drivers/tty/amiserial.c

   1 /*
   2  * Serial driver for the amiga builtin port.
   3  *
   4  * This code was created by taking serial.c version 4.30 from kernel
   5  * release 2.3.22, replacing all hardware related stuff with the
   6  * corresponding amiga hardware actions, and removing all irrelevant
   7  * code. As a consequence, it uses many of the constants and names
   8  * associated with the registers and bits of 16550 compatible UARTS -
   9  * but only to keep track of status, etc in the state variables. It
  10  * was done this was to make it easier to keep the code in line with
  11  * (non hardware specific) changes to serial.c.
  12  *
  13  * The port is registered with the tty driver as minor device 64, and
  14  * therefore other ports should should only use 65 upwards.
  15  *
  16  * Richard Lucock 28/12/99
  17  *
  18  *  Copyright (C) 1991, 1992  Linus Torvalds
  19  *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
  20  *              1998, 1999  Theodore Ts'o
  21  *
  22  */
  23
  24 /*
  25  * Serial driver configuration section.  Here are the various options:
  26  *
  27  * SERIAL_PARANOIA_CHECK
  28  *              Check the magic number for the async_structure where
  29  *              ever possible.
  30  */
  31
  32 #include <linux/delay.h>
  33
  34 #undef SERIAL_PARANOIA_CHECK
  35
  36 /* Set of debugging defines */
  37
  38 #undef SERIAL_DEBUG_INTR
  39 #undef SERIAL_DEBUG_OPEN
  40 #undef SERIAL_DEBUG_FLOW
  41 #undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
  42
  43 /* Sanity checks */
  44
  45 #if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
  46 #define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
  47  tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
  48 #else
  49 #define DBG_CNT(s)
  50 #endif
  51
  52 /*
  53  * End of serial driver configuration section.
  54  */
  55
  56 #include <linux/module.h>
  57
  58 #include <linux/types.h>
  59 #include <linux/serial.h>
  60 #include <linux/serial_reg.h>
  61 static char *serial_version = "4.30";
  62
  63 #include <linux/errno.h>
  64 #include <linux/signal.h>
  65 #include <linux/sched.h>
  66 #include <linux/kernel.h>
  67 #include <linux/timer.h>
  68 #include <linux/interrupt.h>
  69 #include <linux/tty.h>
  70 #include <linux/tty_flip.h>
  71 #include <linux/circ_buf.h>
  72 #include <linux/console.h>
  73 #include <linux/major.h>
  74 #include <linux/string.h>
  75 #include <linux/fcntl.h>
  76 #include <linux/ptrace.h>
  77 #include <linux/ioport.h>
  78 #include <linux/mm.h>
  79 #include <linux/seq_file.h>
  80 #include <linux/slab.h>
  81 #include <linux/init.h>
  82 #include <linux/bitops.h>
  83 #include <linux/platform_device.h>
  84
  85 #include <asm/setup.h>
  86
  87
  88 #include <asm/irq.h>
  89
  90 #include <asm/amigahw.h>
  91 #include <asm/amigaints.h>
  92
  93 struct serial_state {
  94         struct tty_port         tport;
  95         struct circ_buf         xmit;
  96         struct async_icount     icount;
  97
  98         unsigned long           port;
  99         int                     baud_base;
 100         int                     xmit_fifo_size;
 101         int                     custom_divisor;
 102         int                     read_status_mask;
 103         int                     ignore_status_mask;
 104         int                     timeout;
 105         int                     quot;
 106         int                     IER;    /* Interrupt Enable Register */
 107         int                     MCR;    /* Modem control register */
 108         int                     x_char; /* xon/xoff character */
 109 };
 110
 111 #define custom amiga_custom
 112 static char *serial_name = "Amiga-builtin serial driver";
 113
 114 static struct tty_driver *serial_driver;
 115
 116 /* number of characters left in xmit buffer before we ask for more */
 117 #define WAKEUP_CHARS 256
 118
 119 static unsigned char current_ctl_bits;
 120
 121 static void change_speed(struct tty_struct *tty, struct serial_state *info,
 122                 struct ktermios *old);
 123 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 124
 125
 126 static struct serial_state rs_table[1];
 127
 128 #define NR_PORTS ARRAY_SIZE(rs_table)
 129
 130 #include <asm/uaccess.h>
 131
 132 #define serial_isroot() (capable(CAP_SYS_ADMIN))
 133
 134
 135 static inline int serial_paranoia_check(struct serial_state *info,
 136                                         char *name, const char *routine)
 137 {
 138 #ifdef SERIAL_PARANOIA_CHECK
 139         static const char *badmagic =
 140                 "Warning: bad magic number for serial struct (%s) in %s\n";
 141         static const char *badinfo =
 142                 "Warning: null async_struct for (%s) in %s\n";
 143
 144         if (!info) {
 145                 printk(badinfo, name, routine);
 146                 return 1;
 147         }
 148         if (info->magic != SERIAL_MAGIC) {
 149                 printk(badmagic, name, routine);
 150                 return 1;
 151         }
 152 #endif
 153         return 0;
 154 }
 155
 156 /* some serial hardware definitions */
 157 #define SDR_OVRUN   (1<<15)
 158 #define SDR_RBF     (1<<14)
 159 #define SDR_TBE     (1<<13)
 160 #define SDR_TSRE    (1<<12)
 161
 162 #define SERPER_PARENB    (1<<15)
 163
 164 #define AC_SETCLR   (1<<15)
 165 #define AC_UARTBRK  (1<<11)
 166
 167 #define SER_DTR     (1<<7)
 168 #define SER_RTS     (1<<6)
 169 #define SER_DCD     (1<<5)
 170 #define SER_CTS     (1<<4)
 171 #define SER_DSR     (1<<3)
 172
 173 static __inline__ void rtsdtr_ctrl(int bits)
 174 {
 175     ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
 176 }
 177
 178 /*
 179  * ------------------------------------------------------------
 180  * rs_stop() and rs_start()
 181  *
 182  * This routines are called before setting or resetting tty->stopped.
 183  * They enable or disable transmitter interrupts, as necessary.
 184  * ------------------------------------------------------------
 185  */
 186 static void rs_stop(struct tty_struct *tty)
 187 {
 188         struct serial_state *info = tty->driver_data;
 189         unsigned long flags;
 190
 191         if (serial_paranoia_check(info, tty->name, "rs_stop"))
 192                 return;
 193
 194         local_irq_save(flags);
 195         if (info->IER & UART_IER_THRI) {
 196                 info->IER &= ~UART_IER_THRI;
 197                 /* disable Tx interrupt and remove any pending interrupts */
 198                 custom.intena = IF_TBE;
 199                 mb();
 200                 custom.intreq = IF_TBE;
 201                 mb();
 202         }
 203         local_irq_restore(flags);
 204 }
 205
 206 static void rs_start(struct tty_struct *tty)
 207 {
 208         struct serial_state *info = tty->driver_data;
 209         unsigned long flags;
 210
 211         if (serial_paranoia_check(info, tty->name, "rs_start"))
 212                 return;
 213
 214         local_irq_save(flags);
 215         if (info->xmit.head != info->xmit.tail
 216             && info->xmit.buf
 217             && !(info->IER & UART_IER_THRI)) {
 218                 info->IER |= UART_IER_THRI;
 219                 custom.intena = IF_SETCLR | IF_TBE;
 220                 mb();
 221                 /* set a pending Tx Interrupt, transmitter should restart now */
 222                 custom.intreq = IF_SETCLR | IF_TBE;
 223                 mb();
 224         }
 225         local_irq_restore(flags);
 226 }
 227
 228 /*
 229  * ----------------------------------------------------------------------
 230  *
 231  * Here starts the interrupt handling routines.  All of the following
 232  * subroutines are declared as inline and are folded into
 233  * rs_interrupt().  They were separated out for readability's sake.
 234  *
 235  * Note: rs_interrupt() is a "fast" interrupt, which means that it
 236  * runs with interrupts turned off.  People who may want to modify
 237  * rs_interrupt() should try to keep the interrupt handler as fast as
 238  * possible.  After you are done making modifications, it is not a bad
 239  * idea to do:
 240  *
 241  * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
 242  *
 243  * and look at the resulting assemble code in serial.s.
 244  *
 245  *                              - Ted Ts'o (tytso@mit.edu), 7-Mar-93
 246  * -----------------------------------------------------------------------
 247  */
 248
 249 static void receive_chars(struct serial_state *info)
 250 {
 251         int status;
 252         int serdatr;
 253         unsigned char ch, flag;
 254         struct  async_icount *icount;
 255         int oe = 0;
 256
 257         icount = &info->icount;
 258
 259         status = UART_LSR_DR; /* We obviously have a character! */
 260         serdatr = custom.serdatr;
 261         mb();
 262         custom.intreq = IF_RBF;
 263         mb();
 264
 265         if((serdatr & 0x1ff) == 0)
 266             status |= UART_LSR_BI;
 267         if(serdatr & SDR_OVRUN)
 268             status |= UART_LSR_OE;
 269
 270         ch = serdatr & 0xff;
 271         icount->rx++;
 272
 273 #ifdef SERIAL_DEBUG_INTR
 274         printk("DR%02x:%02x...", ch, status);
 275 #endif
 276         flag = TTY_NORMAL;
 277
 278         /*
 279          * We don't handle parity or frame errors - but I have left
 280          * the code in, since I'm not sure that the errors can't be
 281          * detected.
 282          */
 283
 284         if (status & (UART_LSR_BI | UART_LSR_PE |
 285                       UART_LSR_FE | UART_LSR_OE)) {
 286           /*
 287            * For statistics only
 288            */
 289           if (status & UART_LSR_BI) {
 290             status &= ~(UART_LSR_FE | UART_LSR_PE);
 291             icount->brk++;
 292           } else if (status & UART_LSR_PE)
 293             icount->parity++;
 294           else if (status & UART_LSR_FE)
 295             icount->frame++;
 296           if (status & UART_LSR_OE)
 297             icount->overrun++;
 298
 299           /*
 300            * Now check to see if character should be
 301            * ignored, and mask off conditions which
 302            * should be ignored.
 303            */
 304           if (status & info->ignore_status_mask)
 305             goto out;
 306
 307           status &= info->read_status_mask;
 308
 309           if (status & (UART_LSR_BI)) {
 310 #ifdef SERIAL_DEBUG_INTR
 311             printk("handling break....");
 312 #endif
 313             flag = TTY_BREAK;
 314             if (info->tport.flags & ASYNC_SAK)
 315               do_SAK(info->tport.tty);
 316           } else if (status & UART_LSR_PE)
 317             flag = TTY_PARITY;
 318           else if (status & UART_LSR_FE)
 319             flag = TTY_FRAME;
 320           if (status & UART_LSR_OE) {
 321             /*
 322              * Overrun is special, since it's
 323              * reported immediately, and doesn't
 324              * affect the current character
 325              */
 326              oe = 1;
 327           }
 328         }
 329         tty_insert_flip_char(&info->tport, ch, flag);
 330         if (oe == 1)
 331                 tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
 332         tty_flip_buffer_push(&info->tport);
 333 out:
 334         return;
 335 }
 336
 337 static void transmit_chars(struct serial_state *info)
 338 {
 339         custom.intreq = IF_TBE;
 340         mb();
 341         if (info->x_char) {
 342                 custom.serdat = info->x_char | 0x100;
 343                 mb();
 344                 info->icount.tx++;
 345                 info->x_char = 0;
 346                 return;
 347         }
 348         if (info->xmit.head == info->xmit.tail
 349             || info->tport.tty->stopped
 350             || info->tport.tty->hw_stopped) {
 351                 info->IER &= ~UART_IER_THRI;
 352                 custom.intena = IF_TBE;
 353                 mb();
 354                 return;
 355         }
 356
 357         custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
 358         mb();
 359         info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
 360         info->icount.tx++;
 361
 362         if (CIRC_CNT(info->xmit.head,
 363                      info->xmit.tail,
 364                      SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
 365                 tty_wakeup(info->tport.tty);
 366
 367 #ifdef SERIAL_DEBUG_INTR
 368         printk("THRE...");
 369 #endif
 370         if (info->xmit.head == info->xmit.tail) {
 371                 custom.intena = IF_TBE;
 372                 mb();
 373                 info->IER &= ~UART_IER_THRI;
 374         }
 375 }
 376
 377 static void check_modem_status(struct serial_state *info)
 378 {
 379         struct tty_port *port = &info->tport;
 380         unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
 381         unsigned char dstatus;
 382         struct  async_icount *icount;
 383
 384         /* Determine bits that have changed */
 385         dstatus = status ^ current_ctl_bits;
 386         current_ctl_bits = status;
 387
 388         if (dstatus) {
 389                 icount = &info->icount;
 390                 /* update input line counters */
 391                 if (dstatus & SER_DSR)
 392                         icount->dsr++;
 393                 if (dstatus & SER_DCD) {
 394                         icount->dcd++;
 395                 }
 396                 if (dstatus & SER_CTS)
 397                         icount->cts++;
 398                 wake_up_interruptible(&port->delta_msr_wait);
 399         }
 400
 401         if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
 402 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
 403                 printk("ttyS%d CD now %s...", info->line,
 404                        (!(status & SER_DCD)) ? "on" : "off");
 405 #endif
 406                 if (!(status & SER_DCD))
 407                         wake_up_interruptible(&port->open_wait);
 408                 else {
 409 #ifdef SERIAL_DEBUG_OPEN
 410                         printk("doing serial hangup...");
 411 #endif
 412                         if (port->tty)
 413                                 tty_hangup(port->tty);
 414                 }
 415         }
 416         if (tty_port_cts_enabled(port)) {
 417                 if (port->tty->hw_stopped) {
 418                         if (!(status & SER_CTS)) {
 419 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
 420                                 printk("CTS tx start...");
 421 #endif
 422                                 port->tty->hw_stopped = 0;
 423                                 info->IER |= UART_IER_THRI;
 424                                 custom.intena = IF_SETCLR | IF_TBE;
 425                                 mb();
 426                                 /* set a pending Tx Interrupt, transmitter should restart now */
 427                                 custom.intreq = IF_SETCLR | IF_TBE;
 428                                 mb();
 429                                 tty_wakeup(port->tty);
 430                                 return;
 431                         }
 432                 } else {
 433                         if ((status & SER_CTS)) {
 434 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
 435                                 printk("CTS tx stop...");
 436 #endif
 437                                 port->tty->hw_stopped = 1;
 438                                 info->IER &= ~UART_IER_THRI;
 439                                 /* disable Tx interrupt and remove any pending interrupts */
 440                                 custom.intena = IF_TBE;
 441                                 mb();
 442                                 custom.intreq = IF_TBE;
 443                                 mb();
 444                         }
 445                 }
 446         }
 447 }
 448
 449 static irqreturn_t ser_vbl_int( int irq, void *data)
 450 {
 451         /* vbl is just a periodic interrupt we tie into to update modem status */
 452         struct serial_state *info = data;
 453         /*
 454          * TBD - is it better to unregister from this interrupt or to
 455          * ignore it if MSI is clear ?
 456          */
 457         if(info->IER & UART_IER_MSI)
 458           check_modem_status(info);
 459         return IRQ_HANDLED;
 460 }
 461
 462 static irqreturn_t ser_rx_int(int irq, void *dev_id)
 463 {
 464         struct serial_state *info = dev_id;
 465
 466 #ifdef SERIAL_DEBUG_INTR
 467         printk("ser_rx_int...");
 468 #endif
 469
 470         if (!info->tport.tty)
 471                 return IRQ_NONE;
 472
 473         receive_chars(info);
 474 #ifdef SERIAL_DEBUG_INTR
 475         printk("end.\n");
 476 #endif
 477         return IRQ_HANDLED;
 478 }
 479
 480 static irqreturn_t ser_tx_int(int irq, void *dev_id)
 481 {
 482         struct serial_state *info = dev_id;
 483
 484         if (custom.serdatr & SDR_TBE) {
 485 #ifdef SERIAL_DEBUG_INTR
 486           printk("ser_tx_int...");
 487 #endif
 488
 489           if (!info->tport.tty)
 490                 return IRQ_NONE;
 491
 492           transmit_chars(info);
 493 #ifdef SERIAL_DEBUG_INTR
 494           printk("end.\n");
 495 #endif
 496         }
 497         return IRQ_HANDLED;
 498 }
 499
 500 /*
 501  * -------------------------------------------------------------------
 502  * Here ends the serial interrupt routines.
 503  * -------------------------------------------------------------------
 504  */
 505
 506 /*
 507  * ---------------------------------------------------------------
 508  * Low level utility subroutines for the serial driver:  routines to
 509  * figure out the appropriate timeout for an interrupt chain, routines
 510  * to initialize and startup a serial port, and routines to shutdown a
 511  * serial port.  Useful stuff like that.
 512  * ---------------------------------------------------------------
 513  */
 514
 515 static int startup(struct tty_struct *tty, struct serial_state *info)
 516 {
 517         struct tty_port *port = &info->tport;
 518         unsigned long flags;
 519         int     retval=0;
 520         unsigned long page;
 521
 522         page = get_zeroed_page(GFP_KERNEL);
 523         if (!page)
 524                 return -ENOMEM;
 525
 526         local_irq_save(flags);
 527
 528         if (tty_port_initialized(port)) {
 529                 free_page(page);
 530                 goto errout;
 531         }
 532
 533         if (info->xmit.buf)
 534                 free_page(page);
 535         else
 536                 info->xmit.buf = (unsigned char *) page;
 537
 538 #ifdef SERIAL_DEBUG_OPEN
 539         printk("starting up ttys%d ...", info->line);
 540 #endif
 541
 542         /* Clear anything in the input buffer */
 543
 544         custom.intreq = IF_RBF;
 545         mb();
 546
 547         retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
 548         if (retval) {
 549           if (serial_isroot()) {
 550               set_bit(TTY_IO_ERROR, &tty->flags);
 551             retval = 0;
 552           }
 553           goto errout;
 554         }
 555
 556         /* enable both Rx and Tx interrupts */
 557         custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
 558         mb();
 559         info->IER = UART_IER_MSI;
 560
 561         /* remember current state of the DCD and CTS bits */
 562         current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
 563
 564         info->MCR = 0;
 565         if (C_BAUD(tty))
 566           info->MCR = SER_DTR | SER_RTS;
 567         rtsdtr_ctrl(info->MCR);
 568
 569         clear_bit(TTY_IO_ERROR, &tty->flags);
 570         info->xmit.head = info->xmit.tail = 0;
 571
 572         /*
 573          * Set up the tty->alt_speed kludge
 574          */
 575         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
 576                 tty->alt_speed = 57600;
 577         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
 578                 tty->alt_speed = 115200;
 579         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
 580                 tty->alt_speed = 230400;
 581         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
 582                 tty->alt_speed = 460800;
 583
 584         /*
 585          * and set the speed of the serial port
 586          */
 587         change_speed(tty, info, NULL);
 588
 589         tty_port_set_initialized(port, 1);
 590         local_irq_restore(flags);
 591         return 0;
 592
 593 errout:
 594         local_irq_restore(flags);
 595         return retval;
 596 }
 597
 598 /*
 599  * This routine will shutdown a serial port; interrupts are disabled, and
 600  * DTR is dropped if the hangup on close termio flag is on.
 601  */
 602 static void shutdown(struct tty_struct *tty, struct serial_state *info)
 603 {
 604         unsigned long   flags;
 605         struct serial_state *state;
 606
 607         if (!tty_port_initialized(&info->tport))
 608                 return;
 609
 610         state = info;
 611
 612 #ifdef SERIAL_DEBUG_OPEN
 613         printk("Shutting down serial port %d ....\n", info->line);
 614 #endif
 615
 616         local_irq_save(flags); /* Disable interrupts */
 617
 618         /*
 619          * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
 620          * here so the queue might never be waken up
 621          */
 622         wake_up_interruptible(&info->tport.delta_msr_wait);
 623
 624         /*
 625          * Free the IRQ, if necessary
 626          */
 627         free_irq(IRQ_AMIGA_VERTB, info);
 628
 629         if (info->xmit.buf) {
 630                 free_page((unsigned long) info->xmit.buf);
 631                 info->xmit.buf = NULL;
 632         }
 633
 634         info->IER = 0;
 635         custom.intena = IF_RBF | IF_TBE;
 636         mb();
 637
 638         /* disable break condition */
 639         custom.adkcon = AC_UARTBRK;
 640         mb();
 641
 642         if (C_HUPCL(tty))
 643                 info->MCR &= ~(SER_DTR|SER_RTS);
 644         rtsdtr_ctrl(info->MCR);
 645
 646         set_bit(TTY_IO_ERROR, &tty->flags);
 647
 648         tty_port_set_initialized(&info->tport, 0);
 649         local_irq_restore(flags);
 650 }
 651
 652
 653 /*
 654  * This routine is called to set the UART divisor registers to match
 655  * the specified baud rate for a serial port.
 656  */
 657 static void change_speed(struct tty_struct *tty, struct serial_state *info,
 658                          struct ktermios *old_termios)
 659 {
 660         struct tty_port *port = &info->tport;
 661         int     quot = 0, baud_base, baud;
 662         unsigned cflag, cval = 0;
 663         int     bits;
 664         unsigned long   flags;
 665
 666         cflag = tty->termios.c_cflag;
 667
 668         /* Byte size is always 8 bits plus parity bit if requested */
 669
 670         cval = 3; bits = 10;
 671         if (cflag & CSTOPB) {
 672                 cval |= 0x04;
 673                 bits++;
 674         }
 675         if (cflag & PARENB) {
 676                 cval |= UART_LCR_PARITY;
 677                 bits++;
 678         }
 679         if (!(cflag & PARODD))
 680                 cval |= UART_LCR_EPAR;
 681 #ifdef CMSPAR
 682         if (cflag & CMSPAR)
 683                 cval |= UART_LCR_SPAR;
 684 #endif
 685
 686         /* Determine divisor based on baud rate */
 687         baud = tty_get_baud_rate(tty);
 688         if (!baud)
 689                 baud = 9600;    /* B0 transition handled in rs_set_termios */
 690         baud_base = info->baud_base;
 691         if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
 692                 quot = info->custom_divisor;
 693         else {
 694                 if (baud == 134)
 695                         /* Special case since 134 is really 134.5 */
 696                         quot = (2*baud_base / 269);
 697                 else if (baud)
 698                         quot = baud_base / baud;
 699         }
 700         /* If the quotient is zero refuse the change */
 701         if (!quot && old_termios) {
 702                 /* FIXME: Will need updating for new tty in the end */
 703                 tty->termios.c_cflag &= ~CBAUD;
 704                 tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
 705                 baud = tty_get_baud_rate(tty);
 706                 if (!baud)
 707                         baud = 9600;
 708                 if (baud == 38400 &&
 709                     (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
 710                         quot = info->custom_divisor;
 711                 else {
 712                         if (baud == 134)
 713                                 /* Special case since 134 is really 134.5 */
 714                                 quot = (2*baud_base / 269);
 715                         else if (baud)
 716                                 quot = baud_base / baud;
 717                 }
 718         }
 719         /* As a last resort, if the quotient is zero, default to 9600 bps */
 720         if (!quot)
 721                 quot = baud_base / 9600;
 722         info->quot = quot;
 723         info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
 724         info->timeout += HZ/50;         /* Add .02 seconds of slop */
 725
 726         /* CTS flow control flag and modem status interrupts */
 727         info->IER &= ~UART_IER_MSI;
 728         if (port->flags & ASYNC_HARDPPS_CD)
 729                 info->IER |= UART_IER_MSI;
 730         tty_port_set_cts_flow(port, cflag & CRTSCTS);
 731         if (cflag & CRTSCTS)
 732                 info->IER |= UART_IER_MSI;
 733         tty_port_set_check_carrier(port, ~cflag & CLOCAL);
 734         if (~cflag & CLOCAL)
 735                 info->IER |= UART_IER_MSI;
 736         /* TBD:
 737          * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
 738          */
 739
 740         /*
 741          * Set up parity check flag
 742          */
 743
 744         info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
 745         if (I_INPCK(tty))
 746                 info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
 747         if (I_BRKINT(tty) || I_PARMRK(tty))
 748                 info->read_status_mask |= UART_LSR_BI;
 749
 750         /*
 751          * Characters to ignore
 752          */
 753         info->ignore_status_mask = 0;
 754         if (I_IGNPAR(tty))
 755                 info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
 756         if (I_IGNBRK(tty)) {
 757                 info->ignore_status_mask |= UART_LSR_BI;
 758                 /*
 759                  * If we're ignore parity and break indicators, ignore
 760                  * overruns too.  (For real raw support).
 761                  */
 762                 if (I_IGNPAR(tty))
 763                         info->ignore_status_mask |= UART_LSR_OE;
 764         }
 765         /*
 766          * !!! ignore all characters if CREAD is not set
 767          */
 768         if ((cflag & CREAD) == 0)
 769                 info->ignore_status_mask |= UART_LSR_DR;
 770         local_irq_save(flags);
 771
 772         {
 773           short serper;
 774
 775         /* Set up the baud rate */
 776           serper = quot - 1;
 777
 778         /* Enable or disable parity bit */
 779
 780         if(cval & UART_LCR_PARITY)
 781           serper |= (SERPER_PARENB);
 782
 783         custom.serper = serper;
 784         mb();
 785         }
 786
 787         local_irq_restore(flags);
 788 }
 789
 790 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 791 {
 792         struct serial_state *info;
 793         unsigned long flags;
 794
 795         info = tty->driver_data;
 796
 797         if (serial_paranoia_check(info, tty->name, "rs_put_char"))
 798                 return 0;
 799
 800         if (!info->xmit.buf)
 801                 return 0;
 802
 803         local_irq_save(flags);
 804         if (CIRC_SPACE(info->xmit.head,
 805                        info->xmit.tail,
 806                        SERIAL_XMIT_SIZE) == 0) {
 807                 local_irq_restore(flags);
 808                 return 0;
 809         }
 810
 811         info->xmit.buf[info->xmit.head++] = ch;
 812         info->xmit.head &= SERIAL_XMIT_SIZE-1;
 813         local_irq_restore(flags);
 814         return 1;
 815 }
 816
 817 static void rs_flush_chars(struct tty_struct *tty)
 818 {
 819         struct serial_state *info = tty->driver_data;
 820         unsigned long flags;
 821
 822         if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
 823                 return;
 824
 825         if (info->xmit.head == info->xmit.tail
 826             || tty->stopped
 827             || tty->hw_stopped
 828             || !info->xmit.buf)
 829                 return;
 830
 831         local_irq_save(flags);
 832         info->IER |= UART_IER_THRI;
 833         custom.intena = IF_SETCLR | IF_TBE;
 834         mb();
 835         /* set a pending Tx Interrupt, transmitter should restart now */
 836         custom.intreq = IF_SETCLR | IF_TBE;
 837         mb();
 838         local_irq_restore(flags);
 839 }
 840
 841 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
 842 {
 843         int     c, ret = 0;
 844         struct serial_state *info = tty->driver_data;
 845         unsigned long flags;
 846
 847         if (serial_paranoia_check(info, tty->name, "rs_write"))
 848                 return 0;
 849
 850         if (!info->xmit.buf)
 851                 return 0;
 852
 853         local_irq_save(flags);
 854         while (1) {
 855                 c = CIRC_SPACE_TO_END(info->xmit.head,
 856                                       info->xmit.tail,
 857                                       SERIAL_XMIT_SIZE);
 858                 if (count < c)
 859                         c = count;
 860                 if (c <= 0) {
 861                         break;
 862                 }
 863                 memcpy(info->xmit.buf + info->xmit.head, buf, c);
 864                 info->xmit.head = ((info->xmit.head + c) &
 865                                    (SERIAL_XMIT_SIZE-1));
 866                 buf += c;
 867                 count -= c;
 868                 ret += c;
 869         }
 870         local_irq_restore(flags);
 871
 872         if (info->xmit.head != info->xmit.tail
 873             && !tty->stopped
 874             && !tty->hw_stopped
 875             && !(info->IER & UART_IER_THRI)) {
 876                 info->IER |= UART_IER_THRI;
 877                 local_irq_disable();
 878                 custom.intena = IF_SETCLR | IF_TBE;
 879                 mb();
 880                 /* set a pending Tx Interrupt, transmitter should restart now */
 881                 custom.intreq = IF_SETCLR | IF_TBE;
 882                 mb();
 883                 local_irq_restore(flags);
 884         }
 885         return ret;
 886 }
 887
 888 static int rs_write_room(struct tty_struct *tty)
 889 {
 890         struct serial_state *info = tty->driver_data;
 891
 892         if (serial_paranoia_check(info, tty->name, "rs_write_room"))
 893                 return 0;
 894         return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 895 }
 896
 897 static int rs_chars_in_buffer(struct tty_struct *tty)
 898 {
 899         struct serial_state *info = tty->driver_data;
 900
 901         if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
 902                 return 0;
 903         return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 904 }
 905
 906 static void rs_flush_buffer(struct tty_struct *tty)
 907 {
 908         struct serial_state *info = tty->driver_data;
 909         unsigned long flags;
 910
 911         if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
 912                 return;
 913         local_irq_save(flags);
 914         info->xmit.head = info->xmit.tail = 0;
 915         local_irq_restore(flags);
 916         tty_wakeup(tty);
 917 }
 918
 919 /*
 920  * This function is used to send a high-priority XON/XOFF character to
 921  * the device
 922  */
 923 static void rs_send_xchar(struct tty_struct *tty, char ch)
 924 {
 925         struct serial_state *info = tty->driver_data;
 926         unsigned long flags;
 927
 928         if (serial_paranoia_check(info, tty->name, "rs_send_xchar"))
 929                 return;
 930
 931         info->x_char = ch;
 932         if (ch) {
 933                 /* Make sure transmit interrupts are on */
 934
 935                 /* Check this ! */
 936                 local_irq_save(flags);
 937                 if(!(custom.intenar & IF_TBE)) {
 938                     custom.intena = IF_SETCLR | IF_TBE;
 939                     mb();
 940                     /* set a pending Tx Interrupt, transmitter should restart now */
 941                     custom.intreq = IF_SETCLR | IF_TBE;
 942                     mb();
 943                 }
 944                 local_irq_restore(flags);
 945
 946                 info->IER |= UART_IER_THRI;
 947         }
 948 }
 949
 950 /*
 951  * ------------------------------------------------------------
 952  * rs_throttle()
 953  *
 954  * This routine is called by the upper-layer tty layer to signal that
 955  * incoming characters should be throttled.
 956  * ------------------------------------------------------------
 957  */
 958 static void rs_throttle(struct tty_struct * tty)
 959 {
 960         struct serial_state *info = tty->driver_data;
 961         unsigned long flags;
 962 #ifdef SERIAL_DEBUG_THROTTLE
 963         printk("throttle %s ....\n", tty_name(tty));
 964 #endif
 965
 966         if (serial_paranoia_check(info, tty->name, "rs_throttle"))
 967                 return;
 968
 969         if (I_IXOFF(tty))
 970                 rs_send_xchar(tty, STOP_CHAR(tty));
 971
 972         if (C_CRTSCTS(tty))
 973                 info->MCR &= ~SER_RTS;
 974
 975         local_irq_save(flags);
 976         rtsdtr_ctrl(info->MCR);
 977         local_irq_restore(flags);
 978 }
 979
 980 static void rs_unthrottle(struct tty_struct * tty)
 981 {
 982         struct serial_state *info = tty->driver_data;
 983         unsigned long flags;
 984 #ifdef SERIAL_DEBUG_THROTTLE
 985         printk("unthrottle %s ....\n", tty_name(tty));
 986 #endif
 987
 988         if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
 989                 return;
 990
 991         if (I_IXOFF(tty)) {
 992                 if (info->x_char)
 993                         info->x_char = 0;
 994                 else
 995                         rs_send_xchar(tty, START_CHAR(tty));
 996         }
 997         if (C_CRTSCTS(tty))
 998                 info->MCR |= SER_RTS;
 999         local_irq_save(flags);
1000         rtsdtr_ctrl(info->MCR);
1001         local_irq_restore(flags);
1002 }
1003
1004 /*
1005  * ------------------------------------------------------------
1006  * rs_ioctl() and friends
1007  * ------------------------------------------------------------
1008  */
1009
1010 static int get_serial_info(struct tty_struct *tty, struct serial_state *state,
1011                            struct serial_struct __user * retinfo)
1012 {
1013         struct serial_struct tmp;
1014
1015         if (!retinfo)
1016                 return -EFAULT;
1017         memset(&tmp, 0, sizeof(tmp));
1018         tty_lock(tty);
1019         tmp.line = tty->index;
1020         tmp.port = state->port;
1021         tmp.flags = state->tport.flags;
1022         tmp.xmit_fifo_size = state->xmit_fifo_size;
1023         tmp.baud_base = state->baud_base;
1024         tmp.close_delay = state->tport.close_delay;
1025         tmp.closing_wait = state->tport.closing_wait;
1026         tmp.custom_divisor = state->custom_divisor;
1027         tty_unlock(tty);
1028         if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
1029                 return -EFAULT;
1030         return 0;
1031 }
1032
1033 static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
1034                            struct serial_struct __user * new_info)
1035 {
1036         struct tty_port *port = &state->tport;
1037         struct serial_struct new_serial;
1038         bool change_spd;
1039         int                     retval = 0;
1040
1041         if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
1042                 return -EFAULT;
1043
1044         tty_lock(tty);
1045         change_spd = ((new_serial.flags ^ port->flags) & ASYNC_SPD_MASK) ||
1046                 new_serial.custom_divisor != state->custom_divisor;
1047         if (new_serial.irq || new_serial.port != state->port ||
1048                         new_serial.xmit_fifo_size != state->xmit_fifo_size) {
1049                 tty_unlock(tty);
1050                 return -EINVAL;
1051         }
1052
1053         if (!serial_isroot()) {
1054                 if ((new_serial.baud_base != state->baud_base) ||
1055                     (new_serial.close_delay != port->close_delay) ||
1056                     (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
1057                     ((new_serial.flags & ~ASYNC_USR_MASK) !=
1058                      (port->flags & ~ASYNC_USR_MASK))) {
1059                         tty_unlock(tty);
1060                         return -EPERM;
1061                 }
1062                 port->flags = ((port->flags & ~ASYNC_USR_MASK) |
1063                                (new_serial.flags & ASYNC_USR_MASK));
1064                 state->custom_divisor = new_serial.custom_divisor;
1065                 goto check_and_exit;
1066         }
1067
1068         if (new_serial.baud_base < 9600) {
1069                 tty_unlock(tty);
1070                 return -EINVAL;
1071         }
1072
1073         /*
1074          * OK, past this point, all the error checking has been done.
1075          * At this point, we start making changes.....
1076          */
1077
1078         state->baud_base = new_serial.baud_base;
1079         port->flags = ((port->flags & ~ASYNC_FLAGS) |
1080                         (new_serial.flags & ASYNC_FLAGS));
1081         state->custom_divisor = new_serial.custom_divisor;
1082         port->close_delay = new_serial.close_delay * HZ/100;
1083         port->closing_wait = new_serial.closing_wait * HZ/100;
1084         port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1085
1086 check_and_exit:
1087         if (tty_port_initialized(port)) {
1088                 if (change_spd) {
1089                         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
1090                                 tty->alt_speed = 57600;
1091                         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
1092                                 tty->alt_speed = 115200;
1093                         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
1094                                 tty->alt_speed = 230400;
1095                         if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
1096                                 tty->alt_speed = 460800;
1097                         change_speed(tty, state, NULL);
1098                 }
1099         } else
1100                 retval = startup(tty, state);
1101         tty_unlock(tty);
1102         return retval;
1103 }
1104
1105
1106 /*
1107  * get_lsr_info - get line status register info
1108  *
1109  * Purpose: Let user call ioctl() to get info when the UART physically
1110  *          is emptied.  On bus types like RS485, the transmitter must
1111  *          release the bus after transmitting. This must be done when
1112  *          the transmit shift register is empty, not be done when the
1113  *          transmit holding register is empty.  This functionality
1114  *          allows an RS485 driver to be written in user space.
1115  */
1116 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
1117 {
1118         unsigned char status;
1119         unsigned int result;
1120         unsigned long flags;
1121
1122         local_irq_save(flags);
1123         status = custom.serdatr;
1124         mb();
1125         local_irq_restore(flags);
1126         result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1127         if (copy_to_user(value, &result, sizeof(int)))
1128                 return -EFAULT;
1129         return 0;
1130 }
1131
1132
1133 static int rs_tiocmget(struct tty_struct *tty)
1134 {
1135         struct serial_state *info = tty->driver_data;
1136         unsigned char control, status;
1137         unsigned long flags;
1138
1139         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1140                 return -ENODEV;
1141         if (tty_io_error(tty))
1142                 return -EIO;
1143
1144         control = info->MCR;
1145         local_irq_save(flags);
1146         status = ciab.pra;
1147         local_irq_restore(flags);
1148         return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1149                 | ((control & SER_DTR) ? TIOCM_DTR : 0)
1150                 | (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1151                 | (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1152                 | (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1153 }
1154
1155 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1156                                                 unsigned int clear)
1157 {
1158         struct serial_state *info = tty->driver_data;
1159         unsigned long flags;
1160
1161         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1162                 return -ENODEV;
1163         if (tty_io_error(tty))
1164                 return -EIO;
1165
1166         local_irq_save(flags);
1167         if (set & TIOCM_RTS)
1168                 info->MCR |= SER_RTS;
1169         if (set & TIOCM_DTR)
1170                 info->MCR |= SER_DTR;
1171         if (clear & TIOCM_RTS)
1172                 info->MCR &= ~SER_RTS;
1173         if (clear & TIOCM_DTR)
1174                 info->MCR &= ~SER_DTR;
1175         rtsdtr_ctrl(info->MCR);
1176         local_irq_restore(flags);
1177         return 0;
1178 }
1179
1180 /*
1181  * rs_break() --- routine which turns the break handling on or off
1182  */
1183 static int rs_break(struct tty_struct *tty, int break_state)
1184 {
1185         struct serial_state *info = tty->driver_data;
1186         unsigned long flags;
1187
1188         if (serial_paranoia_check(info, tty->name, "rs_break"))
1189                 return -EINVAL;
1190
1191         local_irq_save(flags);
1192         if (break_state == -1)
1193           custom.adkcon = AC_SETCLR | AC_UARTBRK;
1194         else
1195           custom.adkcon = AC_UARTBRK;
1196         mb();
1197         local_irq_restore(flags);
1198         return 0;
1199 }
1200
1201 /*
1202  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1203  * Return: write counters to the user passed counter struct
1204  * NB: both 1->0 and 0->1 transitions are counted except for
1205  *     RI where only 0->1 is counted.
1206  */
1207 static int rs_get_icount(struct tty_struct *tty,
1208                                 struct serial_icounter_struct *icount)
1209 {
1210         struct serial_state *info = tty->driver_data;
1211         struct async_icount cnow;
1212         unsigned long flags;
1213
1214         local_irq_save(flags);
1215         cnow = info->icount;
1216         local_irq_restore(flags);
1217         icount->cts = cnow.cts;
1218         icount->dsr = cnow.dsr;
1219         icount->rng = cnow.rng;
1220         icount->dcd = cnow.dcd;
1221         icount->rx = cnow.rx;
1222         icount->tx = cnow.tx;
1223         icount->frame = cnow.frame;
1224         icount->overrun = cnow.overrun;
1225         icount->parity = cnow.parity;
1226         icount->brk = cnow.brk;
1227         icount->buf_overrun = cnow.buf_overrun;
1228
1229         return 0;
1230 }
1231
1232 static int rs_ioctl(struct tty_struct *tty,
1233                     unsigned int cmd, unsigned long arg)
1234 {
1235         struct serial_state *info = tty->driver_data;
1236         struct async_icount cprev, cnow;        /* kernel counter temps */
1237         void __user *argp = (void __user *)arg;
1238         unsigned long flags;
1239         DEFINE_WAIT(wait);
1240         int ret;
1241
1242         if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1243                 return -ENODEV;
1244
1245         if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
1246             (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
1247             (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1248                 if (tty_io_error(tty))
1249                     return -EIO;
1250         }
1251
1252         switch (cmd) {
1253                 case TIOCGSERIAL:
1254                         return get_serial_info(tty, info, argp);
1255                 case TIOCSSERIAL:
1256                         return set_serial_info(tty, info, argp);
1257                 case TIOCSERCONFIG:
1258                         return 0;
1259
1260                 case TIOCSERGETLSR: /* Get line status register */
1261                         return get_lsr_info(info, argp);
1262
1263                 case TIOCSERGSTRUCT:
1264                         if (copy_to_user(argp,
1265                                          info, sizeof(struct serial_state)))
1266                                 return -EFAULT;
1267                         return 0;
1268
1269                 /*
1270                  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1271                  * - mask passed in arg for lines of interest
1272                  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1273                  * Caller should use TIOCGICOUNT to see which one it was
1274                  */
1275                 case TIOCMIWAIT:
1276                         local_irq_save(flags);
1277                         /* note the counters on entry */
1278                         cprev = info->icount;
1279                         local_irq_restore(flags);
1280                         while (1) {
1281                                 prepare_to_wait(&info->tport.delta_msr_wait,
1282                                                 &wait, TASK_INTERRUPTIBLE);
1283                                 local_irq_save(flags);
1284                                 cnow = info->icount; /* atomic copy */
1285                                 local_irq_restore(flags);
1286                                 if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
1287                                     cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
1288                                         ret = -EIO; /* no change => error */
1289                                         break;
1290                                 }
1291                                 if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1292                                      ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1293                                      ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1294                                      ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1295                                         ret = 0;
1296                                         break;
1297                                 }
1298                                 schedule();
1299                                 /* see if a signal did it */
1300                                 if (signal_pending(current)) {
1301                                         ret = -ERESTARTSYS;
1302                                         break;
1303                                 }
1304                                 cprev = cnow;
1305                         }
1306                         finish_wait(&info->tport.delta_msr_wait, &wait);
1307                         return ret;
1308
1309                 case TIOCSERGWILD:
1310                 case TIOCSERSWILD:
1311                         /* "setserial -W" is called in Debian boot */
1312                         printk ("TIOCSER?WILD ioctl obsolete, ignored.\n");
1313                         return 0;
1314
1315                 default:
1316                         return -ENOIOCTLCMD;
1317                 }
1318         return 0;
1319 }
1320
1321 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1322 {
1323         struct serial_state *info = tty->driver_data;
1324         unsigned long flags;
1325         unsigned int cflag = tty->termios.c_cflag;
1326
1327         change_speed(tty, info, old_termios);
1328
1329         /* Handle transition to B0 status */
1330         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
1331                 info->MCR &= ~(SER_DTR|SER_RTS);
1332                 local_irq_save(flags);
1333                 rtsdtr_ctrl(info->MCR);
1334                 local_irq_restore(flags);
1335         }
1336
1337         /* Handle transition away from B0 status */
1338         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1339                 info->MCR |= SER_DTR;
1340                 if (!C_CRTSCTS(tty) || !tty_throttled(tty))
1341                         info->MCR |= SER_RTS;
1342                 local_irq_save(flags);
1343                 rtsdtr_ctrl(info->MCR);
1344                 local_irq_restore(flags);
1345         }
1346
1347         /* Handle turning off CRTSCTS */
1348         if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1349                 tty->hw_stopped = 0;
1350                 rs_start(tty);
1351         }
1352
1353 #if 0
1354         /*
1355          * No need to wake up processes in open wait, since they
1356          * sample the CLOCAL flag once, and don't recheck it.
1357          * XXX  It's not clear whether the current behavior is correct
1358          * or not.  Hence, this may change.....
1359          */
1360         if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
1361                 wake_up_interruptible(&info->open_wait);
1362 #endif
1363 }
1364
1365 /*
1366  * ------------------------------------------------------------
1367  * rs_close()
1368  *
1369  * This routine is called when the serial port gets closed.  First, we
1370  * wait for the last remaining data to be sent.  Then, we unlink its
1371  * async structure from the interrupt chain if necessary, and we free
1372  * that IRQ if nothing is left in the chain.
1373  * ------------------------------------------------------------
1374  */
1375 static void rs_close(struct tty_struct *tty, struct file * filp)
1376 {
1377         struct serial_state *state = tty->driver_data;
1378         struct tty_port *port = &state->tport;
1379
1380         if (serial_paranoia_check(state, tty->name, "rs_close"))
1381                 return;
1382
1383         if (tty_port_close_start(port, tty, filp) == 0)
1384                 return;
1385
1386         /*
1387          * At this point we stop accepting input.  To do this, we
1388          * disable the receive line status interrupts, and tell the
1389          * interrupt driver to stop checking the data ready bit in the
1390          * line status register.
1391          */
1392         state->read_status_mask &= ~UART_LSR_DR;
1393         if (tty_port_initialized(port)) {
1394                 /* disable receive interrupts */
1395                 custom.intena = IF_RBF;
1396                 mb();
1397                 /* clear any pending receive interrupt */
1398                 custom.intreq = IF_RBF;
1399                 mb();
1400
1401                 /*
1402                  * Before we drop DTR, make sure the UART transmitter
1403                  * has completely drained; this is especially
1404                  * important if there is a transmit FIFO!
1405                  */
1406                 rs_wait_until_sent(tty, state->timeout);
1407         }
1408         shutdown(tty, state);
1409         rs_flush_buffer(tty);
1410
1411         tty_ldisc_flush(tty);
1412         port->tty = NULL;
1413
1414         tty_port_close_end(port, tty);
1415 }
1416
1417 /*
1418  * rs_wait_until_sent() --- wait until the transmitter is empty
1419  */
1420 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1421 {
1422         struct serial_state *info = tty->driver_data;
1423         unsigned long orig_jiffies, char_time;
1424         int lsr;
1425
1426         if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1427                 return;
1428
1429         if (info->xmit_fifo_size == 0)
1430                 return; /* Just in case.... */
1431
1432         orig_jiffies = jiffies;
1433
1434         /*
1435          * Set the check interval to be 1/5 of the estimated time to
1436          * send a single character, and make it at least 1.  The check
1437          * interval should also be less than the timeout.
1438          *
1439          * Note: we have to use pretty tight timings here to satisfy
1440          * the NIST-PCTS.
1441          */
1442         char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1443         char_time = char_time / 5;
1444         if (char_time == 0)
1445                 char_time = 1;
1446         if (timeout)
1447           char_time = min_t(unsigned long, char_time, timeout);
1448         /*
1449          * If the transmitter hasn't cleared in twice the approximate
1450          * amount of time to send the entire FIFO, it probably won't
1451          * ever clear.  This assumes the UART isn't doing flow
1452          * control, which is currently the case.  Hence, if it ever
1453          * takes longer than info->timeout, this is probably due to a
1454          * UART bug of some kind.  So, we clamp the timeout parameter at
1455          * 2*info->timeout.
1456          */
1457         if (!timeout || timeout > 2*info->timeout)
1458                 timeout = 2*info->timeout;
1459 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1460         printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1461         printk("jiff=%lu...", jiffies);
1462 #endif
1463         while(!((lsr = custom.serdatr) & SDR_TSRE)) {
1464 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1465                 printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1466 #endif
1467                 msleep_interruptible(jiffies_to_msecs(char_time));
1468                 if (signal_pending(current))
1469                         break;
1470                 if (timeout && time_after(jiffies, orig_jiffies + timeout))
1471                         break;
1472         }
1473         __set_current_state(TASK_RUNNING);
1474
1475 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1476         printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1477 #endif
1478 }
1479
1480 /*
1481  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1482  */
1483 static void rs_hangup(struct tty_struct *tty)
1484 {
1485         struct serial_state *info = tty->driver_data;
1486
1487         if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1488                 return;
1489
1490         rs_flush_buffer(tty);
1491         shutdown(tty, info);
1492         info->tport.count = 0;
1493         tty_port_set_active(&info->tport, 0);
1494         info->tport.tty = NULL;
1495         wake_up_interruptible(&info->tport.open_wait);
1496 }
1497
1498 /*
1499  * This routine is called whenever a serial port is opened.  It
1500  * enables interrupts for a serial port, linking in its async structure into
1501  * the IRQ chain.   It also performs the serial-specific
1502  * initialization for the tty structure.
1503  */
1504 static int rs_open(struct tty_struct *tty, struct file * filp)
1505 {
1506         struct serial_state *info = rs_table + tty->index;
1507         struct tty_port *port = &info->tport;
1508         int retval;
1509
1510         port->count++;
1511         port->tty = tty;
1512         tty->driver_data = info;
1513         tty->port = port;
1514         if (serial_paranoia_check(info, tty->name, "rs_open"))
1515                 return -ENODEV;
1516
1517         port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1518
1519         retval = startup(tty, info);
1520         if (retval) {
1521                 return retval;
1522         }
1523
1524         return tty_port_block_til_ready(port, tty, filp);
1525 }
1526
1527 /*
1528  * /proc fs routines....
1529  */
1530
1531 static inline void line_info(struct seq_file *m, int line,
1532                 struct serial_state *state)
1533 {
1534         char    stat_buf[30], control, status;
1535         unsigned long flags;
1536
1537         seq_printf(m, "%d: uart:amiga_builtin", line);
1538
1539         local_irq_save(flags);
1540         status = ciab.pra;
1541         control = tty_port_initialized(&state->tport) ? state->MCR : status;
1542         local_irq_restore(flags);
1543
1544         stat_buf[0] = 0;
1545         stat_buf[1] = 0;
1546         if(!(control & SER_RTS))
1547                 strcat(stat_buf, "|RTS");
1548         if(!(status & SER_CTS))
1549                 strcat(stat_buf, "|CTS");
1550         if(!(control & SER_DTR))
1551                 strcat(stat_buf, "|DTR");
1552         if(!(status & SER_DSR))
1553                 strcat(stat_buf, "|DSR");
1554         if(!(status & SER_DCD))
1555                 strcat(stat_buf, "|CD");
1556
1557         if (state->quot)
1558                 seq_printf(m, " baud:%d", state->baud_base / state->quot);
1559
1560         seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1561
1562         if (state->icount.frame)
1563                 seq_printf(m, " fe:%d", state->icount.frame);
1564
1565         if (state->icount.parity)
1566                 seq_printf(m, " pe:%d", state->icount.parity);
1567
1568         if (state->icount.brk)
1569                 seq_printf(m, " brk:%d", state->icount.brk);
1570
1571         if (state->icount.overrun)
1572                 seq_printf(m, " oe:%d", state->icount.overrun);
1573
1574         /*
1575          * Last thing is the RS-232 status lines
1576          */
1577         seq_printf(m, " %s\n", stat_buf+1);
1578 }
1579
1580 static int rs_proc_show(struct seq_file *m, void *v)
1581 {
1582         seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
1583         line_info(m, 0, &rs_table[0]);
1584         return 0;
1585 }
1586
1587 static int rs_proc_open(struct inode *inode, struct file *file)
1588 {
1589         return single_open(file, rs_proc_show, NULL);
1590 }
1591
1592 static const struct file_operations rs_proc_fops = {
1593         .owner          = THIS_MODULE,
1594         .open           = rs_proc_open,
1595         .read           = seq_read,
1596         .llseek         = seq_lseek,
1597         .release        = single_release,
1598 };
1599
1600 /*
1601  * ---------------------------------------------------------------------
1602  * rs_init() and friends
1603  *
1604  * rs_init() is called at boot-time to initialize the serial driver.
1605  * ---------------------------------------------------------------------
1606  */
1607
1608 /*
1609  * This routine prints out the appropriate serial driver version
1610  * number, and identifies which options were configured into this
1611  * driver.
1612  */
1613 static void show_serial_version(void)
1614 {
1615         printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
1616 }
1617
1618
1619 static const struct tty_operations serial_ops = {
1620         .open = rs_open,
1621         .close = rs_close,
1622         .write = rs_write,
1623         .put_char = rs_put_char,
1624         .flush_chars = rs_flush_chars,
1625         .write_room = rs_write_room,
1626         .chars_in_buffer = rs_chars_in_buffer,
1627         .flush_buffer = rs_flush_buffer,
1628         .ioctl = rs_ioctl,
1629         .throttle = rs_throttle,
1630         .unthrottle = rs_unthrottle,
1631         .set_termios = rs_set_termios,
1632         .stop = rs_stop,
1633         .start = rs_start,
1634         .hangup = rs_hangup,
1635         .break_ctl = rs_break,
1636         .send_xchar = rs_send_xchar,
1637         .wait_until_sent = rs_wait_until_sent,
1638         .tiocmget = rs_tiocmget,
1639         .tiocmset = rs_tiocmset,
1640         .get_icount = rs_get_icount,
1641         .proc_fops = &rs_proc_fops,
1642 };
1643
1644 static int amiga_carrier_raised(struct tty_port *port)
1645 {
1646         return !(ciab.pra & SER_DCD);
1647 }
1648
1649 static void amiga_dtr_rts(struct tty_port *port, int raise)
1650 {
1651         struct serial_state *info = container_of(port, struct serial_state,
1652                         tport);
1653         unsigned long flags;
1654
1655         if (raise)
1656                 info->MCR |= SER_DTR|SER_RTS;
1657         else
1658                 info->MCR &= ~(SER_DTR|SER_RTS);
1659
1660         local_irq_save(flags);
1661         rtsdtr_ctrl(info->MCR);
1662         local_irq_restore(flags);
1663 }
1664
1665 static const struct tty_port_operations amiga_port_ops = {
1666         .carrier_raised = amiga_carrier_raised,
1667         .dtr_rts = amiga_dtr_rts,
1668 };
1669
1670 /*
1671  * The serial driver boot-time initialization code!
1672  */
1673 static int __init amiga_serial_probe(struct platform_device *pdev)
1674 {
1675         unsigned long flags;
1676         struct serial_state * state;
1677         int error;
1678
1679         serial_driver = alloc_tty_driver(NR_PORTS);
1680         if (!serial_driver)
1681                 return -ENOMEM;
1682
1683         show_serial_version();
1684
1685         /* Initialize the tty_driver structure */
1686
1687         serial_driver->driver_name = "amiserial";
1688         serial_driver->name = "ttyS";
1689         serial_driver->major = TTY_MAJOR;
1690         serial_driver->minor_start = 64;
1691         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1692         serial_driver->subtype = SERIAL_TYPE_NORMAL;
1693         serial_driver->init_termios = tty_std_termios;
1694         serial_driver->init_termios.c_cflag =
1695                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1696         serial_driver->flags = TTY_DRIVER_REAL_RAW;
1697         tty_set_operations(serial_driver, &serial_ops);
1698
1699         state = rs_table;
1700         state->port = (int)&custom.serdatr; /* Just to give it a value */
1701         state->custom_divisor = 0;
1702         state->icount.cts = state->icount.dsr =
1703           state->icount.rng = state->icount.dcd = 0;
1704         state->icount.rx = state->icount.tx = 0;
1705         state->icount.frame = state->icount.parity = 0;
1706         state->icount.overrun = state->icount.brk = 0;
1707         tty_port_init(&state->tport);
1708         state->tport.ops = &amiga_port_ops;
1709         tty_port_link_device(&state->tport, serial_driver, 0);
1710
1711         error = tty_register_driver(serial_driver);
1712         if (error)
1713                 goto fail_put_tty_driver;
1714
1715         printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1716
1717         /* Hardware set up */
1718
1719         state->baud_base = amiga_colorclock;
1720         state->xmit_fifo_size = 1;
1721
1722         /* set ISRs, and then disable the rx interrupts */
1723         error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1724         if (error)
1725                 goto fail_unregister;
1726
1727         error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1728                             "serial RX", state);
1729         if (error)
1730                 goto fail_free_irq;
1731
1732         local_irq_save(flags);
1733
1734         /* turn off Rx and Tx interrupts */
1735         custom.intena = IF_RBF | IF_TBE;
1736         mb();
1737
1738         /* clear any pending interrupt */
1739         custom.intreq = IF_RBF | IF_TBE;
1740         mb();
1741
1742         local_irq_restore(flags);
1743
1744         /*
1745          * set the appropriate directions for the modem control flags,
1746          * and clear RTS and DTR
1747          */
1748         ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1749         ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1750
1751         platform_set_drvdata(pdev, state);
1752
1753         return 0;
1754
1755 fail_free_irq:
1756         free_irq(IRQ_AMIGA_TBE, state);
1757 fail_unregister:
1758         tty_unregister_driver(serial_driver);
1759 fail_put_tty_driver:
1760         tty_port_destroy(&state->tport);
1761         put_tty_driver(serial_driver);
1762         return error;
1763 }
1764
1765 static int __exit amiga_serial_remove(struct platform_device *pdev)
1766 {
1767         int error;
1768         struct serial_state *state = platform_get_drvdata(pdev);
1769
1770         /* printk("Unloading %s: version %s\n", serial_name, serial_version); */
1771         error = tty_unregister_driver(serial_driver);
1772         if (error)
1773                 printk("SERIAL: failed to unregister serial driver (%d)\n",
1774                        error);
1775         put_tty_driver(serial_driver);
1776         tty_port_destroy(&state->tport);
1777
1778         free_irq(IRQ_AMIGA_TBE, state);
1779         free_irq(IRQ_AMIGA_RBF, state);
1780
1781         return error;
1782 }
1783
1784 static struct platform_driver amiga_serial_driver = {
1785         .remove = __exit_p(amiga_serial_remove),
1786         .driver   = {
1787                 .name   = "amiga-serial",
1788         },
1789 };
1790
1791 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1792
1793
1794 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1795
1796 /*
1797  * ------------------------------------------------------------
1798  * Serial console driver
1799  * ------------------------------------------------------------
1800  */
1801
1802 static void amiga_serial_putc(char c)
1803 {
1804         custom.serdat = (unsigned char)c | 0x100;
1805         while (!(custom.serdatr & 0x2000))
1806                 barrier();
1807 }
1808
1809 /*
1810  *      Print a string to the serial port trying not to disturb
1811  *      any possible real use of the port...
1812  *
1813  *      The console must be locked when we get here.
1814  */
1815 static void serial_console_write(struct console *co, const char *s,
1816                                 unsigned count)
1817 {
1818         unsigned short intena = custom.intenar;
1819
1820         custom.intena = IF_TBE;
1821
1822         while (count--) {
1823                 if (*s == '\n')
1824                         amiga_serial_putc('\r');
1825                 amiga_serial_putc(*s++);
1826         }
1827
1828         custom.intena = IF_SETCLR | (intena & IF_TBE);
1829 }
1830
1831 static struct tty_driver *serial_console_device(struct console *c, int *index)
1832 {
1833         *index = 0;
1834         return serial_driver;
1835 }
1836
1837 static struct console sercons = {
1838         .name =         "ttyS",
1839         .write =        serial_console_write,
1840         .device =       serial_console_device,
1841         .flags =        CON_PRINTBUFFER,
1842         .index =        -1,
1843 };
1844
1845 /*
1846  *      Register console.
1847  */
1848 static int __init amiserial_console_init(void)
1849 {
1850         if (!MACH_IS_AMIGA)
1851                 return -ENODEV;
1852
1853         register_console(&sercons);
1854         return 0;
1855 }
1856 console_initcall(amiserial_console_init);
1857
1858 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1859
1860 MODULE_LICENSE("GPL");
1861 MODULE_ALIAS("platform:amiga-serial");