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