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