drivers/scsi/ppa.c

   1 /* ppa.c   --  low level driver for the IOMEGA PPA3
   2  * parallel port SCSI host adapter.
   3  *
   4  * (The PPA3 is the embedded controller in the ZIP drive.)
   5  *
   6  * (c) 1995,1996 Grant R. Guenther, grant@torque.net,
   7  * under the terms of the GNU General Public License.
   8  *
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/module.h>
  15 #include <linux/blkdev.h>
  16 #include <linux/parport.h>
  17 #include <linux/workqueue.h>
  18 #include <linux/delay.h>
  19 #include <linux/jiffies.h>
  20 #include <asm/io.h>
  21
  22 #include <scsi/scsi.h>
  23 #include <scsi/scsi_cmnd.h>
  24 #include <scsi/scsi_device.h>
  25 #include <scsi/scsi_host.h>
  26
  27
  28 static void ppa_reset_pulse(unsigned int base);
  29
  30 typedef struct {
  31         struct pardevice *dev;  /* Parport device entry         */
  32         int base;               /* Actual port address          */
  33         int mode;               /* Transfer mode                */
  34         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  35         struct delayed_work ppa_tq;     /* Polling interrupt stuff       */
  36         unsigned long jstart;   /* Jiffies at start             */
  37         unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
  38         unsigned int failed:1;  /* Failure flag                 */
  39         unsigned wanted:1;      /* Parport sharing busy flag    */
  40         unsigned int dev_no;    /* Device number                */
  41         wait_queue_head_t *waiting;
  42         struct Scsi_Host *host;
  43         struct list_head list;
  44 } ppa_struct;
  45
  46 #include  "ppa.h"
  47
  48 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  49 {
  50         return *(ppa_struct **)&host->hostdata;
  51 }
  52
  53 static DEFINE_SPINLOCK(arbitration_lock);
  54
  55 static void got_it(ppa_struct *dev)
  56 {
  57         dev->base = dev->dev->port->base;
  58         if (dev->cur_cmd)
  59                 dev->cur_cmd->SCp.phase = 1;
  60         else
  61                 wake_up(dev->waiting);
  62 }
  63
  64 static void ppa_wakeup(void *ref)
  65 {
  66         ppa_struct *dev = (ppa_struct *) ref;
  67         unsigned long flags;
  68
  69         spin_lock_irqsave(&arbitration_lock, flags);
  70         if (dev->wanted) {
  71                 parport_claim(dev->dev);
  72                 got_it(dev);
  73                 dev->wanted = 0;
  74         }
  75         spin_unlock_irqrestore(&arbitration_lock, flags);
  76         return;
  77 }
  78
  79 static int ppa_pb_claim(ppa_struct *dev)
  80 {
  81         unsigned long flags;
  82         int res = 1;
  83         spin_lock_irqsave(&arbitration_lock, flags);
  84         if (parport_claim(dev->dev) == 0) {
  85                 got_it(dev);
  86                 res = 0;
  87         }
  88         dev->wanted = res;
  89         spin_unlock_irqrestore(&arbitration_lock, flags);
  90         return res;
  91 }
  92
  93 static void ppa_pb_dismiss(ppa_struct *dev)
  94 {
  95         unsigned long flags;
  96         int wanted;
  97         spin_lock_irqsave(&arbitration_lock, flags);
  98         wanted = dev->wanted;
  99         dev->wanted = 0;
 100         spin_unlock_irqrestore(&arbitration_lock, flags);
 101         if (!wanted)
 102                 parport_release(dev->dev);
 103 }
 104
 105 static inline void ppa_pb_release(ppa_struct *dev)
 106 {
 107         parport_release(dev->dev);
 108 }
 109
 110 /*
 111  * Start of Chipset kludges
 112  */
 113
 114 /* This is to give the ppa driver a way to modify the timings (and other
 115  * parameters) by writing to the /proc/scsi/ppa/0 file.
 116  * Very simple method really... (To simple, no error checking :( )
 117  * Reason: Kernel hackers HATE having to unload and reload modules for
 118  * testing...
 119  * Also gives a method to use a script to obtain optimum timings (TODO)
 120  */
 121
 122 static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
 123 {
 124         ppa_struct *dev = ppa_dev(host);
 125         unsigned long x;
 126
 127         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 128                 x = simple_strtoul(buffer + 5, NULL, 0);
 129                 dev->mode = x;
 130                 return length;
 131         }
 132         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 133                 x = simple_strtoul(buffer + 10, NULL, 0);
 134                 dev->recon_tmo = x;
 135                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 136                 return length;
 137         }
 138         printk(KERN_WARNING "ppa /proc: invalid variable\n");
 139         return -EINVAL;
 140 }
 141
 142 static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
 143 {
 144         ppa_struct *dev = ppa_dev(host);
 145
 146         seq_printf(m, "Version : %s\n", PPA_VERSION);
 147         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 148         seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
 149 #if PPA_DEBUG > 0
 150         seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
 151 #endif
 152         return 0;
 153 }
 154
 155 static int device_check(ppa_struct *dev);
 156
 157 #if PPA_DEBUG > 0
 158 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 159            y, __func__, __LINE__); ppa_fail_func(x,y);
 160 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 161 #else
 162 static inline void ppa_fail(ppa_struct *dev, int error_code)
 163 #endif
 164 {
 165         /* If we fail a device then we trash status / message bytes */
 166         if (dev->cur_cmd) {
 167                 dev->cur_cmd->result = error_code << 16;
 168                 dev->failed = 1;
 169         }
 170 }
 171
 172 /*
 173  * Wait for the high bit to be set.
 174  *
 175  * In principle, this could be tied to an interrupt, but the adapter
 176  * doesn't appear to be designed to support interrupts.  We spin on
 177  * the 0x80 ready bit.
 178  */
 179 static unsigned char ppa_wait(ppa_struct *dev)
 180 {
 181         int k;
 182         unsigned short ppb = dev->base;
 183         unsigned char r;
 184
 185         k = PPA_SPIN_TMO;
 186         /* Wait for bit 6 and 7 - PJC */
 187         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 188                 udelay(1);
 189                 r = r_str(ppb);
 190         }
 191
 192         /*
 193          * return some status information.
 194          * Semantics: 0xc0 = ZIP wants more data
 195          *            0xd0 = ZIP wants to send more data
 196          *            0xe0 = ZIP is expecting SCSI command data
 197          *            0xf0 = end of transfer, ZIP is sending status
 198          */
 199         if (k)
 200                 return (r & 0xf0);
 201
 202         /* Counter expired - Time out occurred */
 203         ppa_fail(dev, DID_TIME_OUT);
 204         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 205         return 0;               /* command timed out */
 206 }
 207
 208 /*
 209  * Clear EPP Timeout Bit
 210  */
 211 static inline void epp_reset(unsigned short ppb)
 212 {
 213         int i;
 214
 215         i = r_str(ppb);
 216         w_str(ppb, i);
 217         w_str(ppb, i & 0xfe);
 218 }
 219
 220 /*
 221  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 222  */
 223 static inline void ecp_sync(ppa_struct *dev)
 224 {
 225         int i, ppb_hi = dev->dev->port->base_hi;
 226
 227         if (ppb_hi == 0)
 228                 return;
 229
 230         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 231                 for (i = 0; i < 100; i++) {
 232                         if (r_ecr(ppb_hi) & 0x01)
 233                                 return;
 234                         udelay(5);
 235                 }
 236                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 237         }
 238 }
 239
 240 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 241 {
 242         int i;
 243
 244         for (i = len; i; i--) {
 245                 w_dtr(base, *buffer++);
 246                 w_ctr(base, 0xe);
 247                 w_ctr(base, 0xc);
 248         }
 249         return 1;               /* All went well - we hope! */
 250 }
 251
 252 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 253 {
 254         int i;
 255
 256         for (i = len; i; i--) {
 257                 *buffer++ = r_dtr(base);
 258                 w_ctr(base, 0x27);
 259                 w_ctr(base, 0x25);
 260         }
 261         return 1;               /* All went well - we hope! */
 262 }
 263
 264 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 265 {
 266         for (; len; len--) {
 267                 unsigned char h;
 268
 269                 w_ctr(base, 0x4);
 270                 h = r_str(base) & 0xf0;
 271                 w_ctr(base, 0x6);
 272                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 273         }
 274         return 1;               /* All went well - we hope! */
 275 }
 276
 277 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 278 {
 279         int r;
 280         unsigned short ppb = dev->base;
 281
 282         r = ppa_wait(dev);
 283
 284         if ((r & 0x50) != 0x40) {
 285                 ppa_fail(dev, DID_ERROR);
 286                 return 0;
 287         }
 288         switch (dev->mode) {
 289         case PPA_NIBBLE:
 290         case PPA_PS2:
 291                 /* 8 bit output, with a loop */
 292                 r = ppa_byte_out(ppb, buffer, len);
 293                 break;
 294
 295         case PPA_EPP_32:
 296         case PPA_EPP_16:
 297         case PPA_EPP_8:
 298                 epp_reset(ppb);
 299                 w_ctr(ppb, 0x4);
 300 #ifdef CONFIG_SCSI_IZIP_EPP16
 301                 if (!(((long) buffer | len) & 0x01))
 302                         outsw(ppb + 4, buffer, len >> 1);
 303 #else
 304                 if (!(((long) buffer | len) & 0x03))
 305                         outsl(ppb + 4, buffer, len >> 2);
 306 #endif
 307                 else
 308                         outsb(ppb + 4, buffer, len);
 309                 w_ctr(ppb, 0xc);
 310                 r = !(r_str(ppb) & 0x01);
 311                 w_ctr(ppb, 0xc);
 312                 ecp_sync(dev);
 313                 break;
 314
 315         default:
 316                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
 317                 r = 0;
 318         }
 319         return r;
 320 }
 321
 322 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 323 {
 324         int r;
 325         unsigned short ppb = dev->base;
 326
 327         r = ppa_wait(dev);
 328
 329         if ((r & 0x50) != 0x50) {
 330                 ppa_fail(dev, DID_ERROR);
 331                 return 0;
 332         }
 333         switch (dev->mode) {
 334         case PPA_NIBBLE:
 335                 /* 4 bit input, with a loop */
 336                 r = ppa_nibble_in(ppb, buffer, len);
 337                 w_ctr(ppb, 0xc);
 338                 break;
 339
 340         case PPA_PS2:
 341                 /* 8 bit input, with a loop */
 342                 w_ctr(ppb, 0x25);
 343                 r = ppa_byte_in(ppb, buffer, len);
 344                 w_ctr(ppb, 0x4);
 345                 w_ctr(ppb, 0xc);
 346                 break;
 347
 348         case PPA_EPP_32:
 349         case PPA_EPP_16:
 350         case PPA_EPP_8:
 351                 epp_reset(ppb);
 352                 w_ctr(ppb, 0x24);
 353 #ifdef CONFIG_SCSI_IZIP_EPP16
 354                 if (!(((long) buffer | len) & 0x01))
 355                         insw(ppb + 4, buffer, len >> 1);
 356 #else
 357                 if (!(((long) buffer | len) & 0x03))
 358                         insl(ppb + 4, buffer, len >> 2);
 359 #endif
 360                 else
 361                         insb(ppb + 4, buffer, len);
 362                 w_ctr(ppb, 0x2c);
 363                 r = !(r_str(ppb) & 0x01);
 364                 w_ctr(ppb, 0x2c);
 365                 ecp_sync(dev);
 366                 break;
 367
 368         default:
 369                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 370                 r = 0;
 371                 break;
 372         }
 373         return r;
 374 }
 375
 376 /* end of ppa_io.h */
 377 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 378 {
 379         w_dtr(ppb, b);
 380         w_ctr(ppb, 0xc);
 381         w_ctr(ppb, 0xe);
 382         w_ctr(ppb, 0xc);
 383         w_ctr(ppb, 0x4);
 384         w_ctr(ppb, 0xc);
 385 }
 386
 387 static void ppa_disconnect(ppa_struct *dev)
 388 {
 389         unsigned short ppb = dev->base;
 390
 391         ppa_d_pulse(ppb, 0);
 392         ppa_d_pulse(ppb, 0x3c);
 393         ppa_d_pulse(ppb, 0x20);
 394         ppa_d_pulse(ppb, 0xf);
 395 }
 396
 397 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 398 {
 399         w_dtr(ppb, b);
 400         w_ctr(ppb, 0x4);
 401         w_ctr(ppb, 0x6);
 402         w_ctr(ppb, 0x4);
 403         w_ctr(ppb, 0xc);
 404 }
 405
 406 static inline void ppa_connect(ppa_struct *dev, int flag)
 407 {
 408         unsigned short ppb = dev->base;
 409
 410         ppa_c_pulse(ppb, 0);
 411         ppa_c_pulse(ppb, 0x3c);
 412         ppa_c_pulse(ppb, 0x20);
 413         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 414                 ppa_c_pulse(ppb, 0xcf);
 415         else
 416                 ppa_c_pulse(ppb, 0x8f);
 417 }
 418
 419 static int ppa_select(ppa_struct *dev, int target)
 420 {
 421         int k;
 422         unsigned short ppb = dev->base;
 423
 424         /*
 425          * Bit 6 (0x40) is the device selected bit.
 426          * First we must wait till the current device goes off line...
 427          */
 428         k = PPA_SELECT_TMO;
 429         do {
 430                 k--;
 431                 udelay(1);
 432         } while ((r_str(ppb) & 0x40) && (k));
 433         if (!k)
 434                 return 0;
 435
 436         w_dtr(ppb, (1 << target));
 437         w_ctr(ppb, 0xe);
 438         w_ctr(ppb, 0xc);
 439         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 440         w_ctr(ppb, 0x8);
 441
 442         k = PPA_SELECT_TMO;
 443         do {
 444                 k--;
 445                 udelay(1);
 446         }
 447         while (!(r_str(ppb) & 0x40) && (k));
 448         if (!k)
 449                 return 0;
 450
 451         return 1;
 452 }
 453
 454 /*
 455  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 456  * I've tried several different kinds of parallel ports with guest and
 457  * coded this to react in the same ways that it does.
 458  *
 459  * The return value from this function is just a hint about where the
 460  * handshaking failed.
 461  *
 462  */
 463 static int ppa_init(ppa_struct *dev)
 464 {
 465         int retv;
 466         unsigned short ppb = dev->base;
 467
 468         ppa_disconnect(dev);
 469         ppa_connect(dev, CONNECT_NORMAL);
 470
 471         retv = 2;               /* Failed */
 472
 473         w_ctr(ppb, 0xe);
 474         if ((r_str(ppb) & 0x08) == 0x08)
 475                 retv--;
 476
 477         w_ctr(ppb, 0xc);
 478         if ((r_str(ppb) & 0x08) == 0x00)
 479                 retv--;
 480
 481         if (!retv)
 482                 ppa_reset_pulse(ppb);
 483         udelay(1000);           /* Allow devices to settle down */
 484         ppa_disconnect(dev);
 485         udelay(1000);           /* Another delay to allow devices to settle */
 486
 487         if (retv)
 488                 return -EIO;
 489
 490         return device_check(dev);
 491 }
 492
 493 static inline int ppa_send_command(struct scsi_cmnd *cmd)
 494 {
 495         ppa_struct *dev = ppa_dev(cmd->device->host);
 496         int k;
 497
 498         w_ctr(dev->base, 0x0c);
 499
 500         for (k = 0; k < cmd->cmd_len; k++)
 501                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 502                         return 0;
 503         return 1;
 504 }
 505
 506 /*
 507  * The bulk flag enables some optimisations in the data transfer loops,
 508  * it should be true for any command that transfers data in integral
 509  * numbers of sectors.
 510  *
 511  * The driver appears to remain stable if we speed up the parallel port
 512  * i/o in this function, but not elsewhere.
 513  */
 514 static int ppa_completion(struct scsi_cmnd *cmd)
 515 {
 516         /* Return codes:
 517          * -1     Error
 518          *  0     Told to schedule
 519          *  1     Finished data transfer
 520          */
 521         ppa_struct *dev = ppa_dev(cmd->device->host);
 522         unsigned short ppb = dev->base;
 523         unsigned long start_jiffies = jiffies;
 524
 525         unsigned char r, v;
 526         int fast, bulk, status;
 527
 528         v = cmd->cmnd[0];
 529         bulk = ((v == READ_6) ||
 530                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 531
 532         /*
 533          * We only get here if the drive is ready to comunicate,
 534          * hence no need for a full ppa_wait.
 535          */
 536         r = (r_str(ppb) & 0xf0);
 537
 538         while (r != (unsigned char) 0xf0) {
 539                 /*
 540                  * If we have been running for more than a full timer tick
 541                  * then take a rest.
 542                  */
 543                 if (time_after(jiffies, start_jiffies + 1))
 544                         return 0;
 545
 546                 if ((cmd->SCp.this_residual <= 0)) {
 547                         ppa_fail(dev, DID_ERROR);
 548                         return -1;      /* ERROR_RETURN */
 549                 }
 550
 551                 /* On some hardware we have SCSI disconnected (6th bit low)
 552                  * for about 100usecs. It is too expensive to wait a
 553                  * tick on every loop so we busy wait for no more than
 554                  * 500usecs to give the drive a chance first. We do not
 555                  * change things for "normal" hardware since generally
 556                  * the 6th bit is always high.
 557                  * This makes the CPU load higher on some hardware
 558                  * but otherwise we can not get more than 50K/secs
 559                  * on this problem hardware.
 560                  */
 561                 if ((r & 0xc0) != 0xc0) {
 562                         /* Wait for reconnection should be no more than
 563                          * jiffy/2 = 5ms = 5000 loops
 564                          */
 565                         unsigned long k = dev->recon_tmo;
 566                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 567                              k--)
 568                                 udelay(1);
 569
 570                         if (!k)
 571                                 return 0;
 572                 }
 573
 574                 /* determine if we should use burst I/O */
 575                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 576                     ? PPA_BURST_SIZE : 1;
 577
 578                 if (r == (unsigned char) 0xc0)
 579                         status = ppa_out(dev, cmd->SCp.ptr, fast);
 580                 else
 581                         status = ppa_in(dev, cmd->SCp.ptr, fast);
 582
 583                 cmd->SCp.ptr += fast;
 584                 cmd->SCp.this_residual -= fast;
 585
 586                 if (!status) {
 587                         ppa_fail(dev, DID_BUS_BUSY);
 588                         return -1;      /* ERROR_RETURN */
 589                 }
 590                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 591                         /* if scatter/gather, advance to the next segment */
 592                         if (cmd->SCp.buffers_residual--) {
 593                                 cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
 594                                 cmd->SCp.this_residual =
 595                                     cmd->SCp.buffer->length;
 596                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 597                         }
 598                 }
 599                 /* Now check to see if the drive is ready to comunicate */
 600                 r = (r_str(ppb) & 0xf0);
 601                 /* If not, drop back down to the scheduler and wait a timer tick */
 602                 if (!(r & 0x80))
 603                         return 0;
 604         }
 605         return 1;               /* FINISH_RETURN */
 606 }
 607
 608 /*
 609  * Since the PPA itself doesn't generate interrupts, we use
 610  * the scheduler's task queue to generate a stream of call-backs and
 611  * complete the request when the drive is ready.
 612  */
 613 static void ppa_interrupt(struct work_struct *work)
 614 {
 615         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 616         struct scsi_cmnd *cmd = dev->cur_cmd;
 617
 618         if (!cmd) {
 619                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 620                 return;
 621         }
 622         if (ppa_engine(dev, cmd)) {
 623                 schedule_delayed_work(&dev->ppa_tq, 1);
 624                 return;
 625         }
 626         /* Command must of completed hence it is safe to let go... */
 627 #if PPA_DEBUG > 0
 628         switch ((cmd->result >> 16) & 0xff) {
 629         case DID_OK:
 630                 break;
 631         case DID_NO_CONNECT:
 632                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
 633                 break;
 634         case DID_BUS_BUSY:
 635                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 636                 break;
 637         case DID_TIME_OUT:
 638                 printk(KERN_DEBUG "ppa: unknown timeout\n");
 639                 break;
 640         case DID_ABORT:
 641                 printk(KERN_DEBUG "ppa: told to abort\n");
 642                 break;
 643         case DID_PARITY:
 644                 printk(KERN_DEBUG "ppa: parity error (???)\n");
 645                 break;
 646         case DID_ERROR:
 647                 printk(KERN_DEBUG "ppa: internal driver error\n");
 648                 break;
 649         case DID_RESET:
 650                 printk(KERN_DEBUG "ppa: told to reset device\n");
 651                 break;
 652         case DID_BAD_INTR:
 653                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 654                 break;
 655         default:
 656                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 657                        (cmd->result >> 16) & 0xff);
 658         }
 659 #endif
 660
 661         if (cmd->SCp.phase > 1)
 662                 ppa_disconnect(dev);
 663
 664         ppa_pb_dismiss(dev);
 665
 666         dev->cur_cmd = NULL;
 667
 668         cmd->scsi_done(cmd);
 669 }
 670
 671 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 672 {
 673         unsigned short ppb = dev->base;
 674         unsigned char l = 0, h = 0;
 675         int retv;
 676
 677         /* First check for any errors that may of occurred
 678          * Here we check for internal errors
 679          */
 680         if (dev->failed)
 681                 return 0;
 682
 683         switch (cmd->SCp.phase) {
 684         case 0:         /* Phase 0 - Waiting for parport */
 685                 if (time_after(jiffies, dev->jstart + HZ)) {
 686                         /*
 687                          * We waited more than a second
 688                          * for parport to call us
 689                          */
 690                         ppa_fail(dev, DID_BUS_BUSY);
 691                         return 0;
 692                 }
 693                 return 1;       /* wait until ppa_wakeup claims parport */
 694         case 1:         /* Phase 1 - Connected */
 695                 {               /* Perform a sanity check for cable unplugged */
 696                         int retv = 2;   /* Failed */
 697
 698                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 699
 700                         w_ctr(ppb, 0xe);
 701                         if ((r_str(ppb) & 0x08) == 0x08)
 702                                 retv--;
 703
 704                         w_ctr(ppb, 0xc);
 705                         if ((r_str(ppb) & 0x08) == 0x00)
 706                                 retv--;
 707
 708                         if (retv) {
 709                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 710                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 711                                         ppa_fail(dev, DID_BUS_BUSY);
 712                                         return 0;
 713                                 } else {
 714                                         ppa_disconnect(dev);
 715                                         return 1;       /* Try again in a jiffy */
 716                                 }
 717                         }
 718                         cmd->SCp.phase++;
 719                 }
 720                 fallthrough;
 721
 722         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 723                 if (!ppa_select(dev, scmd_id(cmd))) {
 724                         ppa_fail(dev, DID_NO_CONNECT);
 725                         return 0;
 726                 }
 727                 cmd->SCp.phase++;
 728                 fallthrough;
 729
 730         case 3:         /* Phase 3 - Ready to accept a command */
 731                 w_ctr(ppb, 0x0c);
 732                 if (!(r_str(ppb) & 0x80))
 733                         return 1;
 734
 735                 if (!ppa_send_command(cmd))
 736                         return 0;
 737                 cmd->SCp.phase++;
 738                 fallthrough;
 739
 740         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 741                 if (scsi_bufflen(cmd)) {
 742                         cmd->SCp.buffer = scsi_sglist(cmd);
 743                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 744                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 745                 } else {
 746                         cmd->SCp.buffer = NULL;
 747                         cmd->SCp.this_residual = 0;
 748                         cmd->SCp.ptr = NULL;
 749                 }
 750                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 751                 cmd->SCp.phase++;
 752                 fallthrough;
 753
 754         case 5:         /* Phase 5 - Data transfer stage */
 755                 w_ctr(ppb, 0x0c);
 756                 if (!(r_str(ppb) & 0x80))
 757                         return 1;
 758
 759                 retv = ppa_completion(cmd);
 760                 if (retv == -1)
 761                         return 0;
 762                 if (retv == 0)
 763                         return 1;
 764                 cmd->SCp.phase++;
 765                 fallthrough;
 766
 767         case 6:         /* Phase 6 - Read status/message */
 768                 cmd->result = DID_OK << 16;
 769                 /* Check for data overrun */
 770                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
 771                         ppa_fail(dev, DID_ERROR);
 772                         return 0;
 773                 }
 774                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
 775                         /* Check for optional message byte */
 776                         if (ppa_wait(dev) == (unsigned char) 0xf0)
 777                                 ppa_in(dev, &h, 1);
 778                         cmd->result =
 779                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 780                 }
 781                 return 0;       /* Finished */
 782
 783         default:
 784                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
 785         }
 786         return 0;
 787 }
 788
 789 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
 790                 void (*done) (struct scsi_cmnd *))
 791 {
 792         ppa_struct *dev = ppa_dev(cmd->device->host);
 793
 794         if (dev->cur_cmd) {
 795                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 796                 return 0;
 797         }
 798         dev->failed = 0;
 799         dev->jstart = jiffies;
 800         dev->cur_cmd = cmd;
 801         cmd->scsi_done = done;
 802         cmd->result = DID_ERROR << 16;  /* default return code */
 803         cmd->SCp.phase = 0;     /* bus free */
 804
 805         schedule_delayed_work(&dev->ppa_tq, 0);
 806
 807         ppa_pb_claim(dev);
 808
 809         return 0;
 810 }
 811
 812 static DEF_SCSI_QCMD(ppa_queuecommand)
 813
 814 /*
 815  * Apparently the disk->capacity attribute is off by 1 sector
 816  * for all disk drives.  We add the one here, but it should really
 817  * be done in sd.c.  Even if it gets fixed there, this will still
 818  * work.
 819  */
 820 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 821               sector_t capacity, int ip[])
 822 {
 823         ip[0] = 0x40;
 824         ip[1] = 0x20;
 825         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 826         if (ip[2] > 1024) {
 827                 ip[0] = 0xff;
 828                 ip[1] = 0x3f;
 829                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 830                 if (ip[2] > 1023)
 831                         ip[2] = 1023;
 832         }
 833         return 0;
 834 }
 835
 836 static int ppa_abort(struct scsi_cmnd *cmd)
 837 {
 838         ppa_struct *dev = ppa_dev(cmd->device->host);
 839         /*
 840          * There is no method for aborting commands since Iomega
 841          * have tied the SCSI_MESSAGE line high in the interface
 842          */
 843
 844         switch (cmd->SCp.phase) {
 845         case 0:         /* Do not have access to parport */
 846         case 1:         /* Have not connected to interface */
 847                 dev->cur_cmd = NULL;    /* Forget the problem */
 848                 return SUCCESS;
 849         default:                /* SCSI command sent, can not abort */
 850                 return FAILED;
 851         }
 852 }
 853
 854 static void ppa_reset_pulse(unsigned int base)
 855 {
 856         w_dtr(base, 0x40);
 857         w_ctr(base, 0x8);
 858         udelay(30);
 859         w_ctr(base, 0xc);
 860 }
 861
 862 static int ppa_reset(struct scsi_cmnd *cmd)
 863 {
 864         ppa_struct *dev = ppa_dev(cmd->device->host);
 865
 866         if (cmd->SCp.phase)
 867                 ppa_disconnect(dev);
 868         dev->cur_cmd = NULL;    /* Forget the problem */
 869
 870         ppa_connect(dev, CONNECT_NORMAL);
 871         ppa_reset_pulse(dev->base);
 872         mdelay(1);              /* device settle delay */
 873         ppa_disconnect(dev);
 874         mdelay(1);              /* device settle delay */
 875         return SUCCESS;
 876 }
 877
 878 static int device_check(ppa_struct *dev)
 879 {
 880         /* This routine looks for a device and then attempts to use EPP
 881            to send a command. If all goes as planned then EPP is available. */
 882
 883         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 884         int loop, old_mode, status, k, ppb = dev->base;
 885         unsigned char l;
 886
 887         old_mode = dev->mode;
 888         for (loop = 0; loop < 8; loop++) {
 889                 /* Attempt to use EPP for Test Unit Ready */
 890                 if ((ppb & 0x0007) == 0x0000)
 891                         dev->mode = PPA_EPP_32;
 892
 893 second_pass:
 894                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 895                 /* Select SCSI device */
 896                 if (!ppa_select(dev, loop)) {
 897                         ppa_disconnect(dev);
 898                         continue;
 899                 }
 900                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
 901                        loop, PPA_MODE_STRING[dev->mode]);
 902
 903                 /* Send SCSI command */
 904                 status = 1;
 905                 w_ctr(ppb, 0x0c);
 906                 for (l = 0; (l < 6) && (status); l++)
 907                         status = ppa_out(dev, cmd, 1);
 908
 909                 if (!status) {
 910                         ppa_disconnect(dev);
 911                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 912                         w_dtr(ppb, 0x40);
 913                         w_ctr(ppb, 0x08);
 914                         udelay(30);
 915                         w_ctr(ppb, 0x0c);
 916                         udelay(1000);
 917                         ppa_disconnect(dev);
 918                         udelay(1000);
 919                         if (dev->mode == PPA_EPP_32) {
 920                                 dev->mode = old_mode;
 921                                 goto second_pass;
 922                         }
 923                         return -EIO;
 924                 }
 925                 w_ctr(ppb, 0x0c);
 926                 k = 1000000;    /* 1 Second */
 927                 do {
 928                         l = r_str(ppb);
 929                         k--;
 930                         udelay(1);
 931                 } while (!(l & 0x80) && (k));
 932
 933                 l &= 0xf0;
 934
 935                 if (l != 0xf0) {
 936                         ppa_disconnect(dev);
 937                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 938                         ppa_reset_pulse(ppb);
 939                         udelay(1000);
 940                         ppa_disconnect(dev);
 941                         udelay(1000);
 942                         if (dev->mode == PPA_EPP_32) {
 943                                 dev->mode = old_mode;
 944                                 goto second_pass;
 945                         }
 946                         return -EIO;
 947                 }
 948                 ppa_disconnect(dev);
 949                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
 950                        loop, PPA_MODE_STRING[dev->mode]);
 951                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 952                 ppa_reset_pulse(ppb);
 953                 udelay(1000);
 954                 ppa_disconnect(dev);
 955                 udelay(1000);
 956                 return 0;
 957         }
 958         return -ENODEV;
 959 }
 960
 961 static int ppa_adjust_queue(struct scsi_device *device)
 962 {
 963         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 964         return 0;
 965 }
 966
 967 static struct scsi_host_template ppa_template = {
 968         .module                 = THIS_MODULE,
 969         .proc_name              = "ppa",
 970         .show_info              = ppa_show_info,
 971         .write_info             = ppa_write_info,
 972         .name                   = "Iomega VPI0 (ppa) interface",
 973         .queuecommand           = ppa_queuecommand,
 974         .eh_abort_handler       = ppa_abort,
 975         .eh_host_reset_handler  = ppa_reset,
 976         .bios_param             = ppa_biosparam,
 977         .this_id                = -1,
 978         .sg_tablesize           = SG_ALL,
 979         .can_queue              = 1,
 980         .slave_alloc            = ppa_adjust_queue,
 981 };
 982
 983 /***************************************************************************
 984  *                   Parallel port probing routines                        *
 985  ***************************************************************************/
 986
 987 static LIST_HEAD(ppa_hosts);
 988
 989 /*
 990  * Finds the first available device number that can be alloted to the
 991  * new ppa device and returns the address of the previous node so that
 992  * we can add to the tail and have a list in the ascending order.
 993  */
 994
 995 static inline ppa_struct *find_parent(void)
 996 {
 997         ppa_struct *dev, *par = NULL;
 998         unsigned int cnt = 0;
 999
1000         if (list_empty(&ppa_hosts))
1001                 return NULL;
1002
1003         list_for_each_entry(dev, &ppa_hosts, list) {
1004                 if (dev->dev_no != cnt)
1005                         return par;
1006                 cnt++;
1007                 par = dev;
1008         }
1009
1010         return par;
1011 }
1012
1013 static int __ppa_attach(struct parport *pb)
1014 {
1015         struct Scsi_Host *host;
1016         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1017         DEFINE_WAIT(wait);
1018         ppa_struct *dev, *temp;
1019         int ports;
1020         int modes, ppb, ppb_hi;
1021         int err = -ENOMEM;
1022         struct pardev_cb ppa_cb;
1023
1024         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1025         if (!dev)
1026                 return -ENOMEM;
1027         dev->base = -1;
1028         dev->mode = PPA_AUTODETECT;
1029         dev->recon_tmo = PPA_RECON_TMO;
1030         init_waitqueue_head(&waiting);
1031         temp = find_parent();
1032         if (temp)
1033                 dev->dev_no = temp->dev_no + 1;
1034
1035         memset(&ppa_cb, 0, sizeof(ppa_cb));
1036         ppa_cb.private = dev;
1037         ppa_cb.wakeup = ppa_wakeup;
1038
1039         dev->dev = parport_register_dev_model(pb, "ppa", &ppa_cb, dev->dev_no);
1040
1041         if (!dev->dev)
1042                 goto out;
1043
1044         /* Claim the bus so it remembers what we do to the control
1045          * registers. [ CTR and ECP ]
1046          */
1047         err = -EBUSY;
1048         dev->waiting = &waiting;
1049         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1050         if (ppa_pb_claim(dev))
1051                 schedule_timeout(3 * HZ);
1052         if (dev->wanted) {
1053                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1054                                 "a pardevice is owning the port for too long "
1055                                 "time!\n", pb->number);
1056                 ppa_pb_dismiss(dev);
1057                 dev->waiting = NULL;
1058                 finish_wait(&waiting, &wait);
1059                 goto out1;
1060         }
1061         dev->waiting = NULL;
1062         finish_wait(&waiting, &wait);
1063         ppb = dev->base = dev->dev->port->base;
1064         ppb_hi = dev->dev->port->base_hi;
1065         w_ctr(ppb, 0x0c);
1066         modes = dev->dev->port->modes;
1067
1068         /* Mode detection works up the chain of speed
1069          * This avoids a nasty if-then-else-if-... tree
1070          */
1071         dev->mode = PPA_NIBBLE;
1072
1073         if (modes & PARPORT_MODE_TRISTATE)
1074                 dev->mode = PPA_PS2;
1075
1076         if (modes & PARPORT_MODE_ECP) {
1077                 w_ecr(ppb_hi, 0x20);
1078                 dev->mode = PPA_PS2;
1079         }
1080         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1081                 w_ecr(ppb_hi, 0x80);
1082
1083         /* Done configuration */
1084
1085         err = ppa_init(dev);
1086         ppa_pb_release(dev);
1087
1088         if (err)
1089                 goto out1;
1090
1091         /* now the glue ... */
1092         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1093                 ports = 3;
1094         else
1095                 ports = 8;
1096
1097         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1098
1099         err = -ENOMEM;
1100         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1101         if (!host)
1102                 goto out1;
1103         host->io_port = pb->base;
1104         host->n_io_port = ports;
1105         host->dma_channel = -1;
1106         host->unique_id = pb->number;
1107         *(ppa_struct **)&host->hostdata = dev;
1108         dev->host = host;
1109         list_add_tail(&dev->list, &ppa_hosts);
1110         err = scsi_add_host(host, NULL);
1111         if (err)
1112                 goto out2;
1113         scsi_scan_host(host);
1114         return 0;
1115 out2:
1116         list_del_init(&dev->list);
1117         scsi_host_put(host);
1118 out1:
1119         parport_unregister_device(dev->dev);
1120 out:
1121         kfree(dev);
1122         return err;
1123 }
1124
1125 static void ppa_attach(struct parport *pb)
1126 {
1127         __ppa_attach(pb);
1128 }
1129
1130 static void ppa_detach(struct parport *pb)
1131 {
1132         ppa_struct *dev;
1133         list_for_each_entry(dev, &ppa_hosts, list) {
1134                 if (dev->dev->port == pb) {
1135                         list_del_init(&dev->list);
1136                         scsi_remove_host(dev->host);
1137                         scsi_host_put(dev->host);
1138                         parport_unregister_device(dev->dev);
1139                         kfree(dev);
1140                         break;
1141                 }
1142         }
1143 }
1144
1145 static struct parport_driver ppa_driver = {
1146         .name           = "ppa",
1147         .match_port     = ppa_attach,
1148         .detach         = ppa_detach,
1149         .devmodel       = true,
1150 };
1151 module_parport_driver(ppa_driver);
1152
1153 MODULE_LICENSE("GPL");