linux/drivers/scsi/ppa.c
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   1/* ppa.c   --  low level driver for the IOMEGA PPA3 
   2 * parallel port SCSI host adapter.
   3 * 
   4 * (The PPA3 is the embedded controller in the ZIP drive.)
   5 * 
   6 * (c) 1995,1996 Grant R. Guenther, grant@torque.net,
   7 * under the terms of the GNU General Public License.
   8 * 
   9 */
  10
  11#include <linux/init.h>
  12#include <linux/kernel.h>
  13#include <linux/slab.h>
  14#include <linux/module.h>
  15#include <linux/blkdev.h>
  16#include <linux/parport.h>
  17#include <linux/workqueue.h>
  18#include <linux/delay.h>
  19#include <linux/jiffies.h>
  20#include <asm/io.h>
  21
  22#include <scsi/scsi.h>
  23#include <scsi/scsi_cmnd.h>
  24#include <scsi/scsi_device.h>
  25#include <scsi/scsi_host.h>
  26
  27
  28static void ppa_reset_pulse(unsigned int base);
  29
  30typedef struct {
  31        struct pardevice *dev;  /* Parport device entry         */
  32        int base;               /* Actual port address          */
  33        int mode;               /* Transfer mode                */
  34        struct scsi_cmnd *cur_cmd;      /* Current queued command       */
  35        struct delayed_work ppa_tq;     /* Polling interrupt stuff       */
  36        unsigned long jstart;   /* Jiffies at start             */
  37        unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
  38        unsigned int failed:1;  /* Failure flag                 */
  39        unsigned wanted:1;      /* Parport sharing busy flag    */
  40        wait_queue_head_t *waiting;
  41        struct Scsi_Host *host;
  42        struct list_head list;
  43} ppa_struct;
  44
  45#include  "ppa.h"
  46
  47static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
  48{
  49        return *(ppa_struct **)&host->hostdata;
  50}
  51
  52static DEFINE_SPINLOCK(arbitration_lock);
  53
  54static void got_it(ppa_struct *dev)
  55{
  56        dev->base = dev->dev->port->base;
  57        if (dev->cur_cmd)
  58                dev->cur_cmd->SCp.phase = 1;
  59        else
  60                wake_up(dev->waiting);
  61}
  62
  63static void ppa_wakeup(void *ref)
  64{
  65        ppa_struct *dev = (ppa_struct *) ref;
  66        unsigned long flags;
  67
  68        spin_lock_irqsave(&arbitration_lock, flags);
  69        if (dev->wanted) {
  70                parport_claim(dev->dev);
  71                got_it(dev);
  72                dev->wanted = 0;
  73        }
  74        spin_unlock_irqrestore(&arbitration_lock, flags);
  75        return;
  76}
  77
  78static int ppa_pb_claim(ppa_struct *dev)
  79{
  80        unsigned long flags;
  81        int res = 1;
  82        spin_lock_irqsave(&arbitration_lock, flags);
  83        if (parport_claim(dev->dev) == 0) {
  84                got_it(dev);
  85                res = 0;
  86        }
  87        dev->wanted = res;
  88        spin_unlock_irqrestore(&arbitration_lock, flags);
  89        return res;
  90}
  91
  92static void ppa_pb_dismiss(ppa_struct *dev)
  93{
  94        unsigned long flags;
  95        int wanted;
  96        spin_lock_irqsave(&arbitration_lock, flags);
  97        wanted = dev->wanted;
  98        dev->wanted = 0;
  99        spin_unlock_irqrestore(&arbitration_lock, flags);
 100        if (!wanted)
 101                parport_release(dev->dev);
 102}
 103
 104static inline void ppa_pb_release(ppa_struct *dev)
 105{
 106        parport_release(dev->dev);
 107}
 108
 109/*
 110 * Start of Chipset kludges
 111 */
 112
 113/* This is to give the ppa driver a way to modify the timings (and other
 114 * parameters) by writing to the /proc/scsi/ppa/0 file.
 115 * Very simple method really... (To simple, no error checking :( )
 116 * Reason: Kernel hackers HATE having to unload and reload modules for
 117 * testing...
 118 * Also gives a method to use a script to obtain optimum timings (TODO)
 119 */
 120
 121static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
 122{
 123        ppa_struct *dev = ppa_dev(host);
 124        unsigned long x;
 125
 126        if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 127                x = simple_strtoul(buffer + 5, NULL, 0);
 128                dev->mode = x;
 129                return length;
 130        }
 131        if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 132                x = simple_strtoul(buffer + 10, NULL, 0);
 133                dev->recon_tmo = x;
 134                printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 135                return length;
 136        }
 137        printk(KERN_WARNING "ppa /proc: invalid variable\n");
 138        return -EINVAL;
 139}
 140
 141static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
 142{
 143        ppa_struct *dev = ppa_dev(host);
 144
 145        seq_printf(m, "Version : %s\n", PPA_VERSION);
 146        seq_printf(m, "Parport : %s\n", dev->dev->port->name);
 147        seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
 148#if PPA_DEBUG > 0
 149        seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
 150#endif
 151        return 0;
 152}
 153
 154static int device_check(ppa_struct *dev);
 155
 156#if PPA_DEBUG > 0
 157#define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 158           y, __func__, __LINE__); ppa_fail_func(x,y);
 159static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 160#else
 161static inline void ppa_fail(ppa_struct *dev, int error_code)
 162#endif
 163{
 164        /* If we fail a device then we trash status / message bytes */
 165        if (dev->cur_cmd) {
 166                dev->cur_cmd->result = error_code << 16;
 167                dev->failed = 1;
 168        }
 169}
 170
 171/*
 172 * Wait for the high bit to be set.
 173 * 
 174 * In principle, this could be tied to an interrupt, but the adapter
 175 * doesn't appear to be designed to support interrupts.  We spin on
 176 * the 0x80 ready bit. 
 177 */
 178static unsigned char ppa_wait(ppa_struct *dev)
 179{
 180        int k;
 181        unsigned short ppb = dev->base;
 182        unsigned char r;
 183
 184        k = PPA_SPIN_TMO;
 185        /* Wait for bit 6 and 7 - PJC */
 186        for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 187                udelay(1);
 188                r = r_str(ppb);
 189        }
 190
 191        /*
 192         * return some status information.
 193         * Semantics: 0xc0 = ZIP wants more data
 194         *            0xd0 = ZIP wants to send more data
 195         *            0xe0 = ZIP is expecting SCSI command data
 196         *            0xf0 = end of transfer, ZIP is sending status
 197         */
 198        if (k)
 199                return (r & 0xf0);
 200
 201        /* Counter expired - Time out occurred */
 202        ppa_fail(dev, DID_TIME_OUT);
 203        printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 204        return 0;               /* command timed out */
 205}
 206
 207/*
 208 * Clear EPP Timeout Bit 
 209 */
 210static inline void epp_reset(unsigned short ppb)
 211{
 212        int i;
 213
 214        i = r_str(ppb);
 215        w_str(ppb, i);
 216        w_str(ppb, i & 0xfe);
 217}
 218
 219/* 
 220 * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 221 */
 222static inline void ecp_sync(ppa_struct *dev)
 223{
 224        int i, ppb_hi = dev->dev->port->base_hi;
 225
 226        if (ppb_hi == 0)
 227                return;
 228
 229        if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 230                for (i = 0; i < 100; i++) {
 231                        if (r_ecr(ppb_hi) & 0x01)
 232                                return;
 233                        udelay(5);
 234                }
 235                printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 236        }
 237}
 238
 239static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 240{
 241        int i;
 242
 243        for (i = len; i; i--) {
 244                w_dtr(base, *buffer++);
 245                w_ctr(base, 0xe);
 246                w_ctr(base, 0xc);
 247        }
 248        return 1;               /* All went well - we hope! */
 249}
 250
 251static int ppa_byte_in(unsigned short base, char *buffer, int len)
 252{
 253        int i;
 254
 255        for (i = len; i; i--) {
 256                *buffer++ = r_dtr(base);
 257                w_ctr(base, 0x27);
 258                w_ctr(base, 0x25);
 259        }
 260        return 1;               /* All went well - we hope! */
 261}
 262
 263static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 264{
 265        for (; len; len--) {
 266                unsigned char h;
 267
 268                w_ctr(base, 0x4);
 269                h = r_str(base) & 0xf0;
 270                w_ctr(base, 0x6);
 271                *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 272        }
 273        return 1;               /* All went well - we hope! */
 274}
 275
 276static int ppa_out(ppa_struct *dev, char *buffer, int len)
 277{
 278        int r;
 279        unsigned short ppb = dev->base;
 280
 281        r = ppa_wait(dev);
 282
 283        if ((r & 0x50) != 0x40) {
 284                ppa_fail(dev, DID_ERROR);
 285                return 0;
 286        }
 287        switch (dev->mode) {
 288        case PPA_NIBBLE:
 289        case PPA_PS2:
 290                /* 8 bit output, with a loop */
 291                r = ppa_byte_out(ppb, buffer, len);
 292                break;
 293
 294        case PPA_EPP_32:
 295        case PPA_EPP_16:
 296        case PPA_EPP_8:
 297                epp_reset(ppb);
 298                w_ctr(ppb, 0x4);
 299#ifdef CONFIG_SCSI_IZIP_EPP16
 300                if (!(((long) buffer | len) & 0x01))
 301                        outsw(ppb + 4, buffer, len >> 1);
 302#else
 303                if (!(((long) buffer | len) & 0x03))
 304                        outsl(ppb + 4, buffer, len >> 2);
 305#endif
 306                else
 307                        outsb(ppb + 4, buffer, len);
 308                w_ctr(ppb, 0xc);
 309                r = !(r_str(ppb) & 0x01);
 310                w_ctr(ppb, 0xc);
 311                ecp_sync(dev);
 312                break;
 313
 314        default:
 315                printk(KERN_ERR "PPA: bug in ppa_out()\n");
 316                r = 0;
 317        }
 318        return r;
 319}
 320
 321static int ppa_in(ppa_struct *dev, char *buffer, int len)
 322{
 323        int r;
 324        unsigned short ppb = dev->base;
 325
 326        r = ppa_wait(dev);
 327
 328        if ((r & 0x50) != 0x50) {
 329                ppa_fail(dev, DID_ERROR);
 330                return 0;
 331        }
 332        switch (dev->mode) {
 333        case PPA_NIBBLE:
 334                /* 4 bit input, with a loop */
 335                r = ppa_nibble_in(ppb, buffer, len);
 336                w_ctr(ppb, 0xc);
 337                break;
 338
 339        case PPA_PS2:
 340                /* 8 bit input, with a loop */
 341                w_ctr(ppb, 0x25);
 342                r = ppa_byte_in(ppb, buffer, len);
 343                w_ctr(ppb, 0x4);
 344                w_ctr(ppb, 0xc);
 345                break;
 346
 347        case PPA_EPP_32:
 348        case PPA_EPP_16:
 349        case PPA_EPP_8:
 350                epp_reset(ppb);
 351                w_ctr(ppb, 0x24);
 352#ifdef CONFIG_SCSI_IZIP_EPP16
 353                if (!(((long) buffer | len) & 0x01))
 354                        insw(ppb + 4, buffer, len >> 1);
 355#else
 356                if (!(((long) buffer | len) & 0x03))
 357                        insl(ppb + 4, buffer, len >> 2);
 358#endif
 359                else
 360                        insb(ppb + 4, buffer, len);
 361                w_ctr(ppb, 0x2c);
 362                r = !(r_str(ppb) & 0x01);
 363                w_ctr(ppb, 0x2c);
 364                ecp_sync(dev);
 365                break;
 366
 367        default:
 368                printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 369                r = 0;
 370                break;
 371        }
 372        return r;
 373}
 374
 375/* end of ppa_io.h */
 376static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 377{
 378        w_dtr(ppb, b);
 379        w_ctr(ppb, 0xc);
 380        w_ctr(ppb, 0xe);
 381        w_ctr(ppb, 0xc);
 382        w_ctr(ppb, 0x4);
 383        w_ctr(ppb, 0xc);
 384}
 385
 386static void ppa_disconnect(ppa_struct *dev)
 387{
 388        unsigned short ppb = dev->base;
 389
 390        ppa_d_pulse(ppb, 0);
 391        ppa_d_pulse(ppb, 0x3c);
 392        ppa_d_pulse(ppb, 0x20);
 393        ppa_d_pulse(ppb, 0xf);
 394}
 395
 396static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 397{
 398        w_dtr(ppb, b);
 399        w_ctr(ppb, 0x4);
 400        w_ctr(ppb, 0x6);
 401        w_ctr(ppb, 0x4);
 402        w_ctr(ppb, 0xc);
 403}
 404
 405static inline void ppa_connect(ppa_struct *dev, int flag)
 406{
 407        unsigned short ppb = dev->base;
 408
 409        ppa_c_pulse(ppb, 0);
 410        ppa_c_pulse(ppb, 0x3c);
 411        ppa_c_pulse(ppb, 0x20);
 412        if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 413                ppa_c_pulse(ppb, 0xcf);
 414        else
 415                ppa_c_pulse(ppb, 0x8f);
 416}
 417
 418static int ppa_select(ppa_struct *dev, int target)
 419{
 420        int k;
 421        unsigned short ppb = dev->base;
 422
 423        /*
 424         * Bit 6 (0x40) is the device selected bit.
 425         * First we must wait till the current device goes off line...
 426         */
 427        k = PPA_SELECT_TMO;
 428        do {
 429                k--;
 430                udelay(1);
 431        } while ((r_str(ppb) & 0x40) && (k));
 432        if (!k)
 433                return 0;
 434
 435        w_dtr(ppb, (1 << target));
 436        w_ctr(ppb, 0xe);
 437        w_ctr(ppb, 0xc);
 438        w_dtr(ppb, 0x80);       /* This is NOT the initator */
 439        w_ctr(ppb, 0x8);
 440
 441        k = PPA_SELECT_TMO;
 442        do {
 443                k--;
 444                udelay(1);
 445        }
 446        while (!(r_str(ppb) & 0x40) && (k));
 447        if (!k)
 448                return 0;
 449
 450        return 1;
 451}
 452
 453/* 
 454 * This is based on a trace of what the Iomega DOS 'guest' driver does.
 455 * I've tried several different kinds of parallel ports with guest and
 456 * coded this to react in the same ways that it does.
 457 * 
 458 * The return value from this function is just a hint about where the
 459 * handshaking failed.
 460 * 
 461 */
 462static int ppa_init(ppa_struct *dev)
 463{
 464        int retv;
 465        unsigned short ppb = dev->base;
 466
 467        ppa_disconnect(dev);
 468        ppa_connect(dev, CONNECT_NORMAL);
 469
 470        retv = 2;               /* Failed */
 471
 472        w_ctr(ppb, 0xe);
 473        if ((r_str(ppb) & 0x08) == 0x08)
 474                retv--;
 475
 476        w_ctr(ppb, 0xc);
 477        if ((r_str(ppb) & 0x08) == 0x00)
 478                retv--;
 479
 480        if (!retv)
 481                ppa_reset_pulse(ppb);
 482        udelay(1000);           /* Allow devices to settle down */
 483        ppa_disconnect(dev);
 484        udelay(1000);           /* Another delay to allow devices to settle */
 485
 486        if (retv)
 487                return -EIO;
 488
 489        return device_check(dev);
 490}
 491
 492static inline int ppa_send_command(struct scsi_cmnd *cmd)
 493{
 494        ppa_struct *dev = ppa_dev(cmd->device->host);
 495        int k;
 496
 497        w_ctr(dev->base, 0x0c);
 498
 499        for (k = 0; k < cmd->cmd_len; k++)
 500                if (!ppa_out(dev, &cmd->cmnd[k], 1))
 501                        return 0;
 502        return 1;
 503}
 504
 505/*
 506 * The bulk flag enables some optimisations in the data transfer loops,
 507 * it should be true for any command that transfers data in integral
 508 * numbers of sectors.
 509 * 
 510 * The driver appears to remain stable if we speed up the parallel port
 511 * i/o in this function, but not elsewhere.
 512 */
 513static int ppa_completion(struct scsi_cmnd *cmd)
 514{
 515        /* Return codes:
 516         * -1     Error
 517         *  0     Told to schedule
 518         *  1     Finished data transfer
 519         */
 520        ppa_struct *dev = ppa_dev(cmd->device->host);
 521        unsigned short ppb = dev->base;
 522        unsigned long start_jiffies = jiffies;
 523
 524        unsigned char r, v;
 525        int fast, bulk, status;
 526
 527        v = cmd->cmnd[0];
 528        bulk = ((v == READ_6) ||
 529                (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 530
 531        /*
 532         * We only get here if the drive is ready to comunicate,
 533         * hence no need for a full ppa_wait.
 534         */
 535        r = (r_str(ppb) & 0xf0);
 536
 537        while (r != (unsigned char) 0xf0) {
 538                /*
 539                 * If we have been running for more than a full timer tick
 540                 * then take a rest.
 541                 */
 542                if (time_after(jiffies, start_jiffies + 1))
 543                        return 0;
 544
 545                if ((cmd->SCp.this_residual <= 0)) {
 546                        ppa_fail(dev, DID_ERROR);
 547                        return -1;      /* ERROR_RETURN */
 548                }
 549
 550                /* On some hardware we have SCSI disconnected (6th bit low)
 551                 * for about 100usecs. It is too expensive to wait a 
 552                 * tick on every loop so we busy wait for no more than
 553                 * 500usecs to give the drive a chance first. We do not 
 554                 * change things for "normal" hardware since generally 
 555                 * the 6th bit is always high.
 556                 * This makes the CPU load higher on some hardware 
 557                 * but otherwise we can not get more than 50K/secs 
 558                 * on this problem hardware.
 559                 */
 560                if ((r & 0xc0) != 0xc0) {
 561                        /* Wait for reconnection should be no more than 
 562                         * jiffy/2 = 5ms = 5000 loops
 563                         */
 564                        unsigned long k = dev->recon_tmo;
 565                        for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 566                             k--)
 567                                udelay(1);
 568
 569                        if (!k)
 570                                return 0;
 571                }
 572
 573                /* determine if we should use burst I/O */
 574                fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 575                    ? PPA_BURST_SIZE : 1;
 576
 577                if (r == (unsigned char) 0xc0)
 578                        status = ppa_out(dev, cmd->SCp.ptr, fast);
 579                else
 580                        status = ppa_in(dev, cmd->SCp.ptr, fast);
 581
 582                cmd->SCp.ptr += fast;
 583                cmd->SCp.this_residual -= fast;
 584
 585                if (!status) {
 586                        ppa_fail(dev, DID_BUS_BUSY);
 587                        return -1;      /* ERROR_RETURN */
 588                }
 589                if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 590                        /* if scatter/gather, advance to the next segment */
 591                        if (cmd->SCp.buffers_residual--) {
 592                                cmd->SCp.buffer++;
 593                                cmd->SCp.this_residual =
 594                                    cmd->SCp.buffer->length;
 595                                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 596                        }
 597                }
 598                /* Now check to see if the drive is ready to comunicate */
 599                r = (r_str(ppb) & 0xf0);
 600                /* If not, drop back down to the scheduler and wait a timer tick */
 601                if (!(r & 0x80))
 602                        return 0;
 603        }
 604        return 1;               /* FINISH_RETURN */
 605}
 606
 607/*
 608 * Since the PPA itself doesn't generate interrupts, we use
 609 * the scheduler's task queue to generate a stream of call-backs and
 610 * complete the request when the drive is ready.
 611 */
 612static void ppa_interrupt(struct work_struct *work)
 613{
 614        ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 615        struct scsi_cmnd *cmd = dev->cur_cmd;
 616
 617        if (!cmd) {
 618                printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 619                return;
 620        }
 621        if (ppa_engine(dev, cmd)) {
 622                schedule_delayed_work(&dev->ppa_tq, 1);
 623                return;
 624        }
 625        /* Command must of completed hence it is safe to let go... */
 626#if PPA_DEBUG > 0
 627        switch ((cmd->result >> 16) & 0xff) {
 628        case DID_OK:
 629                break;
 630        case DID_NO_CONNECT:
 631                printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
 632                break;
 633        case DID_BUS_BUSY:
 634                printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 635                break;
 636        case DID_TIME_OUT:
 637                printk(KERN_DEBUG "ppa: unknown timeout\n");
 638                break;
 639        case DID_ABORT:
 640                printk(KERN_DEBUG "ppa: told to abort\n");
 641                break;
 642        case DID_PARITY:
 643                printk(KERN_DEBUG "ppa: parity error (???)\n");
 644                break;
 645        case DID_ERROR:
 646                printk(KERN_DEBUG "ppa: internal driver error\n");
 647                break;
 648        case DID_RESET:
 649                printk(KERN_DEBUG "ppa: told to reset device\n");
 650                break;
 651        case DID_BAD_INTR:
 652                printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 653                break;
 654        default:
 655                printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 656                       (cmd->result >> 16) & 0xff);
 657        }
 658#endif
 659
 660        if (cmd->SCp.phase > 1)
 661                ppa_disconnect(dev);
 662
 663        ppa_pb_dismiss(dev);
 664
 665        dev->cur_cmd = NULL;
 666
 667        cmd->scsi_done(cmd);
 668}
 669
 670static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 671{
 672        unsigned short ppb = dev->base;
 673        unsigned char l = 0, h = 0;
 674        int retv;
 675
 676        /* First check for any errors that may of occurred
 677         * Here we check for internal errors
 678         */
 679        if (dev->failed)
 680                return 0;
 681
 682        switch (cmd->SCp.phase) {
 683        case 0:         /* Phase 0 - Waiting for parport */
 684                if (time_after(jiffies, dev->jstart + HZ)) {
 685                        /*
 686                         * We waited more than a second
 687                         * for parport to call us
 688                         */
 689                        ppa_fail(dev, DID_BUS_BUSY);
 690                        return 0;
 691                }
 692                return 1;       /* wait until ppa_wakeup claims parport */
 693        case 1:         /* Phase 1 - Connected */
 694                {               /* Perform a sanity check for cable unplugged */
 695                        int retv = 2;   /* Failed */
 696
 697                        ppa_connect(dev, CONNECT_EPP_MAYBE);
 698
 699                        w_ctr(ppb, 0xe);
 700                        if ((r_str(ppb) & 0x08) == 0x08)
 701                                retv--;
 702
 703                        w_ctr(ppb, 0xc);
 704                        if ((r_str(ppb) & 0x08) == 0x00)
 705                                retv--;
 706
 707                        if (retv) {
 708                                if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 709                                        printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 710                                        ppa_fail(dev, DID_BUS_BUSY);
 711                                        return 0;
 712                                } else {
 713                                        ppa_disconnect(dev);
 714                                        return 1;       /* Try again in a jiffy */
 715                                }
 716                        }
 717                        cmd->SCp.phase++;
 718                }
 719
 720        case 2:         /* Phase 2 - We are now talking to the scsi bus */
 721                if (!ppa_select(dev, scmd_id(cmd))) {
 722                        ppa_fail(dev, DID_NO_CONNECT);
 723                        return 0;
 724                }
 725                cmd->SCp.phase++;
 726
 727        case 3:         /* Phase 3 - Ready to accept a command */
 728                w_ctr(ppb, 0x0c);
 729                if (!(r_str(ppb) & 0x80))
 730                        return 1;
 731
 732                if (!ppa_send_command(cmd))
 733                        return 0;
 734                cmd->SCp.phase++;
 735
 736        case 4:         /* Phase 4 - Setup scatter/gather buffers */
 737                if (scsi_bufflen(cmd)) {
 738                        cmd->SCp.buffer = scsi_sglist(cmd);
 739                        cmd->SCp.this_residual = cmd->SCp.buffer->length;
 740                        cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 741                } else {
 742                        cmd->SCp.buffer = NULL;
 743                        cmd->SCp.this_residual = 0;
 744                        cmd->SCp.ptr = NULL;
 745                }
 746                cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 747                cmd->SCp.phase++;
 748
 749        case 5:         /* Phase 5 - Data transfer stage */
 750                w_ctr(ppb, 0x0c);
 751                if (!(r_str(ppb) & 0x80))
 752                        return 1;
 753
 754                retv = ppa_completion(cmd);
 755                if (retv == -1)
 756                        return 0;
 757                if (retv == 0)
 758                        return 1;
 759                cmd->SCp.phase++;
 760
 761        case 6:         /* Phase 6 - Read status/message */
 762                cmd->result = DID_OK << 16;
 763                /* Check for data overrun */
 764                if (ppa_wait(dev) != (unsigned char) 0xf0) {
 765                        ppa_fail(dev, DID_ERROR);
 766                        return 0;
 767                }
 768                if (ppa_in(dev, &l, 1)) {       /* read status byte */
 769                        /* Check for optional message byte */
 770                        if (ppa_wait(dev) == (unsigned char) 0xf0)
 771                                ppa_in(dev, &h, 1);
 772                        cmd->result =
 773                            (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 774                }
 775                return 0;       /* Finished */
 776                break;
 777
 778        default:
 779                printk(KERN_ERR "ppa: Invalid scsi phase\n");
 780        }
 781        return 0;
 782}
 783
 784static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
 785                void (*done) (struct scsi_cmnd *))
 786{
 787        ppa_struct *dev = ppa_dev(cmd->device->host);
 788
 789        if (dev->cur_cmd) {
 790                printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 791                return 0;
 792        }
 793        dev->failed = 0;
 794        dev->jstart = jiffies;
 795        dev->cur_cmd = cmd;
 796        cmd->scsi_done = done;
 797        cmd->result = DID_ERROR << 16;  /* default return code */
 798        cmd->SCp.phase = 0;     /* bus free */
 799
 800        schedule_delayed_work(&dev->ppa_tq, 0);
 801
 802        ppa_pb_claim(dev);
 803
 804        return 0;
 805}
 806
 807static DEF_SCSI_QCMD(ppa_queuecommand)
 808
 809/*
 810 * Apparently the disk->capacity attribute is off by 1 sector 
 811 * for all disk drives.  We add the one here, but it should really
 812 * be done in sd.c.  Even if it gets fixed there, this will still
 813 * work.
 814 */
 815static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 816              sector_t capacity, int ip[])
 817{
 818        ip[0] = 0x40;
 819        ip[1] = 0x20;
 820        ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 821        if (ip[2] > 1024) {
 822                ip[0] = 0xff;
 823                ip[1] = 0x3f;
 824                ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 825                if (ip[2] > 1023)
 826                        ip[2] = 1023;
 827        }
 828        return 0;
 829}
 830
 831static int ppa_abort(struct scsi_cmnd *cmd)
 832{
 833        ppa_struct *dev = ppa_dev(cmd->device->host);
 834        /*
 835         * There is no method for aborting commands since Iomega
 836         * have tied the SCSI_MESSAGE line high in the interface
 837         */
 838
 839        switch (cmd->SCp.phase) {
 840        case 0:         /* Do not have access to parport */
 841        case 1:         /* Have not connected to interface */
 842                dev->cur_cmd = NULL;    /* Forget the problem */
 843                return SUCCESS;
 844                break;
 845        default:                /* SCSI command sent, can not abort */
 846                return FAILED;
 847                break;
 848        }
 849}
 850
 851static void ppa_reset_pulse(unsigned int base)
 852{
 853        w_dtr(base, 0x40);
 854        w_ctr(base, 0x8);
 855        udelay(30);
 856        w_ctr(base, 0xc);
 857}
 858
 859static int ppa_reset(struct scsi_cmnd *cmd)
 860{
 861        ppa_struct *dev = ppa_dev(cmd->device->host);
 862
 863        if (cmd->SCp.phase)
 864                ppa_disconnect(dev);
 865        dev->cur_cmd = NULL;    /* Forget the problem */
 866
 867        ppa_connect(dev, CONNECT_NORMAL);
 868        ppa_reset_pulse(dev->base);
 869        mdelay(1);              /* device settle delay */
 870        ppa_disconnect(dev);
 871        mdelay(1);              /* device settle delay */
 872        return SUCCESS;
 873}
 874
 875static int device_check(ppa_struct *dev)
 876{
 877        /* This routine looks for a device and then attempts to use EPP
 878           to send a command. If all goes as planned then EPP is available. */
 879
 880        static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 881        int loop, old_mode, status, k, ppb = dev->base;
 882        unsigned char l;
 883
 884        old_mode = dev->mode;
 885        for (loop = 0; loop < 8; loop++) {
 886                /* Attempt to use EPP for Test Unit Ready */
 887                if ((ppb & 0x0007) == 0x0000)
 888                        dev->mode = PPA_EPP_32;
 889
 890second_pass:
 891                ppa_connect(dev, CONNECT_EPP_MAYBE);
 892                /* Select SCSI device */
 893                if (!ppa_select(dev, loop)) {
 894                        ppa_disconnect(dev);
 895                        continue;
 896                }
 897                printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
 898                       loop, PPA_MODE_STRING[dev->mode]);
 899
 900                /* Send SCSI command */
 901                status = 1;
 902                w_ctr(ppb, 0x0c);
 903                for (l = 0; (l < 6) && (status); l++)
 904                        status = ppa_out(dev, cmd, 1);
 905
 906                if (!status) {
 907                        ppa_disconnect(dev);
 908                        ppa_connect(dev, CONNECT_EPP_MAYBE);
 909                        w_dtr(ppb, 0x40);
 910                        w_ctr(ppb, 0x08);
 911                        udelay(30);
 912                        w_ctr(ppb, 0x0c);
 913                        udelay(1000);
 914                        ppa_disconnect(dev);
 915                        udelay(1000);
 916                        if (dev->mode == PPA_EPP_32) {
 917                                dev->mode = old_mode;
 918                                goto second_pass;
 919                        }
 920                        return -EIO;
 921                }
 922                w_ctr(ppb, 0x0c);
 923                k = 1000000;    /* 1 Second */
 924                do {
 925                        l = r_str(ppb);
 926                        k--;
 927                        udelay(1);
 928                } while (!(l & 0x80) && (k));
 929
 930                l &= 0xf0;
 931
 932                if (l != 0xf0) {
 933                        ppa_disconnect(dev);
 934                        ppa_connect(dev, CONNECT_EPP_MAYBE);
 935                        ppa_reset_pulse(ppb);
 936                        udelay(1000);
 937                        ppa_disconnect(dev);
 938                        udelay(1000);
 939                        if (dev->mode == PPA_EPP_32) {
 940                                dev->mode = old_mode;
 941                                goto second_pass;
 942                        }
 943                        return -EIO;
 944                }
 945                ppa_disconnect(dev);
 946                printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
 947                       loop, PPA_MODE_STRING[dev->mode]);
 948                ppa_connect(dev, CONNECT_EPP_MAYBE);
 949                ppa_reset_pulse(ppb);
 950                udelay(1000);
 951                ppa_disconnect(dev);
 952                udelay(1000);
 953                return 0;
 954        }
 955        return -ENODEV;
 956}
 957
 958static int ppa_adjust_queue(struct scsi_device *device)
 959{
 960        blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 961        return 0;
 962}
 963
 964static struct scsi_host_template ppa_template = {
 965        .module                 = THIS_MODULE,
 966        .proc_name              = "ppa",
 967        .show_info              = ppa_show_info,
 968        .write_info             = ppa_write_info,
 969        .name                   = "Iomega VPI0 (ppa) interface",
 970        .queuecommand           = ppa_queuecommand,
 971        .eh_abort_handler       = ppa_abort,
 972        .eh_bus_reset_handler   = ppa_reset,
 973        .eh_host_reset_handler  = ppa_reset,
 974        .bios_param             = ppa_biosparam,
 975        .this_id                = -1,
 976        .sg_tablesize           = SG_ALL,
 977        .cmd_per_lun            = 1,
 978        .use_clustering         = ENABLE_CLUSTERING,
 979        .can_queue              = 1,
 980        .slave_alloc            = ppa_adjust_queue,
 981};
 982
 983/***************************************************************************
 984 *                   Parallel port probing routines                        *
 985 ***************************************************************************/
 986
 987static LIST_HEAD(ppa_hosts);
 988
 989static int __ppa_attach(struct parport *pb)
 990{
 991        struct Scsi_Host *host;
 992        DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
 993        DEFINE_WAIT(wait);
 994        ppa_struct *dev;
 995        int ports;
 996        int modes, ppb, ppb_hi;
 997        int err = -ENOMEM;
 998
 999        dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1000        if (!dev)
1001                return -ENOMEM;
1002        dev->base = -1;
1003        dev->mode = PPA_AUTODETECT;
1004        dev->recon_tmo = PPA_RECON_TMO;
1005        init_waitqueue_head(&waiting);
1006        dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1007                                            NULL, 0, dev);
1008
1009        if (!dev->dev)
1010                goto out;
1011
1012        /* Claim the bus so it remembers what we do to the control
1013         * registers. [ CTR and ECP ]
1014         */
1015        err = -EBUSY;
1016        dev->waiting = &waiting;
1017        prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1018        if (ppa_pb_claim(dev))
1019                schedule_timeout(3 * HZ);
1020        if (dev->wanted) {
1021                printk(KERN_ERR "ppa%d: failed to claim parport because "
1022                                "a pardevice is owning the port for too long "
1023                                "time!\n", pb->number);
1024                ppa_pb_dismiss(dev);
1025                dev->waiting = NULL;
1026                finish_wait(&waiting, &wait);
1027                goto out1;
1028        }
1029        dev->waiting = NULL;
1030        finish_wait(&waiting, &wait);
1031        ppb = dev->base = dev->dev->port->base;
1032        ppb_hi = dev->dev->port->base_hi;
1033        w_ctr(ppb, 0x0c);
1034        modes = dev->dev->port->modes;
1035
1036        /* Mode detection works up the chain of speed
1037         * This avoids a nasty if-then-else-if-... tree
1038         */
1039        dev->mode = PPA_NIBBLE;
1040
1041        if (modes & PARPORT_MODE_TRISTATE)
1042                dev->mode = PPA_PS2;
1043
1044        if (modes & PARPORT_MODE_ECP) {
1045                w_ecr(ppb_hi, 0x20);
1046                dev->mode = PPA_PS2;
1047        }
1048        if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1049                w_ecr(ppb_hi, 0x80);
1050
1051        /* Done configuration */
1052
1053        err = ppa_init(dev);
1054        ppa_pb_release(dev);
1055
1056        if (err)
1057                goto out1;
1058
1059        /* now the glue ... */
1060        if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1061                ports = 3;
1062        else
1063                ports = 8;
1064
1065        INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1066
1067        err = -ENOMEM;
1068        host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1069        if (!host)
1070                goto out1;
1071        host->io_port = pb->base;
1072        host->n_io_port = ports;
1073        host->dma_channel = -1;
1074        host->unique_id = pb->number;
1075        *(ppa_struct **)&host->hostdata = dev;
1076        dev->host = host;
1077        list_add_tail(&dev->list, &ppa_hosts);
1078        err = scsi_add_host(host, NULL);
1079        if (err)
1080                goto out2;
1081        scsi_scan_host(host);
1082        return 0;
1083out2:
1084        list_del_init(&dev->list);
1085        scsi_host_put(host);
1086out1:
1087        parport_unregister_device(dev->dev);
1088out:
1089        kfree(dev);
1090        return err;
1091}
1092
1093static void ppa_attach(struct parport *pb)
1094{
1095        __ppa_attach(pb);
1096}
1097
1098static void ppa_detach(struct parport *pb)
1099{
1100        ppa_struct *dev;
1101        list_for_each_entry(dev, &ppa_hosts, list) {
1102                if (dev->dev->port == pb) {
1103                        list_del_init(&dev->list);
1104                        scsi_remove_host(dev->host);
1105                        scsi_host_put(dev->host);
1106                        parport_unregister_device(dev->dev);
1107                        kfree(dev);
1108                        break;
1109                }
1110        }
1111}
1112
1113static struct parport_driver ppa_driver = {
1114        .name   = "ppa",
1115        .attach = ppa_attach,
1116        .detach = ppa_detach,
1117};
1118
1119static int __init ppa_driver_init(void)
1120{
1121        printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1122        return parport_register_driver(&ppa_driver);
1123}
1124
1125static void __exit ppa_driver_exit(void)
1126{
1127        parport_unregister_driver(&ppa_driver);
1128}
1129
1130module_init(ppa_driver_init);
1131module_exit(ppa_driver_exit);
1132MODULE_LICENSE("GPL");
1133
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