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