drivers/char/rio/riotty.c

   1 /*
   2 ** -----------------------------------------------------------------------------
   3 **
   4 **  Perle Specialix driver for Linux
   5 **  Ported from existing RIO Driver for SCO sources.
   6  *
   7  *  (C) 1990 - 2000 Specialix International Ltd., Byfleet, Surrey, UK.
   8  *
   9  *      This program is free software; you can redistribute it and/or modify
  10  *      it under the terms of the GNU General Public License as published by
  11  *      the Free Software Foundation; either version 2 of the License, or
  12  *      (at your option) any later version.
  13  *
  14  *      This program is distributed in the hope that it will be useful,
  15  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *      GNU General Public License for more details.
  18  *
  19  *      You should have received a copy of the GNU General Public License
  20  *      along with this program; if not, write to the Free Software
  21  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 **
  23 **      Module          : riotty.c
  24 **      SID             : 1.3
  25 **      Last Modified   : 11/6/98 10:33:47
  26 **      Retrieved       : 11/6/98 10:33:50
  27 **
  28 **  ident @(#)riotty.c  1.3
  29 **
  30 ** -----------------------------------------------------------------------------
  31 */
  32 #ifdef SCCS_LABELS
  33 static char *_riotty_c_sccs_ = "@(#)riotty.c    1.3";
  34 #endif
  35
  36
  37 #define __EXPLICIT_DEF_H__
  38
  39 #include <linux/module.h>
  40 #include <linux/slab.h>
  41 #include <linux/errno.h>
  42 #include <linux/tty.h>
  43 #include <linux/string.h>
  44 #include <asm/io.h>
  45 #include <asm/system.h>
  46 #include <asm/string.h>
  47 #include <asm/uaccess.h>
  48
  49 #include <linux/termios.h>
  50
  51 #include <linux/serial.h>
  52
  53 #include <linux/generic_serial.h>
  54
  55
  56 #include "linux_compat.h"
  57 #include "rio_linux.h"
  58 #include "pkt.h"
  59 #include "daemon.h"
  60 #include "rio.h"
  61 #include "riospace.h"
  62 #include "cmdpkt.h"
  63 #include "map.h"
  64 #include "rup.h"
  65 #include "port.h"
  66 #include "riodrvr.h"
  67 #include "rioinfo.h"
  68 #include "func.h"
  69 #include "errors.h"
  70 #include "pci.h"
  71
  72 #include "parmmap.h"
  73 #include "unixrup.h"
  74 #include "board.h"
  75 #include "host.h"
  76 #include "phb.h"
  77 #include "link.h"
  78 #include "cmdblk.h"
  79 #include "route.h"
  80 #include "cirrus.h"
  81 #include "rioioctl.h"
  82 #include "param.h"
  83
  84 static void RIOClearUp(struct Port *PortP);
  85
  86 /* Below belongs in func.h */
  87 int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg);
  88
  89
  90 extern struct rio_info *p;
  91
  92
  93 int riotopen(struct tty_struct *tty, struct file *filp)
  94 {
  95         unsigned int SysPort;
  96         int repeat_this = 250;
  97         struct Port *PortP;     /* pointer to the port structure */
  98         unsigned long flags;
  99         int retval = 0;
 100
 101         func_enter();
 102
 103         /* Make sure driver_data is NULL in case the rio isn't booted jet. Else gs_close
 104            is going to oops.
 105          */
 106         tty->driver_data = NULL;
 107
 108         SysPort = rio_minor(tty);
 109
 110         if (p->RIOFailed) {
 111                 rio_dprintk(RIO_DEBUG_TTY, "System initialisation failed\n");
 112                 func_exit();
 113                 return -ENXIO;
 114         }
 115
 116         rio_dprintk(RIO_DEBUG_TTY, "port open SysPort %d (mapped:%d)\n", SysPort, p->RIOPortp[SysPort]->Mapped);
 117
 118         /*
 119          ** Validate that we have received a legitimate request.
 120          ** Currently, just check that we are opening a port on
 121          ** a host card that actually exists, and that the port
 122          ** has been mapped onto a host.
 123          */
 124         if (SysPort >= RIO_PORTS) {     /* out of range ? */
 125                 rio_dprintk(RIO_DEBUG_TTY, "Illegal port number %d\n", SysPort);
 126                 func_exit();
 127                 return -ENXIO;
 128         }
 129
 130         /*
 131          ** Grab pointer to the port stucture
 132          */
 133         PortP = p->RIOPortp[SysPort];   /* Get control struc */
 134         rio_dprintk(RIO_DEBUG_TTY, "PortP: %p\n", PortP);
 135         if (!PortP->Mapped) {   /* we aren't mapped yet! */
 136                 /*
 137                  ** The system doesn't know which RTA this port
 138                  ** corresponds to.
 139                  */
 140                 rio_dprintk(RIO_DEBUG_TTY, "port not mapped into system\n");
 141                 func_exit();
 142                 return -ENXIO;
 143         }
 144
 145         tty->driver_data = PortP;
 146
 147         PortP->gs.tty = tty;
 148         PortP->gs.count++;
 149
 150         rio_dprintk(RIO_DEBUG_TTY, "%d bytes in tx buffer\n", PortP->gs.xmit_cnt);
 151
 152         retval = gs_init_port(&PortP->gs);
 153         if (retval) {
 154                 PortP->gs.count--;
 155                 return -ENXIO;
 156         }
 157         /*
 158          ** If the host hasn't been booted yet, then
 159          ** fail
 160          */
 161         if ((PortP->HostP->Flags & RUN_STATE) != RC_RUNNING) {
 162                 rio_dprintk(RIO_DEBUG_TTY, "Host not running\n");
 163                 func_exit();
 164                 return -ENXIO;
 165         }
 166
 167         /*
 168          ** If the RTA has not booted yet and the user has choosen to block
 169          ** until the RTA is present then we must spin here waiting for
 170          ** the RTA to boot.
 171          */
 172         /* I find the above code a bit hairy. I find the below code
 173            easier to read and shorter. Now, if it works too that would
 174            be great... -- REW
 175          */
 176         rio_dprintk(RIO_DEBUG_TTY, "Checking if RTA has booted... \n");
 177         while (!(PortP->HostP->Mapping[PortP->RupNum].Flags & RTA_BOOTED)) {
 178                 if (!PortP->WaitUntilBooted) {
 179                         rio_dprintk(RIO_DEBUG_TTY, "RTA never booted\n");
 180                         func_exit();
 181                         return -ENXIO;
 182                 }
 183
 184                 /* Under Linux you'd normally use a wait instead of this
 185                    busy-waiting. I'll stick with the old implementation for
 186                    now. --REW
 187                  */
 188                 if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 189                         rio_dprintk(RIO_DEBUG_TTY, "RTA_wait_for_boot: EINTR in delay \n");
 190                         func_exit();
 191                         return -EINTR;
 192                 }
 193                 if (repeat_this-- <= 0) {
 194                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for RTA to boot timeout\n");
 195                         func_exit();
 196                         return -EIO;
 197                 }
 198         }
 199         rio_dprintk(RIO_DEBUG_TTY, "RTA has been booted\n");
 200         rio_spin_lock_irqsave(&PortP->portSem, flags);
 201         if (p->RIOHalted) {
 202                 goto bombout;
 203         }
 204
 205         /*
 206          ** If the port is in the final throws of being closed,
 207          ** we should wait here (politely), waiting
 208          ** for it to finish, so that it doesn't close us!
 209          */
 210         while ((PortP->State & RIO_CLOSING) && !p->RIOHalted) {
 211                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for RIO_CLOSING to go away\n");
 212                 if (repeat_this-- <= 0) {
 213                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
 214                         RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 215                         retval = -EINTR;
 216                         goto bombout;
 217                 }
 218                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 219                 if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 220                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 221                         retval = -EINTR;
 222                         goto bombout;
 223                 }
 224                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 225         }
 226
 227         if (!PortP->Mapped) {
 228                 rio_dprintk(RIO_DEBUG_TTY, "Port unmapped while closing!\n");
 229                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 230                 retval = -ENXIO;
 231                 func_exit();
 232                 return retval;
 233         }
 234
 235         if (p->RIOHalted) {
 236                 goto bombout;
 237         }
 238
 239 /*
 240 ** 15.10.1998 ARG - ESIL 0761 part fix
 241 ** RIO has it's own CTSFLOW and RTSFLOW flags in 'Config' in the port structure,
 242 ** we need to make sure that the flags are clear when the port is opened.
 243 */
 244         /* Uh? Suppose I turn these on and then another process opens
 245            the port again? The flags get cleared! Not good. -- REW */
 246         if (!(PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 247                 PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);
 248         }
 249
 250         if (!(PortP->firstOpen)) {      /* First time ? */
 251                 rio_dprintk(RIO_DEBUG_TTY, "First open for this port\n");
 252
 253
 254                 PortP->firstOpen++;
 255                 PortP->CookMode = 0;    /* XXX RIOCookMode(tp); */
 256                 PortP->InUse = NOT_INUSE;
 257
 258                 /* Tentative fix for bug PR27. Didn't work. */
 259                 /* PortP->gs.xmit_cnt = 0; */
 260
 261                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 262
 263                 /* Someone explain to me why this delay/config is
 264                    here. If I read the docs correctly the "open"
 265                    command piggybacks the parameters immediately.
 266                    -- REW */
 267                 RIOParam(PortP, RIOC_OPEN, 1, OK_TO_SLEEP); /* Open the port */
 268                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 269
 270                 /*
 271                  ** wait for the port to be not closed.
 272                  */
 273                 while (!(PortP->PortState & PORT_ISOPEN) && !p->RIOHalted) {
 274                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for PORT_ISOPEN-currently %x\n", PortP->PortState);
 275                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 276                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 277                                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for open to finish broken by signal\n");
 278                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 279                                 func_exit();
 280                                 return -EINTR;
 281                         }
 282                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 283                 }
 284
 285                 if (p->RIOHalted) {
 286                         retval = -EIO;
 287                       bombout:
 288                         /*                    RIOClearUp( PortP ); */
 289                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 290                         return retval;
 291                 }
 292                 rio_dprintk(RIO_DEBUG_TTY, "PORT_ISOPEN found\n");
 293         }
 294         rio_dprintk(RIO_DEBUG_TTY, "Modem - test for carrier\n");
 295         /*
 296          ** ACTION
 297          ** insert test for carrier here. -- ???
 298          ** I already see that test here. What's the deal? -- REW
 299          */
 300         if ((PortP->gs.tty->termios->c_cflag & CLOCAL) ||
 301                         (PortP->ModemState & RIOC_MSVR1_CD)) {
 302                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) Modem carr on\n", SysPort);
 303                 /*
 304                    tp->tm.c_state |= CARR_ON;
 305                    wakeup((caddr_t) &tp->tm.c_canq);
 306                  */
 307                 PortP->State |= RIO_CARR_ON;
 308                 wake_up_interruptible(&PortP->gs.open_wait);
 309         } else {        /* no carrier - wait for DCD */
 310                         /*
 311                    while (!(PortP->gs.tty->termios->c_state & CARR_ON) &&
 312                    !(filp->f_flags & O_NONBLOCK) && !p->RIOHalted )
 313                  */
 314                 while (!(PortP->State & RIO_CARR_ON) && !(filp->f_flags & O_NONBLOCK) && !p->RIOHalted) {
 315                                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) sleeping for carr on\n", SysPort);
 316                         /*
 317                            PortP->gs.tty->termios->c_state |= WOPEN;
 318                          */
 319                         PortP->State |= RIO_WOPEN;
 320                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 321                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 322                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 323                                 /*
 324                                  ** ACTION: verify that this is a good thing
 325                                  ** to do here. -- ???
 326                                  ** I think it's OK. -- REW
 327                                  */
 328                                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) sleeping for carr broken by signal\n", SysPort);
 329                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 330                                 /*
 331                                    tp->tm.c_state &= ~WOPEN;
 332                                  */
 333                                 PortP->State &= ~RIO_WOPEN;
 334                                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 335                                 func_exit();
 336                                 return -EINTR;
 337                         }
 338                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 339                 }
 340                 PortP->State &= ~RIO_WOPEN;
 341         }
 342         if (p->RIOHalted)
 343                 goto bombout;
 344         rio_dprintk(RIO_DEBUG_TTY, "Setting RIO_MOPEN\n");
 345         PortP->State |= RIO_MOPEN;
 346
 347         if (p->RIOHalted)
 348                 goto bombout;
 349
 350         rio_dprintk(RIO_DEBUG_TTY, "high level open done\n");
 351
 352         /*
 353          ** Count opens for port statistics reporting
 354          */
 355         if (PortP->statsGather)
 356                 PortP->opens++;
 357
 358         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 359         rio_dprintk(RIO_DEBUG_TTY, "Returning from open\n");
 360         func_exit();
 361         return 0;
 362 }
 363
 364 /*
 365 ** RIOClose the port.
 366 ** The operating system thinks that this is last close for the device.
 367 ** As there are two interfaces to the port (Modem and tty), we need to
 368 ** check that both are closed before we close the device.
 369 */
 370 int riotclose(void *ptr)
 371 {
 372         struct Port *PortP = ptr;       /* pointer to the port structure */
 373         int deleted = 0;
 374         int try = -1;           /* Disable the timeouts by setting them to -1 */
 375         int repeat_this = -1;   /* Congrats to those having 15 years of
 376                                    uptime! (You get to break the driver.) */
 377         unsigned long end_time;
 378         struct tty_struct *tty;
 379         unsigned long flags;
 380         int rv = 0;
 381
 382         rio_dprintk(RIO_DEBUG_TTY, "port close SysPort %d\n", PortP->PortNum);
 383
 384         /* PortP = p->RIOPortp[SysPort]; */
 385         rio_dprintk(RIO_DEBUG_TTY, "Port is at address %p\n", PortP);
 386         /* tp = PortP->TtyP; *//* Get tty */
 387         tty = PortP->gs.tty;
 388         rio_dprintk(RIO_DEBUG_TTY, "TTY is at address %p\n", tty);
 389
 390         if (PortP->gs.closing_wait)
 391                 end_time = jiffies + PortP->gs.closing_wait;
 392         else
 393                 end_time = jiffies + MAX_SCHEDULE_TIMEOUT;
 394
 395         rio_spin_lock_irqsave(&PortP->portSem, flags);
 396
 397         /*
 398          ** Setting this flag will make any process trying to open
 399          ** this port block until we are complete closing it.
 400          */
 401         PortP->State |= RIO_CLOSING;
 402
 403         if ((PortP->State & RIO_DELETED)) {
 404                 rio_dprintk(RIO_DEBUG_TTY, "Close on deleted RTA\n");
 405                 deleted = 1;
 406         }
 407
 408         if (p->RIOHalted) {
 409                 RIOClearUp(PortP);
 410                 rv = -EIO;
 411                 goto close_end;
 412         }
 413
 414         rio_dprintk(RIO_DEBUG_TTY, "Clear bits\n");
 415         /*
 416          ** clear the open bits for this device
 417          */
 418         PortP->State &= ~RIO_MOPEN;
 419         PortP->State &= ~RIO_CARR_ON;
 420         PortP->ModemState &= ~RIOC_MSVR1_CD;
 421         /*
 422          ** If the device was open as both a Modem and a tty line
 423          ** then we need to wimp out here, as the port has not really
 424          ** been finally closed (gee, whizz!) The test here uses the
 425          ** bit for the OTHER mode of operation, to see if THAT is
 426          ** still active!
 427          */
 428         if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 429                 /*
 430                  ** The port is still open for the other task -
 431                  ** return, pretending that we are still active.
 432                  */
 433                 rio_dprintk(RIO_DEBUG_TTY, "Channel %d still open !\n", PortP->PortNum);
 434                 PortP->State &= ~RIO_CLOSING;
 435                 if (PortP->firstOpen)
 436                         PortP->firstOpen--;
 437                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 438                 return -EIO;
 439         }
 440
 441         rio_dprintk(RIO_DEBUG_TTY, "Closing down - everything must go!\n");
 442
 443         PortP->State &= ~RIO_DYNOROD;
 444
 445         /*
 446          ** This is where we wait for the port
 447          ** to drain down before closing. Bye-bye....
 448          ** (We never meant to do this)
 449          */
 450         rio_dprintk(RIO_DEBUG_TTY, "Timeout 1 starts\n");
 451
 452         if (!deleted)
 453                 while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted && (PortP->TxBufferIn != PortP->TxBufferOut)) {
 454                         if (repeat_this-- <= 0) {
 455                                 rv = -EINTR;
 456                                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
 457                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 458                                 goto close_end;
 459                         }
 460                         rio_dprintk(RIO_DEBUG_TTY, "Calling timeout to flush in closing\n");
 461                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 462                         if (RIODelay_ni(PortP, HUNDRED_MS * 10) == RIO_FAIL) {
 463                                 rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
 464                                 rv = -EINTR;
 465                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 466                                 goto close_end;
 467                         }
 468                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 469                 }
 470
 471         PortP->TxBufferIn = PortP->TxBufferOut = 0;
 472         repeat_this = 0xff;
 473
 474         PortP->InUse = 0;
 475         if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 476                 /*
 477                  ** The port has been re-opened for the other task -
 478                  ** return, pretending that we are still active.
 479                  */
 480                 rio_dprintk(RIO_DEBUG_TTY, "Channel %d re-open!\n", PortP->PortNum);
 481                 PortP->State &= ~RIO_CLOSING;
 482                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 483                 if (PortP->firstOpen)
 484                         PortP->firstOpen--;
 485                 return -EIO;
 486         }
 487
 488         if (p->RIOHalted) {
 489                 RIOClearUp(PortP);
 490                 goto close_end;
 491         }
 492
 493         /* Can't call RIOShortCommand with the port locked. */
 494         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 495
 496         if (RIOShortCommand(p, PortP, RIOC_CLOSE, 1, 0) == RIO_FAIL) {
 497                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 498                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 499                 goto close_end;
 500         }
 501
 502         if (!deleted)
 503                 while (try && (PortP->PortState & PORT_ISOPEN)) {
 504                         try--;
 505                         if (time_after(jiffies, end_time)) {
 506                                 rio_dprintk(RIO_DEBUG_TTY, "Run out of tries - force the bugger shut!\n");
 507                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 508                                 break;
 509                         }
 510                         rio_dprintk(RIO_DEBUG_TTY, "Close: PortState:ISOPEN is %d\n", PortP->PortState & PORT_ISOPEN);
 511
 512                         if (p->RIOHalted) {
 513                                 RIOClearUp(PortP);
 514                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 515                                 goto close_end;
 516                         }
 517                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 518                                 rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
 519                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 520                                 break;
 521                         }
 522                 }
 523         rio_spin_lock_irqsave(&PortP->portSem, flags);
 524         rio_dprintk(RIO_DEBUG_TTY, "Close: try was %d on completion\n", try);
 525
 526         /* RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE); */
 527
 528 /*
 529 ** 15.10.1998 ARG - ESIL 0761 part fix
 530 ** RIO has it's own CTSFLOW and RTSFLOW flags in 'Config' in the port structure,** we need to make sure that the flags are clear when the port is opened.
 531 */
 532         PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);
 533
 534         /*
 535          ** Count opens for port statistics reporting
 536          */
 537         if (PortP->statsGather)
 538                 PortP->closes++;
 539
 540 close_end:
 541         /* XXX: Why would a "DELETED" flag be reset here? I'd have
 542            thought that a "deleted" flag means that the port was
 543            permanently gone, but here we can make it reappear by it
 544            being in close during the "deletion".
 545          */
 546         PortP->State &= ~(RIO_CLOSING | RIO_DELETED);
 547         if (PortP->firstOpen)
 548                 PortP->firstOpen--;
 549         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 550         rio_dprintk(RIO_DEBUG_TTY, "Return from close\n");
 551         return rv;
 552 }
 553
 554
 555
 556 static void RIOClearUp(struct Port *PortP)
 557 {
 558         rio_dprintk(RIO_DEBUG_TTY, "RIOHalted set\n");
 559         PortP->Config = 0;      /* Direct semaphore */
 560         PortP->PortState = 0;
 561         PortP->firstOpen = 0;
 562         PortP->FlushCmdBodge = 0;
 563         PortP->ModemState = PortP->CookMode = 0;
 564         PortP->Mapped = 0;
 565         PortP->WflushFlag = 0;
 566         PortP->MagicFlags = 0;
 567         PortP->RxDataStart = 0;
 568         PortP->TxBufferIn = 0;
 569         PortP->TxBufferOut = 0;
 570 }
 571
 572 /*
 573 ** Put a command onto a port.
 574 ** The PortPointer, command, length and arg are passed.
 575 ** The len is the length *inclusive* of the command byte,
 576 ** and so for a command that takes no data, len==1.
 577 ** The arg is a single byte, and is only used if len==2.
 578 ** Other values of len aren't allowed, and will cause
 579 ** a panic.
 580 */
 581 int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg)
 582 {
 583         struct PKT __iomem *PacketP;
 584         int retries = 20;       /* at 10 per second -> 2 seconds */
 585         unsigned long flags;
 586
 587         rio_dprintk(RIO_DEBUG_TTY, "entering shortcommand.\n");
 588
 589         if (PortP->State & RIO_DELETED) {
 590                 rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
 591                 return RIO_FAIL;
 592         }
 593         rio_spin_lock_irqsave(&PortP->portSem, flags);
 594
 595         /*
 596          ** If the port is in use for pre-emptive command, then wait for it to
 597          ** be free again.
 598          */
 599         while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted) {
 600                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for not in use (%d)\n", retries);
 601                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 602                 if (retries-- <= 0) {
 603                         return RIO_FAIL;
 604                 }
 605                 if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
 606                         return RIO_FAIL;
 607                 }
 608                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 609         }
 610         if (PortP->State & RIO_DELETED) {
 611                 rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
 612                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 613                 return RIO_FAIL;
 614         }
 615
 616         while (!can_add_transmit(&PacketP, PortP) && !p->RIOHalted) {
 617                 rio_dprintk(RIO_DEBUG_TTY, "Waiting to add short command to queue (%d)\n", retries);
 618                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 619                 if (retries-- <= 0) {
 620                         rio_dprintk(RIO_DEBUG_TTY, "out of tries. Failing\n");
 621                         return RIO_FAIL;
 622                 }
 623                 if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
 624                         return RIO_FAIL;
 625                 }
 626                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 627         }
 628
 629         if (p->RIOHalted) {
 630                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 631                 return RIO_FAIL;
 632         }
 633
 634         /*
 635          ** set the command byte and the argument byte
 636          */
 637         writeb(command, &PacketP->data[0]);
 638
 639         if (len == 2)
 640                 writeb(arg, &PacketP->data[1]);
 641
 642         /*
 643          ** set the length of the packet and set the command bit.
 644          */
 645         writeb(PKT_CMD_BIT | len, &PacketP->len);
 646
 647         add_transmit(PortP);
 648         /*
 649          ** Count characters transmitted for port statistics reporting
 650          */
 651         if (PortP->statsGather)
 652                 PortP->txchars += len;
 653
 654         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 655         return p->RIOHalted ? RIO_FAIL : ~RIO_FAIL;
 656 }
 657
 658