drivers/block/amiflop.c

   1 /*
   2  *  linux/amiga/amiflop.c
   3  *
   4  *  Copyright (C) 1993  Greg Harp
   5  *  Portions of this driver are based on code contributed by Brad Pepers
   6  *
   7  *  revised 28.5.95 by Joerg Dorchain
   8  *  - now no bugs(?) any more for both HD & DD
   9  *  - added support for 40 Track 5.25" drives, 80-track hopefully behaves
  10  *    like 3.5" dd (no way to test - are there any 5.25" drives out there
  11  *    that work on an A4000?)
  12  *  - wrote formatting routine (maybe dirty, but works)
  13  *
  14  *  june/july 1995 added ms-dos support by Joerg Dorchain
  15  *  (portions based on messydos.device and various contributors)
  16  *  - currently only 9 and 18 sector disks
  17  *
  18  *  - fixed a bug with the internal trackbuffer when using multiple
  19  *    disks the same time
  20  *  - made formatting a bit safer
  21  *  - added command line and machine based default for "silent" df0
  22  *
  23  *  december 1995 adapted for 1.2.13pl4 by Joerg Dorchain
  24  *  - works but I think it's inefficient. (look in redo_fd_request)
  25  *    But the changes were very efficient. (only three and a half lines)
  26  *
  27  *  january 1996 added special ioctl for tracking down read/write problems
  28  *  - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data
  29  *    is copied to area. (area should be large enough since no checking is
  30  *    done - 30K is currently sufficient). return the actual size of the
  31  *    trackbuffer
  32  *  - replaced udelays() by a timer (CIAA timer B) for the waits
  33  *    needed for the disk mechanic.
  34  *
  35  *  february 1996 fixed error recovery and multiple disk access
  36  *  - both got broken the first time I tampered with the driver :-(
  37  *  - still not safe, but better than before
  38  *
  39  *  revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.
  40  *  - Minor changes to accept the kdev_t.
  41  *  - Replaced some more udelays with ms_delays. Udelay is just a loop,
  42  *    and so the delay will be different depending on the given
  43  *    processor :-(
  44  *  - The driver could use a major cleanup because of the new
  45  *    major/minor handling that came with kdev_t. It seems to work for
  46  *    the time being, but I can't guarantee that it will stay like
  47  *    that when we start using 16 (24?) bit minors.
  48  *
  49  * restructured jan 1997 by Joerg Dorchain
  50  * - Fixed Bug accessing multiple disks
  51  * - some code cleanup
  52  * - added trackbuffer for each drive to speed things up
  53  * - fixed some race conditions (who finds the next may send it to me ;-)
  54  */
  55
  56 #include <linux/module.h>
  57
  58 #include <linux/fd.h>
  59 #include <linux/hdreg.h>
  60 #include <linux/delay.h>
  61 #include <linux/init.h>
  62 #include <linux/amifdreg.h>
  63 #include <linux/amifd.h>
  64 #include <linux/buffer_head.h>
  65 #include <linux/blkdev.h>
  66 #include <linux/elevator.h>
  67 #include <linux/interrupt.h>
  68
  69 #include <asm/setup.h>
  70 #include <asm/uaccess.h>
  71 #include <asm/amigahw.h>
  72 #include <asm/amigaints.h>
  73 #include <asm/irq.h>
  74
  75 #undef DEBUG /* print _LOTS_ of infos */
  76
  77 #define RAW_IOCTL
  78 #ifdef RAW_IOCTL
  79 #define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
  80 #endif
  81
  82 /*
  83  *  Defines
  84  */
  85
  86 /*
  87  *  Error codes
  88  */
  89 #define FD_OK           0       /* operation succeeded */
  90 #define FD_ERROR        -1      /* general error (seek, read, write, etc) */
  91 #define FD_NOUNIT       1       /* unit does not exist */
  92 #define FD_UNITBUSY     2       /* unit already active */
  93 #define FD_NOTACTIVE    3       /* unit is not active */
  94 #define FD_NOTREADY     4       /* unit is not ready (motor not on/no disk) */
  95
  96 #define MFM_NOSYNC      1
  97 #define MFM_HEADER      2
  98 #define MFM_DATA        3
  99 #define MFM_TRACK       4
 100
 101 /*
 102  *  Floppy ID values
 103  */
 104 #define FD_NODRIVE      0x00000000  /* response when no unit is present */
 105 #define FD_DD_3         0xffffffff  /* double-density 3.5" (880K) drive */
 106 #define FD_HD_3         0x55555555  /* high-density 3.5" (1760K) drive */
 107 #define FD_DD_5         0xaaaaaaaa  /* double-density 5.25" (440K) drive */
 108
 109 static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
 110
 111 module_param(fd_def_df0, ulong, 0);
 112 MODULE_LICENSE("GPL");
 113
 114 static struct request_queue *floppy_queue;
 115
 116 /*
 117  *  Macros
 118  */
 119 #define MOTOR_ON        (ciab.prb &= ~DSKMOTOR)
 120 #define MOTOR_OFF       (ciab.prb |= DSKMOTOR)
 121 #define SELECT(mask)    (ciab.prb &= ~mask)
 122 #define DESELECT(mask)  (ciab.prb |= mask)
 123 #define SELMASK(drive)  (1 << (3 + (drive & 3)))
 124
 125 static struct fd_drive_type drive_types[] = {
 126 /*  code        name       tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
 127 /*  warning: times are now in milliseconds (ms)                    */
 128 { FD_DD_3,      "DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
 129 { FD_HD_3,      "HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
 130 { FD_DD_5,      "DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
 131 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
 132 };
 133 static int num_dr_types = ARRAY_SIZE(drive_types);
 134
 135 static int amiga_read(int), dos_read(int);
 136 static void amiga_write(int), dos_write(int);
 137 static struct fd_data_type data_types[] = {
 138         { "Amiga", 11 , amiga_read, amiga_write},
 139         { "MS-Dos", 9, dos_read, dos_write}
 140 };
 141
 142 /* current info on each unit */
 143 static struct amiga_floppy_struct unit[FD_MAX_UNITS];
 144
 145 static struct timer_list flush_track_timer[FD_MAX_UNITS];
 146 static struct timer_list post_write_timer;
 147 static struct timer_list motor_on_timer;
 148 static struct timer_list motor_off_timer[FD_MAX_UNITS];
 149 static int on_attempts;
 150
 151 /* Synchronization of FDC access */
 152 /* request loop (trackbuffer) */
 153 static volatile int fdc_busy = -1;
 154 static volatile int fdc_nested;
 155 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
 156
 157 static DECLARE_COMPLETION(motor_on_completion);
 158
 159 static volatile int selected = -1;      /* currently selected drive */
 160
 161 static int writepending;
 162 static int writefromint;
 163 static char *raw_buf;
 164
 165 static DEFINE_SPINLOCK(amiflop_lock);
 166
 167 #define RAW_BUF_SIZE 30000  /* size of raw disk data */
 168
 169 /*
 170  * These are global variables, as that's the easiest way to give
 171  * information to interrupts. They are the data used for the current
 172  * request.
 173  */
 174 static volatile char block_flag;
 175 static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
 176
 177 /* MS-Dos MFM Coding tables (should go quick and easy) */
 178 static unsigned char mfmencode[16]={
 179         0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
 180         0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
 181 };
 182 static unsigned char mfmdecode[128];
 183
 184 /* floppy internal millisecond timer stuff */
 185 static DECLARE_COMPLETION(ms_wait_completion);
 186 #define MS_TICKS ((amiga_eclock+50)/1000)
 187
 188 /*
 189  * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
 190  * max X times - some types of errors increase the errorcount by 2 or
 191  * even 3, so we might actually retry only X/2 times before giving up.
 192  */
 193 #define MAX_ERRORS 12
 194
 195 #define custom amiga_custom
 196
 197 /* Prevent "aliased" accesses. */
 198 static int fd_ref[4] = { 0,0,0,0 };
 199 static int fd_device[4] = { 0, 0, 0, 0 };
 200
 201 /*
 202  * Here come the actual hardware access and helper functions.
 203  * They are not reentrant and single threaded because all drives
 204  * share the same hardware and the same trackbuffer.
 205  */
 206
 207 /* Milliseconds timer */
 208
 209 static irqreturn_t ms_isr(int irq, void *dummy)
 210 {
 211         complete(&ms_wait_completion);
 212         return IRQ_HANDLED;
 213 }
 214
 215 /* all waits are queued up
 216    A more generic routine would do a schedule a la timer.device */
 217 static void ms_delay(int ms)
 218 {
 219         int ticks;
 220         static DEFINE_MUTEX(mutex);
 221
 222         if (ms > 0) {
 223                 mutex_lock(&mutex);
 224                 ticks = MS_TICKS*ms-1;
 225                 ciaa.tblo=ticks%256;
 226                 ciaa.tbhi=ticks/256;
 227                 ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
 228                 wait_for_completion(&ms_wait_completion);
 229                 mutex_unlock(&mutex);
 230         }
 231 }
 232
 233 /* Hardware semaphore */
 234
 235 /* returns true when we would get the semaphore */
 236 static inline int try_fdc(int drive)
 237 {
 238         drive &= 3;
 239         return ((fdc_busy < 0) || (fdc_busy == drive));
 240 }
 241
 242 static void get_fdc(int drive)
 243 {
 244         unsigned long flags;
 245
 246         drive &= 3;
 247 #ifdef DEBUG
 248         printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
 249 #endif
 250         local_irq_save(flags);
 251         wait_event(fdc_wait, try_fdc(drive));
 252         fdc_busy = drive;
 253         fdc_nested++;
 254         local_irq_restore(flags);
 255 }
 256
 257 static inline void rel_fdc(void)
 258 {
 259 #ifdef DEBUG
 260         if (fdc_nested == 0)
 261                 printk("fd: unmatched rel_fdc\n");
 262         printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
 263 #endif
 264         fdc_nested--;
 265         if (fdc_nested == 0) {
 266                 fdc_busy = -1;
 267                 wake_up(&fdc_wait);
 268         }
 269 }
 270
 271 static void fd_select (int drive)
 272 {
 273         unsigned char prb = ~0;
 274
 275         drive&=3;
 276 #ifdef DEBUG
 277         printk("selecting %d\n",drive);
 278 #endif
 279         if (drive == selected)
 280                 return;
 281         get_fdc(drive);
 282         selected = drive;
 283
 284         if (unit[drive].track % 2 != 0)
 285                 prb &= ~DSKSIDE;
 286         if (unit[drive].motor == 1)
 287                 prb &= ~DSKMOTOR;
 288         ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
 289         ciab.prb = prb;
 290         prb &= ~SELMASK(drive);
 291         ciab.prb = prb;
 292         rel_fdc();
 293 }
 294
 295 static void fd_deselect (int drive)
 296 {
 297         unsigned char prb;
 298         unsigned long flags;
 299
 300         drive&=3;
 301 #ifdef DEBUG
 302         printk("deselecting %d\n",drive);
 303 #endif
 304         if (drive != selected) {
 305                 printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
 306                 return;
 307         }
 308
 309         get_fdc(drive);
 310         local_irq_save(flags);
 311
 312         selected = -1;
 313
 314         prb = ciab.prb;
 315         prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
 316         ciab.prb = prb;
 317
 318         local_irq_restore (flags);
 319         rel_fdc();
 320
 321 }
 322
 323 static void motor_on_callback(unsigned long nr)
 324 {
 325         if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
 326                 complete_all(&motor_on_completion);
 327         } else {
 328                 motor_on_timer.expires = jiffies + HZ/10;
 329                 add_timer(&motor_on_timer);
 330         }
 331 }
 332
 333 static int fd_motor_on(int nr)
 334 {
 335         nr &= 3;
 336
 337         del_timer(motor_off_timer + nr);
 338
 339         if (!unit[nr].motor) {
 340                 unit[nr].motor = 1;
 341                 fd_select(nr);
 342
 343                 INIT_COMPLETION(motor_on_completion);
 344                 motor_on_timer.data = nr;
 345                 mod_timer(&motor_on_timer, jiffies + HZ/2);
 346
 347                 on_attempts = 10;
 348                 wait_for_completion(&motor_on_completion);
 349                 fd_deselect(nr);
 350         }
 351
 352         if (on_attempts == 0) {
 353                 on_attempts = -1;
 354 #if 0
 355                 printk (KERN_ERR "motor_on failed, turning motor off\n");
 356                 fd_motor_off (nr);
 357                 return 0;
 358 #else
 359                 printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
 360 #endif
 361         }
 362
 363         return 1;
 364 }
 365
 366 static void fd_motor_off(unsigned long drive)
 367 {
 368         long calledfromint;
 369 #ifdef MODULE
 370         long decusecount;
 371
 372         decusecount = drive & 0x40000000;
 373 #endif
 374         calledfromint = drive & 0x80000000;
 375         drive&=3;
 376         if (calledfromint && !try_fdc(drive)) {
 377                 /* We would be blocked in an interrupt, so try again later */
 378                 motor_off_timer[drive].expires = jiffies + 1;
 379                 add_timer(motor_off_timer + drive);
 380                 return;
 381         }
 382         unit[drive].motor = 0;
 383         fd_select(drive);
 384         udelay (1);
 385         fd_deselect(drive);
 386 }
 387
 388 static void floppy_off (unsigned int nr)
 389 {
 390         int drive;
 391
 392         drive = nr & 3;
 393         /* called this way it is always from interrupt */
 394         motor_off_timer[drive].data = nr | 0x80000000;
 395         mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
 396 }
 397
 398 static int fd_calibrate(int drive)
 399 {
 400         unsigned char prb;
 401         int n;
 402
 403         drive &= 3;
 404         get_fdc(drive);
 405         if (!fd_motor_on (drive))
 406                 return 0;
 407         fd_select (drive);
 408         prb = ciab.prb;
 409         prb |= DSKSIDE;
 410         prb &= ~DSKDIREC;
 411         ciab.prb = prb;
 412         for (n = unit[drive].type->tracks/2; n != 0; --n) {
 413                 if (ciaa.pra & DSKTRACK0)
 414                         break;
 415                 prb &= ~DSKSTEP;
 416                 ciab.prb = prb;
 417                 prb |= DSKSTEP;
 418                 udelay (2);
 419                 ciab.prb = prb;
 420                 ms_delay(unit[drive].type->step_delay);
 421         }
 422         ms_delay (unit[drive].type->settle_time);
 423         prb |= DSKDIREC;
 424         n = unit[drive].type->tracks + 20;
 425         for (;;) {
 426                 prb &= ~DSKSTEP;
 427                 ciab.prb = prb;
 428                 prb |= DSKSTEP;
 429                 udelay (2);
 430                 ciab.prb = prb;
 431                 ms_delay(unit[drive].type->step_delay + 1);
 432                 if ((ciaa.pra & DSKTRACK0) == 0)
 433                         break;
 434                 if (--n == 0) {
 435                         printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
 436                         fd_motor_off (drive);
 437                         unit[drive].track = -1;
 438                         rel_fdc();
 439                         return 0;
 440                 }
 441         }
 442         unit[drive].track = 0;
 443         ms_delay(unit[drive].type->settle_time);
 444
 445         rel_fdc();
 446         fd_deselect(drive);
 447         return 1;
 448 }
 449
 450 static int fd_seek(int drive, int track)
 451 {
 452         unsigned char prb;
 453         int cnt;
 454
 455 #ifdef DEBUG
 456         printk("seeking drive %d to track %d\n",drive,track);
 457 #endif
 458         drive &= 3;
 459         get_fdc(drive);
 460         if (unit[drive].track == track) {
 461                 rel_fdc();
 462                 return 1;
 463         }
 464         if (!fd_motor_on(drive)) {
 465                 rel_fdc();
 466                 return 0;
 467         }
 468         if (unit[drive].track < 0 && !fd_calibrate(drive)) {
 469                 rel_fdc();
 470                 return 0;
 471         }
 472
 473         fd_select (drive);
 474         cnt = unit[drive].track/2 - track/2;
 475         prb = ciab.prb;
 476         prb |= DSKSIDE | DSKDIREC;
 477         if (track % 2 != 0)
 478                 prb &= ~DSKSIDE;
 479         if (cnt < 0) {
 480                 cnt = - cnt;
 481                 prb &= ~DSKDIREC;
 482         }
 483         ciab.prb = prb;
 484         if (track % 2 != unit[drive].track % 2)
 485                 ms_delay (unit[drive].type->side_time);
 486         unit[drive].track = track;
 487         if (cnt == 0) {
 488                 rel_fdc();
 489                 fd_deselect(drive);
 490                 return 1;
 491         }
 492         do {
 493                 prb &= ~DSKSTEP;
 494                 ciab.prb = prb;
 495                 prb |= DSKSTEP;
 496                 udelay (1);
 497                 ciab.prb = prb;
 498                 ms_delay (unit[drive].type->step_delay);
 499         } while (--cnt != 0);
 500         ms_delay (unit[drive].type->settle_time);
 501
 502         rel_fdc();
 503         fd_deselect(drive);
 504         return 1;
 505 }
 506
 507 static unsigned long fd_get_drive_id(int drive)
 508 {
 509         int i;
 510         ulong id = 0;
 511
 512         drive&=3;
 513         get_fdc(drive);
 514         /* set up for ID */
 515         MOTOR_ON;
 516         udelay(2);
 517         SELECT(SELMASK(drive));
 518         udelay(2);
 519         DESELECT(SELMASK(drive));
 520         udelay(2);
 521         MOTOR_OFF;
 522         udelay(2);
 523         SELECT(SELMASK(drive));
 524         udelay(2);
 525         DESELECT(SELMASK(drive));
 526         udelay(2);
 527
 528         /* loop and read disk ID */
 529         for (i=0; i<32; i++) {
 530                 SELECT(SELMASK(drive));
 531                 udelay(2);
 532
 533                 /* read and store value of DSKRDY */
 534                 id <<= 1;
 535                 id |= (ciaa.pra & DSKRDY) ? 0 : 1;      /* cia regs are low-active! */
 536
 537                 DESELECT(SELMASK(drive));
 538         }
 539
 540         rel_fdc();
 541
 542         /*
 543          * RB: At least A500/A2000's df0: don't identify themselves.
 544          * As every (real) Amiga has at least a 3.5" DD drive as df0:
 545          * we default to that if df0: doesn't identify as a certain
 546          * type.
 547          */
 548         if(drive == 0 && id == FD_NODRIVE)
 549         {
 550                 id = fd_def_df0;
 551                 printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
 552         }
 553         /* return the ID value */
 554         return (id);
 555 }
 556
 557 static irqreturn_t fd_block_done(int irq, void *dummy)
 558 {
 559         if (block_flag)
 560                 custom.dsklen = 0x4000;
 561
 562         if (block_flag == 2) { /* writing */
 563                 writepending = 2;
 564                 post_write_timer.expires = jiffies + 1; /* at least 2 ms */
 565                 post_write_timer.data = selected;
 566                 add_timer(&post_write_timer);
 567         }
 568         else {                /* reading */
 569                 block_flag = 0;
 570                 wake_up (&wait_fd_block);
 571         }
 572         return IRQ_HANDLED;
 573 }
 574
 575 static void raw_read(int drive)
 576 {
 577         drive&=3;
 578         get_fdc(drive);
 579         wait_event(wait_fd_block, !block_flag);
 580         fd_select(drive);
 581         /* setup adkcon bits correctly */
 582         custom.adkcon = ADK_MSBSYNC;
 583         custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
 584
 585         custom.dsksync = MFM_SYNC;
 586
 587         custom.dsklen = 0;
 588         custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
 589         custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
 590         custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
 591
 592         block_flag = 1;
 593
 594         wait_event(wait_fd_block, !block_flag);
 595
 596         custom.dsklen = 0;
 597         fd_deselect(drive);
 598         rel_fdc();
 599 }
 600
 601 static int raw_write(int drive)
 602 {
 603         ushort adk;
 604
 605         drive&=3;
 606         get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
 607         if ((ciaa.pra & DSKPROT) == 0) {
 608                 rel_fdc();
 609                 return 0;
 610         }
 611         wait_event(wait_fd_block, !block_flag);
 612         fd_select(drive);
 613         /* clear adkcon bits */
 614         custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
 615         /* set appropriate adkcon bits */
 616         adk = ADK_SETCLR|ADK_FAST;
 617         if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
 618                 adk |= ADK_PRECOMP1;
 619         else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
 620                 adk |= ADK_PRECOMP0;
 621         custom.adkcon = adk;
 622
 623         custom.dsklen = DSKLEN_WRITE;
 624         custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
 625         custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
 626         custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
 627
 628         block_flag = 2;
 629         return 1;
 630 }
 631
 632 /*
 633  * to be called at least 2ms after the write has finished but before any
 634  * other access to the hardware.
 635  */
 636 static void post_write (unsigned long drive)
 637 {
 638 #ifdef DEBUG
 639         printk("post_write for drive %ld\n",drive);
 640 #endif
 641         drive &= 3;
 642         custom.dsklen = 0;
 643         block_flag = 0;
 644         writepending = 0;
 645         writefromint = 0;
 646         unit[drive].dirty = 0;
 647         wake_up(&wait_fd_block);
 648         fd_deselect(drive);
 649         rel_fdc(); /* corresponds to get_fdc() in raw_write */
 650 }
 651
 652
 653 /*
 654  * The following functions are to convert the block contents into raw data
 655  * written to disk and vice versa.
 656  * (Add other formats here ;-))
 657  */
 658
 659 static unsigned long scan_sync(unsigned long raw, unsigned long end)
 660 {
 661         ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
 662
 663         while (ptr < endp && *ptr++ != 0x4489)
 664                 ;
 665         if (ptr < endp) {
 666                 while (*ptr == 0x4489 && ptr < endp)
 667                         ptr++;
 668                 return (ulong)ptr;
 669         }
 670         return 0;
 671 }
 672
 673 static inline unsigned long checksum(unsigned long *addr, int len)
 674 {
 675         unsigned long csum = 0;
 676
 677         len /= sizeof(*addr);
 678         while (len-- > 0)
 679                 csum ^= *addr++;
 680         csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
 681
 682         return csum;
 683 }
 684
 685 static unsigned long decode (unsigned long *data, unsigned long *raw,
 686                              int len)
 687 {
 688         ulong *odd, *even;
 689
 690         /* convert length from bytes to longwords */
 691         len >>= 2;
 692         odd = raw;
 693         even = odd + len;
 694
 695         /* prepare return pointer */
 696         raw += len * 2;
 697
 698         do {
 699                 *data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
 700         } while (--len != 0);
 701
 702         return (ulong)raw;
 703 }
 704
 705 struct header {
 706         unsigned char magic;
 707         unsigned char track;
 708         unsigned char sect;
 709         unsigned char ord;
 710         unsigned char labels[16];
 711         unsigned long hdrchk;
 712         unsigned long datachk;
 713 };
 714
 715 static int amiga_read(int drive)
 716 {
 717         unsigned long raw;
 718         unsigned long end;
 719         int scnt;
 720         unsigned long csum;
 721         struct header hdr;
 722
 723         drive&=3;
 724         raw = (long) raw_buf;
 725         end = raw + unit[drive].type->read_size;
 726
 727         for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
 728                 if (!(raw = scan_sync(raw, end))) {
 729                         printk (KERN_INFO "can't find sync for sector %d\n", scnt);
 730                         return MFM_NOSYNC;
 731                 }
 732
 733                 raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
 734                 raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
 735                 raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
 736                 raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
 737                 csum = checksum((ulong *)&hdr,
 738                                 (char *)&hdr.hdrchk-(char *)&hdr);
 739
 740 #ifdef DEBUG
 741                 printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
 742                         hdr.magic, hdr.track, hdr.sect, hdr.ord,
 743                         *(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
 744                         *(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
 745                         hdr.hdrchk, hdr.datachk);
 746 #endif
 747
 748                 if (hdr.hdrchk != csum) {
 749                         printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
 750                         return MFM_HEADER;
 751                 }
 752
 753                 /* verify track */
 754                 if (hdr.track != unit[drive].track) {
 755                         printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
 756                         return MFM_TRACK;
 757                 }
 758
 759                 raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
 760                               (ulong *)raw, 512);
 761                 csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
 762
 763                 if (hdr.datachk != csum) {
 764                         printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
 765                                hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
 766                                hdr.datachk, csum);
 767                         printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
 768                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
 769                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
 770                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
 771                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
 772                         return MFM_DATA;
 773                 }
 774         }
 775
 776         return 0;
 777 }
 778
 779 static void encode(unsigned long data, unsigned long *dest)
 780 {
 781         unsigned long data2;
 782
 783         data &= 0x55555555;
 784         data2 = data ^ 0x55555555;
 785         data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
 786
 787         if (*(dest - 1) & 0x00000001)
 788                 data &= 0x7FFFFFFF;
 789
 790         *dest = data;
 791 }
 792
 793 static void encode_block(unsigned long *dest, unsigned long *src, int len)
 794 {
 795         int cnt, to_cnt = 0;
 796         unsigned long data;
 797
 798         /* odd bits */
 799         for (cnt = 0; cnt < len / 4; cnt++) {
 800                 data = src[cnt] >> 1;
 801                 encode(data, dest + to_cnt++);
 802         }
 803
 804         /* even bits */
 805         for (cnt = 0; cnt < len / 4; cnt++) {
 806                 data = src[cnt];
 807                 encode(data, dest + to_cnt++);
 808         }
 809 }
 810
 811 static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
 812 {
 813         struct header hdr;
 814         int i;
 815
 816         disk&=3;
 817         *raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
 818         raw++;
 819         *raw++ = 0x44894489;
 820
 821         hdr.magic = 0xFF;
 822         hdr.track = unit[disk].track;
 823         hdr.sect = cnt;
 824         hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
 825         for (i = 0; i < 16; i++)
 826                 hdr.labels[i] = 0;
 827         hdr.hdrchk = checksum((ulong *)&hdr,
 828                               (char *)&hdr.hdrchk-(char *)&hdr);
 829         hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
 830
 831         encode_block(raw, (ulong *)&hdr.magic, 4);
 832         raw += 2;
 833         encode_block(raw, (ulong *)&hdr.labels, 16);
 834         raw += 8;
 835         encode_block(raw, (ulong *)&hdr.hdrchk, 4);
 836         raw += 2;
 837         encode_block(raw, (ulong *)&hdr.datachk, 4);
 838         raw += 2;
 839         encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
 840         raw += 256;
 841
 842         return raw;
 843 }
 844
 845 static void amiga_write(int disk)
 846 {
 847         unsigned int cnt;
 848         unsigned long *ptr = (unsigned long *)raw_buf;
 849
 850         disk&=3;
 851         /* gap space */
 852         for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
 853                 *ptr++ = 0xaaaaaaaa;
 854
 855         /* sectors */
 856         for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
 857                 ptr = putsec (disk, ptr, cnt);
 858         *(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
 859 }
 860
 861
 862 struct dos_header {
 863         unsigned char track,   /* 0-80 */
 864                 side,    /* 0-1 */
 865                 sec,     /* 0-...*/
 866                 len_desc;/* 2 */
 867         unsigned short crc;     /* on 68000 we got an alignment problem,
 868                                    but this compiler solves it  by adding silently
 869                                    adding a pad byte so data won't fit
 870                                    and this took about 3h to discover.... */
 871         unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
 872 };
 873
 874 /* crc routines are borrowed from the messydos-handler  */
 875
 876 /* excerpt from the messydos-device
 877 ; The CRC is computed not only over the actual data, but including
 878 ; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
 879 ; As we don't read or encode these fields into our buffers, we have to
 880 ; preload the registers containing the CRC with the values they would have
 881 ; after stepping over these fields.
 882 ;
 883 ; How CRCs "really" work:
 884 ;
 885 ; First, you should regard a bitstring as a series of coefficients of
 886 ; polynomials. We calculate with these polynomials in modulo-2
 887 ; arithmetic, in which both add and subtract are done the same as
 888 ; exclusive-or. Now, we modify our data (a very long polynomial) in
 889 ; such a way that it becomes divisible by the CCITT-standard 16-bit
 890 ;                16   12   5
 891 ; polynomial:   x  + x  + x + 1, represented by $11021. The easiest
 892 ; way to do this would be to multiply (using proper arithmetic) our
 893 ; datablock with $11021. So we have:
 894 ;   data * $11021                =
 895 ;   data * ($10000 + $1021)      =
 896 ;   data * $10000 + data * $1021
 897 ; The left part of this is simple: Just add two 0 bytes. But then
 898 ; the right part (data $1021) remains difficult and even could have
 899 ; a carry into the left part. The solution is to use a modified
 900 ; multiplication, which has a result that is not correct, but with
 901 ; a difference of any multiple of $11021. We then only need to keep
 902 ; the 16 least significant bits of the result.
 903 ;
 904 ; The following algorithm does this for us:
 905 ;
 906 ;   unsigned char *data, c, crclo, crchi;
 907 ;   while (not done) {
 908 ;       c = *data++ + crchi;
 909 ;       crchi = (@ c) >> 8 + crclo;
 910 ;       crclo = @ c;
 911 ;   }
 912 ;
 913 ; Remember, + is done with EOR, the @ operator is in two tables (high
 914 ; and low byte separately), which is calculated as
 915 ;
 916 ;      $1021 * (c & $F0)
 917 ;  xor $1021 * (c & $0F)
 918 ;  xor $1021 * (c >> 4)         (* is regular multiplication)
 919 ;
 920 ;
 921 ; Anyway, the end result is the same as the remainder of the division of
 922 ; the data by $11021. I am afraid I need to study theory a bit more...
 923
 924
 925 my only works was to code this from manx to C....
 926
 927 */
 928
 929 static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
 930 {
 931         static unsigned char CRCTable1[] = {
 932                 0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
 933                 0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
 934                 0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
 935                 0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
 936                 0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
 937                 0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
 938                 0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
 939                 0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
 940                 0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
 941                 0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
 942                 0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
 943                 0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
 944                 0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
 945                 0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
 946                 0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
 947                 0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
 948         };
 949
 950         static unsigned char CRCTable2[] = {
 951                 0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
 952                 0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
 953                 0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
 954                 0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
 955                 0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
 956                 0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
 957                 0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
 958                 0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
 959                 0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
 960                 0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
 961                 0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
 962                 0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
 963                 0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
 964                 0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
 965                 0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
 966                 0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
 967         };
 968
 969 /* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
 970         register int i;
 971         register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
 972
 973         CRCT1=CRCTable1;
 974         CRCT2=CRCTable2;
 975         data=data_a3;
 976         crcl=data_d1;
 977         crch=data_d0;
 978         for (i=data_d3; i>=0; i--) {
 979                 c = (*data++) ^ crch;
 980                 crch = CRCT1[c] ^ crcl;
 981                 crcl = CRCT2[c];
 982         }
 983         return (crch<<8)|crcl;
 984 }
 985
 986 static inline ushort dos_hdr_crc (struct dos_header *hdr)
 987 {
 988         return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
 989 }
 990
 991 static inline ushort dos_data_crc(unsigned char *data)
 992 {
 993         return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
 994 }
 995
 996 static inline unsigned char dos_decode_byte(ushort word)
 997 {
 998         register ushort w2;
 999         register unsigned char byte;
1000         register unsigned char *dec = mfmdecode;
1001
1002         w2=word;
1003         w2>>=8;
1004         w2&=127;
1005         byte = dec[w2];
1006         byte <<= 4;
1007         w2 = word & 127;
1008         byte |= dec[w2];
1009         return byte;
1010 }
1011
1012 static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1013 {
1014         int i;
1015
1016         for (i = 0; i < len; i++)
1017                 *data++=dos_decode_byte(*raw++);
1018         return ((ulong)raw);
1019 }
1020
1021 #ifdef DEBUG
1022 static void dbg(unsigned long ptr)
1023 {
1024         printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1025                ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1026                ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1027 }
1028 #endif
1029
1030 static int dos_read(int drive)
1031 {
1032         unsigned long end;
1033         unsigned long raw;
1034         int scnt;
1035         unsigned short crc,data_crc[2];
1036         struct dos_header hdr;
1037
1038         drive&=3;
1039         raw = (long) raw_buf;
1040         end = raw + unit[drive].type->read_size;
1041
1042         for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1043                 do { /* search for the right sync of each sec-hdr */
1044                         if (!(raw = scan_sync (raw, end))) {
1045                                 printk(KERN_INFO "dos_read: no hdr sync on "
1046                                        "track %d, unit %d for sector %d\n",
1047                                        unit[drive].track,drive,scnt);
1048                                 return MFM_NOSYNC;
1049                         }
1050 #ifdef DEBUG
1051                         dbg(raw);
1052 #endif
1053                 } while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1054                 raw+=2; /* skip over headermark */
1055                 raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1056                 crc = dos_hdr_crc(&hdr);
1057
1058 #ifdef DEBUG
1059                 printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1060                        hdr.sec, hdr.len_desc, hdr.crc);
1061 #endif
1062
1063                 if (crc != hdr.crc) {
1064                         printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1065                                hdr.crc, crc);
1066                         return MFM_HEADER;
1067                 }
1068                 if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1069                         printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1070                                hdr.track,
1071                                unit[drive].track/unit[drive].type->heads);
1072                         return MFM_TRACK;
1073                 }
1074
1075                 if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1076                         printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1077                                hdr.side,
1078                                unit[drive].track%unit[drive].type->heads);
1079                         return MFM_TRACK;
1080                 }
1081
1082                 if (hdr.len_desc != 2) {
1083                         printk(KERN_INFO "dos_read: unknown sector len "
1084                                "descriptor %d\n", hdr.len_desc);
1085                         return MFM_DATA;
1086                 }
1087 #ifdef DEBUG
1088                 printk("hdr accepted\n");
1089 #endif
1090                 if (!(raw = scan_sync (raw, end))) {
1091                         printk(KERN_INFO "dos_read: no data sync on track "
1092                                "%d, unit %d for sector%d, disk sector %d\n",
1093                                unit[drive].track, drive, scnt, hdr.sec);
1094                         return MFM_NOSYNC;
1095                 }
1096 #ifdef DEBUG
1097                 dbg(raw);
1098 #endif
1099
1100                 if (*((ushort *)raw)!=0x5545) {
1101                         printk(KERN_INFO "dos_read: no data mark after "
1102                                "sync (%d,%d,%d,%d) sc=%d\n",
1103                                hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1104                         return MFM_NOSYNC;
1105                 }
1106
1107                 raw+=2;  /* skip data mark (included in checksum) */
1108                 raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1109                 raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1110                 crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1111
1112                 if (crc != data_crc[0]) {
1113                         printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1114                                "sc=%d, %x %x\n", hdr.track, hdr.side,
1115                                hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1116                         printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1117                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1118                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1119                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1120                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1121                         return MFM_DATA;
1122                 }
1123         }
1124         return 0;
1125 }
1126
1127 static inline ushort dos_encode_byte(unsigned char byte)
1128 {
1129         register unsigned char *enc, b2, b1;
1130         register ushort word;
1131
1132         enc=mfmencode;
1133         b1=byte;
1134         b2=b1>>4;
1135         b1&=15;
1136         word=enc[b2] <<8 | enc [b1];
1137         return (word|((word&(256|64)) ? 0: 128));
1138 }
1139
1140 static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1141 {
1142         int i;
1143
1144         for (i = 0; i < len; i++) {
1145                 *dest=dos_encode_byte(*src++);
1146                 *dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1147                 dest++;
1148         }
1149 }
1150
1151 static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1152 {
1153         static struct dos_header hdr={0,0,0,2,0,
1154           {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1155         int i;
1156         static ushort crc[2]={0,0x4e4e};
1157
1158         drive&=3;
1159 /* id gap 1 */
1160 /* the MFM word before is always 9254 */
1161         for(i=0;i<6;i++)
1162                 *raw++=0xaaaaaaaa;
1163 /* 3 sync + 1 headermark */
1164         *raw++=0x44894489;
1165         *raw++=0x44895554;
1166
1167 /* fill in the variable parts of the header */
1168         hdr.track=unit[drive].track/unit[drive].type->heads;
1169         hdr.side=unit[drive].track%unit[drive].type->heads;
1170         hdr.sec=cnt+1;
1171         hdr.crc=dos_hdr_crc(&hdr);
1172
1173 /* header (without "magic") and id gap 2*/
1174         dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1175         raw+=14;
1176
1177 /*id gap 3 */
1178         for(i=0;i<6;i++)
1179                 *raw++=0xaaaaaaaa;
1180
1181 /* 3 syncs and 1 datamark */
1182         *raw++=0x44894489;
1183         *raw++=0x44895545;
1184
1185 /* data */
1186         dos_encode_block((ushort *)raw,
1187                          (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1188         raw+=256;
1189
1190 /*data crc + jd's special gap (long words :-/) */
1191         crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1192         dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1193         raw+=2;
1194
1195 /* data gap */
1196         for(i=0;i<38;i++)
1197                 *raw++=0x92549254;
1198
1199         return raw; /* wrote 652 MFM words */
1200 }
1201
1202 static void dos_write(int disk)
1203 {
1204         int cnt;
1205         unsigned long raw = (unsigned long) raw_buf;
1206         unsigned long *ptr=(unsigned long *)raw;
1207
1208         disk&=3;
1209 /* really gap4 + indexgap , but we write it first and round it up */
1210         for (cnt=0;cnt<425;cnt++)
1211                 *ptr++=0x92549254;
1212
1213 /* the following is just guessed */
1214         if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1215                 for(cnt=0;cnt<473;cnt++)
1216                         *ptr++=0x92549254;
1217
1218 /* now the index marks...*/
1219         for (cnt=0;cnt<20;cnt++)
1220                 *ptr++=0x92549254;
1221         for (cnt=0;cnt<6;cnt++)
1222                 *ptr++=0xaaaaaaaa;
1223         *ptr++=0x52245224;
1224         *ptr++=0x52245552;
1225         for (cnt=0;cnt<20;cnt++)
1226                 *ptr++=0x92549254;
1227
1228 /* sectors */
1229         for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1230                 ptr=ms_putsec(disk,ptr,cnt);
1231
1232         *(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1233 }
1234
1235 /*
1236  * Here comes the high level stuff (i.e. the filesystem interface)
1237  * and helper functions.
1238  * Normally this should be the only part that has to be adapted to
1239  * different kernel versions.
1240  */
1241
1242 /* FIXME: this assumes the drive is still spinning -
1243  * which is only true if we complete writing a track within three seconds
1244  */
1245 static void flush_track_callback(unsigned long nr)
1246 {
1247         nr&=3;
1248         writefromint = 1;
1249         if (!try_fdc(nr)) {
1250                 /* we might block in an interrupt, so try again later */
1251                 flush_track_timer[nr].expires = jiffies + 1;
1252                 add_timer(flush_track_timer + nr);
1253                 return;
1254         }
1255         get_fdc(nr);
1256         (*unit[nr].dtype->write_fkt)(nr);
1257         if (!raw_write(nr)) {
1258                 printk (KERN_NOTICE "floppy disk write protected\n");
1259                 writefromint = 0;
1260                 writepending = 0;
1261         }
1262         rel_fdc();
1263 }
1264
1265 static int non_int_flush_track (unsigned long nr)
1266 {
1267         unsigned long flags;
1268
1269         nr&=3;
1270         writefromint = 0;
1271         del_timer(&post_write_timer);
1272         get_fdc(nr);
1273         if (!fd_motor_on(nr)) {
1274                 writepending = 0;
1275                 rel_fdc();
1276                 return 0;
1277         }
1278         local_irq_save(flags);
1279         if (writepending != 2) {
1280                 local_irq_restore(flags);
1281                 (*unit[nr].dtype->write_fkt)(nr);
1282                 if (!raw_write(nr)) {
1283                         printk (KERN_NOTICE "floppy disk write protected "
1284                                 "in write!\n");
1285                         writepending = 0;
1286                         return 0;
1287                 }
1288                 wait_event(wait_fd_block, block_flag != 2);
1289         }
1290         else {
1291                 local_irq_restore(flags);
1292                 ms_delay(2); /* 2 ms post_write delay */
1293                 post_write(nr);
1294         }
1295         rel_fdc();
1296         return 1;
1297 }
1298
1299 static int get_track(int drive, int track)
1300 {
1301         int error, errcnt;
1302
1303         drive&=3;
1304         if (unit[drive].track == track)
1305                 return 0;
1306         get_fdc(drive);
1307         if (!fd_motor_on(drive)) {
1308                 rel_fdc();
1309                 return -1;
1310         }
1311
1312         if (unit[drive].dirty == 1) {
1313                 del_timer (flush_track_timer + drive);
1314                 non_int_flush_track (drive);
1315         }
1316         errcnt = 0;
1317         while (errcnt < MAX_ERRORS) {
1318                 if (!fd_seek(drive, track))
1319                         return -1;
1320                 raw_read(drive);
1321                 error = (*unit[drive].dtype->read_fkt)(drive);
1322                 if (error == 0) {
1323                         rel_fdc();
1324                         return 0;
1325                 }
1326                 /* Read Error Handling: recalibrate and try again */
1327                 unit[drive].track = -1;
1328                 errcnt++;
1329         }
1330         rel_fdc();
1331         return -1;
1332 }
1333
1334 static void redo_fd_request(void)
1335 {
1336         struct request *rq;
1337         unsigned int cnt, block, track, sector;
1338         int drive;
1339         struct amiga_floppy_struct *floppy;
1340         char *data;
1341         unsigned long flags;
1342         int err;
1343
1344 next_req:
1345         rq = blk_fetch_request(floppy_queue);
1346         if (!rq) {
1347                 /* Nothing left to do */
1348                 return;
1349         }
1350
1351         floppy = rq->rq_disk->private_data;
1352         drive = floppy - unit;
1353
1354 next_segment:
1355         /* Here someone could investigate to be more efficient */
1356         for (cnt = 0, err = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
1357 #ifdef DEBUG
1358                 printk("fd: sector %ld + %d requested for %s\n",
1359                        blk_rq_pos(rq), cnt,
1360                        (rq_data_dir(rq) == READ) ? "read" : "write");
1361 #endif
1362                 block = blk_rq_pos(rq) + cnt;
1363                 if ((int)block > floppy->blocks) {
1364                         err = -EIO;
1365                         break;
1366                 }
1367
1368                 track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1369                 sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1370                 data = rq->buffer + 512 * cnt;
1371 #ifdef DEBUG
1372                 printk("access to track %d, sector %d, with buffer at "
1373                        "0x%08lx\n", track, sector, data);
1374 #endif
1375
1376                 if (get_track(drive, track) == -1) {
1377                         err = -EIO;
1378                         break;
1379                 }
1380
1381                 if (rq_data_dir(rq) == READ) {
1382                         memcpy(data, floppy->trackbuf + sector * 512, 512);
1383                 } else {
1384                         memcpy(floppy->trackbuf + sector * 512, data, 512);
1385
1386                         /* keep the drive spinning while writes are scheduled */
1387                         if (!fd_motor_on(drive)) {
1388                                 err = -EIO;
1389                                 break;
1390                         }
1391                         /*
1392                          * setup a callback to write the track buffer
1393                          * after a short (1 tick) delay.
1394                          */
1395                         local_irq_save(flags);
1396
1397                         floppy->dirty = 1;
1398                         /* reset the timer */
1399                         mod_timer (flush_track_timer + drive, jiffies + 1);
1400                         local_irq_restore(flags);
1401                 }
1402         }
1403
1404         if (__blk_end_request_cur(rq, err))
1405                 goto next_segment;
1406         goto next_req;
1407 }
1408
1409 static void do_fd_request(struct request_queue * q)
1410 {
1411         redo_fd_request();
1412 }
1413
1414 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1415 {
1416         int drive = MINOR(bdev->bd_dev) & 3;
1417
1418         geo->heads = unit[drive].type->heads;
1419         geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1420         geo->cylinders = unit[drive].type->tracks;
1421         return 0;
1422 }
1423
1424 static int fd_ioctl(struct block_device *bdev, fmode_t mode,
1425                     unsigned int cmd, unsigned long param)
1426 {
1427         struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1428         int drive = p - unit;
1429         static struct floppy_struct getprm;
1430         void __user *argp = (void __user *)param;
1431
1432         switch(cmd){
1433         case FDFMTBEG:
1434                 get_fdc(drive);
1435                 if (fd_ref[drive] > 1) {
1436                         rel_fdc();
1437                         return -EBUSY;
1438                 }
1439                 fsync_bdev(bdev);
1440                 if (fd_motor_on(drive) == 0) {
1441                         rel_fdc();
1442                         return -ENODEV;
1443                 }
1444                 if (fd_calibrate(drive) == 0) {
1445                         rel_fdc();
1446                         return -ENXIO;
1447                 }
1448                 floppy_off(drive);
1449                 rel_fdc();
1450                 break;
1451         case FDFMTTRK:
1452                 if (param < p->type->tracks * p->type->heads)
1453                 {
1454                         get_fdc(drive);
1455                         if (fd_seek(drive,param) != 0){
1456                                 memset(p->trackbuf, FD_FILL_BYTE,
1457                                        p->dtype->sects * p->type->sect_mult * 512);
1458                                 non_int_flush_track(drive);
1459                         }
1460                         floppy_off(drive);
1461                         rel_fdc();
1462                 }
1463                 else
1464                         return -EINVAL;
1465                 break;
1466         case FDFMTEND:
1467                 floppy_off(drive);
1468                 invalidate_bdev(bdev);
1469                 break;
1470         case FDGETPRM:
1471                 memset((void *)&getprm, 0, sizeof (getprm));
1472                 getprm.track=p->type->tracks;
1473                 getprm.head=p->type->heads;
1474                 getprm.sect=p->dtype->sects * p->type->sect_mult;
1475                 getprm.size=p->blocks;
1476                 if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1477                         return -EFAULT;
1478                 break;
1479         case FDSETPRM:
1480         case FDDEFPRM:
1481                 return -EINVAL;
1482         case FDFLUSH: /* unconditionally, even if not needed */
1483                 del_timer (flush_track_timer + drive);
1484                 non_int_flush_track(drive);
1485                 break;
1486 #ifdef RAW_IOCTL
1487         case IOCTL_RAW_TRACK:
1488                 if (copy_to_user(argp, raw_buf, p->type->read_size))
1489                         return -EFAULT;
1490                 else
1491                         return p->type->read_size;
1492 #endif
1493         default:
1494                 printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1495                        cmd, drive);
1496                 return -ENOSYS;
1497         }
1498         return 0;
1499 }
1500
1501 static void fd_probe(int dev)
1502 {
1503         unsigned long code;
1504         int type;
1505         int drive;
1506
1507         drive = dev & 3;
1508         code = fd_get_drive_id(drive);
1509
1510         /* get drive type */
1511         for (type = 0; type < num_dr_types; type++)
1512                 if (drive_types[type].code == code)
1513                         break;
1514
1515         if (type >= num_dr_types) {
1516                 printk(KERN_WARNING "fd_probe: unsupported drive type "
1517                        "%08lx found\n", code);
1518                 unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1519                 return;
1520         }
1521
1522         unit[drive].type = drive_types + type;
1523         unit[drive].track = -1;
1524
1525         unit[drive].disk = -1;
1526         unit[drive].motor = 0;
1527         unit[drive].busy = 0;
1528         unit[drive].status = -1;
1529 }
1530
1531 /*
1532  * floppy_open check for aliasing (/dev/fd0 can be the same as
1533  * /dev/PS0 etc), and disallows simultaneous access to the same
1534  * drive with different device numbers.
1535  */
1536 static int floppy_open(struct block_device *bdev, fmode_t mode)
1537 {
1538         int drive = MINOR(bdev->bd_dev) & 3;
1539         int system =  (MINOR(bdev->bd_dev) & 4) >> 2;
1540         int old_dev;
1541         unsigned long flags;
1542
1543         old_dev = fd_device[drive];
1544
1545         if (fd_ref[drive] && old_dev != system)
1546                 return -EBUSY;
1547
1548         if (mode & (FMODE_READ|FMODE_WRITE)) {
1549                 check_disk_change(bdev);
1550                 if (mode & FMODE_WRITE) {
1551                         int wrprot;
1552
1553                         get_fdc(drive);
1554                         fd_select (drive);
1555                         wrprot = !(ciaa.pra & DSKPROT);
1556                         fd_deselect (drive);
1557                         rel_fdc();
1558
1559                         if (wrprot)
1560                                 return -EROFS;
1561                 }
1562         }
1563
1564         local_irq_save(flags);
1565         fd_ref[drive]++;
1566         fd_device[drive] = system;
1567         local_irq_restore(flags);
1568
1569         unit[drive].dtype=&data_types[system];
1570         unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1571                 data_types[system].sects*unit[drive].type->sect_mult;
1572         set_capacity(unit[drive].gendisk, unit[drive].blocks);
1573
1574         printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1575                unit[drive].type->name, data_types[system].name);
1576
1577         return 0;
1578 }
1579
1580 static int floppy_release(struct gendisk *disk, fmode_t mode)
1581 {
1582         struct amiga_floppy_struct *p = disk->private_data;
1583         int drive = p - unit;
1584
1585         if (unit[drive].dirty == 1) {
1586                 del_timer (flush_track_timer + drive);
1587                 non_int_flush_track (drive);
1588         }
1589
1590         if (!fd_ref[drive]--) {
1591                 printk(KERN_CRIT "floppy_release with fd_ref == 0");
1592                 fd_ref[drive] = 0;
1593         }
1594 #ifdef MODULE
1595 /* the mod_use counter is handled this way */
1596         floppy_off (drive | 0x40000000);
1597 #endif
1598         return 0;
1599 }
1600
1601 /*
1602  * floppy-change is never called from an interrupt, so we can relax a bit
1603  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1604  * to the desired drive, but it will probably not survive the sleep if
1605  * several floppies are used at the same time: thus the loop.
1606  */
1607 static int amiga_floppy_change(struct gendisk *disk)
1608 {
1609         struct amiga_floppy_struct *p = disk->private_data;
1610         int drive = p - unit;
1611         int changed;
1612         static int first_time = 1;
1613
1614         if (first_time)
1615                 changed = first_time--;
1616         else {
1617                 get_fdc(drive);
1618                 fd_select (drive);
1619                 changed = !(ciaa.pra & DSKCHANGE);
1620                 fd_deselect (drive);
1621                 rel_fdc();
1622         }
1623
1624         if (changed) {
1625                 fd_probe(drive);
1626                 p->track = -1;
1627                 p->dirty = 0;
1628                 writepending = 0; /* if this was true before, too bad! */
1629                 writefromint = 0;
1630                 return 1;
1631         }
1632         return 0;
1633 }
1634
1635 static struct block_device_operations floppy_fops = {
1636         .owner          = THIS_MODULE,
1637         .open           = floppy_open,
1638         .release        = floppy_release,
1639         .locked_ioctl   = fd_ioctl,
1640         .getgeo         = fd_getgeo,
1641         .media_changed  = amiga_floppy_change,
1642 };
1643
1644 static int __init fd_probe_drives(void)
1645 {
1646         int drive,drives,nomem;
1647
1648         printk(KERN_INFO "FD: probing units\nfound ");
1649         drives=0;
1650         nomem=0;
1651         for(drive=0;drive<FD_MAX_UNITS;drive++) {
1652                 struct gendisk *disk;
1653                 fd_probe(drive);
1654                 if (unit[drive].type->code == FD_NODRIVE)
1655                         continue;
1656                 disk = alloc_disk(1);
1657                 if (!disk) {
1658                         unit[drive].type->code = FD_NODRIVE;
1659                         continue;
1660                 }
1661                 unit[drive].gendisk = disk;
1662                 drives++;
1663                 if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1664                         printk("no mem for ");
1665                         unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1666                         drives--;
1667                         nomem = 1;
1668                 }
1669                 printk("fd%d ",drive);
1670                 disk->major = FLOPPY_MAJOR;
1671                 disk->first_minor = drive;
1672                 disk->fops = &floppy_fops;
1673                 sprintf(disk->disk_name, "fd%d", drive);
1674                 disk->private_data = &unit[drive];
1675                 disk->queue = floppy_queue;
1676                 set_capacity(disk, 880*2);
1677                 add_disk(disk);
1678         }
1679         if ((drives > 0) || (nomem == 0)) {
1680                 if (drives == 0)
1681                         printk("no drives");
1682                 printk("\n");
1683                 return drives;
1684         }
1685         printk("\n");
1686         return -ENOMEM;
1687 }
1688
1689 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1690 {
1691         int drive = *part & 3;
1692         if (unit[drive].type->code == FD_NODRIVE)
1693                 return NULL;
1694         *part = 0;
1695         return get_disk(unit[drive].gendisk);
1696 }
1697
1698 static int __init amiga_floppy_init(void)
1699 {
1700         int i, ret;
1701
1702         if (!MACH_IS_AMIGA)
1703                 return -ENODEV;
1704
1705         if (!AMIGAHW_PRESENT(AMI_FLOPPY))
1706                 return -ENODEV;
1707
1708         if (register_blkdev(FLOPPY_MAJOR,"fd"))
1709                 return -EBUSY;
1710
1711         /*
1712          *  We request DSKPTR, DSKLEN and DSKDATA only, because the other
1713          *  floppy registers are too spreaded over the custom register space
1714          */
1715         ret = -EBUSY;
1716         if (!request_mem_region(CUSTOM_PHYSADDR+0x20, 8, "amiflop [Paula]")) {
1717                 printk("fd: cannot get floppy registers\n");
1718                 goto out_blkdev;
1719         }
1720
1721         ret = -ENOMEM;
1722         if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1723             NULL) {
1724                 printk("fd: cannot get chip mem buffer\n");
1725                 goto out_memregion;
1726         }
1727
1728         ret = -EBUSY;
1729         if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1730                 printk("fd: cannot get irq for dma\n");
1731                 goto out_irq;
1732         }
1733
1734         if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1735                 printk("fd: cannot get irq for timer\n");
1736                 goto out_irq2;
1737         }
1738
1739         ret = -ENOMEM;
1740         floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
1741         if (!floppy_queue)
1742                 goto out_queue;
1743
1744         ret = -ENODEV;
1745         if (fd_probe_drives() < 1) /* No usable drives */
1746                 goto out_probe;
1747
1748         blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1749                                 floppy_find, NULL, NULL);
1750
1751         /* initialize variables */
1752         init_timer(&motor_on_timer);
1753         motor_on_timer.expires = 0;
1754         motor_on_timer.data = 0;
1755         motor_on_timer.function = motor_on_callback;
1756         for (i = 0; i < FD_MAX_UNITS; i++) {
1757                 init_timer(&motor_off_timer[i]);
1758                 motor_off_timer[i].expires = 0;
1759                 motor_off_timer[i].data = i|0x80000000;
1760                 motor_off_timer[i].function = fd_motor_off;
1761                 init_timer(&flush_track_timer[i]);
1762                 flush_track_timer[i].expires = 0;
1763                 flush_track_timer[i].data = i;
1764                 flush_track_timer[i].function = flush_track_callback;
1765
1766                 unit[i].track = -1;
1767         }
1768
1769         init_timer(&post_write_timer);
1770         post_write_timer.expires = 0;
1771         post_write_timer.data = 0;
1772         post_write_timer.function = post_write;
1773
1774         for (i = 0; i < 128; i++)
1775                 mfmdecode[i]=255;
1776         for (i = 0; i < 16; i++)
1777                 mfmdecode[mfmencode[i]]=i;
1778
1779         /* make sure that disk DMA is enabled */
1780         custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1781
1782         /* init ms timer */
1783         ciaa.crb = 8; /* one-shot, stop */
1784         return 0;
1785
1786 out_probe:
1787         blk_cleanup_queue(floppy_queue);
1788 out_queue:
1789         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1790 out_irq2:
1791         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1792 out_irq:
1793         amiga_chip_free(raw_buf);
1794 out_memregion:
1795         release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1796 out_blkdev:
1797         unregister_blkdev(FLOPPY_MAJOR,"fd");
1798         return ret;
1799 }
1800
1801 module_init(amiga_floppy_init);
1802 #ifdef MODULE
1803
1804 #if 0 /* not safe to unload */
1805 void cleanup_module(void)
1806 {
1807         int i;
1808
1809         for( i = 0; i < FD_MAX_UNITS; i++) {
1810                 if (unit[i].type->code != FD_NODRIVE) {
1811                         del_gendisk(unit[i].gendisk);
1812                         put_disk(unit[i].gendisk);
1813                         kfree(unit[i].trackbuf);
1814                 }
1815         }
1816         blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
1817         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1818         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1819         custom.dmacon = DMAF_DISK; /* disable DMA */
1820         amiga_chip_free(raw_buf);
1821         blk_cleanup_queue(floppy_queue);
1822         release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1823         unregister_blkdev(FLOPPY_MAJOR, "fd");
1824 }
1825 #endif
1826
1827 #else
1828 static int __init amiga_floppy_setup (char *str)
1829 {
1830         int n;
1831         if (!MACH_IS_AMIGA)
1832                 return 0;
1833         if (!get_option(&str, &n))
1834                 return 0;
1835         printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1836         fd_def_df0 = n;
1837         return 1;
1838 }
1839
1840 __setup("floppy=", amiga_floppy_setup);
1841 #endif