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