drivers/serial/dz.c

   1 /*
   2  * dz.c: Serial port driver for DECstations equipped
   3  *       with the DZ chipset.
   4  *
   5  * Copyright (C) 1998 Olivier A. D. Lebaillif
   6  *
   7  * Email: olivier.lebaillif@ifrsys.com
   8  *
   9  * Copyright (C) 2004, 2006  Maciej W. Rozycki
  10  *
  11  * [31-AUG-98] triemer
  12  * Changed IRQ to use Harald's dec internals interrupts.h
  13  * removed base_addr code - moving address assignment to setup.c
  14  * Changed name of dz_init to rs_init to be consistent with tc code
  15  * [13-NOV-98] triemer fixed code to receive characters
  16  *    after patches by harald to irq code.
  17  * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
  18  *            field from "current" - somewhere between 2.1.121 and 2.1.131
  19  Qua Jun 27 15:02:26 BRT 2001
  20  * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
  21  *
  22  * Parts (C) 1999 David Airlie, airlied@linux.ie
  23  * [07-SEP-99] Bugfixes
  24  *
  25  * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
  26  * Converted to new serial core
  27  */
  28
  29 #undef DEBUG_DZ
  30
  31 #if defined(CONFIG_SERIAL_DZ_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  32 #define SUPPORT_SYSRQ
  33 #endif
  34
  35 #include <linux/delay.h>
  36 #include <linux/module.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/init.h>
  39 #include <linux/console.h>
  40 #include <linux/sysrq.h>
  41 #include <linux/tty.h>
  42 #include <linux/tty_flip.h>
  43 #include <linux/serial_core.h>
  44 #include <linux/serial.h>
  45
  46 #include <asm/bootinfo.h>
  47 #include <asm/dec/interrupts.h>
  48 #include <asm/dec/kn01.h>
  49 #include <asm/dec/kn02.h>
  50 #include <asm/dec/machtype.h>
  51 #include <asm/dec/prom.h>
  52 #include <asm/irq.h>
  53 #include <asm/system.h>
  54 #include <asm/uaccess.h>
  55
  56 #include "dz.h"
  57
  58 static char *dz_name = "DECstation DZ serial driver version ";
  59 static char *dz_version = "1.03";
  60
  61 struct dz_port {
  62         struct uart_port        port;
  63         unsigned int            cflag;
  64 };
  65
  66 static struct dz_port dz_ports[DZ_NB_PORT];
  67
  68 /*
  69  * ------------------------------------------------------------
  70  * dz_in () and dz_out ()
  71  *
  72  * These routines are used to access the registers of the DZ
  73  * chip, hiding relocation differences between implementation.
  74  * ------------------------------------------------------------
  75  */
  76
  77 static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
  78 {
  79         volatile unsigned short *addr =
  80                 (volatile unsigned short *) (dport->port.membase + offset);
  81
  82         return *addr;
  83 }
  84
  85 static inline void dz_out(struct dz_port *dport, unsigned offset,
  86                           unsigned short value)
  87 {
  88         volatile unsigned short *addr =
  89                 (volatile unsigned short *) (dport->port.membase + offset);
  90
  91         *addr = value;
  92 }
  93
  94 /*
  95  * ------------------------------------------------------------
  96  * rs_stop () and rs_start ()
  97  *
  98  * These routines are called before setting or resetting
  99  * tty->stopped. They enable or disable transmitter interrupts,
 100  * as necessary.
 101  * ------------------------------------------------------------
 102  */
 103
 104 static void dz_stop_tx(struct uart_port *uport)
 105 {
 106         struct dz_port *dport = (struct dz_port *)uport;
 107         unsigned short tmp, mask = 1 << dport->port.line;
 108         unsigned long flags;
 109
 110         spin_lock_irqsave(&dport->port.lock, flags);
 111         tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 112         tmp &= ~mask;                   /* clear the TX flag */
 113         dz_out(dport, DZ_TCR, tmp);
 114         spin_unlock_irqrestore(&dport->port.lock, flags);
 115 }
 116
 117 static void dz_start_tx(struct uart_port *uport)
 118 {
 119         struct dz_port *dport = (struct dz_port *)uport;
 120         unsigned short tmp, mask = 1 << dport->port.line;
 121         unsigned long flags;
 122
 123         spin_lock_irqsave(&dport->port.lock, flags);
 124         tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 125         tmp |= mask;                    /* set the TX flag */
 126         dz_out(dport, DZ_TCR, tmp);
 127         spin_unlock_irqrestore(&dport->port.lock, flags);
 128 }
 129
 130 static void dz_stop_rx(struct uart_port *uport)
 131 {
 132         struct dz_port *dport = (struct dz_port *)uport;
 133         unsigned long flags;
 134
 135         spin_lock_irqsave(&dport->port.lock, flags);
 136         dport->cflag &= ~DZ_CREAD;
 137         dz_out(dport, DZ_LPR, dport->cflag | dport->port.line);
 138         spin_unlock_irqrestore(&dport->port.lock, flags);
 139 }
 140
 141 static void dz_enable_ms(struct uart_port *port)
 142 {
 143         /* nothing to do */
 144 }
 145
 146 /*
 147  * ------------------------------------------------------------
 148  *
 149  * Here start the interrupt handling routines.  All of the following
 150  * subroutines are declared as inline and are folded into
 151  * dz_interrupt.  They were separated out for readability's sake.
 152  *
 153  * Note: dz_interrupt() is a "fast" interrupt, which means that it
 154  * runs with interrupts turned off.  People who may want to modify
 155  * dz_interrupt() should try to keep the interrupt handler as fast as
 156  * possible.  After you are done making modifications, it is not a bad
 157  * idea to do:
 158  *
 159  *      make drivers/serial/dz.s
 160  *
 161  * and look at the resulting assemble code in dz.s.
 162  *
 163  * ------------------------------------------------------------
 164  */
 165
 166 /*
 167  * ------------------------------------------------------------
 168  * receive_char ()
 169  *
 170  * This routine deals with inputs from any lines.
 171  * ------------------------------------------------------------
 172  */
 173 static inline void dz_receive_chars(struct dz_port *dport_in,
 174                                     struct pt_regs *regs)
 175 {
 176         struct dz_port *dport;
 177         struct tty_struct *tty = NULL;
 178         struct uart_icount *icount;
 179         int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
 180         unsigned short status;
 181         unsigned char ch, flag;
 182         int i;
 183
 184         while ((status = dz_in(dport_in, DZ_RBUF)) & DZ_DVAL) {
 185                 dport = &dz_ports[LINE(status)];
 186                 tty = dport->port.info->tty;    /* point to the proper dev */
 187
 188                 ch = UCHAR(status);             /* grab the char */
 189
 190                 icount = &dport->port.icount;
 191                 icount->rx++;
 192
 193                 flag = TTY_NORMAL;
 194                 if (status & DZ_FERR) {         /* frame error */
 195                         /*
 196                          * There is no separate BREAK status bit, so
 197                          * treat framing errors as BREAKs for Magic SysRq
 198                          * and SAK; normally, otherwise.
 199                          */
 200                         if (uart_handle_break(&dport->port))
 201                                 continue;
 202                         if (dport->port.flags & UPF_SAK)
 203                                 flag = TTY_BREAK;
 204                         else
 205                                 flag = TTY_FRAME;
 206                 } else if (status & DZ_OERR)    /* overrun error */
 207                         flag = TTY_OVERRUN;
 208                 else if (status & DZ_PERR)      /* parity error */
 209                         flag = TTY_PARITY;
 210
 211                 /* keep track of the statistics */
 212                 switch (flag) {
 213                 case TTY_FRAME:
 214                         icount->frame++;
 215                         break;
 216                 case TTY_PARITY:
 217                         icount->parity++;
 218                         break;
 219                 case TTY_OVERRUN:
 220                         icount->overrun++;
 221                         break;
 222                 case TTY_BREAK:
 223                         icount->brk++;
 224                         break;
 225                 default:
 226                         break;
 227                 }
 228
 229                 if (uart_handle_sysrq_char(&dport->port, ch, regs))
 230                         continue;
 231
 232                 if ((status & dport->port.ignore_status_mask) == 0) {
 233                         uart_insert_char(&dport->port,
 234                                          status, DZ_OERR, ch, flag);
 235                         lines_rx[LINE(status)] = 1;
 236                 }
 237         }
 238         for (i = 0; i < DZ_NB_PORT; i++)
 239                 if (lines_rx[i])
 240                         tty_flip_buffer_push(dz_ports[i].port.info->tty);
 241 }
 242
 243 /*
 244  * ------------------------------------------------------------
 245  * transmit_char ()
 246  *
 247  * This routine deals with outputs to any lines.
 248  * ------------------------------------------------------------
 249  */
 250 static inline void dz_transmit_chars(struct dz_port *dport_in)
 251 {
 252         struct dz_port *dport;
 253         struct circ_buf *xmit;
 254         unsigned short status;
 255         unsigned char tmp;
 256
 257         status = dz_in(dport_in, DZ_CSR);
 258         dport = &dz_ports[LINE(status)];
 259         xmit = &dport->port.info->xmit;
 260
 261         if (dport->port.x_char) {               /* XON/XOFF chars */
 262                 dz_out(dport, DZ_TDR, dport->port.x_char);
 263                 dport->port.icount.tx++;
 264                 dport->port.x_char = 0;
 265                 return;
 266         }
 267         /* If nothing to do or stopped or hardware stopped. */
 268         if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
 269                 dz_stop_tx(&dport->port);
 270                 return;
 271         }
 272
 273         /*
 274          * If something to do... (remember the dz has no output fifo,
 275          * so we go one char at a time) :-<
 276          */
 277         tmp = xmit->buf[xmit->tail];
 278         xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
 279         dz_out(dport, DZ_TDR, tmp);
 280         dport->port.icount.tx++;
 281
 282         if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
 283                 uart_write_wakeup(&dport->port);
 284
 285         /* Are we are done. */
 286         if (uart_circ_empty(xmit))
 287                 dz_stop_tx(&dport->port);
 288 }
 289
 290 /*
 291  * ------------------------------------------------------------
 292  * check_modem_status()
 293  *
 294  * DS 3100 & 5100: Only valid for the MODEM line, duh!
 295  * DS 5000/200: Valid for the MODEM and PRINTER line.
 296  * ------------------------------------------------------------
 297  */
 298 static inline void check_modem_status(struct dz_port *dport)
 299 {
 300         /*
 301          * FIXME:
 302          * 1. No status change interrupt; use a timer.
 303          * 2. Handle the 3100/5000 as appropriate. --macro
 304          */
 305         unsigned short status;
 306
 307         /* If not the modem line just return.  */
 308         if (dport->port.line != DZ_MODEM)
 309                 return;
 310
 311         status = dz_in(dport, DZ_MSR);
 312
 313         /* it's easy, since DSR2 is the only bit in the register */
 314         if (status)
 315                 dport->port.icount.dsr++;
 316 }
 317
 318 /*
 319  * ------------------------------------------------------------
 320  * dz_interrupt ()
 321  *
 322  * this is the main interrupt routine for the DZ chip.
 323  * It deals with the multiple ports.
 324  * ------------------------------------------------------------
 325  */
 326 static irqreturn_t dz_interrupt(int irq, void *dev)
 327 {
 328         struct dz_port *dport = (struct dz_port *)dev;
 329         unsigned short status;
 330
 331         /* get the reason why we just got an irq */
 332         status = dz_in(dport, DZ_CSR);
 333
 334         if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
 335                 dz_receive_chars(dport, regs);
 336
 337         if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
 338                 dz_transmit_chars(dport);
 339
 340         return IRQ_HANDLED;
 341 }
 342
 343 /*
 344  * -------------------------------------------------------------------
 345  * Here ends the DZ interrupt routines.
 346  * -------------------------------------------------------------------
 347  */
 348
 349 static unsigned int dz_get_mctrl(struct uart_port *uport)
 350 {
 351         /*
 352          * FIXME: Handle the 3100/5000 as appropriate. --macro
 353          */
 354         struct dz_port *dport = (struct dz_port *)uport;
 355         unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
 356
 357         if (dport->port.line == DZ_MODEM) {
 358                 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
 359                         mctrl &= ~TIOCM_DSR;
 360         }
 361
 362         return mctrl;
 363 }
 364
 365 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
 366 {
 367         /*
 368          * FIXME: Handle the 3100/5000 as appropriate. --macro
 369          */
 370         struct dz_port *dport = (struct dz_port *)uport;
 371         unsigned short tmp;
 372
 373         if (dport->port.line == DZ_MODEM) {
 374                 tmp = dz_in(dport, DZ_TCR);
 375                 if (mctrl & TIOCM_DTR)
 376                         tmp &= ~DZ_MODEM_DTR;
 377                 else
 378                         tmp |= DZ_MODEM_DTR;
 379                 dz_out(dport, DZ_TCR, tmp);
 380         }
 381 }
 382
 383 /*
 384  * -------------------------------------------------------------------
 385  * startup ()
 386  *
 387  * various initialization tasks
 388  * -------------------------------------------------------------------
 389  */
 390 static int dz_startup(struct uart_port *uport)
 391 {
 392         struct dz_port *dport = (struct dz_port *)uport;
 393         unsigned long flags;
 394         unsigned short tmp;
 395
 396         spin_lock_irqsave(&dport->port.lock, flags);
 397
 398         /* enable the interrupt and the scanning */
 399         tmp = dz_in(dport, DZ_CSR);
 400         tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
 401         dz_out(dport, DZ_CSR, tmp);
 402
 403         spin_unlock_irqrestore(&dport->port.lock, flags);
 404
 405         return 0;
 406 }
 407
 408 /*
 409  * -------------------------------------------------------------------
 410  * shutdown ()
 411  *
 412  * This routine will shutdown a serial port; interrupts are disabled, and
 413  * DTR is dropped if the hangup on close termio flag is on.
 414  * -------------------------------------------------------------------
 415  */
 416 static void dz_shutdown(struct uart_port *uport)
 417 {
 418         dz_stop_tx(uport);
 419 }
 420
 421 /*
 422  * -------------------------------------------------------------------
 423  * dz_tx_empty() -- get the transmitter empty status
 424  *
 425  * Purpose: Let user call ioctl() to get info when the UART physically
 426  *          is emptied.  On bus types like RS485, the transmitter must
 427  *          release the bus after transmitting. This must be done when
 428  *          the transmit shift register is empty, not be done when the
 429  *          transmit holding register is empty.  This functionality
 430  *          allows an RS485 driver to be written in user space.
 431  * -------------------------------------------------------------------
 432  */
 433 static unsigned int dz_tx_empty(struct uart_port *uport)
 434 {
 435         struct dz_port *dport = (struct dz_port *)uport;
 436         unsigned short tmp, mask = 1 << dport->port.line;
 437
 438         tmp = dz_in(dport, DZ_TCR);
 439         tmp &= mask;
 440
 441         return tmp ? 0 : TIOCSER_TEMT;
 442 }
 443
 444 static void dz_break_ctl(struct uart_port *uport, int break_state)
 445 {
 446         /*
 447          * FIXME: Can't access BREAK bits in TDR easily;
 448          * reuse the code for polled TX. --macro
 449          */
 450         struct dz_port *dport = (struct dz_port *)uport;
 451         unsigned long flags;
 452         unsigned short tmp, mask = 1 << dport->port.line;
 453
 454         spin_lock_irqsave(&uport->lock, flags);
 455         tmp = dz_in(dport, DZ_TCR);
 456         if (break_state)
 457                 tmp |= mask;
 458         else
 459                 tmp &= ~mask;
 460         dz_out(dport, DZ_TCR, tmp);
 461         spin_unlock_irqrestore(&uport->lock, flags);
 462 }
 463
 464 static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
 465                            struct ktermios *old_termios)
 466 {
 467         struct dz_port *dport = (struct dz_port *)uport;
 468         unsigned long flags;
 469         unsigned int cflag, baud;
 470
 471         cflag = dport->port.line;
 472
 473         switch (termios->c_cflag & CSIZE) {
 474         case CS5:
 475                 cflag |= DZ_CS5;
 476                 break;
 477         case CS6:
 478                 cflag |= DZ_CS6;
 479                 break;
 480         case CS7:
 481                 cflag |= DZ_CS7;
 482                 break;
 483         case CS8:
 484         default:
 485                 cflag |= DZ_CS8;
 486         }
 487
 488         if (termios->c_cflag & CSTOPB)
 489                 cflag |= DZ_CSTOPB;
 490         if (termios->c_cflag & PARENB)
 491                 cflag |= DZ_PARENB;
 492         if (termios->c_cflag & PARODD)
 493                 cflag |= DZ_PARODD;
 494
 495         baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
 496         switch (baud) {
 497         case 50:
 498                 cflag |= DZ_B50;
 499                 break;
 500         case 75:
 501                 cflag |= DZ_B75;
 502                 break;
 503         case 110:
 504                 cflag |= DZ_B110;
 505                 break;
 506         case 134:
 507                 cflag |= DZ_B134;
 508                 break;
 509         case 150:
 510                 cflag |= DZ_B150;
 511                 break;
 512         case 300:
 513                 cflag |= DZ_B300;
 514                 break;
 515         case 600:
 516                 cflag |= DZ_B600;
 517                 break;
 518         case 1200:
 519                 cflag |= DZ_B1200;
 520                 break;
 521         case 1800:
 522                 cflag |= DZ_B1800;
 523                 break;
 524         case 2000:
 525                 cflag |= DZ_B2000;
 526                 break;
 527         case 2400:
 528                 cflag |= DZ_B2400;
 529                 break;
 530         case 3600:
 531                 cflag |= DZ_B3600;
 532                 break;
 533         case 4800:
 534                 cflag |= DZ_B4800;
 535                 break;
 536         case 7200:
 537                 cflag |= DZ_B7200;
 538                 break;
 539         case 9600:
 540         default:
 541                 cflag |= DZ_B9600;
 542         }
 543
 544         if (termios->c_cflag & CREAD)
 545                 cflag |= DZ_RXENAB;
 546
 547         spin_lock_irqsave(&dport->port.lock, flags);
 548
 549         dz_out(dport, DZ_LPR, cflag | dport->port.line);
 550         dport->cflag = cflag;
 551
 552         /* setup accept flag */
 553         dport->port.read_status_mask = DZ_OERR;
 554         if (termios->c_iflag & INPCK)
 555                 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
 556
 557         /* characters to ignore */
 558         uport->ignore_status_mask = 0;
 559         if (termios->c_iflag & IGNPAR)
 560                 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
 561
 562         spin_unlock_irqrestore(&dport->port.lock, flags);
 563 }
 564
 565 static const char *dz_type(struct uart_port *port)
 566 {
 567         return "DZ";
 568 }
 569
 570 static void dz_release_port(struct uart_port *port)
 571 {
 572         /* nothing to do */
 573 }
 574
 575 static int dz_request_port(struct uart_port *port)
 576 {
 577         return 0;
 578 }
 579
 580 static void dz_config_port(struct uart_port *port, int flags)
 581 {
 582         if (flags & UART_CONFIG_TYPE)
 583                 port->type = PORT_DZ;
 584 }
 585
 586 /*
 587  * verify the new serial_struct (for TIOCSSERIAL).
 588  */
 589 static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
 590 {
 591         int ret = 0;
 592         if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
 593                 ret = -EINVAL;
 594         if (ser->irq != port->irq)
 595                 ret = -EINVAL;
 596         return ret;
 597 }
 598
 599 static struct uart_ops dz_ops = {
 600         .tx_empty       = dz_tx_empty,
 601         .get_mctrl      = dz_get_mctrl,
 602         .set_mctrl      = dz_set_mctrl,
 603         .stop_tx        = dz_stop_tx,
 604         .start_tx       = dz_start_tx,
 605         .stop_rx        = dz_stop_rx,
 606         .enable_ms      = dz_enable_ms,
 607         .break_ctl      = dz_break_ctl,
 608         .startup        = dz_startup,
 609         .shutdown       = dz_shutdown,
 610         .set_termios    = dz_set_termios,
 611         .type           = dz_type,
 612         .release_port   = dz_release_port,
 613         .request_port   = dz_request_port,
 614         .config_port    = dz_config_port,
 615         .verify_port    = dz_verify_port,
 616 };
 617
 618 static void __init dz_init_ports(void)
 619 {
 620         static int first = 1;
 621         struct dz_port *dport;
 622         unsigned long base;
 623         int i;
 624
 625         if (!first)
 626                 return;
 627         first = 0;
 628
 629         if (mips_machtype == MACH_DS23100 ||
 630             mips_machtype == MACH_DS5100)
 631                 base = CKSEG1ADDR(KN01_SLOT_BASE + KN01_DZ11);
 632         else
 633                 base = CKSEG1ADDR(KN02_SLOT_BASE + KN02_DZ11);
 634
 635         for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
 636                 spin_lock_init(&dport->port.lock);
 637                 dport->port.membase     = (char *) base;
 638                 dport->port.iotype      = UPIO_MEM;
 639                 dport->port.irq         = dec_interrupt[DEC_IRQ_DZ11];
 640                 dport->port.line        = i;
 641                 dport->port.fifosize    = 1;
 642                 dport->port.ops         = &dz_ops;
 643                 dport->port.flags       = UPF_BOOT_AUTOCONF;
 644         }
 645 }
 646
 647 static void dz_reset(struct dz_port *dport)
 648 {
 649         dz_out(dport, DZ_CSR, DZ_CLR);
 650         while (dz_in(dport, DZ_CSR) & DZ_CLR);
 651         iob();
 652
 653         /* enable scanning */
 654         dz_out(dport, DZ_CSR, DZ_MSE);
 655 }
 656
 657 #ifdef CONFIG_SERIAL_DZ_CONSOLE
 658 /*
 659  * -------------------------------------------------------------------
 660  * dz_console_putchar() -- transmit a character
 661  *
 662  * Polled transmission.  This is tricky.  We need to mask transmit
 663  * interrupts so that they do not interfere, enable the transmitter
 664  * for the line requested and then wait till the transmit scanner
 665  * requests data for this line.  But it may request data for another
 666  * line first, in which case we have to disable its transmitter and
 667  * repeat waiting till our line pops up.  Only then the character may
 668  * be transmitted.  Finally, the state of the transmitter mask is
 669  * restored.  Welcome to the world of PDP-11!
 670  * -------------------------------------------------------------------
 671  */
 672 static void dz_console_putchar(struct uart_port *uport, int ch)
 673 {
 674         struct dz_port *dport = (struct dz_port *)uport;
 675         unsigned long flags;
 676         unsigned short csr, tcr, trdy, mask;
 677         int loops = 10000;
 678
 679         spin_lock_irqsave(&dport->port.lock, flags);
 680         csr = dz_in(dport, DZ_CSR);
 681         dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
 682         tcr = dz_in(dport, DZ_TCR);
 683         tcr |= 1 << dport->port.line;
 684         mask = tcr;
 685         dz_out(dport, DZ_TCR, mask);
 686         iob();
 687         spin_unlock_irqrestore(&dport->port.lock, flags);
 688
 689         while (loops--) {
 690                 trdy = dz_in(dport, DZ_CSR);
 691                 if (!(trdy & DZ_TRDY))
 692                         continue;
 693                 trdy = (trdy & DZ_TLINE) >> 8;
 694                 if (trdy == dport->port.line)
 695                         break;
 696                 mask &= ~(1 << trdy);
 697                 dz_out(dport, DZ_TCR, mask);
 698                 iob();
 699                 udelay(2);
 700         }
 701
 702         if (loops)                              /* Cannot send otherwise. */
 703                 dz_out(dport, DZ_TDR, ch);
 704
 705         dz_out(dport, DZ_TCR, tcr);
 706         dz_out(dport, DZ_CSR, csr);
 707 }
 708
 709 /*
 710  * -------------------------------------------------------------------
 711  * dz_console_print ()
 712  *
 713  * dz_console_print is registered for printk.
 714  * The console must be locked when we get here.
 715  * -------------------------------------------------------------------
 716  */
 717 static void dz_console_print(struct console *co,
 718                              const char *str,
 719                              unsigned int count)
 720 {
 721         struct dz_port *dport = &dz_ports[co->index];
 722 #ifdef DEBUG_DZ
 723         prom_printf((char *) str);
 724 #endif
 725         uart_console_write(&dport->port, str, count, dz_console_putchar);
 726 }
 727
 728 static int __init dz_console_setup(struct console *co, char *options)
 729 {
 730         struct dz_port *dport = &dz_ports[co->index];
 731         int baud = 9600;
 732         int bits = 8;
 733         int parity = 'n';
 734         int flow = 'n';
 735
 736         if (options)
 737                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 738
 739         dz_reset(dport);
 740
 741         return uart_set_options(&dport->port, co, baud, parity, bits, flow);
 742 }
 743
 744 static struct uart_driver dz_reg;
 745 static struct console dz_sercons = {
 746         .name   = "ttyS",
 747         .write  = dz_console_print,
 748         .device = uart_console_device,
 749         .setup  = dz_console_setup,
 750         .flags  = CON_PRINTBUFFER,
 751         .index  = -1,
 752         .data   = &dz_reg,
 753 };
 754
 755 static int __init dz_serial_console_init(void)
 756 {
 757         if (!IOASIC) {
 758                 dz_init_ports();
 759                 register_console(&dz_sercons);
 760                 return 0;
 761         } else
 762                 return -ENXIO;
 763 }
 764
 765 console_initcall(dz_serial_console_init);
 766
 767 #define SERIAL_DZ_CONSOLE       &dz_sercons
 768 #else
 769 #define SERIAL_DZ_CONSOLE       NULL
 770 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
 771
 772 static struct uart_driver dz_reg = {
 773         .owner                  = THIS_MODULE,
 774         .driver_name            = "serial",
 775         .dev_name               = "ttyS",
 776         .major                  = TTY_MAJOR,
 777         .minor                  = 64,
 778         .nr                     = DZ_NB_PORT,
 779         .cons                   = SERIAL_DZ_CONSOLE,
 780 };
 781
 782 static int __init dz_init(void)
 783 {
 784         int ret, i;
 785
 786         if (IOASIC)
 787                 return -ENXIO;
 788
 789         printk("%s%s\n", dz_name, dz_version);
 790
 791         dz_init_ports();
 792
 793 #ifndef CONFIG_SERIAL_DZ_CONSOLE
 794         /* reset the chip */
 795         dz_reset(&dz_ports[0]);
 796 #endif
 797
 798         if (request_irq(dz_ports[0].port.irq, dz_interrupt,
 799                         IRQF_DISABLED, "DZ", &dz_ports[0]))
 800                 panic("Unable to register DZ interrupt");
 801
 802         ret = uart_register_driver(&dz_reg);
 803         if (ret != 0)
 804                 return ret;
 805
 806         for (i = 0; i < DZ_NB_PORT; i++)
 807                 uart_add_one_port(&dz_reg, &dz_ports[i].port);
 808
 809         return ret;
 810 }
 811
 812 module_init(dz_init);
 813
 814 MODULE_DESCRIPTION("DECstation DZ serial driver");
 815 MODULE_LICENSE("GPL");