901         serial_driver.termios_locked = serial_termios_locked;
1902
1903         serial_driver.open = rs_open;
1904         serial_driver.close = rs_close;
1905         serial_driver.write = rs_write;
1906         serial_driver.flush_chars = rs_flush_chars;
1907         serial_driver.write_room = rs_write_room;
1908         serial_driver.chars_in_buffer = rs_chars_in_buffer;
1909         serial_driver.flush_buffer = rs_flush_buffer;
1910         serial_driver.ioctl = rs_ioctl;
1911         serial_driver.throttle = rs_throttle;
1912         serial_driver.unthrottle = rs_unthrottle;
1913         serial_driver.set_termios = rs_set_termios;
1914         serial_driver.stop = rs_stop;
1915         serial_driver.start = rs_start;
1916         serial_driver.hangup = rs_hangup;
1917         serial_driver.break_ctl = rs_break;
1918         serial_driver.wait_until_sent = rs_wait_until_sent;
1919
1920         /*
1921          * The callout device is just like normal device except for
1922          * major number and the subtype code.
1923          */
1924         callout_driver = serial_driver;
1925 #if (LINUX_VERSION_CODE > 0x2032D && defined(CONFIG_DEVFS_FS))
1926         callout_driver.name = "cua/%d";
1927 #else
1928         callout_driver.name = "cua";
1929 #endif
1930         callout_driver.major = TTYAUX_MAJOR;
1931         callout_driver.subtype = SERIAL_TYPE_CALLOUT;
1932
1933         if (tty_register_driver(&serial_driver))
1934                 panic("Couldn't register serial driver");
1935         if (tty_register_driver(&callout_driver))
1936                 panic("Couldn't register callout driver");
1937
1938         for (info = zs_chain, i = 0; info; info = info->zs_next, i++) {
1939
1940                 /* Needed before interrupts are enabled. */
1941                 info->tty = 0;
1942                 info->x_char = 0;
1943
1944                 if (info->hook && info->hook->init_info) {
1945                         (*info->hook->init_info)(info);
1946                         continue;
1947                 }
1948
1949                 info->magic = SERIAL_MAGIC;
1950                 info->port = (int) info->zs_channel->control;
1951                 info->line = i;
1952                 info->custom_divisor = 16;
1953                 info->close_delay = 50;
1954                 info->closing_wait = 3000;
1955                 info->event = 0;
1956                 info->count = 0;
1957                 info->blocked_open = 0;
1958                 info->tqueue.routine = do_softint;
1959                 info->tqueue.data = info;
1960                 info->callout_termios = callout_driver.init_termios;
1961                 info->normal_termios = serial_driver.init_termios;
1962                 init_waitqueue_head(&info->open_wait);
1963                 init_waitqueue_head(&info->close_wait);
1964                 printk("ttyS%02d at 0x%08x (irq = %d) is a Z85C30 SCC\n",
1965                        info->line, info->port, info->irq);
1966                 tty_register_devfs(&serial_driver, 0,
1967                                    serial_driver.minor_start + info->line);
1968                 tty_register_devfs(&callout_driver, 0,
1969                                    callout_driver.minor_start + info->line);
1970
1971         }
1972
1973         for (channel = 0; channel < zs_channels_found; ++channel) {
1974                 zs_soft[channel].clk_divisor = 16;
1975                 zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);
1976
1977                 if (request_irq(zs_soft[channel].irq, rs_interrupt, SA_SHIRQ,
1978                                 "scc", &zs_soft[channel]))
1979                         printk(KERN_ERR "decserial: can't get irq %d\n",
1980                                zs_soft[channel].irq);
1981
1982                 if (zs_soft[channel].hook) {
1983                         zs_startup(&zs_soft[channel]);
1984                         if (zs_soft[channel].hook->init_channel)
1985                                 (*zs_soft[channel].hook->init_channel)
1986                                         (&zs_soft[channel]);
1987                 }
1988         }
1989
1990         return 0;
1991 }
1992
1993 /*
1994  * polling I/O routines
1995  */
1996 static int
1997 zs_poll_tx_char(struct dec_serial *info, unsigned char ch)
1998 {
1999         struct dec_zschannel *chan = info->zs_channel;
2000         int    ret;
2001
2002         if(chan) {
2003                 int loops = 10000;
2004
2005                 while (loops && !(read_zsreg(chan, 0) & Tx_BUF_EMP))
2006                         loops--;
2007
2008                 if (loops) {
2009                         write_zsdata(chan, ch);
2010                         ret = 0;
2011                 } else
2012                         ret = -EAGAIN;
2013
2014                 return ret;
2015         } else
2016                 return -ENODEV;
2017 }
2018
2019 static int
2020 zs_poll_rx_char(struct dec_serial *info)
2021 {
2022         struct dec_zschannel *chan = info->zs_channel;
2023         int    ret;
2024
2025         if(chan) {
2026                 int loops = 10000;
2027
2028                 while (loops && !(read_zsreg(chan, 0) & Rx_CH_AV))
2029                         loops--;
2030
2031                 if (loops)
2032                         ret = read_zsdata(chan);
2033                 else
2034                         ret = -EAGAIN;
2035
2036                 return ret;
2037         } else
2038                 return -ENODEV;
2039 }
2040
2041 unsigned int register_zs_hook(unsigned int channel, struct zs_hook *hook)
2042 {
2043         struct dec_serial *info = &zs_soft[channel];
2044
2045         if (info->hook) {
2046                 printk(__FUNCTION__": line %d has already a hook registered\n", channel);
2047
2048                 return 0;
2049         } else {
2050                 hook->poll_rx_char = zs_poll_rx_char;
2051                 hook->poll_tx_char = zs_poll_tx_char;
2052                 info->hook = hook;
2053
2054                 return 1;
2055         }
2056 }
2057
2058 unsigned int unregister_zs_hook(unsigned int channel)
2059 {
2060         struct dec_serial *info = &zs_soft[channel];
2061
2062         if (info->hook) {
2063                 info->hook = NULL;
2064                 return 1;
2065         } else {
2066                 printk(__FUNCTION__": trying to unregister hook on line %d,"
2067                        " but none is registered\n", channel);
2068                 return 0;
2069         }
2070 }
2071
2072 /*
2073  * ------------------------------------------------------------
2074  * Serial console driver
2075  * ------------------------------------------------------------
2076  */
2077 #ifdef CONFIG_SERIAL_DEC_CONSOLE
2078
2079
2080 /*
2081  *      Print a string to the serial port trying not to disturb
2082  *      any possible real use of the port...
2083  */
2084 static void serial_console_write(struct console *co, const char *s,
2085                                  unsigned count)
2086 {
2087         struct dec_serial *info;
2088         int i;
2089
2090         info = zs_soft + co->index;
2091
2092         for (i = 0; i < count; i++, s++) {
2093                 if(*s == '\n')
2094                         zs_poll_tx_char(info, '\r');
2095                 zs_poll_tx_char(info, *s);
2096         }
2097 }
2098
2099 static kdev_t serial_console_device(struct console *c)
2100 {
2101         return MKDEV(TTY_MAJOR, 64 + c->index);
2102 }
2103
2104 /*
2105  *      Setup initial baud/bits/parity. We do two things here:
2106  *      - construct a cflag setting for the first rs_open()
2107  *      - initialize the serial port
2108  *      Return non-zero if we didn't find a serial port.
2109  */
2110 static int __init serial_console_setup(struct console *co, char *options)
2111 {
2112         struct dec_serial *info;
2113         int baud = 9600;
2114         int bits = 8;
2115         int parity = 'n';
2116         int cflag = CREAD | HUPCL | CLOCAL;
2117         int clk_divisor = 16;
2118         int brg;
2119         char *s;
2120         unsigned long flags;
2121
2122         if(!BUS_PRESENT)
2123                 return -ENODEV;
2124
2125         info = zs_soft + co->index;
2126
2127         if (zs_chain == 0)
2128                 probe_sccs();
2129
2130         info->is_cons = 1;
2131
2132         if (options) {
2133                 baud = simple_strtoul(options, NULL, 10);
2134                 s = options;
2135                 while(*s >= '0' && *s <= '9')
2136                         s++;
2137                 if (*s)
2138                         parity = *s++;
2139                 if (*s)
2140                         bits   = *s - '0';
2141         }
2142
2143         /*
2144          *      Now construct a cflag setting.
2145          */
2146         switch(baud) {
2147         case 1200:
2148                 cflag |= B1200;
2149                 break;
2150         case 2400:
2151                 cflag |= B2400;
2152                 break;
2153         case 4800:
2154                 cflag |= B4800;
2155                 break;
2156         case 19200:
2157                 cflag |= B19200;
2158                 break;
2159         case 38400:
2160                 cflag |= B38400;
2161                 break;
2162         case 57600:
2163                 cflag |= B57600;
2164                 break;
2165         case 115200:
2166                 cflag |= B115200;
2167                 break;
2168         case 9600:
2169         default:
2170                 cflag |= B9600;
2171                 /*
2172                  * Set this to a sane value to prevent a divide error.
2173                  */
2174                 baud  = 9600;
2175                 break;
2176         }
2177         switch(bits) {
2178         case 7:
2179                 cflag |= CS7;
2180                 break;
2181         default:
2182         case 8:
2183                 cflag |= CS8;
2184                 break;
2185         }
2186         switch(parity) {
2187         case 'o': case 'O':
2188                 cflag |= PARODD;
2189                 break;
2190         case 'e': case 'E':
2191                 cflag |= PARENB;
2192                 break;
2193         }
2194         co->cflag = cflag;
2195
2196         save_and_cli(flags);
2197
2198         /*
2199          * Set up the baud rate generator.
2200          */
2201         brg = BPS_TO_BRG(baud, zs_parms->clock / clk_divisor);
2202         info->zs_channel->curregs[R12] = (brg & 255);
2203         info->zs_channel->curregs[R13] = ((brg >> 8) & 255);
2204
2205         /*
2206          * Set byte size and parity.
2207          */
2208         if (bits == 7) {
2209                 info->zs_channel->curregs[R3] |= Rx7;
2210                 info->zs_channel->curregs[R5] |= Tx7;
2211         } else {
2212                 info->zs_channel->curregs[R3] |= Rx8;
2213                 info->zs_channel->curregs[R5] |= Tx8;
2214         }
2215         if (cflag & PARENB) {
2216                 info->zs_channel->curregs[R4] |= PAR_ENA;
2217         }
2218         if (!(cflag & PARODD)) {
2219                 info->zs_channel->curregs[R4] |= PAR_EVEN;
2220         }
2221         info->zs_channel->curregs[R4] |= SB1;
2222
2223         /*
2224          * Turn on RTS and DTR.
2225          */
2226         zs_rtsdtr(info, RTS | DTR, 1);
2227
2228         /*
2229          * Finally, enable sequencing.
2230          */
2231         info->zs_channel->curregs[R3] |= RxENABLE;
2232         info->zs_channel->curregs[R5] |= TxENAB;
2233
2234         /*
2235          * Clear the interrupt registers.
2236          */
2237         write_zsreg(info->zs_channel, R0, ERR_RES);
2238         write_zsreg(info->zs_channel, R0, RES_H_IUS);
2239
2240         /*
2241          * Load up the new values.
2242          */
2243         load_zsregs(info->zs_channel, info->zs_channel->curregs);
2244
2245         /* Save the current value of RR0 */
2246         info->read_reg_zero = read_zsreg(info->zs_channel, R0);
2247
2248         zs_soft[co->index].clk_divisor = clk_divisor;
2249         zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);
2250
2251         restore_flags(flags);
2252
2253         return 0;
2254 }
2255
2256 static struct console sercons = {
2257         .name           = "ttyS",
2258         .write          = serial_console_write,
2259         .device         = serial_console_device,
2260         .setup          = serial_console_setup,
2261         .flags          = CON_PRINTBUFFER,
2262         .index          = -1,
2263 };
2264
2265 /*
2266  *      Register console.
2267  */
2268 void __init zs_serial_console_init(void)
2269 {
2270         register_console(&sercons);
2271 }
2272 #endif /* ifdef CONFIG_SERIAL_DEC_CONSOLE */
2273
2274 #ifdef CONFIG_KGDB
2275 struct dec_zschannel *zs_kgdbchan;
2276 static unsigned char scc_inittab[] = {
2277         9,  0x80,       /* reset A side (CHRA) */
2278         13, 0,          /* set baud rate divisor */
2279         12, 1,
2280         14, 1,          /* baud rate gen enable, src=rtxc (BRENABL) */
2281         11, 0x50,       /* clocks = br gen (RCBR | TCBR) */
2282         5,  0x6a,       /* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
2283         4,  0x44,       /* x16 clock, 1 stop (SB1 | X16CLK)*/
2284         3,  0xc1,       /* rx enable, 8 bits (RxENABLE | Rx8)*/
2285 };
2286
2287 /* These are for receiving and sending characters under the kgdb
2288  * source level kernel debugger.
2289  */
2290 void putDebugChar(char kgdb_char)
2291 {
2292         struct dec_zschannel *chan = zs_kgdbchan;
2293         while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
2294                 RECOVERY_DELAY;
2295         write_zsdata(chan, kgdb_char);
2296 }
2297 char getDebugChar(void)
2298 {
2299         struct dec_zschannel *chan = zs_kgdbchan;
2300         while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
2301                 eieio(); /*barrier();*/
2302         return read_zsdata(chan);
2303 }
2304 void kgdb_interruptible(int yes)
2305 {
2306         struct dec_zschannel *chan = zs_kgdbchan;
2307         int one, nine;
2308         nine = read_zsreg(chan, 9);
2309         if (yes == 1) {
2310                 one = EXT_INT_ENAB|RxINT_ALL;
2311                 nine |= MIE;
2312                 printk("turning serial ints on\n");
2313         } else {
2314                 one = RxINT_DISAB;
2315                 nine &= ~MIE;
2316                 printk("turning serial ints off\n");
2317         }
2318         write_zsreg(chan, 1, one);
2319         write_zsreg(chan, 9, nine);
2320 }
2321
2322 static int kgdbhook_init_channel(struct dec_serial* info)
2323 {
2324         return 0;
2325 }
2326
2327 static void kgdbhook_init_info(struct dec_serial* info)
2328 {
2329 }
2330
2331 static void kgdbhook_rx_char(struct dec_serial* info,
2332                              unsigned char ch, unsigned char stat)
2333 {
2334         if (ch == 0x03 || ch == '$')
2335                 breakpoint();
2336         if (stat & (Rx_OVR|FRM_ERR|PAR_ERR))
2337                 write_zsreg(info->zs_channel, 0, ERR_RES);
2338 }
2339
2340 /* This sets up the serial port we're using, and turns on
2341  * interrupts for that channel, so kgdb is usable once we're done.
2342  */
2343 static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
2344 {
2345         int brg;
2346         int i, x;
2347         volatile char *sccc = ms->control;
2348         brg = BPS_TO_BRG(bps, zs_parms->clock/16);
2349         printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
2350         for (i = 20000; i != 0; --i) {
2351                 x = *sccc; eieio();
2352         }
2353         for (i = 0; i < sizeof(scc_inittab); ++i) {
2354                 write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
2355                 i++;
2356         }
2357 }
2358 /* This is called at boot time to prime the kgdb serial debugging
2359  * serial line.  The 'tty_num' argument is 0 for /dev/ttya and 1
2360  * for /dev/ttyb which is determined in setup_arch() from the
2361  * boot command line flags.
2362  */
2363 struct zs_hook zs_kgdbhook = {
2364         init_channel : kgdbhook_init_channel,
2365         init_info    : kgdbhook_init_info,
2366         cflags       : B38400|CS8|CLOCAL,
2367         rx_char      : kgdbhook_rx_char,
2368 }
2369
2370 void __init zs_kgdb_hook(int tty_num)
2371 {
2372         /* Find out how many Z8530 SCCs we have */
2373         if (zs_chain == 0)
2374                 probe_sccs();
2375         zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
2376         zs_kgdbchan = zs_soft[tty_num].zs_channel;
2377         zs_soft[tty_num].change_needed = 0;
2378         zs_soft[tty_num].clk_divisor = 16;
2379         zs_soft[tty_num].zs_baud = 38400;
2380         zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
2381         /* Turn on transmitter/receiver at 8-bits/char */
2382         kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
2383         printk("KGDB: on channel %d initialized\n", tty_num);
2384         set_debug_traps(); /* init stub */
2385 }
2386 #endif /* ifdef CONFIG_KGDB */
2387
2388