git.oblomov.eu Git - linux-2.6/blob - drivers/scsi/imm.c

   1 /* imm.c   --  low level driver for the IOMEGA MatchMaker
   2  * parallel port SCSI host adapter.
   3  *
   4  * (The IMM is the embedded controller in the ZIP Plus drive.)
   5  *
   6  * Current Maintainer: David Campbell (Perth, Western Australia)
   7  *                     campbell@torque.net
   8  *
   9  * My unoffical company acronym list is 21 pages long:
  10  *      FLA:    Four letter acronym with built in facility for
  11  *              future expansion to five letters.
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/parport.h>
  20 #include <linux/workqueue.h>
  21 #include <asm/io.h>
  22
  23 #include <scsi/scsi.h>
  24 #include <scsi/scsi_cmnd.h>
  25 #include <scsi/scsi_device.h>
  26 #include <scsi/scsi_host.h>
  27
  28 /* The following #define is to avoid a clash with hosts.c */
  29 #define IMM_PROBE_SPP   0x0001
  30 #define IMM_PROBE_PS2   0x0002
  31 #define IMM_PROBE_ECR   0x0010
  32 #define IMM_PROBE_EPP17 0x0100
  33 #define IMM_PROBE_EPP19 0x0200
  34
  35
  36 typedef struct {
  37         struct pardevice *dev;  /* Parport device entry         */
  38         int base;               /* Actual port address          */
  39         int base_hi;            /* Hi Base address for ECP-ISA chipset */
  40         int mode;               /* Transfer mode                */
  41         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  42         struct work_struct imm_tq;      /* Polling interrupt stuff       */
  43         unsigned long jstart;   /* Jiffies at start             */
  44         unsigned failed:1;      /* Failure flag                 */
  45         unsigned dp:1;          /* Data phase present           */
  46         unsigned rd:1;          /* Read data in data phase      */
  47         unsigned wanted:1;      /* Parport sharing busy flag    */
  48         wait_queue_head_t *waiting;
  49         struct Scsi_Host *host;
  50         struct list_head list;
  51 } imm_struct;
  52
  53 static void imm_reset_pulse(unsigned int base);
  54 static int device_check(imm_struct *dev);
  55
  56 #include "imm.h"
  57
  58 static inline imm_struct *imm_dev(struct Scsi_Host *host)
  59 {
  60         return *(imm_struct **)&host->hostdata;
  61 }
  62
  63 static DEFINE_SPINLOCK(arbitration_lock);
  64
  65 static void got_it(imm_struct *dev)
  66 {
  67         dev->base = dev->dev->port->base;
  68         if (dev->cur_cmd)
  69                 dev->cur_cmd->SCp.phase = 1;
  70         else
  71                 wake_up(dev->waiting);
  72 }
  73
  74 static void imm_wakeup(void *ref)
  75 {
  76         imm_struct *dev = (imm_struct *) ref;
  77         unsigned long flags;
  78
  79         spin_lock_irqsave(&arbitration_lock, flags);
  80         if (dev->wanted) {
  81                 parport_claim(dev->dev);
  82                 got_it(dev);
  83                 dev->wanted = 0;
  84         }
  85         spin_unlock_irqrestore(&arbitration_lock, flags);
  86 }
  87
  88 static int imm_pb_claim(imm_struct *dev)
  89 {
  90         unsigned long flags;
  91         int res = 1;
  92         spin_lock_irqsave(&arbitration_lock, flags);
  93         if (parport_claim(dev->dev) == 0) {
  94                 got_it(dev);
  95                 res = 0;
  96         }
  97         dev->wanted = res;
  98         spin_unlock_irqrestore(&arbitration_lock, flags);
  99         return res;
 100 }
 101
 102 static void imm_pb_dismiss(imm_struct *dev)
 103 {
 104         unsigned long flags;
 105         int wanted;
 106         spin_lock_irqsave(&arbitration_lock, flags);
 107         wanted = dev->wanted;
 108         dev->wanted = 0;
 109         spin_unlock_irqrestore(&arbitration_lock, flags);
 110         if (!wanted)
 111                 parport_release(dev->dev);
 112 }
 113
 114 static inline void imm_pb_release(imm_struct *dev)
 115 {
 116         parport_release(dev->dev);
 117 }
 118
 119 /* This is to give the imm driver a way to modify the timings (and other
 120  * parameters) by writing to the /proc/scsi/imm/0 file.
 121  * Very simple method really... (Too simple, no error checking :( )
 122  * Reason: Kernel hackers HATE having to unload and reload modules for
 123  * testing...
 124  * Also gives a method to use a script to obtain optimum timings (TODO)
 125  */
 126 static inline int imm_proc_write(imm_struct *dev, char *buffer, int length)
 127 {
 128         unsigned long x;
 129
 130         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 131                 x = simple_strtoul(buffer + 5, NULL, 0);
 132                 dev->mode = x;
 133                 return length;
 134         }
 135         printk("imm /proc: invalid variable\n");
 136         return (-EINVAL);
 137 }
 138
 139 static int imm_proc_info(struct Scsi_Host *host, char *buffer, char **start,
 140                         off_t offset, int length, int inout)
 141 {
 142         imm_struct *dev = imm_dev(host);
 143         int len = 0;
 144
 145         if (inout)
 146                 return imm_proc_write(dev, buffer, length);
 147
 148         len += sprintf(buffer + len, "Version : %s\n", IMM_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                     IMM_MODE_STRING[dev->mode]);
 155
 156         /* Request for beyond end of buffer */
 157         if (offset > len)
 158                 return 0;
 159
 160         *start = buffer + offset;
 161         len -= offset;
 162         if (len > length)
 163                 len = length;
 164         return len;
 165 }
 166
 167 #if IMM_DEBUG > 0
 168 #define imm_fail(x,y) printk("imm: imm_fail(%i) from %s at line %d\n",\
 169            y, __FUNCTION__, __LINE__); imm_fail_func(x,y);
 170 static inline void
 171 imm_fail_func(imm_struct *dev, int error_code)
 172 #else
 173 static inline void
 174 imm_fail(imm_struct *dev, int error_code)
 175 #endif
 176 {
 177         /* If we fail a device then we trash status / message bytes */
 178         if (dev->cur_cmd) {
 179                 dev->cur_cmd->result = error_code << 16;
 180                 dev->failed = 1;
 181         }
 182 }
 183
 184 /*
 185  * Wait for the high bit to be set.
 186  *
 187  * In principle, this could be tied to an interrupt, but the adapter
 188  * doesn't appear to be designed to support interrupts.  We spin on
 189  * the 0x80 ready bit.
 190  */
 191 static unsigned char imm_wait(imm_struct *dev)
 192 {
 193         int k;
 194         unsigned short ppb = dev->base;
 195         unsigned char r;
 196
 197         w_ctr(ppb, 0x0c);
 198
 199         k = IMM_SPIN_TMO;
 200         do {
 201                 r = r_str(ppb);
 202                 k--;
 203                 udelay(1);
 204         }
 205         while (!(r & 0x80) && (k));
 206
 207         /*
 208          * STR register (LPT base+1) to SCSI mapping:
 209          *
 210          * STR      imm     imm
 211          * ===================================
 212          * 0x80     S_REQ   S_REQ
 213          * 0x40     !S_BSY  (????)
 214          * 0x20     !S_CD   !S_CD
 215          * 0x10     !S_IO   !S_IO
 216          * 0x08     (????)  !S_BSY
 217          *
 218          * imm      imm     meaning
 219          * ==================================
 220          * 0xf0     0xb8    Bit mask
 221          * 0xc0     0x88    ZIP wants more data
 222          * 0xd0     0x98    ZIP wants to send more data
 223          * 0xe0     0xa8    ZIP is expecting SCSI command data
 224          * 0xf0     0xb8    end of transfer, ZIP is sending status
 225          */
 226         w_ctr(ppb, 0x04);
 227         if (k)
 228                 return (r & 0xb8);
 229
 230         /* Counter expired - Time out occurred */
 231         imm_fail(dev, DID_TIME_OUT);
 232         printk("imm timeout in imm_wait\n");
 233         return 0;               /* command timed out */
 234 }
 235
 236 static int imm_negotiate(imm_struct * tmp)
 237 {
 238         /*
 239          * The following is supposedly the IEEE 1284-1994 negotiate
 240          * sequence. I have yet to obtain a copy of the above standard
 241          * so this is a bit of a guess...
 242          *
 243          * A fair chunk of this is based on the Linux parport implementation
 244          * of IEEE 1284.
 245          *
 246          * Return 0 if data available
 247          *        1 if no data available
 248          */
 249
 250         unsigned short base = tmp->base;
 251         unsigned char a, mode;
 252
 253         switch (tmp->mode) {
 254         case IMM_NIBBLE:
 255                 mode = 0x00;
 256                 break;
 257         case IMM_PS2:
 258                 mode = 0x01;
 259                 break;
 260         default:
 261                 return 0;
 262         }
 263
 264         w_ctr(base, 0x04);
 265         udelay(5);
 266         w_dtr(base, mode);
 267         udelay(100);
 268         w_ctr(base, 0x06);
 269         udelay(5);
 270         a = (r_str(base) & 0x20) ? 0 : 1;
 271         udelay(5);
 272         w_ctr(base, 0x07);
 273         udelay(5);
 274         w_ctr(base, 0x06);
 275
 276         if (a) {
 277                 printk
 278                     ("IMM: IEEE1284 negotiate indicates no data available.\n");
 279                 imm_fail(tmp, DID_ERROR);
 280         }
 281         return a;
 282 }
 283
 284 /*
 285  * Clear EPP timeout bit.
 286  */
 287 static inline void epp_reset(unsigned short ppb)
 288 {
 289         int i;
 290
 291         i = r_str(ppb);
 292         w_str(ppb, i);
 293         w_str(ppb, i & 0xfe);
 294 }
 295
 296 /*
 297  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 298  */
 299 static inline void ecp_sync(imm_struct *dev)
 300 {
 301         int i, ppb_hi = dev->base_hi;
 302
 303         if (ppb_hi == 0)
 304                 return;
 305
 306         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 307                 for (i = 0; i < 100; i++) {
 308                         if (r_ecr(ppb_hi) & 0x01)
 309                                 return;
 310                         udelay(5);
 311                 }
 312                 printk("imm: ECP sync failed as data still present in FIFO.\n");
 313         }
 314 }
 315
 316 static int imm_byte_out(unsigned short base, const char *buffer, int len)
 317 {
 318         int i;
 319
 320         w_ctr(base, 0x4);       /* apparently a sane mode */
 321         for (i = len >> 1; i; i--) {
 322                 w_dtr(base, *buffer++);
 323                 w_ctr(base, 0x5);       /* Drop STROBE low */
 324                 w_dtr(base, *buffer++);
 325                 w_ctr(base, 0x0);       /* STROBE high + INIT low */
 326         }
 327         w_ctr(base, 0x4);       /* apparently a sane mode */
 328         return 1;               /* All went well - we hope! */
 329 }
 330
 331 static int imm_nibble_in(unsigned short base, char *buffer, int len)
 332 {
 333         unsigned char l;
 334         int i;
 335
 336         /*
 337          * The following is based on documented timing signals
 338          */
 339         w_ctr(base, 0x4);
 340         for (i = len; i; i--) {
 341                 w_ctr(base, 0x6);
 342                 l = (r_str(base) & 0xf0) >> 4;
 343                 w_ctr(base, 0x5);
 344                 *buffer++ = (r_str(base) & 0xf0) | l;
 345                 w_ctr(base, 0x4);
 346         }
 347         return 1;               /* All went well - we hope! */
 348 }
 349
 350 static int imm_byte_in(unsigned short base, char *buffer, int len)
 351 {
 352         int i;
 353
 354         /*
 355          * The following is based on documented timing signals
 356          */
 357         w_ctr(base, 0x4);
 358         for (i = len; i; i--) {
 359                 w_ctr(base, 0x26);
 360                 *buffer++ = r_dtr(base);
 361                 w_ctr(base, 0x25);
 362         }
 363         return 1;               /* All went well - we hope! */
 364 }
 365
 366 static int imm_out(imm_struct *dev, char *buffer, int len)
 367 {
 368         unsigned short ppb = dev->base;
 369         int r = imm_wait(dev);
 370
 371         /*
 372          * Make sure that:
 373          * a) the SCSI bus is BUSY (device still listening)
 374          * b) the device is listening
 375          */
 376         if ((r & 0x18) != 0x08) {
 377                 imm_fail(dev, DID_ERROR);
 378                 printk("IMM: returned SCSI status %2x\n", r);
 379                 return 0;
 380         }
 381         switch (dev->mode) {
 382         case IMM_EPP_32:
 383         case IMM_EPP_16:
 384         case IMM_EPP_8:
 385                 epp_reset(ppb);
 386                 w_ctr(ppb, 0x4);
 387 #ifdef CONFIG_SCSI_IZIP_EPP16
 388                 if (!(((long) buffer | len) & 0x01))
 389                         outsw(ppb + 4, buffer, len >> 1);
 390 #else
 391                 if (!(((long) buffer | len) & 0x03))
 392                         outsl(ppb + 4, buffer, len >> 2);
 393 #endif
 394                 else
 395                         outsb(ppb + 4, buffer, len);
 396                 w_ctr(ppb, 0xc);
 397                 r = !(r_str(ppb) & 0x01);
 398                 w_ctr(ppb, 0xc);
 399                 ecp_sync(dev);
 400                 break;
 401
 402         case IMM_NIBBLE:
 403         case IMM_PS2:
 404                 /* 8 bit output, with a loop */
 405                 r = imm_byte_out(ppb, buffer, len);
 406                 break;
 407
 408         default:
 409                 printk("IMM: bug in imm_out()\n");
 410                 r = 0;
 411         }
 412         return r;
 413 }
 414
 415 static int imm_in(imm_struct *dev, char *buffer, int len)
 416 {
 417         unsigned short ppb = dev->base;
 418         int r = imm_wait(dev);
 419
 420         /*
 421          * Make sure that:
 422          * a) the SCSI bus is BUSY (device still listening)
 423          * b) the device is sending data
 424          */
 425         if ((r & 0x18) != 0x18) {
 426                 imm_fail(dev, DID_ERROR);
 427                 return 0;
 428         }
 429         switch (dev->mode) {
 430         case IMM_NIBBLE:
 431                 /* 4 bit input, with a loop */
 432                 r = imm_nibble_in(ppb, buffer, len);
 433                 w_ctr(ppb, 0xc);
 434                 break;
 435
 436         case IMM_PS2:
 437                 /* 8 bit input, with a loop */
 438                 r = imm_byte_in(ppb, buffer, len);
 439                 w_ctr(ppb, 0xc);
 440                 break;
 441
 442         case IMM_EPP_32:
 443         case IMM_EPP_16:
 444         case IMM_EPP_8:
 445                 epp_reset(ppb);
 446                 w_ctr(ppb, 0x24);
 447 #ifdef CONFIG_SCSI_IZIP_EPP16
 448                 if (!(((long) buffer | len) & 0x01))
 449                         insw(ppb + 4, buffer, len >> 1);
 450 #else
 451                 if (!(((long) buffer | len) & 0x03))
 452                         insl(ppb + 4, buffer, len >> 2);
 453 #endif
 454                 else
 455                         insb(ppb + 4, buffer, len);
 456                 w_ctr(ppb, 0x2c);
 457                 r = !(r_str(ppb) & 0x01);
 458                 w_ctr(ppb, 0x2c);
 459                 ecp_sync(dev);
 460                 break;
 461
 462         default:
 463                 printk("IMM: bug in imm_ins()\n");
 464                 r = 0;
 465                 break;
 466         }
 467         return r;
 468 }
 469
 470 static int imm_cpp(unsigned short ppb, unsigned char b)
 471 {
 472         /*
 473          * Comments on udelay values refer to the
 474          * Command Packet Protocol (CPP) timing diagram.
 475          */
 476
 477         unsigned char s1, s2, s3;
 478         w_ctr(ppb, 0x0c);
 479         udelay(2);              /* 1 usec - infinite */
 480         w_dtr(ppb, 0xaa);
 481         udelay(10);             /* 7 usec - infinite */
 482         w_dtr(ppb, 0x55);
 483         udelay(10);             /* 7 usec - infinite */
 484         w_dtr(ppb, 0x00);
 485         udelay(10);             /* 7 usec - infinite */
 486         w_dtr(ppb, 0xff);
 487         udelay(10);             /* 7 usec - infinite */
 488         s1 = r_str(ppb) & 0xb8;
 489         w_dtr(ppb, 0x87);
 490         udelay(10);             /* 7 usec - infinite */
 491         s2 = r_str(ppb) & 0xb8;
 492         w_dtr(ppb, 0x78);
 493         udelay(10);             /* 7 usec - infinite */
 494         s3 = r_str(ppb) & 0x38;
 495         /*
 496          * Values for b are:
 497          * 0000 00aa    Assign address aa to current device
 498          * 0010 00aa    Select device aa in EPP Winbond mode
 499          * 0010 10aa    Select device aa in EPP mode
 500          * 0011 xxxx    Deselect all devices
 501          * 0110 00aa    Test device aa
 502          * 1101 00aa    Select device aa in ECP mode
 503          * 1110 00aa    Select device aa in Compatible mode
 504          */
 505         w_dtr(ppb, b);
 506         udelay(2);              /* 1 usec - infinite */
 507         w_ctr(ppb, 0x0c);
 508         udelay(10);             /* 7 usec - infinite */
 509         w_ctr(ppb, 0x0d);
 510         udelay(2);              /* 1 usec - infinite */
 511         w_ctr(ppb, 0x0c);
 512         udelay(10);             /* 7 usec - infinite */
 513         w_dtr(ppb, 0xff);
 514         udelay(10);             /* 7 usec - infinite */
 515
 516         /*
 517          * The following table is electrical pin values.
 518          * (BSY is inverted at the CTR register)
 519          *
 520          *       BSY  ACK  POut SEL  Fault
 521          * S1    0    X    1    1    1
 522          * S2    1    X    0    1    1
 523          * S3    L    X    1    1    S
 524          *
 525          * L => Last device in chain
 526          * S => Selected
 527          *
 528          * Observered values for S1,S2,S3 are:
 529          * Disconnect => f8/58/78
 530          * Connect    => f8/58/70
 531          */
 532         if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x30))
 533                 return 1;       /* Connected */
 534         if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x38))
 535                 return 0;       /* Disconnected */
 536
 537         return -1;              /* No device present */
 538 }
 539
 540 static inline int imm_connect(imm_struct *dev, int flag)
 541 {
 542         unsigned short ppb = dev->base;
 543
 544         imm_cpp(ppb, 0xe0);     /* Select device 0 in compatible mode */
 545         imm_cpp(ppb, 0x30);     /* Disconnect all devices */
 546
 547         if ((dev->mode == IMM_EPP_8) ||
 548             (dev->mode == IMM_EPP_16) ||
 549             (dev->mode == IMM_EPP_32))
 550                 return imm_cpp(ppb, 0x28);      /* Select device 0 in EPP mode */
 551         return imm_cpp(ppb, 0xe0);      /* Select device 0 in compatible mode */
 552 }
 553
 554 static void imm_disconnect(imm_struct *dev)
 555 {
 556         imm_cpp(dev->base, 0x30);       /* Disconnect all devices */
 557 }
 558
 559 static int imm_select(imm_struct *dev, int target)
 560 {
 561         int k;
 562         unsigned short ppb = dev->base;
 563
 564         /*
 565          * Firstly we want to make sure there is nothing
 566          * holding onto the SCSI bus.
 567          */
 568         w_ctr(ppb, 0xc);
 569
 570         k = IMM_SELECT_TMO;
 571         do {
 572                 k--;
 573         } while ((r_str(ppb) & 0x08) && (k));
 574
 575         if (!k)
 576                 return 0;
 577
 578         /*
 579          * Now assert the SCSI ID (HOST and TARGET) on the data bus
 580          */
 581         w_ctr(ppb, 0x4);
 582         w_dtr(ppb, 0x80 | (1 << target));
 583         udelay(1);
 584
 585         /*
 586          * Deassert SELIN first followed by STROBE
 587          */
 588         w_ctr(ppb, 0xc);
 589         w_ctr(ppb, 0xd);
 590
 591         /*
 592          * ACK should drop low while SELIN is deasserted.
 593          * FAULT should drop low when the SCSI device latches the bus.
 594          */
 595         k = IMM_SELECT_TMO;
 596         do {
 597                 k--;
 598         }
 599         while (!(r_str(ppb) & 0x08) && (k));
 600
 601         /*
 602          * Place the interface back into a sane state (status mode)
 603          */
 604         w_ctr(ppb, 0xc);
 605         return (k) ? 1 : 0;
 606 }
 607
 608 static int imm_init(imm_struct *dev)
 609 {
 610         if (imm_connect(dev, 0) != 1)
 611                 return -EIO;
 612         imm_reset_pulse(dev->base);
 613         udelay(1000);   /* Delay to allow devices to settle */
 614         imm_disconnect(dev);
 615         udelay(1000);   /* Another delay to allow devices to settle */
 616         return device_check(dev);
 617 }
 618
 619 static inline int imm_send_command(struct scsi_cmnd *cmd)
 620 {
 621         imm_struct *dev = imm_dev(cmd->device->host);
 622         int k;
 623
 624         /* NOTE: IMM uses byte pairs */
 625         for (k = 0; k < cmd->cmd_len; k += 2)
 626                 if (!imm_out(dev, &cmd->cmnd[k], 2))
 627                         return 0;
 628         return 1;
 629 }
 630
 631 /*
 632  * The bulk flag enables some optimisations in the data transfer loops,
 633  * it should be true for any command that transfers data in integral
 634  * numbers of sectors.
 635  *
 636  * The driver appears to remain stable if we speed up the parallel port
 637  * i/o in this function, but not elsewhere.
 638  */
 639 static int imm_completion(struct scsi_cmnd *cmd)
 640 {
 641         /* Return codes:
 642          * -1     Error
 643          *  0     Told to schedule
 644          *  1     Finished data transfer
 645          */
 646         imm_struct *dev = imm_dev(cmd->device->host);
 647         unsigned short ppb = dev->base;
 648         unsigned long start_jiffies = jiffies;
 649
 650         unsigned char r, v;
 651         int fast, bulk, status;
 652
 653         v = cmd->cmnd[0];
 654         bulk = ((v == READ_6) ||
 655                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 656
 657         /*
 658          * We only get here if the drive is ready to comunicate,
 659          * hence no need for a full imm_wait.
 660          */
 661         w_ctr(ppb, 0x0c);
 662         r = (r_str(ppb) & 0xb8);
 663
 664         /*
 665          * while (device is not ready to send status byte)
 666          *     loop;
 667          */
 668         while (r != (unsigned char) 0xb8) {
 669                 /*
 670                  * If we have been running for more than a full timer tick
 671                  * then take a rest.
 672                  */
 673                 if (time_after(jiffies, start_jiffies + 1))
 674                         return 0;
 675
 676                 /*
 677                  * FAIL if:
 678                  * a) Drive status is screwy (!ready && !present)
 679                  * b) Drive is requesting/sending more data than expected
 680                  */
 681                 if (((r & 0x88) != 0x88) || (cmd->SCp.this_residual <= 0)) {
 682                         imm_fail(dev, DID_ERROR);
 683                         return -1;      /* ERROR_RETURN */
 684                 }
 685                 /* determine if we should use burst I/O */
 686                 if (dev->rd == 0) {
 687                         fast = (bulk
 688                                 && (cmd->SCp.this_residual >=
 689                                     IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 2;
 690                         status = imm_out(dev, cmd->SCp.ptr, fast);
 691                 } else {
 692                         fast = (bulk
 693                                 && (cmd->SCp.this_residual >=
 694                                     IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 1;
 695                         status = imm_in(dev, cmd->SCp.ptr, fast);
 696                 }
 697
 698                 cmd->SCp.ptr += fast;
 699                 cmd->SCp.this_residual -= fast;
 700
 701                 if (!status) {
 702                         imm_fail(dev, DID_BUS_BUSY);
 703                         return -1;      /* ERROR_RETURN */
 704                 }
 705                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 706                         /* if scatter/gather, advance to the next segment */
 707                         if (cmd->SCp.buffers_residual--) {
 708                                 cmd->SCp.buffer++;
 709                                 cmd->SCp.this_residual =
 710                                     cmd->SCp.buffer->length;
 711                                 cmd->SCp.ptr =
 712                                     page_address(cmd->SCp.buffer->page) +
 713                                     cmd->SCp.buffer->offset;
 714
 715                                 /*
 716                                  * Make sure that we transfer even number of bytes
 717                                  * otherwise it makes imm_byte_out() messy.
 718                                  */
 719                                 if (cmd->SCp.this_residual & 0x01)
 720                                         cmd->SCp.this_residual++;
 721                         }
 722                 }
 723                 /* Now check to see if the drive is ready to comunicate */
 724                 w_ctr(ppb, 0x0c);
 725                 r = (r_str(ppb) & 0xb8);
 726
 727                 /* If not, drop back down to the scheduler and wait a timer tick */
 728                 if (!(r & 0x80))
 729                         return 0;
 730         }
 731         return 1;               /* FINISH_RETURN */
 732 }
 733
 734 /*
 735  * Since the IMM itself doesn't generate interrupts, we use
 736  * the scheduler's task queue to generate a stream of call-backs and
 737  * complete the request when the drive is ready.
 738  */
 739 static void imm_interrupt(void *data)
 740 {
 741         imm_struct *dev = (imm_struct *) data;
 742         struct scsi_cmnd *cmd = dev->cur_cmd;
 743         struct Scsi_Host *host = cmd->device->host;
 744         unsigned long flags;
 745
 746         if (!cmd) {
 747                 printk("IMM: bug in imm_interrupt\n");
 748                 return;
 749         }
 750         if (imm_engine(dev, cmd)) {
 751                 INIT_WORK(&dev->imm_tq, imm_interrupt, (void *) dev);
 752                 schedule_delayed_work(&dev->imm_tq, 1);
 753                 return;
 754         }
 755         /* Command must of completed hence it is safe to let go... */
 756 #if IMM_DEBUG > 0
 757         switch ((cmd->result >> 16) & 0xff) {
 758         case DID_OK:
 759                 break;
 760         case DID_NO_CONNECT:
 761                 printk("imm: no device at SCSI ID %i\n", cmd->device->id);
 762                 break;
 763         case DID_BUS_BUSY:
 764                 printk("imm: BUS BUSY - EPP timeout detected\n");
 765                 break;
 766         case DID_TIME_OUT:
 767                 printk("imm: unknown timeout\n");
 768                 break;
 769         case DID_ABORT:
 770                 printk("imm: told to abort\n");
 771                 break;
 772         case DID_PARITY:
 773                 printk("imm: parity error (???)\n");
 774                 break;
 775         case DID_ERROR:
 776                 printk("imm: internal driver error\n");
 777                 break;
 778         case DID_RESET:
 779                 printk("imm: told to reset device\n");
 780                 break;
 781         case DID_BAD_INTR:
 782                 printk("imm: bad interrupt (???)\n");
 783                 break;
 784         default:
 785                 printk("imm: bad return code (%02x)\n",
 786                        (cmd->result >> 16) & 0xff);
 787         }
 788 #endif
 789
 790         if (cmd->SCp.phase > 1)
 791                 imm_disconnect(dev);
 792
 793         imm_pb_dismiss(dev);
 794
 795         spin_lock_irqsave(host->host_lock, flags);
 796         dev->cur_cmd = NULL;
 797         cmd->scsi_done(cmd);
 798         spin_unlock_irqrestore(host->host_lock, flags);
 799         return;
 800 }
 801
 802 static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
 803 {
 804         unsigned short ppb = dev->base;
 805         unsigned char l = 0, h = 0;
 806         int retv, x;
 807
 808         /* First check for any errors that may have occurred
 809          * Here we check for internal errors
 810          */
 811         if (dev->failed)
 812                 return 0;
 813
 814         switch (cmd->SCp.phase) {
 815         case 0:         /* Phase 0 - Waiting for parport */
 816                 if (time_after(jiffies, dev->jstart + HZ)) {
 817                         /*
 818                          * We waited more than a second
 819                          * for parport to call us
 820                          */
 821                         imm_fail(dev, DID_BUS_BUSY);
 822                         return 0;
 823                 }
 824                 return 1;       /* wait until imm_wakeup claims parport */
 825                 /* Phase 1 - Connected */
 826         case 1:
 827                 imm_connect(dev, CONNECT_EPP_MAYBE);
 828                 cmd->SCp.phase++;
 829
 830                 /* Phase 2 - We are now talking to the scsi bus */
 831         case 2:
 832                 if (!imm_select(dev, cmd->device->id)) {
 833                         imm_fail(dev, DID_NO_CONNECT);
 834                         return 0;
 835                 }
 836                 cmd->SCp.phase++;
 837
 838                 /* Phase 3 - Ready to accept a command */
 839         case 3:
 840                 w_ctr(ppb, 0x0c);
 841                 if (!(r_str(ppb) & 0x80))
 842                         return 1;
 843
 844                 if (!imm_send_command(cmd))
 845                         return 0;
 846                 cmd->SCp.phase++;
 847
 848                 /* Phase 4 - Setup scatter/gather buffers */
 849         case 4:
 850                 if (cmd->use_sg) {
 851                         /* if many buffers are available, start filling the first */
 852                         cmd->SCp.buffer =
 853                             (struct scatterlist *) cmd->request_buffer;
 854                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 855                         cmd->SCp.ptr =
 856                             page_address(cmd->SCp.buffer->page) +
 857                             cmd->SCp.buffer->offset;
 858                 } else {
 859                         /* else fill the only available buffer */
 860                         cmd->SCp.buffer = NULL;
 861                         cmd->SCp.this_residual = cmd->request_bufflen;
 862                         cmd->SCp.ptr = cmd->request_buffer;
 863                 }
 864                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
 865                 cmd->SCp.phase++;
 866                 if (cmd->SCp.this_residual & 0x01)
 867                         cmd->SCp.this_residual++;
 868                 /* Phase 5 - Pre-Data transfer stage */
 869         case 5:
 870                 /* Spin lock for BUSY */
 871                 w_ctr(ppb, 0x0c);
 872                 if (!(r_str(ppb) & 0x80))
 873                         return 1;
 874
 875                 /* Require negotiation for read requests */
 876                 x = (r_str(ppb) & 0xb8);
 877                 dev->rd = (x & 0x10) ? 1 : 0;
 878                 dev->dp = (x & 0x20) ? 0 : 1;
 879
 880                 if ((dev->dp) && (dev->rd))
 881                         if (imm_negotiate(dev))
 882                                 return 0;
 883                 cmd->SCp.phase++;
 884
 885                 /* Phase 6 - Data transfer stage */
 886         case 6:
 887                 /* Spin lock for BUSY */
 888                 w_ctr(ppb, 0x0c);
 889                 if (!(r_str(ppb) & 0x80))
 890                         return 1;
 891
 892                 if (dev->dp) {
 893                         retv = imm_completion(cmd);
 894                         if (retv == -1)
 895                                 return 0;
 896                         if (retv == 0)
 897                                 return 1;
 898                 }
 899                 cmd->SCp.phase++;
 900
 901                 /* Phase 7 - Post data transfer stage */
 902         case 7:
 903                 if ((dev->dp) && (dev->rd)) {
 904                         if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
 905                                 w_ctr(ppb, 0x4);
 906                                 w_ctr(ppb, 0xc);
 907                                 w_ctr(ppb, 0xe);
 908                                 w_ctr(ppb, 0x4);
 909                         }
 910                 }
 911                 cmd->SCp.phase++;
 912
 913                 /* Phase 8 - Read status/message */
 914         case 8:
 915                 /* Check for data overrun */
 916                 if (imm_wait(dev) != (unsigned char) 0xb8) {
 917                         imm_fail(dev, DID_ERROR);
 918                         return 0;
 919                 }
 920                 if (imm_negotiate(dev))
 921                         return 0;
 922                 if (imm_in(dev, &l, 1)) {       /* read status byte */
 923                         /* Check for optional message byte */
 924                         if (imm_wait(dev) == (unsigned char) 0xb8)
 925                                 imm_in(dev, &h, 1);
 926                         cmd->result = (DID_OK << 16) + (l & STATUS_MASK);
 927                 }
 928                 if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
 929                         w_ctr(ppb, 0x4);
 930                         w_ctr(ppb, 0xc);
 931                         w_ctr(ppb, 0xe);
 932                         w_ctr(ppb, 0x4);
 933                 }
 934                 return 0;       /* Finished */
 935                 break;
 936
 937         default:
 938                 printk("imm: Invalid scsi phase\n");
 939         }
 940         return 0;
 941 }
 942
 943 static int imm_queuecommand(struct scsi_cmnd *cmd,
 944                 void (*done)(struct scsi_cmnd *))
 945 {
 946         imm_struct *dev = imm_dev(cmd->device->host);
 947
 948         if (dev->cur_cmd) {
 949                 printk("IMM: bug in imm_queuecommand\n");
 950                 return 0;
 951         }
 952         dev->failed = 0;
 953         dev->jstart = jiffies;
 954         dev->cur_cmd = cmd;
 955         cmd->scsi_done = done;
 956         cmd->result = DID_ERROR << 16;  /* default return code */
 957         cmd->SCp.phase = 0;     /* bus free */
 958
 959         INIT_WORK(&dev->imm_tq, imm_interrupt, dev);
 960         schedule_work(&dev->imm_tq);
 961
 962         imm_pb_claim(dev);
 963
 964         return 0;
 965 }
 966
 967 /*
 968  * Apparently the disk->capacity attribute is off by 1 sector
 969  * for all disk drives.  We add the one here, but it should really
 970  * be done in sd.c.  Even if it gets fixed there, this will still
 971  * work.
 972  */
 973 static int imm_biosparam(struct scsi_device *sdev, struct block_device *dev,
 974                          sector_t capacity, int ip[])
 975 {
 976         ip[0] = 0x40;
 977         ip[1] = 0x20;
 978         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 979         if (ip[2] > 1024) {
 980                 ip[0] = 0xff;
 981                 ip[1] = 0x3f;
 982                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 983         }
 984         return 0;
 985 }
 986
 987 static int imm_abort(struct scsi_cmnd *cmd)
 988 {
 989         imm_struct *dev = imm_dev(cmd->device->host);
 990         /*
 991          * There is no method for aborting commands since Iomega
 992          * have tied the SCSI_MESSAGE line high in the interface
 993          */
 994
 995         switch (cmd->SCp.phase) {
 996         case 0:         /* Do not have access to parport */
 997         case 1:         /* Have not connected to interface */
 998                 dev->cur_cmd = NULL;    /* Forget the problem */
 999                 return SUCCESS;
1000                 break;
1001         default:                /* SCSI command sent, can not abort */
1002                 return FAILED;
1003                 break;
1004         }
1005 }
1006
1007 static void imm_reset_pulse(unsigned int base)
1008 {
1009         w_ctr(base, 0x04);
1010         w_dtr(base, 0x40);
1011         udelay(1);
1012         w_ctr(base, 0x0c);
1013         w_ctr(base, 0x0d);
1014         udelay(50);
1015         w_ctr(base, 0x0c);
1016         w_ctr(base, 0x04);
1017 }
1018
1019 static int imm_reset(struct scsi_cmnd *cmd)
1020 {
1021         imm_struct *dev = imm_dev(cmd->device->host);
1022
1023         if (cmd->SCp.phase)
1024                 imm_disconnect(dev);
1025         dev->cur_cmd = NULL;    /* Forget the problem */
1026
1027         imm_connect(dev, CONNECT_NORMAL);
1028         imm_reset_pulse(dev->base);
1029         udelay(1000);           /* device settle delay */
1030         imm_disconnect(dev);
1031         udelay(1000);           /* device settle delay */
1032         return SUCCESS;
1033 }
1034
1035 static int device_check(imm_struct *dev)
1036 {
1037         /* This routine looks for a device and then attempts to use EPP
1038            to send a command. If all goes as planned then EPP is available. */
1039
1040         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
1041         int loop, old_mode, status, k, ppb = dev->base;
1042         unsigned char l;
1043
1044         old_mode = dev->mode;
1045         for (loop = 0; loop < 8; loop++) {
1046                 /* Attempt to use EPP for Test Unit Ready */
1047                 if ((ppb & 0x0007) == 0x0000)
1048                         dev->mode = IMM_EPP_32;
1049
1050               second_pass:
1051                 imm_connect(dev, CONNECT_EPP_MAYBE);
1052                 /* Select SCSI device */
1053                 if (!imm_select(dev, loop)) {
1054                         imm_disconnect(dev);
1055                         continue;
1056                 }
1057                 printk("imm: Found device at ID %i, Attempting to use %s\n",
1058                        loop, IMM_MODE_STRING[dev->mode]);
1059
1060                 /* Send SCSI command */
1061                 status = 1;
1062                 w_ctr(ppb, 0x0c);
1063                 for (l = 0; (l < 3) && (status); l++)
1064                         status = imm_out(dev, &cmd[l << 1], 2);
1065
1066                 if (!status) {
1067                         imm_disconnect(dev);
1068                         imm_connect(dev, CONNECT_EPP_MAYBE);
1069                         imm_reset_pulse(dev->base);
1070                         udelay(1000);
1071                         imm_disconnect(dev);
1072                         udelay(1000);
1073                         if (dev->mode == IMM_EPP_32) {
1074                                 dev->mode = old_mode;
1075                                 goto second_pass;
1076                         }
1077                         printk("imm: Unable to establish communication\n");
1078                         return -EIO;
1079                 }
1080                 w_ctr(ppb, 0x0c);
1081
1082                 k = 1000000;    /* 1 Second */
1083                 do {
1084                         l = r_str(ppb);
1085                         k--;
1086                         udelay(1);
1087                 } while (!(l & 0x80) && (k));
1088
1089                 l &= 0xb8;
1090
1091                 if (l != 0xb8) {
1092                         imm_disconnect(dev);
1093                         imm_connect(dev, CONNECT_EPP_MAYBE);
1094                         imm_reset_pulse(dev->base);
1095                         udelay(1000);
1096                         imm_disconnect(dev);
1097                         udelay(1000);
1098                         if (dev->mode == IMM_EPP_32) {
1099                                 dev->mode = old_mode;
1100                                 goto second_pass;
1101                         }
1102                         printk
1103                             ("imm: Unable to establish communication\n");
1104                         return -EIO;
1105                 }
1106                 imm_disconnect(dev);
1107                 printk
1108                     ("imm: Communication established at 0x%x with ID %i using %s\n",
1109                      ppb, loop, IMM_MODE_STRING[dev->mode]);
1110                 imm_connect(dev, CONNECT_EPP_MAYBE);
1111                 imm_reset_pulse(dev->base);
1112                 udelay(1000);
1113                 imm_disconnect(dev);
1114                 udelay(1000);
1115                 return 0;
1116         }
1117         printk("imm: No devices found\n");
1118         return -ENODEV;
1119 }
1120
1121 static int imm_adjust_queue(struct scsi_device *device)
1122 {
1123         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
1124         return 0;
1125 }
1126
1127 static struct scsi_host_template imm_template = {
1128         .module                 = THIS_MODULE,
1129         .proc_name              = "imm",
1130         .proc_info              = imm_proc_info,
1131         .name                   = "Iomega VPI2 (imm) interface",
1132         .queuecommand           = imm_queuecommand,
1133         .eh_abort_handler       = imm_abort,
1134         .eh_bus_reset_handler   = imm_reset,
1135         .eh_host_reset_handler  = imm_reset,
1136         .bios_param             = imm_biosparam,
1137         .this_id                = 7,
1138         .sg_tablesize           = SG_ALL,
1139         .cmd_per_lun            = 1,
1140         .use_clustering         = ENABLE_CLUSTERING,
1141         .can_queue              = 1,
1142         .slave_alloc            = imm_adjust_queue,
1143         .unchecked_isa_dma      = 1, /* imm cannot deal with highmem, so
1144                                       * this is an easy trick to ensure
1145                                       * all io pages for this host reside
1146                                       * in low memory */
1147 };
1148
1149 /***************************************************************************
1150  *                   Parallel port probing routines                        *
1151  ***************************************************************************/
1152
1153 static LIST_HEAD(imm_hosts);
1154
1155 static int __imm_attach(struct parport *pb)
1156 {
1157         struct Scsi_Host *host;
1158         imm_struct *dev;
1159         DECLARE_WAIT_QUEUE_HEAD(waiting);
1160         DEFINE_WAIT(wait);
1161         int ports;
1162         int modes, ppb;
1163         int err = -ENOMEM;
1164
1165         init_waitqueue_head(&waiting);
1166
1167         dev = kmalloc(sizeof(imm_struct), GFP_KERNEL);
1168         if (!dev)
1169                 return -ENOMEM;
1170
1171         memset(dev, 0, sizeof(imm_struct));
1172
1173         dev->base = -1;
1174         dev->mode = IMM_AUTODETECT;
1175         INIT_LIST_HEAD(&dev->list);
1176
1177         dev->dev = parport_register_device(pb, "imm", NULL, imm_wakeup,
1178                                                 NULL, 0, dev);
1179
1180         if (!dev->dev)
1181                 goto out;
1182
1183
1184         /* Claim the bus so it remembers what we do to the control
1185          * registers. [ CTR and ECP ]
1186          */
1187         err = -EBUSY;
1188         dev->waiting = &waiting;
1189         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1190         if (imm_pb_claim(dev))
1191                 schedule_timeout(3 * HZ);
1192         if (dev->wanted) {
1193                 printk(KERN_ERR "imm%d: failed to claim parport because "
1194                         "a pardevice is owning the port for too long "
1195                         "time!\n", pb->number);
1196                 imm_pb_dismiss(dev);
1197                 dev->waiting = NULL;
1198                 finish_wait(&waiting, &wait);
1199                 goto out1;
1200         }
1201         dev->waiting = NULL;
1202         finish_wait(&waiting, &wait);
1203         ppb = dev->base = dev->dev->port->base;
1204         dev->base_hi = dev->dev->port->base_hi;
1205         w_ctr(ppb, 0x0c);
1206         modes = dev->dev->port->modes;
1207
1208         /* Mode detection works up the chain of speed
1209          * This avoids a nasty if-then-else-if-... tree
1210          */
1211         dev->mode = IMM_NIBBLE;
1212
1213         if (modes & PARPORT_MODE_TRISTATE)
1214                 dev->mode = IMM_PS2;
1215
1216         /* Done configuration */
1217
1218         err = imm_init(dev);
1219
1220         imm_pb_release(dev);
1221
1222         if (err)
1223                 goto out1;
1224
1225         /* now the glue ... */
1226         if (dev->mode == IMM_NIBBLE || dev->mode == IMM_PS2)
1227                 ports = 3;
1228         else
1229                 ports = 8;
1230
1231         INIT_WORK(&dev->imm_tq, imm_interrupt, dev);
1232
1233         err = -ENOMEM;
1234         host = scsi_host_alloc(&imm_template, sizeof(imm_struct *));
1235         if (!host)
1236                 goto out1;
1237         host->io_port = pb->base;
1238         host->n_io_port = ports;
1239         host->dma_channel = -1;
1240         host->unique_id = pb->number;
1241         *(imm_struct **)&host->hostdata = dev;
1242         dev->host = host;
1243         list_add_tail(&dev->list, &imm_hosts);
1244         err = scsi_add_host(host, NULL);
1245         if (err)
1246                 goto out2;
1247         scsi_scan_host(host);
1248         return 0;
1249
1250 out2:
1251         list_del_init(&dev->list);
1252         scsi_host_put(host);
1253 out1:
1254         parport_unregister_device(dev->dev);
1255 out:
1256         kfree(dev);
1257         return err;
1258 }
1259
1260 static void imm_attach(struct parport *pb)
1261 {
1262         __imm_attach(pb);
1263 }
1264
1265 static void imm_detach(struct parport *pb)
1266 {
1267         imm_struct *dev;
1268         list_for_each_entry(dev, &imm_hosts, list) {
1269                 if (dev->dev->port == pb) {
1270                         list_del_init(&dev->list);
1271                         scsi_remove_host(dev->host);
1272                         scsi_host_put(dev->host);
1273                         parport_unregister_device(dev->dev);
1274                         kfree(dev);
1275                         break;
1276                 }
1277         }
1278 }
1279
1280 static struct parport_driver imm_driver = {
1281         .name   = "imm",
1282         .attach = imm_attach,
1283         .detach = imm_detach,
1284 };
1285
1286 static int __init imm_driver_init(void)
1287 {
1288         printk("imm: Version %s\n", IMM_VERSION);
1289         return parport_register_driver(&imm_driver);
1290 }
1291
1292 static void __exit imm_driver_exit(void)
1293 {
1294         parport_unregister_driver(&imm_driver);
1295 }
1296
1297 module_init(imm_driver_init);
1298 module_exit(imm_driver_exit);
1299
1300 MODULE_LICENSE("GPL");