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_proc_write(ppa_struct *dev, char *buffer, int length)
 122{
 123        unsigned long x;
 124
 125        if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
 126                x = simple_strtoul(buffer + 5, NULL, 0);
 127                dev->mode = x;
 128                return length;
 129        }
 130        if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
 131                x = simple_strtoul(buffer + 10, NULL, 0);
 132                dev->recon_tmo = x;
 133                printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
 134                return length;
 135        }
 136        printk(KERN_WARNING "ppa /proc: invalid variable\n");
 137        return -EINVAL;
 138}
 139
 140static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
 141{
 142        int len = 0;
 143        ppa_struct *dev = ppa_dev(host);
 144
 145        if (inout)
 146                return ppa_proc_write(dev, buffer, length);
 147
 148        len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
 149        len +=
 150            sprintf(buffer + len, "Parport : %s\n",
 151                    dev->dev->port->name);
 152        len +=
 153            sprintf(buffer + len, "Mode    : %s\n",
 154                    PPA_MODE_STRING[dev->mode]);
 155#if PPA_DEBUG > 0
 156        len +=
 157            sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
 158#endif
 159
 160        /* Request for beyond end of buffer */
 161        if (offset > length)
 162                return 0;
 163
 164        *start = buffer + offset;
 165        len -= offset;
 166        if (len > length)
 167                len = length;
 168        return len;
 169}
 170
 171static int device_check(ppa_struct *dev);
 172
 173#if PPA_DEBUG > 0
 174#define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
 175           y, __func__, __LINE__); ppa_fail_func(x,y);
 176static inline void ppa_fail_func(ppa_struct *dev, int error_code)
 177#else
 178static inline void ppa_fail(ppa_struct *dev, int error_code)
 179#endif
 180{
 181        /* If we fail a device then we trash status / message bytes */
 182        if (dev->cur_cmd) {
 183                dev->cur_cmd->result = error_code << 16;
 184                dev->failed = 1;
 185        }
 186}
 187
 188/*
 189 * Wait for the high bit to be set.
 190 * 
 191 * In principle, this could be tied to an interrupt, but the adapter
 192 * doesn't appear to be designed to support interrupts.  We spin on
 193 * the 0x80 ready bit. 
 194 */
 195static unsigned char ppa_wait(ppa_struct *dev)
 196{
 197        int k;
 198        unsigned short ppb = dev->base;
 199        unsigned char r;
 200
 201        k = PPA_SPIN_TMO;
 202        /* Wait for bit 6 and 7 - PJC */
 203        for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
 204                udelay(1);
 205                r = r_str(ppb);
 206        }
 207
 208        /*
 209         * return some status information.
 210         * Semantics: 0xc0 = ZIP wants more data
 211         *            0xd0 = ZIP wants to send more data
 212         *            0xe0 = ZIP is expecting SCSI command data
 213         *            0xf0 = end of transfer, ZIP is sending status
 214         */
 215        if (k)
 216                return (r & 0xf0);
 217
 218        /* Counter expired - Time out occurred */
 219        ppa_fail(dev, DID_TIME_OUT);
 220        printk(KERN_WARNING "ppa timeout in ppa_wait\n");
 221        return 0;               /* command timed out */
 222}
 223
 224/*
 225 * Clear EPP Timeout Bit 
 226 */
 227static inline void epp_reset(unsigned short ppb)
 228{
 229        int i;
 230
 231        i = r_str(ppb);
 232        w_str(ppb, i);
 233        w_str(ppb, i & 0xfe);
 234}
 235
 236/* 
 237 * Wait for empty ECP fifo (if we are in ECP fifo mode only)
 238 */
 239static inline void ecp_sync(ppa_struct *dev)
 240{
 241        int i, ppb_hi = dev->dev->port->base_hi;
 242
 243        if (ppb_hi == 0)
 244                return;
 245
 246        if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
 247                for (i = 0; i < 100; i++) {
 248                        if (r_ecr(ppb_hi) & 0x01)
 249                                return;
 250                        udelay(5);
 251                }
 252                printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
 253        }
 254}
 255
 256static int ppa_byte_out(unsigned short base, const char *buffer, int len)
 257{
 258        int i;
 259
 260        for (i = len; i; i--) {
 261                w_dtr(base, *buffer++);
 262                w_ctr(base, 0xe);
 263                w_ctr(base, 0xc);
 264        }
 265        return 1;               /* All went well - we hope! */
 266}
 267
 268static int ppa_byte_in(unsigned short base, char *buffer, int len)
 269{
 270        int i;
 271
 272        for (i = len; i; i--) {
 273                *buffer++ = r_dtr(base);
 274                w_ctr(base, 0x27);
 275                w_ctr(base, 0x25);
 276        }
 277        return 1;               /* All went well - we hope! */
 278}
 279
 280static int ppa_nibble_in(unsigned short base, char *buffer, int len)
 281{
 282        for (; len; len--) {
 283                unsigned char h;
 284
 285                w_ctr(base, 0x4);
 286                h = r_str(base) & 0xf0;
 287                w_ctr(base, 0x6);
 288                *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
 289        }
 290        return 1;               /* All went well - we hope! */
 291}
 292
 293static int ppa_out(ppa_struct *dev, char *buffer, int len)
 294{
 295        int r;
 296        unsigned short ppb = dev->base;
 297
 298        r = ppa_wait(dev);
 299
 300        if ((r & 0x50) != 0x40) {
 301                ppa_fail(dev, DID_ERROR);
 302                return 0;
 303        }
 304        switch (dev->mode) {
 305        case PPA_NIBBLE:
 306        case PPA_PS2:
 307                /* 8 bit output, with a loop */
 308                r = ppa_byte_out(ppb, buffer, len);
 309                break;
 310
 311        case PPA_EPP_32:
 312        case PPA_EPP_16:
 313        case PPA_EPP_8:
 314                epp_reset(ppb);
 315                w_ctr(ppb, 0x4);
 316#ifdef CONFIG_SCSI_IZIP_EPP16
 317                if (!(((long) buffer | len) & 0x01))
 318                        outsw(ppb + 4, buffer, len >> 1);
 319#else
 320                if (!(((long) buffer | len) & 0x03))
 321                        outsl(ppb + 4, buffer, len >> 2);
 322#endif
 323                else
 324                        outsb(ppb + 4, buffer, len);
 325                w_ctr(ppb, 0xc);
 326                r = !(r_str(ppb) & 0x01);
 327                w_ctr(ppb, 0xc);
 328                ecp_sync(dev);
 329                break;
 330
 331        default:
 332                printk(KERN_ERR "PPA: bug in ppa_out()\n");
 333                r = 0;
 334        }
 335        return r;
 336}
 337
 338static int ppa_in(ppa_struct *dev, char *buffer, int len)
 339{
 340        int r;
 341        unsigned short ppb = dev->base;
 342
 343        r = ppa_wait(dev);
 344
 345        if ((r & 0x50) != 0x50) {
 346                ppa_fail(dev, DID_ERROR);
 347                return 0;
 348        }
 349        switch (dev->mode) {
 350        case PPA_NIBBLE:
 351                /* 4 bit input, with a loop */
 352                r = ppa_nibble_in(ppb, buffer, len);
 353                w_ctr(ppb, 0xc);
 354                break;
 355
 356        case PPA_PS2:
 357                /* 8 bit input, with a loop */
 358                w_ctr(ppb, 0x25);
 359                r = ppa_byte_in(ppb, buffer, len);
 360                w_ctr(ppb, 0x4);
 361                w_ctr(ppb, 0xc);
 362                break;
 363
 364        case PPA_EPP_32:
 365        case PPA_EPP_16:
 366        case PPA_EPP_8:
 367                epp_reset(ppb);
 368                w_ctr(ppb, 0x24);
 369#ifdef CONFIG_SCSI_IZIP_EPP16
 370                if (!(((long) buffer | len) & 0x01))
 371                        insw(ppb + 4, buffer, len >> 1);
 372#else
 373                if (!(((long) buffer | len) & 0x03))
 374                        insl(ppb + 4, buffer, len >> 2);
 375#endif
 376                else
 377                        insb(ppb + 4, buffer, len);
 378                w_ctr(ppb, 0x2c);
 379                r = !(r_str(ppb) & 0x01);
 380                w_ctr(ppb, 0x2c);
 381                ecp_sync(dev);
 382                break;
 383
 384        default:
 385                printk(KERN_ERR "PPA: bug in ppa_ins()\n");
 386                r = 0;
 387                break;
 388        }
 389        return r;
 390}
 391
 392/* end of ppa_io.h */
 393static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
 394{
 395        w_dtr(ppb, b);
 396        w_ctr(ppb, 0xc);
 397        w_ctr(ppb, 0xe);
 398        w_ctr(ppb, 0xc);
 399        w_ctr(ppb, 0x4);
 400        w_ctr(ppb, 0xc);
 401}
 402
 403static void ppa_disconnect(ppa_struct *dev)
 404{
 405        unsigned short ppb = dev->base;
 406
 407        ppa_d_pulse(ppb, 0);
 408        ppa_d_pulse(ppb, 0x3c);
 409        ppa_d_pulse(ppb, 0x20);
 410        ppa_d_pulse(ppb, 0xf);
 411}
 412
 413static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
 414{
 415        w_dtr(ppb, b);
 416        w_ctr(ppb, 0x4);
 417        w_ctr(ppb, 0x6);
 418        w_ctr(ppb, 0x4);
 419        w_ctr(ppb, 0xc);
 420}
 421
 422static inline void ppa_connect(ppa_struct *dev, int flag)
 423{
 424        unsigned short ppb = dev->base;
 425
 426        ppa_c_pulse(ppb, 0);
 427        ppa_c_pulse(ppb, 0x3c);
 428        ppa_c_pulse(ppb, 0x20);
 429        if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
 430                ppa_c_pulse(ppb, 0xcf);
 431        else
 432                ppa_c_pulse(ppb, 0x8f);
 433}
 434
 435static int ppa_select(ppa_struct *dev, int target)
 436{
 437        int k;
 438        unsigned short ppb = dev->base;
 439
 440        /*
 441         * Bit 6 (0x40) is the device selected bit.
 442         * First we must wait till the current device goes off line...
 443         */
 444        k = PPA_SELECT_TMO;
 445        do {
 446                k--;
 447                udelay(1);
 448        } while ((r_str(ppb) & 0x40) && (k));
 449        if (!k)
 450                return 0;
 451
 452        w_dtr(ppb, (1 << target));
 453        w_ctr(ppb, 0xe);
 454        w_ctr(ppb, 0xc);
 455        w_dtr(ppb, 0x80);       /* This is NOT the initator */
 456        w_ctr(ppb, 0x8);
 457
 458        k = PPA_SELECT_TMO;
 459        do {
 460                k--;
 461                udelay(1);
 462        }
 463        while (!(r_str(ppb) & 0x40) && (k));
 464        if (!k)
 465                return 0;
 466
 467        return 1;
 468}
 469
 470/* 
 471 * This is based on a trace of what the Iomega DOS 'guest' driver does.
 472 * I've tried several different kinds of parallel ports with guest and
 473 * coded this to react in the same ways that it does.
 474 * 
 475 * The return value from this function is just a hint about where the
 476 * handshaking failed.
 477 * 
 478 */
 479static int ppa_init(ppa_struct *dev)
 480{
 481        int retv;
 482        unsigned short ppb = dev->base;
 483
 484        ppa_disconnect(dev);
 485        ppa_connect(dev, CONNECT_NORMAL);
 486
 487        retv = 2;               /* Failed */
 488
 489        w_ctr(ppb, 0xe);
 490        if ((r_str(ppb) & 0x08) == 0x08)
 491                retv--;
 492
 493        w_ctr(ppb, 0xc);
 494        if ((r_str(ppb) & 0x08) == 0x00)
 495                retv--;
 496
 497        if (!retv)
 498                ppa_reset_pulse(ppb);
 499        udelay(1000);           /* Allow devices to settle down */
 500        ppa_disconnect(dev);
 501        udelay(1000);           /* Another delay to allow devices to settle */
 502
 503        if (retv)
 504                return -EIO;
 505
 506        return device_check(dev);
 507}
 508
 509static inline int ppa_send_command(struct scsi_cmnd *cmd)
 510{
 511        ppa_struct *dev = ppa_dev(cmd->device->host);
 512        int k;
 513
 514        w_ctr(dev->base, 0x0c);
 515
 516        for (k = 0; k < cmd->cmd_len; k++)
 517                if (!ppa_out(dev, &cmd->cmnd[k], 1))
 518                        return 0;
 519        return 1;
 520}
 521
 522/*
 523 * The bulk flag enables some optimisations in the data transfer loops,
 524 * it should be true for any command that transfers data in integral
 525 * numbers of sectors.
 526 * 
 527 * The driver appears to remain stable if we speed up the parallel port
 528 * i/o in this function, but not elsewhere.
 529 */
 530static int ppa_completion(struct scsi_cmnd *cmd)
 531{
 532        /* Return codes:
 533         * -1     Error
 534         *  0     Told to schedule
 535         *  1     Finished data transfer
 536         */
 537        ppa_struct *dev = ppa_dev(cmd->device->host);
 538        unsigned short ppb = dev->base;
 539        unsigned long start_jiffies = jiffies;
 540
 541        unsigned char r, v;
 542        int fast, bulk, status;
 543
 544        v = cmd->cmnd[0];
 545        bulk = ((v == READ_6) ||
 546                (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
 547
 548        /*
 549         * We only get here if the drive is ready to comunicate,
 550         * hence no need for a full ppa_wait.
 551         */
 552        r = (r_str(ppb) & 0xf0);
 553
 554        while (r != (unsigned char) 0xf0) {
 555                /*
 556                 * If we have been running for more than a full timer tick
 557                 * then take a rest.
 558                 */
 559                if (time_after(jiffies, start_jiffies + 1))
 560                        return 0;
 561
 562                if ((cmd->SCp.this_residual <= 0)) {
 563                        ppa_fail(dev, DID_ERROR);
 564                        return -1;      /* ERROR_RETURN */
 565                }
 566
 567                /* On some hardware we have SCSI disconnected (6th bit low)
 568                 * for about 100usecs. It is too expensive to wait a 
 569                 * tick on every loop so we busy wait for no more than
 570                 * 500usecs to give the drive a chance first. We do not 
 571                 * change things for "normal" hardware since generally 
 572                 * the 6th bit is always high.
 573                 * This makes the CPU load higher on some hardware 
 574                 * but otherwise we can not get more than 50K/secs 
 575                 * on this problem hardware.
 576                 */
 577                if ((r & 0xc0) != 0xc0) {
 578                        /* Wait for reconnection should be no more than 
 579                         * jiffy/2 = 5ms = 5000 loops
 580                         */
 581                        unsigned long k = dev->recon_tmo;
 582                        for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
 583                             k--)
 584                                udelay(1);
 585
 586                        if (!k)
 587                                return 0;
 588                }
 589
 590                /* determine if we should use burst I/O */
 591                fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
 592                    ? PPA_BURST_SIZE : 1;
 593
 594                if (r == (unsigned char) 0xc0)
 595                        status = ppa_out(dev, cmd->SCp.ptr, fast);
 596                else
 597                        status = ppa_in(dev, cmd->SCp.ptr, fast);
 598
 599                cmd->SCp.ptr += fast;
 600                cmd->SCp.this_residual -= fast;
 601
 602                if (!status) {
 603                        ppa_fail(dev, DID_BUS_BUSY);
 604                        return -1;      /* ERROR_RETURN */
 605                }
 606                if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
 607                        /* if scatter/gather, advance to the next segment */
 608                        if (cmd->SCp.buffers_residual--) {
 609                                cmd->SCp.buffer++;
 610                                cmd->SCp.this_residual =
 611                                    cmd->SCp.buffer->length;
 612                                cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 613                        }
 614                }
 615                /* Now check to see if the drive is ready to comunicate */
 616                r = (r_str(ppb) & 0xf0);
 617                /* If not, drop back down to the scheduler and wait a timer tick */
 618                if (!(r & 0x80))
 619                        return 0;
 620        }
 621        return 1;               /* FINISH_RETURN */
 622}
 623
 624/*
 625 * Since the PPA itself doesn't generate interrupts, we use
 626 * the scheduler's task queue to generate a stream of call-backs and
 627 * complete the request when the drive is ready.
 628 */
 629static void ppa_interrupt(struct work_struct *work)
 630{
 631        ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
 632        struct scsi_cmnd *cmd = dev->cur_cmd;
 633
 634        if (!cmd) {
 635                printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
 636                return;
 637        }
 638        if (ppa_engine(dev, cmd)) {
 639                schedule_delayed_work(&dev->ppa_tq, 1);
 640                return;
 641        }
 642        /* Command must of completed hence it is safe to let go... */
 643#if PPA_DEBUG > 0
 644        switch ((cmd->result >> 16) & 0xff) {
 645        case DID_OK:
 646                break;
 647        case DID_NO_CONNECT:
 648                printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
 649                break;
 650        case DID_BUS_BUSY:
 651                printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
 652                break;
 653        case DID_TIME_OUT:
 654                printk(KERN_DEBUG "ppa: unknown timeout\n");
 655                break;
 656        case DID_ABORT:
 657                printk(KERN_DEBUG "ppa: told to abort\n");
 658                break;
 659        case DID_PARITY:
 660                printk(KERN_DEBUG "ppa: parity error (???)\n");
 661                break;
 662        case DID_ERROR:
 663                printk(KERN_DEBUG "ppa: internal driver error\n");
 664                break;
 665        case DID_RESET:
 666                printk(KERN_DEBUG "ppa: told to reset device\n");
 667                break;
 668        case DID_BAD_INTR:
 669                printk(KERN_WARNING "ppa: bad interrupt (???)\n");
 670                break;
 671        default:
 672                printk(KERN_WARNING "ppa: bad return code (%02x)\n",
 673                       (cmd->result >> 16) & 0xff);
 674        }
 675#endif
 676
 677        if (cmd->SCp.phase > 1)
 678                ppa_disconnect(dev);
 679
 680        ppa_pb_dismiss(dev);
 681
 682        dev->cur_cmd = NULL;
 683
 684        cmd->scsi_done(cmd);
 685}
 686
 687static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
 688{
 689        unsigned short ppb = dev->base;
 690        unsigned char l = 0, h = 0;
 691        int retv;
 692
 693        /* First check for any errors that may of occurred
 694         * Here we check for internal errors
 695         */
 696        if (dev->failed)
 697                return 0;
 698
 699        switch (cmd->SCp.phase) {
 700        case 0:         /* Phase 0 - Waiting for parport */
 701                if (time_after(jiffies, dev->jstart + HZ)) {
 702                        /*
 703                         * We waited more than a second
 704                         * for parport to call us
 705                         */
 706                        ppa_fail(dev, DID_BUS_BUSY);
 707                        return 0;
 708                }
 709                return 1;       /* wait until ppa_wakeup claims parport */
 710        case 1:         /* Phase 1 - Connected */
 711                {               /* Perform a sanity check for cable unplugged */
 712                        int retv = 2;   /* Failed */
 713
 714                        ppa_connect(dev, CONNECT_EPP_MAYBE);
 715
 716                        w_ctr(ppb, 0xe);
 717                        if ((r_str(ppb) & 0x08) == 0x08)
 718                                retv--;
 719
 720                        w_ctr(ppb, 0xc);
 721                        if ((r_str(ppb) & 0x08) == 0x00)
 722                                retv--;
 723
 724                        if (retv) {
 725                                if (time_after(jiffies, dev->jstart + (1 * HZ))) {
 726                                        printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
 727                                        ppa_fail(dev, DID_BUS_BUSY);
 728                                        return 0;
 729                                } else {
 730                                        ppa_disconnect(dev);
 731                                        return 1;       /* Try again in a jiffy */
 732                                }
 733                        }
 734                        cmd->SCp.phase++;
 735                }
 736
 737        case 2:         /* Phase 2 - We are now talking to the scsi bus */
 738                if (!ppa_select(dev, scmd_id(cmd))) {
 739                        ppa_fail(dev, DID_NO_CONNECT);
 740                        return 0;
 741                }
 742                cmd->SCp.phase++;
 743
 744        case 3:         /* Phase 3 - Ready to accept a command */
 745                w_ctr(ppb, 0x0c);
 746                if (!(r_str(ppb) & 0x80))
 747                        return 1;
 748
 749                if (!ppa_send_command(cmd))
 750                        return 0;
 751                cmd->SCp.phase++;
 752
 753        case 4:         /* Phase 4 - Setup scatter/gather buffers */
 754                if (scsi_bufflen(cmd)) {
 755                        cmd->SCp.buffer = scsi_sglist(cmd);
 756                        cmd->SCp.this_residual = cmd->SCp.buffer->length;
 757                        cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 758                } else {
 759                        cmd->SCp.buffer = NULL;
 760                        cmd->SCp.this_residual = 0;
 761                        cmd->SCp.ptr = NULL;
 762                }
 763                cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
 764                cmd->SCp.phase++;
 765
 766        case 5:         /* Phase 5 - Data transfer stage */
 767                w_ctr(ppb, 0x0c);
 768                if (!(r_str(ppb) & 0x80))
 769                        return 1;
 770
 771                retv = ppa_completion(cmd);
 772                if (retv == -1)
 773                        return 0;
 774                if (retv == 0)
 775                        return 1;
 776                cmd->SCp.phase++;
 777
 778        case 6:         /* Phase 6 - Read status/message */
 779                cmd->result = DID_OK << 16;
 780                /* Check for data overrun */
 781                if (ppa_wait(dev) != (unsigned char) 0xf0) {
 782                        ppa_fail(dev, DID_ERROR);
 783                        return 0;
 784                }
 785                if (ppa_in(dev, &l, 1)) {       /* read status byte */
 786                        /* Check for optional message byte */
 787                        if (ppa_wait(dev) == (unsigned char) 0xf0)
 788                                ppa_in(dev, &h, 1);
 789                        cmd->result =
 790                            (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
 791                }
 792                return 0;       /* Finished */
 793                break;
 794
 795        default:
 796                printk(KERN_ERR "ppa: Invalid scsi phase\n");
 797        }
 798        return 0;
 799}
 800
 801static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
 802                void (*done) (struct scsi_cmnd *))
 803{
 804        ppa_struct *dev = ppa_dev(cmd->device->host);
 805
 806        if (dev->cur_cmd) {
 807                printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
 808                return 0;
 809        }
 810        dev->failed = 0;
 811        dev->jstart = jiffies;
 812        dev->cur_cmd = cmd;
 813        cmd->scsi_done = done;
 814        cmd->result = DID_ERROR << 16;  /* default return code */
 815        cmd->SCp.phase = 0;     /* bus free */
 816
 817        schedule_delayed_work(&dev->ppa_tq, 0);
 818
 819        ppa_pb_claim(dev);
 820
 821        return 0;
 822}
 823
 824static DEF_SCSI_QCMD(ppa_queuecommand)
 825
 826/*
 827 * Apparently the disk->capacity attribute is off by 1 sector 
 828 * for all disk drives.  We add the one here, but it should really
 829 * be done in sd.c.  Even if it gets fixed there, this will still
 830 * work.
 831 */
 832static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
 833              sector_t capacity, int ip[])
 834{
 835        ip[0] = 0x40;
 836        ip[1] = 0x20;
 837        ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 838        if (ip[2] > 1024) {
 839                ip[0] = 0xff;
 840                ip[1] = 0x3f;
 841                ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
 842                if (ip[2] > 1023)
 843                        ip[2] = 1023;
 844        }
 845        return 0;
 846}
 847
 848static int ppa_abort(struct scsi_cmnd *cmd)
 849{
 850        ppa_struct *dev = ppa_dev(cmd->device->host);
 851        /*
 852         * There is no method for aborting commands since Iomega
 853         * have tied the SCSI_MESSAGE line high in the interface
 854         */
 855
 856        switch (cmd->SCp.phase) {
 857        case 0:         /* Do not have access to parport */
 858        case 1:         /* Have not connected to interface */
 859                dev->cur_cmd = NULL;    /* Forget the problem */
 860                return SUCCESS;
 861                break;
 862        default:                /* SCSI command sent, can not abort */
 863                return FAILED;
 864                break;
 865        }
 866}
 867
 868static void ppa_reset_pulse(unsigned int base)
 869{
 870        w_dtr(base, 0x40);
 871        w_ctr(base, 0x8);
 872        udelay(30);
 873        w_ctr(base, 0xc);
 874}
 875
 876static int ppa_reset(struct scsi_cmnd *cmd)
 877{
 878        ppa_struct *dev = ppa_dev(cmd->device->host);
 879
 880        if (cmd->SCp.phase)
 881                ppa_disconnect(dev);
 882        dev->cur_cmd = NULL;    /* Forget the problem */
 883
 884        ppa_connect(dev, CONNECT_NORMAL);
 885        ppa_reset_pulse(dev->base);
 886        mdelay(1);              /* device settle delay */
 887        ppa_disconnect(dev);
 888        mdelay(1);              /* device settle delay */
 889        return SUCCESS;
 890}
 891
 892static int device_check(ppa_struct *dev)
 893{
 894        /* This routine looks for a device and then attempts to use EPP
 895           to send a command. If all goes as planned then EPP is available. */
 896
 897        static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 898        int loop, old_mode, status, k, ppb = dev->base;
 899        unsigned char l;
 900
 901        old_mode = dev->mode;
 902        for (loop = 0; loop < 8; loop++) {
 903                /* Attempt to use EPP for Test Unit Ready */
 904                if ((ppb & 0x0007) == 0x0000)
 905                        dev->mode = PPA_EPP_32;
 906
 907second_pass:
 908                ppa_connect(dev, CONNECT_EPP_MAYBE);
 909                /* Select SCSI device */
 910                if (!ppa_select(dev, loop)) {
 911                        ppa_disconnect(dev);
 912                        continue;
 913                }
 914                printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
 915                       loop, PPA_MODE_STRING[dev->mode]);
 916
 917                /* Send SCSI command */
 918                status = 1;
 919                w_ctr(ppb, 0x0c);
 920                for (l = 0; (l < 6) && (status); l++)
 921                        status = ppa_out(dev, cmd, 1);
 922
 923                if (!status) {
 924                        ppa_disconnect(dev);
 925                        ppa_connect(dev, CONNECT_EPP_MAYBE);
 926                        w_dtr(ppb, 0x40);
 927                        w_ctr(ppb, 0x08);
 928                        udelay(30);
 929                        w_ctr(ppb, 0x0c);
 930                        udelay(1000);
 931                        ppa_disconnect(dev);
 932                        udelay(1000);
 933                        if (dev->mode == PPA_EPP_32) {
 934                                dev->mode = old_mode;
 935                                goto second_pass;
 936                        }
 937                        return -EIO;
 938                }
 939                w_ctr(ppb, 0x0c);
 940                k = 1000000;    /* 1 Second */
 941                do {
 942                        l = r_str(ppb);
 943                        k--;
 944                        udelay(1);
 945                } while (!(l & 0x80) && (k));
 946
 947                l &= 0xf0;
 948
 949                if (l != 0xf0) {
 950                        ppa_disconnect(dev);
 951                        ppa_connect(dev, CONNECT_EPP_MAYBE);
 952                        ppa_reset_pulse(ppb);
 953                        udelay(1000);
 954                        ppa_disconnect(dev);
 955                        udelay(1000);
 956                        if (dev->mode == PPA_EPP_32) {
 957                                dev->mode = old_mode;
 958                                goto second_pass;
 959                        }
 960                        return -EIO;
 961                }
 962                ppa_disconnect(dev);
 963                printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
 964                       loop, PPA_MODE_STRING[dev->mode]);
 965                ppa_connect(dev, CONNECT_EPP_MAYBE);
 966                ppa_reset_pulse(ppb);
 967                udelay(1000);
 968                ppa_disconnect(dev);
 969                udelay(1000);
 970                return 0;
 971        }
 972        return -ENODEV;
 973}
 974
 975static int ppa_adjust_queue(struct scsi_device *device)
 976{
 977        blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
 978        return 0;
 979}
 980
 981static struct scsi_host_template ppa_template = {
 982        .module                 = THIS_MODULE,
 983        .proc_name              = "ppa",
 984        .proc_info              = ppa_proc_info,
 985        .name                   = "Iomega VPI0 (ppa) interface",
 986        .queuecommand           = ppa_queuecommand,
 987        .eh_abort_handler       = ppa_abort,
 988        .eh_bus_reset_handler   = ppa_reset,
 989        .eh_host_reset_handler  = ppa_reset,
 990        .bios_param             = ppa_biosparam,
 991        .this_id                = -1,
 992        .sg_tablesize           = SG_ALL,
 993        .cmd_per_lun            = 1,
 994        .use_clustering         = ENABLE_CLUSTERING,
 995        .can_queue              = 1,
 996        .slave_alloc            = ppa_adjust_queue,
 997};
 998
 999/***************************************************************************
1000 *                   Parallel port probing routines                        *
1001 ***************************************************************************/
1002
1003static LIST_HEAD(ppa_hosts);
1004
1005static int __ppa_attach(struct parport *pb)
1006{
1007        struct Scsi_Host *host;
1008        DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1009        DEFINE_WAIT(wait);
1010        ppa_struct *dev;
1011        int ports;
1012        int modes, ppb, ppb_hi;
1013        int err = -ENOMEM;
1014
1015        dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1016        if (!dev)
1017                return -ENOMEM;
1018        dev->base = -1;
1019        dev->mode = PPA_AUTODETECT;
1020        dev->recon_tmo = PPA_RECON_TMO;
1021        init_waitqueue_head(&waiting);
1022        dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1023                                            NULL, 0, dev);
1024
1025        if (!dev->dev)
1026                goto out;
1027
1028        /* Claim the bus so it remembers what we do to the control
1029         * registers. [ CTR and ECP ]
1030         */
1031        err = -EBUSY;
1032        dev->waiting = &waiting;
1033        prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1034        if (ppa_pb_claim(dev))
1035                schedule_timeout(3 * HZ);
1036        if (dev->wanted) {
1037                printk(KERN_ERR "ppa%d: failed to claim parport because "
1038                                "a pardevice is owning the port for too long "
1039                                "time!\n", pb->number);
1040                ppa_pb_dismiss(dev);
1041                dev->waiting = NULL;
1042                finish_wait(&waiting, &wait);
1043                goto out1;
1044        }
1045        dev->waiting = NULL;
1046        finish_wait(&waiting, &wait);
1047        ppb = dev->base = dev->dev->port->base;
1048        ppb_hi = dev->dev->port->base_hi;
1049        w_ctr(ppb, 0x0c);
1050        modes = dev->dev->port->modes;
1051
1052        /* Mode detection works up the chain of speed
1053         * This avoids a nasty if-then-else-if-... tree
1054         */
1055        dev->mode = PPA_NIBBLE;
1056
1057        if (modes & PARPORT_MODE_TRISTATE)
1058                dev->mode = PPA_PS2;
1059
1060        if (modes & PARPORT_MODE_ECP) {
1061                w_ecr(ppb_hi, 0x20);
1062                dev->mode = PPA_PS2;
1063        }
1064        if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1065                w_ecr(ppb_hi, 0x80);
1066
1067        /* Done configuration */
1068
1069        err = ppa_init(dev);
1070        ppa_pb_release(dev);
1071
1072        if (err)
1073                goto out1;
1074
1075        /* now the glue ... */
1076        if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1077                ports = 3;
1078        else
1079                ports = 8;
1080
1081        INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1082
1083        err = -ENOMEM;
1084        host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1085        if (!host)
1086                goto out1;
1087        host->io_port = pb->base;
1088        host->n_io_port = ports;
1089        host->dma_channel = -1;
1090        host->unique_id = pb->number;
1091        *(ppa_struct **)&host->hostdata = dev;
1092        dev->host = host;
1093        list_add_tail(&dev->list, &ppa_hosts);
1094        err = scsi_add_host(host, NULL);
1095        if (err)
1096                goto out2;
1097        scsi_scan_host(host);
1098        return 0;
1099out2:
1100        list_del_init(&dev->list);
1101        scsi_host_put(host);
1102out1:
1103        parport_unregister_device(dev->dev);
1104out:
1105        kfree(dev);
1106        return err;
1107}
1108
1109static void ppa_attach(struct parport *pb)
1110{
1111        __ppa_attach(pb);
1112}
1113
1114static void ppa_detach(struct parport *pb)
1115{
1116        ppa_struct *dev;
1117        list_for_each_entry(dev, &ppa_hosts, list) {
1118                if (dev->dev->port == pb) {
1119                        list_del_init(&dev->list);
1120                        scsi_remove_host(dev->host);
1121                        scsi_host_put(dev->host);
1122                        parport_unregister_device(dev->dev);
1123                        kfree(dev);
1124                        break;
1125                }
1126        }
1127}
1128
1129static struct parport_driver ppa_driver = {
1130        .name   = "ppa",
1131        .attach = ppa_attach,
1132        .detach = ppa_detach,
1133};
1134
1135static int __init ppa_driver_init(void)
1136{
1137        printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1138        return parport_register_driver(&ppa_driver);
1139}
1140
1141static void __exit ppa_driver_exit(void)
1142{
1143        parport_unregister_driver(&ppa_driver);
1144}
1145
1146module_init(ppa_driver_init);
1147module_exit(ppa_driver_exit);
1148MODULE_LICENSE("GPL");
1149
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