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  * Current Maintainer: David Campbell (Perth, Western Australia, GMT+0800)
  10  *                     campbell@torque.net
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/blkdev.h>
  18 #include <asm/io.h>
  19 #include <linux/parport.h>
  20 #include <linux/workqueue.h>
  21 #include "scsi.h"
  22 #include "hosts.h"
  23 static void ppa_reset_pulse(unsigned int base);
  24
  25 typedef struct {
  26         struct pardevice *dev;  /* Parport device entry         */
  27         int base;               /* Actual port address          */
  28         int mode;               /* Transfer mode                */
  29         Scsi_Cmnd *cur_cmd;     /* Current queued command       */
  30         struct work_struct ppa_tq;      /* Polling interrupt stuff       */
  31         unsigned long jstart;   /* Jiffies at start             */
  32         unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
  33         unsigned int failed:1;  /* Failure flag                 */
  34         unsigned wanted:1;      /* Parport sharing busy flag    */
  35         wait_queue_head_t *waiting;
  36         struct Scsi_Host *host;
  37         struct list_head list;
  38 } ppa_struct;
  39
  40 #include  "ppa.h"
  41
  42 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  43 {
  44         return *(ppa_struct **)&host->hostdata;
  45 }
  46
  47 static spinlock_t arbitration_lock = SPIN_LOCK_UNLOCKED;
  48
  49 static void got_it(ppa_struct *dev)
  50 {
  51         dev->base = dev->dev->port->base;
  52         if (dev->cur_cmd)
  53                 dev->cur_cmd->SCp.phase = 1;
  54         else
  55                 wake_up(dev->waiting);
  56 }
  57
  58 static void ppa_wakeup(void *ref)
  59 {
  60         ppa_struct *dev = (ppa_struct *) ref;
  61         unsigned long flags;
  62
  63         spin_lock_irqsave(&arbitration_lock, flags);
  64         if (dev->wanted) {
  65                 parport_claim(dev->dev);
  66                 got_it(dev);
  67                 dev->wanted = 0;
  68         }
  69         spin_unlock_irqrestore(&arbitration_lock, flags);
  70         return;
  71 }
  72
  73 static int ppa_pb_claim(ppa_struct *dev)
  74 {
  75         unsigned long flags;
  76         int res = 1;
  77         spin_lock_irqsave(&arbitration_lock, flags);
  78         if (parport_claim(dev->dev) == 0) {
  79                 got_it(dev);
  80                 res = 0;
  81         }
  82         dev->wanted = res;
  83         spin_unlock_irqrestore(&arbitration_lock, flags);
  84         return res;
  85 }
  86
  87 static void ppa_pb_dismiss(ppa_struct *dev)
  88 {
  89         unsigned long flags;
  90         int wanted;
  91         spin_lock_irqsave(&arbitration_lock, flags);
  92         wanted = dev->wanted;
  93         dev->wanted = 0;
  94         spin_unlock_irqrestore(&arbitration_lock, flags);
  95         if (!wanted)
  96                 parport_release(dev->dev);
  97 }
  98
  99 static inline void ppa_pb_release(ppa_struct *dev)
 100 {
 101         parport_release(dev->dev);
 102 }
 103
 104 /*
 105  * Start of Chipset kludges
 106  */
 107
 108 /* This is to give the ppa driver a way to modify the timings (and other
 109  * parameters) by writing to the /proc/scsi/ppa/0 file.
 110  * Very simple method really... (To simple, no error checking :( )
 111  * Reason: Kernel hackers HATE having to unload and reload modules for
 112  * testing...
 113  * Also gives a method to use a script to obtain optimum timings (TODO)
 114  */
 115
 116 static inline int ppa_proc_write(ppa_struct *dev, char *buffer, int length)
 117 {
 118         unsigned long x;
 119
 120         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 121                 x = simple_strtoul(buffer + 5, NULL, 0);
 122                 dev->mode = x;
 123                 return length;
 124         }
 125         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 126                 x = simple_strtoul(buffer + 10, NULL, 0);
 127                 dev->recon_tmo = x;
 128                 printk("ppa: recon_tmo set to %ld\n", x);
 129                 return length;
 130         }
 131         printk("ppa /proc: invalid variable\n");
 132         return (-EINVAL);
 133 }
 134
 135 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
 136 {
 137         int len = 0;
 138         ppa_struct *dev = ppa_dev(host);
 139
 140         if (inout)
 141                 return ppa_proc_write(dev, buffer, length);
 142
 143         len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
 144         len +=
 145             sprintf(buffer + len, "Parport : %s\n",
 146                     dev->dev->port->name);
 147         len +=
 148             sprintf(buffer + len, "Mode    : %s\n",
 149                     PPA_MODE_STRING[dev->mode]);
 150 #if PPA_DEBUG > 0
 151         len +=
 152             sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
 153 #endif
 154
 155         /* Request for beyond end of buffer */
 156         if (offset > length)
 157                 return 0;
 158
 159         *start = buffer + offset;
 160         len -= offset;
 161         if (len > length)
 162                 len = length;
 163         return len;
 164 }
 165
 166 static int device_check(ppa_struct *dev);
 167
 168 #if PPA_DEBUG > 0
 169 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 170            y, __FUNCTION__, __LINE__); ppa_fail_func(x,y);
 171 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 172 #else
 173 static inline void ppa_fail(ppa_struct *dev, int error_code)
 174 #endif
 175 {
 176         /* If we fail a device then we trash status / message bytes */
 177         if (dev->cur_cmd) {
 178                 dev->cur_cmd->result = error_code << 16;
 179                 dev->failed = 1;
 180         }
 181 }
 182
 183 /*
 184  * Wait for the high bit to be set.
 185  *
 186  * In principle, this could be tied to an interrupt, but the adapter
 187  * doesn't appear to be designed to support interrupts.  We spin on
 188  * the 0x80 ready bit.
 189  */
 190 static unsigned char ppa_wait(ppa_struct *dev)
 191 {
 192         int k;
 193         unsigned short ppb = dev->base;
 194         unsigned char r;
 195
 196         k = PPA_SPIN_TMO;
 197         /* Wait for bit 6 and 7 - PJC */
 198         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 199                 udelay(1);
 200                 r = r_str(ppb);
 201         }
 202
 203         /*
 204          * return some status information.
 205          * Semantics: 0xc0 = ZIP wants more data
 206          *            0xd0 = ZIP wants to send more data
 207          *            0xe0 = ZIP is expecting SCSI command data
 208          *            0xf0 = end of transfer, ZIP is sending status
 209          */
 210         if (k)
 211                 return (r & 0xf0);
 212
 213         /* Counter expired - Time out occurred */
 214         ppa_fail(dev, DID_TIME_OUT);
 215         printk("ppa timeout in ppa_wait\n");
 216         return 0;               /* command timed out */
 217 }
 218
 219 /*
 220  * Clear EPP Timeout Bit
 221  */
 222 static inline void epp_reset(unsigned short ppb)
 223 {
 224         int i;
 225
 226         i = r_str(ppb);
 227         w_str(ppb, i);
 228         w_str(ppb, i & 0xfe);
 229 }
 230
 231 /*
 232  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 233  */
 234 static inline void ecp_sync(ppa_struct *dev)
 235 {
 236         int i, ppb_hi = dev->dev->port->base_hi;
 237
 238         if (ppb_hi == 0)
 239                 return;
 240
 241         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 242                 for (i = 0; i < 100; i++) {
 243                         if (r_ecr(ppb_hi) & 0x01)
 244                                 return;
 245                         udelay(5);
 246                 }
 247                 printk("ppa: ECP sync failed as data still present in FIFO.\n");
 248         }
 249 }
 250
 251 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 252 {
 253         int i;
 254
 255         for (i = len; i; i--) {
 256                 w_dtr(base, *buffer++);
 257                 w_ctr(base, 0xe);
 258                 w_ctr(base, 0xc);
 259         }
 260         return 1;               /* All went well - we hope! */
 261 }
 262
 263 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 264 {
 265         int i;
 266
 267         for (i = len; i; i--) {
 268                 *buffer++ = r_dtr(base);
 269                 w_ctr(base, 0x27);
 270                 w_ctr(base, 0x25);
 271         }
 272         return 1;               /* All went well - we hope! */
 273 }
 274
 275 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 276 {
 277         for (; len; len--) {
 278                 unsigned char h;
 279
 280                 w_ctr(base, 0x4);
 281                 h = r_str(base) & 0xf0;
 282                 w_ctr(base, 0x6);
 283                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 284         }
 285         return 1;               /* All went well - we hope! */
 286 }
 287
 288 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 289 {
 290         int r;
 291         unsigned short ppb = dev->base;
 292
 293         r = ppa_wait(dev);
 294
 295         if ((r & 0x50) != 0x40) {
 296                 ppa_fail(dev, DID_ERROR);
 297                 return 0;
 298         }
 299         switch (dev->mode) {
 300         case PPA_NIBBLE:
 301         case PPA_PS2:
 302                 /* 8 bit output, with a loop */
 303                 r = ppa_byte_out(ppb, buffer, len);
 304                 break;
 305
 306         case PPA_EPP_32:
 307         case PPA_EPP_16:
 308         case PPA_EPP_8:
 309                 epp_reset(ppb);
 310                 w_ctr(ppb, 0x4);
 311 #ifdef CONFIG_SCSI_IZIP_EPP16
 312                 if (!(((long) buffer | len) & 0x01))
 313                         outsw(ppb + 4, buffer, len >> 1);
 314 #else
 315                 if (!(((long) buffer | len) & 0x03))
 316                         outsl(ppb + 4, buffer, len >> 2);
 317 #endif
 318                 else
 319                         outsb(ppb + 4, buffer, len);
 320                 w_ctr(ppb, 0xc);
 321                 r = !(r_str(ppb) & 0x01);
 322                 w_ctr(ppb, 0xc);
 323                 ecp_sync(dev);
 324                 break;
 325
 326         default:
 327                 printk("PPA: bug in ppa_out()\n");
 328                 r = 0;
 329         }
 330         return r;
 331 }
 332
 333 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 334 {
 335         int r;
 336         unsigned short ppb = dev->base;
 337
 338         r = ppa_wait(dev);
 339
 340         if ((r & 0x50) != 0x50) {
 341                 ppa_fail(dev, DID_ERROR);
 342                 return 0;
 343         }
 344         switch (dev->mode) {
 345         case PPA_NIBBLE:
 346                 /* 4 bit input, with a loop */
 347                 r = ppa_nibble_in(ppb, buffer, len);
 348                 w_ctr(ppb, 0xc);
 349                 break;
 350
 351         case PPA_PS2:
 352                 /* 8 bit input, with a loop */
 353                 w_ctr(ppb, 0x25);
 354                 r = ppa_byte_in(ppb, buffer, len);
 355                 w_ctr(ppb, 0x4);
 356                 w_ctr(ppb, 0xc);
 357                 break;
 358
 359         case PPA_EPP_32:
 360         case PPA_EPP_16:
 361         case PPA_EPP_8:
 362                 epp_reset(ppb);
 363                 w_ctr(ppb, 0x24);
 364 #ifdef CONFIG_SCSI_IZIP_EPP16
 365                 if (!(((long) buffer | len) & 0x01))
 366                         insw(ppb + 4, buffer, len >> 1);
 367 #else
 368                 if (!(((long) buffer | len) & 0x03))
 369                         insl(ppb + 4, buffer, len >> 2);
 370 #endif
 371                 else
 372                         insb(ppb + 4, buffer, len);
 373                 w_ctr(ppb, 0x2c);
 374                 r = !(r_str(ppb) & 0x01);
 375                 w_ctr(ppb, 0x2c);
 376                 ecp_sync(dev);
 377                 break;
 378
 379         default:
 380                 printk("PPA: bug in ppa_ins()\n");
 381                 r = 0;
 382                 break;
 383         }
 384         return r;
 385 }
 386
 387 /* end of ppa_io.h */
 388 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 389 {
 390         w_dtr(ppb, b);
 391         w_ctr(ppb, 0xc);
 392         w_ctr(ppb, 0xe);
 393         w_ctr(ppb, 0xc);
 394         w_ctr(ppb, 0x4);
 395         w_ctr(ppb, 0xc);
 396 }
 397
 398 static void ppa_disconnect(ppa_struct *dev)
 399 {
 400         unsigned short ppb = dev->base;
 401
 402         ppa_d_pulse(ppb, 0);
 403         ppa_d_pulse(ppb, 0x3c);
 404         ppa_d_pulse(ppb, 0x20);
 405         ppa_d_pulse(ppb, 0xf);
 406 }
 407
 408 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 409 {
 410         w_dtr(ppb, b);
 411         w_ctr(ppb, 0x4);
 412         w_ctr(ppb, 0x6);
 413         w_ctr(ppb, 0x4);
 414         w_ctr(ppb, 0xc);
 415 }
 416
 417 static inline void ppa_connect(ppa_struct *dev, int flag)
 418 {
 419         unsigned short ppb = dev->base;
 420
 421         ppa_c_pulse(ppb, 0);
 422         ppa_c_pulse(ppb, 0x3c);
 423         ppa_c_pulse(ppb, 0x20);
 424         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 425                 ppa_c_pulse(ppb, 0xcf);
 426         else
 427                 ppa_c_pulse(ppb, 0x8f);
 428 }
 429
 430 static int ppa_select(ppa_struct *dev, int target)
 431 {
 432         int k;
 433         unsigned short ppb = dev->base;
 434
 435         /*
 436          * Bit 6 (0x40) is the device selected bit.
 437          * First we must wait till the current device goes off line...
 438          */
 439         k = PPA_SELECT_TMO;
 440         do {
 441                 k--;
 442                 udelay(1);
 443         } while ((r_str(ppb) & 0x40) && (k));
 444         if (!k)
 445                 return 0;
 446
 447         w_dtr(ppb, (1 << target));
 448         w_ctr(ppb, 0xe);
 449         w_ctr(ppb, 0xc);
 450         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 451         w_ctr(ppb, 0x8);
 452
 453         k = PPA_SELECT_TMO;
 454         do {
 455                 k--;
 456                 udelay(1);
 457         }
 458         while (!(r_str(ppb) & 0x40) && (k));
 459         if (!k)
 460                 return 0;
 461
 462         return 1;
 463 }
 464
 465 /*
 466  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 467  * I've tried several different kinds of parallel ports with guest and
 468  * coded this to react in the same ways that it does.
 469  *
 470  * The return value from this function is just a hint about where the
 471  * handshaking failed.
 472  *
 473  */
 474 static int ppa_init(ppa_struct *dev)
 475 {
 476         int retv;
 477         unsigned short ppb = dev->base;
 478
 479         ppa_disconnect(dev);
 480         ppa_connect(dev, CONNECT_NORMAL);
 481
 482         retv = 2;               /* Failed */
 483
 484         w_ctr(ppb, 0xe);
 485         if ((r_str(ppb) & 0x08) == 0x08)
 486                 retv--;
 487
 488         w_ctr(ppb, 0xc);
 489         if ((r_str(ppb) & 0x08) == 0x00)
 490                 retv--;
 491
 492         if (!retv)
 493                 ppa_reset_pulse(ppb);
 494         udelay(1000);           /* Allow devices to settle down */
 495         ppa_disconnect(dev);
 496         udelay(1000);           /* Another delay to allow devices to settle */
 497
 498         if (retv)
 499                 return -EIO;
 500
 501         return device_check(dev);
 502 }
 503
 504 static inline int ppa_send_command(Scsi_Cmnd *cmd)
 505 {
 506         ppa_struct *dev = ppa_dev(cmd->device->host);
 507         int k;
 508
 509         w_ctr(dev->base, 0x0c);
 510
 511         for (k = 0; k < cmd->cmd_len; k++)
 512                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 513                         return 0;
 514         return 1;
 515 }
 516
 517 /*
 518  * The bulk flag enables some optimisations in the data transfer loops,
 519  * it should be true for any command that transfers data in integral
 520  * numbers of sectors.
 521  *
 522  * The driver appears to remain stable if we speed up the parallel port
 523  * i/o in this function, but not elsewhere.
 524  */
 525 static int ppa_completion(Scsi_Cmnd *cmd)
 526 {
 527         /* Return codes:
 528          * -1     Error
 529          *  0     Told to schedule
 530          *  1     Finished data transfer
 531          */
 532         ppa_struct *dev = ppa_dev(cmd->device->host);
 533         unsigned short ppb = dev->base;
 534         unsigned long start_jiffies = jiffies;
 535
 536         unsigned char r, v;
 537         int fast, bulk, status;
 538
 539         v = cmd->cmnd[0];
 540         bulk = ((v == READ_6) ||
 541                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 542
 543         /*
 544          * We only get here if the drive is ready to comunicate,
 545          * hence no need for a full ppa_wait.
 546          */
 547         r = (r_str(ppb) & 0xf0);
 548
 549         while (r != (unsigned char) 0xf0) {
 550                 /*
 551                  * If we have been running for more than a full timer tick
 552                  * then take a rest.
 553                  */
 554                 if (time_after(jiffies, start_jiffies + 1))
 555                         return 0;
 556
 557                 if ((cmd->SCp.this_residual <= 0)) {
 558                         ppa_fail(dev, DID_ERROR);
 559                         return -1;      /* ERROR_RETURN */
 560                 }
 561
 562                 /* On some hardware we have SCSI disconnected (6th bit low)
 563                  * for about 100usecs. It is too expensive to wait a
 564                  * tick on every loop so we busy wait for no more than
 565                  * 500usecs to give the drive a chance first. We do not
 566                  * change things for "normal" hardware since generally
 567                  * the 6th bit is always high.
 568                  * This makes the CPU load higher on some hardware
 569                  * but otherwise we can not get more than 50K/secs
 570                  * on this problem hardware.
 571                  */
 572                 if ((r & 0xc0) != 0xc0) {
 573                         /* Wait for reconnection should be no more than
 574                          * jiffy/2 = 5ms = 5000 loops
 575                          */
 576                         unsigned long k = dev->recon_tmo;
 577                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 578                              k--)
 579                                 udelay(1);
 580
 581                         if (!k)
 582                                 return 0;
 583                 }
 584
 585                 /* determine if we should use burst I/O */
 586                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 587                     ? PPA_BURST_SIZE : 1;
 588
 589                 if (r == (unsigned char) 0xc0)
 590                         status = ppa_out(dev, cmd->SCp.ptr, fast);
 591                 else
 592                         status = ppa_in(dev, cmd->SCp.ptr, fast);
 593
 594                 cmd->SCp.ptr += fast;
 595                 cmd->SCp.this_residual -= fast;
 596
 597                 if (!status) {
 598                         ppa_fail(dev, DID_BUS_BUSY);
 599                         return -1;      /* ERROR_RETURN */
 600                 }
 601                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 602                         /* if scatter/gather, advance to the next segment */
 603                         if (cmd->SCp.buffers_residual--) {
 604                                 cmd->SCp.buffer++;
 605                                 cmd->SCp.this_residual =
 606                                     cmd->SCp.buffer->length;
 607                                 cmd->SCp.ptr =
 608                                     page_address(cmd->SCp.buffer->page) +
 609                                     cmd->SCp.buffer->offset;
 610                         }
 611                 }
 612                 /* Now check to see if the drive is ready to comunicate */
 613                 r = (r_str(ppb) & 0xf0);
 614                 /* If not, drop back down to the scheduler and wait a timer tick */
 615                 if (!(r & 0x80))
 616                         return 0;
 617         }
 618         return 1;               /* FINISH_RETURN */
 619 }
 620
 621 /*
 622  * Since the PPA itself doesn't generate interrupts, we use
 623  * the scheduler's task queue to generate a stream of call-backs and
 624  * complete the request when the drive is ready.
 625  */
 626 static void ppa_interrupt(void *data)
 627 {
 628         ppa_struct *dev = (ppa_struct *) data;
 629         Scsi_Cmnd *cmd = dev->cur_cmd;
 630
 631         if (!cmd) {
 632                 printk("PPA: bug in ppa_interrupt\n");
 633                 return;
 634         }
 635         if (ppa_engine(dev, cmd)) {
 636                 dev->ppa_tq.data = (void *) dev;
 637                 schedule_delayed_work(&dev->ppa_tq, 1);
 638                 return;
 639         }
 640         /* Command must of completed hence it is safe to let go... */
 641 #if PPA_DEBUG > 0
 642         switch ((cmd->result >> 16) & 0xff) {
 643         case DID_OK:
 644                 break;
 645         case DID_NO_CONNECT:
 646                 printk("ppa: no device at SCSI ID %i\n", cmd->device->target);
 647                 break;
 648         case DID_BUS_BUSY:
 649                 printk("ppa: BUS BUSY - EPP timeout detected\n");
 650                 break;
 651         case DID_TIME_OUT:
 652                 printk("ppa: unknown timeout\n");
 653                 break;
 654         case DID_ABORT:
 655                 printk("ppa: told to abort\n");
 656                 break;
 657         case DID_PARITY:
 658                 printk("ppa: parity error (???)\n");
 659                 break;
 660         case DID_ERROR:
 661                 printk("ppa: internal driver error\n");
 662                 break;
 663         case DID_RESET:
 664                 printk("ppa: told to reset device\n");
 665                 break;
 666         case DID_BAD_INTR:
 667                 printk("ppa: bad interrupt (???)\n");
 668                 break;
 669         default:
 670                 printk("ppa: bad return code (%02x)\n",
 671                        (cmd->result >> 16) & 0xff);
 672         }
 673 #endif
 674
 675         if (cmd->SCp.phase > 1)
 676                 ppa_disconnect(dev);
 677
 678         ppa_pb_dismiss(dev);
 679
 680         dev->cur_cmd = 0;
 681
 682         cmd->scsi_done(cmd);
 683 }
 684
 685 static int ppa_engine(ppa_struct *dev, Scsi_Cmnd *cmd)
 686 {
 687         unsigned short ppb = dev->base;
 688         unsigned char l = 0, h = 0;
 689         int retv;
 690
 691         /* First check for any errors that may of occurred
 692          * Here we check for internal errors
 693          */
 694         if (dev->failed)
 695                 return 0;
 696
 697         switch (cmd->SCp.phase) {
 698         case 0:         /* Phase 0 - Waiting for parport */
 699                 if (time_after(jiffies, dev->jstart + HZ)) {
 700                         /*
 701                          * We waited more than a second
 702                          * for parport to call us
 703                          */
 704                         ppa_fail(dev, DID_BUS_BUSY);
 705                         return 0;
 706                 }
 707                 return 1;       /* wait until ppa_wakeup claims parport */
 708         case 1:         /* Phase 1 - Connected */
 709                 {               /* Perform a sanity check for cable unplugged */
 710                         int retv = 2;   /* Failed */
 711
 712                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 713
 714                         w_ctr(ppb, 0xe);
 715                         if ((r_str(ppb) & 0x08) == 0x08)
 716                                 retv--;
 717
 718                         w_ctr(ppb, 0xc);
 719                         if ((r_str(ppb) & 0x08) == 0x00)
 720                                 retv--;
 721
 722                         if (retv) {
 723                                 if ((jiffies - dev->jstart) > (1 * HZ)) {
 724                                         printk
 725                                             ("ppa: Parallel port cable is unplugged!!\n");
 726                                         ppa_fail(dev, DID_BUS_BUSY);
 727                                         return 0;
 728                                 } else {
 729                                         ppa_disconnect(dev);
 730                                         return 1;       /* Try again in a jiffy */
 731                                 }
 732                         }
 733                         cmd->SCp.phase++;
 734                 }
 735
 736         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 737                 if (!ppa_select(dev, cmd->device->id)) {
 738                         ppa_fail(dev, DID_NO_CONNECT);
 739                         return 0;
 740                 }
 741                 cmd->SCp.phase++;
 742
 743         case 3:         /* Phase 3 - Ready to accept a command */
 744                 w_ctr(ppb, 0x0c);
 745                 if (!(r_str(ppb) & 0x80))
 746                         return 1;
 747
 748                 if (!ppa_send_command(cmd))
 749                         return 0;
 750                 cmd->SCp.phase++;
 751
 752         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 753                 if (cmd->use_sg) {
 754                         /* if many buffers are available, start filling the first */
 755                         cmd->SCp.buffer =
 756                             (struct scatterlist *) cmd->request_buffer;
 757                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 758                         cmd->SCp.ptr =
 759                             page_address(cmd->SCp.buffer->page) +
 760                             cmd->SCp.buffer->offset;
 761                 } else {
 762                         /* else fill the only available buffer */
 763                         cmd->SCp.buffer = NULL;
 764                         cmd->SCp.this_residual = cmd->request_bufflen;
 765                         cmd->SCp.ptr = cmd->request_buffer;
 766                 }
 767                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
 768                 cmd->SCp.phase++;
 769
 770         case 5:         /* Phase 5 - Data transfer stage */
 771                 w_ctr(ppb, 0x0c);
 772                 if (!(r_str(ppb) & 0x80))
 773                         return 1;
 774
 775                 retv = ppa_completion(cmd);
 776                 if (retv == -1)
 777                         return 0;
 778                 if (retv == 0)
 779                         return 1;
 780                 cmd->SCp.phase++;
 781
 782         case 6:         /* Phase 6 - Read status/message */
 783                 cmd->result = DID_OK << 16;
 784                 /* Check for data overrun */
 785                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
 786                         ppa_fail(dev, DID_ERROR);
 787                         return 0;
 788                 }
 789                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
 790                         /* Check for optional message byte */
 791                         if (ppa_wait(dev) == (unsigned char) 0xf0)
 792                                 ppa_in(dev, &h, 1);
 793                         cmd->result =
 794                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 795                 }
 796                 return 0;       /* Finished */
 797                 break;
 798
 799         default:
 800                 printk("ppa: Invalid scsi phase\n");
 801         }
 802         return 0;
 803 }
 804
 805 static int ppa_queuecommand(Scsi_Cmnd *cmd, void (*done) (Scsi_Cmnd *))
 806 {
 807         ppa_struct *dev = ppa_dev(cmd->device->host);
 808
 809         if (dev->cur_cmd) {
 810                 printk("PPA: bug in ppa_queuecommand\n");
 811                 return 0;
 812         }
 813         dev->failed = 0;
 814         dev->jstart = jiffies;
 815         dev->cur_cmd = cmd;
 816         cmd->scsi_done = done;
 817         cmd->result = DID_ERROR << 16;  /* default return code */
 818         cmd->SCp.phase = 0;     /* bus free */
 819
 820         dev->ppa_tq.data = dev;
 821         schedule_work(&dev->ppa_tq);
 822
 823         ppa_pb_claim(dev);
 824
 825         return 0;
 826 }
 827
 828 /*
 829  * Apparently the disk->capacity attribute is off by 1 sector
 830  * for all disk drives.  We add the one here, but it should really
 831  * be done in sd.c.  Even if it gets fixed there, this will still
 832  * work.
 833  */
 834 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 835               sector_t capacity, int ip[])
 836 {
 837         ip[0] = 0x40;
 838         ip[1] = 0x20;
 839         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 840         if (ip[2] > 1024) {
 841                 ip[0] = 0xff;
 842                 ip[1] = 0x3f;
 843                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 844                 if (ip[2] > 1023)
 845                         ip[2] = 1023;
 846         }
 847         return 0;
 848 }
 849
 850 static int ppa_abort(Scsi_Cmnd *cmd)
 851 {
 852         ppa_struct *dev = ppa_dev(cmd->device->host);
 853         /*
 854          * There is no method for aborting commands since Iomega
 855          * have tied the SCSI_MESSAGE line high in the interface
 856          */
 857
 858         switch (cmd->SCp.phase) {
 859         case 0:         /* Do not have access to parport */
 860         case 1:         /* Have not connected to interface */
 861                 dev->cur_cmd = NULL;    /* Forget the problem */
 862                 return SUCCESS;
 863                 break;
 864         default:                /* SCSI command sent, can not abort */
 865                 return FAILED;
 866                 break;
 867         }
 868 }
 869
 870 static void ppa_reset_pulse(unsigned int base)
 871 {
 872         w_dtr(base, 0x40);
 873         w_ctr(base, 0x8);
 874         udelay(30);
 875         w_ctr(base, 0xc);
 876 }
 877
 878 static int ppa_reset(Scsi_Cmnd *cmd)
 879 {
 880         ppa_struct *dev = ppa_dev(cmd->device->host);
 881
 882         if (cmd->SCp.phase)
 883                 ppa_disconnect(dev);
 884         dev->cur_cmd = NULL;    /* Forget the problem */
 885
 886         ppa_connect(dev, CONNECT_NORMAL);
 887         ppa_reset_pulse(dev->base);
 888         udelay(1000);           /* device settle delay */
 889         ppa_disconnect(dev);
 890         udelay(1000);           /* device settle delay */
 891         return SUCCESS;
 892 }
 893
 894 static int device_check(ppa_struct *dev)
 895 {
 896         /* This routine looks for a device and then attempts to use EPP
 897            to send a command. If all goes as planned then EPP is available. */
 898
 899         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 900         int loop, old_mode, status, k, ppb = dev->base;
 901         unsigned char l;
 902
 903         old_mode = dev->mode;
 904         for (loop = 0; loop < 8; loop++) {
 905                 /* Attempt to use EPP for Test Unit Ready */
 906                 if ((ppb & 0x0007) == 0x0000)
 907                         dev->mode = PPA_EPP_32;
 908
 909               second_pass:
 910                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 911                 /* Select SCSI device */
 912                 if (!ppa_select(dev, loop)) {
 913                         ppa_disconnect(dev);
 914                         continue;
 915                 }
 916                 printk("ppa: Found device at ID %i, Attempting to use %s\n",
 917                        loop, PPA_MODE_STRING[dev->mode]);
 918
 919                 /* Send SCSI command */
 920                 status = 1;
 921                 w_ctr(ppb, 0x0c);
 922                 for (l = 0; (l < 6) && (status); l++)
 923                         status = ppa_out(dev, cmd, 1);
 924
 925                 if (!status) {
 926                         ppa_disconnect(dev);
 927                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 928                         w_dtr(ppb, 0x40);
 929                         w_ctr(ppb, 0x08);
 930                         udelay(30);
 931                         w_ctr(ppb, 0x0c);
 932                         udelay(1000);
 933                         ppa_disconnect(dev);
 934                         udelay(1000);
 935                         if (dev->mode == PPA_EPP_32) {
 936                                 dev->mode = old_mode;
 937                                 goto second_pass;
 938                         }
 939                         return -EIO;
 940                 }
 941                 w_ctr(ppb, 0x0c);
 942                 k = 1000000;    /* 1 Second */
 943                 do {
 944                         l = r_str(ppb);
 945                         k--;
 946                         udelay(1);
 947                 } while (!(l & 0x80) && (k));
 948
 949                 l &= 0xf0;
 950
 951                 if (l != 0xf0) {
 952                         ppa_disconnect(dev);
 953                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 954                         ppa_reset_pulse(ppb);
 955                         udelay(1000);
 956                         ppa_disconnect(dev);
 957                         udelay(1000);
 958                         if (dev->mode == PPA_EPP_32) {
 959                                 dev->mode = old_mode;
 960                                 goto second_pass;
 961                         }
 962                         return -EIO;
 963                 }
 964                 ppa_disconnect(dev);
 965                 printk("ppa: Communication established with ID %i using %s\n",
 966                        loop, PPA_MODE_STRING[dev->mode]);
 967                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 968                 ppa_reset_pulse(ppb);
 969                 udelay(1000);
 970                 ppa_disconnect(dev);
 971                 udelay(1000);
 972                 return 0;
 973         }
 974         return -ENODEV;
 975 }
 976
 977 static Scsi_Host_Template ppa_template = {
 978         .module                 = THIS_MODULE,
 979         .proc_name              = "ppa",
 980         .proc_info              = ppa_proc_info,
 981         .name                   = "Iomega VPI0 (ppa) interface",
 982         .queuecommand           = ppa_queuecommand,
 983         .eh_abort_handler       = ppa_abort,
 984         .eh_bus_reset_handler   = ppa_reset,
 985         .eh_host_reset_handler  = ppa_reset,
 986         .bios_param             = ppa_biosparam,
 987         .this_id                = -1,
 988         .sg_tablesize           = SG_ALL,
 989         .cmd_per_lun            = 1,
 990         .use_clustering         = ENABLE_CLUSTERING,
 991         .can_queue              = 1,
 992 };
 993
 994 /***************************************************************************
 995  *                   Parallel port probing routines                        *
 996  ***************************************************************************/
 997
 998 static LIST_HEAD(ppa_hosts);
 999
1000 static int __ppa_attach(struct parport *pb)
1001 {
1002         struct Scsi_Host *host;
1003         DECLARE_WAIT_QUEUE_HEAD(waiting);
1004         DEFINE_WAIT(wait);
1005         ppa_struct *dev;
1006         int ports;
1007         int modes, ppb, ppb_hi;
1008         int err = -ENOMEM;
1009
1010         dev = kmalloc(sizeof(ppa_struct), GFP_KERNEL);
1011         if (!dev)
1012                 return -ENOMEM;
1013         memset(dev, 0, sizeof(ppa_struct));
1014         dev->base = -1;
1015         dev->mode = PPA_AUTODETECT;
1016         dev->recon_tmo = PPA_RECON_TMO;
1017         init_waitqueue_head(&waiting);
1018         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1019                                             NULL, 0, dev);
1020
1021         if (!dev->dev)
1022                 goto out;
1023
1024         /* Claim the bus so it remembers what we do to the control
1025          * registers. [ CTR and ECP ]
1026          */
1027         err = -EBUSY;
1028         dev->waiting = &waiting;
1029         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1030         if (ppa_pb_claim(dev))
1031                 schedule_timeout(3 * HZ);
1032         if (dev->wanted) {
1033                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1034                                 "a pardevice is owning the port for too long "
1035                                 "time!\n", pb->number);
1036                 ppa_pb_dismiss(dev);
1037                 dev->waiting = NULL;
1038                 finish_wait(&waiting, &wait);
1039                 goto out1;
1040         }
1041         dev->waiting = NULL;
1042         finish_wait(&waiting, &wait);
1043         ppb = dev->base = dev->dev->port->base;
1044         ppb_hi = dev->dev->port->base_hi;
1045         w_ctr(ppb, 0x0c);
1046         modes = dev->dev->port->modes;
1047
1048         /* Mode detection works up the chain of speed
1049          * This avoids a nasty if-then-else-if-... tree
1050          */
1051         dev->mode = PPA_NIBBLE;
1052
1053         if (modes & PARPORT_MODE_TRISTATE)
1054                 dev->mode = PPA_PS2;
1055
1056         if (modes & PARPORT_MODE_ECP) {
1057                 w_ecr(ppb_hi, 0x20);
1058                 dev->mode = PPA_PS2;
1059         }
1060         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1061                 w_ecr(ppb_hi, 0x80);
1062
1063         /* Done configuration */
1064
1065         err = ppa_init(dev);
1066         ppa_pb_release(dev);
1067
1068         if (err)
1069                 goto out1;
1070
1071         /* now the glue ... */
1072         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1073                 ports = 3;
1074         else
1075                 ports = 8;
1076
1077         INIT_WORK(&dev->ppa_tq, ppa_interrupt, dev);
1078
1079         err = -ENOMEM;
1080         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1081         if (!host)
1082                 goto out1;
1083         host->io_port = pb->base;
1084         host->n_io_port = ports;
1085         host->dma_channel = -1;
1086         host->unique_id = pb->number;
1087         *(ppa_struct **)&host->hostdata = dev;
1088         dev->host = host;
1089         list_add_tail(&dev->list, &ppa_hosts);
1090         err = scsi_add_host(host, NULL);
1091         if (err)
1092                 goto out2;
1093         scsi_scan_host(host);
1094         return 0;
1095 out2:
1096         list_del_init(&dev->list);
1097         scsi_host_put(host);
1098 out1:
1099         parport_unregister_device(dev->dev);
1100 out:
1101         kfree(dev);
1102         return err;
1103 }
1104
1105 static void ppa_attach(struct parport *pb)
1106 {
1107         __ppa_attach(pb);
1108 }
1109
1110 static void ppa_detach(struct parport *pb)
1111 {
1112         ppa_struct *dev;
1113         list_for_each_entry(dev, &ppa_hosts, list) {
1114                 if (dev->dev->port == pb) {
1115                         list_del_init(&dev->list);
1116                         scsi_remove_host(dev->host);
1117                         scsi_host_put(dev->host);
1118                         parport_unregister_device(dev->dev);
1119                         kfree(dev);
1120                         break;
1121                 }
1122         }
1123 }
1124
1125 static struct parport_driver ppa_driver = {
1126         .name   = "ppa",
1127         .attach = ppa_attach,
1128         .detach = ppa_detach,
1129 };
1130
1131 static int __init ppa_driver_init(void)
1132 {
1133         printk("ppa: Version %s\n", PPA_VERSION);
1134         return parport_register_driver(&ppa_driver);
1135 }
1136
1137 static void __exit ppa_driver_exit(void)
1138 {
1139         parport_unregister_driver(&ppa_driver);
1140 }
1141
1142 module_init(ppa_driver_init);
1143 module_exit(ppa_driver_exit);
1144 MODULE_LICENSE("GPL");