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 <linux/parport.h>
  19 #include <linux/workqueue.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 work_struct 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_proc_write(ppa_struct *dev, char *buffer, int length)
 122 {
 123         unsigned long x;
 124
 125         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 126                 x = simple_strtoul(buffer + 5, NULL, 0);
 127                 dev->mode = x;
 128                 return length;
 129         }
 130         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 131                 x = simple_strtoul(buffer + 10, NULL, 0);
 132                 dev->recon_tmo = x;
 133                 printk("ppa: recon_tmo set to %ld\n", x);
 134                 return length;
 135         }
 136         printk("ppa /proc: invalid variable\n");
 137         return (-EINVAL);
 138 }
 139
 140 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
 141 {
 142         int len = 0;
 143         ppa_struct *dev = ppa_dev(host);
 144
 145         if (inout)
 146                 return ppa_proc_write(dev, buffer, length);
 147
 148         len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
 149         len +=
 150             sprintf(buffer + len, "Parport : %s\n",
 151                     dev->dev->port->name);
 152         len +=
 153             sprintf(buffer + len, "Mode    : %s\n",
 154                     PPA_MODE_STRING[dev->mode]);
 155 #if PPA_DEBUG > 0
 156         len +=
 157             sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
 158 #endif
 159
 160         /* Request for beyond end of buffer */
 161         if (offset > length)
 162                 return 0;
 163
 164         *start = buffer + offset;
 165         len -= offset;
 166         if (len > length)
 167                 len = length;
 168         return len;
 169 }
 170
 171 static int device_check(ppa_struct *dev);
 172
 173 #if PPA_DEBUG > 0
 174 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 175            y, __FUNCTION__, __LINE__); ppa_fail_func(x,y);
 176 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 177 #else
 178 static inline void ppa_fail(ppa_struct *dev, int error_code)
 179 #endif
 180 {
 181         /* If we fail a device then we trash status / message bytes */
 182         if (dev->cur_cmd) {
 183                 dev->cur_cmd->result = error_code << 16;
 184                 dev->failed = 1;
 185         }
 186 }
 187
 188 /*
 189  * Wait for the high bit to be set.
 190  *
 191  * In principle, this could be tied to an interrupt, but the adapter
 192  * doesn't appear to be designed to support interrupts.  We spin on
 193  * the 0x80 ready bit.
 194  */
 195 static unsigned char ppa_wait(ppa_struct *dev)
 196 {
 197         int k;
 198         unsigned short ppb = dev->base;
 199         unsigned char r;
 200
 201         k = PPA_SPIN_TMO;
 202         /* Wait for bit 6 and 7 - PJC */
 203         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 204                 udelay(1);
 205                 r = r_str(ppb);
 206         }
 207
 208         /*
 209          * return some status information.
 210          * Semantics: 0xc0 = ZIP wants more data
 211          *            0xd0 = ZIP wants to send more data
 212          *            0xe0 = ZIP is expecting SCSI command data
 213          *            0xf0 = end of transfer, ZIP is sending status
 214          */
 215         if (k)
 216                 return (r & 0xf0);
 217
 218         /* Counter expired - Time out occurred */
 219         ppa_fail(dev, DID_TIME_OUT);
 220         printk("ppa timeout in ppa_wait\n");
 221         return 0;               /* command timed out */
 222 }
 223
 224 /*
 225  * Clear EPP Timeout Bit
 226  */
 227 static inline void epp_reset(unsigned short ppb)
 228 {
 229         int i;
 230
 231         i = r_str(ppb);
 232         w_str(ppb, i);
 233         w_str(ppb, i & 0xfe);
 234 }
 235
 236 /*
 237  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 238  */
 239 static inline void ecp_sync(ppa_struct *dev)
 240 {
 241         int i, ppb_hi = dev->dev->port->base_hi;
 242
 243         if (ppb_hi == 0)
 244                 return;
 245
 246         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 247                 for (i = 0; i < 100; i++) {
 248                         if (r_ecr(ppb_hi) & 0x01)
 249                                 return;
 250                         udelay(5);
 251                 }
 252                 printk("ppa: ECP sync failed as data still present in FIFO.\n");
 253         }
 254 }
 255
 256 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 257 {
 258         int i;
 259
 260         for (i = len; i; i--) {
 261                 w_dtr(base, *buffer++);
 262                 w_ctr(base, 0xe);
 263                 w_ctr(base, 0xc);
 264         }
 265         return 1;               /* All went well - we hope! */
 266 }
 267
 268 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 269 {
 270         int i;
 271
 272         for (i = len; i; i--) {
 273                 *buffer++ = r_dtr(base);
 274                 w_ctr(base, 0x27);
 275                 w_ctr(base, 0x25);
 276         }
 277         return 1;               /* All went well - we hope! */
 278 }
 279
 280 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 281 {
 282         for (; len; len--) {
 283                 unsigned char h;
 284
 285                 w_ctr(base, 0x4);
 286                 h = r_str(base) & 0xf0;
 287                 w_ctr(base, 0x6);
 288                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 289         }
 290         return 1;               /* All went well - we hope! */
 291 }
 292
 293 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 294 {
 295         int r;
 296         unsigned short ppb = dev->base;
 297
 298         r = ppa_wait(dev);
 299
 300         if ((r & 0x50) != 0x40) {
 301                 ppa_fail(dev, DID_ERROR);
 302                 return 0;
 303         }
 304         switch (dev->mode) {
 305         case PPA_NIBBLE:
 306         case PPA_PS2:
 307                 /* 8 bit output, with a loop */
 308                 r = ppa_byte_out(ppb, buffer, len);
 309                 break;
 310
 311         case PPA_EPP_32:
 312         case PPA_EPP_16:
 313         case PPA_EPP_8:
 314                 epp_reset(ppb);
 315                 w_ctr(ppb, 0x4);
 316 #ifdef CONFIG_SCSI_IZIP_EPP16
 317                 if (!(((long) buffer | len) & 0x01))
 318                         outsw(ppb + 4, buffer, len >> 1);
 319 #else
 320                 if (!(((long) buffer | len) & 0x03))
 321                         outsl(ppb + 4, buffer, len >> 2);
 322 #endif
 323                 else
 324                         outsb(ppb + 4, buffer, len);
 325                 w_ctr(ppb, 0xc);
 326                 r = !(r_str(ppb) & 0x01);
 327                 w_ctr(ppb, 0xc);
 328                 ecp_sync(dev);
 329                 break;
 330
 331         default:
 332                 printk("PPA: bug in ppa_out()\n");
 333                 r = 0;
 334         }
 335         return r;
 336 }
 337
 338 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 339 {
 340         int r;
 341         unsigned short ppb = dev->base;
 342
 343         r = ppa_wait(dev);
 344
 345         if ((r & 0x50) != 0x50) {
 346                 ppa_fail(dev, DID_ERROR);
 347                 return 0;
 348         }
 349         switch (dev->mode) {
 350         case PPA_NIBBLE:
 351                 /* 4 bit input, with a loop */
 352                 r = ppa_nibble_in(ppb, buffer, len);
 353                 w_ctr(ppb, 0xc);
 354                 break;
 355
 356         case PPA_PS2:
 357                 /* 8 bit input, with a loop */
 358                 w_ctr(ppb, 0x25);
 359                 r = ppa_byte_in(ppb, buffer, len);
 360                 w_ctr(ppb, 0x4);
 361                 w_ctr(ppb, 0xc);
 362                 break;
 363
 364         case PPA_EPP_32:
 365         case PPA_EPP_16:
 366         case PPA_EPP_8:
 367                 epp_reset(ppb);
 368                 w_ctr(ppb, 0x24);
 369 #ifdef CONFIG_SCSI_IZIP_EPP16
 370                 if (!(((long) buffer | len) & 0x01))
 371                         insw(ppb + 4, buffer, len >> 1);
 372 #else
 373                 if (!(((long) buffer | len) & 0x03))
 374                         insl(ppb + 4, buffer, len >> 2);
 375 #endif
 376                 else
 377                         insb(ppb + 4, buffer, len);
 378                 w_ctr(ppb, 0x2c);
 379                 r = !(r_str(ppb) & 0x01);
 380                 w_ctr(ppb, 0x2c);
 381                 ecp_sync(dev);
 382                 break;
 383
 384         default:
 385                 printk("PPA: bug in ppa_ins()\n");
 386                 r = 0;
 387                 break;
 388         }
 389         return r;
 390 }
 391
 392 /* end of ppa_io.h */
 393 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 394 {
 395         w_dtr(ppb, b);
 396         w_ctr(ppb, 0xc);
 397         w_ctr(ppb, 0xe);
 398         w_ctr(ppb, 0xc);
 399         w_ctr(ppb, 0x4);
 400         w_ctr(ppb, 0xc);
 401 }
 402
 403 static void ppa_disconnect(ppa_struct *dev)
 404 {
 405         unsigned short ppb = dev->base;
 406
 407         ppa_d_pulse(ppb, 0);
 408         ppa_d_pulse(ppb, 0x3c);
 409         ppa_d_pulse(ppb, 0x20);
 410         ppa_d_pulse(ppb, 0xf);
 411 }
 412
 413 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 414 {
 415         w_dtr(ppb, b);
 416         w_ctr(ppb, 0x4);
 417         w_ctr(ppb, 0x6);
 418         w_ctr(ppb, 0x4);
 419         w_ctr(ppb, 0xc);
 420 }
 421
 422 static inline void ppa_connect(ppa_struct *dev, int flag)
 423 {
 424         unsigned short ppb = dev->base;
 425
 426         ppa_c_pulse(ppb, 0);
 427         ppa_c_pulse(ppb, 0x3c);
 428         ppa_c_pulse(ppb, 0x20);
 429         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 430                 ppa_c_pulse(ppb, 0xcf);
 431         else
 432                 ppa_c_pulse(ppb, 0x8f);
 433 }
 434
 435 static int ppa_select(ppa_struct *dev, int target)
 436 {
 437         int k;
 438         unsigned short ppb = dev->base;
 439
 440         /*
 441          * Bit 6 (0x40) is the device selected bit.
 442          * First we must wait till the current device goes off line...
 443          */
 444         k = PPA_SELECT_TMO;
 445         do {
 446                 k--;
 447                 udelay(1);
 448         } while ((r_str(ppb) & 0x40) && (k));
 449         if (!k)
 450                 return 0;
 451
 452         w_dtr(ppb, (1 << target));
 453         w_ctr(ppb, 0xe);
 454         w_ctr(ppb, 0xc);
 455         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 456         w_ctr(ppb, 0x8);
 457
 458         k = PPA_SELECT_TMO;
 459         do {
 460                 k--;
 461                 udelay(1);
 462         }
 463         while (!(r_str(ppb) & 0x40) && (k));
 464         if (!k)
 465                 return 0;
 466
 467         return 1;
 468 }
 469
 470 /*
 471  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 472  * I've tried several different kinds of parallel ports with guest and
 473  * coded this to react in the same ways that it does.
 474  *
 475  * The return value from this function is just a hint about where the
 476  * handshaking failed.
 477  *
 478  */
 479 static int ppa_init(ppa_struct *dev)
 480 {
 481         int retv;
 482         unsigned short ppb = dev->base;
 483
 484         ppa_disconnect(dev);
 485         ppa_connect(dev, CONNECT_NORMAL);
 486
 487         retv = 2;               /* Failed */
 488
 489         w_ctr(ppb, 0xe);
 490         if ((r_str(ppb) & 0x08) == 0x08)
 491                 retv--;
 492
 493         w_ctr(ppb, 0xc);
 494         if ((r_str(ppb) & 0x08) == 0x00)
 495                 retv--;
 496
 497         if (!retv)
 498                 ppa_reset_pulse(ppb);
 499         udelay(1000);           /* Allow devices to settle down */
 500         ppa_disconnect(dev);
 501         udelay(1000);           /* Another delay to allow devices to settle */
 502
 503         if (retv)
 504                 return -EIO;
 505
 506         return device_check(dev);
 507 }
 508
 509 static inline int ppa_send_command(struct scsi_cmnd *cmd)
 510 {
 511         ppa_struct *dev = ppa_dev(cmd->device->host);
 512         int k;
 513
 514         w_ctr(dev->base, 0x0c);
 515
 516         for (k = 0; k < cmd->cmd_len; k++)
 517                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 518                         return 0;
 519         return 1;
 520 }
 521
 522 /*
 523  * The bulk flag enables some optimisations in the data transfer loops,
 524  * it should be true for any command that transfers data in integral
 525  * numbers of sectors.
 526  *
 527  * The driver appears to remain stable if we speed up the parallel port
 528  * i/o in this function, but not elsewhere.
 529  */
 530 static int ppa_completion(struct scsi_cmnd *cmd)
 531 {
 532         /* Return codes:
 533          * -1     Error
 534          *  0     Told to schedule
 535          *  1     Finished data transfer
 536          */
 537         ppa_struct *dev = ppa_dev(cmd->device->host);
 538         unsigned short ppb = dev->base;
 539         unsigned long start_jiffies = jiffies;
 540
 541         unsigned char r, v;
 542         int fast, bulk, status;
 543
 544         v = cmd->cmnd[0];
 545         bulk = ((v == READ_6) ||
 546                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 547
 548         /*
 549          * We only get here if the drive is ready to comunicate,
 550          * hence no need for a full ppa_wait.
 551          */
 552         r = (r_str(ppb) & 0xf0);
 553
 554         while (r != (unsigned char) 0xf0) {
 555                 /*
 556                  * If we have been running for more than a full timer tick
 557                  * then take a rest.
 558                  */
 559                 if (time_after(jiffies, start_jiffies + 1))
 560                         return 0;
 561
 562                 if ((cmd->SCp.this_residual <= 0)) {
 563                         ppa_fail(dev, DID_ERROR);
 564                         return -1;      /* ERROR_RETURN */
 565                 }
 566
 567                 /* On some hardware we have SCSI disconnected (6th bit low)
 568                  * for about 100usecs. It is too expensive to wait a
 569                  * tick on every loop so we busy wait for no more than
 570                  * 500usecs to give the drive a chance first. We do not
 571                  * change things for "normal" hardware since generally
 572                  * the 6th bit is always high.
 573                  * This makes the CPU load higher on some hardware
 574                  * but otherwise we can not get more than 50K/secs
 575                  * on this problem hardware.
 576                  */
 577                 if ((r & 0xc0) != 0xc0) {
 578                         /* Wait for reconnection should be no more than
 579                          * jiffy/2 = 5ms = 5000 loops
 580                          */
 581                         unsigned long k = dev->recon_tmo;
 582                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 583                              k--)
 584                                 udelay(1);
 585
 586                         if (!k)
 587                                 return 0;
 588                 }
 589
 590                 /* determine if we should use burst I/O */
 591                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 592                     ? PPA_BURST_SIZE : 1;
 593
 594                 if (r == (unsigned char) 0xc0)
 595                         status = ppa_out(dev, cmd->SCp.ptr, fast);
 596                 else
 597                         status = ppa_in(dev, cmd->SCp.ptr, fast);
 598
 599                 cmd->SCp.ptr += fast;
 600                 cmd->SCp.this_residual -= fast;
 601
 602                 if (!status) {
 603                         ppa_fail(dev, DID_BUS_BUSY);
 604                         return -1;      /* ERROR_RETURN */
 605                 }
 606                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 607                         /* if scatter/gather, advance to the next segment */
 608                         if (cmd->SCp.buffers_residual--) {
 609                                 cmd->SCp.buffer++;
 610                                 cmd->SCp.this_residual =
 611                                     cmd->SCp.buffer->length;
 612                                 cmd->SCp.ptr =
 613                                     page_address(cmd->SCp.buffer->page) +
 614                                     cmd->SCp.buffer->offset;
 615                         }
 616                 }
 617                 /* Now check to see if the drive is ready to comunicate */
 618                 r = (r_str(ppb) & 0xf0);
 619                 /* If not, drop back down to the scheduler and wait a timer tick */
 620                 if (!(r & 0x80))
 621                         return 0;
 622         }
 623         return 1;               /* FINISH_RETURN */
 624 }
 625
 626 /*
 627  * Since the PPA itself doesn't generate interrupts, we use
 628  * the scheduler's task queue to generate a stream of call-backs and
 629  * complete the request when the drive is ready.
 630  */
 631 static void ppa_interrupt(void *data)
 632 {
 633         ppa_struct *dev = (ppa_struct *) data;
 634         struct scsi_cmnd *cmd = dev->cur_cmd;
 635
 636         if (!cmd) {
 637                 printk("PPA: bug in ppa_interrupt\n");
 638                 return;
 639         }
 640         if (ppa_engine(dev, cmd)) {
 641                 dev->ppa_tq.data = (void *) dev;
 642                 schedule_delayed_work(&dev->ppa_tq, 1);
 643                 return;
 644         }
 645         /* Command must of completed hence it is safe to let go... */
 646 #if PPA_DEBUG > 0
 647         switch ((cmd->result >> 16) & 0xff) {
 648         case DID_OK:
 649                 break;
 650         case DID_NO_CONNECT:
 651                 printk("ppa: no device at SCSI ID %i\n", cmd->device->target);
 652                 break;
 653         case DID_BUS_BUSY:
 654                 printk("ppa: BUS BUSY - EPP timeout detected\n");
 655                 break;
 656         case DID_TIME_OUT:
 657                 printk("ppa: unknown timeout\n");
 658                 break;
 659         case DID_ABORT:
 660                 printk("ppa: told to abort\n");
 661                 break;
 662         case DID_PARITY:
 663                 printk("ppa: parity error (???)\n");
 664                 break;
 665         case DID_ERROR:
 666                 printk("ppa: internal driver error\n");
 667                 break;
 668         case DID_RESET:
 669                 printk("ppa: told to reset device\n");
 670                 break;
 671         case DID_BAD_INTR:
 672                 printk("ppa: bad interrupt (???)\n");
 673                 break;
 674         default:
 675                 printk("ppa: bad return code (%02x)\n",
 676                        (cmd->result >> 16) & 0xff);
 677         }
 678 #endif
 679
 680         if (cmd->SCp.phase > 1)
 681                 ppa_disconnect(dev);
 682
 683         ppa_pb_dismiss(dev);
 684
 685         dev->cur_cmd = NULL;
 686
 687         cmd->scsi_done(cmd);
 688 }
 689
 690 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 691 {
 692         unsigned short ppb = dev->base;
 693         unsigned char l = 0, h = 0;
 694         int retv;
 695
 696         /* First check for any errors that may of occurred
 697          * Here we check for internal errors
 698          */
 699         if (dev->failed)
 700                 return 0;
 701
 702         switch (cmd->SCp.phase) {
 703         case 0:         /* Phase 0 - Waiting for parport */
 704                 if (time_after(jiffies, dev->jstart + HZ)) {
 705                         /*
 706                          * We waited more than a second
 707                          * for parport to call us
 708                          */
 709                         ppa_fail(dev, DID_BUS_BUSY);
 710                         return 0;
 711                 }
 712                 return 1;       /* wait until ppa_wakeup claims parport */
 713         case 1:         /* Phase 1 - Connected */
 714                 {               /* Perform a sanity check for cable unplugged */
 715                         int retv = 2;   /* Failed */
 716
 717                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 718
 719                         w_ctr(ppb, 0xe);
 720                         if ((r_str(ppb) & 0x08) == 0x08)
 721                                 retv--;
 722
 723                         w_ctr(ppb, 0xc);
 724                         if ((r_str(ppb) & 0x08) == 0x00)
 725                                 retv--;
 726
 727                         if (retv) {
 728                                 if ((jiffies - dev->jstart) > (1 * HZ)) {
 729                                         printk
 730                                             ("ppa: Parallel port cable is unplugged!!\n");
 731                                         ppa_fail(dev, DID_BUS_BUSY);
 732                                         return 0;
 733                                 } else {
 734                                         ppa_disconnect(dev);
 735                                         return 1;       /* Try again in a jiffy */
 736                                 }
 737                         }
 738                         cmd->SCp.phase++;
 739                 }
 740
 741         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 742                 if (!ppa_select(dev, cmd->device->id)) {
 743                         ppa_fail(dev, DID_NO_CONNECT);
 744                         return 0;
 745                 }
 746                 cmd->SCp.phase++;
 747
 748         case 3:         /* Phase 3 - Ready to accept a command */
 749                 w_ctr(ppb, 0x0c);
 750                 if (!(r_str(ppb) & 0x80))
 751                         return 1;
 752
 753                 if (!ppa_send_command(cmd))
 754                         return 0;
 755                 cmd->SCp.phase++;
 756
 757         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 758                 if (cmd->use_sg) {
 759                         /* if many buffers are available, start filling the first */
 760                         cmd->SCp.buffer =
 761                             (struct scatterlist *) cmd->request_buffer;
 762                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 763                         cmd->SCp.ptr =
 764                             page_address(cmd->SCp.buffer->page) +
 765                             cmd->SCp.buffer->offset;
 766                 } else {
 767                         /* else fill the only available buffer */
 768                         cmd->SCp.buffer = NULL;
 769                         cmd->SCp.this_residual = cmd->request_bufflen;
 770                         cmd->SCp.ptr = cmd->request_buffer;
 771                 }
 772                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
 773                 cmd->SCp.phase++;
 774
 775         case 5:         /* Phase 5 - Data transfer stage */
 776                 w_ctr(ppb, 0x0c);
 777                 if (!(r_str(ppb) & 0x80))
 778                         return 1;
 779
 780                 retv = ppa_completion(cmd);
 781                 if (retv == -1)
 782                         return 0;
 783                 if (retv == 0)
 784                         return 1;
 785                 cmd->SCp.phase++;
 786
 787         case 6:         /* Phase 6 - Read status/message */
 788                 cmd->result = DID_OK << 16;
 789                 /* Check for data overrun */
 790                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
 791                         ppa_fail(dev, DID_ERROR);
 792                         return 0;
 793                 }
 794                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
 795                         /* Check for optional message byte */
 796                         if (ppa_wait(dev) == (unsigned char) 0xf0)
 797                                 ppa_in(dev, &h, 1);
 798                         cmd->result =
 799                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 800                 }
 801                 return 0;       /* Finished */
 802                 break;
 803
 804         default:
 805                 printk("ppa: Invalid scsi phase\n");
 806         }
 807         return 0;
 808 }
 809
 810 static int ppa_queuecommand(struct scsi_cmnd *cmd,
 811                 void (*done) (struct scsi_cmnd *))
 812 {
 813         ppa_struct *dev = ppa_dev(cmd->device->host);
 814
 815         if (dev->cur_cmd) {
 816                 printk("PPA: bug in ppa_queuecommand\n");
 817                 return 0;
 818         }
 819         dev->failed = 0;
 820         dev->jstart = jiffies;
 821         dev->cur_cmd = cmd;
 822         cmd->scsi_done = done;
 823         cmd->result = DID_ERROR << 16;  /* default return code */
 824         cmd->SCp.phase = 0;     /* bus free */
 825
 826         dev->ppa_tq.data = dev;
 827         schedule_work(&dev->ppa_tq);
 828
 829         ppa_pb_claim(dev);
 830
 831         return 0;
 832 }
 833
 834 /*
 835  * Apparently the disk->capacity attribute is off by 1 sector
 836  * for all disk drives.  We add the one here, but it should really
 837  * be done in sd.c.  Even if it gets fixed there, this will still
 838  * work.
 839  */
 840 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 841               sector_t capacity, int ip[])
 842 {
 843         ip[0] = 0x40;
 844         ip[1] = 0x20;
 845         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 846         if (ip[2] > 1024) {
 847                 ip[0] = 0xff;
 848                 ip[1] = 0x3f;
 849                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 850                 if (ip[2] > 1023)
 851                         ip[2] = 1023;
 852         }
 853         return 0;
 854 }
 855
 856 static int ppa_abort(struct scsi_cmnd *cmd)
 857 {
 858         ppa_struct *dev = ppa_dev(cmd->device->host);
 859         /*
 860          * There is no method for aborting commands since Iomega
 861          * have tied the SCSI_MESSAGE line high in the interface
 862          */
 863
 864         switch (cmd->SCp.phase) {
 865         case 0:         /* Do not have access to parport */
 866         case 1:         /* Have not connected to interface */
 867                 dev->cur_cmd = NULL;    /* Forget the problem */
 868                 return SUCCESS;
 869                 break;
 870         default:                /* SCSI command sent, can not abort */
 871                 return FAILED;
 872                 break;
 873         }
 874 }
 875
 876 static void ppa_reset_pulse(unsigned int base)
 877 {
 878         w_dtr(base, 0x40);
 879         w_ctr(base, 0x8);
 880         udelay(30);
 881         w_ctr(base, 0xc);
 882 }
 883
 884 static int ppa_reset(struct scsi_cmnd *cmd)
 885 {
 886         ppa_struct *dev = ppa_dev(cmd->device->host);
 887
 888         if (cmd->SCp.phase)
 889                 ppa_disconnect(dev);
 890         dev->cur_cmd = NULL;    /* Forget the problem */
 891
 892         ppa_connect(dev, CONNECT_NORMAL);
 893         ppa_reset_pulse(dev->base);
 894         udelay(1000);           /* device settle delay */
 895         ppa_disconnect(dev);
 896         udelay(1000);           /* device settle delay */
 897         return SUCCESS;
 898 }
 899
 900 static int device_check(ppa_struct *dev)
 901 {
 902         /* This routine looks for a device and then attempts to use EPP
 903            to send a command. If all goes as planned then EPP is available. */
 904
 905         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 906         int loop, old_mode, status, k, ppb = dev->base;
 907         unsigned char l;
 908
 909         old_mode = dev->mode;
 910         for (loop = 0; loop < 8; loop++) {
 911                 /* Attempt to use EPP for Test Unit Ready */
 912                 if ((ppb & 0x0007) == 0x0000)
 913                         dev->mode = PPA_EPP_32;
 914
 915               second_pass:
 916                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 917                 /* Select SCSI device */
 918                 if (!ppa_select(dev, loop)) {
 919                         ppa_disconnect(dev);
 920                         continue;
 921                 }
 922                 printk("ppa: Found device at ID %i, Attempting to use %s\n",
 923                        loop, PPA_MODE_STRING[dev->mode]);
 924
 925                 /* Send SCSI command */
 926                 status = 1;
 927                 w_ctr(ppb, 0x0c);
 928                 for (l = 0; (l < 6) && (status); l++)
 929                         status = ppa_out(dev, cmd, 1);
 930
 931                 if (!status) {
 932                         ppa_disconnect(dev);
 933                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 934                         w_dtr(ppb, 0x40);
 935                         w_ctr(ppb, 0x08);
 936                         udelay(30);
 937                         w_ctr(ppb, 0x0c);
 938                         udelay(1000);
 939                         ppa_disconnect(dev);
 940                         udelay(1000);
 941                         if (dev->mode == PPA_EPP_32) {
 942                                 dev->mode = old_mode;
 943                                 goto second_pass;
 944                         }
 945                         return -EIO;
 946                 }
 947                 w_ctr(ppb, 0x0c);
 948                 k = 1000000;    /* 1 Second */
 949                 do {
 950                         l = r_str(ppb);
 951                         k--;
 952                         udelay(1);
 953                 } while (!(l & 0x80) && (k));
 954
 955                 l &= 0xf0;
 956
 957                 if (l != 0xf0) {
 958                         ppa_disconnect(dev);
 959                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 960                         ppa_reset_pulse(ppb);
 961                         udelay(1000);
 962                         ppa_disconnect(dev);
 963                         udelay(1000);
 964                         if (dev->mode == PPA_EPP_32) {
 965                                 dev->mode = old_mode;
 966                                 goto second_pass;
 967                         }
 968                         return -EIO;
 969                 }
 970                 ppa_disconnect(dev);
 971                 printk("ppa: Communication established with ID %i using %s\n",
 972                        loop, PPA_MODE_STRING[dev->mode]);
 973                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 974                 ppa_reset_pulse(ppb);
 975                 udelay(1000);
 976                 ppa_disconnect(dev);
 977                 udelay(1000);
 978                 return 0;
 979         }
 980         return -ENODEV;
 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 };
 999
1000 /***************************************************************************
1001  *                   Parallel port probing routines                        *
1002  ***************************************************************************/
1003
1004 static LIST_HEAD(ppa_hosts);
1005
1006 static int __ppa_attach(struct parport *pb)
1007 {
1008         struct Scsi_Host *host;
1009         DECLARE_WAIT_QUEUE_HEAD(waiting);
1010         DEFINE_WAIT(wait);
1011         ppa_struct *dev;
1012         int ports;
1013         int modes, ppb, ppb_hi;
1014         int err = -ENOMEM;
1015
1016         dev = kmalloc(sizeof(ppa_struct), GFP_KERNEL);
1017         if (!dev)
1018                 return -ENOMEM;
1019         memset(dev, 0, sizeof(ppa_struct));
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_WORK(&dev->ppa_tq, ppa_interrupt, dev);
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("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");