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 struct scsi_pointer *ppa_scsi_pointer(struct scsi_cmnd *cmd)
  49 {
  50         return scsi_cmd_priv(cmd);
  51 }
  52
  53 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  54 {
  55         return *(ppa_struct **)&host->hostdata;
  56 }
  57
  58 static DEFINE_SPINLOCK(arbitration_lock);
  59
  60 static void got_it(ppa_struct *dev)
  61 {
  62         dev->base = dev->dev->port->base;
  63         if (dev->cur_cmd)
  64                 ppa_scsi_pointer(dev->cur_cmd)->phase = 1;
  65         else
  66                 wake_up(dev->waiting);
  67 }
  68
  69 static void ppa_wakeup(void *ref)
  70 {
  71         ppa_struct *dev = (ppa_struct *) ref;
  72         unsigned long flags;
  73
  74         spin_lock_irqsave(&arbitration_lock, flags);
  75         if (dev->wanted) {
  76                 parport_claim(dev->dev);
  77                 got_it(dev);
  78                 dev->wanted = 0;
  79         }
  80         spin_unlock_irqrestore(&arbitration_lock, flags);
  81         return;
  82 }
  83
  84 static int ppa_pb_claim(ppa_struct *dev)
  85 {
  86         unsigned long flags;
  87         int res = 1;
  88         spin_lock_irqsave(&arbitration_lock, flags);
  89         if (parport_claim(dev->dev) == 0) {
  90                 got_it(dev);
  91                 res = 0;
  92         }
  93         dev->wanted = res;
  94         spin_unlock_irqrestore(&arbitration_lock, flags);
  95         return res;
  96 }
  97
  98 static void ppa_pb_dismiss(ppa_struct *dev)
  99 {
 100         unsigned long flags;
 101         int wanted;
 102         spin_lock_irqsave(&arbitration_lock, flags);
 103         wanted = dev->wanted;
 104         dev->wanted = 0;
 105         spin_unlock_irqrestore(&arbitration_lock, flags);
 106         if (!wanted)
 107                 parport_release(dev->dev);
 108 }
 109
 110 static inline void ppa_pb_release(ppa_struct *dev)
 111 {
 112         parport_release(dev->dev);
 113 }
 114
 115 /*
 116  * Start of Chipset kludges
 117  */
 118
 119 /* This is to give the ppa driver a way to modify the timings (and other
 120  * parameters) by writing to the /proc/scsi/ppa/0 file.
 121  * Very simple method really... (To 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
 127 static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
 128 {
 129         ppa_struct *dev = ppa_dev(host);
 130         unsigned long x;
 131
 132         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 133                 x = simple_strtoul(buffer + 5, NULL, 0);
 134                 dev->mode = x;
 135                 return length;
 136         }
 137         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 138                 x = simple_strtoul(buffer + 10, NULL, 0);
 139                 dev->recon_tmo = x;
 140                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 141                 return length;
 142         }
 143         printk(KERN_WARNING "ppa /proc: invalid variable\n");
 144         return -EINVAL;
 145 }
 146
 147 static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
 148 {
 149         ppa_struct *dev = ppa_dev(host);
 150
 151         seq_printf(m, "Version : %s\n", PPA_VERSION);
 152         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 153         seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
 154 #if PPA_DEBUG > 0
 155         seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
 156 #endif
 157         return 0;
 158 }
 159
 160 static int device_check(ppa_struct *dev);
 161
 162 #if PPA_DEBUG > 0
 163 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 164            y, __func__, __LINE__); ppa_fail_func(x,y);
 165 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 166 #else
 167 static inline void ppa_fail(ppa_struct *dev, int error_code)
 168 #endif
 169 {
 170         /* If we fail a device then we trash status / message bytes */
 171         if (dev->cur_cmd) {
 172                 dev->cur_cmd->result = error_code << 16;
 173                 dev->failed = 1;
 174         }
 175 }
 176
 177 /*
 178  * Wait for the high bit to be set.
 179  *
 180  * In principle, this could be tied to an interrupt, but the adapter
 181  * doesn't appear to be designed to support interrupts.  We spin on
 182  * the 0x80 ready bit.
 183  */
 184 static unsigned char ppa_wait(ppa_struct *dev)
 185 {
 186         int k;
 187         unsigned short ppb = dev->base;
 188         unsigned char r;
 189
 190         k = PPA_SPIN_TMO;
 191         /* Wait for bit 6 and 7 - PJC */
 192         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 193                 udelay(1);
 194                 r = r_str(ppb);
 195         }
 196
 197         /*
 198          * return some status information.
 199          * Semantics: 0xc0 = ZIP wants more data
 200          *            0xd0 = ZIP wants to send more data
 201          *            0xe0 = ZIP is expecting SCSI command data
 202          *            0xf0 = end of transfer, ZIP is sending status
 203          */
 204         if (k)
 205                 return (r & 0xf0);
 206
 207         /* Counter expired - Time out occurred */
 208         ppa_fail(dev, DID_TIME_OUT);
 209         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 210         return 0;               /* command timed out */
 211 }
 212
 213 /*
 214  * Clear EPP Timeout Bit
 215  */
 216 static inline void epp_reset(unsigned short ppb)
 217 {
 218         int i;
 219
 220         i = r_str(ppb);
 221         w_str(ppb, i);
 222         w_str(ppb, i & 0xfe);
 223 }
 224
 225 /*
 226  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 227  */
 228 static inline void ecp_sync(ppa_struct *dev)
 229 {
 230         int i, ppb_hi = dev->dev->port->base_hi;
 231
 232         if (ppb_hi == 0)
 233                 return;
 234
 235         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 236                 for (i = 0; i < 100; i++) {
 237                         if (r_ecr(ppb_hi) & 0x01)
 238                                 return;
 239                         udelay(5);
 240                 }
 241                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 242         }
 243 }
 244
 245 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 246 {
 247         int i;
 248
 249         for (i = len; i; i--) {
 250                 w_dtr(base, *buffer++);
 251                 w_ctr(base, 0xe);
 252                 w_ctr(base, 0xc);
 253         }
 254         return 1;               /* All went well - we hope! */
 255 }
 256
 257 static int ppa_byte_in(unsigned short base, char *buffer, int len)
 258 {
 259         int i;
 260
 261         for (i = len; i; i--) {
 262                 *buffer++ = r_dtr(base);
 263                 w_ctr(base, 0x27);
 264                 w_ctr(base, 0x25);
 265         }
 266         return 1;               /* All went well - we hope! */
 267 }
 268
 269 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 270 {
 271         for (; len; len--) {
 272                 unsigned char h;
 273
 274                 w_ctr(base, 0x4);
 275                 h = r_str(base) & 0xf0;
 276                 w_ctr(base, 0x6);
 277                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 278         }
 279         return 1;               /* All went well - we hope! */
 280 }
 281
 282 static int ppa_out(ppa_struct *dev, char *buffer, int len)
 283 {
 284         int r;
 285         unsigned short ppb = dev->base;
 286
 287         r = ppa_wait(dev);
 288
 289         if ((r & 0x50) != 0x40) {
 290                 ppa_fail(dev, DID_ERROR);
 291                 return 0;
 292         }
 293         switch (dev->mode) {
 294         case PPA_NIBBLE:
 295         case PPA_PS2:
 296                 /* 8 bit output, with a loop */
 297                 r = ppa_byte_out(ppb, buffer, len);
 298                 break;
 299
 300         case PPA_EPP_32:
 301         case PPA_EPP_16:
 302         case PPA_EPP_8:
 303                 epp_reset(ppb);
 304                 w_ctr(ppb, 0x4);
 305 #ifdef CONFIG_SCSI_IZIP_EPP16
 306                 if (!(((long) buffer | len) & 0x01))
 307                         outsw(ppb + 4, buffer, len >> 1);
 308 #else
 309                 if (!(((long) buffer | len) & 0x03))
 310                         outsl(ppb + 4, buffer, len >> 2);
 311 #endif
 312                 else
 313                         outsb(ppb + 4, buffer, len);
 314                 w_ctr(ppb, 0xc);
 315                 r = !(r_str(ppb) & 0x01);
 316                 w_ctr(ppb, 0xc);
 317                 ecp_sync(dev);
 318                 break;
 319
 320         default:
 321                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
 322                 r = 0;
 323         }
 324         return r;
 325 }
 326
 327 static int ppa_in(ppa_struct *dev, char *buffer, int len)
 328 {
 329         int r;
 330         unsigned short ppb = dev->base;
 331
 332         r = ppa_wait(dev);
 333
 334         if ((r & 0x50) != 0x50) {
 335                 ppa_fail(dev, DID_ERROR);
 336                 return 0;
 337         }
 338         switch (dev->mode) {
 339         case PPA_NIBBLE:
 340                 /* 4 bit input, with a loop */
 341                 r = ppa_nibble_in(ppb, buffer, len);
 342                 w_ctr(ppb, 0xc);
 343                 break;
 344
 345         case PPA_PS2:
 346                 /* 8 bit input, with a loop */
 347                 w_ctr(ppb, 0x25);
 348                 r = ppa_byte_in(ppb, buffer, len);
 349                 w_ctr(ppb, 0x4);
 350                 w_ctr(ppb, 0xc);
 351                 break;
 352
 353         case PPA_EPP_32:
 354         case PPA_EPP_16:
 355         case PPA_EPP_8:
 356                 epp_reset(ppb);
 357                 w_ctr(ppb, 0x24);
 358 #ifdef CONFIG_SCSI_IZIP_EPP16
 359                 if (!(((long) buffer | len) & 0x01))
 360                         insw(ppb + 4, buffer, len >> 1);
 361 #else
 362                 if (!(((long) buffer | len) & 0x03))
 363                         insl(ppb + 4, buffer, len >> 2);
 364 #endif
 365                 else
 366                         insb(ppb + 4, buffer, len);
 367                 w_ctr(ppb, 0x2c);
 368                 r = !(r_str(ppb) & 0x01);
 369                 w_ctr(ppb, 0x2c);
 370                 ecp_sync(dev);
 371                 break;
 372
 373         default:
 374                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 375                 r = 0;
 376                 break;
 377         }
 378         return r;
 379 }
 380
 381 /* end of ppa_io.h */
 382 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 383 {
 384         w_dtr(ppb, b);
 385         w_ctr(ppb, 0xc);
 386         w_ctr(ppb, 0xe);
 387         w_ctr(ppb, 0xc);
 388         w_ctr(ppb, 0x4);
 389         w_ctr(ppb, 0xc);
 390 }
 391
 392 static void ppa_disconnect(ppa_struct *dev)
 393 {
 394         unsigned short ppb = dev->base;
 395
 396         ppa_d_pulse(ppb, 0);
 397         ppa_d_pulse(ppb, 0x3c);
 398         ppa_d_pulse(ppb, 0x20);
 399         ppa_d_pulse(ppb, 0xf);
 400 }
 401
 402 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 403 {
 404         w_dtr(ppb, b);
 405         w_ctr(ppb, 0x4);
 406         w_ctr(ppb, 0x6);
 407         w_ctr(ppb, 0x4);
 408         w_ctr(ppb, 0xc);
 409 }
 410
 411 static inline void ppa_connect(ppa_struct *dev, int flag)
 412 {
 413         unsigned short ppb = dev->base;
 414
 415         ppa_c_pulse(ppb, 0);
 416         ppa_c_pulse(ppb, 0x3c);
 417         ppa_c_pulse(ppb, 0x20);
 418         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 419                 ppa_c_pulse(ppb, 0xcf);
 420         else
 421                 ppa_c_pulse(ppb, 0x8f);
 422 }
 423
 424 static int ppa_select(ppa_struct *dev, int target)
 425 {
 426         int k;
 427         unsigned short ppb = dev->base;
 428
 429         /*
 430          * Bit 6 (0x40) is the device selected bit.
 431          * First we must wait till the current device goes off line...
 432          */
 433         k = PPA_SELECT_TMO;
 434         do {
 435                 k--;
 436                 udelay(1);
 437         } while ((r_str(ppb) & 0x40) && (k));
 438         if (!k)
 439                 return 0;
 440
 441         w_dtr(ppb, (1 << target));
 442         w_ctr(ppb, 0xe);
 443         w_ctr(ppb, 0xc);
 444         w_dtr(ppb, 0x80);       /* This is NOT the initator */
 445         w_ctr(ppb, 0x8);
 446
 447         k = PPA_SELECT_TMO;
 448         do {
 449                 k--;
 450                 udelay(1);
 451         }
 452         while (!(r_str(ppb) & 0x40) && (k));
 453         if (!k)
 454                 return 0;
 455
 456         return 1;
 457 }
 458
 459 /*
 460  * This is based on a trace of what the Iomega DOS 'guest' driver does.
 461  * I've tried several different kinds of parallel ports with guest and
 462  * coded this to react in the same ways that it does.
 463  *
 464  * The return value from this function is just a hint about where the
 465  * handshaking failed.
 466  *
 467  */
 468 static int ppa_init(ppa_struct *dev)
 469 {
 470         int retv;
 471         unsigned short ppb = dev->base;
 472
 473         ppa_disconnect(dev);
 474         ppa_connect(dev, CONNECT_NORMAL);
 475
 476         retv = 2;               /* Failed */
 477
 478         w_ctr(ppb, 0xe);
 479         if ((r_str(ppb) & 0x08) == 0x08)
 480                 retv--;
 481
 482         w_ctr(ppb, 0xc);
 483         if ((r_str(ppb) & 0x08) == 0x00)
 484                 retv--;
 485
 486         if (!retv)
 487                 ppa_reset_pulse(ppb);
 488         udelay(1000);           /* Allow devices to settle down */
 489         ppa_disconnect(dev);
 490         udelay(1000);           /* Another delay to allow devices to settle */
 491
 492         if (retv)
 493                 return -EIO;
 494
 495         return device_check(dev);
 496 }
 497
 498 static inline int ppa_send_command(struct scsi_cmnd *cmd)
 499 {
 500         ppa_struct *dev = ppa_dev(cmd->device->host);
 501         int k;
 502
 503         w_ctr(dev->base, 0x0c);
 504
 505         for (k = 0; k < cmd->cmd_len; k++)
 506                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
 507                         return 0;
 508         return 1;
 509 }
 510
 511 /*
 512  * The bulk flag enables some optimisations in the data transfer loops,
 513  * it should be true for any command that transfers data in integral
 514  * numbers of sectors.
 515  *
 516  * The driver appears to remain stable if we speed up the parallel port
 517  * i/o in this function, but not elsewhere.
 518  */
 519 static int ppa_completion(struct scsi_cmnd *const cmd)
 520 {
 521         /* Return codes:
 522          * -1     Error
 523          *  0     Told to schedule
 524          *  1     Finished data transfer
 525          */
 526         struct scsi_pointer *scsi_pointer = ppa_scsi_pointer(cmd);
 527         ppa_struct *dev = ppa_dev(cmd->device->host);
 528         unsigned short ppb = dev->base;
 529         unsigned long start_jiffies = jiffies;
 530
 531         unsigned char r, v;
 532         int fast, bulk, status;
 533
 534         v = cmd->cmnd[0];
 535         bulk = ((v == READ_6) ||
 536                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 537
 538         /*
 539          * We only get here if the drive is ready to comunicate,
 540          * hence no need for a full ppa_wait.
 541          */
 542         r = (r_str(ppb) & 0xf0);
 543
 544         while (r != (unsigned char) 0xf0) {
 545                 /*
 546                  * If we have been running for more than a full timer tick
 547                  * then take a rest.
 548                  */
 549                 if (time_after(jiffies, start_jiffies + 1))
 550                         return 0;
 551
 552                 if (scsi_pointer->this_residual <= 0) {
 553                         ppa_fail(dev, DID_ERROR);
 554                         return -1;      /* ERROR_RETURN */
 555                 }
 556
 557                 /* On some hardware we have SCSI disconnected (6th bit low)
 558                  * for about 100usecs. It is too expensive to wait a
 559                  * tick on every loop so we busy wait for no more than
 560                  * 500usecs to give the drive a chance first. We do not
 561                  * change things for "normal" hardware since generally
 562                  * the 6th bit is always high.
 563                  * This makes the CPU load higher on some hardware
 564                  * but otherwise we can not get more than 50K/secs
 565                  * on this problem hardware.
 566                  */
 567                 if ((r & 0xc0) != 0xc0) {
 568                         /* Wait for reconnection should be no more than
 569                          * jiffy/2 = 5ms = 5000 loops
 570                          */
 571                         unsigned long k = dev->recon_tmo;
 572                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 573                              k--)
 574                                 udelay(1);
 575
 576                         if (!k)
 577                                 return 0;
 578                 }
 579
 580                 /* determine if we should use burst I/O */
 581                 fast = bulk && scsi_pointer->this_residual >= PPA_BURST_SIZE ?
 582                         PPA_BURST_SIZE : 1;
 583
 584                 if (r == (unsigned char) 0xc0)
 585                         status = ppa_out(dev, scsi_pointer->ptr, fast);
 586                 else
 587                         status = ppa_in(dev, scsi_pointer->ptr, fast);
 588
 589                 scsi_pointer->ptr += fast;
 590                 scsi_pointer->this_residual -= fast;
 591
 592                 if (!status) {
 593                         ppa_fail(dev, DID_BUS_BUSY);
 594                         return -1;      /* ERROR_RETURN */
 595                 }
 596                 if (scsi_pointer->buffer && !scsi_pointer->this_residual) {
 597                         /* if scatter/gather, advance to the next segment */
 598                         if (scsi_pointer->buffers_residual--) {
 599                                 scsi_pointer->buffer =
 600                                         sg_next(scsi_pointer->buffer);
 601                                 scsi_pointer->this_residual =
 602                                     scsi_pointer->buffer->length;
 603                                 scsi_pointer->ptr =
 604                                         sg_virt(scsi_pointer->buffer);
 605                         }
 606                 }
 607                 /* Now check to see if the drive is ready to comunicate */
 608                 r = (r_str(ppb) & 0xf0);
 609                 /* If not, drop back down to the scheduler and wait a timer tick */
 610                 if (!(r & 0x80))
 611                         return 0;
 612         }
 613         return 1;               /* FINISH_RETURN */
 614 }
 615
 616 /*
 617  * Since the PPA itself doesn't generate interrupts, we use
 618  * the scheduler's task queue to generate a stream of call-backs and
 619  * complete the request when the drive is ready.
 620  */
 621 static void ppa_interrupt(struct work_struct *work)
 622 {
 623         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 624         struct scsi_cmnd *cmd = dev->cur_cmd;
 625
 626         if (!cmd) {
 627                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 628                 return;
 629         }
 630         if (ppa_engine(dev, cmd)) {
 631                 schedule_delayed_work(&dev->ppa_tq, 1);
 632                 return;
 633         }
 634         /* Command must of completed hence it is safe to let go... */
 635 #if PPA_DEBUG > 0
 636         switch ((cmd->result >> 16) & 0xff) {
 637         case DID_OK:
 638                 break;
 639         case DID_NO_CONNECT:
 640                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
 641                 break;
 642         case DID_BUS_BUSY:
 643                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 644                 break;
 645         case DID_TIME_OUT:
 646                 printk(KERN_DEBUG "ppa: unknown timeout\n");
 647                 break;
 648         case DID_ABORT:
 649                 printk(KERN_DEBUG "ppa: told to abort\n");
 650                 break;
 651         case DID_PARITY:
 652                 printk(KERN_DEBUG "ppa: parity error (???)\n");
 653                 break;
 654         case DID_ERROR:
 655                 printk(KERN_DEBUG "ppa: internal driver error\n");
 656                 break;
 657         case DID_RESET:
 658                 printk(KERN_DEBUG "ppa: told to reset device\n");
 659                 break;
 660         case DID_BAD_INTR:
 661                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 662                 break;
 663         default:
 664                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 665                        (cmd->result >> 16) & 0xff);
 666         }
 667 #endif
 668
 669         if (ppa_scsi_pointer(cmd)->phase > 1)
 670                 ppa_disconnect(dev);
 671
 672         ppa_pb_dismiss(dev);
 673
 674         dev->cur_cmd = NULL;
 675
 676         scsi_done(cmd);
 677 }
 678
 679 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 680 {
 681         struct scsi_pointer *scsi_pointer = ppa_scsi_pointer(cmd);
 682         unsigned short ppb = dev->base;
 683         unsigned char l = 0, h = 0;
 684         int retv;
 685
 686         /* First check for any errors that may of occurred
 687          * Here we check for internal errors
 688          */
 689         if (dev->failed)
 690                 return 0;
 691
 692         switch (scsi_pointer->phase) {
 693         case 0:         /* Phase 0 - Waiting for parport */
 694                 if (time_after(jiffies, dev->jstart + HZ)) {
 695                         /*
 696                          * We waited more than a second
 697                          * for parport to call us
 698                          */
 699                         ppa_fail(dev, DID_BUS_BUSY);
 700                         return 0;
 701                 }
 702                 return 1;       /* wait until ppa_wakeup claims parport */
 703         case 1:         /* Phase 1 - Connected */
 704                 {               /* Perform a sanity check for cable unplugged */
 705                         int retv = 2;   /* Failed */
 706
 707                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 708
 709                         w_ctr(ppb, 0xe);
 710                         if ((r_str(ppb) & 0x08) == 0x08)
 711                                 retv--;
 712
 713                         w_ctr(ppb, 0xc);
 714                         if ((r_str(ppb) & 0x08) == 0x00)
 715                                 retv--;
 716
 717                         if (retv) {
 718                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 719                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 720                                         ppa_fail(dev, DID_BUS_BUSY);
 721                                         return 0;
 722                                 } else {
 723                                         ppa_disconnect(dev);
 724                                         return 1;       /* Try again in a jiffy */
 725                                 }
 726                         }
 727                         scsi_pointer->phase++;
 728                 }
 729                 fallthrough;
 730
 731         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 732                 if (!ppa_select(dev, scmd_id(cmd))) {
 733                         ppa_fail(dev, DID_NO_CONNECT);
 734                         return 0;
 735                 }
 736                 scsi_pointer->phase++;
 737                 fallthrough;
 738
 739         case 3:         /* Phase 3 - Ready to accept a command */
 740                 w_ctr(ppb, 0x0c);
 741                 if (!(r_str(ppb) & 0x80))
 742                         return 1;
 743
 744                 if (!ppa_send_command(cmd))
 745                         return 0;
 746                 scsi_pointer->phase++;
 747                 fallthrough;
 748
 749         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 750                 if (scsi_bufflen(cmd)) {
 751                         scsi_pointer->buffer = scsi_sglist(cmd);
 752                         scsi_pointer->this_residual =
 753                                 scsi_pointer->buffer->length;
 754                         scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
 755                 } else {
 756                         scsi_pointer->buffer = NULL;
 757                         scsi_pointer->this_residual = 0;
 758                         scsi_pointer->ptr = NULL;
 759                 }
 760                 scsi_pointer->buffers_residual = scsi_sg_count(cmd) - 1;
 761                 scsi_pointer->phase++;
 762                 fallthrough;
 763
 764         case 5:         /* Phase 5 - Data transfer stage */
 765                 w_ctr(ppb, 0x0c);
 766                 if (!(r_str(ppb) & 0x80))
 767                         return 1;
 768
 769                 retv = ppa_completion(cmd);
 770                 if (retv == -1)
 771                         return 0;
 772                 if (retv == 0)
 773                         return 1;
 774                 scsi_pointer->phase++;
 775                 fallthrough;
 776
 777         case 6:         /* Phase 6 - Read status/message */
 778                 cmd->result = DID_OK << 16;
 779                 /* Check for data overrun */
 780                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
 781                         ppa_fail(dev, DID_ERROR);
 782                         return 0;
 783                 }
 784                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
 785                         /* Check for optional message byte */
 786                         if (ppa_wait(dev) == (unsigned char) 0xf0)
 787                                 ppa_in(dev, &h, 1);
 788                         cmd->result =
 789                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 790                 }
 791                 return 0;       /* Finished */
 792
 793         default:
 794                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
 795         }
 796         return 0;
 797 }
 798
 799 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd)
 800 {
 801         ppa_struct *dev = ppa_dev(cmd->device->host);
 802
 803         if (dev->cur_cmd) {
 804                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 805                 return 0;
 806         }
 807         dev->failed = 0;
 808         dev->jstart = jiffies;
 809         dev->cur_cmd = cmd;
 810         cmd->result = DID_ERROR << 16;  /* default return code */
 811         ppa_scsi_pointer(cmd)->phase = 0;       /* bus free */
 812
 813         schedule_delayed_work(&dev->ppa_tq, 0);
 814
 815         ppa_pb_claim(dev);
 816
 817         return 0;
 818 }
 819
 820 static DEF_SCSI_QCMD(ppa_queuecommand)
 821
 822 /*
 823  * Apparently the disk->capacity attribute is off by 1 sector
 824  * for all disk drives.  We add the one here, but it should really
 825  * be done in sd.c.  Even if it gets fixed there, this will still
 826  * work.
 827  */
 828 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 829               sector_t capacity, int ip[])
 830 {
 831         ip[0] = 0x40;
 832         ip[1] = 0x20;
 833         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 834         if (ip[2] > 1024) {
 835                 ip[0] = 0xff;
 836                 ip[1] = 0x3f;
 837                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 838                 if (ip[2] > 1023)
 839                         ip[2] = 1023;
 840         }
 841         return 0;
 842 }
 843
 844 static int ppa_abort(struct scsi_cmnd *cmd)
 845 {
 846         ppa_struct *dev = ppa_dev(cmd->device->host);
 847         /*
 848          * There is no method for aborting commands since Iomega
 849          * have tied the SCSI_MESSAGE line high in the interface
 850          */
 851
 852         switch (ppa_scsi_pointer(cmd)->phase) {
 853         case 0:         /* Do not have access to parport */
 854         case 1:         /* Have not connected to interface */
 855                 dev->cur_cmd = NULL;    /* Forget the problem */
 856                 return SUCCESS;
 857         default:                /* SCSI command sent, can not abort */
 858                 return FAILED;
 859         }
 860 }
 861
 862 static void ppa_reset_pulse(unsigned int base)
 863 {
 864         w_dtr(base, 0x40);
 865         w_ctr(base, 0x8);
 866         udelay(30);
 867         w_ctr(base, 0xc);
 868 }
 869
 870 static int ppa_reset(struct scsi_cmnd *cmd)
 871 {
 872         ppa_struct *dev = ppa_dev(cmd->device->host);
 873
 874         if (ppa_scsi_pointer(cmd)->phase)
 875                 ppa_disconnect(dev);
 876         dev->cur_cmd = NULL;    /* Forget the problem */
 877
 878         ppa_connect(dev, CONNECT_NORMAL);
 879         ppa_reset_pulse(dev->base);
 880         mdelay(1);              /* device settle delay */
 881         ppa_disconnect(dev);
 882         mdelay(1);              /* device settle delay */
 883         return SUCCESS;
 884 }
 885
 886 static int device_check(ppa_struct *dev)
 887 {
 888         /* This routine looks for a device and then attempts to use EPP
 889            to send a command. If all goes as planned then EPP is available. */
 890
 891         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 892         int loop, old_mode, status, k, ppb = dev->base;
 893         unsigned char l;
 894
 895         old_mode = dev->mode;
 896         for (loop = 0; loop < 8; loop++) {
 897                 /* Attempt to use EPP for Test Unit Ready */
 898                 if ((ppb & 0x0007) == 0x0000)
 899                         dev->mode = PPA_EPP_32;
 900
 901 second_pass:
 902                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 903                 /* Select SCSI device */
 904                 if (!ppa_select(dev, loop)) {
 905                         ppa_disconnect(dev);
 906                         continue;
 907                 }
 908                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
 909                        loop, PPA_MODE_STRING[dev->mode]);
 910
 911                 /* Send SCSI command */
 912                 status = 1;
 913                 w_ctr(ppb, 0x0c);
 914                 for (l = 0; (l < 6) && (status); l++)
 915                         status = ppa_out(dev, cmd, 1);
 916
 917                 if (!status) {
 918                         ppa_disconnect(dev);
 919                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 920                         w_dtr(ppb, 0x40);
 921                         w_ctr(ppb, 0x08);
 922                         udelay(30);
 923                         w_ctr(ppb, 0x0c);
 924                         udelay(1000);
 925                         ppa_disconnect(dev);
 926                         udelay(1000);
 927                         if (dev->mode == PPA_EPP_32) {
 928                                 dev->mode = old_mode;
 929                                 goto second_pass;
 930                         }
 931                         return -EIO;
 932                 }
 933                 w_ctr(ppb, 0x0c);
 934                 k = 1000000;    /* 1 Second */
 935                 do {
 936                         l = r_str(ppb);
 937                         k--;
 938                         udelay(1);
 939                 } while (!(l & 0x80) && (k));
 940
 941                 l &= 0xf0;
 942
 943                 if (l != 0xf0) {
 944                         ppa_disconnect(dev);
 945                         ppa_connect(dev, CONNECT_EPP_MAYBE);
 946                         ppa_reset_pulse(ppb);
 947                         udelay(1000);
 948                         ppa_disconnect(dev);
 949                         udelay(1000);
 950                         if (dev->mode == PPA_EPP_32) {
 951                                 dev->mode = old_mode;
 952                                 goto second_pass;
 953                         }
 954                         return -EIO;
 955                 }
 956                 ppa_disconnect(dev);
 957                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
 958                        loop, PPA_MODE_STRING[dev->mode]);
 959                 ppa_connect(dev, CONNECT_EPP_MAYBE);
 960                 ppa_reset_pulse(ppb);
 961                 udelay(1000);
 962                 ppa_disconnect(dev);
 963                 udelay(1000);
 964                 return 0;
 965         }
 966         return -ENODEV;
 967 }
 968
 969 static int ppa_adjust_queue(struct scsi_device *device)
 970 {
 971         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 972         return 0;
 973 }
 974
 975 static struct scsi_host_template ppa_template = {
 976         .module                 = THIS_MODULE,
 977         .proc_name              = "ppa",
 978         .show_info              = ppa_show_info,
 979         .write_info             = ppa_write_info,
 980         .name                   = "Iomega VPI0 (ppa) interface",
 981         .queuecommand           = ppa_queuecommand,
 982         .eh_abort_handler       = ppa_abort,
 983         .eh_host_reset_handler  = ppa_reset,
 984         .bios_param             = ppa_biosparam,
 985         .this_id                = -1,
 986         .sg_tablesize           = SG_ALL,
 987         .can_queue              = 1,
 988         .slave_alloc            = ppa_adjust_queue,
 989         .cmd_size               = sizeof(struct scsi_pointer),
 990 };
 991
 992 /***************************************************************************
 993  *                   Parallel port probing routines                        *
 994  ***************************************************************************/
 995
 996 static LIST_HEAD(ppa_hosts);
 997
 998 /*
 999  * Finds the first available device number that can be alloted to the
1000  * new ppa device and returns the address of the previous node so that
1001  * we can add to the tail and have a list in the ascending order.
1002  */
1003
1004 static inline ppa_struct *find_parent(void)
1005 {
1006         ppa_struct *dev, *par = NULL;
1007         unsigned int cnt = 0;
1008
1009         if (list_empty(&ppa_hosts))
1010                 return NULL;
1011
1012         list_for_each_entry(dev, &ppa_hosts, list) {
1013                 if (dev->dev_no != cnt)
1014                         return par;
1015                 cnt++;
1016                 par = dev;
1017         }
1018
1019         return par;
1020 }
1021
1022 static int __ppa_attach(struct parport *pb)
1023 {
1024         struct Scsi_Host *host;
1025         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1026         DEFINE_WAIT(wait);
1027         ppa_struct *dev, *temp;
1028         int ports;
1029         int modes, ppb, ppb_hi;
1030         int err = -ENOMEM;
1031         struct pardev_cb ppa_cb;
1032
1033         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1034         if (!dev)
1035                 return -ENOMEM;
1036         dev->base = -1;
1037         dev->mode = PPA_AUTODETECT;
1038         dev->recon_tmo = PPA_RECON_TMO;
1039         init_waitqueue_head(&waiting);
1040         temp = find_parent();
1041         if (temp)
1042                 dev->dev_no = temp->dev_no + 1;
1043
1044         memset(&ppa_cb, 0, sizeof(ppa_cb));
1045         ppa_cb.private = dev;
1046         ppa_cb.wakeup = ppa_wakeup;
1047
1048         dev->dev = parport_register_dev_model(pb, "ppa", &ppa_cb, dev->dev_no);
1049
1050         if (!dev->dev)
1051                 goto out;
1052
1053         /* Claim the bus so it remembers what we do to the control
1054          * registers. [ CTR and ECP ]
1055          */
1056         err = -EBUSY;
1057         dev->waiting = &waiting;
1058         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1059         if (ppa_pb_claim(dev))
1060                 schedule_timeout(3 * HZ);
1061         if (dev->wanted) {
1062                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1063                                 "a pardevice is owning the port for too long "
1064                                 "time!\n", pb->number);
1065                 ppa_pb_dismiss(dev);
1066                 dev->waiting = NULL;
1067                 finish_wait(&waiting, &wait);
1068                 goto out1;
1069         }
1070         dev->waiting = NULL;
1071         finish_wait(&waiting, &wait);
1072         ppb = dev->base = dev->dev->port->base;
1073         ppb_hi = dev->dev->port->base_hi;
1074         w_ctr(ppb, 0x0c);
1075         modes = dev->dev->port->modes;
1076
1077         /* Mode detection works up the chain of speed
1078          * This avoids a nasty if-then-else-if-... tree
1079          */
1080         dev->mode = PPA_NIBBLE;
1081
1082         if (modes & PARPORT_MODE_TRISTATE)
1083                 dev->mode = PPA_PS2;
1084
1085         if (modes & PARPORT_MODE_ECP) {
1086                 w_ecr(ppb_hi, 0x20);
1087                 dev->mode = PPA_PS2;
1088         }
1089         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1090                 w_ecr(ppb_hi, 0x80);
1091
1092         /* Done configuration */
1093
1094         err = ppa_init(dev);
1095         ppa_pb_release(dev);
1096
1097         if (err)
1098                 goto out1;
1099
1100         /* now the glue ... */
1101         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1102                 ports = 3;
1103         else
1104                 ports = 8;
1105
1106         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1107
1108         err = -ENOMEM;
1109         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1110         if (!host)
1111                 goto out1;
1112         host->io_port = pb->base;
1113         host->n_io_port = ports;
1114         host->dma_channel = -1;
1115         host->unique_id = pb->number;
1116         *(ppa_struct **)&host->hostdata = dev;
1117         dev->host = host;
1118         list_add_tail(&dev->list, &ppa_hosts);
1119         err = scsi_add_host(host, NULL);
1120         if (err)
1121                 goto out2;
1122         scsi_scan_host(host);
1123         return 0;
1124 out2:
1125         list_del_init(&dev->list);
1126         scsi_host_put(host);
1127 out1:
1128         parport_unregister_device(dev->dev);
1129 out:
1130         kfree(dev);
1131         return err;
1132 }
1133
1134 static void ppa_attach(struct parport *pb)
1135 {
1136         __ppa_attach(pb);
1137 }
1138
1139 static void ppa_detach(struct parport *pb)
1140 {
1141         ppa_struct *dev;
1142         list_for_each_entry(dev, &ppa_hosts, list) {
1143                 if (dev->dev->port == pb) {
1144                         list_del_init(&dev->list);
1145                         scsi_remove_host(dev->host);
1146                         scsi_host_put(dev->host);
1147                         parport_unregister_device(dev->dev);
1148                         kfree(dev);
1149                         break;
1150                 }
1151         }
1152 }
1153
1154 static struct parport_driver ppa_driver = {
1155         .name           = "ppa",
1156         .match_port     = ppa_attach,
1157         .detach         = ppa_detach,
1158         .devmodel       = true,
1159 };
1160 module_parport_driver(ppa_driver);
1161
1162 MODULE_LICENSE("GPL");