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/module.h>
  14 #include <linux/blkdev.h>
  15 #include <linux/parport.h>
  16 #include <linux/workqueue.h>
  17 #include <linux/delay.h>
  18 #include <linux/jiffies.h>
  19 #include <asm/io.h>
  20
  21 #include <scsi/scsi.h>
  22 #include <scsi/scsi_cmnd.h>
  23 #include <scsi/scsi_device.h>
  24 #include <scsi/scsi_host.h>
  25
  26
  27 static void ppa_reset_pulse(unsigned int base);
  28
  29 typedef struct {
  30         struct pardevice *dev;  /* Parport device entry         */
  31         int base;               /* Actual port address          */
  32         int mode;               /* Transfer mode                */
  33         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  34         struct delayed_work ppa_tq;     /* Polling interrupt stuff       */
  35         unsigned long jstart;   /* Jiffies at start             */
  36         unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
  37         unsigned int failed:1;  /* Failure flag                 */
  38         unsigned wanted:1;      /* Parport sharing busy flag    */
  39         wait_queue_head_t *waiting;
  40         struct Scsi_Host *host;
  41         struct list_head list;
  42 } ppa_struct;
  43
  44 #include  "ppa.h"
  45
  46 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  47 {
  48         return *(ppa_struct **)&host->hostdata;
  49 }
  50
  51 static DEFINE_SPINLOCK(arbitration_lock);
  52
  53 static void got_it(ppa_struct *dev)
  54 {
  55         dev->base = dev->dev->port->base;
  56         if (dev->cur_cmd)
  57                 dev->cur_cmd->SCp.phase = 1;
  58         else
  59                 wake_up(dev->waiting);
  60 }
  61
  62 static void ppa_wakeup(void *ref)
  63 {
  64         ppa_struct *dev = (ppa_struct *) ref;
  65         unsigned long flags;
  66
  67         spin_lock_irqsave(&arbitration_lock, flags);
  68         if (dev->wanted) {
  69                 parport_claim(dev->dev);
  70                 got_it(dev);
  71                 dev->wanted = 0;
  72         }
  73         spin_unlock_irqrestore(&arbitration_lock, flags);
  74         return;
  75 }
  76
  77 static int ppa_pb_claim(ppa_struct *dev)
  78 {
  79         unsigned long flags;
  80         int res = 1;
  81         spin_lock_irqsave(&arbitration_lock, flags);
  82         if (parport_claim(dev->dev) == 0) {
  83                 got_it(dev);
  84                 res = 0;
  85         }
  86         dev->wanted = res;
  87         spin_unlock_irqrestore(&arbitration_lock, flags);
  88         return res;
  89 }
  90
  91 static void ppa_pb_dismiss(ppa_struct *dev)
  92 {
  93         unsigned long flags;
  94         int wanted;
  95         spin_lock_irqsave(&arbitration_lock, flags);
  96         wanted = dev->wanted;
  97         dev->wanted = 0;
  98         spin_unlock_irqrestore(&arbitration_lock, flags);
  99         if (!wanted)
 100                 parport_release(dev->dev);
 101 }
 102
 103 static inline void ppa_pb_release(ppa_struct *dev)
 104 {
 105         parport_release(dev->dev);
 106 }
 107
 108 /*
 109  * Start of Chipset kludges
 110  */
 111
 112 /* This is to give the ppa driver a way to modify the timings (and other
 113  * parameters) by writing to the /proc/scsi/ppa/0 file.
 114  * Very simple method really... (To simple, no error checking :( )
 115  * Reason: Kernel hackers HATE having to unload and reload modules for
 116  * testing...
 117  * Also gives a method to use a script to obtain optimum timings (TODO)
 118  */
 119
 120 static inline int ppa_proc_write(ppa_struct *dev, char *buffer, int length)
 121 {
 122         unsigned long x;
 123
 124         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 125                 x = simple_strtoul(buffer + 5, NULL, 0);
 126                 dev->mode = x;
 127                 return length;
 128         }
 129         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 130                 x = simple_strtoul(buffer + 10, NULL, 0);
 131                 dev->recon_tmo = x;
 132                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 133                 return length;
 134         }
 135         printk(KERN_WARNING "ppa /proc: invalid variable\n");
 136         return -EINVAL;
 137 }
 138
 139 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
 140 {
 141         int len = 0;
 142         ppa_struct *dev = ppa_dev(host);
 143
 144         if (inout)
 145                 return ppa_proc_write(dev, buffer, length);
 146
 147         len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
 148         len +=
 149             sprintf(buffer + len, "Parport : %s\n",
 150                     dev->dev->port->name);
 151         len +=
 152             sprintf(buffer + len, "Mode    : %s\n",
 153                     PPA_MODE_STRING[dev->mode]);
 154 #if PPA_DEBUG > 0
 155         len +=
 156             sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
 157 #endif
 158
 159         /* Request for beyond end of buffer */
 160         if (offset > length)
 161                 return 0;
 162
 163         *start = buffer + offset;
 164         len -= offset;
 165         if (len > length)
 166                 len = length;
 167         return len;
 168 }
 169
 170 static int device_check(ppa_struct *dev);
 171
 172 #if PPA_DEBUG > 0
 173 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 174            y, __FUNCTION__, __LINE__); ppa_fail_func(x,y);
 175 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 176 #else
 177 static inline void ppa_fail(ppa_struct *dev, int error_code)
 178 #endif
 179 {
 180         /* If we fail a device then we trash status / message bytes */
 181         if (dev->cur_cmd) {
 182                 dev->cur_cmd->result = error_code << 16;
 183                 dev->failed = 1;
 184         }
 185 }
 186
 187 /*
 188  * Wait for the high bit to be set.
 189  *
 190  * In principle, this could be tied to an interrupt, but the adapter
 191  * doesn't appear to be designed to support interrupts.  We spin on
 192  * the 0x80 ready bit.
 193  */
 194 static unsigned char ppa_wait(ppa_struct *dev)
 195 {
 196         int k;
 197         unsigned short ppb = dev->base;
 198         unsigned char r;
 199
 200         k = PPA_SPIN_TMO;
 201         /* Wait for bit 6 and 7 - PJC */
 202         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 203                 udelay(1);
 204                 r = r_str(ppb);
 205         }
 206
 207         /*
 208          * return some status information.
 209          * Semantics: 0xc0 = ZIP wants more data
 210          *            0xd0 = ZIP wants to send more data
 211          *            0xe0 = ZIP is expecting SCSI command data
 212          *            0xf0 = end of transfer, ZIP is sending status
 213          */
 214         if (k)
 215                 return (r & 0xf0);
 216
 217         /* Counter expired - Time out occurred */
 218         ppa_fail(dev, DID_TIME_OUT);
 219         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 220         return 0;               /* command timed out */
 221 }
 222
 223 /*
 224  * Clear EPP Timeout Bit
 225  */
 226 static inline void epp_reset(unsigned short ppb)
 227 {
 228         int i;
 229
 230         i = r_str(ppb);
 231         w_str(ppb, i);
 232         w_str(ppb, i & 0xfe);
 233 }
 234
 235 /*
 236  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 237  */
 238 static inline void ecp_sync(ppa_struct *dev)
 239 {
 240         int i, ppb_hi = dev->dev->port->base_hi;
 241
 242         if (ppb_hi == 0)
 243                 return;
 244
 245         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 246                 for (i = 0; i < 100; i++) {
 247                         if (r_ecr(ppb_hi) & 0x01)
 248                                 return;
 249                         udelay(5);
 250                 }
 251                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 252         }
 253 }
 254
 255 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 256 {
 257         int i;
 258
 259         for (i = len; i; i--) {
 260                 w_dtr(base, *buffer++);
 261                 w_ctr(base, 0xe);
 262                 w_ctr(base, 0xc);
 263         }
 264         return 1;               /* All went well - we hope! */
 265 }
 266
 267 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 268 {
 269         int i;
 270
 271         for (i = len; i; i--) {
 272                 *buffer++ = r_dtr(base);
 273                 w_ctr(base, 0x27);
 274                 w_ctr(base, 0x25);
 275         }
 276         return 1;               /* All went well - we hope! */
 277 }
 278
 279 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 280 {
 281         for (; len; len--) {
 282                 unsigned char h;
 283
 284                 w_ctr(base, 0x4);
 285                 h = r_str(base) & 0xf0;
 286                 w_ctr(base, 0x6);
 287                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 288         }
 289         return 1;               /* All went well - we hope! */
 290 }
 291
 292 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 293 {
 294         int r;
 295         unsigned short ppb = dev->base;
 296
 297         r = ppa_wait(dev);
 298
 299         if ((r & 0x50) != 0x40) {
 300                 ppa_fail(dev, DID_ERROR);
 301                 return 0;
 302         }
 303         switch (dev->mode) {
 304         case PPA_NIBBLE:
 305         case PPA_PS2:
 306                 /* 8 bit output, with a loop */
 307                 r = ppa_byte_out(ppb, buffer, len);
 308                 break;
 309
 310         case PPA_EPP_32:
 311         case PPA_EPP_16:
 312         case PPA_EPP_8:
 313                 epp_reset(ppb);
 314                 w_ctr(ppb, 0x4);
 315 #ifdef CONFIG_SCSI_IZIP_EPP16
 316                 if (!(((long) buffer | len) & 0x01))
 317                         outsw(ppb + 4, buffer, len >> 1);
 318 #else
 319                 if (!(((long) buffer | len) & 0x03))
 320                         outsl(ppb + 4, buffer, len >> 2);
 321 #endif
 322                 else
 323                         outsb(ppb + 4, buffer, len);
 324                 w_ctr(ppb, 0xc);
 325                 r = !(r_str(ppb) & 0x01);
 326                 w_ctr(ppb, 0xc);
 327                 ecp_sync(dev);
 328                 break;
 329
 330         default:
 331                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
 332                 r = 0;
 333         }
 334         return r;
 335 }
 336
 337 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 338 {
 339         int r;
 340         unsigned short ppb = dev->base;
 341
 342         r = ppa_wait(dev);
 343
 344         if ((r & 0x50) != 0x50) {
 345                 ppa_fail(dev, DID_ERROR);
 346                 return 0;
 347         }
 348         switch (dev->mode) {
 349         case PPA_NIBBLE:
 350                 /* 4 bit input, with a loop */
 351                 r = ppa_nibble_in(ppb, buffer, len);
 352                 w_ctr(ppb, 0xc);
 353                 break;
 354
 355         case PPA_PS2:
 356                 /* 8 bit input, with a loop */
 357                 w_ctr(ppb, 0x25);
 358                 r = ppa_byte_in(ppb, buffer, len);
 359                 w_ctr(ppb, 0x4);
 360                 w_ctr(ppb, 0xc);
 361                 break;
 362
 363         case PPA_EPP_32:
 364         case PPA_EPP_16:
 365         case PPA_EPP_8:
 366                 epp_reset(ppb);
 367                 w_ctr(ppb, 0x24);
 368 #ifdef CONFIG_SCSI_IZIP_EPP16
 369                 if (!(((long) buffer | len) & 0x01))
 370                         insw(ppb + 4, buffer, len >> 1);
 371 #else
 372                 if (!(((long) buffer | len) & 0x03))
 373                         insl(ppb + 4, buffer, len >> 2);
 374 #endif
 375                 else
 376                         insb(ppb + 4, buffer, len);
 377                 w_ctr(ppb, 0x2c);
 378                 r = !(r_str(ppb) & 0x01);
 379                 w_ctr(ppb, 0x2c);
 380                 ecp_sync(dev);
 381                 break;
 382
 383         default:
 384                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 385                 r = 0;
 386                 break;
 387         }
 388         return r;
 389 }
 390
 391 /* end of ppa_io.h */
 392 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 393 {
 394         w_dtr(ppb, b);
 395         w_ctr(ppb, 0xc);
 396         w_ctr(ppb, 0xe);
 397         w_ctr(ppb, 0xc);
 398         w_ctr(ppb, 0x4);
 399         w_ctr(ppb, 0xc);
 400 }
 401
 402 static void ppa_disconnect(ppa_struct *dev)
 403 {
 404         unsigned short ppb = dev->base;
 405
 406         ppa_d_pulse(ppb, 0);
 407         ppa_d_pulse(ppb, 0x3c);
 408         ppa_d_pulse(ppb, 0x20);
 409         ppa_d_pulse(ppb, 0xf);
 410 }
 411
 412 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 413 {
 414         w_dtr(ppb, b);
 415         w_ctr(ppb, 0x4);
 416         w_ctr(ppb, 0x6);
 417         w_ctr(ppb, 0x4);
 418         w_ctr(ppb, 0xc);
 419 }
 420
 421 static inline void ppa_connect(ppa_struct *dev, int flag)
 422 {
 423         unsigned short ppb = dev->base;
 424
 425         ppa_c_pulse(ppb, 0);
 426         ppa_c_pulse(ppb, 0x3c);
 427         ppa_c_pulse(ppb, 0x20);
 428         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 429                 ppa_c_pulse(ppb, 0xcf);
 430         else
 431                 ppa_c_pulse(ppb, 0x8f);
 432 }
 433
 434 static int ppa_select(ppa_struct *dev, int target)
 435 {
 436         int k;
 437         unsigned short ppb = dev->base;
 438
 439         /*
 440          * Bit 6 (0x40) is the device selected bit.
 441          * First we must wait till the current device goes off line...
 442          */
 443         k = PPA_SELECT_TMO;
 444         do {
 445                 k--;
 446                 udelay(1);
 447         } while ((r_str(ppb) & 0x40) && (k));
 448         if (!k)
 449                 return 0;
 450
 451         w_dtr(ppb, (1 << target));
 452         w_ctr(ppb, 0xe);
 453         w_ctr(ppb, 0xc);
 454         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 455         w_ctr(ppb, 0x8);
 456
 457         k = PPA_SELECT_TMO;
 458         do {
 459                 k--;
 460                 udelay(1);
 461         }
 462         while (!(r_str(ppb) & 0x40) && (k));
 463         if (!k)
 464                 return 0;
 465
 466         return 1;
 467 }
 468
 469 /*
 470  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 471  * I've tried several different kinds of parallel ports with guest and
 472  * coded this to react in the same ways that it does.
 473  *
 474  * The return value from this function is just a hint about where the
 475  * handshaking failed.
 476  *
 477  */
 478 static int ppa_init(ppa_struct *dev)
 479 {
 480         int retv;
 481         unsigned short ppb = dev->base;
 482
 483         ppa_disconnect(dev);
 484         ppa_connect(dev, CONNECT_NORMAL);
 485
 486         retv = 2;               /* Failed */
 487
 488         w_ctr(ppb, 0xe);
 489         if ((r_str(ppb) & 0x08) == 0x08)
 490                 retv--;
 491
 492         w_ctr(ppb, 0xc);
 493         if ((r_str(ppb) & 0x08) == 0x00)
 494                 retv--;
 495
 496         if (!retv)
 497                 ppa_reset_pulse(ppb);
 498         udelay(1000);           /* Allow devices to settle down */
 499         ppa_disconnect(dev);
 500         udelay(1000);           /* Another delay to allow devices to settle */
 501
 502         if (retv)
 503                 return -EIO;
 504
 505         return device_check(dev);
 506 }
 507
 508 static inline int ppa_send_command(struct scsi_cmnd *cmd)
 509 {
 510         ppa_struct *dev = ppa_dev(cmd->device->host);
 511         int k;
 512
 513         w_ctr(dev->base, 0x0c);
 514
 515         for (k = 0; k < cmd->cmd_len; k++)
 516                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 517                         return 0;
 518         return 1;
 519 }
 520
 521 /*
 522  * The bulk flag enables some optimisations in the data transfer loops,
 523  * it should be true for any command that transfers data in integral
 524  * numbers of sectors.
 525  *
 526  * The driver appears to remain stable if we speed up the parallel port
 527  * i/o in this function, but not elsewhere.
 528  */
 529 static int ppa_completion(struct scsi_cmnd *cmd)
 530 {
 531         /* Return codes:
 532          * -1     Error
 533          *  0     Told to schedule
 534          *  1     Finished data transfer
 535          */
 536         ppa_struct *dev = ppa_dev(cmd->device->host);
 537         unsigned short ppb = dev->base;
 538         unsigned long start_jiffies = jiffies;
 539
 540         unsigned char r, v;
 541         int fast, bulk, status;
 542
 543         v = cmd->cmnd[0];
 544         bulk = ((v == READ_6) ||
 545                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 546
 547         /*
 548          * We only get here if the drive is ready to comunicate,
 549          * hence no need for a full ppa_wait.
 550          */
 551         r = (r_str(ppb) & 0xf0);
 552
 553         while (r != (unsigned char) 0xf0) {
 554                 /*
 555                  * If we have been running for more than a full timer tick
 556                  * then take a rest.
 557                  */
 558                 if (time_after(jiffies, start_jiffies + 1))
 559                         return 0;
 560
 561                 if ((cmd->SCp.this_residual <= 0)) {
 562                         ppa_fail(dev, DID_ERROR);
 563                         return -1;      /* ERROR_RETURN */
 564                 }
 565
 566                 /* On some hardware we have SCSI disconnected (6th bit low)
 567                  * for about 100usecs. It is too expensive to wait a
 568                  * tick on every loop so we busy wait for no more than
 569                  * 500usecs to give the drive a chance first. We do not
 570                  * change things for "normal" hardware since generally
 571                  * the 6th bit is always high.
 572                  * This makes the CPU load higher on some hardware
 573                  * but otherwise we can not get more than 50K/secs
 574                  * on this problem hardware.
 575                  */
 576                 if ((r & 0xc0) != 0xc0) {
 577                         /* Wait for reconnection should be no more than
 578                          * jiffy/2 = 5ms = 5000 loops
 579                          */
 580                         unsigned long k = dev->recon_tmo;
 581                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 582                              k--)
 583                                 udelay(1);
 584
 585                         if (!k)
 586                                 return 0;
 587                 }
 588
 589                 /* determine if we should use burst I/O */
 590                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 591                     ? PPA_BURST_SIZE : 1;
 592
 593                 if (r == (unsigned char) 0xc0)
 594                         status = ppa_out(dev, cmd->SCp.ptr, fast);
 595                 else
 596                         status = ppa_in(dev, cmd->SCp.ptr, fast);
 597
 598                 cmd->SCp.ptr += fast;
 599                 cmd->SCp.this_residual -= fast;
 600
 601                 if (!status) {
 602                         ppa_fail(dev, DID_BUS_BUSY);
 603                         return -1;      /* ERROR_RETURN */
 604                 }
 605                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 606                         /* if scatter/gather, advance to the next segment */
 607                         if (cmd->SCp.buffers_residual--) {
 608                                 cmd->SCp.buffer++;
 609                                 cmd->SCp.this_residual =
 610                                     cmd->SCp.buffer->length;
 611                                 cmd->SCp.ptr =
 612                                     page_address(cmd->SCp.buffer->page) +
 613                                     cmd->SCp.buffer->offset;
 614                         }
 615                 }
 616                 /* Now check to see if the drive is ready to comunicate */
 617                 r = (r_str(ppb) & 0xf0);
 618                 /* If not, drop back down to the scheduler and wait a timer tick */
 619                 if (!(r & 0x80))
 620                         return 0;
 621         }
 622         return 1;               /* FINISH_RETURN */
 623 }
 624
 625 /*
 626  * Since the PPA itself doesn't generate interrupts, we use
 627  * the scheduler's task queue to generate a stream of call-backs and
 628  * complete the request when the drive is ready.
 629  */
 630 static void ppa_interrupt(struct work_struct *work)
 631 {
 632         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 633         struct scsi_cmnd *cmd = dev->cur_cmd;
 634
 635         if (!cmd) {
 636                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 637                 return;
 638         }
 639         if (ppa_engine(dev, cmd)) {
 640                 schedule_delayed_work(&dev->ppa_tq, 1);
 641                 return;
 642         }
 643         /* Command must of completed hence it is safe to let go... */
 644 #if PPA_DEBUG > 0
 645         switch ((cmd->result >> 16) & 0xff) {
 646         case DID_OK:
 647                 break;
 648         case DID_NO_CONNECT:
 649                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
 650                 break;
 651         case DID_BUS_BUSY:
 652                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 653                 break;
 654         case DID_TIME_OUT:
 655                 printk(KERN_DEBUG "ppa: unknown timeout\n");
 656                 break;
 657         case DID_ABORT:
 658                 printk(KERN_DEBUG "ppa: told to abort\n");
 659                 break;
 660         case DID_PARITY:
 661                 printk(KERN_DEBUG "ppa: parity error (???)\n");
 662                 break;
 663         case DID_ERROR:
 664                 printk(KERN_DEBUG "ppa: internal driver error\n");
 665                 break;
 666         case DID_RESET:
 667                 printk(KERN_DEBUG "ppa: told to reset device\n");
 668                 break;
 669         case DID_BAD_INTR:
 670                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 671                 break;
 672         default:
 673                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 674                        (cmd->result >> 16) & 0xff);
 675         }
 676 #endif
 677
 678         if (cmd->SCp.phase > 1)
 679                 ppa_disconnect(dev);
 680
 681         ppa_pb_dismiss(dev);
 682
 683         dev->cur_cmd = NULL;
 684
 685         cmd->scsi_done(cmd);
 686 }
 687
 688 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 689 {
 690         unsigned short ppb = dev->base;
 691         unsigned char l = 0, h = 0;
 692         int retv;
 693
 694         /* First check for any errors that may of occurred
 695          * Here we check for internal errors
 696          */
 697         if (dev->failed)
 698                 return 0;
 699
 700         switch (cmd->SCp.phase) {
 701         case 0:         /* Phase 0 - Waiting for parport */
 702                 if (time_after(jiffies, dev->jstart + HZ)) {
 703                         /*
 704                          * We waited more than a second
 705                          * for parport to call us
 706                          */
 707                         ppa_fail(dev, DID_BUS_BUSY);
 708                         return 0;
 709                 }
 710                 return 1;       /* wait until ppa_wakeup claims parport */
 711         case 1:         /* Phase 1 - Connected */
 712                 {               /* Perform a sanity check for cable unplugged */
 713                         int retv = 2;   /* Failed */
 714
 715                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 716
 717                         w_ctr(ppb, 0xe);
 718                         if ((r_str(ppb) & 0x08) == 0x08)
 719                                 retv--;
 720
 721                         w_ctr(ppb, 0xc);
 722                         if ((r_str(ppb) & 0x08) == 0x00)
 723                                 retv--;
 724
 725                         if (retv) {
 726                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 727                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 728                                         ppa_fail(dev, DID_BUS_BUSY);
 729                                         return 0;
 730                                 } else {
 731                                         ppa_disconnect(dev);
 732                                         return 1;       /* Try again in a jiffy */
 733                                 }
 734                         }
 735                         cmd->SCp.phase++;
 736                 }
 737
 738         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 739                 if (!ppa_select(dev, scmd_id(cmd))) {
 740                         ppa_fail(dev, DID_NO_CONNECT);
 741                         return 0;
 742                 }
 743                 cmd->SCp.phase++;
 744
 745         case 3:         /* Phase 3 - Ready to accept a command */
 746                 w_ctr(ppb, 0x0c);
 747                 if (!(r_str(ppb) & 0x80))
 748                         return 1;
 749
 750                 if (!ppa_send_command(cmd))
 751                         return 0;
 752                 cmd->SCp.phase++;
 753
 754         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 755                 if (cmd->use_sg) {
 756                         /* if many buffers are available, start filling the first */
 757                         cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
 758                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 759                         cmd->SCp.ptr = 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(KERN_ERR "ppa: Invalid scsi phase\n");
 801         }
 802         return 0;
 803 }
 804
 805 static int ppa_queuecommand(struct scsi_cmnd *cmd,
 806                 void (*done) (struct scsi_cmnd *))
 807 {
 808         ppa_struct *dev = ppa_dev(cmd->device->host);
 809
 810         if (dev->cur_cmd) {
 811                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 812                 return 0;
 813         }
 814         dev->failed = 0;
 815         dev->jstart = jiffies;
 816         dev->cur_cmd = cmd;
 817         cmd->scsi_done = done;
 818         cmd->result = DID_ERROR << 16;  /* default return code */
 819         cmd->SCp.phase = 0;     /* bus free */
 820
 821         schedule_delayed_work(&dev->ppa_tq, 0);
 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(struct 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(struct 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         mdelay(1);              /* device settle delay */
 889         ppa_disconnect(dev);
 890         mdelay(1);              /* 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 u8 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(KERN_INFO "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(KERN_INFO "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 int ppa_adjust_queue(struct scsi_device *device)
 978 {
 979         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 980         return 0;
 981 }
 982
 983 static struct scsi_host_template ppa_template = {
 984         .module                 = THIS_MODULE,
 985         .proc_name              = "ppa",
 986         .proc_info              = ppa_proc_info,
 987         .name                   = "Iomega VPI0 (ppa) interface",
 988         .queuecommand           = ppa_queuecommand,
 989         .eh_abort_handler       = ppa_abort,
 990         .eh_bus_reset_handler   = ppa_reset,
 991         .eh_host_reset_handler  = ppa_reset,
 992         .bios_param             = ppa_biosparam,
 993         .this_id                = -1,
 994         .sg_tablesize           = SG_ALL,
 995         .cmd_per_lun            = 1,
 996         .use_clustering         = ENABLE_CLUSTERING,
 997         .can_queue              = 1,
 998         .slave_alloc            = ppa_adjust_queue,
 999 };
1000
1001 /***************************************************************************
1002  *                   Parallel port probing routines                        *
1003  ***************************************************************************/
1004
1005 static LIST_HEAD(ppa_hosts);
1006
1007 static int __ppa_attach(struct parport *pb)
1008 {
1009         struct Scsi_Host *host;
1010         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1011         DEFINE_WAIT(wait);
1012         ppa_struct *dev;
1013         int ports;
1014         int modes, ppb, ppb_hi;
1015         int err = -ENOMEM;
1016
1017         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1018         if (!dev)
1019                 return -ENOMEM;
1020         dev->base = -1;
1021         dev->mode = PPA_AUTODETECT;
1022         dev->recon_tmo = PPA_RECON_TMO;
1023         init_waitqueue_head(&waiting);
1024         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1025                                             NULL, 0, dev);
1026
1027         if (!dev->dev)
1028                 goto out;
1029
1030         /* Claim the bus so it remembers what we do to the control
1031          * registers. [ CTR and ECP ]
1032          */
1033         err = -EBUSY;
1034         dev->waiting = &waiting;
1035         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1036         if (ppa_pb_claim(dev))
1037                 schedule_timeout(3 * HZ);
1038         if (dev->wanted) {
1039                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1040                                 "a pardevice is owning the port for too long "
1041                                 "time!\n", pb->number);
1042                 ppa_pb_dismiss(dev);
1043                 dev->waiting = NULL;
1044                 finish_wait(&waiting, &wait);
1045                 goto out1;
1046         }
1047         dev->waiting = NULL;
1048         finish_wait(&waiting, &wait);
1049         ppb = dev->base = dev->dev->port->base;
1050         ppb_hi = dev->dev->port->base_hi;
1051         w_ctr(ppb, 0x0c);
1052         modes = dev->dev->port->modes;
1053
1054         /* Mode detection works up the chain of speed
1055          * This avoids a nasty if-then-else-if-... tree
1056          */
1057         dev->mode = PPA_NIBBLE;
1058
1059         if (modes & PARPORT_MODE_TRISTATE)
1060                 dev->mode = PPA_PS2;
1061
1062         if (modes & PARPORT_MODE_ECP) {
1063                 w_ecr(ppb_hi, 0x20);
1064                 dev->mode = PPA_PS2;
1065         }
1066         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1067                 w_ecr(ppb_hi, 0x80);
1068
1069         /* Done configuration */
1070
1071         err = ppa_init(dev);
1072         ppa_pb_release(dev);
1073
1074         if (err)
1075                 goto out1;
1076
1077         /* now the glue ... */
1078         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1079                 ports = 3;
1080         else
1081                 ports = 8;
1082
1083         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1084
1085         err = -ENOMEM;
1086         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1087         if (!host)
1088                 goto out1;
1089         host->io_port = pb->base;
1090         host->n_io_port = ports;
1091         host->dma_channel = -1;
1092         host->unique_id = pb->number;
1093         *(ppa_struct **)&host->hostdata = dev;
1094         dev->host = host;
1095         list_add_tail(&dev->list, &ppa_hosts);
1096         err = scsi_add_host(host, NULL);
1097         if (err)
1098                 goto out2;
1099         scsi_scan_host(host);
1100         return 0;
1101 out2:
1102         list_del_init(&dev->list);
1103         scsi_host_put(host);
1104 out1:
1105         parport_unregister_device(dev->dev);
1106 out:
1107         kfree(dev);
1108         return err;
1109 }
1110
1111 static void ppa_attach(struct parport *pb)
1112 {
1113         __ppa_attach(pb);
1114 }
1115
1116 static void ppa_detach(struct parport *pb)
1117 {
1118         ppa_struct *dev;
1119         list_for_each_entry(dev, &ppa_hosts, list) {
1120                 if (dev->dev->port == pb) {
1121                         list_del_init(&dev->list);
1122                         scsi_remove_host(dev->host);
1123                         scsi_host_put(dev->host);
1124                         parport_unregister_device(dev->dev);
1125                         kfree(dev);
1126                         break;
1127                 }
1128         }
1129 }
1130
1131 static struct parport_driver ppa_driver = {
1132         .name   = "ppa",
1133         .attach = ppa_attach,
1134         .detach = ppa_detach,
1135 };
1136
1137 static int __init ppa_driver_init(void)
1138 {
1139         printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1140         return parport_register_driver(&ppa_driver);
1141 }
1142
1143 static void __exit ppa_driver_exit(void)
1144 {
1145         parport_unregister_driver(&ppa_driver);
1146 }
1147
1148 module_init(ppa_driver_init);
1149 module_exit(ppa_driver_exit);
1150 MODULE_LICENSE("GPL");