drivers/scsi/imm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* imm.c   --  low level driver for the IOMEGA MatchMaker
   3  * parallel port SCSI host adapter.
   4  *
   5  * (The IMM is the embedded controller in the ZIP Plus drive.)
   6  *
   7  * My unofficial company acronym list is 21 pages long:
   8  *      FLA:    Four letter acronym with built in facility for
   9  *              future expansion to five letters.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/kernel.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/slab.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 /* The following #define is to avoid a clash with hosts.c */
  28 #define IMM_PROBE_SPP   0x0001
  29 #define IMM_PROBE_PS2   0x0002
  30 #define IMM_PROBE_ECR   0x0010
  31 #define IMM_PROBE_EPP17 0x0100
  32 #define IMM_PROBE_EPP19 0x0200
  33
  34
  35 typedef struct {
  36         struct pardevice *dev;  /* Parport device entry         */
  37         int base;               /* Actual port address          */
  38         int base_hi;            /* Hi Base address for ECP-ISA chipset */
  39         int mode;               /* Transfer mode                */
  40         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  41         struct delayed_work imm_tq;     /* Polling interrupt stuff       */
  42         unsigned long jstart;   /* Jiffies at start             */
  43         unsigned failed:1;      /* Failure flag                 */
  44         unsigned dp:1;          /* Data phase present           */
  45         unsigned rd:1;          /* Read data in data phase      */
  46         unsigned wanted:1;      /* Parport sharing busy flag    */
  47         unsigned int dev_no;    /* Device number                */
  48         wait_queue_head_t *waiting;
  49         struct Scsi_Host *host;
  50         struct list_head list;
  51 } imm_struct;
  52
  53 static void imm_reset_pulse(unsigned int base);
  54 static int device_check(imm_struct *dev);
  55
  56 #include "imm.h"
  57
  58 static inline imm_struct *imm_dev(struct Scsi_Host *host)
  59 {
  60         return *(imm_struct **)&host->hostdata;
  61 }
  62
  63 static DEFINE_SPINLOCK(arbitration_lock);
  64
  65 static void got_it(imm_struct *dev)
  66 {
  67         dev->base = dev->dev->port->base;
  68         if (dev->cur_cmd)
  69                 dev->cur_cmd->SCp.phase = 1;
  70         else
  71                 wake_up(dev->waiting);
  72 }
  73
  74 static void imm_wakeup(void *ref)
  75 {
  76         imm_struct *dev = (imm_struct *) ref;
  77         unsigned long flags;
  78
  79         spin_lock_irqsave(&arbitration_lock, flags);
  80         if (dev->wanted) {
  81                 if (parport_claim(dev->dev) == 0) {
  82                         got_it(dev);
  83                         dev->wanted = 0;
  84                 }
  85         }
  86         spin_unlock_irqrestore(&arbitration_lock, flags);
  87 }
  88
  89 static int imm_pb_claim(imm_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 imm_pb_dismiss(imm_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 imm_pb_release(imm_struct *dev)
 116 {
 117         parport_release(dev->dev);
 118 }
 119
 120 /* This is to give the imm driver a way to modify the timings (and other
 121  * parameters) by writing to the /proc/scsi/imm/0 file.
 122  * Very simple method really... (Too simple, no error checking :( )
 123  * Reason: Kernel hackers HATE having to unload and reload modules for
 124  * testing...
 125  * Also gives a method to use a script to obtain optimum timings (TODO)
 126  */
 127 static int imm_write_info(struct Scsi_Host *host, char *buffer, int length)
 128 {
 129         imm_struct *dev = imm_dev(host);
 130
 131         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 132                 dev->mode = simple_strtoul(buffer + 5, NULL, 0);
 133                 return length;
 134         }
 135         printk("imm /proc: invalid variable\n");
 136         return -EINVAL;
 137 }
 138
 139 static int imm_show_info(struct seq_file *m, struct Scsi_Host *host)
 140 {
 141         imm_struct *dev = imm_dev(host);
 142
 143         seq_printf(m, "Version : %s\n", IMM_VERSION);
 144         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 145         seq_printf(m, "Mode    : %s\n", IMM_MODE_STRING[dev->mode]);
 146         return 0;
 147 }
 148
 149 #if IMM_DEBUG > 0
 150 #define imm_fail(x,y) printk("imm: imm_fail(%i) from %s at line %d\n",\
 151            y, __func__, __LINE__); imm_fail_func(x,y);
 152 static inline void
 153 imm_fail_func(imm_struct *dev, int error_code)
 154 #else
 155 static inline void
 156 imm_fail(imm_struct *dev, int error_code)
 157 #endif
 158 {
 159         /* If we fail a device then we trash status / message bytes */
 160         if (dev->cur_cmd) {
 161                 dev->cur_cmd->result = error_code << 16;
 162                 dev->failed = 1;
 163         }
 164 }
 165
 166 /*
 167  * Wait for the high bit to be set.
 168  *
 169  * In principle, this could be tied to an interrupt, but the adapter
 170  * doesn't appear to be designed to support interrupts.  We spin on
 171  * the 0x80 ready bit.
 172  */
 173 static unsigned char imm_wait(imm_struct *dev)
 174 {
 175         int k;
 176         unsigned short ppb = dev->base;
 177         unsigned char r;
 178
 179         w_ctr(ppb, 0x0c);
 180
 181         k = IMM_SPIN_TMO;
 182         do {
 183                 r = r_str(ppb);
 184                 k--;
 185                 udelay(1);
 186         }
 187         while (!(r & 0x80) && (k));
 188
 189         /*
 190          * STR register (LPT base+1) to SCSI mapping:
 191          *
 192          * STR      imm     imm
 193          * ===================================
 194          * 0x80     S_REQ   S_REQ
 195          * 0x40     !S_BSY  (????)
 196          * 0x20     !S_CD   !S_CD
 197          * 0x10     !S_IO   !S_IO
 198          * 0x08     (????)  !S_BSY
 199          *
 200          * imm      imm     meaning
 201          * ==================================
 202          * 0xf0     0xb8    Bit mask
 203          * 0xc0     0x88    ZIP wants more data
 204          * 0xd0     0x98    ZIP wants to send more data
 205          * 0xe0     0xa8    ZIP is expecting SCSI command data
 206          * 0xf0     0xb8    end of transfer, ZIP is sending status
 207          */
 208         w_ctr(ppb, 0x04);
 209         if (k)
 210                 return (r & 0xb8);
 211
 212         /* Counter expired - Time out occurred */
 213         imm_fail(dev, DID_TIME_OUT);
 214         printk("imm timeout in imm_wait\n");
 215         return 0;               /* command timed out */
 216 }
 217
 218 static int imm_negotiate(imm_struct * tmp)
 219 {
 220         /*
 221          * The following is supposedly the IEEE 1284-1994 negotiate
 222          * sequence. I have yet to obtain a copy of the above standard
 223          * so this is a bit of a guess...
 224          *
 225          * A fair chunk of this is based on the Linux parport implementation
 226          * of IEEE 1284.
 227          *
 228          * Return 0 if data available
 229          *        1 if no data available
 230          */
 231
 232         unsigned short base = tmp->base;
 233         unsigned char a, mode;
 234
 235         switch (tmp->mode) {
 236         case IMM_NIBBLE:
 237                 mode = 0x00;
 238                 break;
 239         case IMM_PS2:
 240                 mode = 0x01;
 241                 break;
 242         default:
 243                 return 0;
 244         }
 245
 246         w_ctr(base, 0x04);
 247         udelay(5);
 248         w_dtr(base, mode);
 249         udelay(100);
 250         w_ctr(base, 0x06);
 251         udelay(5);
 252         a = (r_str(base) & 0x20) ? 0 : 1;
 253         udelay(5);
 254         w_ctr(base, 0x07);
 255         udelay(5);
 256         w_ctr(base, 0x06);
 257
 258         if (a) {
 259                 printk
 260                     ("IMM: IEEE1284 negotiate indicates no data available.\n");
 261                 imm_fail(tmp, DID_ERROR);
 262         }
 263         return a;
 264 }
 265
 266 /*
 267  * Clear EPP timeout bit.
 268  */
 269 static inline void epp_reset(unsigned short ppb)
 270 {
 271         int i;
 272
 273         i = r_str(ppb);
 274         w_str(ppb, i);
 275         w_str(ppb, i & 0xfe);
 276 }
 277
 278 /*
 279  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 280  */
 281 static inline void ecp_sync(imm_struct *dev)
 282 {
 283         int i, ppb_hi = dev->base_hi;
 284
 285         if (ppb_hi == 0)
 286                 return;
 287
 288         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 289                 for (i = 0; i < 100; i++) {
 290                         if (r_ecr(ppb_hi) & 0x01)
 291                                 return;
 292                         udelay(5);
 293                 }
 294                 printk("imm: ECP sync failed as data still present in FIFO.\n");
 295         }
 296 }
 297
 298 static int imm_byte_out(unsigned short base, const char *buffer, int len)
 299 {
 300         int i;
 301
 302         w_ctr(base, 0x4);       /* apparently a sane mode */
 303         for (i = len >> 1; i; i--) {
 304                 w_dtr(base, *buffer++);
 305                 w_ctr(base, 0x5);       /* Drop STROBE low */
 306                 w_dtr(base, *buffer++);
 307                 w_ctr(base, 0x0);       /* STROBE high + INIT low */
 308         }
 309         w_ctr(base, 0x4);       /* apparently a sane mode */
 310         return 1;               /* All went well - we hope! */
 311 }
 312
 313 static int imm_nibble_in(unsigned short base, char *buffer, int len)
 314 {
 315         unsigned char l;
 316         int i;
 317
 318         /*
 319          * The following is based on documented timing signals
 320          */
 321         w_ctr(base, 0x4);
 322         for (i = len; i; i--) {
 323                 w_ctr(base, 0x6);
 324                 l = (r_str(base) & 0xf0) >> 4;
 325                 w_ctr(base, 0x5);
 326                 *buffer++ = (r_str(base) & 0xf0) | l;
 327                 w_ctr(base, 0x4);
 328         }
 329         return 1;               /* All went well - we hope! */
 330 }
 331
 332 static int imm_byte_in(unsigned short base, char *buffer, int len)
 333 {
 334         int i;
 335
 336         /*
 337          * The following is based on documented timing signals
 338          */
 339         w_ctr(base, 0x4);
 340         for (i = len; i; i--) {
 341                 w_ctr(base, 0x26);
 342                 *buffer++ = r_dtr(base);
 343                 w_ctr(base, 0x25);
 344         }
 345         return 1;               /* All went well - we hope! */
 346 }
 347
 348 static int imm_out(imm_struct *dev, char *buffer, int len)
 349 {
 350         unsigned short ppb = dev->base;
 351         int r = imm_wait(dev);
 352
 353         /*
 354          * Make sure that:
 355          * a) the SCSI bus is BUSY (device still listening)
 356          * b) the device is listening
 357          */
 358         if ((r & 0x18) != 0x08) {
 359                 imm_fail(dev, DID_ERROR);
 360                 printk("IMM: returned SCSI status %2x\n", r);
 361                 return 0;
 362         }
 363         switch (dev->mode) {
 364         case IMM_EPP_32:
 365         case IMM_EPP_16:
 366         case IMM_EPP_8:
 367                 epp_reset(ppb);
 368                 w_ctr(ppb, 0x4);
 369 #ifdef CONFIG_SCSI_IZIP_EPP16
 370                 if (!(((long) buffer | len) & 0x01))
 371                         outsw(ppb + 4, buffer, len >> 1);
 372 #else
 373                 if (!(((long) buffer | len) & 0x03))
 374                         outsl(ppb + 4, buffer, len >> 2);
 375 #endif
 376                 else
 377                         outsb(ppb + 4, buffer, len);
 378                 w_ctr(ppb, 0xc);
 379                 r = !(r_str(ppb) & 0x01);
 380                 w_ctr(ppb, 0xc);
 381                 ecp_sync(dev);
 382                 break;
 383
 384         case IMM_NIBBLE:
 385         case IMM_PS2:
 386                 /* 8 bit output, with a loop */
 387                 r = imm_byte_out(ppb, buffer, len);
 388                 break;
 389
 390         default:
 391                 printk("IMM: bug in imm_out()\n");
 392                 r = 0;
 393         }
 394         return r;
 395 }
 396
 397 static int imm_in(imm_struct *dev, char *buffer, int len)
 398 {
 399         unsigned short ppb = dev->base;
 400         int r = imm_wait(dev);
 401
 402         /*
 403          * Make sure that:
 404          * a) the SCSI bus is BUSY (device still listening)
 405          * b) the device is sending data
 406          */
 407         if ((r & 0x18) != 0x18) {
 408                 imm_fail(dev, DID_ERROR);
 409                 return 0;
 410         }
 411         switch (dev->mode) {
 412         case IMM_NIBBLE:
 413                 /* 4 bit input, with a loop */
 414                 r = imm_nibble_in(ppb, buffer, len);
 415                 w_ctr(ppb, 0xc);
 416                 break;
 417
 418         case IMM_PS2:
 419                 /* 8 bit input, with a loop */
 420                 r = imm_byte_in(ppb, buffer, len);
 421                 w_ctr(ppb, 0xc);
 422                 break;
 423
 424         case IMM_EPP_32:
 425         case IMM_EPP_16:
 426         case IMM_EPP_8:
 427                 epp_reset(ppb);
 428                 w_ctr(ppb, 0x24);
 429 #ifdef CONFIG_SCSI_IZIP_EPP16
 430                 if (!(((long) buffer | len) & 0x01))
 431                         insw(ppb + 4, buffer, len >> 1);
 432 #else
 433                 if (!(((long) buffer | len) & 0x03))
 434                         insl(ppb + 4, buffer, len >> 2);
 435 #endif
 436                 else
 437                         insb(ppb + 4, buffer, len);
 438                 w_ctr(ppb, 0x2c);
 439                 r = !(r_str(ppb) & 0x01);
 440                 w_ctr(ppb, 0x2c);
 441                 ecp_sync(dev);
 442                 break;
 443
 444         default:
 445                 printk("IMM: bug in imm_ins()\n");
 446                 r = 0;
 447                 break;
 448         }
 449         return r;
 450 }
 451
 452 static int imm_cpp(unsigned short ppb, unsigned char b)
 453 {
 454         /*
 455          * Comments on udelay values refer to the
 456          * Command Packet Protocol (CPP) timing diagram.
 457          */
 458
 459         unsigned char s1, s2, s3;
 460         w_ctr(ppb, 0x0c);
 461         udelay(2);              /* 1 usec - infinite */
 462         w_dtr(ppb, 0xaa);
 463         udelay(10);             /* 7 usec - infinite */
 464         w_dtr(ppb, 0x55);
 465         udelay(10);             /* 7 usec - infinite */
 466         w_dtr(ppb, 0x00);
 467         udelay(10);             /* 7 usec - infinite */
 468         w_dtr(ppb, 0xff);
 469         udelay(10);             /* 7 usec - infinite */
 470         s1 = r_str(ppb) & 0xb8;
 471         w_dtr(ppb, 0x87);
 472         udelay(10);             /* 7 usec - infinite */
 473         s2 = r_str(ppb) & 0xb8;
 474         w_dtr(ppb, 0x78);
 475         udelay(10);             /* 7 usec - infinite */
 476         s3 = r_str(ppb) & 0x38;
 477         /*
 478          * Values for b are:
 479          * 0000 00aa    Assign address aa to current device
 480          * 0010 00aa    Select device aa in EPP Winbond mode
 481          * 0010 10aa    Select device aa in EPP mode
 482          * 0011 xxxx    Deselect all devices
 483          * 0110 00aa    Test device aa
 484          * 1101 00aa    Select device aa in ECP mode
 485          * 1110 00aa    Select device aa in Compatible mode
 486          */
 487         w_dtr(ppb, b);
 488         udelay(2);              /* 1 usec - infinite */
 489         w_ctr(ppb, 0x0c);
 490         udelay(10);             /* 7 usec - infinite */
 491         w_ctr(ppb, 0x0d);
 492         udelay(2);              /* 1 usec - infinite */
 493         w_ctr(ppb, 0x0c);
 494         udelay(10);             /* 7 usec - infinite */
 495         w_dtr(ppb, 0xff);
 496         udelay(10);             /* 7 usec - infinite */
 497
 498         /*
 499          * The following table is electrical pin values.
 500          * (BSY is inverted at the CTR register)
 501          *
 502          *       BSY  ACK  POut SEL  Fault
 503          * S1    0    X    1    1    1
 504          * S2    1    X    0    1    1
 505          * S3    L    X    1    1    S
 506          *
 507          * L => Last device in chain
 508          * S => Selected
 509          *
 510          * Observered values for S1,S2,S3 are:
 511          * Disconnect => f8/58/78
 512          * Connect    => f8/58/70
 513          */
 514         if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x30))
 515                 return 1;       /* Connected */
 516         if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x38))
 517                 return 0;       /* Disconnected */
 518
 519         return -1;              /* No device present */
 520 }
 521
 522 static inline int imm_connect(imm_struct *dev, int flag)
 523 {
 524         unsigned short ppb = dev->base;
 525
 526         imm_cpp(ppb, 0xe0);     /* Select device 0 in compatible mode */
 527         imm_cpp(ppb, 0x30);     /* Disconnect all devices */
 528
 529         if ((dev->mode == IMM_EPP_8) ||
 530             (dev->mode == IMM_EPP_16) ||
 531             (dev->mode == IMM_EPP_32))
 532                 return imm_cpp(ppb, 0x28);      /* Select device 0 in EPP mode */
 533         return imm_cpp(ppb, 0xe0);      /* Select device 0 in compatible mode */
 534 }
 535
 536 static void imm_disconnect(imm_struct *dev)
 537 {
 538         imm_cpp(dev->base, 0x30);       /* Disconnect all devices */
 539 }
 540
 541 static int imm_select(imm_struct *dev, int target)
 542 {
 543         int k;
 544         unsigned short ppb = dev->base;
 545
 546         /*
 547          * Firstly we want to make sure there is nothing
 548          * holding onto the SCSI bus.
 549          */
 550         w_ctr(ppb, 0xc);
 551
 552         k = IMM_SELECT_TMO;
 553         do {
 554                 k--;
 555         } while ((r_str(ppb) & 0x08) && (k));
 556
 557         if (!k)
 558                 return 0;
 559
 560         /*
 561          * Now assert the SCSI ID (HOST and TARGET) on the data bus
 562          */
 563         w_ctr(ppb, 0x4);
 564         w_dtr(ppb, 0x80 | (1 << target));
 565         udelay(1);
 566
 567         /*
 568          * Deassert SELIN first followed by STROBE
 569          */
 570         w_ctr(ppb, 0xc);
 571         w_ctr(ppb, 0xd);
 572
 573         /*
 574          * ACK should drop low while SELIN is deasserted.
 575          * FAULT should drop low when the SCSI device latches the bus.
 576          */
 577         k = IMM_SELECT_TMO;
 578         do {
 579                 k--;
 580         }
 581         while (!(r_str(ppb) & 0x08) && (k));
 582
 583         /*
 584          * Place the interface back into a sane state (status mode)
 585          */
 586         w_ctr(ppb, 0xc);
 587         return (k) ? 1 : 0;
 588 }
 589
 590 static int imm_init(imm_struct *dev)
 591 {
 592         if (imm_connect(dev, 0) != 1)
 593                 return -EIO;
 594         imm_reset_pulse(dev->base);
 595         mdelay(1);      /* Delay to allow devices to settle */
 596         imm_disconnect(dev);
 597         mdelay(1);      /* Another delay to allow devices to settle */
 598         return device_check(dev);
 599 }
 600
 601 static inline int imm_send_command(struct scsi_cmnd *cmd)
 602 {
 603         imm_struct *dev = imm_dev(cmd->device->host);
 604         int k;
 605
 606         /* NOTE: IMM uses byte pairs */
 607         for (k = 0; k < cmd->cmd_len; k += 2)
 608                 if (!imm_out(dev, &cmd->cmnd[k], 2))
 609                         return 0;
 610         return 1;
 611 }
 612
 613 /*
 614  * The bulk flag enables some optimisations in the data transfer loops,
 615  * it should be true for any command that transfers data in integral
 616  * numbers of sectors.
 617  *
 618  * The driver appears to remain stable if we speed up the parallel port
 619  * i/o in this function, but not elsewhere.
 620  */
 621 static int imm_completion(struct scsi_cmnd *cmd)
 622 {
 623         /* Return codes:
 624          * -1     Error
 625          *  0     Told to schedule
 626          *  1     Finished data transfer
 627          */
 628         imm_struct *dev = imm_dev(cmd->device->host);
 629         unsigned short ppb = dev->base;
 630         unsigned long start_jiffies = jiffies;
 631
 632         unsigned char r, v;
 633         int fast, bulk, status;
 634
 635         v = cmd->cmnd[0];
 636         bulk = ((v == READ_6) ||
 637                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 638
 639         /*
 640          * We only get here if the drive is ready to comunicate,
 641          * hence no need for a full imm_wait.
 642          */
 643         w_ctr(ppb, 0x0c);
 644         r = (r_str(ppb) & 0xb8);
 645
 646         /*
 647          * while (device is not ready to send status byte)
 648          *     loop;
 649          */
 650         while (r != (unsigned char) 0xb8) {
 651                 /*
 652                  * If we have been running for more than a full timer tick
 653                  * then take a rest.
 654                  */
 655                 if (time_after(jiffies, start_jiffies + 1))
 656                         return 0;
 657
 658                 /*
 659                  * FAIL if:
 660                  * a) Drive status is screwy (!ready && !present)
 661                  * b) Drive is requesting/sending more data than expected
 662                  */
 663                 if (((r & 0x88) != 0x88) || (cmd->SCp.this_residual <= 0)) {
 664                         imm_fail(dev, DID_ERROR);
 665                         return -1;      /* ERROR_RETURN */
 666                 }
 667                 /* determine if we should use burst I/O */
 668                 if (dev->rd == 0) {
 669                         fast = (bulk
 670                                 && (cmd->SCp.this_residual >=
 671                                     IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 2;
 672                         status = imm_out(dev, cmd->SCp.ptr, fast);
 673                 } else {
 674                         fast = (bulk
 675                                 && (cmd->SCp.this_residual >=
 676                                     IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 1;
 677                         status = imm_in(dev, cmd->SCp.ptr, fast);
 678                 }
 679
 680                 cmd->SCp.ptr += fast;
 681                 cmd->SCp.this_residual -= fast;
 682
 683                 if (!status) {
 684                         imm_fail(dev, DID_BUS_BUSY);
 685                         return -1;      /* ERROR_RETURN */
 686                 }
 687                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 688                         /* if scatter/gather, advance to the next segment */
 689                         if (cmd->SCp.buffers_residual--) {
 690                                 cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
 691                                 cmd->SCp.this_residual =
 692                                     cmd->SCp.buffer->length;
 693                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 694
 695                                 /*
 696                                  * Make sure that we transfer even number of bytes
 697                                  * otherwise it makes imm_byte_out() messy.
 698                                  */
 699                                 if (cmd->SCp.this_residual & 0x01)
 700                                         cmd->SCp.this_residual++;
 701                         }
 702                 }
 703                 /* Now check to see if the drive is ready to comunicate */
 704                 w_ctr(ppb, 0x0c);
 705                 r = (r_str(ppb) & 0xb8);
 706
 707                 /* If not, drop back down to the scheduler and wait a timer tick */
 708                 if (!(r & 0x80))
 709                         return 0;
 710         }
 711         return 1;               /* FINISH_RETURN */
 712 }
 713
 714 /*
 715  * Since the IMM itself doesn't generate interrupts, we use
 716  * the scheduler's task queue to generate a stream of call-backs and
 717  * complete the request when the drive is ready.
 718  */
 719 static void imm_interrupt(struct work_struct *work)
 720 {
 721         imm_struct *dev = container_of(work, imm_struct, imm_tq.work);
 722         struct scsi_cmnd *cmd = dev->cur_cmd;
 723         struct Scsi_Host *host = cmd->device->host;
 724         unsigned long flags;
 725
 726         if (imm_engine(dev, cmd)) {
 727                 schedule_delayed_work(&dev->imm_tq, 1);
 728                 return;
 729         }
 730         /* Command must of completed hence it is safe to let go... */
 731 #if IMM_DEBUG > 0
 732         switch ((cmd->result >> 16) & 0xff) {
 733         case DID_OK:
 734                 break;
 735         case DID_NO_CONNECT:
 736                 printk("imm: no device at SCSI ID %i\n", cmd->device->id);
 737                 break;
 738         case DID_BUS_BUSY:
 739                 printk("imm: BUS BUSY - EPP timeout detected\n");
 740                 break;
 741         case DID_TIME_OUT:
 742                 printk("imm: unknown timeout\n");
 743                 break;
 744         case DID_ABORT:
 745                 printk("imm: told to abort\n");
 746                 break;
 747         case DID_PARITY:
 748                 printk("imm: parity error (???)\n");
 749                 break;
 750         case DID_ERROR:
 751                 printk("imm: internal driver error\n");
 752                 break;
 753         case DID_RESET:
 754                 printk("imm: told to reset device\n");
 755                 break;
 756         case DID_BAD_INTR:
 757                 printk("imm: bad interrupt (???)\n");
 758                 break;
 759         default:
 760                 printk("imm: bad return code (%02x)\n",
 761                        (cmd->result >> 16) & 0xff);
 762         }
 763 #endif
 764
 765         if (cmd->SCp.phase > 1)
 766                 imm_disconnect(dev);
 767
 768         imm_pb_dismiss(dev);
 769
 770         spin_lock_irqsave(host->host_lock, flags);
 771         dev->cur_cmd = NULL;
 772         cmd->scsi_done(cmd);
 773         spin_unlock_irqrestore(host->host_lock, flags);
 774         return;
 775 }
 776
 777 static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
 778 {
 779         unsigned short ppb = dev->base;
 780         unsigned char l = 0, h = 0;
 781         int retv, x;
 782
 783         /* First check for any errors that may have occurred
 784          * Here we check for internal errors
 785          */
 786         if (dev->failed)
 787                 return 0;
 788
 789         switch (cmd->SCp.phase) {
 790         case 0:         /* Phase 0 - Waiting for parport */
 791                 if (time_after(jiffies, dev->jstart + HZ)) {
 792                         /*
 793                          * We waited more than a second
 794                          * for parport to call us
 795                          */
 796                         imm_fail(dev, DID_BUS_BUSY);
 797                         return 0;
 798                 }
 799                 return 1;       /* wait until imm_wakeup claims parport */
 800
 801         case 1:         /* Phase 1 - Connected */
 802                 imm_connect(dev, CONNECT_EPP_MAYBE);
 803                 cmd->SCp.phase++;
 804                 fallthrough;
 805
 806         case 2:         /* Phase 2 - We are now talking to the scsi bus */
 807                 if (!imm_select(dev, scmd_id(cmd))) {
 808                         imm_fail(dev, DID_NO_CONNECT);
 809                         return 0;
 810                 }
 811                 cmd->SCp.phase++;
 812                 fallthrough;
 813
 814         case 3:         /* Phase 3 - Ready to accept a command */
 815                 w_ctr(ppb, 0x0c);
 816                 if (!(r_str(ppb) & 0x80))
 817                         return 1;
 818
 819                 if (!imm_send_command(cmd))
 820                         return 0;
 821                 cmd->SCp.phase++;
 822                 fallthrough;
 823
 824         case 4:         /* Phase 4 - Setup scatter/gather buffers */
 825                 if (scsi_bufflen(cmd)) {
 826                         cmd->SCp.buffer = scsi_sglist(cmd);
 827                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
 828                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 829                 } else {
 830                         cmd->SCp.buffer = NULL;
 831                         cmd->SCp.this_residual = 0;
 832                         cmd->SCp.ptr = NULL;
 833                 }
 834                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 835                 cmd->SCp.phase++;
 836                 if (cmd->SCp.this_residual & 0x01)
 837                         cmd->SCp.this_residual++;
 838                 fallthrough;
 839
 840         case 5:         /* Phase 5 - Pre-Data transfer stage */
 841                 /* Spin lock for BUSY */
 842                 w_ctr(ppb, 0x0c);
 843                 if (!(r_str(ppb) & 0x80))
 844                         return 1;
 845
 846                 /* Require negotiation for read requests */
 847                 x = (r_str(ppb) & 0xb8);
 848                 dev->rd = (x & 0x10) ? 1 : 0;
 849                 dev->dp = (x & 0x20) ? 0 : 1;
 850
 851                 if ((dev->dp) && (dev->rd))
 852                         if (imm_negotiate(dev))
 853                                 return 0;
 854                 cmd->SCp.phase++;
 855                 fallthrough;
 856
 857         case 6:         /* Phase 6 - Data transfer stage */
 858                 /* Spin lock for BUSY */
 859                 w_ctr(ppb, 0x0c);
 860                 if (!(r_str(ppb) & 0x80))
 861                         return 1;
 862
 863                 if (dev->dp) {
 864                         retv = imm_completion(cmd);
 865                         if (retv == -1)
 866                                 return 0;
 867                         if (retv == 0)
 868                                 return 1;
 869                 }
 870                 cmd->SCp.phase++;
 871                 fallthrough;
 872
 873         case 7:         /* Phase 7 - Post data transfer stage */
 874                 if ((dev->dp) && (dev->rd)) {
 875                         if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
 876                                 w_ctr(ppb, 0x4);
 877                                 w_ctr(ppb, 0xc);
 878                                 w_ctr(ppb, 0xe);
 879                                 w_ctr(ppb, 0x4);
 880                         }
 881                 }
 882                 cmd->SCp.phase++;
 883                 fallthrough;
 884
 885         case 8:         /* Phase 8 - Read status/message */
 886                 /* Check for data overrun */
 887                 if (imm_wait(dev) != (unsigned char) 0xb8) {
 888                         imm_fail(dev, DID_ERROR);
 889                         return 0;
 890                 }
 891                 if (imm_negotiate(dev))
 892                         return 0;
 893                 if (imm_in(dev, &l, 1)) {       /* read status byte */
 894                         /* Check for optional message byte */
 895                         if (imm_wait(dev) == (unsigned char) 0xb8)
 896                                 imm_in(dev, &h, 1);
 897                         cmd->result = (DID_OK << 16) | (l & STATUS_MASK);
 898                 }
 899                 if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
 900                         w_ctr(ppb, 0x4);
 901                         w_ctr(ppb, 0xc);
 902                         w_ctr(ppb, 0xe);
 903                         w_ctr(ppb, 0x4);
 904                 }
 905                 return 0;       /* Finished */
 906
 907         default:
 908                 printk("imm: Invalid scsi phase\n");
 909         }
 910         return 0;
 911 }
 912
 913 static int imm_queuecommand_lck(struct scsi_cmnd *cmd,
 914                 void (*done)(struct scsi_cmnd *))
 915 {
 916         imm_struct *dev = imm_dev(cmd->device->host);
 917
 918         if (dev->cur_cmd) {
 919                 printk("IMM: bug in imm_queuecommand\n");
 920                 return 0;
 921         }
 922         dev->failed = 0;
 923         dev->jstart = jiffies;
 924         dev->cur_cmd = cmd;
 925         cmd->scsi_done = done;
 926         cmd->result = DID_ERROR << 16;  /* default return code */
 927         cmd->SCp.phase = 0;     /* bus free */
 928
 929         schedule_delayed_work(&dev->imm_tq, 0);
 930
 931         imm_pb_claim(dev);
 932
 933         return 0;
 934 }
 935
 936 static DEF_SCSI_QCMD(imm_queuecommand)
 937
 938 /*
 939  * Apparently the disk->capacity attribute is off by 1 sector
 940  * for all disk drives.  We add the one here, but it should really
 941  * be done in sd.c.  Even if it gets fixed there, this will still
 942  * work.
 943  */
 944 static int imm_biosparam(struct scsi_device *sdev, struct block_device *dev,
 945                          sector_t capacity, int ip[])
 946 {
 947         ip[0] = 0x40;
 948         ip[1] = 0x20;
 949         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 950         if (ip[2] > 1024) {
 951                 ip[0] = 0xff;
 952                 ip[1] = 0x3f;
 953                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 954         }
 955         return 0;
 956 }
 957
 958 static int imm_abort(struct scsi_cmnd *cmd)
 959 {
 960         imm_struct *dev = imm_dev(cmd->device->host);
 961         /*
 962          * There is no method for aborting commands since Iomega
 963          * have tied the SCSI_MESSAGE line high in the interface
 964          */
 965
 966         switch (cmd->SCp.phase) {
 967         case 0:         /* Do not have access to parport */
 968         case 1:         /* Have not connected to interface */
 969                 dev->cur_cmd = NULL;    /* Forget the problem */
 970                 return SUCCESS;
 971         default:                /* SCSI command sent, can not abort */
 972                 return FAILED;
 973         }
 974 }
 975
 976 static void imm_reset_pulse(unsigned int base)
 977 {
 978         w_ctr(base, 0x04);
 979         w_dtr(base, 0x40);
 980         udelay(1);
 981         w_ctr(base, 0x0c);
 982         w_ctr(base, 0x0d);
 983         udelay(50);
 984         w_ctr(base, 0x0c);
 985         w_ctr(base, 0x04);
 986 }
 987
 988 static int imm_reset(struct scsi_cmnd *cmd)
 989 {
 990         imm_struct *dev = imm_dev(cmd->device->host);
 991
 992         if (cmd->SCp.phase)
 993                 imm_disconnect(dev);
 994         dev->cur_cmd = NULL;    /* Forget the problem */
 995
 996         imm_connect(dev, CONNECT_NORMAL);
 997         imm_reset_pulse(dev->base);
 998         mdelay(1);              /* device settle delay */
 999         imm_disconnect(dev);
1000         mdelay(1);              /* device settle delay */
1001         return SUCCESS;
1002 }
1003
1004 static int device_check(imm_struct *dev)
1005 {
1006         /* This routine looks for a device and then attempts to use EPP
1007            to send a command. If all goes as planned then EPP is available. */
1008
1009         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
1010         int loop, old_mode, status, k, ppb = dev->base;
1011         unsigned char l;
1012
1013         old_mode = dev->mode;
1014         for (loop = 0; loop < 8; loop++) {
1015                 /* Attempt to use EPP for Test Unit Ready */
1016                 if ((ppb & 0x0007) == 0x0000)
1017                         dev->mode = IMM_EPP_32;
1018
1019               second_pass:
1020                 imm_connect(dev, CONNECT_EPP_MAYBE);
1021                 /* Select SCSI device */
1022                 if (!imm_select(dev, loop)) {
1023                         imm_disconnect(dev);
1024                         continue;
1025                 }
1026                 printk("imm: Found device at ID %i, Attempting to use %s\n",
1027                        loop, IMM_MODE_STRING[dev->mode]);
1028
1029                 /* Send SCSI command */
1030                 status = 1;
1031                 w_ctr(ppb, 0x0c);
1032                 for (l = 0; (l < 3) && (status); l++)
1033                         status = imm_out(dev, &cmd[l << 1], 2);
1034
1035                 if (!status) {
1036                         imm_disconnect(dev);
1037                         imm_connect(dev, CONNECT_EPP_MAYBE);
1038                         imm_reset_pulse(dev->base);
1039                         udelay(1000);
1040                         imm_disconnect(dev);
1041                         udelay(1000);
1042                         if (dev->mode == IMM_EPP_32) {
1043                                 dev->mode = old_mode;
1044                                 goto second_pass;
1045                         }
1046                         printk("imm: Unable to establish communication\n");
1047                         return -EIO;
1048                 }
1049                 w_ctr(ppb, 0x0c);
1050
1051                 k = 1000000;    /* 1 Second */
1052                 do {
1053                         l = r_str(ppb);
1054                         k--;
1055                         udelay(1);
1056                 } while (!(l & 0x80) && (k));
1057
1058                 l &= 0xb8;
1059
1060                 if (l != 0xb8) {
1061                         imm_disconnect(dev);
1062                         imm_connect(dev, CONNECT_EPP_MAYBE);
1063                         imm_reset_pulse(dev->base);
1064                         udelay(1000);
1065                         imm_disconnect(dev);
1066                         udelay(1000);
1067                         if (dev->mode == IMM_EPP_32) {
1068                                 dev->mode = old_mode;
1069                                 goto second_pass;
1070                         }
1071                         printk
1072                             ("imm: Unable to establish communication\n");
1073                         return -EIO;
1074                 }
1075                 imm_disconnect(dev);
1076                 printk
1077                     ("imm: Communication established at 0x%x with ID %i using %s\n",
1078                      ppb, loop, IMM_MODE_STRING[dev->mode]);
1079                 imm_connect(dev, CONNECT_EPP_MAYBE);
1080                 imm_reset_pulse(dev->base);
1081                 udelay(1000);
1082                 imm_disconnect(dev);
1083                 udelay(1000);
1084                 return 0;
1085         }
1086         printk("imm: No devices found\n");
1087         return -ENODEV;
1088 }
1089
1090 /*
1091  * imm cannot deal with highmem, so this causes all IO pages for this host
1092  * to reside in low memory (hence mapped)
1093  */
1094 static int imm_adjust_queue(struct scsi_device *device)
1095 {
1096         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
1097         return 0;
1098 }
1099
1100 static struct scsi_host_template imm_template = {
1101         .module                 = THIS_MODULE,
1102         .proc_name              = "imm",
1103         .show_info              = imm_show_info,
1104         .write_info             = imm_write_info,
1105         .name                   = "Iomega VPI2 (imm) interface",
1106         .queuecommand           = imm_queuecommand,
1107         .eh_abort_handler       = imm_abort,
1108         .eh_host_reset_handler  = imm_reset,
1109         .bios_param             = imm_biosparam,
1110         .this_id                = 7,
1111         .sg_tablesize           = SG_ALL,
1112         .can_queue              = 1,
1113         .slave_alloc            = imm_adjust_queue,
1114 };
1115
1116 /***************************************************************************
1117  *                   Parallel port probing routines                        *
1118  ***************************************************************************/
1119
1120 static LIST_HEAD(imm_hosts);
1121
1122 /*
1123  * Finds the first available device number that can be alloted to the
1124  * new imm device and returns the address of the previous node so that
1125  * we can add to the tail and have a list in the ascending order.
1126  */
1127
1128 static inline imm_struct *find_parent(void)
1129 {
1130         imm_struct *dev, *par = NULL;
1131         unsigned int cnt = 0;
1132
1133         if (list_empty(&imm_hosts))
1134                 return NULL;
1135
1136         list_for_each_entry(dev, &imm_hosts, list) {
1137                 if (dev->dev_no != cnt)
1138                         return par;
1139                 cnt++;
1140                 par = dev;
1141         }
1142
1143         return par;
1144 }
1145
1146 static int __imm_attach(struct parport *pb)
1147 {
1148         struct Scsi_Host *host;
1149         imm_struct *dev, *temp;
1150         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1151         DEFINE_WAIT(wait);
1152         int ports;
1153         int modes, ppb;
1154         int err = -ENOMEM;
1155         struct pardev_cb imm_cb;
1156
1157         init_waitqueue_head(&waiting);
1158
1159         dev = kzalloc(sizeof(imm_struct), GFP_KERNEL);
1160         if (!dev)
1161                 return -ENOMEM;
1162
1163
1164         dev->base = -1;
1165         dev->mode = IMM_AUTODETECT;
1166         INIT_LIST_HEAD(&dev->list);
1167
1168         temp = find_parent();
1169         if (temp)
1170                 dev->dev_no = temp->dev_no + 1;
1171
1172         memset(&imm_cb, 0, sizeof(imm_cb));
1173         imm_cb.private = dev;
1174         imm_cb.wakeup = imm_wakeup;
1175
1176         dev->dev = parport_register_dev_model(pb, "imm", &imm_cb, dev->dev_no);
1177         if (!dev->dev)
1178                 goto out;
1179
1180
1181         /* Claim the bus so it remembers what we do to the control
1182          * registers. [ CTR and ECP ]
1183          */
1184         err = -EBUSY;
1185         dev->waiting = &waiting;
1186         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1187         if (imm_pb_claim(dev))
1188                 schedule_timeout(3 * HZ);
1189         if (dev->wanted) {
1190                 printk(KERN_ERR "imm%d: failed to claim parport because "
1191                         "a pardevice is owning the port for too long "
1192                         "time!\n", pb->number);
1193                 imm_pb_dismiss(dev);
1194                 dev->waiting = NULL;
1195                 finish_wait(&waiting, &wait);
1196                 goto out1;
1197         }
1198         dev->waiting = NULL;
1199         finish_wait(&waiting, &wait);
1200         ppb = dev->base = dev->dev->port->base;
1201         dev->base_hi = dev->dev->port->base_hi;
1202         w_ctr(ppb, 0x0c);
1203         modes = dev->dev->port->modes;
1204
1205         /* Mode detection works up the chain of speed
1206          * This avoids a nasty if-then-else-if-... tree
1207          */
1208         dev->mode = IMM_NIBBLE;
1209
1210         if (modes & PARPORT_MODE_TRISTATE)
1211                 dev->mode = IMM_PS2;
1212
1213         /* Done configuration */
1214
1215         err = imm_init(dev);
1216
1217         imm_pb_release(dev);
1218
1219         if (err)
1220                 goto out1;
1221
1222         /* now the glue ... */
1223         if (dev->mode == IMM_NIBBLE || dev->mode == IMM_PS2)
1224                 ports = 3;
1225         else
1226                 ports = 8;
1227
1228         INIT_DELAYED_WORK(&dev->imm_tq, imm_interrupt);
1229
1230         err = -ENOMEM;
1231         host = scsi_host_alloc(&imm_template, sizeof(imm_struct *));
1232         if (!host)
1233                 goto out1;
1234         host->io_port = pb->base;
1235         host->n_io_port = ports;
1236         host->dma_channel = -1;
1237         host->unique_id = pb->number;
1238         *(imm_struct **)&host->hostdata = dev;
1239         dev->host = host;
1240         if (!temp)
1241                 list_add_tail(&dev->list, &imm_hosts);
1242         else
1243                 list_add_tail(&dev->list, &temp->list);
1244         err = scsi_add_host(host, NULL);
1245         if (err)
1246                 goto out2;
1247         scsi_scan_host(host);
1248         return 0;
1249
1250 out2:
1251         list_del_init(&dev->list);
1252         scsi_host_put(host);
1253 out1:
1254         parport_unregister_device(dev->dev);
1255 out:
1256         kfree(dev);
1257         return err;
1258 }
1259
1260 static void imm_attach(struct parport *pb)
1261 {
1262         __imm_attach(pb);
1263 }
1264
1265 static void imm_detach(struct parport *pb)
1266 {
1267         imm_struct *dev;
1268         list_for_each_entry(dev, &imm_hosts, list) {
1269                 if (dev->dev->port == pb) {
1270                         list_del_init(&dev->list);
1271                         scsi_remove_host(dev->host);
1272                         scsi_host_put(dev->host);
1273                         parport_unregister_device(dev->dev);
1274                         kfree(dev);
1275                         break;
1276                 }
1277         }
1278 }
1279
1280 static struct parport_driver imm_driver = {
1281         .name           = "imm",
1282         .match_port     = imm_attach,
1283         .detach         = imm_detach,
1284         .devmodel       = true,
1285 };
1286
1287 static int __init imm_driver_init(void)
1288 {
1289         printk("imm: Version %s\n", IMM_VERSION);
1290         return parport_register_driver(&imm_driver);
1291 }
1292
1293 static void __exit imm_driver_exit(void)
1294 {
1295         parport_unregister_driver(&imm_driver);
1296 }
1297
1298 module_init(imm_driver_init);
1299 module_exit(imm_driver_exit);
1300
1301 MODULE_LICENSE("GPL");