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 unsigned int mode = PPA_AUTODETECT;
  49 module_param(mode, uint, 0644);
  50 MODULE_PARM_DESC(mode, "Transfer mode (0 = Autodetect, 1 = SPP 4-bit, "
  51         "2 = SPP 8-bit, 3 = EPP 8-bit, 4 = EPP 16-bit, 5 = EPP 32-bit");
  52
  53 static struct scsi_pointer *ppa_scsi_pointer(struct scsi_cmnd *cmd)
  54 {
  55         return scsi_cmd_priv(cmd);
  56 }
  57
  58 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  59 {
  60         return *(ppa_struct **)&host->hostdata;
  61 }
  62
  63 static DEFINE_SPINLOCK(arbitration_lock);
  64
  65 static void got_it(ppa_struct *dev)
  66 {
  67         dev->base = dev->dev->port->base;
  68         if (dev->cur_cmd)
  69                 ppa_scsi_pointer(dev->cur_cmd)->phase = 1;
  70         else
  71                 wake_up(dev->waiting);
  72 }
  73
  74 static void ppa_wakeup(void *ref)
  75 {
  76         ppa_struct *dev = (ppa_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         return;
  87 }
  88
  89 static int ppa_pb_claim(ppa_struct *dev)
  90 {
  91         unsigned long flags;
  92         int res = 1;
  93         spin_lock_irqsave(&arbitration_lock, flags);
  94         if (parport_claim(dev->dev) == 0) {
  95                 got_it(dev);
  96                 res = 0;
  97         }
  98         dev->wanted = res;
  99         spin_unlock_irqrestore(&arbitration_lock, flags);
 100         return res;
 101 }
 102
 103 static void ppa_pb_dismiss(ppa_struct *dev)
 104 {
 105         unsigned long flags;
 106         int wanted;
 107         spin_lock_irqsave(&arbitration_lock, flags);
 108         wanted = dev->wanted;
 109         dev->wanted = 0;
 110         spin_unlock_irqrestore(&arbitration_lock, flags);
 111         if (!wanted)
 112                 parport_release(dev->dev);
 113 }
 114
 115 static inline void ppa_pb_release(ppa_struct *dev)
 116 {
 117         parport_release(dev->dev);
 118 }
 119
 120 /*
 121  * Start of Chipset kludges
 122  */
 123
 124 /* This is to give the ppa driver a way to modify the timings (and other
 125  * parameters) by writing to the /proc/scsi/ppa/0 file.
 126  * Very simple method really... (To simple, no error checking :( )
 127  * Reason: Kernel hackers HATE having to unload and reload modules for
 128  * testing...
 129  * Also gives a method to use a script to obtain optimum timings (TODO)
 130  */
 131
 132 static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
 133 {
 134         ppa_struct *dev = ppa_dev(host);
 135         unsigned long x;
 136
 137         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 138                 x = simple_strtoul(buffer + 5, NULL, 0);
 139                 dev->mode = x;
 140                 return length;
 141         }
 142         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 143                 x = simple_strtoul(buffer + 10, NULL, 0);
 144                 dev->recon_tmo = x;
 145                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 146                 return length;
 147         }
 148         printk(KERN_WARNING "ppa /proc: invalid variable\n");
 149         return -EINVAL;
 150 }
 151
 152 static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
 153 {
 154         ppa_struct *dev = ppa_dev(host);
 155
 156         seq_printf(m, "Version : %s\n", PPA_VERSION);
 157         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 158         seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
 159 #if PPA_DEBUG > 0
 160         seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
 161 #endif
 162         return 0;
 163 }
 164
 165 static int device_check(ppa_struct *dev, bool autodetect);
 166
 167 #if PPA_DEBUG > 0
 168 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 169            y, __func__, __LINE__); ppa_fail_func(x,y);
 170 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 171 #else
 172 static inline void ppa_fail(ppa_struct *dev, int error_code)
 173 #endif
 174 {
 175         /* If we fail a device then we trash status / message bytes */
 176         if (dev->cur_cmd) {
 177                 dev->cur_cmd->result = error_code << 16;
 178                 dev->failed = 1;
 179         }
 180 }
 181
 182 /*
 183  * Wait for the high bit to be set.
 184  *
 185  * In principle, this could be tied to an interrupt, but the adapter
 186  * doesn't appear to be designed to support interrupts.  We spin on
 187  * the 0x80 ready bit.
 188  */
 189 static unsigned char ppa_wait(ppa_struct *dev)
 190 {
 191         int k;
 192         unsigned short ppb = dev->base;
 193         unsigned char r;
 194
 195         k = PPA_SPIN_TMO;
 196         /* Wait for bit 6 and 7 - PJC */
 197         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 198                 udelay(1);
 199                 r = r_str(ppb);
 200         }
 201
 202         /*
 203          * return some status information.
 204          * Semantics: 0xc0 = ZIP wants more data
 205          *            0xd0 = ZIP wants to send more data
 206          *            0xe0 = ZIP is expecting SCSI command data
 207          *            0xf0 = end of transfer, ZIP is sending status
 208          */
 209         if (k)
 210                 return (r & 0xf0);
 211
 212         /* Counter expired - Time out occurred */
 213         ppa_fail(dev, DID_TIME_OUT);
 214         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 215         return 0;               /* command timed out */
 216 }
 217
 218 /*
 219  * Clear EPP Timeout Bit
 220  */
 221 static inline void epp_reset(unsigned short ppb)
 222 {
 223         int i;
 224
 225         i = r_str(ppb);
 226         w_str(ppb, i);
 227         w_str(ppb, i & 0xfe);
 228 }
 229
 230 /*
 231  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 232  */
 233 static inline void ecp_sync(ppa_struct *dev)
 234 {
 235         int i, ppb_hi = dev->dev->port->base_hi;
 236
 237         if (ppb_hi == 0)
 238                 return;
 239
 240         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 241                 for (i = 0; i < 100; i++) {
 242                         if (r_ecr(ppb_hi) & 0x01)
 243                                 return;
 244                         udelay(5);
 245                 }
 246                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 247         }
 248 }
 249
 250 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 251 {
 252         int i;
 253
 254         for (i = len; i; i--) {
 255                 w_dtr(base, *buffer++);
 256                 w_ctr(base, 0xe);
 257                 w_ctr(base, 0xc);
 258         }
 259         return 1;               /* All went well - we hope! */
 260 }
 261
 262 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 263 {
 264         int i;
 265
 266         for (i = len; i; i--) {
 267                 *buffer++ = r_dtr(base);
 268                 w_ctr(base, 0x27);
 269                 w_ctr(base, 0x25);
 270         }
 271         return 1;               /* All went well - we hope! */
 272 }
 273
 274 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 275 {
 276         for (; len; len--) {
 277                 unsigned char h;
 278
 279                 w_ctr(base, 0x4);
 280                 h = r_str(base) & 0xf0;
 281                 w_ctr(base, 0x6);
 282                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 283         }
 284         return 1;               /* All went well - we hope! */
 285 }
 286
 287 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 288 {
 289         int r;
 290         unsigned short ppb = dev->base;
 291
 292         r = ppa_wait(dev);
 293
 294         if ((r & 0x50) != 0x40) {
 295                 ppa_fail(dev, DID_ERROR);
 296                 return 0;
 297         }
 298         switch (dev->mode) {
 299         case PPA_NIBBLE:
 300         case PPA_PS2:
 301                 /* 8 bit output, with a loop */
 302                 r = ppa_byte_out(ppb, buffer, len);
 303                 break;
 304
 305         case PPA_EPP_32:
 306         case PPA_EPP_16:
 307         case PPA_EPP_8:
 308                 epp_reset(ppb);
 309                 w_ctr(ppb, 0x4);
 310                 if (dev->mode == PPA_EPP_32 && !(((long) buffer | len) & 0x01))
 311                         outsl(ppb + 4, buffer, len >> 2);
 312                 else if (dev->mode == PPA_EPP_16 && !(((long) buffer | len) & 0x03))
 313                         outsw(ppb + 4, buffer, len >> 1);
 314                 else
 315                         outsb(ppb + 4, buffer, len);
 316                 w_ctr(ppb, 0xc);
 317                 r = !(r_str(ppb) & 0x01);
 318                 w_ctr(ppb, 0xc);
 319                 ecp_sync(dev);
 320                 break;
 321
 322         default:
 323                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
 324                 r = 0;
 325         }
 326         return r;
 327 }
 328
 329 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 330 {
 331         int r;
 332         unsigned short ppb = dev->base;
 333
 334         r = ppa_wait(dev);
 335
 336         if ((r & 0x50) != 0x50) {
 337                 ppa_fail(dev, DID_ERROR);
 338                 return 0;
 339         }
 340         switch (dev->mode) {
 341         case PPA_NIBBLE:
 342                 /* 4 bit input, with a loop */
 343                 r = ppa_nibble_in(ppb, buffer, len);
 344                 w_ctr(ppb, 0xc);
 345                 break;
 346
 347         case PPA_PS2:
 348                 /* 8 bit input, with a loop */
 349                 w_ctr(ppb, 0x25);
 350                 r = ppa_byte_in(ppb, buffer, len);
 351                 w_ctr(ppb, 0x4);
 352                 w_ctr(ppb, 0xc);
 353                 break;
 354
 355         case PPA_EPP_32:
 356         case PPA_EPP_16:
 357         case PPA_EPP_8:
 358                 epp_reset(ppb);
 359                 w_ctr(ppb, 0x24);
 360                 if (dev->mode == PPA_EPP_32 && !(((long) buffer | len) & 0x03))
 361                         insl(ppb + 4, buffer, len >> 2);
 362                 else if (dev->mode == PPA_EPP_16 && !(((long) buffer | len) & 0x01))
 363                         insw(ppb + 4, buffer, len >> 1);
 364                 else
 365                         insb(ppb + 4, buffer, len);
 366                 w_ctr(ppb, 0x2c);
 367                 r = !(r_str(ppb) & 0x01);
 368                 w_ctr(ppb, 0x2c);
 369                 ecp_sync(dev);
 370                 break;
 371
 372         default:
 373                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 374                 r = 0;
 375                 break;
 376         }
 377         return r;
 378 }
 379
 380 /* end of ppa_io.h */
 381 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 382 {
 383         w_dtr(ppb, b);
 384         w_ctr(ppb, 0xc);
 385         w_ctr(ppb, 0xe);
 386         w_ctr(ppb, 0xc);
 387         w_ctr(ppb, 0x4);
 388         w_ctr(ppb, 0xc);
 389 }
 390
 391 static void ppa_disconnect(ppa_struct *dev)
 392 {
 393         unsigned short ppb = dev->base;
 394
 395         ppa_d_pulse(ppb, 0);
 396         ppa_d_pulse(ppb, 0x3c);
 397         ppa_d_pulse(ppb, 0x20);
 398         ppa_d_pulse(ppb, 0xf);
 399 }
 400
 401 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 402 {
 403         w_dtr(ppb, b);
 404         w_ctr(ppb, 0x4);
 405         w_ctr(ppb, 0x6);
 406         w_ctr(ppb, 0x4);
 407         w_ctr(ppb, 0xc);
 408 }
 409
 410 static inline void ppa_connect(ppa_struct *dev, int flag)
 411 {
 412         unsigned short ppb = dev->base;
 413
 414         ppa_c_pulse(ppb, 0);
 415         ppa_c_pulse(ppb, 0x3c);
 416         ppa_c_pulse(ppb, 0x20);
 417         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 418                 ppa_c_pulse(ppb, 0xcf);
 419         else
 420                 ppa_c_pulse(ppb, 0x8f);
 421 }
 422
 423 static int ppa_select(ppa_struct *dev, int target)
 424 {
 425         int k;
 426         unsigned short ppb = dev->base;
 427
 428         /*
 429          * Bit 6 (0x40) is the device selected bit.
 430          * First we must wait till the current device goes off line...
 431          */
 432         k = PPA_SELECT_TMO;
 433         do {
 434                 k--;
 435                 udelay(1);
 436         } while ((r_str(ppb) & 0x40) && (k));
 437         if (!k)
 438                 return 0;
 439
 440         w_dtr(ppb, (1 << target));
 441         w_ctr(ppb, 0xe);
 442         w_ctr(ppb, 0xc);
 443         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 444         w_ctr(ppb, 0x8);
 445
 446         k = PPA_SELECT_TMO;
 447         do {
 448                 k--;
 449                 udelay(1);
 450         }
 451         while (!(r_str(ppb) & 0x40) && (k));
 452         if (!k)
 453                 return 0;
 454
 455         return 1;
 456 }
 457
 458 /*
 459  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 460  * I've tried several different kinds of parallel ports with guest and
 461  * coded this to react in the same ways that it does.
 462  *
 463  * The return value from this function is just a hint about where the
 464  * handshaking failed.
 465  *
 466  */
 467 static int ppa_init(ppa_struct *dev)
 468 {
 469         int retv;
 470         unsigned short ppb = dev->base;
 471         bool autodetect = dev->mode == PPA_AUTODETECT;
 472
 473         if (autodetect) {
 474                 int modes = dev->dev->port->modes;
 475                 int ppb_hi = dev->dev->port->base_hi;
 476
 477                 /* Mode detection works up the chain of speed
 478                  * This avoids a nasty if-then-else-if-... tree
 479                  */
 480                 dev->mode = PPA_NIBBLE;
 481
 482                 if (modes & PARPORT_MODE_TRISTATE)
 483                         dev->mode = PPA_PS2;
 484
 485                 if (modes & PARPORT_MODE_ECP) {
 486                         w_ecr(ppb_hi, 0x20);
 487                         dev->mode = PPA_PS2;
 488                 }
 489                 if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
 490                         w_ecr(ppb_hi, 0x80);
 491         }
 492
 493         ppa_disconnect(dev);
 494         ppa_connect(dev, CONNECT_NORMAL);
 495
 496         retv = 2;               /* Failed */
 497
 498         w_ctr(ppb, 0xe);
 499         if ((r_str(ppb) & 0x08) == 0x08)
 500                 retv--;
 501
 502         w_ctr(ppb, 0xc);
 503         if ((r_str(ppb) & 0x08) == 0x00)
 504                 retv--;
 505
 506         if (!retv)
 507                 ppa_reset_pulse(ppb);
 508         udelay(1000);           /* Allow devices to settle down */
 509         ppa_disconnect(dev);
 510         udelay(1000);           /* Another delay to allow devices to settle */
 511
 512         if (retv)
 513                 return -EIO;
 514
 515         return device_check(dev, autodetect);
 516 }
 517
 518 static inline int ppa_send_command(struct scsi_cmnd *cmd)
 519 {
 520         ppa_struct *dev = ppa_dev(cmd->device->host);
 521         int k;
 522
 523         w_ctr(dev->base, 0x0c);
 524
 525         for (k = 0; k < cmd->cmd_len; k++)
 526                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 527                         return 0;
 528         return 1;
 529 }
 530
 531 /*
 532  * The bulk flag enables some optimisations in the data transfer loops,
 533  * it should be true for any command that transfers data in integral
 534  * numbers of sectors.
 535  *
 536  * The driver appears to remain stable if we speed up the parallel port
 537  * i/o in this function, but not elsewhere.
 538  */
 539 static int ppa_completion(struct scsi_cmnd *const cmd)
 540 {
 541         /* Return codes:
 542          * -1     Error
 543          *  0     Told to schedule
 544          *  1     Finished data transfer
 545          */
 546         struct scsi_pointer *scsi_pointer = ppa_scsi_pointer(cmd);
 547         ppa_struct *dev = ppa_dev(cmd->device->host);
 548         unsigned short ppb = dev->base;
 549         unsigned long start_jiffies = jiffies;
 550
 551         unsigned char r, v;
 552         int fast, bulk, status;
 553
 554         v = cmd->cmnd[0];
 555         bulk = ((v == READ_6) ||
 556                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 557
 558         /*
 559          * We only get here if the drive is ready to comunicate,
 560          * hence no need for a full ppa_wait.
 561          */
 562         r = (r_str(ppb) & 0xf0);
 563
 564         while (r != (unsigned char) 0xf0) {
 565                 /*
 566                  * If we have been running for more than a full timer tick
 567                  * then take a rest.
 568                  */
 569                 if (time_after(jiffies, start_jiffies + 1))
 570                         return 0;
 571
 572                 if (scsi_pointer->this_residual <= 0) {
 573                         ppa_fail(dev, DID_ERROR);
 574                         return -1;      /* ERROR_RETURN */
 575                 }
 576
 577                 /* On some hardware we have SCSI disconnected (6th bit low)
 578                  * for about 100usecs. It is too expensive to wait a
 579                  * tick on every loop so we busy wait for no more than
 580                  * 500usecs to give the drive a chance first. We do not
 581                  * change things for "normal" hardware since generally
 582                  * the 6th bit is always high.
 583                  * This makes the CPU load higher on some hardware
 584                  * but otherwise we can not get more than 50K/secs
 585                  * on this problem hardware.
 586                  */
 587                 if ((r & 0xc0) != 0xc0) {
 588                         /* Wait for reconnection should be no more than
 589                          * jiffy/2 = 5ms = 5000 loops
 590                          */
 591                         unsigned long k = dev->recon_tmo;
 592                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 593                              k--)
 594                                 udelay(1);
 595
 596                         if (!k)
 597                                 return 0;
 598                 }
 599
 600                 /* determine if we should use burst I/O */
 601                 fast = bulk && scsi_pointer->this_residual >= PPA_BURST_SIZE ?
 602                         PPA_BURST_SIZE : 1;
 603
 604                 if (r == (unsigned char) 0xc0)
 605                         status = ppa_out(dev, scsi_pointer->ptr, fast);
 606                 else
 607                         status = ppa_in(dev, scsi_pointer->ptr, fast);
 608
 609                 scsi_pointer->ptr += fast;
 610                 scsi_pointer->this_residual -= fast;
 611
 612                 if (!status) {
 613                         ppa_fail(dev, DID_BUS_BUSY);
 614                         return -1;      /* ERROR_RETURN */
 615                 }
 616                 if (scsi_pointer->buffer && !scsi_pointer->this_residual) {
 617                         /* if scatter/gather, advance to the next segment */
 618                         if (scsi_pointer->buffers_residual--) {
 619                                 scsi_pointer->buffer =
 620                                         sg_next(scsi_pointer->buffer);
 621                                 scsi_pointer->this_residual =
 622                                     scsi_pointer->buffer->length;
 623                                 scsi_pointer->ptr =
 624                                         sg_virt(scsi_pointer->buffer);
 625                         }
 626                 }
 627                 /* Now check to see if the drive is ready to comunicate */
 628                 r = (r_str(ppb) & 0xf0);
 629                 /* If not, drop back down to the scheduler and wait a timer tick */
 630                 if (!(r & 0x80))
 631                         return 0;
 632         }
 633         return 1;               /* FINISH_RETURN */
 634 }
 635
 636 /*
 637  * Since the PPA itself doesn't generate interrupts, we use
 638  * the scheduler's task queue to generate a stream of call-backs and
 639  * complete the request when the drive is ready.
 640  */
 641 static void ppa_interrupt(struct work_struct *work)
 642 {
 643         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 644         struct scsi_cmnd *cmd = dev->cur_cmd;
 645
 646         if (!cmd) {
 647                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 648                 return;
 649         }
 650         if (ppa_engine(dev, cmd)) {
 651                 schedule_delayed_work(&dev->ppa_tq, 1);
 652                 return;
 653         }
 654         /* Command must of completed hence it is safe to let go... */
 655 #if PPA_DEBUG > 0
 656         switch ((cmd->result >> 16) & 0xff) {
 657         case DID_OK:
 658                 break;
 659         case DID_NO_CONNECT:
 660                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", scmd_id(cmd));
 661                 break;
 662         case DID_BUS_BUSY:
 663                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 664                 break;
 665         case DID_TIME_OUT:
 666                 printk(KERN_DEBUG "ppa: unknown timeout\n");
 667                 break;
 668         case DID_ABORT:
 669                 printk(KERN_DEBUG "ppa: told to abort\n");
 670                 break;
 671         case DID_PARITY:
 672                 printk(KERN_DEBUG "ppa: parity error (???)\n");
 673                 break;
 674         case DID_ERROR:
 675                 printk(KERN_DEBUG "ppa: internal driver error\n");
 676                 break;
 677         case DID_RESET:
 678                 printk(KERN_DEBUG "ppa: told to reset device\n");
 679                 break;
 680         case DID_BAD_INTR:
 681                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 682                 break;
 683         default:
 684                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 685                        (cmd->result >> 16) & 0xff);
 686         }
 687 #endif
 688
 689         if (ppa_scsi_pointer(cmd)->phase > 1)
 690                 ppa_disconnect(dev);
 691
 692         ppa_pb_dismiss(dev);
 693
 694         dev->cur_cmd = NULL;
 695
 696         scsi_done(cmd);
 697 }
 698
 699 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 700 {
 701         struct scsi_pointer *scsi_pointer = ppa_scsi_pointer(cmd);
 702         unsigned short ppb = dev->base;
 703         unsigned char l = 0, h = 0;
 704         int retv;
 705
 706         /* First check for any errors that may of occurred
 707          * Here we check for internal errors
 708          */
 709         if (dev->failed)
 710                 return 0;
 711
 712         switch (scsi_pointer->phase) {
 713         case 0:         /* Phase 0 - Waiting for parport */
 714                 if (time_after(jiffies, dev->jstart + HZ)) {
 715                         /*
 716                          * We waited more than a second
 717                          * for parport to call us
 718                          */
 719                         ppa_fail(dev, DID_BUS_BUSY);
 720                         return 0;
 721                 }
 722                 return 1;       /* wait until ppa_wakeup claims parport */
 723         case 1:         /* Phase 1 - Connected */
 724                 {               /* Perform a sanity check for cable unplugged */
 725                         int retv = 2;   /* Failed */
 726
 727                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 728
 729                         w_ctr(ppb, 0xe);
 730                         if ((r_str(ppb) & 0x08) == 0x08)
 731                                 retv--;
 732
 733                         w_ctr(ppb, 0xc);
 734                         if ((r_str(ppb) & 0x08) == 0x00)
 735                                 retv--;
 736
 737                         if (retv) {
 738                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 739                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 740                                         ppa_fail(dev, DID_BUS_BUSY);
 741                                         return 0;
 742                                 } else {
 743                                         ppa_disconnect(dev);
 744                                         return 1;       /* Try again in a jiffy */
 745                                 }
 746                         }
 747                         scsi_pointer->phase++;
 748                 }
 749                 fallthrough;
 750
 751         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 752                 if (!ppa_select(dev, scmd_id(cmd))) {
 753                         ppa_fail(dev, DID_NO_CONNECT);
 754                         return 0;
 755                 }
 756                 scsi_pointer->phase++;
 757                 fallthrough;
 758
 759         case 3:         /* Phase 3 - Ready to accept a command */
 760                 w_ctr(ppb, 0x0c);
 761                 if (!(r_str(ppb) & 0x80))
 762                         return 1;
 763
 764                 if (!ppa_send_command(cmd))
 765                         return 0;
 766                 scsi_pointer->phase++;
 767                 fallthrough;
 768
 769         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 770                 if (scsi_bufflen(cmd)) {
 771                         scsi_pointer->buffer = scsi_sglist(cmd);
 772                         scsi_pointer->this_residual =
 773                                 scsi_pointer->buffer->length;
 774                         scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
 775                 } else {
 776                         scsi_pointer->buffer = NULL;
 777                         scsi_pointer->this_residual = 0;
 778                         scsi_pointer->ptr = NULL;
 779                 }
 780                 scsi_pointer->buffers_residual = scsi_sg_count(cmd) - 1;
 781                 scsi_pointer->phase++;
 782                 fallthrough;
 783
 784         case 5:         /* Phase 5 - Data transfer stage */
 785                 w_ctr(ppb, 0x0c);
 786                 if (!(r_str(ppb) & 0x80))
 787                         return 1;
 788
 789                 retv = ppa_completion(cmd);
 790                 if (retv == -1)
 791                         return 0;
 792                 if (retv == 0)
 793                         return 1;
 794                 scsi_pointer->phase++;
 795                 fallthrough;
 796
 797         case 6:         /* Phase 6 - Read status/message */
 798                 cmd->result = DID_OK << 16;
 799                 /* Check for data overrun */
 800                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
 801                         ppa_fail(dev, DID_ERROR);
 802                         return 0;
 803                 }
 804                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
 805                         /* Check for optional message byte */
 806                         if (ppa_wait(dev) == (unsigned char) 0xf0)
 807                                 ppa_in(dev, &h, 1);
 808                         cmd->result =
 809                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 810                 }
 811                 return 0;       /* Finished */
 812
 813         default:
 814                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
 815         }
 816         return 0;
 817 }
 818
 819 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd)
 820 {
 821         ppa_struct *dev = ppa_dev(cmd->device->host);
 822
 823         if (dev->cur_cmd) {
 824                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 825                 return 0;
 826         }
 827         dev->failed = 0;
 828         dev->jstart = jiffies;
 829         dev->cur_cmd = cmd;
 830         cmd->result = DID_ERROR << 16;  /* default return code */
 831         ppa_scsi_pointer(cmd)->phase = 0;       /* bus free */
 832
 833         schedule_delayed_work(&dev->ppa_tq, 0);
 834
 835         ppa_pb_claim(dev);
 836
 837         return 0;
 838 }
 839
 840 static DEF_SCSI_QCMD(ppa_queuecommand)
 841
 842 /*
 843  * Apparently the disk->capacity attribute is off by 1 sector
 844  * for all disk drives.  We add the one here, but it should really
 845  * be done in sd.c.  Even if it gets fixed there, this will still
 846  * work.
 847  */
 848 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 849               sector_t capacity, int ip[])
 850 {
 851         ip[0] = 0x40;
 852         ip[1] = 0x20;
 853         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 854         if (ip[2] > 1024) {
 855                 ip[0] = 0xff;
 856                 ip[1] = 0x3f;
 857                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 858                 if (ip[2] > 1023)
 859                         ip[2] = 1023;
 860         }
 861         return 0;
 862 }
 863
 864 static int ppa_abort(struct scsi_cmnd *cmd)
 865 {
 866         ppa_struct *dev = ppa_dev(cmd->device->host);
 867         /*
 868          * There is no method for aborting commands since Iomega
 869          * have tied the SCSI_MESSAGE line high in the interface
 870          */
 871
 872         switch (ppa_scsi_pointer(cmd)->phase) {
 873         case 0:         /* Do not have access to parport */
 874         case 1:         /* Have not connected to interface */
 875                 dev->cur_cmd = NULL;    /* Forget the problem */
 876                 return SUCCESS;
 877         default:                /* SCSI command sent, can not abort */
 878                 return FAILED;
 879         }
 880 }
 881
 882 static void ppa_reset_pulse(unsigned int base)
 883 {
 884         w_dtr(base, 0x40);
 885         w_ctr(base, 0x8);
 886         udelay(30);
 887         w_ctr(base, 0xc);
 888 }
 889
 890 static int ppa_reset(struct scsi_cmnd *cmd)
 891 {
 892         ppa_struct *dev = ppa_dev(cmd->device->host);
 893
 894         if (ppa_scsi_pointer(cmd)->phase)
 895                 ppa_disconnect(dev);
 896         dev->cur_cmd = NULL;    /* Forget the problem */
 897
 898         ppa_connect(dev, CONNECT_NORMAL);
 899         ppa_reset_pulse(dev->base);
 900         mdelay(1);              /* device settle delay */
 901         ppa_disconnect(dev);
 902         mdelay(1);              /* device settle delay */
 903         return SUCCESS;
 904 }
 905
 906 static int device_check(ppa_struct *dev, bool autodetect)
 907 {
 908         /* This routine looks for a device and then attempts to use EPP
 909            to send a command. If all goes as planned then EPP is available. */
 910
 911         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 912         int loop, old_mode, status, k, ppb = dev->base;
 913         unsigned char l;
 914
 915         old_mode = dev->mode;
 916         for (loop = 0; loop < 8; loop++) {
 917                 /* Attempt to use EPP for Test Unit Ready */
 918                 if (autodetect && (ppb & 0x0007) == 0x0000)
 919                         dev->mode = PPA_EPP_8;
 920
 921 second_pass:
 922                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 923                 /* Select SCSI device */
 924                 if (!ppa_select(dev, loop)) {
 925                         ppa_disconnect(dev);
 926                         continue;
 927                 }
 928                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
 929                        loop, PPA_MODE_STRING[dev->mode]);
 930
 931                 /* Send SCSI command */
 932                 status = 1;
 933                 w_ctr(ppb, 0x0c);
 934                 for (l = 0; (l < 6) && (status); l++)
 935                         status = ppa_out(dev, cmd, 1);
 936
 937                 if (!status) {
 938                         ppa_disconnect(dev);
 939                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 940                         w_dtr(ppb, 0x40);
 941                         w_ctr(ppb, 0x08);
 942                         udelay(30);
 943                         w_ctr(ppb, 0x0c);
 944                         udelay(1000);
 945                         ppa_disconnect(dev);
 946                         udelay(1000);
 947                         if (dev->mode != old_mode) {
 948                                 dev->mode = old_mode;
 949                                 goto second_pass;
 950                         }
 951                         return -EIO;
 952                 }
 953                 w_ctr(ppb, 0x0c);
 954                 k = 1000000;    /* 1 Second */
 955                 do {
 956                         l = r_str(ppb);
 957                         k--;
 958                         udelay(1);
 959                 } while (!(l & 0x80) && (k));
 960
 961                 l &= 0xf0;
 962
 963                 if (l != 0xf0) {
 964                         ppa_disconnect(dev);
 965                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 966                         ppa_reset_pulse(ppb);
 967                         udelay(1000);
 968                         ppa_disconnect(dev);
 969                         udelay(1000);
 970                         if (dev->mode != old_mode) {
 971                                 dev->mode = old_mode;
 972                                 goto second_pass;
 973                         }
 974                         return -EIO;
 975                 }
 976                 ppa_disconnect(dev);
 977                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
 978                        loop, PPA_MODE_STRING[dev->mode]);
 979                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 980                 ppa_reset_pulse(ppb);
 981                 udelay(1000);
 982                 ppa_disconnect(dev);
 983                 udelay(1000);
 984                 return 0;
 985         }
 986         return -ENODEV;
 987 }
 988
 989 static int ppa_adjust_queue(struct scsi_device *device)
 990 {
 991         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 992         return 0;
 993 }
 994
 995 static const struct scsi_host_template ppa_template = {
 996         .module                 = THIS_MODULE,
 997         .proc_name              = "ppa",
 998         .show_info              = ppa_show_info,
 999         .write_info             = ppa_write_info,
1000         .name                   = "Iomega VPI0 (ppa) interface",
1001         .queuecommand           = ppa_queuecommand,
1002         .eh_abort_handler       = ppa_abort,
1003         .eh_host_reset_handler  = ppa_reset,
1004         .bios_param             = ppa_biosparam,
1005         .this_id                = -1,
1006         .sg_tablesize           = SG_ALL,
1007         .can_queue              = 1,
1008         .slave_alloc            = ppa_adjust_queue,
1009         .cmd_size               = sizeof(struct scsi_pointer),
1010 };
1011
1012 /***************************************************************************
1013  *                   Parallel port probing routines                        *
1014  ***************************************************************************/
1015
1016 static LIST_HEAD(ppa_hosts);
1017
1018 /*
1019  * Finds the first available device number that can be alloted to the
1020  * new ppa device and returns the address of the previous node so that
1021  * we can add to the tail and have a list in the ascending order.
1022  */
1023
1024 static inline ppa_struct *find_parent(void)
1025 {
1026         ppa_struct *dev, *par = NULL;
1027         unsigned int cnt = 0;
1028
1029         if (list_empty(&ppa_hosts))
1030                 return NULL;
1031
1032         list_for_each_entry(dev, &ppa_hosts, list) {
1033                 if (dev->dev_no != cnt)
1034                         return par;
1035                 cnt++;
1036                 par = dev;
1037         }
1038
1039         return par;
1040 }
1041
1042 static int __ppa_attach(struct parport *pb)
1043 {
1044         struct Scsi_Host *host;
1045         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1046         DEFINE_WAIT(wait);
1047         ppa_struct *dev, *temp;
1048         int ports;
1049         int err = -ENOMEM;
1050         struct pardev_cb ppa_cb;
1051
1052         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1053         if (!dev)
1054                 return -ENOMEM;
1055         dev->base = -1;
1056         dev->mode = mode < PPA_UNKNOWN ? mode : PPA_AUTODETECT;
1057         dev->recon_tmo = PPA_RECON_TMO;
1058         init_waitqueue_head(&waiting);
1059         temp = find_parent();
1060         if (temp)
1061                 dev->dev_no = temp->dev_no + 1;
1062
1063         memset(&ppa_cb, 0, sizeof(ppa_cb));
1064         ppa_cb.private = dev;
1065         ppa_cb.wakeup = ppa_wakeup;
1066
1067         dev->dev = parport_register_dev_model(pb, "ppa", &ppa_cb, dev->dev_no);
1068
1069         if (!dev->dev)
1070                 goto out;
1071
1072         /* Claim the bus so it remembers what we do to the control
1073          * registers. [ CTR and ECP ]
1074          */
1075         err = -EBUSY;
1076         dev->waiting = &waiting;
1077         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1078         if (ppa_pb_claim(dev))
1079                 schedule_timeout(3 * HZ);
1080         if (dev->wanted) {
1081                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1082                                 "a pardevice is owning the port for too long "
1083                                 "time!\n", pb->number);
1084                 ppa_pb_dismiss(dev);
1085                 dev->waiting = NULL;
1086                 finish_wait(&waiting, &wait);
1087                 goto out1;
1088         }
1089         dev->waiting = NULL;
1090         finish_wait(&waiting, &wait);
1091         dev->base = dev->dev->port->base;
1092         w_ctr(dev->base, 0x0c);
1093
1094         /* Done configuration */
1095
1096         err = ppa_init(dev);
1097         ppa_pb_release(dev);
1098
1099         if (err)
1100                 goto out1;
1101
1102         /* now the glue ... */
1103         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1104                 ports = 3;
1105         else
1106                 ports = 8;
1107
1108         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1109
1110         err = -ENOMEM;
1111         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1112         if (!host)
1113                 goto out1;
1114         host->io_port = pb->base;
1115         host->n_io_port = ports;
1116         host->dma_channel = -1;
1117         host->unique_id = pb->number;
1118         *(ppa_struct **)&host->hostdata = dev;
1119         dev->host = host;
1120         list_add_tail(&dev->list, &ppa_hosts);
1121         err = scsi_add_host(host, NULL);
1122         if (err)
1123                 goto out2;
1124         scsi_scan_host(host);
1125         return 0;
1126 out2:
1127         list_del_init(&dev->list);
1128         scsi_host_put(host);
1129 out1:
1130         parport_unregister_device(dev->dev);
1131 out:
1132         kfree(dev);
1133         return err;
1134 }
1135
1136 static void ppa_attach(struct parport *pb)
1137 {
1138         __ppa_attach(pb);
1139 }
1140
1141 static void ppa_detach(struct parport *pb)
1142 {
1143         ppa_struct *dev;
1144         list_for_each_entry(dev, &ppa_hosts, list) {
1145                 if (dev->dev->port == pb) {
1146                         list_del_init(&dev->list);
1147                         scsi_remove_host(dev->host);
1148                         scsi_host_put(dev->host);
1149                         parport_unregister_device(dev->dev);
1150                         kfree(dev);
1151                         break;
1152                 }
1153         }
1154 }
1155
1156 static struct parport_driver ppa_driver = {
1157         .name           = "ppa",
1158         .match_port     = ppa_attach,
1159         .detach         = ppa_detach,
1160         .devmodel       = true,
1161 };
1162 module_parport_driver(ppa_driver);
1163
1164 MODULE_LICENSE("GPL");