drivers/serial/dz.c

   1 /*
   2  * dz.c: Serial port driver for DECStations equiped
   3  *       with the DZ chipset.
   4  *
   5  * Copyright (C) 1998 Olivier A. D. Lebaillif
   6  *
   7  * Email: olivier.lebaillif@ifrsys.com
   8  *
   9  * [31-AUG-98] triemer
  10  * Changed IRQ to use Harald's dec internals interrupts.h
  11  * removed base_addr code - moving address assignment to setup.c
  12  * Changed name of dz_init to rs_init to be consistent with tc code
  13  * [13-NOV-98] triemer fixed code to receive characters
  14  *    after patches by harald to irq code.
  15  * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
  16  *            field from "current" - somewhere between 2.1.121 and 2.1.131
  17  Qua Jun 27 15:02:26 BRT 2001
  18  * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
  19  *
  20  * Parts (C) 1999 David Airlie, airlied@linux.ie
  21  * [07-SEP-99] Bugfixes
  22  *
  23  * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
  24  * Converted to new serial core
  25  */
  26
  27 #undef DEBUG_DZ
  28
  29 #include <linux/config.h>
  30 #include <linux/module.h>
  31 #include <linux/tty.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/init.h>
  34 #include <linux/console.h>
  35 #include <linux/serial.h>
  36 #include <linux/serial_core.h>
  37
  38 #include <asm/bootinfo.h>
  39 #include <asm/dec/interrupts.h>
  40 #include <asm/dec/kn01.h>
  41 #include <asm/dec/kn02.h>
  42 #include <asm/dec/machtype.h>
  43 #include <asm/dec/prom.h>
  44 #include <asm/irq.h>
  45 #include <asm/system.h>
  46 #include <asm/uaccess.h>
  47
  48 #define CONSOLE_LINE (3)        /* for definition of struct console */
  49
  50 #include "dz.h"
  51
  52 #define DZ_INTR_DEBUG 1
  53
  54 static char *dz_name = "DECstation DZ serial driver version ";
  55 static char *dz_version = "1.02";
  56
  57 struct dz_port {
  58         struct uart_port        port;
  59         unsigned int            cflag;
  60 };
  61
  62 static struct dz_port dz_ports[DZ_NB_PORT];
  63
  64 #ifdef DEBUG_DZ
  65 /*
  66  * debugging code to send out chars via prom
  67  */
  68 static void debug_console(const char *s, int count)
  69 {
  70         unsigned i;
  71
  72         for (i = 0; i < count; i++) {
  73                 if (*s == 10)
  74                         prom_printf("%c", 13);
  75                 prom_printf("%c", *s++);
  76         }
  77 }
  78 #endif
  79
  80 /*
  81  * ------------------------------------------------------------
  82  * dz_in () and dz_out ()
  83  *
  84  * These routines are used to access the registers of the DZ
  85  * chip, hiding relocation differences between implementation.
  86  * ------------------------------------------------------------
  87  */
  88
  89 static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
  90 {
  91         volatile unsigned short *addr =
  92                 (volatile unsigned short *) (dport->port.membase + offset);
  93         return *addr;
  94 }
  95
  96 static inline void dz_out(struct dz_port *dport, unsigned offset,
  97                           unsigned short value)
  98 {
  99         volatile unsigned short *addr =
 100                 (volatile unsigned short *) (dport->port.membase + offset);
 101         *addr = value;
 102 }
 103
 104 /*
 105  * ------------------------------------------------------------
 106  * rs_stop () and rs_start ()
 107  *
 108  * These routines are called before setting or resetting
 109  * tty->stopped. They enable or disable transmitter interrupts,
 110  * as necessary.
 111  * ------------------------------------------------------------
 112  */
 113
 114 static void dz_stop_tx(struct uart_port *uport, unsigned int tty_stop)
 115 {
 116         struct dz_port *dport = (struct dz_port *)uport;
 117         unsigned short tmp, mask = 1 << dport->port.line;
 118         unsigned long flags;
 119
 120         spin_lock_irqsave(&dport->port.lock, flags);
 121         tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 122         tmp &= ~mask;                   /* clear the TX flag */
 123         dz_out(dport, DZ_TCR, tmp);
 124         spin_unlock_irqrestore(&dport->port.lock, flags);
 125 }
 126
 127 static void dz_start_tx(struct uart_port *uport, unsigned int tty_start)
 128 {
 129         struct dz_port *dport = (struct dz_port *)uport;
 130         unsigned short tmp, mask = 1 << dport->port.line;
 131         unsigned long flags;
 132
 133         spin_lock_irqsave(&dport->port.lock, flags);
 134         tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 135         tmp |= mask;                    /* set the TX flag */
 136         dz_out(dport, DZ_TCR, tmp);
 137         spin_unlock_irqrestore(&dport->port.lock, flags);
 138 }
 139
 140 static void dz_stop_rx(struct uart_port *uport)
 141 {
 142         struct dz_port *dport = (struct dz_port *)uport;
 143         unsigned long flags;
 144
 145         spin_lock_irqsave(&dport->port.lock, flags);
 146         dport->cflag &= ~DZ_CREAD;
 147         dz_out(dport, DZ_LPR, dport->cflag);
 148         spin_unlock_irqrestore(&dport->port.lock, flags);
 149 }
 150
 151 static void dz_enable_ms(struct uart_port *port)
 152 {
 153         /* nothing to do */
 154 }
 155
 156 /*
 157  * ------------------------------------------------------------
 158  * Here starts the interrupt handling routines.  All of the
 159  * following subroutines are declared as inline and are folded
 160  * into dz_interrupt.  They were separated out for readability's
 161  * sake.
 162  *
 163  * Note: rs_interrupt() is a "fast" interrupt, which means that it
 164  * runs with interrupts turned off.  People who may want to modify
 165  * rs_interrupt() should try to keep the interrupt handler as fast as
 166  * possible.  After you are done making modifications, it is not a bad
 167  * idea to do:
 168  *
 169  *      make drivers/serial/dz.s
 170  *
 171  * and look at the resulting assemble code in dz.s.
 172  *
 173  * ------------------------------------------------------------
 174  */
 175
 176 /*
 177  * ------------------------------------------------------------
 178  * receive_char ()
 179  *
 180  * This routine deals with inputs from any lines.
 181  * ------------------------------------------------------------
 182  */
 183 static inline void dz_receive_chars(struct dz_port *dport)
 184 {
 185         struct tty_struct *tty = NULL;
 186         struct uart_icount *icount;
 187         int ignore = 0;
 188         unsigned short status, tmp;
 189         unsigned char ch;
 190
 191         /* this code is going to be a problem...
 192            the call to tty_flip_buffer is going to need
 193            to be rethought...
 194          */
 195         do {
 196                 status = dz_in(dport, DZ_RBUF);
 197
 198                 /* punt so we don't get duplicate characters */
 199                 if (!(status & DZ_DVAL))
 200                         goto ignore_char;
 201
 202
 203                 ch = UCHAR(status);     /* grab the char */
 204
 205 #if 0
 206                 if (info->is_console) {
 207                         if (ch == 0)
 208                                 return;         /* it's a break ... */
 209                 }
 210 #endif
 211
 212                 tty = dport->port.info->tty;/* now tty points to the proper dev */
 213                 icount = &dport->port.icount;
 214
 215                 if (!tty)
 216                         break;
 217                 if (tty->flip.count >= TTY_FLIPBUF_SIZE)
 218                         break;
 219
 220                 *tty->flip.char_buf_ptr = ch;
 221                 *tty->flip.flag_buf_ptr = 0;
 222                 icount->rx++;
 223
 224                 /* keep track of the statistics */
 225                 if (status & (DZ_OERR | DZ_FERR | DZ_PERR)) {
 226                         if (status & DZ_PERR)   /* parity error */
 227                                 icount->parity++;
 228                         else if (status & DZ_FERR)      /* frame error */
 229                                 icount->frame++;
 230                         if (status & DZ_OERR)   /* overrun error */
 231                                 icount->overrun++;
 232
 233                         /*  check to see if we should ignore the character
 234                            and mask off conditions that should be ignored
 235                          */
 236
 237                         if (status & dport->port.ignore_status_mask) {
 238                                 if (++ignore > 100)
 239                                         break;
 240                                 goto ignore_char;
 241                         }
 242                         /* mask off the error conditions we want to ignore */
 243                         tmp = status & dport->port.read_status_mask;
 244
 245                         if (tmp & DZ_PERR) {
 246                                 *tty->flip.flag_buf_ptr = TTY_PARITY;
 247 #ifdef DEBUG_DZ
 248                                 debug_console("PERR\n", 5);
 249 #endif
 250                         } else if (tmp & DZ_FERR) {
 251                                 *tty->flip.flag_buf_ptr = TTY_FRAME;
 252 #ifdef DEBUG_DZ
 253                                 debug_console("FERR\n", 5);
 254 #endif
 255                         }
 256                         if (tmp & DZ_OERR) {
 257 #ifdef DEBUG_DZ
 258                                 debug_console("OERR\n", 5);
 259 #endif
 260                                 if (tty->flip.count < TTY_FLIPBUF_SIZE) {
 261                                         tty->flip.count++;
 262                                         tty->flip.flag_buf_ptr++;
 263                                         tty->flip.char_buf_ptr++;
 264                                         *tty->flip.flag_buf_ptr = TTY_OVERRUN;
 265                                 }
 266                         }
 267                 }
 268                 tty->flip.flag_buf_ptr++;
 269                 tty->flip.char_buf_ptr++;
 270                 tty->flip.count++;
 271               ignore_char:
 272         } while (status & DZ_DVAL);
 273
 274         if (tty)
 275                 tty_flip_buffer_push(tty);
 276 }
 277
 278 /*
 279  * ------------------------------------------------------------
 280  * transmit_char ()
 281  *
 282  * This routine deals with outputs to any lines.
 283  * ------------------------------------------------------------
 284  */
 285 static inline void dz_transmit_chars(struct dz_port *dport)
 286 {
 287         struct circ_buf *xmit = &dport->port.info->xmit;
 288         unsigned char tmp;
 289
 290         if (dport->port.x_char) {       /* XON/XOFF chars */
 291                 dz_out(dport, DZ_TDR, dport->port.x_char);
 292                 dport->port.icount.tx++;
 293                 dport->port.x_char = 0;
 294                 return;
 295         }
 296         /* if nothing to do or stopped or hardware stopped */
 297         if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
 298                 dz_stop_tx(&dport->port, 0);
 299                 return;
 300         }
 301
 302         /*
 303          * if something to do ... (rember the dz has no output fifo so we go
 304          * one char at a time :-<
 305          */
 306         tmp = xmit->buf[xmit->tail];
 307         xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
 308         dz_out(dport, DZ_TDR, tmp);
 309         dport->port.icount.tx++;
 310
 311         if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
 312                 uart_write_wakeup(&dport->port);
 313
 314         /* Are we done */
 315         if (uart_circ_empty(xmit))
 316                 dz_stop_tx(&dport->port, 0);
 317 }
 318
 319 /*
 320  * ------------------------------------------------------------
 321  * check_modem_status ()
 322  *
 323  * Only valid for the MODEM line duh !
 324  * ------------------------------------------------------------
 325  */
 326 static inline void check_modem_status(struct dz_port *dport)
 327 {
 328         unsigned short status;
 329
 330         /* if not ne modem line just return */
 331         if (dport->port.line != DZ_MODEM)
 332                 return;
 333
 334         status = dz_in(dport, DZ_MSR);
 335
 336         /* it's easy, since DSR2 is the only bit in the register */
 337         if (status)
 338                 dport->port.icount.dsr++;
 339 }
 340
 341 /*
 342  * ------------------------------------------------------------
 343  * dz_interrupt ()
 344  *
 345  * this is the main interrupt routine for the DZ chip.
 346  * It deals with the multiple ports.
 347  * ------------------------------------------------------------
 348  */
 349 static irqreturn_t dz_interrupt(int irq, void *dev, struct pt_regs *regs)
 350 {
 351         struct dz_port *dport;
 352         unsigned short status;
 353
 354         /* get the reason why we just got an irq */
 355         status = dz_in((struct dz_port *)dev, DZ_CSR);
 356         dport = &dz_ports[LINE(status)];
 357
 358         if (status & DZ_RDONE)
 359                 dz_receive_chars(dport);
 360
 361         if (status & DZ_TRDY)
 362                 dz_transmit_chars(dport);
 363
 364         /* FIXME: what about check modem status??? --rmk */
 365
 366         return IRQ_HANDLED;
 367 }
 368
 369 /*
 370  * -------------------------------------------------------------------
 371  * Here ends the DZ interrupt routines.
 372  * -------------------------------------------------------------------
 373  */
 374
 375 static unsigned int dz_get_mctrl(struct uart_port *uport)
 376 {
 377         struct dz_port *dport = (struct dz_port *)uport;
 378         unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
 379
 380         if (dport->port.line == DZ_MODEM) {
 381                 /*
 382                  * CHECKME: This is a guess from the other code... --rmk
 383                  */
 384                 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
 385                         mctrl &= ~TIOCM_DSR;
 386         }
 387
 388         return mctrl;
 389 }
 390
 391 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
 392 {
 393         struct dz_port *dport = (struct dz_port *)uport;
 394         unsigned short tmp;
 395
 396         if (dport->port.line == DZ_MODEM) {
 397                 tmp = dz_in(dport, DZ_TCR);
 398                 if (mctrl & TIOCM_DTR)
 399                         tmp &= ~DZ_MODEM_DTR;
 400                 else
 401                         tmp |= DZ_MODEM_DTR;
 402                 dz_out(dport, DZ_TCR, tmp);
 403         }
 404 }
 405
 406 /*
 407  * -------------------------------------------------------------------
 408  * startup ()
 409  *
 410  * various initialization tasks
 411  * -------------------------------------------------------------------
 412  */
 413 static int dz_startup(struct uart_port *uport)
 414 {
 415         struct dz_port *dport = (struct dz_port *)uport;
 416         unsigned long flags;
 417         unsigned short tmp;
 418
 419         /* The dz lines for the mouse/keyboard must be
 420          * opened using their respective drivers.
 421          */
 422         if ((dport->port.line == DZ_KEYBOARD) ||
 423             (dport->port.line == DZ_MOUSE))
 424                 return -ENODEV;
 425
 426         spin_lock_irqsave(&dport->port.lock, flags);
 427
 428         /* enable the interrupt and the scanning */
 429         tmp = dz_in(dport, DZ_CSR);
 430         tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
 431         dz_out(dport, DZ_CSR, tmp);
 432
 433         spin_unlock_irqrestore(&dport->port.lock, flags);
 434
 435         return 0;
 436 }
 437
 438 /*
 439  * -------------------------------------------------------------------
 440  * shutdown ()
 441  *
 442  * This routine will shutdown a serial port; interrupts are disabled, and
 443  * DTR is dropped if the hangup on close termio flag is on.
 444  * -------------------------------------------------------------------
 445  */
 446 static void dz_shutdown(struct uart_port *uport)
 447 {
 448         dz_stop_tx(uport, 0);
 449 }
 450
 451 /*
 452  * get_lsr_info - get line status register info
 453  *
 454  * Purpose: Let user call ioctl() to get info when the UART physically
 455  *          is emptied.  On bus types like RS485, the transmitter must
 456  *          release the bus after transmitting. This must be done when
 457  *          the transmit shift register is empty, not be done when the
 458  *          transmit holding register is empty.  This functionality
 459  *          allows an RS485 driver to be written in user space.
 460  */
 461 static unsigned int dz_tx_empty(struct uart_port *uport)
 462 {
 463         struct dz_port *dport = (struct dz_port *)uport;
 464         unsigned short status = dz_in(dport, DZ_LPR);
 465
 466         /* FIXME: this appears to be obviously broken --rmk. */
 467         return status ? TIOCSER_TEMT : 0;
 468 }
 469
 470 static void dz_break_ctl(struct uart_port *uport, int break_state)
 471 {
 472         struct dz_port *dport = (struct dz_port *)uport;
 473         unsigned long flags;
 474         unsigned short tmp, mask = 1 << uport->line;
 475
 476         spin_lock_irqsave(&uport->lock, flags);
 477         tmp = dz_in(dport, DZ_TCR);
 478         if (break_state)
 479                 tmp |= mask;
 480         else
 481                 tmp &= ~mask;
 482         dz_out(dport, DZ_TCR, tmp);
 483         spin_unlock_irqrestore(&uport->lock, flags);
 484 }
 485
 486 static void dz_set_termios(struct uart_port *uport, struct termios *termios,
 487                            struct termios *old_termios)
 488 {
 489         struct dz_port *dport = (struct dz_port *)uport;
 490         unsigned long flags;
 491         unsigned int cflag, baud;
 492
 493         cflag = dport->port.line;
 494
 495         switch (termios->c_cflag & CSIZE) {
 496         case CS5:
 497                 cflag |= DZ_CS5;
 498                 break;
 499         case CS6:
 500                 cflag |= DZ_CS6;
 501                 break;
 502         case CS7:
 503                 cflag |= DZ_CS7;
 504                 break;
 505         case CS8:
 506         default:
 507                 cflag |= DZ_CS8;
 508         }
 509
 510         if (termios->c_cflag & CSTOPB)
 511                 cflag |= DZ_CSTOPB;
 512         if (termios->c_cflag & PARENB)
 513                 cflag |= DZ_PARENB;
 514         if (termios->c_cflag & PARODD)
 515                 cflag |= DZ_PARODD;
 516
 517         baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
 518         switch (baud) {
 519         case 50:
 520                 cflag |= DZ_B50;
 521                 break;
 522         case 75:
 523                 cflag |= DZ_B75;
 524                 break;
 525         case 110:
 526                 cflag |= DZ_B110;
 527                 break;
 528         case 134:
 529                 cflag |= DZ_B134;
 530                 break;
 531         case 150:
 532                 cflag |= DZ_B150;
 533                 break;
 534         case 300:
 535                 cflag |= DZ_B300;
 536                 break;
 537         case 600:
 538                 cflag |= DZ_B600;
 539                 break;
 540         case 1200:
 541                 cflag |= DZ_B1200;
 542                 break;
 543         case 1800:
 544                 cflag |= DZ_B1800;
 545                 break;
 546         case 2000:
 547                 cflag |= DZ_B2000;
 548                 break;
 549         case 2400:
 550                 cflag |= DZ_B2400;
 551                 break;
 552         case 3600:
 553                 cflag |= DZ_B3600;
 554                 break;
 555         case 4800:
 556                 cflag |= DZ_B4800;
 557                 break;
 558         case 7200:
 559                 cflag |= DZ_B7200;
 560                 break;
 561         case 9600:
 562         default:
 563                 cflag |= DZ_B9600;
 564         }
 565
 566         if (termios->c_cflag & CREAD)
 567                 cflag |= DZ_RXENAB;
 568
 569         spin_lock_irqsave(&dport->port.lock, flags);
 570
 571         dz_out(dport, DZ_LPR, cflag);
 572         dport->cflag = cflag;
 573
 574         /* setup accept flag */
 575         dport->port.read_status_mask = DZ_OERR;
 576         if (termios->c_iflag & INPCK)
 577                 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
 578
 579         /* characters to ignore */
 580         uport->ignore_status_mask = 0;
 581         if (termios->c_iflag & IGNPAR)
 582                 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
 583
 584         spin_unlock_irqrestore(&dport->port.lock, flags);
 585 }
 586
 587 static const char *dz_type(struct uart_port *port)
 588 {
 589         return "DZ";
 590 }
 591
 592 static void dz_release_port(struct uart_port *port)
 593 {
 594         /* nothing to do */
 595 }
 596
 597 static int dz_request_port(struct uart_port *port)
 598 {
 599         return 0;
 600 }
 601
 602 static void dz_config_port(struct uart_port *port, int flags)
 603 {
 604         if (flags & UART_CONFIG_TYPE)
 605                 port->type = PORT_DZ;
 606 }
 607
 608 /*
 609  * verify the new serial_struct (for TIOCSSERIAL).
 610  */
 611 static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
 612 {
 613         int ret = 0;
 614         if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
 615                 ret = -EINVAL;
 616         if (ser->irq != port->irq)
 617                 ret = -EINVAL;
 618         return ret;
 619 }
 620
 621 static struct uart_ops dz_ops = {
 622         .tx_empty       = dz_tx_empty,
 623         .get_mctrl      = dz_get_mctrl,
 624         .set_mctrl      = dz_set_mctrl,
 625         .stop_tx        = dz_stop_tx,
 626         .start_tx       = dz_start_tx,
 627         .stop_rx        = dz_stop_rx,
 628         .enable_ms      = dz_enable_ms,
 629         .break_ctl      = dz_break_ctl,
 630         .startup        = dz_startup,
 631         .shutdown       = dz_shutdown,
 632         .set_termios    = dz_set_termios,
 633         .type           = dz_type,
 634         .release_port   = dz_release_port,
 635         .request_port   = dz_request_port,
 636         .config_port    = dz_config_port,
 637         .verify_port    = dz_verify_port,
 638 };
 639
 640 static void __init dz_init_ports(void)
 641 {
 642         static int first = 1;
 643         struct dz_port *dport;
 644         unsigned long base;
 645         int i;
 646
 647         if (!first)
 648                 return;
 649         first = 0;
 650
 651         if (mips_machtype == MACH_DS23100 ||
 652             mips_machtype == MACH_DS5100)
 653                 base = (unsigned long) KN01_DZ11_BASE;
 654         else
 655                 base = (unsigned long) KN02_DZ11_BASE;
 656
 657         for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
 658                 spin_lock_init(&dport->port.lock);
 659                 dport->port.membase     = (char *) base;
 660                 dport->port.iotype      = SERIAL_IO_PORT;
 661                 dport->port.irq         = dec_interrupt[DEC_IRQ_DZ11];
 662                 dport->port.line        = i;
 663                 dport->port.fifosize    = 1;
 664                 dport->port.ops         = &dz_ops;
 665                 dport->port.flags       = UPF_BOOT_AUTOCONF;
 666         }
 667 }
 668
 669 static void dz_reset(struct dz_port *dport)
 670 {
 671         dz_out(dport, DZ_CSR, DZ_CLR);
 672
 673         while (dz_in(dport, DZ_CSR) & DZ_CLR);
 674                 /* FIXME: cpu_relax? */
 675
 676         iob();
 677
 678         /* enable scanning */
 679         dz_out(dport, DZ_CSR, DZ_MSE);
 680 }
 681
 682 #ifdef CONFIG_SERIAL_DZ_CONSOLE
 683 static void dz_console_put_char(struct dz_port *dport, unsigned char ch)
 684 {
 685         unsigned long flags;
 686         int loops = 2500;
 687         unsigned short tmp = ch;
 688         /* this code sends stuff out to serial device - spinning its
 689            wheels and waiting. */
 690
 691         spin_lock_irqsave(&dport->port.lock, flags);
 692
 693         /* spin our wheels */
 694         while (((dz_in(dport, DZ_CSR) & DZ_TRDY) != DZ_TRDY) && loops--)
 695                 /* FIXME: cpu_relax, udelay? --rmk */
 696                 ;
 697
 698         /* Actually transmit the character. */
 699         dz_out(dport, DZ_TDR, tmp);
 700
 701         spin_unlock_irqrestore(&dport->port.lock, flags);
 702 }
 703 /*
 704  * -------------------------------------------------------------------
 705  * dz_console_print ()
 706  *
 707  * dz_console_print is registered for printk.
 708  * The console must be locked when we get here.
 709  * -------------------------------------------------------------------
 710  */
 711 static void dz_console_print(struct console *cons,
 712                              const char *str,
 713                              unsigned int count)
 714 {
 715         struct dz_port *dport = &dz_ports[CONSOLE_LINE];
 716 #ifdef DEBUG_DZ
 717         prom_printf((char *) str);
 718 #endif
 719         while (count--) {
 720                 if (*str == '\n')
 721                         dz_console_put_char(dport, '\r');
 722                 dz_console_put_char(dport, *str++);
 723         }
 724 }
 725
 726 static int __init dz_console_setup(struct console *co, char *options)
 727 {
 728         struct dz_port *dport = &dz_ports[CONSOLE_LINE];
 729         int baud = 9600;
 730         int bits = 8;
 731         int parity = 'n';
 732         int flow = 'n';
 733         int ret;
 734         unsigned short mask, tmp;
 735
 736         if (options)
 737                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 738
 739         dz_reset(dport);
 740
 741         ret = uart_set_options(&dport->port, co, baud, parity, bits, flow);
 742         if (ret == 0) {
 743                 mask = 1 << dport->port.line;
 744                 tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 745                 if (!(tmp & mask)) {
 746                         tmp |= mask;            /* set the TX flag */
 747                         dz_out(dport, DZ_TCR, tmp);
 748                 }
 749         }
 750
 751         return ret;
 752 }
 753
 754 static struct console dz_sercons =
 755 {
 756         .name   = "ttyS",
 757         .write  = dz_console_print,
 758         .device = uart_console_device,
 759         .setup  = dz_console_setup,
 760         .flags  = CON_CONSDEV | CON_PRINTBUFFER,
 761         .index  = CONSOLE_LINE,
 762 };
 763
 764 void __init dz_serial_console_init(void)
 765 {
 766         dz_init_ports();
 767
 768         register_console(&dz_sercons);
 769 }
 770
 771 #define SERIAL_DZ_CONSOLE       &dz_sercons
 772 #else
 773 #define SERIAL_DZ_CONSOLE       NULL
 774 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
 775
 776 static struct uart_driver dz_reg = {
 777         .owner                  = THIS_MODULE,
 778         .driver_name            = "serial",
 779 #ifdef CONFIG_DEVFS
 780         .dev_name               = "tts/%d",
 781 #else
 782         .dev_name               = "ttyS%d",
 783 #endif
 784         .major                  = TTY_MAJOR,
 785         .minor                  = 64,
 786         .nr                     = DZ_NB_PORT,
 787         .cons                   = SERIAL_DZ_CONSOLE,
 788 };
 789
 790 int __init dz_init(void)
 791 {
 792         unsigned long flags;
 793         int ret, i;
 794
 795         printk("%s%s\n", dz_name, dz_version);
 796
 797         dz_init_ports();
 798
 799         save_flags(flags);
 800         cli();
 801
 802 #ifndef CONFIG_SERIAL_DZ_CONSOLE
 803         /* reset the chip */
 804         dz_reset(&dz_ports[0]);
 805 #endif
 806
 807         /* order matters here... the trick is that flags
 808            is updated... in request_irq - to immediatedly obliterate
 809            it is unwise. */
 810         restore_flags(flags);
 811
 812         if (request_irq(dz_ports[0].port.irq, dz_interrupt,
 813                         SA_INTERRUPT, "DZ", &dz_ports[0]))
 814                 panic("Unable to register DZ interrupt");
 815
 816         ret = uart_register_driver(&dz_reg);
 817         if (ret != 0)
 818                 return ret;
 819
 820         for (i = 0; i < DZ_NB_PORT; i++)
 821                 uart_add_one_port(&dz_reg, &dz_ports[i].port);
 822
 823         return ret;
 824 }
 825
 826 MODULE_DESCRIPTION("DECstation DZ serial driver");
 827 MODULE_LICENSE("GPL");