drivers/scsi/ppa.c

   1 /* ppa.c   --  low level driver for the IOMEGA PPA3
   2  * parallel port SCSI host adapter.
   3  *
   4  * (The PPA3 is the embedded controller in the ZIP drive.)
   5  *
   6  * (c) 1995,1996 Grant R. Guenther, grant@torque.net,
   7  * under the terms of the GNU General Public License.
   8  *
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/module.h>
  15 #include <linux/blkdev.h>
  16 #include <linux/parport.h>
  17 #include <linux/workqueue.h>
  18 #include <linux/delay.h>
  19 #include <linux/jiffies.h>
  20 #include <asm/io.h>
  21
  22 #include <scsi/scsi.h>
  23 #include <scsi/scsi_cmnd.h>
  24 #include <scsi/scsi_device.h>
  25 #include <scsi/scsi_host.h>
  26
  27
  28 static void ppa_reset_pulse(unsigned int base);
  29
  30 typedef struct {
  31         struct pardevice *dev;  /* Parport device entry         */
  32         int base;               /* Actual port address          */
  33         int mode;               /* Transfer mode                */
  34         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  35         struct delayed_work ppa_tq;     /* Polling interrupt stuff       */
  36         unsigned long jstart;   /* Jiffies at start             */
  37         unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
  38         unsigned int failed:1;  /* Failure flag                 */
  39         unsigned wanted:1;      /* Parport sharing busy flag    */
  40         wait_queue_head_t *waiting;
  41         struct Scsi_Host *host;
  42         struct list_head list;
  43 } ppa_struct;
  44
  45 #include  "ppa.h"
  46
  47 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  48 {
  49         return *(ppa_struct **)&host->hostdata;
  50 }
  51
  52 static DEFINE_SPINLOCK(arbitration_lock);
  53
  54 static void got_it(ppa_struct *dev)
  55 {
  56         dev->base = dev->dev->port->base;
  57         if (dev->cur_cmd)
  58                 dev->cur_cmd->SCp.phase = 1;
  59         else
  60                 wake_up(dev->waiting);
  61 }
  62
  63 static void ppa_wakeup(void *ref)
  64 {
  65         ppa_struct *dev = (ppa_struct *) ref;
  66         unsigned long flags;
  67
  68         spin_lock_irqsave(&arbitration_lock, flags);
  69         if (dev->wanted) {
  70                 parport_claim(dev->dev);
  71                 got_it(dev);
  72                 dev->wanted = 0;
  73         }
  74         spin_unlock_irqrestore(&arbitration_lock, flags);
  75         return;
  76 }
  77
  78 static int ppa_pb_claim(ppa_struct *dev)
  79 {
  80         unsigned long flags;
  81         int res = 1;
  82         spin_lock_irqsave(&arbitration_lock, flags);
  83         if (parport_claim(dev->dev) == 0) {
  84                 got_it(dev);
  85                 res = 0;
  86         }
  87         dev->wanted = res;
  88         spin_unlock_irqrestore(&arbitration_lock, flags);
  89         return res;
  90 }
  91
  92 static void ppa_pb_dismiss(ppa_struct *dev)
  93 {
  94         unsigned long flags;
  95         int wanted;
  96         spin_lock_irqsave(&arbitration_lock, flags);
  97         wanted = dev->wanted;
  98         dev->wanted = 0;
  99         spin_unlock_irqrestore(&arbitration_lock, flags);
 100         if (!wanted)
 101                 parport_release(dev->dev);
 102 }
 103
 104 static inline void ppa_pb_release(ppa_struct *dev)
 105 {
 106         parport_release(dev->dev);
 107 }
 108
 109 /*
 110  * Start of Chipset kludges
 111  */
 112
 113 /* This is to give the ppa driver a way to modify the timings (and other
 114  * parameters) by writing to the /proc/scsi/ppa/0 file.
 115  * Very simple method really... (To simple, no error checking :( )
 116  * Reason: Kernel hackers HATE having to unload and reload modules for
 117  * testing...
 118  * Also gives a method to use a script to obtain optimum timings (TODO)
 119  */
 120
 121 static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
 122 {
 123         ppa_struct *dev = ppa_dev(host);
 124         unsigned long x;
 125
 126         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 127                 x = simple_strtoul(buffer + 5, NULL, 0);
 128                 dev->mode = x;
 129                 return length;
 130         }
 131         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 132                 x = simple_strtoul(buffer + 10, NULL, 0);
 133                 dev->recon_tmo = x;
 134                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 135                 return length;
 136         }
 137         printk(KERN_WARNING "ppa /proc: invalid variable\n");
 138         return -EINVAL;
 139 }
 140
 141 static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
 142 {
 143         ppa_struct *dev = ppa_dev(host);
 144
 145         seq_printf(m, "Version : %s\n", PPA_VERSION);
 146         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 147         seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
 148 #if PPA_DEBUG > 0
 149         seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
 150 #endif
 151         return 0;
 152 }
 153
 154 static int device_check(ppa_struct *dev);
 155
 156 #if PPA_DEBUG > 0
 157 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 158            y, __func__, __LINE__); ppa_fail_func(x,y);
 159 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 160 #else
 161 static inline void ppa_fail(ppa_struct *dev, int error_code)
 162 #endif
 163 {
 164         /* If we fail a device then we trash status / message bytes */
 165         if (dev->cur_cmd) {
 166                 dev->cur_cmd->result = error_code << 16;
 167                 dev->failed = 1;
 168         }
 169 }
 170
 171 /*
 172  * Wait for the high bit to be set.
 173  *
 174  * In principle, this could be tied to an interrupt, but the adapter
 175  * doesn't appear to be designed to support interrupts.  We spin on
 176  * the 0x80 ready bit.
 177  */
 178 static unsigned char ppa_wait(ppa_struct *dev)
 179 {
 180         int k;
 181         unsigned short ppb = dev->base;
 182         unsigned char r;
 183
 184         k = PPA_SPIN_TMO;
 185         /* Wait for bit 6 and 7 - PJC */
 186         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 187                 udelay(1);
 188                 r = r_str(ppb);
 189         }
 190
 191         /*
 192          * return some status information.
 193          * Semantics: 0xc0 = ZIP wants more data
 194          *            0xd0 = ZIP wants to send more data
 195          *            0xe0 = ZIP is expecting SCSI command data
 196          *            0xf0 = end of transfer, ZIP is sending status
 197          */
 198         if (k)
 199                 return (r & 0xf0);
 200
 201         /* Counter expired - Time out occurred */
 202         ppa_fail(dev, DID_TIME_OUT);
 203         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 204         return 0;               /* command timed out */
 205 }
 206
 207 /*
 208  * Clear EPP Timeout Bit
 209  */
 210 static inline void epp_reset(unsigned short ppb)
 211 {
 212         int i;
 213
 214         i = r_str(ppb);
 215         w_str(ppb, i);
 216         w_str(ppb, i & 0xfe);
 217 }
 218
 219 /*
 220  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 221  */
 222 static inline void ecp_sync(ppa_struct *dev)
 223 {
 224         int i, ppb_hi = dev->dev->port->base_hi;
 225
 226         if (ppb_hi == 0)
 227                 return;
 228
 229         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 230                 for (i = 0; i < 100; i++) {
 231                         if (r_ecr(ppb_hi) & 0x01)
 232                                 return;
 233                         udelay(5);
 234                 }
 235                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 236         }
 237 }
 238
 239 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 240 {
 241         int i;
 242
 243         for (i = len; i; i--) {
 244                 w_dtr(base, *buffer++);
 245                 w_ctr(base, 0xe);
 246                 w_ctr(base, 0xc);
 247         }
 248         return 1;               /* All went well - we hope! */
 249 }
 250
 251 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 252 {
 253         int i;
 254
 255         for (i = len; i; i--) {
 256                 *buffer++ = r_dtr(base);
 257                 w_ctr(base, 0x27);
 258                 w_ctr(base, 0x25);
 259         }
 260         return 1;               /* All went well - we hope! */
 261 }
 262
 263 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 264 {
 265         for (; len; len--) {
 266                 unsigned char h;
 267
 268                 w_ctr(base, 0x4);
 269                 h = r_str(base) & 0xf0;
 270                 w_ctr(base, 0x6);
 271                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 272         }
 273         return 1;               /* All went well - we hope! */
 274 }
 275
 276 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 277 {
 278         int r;
 279         unsigned short ppb = dev->base;
 280
 281         r = ppa_wait(dev);
 282
 283         if ((r & 0x50) != 0x40) {
 284                 ppa_fail(dev, DID_ERROR);
 285                 return 0;
 286         }
 287         switch (dev->mode) {
 288         case PPA_NIBBLE:
 289         case PPA_PS2:
 290                 /* 8 bit output, with a loop */
 291                 r = ppa_byte_out(ppb, buffer, len);
 292                 break;
 293
 294         case PPA_EPP_32:
 295         case PPA_EPP_16:
 296         case PPA_EPP_8:
 297                 epp_reset(ppb);
 298                 w_ctr(ppb, 0x4);
 299 #ifdef CONFIG_SCSI_IZIP_EPP16
 300                 if (!(((long) buffer | len) & 0x01))
 301                         outsw(ppb + 4, buffer, len >> 1);
 302 #else
 303                 if (!(((long) buffer | len) & 0x03))
 304                         outsl(ppb + 4, buffer, len >> 2);
 305 #endif
 306                 else
 307                         outsb(ppb + 4, buffer, len);
 308                 w_ctr(ppb, 0xc);
 309                 r = !(r_str(ppb) & 0x01);
 310                 w_ctr(ppb, 0xc);
 311                 ecp_sync(dev);
 312                 break;
 313
 314         default:
 315                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
 316                 r = 0;
 317         }
 318         return r;
 319 }
 320
 321 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 322 {
 323         int r;
 324         unsigned short ppb = dev->base;
 325
 326         r = ppa_wait(dev);
 327
 328         if ((r & 0x50) != 0x50) {
 329                 ppa_fail(dev, DID_ERROR);
 330                 return 0;
 331         }
 332         switch (dev->mode) {
 333         case PPA_NIBBLE:
 334                 /* 4 bit input, with a loop */
 335                 r = ppa_nibble_in(ppb, buffer, len);
 336                 w_ctr(ppb, 0xc);
 337                 break;
 338
 339         case PPA_PS2:
 340                 /* 8 bit input, with a loop */
 341                 w_ctr(ppb, 0x25);
 342                 r = ppa_byte_in(ppb, buffer, len);
 343                 w_ctr(ppb, 0x4);
 344                 w_ctr(ppb, 0xc);
 345                 break;
 346
 347         case PPA_EPP_32:
 348         case PPA_EPP_16:
 349         case PPA_EPP_8:
 350                 epp_reset(ppb);
 351                 w_ctr(ppb, 0x24);
 352 #ifdef CONFIG_SCSI_IZIP_EPP16
 353                 if (!(((long) buffer | len) & 0x01))
 354                         insw(ppb + 4, buffer, len >> 1);
 355 #else
 356                 if (!(((long) buffer | len) & 0x03))
 357                         insl(ppb + 4, buffer, len >> 2);
 358 #endif
 359                 else
 360                         insb(ppb + 4, buffer, len);
 361                 w_ctr(ppb, 0x2c);
 362                 r = !(r_str(ppb) & 0x01);
 363                 w_ctr(ppb, 0x2c);
 364                 ecp_sync(dev);
 365                 break;
 366
 367         default:
 368                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 369                 r = 0;
 370                 break;
 371         }
 372         return r;
 373 }
 374
 375 /* end of ppa_io.h */
 376 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 377 {
 378         w_dtr(ppb, b);
 379         w_ctr(ppb, 0xc);
 380         w_ctr(ppb, 0xe);
 381         w_ctr(ppb, 0xc);
 382         w_ctr(ppb, 0x4);
 383         w_ctr(ppb, 0xc);
 384 }
 385
 386 static void ppa_disconnect(ppa_struct *dev)
 387 {
 388         unsigned short ppb = dev->base;
 389
 390         ppa_d_pulse(ppb, 0);
 391         ppa_d_pulse(ppb, 0x3c);
 392         ppa_d_pulse(ppb, 0x20);
 393         ppa_d_pulse(ppb, 0xf);
 394 }
 395
 396 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 397 {
 398         w_dtr(ppb, b);
 399         w_ctr(ppb, 0x4);
 400         w_ctr(ppb, 0x6);
 401         w_ctr(ppb, 0x4);
 402         w_ctr(ppb, 0xc);
 403 }
 404
 405 static inline void ppa_connect(ppa_struct *dev, int flag)
 406 {
 407         unsigned short ppb = dev->base;
 408
 409         ppa_c_pulse(ppb, 0);
 410         ppa_c_pulse(ppb, 0x3c);
 411         ppa_c_pulse(ppb, 0x20);
 412         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 413                 ppa_c_pulse(ppb, 0xcf);
 414         else
 415                 ppa_c_pulse(ppb, 0x8f);
 416 }
 417
 418 static int ppa_select(ppa_struct *dev, int target)
 419 {
 420         int k;
 421         unsigned short ppb = dev->base;
 422
 423         /*
 424          * Bit 6 (0x40) is the device selected bit.
 425          * First we must wait till the current device goes off line...
 426          */
 427         k = PPA_SELECT_TMO;
 428         do {
 429                 k--;
 430                 udelay(1);
 431         } while ((r_str(ppb) & 0x40) && (k));
 432         if (!k)
 433                 return 0;
 434
 435         w_dtr(ppb, (1 << target));
 436         w_ctr(ppb, 0xe);
 437         w_ctr(ppb, 0xc);
 438         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 439         w_ctr(ppb, 0x8);
 440
 441         k = PPA_SELECT_TMO;
 442         do {
 443                 k--;
 444                 udelay(1);
 445         }
 446         while (!(r_str(ppb) & 0x40) && (k));
 447         if (!k)
 448                 return 0;
 449
 450         return 1;
 451 }
 452
 453 /*
 454  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 455  * I've tried several different kinds of parallel ports with guest and
 456  * coded this to react in the same ways that it does.
 457  *
 458  * The return value from this function is just a hint about where the
 459  * handshaking failed.
 460  *
 461  */
 462 static int ppa_init(ppa_struct *dev)
 463 {
 464         int retv;
 465         unsigned short ppb = dev->base;
 466
 467         ppa_disconnect(dev);
 468         ppa_connect(dev, CONNECT_NORMAL);
 469
 470         retv = 2;               /* Failed */
 471
 472         w_ctr(ppb, 0xe);
 473         if ((r_str(ppb) & 0x08) == 0x08)
 474                 retv--;
 475
 476         w_ctr(ppb, 0xc);
 477         if ((r_str(ppb) & 0x08) == 0x00)
 478                 retv--;
 479
 480         if (!retv)
 481                 ppa_reset_pulse(ppb);
 482         udelay(1000);           /* Allow devices to settle down */
 483         ppa_disconnect(dev);
 484         udelay(1000);           /* Another delay to allow devices to settle */
 485
 486         if (retv)
 487                 return -EIO;
 488
 489         return device_check(dev);
 490 }
 491
 492 static inline int ppa_send_command(struct scsi_cmnd *cmd)
 493 {
 494         ppa_struct *dev = ppa_dev(cmd->device->host);
 495         int k;
 496
 497         w_ctr(dev->base, 0x0c);
 498
 499         for (k = 0; k < cmd->cmd_len; k++)
 500                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 501                         return 0;
 502         return 1;
 503 }
 504
 505 /*
 506  * The bulk flag enables some optimisations in the data transfer loops,
 507  * it should be true for any command that transfers data in integral
 508  * numbers of sectors.
 509  *
 510  * The driver appears to remain stable if we speed up the parallel port
 511  * i/o in this function, but not elsewhere.
 512  */
 513 static int ppa_completion(struct scsi_cmnd *cmd)
 514 {
 515         /* Return codes:
 516          * -1     Error
 517          *  0     Told to schedule
 518          *  1     Finished data transfer
 519          */
 520         ppa_struct *dev = ppa_dev(cmd->device->host);
 521         unsigned short ppb = dev->base;
 522         unsigned long start_jiffies = jiffies;
 523
 524         unsigned char r, v;
 525         int fast, bulk, status;
 526
 527         v = cmd->cmnd[0];
 528         bulk = ((v == READ_6) ||
 529                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 530
 531         /*
 532          * We only get here if the drive is ready to comunicate,
 533          * hence no need for a full ppa_wait.
 534          */
 535         r = (r_str(ppb) & 0xf0);
 536
 537         while (r != (unsigned char) 0xf0) {
 538                 /*
 539                  * If we have been running for more than a full timer tick
 540                  * then take a rest.
 541                  */
 542                 if (time_after(jiffies, start_jiffies + 1))
 543                         return 0;
 544
 545                 if ((cmd->SCp.this_residual <= 0)) {
 546                         ppa_fail(dev, DID_ERROR);
 547                         return -1;      /* ERROR_RETURN */
 548                 }
 549
 550                 /* On some hardware we have SCSI disconnected (6th bit low)
 551                  * for about 100usecs. It is too expensive to wait a
 552                  * tick on every loop so we busy wait for no more than
 553                  * 500usecs to give the drive a chance first. We do not
 554                  * change things for "normal" hardware since generally
 555                  * the 6th bit is always high.
 556                  * This makes the CPU load higher on some hardware
 557                  * but otherwise we can not get more than 50K/secs
 558                  * on this problem hardware.
 559                  */
 560                 if ((r & 0xc0) != 0xc0) {
 561                         /* Wait for reconnection should be no more than
 562                          * jiffy/2 = 5ms = 5000 loops
 563                          */
 564                         unsigned long k = dev->recon_tmo;
 565                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 566                              k--)
 567                                 udelay(1);
 568
 569                         if (!k)
 570                                 return 0;
 571                 }
 572
 573                 /* determine if we should use burst I/O */
 574                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 575                     ? PPA_BURST_SIZE : 1;
 576
 577                 if (r == (unsigned char) 0xc0)
 578                         status = ppa_out(dev, cmd->SCp.ptr, fast);
 579                 else
 580                         status = ppa_in(dev, cmd->SCp.ptr, fast);
 581
 582                 cmd->SCp.ptr += fast;
 583                 cmd->SCp.this_residual -= fast;
 584
 585                 if (!status) {
 586                         ppa_fail(dev, DID_BUS_BUSY);
 587                         return -1;      /* ERROR_RETURN */
 588                 }
 589                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 590                         /* if scatter/gather, advance to the next segment */
 591                         if (cmd->SCp.buffers_residual--) {
 592                                 cmd->SCp.buffer++;
 593                                 cmd->SCp.this_residual =
 594                                     cmd->SCp.buffer->length;
 595                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 596                         }
 597                 }
 598                 /* Now check to see if the drive is ready to comunicate */
 599                 r = (r_str(ppb) & 0xf0);
 600                 /* If not, drop back down to the scheduler and wait a timer tick */
 601                 if (!(r & 0x80))
 602                         return 0;
 603         }
 604         return 1;               /* FINISH_RETURN */
 605 }
 606
 607 /*
 608  * Since the PPA itself doesn't generate interrupts, we use
 609  * the scheduler's task queue to generate a stream of call-backs and
 610  * complete the request when the drive is ready.
 611  */
 612 static void ppa_interrupt(struct work_struct *work)
 613 {
 614         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 615         struct scsi_cmnd *cmd = dev->cur_cmd;
 616
 617         if (!cmd) {
 618                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 619                 return;
 620         }
 621         if (ppa_engine(dev, cmd)) {
 622                 schedule_delayed_work(&dev->ppa_tq, 1);
 623                 return;
 624         }
 625         /* Command must of completed hence it is safe to let go... */
 626 #if PPA_DEBUG > 0
 627         switch ((cmd->result >> 16) & 0xff) {
 628         case DID_OK:
 629                 break;
 630         case DID_NO_CONNECT:
 631                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
 632                 break;
 633         case DID_BUS_BUSY:
 634                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 635                 break;
 636         case DID_TIME_OUT:
 637                 printk(KERN_DEBUG "ppa: unknown timeout\n");
 638                 break;
 639         case DID_ABORT:
 640                 printk(KERN_DEBUG "ppa: told to abort\n");
 641                 break;
 642         case DID_PARITY:
 643                 printk(KERN_DEBUG "ppa: parity error (???)\n");
 644                 break;
 645         case DID_ERROR:
 646                 printk(KERN_DEBUG "ppa: internal driver error\n");
 647                 break;
 648         case DID_RESET:
 649                 printk(KERN_DEBUG "ppa: told to reset device\n");
 650                 break;
 651         case DID_BAD_INTR:
 652                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 653                 break;
 654         default:
 655                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 656                        (cmd->result >> 16) & 0xff);
 657         }
 658 #endif
 659
 660         if (cmd->SCp.phase > 1)
 661                 ppa_disconnect(dev);
 662
 663         ppa_pb_dismiss(dev);
 664
 665         dev->cur_cmd = NULL;
 666
 667         cmd->scsi_done(cmd);
 668 }
 669
 670 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 671 {
 672         unsigned short ppb = dev->base;
 673         unsigned char l = 0, h = 0;
 674         int retv;
 675
 676         /* First check for any errors that may of occurred
 677          * Here we check for internal errors
 678          */
 679         if (dev->failed)
 680                 return 0;
 681
 682         switch (cmd->SCp.phase) {
 683         case 0:         /* Phase 0 - Waiting for parport */
 684                 if (time_after(jiffies, dev->jstart + HZ)) {
 685                         /*
 686                          * We waited more than a second
 687                          * for parport to call us
 688                          */
 689                         ppa_fail(dev, DID_BUS_BUSY);
 690                         return 0;
 691                 }
 692                 return 1;       /* wait until ppa_wakeup claims parport */
 693         case 1:         /* Phase 1 - Connected */
 694                 {               /* Perform a sanity check for cable unplugged */
 695                         int retv = 2;   /* Failed */
 696
 697                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 698
 699                         w_ctr(ppb, 0xe);
 700                         if ((r_str(ppb) & 0x08) == 0x08)
 701                                 retv--;
 702
 703                         w_ctr(ppb, 0xc);
 704                         if ((r_str(ppb) & 0x08) == 0x00)
 705                                 retv--;
 706
 707                         if (retv) {
 708                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 709                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 710                                         ppa_fail(dev, DID_BUS_BUSY);
 711                                         return 0;
 712                                 } else {
 713                                         ppa_disconnect(dev);
 714                                         return 1;       /* Try again in a jiffy */
 715                                 }
 716                         }
 717                         cmd->SCp.phase++;
 718                 }
 719
 720         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 721                 if (!ppa_select(dev, scmd_id(cmd))) {
 722                         ppa_fail(dev, DID_NO_CONNECT);
 723                         return 0;
 724                 }
 725                 cmd->SCp.phase++;
 726
 727         case 3:         /* Phase 3 - Ready to accept a command */
 728                 w_ctr(ppb, 0x0c);
 729                 if (!(r_str(ppb) & 0x80))
 730                         return 1;
 731
 732                 if (!ppa_send_command(cmd))
 733                         return 0;
 734                 cmd->SCp.phase++;
 735
 736         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 737                 if (scsi_bufflen(cmd)) {
 738                         cmd->SCp.buffer = scsi_sglist(cmd);
 739                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 740                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 741                 } else {
 742                         cmd->SCp.buffer = NULL;
 743                         cmd->SCp.this_residual = 0;
 744                         cmd->SCp.ptr = NULL;
 745                 }
 746                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 747                 cmd->SCp.phase++;
 748
 749         case 5:         /* Phase 5 - Data transfer stage */
 750                 w_ctr(ppb, 0x0c);
 751                 if (!(r_str(ppb) & 0x80))
 752                         return 1;
 753
 754                 retv = ppa_completion(cmd);
 755                 if (retv == -1)
 756                         return 0;
 757                 if (retv == 0)
 758                         return 1;
 759                 cmd->SCp.phase++;
 760
 761         case 6:         /* Phase 6 - Read status/message */
 762                 cmd->result = DID_OK << 16;
 763                 /* Check for data overrun */
 764                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
 765                         ppa_fail(dev, DID_ERROR);
 766                         return 0;
 767                 }
 768                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
 769                         /* Check for optional message byte */
 770                         if (ppa_wait(dev) == (unsigned char) 0xf0)
 771                                 ppa_in(dev, &h, 1);
 772                         cmd->result =
 773                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 774                 }
 775                 return 0;       /* Finished */
 776                 break;
 777
 778         default:
 779                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
 780         }
 781         return 0;
 782 }
 783
 784 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
 785                 void (*done) (struct scsi_cmnd *))
 786 {
 787         ppa_struct *dev = ppa_dev(cmd->device->host);
 788
 789         if (dev->cur_cmd) {
 790                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 791                 return 0;
 792         }
 793         dev->failed = 0;
 794         dev->jstart = jiffies;
 795         dev->cur_cmd = cmd;
 796         cmd->scsi_done = done;
 797         cmd->result = DID_ERROR << 16;  /* default return code */
 798         cmd->SCp.phase = 0;     /* bus free */
 799
 800         schedule_delayed_work(&dev->ppa_tq, 0);
 801
 802         ppa_pb_claim(dev);
 803
 804         return 0;
 805 }
 806
 807 static DEF_SCSI_QCMD(ppa_queuecommand)
 808
 809 /*
 810  * Apparently the disk->capacity attribute is off by 1 sector
 811  * for all disk drives.  We add the one here, but it should really
 812  * be done in sd.c.  Even if it gets fixed there, this will still
 813  * work.
 814  */
 815 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 816               sector_t capacity, int ip[])
 817 {
 818         ip[0] = 0x40;
 819         ip[1] = 0x20;
 820         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 821         if (ip[2] > 1024) {
 822                 ip[0] = 0xff;
 823                 ip[1] = 0x3f;
 824                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 825                 if (ip[2] > 1023)
 826                         ip[2] = 1023;
 827         }
 828         return 0;
 829 }
 830
 831 static int ppa_abort(struct scsi_cmnd *cmd)
 832 {
 833         ppa_struct *dev = ppa_dev(cmd->device->host);
 834         /*
 835          * There is no method for aborting commands since Iomega
 836          * have tied the SCSI_MESSAGE line high in the interface
 837          */
 838
 839         switch (cmd->SCp.phase) {
 840         case 0:         /* Do not have access to parport */
 841         case 1:         /* Have not connected to interface */
 842                 dev->cur_cmd = NULL;    /* Forget the problem */
 843                 return SUCCESS;
 844                 break;
 845         default:                /* SCSI command sent, can not abort */
 846                 return FAILED;
 847                 break;
 848         }
 849 }
 850
 851 static void ppa_reset_pulse(unsigned int base)
 852 {
 853         w_dtr(base, 0x40);
 854         w_ctr(base, 0x8);
 855         udelay(30);
 856         w_ctr(base, 0xc);
 857 }
 858
 859 static int ppa_reset(struct scsi_cmnd *cmd)
 860 {
 861         ppa_struct *dev = ppa_dev(cmd->device->host);
 862
 863         if (cmd->SCp.phase)
 864                 ppa_disconnect(dev);
 865         dev->cur_cmd = NULL;    /* Forget the problem */
 866
 867         ppa_connect(dev, CONNECT_NORMAL);
 868         ppa_reset_pulse(dev->base);
 869         mdelay(1);              /* device settle delay */
 870         ppa_disconnect(dev);
 871         mdelay(1);              /* device settle delay */
 872         return SUCCESS;
 873 }
 874
 875 static int device_check(ppa_struct *dev)
 876 {
 877         /* This routine looks for a device and then attempts to use EPP
 878            to send a command. If all goes as planned then EPP is available. */
 879
 880         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 881         int loop, old_mode, status, k, ppb = dev->base;
 882         unsigned char l;
 883
 884         old_mode = dev->mode;
 885         for (loop = 0; loop < 8; loop++) {
 886                 /* Attempt to use EPP for Test Unit Ready */
 887                 if ((ppb & 0x0007) == 0x0000)
 888                         dev->mode = PPA_EPP_32;
 889
 890 second_pass:
 891                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 892                 /* Select SCSI device */
 893                 if (!ppa_select(dev, loop)) {
 894                         ppa_disconnect(dev);
 895                         continue;
 896                 }
 897                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
 898                        loop, PPA_MODE_STRING[dev->mode]);
 899
 900                 /* Send SCSI command */
 901                 status = 1;
 902                 w_ctr(ppb, 0x0c);
 903                 for (l = 0; (l < 6) && (status); l++)
 904                         status = ppa_out(dev, cmd, 1);
 905
 906                 if (!status) {
 907                         ppa_disconnect(dev);
 908                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 909                         w_dtr(ppb, 0x40);
 910                         w_ctr(ppb, 0x08);
 911                         udelay(30);
 912                         w_ctr(ppb, 0x0c);
 913                         udelay(1000);
 914                         ppa_disconnect(dev);
 915                         udelay(1000);
 916                         if (dev->mode == PPA_EPP_32) {
 917                                 dev->mode = old_mode;
 918                                 goto second_pass;
 919                         }
 920                         return -EIO;
 921                 }
 922                 w_ctr(ppb, 0x0c);
 923                 k = 1000000;    /* 1 Second */
 924                 do {
 925                         l = r_str(ppb);
 926                         k--;
 927                         udelay(1);
 928                 } while (!(l & 0x80) && (k));
 929
 930                 l &= 0xf0;
 931
 932                 if (l != 0xf0) {
 933                         ppa_disconnect(dev);
 934                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 935                         ppa_reset_pulse(ppb);
 936                         udelay(1000);
 937                         ppa_disconnect(dev);
 938                         udelay(1000);
 939                         if (dev->mode == PPA_EPP_32) {
 940                                 dev->mode = old_mode;
 941                                 goto second_pass;
 942                         }
 943                         return -EIO;
 944                 }
 945                 ppa_disconnect(dev);
 946                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
 947                        loop, PPA_MODE_STRING[dev->mode]);
 948                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 949                 ppa_reset_pulse(ppb);
 950                 udelay(1000);
 951                 ppa_disconnect(dev);
 952                 udelay(1000);
 953                 return 0;
 954         }
 955         return -ENODEV;
 956 }
 957
 958 static int ppa_adjust_queue(struct scsi_device *device)
 959 {
 960         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 961         return 0;
 962 }
 963
 964 static struct scsi_host_template ppa_template = {
 965         .module                 = THIS_MODULE,
 966         .proc_name              = "ppa",
 967         .show_info              = ppa_show_info,
 968         .write_info             = ppa_write_info,
 969         .name                   = "Iomega VPI0 (ppa) interface",
 970         .queuecommand           = ppa_queuecommand,
 971         .eh_abort_handler       = ppa_abort,
 972         .eh_bus_reset_handler   = ppa_reset,
 973         .eh_host_reset_handler  = ppa_reset,
 974         .bios_param             = ppa_biosparam,
 975         .this_id                = -1,
 976         .sg_tablesize           = SG_ALL,
 977         .cmd_per_lun            = 1,
 978         .use_clustering         = ENABLE_CLUSTERING,
 979         .can_queue              = 1,
 980         .slave_alloc            = ppa_adjust_queue,
 981 };
 982
 983 /***************************************************************************
 984  *                   Parallel port probing routines                        *
 985  ***************************************************************************/
 986
 987 static LIST_HEAD(ppa_hosts);
 988
 989 static int __ppa_attach(struct parport *pb)
 990 {
 991         struct Scsi_Host *host;
 992         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
 993         DEFINE_WAIT(wait);
 994         ppa_struct *dev;
 995         int ports;
 996         int modes, ppb, ppb_hi;
 997         int err = -ENOMEM;
 998
 999         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1000         if (!dev)
1001                 return -ENOMEM;
1002         dev->base = -1;
1003         dev->mode = PPA_AUTODETECT;
1004         dev->recon_tmo = PPA_RECON_TMO;
1005         init_waitqueue_head(&waiting);
1006         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1007                                             NULL, 0, dev);
1008
1009         if (!dev->dev)
1010                 goto out;
1011
1012         /* Claim the bus so it remembers what we do to the control
1013          * registers. [ CTR and ECP ]
1014          */
1015         err = -EBUSY;
1016         dev->waiting = &waiting;
1017         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1018         if (ppa_pb_claim(dev))
1019                 schedule_timeout(3 * HZ);
1020         if (dev->wanted) {
1021                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1022                                 "a pardevice is owning the port for too long "
1023                                 "time!\n", pb->number);
1024                 ppa_pb_dismiss(dev);
1025                 dev->waiting = NULL;
1026                 finish_wait(&waiting, &wait);
1027                 goto out1;
1028         }
1029         dev->waiting = NULL;
1030         finish_wait(&waiting, &wait);
1031         ppb = dev->base = dev->dev->port->base;
1032         ppb_hi = dev->dev->port->base_hi;
1033         w_ctr(ppb, 0x0c);
1034         modes = dev->dev->port->modes;
1035
1036         /* Mode detection works up the chain of speed
1037          * This avoids a nasty if-then-else-if-... tree
1038          */
1039         dev->mode = PPA_NIBBLE;
1040
1041         if (modes & PARPORT_MODE_TRISTATE)
1042                 dev->mode = PPA_PS2;
1043
1044         if (modes & PARPORT_MODE_ECP) {
1045                 w_ecr(ppb_hi, 0x20);
1046                 dev->mode = PPA_PS2;
1047         }
1048         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1049                 w_ecr(ppb_hi, 0x80);
1050
1051         /* Done configuration */
1052
1053         err = ppa_init(dev);
1054         ppa_pb_release(dev);
1055
1056         if (err)
1057                 goto out1;
1058
1059         /* now the glue ... */
1060         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1061                 ports = 3;
1062         else
1063                 ports = 8;
1064
1065         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1066
1067         err = -ENOMEM;
1068         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1069         if (!host)
1070                 goto out1;
1071         host->io_port = pb->base;
1072         host->n_io_port = ports;
1073         host->dma_channel = -1;
1074         host->unique_id = pb->number;
1075         *(ppa_struct **)&host->hostdata = dev;
1076         dev->host = host;
1077         list_add_tail(&dev->list, &ppa_hosts);
1078         err = scsi_add_host(host, NULL);
1079         if (err)
1080                 goto out2;
1081         scsi_scan_host(host);
1082         return 0;
1083 out2:
1084         list_del_init(&dev->list);
1085         scsi_host_put(host);
1086 out1:
1087         parport_unregister_device(dev->dev);
1088 out:
1089         kfree(dev);
1090         return err;
1091 }
1092
1093 static void ppa_attach(struct parport *pb)
1094 {
1095         __ppa_attach(pb);
1096 }
1097
1098 static void ppa_detach(struct parport *pb)
1099 {
1100         ppa_struct *dev;
1101         list_for_each_entry(dev, &ppa_hosts, list) {
1102                 if (dev->dev->port == pb) {
1103                         list_del_init(&dev->list);
1104                         scsi_remove_host(dev->host);
1105                         scsi_host_put(dev->host);
1106                         parport_unregister_device(dev->dev);
1107                         kfree(dev);
1108                         break;
1109                 }
1110         }
1111 }
1112
1113 static struct parport_driver ppa_driver = {
1114         .name   = "ppa",
1115         .attach = ppa_attach,
1116         .detach = ppa_detach,
1117 };
1118
1119 static int __init ppa_driver_init(void)
1120 {
1121         printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1122         return parport_register_driver(&ppa_driver);
1123 }
1124
1125 static void __exit ppa_driver_exit(void)
1126 {
1127         parport_unregister_driver(&ppa_driver);
1128 }
1129
1130 module_init(ppa_driver_init);
1131 module_exit(ppa_driver_exit);
1132 MODULE_LICENSE("GPL");