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, 2007  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/bitops.h>
  36 #include <linux/compiler.h>
  37 #include <linux/console.h>
  38 #include <linux/delay.h>
  39 #include <linux/errno.h>
  40 #include <linux/init.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/ioport.h>
  43 #include <linux/kernel.h>
  44 #include <linux/major.h>
  45 #include <linux/module.h>
  46 #include <linux/serial.h>
  47 #include <linux/serial_core.h>
  48 #include <linux/sysrq.h>
  49 #include <linux/tty.h>
  50
  51 #include <asm/atomic.h>
  52 #include <asm/bootinfo.h>
  53 #include <asm/io.h>
  54 #include <asm/system.h>
  55
  56 #include <asm/dec/interrupts.h>
  57 #include <asm/dec/kn01.h>
  58 #include <asm/dec/kn02.h>
  59 #include <asm/dec/machtype.h>
  60 #include <asm/dec/prom.h>
  61 #include <asm/dec/system.h>
  62
  63 #include "dz.h"
  64
  65
  66 MODULE_DESCRIPTION("DECstation DZ serial driver");
  67 MODULE_LICENSE("GPL");
  68
  69
  70 static char dz_name[] __initdata = "DECstation DZ serial driver version ";
  71 static char dz_version[] __initdata = "1.04";
  72
  73 struct dz_port {
  74         struct dz_mux           *mux;
  75         struct uart_port        port;
  76         unsigned int            cflag;
  77 };
  78
  79 struct dz_mux {
  80         struct dz_port          dport[DZ_NB_PORT];
  81         atomic_t                map_guard;
  82         atomic_t                irq_guard;
  83         int                     initialised;
  84 };
  85
  86 static struct dz_mux dz_mux;
  87
  88 static inline struct dz_port *to_dport(struct uart_port *uport)
  89 {
  90         return container_of(uport, struct dz_port, port);
  91 }
  92
  93 /*
  94  * ------------------------------------------------------------
  95  * dz_in () and dz_out ()
  96  *
  97  * These routines are used to access the registers of the DZ
  98  * chip, hiding relocation differences between implementation.
  99  * ------------------------------------------------------------
 100  */
 101
 102 static u16 dz_in(struct dz_port *dport, unsigned offset)
 103 {
 104         void __iomem *addr = dport->port.membase + offset;
 105
 106         return readw(addr);
 107 }
 108
 109 static void dz_out(struct dz_port *dport, unsigned offset, u16 value)
 110 {
 111         void __iomem *addr = dport->port.membase + offset;
 112
 113         writew(value, addr);
 114 }
 115
 116 /*
 117  * ------------------------------------------------------------
 118  * rs_stop () and rs_start ()
 119  *
 120  * These routines are called before setting or resetting
 121  * tty->stopped. They enable or disable transmitter interrupts,
 122  * as necessary.
 123  * ------------------------------------------------------------
 124  */
 125
 126 static void dz_stop_tx(struct uart_port *uport)
 127 {
 128         struct dz_port *dport = to_dport(uport);
 129         u16 tmp, mask = 1 << dport->port.line;
 130
 131         tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 132         tmp &= ~mask;                   /* clear the TX flag */
 133         dz_out(dport, DZ_TCR, tmp);
 134 }
 135
 136 static void dz_start_tx(struct uart_port *uport)
 137 {
 138         struct dz_port *dport = to_dport(uport);
 139         u16 tmp, mask = 1 << dport->port.line;
 140
 141         tmp = dz_in(dport, DZ_TCR);     /* read the TX flag */
 142         tmp |= mask;                    /* set the TX flag */
 143         dz_out(dport, DZ_TCR, tmp);
 144 }
 145
 146 static void dz_stop_rx(struct uart_port *uport)
 147 {
 148         struct dz_port *dport = to_dport(uport);
 149
 150         dport->cflag &= ~DZ_RXENAB;
 151         dz_out(dport, DZ_LPR, dport->cflag);
 152 }
 153
 154 static void dz_enable_ms(struct uart_port *uport)
 155 {
 156         /* nothing to do */
 157 }
 158
 159 /*
 160  * ------------------------------------------------------------
 161  *
 162  * Here start the interrupt handling routines.  All of the following
 163  * subroutines are declared as inline and are folded into
 164  * dz_interrupt.  They were separated out for readability's sake.
 165  *
 166  * Note: dz_interrupt() is a "fast" interrupt, which means that it
 167  * runs with interrupts turned off.  People who may want to modify
 168  * dz_interrupt() should try to keep the interrupt handler as fast as
 169  * possible.  After you are done making modifications, it is not a bad
 170  * idea to do:
 171  *
 172  *      make drivers/serial/dz.s
 173  *
 174  * and look at the resulting assemble code in dz.s.
 175  *
 176  * ------------------------------------------------------------
 177  */
 178
 179 /*
 180  * ------------------------------------------------------------
 181  * receive_char ()
 182  *
 183  * This routine deals with inputs from any lines.
 184  * ------------------------------------------------------------
 185  */
 186 static inline void dz_receive_chars(struct dz_mux *mux)
 187 {
 188         struct uart_port *uport;
 189         struct dz_port *dport = &mux->dport[0];
 190         struct tty_struct *tty = NULL;
 191         struct uart_icount *icount;
 192         int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
 193         unsigned char ch, flag;
 194         u16 status;
 195         int i;
 196
 197         while ((status = dz_in(dport, DZ_RBUF)) & DZ_DVAL) {
 198                 dport = &mux->dport[LINE(status)];
 199                 uport = &dport->port;
 200                 tty = uport->info->port.tty;    /* point to the proper dev */
 201
 202                 ch = UCHAR(status);             /* grab the char */
 203                 flag = TTY_NORMAL;
 204
 205                 icount = &uport->icount;
 206                 icount->rx++;
 207
 208                 if (unlikely(status & (DZ_OERR | DZ_FERR | DZ_PERR))) {
 209
 210                         /*
 211                          * There is no separate BREAK status bit, so treat
 212                          * null characters with framing errors as BREAKs;
 213                          * normally, otherwise.  For this move the Framing
 214                          * Error bit to a simulated BREAK bit.
 215                          */
 216                         if (!ch) {
 217                                 status |= (status & DZ_FERR) >>
 218                                           (ffs(DZ_FERR) - ffs(DZ_BREAK));
 219                                 status &= ~DZ_FERR;
 220                         }
 221
 222                         /* Handle SysRq/SAK & keep track of the statistics. */
 223                         if (status & DZ_BREAK) {
 224                                 icount->brk++;
 225                                 if (uart_handle_break(uport))
 226                                         continue;
 227                         } else if (status & DZ_FERR)
 228                                 icount->frame++;
 229                         else if (status & DZ_PERR)
 230                                 icount->parity++;
 231                         if (status & DZ_OERR)
 232                                 icount->overrun++;
 233
 234                         status &= uport->read_status_mask;
 235                         if (status & DZ_BREAK)
 236                                 flag = TTY_BREAK;
 237                         else if (status & DZ_FERR)
 238                                 flag = TTY_FRAME;
 239                         else if (status & DZ_PERR)
 240                                 flag = TTY_PARITY;
 241
 242                 }
 243
 244                 if (uart_handle_sysrq_char(uport, ch))
 245                         continue;
 246
 247                 uart_insert_char(uport, status, DZ_OERR, ch, flag);
 248                 lines_rx[LINE(status)] = 1;
 249         }
 250         for (i = 0; i < DZ_NB_PORT; i++)
 251                 if (lines_rx[i])
 252                         tty_flip_buffer_push(mux->dport[i].port.info->port.tty);
 253 }
 254
 255 /*
 256  * ------------------------------------------------------------
 257  * transmit_char ()
 258  *
 259  * This routine deals with outputs to any lines.
 260  * ------------------------------------------------------------
 261  */
 262 static inline void dz_transmit_chars(struct dz_mux *mux)
 263 {
 264         struct dz_port *dport = &mux->dport[0];
 265         struct circ_buf *xmit;
 266         unsigned char tmp;
 267         u16 status;
 268
 269         status = dz_in(dport, DZ_CSR);
 270         dport = &mux->dport[LINE(status)];
 271         xmit = &dport->port.info->xmit;
 272
 273         if (dport->port.x_char) {               /* XON/XOFF chars */
 274                 dz_out(dport, DZ_TDR, dport->port.x_char);
 275                 dport->port.icount.tx++;
 276                 dport->port.x_char = 0;
 277                 return;
 278         }
 279         /* If nothing to do or stopped or hardware stopped. */
 280         if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
 281                 spin_lock(&dport->port.lock);
 282                 dz_stop_tx(&dport->port);
 283                 spin_unlock(&dport->port.lock);
 284                 return;
 285         }
 286
 287         /*
 288          * If something to do... (remember the dz has no output fifo,
 289          * so we go one char at a time) :-<
 290          */
 291         tmp = xmit->buf[xmit->tail];
 292         xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
 293         dz_out(dport, DZ_TDR, tmp);
 294         dport->port.icount.tx++;
 295
 296         if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
 297                 uart_write_wakeup(&dport->port);
 298
 299         /* Are we are done. */
 300         if (uart_circ_empty(xmit)) {
 301                 spin_lock(&dport->port.lock);
 302                 dz_stop_tx(&dport->port);
 303                 spin_unlock(&dport->port.lock);
 304         }
 305 }
 306
 307 /*
 308  * ------------------------------------------------------------
 309  * check_modem_status()
 310  *
 311  * DS 3100 & 5100: Only valid for the MODEM line, duh!
 312  * DS 5000/200: Valid for the MODEM and PRINTER line.
 313  * ------------------------------------------------------------
 314  */
 315 static inline void check_modem_status(struct dz_port *dport)
 316 {
 317         /*
 318          * FIXME:
 319          * 1. No status change interrupt; use a timer.
 320          * 2. Handle the 3100/5000 as appropriate. --macro
 321          */
 322         u16 status;
 323
 324         /* If not the modem line just return.  */
 325         if (dport->port.line != DZ_MODEM)
 326                 return;
 327
 328         status = dz_in(dport, DZ_MSR);
 329
 330         /* it's easy, since DSR2 is the only bit in the register */
 331         if (status)
 332                 dport->port.icount.dsr++;
 333 }
 334
 335 /*
 336  * ------------------------------------------------------------
 337  * dz_interrupt ()
 338  *
 339  * this is the main interrupt routine for the DZ chip.
 340  * It deals with the multiple ports.
 341  * ------------------------------------------------------------
 342  */
 343 static irqreturn_t dz_interrupt(int irq, void *dev_id)
 344 {
 345         struct dz_mux *mux = dev_id;
 346         struct dz_port *dport = &mux->dport[0];
 347         u16 status;
 348
 349         /* get the reason why we just got an irq */
 350         status = dz_in(dport, DZ_CSR);
 351
 352         if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
 353                 dz_receive_chars(mux);
 354
 355         if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
 356                 dz_transmit_chars(mux);
 357
 358         return IRQ_HANDLED;
 359 }
 360
 361 /*
 362  * -------------------------------------------------------------------
 363  * Here ends the DZ interrupt routines.
 364  * -------------------------------------------------------------------
 365  */
 366
 367 static unsigned int dz_get_mctrl(struct uart_port *uport)
 368 {
 369         /*
 370          * FIXME: Handle the 3100/5000 as appropriate. --macro
 371          */
 372         struct dz_port *dport = to_dport(uport);
 373         unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
 374
 375         if (dport->port.line == DZ_MODEM) {
 376                 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
 377                         mctrl &= ~TIOCM_DSR;
 378         }
 379
 380         return mctrl;
 381 }
 382
 383 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
 384 {
 385         /*
 386          * FIXME: Handle the 3100/5000 as appropriate. --macro
 387          */
 388         struct dz_port *dport = to_dport(uport);
 389         u16 tmp;
 390
 391         if (dport->port.line == DZ_MODEM) {
 392                 tmp = dz_in(dport, DZ_TCR);
 393                 if (mctrl & TIOCM_DTR)
 394                         tmp &= ~DZ_MODEM_DTR;
 395                 else
 396                         tmp |= DZ_MODEM_DTR;
 397                 dz_out(dport, DZ_TCR, tmp);
 398         }
 399 }
 400
 401 /*
 402  * -------------------------------------------------------------------
 403  * startup ()
 404  *
 405  * various initialization tasks
 406  * -------------------------------------------------------------------
 407  */
 408 static int dz_startup(struct uart_port *uport)
 409 {
 410         struct dz_port *dport = to_dport(uport);
 411         struct dz_mux *mux = dport->mux;
 412         unsigned long flags;
 413         int irq_guard;
 414         int ret;
 415         u16 tmp;
 416
 417         irq_guard = atomic_add_return(1, &mux->irq_guard);
 418         if (irq_guard != 1)
 419                 return 0;
 420
 421         ret = request_irq(dport->port.irq, dz_interrupt,
 422                           IRQF_SHARED, "dz", mux);
 423         if (ret) {
 424                 atomic_add(-1, &mux->irq_guard);
 425                 printk(KERN_ERR "dz: Cannot get IRQ %d!\n", dport->port.irq);
 426                 return ret;
 427         }
 428
 429         spin_lock_irqsave(&dport->port.lock, flags);
 430
 431         /* Enable interrupts.  */
 432         tmp = dz_in(dport, DZ_CSR);
 433         tmp |= DZ_RIE | DZ_TIE;
 434         dz_out(dport, DZ_CSR, tmp);
 435
 436         spin_unlock_irqrestore(&dport->port.lock, flags);
 437
 438         return 0;
 439 }
 440
 441 /*
 442  * -------------------------------------------------------------------
 443  * shutdown ()
 444  *
 445  * This routine will shutdown a serial port; interrupts are disabled, and
 446  * DTR is dropped if the hangup on close termio flag is on.
 447  * -------------------------------------------------------------------
 448  */
 449 static void dz_shutdown(struct uart_port *uport)
 450 {
 451         struct dz_port *dport = to_dport(uport);
 452         struct dz_mux *mux = dport->mux;
 453         unsigned long flags;
 454         int irq_guard;
 455         u16 tmp;
 456
 457         spin_lock_irqsave(&dport->port.lock, flags);
 458         dz_stop_tx(&dport->port);
 459         spin_unlock_irqrestore(&dport->port.lock, flags);
 460
 461         irq_guard = atomic_add_return(-1, &mux->irq_guard);
 462         if (!irq_guard) {
 463                 /* Disable interrupts.  */
 464                 tmp = dz_in(dport, DZ_CSR);
 465                 tmp &= ~(DZ_RIE | DZ_TIE);
 466                 dz_out(dport, DZ_CSR, tmp);
 467
 468                 free_irq(dport->port.irq, mux);
 469         }
 470 }
 471
 472 /*
 473  * -------------------------------------------------------------------
 474  * dz_tx_empty() -- get the transmitter empty status
 475  *
 476  * Purpose: Let user call ioctl() to get info when the UART physically
 477  *          is emptied.  On bus types like RS485, the transmitter must
 478  *          release the bus after transmitting. This must be done when
 479  *          the transmit shift register is empty, not be done when the
 480  *          transmit holding register is empty.  This functionality
 481  *          allows an RS485 driver to be written in user space.
 482  * -------------------------------------------------------------------
 483  */
 484 static unsigned int dz_tx_empty(struct uart_port *uport)
 485 {
 486         struct dz_port *dport = to_dport(uport);
 487         unsigned short tmp, mask = 1 << dport->port.line;
 488
 489         tmp = dz_in(dport, DZ_TCR);
 490         tmp &= mask;
 491
 492         return tmp ? 0 : TIOCSER_TEMT;
 493 }
 494
 495 static void dz_break_ctl(struct uart_port *uport, int break_state)
 496 {
 497         /*
 498          * FIXME: Can't access BREAK bits in TDR easily;
 499          * reuse the code for polled TX. --macro
 500          */
 501         struct dz_port *dport = to_dport(uport);
 502         unsigned long flags;
 503         unsigned short tmp, mask = 1 << dport->port.line;
 504
 505         spin_lock_irqsave(&uport->lock, flags);
 506         tmp = dz_in(dport, DZ_TCR);
 507         if (break_state)
 508                 tmp |= mask;
 509         else
 510                 tmp &= ~mask;
 511         dz_out(dport, DZ_TCR, tmp);
 512         spin_unlock_irqrestore(&uport->lock, flags);
 513 }
 514
 515 static int dz_encode_baud_rate(unsigned int baud)
 516 {
 517         switch (baud) {
 518         case 50:
 519                 return DZ_B50;
 520         case 75:
 521                 return DZ_B75;
 522         case 110:
 523                 return DZ_B110;
 524         case 134:
 525                 return DZ_B134;
 526         case 150:
 527                 return DZ_B150;
 528         case 300:
 529                 return DZ_B300;
 530         case 600:
 531                 return DZ_B600;
 532         case 1200:
 533                 return DZ_B1200;
 534         case 1800:
 535                 return DZ_B1800;
 536         case 2000:
 537                 return DZ_B2000;
 538         case 2400:
 539                 return DZ_B2400;
 540         case 3600:
 541                 return DZ_B3600;
 542         case 4800:
 543                 return DZ_B4800;
 544         case 7200:
 545                 return DZ_B7200;
 546         case 9600:
 547                 return DZ_B9600;
 548         default:
 549                 return -1;
 550         }
 551 }
 552
 553
 554 static void dz_reset(struct dz_port *dport)
 555 {
 556         struct dz_mux *mux = dport->mux;
 557
 558         if (mux->initialised)
 559                 return;
 560
 561         dz_out(dport, DZ_CSR, DZ_CLR);
 562         while (dz_in(dport, DZ_CSR) & DZ_CLR);
 563         iob();
 564
 565         /* Enable scanning.  */
 566         dz_out(dport, DZ_CSR, DZ_MSE);
 567
 568         mux->initialised = 1;
 569 }
 570
 571 static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
 572                            struct ktermios *old_termios)
 573 {
 574         struct dz_port *dport = to_dport(uport);
 575         unsigned long flags;
 576         unsigned int cflag, baud;
 577         int bflag;
 578
 579         cflag = dport->port.line;
 580
 581         switch (termios->c_cflag & CSIZE) {
 582         case CS5:
 583                 cflag |= DZ_CS5;
 584                 break;
 585         case CS6:
 586                 cflag |= DZ_CS6;
 587                 break;
 588         case CS7:
 589                 cflag |= DZ_CS7;
 590                 break;
 591         case CS8:
 592         default:
 593                 cflag |= DZ_CS8;
 594         }
 595
 596         if (termios->c_cflag & CSTOPB)
 597                 cflag |= DZ_CSTOPB;
 598         if (termios->c_cflag & PARENB)
 599                 cflag |= DZ_PARENB;
 600         if (termios->c_cflag & PARODD)
 601                 cflag |= DZ_PARODD;
 602
 603         baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
 604         bflag = dz_encode_baud_rate(baud);
 605         if (bflag < 0)  {                       /* Try to keep unchanged.  */
 606                 baud = uart_get_baud_rate(uport, old_termios, NULL, 50, 9600);
 607                 bflag = dz_encode_baud_rate(baud);
 608                 if (bflag < 0)  {               /* Resort to 9600.  */
 609                         baud = 9600;
 610                         bflag = DZ_B9600;
 611                 }
 612                 tty_termios_encode_baud_rate(termios, baud, baud);
 613         }
 614         cflag |= bflag;
 615
 616         if (termios->c_cflag & CREAD)
 617                 cflag |= DZ_RXENAB;
 618
 619         spin_lock_irqsave(&dport->port.lock, flags);
 620
 621         uart_update_timeout(uport, termios->c_cflag, baud);
 622
 623         dz_out(dport, DZ_LPR, cflag);
 624         dport->cflag = cflag;
 625
 626         /* setup accept flag */
 627         dport->port.read_status_mask = DZ_OERR;
 628         if (termios->c_iflag & INPCK)
 629                 dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
 630         if (termios->c_iflag & (BRKINT | PARMRK))
 631                 dport->port.read_status_mask |= DZ_BREAK;
 632
 633         /* characters to ignore */
 634         uport->ignore_status_mask = 0;
 635         if ((termios->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
 636                 dport->port.ignore_status_mask |= DZ_OERR;
 637         if (termios->c_iflag & IGNPAR)
 638                 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
 639         if (termios->c_iflag & IGNBRK)
 640                 dport->port.ignore_status_mask |= DZ_BREAK;
 641
 642         spin_unlock_irqrestore(&dport->port.lock, flags);
 643 }
 644
 645 /*
 646  * Hack alert!
 647  * Required solely so that the initial PROM-based console
 648  * works undisturbed in parallel with this one.
 649  */
 650 static void dz_pm(struct uart_port *uport, unsigned int state,
 651                   unsigned int oldstate)
 652 {
 653         struct dz_port *dport = to_dport(uport);
 654         unsigned long flags;
 655
 656         spin_lock_irqsave(&dport->port.lock, flags);
 657         if (state < 3)
 658                 dz_start_tx(&dport->port);
 659         else
 660                 dz_stop_tx(&dport->port);
 661         spin_unlock_irqrestore(&dport->port.lock, flags);
 662 }
 663
 664
 665 static const char *dz_type(struct uart_port *uport)
 666 {
 667         return "DZ";
 668 }
 669
 670 static void dz_release_port(struct uart_port *uport)
 671 {
 672         struct dz_mux *mux = to_dport(uport)->mux;
 673         int map_guard;
 674
 675         iounmap(uport->membase);
 676         uport->membase = NULL;
 677
 678         map_guard = atomic_add_return(-1, &mux->map_guard);
 679         if (!map_guard)
 680                 release_mem_region(uport->mapbase, dec_kn_slot_size);
 681 }
 682
 683 static int dz_map_port(struct uart_port *uport)
 684 {
 685         if (!uport->membase)
 686                 uport->membase = ioremap_nocache(uport->mapbase,
 687                                                  dec_kn_slot_size);
 688         if (!uport->membase) {
 689                 printk(KERN_ERR "dz: Cannot map MMIO\n");
 690                 return -ENOMEM;
 691         }
 692         return 0;
 693 }
 694
 695 static int dz_request_port(struct uart_port *uport)
 696 {
 697         struct dz_mux *mux = to_dport(uport)->mux;
 698         int map_guard;
 699         int ret;
 700
 701         map_guard = atomic_add_return(1, &mux->map_guard);
 702         if (map_guard == 1) {
 703                 if (!request_mem_region(uport->mapbase, dec_kn_slot_size,
 704                                         "dz")) {
 705                         atomic_add(-1, &mux->map_guard);
 706                         printk(KERN_ERR
 707                                "dz: Unable to reserve MMIO resource\n");
 708                         return -EBUSY;
 709                 }
 710         }
 711         ret = dz_map_port(uport);
 712         if (ret) {
 713                 map_guard = atomic_add_return(-1, &mux->map_guard);
 714                 if (!map_guard)
 715                         release_mem_region(uport->mapbase, dec_kn_slot_size);
 716                 return ret;
 717         }
 718         return 0;
 719 }
 720
 721 static void dz_config_port(struct uart_port *uport, int flags)
 722 {
 723         struct dz_port *dport = to_dport(uport);
 724
 725         if (flags & UART_CONFIG_TYPE) {
 726                 if (dz_request_port(uport))
 727                         return;
 728
 729                 uport->type = PORT_DZ;
 730
 731                 dz_reset(dport);
 732         }
 733 }
 734
 735 /*
 736  * Verify the new serial_struct (for TIOCSSERIAL).
 737  */
 738 static int dz_verify_port(struct uart_port *uport, struct serial_struct *ser)
 739 {
 740         int ret = 0;
 741
 742         if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
 743                 ret = -EINVAL;
 744         if (ser->irq != uport->irq)
 745                 ret = -EINVAL;
 746         return ret;
 747 }
 748
 749 static struct uart_ops dz_ops = {
 750         .tx_empty       = dz_tx_empty,
 751         .get_mctrl      = dz_get_mctrl,
 752         .set_mctrl      = dz_set_mctrl,
 753         .stop_tx        = dz_stop_tx,
 754         .start_tx       = dz_start_tx,
 755         .stop_rx        = dz_stop_rx,
 756         .enable_ms      = dz_enable_ms,
 757         .break_ctl      = dz_break_ctl,
 758         .startup        = dz_startup,
 759         .shutdown       = dz_shutdown,
 760         .set_termios    = dz_set_termios,
 761         .pm             = dz_pm,
 762         .type           = dz_type,
 763         .release_port   = dz_release_port,
 764         .request_port   = dz_request_port,
 765         .config_port    = dz_config_port,
 766         .verify_port    = dz_verify_port,
 767 };
 768
 769 static void __init dz_init_ports(void)
 770 {
 771         static int first = 1;
 772         unsigned long base;
 773         int line;
 774
 775         if (!first)
 776                 return;
 777         first = 0;
 778
 779         if (mips_machtype == MACH_DS23100 || mips_machtype == MACH_DS5100)
 780                 base = dec_kn_slot_base + KN01_DZ11;
 781         else
 782                 base = dec_kn_slot_base + KN02_DZ11;
 783
 784         for (line = 0; line < DZ_NB_PORT; line++) {
 785                 struct dz_port *dport = &dz_mux.dport[line];
 786                 struct uart_port *uport = &dport->port;
 787
 788                 dport->mux      = &dz_mux;
 789
 790                 uport->irq      = dec_interrupt[DEC_IRQ_DZ11];
 791                 uport->fifosize = 1;
 792                 uport->iotype   = UPIO_MEM;
 793                 uport->flags    = UPF_BOOT_AUTOCONF;
 794                 uport->ops      = &dz_ops;
 795                 uport->line     = line;
 796                 uport->mapbase  = base;
 797         }
 798 }
 799
 800 #ifdef CONFIG_SERIAL_DZ_CONSOLE
 801 /*
 802  * -------------------------------------------------------------------
 803  * dz_console_putchar() -- transmit a character
 804  *
 805  * Polled transmission.  This is tricky.  We need to mask transmit
 806  * interrupts so that they do not interfere, enable the transmitter
 807  * for the line requested and then wait till the transmit scanner
 808  * requests data for this line.  But it may request data for another
 809  * line first, in which case we have to disable its transmitter and
 810  * repeat waiting till our line pops up.  Only then the character may
 811  * be transmitted.  Finally, the state of the transmitter mask is
 812  * restored.  Welcome to the world of PDP-11!
 813  * -------------------------------------------------------------------
 814  */
 815 static void dz_console_putchar(struct uart_port *uport, int ch)
 816 {
 817         struct dz_port *dport = to_dport(uport);
 818         unsigned long flags;
 819         unsigned short csr, tcr, trdy, mask;
 820         int loops = 10000;
 821
 822         spin_lock_irqsave(&dport->port.lock, flags);
 823         csr = dz_in(dport, DZ_CSR);
 824         dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
 825         tcr = dz_in(dport, DZ_TCR);
 826         tcr |= 1 << dport->port.line;
 827         mask = tcr;
 828         dz_out(dport, DZ_TCR, mask);
 829         iob();
 830         spin_unlock_irqrestore(&dport->port.lock, flags);
 831
 832         do {
 833                 trdy = dz_in(dport, DZ_CSR);
 834                 if (!(trdy & DZ_TRDY))
 835                         continue;
 836                 trdy = (trdy & DZ_TLINE) >> 8;
 837                 if (trdy == dport->port.line)
 838                         break;
 839                 mask &= ~(1 << trdy);
 840                 dz_out(dport, DZ_TCR, mask);
 841                 iob();
 842                 udelay(2);
 843         } while (--loops);
 844
 845         if (loops)                              /* Cannot send otherwise. */
 846                 dz_out(dport, DZ_TDR, ch);
 847
 848         dz_out(dport, DZ_TCR, tcr);
 849         dz_out(dport, DZ_CSR, csr);
 850 }
 851
 852 /*
 853  * -------------------------------------------------------------------
 854  * dz_console_print ()
 855  *
 856  * dz_console_print is registered for printk.
 857  * The console must be locked when we get here.
 858  * -------------------------------------------------------------------
 859  */
 860 static void dz_console_print(struct console *co,
 861                              const char *str,
 862                              unsigned int count)
 863 {
 864         struct dz_port *dport = &dz_mux.dport[co->index];
 865 #ifdef DEBUG_DZ
 866         prom_printf((char *) str);
 867 #endif
 868         uart_console_write(&dport->port, str, count, dz_console_putchar);
 869 }
 870
 871 static int __init dz_console_setup(struct console *co, char *options)
 872 {
 873         struct dz_port *dport = &dz_mux.dport[co->index];
 874         struct uart_port *uport = &dport->port;
 875         int baud = 9600;
 876         int bits = 8;
 877         int parity = 'n';
 878         int flow = 'n';
 879         int ret;
 880
 881         ret = dz_map_port(uport);
 882         if (ret)
 883                 return ret;
 884
 885         spin_lock_init(&dport->port.lock);      /* For dz_pm().  */
 886
 887         dz_reset(dport);
 888         dz_pm(uport, 0, -1);
 889
 890         if (options)
 891                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 892
 893         return uart_set_options(&dport->port, co, baud, parity, bits, flow);
 894 }
 895
 896 static struct uart_driver dz_reg;
 897 static struct console dz_console = {
 898         .name   = "ttyS",
 899         .write  = dz_console_print,
 900         .device = uart_console_device,
 901         .setup  = dz_console_setup,
 902         .flags  = CON_PRINTBUFFER,
 903         .index  = -1,
 904         .data   = &dz_reg,
 905 };
 906
 907 static int __init dz_serial_console_init(void)
 908 {
 909         if (!IOASIC) {
 910                 dz_init_ports();
 911                 register_console(&dz_console);
 912                 return 0;
 913         } else
 914                 return -ENXIO;
 915 }
 916
 917 console_initcall(dz_serial_console_init);
 918
 919 #define SERIAL_DZ_CONSOLE       &dz_console
 920 #else
 921 #define SERIAL_DZ_CONSOLE       NULL
 922 #endif /* CONFIG_SERIAL_DZ_CONSOLE */
 923
 924 static struct uart_driver dz_reg = {
 925         .owner                  = THIS_MODULE,
 926         .driver_name            = "serial",
 927         .dev_name               = "ttyS",
 928         .major                  = TTY_MAJOR,
 929         .minor                  = 64,
 930         .nr                     = DZ_NB_PORT,
 931         .cons                   = SERIAL_DZ_CONSOLE,
 932 };
 933
 934 static int __init dz_init(void)
 935 {
 936         int ret, i;
 937
 938         if (IOASIC)
 939                 return -ENXIO;
 940
 941         printk("%s%s\n", dz_name, dz_version);
 942
 943         dz_init_ports();
 944
 945         ret = uart_register_driver(&dz_reg);
 946         if (ret)
 947                 return ret;
 948
 949         for (i = 0; i < DZ_NB_PORT; i++)
 950                 uart_add_one_port(&dz_reg, &dz_mux.dport[i].port);
 951
 952         return 0;
 953 }
 954
 955 module_init(dz_init);