linux/drivers/scsi/imm.c
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   1/* imm.c   --  low level driver for the IOMEGA MatchMaker
   2 * parallel port SCSI host adapter.
   3 * 
   4 * (The IMM is the embedded controller in the ZIP Plus drive.)
   5 * 
   6 * My unofficial company acronym list is 21 pages long:
   7 *      FLA:    Four letter acronym with built in facility for
   8 *              future expansion to five letters.
   9 */
  10
  11#include <linux/init.h>
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/blkdev.h>
  15#include <linux/parport.h>
  16#include <linux/workqueue.h>
  17#include <linux/delay.h>
  18#include <linux/slab.h>
  19#include <asm/io.h>
  20
  21#include <scsi/scsi.h>
  22#include <scsi/scsi_cmnd.h>
  23#include <scsi/scsi_device.h>
  24#include <scsi/scsi_host.h>
  25
  26/* The following #define is to avoid a clash with hosts.c */
  27#define IMM_PROBE_SPP   0x0001
  28#define IMM_PROBE_PS2   0x0002
  29#define IMM_PROBE_ECR   0x0010
  30#define IMM_PROBE_EPP17 0x0100
  31#define IMM_PROBE_EPP19 0x0200
  32
  33
  34typedef struct {
  35        struct pardevice *dev;  /* Parport device entry         */
  36        int base;               /* Actual port address          */
  37        int base_hi;            /* Hi Base address for ECP-ISA chipset */
  38        int mode;               /* Transfer mode                */
  39        struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  40        struct delayed_work imm_tq;     /* Polling interrupt stuff       */
  41        unsigned long jstart;   /* Jiffies at start             */
  42        unsigned failed:1;      /* Failure flag                 */
  43        unsigned dp:1;          /* Data phase present           */
  44        unsigned rd:1;          /* Read data in data phase      */
  45        unsigned wanted:1;      /* Parport sharing busy flag    */
  46        unsigned int dev_no;    /* Device number                */
  47        wait_queue_head_t *waiting;
  48        struct Scsi_Host *host;
  49        struct list_head list;
  50} imm_struct;
  51
  52static void imm_reset_pulse(unsigned int base);
  53static int device_check(imm_struct *dev);
  54
  55#include "imm.h"
  56
  57static inline imm_struct *imm_dev(struct Scsi_Host *host)
  58{
  59        return *(imm_struct **)&host->hostdata;
  60}
  61
  62static DEFINE_SPINLOCK(arbitration_lock);
  63
  64static void got_it(imm_struct *dev)
  65{
  66        dev->base = dev->dev->port->base;
  67        if (dev->cur_cmd)
  68                dev->cur_cmd->SCp.phase = 1;
  69        else
  70                wake_up(dev->waiting);
  71}
  72
  73static void imm_wakeup(void *ref)
  74{
  75        imm_struct *dev = (imm_struct *) ref;
  76        unsigned long flags;
  77
  78        spin_lock_irqsave(&arbitration_lock, flags);
  79        if (dev->wanted) {
  80                if (parport_claim(dev->dev) == 0) {
  81                        got_it(dev);
  82                        dev->wanted = 0;
  83                }
  84        }
  85        spin_unlock_irqrestore(&arbitration_lock, flags);
  86}
  87
  88static int imm_pb_claim(imm_struct *dev)
  89{
  90        unsigned long flags;
  91        int res = 1;
  92        spin_lock_irqsave(&arbitration_lock, flags);
  93        if (parport_claim(dev->dev) == 0) {
  94                got_it(dev);
  95                res = 0;
  96        }
  97        dev->wanted = res;
  98        spin_unlock_irqrestore(&arbitration_lock, flags);
  99        return res;
 100}
 101
 102static void imm_pb_dismiss(imm_struct *dev)
 103{
 104        unsigned long flags;
 105        int wanted;
 106        spin_lock_irqsave(&arbitration_lock, flags);
 107        wanted = dev->wanted;
 108        dev->wanted = 0;
 109        spin_unlock_irqrestore(&arbitration_lock, flags);
 110        if (!wanted)
 111                parport_release(dev->dev);
 112}
 113
 114static inline void imm_pb_release(imm_struct *dev)
 115{
 116        parport_release(dev->dev);
 117}
 118
 119/* This is to give the imm driver a way to modify the timings (and other
 120 * parameters) by writing to the /proc/scsi/imm/0 file.
 121 * Very simple method really... (Too simple, no error checking :( )
 122 * Reason: Kernel hackers HATE having to unload and reload modules for
 123 * testing...
 124 * Also gives a method to use a script to obtain optimum timings (TODO)
 125 */
 126static int imm_write_info(struct Scsi_Host *host, char *buffer, int length)
 127{
 128        imm_struct *dev = imm_dev(host);
 129
 130        if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 131                dev->mode = simple_strtoul(buffer + 5, NULL, 0);
 132                return length;
 133        }
 134        printk("imm /proc: invalid variable\n");
 135        return -EINVAL;
 136}
 137
 138static int imm_show_info(struct seq_file *m, struct Scsi_Host *host)
 139{
 140        imm_struct *dev = imm_dev(host);
 141
 142        seq_printf(m, "Version : %s\n", IMM_VERSION);
 143        seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 144        seq_printf(m, "Mode    : %s\n", IMM_MODE_STRING[dev->mode]);
 145        return 0;
 146}
 147
 148#if IMM_DEBUG > 0
 149#define imm_fail(x,y) printk("imm: imm_fail(%i) from %s at line %d\n",\
 150           y, __func__, __LINE__); imm_fail_func(x,y);
 151static inline void
 152imm_fail_func(imm_struct *dev, int error_code)
 153#else
 154static inline void
 155imm_fail(imm_struct *dev, int error_code)
 156#endif
 157{
 158        /* If we fail a device then we trash status / message bytes */
 159        if (dev->cur_cmd) {
 160                dev->cur_cmd->result = error_code << 16;
 161                dev->failed = 1;
 162        }
 163}
 164
 165/*
 166 * Wait for the high bit to be set.
 167 * 
 168 * In principle, this could be tied to an interrupt, but the adapter
 169 * doesn't appear to be designed to support interrupts.  We spin on
 170 * the 0x80 ready bit. 
 171 */
 172static unsigned char imm_wait(imm_struct *dev)
 173{
 174        int k;
 175        unsigned short ppb = dev->base;
 176        unsigned char r;
 177
 178        w_ctr(ppb, 0x0c);
 179
 180        k = IMM_SPIN_TMO;
 181        do {
 182                r = r_str(ppb);
 183                k--;
 184                udelay(1);
 185        }
 186        while (!(r & 0x80) && (k));
 187
 188        /*
 189         * STR register (LPT base+1) to SCSI mapping:
 190         *
 191         * STR      imm     imm
 192         * ===================================
 193         * 0x80     S_REQ   S_REQ
 194         * 0x40     !S_BSY  (????)
 195         * 0x20     !S_CD   !S_CD
 196         * 0x10     !S_IO   !S_IO
 197         * 0x08     (????)  !S_BSY
 198         *
 199         * imm      imm     meaning
 200         * ==================================
 201         * 0xf0     0xb8    Bit mask
 202         * 0xc0     0x88    ZIP wants more data
 203         * 0xd0     0x98    ZIP wants to send more data
 204         * 0xe0     0xa8    ZIP is expecting SCSI command data
 205         * 0xf0     0xb8    end of transfer, ZIP is sending status
 206         */
 207        w_ctr(ppb, 0x04);
 208        if (k)
 209                return (r & 0xb8);
 210
 211        /* Counter expired - Time out occurred */
 212        imm_fail(dev, DID_TIME_OUT);
 213        printk("imm timeout in imm_wait\n");
 214        return 0;               /* command timed out */
 215}
 216
 217static int imm_negotiate(imm_struct * tmp)
 218{
 219        /*
 220         * The following is supposedly the IEEE 1284-1994 negotiate
 221         * sequence. I have yet to obtain a copy of the above standard
 222         * so this is a bit of a guess...
 223         *
 224         * A fair chunk of this is based on the Linux parport implementation
 225         * of IEEE 1284.
 226         *
 227         * Return 0 if data available
 228         *        1 if no data available
 229         */
 230
 231        unsigned short base = tmp->base;
 232        unsigned char a, mode;
 233
 234        switch (tmp->mode) {
 235        case IMM_NIBBLE:
 236                mode = 0x00;
 237                break;
 238        case IMM_PS2:
 239                mode = 0x01;
 240                break;
 241        default:
 242                return 0;
 243        }
 244
 245        w_ctr(base, 0x04);
 246        udelay(5);
 247        w_dtr(base, mode);
 248        udelay(100);
 249        w_ctr(base, 0x06);
 250        udelay(5);
 251        a = (r_str(base) & 0x20) ? 0 : 1;
 252        udelay(5);
 253        w_ctr(base, 0x07);
 254        udelay(5);
 255        w_ctr(base, 0x06);
 256
 257        if (a) {
 258                printk
 259                    ("IMM: IEEE1284 negotiate indicates no data available.\n");
 260                imm_fail(tmp, DID_ERROR);
 261        }
 262        return a;
 263}
 264
 265/* 
 266 * Clear EPP timeout bit. 
 267 */
 268static inline void epp_reset(unsigned short ppb)
 269{
 270        int i;
 271
 272        i = r_str(ppb);
 273        w_str(ppb, i);
 274        w_str(ppb, i & 0xfe);
 275}
 276
 277/* 
 278 * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 279 */
 280static inline void ecp_sync(imm_struct *dev)
 281{
 282        int i, ppb_hi = dev->base_hi;
 283
 284        if (ppb_hi == 0)
 285                return;
 286
 287        if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 288                for (i = 0; i < 100; i++) {
 289                        if (r_ecr(ppb_hi) & 0x01)
 290                                return;
 291                        udelay(5);
 292                }
 293                printk("imm: ECP sync failed as data still present in FIFO.\n");
 294        }
 295}
 296
 297static int imm_byte_out(unsigned short base, const char *buffer, int len)
 298{
 299        int i;
 300
 301        w_ctr(base, 0x4);       /* apparently a sane mode */
 302        for (i = len >> 1; i; i--) {
 303                w_dtr(base, *buffer++);
 304                w_ctr(base, 0x5);       /* Drop STROBE low */
 305                w_dtr(base, *buffer++);
 306                w_ctr(base, 0x0);       /* STROBE high + INIT low */
 307        }
 308        w_ctr(base, 0x4);       /* apparently a sane mode */
 309        return 1;               /* All went well - we hope! */
 310}
 311
 312static int imm_nibble_in(unsigned short base, char *buffer, int len)
 313{
 314        unsigned char l;
 315        int i;
 316
 317        /*
 318         * The following is based on documented timing signals
 319         */
 320        w_ctr(base, 0x4);
 321        for (i = len; i; i--) {
 322                w_ctr(base, 0x6);
 323                l = (r_str(base) & 0xf0) >> 4;
 324                w_ctr(base, 0x5);
 325                *buffer++ = (r_str(base) & 0xf0) | l;
 326                w_ctr(base, 0x4);
 327        }
 328        return 1;               /* All went well - we hope! */
 329}
 330
 331static int imm_byte_in(unsigned short base, char *buffer, int len)
 332{
 333        int i;
 334
 335        /*
 336         * The following is based on documented timing signals
 337         */
 338        w_ctr(base, 0x4);
 339        for (i = len; i; i--) {
 340                w_ctr(base, 0x26);
 341                *buffer++ = r_dtr(base);
 342                w_ctr(base, 0x25);
 343        }
 344        return 1;               /* All went well - we hope! */
 345}
 346
 347static int imm_out(imm_struct *dev, char *buffer, int len)
 348{
 349        unsigned short ppb = dev->base;
 350        int r = imm_wait(dev);
 351
 352        /*
 353         * Make sure that:
 354         * a) the SCSI bus is BUSY (device still listening)
 355         * b) the device is listening
 356         */
 357        if ((r & 0x18) != 0x08) {
 358                imm_fail(dev, DID_ERROR);
 359                printk("IMM: returned SCSI status %2x\n", r);
 360                return 0;
 361        }
 362        switch (dev->mode) {
 363        case IMM_EPP_32:
 364        case IMM_EPP_16:
 365        case IMM_EPP_8:
 366                epp_reset(ppb);
 367                w_ctr(ppb, 0x4);
 368#ifdef CONFIG_SCSI_IZIP_EPP16
 369                if (!(((long) buffer | len) & 0x01))
 370                        outsw(ppb + 4, buffer, len >> 1);
 371#else
 372                if (!(((long) buffer | len) & 0x03))
 373                        outsl(ppb + 4, buffer, len >> 2);
 374#endif
 375                else
 376                        outsb(ppb + 4, buffer, len);
 377                w_ctr(ppb, 0xc);
 378                r = !(r_str(ppb) & 0x01);
 379                w_ctr(ppb, 0xc);
 380                ecp_sync(dev);
 381                break;
 382
 383        case IMM_NIBBLE:
 384        case IMM_PS2:
 385                /* 8 bit output, with a loop */
 386                r = imm_byte_out(ppb, buffer, len);
 387                break;
 388
 389        default:
 390                printk("IMM: bug in imm_out()\n");
 391                r = 0;
 392        }
 393        return r;
 394}
 395
 396static int imm_in(imm_struct *dev, char *buffer, int len)
 397{
 398        unsigned short ppb = dev->base;
 399        int r = imm_wait(dev);
 400
 401        /*
 402         * Make sure that:
 403         * a) the SCSI bus is BUSY (device still listening)
 404         * b) the device is sending data
 405         */
 406        if ((r & 0x18) != 0x18) {
 407                imm_fail(dev, DID_ERROR);
 408                return 0;
 409        }
 410        switch (dev->mode) {
 411        case IMM_NIBBLE:
 412                /* 4 bit input, with a loop */
 413                r = imm_nibble_in(ppb, buffer, len);
 414                w_ctr(ppb, 0xc);
 415                break;
 416
 417        case IMM_PS2:
 418                /* 8 bit input, with a loop */
 419                r = imm_byte_in(ppb, buffer, len);
 420                w_ctr(ppb, 0xc);
 421                break;
 422
 423        case IMM_EPP_32:
 424        case IMM_EPP_16:
 425        case IMM_EPP_8:
 426                epp_reset(ppb);
 427                w_ctr(ppb, 0x24);
 428#ifdef CONFIG_SCSI_IZIP_EPP16
 429                if (!(((long) buffer | len) & 0x01))
 430                        insw(ppb + 4, buffer, len >> 1);
 431#else
 432                if (!(((long) buffer | len) & 0x03))
 433                        insl(ppb + 4, buffer, len >> 2);
 434#endif
 435                else
 436                        insb(ppb + 4, buffer, len);
 437                w_ctr(ppb, 0x2c);
 438                r = !(r_str(ppb) & 0x01);
 439                w_ctr(ppb, 0x2c);
 440                ecp_sync(dev);
 441                break;
 442
 443        default:
 444                printk("IMM: bug in imm_ins()\n");
 445                r = 0;
 446                break;
 447        }
 448        return r;
 449}
 450
 451static int imm_cpp(unsigned short ppb, unsigned char b)
 452{
 453        /*
 454         * Comments on udelay values refer to the
 455         * Command Packet Protocol (CPP) timing diagram.
 456         */
 457
 458        unsigned char s1, s2, s3;
 459        w_ctr(ppb, 0x0c);
 460        udelay(2);              /* 1 usec - infinite */
 461        w_dtr(ppb, 0xaa);
 462        udelay(10);             /* 7 usec - infinite */
 463        w_dtr(ppb, 0x55);
 464        udelay(10);             /* 7 usec - infinite */
 465        w_dtr(ppb, 0x00);
 466        udelay(10);             /* 7 usec - infinite */
 467        w_dtr(ppb, 0xff);
 468        udelay(10);             /* 7 usec - infinite */
 469        s1 = r_str(ppb) & 0xb8;
 470        w_dtr(ppb, 0x87);
 471        udelay(10);             /* 7 usec - infinite */
 472        s2 = r_str(ppb) & 0xb8;
 473        w_dtr(ppb, 0x78);
 474        udelay(10);             /* 7 usec - infinite */
 475        s3 = r_str(ppb) & 0x38;
 476        /*
 477         * Values for b are:
 478         * 0000 00aa    Assign address aa to current device
 479         * 0010 00aa    Select device aa in EPP Winbond mode
 480         * 0010 10aa    Select device aa in EPP mode
 481         * 0011 xxxx    Deselect all devices
 482         * 0110 00aa    Test device aa
 483         * 1101 00aa    Select device aa in ECP mode
 484         * 1110 00aa    Select device aa in Compatible mode
 485         */
 486        w_dtr(ppb, b);
 487        udelay(2);              /* 1 usec - infinite */
 488        w_ctr(ppb, 0x0c);
 489        udelay(10);             /* 7 usec - infinite */
 490        w_ctr(ppb, 0x0d);
 491        udelay(2);              /* 1 usec - infinite */
 492        w_ctr(ppb, 0x0c);
 493        udelay(10);             /* 7 usec - infinite */
 494        w_dtr(ppb, 0xff);
 495        udelay(10);             /* 7 usec - infinite */
 496
 497        /*
 498         * The following table is electrical pin values.
 499         * (BSY is inverted at the CTR register)
 500         *
 501         *       BSY  ACK  POut SEL  Fault
 502         * S1    0    X    1    1    1
 503         * S2    1    X    0    1    1
 504         * S3    L    X    1    1    S
 505         *
 506         * L => Last device in chain
 507         * S => Selected
 508         *
 509         * Observered values for S1,S2,S3 are:
 510         * Disconnect => f8/58/78
 511         * Connect    => f8/58/70
 512         */
 513        if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x30))
 514                return 1;       /* Connected */
 515        if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x38))
 516                return 0;       /* Disconnected */
 517
 518        return -1;              /* No device present */
 519}
 520
 521static inline int imm_connect(imm_struct *dev, int flag)
 522{
 523        unsigned short ppb = dev->base;
 524
 525        imm_cpp(ppb, 0xe0);     /* Select device 0 in compatible mode */
 526        imm_cpp(ppb, 0x30);     /* Disconnect all devices */
 527
 528        if ((dev->mode == IMM_EPP_8) ||
 529            (dev->mode == IMM_EPP_16) ||
 530            (dev->mode == IMM_EPP_32))
 531                return imm_cpp(ppb, 0x28);      /* Select device 0 in EPP mode */
 532        return imm_cpp(ppb, 0xe0);      /* Select device 0 in compatible mode */
 533}
 534
 535static void imm_disconnect(imm_struct *dev)
 536{
 537        imm_cpp(dev->base, 0x30);       /* Disconnect all devices */
 538}
 539
 540static int imm_select(imm_struct *dev, int target)
 541{
 542        int k;
 543        unsigned short ppb = dev->base;
 544
 545        /*
 546         * Firstly we want to make sure there is nothing
 547         * holding onto the SCSI bus.
 548         */
 549        w_ctr(ppb, 0xc);
 550
 551        k = IMM_SELECT_TMO;
 552        do {
 553                k--;
 554        } while ((r_str(ppb) & 0x08) && (k));
 555
 556        if (!k)
 557                return 0;
 558
 559        /*
 560         * Now assert the SCSI ID (HOST and TARGET) on the data bus
 561         */
 562        w_ctr(ppb, 0x4);
 563        w_dtr(ppb, 0x80 | (1 << target));
 564        udelay(1);
 565
 566        /*
 567         * Deassert SELIN first followed by STROBE
 568         */
 569        w_ctr(ppb, 0xc);
 570        w_ctr(ppb, 0xd);
 571
 572        /*
 573         * ACK should drop low while SELIN is deasserted.
 574         * FAULT should drop low when the SCSI device latches the bus.
 575         */
 576        k = IMM_SELECT_TMO;
 577        do {
 578                k--;
 579        }
 580        while (!(r_str(ppb) & 0x08) && (k));
 581
 582        /*
 583         * Place the interface back into a sane state (status mode)
 584         */
 585        w_ctr(ppb, 0xc);
 586        return (k) ? 1 : 0;
 587}
 588
 589static int imm_init(imm_struct *dev)
 590{
 591        if (imm_connect(dev, 0) != 1)
 592                return -EIO;
 593        imm_reset_pulse(dev->base);
 594        mdelay(1);      /* Delay to allow devices to settle */
 595        imm_disconnect(dev);
 596        mdelay(1);      /* Another delay to allow devices to settle */
 597        return device_check(dev);
 598}
 599
 600static inline int imm_send_command(struct scsi_cmnd *cmd)
 601{
 602        imm_struct *dev = imm_dev(cmd->device->host);
 603        int k;
 604
 605        /* NOTE: IMM uses byte pairs */
 606        for (k = 0; k < cmd->cmd_len; k += 2)
 607                if (!imm_out(dev, &cmd->cmnd[k], 2))
 608                        return 0;
 609        return 1;
 610}
 611
 612/*
 613 * The bulk flag enables some optimisations in the data transfer loops,
 614 * it should be true for any command that transfers data in integral
 615 * numbers of sectors.
 616 * 
 617 * The driver appears to remain stable if we speed up the parallel port
 618 * i/o in this function, but not elsewhere.
 619 */
 620static int imm_completion(struct scsi_cmnd *cmd)
 621{
 622        /* Return codes:
 623         * -1     Error
 624         *  0     Told to schedule
 625         *  1     Finished data transfer
 626         */
 627        imm_struct *dev = imm_dev(cmd->device->host);
 628        unsigned short ppb = dev->base;
 629        unsigned long start_jiffies = jiffies;
 630
 631        unsigned char r, v;
 632        int fast, bulk, status;
 633
 634        v = cmd->cmnd[0];
 635        bulk = ((v == READ_6) ||
 636                (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 637
 638        /*
 639         * We only get here if the drive is ready to comunicate,
 640         * hence no need for a full imm_wait.
 641         */
 642        w_ctr(ppb, 0x0c);
 643        r = (r_str(ppb) & 0xb8);
 644
 645        /*
 646         * while (device is not ready to send status byte)
 647         *     loop;
 648         */
 649        while (r != (unsigned char) 0xb8) {
 650                /*
 651                 * If we have been running for more than a full timer tick
 652                 * then take a rest.
 653                 */
 654                if (time_after(jiffies, start_jiffies + 1))
 655                        return 0;
 656
 657                /*
 658                 * FAIL if:
 659                 * a) Drive status is screwy (!ready && !present)
 660                 * b) Drive is requesting/sending more data than expected
 661                 */
 662                if (((r & 0x88) != 0x88) || (cmd->SCp.this_residual <= 0)) {
 663                        imm_fail(dev, DID_ERROR);
 664                        return -1;      /* ERROR_RETURN */
 665                }
 666                /* determine if we should use burst I/O */
 667                if (dev->rd == 0) {
 668                        fast = (bulk
 669                                && (cmd->SCp.this_residual >=
 670                                    IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 2;
 671                        status = imm_out(dev, cmd->SCp.ptr, fast);
 672                } else {
 673                        fast = (bulk
 674                                && (cmd->SCp.this_residual >=
 675                                    IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 1;
 676                        status = imm_in(dev, cmd->SCp.ptr, fast);
 677                }
 678
 679                cmd->SCp.ptr += fast;
 680                cmd->SCp.this_residual -= fast;
 681
 682                if (!status) {
 683                        imm_fail(dev, DID_BUS_BUSY);
 684                        return -1;      /* ERROR_RETURN */
 685                }
 686                if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 687                        /* if scatter/gather, advance to the next segment */
 688                        if (cmd->SCp.buffers_residual--) {
 689                                cmd->SCp.buffer++;
 690                                cmd->SCp.this_residual =
 691                                    cmd->SCp.buffer->length;
 692                                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 693
 694                                /*
 695                                 * Make sure that we transfer even number of bytes
 696                                 * otherwise it makes imm_byte_out() messy.
 697                                 */
 698                                if (cmd->SCp.this_residual & 0x01)
 699                                        cmd->SCp.this_residual++;
 700                        }
 701                }
 702                /* Now check to see if the drive is ready to comunicate */
 703                w_ctr(ppb, 0x0c);
 704                r = (r_str(ppb) & 0xb8);
 705
 706                /* If not, drop back down to the scheduler and wait a timer tick */
 707                if (!(r & 0x80))
 708                        return 0;
 709        }
 710        return 1;               /* FINISH_RETURN */
 711}
 712
 713/*
 714 * Since the IMM itself doesn't generate interrupts, we use
 715 * the scheduler's task queue to generate a stream of call-backs and
 716 * complete the request when the drive is ready.
 717 */
 718static void imm_interrupt(struct work_struct *work)
 719{
 720        imm_struct *dev = container_of(work, imm_struct, imm_tq.work);
 721        struct scsi_cmnd *cmd = dev->cur_cmd;
 722        struct Scsi_Host *host = cmd->device->host;
 723        unsigned long flags;
 724
 725        if (imm_engine(dev, cmd)) {
 726                schedule_delayed_work(&dev->imm_tq, 1);
 727                return;
 728        }
 729        /* Command must of completed hence it is safe to let go... */
 730#if IMM_DEBUG > 0
 731        switch ((cmd->result >> 16) & 0xff) {
 732        case DID_OK:
 733                break;
 734        case DID_NO_CONNECT:
 735                printk("imm: no device at SCSI ID %i\n", cmd->device->id);
 736                break;
 737        case DID_BUS_BUSY:
 738                printk("imm: BUS BUSY - EPP timeout detected\n");
 739                break;
 740        case DID_TIME_OUT:
 741                printk("imm: unknown timeout\n");
 742                break;
 743        case DID_ABORT:
 744                printk("imm: told to abort\n");
 745                break;
 746        case DID_PARITY:
 747                printk("imm: parity error (???)\n");
 748                break;
 749        case DID_ERROR:
 750                printk("imm: internal driver error\n");
 751                break;
 752        case DID_RESET:
 753                printk("imm: told to reset device\n");
 754                break;
 755        case DID_BAD_INTR:
 756                printk("imm: bad interrupt (???)\n");
 757                break;
 758        default:
 759                printk("imm: bad return code (%02x)\n",
 760                       (cmd->result >> 16) & 0xff);
 761        }
 762#endif
 763
 764        if (cmd->SCp.phase > 1)
 765                imm_disconnect(dev);
 766
 767        imm_pb_dismiss(dev);
 768
 769        spin_lock_irqsave(host->host_lock, flags);
 770        dev->cur_cmd = NULL;
 771        cmd->scsi_done(cmd);
 772        spin_unlock_irqrestore(host->host_lock, flags);
 773        return;
 774}
 775
 776static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
 777{
 778        unsigned short ppb = dev->base;
 779        unsigned char l = 0, h = 0;
 780        int retv, x;
 781
 782        /* First check for any errors that may have occurred
 783         * Here we check for internal errors
 784         */
 785        if (dev->failed)
 786                return 0;
 787
 788        switch (cmd->SCp.phase) {
 789        case 0:         /* Phase 0 - Waiting for parport */
 790                if (time_after(jiffies, dev->jstart + HZ)) {
 791                        /*
 792                         * We waited more than a second
 793                         * for parport to call us
 794                         */
 795                        imm_fail(dev, DID_BUS_BUSY);
 796                        return 0;
 797                }
 798                return 1;       /* wait until imm_wakeup claims parport */
 799                /* Phase 1 - Connected */
 800        case 1:
 801                imm_connect(dev, CONNECT_EPP_MAYBE);
 802                cmd->SCp.phase++;
 803
 804                /* Phase 2 - We are now talking to the scsi bus */
 805        case 2:
 806                if (!imm_select(dev, scmd_id(cmd))) {
 807                        imm_fail(dev, DID_NO_CONNECT);
 808                        return 0;
 809                }
 810                cmd->SCp.phase++;
 811
 812                /* Phase 3 - Ready to accept a command */
 813        case 3:
 814                w_ctr(ppb, 0x0c);
 815                if (!(r_str(ppb) & 0x80))
 816                        return 1;
 817
 818                if (!imm_send_command(cmd))
 819                        return 0;
 820                cmd->SCp.phase++;
 821
 822                /* Phase 4 - Setup scatter/gather buffers */
 823        case 4:
 824                if (scsi_bufflen(cmd)) {
 825                        cmd->SCp.buffer = scsi_sglist(cmd);
 826                        cmd->SCp.this_residual = cmd->SCp.buffer->length;
 827                        cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 828                } else {
 829                        cmd->SCp.buffer = NULL;
 830                        cmd->SCp.this_residual = 0;
 831                        cmd->SCp.ptr = NULL;
 832                }
 833                cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 834                cmd->SCp.phase++;
 835                if (cmd->SCp.this_residual & 0x01)
 836                        cmd->SCp.this_residual++;
 837                /* Phase 5 - Pre-Data transfer stage */
 838        case 5:
 839                /* Spin lock for BUSY */
 840                w_ctr(ppb, 0x0c);
 841                if (!(r_str(ppb) & 0x80))
 842                        return 1;
 843
 844                /* Require negotiation for read requests */
 845                x = (r_str(ppb) & 0xb8);
 846                dev->rd = (x & 0x10) ? 1 : 0;
 847                dev->dp = (x & 0x20) ? 0 : 1;
 848
 849                if ((dev->dp) && (dev->rd))
 850                        if (imm_negotiate(dev))
 851                                return 0;
 852                cmd->SCp.phase++;
 853
 854                /* Phase 6 - Data transfer stage */
 855        case 6:
 856                /* Spin lock for BUSY */
 857                w_ctr(ppb, 0x0c);
 858                if (!(r_str(ppb) & 0x80))
 859                        return 1;
 860
 861                if (dev->dp) {
 862                        retv = imm_completion(cmd);
 863                        if (retv == -1)
 864                                return 0;
 865                        if (retv == 0)
 866                                return 1;
 867                }
 868                cmd->SCp.phase++;
 869
 870                /* Phase 7 - Post data transfer stage */
 871        case 7:
 872                if ((dev->dp) && (dev->rd)) {
 873                        if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
 874                                w_ctr(ppb, 0x4);
 875                                w_ctr(ppb, 0xc);
 876                                w_ctr(ppb, 0xe);
 877                                w_ctr(ppb, 0x4);
 878                        }
 879                }
 880                cmd->SCp.phase++;
 881
 882                /* Phase 8 - Read status/message */
 883        case 8:
 884                /* Check for data overrun */
 885                if (imm_wait(dev) != (unsigned char) 0xb8) {
 886                        imm_fail(dev, DID_ERROR);
 887                        return 0;
 888                }
 889                if (imm_negotiate(dev))
 890                        return 0;
 891                if (imm_in(dev, &l, 1)) {       /* read status byte */
 892                        /* Check for optional message byte */
 893                        if (imm_wait(dev) == (unsigned char) 0xb8)
 894                                imm_in(dev, &h, 1);
 895                        cmd->result = (DID_OK << 16) | (l & STATUS_MASK);
 896                }
 897                if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
 898                        w_ctr(ppb, 0x4);
 899                        w_ctr(ppb, 0xc);
 900                        w_ctr(ppb, 0xe);
 901                        w_ctr(ppb, 0x4);
 902                }
 903                return 0;       /* Finished */
 904                break;
 905
 906        default:
 907                printk("imm: Invalid scsi phase\n");
 908        }
 909        return 0;
 910}
 911
 912static int imm_queuecommand_lck(struct scsi_cmnd *cmd,
 913                void (*done)(struct scsi_cmnd *))
 914{
 915        imm_struct *dev = imm_dev(cmd->device->host);
 916
 917        if (dev->cur_cmd) {
 918                printk("IMM: bug in imm_queuecommand\n");
 919                return 0;
 920        }
 921        dev->failed = 0;
 922        dev->jstart = jiffies;
 923        dev->cur_cmd = cmd;
 924        cmd->scsi_done = done;
 925        cmd->result = DID_ERROR << 16;  /* default return code */
 926        cmd->SCp.phase = 0;     /* bus free */
 927
 928        schedule_delayed_work(&dev->imm_tq, 0);
 929
 930        imm_pb_claim(dev);
 931
 932        return 0;
 933}
 934
 935static DEF_SCSI_QCMD(imm_queuecommand)
 936
 937/*
 938 * Apparently the disk->capacity attribute is off by 1 sector 
 939 * for all disk drives.  We add the one here, but it should really
 940 * be done in sd.c.  Even if it gets fixed there, this will still
 941 * work.
 942 */
 943static int imm_biosparam(struct scsi_device *sdev, struct block_device *dev,
 944                         sector_t capacity, int ip[])
 945{
 946        ip[0] = 0x40;
 947        ip[1] = 0x20;
 948        ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 949        if (ip[2] > 1024) {
 950                ip[0] = 0xff;
 951                ip[1] = 0x3f;
 952                ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 953        }
 954        return 0;
 955}
 956
 957static int imm_abort(struct scsi_cmnd *cmd)
 958{
 959        imm_struct *dev = imm_dev(cmd->device->host);
 960        /*
 961         * There is no method for aborting commands since Iomega
 962         * have tied the SCSI_MESSAGE line high in the interface
 963         */
 964
 965        switch (cmd->SCp.phase) {
 966        case 0:         /* Do not have access to parport */
 967        case 1:         /* Have not connected to interface */
 968                dev->cur_cmd = NULL;    /* Forget the problem */
 969                return SUCCESS;
 970                break;
 971        default:                /* SCSI command sent, can not abort */
 972                return FAILED;
 973                break;
 974        }
 975}
 976
 977static void imm_reset_pulse(unsigned int base)
 978{
 979        w_ctr(base, 0x04);
 980        w_dtr(base, 0x40);
 981        udelay(1);
 982        w_ctr(base, 0x0c);
 983        w_ctr(base, 0x0d);
 984        udelay(50);
 985        w_ctr(base, 0x0c);
 986        w_ctr(base, 0x04);
 987}
 988
 989static int imm_reset(struct scsi_cmnd *cmd)
 990{
 991        imm_struct *dev = imm_dev(cmd->device->host);
 992
 993        if (cmd->SCp.phase)
 994                imm_disconnect(dev);
 995        dev->cur_cmd = NULL;    /* Forget the problem */
 996
 997        imm_connect(dev, CONNECT_NORMAL);
 998        imm_reset_pulse(dev->base);
 999        mdelay(1);              /* device settle delay */
1000        imm_disconnect(dev);
1001        mdelay(1);              /* device settle delay */
1002        return SUCCESS;
1003}
1004
1005static int device_check(imm_struct *dev)
1006{
1007        /* This routine looks for a device and then attempts to use EPP
1008           to send a command. If all goes as planned then EPP is available. */
1009
1010        static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
1011        int loop, old_mode, status, k, ppb = dev->base;
1012        unsigned char l;
1013
1014        old_mode = dev->mode;
1015        for (loop = 0; loop < 8; loop++) {
1016                /* Attempt to use EPP for Test Unit Ready */
1017                if ((ppb & 0x0007) == 0x0000)
1018                        dev->mode = IMM_EPP_32;
1019
1020              second_pass:
1021                imm_connect(dev, CONNECT_EPP_MAYBE);
1022                /* Select SCSI device */
1023                if (!imm_select(dev, loop)) {
1024                        imm_disconnect(dev);
1025                        continue;
1026                }
1027                printk("imm: Found device at ID %i, Attempting to use %s\n",
1028                       loop, IMM_MODE_STRING[dev->mode]);
1029
1030                /* Send SCSI command */
1031                status = 1;
1032                w_ctr(ppb, 0x0c);
1033                for (l = 0; (l < 3) && (status); l++)
1034                        status = imm_out(dev, &cmd[l << 1], 2);
1035
1036                if (!status) {
1037                        imm_disconnect(dev);
1038                        imm_connect(dev, CONNECT_EPP_MAYBE);
1039                        imm_reset_pulse(dev->base);
1040                        udelay(1000);
1041                        imm_disconnect(dev);
1042                        udelay(1000);
1043                        if (dev->mode == IMM_EPP_32) {
1044                                dev->mode = old_mode;
1045                                goto second_pass;
1046                        }
1047                        printk("imm: Unable to establish communication\n");
1048                        return -EIO;
1049                }
1050                w_ctr(ppb, 0x0c);
1051
1052                k = 1000000;    /* 1 Second */
1053                do {
1054                        l = r_str(ppb);
1055                        k--;
1056                        udelay(1);
1057                } while (!(l & 0x80) && (k));
1058
1059                l &= 0xb8;
1060
1061                if (l != 0xb8) {
1062                        imm_disconnect(dev);
1063                        imm_connect(dev, CONNECT_EPP_MAYBE);
1064                        imm_reset_pulse(dev->base);
1065                        udelay(1000);
1066                        imm_disconnect(dev);
1067                        udelay(1000);
1068                        if (dev->mode == IMM_EPP_32) {
1069                                dev->mode = old_mode;
1070                                goto second_pass;
1071                        }
1072                        printk
1073                            ("imm: Unable to establish communication\n");
1074                        return -EIO;
1075                }
1076                imm_disconnect(dev);
1077                printk
1078                    ("imm: Communication established at 0x%x with ID %i using %s\n",
1079                     ppb, loop, IMM_MODE_STRING[dev->mode]);
1080                imm_connect(dev, CONNECT_EPP_MAYBE);
1081                imm_reset_pulse(dev->base);
1082                udelay(1000);
1083                imm_disconnect(dev);
1084                udelay(1000);
1085                return 0;
1086        }
1087        printk("imm: No devices found\n");
1088        return -ENODEV;
1089}
1090
1091/*
1092 * imm cannot deal with highmem, so this causes all IO pages for this host
1093 * to reside in low memory (hence mapped)
1094 */
1095static int imm_adjust_queue(struct scsi_device *device)
1096{
1097        blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
1098        return 0;
1099}
1100
1101static struct scsi_host_template imm_template = {
1102        .module                 = THIS_MODULE,
1103        .proc_name              = "imm",
1104        .show_info              = imm_show_info,
1105        .write_info             = imm_write_info,
1106        .name                   = "Iomega VPI2 (imm) interface",
1107        .queuecommand           = imm_queuecommand,
1108        .eh_abort_handler       = imm_abort,
1109        .eh_host_reset_handler  = imm_reset,
1110        .bios_param             = imm_biosparam,
1111        .this_id                = 7,
1112        .sg_tablesize           = SG_ALL,
1113        .use_clustering         = ENABLE_CLUSTERING,
1114        .can_queue              = 1,
1115        .slave_alloc            = imm_adjust_queue,
1116};
1117
1118/***************************************************************************
1119 *                   Parallel port probing routines                        *
1120 ***************************************************************************/
1121
1122static LIST_HEAD(imm_hosts);
1123
1124/*
1125 * Finds the first available device number that can be alloted to the
1126 * new imm device and returns the address of the previous node so that
1127 * we can add to the tail and have a list in the ascending order.
1128 */
1129
1130static inline imm_struct *find_parent(void)
1131{
1132        imm_struct *dev, *par = NULL;
1133        unsigned int cnt = 0;
1134
1135        if (list_empty(&imm_hosts))
1136                return NULL;
1137
1138        list_for_each_entry(dev, &imm_hosts, list) {
1139                if (dev->dev_no != cnt)
1140                        return par;
1141                cnt++;
1142                par = dev;
1143        }
1144
1145        return par;
1146}
1147
1148static int __imm_attach(struct parport *pb)
1149{
1150        struct Scsi_Host *host;
1151        imm_struct *dev, *temp;
1152        DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1153        DEFINE_WAIT(wait);
1154        int ports;
1155        int modes, ppb;
1156        int err = -ENOMEM;
1157        struct pardev_cb imm_cb;
1158
1159        init_waitqueue_head(&waiting);
1160
1161        dev = kzalloc(sizeof(imm_struct), GFP_KERNEL);
1162        if (!dev)
1163                return -ENOMEM;
1164
1165
1166        dev->base = -1;
1167        dev->mode = IMM_AUTODETECT;
1168        INIT_LIST_HEAD(&dev->list);
1169
1170        temp = find_parent();
1171        if (temp)
1172                dev->dev_no = temp->dev_no + 1;
1173
1174        memset(&imm_cb, 0, sizeof(imm_cb));
1175        imm_cb.private = dev;
1176        imm_cb.wakeup = imm_wakeup;
1177
1178        dev->dev = parport_register_dev_model(pb, "imm", &imm_cb, dev->dev_no);
1179        if (!dev->dev)
1180                goto out;
1181
1182
1183        /* Claim the bus so it remembers what we do to the control
1184         * registers. [ CTR and ECP ]
1185         */
1186        err = -EBUSY;
1187        dev->waiting = &waiting;
1188        prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1189        if (imm_pb_claim(dev))
1190                schedule_timeout(3 * HZ);
1191        if (dev->wanted) {
1192                printk(KERN_ERR "imm%d: failed to claim parport because "
1193                        "a pardevice is owning the port for too long "
1194                        "time!\n", pb->number);
1195                imm_pb_dismiss(dev);
1196                dev->waiting = NULL;
1197                finish_wait(&waiting, &wait);
1198                goto out1;
1199        }
1200        dev->waiting = NULL;
1201        finish_wait(&waiting, &wait);
1202        ppb = dev->base = dev->dev->port->base;
1203        dev->base_hi = dev->dev->port->base_hi;
1204        w_ctr(ppb, 0x0c);
1205        modes = dev->dev->port->modes;
1206
1207        /* Mode detection works up the chain of speed
1208         * This avoids a nasty if-then-else-if-... tree
1209         */
1210        dev->mode = IMM_NIBBLE;
1211
1212        if (modes & PARPORT_MODE_TRISTATE)
1213                dev->mode = IMM_PS2;
1214
1215        /* Done configuration */
1216
1217        err = imm_init(dev);
1218
1219        imm_pb_release(dev);
1220
1221        if (err)
1222                goto out1;
1223
1224        /* now the glue ... */
1225        if (dev->mode == IMM_NIBBLE || dev->mode == IMM_PS2)
1226                ports = 3;
1227        else
1228                ports = 8;
1229
1230        INIT_DELAYED_WORK(&dev->imm_tq, imm_interrupt);
1231
1232        err = -ENOMEM;
1233        host = scsi_host_alloc(&imm_template, sizeof(imm_struct *));
1234        if (!host)
1235                goto out1;
1236        host->io_port = pb->base;
1237        host->n_io_port = ports;
1238        host->dma_channel = -1;
1239        host->unique_id = pb->number;
1240        *(imm_struct **)&host->hostdata = dev;
1241        dev->host = host;
1242        if (!temp)
1243                list_add_tail(&dev->list, &imm_hosts);
1244        else
1245                list_add_tail(&dev->list, &temp->list);
1246        err = scsi_add_host(host, NULL);
1247        if (err)
1248                goto out2;
1249        scsi_scan_host(host);
1250        return 0;
1251
1252out2:
1253        list_del_init(&dev->list);
1254        scsi_host_put(host);
1255out1:
1256        parport_unregister_device(dev->dev);
1257out:
1258        kfree(dev);
1259        return err;
1260}
1261
1262static void imm_attach(struct parport *pb)
1263{
1264        __imm_attach(pb);
1265}
1266
1267static void imm_detach(struct parport *pb)
1268{
1269        imm_struct *dev;
1270        list_for_each_entry(dev, &imm_hosts, list) {
1271                if (dev->dev->port == pb) {
1272                        list_del_init(&dev->list);
1273                        scsi_remove_host(dev->host);
1274                        scsi_host_put(dev->host);
1275                        parport_unregister_device(dev->dev);
1276                        kfree(dev);
1277                        break;
1278                }
1279        }
1280}
1281
1282static struct parport_driver imm_driver = {
1283        .name           = "imm",
1284        .match_port     = imm_attach,
1285        .detach         = imm_detach,
1286        .devmodel       = true,
1287};
1288
1289static int __init imm_driver_init(void)
1290{
1291        printk("imm: Version %s\n", IMM_VERSION);
1292        return parport_register_driver(&imm_driver);
1293}
1294
1295static void __exit imm_driver_exit(void)
1296{
1297        parport_unregister_driver(&imm_driver);
1298}
1299
1300module_init(imm_driver_init);
1301module_exit(imm_driver_exit);
1302
1303MODULE_LICENSE("GPL");
1304