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 #include <linux/slab.h>
  58
  59 #include <linux/fd.h>
  60 #include <linux/hdreg.h>
  61 #include <linux/delay.h>
  62 #include <linux/init.h>
  63 #include <linux/mutex.h>
  64 #include <linux/amifdreg.h>
  65 #include <linux/amifd.h>
  66 #include <linux/buffer_head.h>
  67 #include <linux/blkdev.h>
  68 #include <linux/elevator.h>
  69 #include <linux/interrupt.h>
  70 #include <linux/platform_device.h>
  71
  72 #include <asm/setup.h>
  73 #include <asm/uaccess.h>
  74 #include <asm/amigahw.h>
  75 #include <asm/amigaints.h>
  76 #include <asm/irq.h>
  77
  78 #undef DEBUG /* print _LOTS_ of infos */
  79
  80 #define RAW_IOCTL
  81 #ifdef RAW_IOCTL
  82 #define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
  83 #endif
  84
  85 /*
  86  *  Defines
  87  */
  88
  89 /*
  90  *  Error codes
  91  */
  92 #define FD_OK           0       /* operation succeeded */
  93 #define FD_ERROR        -1      /* general error (seek, read, write, etc) */
  94 #define FD_NOUNIT       1       /* unit does not exist */
  95 #define FD_UNITBUSY     2       /* unit already active */
  96 #define FD_NOTACTIVE    3       /* unit is not active */
  97 #define FD_NOTREADY     4       /* unit is not ready (motor not on/no disk) */
  98
  99 #define MFM_NOSYNC      1
 100 #define MFM_HEADER      2
 101 #define MFM_DATA        3
 102 #define MFM_TRACK       4
 103
 104 /*
 105  *  Floppy ID values
 106  */
 107 #define FD_NODRIVE      0x00000000  /* response when no unit is present */
 108 #define FD_DD_3         0xffffffff  /* double-density 3.5" (880K) drive */
 109 #define FD_HD_3         0x55555555  /* high-density 3.5" (1760K) drive */
 110 #define FD_DD_5         0xaaaaaaaa  /* double-density 5.25" (440K) drive */
 111
 112 static DEFINE_MUTEX(amiflop_mutex);
 113 static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
 114
 115 module_param(fd_def_df0, ulong, 0);
 116 MODULE_LICENSE("GPL");
 117
 118 static struct request_queue *floppy_queue;
 119
 120 /*
 121  *  Macros
 122  */
 123 #define MOTOR_ON        (ciab.prb &= ~DSKMOTOR)
 124 #define MOTOR_OFF       (ciab.prb |= DSKMOTOR)
 125 #define SELECT(mask)    (ciab.prb &= ~mask)
 126 #define DESELECT(mask)  (ciab.prb |= mask)
 127 #define SELMASK(drive)  (1 << (3 + (drive & 3)))
 128
 129 static struct fd_drive_type drive_types[] = {
 130 /*  code        name       tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
 131 /*  warning: times are now in milliseconds (ms)                    */
 132 { FD_DD_3,      "DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
 133 { FD_HD_3,      "HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
 134 { FD_DD_5,      "DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
 135 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
 136 };
 137 static int num_dr_types = ARRAY_SIZE(drive_types);
 138
 139 static int amiga_read(int), dos_read(int);
 140 static void amiga_write(int), dos_write(int);
 141 static struct fd_data_type data_types[] = {
 142         { "Amiga", 11 , amiga_read, amiga_write},
 143         { "MS-Dos", 9, dos_read, dos_write}
 144 };
 145
 146 /* current info on each unit */
 147 static struct amiga_floppy_struct unit[FD_MAX_UNITS];
 148
 149 static struct timer_list flush_track_timer[FD_MAX_UNITS];
 150 static struct timer_list post_write_timer;
 151 static struct timer_list motor_on_timer;
 152 static struct timer_list motor_off_timer[FD_MAX_UNITS];
 153 static int on_attempts;
 154
 155 /* Synchronization of FDC access */
 156 /* request loop (trackbuffer) */
 157 static volatile int fdc_busy = -1;
 158 static volatile int fdc_nested;
 159 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
 160
 161 static DECLARE_COMPLETION(motor_on_completion);
 162
 163 static volatile int selected = -1;      /* currently selected drive */
 164
 165 static int writepending;
 166 static int writefromint;
 167 static char *raw_buf;
 168
 169 static DEFINE_SPINLOCK(amiflop_lock);
 170
 171 #define RAW_BUF_SIZE 30000  /* size of raw disk data */
 172
 173 /*
 174  * These are global variables, as that's the easiest way to give
 175  * information to interrupts. They are the data used for the current
 176  * request.
 177  */
 178 static volatile char block_flag;
 179 static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
 180
 181 /* MS-Dos MFM Coding tables (should go quick and easy) */
 182 static unsigned char mfmencode[16]={
 183         0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
 184         0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
 185 };
 186 static unsigned char mfmdecode[128];
 187
 188 /* floppy internal millisecond timer stuff */
 189 static DECLARE_COMPLETION(ms_wait_completion);
 190 #define MS_TICKS ((amiga_eclock+50)/1000)
 191
 192 /*
 193  * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
 194  * max X times - some types of errors increase the errorcount by 2 or
 195  * even 3, so we might actually retry only X/2 times before giving up.
 196  */
 197 #define MAX_ERRORS 12
 198
 199 #define custom amiga_custom
 200
 201 /* Prevent "aliased" accesses. */
 202 static int fd_ref[4] = { 0,0,0,0 };
 203 static int fd_device[4] = { 0, 0, 0, 0 };
 204
 205 /*
 206  * Here come the actual hardware access and helper functions.
 207  * They are not reentrant and single threaded because all drives
 208  * share the same hardware and the same trackbuffer.
 209  */
 210
 211 /* Milliseconds timer */
 212
 213 static irqreturn_t ms_isr(int irq, void *dummy)
 214 {
 215         complete(&ms_wait_completion);
 216         return IRQ_HANDLED;
 217 }
 218
 219 /* all waits are queued up
 220    A more generic routine would do a schedule a la timer.device */
 221 static void ms_delay(int ms)
 222 {
 223         int ticks;
 224         static DEFINE_MUTEX(mutex);
 225
 226         if (ms > 0) {
 227                 mutex_lock(&mutex);
 228                 ticks = MS_TICKS*ms-1;
 229                 ciaa.tblo=ticks%256;
 230                 ciaa.tbhi=ticks/256;
 231                 ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
 232                 wait_for_completion(&ms_wait_completion);
 233                 mutex_unlock(&mutex);
 234         }
 235 }
 236
 237 /* Hardware semaphore */
 238
 239 /* returns true when we would get the semaphore */
 240 static inline int try_fdc(int drive)
 241 {
 242         drive &= 3;
 243         return ((fdc_busy < 0) || (fdc_busy == drive));
 244 }
 245
 246 static void get_fdc(int drive)
 247 {
 248         unsigned long flags;
 249
 250         drive &= 3;
 251 #ifdef DEBUG
 252         printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
 253 #endif
 254         local_irq_save(flags);
 255         wait_event(fdc_wait, try_fdc(drive));
 256         fdc_busy = drive;
 257         fdc_nested++;
 258         local_irq_restore(flags);
 259 }
 260
 261 static inline void rel_fdc(void)
 262 {
 263 #ifdef DEBUG
 264         if (fdc_nested == 0)
 265                 printk("fd: unmatched rel_fdc\n");
 266         printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
 267 #endif
 268         fdc_nested--;
 269         if (fdc_nested == 0) {
 270                 fdc_busy = -1;
 271                 wake_up(&fdc_wait);
 272         }
 273 }
 274
 275 static void fd_select (int drive)
 276 {
 277         unsigned char prb = ~0;
 278
 279         drive&=3;
 280 #ifdef DEBUG
 281         printk("selecting %d\n",drive);
 282 #endif
 283         if (drive == selected)
 284                 return;
 285         get_fdc(drive);
 286         selected = drive;
 287
 288         if (unit[drive].track % 2 != 0)
 289                 prb &= ~DSKSIDE;
 290         if (unit[drive].motor == 1)
 291                 prb &= ~DSKMOTOR;
 292         ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
 293         ciab.prb = prb;
 294         prb &= ~SELMASK(drive);
 295         ciab.prb = prb;
 296         rel_fdc();
 297 }
 298
 299 static void fd_deselect (int drive)
 300 {
 301         unsigned char prb;
 302         unsigned long flags;
 303
 304         drive&=3;
 305 #ifdef DEBUG
 306         printk("deselecting %d\n",drive);
 307 #endif
 308         if (drive != selected) {
 309                 printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
 310                 return;
 311         }
 312
 313         get_fdc(drive);
 314         local_irq_save(flags);
 315
 316         selected = -1;
 317
 318         prb = ciab.prb;
 319         prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
 320         ciab.prb = prb;
 321
 322         local_irq_restore (flags);
 323         rel_fdc();
 324
 325 }
 326
 327 static void motor_on_callback(unsigned long nr)
 328 {
 329         if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
 330                 complete_all(&motor_on_completion);
 331         } else {
 332                 motor_on_timer.expires = jiffies + HZ/10;
 333                 add_timer(&motor_on_timer);
 334         }
 335 }
 336
 337 static int fd_motor_on(int nr)
 338 {
 339         nr &= 3;
 340
 341         del_timer(motor_off_timer + nr);
 342
 343         if (!unit[nr].motor) {
 344                 unit[nr].motor = 1;
 345                 fd_select(nr);
 346
 347                 INIT_COMPLETION(motor_on_completion);
 348                 motor_on_timer.data = nr;
 349                 mod_timer(&motor_on_timer, jiffies + HZ/2);
 350
 351                 on_attempts = 10;
 352                 wait_for_completion(&motor_on_completion);
 353                 fd_deselect(nr);
 354         }
 355
 356         if (on_attempts == 0) {
 357                 on_attempts = -1;
 358 #if 0
 359                 printk (KERN_ERR "motor_on failed, turning motor off\n");
 360                 fd_motor_off (nr);
 361                 return 0;
 362 #else
 363                 printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
 364 #endif
 365         }
 366
 367         return 1;
 368 }
 369
 370 static void fd_motor_off(unsigned long drive)
 371 {
 372         long calledfromint;
 373 #ifdef MODULE
 374         long decusecount;
 375
 376         decusecount = drive & 0x40000000;
 377 #endif
 378         calledfromint = drive & 0x80000000;
 379         drive&=3;
 380         if (calledfromint && !try_fdc(drive)) {
 381                 /* We would be blocked in an interrupt, so try again later */
 382                 motor_off_timer[drive].expires = jiffies + 1;
 383                 add_timer(motor_off_timer + drive);
 384                 return;
 385         }
 386         unit[drive].motor = 0;
 387         fd_select(drive);
 388         udelay (1);
 389         fd_deselect(drive);
 390 }
 391
 392 static void floppy_off (unsigned int nr)
 393 {
 394         int drive;
 395
 396         drive = nr & 3;
 397         /* called this way it is always from interrupt */
 398         motor_off_timer[drive].data = nr | 0x80000000;
 399         mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
 400 }
 401
 402 static int fd_calibrate(int drive)
 403 {
 404         unsigned char prb;
 405         int n;
 406
 407         drive &= 3;
 408         get_fdc(drive);
 409         if (!fd_motor_on (drive))
 410                 return 0;
 411         fd_select (drive);
 412         prb = ciab.prb;
 413         prb |= DSKSIDE;
 414         prb &= ~DSKDIREC;
 415         ciab.prb = prb;
 416         for (n = unit[drive].type->tracks/2; n != 0; --n) {
 417                 if (ciaa.pra & DSKTRACK0)
 418                         break;
 419                 prb &= ~DSKSTEP;
 420                 ciab.prb = prb;
 421                 prb |= DSKSTEP;
 422                 udelay (2);
 423                 ciab.prb = prb;
 424                 ms_delay(unit[drive].type->step_delay);
 425         }
 426         ms_delay (unit[drive].type->settle_time);
 427         prb |= DSKDIREC;
 428         n = unit[drive].type->tracks + 20;
 429         for (;;) {
 430                 prb &= ~DSKSTEP;
 431                 ciab.prb = prb;
 432                 prb |= DSKSTEP;
 433                 udelay (2);
 434                 ciab.prb = prb;
 435                 ms_delay(unit[drive].type->step_delay + 1);
 436                 if ((ciaa.pra & DSKTRACK0) == 0)
 437                         break;
 438                 if (--n == 0) {
 439                         printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
 440                         fd_motor_off (drive);
 441                         unit[drive].track = -1;
 442                         rel_fdc();
 443                         return 0;
 444                 }
 445         }
 446         unit[drive].track = 0;
 447         ms_delay(unit[drive].type->settle_time);
 448
 449         rel_fdc();
 450         fd_deselect(drive);
 451         return 1;
 452 }
 453
 454 static int fd_seek(int drive, int track)
 455 {
 456         unsigned char prb;
 457         int cnt;
 458
 459 #ifdef DEBUG
 460         printk("seeking drive %d to track %d\n",drive,track);
 461 #endif
 462         drive &= 3;
 463         get_fdc(drive);
 464         if (unit[drive].track == track) {
 465                 rel_fdc();
 466                 return 1;
 467         }
 468         if (!fd_motor_on(drive)) {
 469                 rel_fdc();
 470                 return 0;
 471         }
 472         if (unit[drive].track < 0 && !fd_calibrate(drive)) {
 473                 rel_fdc();
 474                 return 0;
 475         }
 476
 477         fd_select (drive);
 478         cnt = unit[drive].track/2 - track/2;
 479         prb = ciab.prb;
 480         prb |= DSKSIDE | DSKDIREC;
 481         if (track % 2 != 0)
 482                 prb &= ~DSKSIDE;
 483         if (cnt < 0) {
 484                 cnt = - cnt;
 485                 prb &= ~DSKDIREC;
 486         }
 487         ciab.prb = prb;
 488         if (track % 2 != unit[drive].track % 2)
 489                 ms_delay (unit[drive].type->side_time);
 490         unit[drive].track = track;
 491         if (cnt == 0) {
 492                 rel_fdc();
 493                 fd_deselect(drive);
 494                 return 1;
 495         }
 496         do {
 497                 prb &= ~DSKSTEP;
 498                 ciab.prb = prb;
 499                 prb |= DSKSTEP;
 500                 udelay (1);
 501                 ciab.prb = prb;
 502                 ms_delay (unit[drive].type->step_delay);
 503         } while (--cnt != 0);
 504         ms_delay (unit[drive].type->settle_time);
 505
 506         rel_fdc();
 507         fd_deselect(drive);
 508         return 1;
 509 }
 510
 511 static unsigned long fd_get_drive_id(int drive)
 512 {
 513         int i;
 514         ulong id = 0;
 515
 516         drive&=3;
 517         get_fdc(drive);
 518         /* set up for ID */
 519         MOTOR_ON;
 520         udelay(2);
 521         SELECT(SELMASK(drive));
 522         udelay(2);
 523         DESELECT(SELMASK(drive));
 524         udelay(2);
 525         MOTOR_OFF;
 526         udelay(2);
 527         SELECT(SELMASK(drive));
 528         udelay(2);
 529         DESELECT(SELMASK(drive));
 530         udelay(2);
 531
 532         /* loop and read disk ID */
 533         for (i=0; i<32; i++) {
 534                 SELECT(SELMASK(drive));
 535                 udelay(2);
 536
 537                 /* read and store value of DSKRDY */
 538                 id <<= 1;
 539                 id |= (ciaa.pra & DSKRDY) ? 0 : 1;      /* cia regs are low-active! */
 540
 541                 DESELECT(SELMASK(drive));
 542         }
 543
 544         rel_fdc();
 545
 546         /*
 547          * RB: At least A500/A2000's df0: don't identify themselves.
 548          * As every (real) Amiga has at least a 3.5" DD drive as df0:
 549          * we default to that if df0: doesn't identify as a certain
 550          * type.
 551          */
 552         if(drive == 0 && id == FD_NODRIVE)
 553         {
 554                 id = fd_def_df0;
 555                 printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
 556         }
 557         /* return the ID value */
 558         return (id);
 559 }
 560
 561 static irqreturn_t fd_block_done(int irq, void *dummy)
 562 {
 563         if (block_flag)
 564                 custom.dsklen = 0x4000;
 565
 566         if (block_flag == 2) { /* writing */
 567                 writepending = 2;
 568                 post_write_timer.expires = jiffies + 1; /* at least 2 ms */
 569                 post_write_timer.data = selected;
 570                 add_timer(&post_write_timer);
 571         }
 572         else {                /* reading */
 573                 block_flag = 0;
 574                 wake_up (&wait_fd_block);
 575         }
 576         return IRQ_HANDLED;
 577 }
 578
 579 static void raw_read(int drive)
 580 {
 581         drive&=3;
 582         get_fdc(drive);
 583         wait_event(wait_fd_block, !block_flag);
 584         fd_select(drive);
 585         /* setup adkcon bits correctly */
 586         custom.adkcon = ADK_MSBSYNC;
 587         custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
 588
 589         custom.dsksync = MFM_SYNC;
 590
 591         custom.dsklen = 0;
 592         custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
 593         custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
 594         custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
 595
 596         block_flag = 1;
 597
 598         wait_event(wait_fd_block, !block_flag);
 599
 600         custom.dsklen = 0;
 601         fd_deselect(drive);
 602         rel_fdc();
 603 }
 604
 605 static int raw_write(int drive)
 606 {
 607         ushort adk;
 608
 609         drive&=3;
 610         get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
 611         if ((ciaa.pra & DSKPROT) == 0) {
 612                 rel_fdc();
 613                 return 0;
 614         }
 615         wait_event(wait_fd_block, !block_flag);
 616         fd_select(drive);
 617         /* clear adkcon bits */
 618         custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
 619         /* set appropriate adkcon bits */
 620         adk = ADK_SETCLR|ADK_FAST;
 621         if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
 622                 adk |= ADK_PRECOMP1;
 623         else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
 624                 adk |= ADK_PRECOMP0;
 625         custom.adkcon = adk;
 626
 627         custom.dsklen = DSKLEN_WRITE;
 628         custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
 629         custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
 630         custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
 631
 632         block_flag = 2;
 633         return 1;
 634 }
 635
 636 /*
 637  * to be called at least 2ms after the write has finished but before any
 638  * other access to the hardware.
 639  */
 640 static void post_write (unsigned long drive)
 641 {
 642 #ifdef DEBUG
 643         printk("post_write for drive %ld\n",drive);
 644 #endif
 645         drive &= 3;
 646         custom.dsklen = 0;
 647         block_flag = 0;
 648         writepending = 0;
 649         writefromint = 0;
 650         unit[drive].dirty = 0;
 651         wake_up(&wait_fd_block);
 652         fd_deselect(drive);
 653         rel_fdc(); /* corresponds to get_fdc() in raw_write */
 654 }
 655
 656
 657 /*
 658  * The following functions are to convert the block contents into raw data
 659  * written to disk and vice versa.
 660  * (Add other formats here ;-))
 661  */
 662
 663 static unsigned long scan_sync(unsigned long raw, unsigned long end)
 664 {
 665         ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
 666
 667         while (ptr < endp && *ptr++ != 0x4489)
 668                 ;
 669         if (ptr < endp) {
 670                 while (*ptr == 0x4489 && ptr < endp)
 671                         ptr++;
 672                 return (ulong)ptr;
 673         }
 674         return 0;
 675 }
 676
 677 static inline unsigned long checksum(unsigned long *addr, int len)
 678 {
 679         unsigned long csum = 0;
 680
 681         len /= sizeof(*addr);
 682         while (len-- > 0)
 683                 csum ^= *addr++;
 684         csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
 685
 686         return csum;
 687 }
 688
 689 static unsigned long decode (unsigned long *data, unsigned long *raw,
 690                              int len)
 691 {
 692         ulong *odd, *even;
 693
 694         /* convert length from bytes to longwords */
 695         len >>= 2;
 696         odd = raw;
 697         even = odd + len;
 698
 699         /* prepare return pointer */
 700         raw += len * 2;
 701
 702         do {
 703                 *data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
 704         } while (--len != 0);
 705
 706         return (ulong)raw;
 707 }
 708
 709 struct header {
 710         unsigned char magic;
 711         unsigned char track;
 712         unsigned char sect;
 713         unsigned char ord;
 714         unsigned char labels[16];
 715         unsigned long hdrchk;
 716         unsigned long datachk;
 717 };
 718
 719 static int amiga_read(int drive)
 720 {
 721         unsigned long raw;
 722         unsigned long end;
 723         int scnt;
 724         unsigned long csum;
 725         struct header hdr;
 726
 727         drive&=3;
 728         raw = (long) raw_buf;
 729         end = raw + unit[drive].type->read_size;
 730
 731         for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
 732                 if (!(raw = scan_sync(raw, end))) {
 733                         printk (KERN_INFO "can't find sync for sector %d\n", scnt);
 734                         return MFM_NOSYNC;
 735                 }
 736
 737                 raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
 738                 raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
 739                 raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
 740                 raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
 741                 csum = checksum((ulong *)&hdr,
 742                                 (char *)&hdr.hdrchk-(char *)&hdr);
 743
 744 #ifdef DEBUG
 745                 printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
 746                         hdr.magic, hdr.track, hdr.sect, hdr.ord,
 747                         *(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
 748                         *(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
 749                         hdr.hdrchk, hdr.datachk);
 750 #endif
 751
 752                 if (hdr.hdrchk != csum) {
 753                         printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
 754                         return MFM_HEADER;
 755                 }
 756
 757                 /* verify track */
 758                 if (hdr.track != unit[drive].track) {
 759                         printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
 760                         return MFM_TRACK;
 761                 }
 762
 763                 raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
 764                               (ulong *)raw, 512);
 765                 csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
 766
 767                 if (hdr.datachk != csum) {
 768                         printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
 769                                hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
 770                                hdr.datachk, csum);
 771                         printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
 772                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
 773                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
 774                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
 775                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
 776                         return MFM_DATA;
 777                 }
 778         }
 779
 780         return 0;
 781 }
 782
 783 static void encode(unsigned long data, unsigned long *dest)
 784 {
 785         unsigned long data2;
 786
 787         data &= 0x55555555;
 788         data2 = data ^ 0x55555555;
 789         data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
 790
 791         if (*(dest - 1) & 0x00000001)
 792                 data &= 0x7FFFFFFF;
 793
 794         *dest = data;
 795 }
 796
 797 static void encode_block(unsigned long *dest, unsigned long *src, int len)
 798 {
 799         int cnt, to_cnt = 0;
 800         unsigned long data;
 801
 802         /* odd bits */
 803         for (cnt = 0; cnt < len / 4; cnt++) {
 804                 data = src[cnt] >> 1;
 805                 encode(data, dest + to_cnt++);
 806         }
 807
 808         /* even bits */
 809         for (cnt = 0; cnt < len / 4; cnt++) {
 810                 data = src[cnt];
 811                 encode(data, dest + to_cnt++);
 812         }
 813 }
 814
 815 static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
 816 {
 817         struct header hdr;
 818         int i;
 819
 820         disk&=3;
 821         *raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
 822         raw++;
 823         *raw++ = 0x44894489;
 824
 825         hdr.magic = 0xFF;
 826         hdr.track = unit[disk].track;
 827         hdr.sect = cnt;
 828         hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
 829         for (i = 0; i < 16; i++)
 830                 hdr.labels[i] = 0;
 831         hdr.hdrchk = checksum((ulong *)&hdr,
 832                               (char *)&hdr.hdrchk-(char *)&hdr);
 833         hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
 834
 835         encode_block(raw, (ulong *)&hdr.magic, 4);
 836         raw += 2;
 837         encode_block(raw, (ulong *)&hdr.labels, 16);
 838         raw += 8;
 839         encode_block(raw, (ulong *)&hdr.hdrchk, 4);
 840         raw += 2;
 841         encode_block(raw, (ulong *)&hdr.datachk, 4);
 842         raw += 2;
 843         encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
 844         raw += 256;
 845
 846         return raw;
 847 }
 848
 849 static void amiga_write(int disk)
 850 {
 851         unsigned int cnt;
 852         unsigned long *ptr = (unsigned long *)raw_buf;
 853
 854         disk&=3;
 855         /* gap space */
 856         for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
 857                 *ptr++ = 0xaaaaaaaa;
 858
 859         /* sectors */
 860         for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
 861                 ptr = putsec (disk, ptr, cnt);
 862         *(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
 863 }
 864
 865
 866 struct dos_header {
 867         unsigned char track,   /* 0-80 */
 868                 side,    /* 0-1 */
 869                 sec,     /* 0-...*/
 870                 len_desc;/* 2 */
 871         unsigned short crc;     /* on 68000 we got an alignment problem,
 872                                    but this compiler solves it  by adding silently
 873                                    adding a pad byte so data won't fit
 874                                    and this took about 3h to discover.... */
 875         unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
 876 };
 877
 878 /* crc routines are borrowed from the messydos-handler  */
 879
 880 /* excerpt from the messydos-device
 881 ; The CRC is computed not only over the actual data, but including
 882 ; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
 883 ; As we don't read or encode these fields into our buffers, we have to
 884 ; preload the registers containing the CRC with the values they would have
 885 ; after stepping over these fields.
 886 ;
 887 ; How CRCs "really" work:
 888 ;
 889 ; First, you should regard a bitstring as a series of coefficients of
 890 ; polynomials. We calculate with these polynomials in modulo-2
 891 ; arithmetic, in which both add and subtract are done the same as
 892 ; exclusive-or. Now, we modify our data (a very long polynomial) in
 893 ; such a way that it becomes divisible by the CCITT-standard 16-bit
 894 ;                16   12   5
 895 ; polynomial:   x  + x  + x + 1, represented by $11021. The easiest
 896 ; way to do this would be to multiply (using proper arithmetic) our
 897 ; datablock with $11021. So we have:
 898 ;   data * $11021                =
 899 ;   data * ($10000 + $1021)      =
 900 ;   data * $10000 + data * $1021
 901 ; The left part of this is simple: Just add two 0 bytes. But then
 902 ; the right part (data $1021) remains difficult and even could have
 903 ; a carry into the left part. The solution is to use a modified
 904 ; multiplication, which has a result that is not correct, but with
 905 ; a difference of any multiple of $11021. We then only need to keep
 906 ; the 16 least significant bits of the result.
 907 ;
 908 ; The following algorithm does this for us:
 909 ;
 910 ;   unsigned char *data, c, crclo, crchi;
 911 ;   while (not done) {
 912 ;       c = *data++ + crchi;
 913 ;       crchi = (@ c) >> 8 + crclo;
 914 ;       crclo = @ c;
 915 ;   }
 916 ;
 917 ; Remember, + is done with EOR, the @ operator is in two tables (high
 918 ; and low byte separately), which is calculated as
 919 ;
 920 ;      $1021 * (c & $F0)
 921 ;  xor $1021 * (c & $0F)
 922 ;  xor $1021 * (c >> 4)         (* is regular multiplication)
 923 ;
 924 ;
 925 ; Anyway, the end result is the same as the remainder of the division of
 926 ; the data by $11021. I am afraid I need to study theory a bit more...
 927
 928
 929 my only works was to code this from manx to C....
 930
 931 */
 932
 933 static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
 934 {
 935         static unsigned char CRCTable1[] = {
 936                 0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
 937                 0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
 938                 0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
 939                 0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
 940                 0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
 941                 0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
 942                 0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
 943                 0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
 944                 0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
 945                 0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
 946                 0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
 947                 0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
 948                 0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
 949                 0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
 950                 0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
 951                 0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
 952         };
 953
 954         static unsigned char CRCTable2[] = {
 955                 0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
 956                 0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
 957                 0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
 958                 0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
 959                 0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
 960                 0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
 961                 0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
 962                 0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
 963                 0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
 964                 0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
 965                 0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
 966                 0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
 967                 0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
 968                 0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
 969                 0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
 970                 0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
 971         };
 972
 973 /* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
 974         register int i;
 975         register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
 976
 977         CRCT1=CRCTable1;
 978         CRCT2=CRCTable2;
 979         data=data_a3;
 980         crcl=data_d1;
 981         crch=data_d0;
 982         for (i=data_d3; i>=0; i--) {
 983                 c = (*data++) ^ crch;
 984                 crch = CRCT1[c] ^ crcl;
 985                 crcl = CRCT2[c];
 986         }
 987         return (crch<<8)|crcl;
 988 }
 989
 990 static inline ushort dos_hdr_crc (struct dos_header *hdr)
 991 {
 992         return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
 993 }
 994
 995 static inline ushort dos_data_crc(unsigned char *data)
 996 {
 997         return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
 998 }
 999
1000 static inline unsigned char dos_decode_byte(ushort word)
1001 {
1002         register ushort w2;
1003         register unsigned char byte;
1004         register unsigned char *dec = mfmdecode;
1005
1006         w2=word;
1007         w2>>=8;
1008         w2&=127;
1009         byte = dec[w2];
1010         byte <<= 4;
1011         w2 = word & 127;
1012         byte |= dec[w2];
1013         return byte;
1014 }
1015
1016 static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1017 {
1018         int i;
1019
1020         for (i = 0; i < len; i++)
1021                 *data++=dos_decode_byte(*raw++);
1022         return ((ulong)raw);
1023 }
1024
1025 #ifdef DEBUG
1026 static void dbg(unsigned long ptr)
1027 {
1028         printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1029                ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1030                ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1031 }
1032 #endif
1033
1034 static int dos_read(int drive)
1035 {
1036         unsigned long end;
1037         unsigned long raw;
1038         int scnt;
1039         unsigned short crc,data_crc[2];
1040         struct dos_header hdr;
1041
1042         drive&=3;
1043         raw = (long) raw_buf;
1044         end = raw + unit[drive].type->read_size;
1045
1046         for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1047                 do { /* search for the right sync of each sec-hdr */
1048                         if (!(raw = scan_sync (raw, end))) {
1049                                 printk(KERN_INFO "dos_read: no hdr sync on "
1050                                        "track %d, unit %d for sector %d\n",
1051                                        unit[drive].track,drive,scnt);
1052                                 return MFM_NOSYNC;
1053                         }
1054 #ifdef DEBUG
1055                         dbg(raw);
1056 #endif
1057                 } while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1058                 raw+=2; /* skip over headermark */
1059                 raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1060                 crc = dos_hdr_crc(&hdr);
1061
1062 #ifdef DEBUG
1063                 printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1064                        hdr.sec, hdr.len_desc, hdr.crc);
1065 #endif
1066
1067                 if (crc != hdr.crc) {
1068                         printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1069                                hdr.crc, crc);
1070                         return MFM_HEADER;
1071                 }
1072                 if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1073                         printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1074                                hdr.track,
1075                                unit[drive].track/unit[drive].type->heads);
1076                         return MFM_TRACK;
1077                 }
1078
1079                 if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1080                         printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1081                                hdr.side,
1082                                unit[drive].track%unit[drive].type->heads);
1083                         return MFM_TRACK;
1084                 }
1085
1086                 if (hdr.len_desc != 2) {
1087                         printk(KERN_INFO "dos_read: unknown sector len "
1088                                "descriptor %d\n", hdr.len_desc);
1089                         return MFM_DATA;
1090                 }
1091 #ifdef DEBUG
1092                 printk("hdr accepted\n");
1093 #endif
1094                 if (!(raw = scan_sync (raw, end))) {
1095                         printk(KERN_INFO "dos_read: no data sync on track "
1096                                "%d, unit %d for sector%d, disk sector %d\n",
1097                                unit[drive].track, drive, scnt, hdr.sec);
1098                         return MFM_NOSYNC;
1099                 }
1100 #ifdef DEBUG
1101                 dbg(raw);
1102 #endif
1103
1104                 if (*((ushort *)raw)!=0x5545) {
1105                         printk(KERN_INFO "dos_read: no data mark after "
1106                                "sync (%d,%d,%d,%d) sc=%d\n",
1107                                hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1108                         return MFM_NOSYNC;
1109                 }
1110
1111                 raw+=2;  /* skip data mark (included in checksum) */
1112                 raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1113                 raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1114                 crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1115
1116                 if (crc != data_crc[0]) {
1117                         printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1118                                "sc=%d, %x %x\n", hdr.track, hdr.side,
1119                                hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1120                         printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1121                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1122                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1123                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1124                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1125                         return MFM_DATA;
1126                 }
1127         }
1128         return 0;
1129 }
1130
1131 static inline ushort dos_encode_byte(unsigned char byte)
1132 {
1133         register unsigned char *enc, b2, b1;
1134         register ushort word;
1135
1136         enc=mfmencode;
1137         b1=byte;
1138         b2=b1>>4;
1139         b1&=15;
1140         word=enc[b2] <<8 | enc [b1];
1141         return (word|((word&(256|64)) ? 0: 128));
1142 }
1143
1144 static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1145 {
1146         int i;
1147
1148         for (i = 0; i < len; i++) {
1149                 *dest=dos_encode_byte(*src++);
1150                 *dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1151                 dest++;
1152         }
1153 }
1154
1155 static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1156 {
1157         static struct dos_header hdr={0,0,0,2,0,
1158           {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1159         int i;
1160         static ushort crc[2]={0,0x4e4e};
1161
1162         drive&=3;
1163 /* id gap 1 */
1164 /* the MFM word before is always 9254 */
1165         for(i=0;i<6;i++)
1166                 *raw++=0xaaaaaaaa;
1167 /* 3 sync + 1 headermark */
1168         *raw++=0x44894489;
1169         *raw++=0x44895554;
1170
1171 /* fill in the variable parts of the header */
1172         hdr.track=unit[drive].track/unit[drive].type->heads;
1173         hdr.side=unit[drive].track%unit[drive].type->heads;
1174         hdr.sec=cnt+1;
1175         hdr.crc=dos_hdr_crc(&hdr);
1176
1177 /* header (without "magic") and id gap 2*/
1178         dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1179         raw+=14;
1180
1181 /*id gap 3 */
1182         for(i=0;i<6;i++)
1183                 *raw++=0xaaaaaaaa;
1184
1185 /* 3 syncs and 1 datamark */
1186         *raw++=0x44894489;
1187         *raw++=0x44895545;
1188
1189 /* data */
1190         dos_encode_block((ushort *)raw,
1191                          (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1192         raw+=256;
1193
1194 /*data crc + jd's special gap (long words :-/) */
1195         crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1196         dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1197         raw+=2;
1198
1199 /* data gap */
1200         for(i=0;i<38;i++)
1201                 *raw++=0x92549254;
1202
1203         return raw; /* wrote 652 MFM words */
1204 }
1205
1206 static void dos_write(int disk)
1207 {
1208         int cnt;
1209         unsigned long raw = (unsigned long) raw_buf;
1210         unsigned long *ptr=(unsigned long *)raw;
1211
1212         disk&=3;
1213 /* really gap4 + indexgap , but we write it first and round it up */
1214         for (cnt=0;cnt<425;cnt++)
1215                 *ptr++=0x92549254;
1216
1217 /* the following is just guessed */
1218         if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1219                 for(cnt=0;cnt<473;cnt++)
1220                         *ptr++=0x92549254;
1221
1222 /* now the index marks...*/
1223         for (cnt=0;cnt<20;cnt++)
1224                 *ptr++=0x92549254;
1225         for (cnt=0;cnt<6;cnt++)
1226                 *ptr++=0xaaaaaaaa;
1227         *ptr++=0x52245224;
1228         *ptr++=0x52245552;
1229         for (cnt=0;cnt<20;cnt++)
1230                 *ptr++=0x92549254;
1231
1232 /* sectors */
1233         for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1234                 ptr=ms_putsec(disk,ptr,cnt);
1235
1236         *(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1237 }
1238
1239 /*
1240  * Here comes the high level stuff (i.e. the filesystem interface)
1241  * and helper functions.
1242  * Normally this should be the only part that has to be adapted to
1243  * different kernel versions.
1244  */
1245
1246 /* FIXME: this assumes the drive is still spinning -
1247  * which is only true if we complete writing a track within three seconds
1248  */
1249 static void flush_track_callback(unsigned long nr)
1250 {
1251         nr&=3;
1252         writefromint = 1;
1253         if (!try_fdc(nr)) {
1254                 /* we might block in an interrupt, so try again later */
1255                 flush_track_timer[nr].expires = jiffies + 1;
1256                 add_timer(flush_track_timer + nr);
1257                 return;
1258         }
1259         get_fdc(nr);
1260         (*unit[nr].dtype->write_fkt)(nr);
1261         if (!raw_write(nr)) {
1262                 printk (KERN_NOTICE "floppy disk write protected\n");
1263                 writefromint = 0;
1264                 writepending = 0;
1265         }
1266         rel_fdc();
1267 }
1268
1269 static int non_int_flush_track (unsigned long nr)
1270 {
1271         unsigned long flags;
1272
1273         nr&=3;
1274         writefromint = 0;
1275         del_timer(&post_write_timer);
1276         get_fdc(nr);
1277         if (!fd_motor_on(nr)) {
1278                 writepending = 0;
1279                 rel_fdc();
1280                 return 0;
1281         }
1282         local_irq_save(flags);
1283         if (writepending != 2) {
1284                 local_irq_restore(flags);
1285                 (*unit[nr].dtype->write_fkt)(nr);
1286                 if (!raw_write(nr)) {
1287                         printk (KERN_NOTICE "floppy disk write protected "
1288                                 "in write!\n");
1289                         writepending = 0;
1290                         return 0;
1291                 }
1292                 wait_event(wait_fd_block, block_flag != 2);
1293         }
1294         else {
1295                 local_irq_restore(flags);
1296                 ms_delay(2); /* 2 ms post_write delay */
1297                 post_write(nr);
1298         }
1299         rel_fdc();
1300         return 1;
1301 }
1302
1303 static int get_track(int drive, int track)
1304 {
1305         int error, errcnt;
1306
1307         drive&=3;
1308         if (unit[drive].track == track)
1309                 return 0;
1310         get_fdc(drive);
1311         if (!fd_motor_on(drive)) {
1312                 rel_fdc();
1313                 return -1;
1314         }
1315
1316         if (unit[drive].dirty == 1) {
1317                 del_timer (flush_track_timer + drive);
1318                 non_int_flush_track (drive);
1319         }
1320         errcnt = 0;
1321         while (errcnt < MAX_ERRORS) {
1322                 if (!fd_seek(drive, track))
1323                         return -1;
1324                 raw_read(drive);
1325                 error = (*unit[drive].dtype->read_fkt)(drive);
1326                 if (error == 0) {
1327                         rel_fdc();
1328                         return 0;
1329                 }
1330                 /* Read Error Handling: recalibrate and try again */
1331                 unit[drive].track = -1;
1332                 errcnt++;
1333         }
1334         rel_fdc();
1335         return -1;
1336 }
1337
1338 static void redo_fd_request(void)
1339 {
1340         struct request *rq;
1341         unsigned int cnt, block, track, sector;
1342         int drive;
1343         struct amiga_floppy_struct *floppy;
1344         char *data;
1345         unsigned long flags;
1346         int err;
1347
1348 next_req:
1349         rq = blk_fetch_request(floppy_queue);
1350         if (!rq) {
1351                 /* Nothing left to do */
1352                 return;
1353         }
1354
1355         floppy = rq->rq_disk->private_data;
1356         drive = floppy - unit;
1357
1358 next_segment:
1359         /* Here someone could investigate to be more efficient */
1360         for (cnt = 0, err = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
1361 #ifdef DEBUG
1362                 printk("fd: sector %ld + %d requested for %s\n",
1363                        blk_rq_pos(rq), cnt,
1364                        (rq_data_dir(rq) == READ) ? "read" : "write");
1365 #endif
1366                 block = blk_rq_pos(rq) + cnt;
1367                 if ((int)block > floppy->blocks) {
1368                         err = -EIO;
1369                         break;
1370                 }
1371
1372                 track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1373                 sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1374                 data = rq->buffer + 512 * cnt;
1375 #ifdef DEBUG
1376                 printk("access to track %d, sector %d, with buffer at "
1377                        "0x%08lx\n", track, sector, data);
1378 #endif
1379
1380                 if (get_track(drive, track) == -1) {
1381                         err = -EIO;
1382                         break;
1383                 }
1384
1385                 if (rq_data_dir(rq) == READ) {
1386                         memcpy(data, floppy->trackbuf + sector * 512, 512);
1387                 } else {
1388                         memcpy(floppy->trackbuf + sector * 512, data, 512);
1389
1390                         /* keep the drive spinning while writes are scheduled */
1391                         if (!fd_motor_on(drive)) {
1392                                 err = -EIO;
1393                                 break;
1394                         }
1395                         /*
1396                          * setup a callback to write the track buffer
1397                          * after a short (1 tick) delay.
1398                          */
1399                         local_irq_save(flags);
1400
1401                         floppy->dirty = 1;
1402                         /* reset the timer */
1403                         mod_timer (flush_track_timer + drive, jiffies + 1);
1404                         local_irq_restore(flags);
1405                 }
1406         }
1407
1408         if (__blk_end_request_cur(rq, err))
1409                 goto next_segment;
1410         goto next_req;
1411 }
1412
1413 static void do_fd_request(struct request_queue * q)
1414 {
1415         redo_fd_request();
1416 }
1417
1418 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1419 {
1420         int drive = MINOR(bdev->bd_dev) & 3;
1421
1422         geo->heads = unit[drive].type->heads;
1423         geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1424         geo->cylinders = unit[drive].type->tracks;
1425         return 0;
1426 }
1427
1428 static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
1429                     unsigned int cmd, unsigned long param)
1430 {
1431         struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1432         int drive = p - unit;
1433         static struct floppy_struct getprm;
1434         void __user *argp = (void __user *)param;
1435
1436         switch(cmd){
1437         case FDFMTBEG:
1438                 get_fdc(drive);
1439                 if (fd_ref[drive] > 1) {
1440                         rel_fdc();
1441                         return -EBUSY;
1442                 }
1443                 fsync_bdev(bdev);
1444                 if (fd_motor_on(drive) == 0) {
1445                         rel_fdc();
1446                         return -ENODEV;
1447                 }
1448                 if (fd_calibrate(drive) == 0) {
1449                         rel_fdc();
1450                         return -ENXIO;
1451                 }
1452                 floppy_off(drive);
1453                 rel_fdc();
1454                 break;
1455         case FDFMTTRK:
1456                 if (param < p->type->tracks * p->type->heads)
1457                 {
1458                         get_fdc(drive);
1459                         if (fd_seek(drive,param) != 0){
1460                                 memset(p->trackbuf, FD_FILL_BYTE,
1461                                        p->dtype->sects * p->type->sect_mult * 512);
1462                                 non_int_flush_track(drive);
1463                         }
1464                         floppy_off(drive);
1465                         rel_fdc();
1466                 }
1467                 else
1468                         return -EINVAL;
1469                 break;
1470         case FDFMTEND:
1471                 floppy_off(drive);
1472                 invalidate_bdev(bdev);
1473                 break;
1474         case FDGETPRM:
1475                 memset((void *)&getprm, 0, sizeof (getprm));
1476                 getprm.track=p->type->tracks;
1477                 getprm.head=p->type->heads;
1478                 getprm.sect=p->dtype->sects * p->type->sect_mult;
1479                 getprm.size=p->blocks;
1480                 if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1481                         return -EFAULT;
1482                 break;
1483         case FDSETPRM:
1484         case FDDEFPRM:
1485                 return -EINVAL;
1486         case FDFLUSH: /* unconditionally, even if not needed */
1487                 del_timer (flush_track_timer + drive);
1488                 non_int_flush_track(drive);
1489                 break;
1490 #ifdef RAW_IOCTL
1491         case IOCTL_RAW_TRACK:
1492                 if (copy_to_user(argp, raw_buf, p->type->read_size))
1493                         return -EFAULT;
1494                 else
1495                         return p->type->read_size;
1496 #endif
1497         default:
1498                 printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1499                        cmd, drive);
1500                 return -ENOSYS;
1501         }
1502         return 0;
1503 }
1504
1505 static int fd_ioctl(struct block_device *bdev, fmode_t mode,
1506                              unsigned int cmd, unsigned long param)
1507 {
1508         int ret;
1509
1510         mutex_lock(&amiflop_mutex);
1511         ret = fd_locked_ioctl(bdev, mode, cmd, param);
1512         mutex_unlock(&amiflop_mutex);
1513
1514         return ret;
1515 }
1516
1517 static void fd_probe(int dev)
1518 {
1519         unsigned long code;
1520         int type;
1521         int drive;
1522
1523         drive = dev & 3;
1524         code = fd_get_drive_id(drive);
1525
1526         /* get drive type */
1527         for (type = 0; type < num_dr_types; type++)
1528                 if (drive_types[type].code == code)
1529                         break;
1530
1531         if (type >= num_dr_types) {
1532                 printk(KERN_WARNING "fd_probe: unsupported drive type "
1533                        "%08lx found\n", code);
1534                 unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1535                 return;
1536         }
1537
1538         unit[drive].type = drive_types + type;
1539         unit[drive].track = -1;
1540
1541         unit[drive].disk = -1;
1542         unit[drive].motor = 0;
1543         unit[drive].busy = 0;
1544         unit[drive].status = -1;
1545 }
1546
1547 /*
1548  * floppy_open check for aliasing (/dev/fd0 can be the same as
1549  * /dev/PS0 etc), and disallows simultaneous access to the same
1550  * drive with different device numbers.
1551  */
1552 static int floppy_open(struct block_device *bdev, fmode_t mode)
1553 {
1554         int drive = MINOR(bdev->bd_dev) & 3;
1555         int system =  (MINOR(bdev->bd_dev) & 4) >> 2;
1556         int old_dev;
1557         unsigned long flags;
1558
1559         mutex_lock(&amiflop_mutex);
1560         old_dev = fd_device[drive];
1561
1562         if (fd_ref[drive] && old_dev != system) {
1563                 mutex_unlock(&amiflop_mutex);
1564                 return -EBUSY;
1565         }
1566
1567         if (mode & (FMODE_READ|FMODE_WRITE)) {
1568                 check_disk_change(bdev);
1569                 if (mode & FMODE_WRITE) {
1570                         int wrprot;
1571
1572                         get_fdc(drive);
1573                         fd_select (drive);
1574                         wrprot = !(ciaa.pra & DSKPROT);
1575                         fd_deselect (drive);
1576                         rel_fdc();
1577
1578                         if (wrprot) {
1579                                 mutex_unlock(&amiflop_mutex);
1580                                 return -EROFS;
1581                         }
1582                 }
1583         }
1584
1585         local_irq_save(flags);
1586         fd_ref[drive]++;
1587         fd_device[drive] = system;
1588         local_irq_restore(flags);
1589
1590         unit[drive].dtype=&data_types[system];
1591         unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1592                 data_types[system].sects*unit[drive].type->sect_mult;
1593         set_capacity(unit[drive].gendisk, unit[drive].blocks);
1594
1595         printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1596                unit[drive].type->name, data_types[system].name);
1597
1598         mutex_unlock(&amiflop_mutex);
1599         return 0;
1600 }
1601
1602 static int floppy_release(struct gendisk *disk, fmode_t mode)
1603 {
1604         struct amiga_floppy_struct *p = disk->private_data;
1605         int drive = p - unit;
1606
1607         mutex_lock(&amiflop_mutex);
1608         if (unit[drive].dirty == 1) {
1609                 del_timer (flush_track_timer + drive);
1610                 non_int_flush_track (drive);
1611         }
1612
1613         if (!fd_ref[drive]--) {
1614                 printk(KERN_CRIT "floppy_release with fd_ref == 0");
1615                 fd_ref[drive] = 0;
1616         }
1617 #ifdef MODULE
1618 /* the mod_use counter is handled this way */
1619         floppy_off (drive | 0x40000000);
1620 #endif
1621         mutex_unlock(&amiflop_mutex);
1622         return 0;
1623 }
1624
1625 /*
1626  * floppy-change is never called from an interrupt, so we can relax a bit
1627  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1628  * to the desired drive, but it will probably not survive the sleep if
1629  * several floppies are used at the same time: thus the loop.
1630  */
1631 static int amiga_floppy_change(struct gendisk *disk)
1632 {
1633         struct amiga_floppy_struct *p = disk->private_data;
1634         int drive = p - unit;
1635         int changed;
1636         static int first_time = 1;
1637
1638         if (first_time)
1639                 changed = first_time--;
1640         else {
1641                 get_fdc(drive);
1642                 fd_select (drive);
1643                 changed = !(ciaa.pra & DSKCHANGE);
1644                 fd_deselect (drive);
1645                 rel_fdc();
1646         }
1647
1648         if (changed) {
1649                 fd_probe(drive);
1650                 p->track = -1;
1651                 p->dirty = 0;
1652                 writepending = 0; /* if this was true before, too bad! */
1653                 writefromint = 0;
1654                 return 1;
1655         }
1656         return 0;
1657 }
1658
1659 static const struct block_device_operations floppy_fops = {
1660         .owner          = THIS_MODULE,
1661         .open           = floppy_open,
1662         .release        = floppy_release,
1663         .ioctl          = fd_ioctl,
1664         .getgeo         = fd_getgeo,
1665         .media_changed  = amiga_floppy_change,
1666 };
1667
1668 static int __init fd_probe_drives(void)
1669 {
1670         int drive,drives,nomem;
1671
1672         printk(KERN_INFO "FD: probing units\nfound ");
1673         drives=0;
1674         nomem=0;
1675         for(drive=0;drive<FD_MAX_UNITS;drive++) {
1676                 struct gendisk *disk;
1677                 fd_probe(drive);
1678                 if (unit[drive].type->code == FD_NODRIVE)
1679                         continue;
1680                 disk = alloc_disk(1);
1681                 if (!disk) {
1682                         unit[drive].type->code = FD_NODRIVE;
1683                         continue;
1684                 }
1685                 unit[drive].gendisk = disk;
1686                 drives++;
1687                 if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1688                         printk("no mem for ");
1689                         unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1690                         drives--;
1691                         nomem = 1;
1692                 }
1693                 printk("fd%d ",drive);
1694                 disk->major = FLOPPY_MAJOR;
1695                 disk->first_minor = drive;
1696                 disk->fops = &floppy_fops;
1697                 sprintf(disk->disk_name, "fd%d", drive);
1698                 disk->private_data = &unit[drive];
1699                 disk->queue = floppy_queue;
1700                 set_capacity(disk, 880*2);
1701                 add_disk(disk);
1702         }
1703         if ((drives > 0) || (nomem == 0)) {
1704                 if (drives == 0)
1705                         printk("no drives");
1706                 printk("\n");
1707                 return drives;
1708         }
1709         printk("\n");
1710         return -ENOMEM;
1711 }
1712
1713 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1714 {
1715         int drive = *part & 3;
1716         if (unit[drive].type->code == FD_NODRIVE)
1717                 return NULL;
1718         *part = 0;
1719         return get_disk(unit[drive].gendisk);
1720 }
1721
1722 static int __init amiga_floppy_probe(struct platform_device *pdev)
1723 {
1724         int i, ret;
1725
1726         if (register_blkdev(FLOPPY_MAJOR,"fd"))
1727                 return -EBUSY;
1728
1729         ret = -ENOMEM;
1730         if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1731             NULL) {
1732                 printk("fd: cannot get chip mem buffer\n");
1733                 goto out_blkdev;
1734         }
1735
1736         ret = -EBUSY;
1737         if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1738                 printk("fd: cannot get irq for dma\n");
1739                 goto out_irq;
1740         }
1741
1742         if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1743                 printk("fd: cannot get irq for timer\n");
1744                 goto out_irq2;
1745         }
1746
1747         ret = -ENOMEM;
1748         floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
1749         if (!floppy_queue)
1750                 goto out_queue;
1751
1752         ret = -ENODEV;
1753         if (fd_probe_drives() < 1) /* No usable drives */
1754                 goto out_probe;
1755
1756         blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1757                                 floppy_find, NULL, NULL);
1758
1759         /* initialize variables */
1760         init_timer(&motor_on_timer);
1761         motor_on_timer.expires = 0;
1762         motor_on_timer.data = 0;
1763         motor_on_timer.function = motor_on_callback;
1764         for (i = 0; i < FD_MAX_UNITS; i++) {
1765                 init_timer(&motor_off_timer[i]);
1766                 motor_off_timer[i].expires = 0;
1767                 motor_off_timer[i].data = i|0x80000000;
1768                 motor_off_timer[i].function = fd_motor_off;
1769                 init_timer(&flush_track_timer[i]);
1770                 flush_track_timer[i].expires = 0;
1771                 flush_track_timer[i].data = i;
1772                 flush_track_timer[i].function = flush_track_callback;
1773
1774                 unit[i].track = -1;
1775         }
1776
1777         init_timer(&post_write_timer);
1778         post_write_timer.expires = 0;
1779         post_write_timer.data = 0;
1780         post_write_timer.function = post_write;
1781
1782         for (i = 0; i < 128; i++)
1783                 mfmdecode[i]=255;
1784         for (i = 0; i < 16; i++)
1785                 mfmdecode[mfmencode[i]]=i;
1786
1787         /* make sure that disk DMA is enabled */
1788         custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1789
1790         /* init ms timer */
1791         ciaa.crb = 8; /* one-shot, stop */
1792         return 0;
1793
1794 out_probe:
1795         blk_cleanup_queue(floppy_queue);
1796 out_queue:
1797         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1798 out_irq2:
1799         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1800 out_irq:
1801         amiga_chip_free(raw_buf);
1802 out_blkdev:
1803         unregister_blkdev(FLOPPY_MAJOR,"fd");
1804         return ret;
1805 }
1806
1807 #if 0 /* not safe to unload */
1808 static int __exit amiga_floppy_remove(struct platform_device *pdev)
1809 {
1810         int i;
1811
1812         for( i = 0; i < FD_MAX_UNITS; i++) {
1813                 if (unit[i].type->code != FD_NODRIVE) {
1814                         del_gendisk(unit[i].gendisk);
1815                         put_disk(unit[i].gendisk);
1816                         kfree(unit[i].trackbuf);
1817                 }
1818         }
1819         blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
1820         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1821         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1822         custom.dmacon = DMAF_DISK; /* disable DMA */
1823         amiga_chip_free(raw_buf);
1824         blk_cleanup_queue(floppy_queue);
1825         unregister_blkdev(FLOPPY_MAJOR, "fd");
1826 }
1827 #endif
1828
1829 static struct platform_driver amiga_floppy_driver = {
1830         .driver   = {
1831                 .name   = "amiga-floppy",
1832                 .owner  = THIS_MODULE,
1833         },
1834 };
1835
1836 static int __init amiga_floppy_init(void)
1837 {
1838         return platform_driver_probe(&amiga_floppy_driver, amiga_floppy_probe);
1839 }
1840
1841 module_init(amiga_floppy_init);
1842
1843 #ifndef MODULE
1844 static int __init amiga_floppy_setup (char *str)
1845 {
1846         int n;
1847         if (!MACH_IS_AMIGA)
1848                 return 0;
1849         if (!get_option(&str, &n))
1850                 return 0;
1851         printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1852         fd_def_df0 = n;
1853         return 1;
1854 }
1855
1856 __setup("floppy=", amiga_floppy_setup);
1857 #endif
1858
1859 MODULE_ALIAS("platform:amiga-floppy");