block: push down BKL into .open and .release
[linux-2.6.git] / 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/smp_lock.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 unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
113
114 module_param(fd_def_df0, ulong, 0);
115 MODULE_LICENSE("GPL");
116
117 static struct request_queue *floppy_queue;
118
119 /*
120  *  Macros
121  */
122 #define MOTOR_ON        (ciab.prb &= ~DSKMOTOR)
123 #define MOTOR_OFF       (ciab.prb |= DSKMOTOR)
124 #define SELECT(mask)    (ciab.prb &= ~mask)
125 #define DESELECT(mask)  (ciab.prb |= mask)
126 #define SELMASK(drive)  (1 << (3 + (drive & 3)))
127
128 static struct fd_drive_type drive_types[] = {
129 /*  code        name       tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
130 /*  warning: times are now in milliseconds (ms)                    */
131 { FD_DD_3,      "DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
132 { FD_HD_3,      "HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
133 { FD_DD_5,      "DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
134 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
135 };
136 static int num_dr_types = ARRAY_SIZE(drive_types);
137
138 static int amiga_read(int), dos_read(int);
139 static void amiga_write(int), dos_write(int);
140 static struct fd_data_type data_types[] = {
141         { "Amiga", 11 , amiga_read, amiga_write},
142         { "MS-Dos", 9, dos_read, dos_write}
143 };
144
145 /* current info on each unit */
146 static struct amiga_floppy_struct unit[FD_MAX_UNITS];
147
148 static struct timer_list flush_track_timer[FD_MAX_UNITS];
149 static struct timer_list post_write_timer;
150 static struct timer_list motor_on_timer;
151 static struct timer_list motor_off_timer[FD_MAX_UNITS];
152 static int on_attempts;
153
154 /* Synchronization of FDC access */
155 /* request loop (trackbuffer) */
156 static volatile int fdc_busy = -1;
157 static volatile int fdc_nested;
158 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
159  
160 static DECLARE_COMPLETION(motor_on_completion);
161
162 static volatile int selected = -1;      /* currently selected drive */
163
164 static int writepending;
165 static int writefromint;
166 static char *raw_buf;
167
168 static DEFINE_SPINLOCK(amiflop_lock);
169
170 #define RAW_BUF_SIZE 30000  /* size of raw disk data */
171
172 /*
173  * These are global variables, as that's the easiest way to give
174  * information to interrupts. They are the data used for the current
175  * request.
176  */
177 static volatile char block_flag;
178 static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
179
180 /* MS-Dos MFM Coding tables (should go quick and easy) */
181 static unsigned char mfmencode[16]={
182         0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
183         0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
184 };
185 static unsigned char mfmdecode[128];
186
187 /* floppy internal millisecond timer stuff */
188 static DECLARE_COMPLETION(ms_wait_completion);
189 #define MS_TICKS ((amiga_eclock+50)/1000)
190
191 /*
192  * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
193  * max X times - some types of errors increase the errorcount by 2 or
194  * even 3, so we might actually retry only X/2 times before giving up.
195  */
196 #define MAX_ERRORS 12
197
198 #define custom amiga_custom
199
200 /* Prevent "aliased" accesses. */
201 static int fd_ref[4] = { 0,0,0,0 };
202 static int fd_device[4] = { 0, 0, 0, 0 };
203
204 /*
205  * Here come the actual hardware access and helper functions.
206  * They are not reentrant and single threaded because all drives
207  * share the same hardware and the same trackbuffer.
208  */
209
210 /* Milliseconds timer */
211
212 static irqreturn_t ms_isr(int irq, void *dummy)
213 {
214         complete(&ms_wait_completion);
215         return IRQ_HANDLED;
216 }
217
218 /* all waits are queued up 
219    A more generic routine would do a schedule a la timer.device */
220 static void ms_delay(int ms)
221 {
222         int ticks;
223         static DEFINE_MUTEX(mutex);
224
225         if (ms > 0) {
226                 mutex_lock(&mutex);
227                 ticks = MS_TICKS*ms-1;
228                 ciaa.tblo=ticks%256;
229                 ciaa.tbhi=ticks/256;
230                 ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
231                 wait_for_completion(&ms_wait_completion);
232                 mutex_unlock(&mutex);
233         }
234 }
235
236 /* Hardware semaphore */
237
238 /* returns true when we would get the semaphore */
239 static inline int try_fdc(int drive)
240 {
241         drive &= 3;
242         return ((fdc_busy < 0) || (fdc_busy == drive));
243 }
244
245 static void get_fdc(int drive)
246 {
247         unsigned long flags;
248
249         drive &= 3;
250 #ifdef DEBUG
251         printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
252 #endif
253         local_irq_save(flags);
254         wait_event(fdc_wait, try_fdc(drive));
255         fdc_busy = drive;
256         fdc_nested++;
257         local_irq_restore(flags);
258 }
259
260 static inline void rel_fdc(void)
261 {
262 #ifdef DEBUG
263         if (fdc_nested == 0)
264                 printk("fd: unmatched rel_fdc\n");
265         printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
266 #endif
267         fdc_nested--;
268         if (fdc_nested == 0) {
269                 fdc_busy = -1;
270                 wake_up(&fdc_wait);
271         }
272 }
273
274 static void fd_select (int drive)
275 {
276         unsigned char prb = ~0;
277
278         drive&=3;
279 #ifdef DEBUG
280         printk("selecting %d\n",drive);
281 #endif
282         if (drive == selected)
283                 return;
284         get_fdc(drive);
285         selected = drive;
286
287         if (unit[drive].track % 2 != 0)
288                 prb &= ~DSKSIDE;
289         if (unit[drive].motor == 1)
290                 prb &= ~DSKMOTOR;
291         ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
292         ciab.prb = prb;
293         prb &= ~SELMASK(drive);
294         ciab.prb = prb;
295         rel_fdc();
296 }
297
298 static void fd_deselect (int drive)
299 {
300         unsigned char prb;
301         unsigned long flags;
302
303         drive&=3;
304 #ifdef DEBUG
305         printk("deselecting %d\n",drive);
306 #endif
307         if (drive != selected) {
308                 printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
309                 return;
310         }
311
312         get_fdc(drive);
313         local_irq_save(flags);
314
315         selected = -1;
316
317         prb = ciab.prb;
318         prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
319         ciab.prb = prb;
320
321         local_irq_restore (flags);
322         rel_fdc();
323
324 }
325
326 static void motor_on_callback(unsigned long nr)
327 {
328         if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
329                 complete_all(&motor_on_completion);
330         } else {
331                 motor_on_timer.expires = jiffies + HZ/10;
332                 add_timer(&motor_on_timer);
333         }
334 }
335
336 static int fd_motor_on(int nr)
337 {
338         nr &= 3;
339
340         del_timer(motor_off_timer + nr);
341
342         if (!unit[nr].motor) {
343                 unit[nr].motor = 1;
344                 fd_select(nr);
345
346                 INIT_COMPLETION(motor_on_completion);
347                 motor_on_timer.data = nr;
348                 mod_timer(&motor_on_timer, jiffies + HZ/2);
349
350                 on_attempts = 10;
351                 wait_for_completion(&motor_on_completion);
352                 fd_deselect(nr);
353         }
354
355         if (on_attempts == 0) {
356                 on_attempts = -1;
357 #if 0
358                 printk (KERN_ERR "motor_on failed, turning motor off\n");
359                 fd_motor_off (nr);
360                 return 0;
361 #else
362                 printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
363 #endif
364         }
365
366         return 1;
367 }
368
369 static void fd_motor_off(unsigned long drive)
370 {
371         long calledfromint;
372 #ifdef MODULE
373         long decusecount;
374
375         decusecount = drive & 0x40000000;
376 #endif
377         calledfromint = drive & 0x80000000;
378         drive&=3;
379         if (calledfromint && !try_fdc(drive)) {
380                 /* We would be blocked in an interrupt, so try again later */
381                 motor_off_timer[drive].expires = jiffies + 1;
382                 add_timer(motor_off_timer + drive);
383                 return;
384         }
385         unit[drive].motor = 0;
386         fd_select(drive);
387         udelay (1);
388         fd_deselect(drive);
389 }
390
391 static void floppy_off (unsigned int nr)
392 {
393         int drive;
394
395         drive = nr & 3;
396         /* called this way it is always from interrupt */
397         motor_off_timer[drive].data = nr | 0x80000000;
398         mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
399 }
400
401 static int fd_calibrate(int drive)
402 {
403         unsigned char prb;
404         int n;
405
406         drive &= 3;
407         get_fdc(drive);
408         if (!fd_motor_on (drive))
409                 return 0;
410         fd_select (drive);
411         prb = ciab.prb;
412         prb |= DSKSIDE;
413         prb &= ~DSKDIREC;
414         ciab.prb = prb;
415         for (n = unit[drive].type->tracks/2; n != 0; --n) {
416                 if (ciaa.pra & DSKTRACK0)
417                         break;
418                 prb &= ~DSKSTEP;
419                 ciab.prb = prb;
420                 prb |= DSKSTEP;
421                 udelay (2);
422                 ciab.prb = prb;
423                 ms_delay(unit[drive].type->step_delay);
424         }
425         ms_delay (unit[drive].type->settle_time);
426         prb |= DSKDIREC;
427         n = unit[drive].type->tracks + 20;
428         for (;;) {
429                 prb &= ~DSKSTEP;
430                 ciab.prb = prb;
431                 prb |= DSKSTEP;
432                 udelay (2);
433                 ciab.prb = prb;
434                 ms_delay(unit[drive].type->step_delay + 1);
435                 if ((ciaa.pra & DSKTRACK0) == 0)
436                         break;
437                 if (--n == 0) {
438                         printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
439                         fd_motor_off (drive);
440                         unit[drive].track = -1;
441                         rel_fdc();
442                         return 0;
443                 }
444         }
445         unit[drive].track = 0;
446         ms_delay(unit[drive].type->settle_time);
447
448         rel_fdc();
449         fd_deselect(drive);
450         return 1;
451 }
452
453 static int fd_seek(int drive, int track)
454 {
455         unsigned char prb;
456         int cnt;
457
458 #ifdef DEBUG
459         printk("seeking drive %d to track %d\n",drive,track);
460 #endif
461         drive &= 3;
462         get_fdc(drive);
463         if (unit[drive].track == track) {
464                 rel_fdc();
465                 return 1;
466         }
467         if (!fd_motor_on(drive)) {
468                 rel_fdc();
469                 return 0;
470         }
471         if (unit[drive].track < 0 && !fd_calibrate(drive)) {
472                 rel_fdc();
473                 return 0;
474         }
475
476         fd_select (drive);
477         cnt = unit[drive].track/2 - track/2;
478         prb = ciab.prb;
479         prb |= DSKSIDE | DSKDIREC;
480         if (track % 2 != 0)
481                 prb &= ~DSKSIDE;
482         if (cnt < 0) {
483                 cnt = - cnt;
484                 prb &= ~DSKDIREC;
485         }
486         ciab.prb = prb;
487         if (track % 2 != unit[drive].track % 2)
488                 ms_delay (unit[drive].type->side_time);
489         unit[drive].track = track;
490         if (cnt == 0) {
491                 rel_fdc();
492                 fd_deselect(drive);
493                 return 1;
494         }
495         do {
496                 prb &= ~DSKSTEP;
497                 ciab.prb = prb;
498                 prb |= DSKSTEP;
499                 udelay (1);
500                 ciab.prb = prb;
501                 ms_delay (unit[drive].type->step_delay);
502         } while (--cnt != 0);
503         ms_delay (unit[drive].type->settle_time);
504
505         rel_fdc();
506         fd_deselect(drive);
507         return 1;
508 }
509
510 static unsigned long fd_get_drive_id(int drive)
511 {
512         int i;
513         ulong id = 0;
514
515         drive&=3;
516         get_fdc(drive);
517         /* set up for ID */
518         MOTOR_ON;
519         udelay(2);
520         SELECT(SELMASK(drive));
521         udelay(2);
522         DESELECT(SELMASK(drive));
523         udelay(2);
524         MOTOR_OFF;
525         udelay(2);
526         SELECT(SELMASK(drive));
527         udelay(2);
528         DESELECT(SELMASK(drive));
529         udelay(2);
530
531         /* loop and read disk ID */
532         for (i=0; i<32; i++) {
533                 SELECT(SELMASK(drive));
534                 udelay(2);
535
536                 /* read and store value of DSKRDY */
537                 id <<= 1;
538                 id |= (ciaa.pra & DSKRDY) ? 0 : 1;      /* cia regs are low-active! */
539
540                 DESELECT(SELMASK(drive));
541         }
542
543         rel_fdc();
544
545         /*
546          * RB: At least A500/A2000's df0: don't identify themselves.
547          * As every (real) Amiga has at least a 3.5" DD drive as df0:
548          * we default to that if df0: doesn't identify as a certain
549          * type.
550          */
551         if(drive == 0 && id == FD_NODRIVE)
552         {
553                 id = fd_def_df0;
554                 printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
555         }
556         /* return the ID value */
557         return (id);
558 }
559
560 static irqreturn_t fd_block_done(int irq, void *dummy)
561 {
562         if (block_flag)
563                 custom.dsklen = 0x4000;
564
565         if (block_flag == 2) { /* writing */
566                 writepending = 2;
567                 post_write_timer.expires = jiffies + 1; /* at least 2 ms */
568                 post_write_timer.data = selected;
569                 add_timer(&post_write_timer);
570         }
571         else {                /* reading */
572                 block_flag = 0;
573                 wake_up (&wait_fd_block);
574         }
575         return IRQ_HANDLED;
576 }
577
578 static void raw_read(int drive)
579 {
580         drive&=3;
581         get_fdc(drive);
582         wait_event(wait_fd_block, !block_flag);
583         fd_select(drive);
584         /* setup adkcon bits correctly */
585         custom.adkcon = ADK_MSBSYNC;
586         custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
587
588         custom.dsksync = MFM_SYNC;
589
590         custom.dsklen = 0;
591         custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
592         custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
593         custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
594
595         block_flag = 1;
596
597         wait_event(wait_fd_block, !block_flag);
598
599         custom.dsklen = 0;
600         fd_deselect(drive);
601         rel_fdc();
602 }
603
604 static int raw_write(int drive)
605 {
606         ushort adk;
607
608         drive&=3;
609         get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
610         if ((ciaa.pra & DSKPROT) == 0) {
611                 rel_fdc();
612                 return 0;
613         }
614         wait_event(wait_fd_block, !block_flag);
615         fd_select(drive);
616         /* clear adkcon bits */
617         custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
618         /* set appropriate adkcon bits */
619         adk = ADK_SETCLR|ADK_FAST;
620         if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
621                 adk |= ADK_PRECOMP1;
622         else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
623                 adk |= ADK_PRECOMP0;
624         custom.adkcon = adk;
625
626         custom.dsklen = DSKLEN_WRITE;
627         custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
628         custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
629         custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
630
631         block_flag = 2;
632         return 1;
633 }
634
635 /*
636  * to be called at least 2ms after the write has finished but before any
637  * other access to the hardware.
638  */
639 static void post_write (unsigned long drive)
640 {
641 #ifdef DEBUG
642         printk("post_write for drive %ld\n",drive);
643 #endif
644         drive &= 3;
645         custom.dsklen = 0;
646         block_flag = 0;
647         writepending = 0;
648         writefromint = 0;
649         unit[drive].dirty = 0;
650         wake_up(&wait_fd_block);
651         fd_deselect(drive);
652         rel_fdc(); /* corresponds to get_fdc() in raw_write */
653 }
654
655
656 /*
657  * The following functions are to convert the block contents into raw data
658  * written to disk and vice versa.
659  * (Add other formats here ;-))
660  */
661
662 static unsigned long scan_sync(unsigned long raw, unsigned long end)
663 {
664         ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
665
666         while (ptr < endp && *ptr++ != 0x4489)
667                 ;
668         if (ptr < endp) {
669                 while (*ptr == 0x4489 && ptr < endp)
670                         ptr++;
671                 return (ulong)ptr;
672         }
673         return 0;
674 }
675
676 static inline unsigned long checksum(unsigned long *addr, int len)
677 {
678         unsigned long csum = 0;
679
680         len /= sizeof(*addr);
681         while (len-- > 0)
682                 csum ^= *addr++;
683         csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
684
685         return csum;
686 }
687
688 static unsigned long decode (unsigned long *data, unsigned long *raw,
689                              int len)
690 {
691         ulong *odd, *even;
692
693         /* convert length from bytes to longwords */
694         len >>= 2;
695         odd = raw;
696         even = odd + len;
697
698         /* prepare return pointer */
699         raw += len * 2;
700
701         do {
702                 *data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
703         } while (--len != 0);
704
705         return (ulong)raw;
706 }
707
708 struct header {
709         unsigned char magic;
710         unsigned char track;
711         unsigned char sect;
712         unsigned char ord;
713         unsigned char labels[16];
714         unsigned long hdrchk;
715         unsigned long datachk;
716 };
717
718 static int amiga_read(int drive)
719 {
720         unsigned long raw;
721         unsigned long end;
722         int scnt;
723         unsigned long csum;
724         struct header hdr;
725
726         drive&=3;
727         raw = (long) raw_buf;
728         end = raw + unit[drive].type->read_size;
729
730         for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
731                 if (!(raw = scan_sync(raw, end))) {
732                         printk (KERN_INFO "can't find sync for sector %d\n", scnt);
733                         return MFM_NOSYNC;
734                 }
735
736                 raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
737                 raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
738                 raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
739                 raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
740                 csum = checksum((ulong *)&hdr,
741                                 (char *)&hdr.hdrchk-(char *)&hdr);
742
743 #ifdef DEBUG
744                 printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
745                         hdr.magic, hdr.track, hdr.sect, hdr.ord,
746                         *(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
747                         *(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
748                         hdr.hdrchk, hdr.datachk);
749 #endif
750
751                 if (hdr.hdrchk != csum) {
752                         printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
753                         return MFM_HEADER;
754                 }
755
756                 /* verify track */
757                 if (hdr.track != unit[drive].track) {
758                         printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
759                         return MFM_TRACK;
760                 }
761
762                 raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
763                               (ulong *)raw, 512);
764                 csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
765
766                 if (hdr.datachk != csum) {
767                         printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
768                                hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
769                                hdr.datachk, csum);
770                         printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
771                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
772                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
773                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
774                                 ((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
775                         return MFM_DATA;
776                 }
777         }
778
779         return 0;
780 }
781
782 static void encode(unsigned long data, unsigned long *dest)
783 {
784         unsigned long data2;
785
786         data &= 0x55555555;
787         data2 = data ^ 0x55555555;
788         data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
789
790         if (*(dest - 1) & 0x00000001)
791                 data &= 0x7FFFFFFF;
792
793         *dest = data;
794 }
795
796 static void encode_block(unsigned long *dest, unsigned long *src, int len)
797 {
798         int cnt, to_cnt = 0;
799         unsigned long data;
800
801         /* odd bits */
802         for (cnt = 0; cnt < len / 4; cnt++) {
803                 data = src[cnt] >> 1;
804                 encode(data, dest + to_cnt++);
805         }
806
807         /* even bits */
808         for (cnt = 0; cnt < len / 4; cnt++) {
809                 data = src[cnt];
810                 encode(data, dest + to_cnt++);
811         }
812 }
813
814 static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
815 {
816         struct header hdr;
817         int i;
818
819         disk&=3;
820         *raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
821         raw++;
822         *raw++ = 0x44894489;
823
824         hdr.magic = 0xFF;
825         hdr.track = unit[disk].track;
826         hdr.sect = cnt;
827         hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
828         for (i = 0; i < 16; i++)
829                 hdr.labels[i] = 0;
830         hdr.hdrchk = checksum((ulong *)&hdr,
831                               (char *)&hdr.hdrchk-(char *)&hdr);
832         hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
833
834         encode_block(raw, (ulong *)&hdr.magic, 4);
835         raw += 2;
836         encode_block(raw, (ulong *)&hdr.labels, 16);
837         raw += 8;
838         encode_block(raw, (ulong *)&hdr.hdrchk, 4);
839         raw += 2;
840         encode_block(raw, (ulong *)&hdr.datachk, 4);
841         raw += 2;
842         encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
843         raw += 256;
844
845         return raw;
846 }
847
848 static void amiga_write(int disk)
849 {
850         unsigned int cnt;
851         unsigned long *ptr = (unsigned long *)raw_buf;
852
853         disk&=3;
854         /* gap space */
855         for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
856                 *ptr++ = 0xaaaaaaaa;
857
858         /* sectors */
859         for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
860                 ptr = putsec (disk, ptr, cnt);
861         *(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
862 }
863
864
865 struct dos_header {
866         unsigned char track,   /* 0-80 */
867                 side,    /* 0-1 */
868                 sec,     /* 0-...*/
869                 len_desc;/* 2 */
870         unsigned short crc;     /* on 68000 we got an alignment problem, 
871                                    but this compiler solves it  by adding silently 
872                                    adding a pad byte so data won't fit
873                                    and this took about 3h to discover.... */
874         unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
875 };
876
877 /* crc routines are borrowed from the messydos-handler  */
878
879 /* excerpt from the messydos-device           
880 ; The CRC is computed not only over the actual data, but including
881 ; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
882 ; As we don't read or encode these fields into our buffers, we have to
883 ; preload the registers containing the CRC with the values they would have
884 ; after stepping over these fields.
885 ;
886 ; How CRCs "really" work:
887 ;
888 ; First, you should regard a bitstring as a series of coefficients of
889 ; polynomials. We calculate with these polynomials in modulo-2
890 ; arithmetic, in which both add and subtract are done the same as
891 ; exclusive-or. Now, we modify our data (a very long polynomial) in
892 ; such a way that it becomes divisible by the CCITT-standard 16-bit
893 ;                16   12   5
894 ; polynomial:   x  + x  + x + 1, represented by $11021. The easiest
895 ; way to do this would be to multiply (using proper arithmetic) our
896 ; datablock with $11021. So we have:
897 ;   data * $11021                =
898 ;   data * ($10000 + $1021)      =
899 ;   data * $10000 + data * $1021
900 ; The left part of this is simple: Just add two 0 bytes. But then
901 ; the right part (data $1021) remains difficult and even could have
902 ; a carry into the left part. The solution is to use a modified
903 ; multiplication, which has a result that is not correct, but with
904 ; a difference of any multiple of $11021. We then only need to keep
905 ; the 16 least significant bits of the result.
906 ;
907 ; The following algorithm does this for us:
908 ;
909 ;   unsigned char *data, c, crclo, crchi;
910 ;   while (not done) {
911 ;       c = *data++ + crchi;
912 ;       crchi = (@ c) >> 8 + crclo;
913 ;       crclo = @ c;
914 ;   }
915 ;
916 ; Remember, + is done with EOR, the @ operator is in two tables (high
917 ; and low byte separately), which is calculated as
918 ;
919 ;      $1021 * (c & $F0)
920 ;  xor $1021 * (c & $0F)
921 ;  xor $1021 * (c >> 4)         (* is regular multiplication)
922 ;
923 ;
924 ; Anyway, the end result is the same as the remainder of the division of
925 ; the data by $11021. I am afraid I need to study theory a bit more...
926
927
928 my only works was to code this from manx to C....
929
930 */
931
932 static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
933 {
934         static unsigned char CRCTable1[] = {
935                 0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
936                 0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
937                 0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
938                 0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
939                 0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
940                 0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
941                 0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
942                 0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
943                 0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
944                 0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
945                 0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
946                 0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
947                 0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
948                 0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
949                 0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
950                 0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
951         };
952
953         static unsigned char CRCTable2[] = {
954                 0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
955                 0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
956                 0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
957                 0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
958                 0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
959                 0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
960                 0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
961                 0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
962                 0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
963                 0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
964                 0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
965                 0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
966                 0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
967                 0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
968                 0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
969                 0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
970         };
971
972 /* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
973         register int i;
974         register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
975
976         CRCT1=CRCTable1;
977         CRCT2=CRCTable2;
978         data=data_a3;
979         crcl=data_d1;
980         crch=data_d0;
981         for (i=data_d3; i>=0; i--) {
982                 c = (*data++) ^ crch;
983                 crch = CRCT1[c] ^ crcl;
984                 crcl = CRCT2[c];
985         }
986         return (crch<<8)|crcl;
987 }
988
989 static inline ushort dos_hdr_crc (struct dos_header *hdr)
990 {
991         return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
992 }
993
994 static inline ushort dos_data_crc(unsigned char *data)
995 {
996         return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
997 }
998
999 static inline unsigned char dos_decode_byte(ushort word)
1000 {
1001         register ushort w2;
1002         register unsigned char byte;
1003         register unsigned char *dec = mfmdecode;
1004
1005         w2=word;
1006         w2>>=8;
1007         w2&=127;
1008         byte = dec[w2];
1009         byte <<= 4;
1010         w2 = word & 127;
1011         byte |= dec[w2];
1012         return byte;
1013 }
1014
1015 static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1016 {
1017         int i;
1018
1019         for (i = 0; i < len; i++)
1020                 *data++=dos_decode_byte(*raw++);
1021         return ((ulong)raw);
1022 }
1023
1024 #ifdef DEBUG
1025 static void dbg(unsigned long ptr)
1026 {
1027         printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1028                ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1029                ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1030 }
1031 #endif
1032
1033 static int dos_read(int drive)
1034 {
1035         unsigned long end;
1036         unsigned long raw;
1037         int scnt;
1038         unsigned short crc,data_crc[2];
1039         struct dos_header hdr;
1040
1041         drive&=3;
1042         raw = (long) raw_buf;
1043         end = raw + unit[drive].type->read_size;
1044
1045         for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1046                 do { /* search for the right sync of each sec-hdr */
1047                         if (!(raw = scan_sync (raw, end))) {
1048                                 printk(KERN_INFO "dos_read: no hdr sync on "
1049                                        "track %d, unit %d for sector %d\n",
1050                                        unit[drive].track,drive,scnt);
1051                                 return MFM_NOSYNC;
1052                         }
1053 #ifdef DEBUG
1054                         dbg(raw);
1055 #endif
1056                 } while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1057                 raw+=2; /* skip over headermark */
1058                 raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1059                 crc = dos_hdr_crc(&hdr);
1060
1061 #ifdef DEBUG
1062                 printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1063                        hdr.sec, hdr.len_desc, hdr.crc);
1064 #endif
1065
1066                 if (crc != hdr.crc) {
1067                         printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1068                                hdr.crc, crc);
1069                         return MFM_HEADER;
1070                 }
1071                 if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1072                         printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1073                                hdr.track,
1074                                unit[drive].track/unit[drive].type->heads);
1075                         return MFM_TRACK;
1076                 }
1077
1078                 if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1079                         printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1080                                hdr.side,
1081                                unit[drive].track%unit[drive].type->heads);
1082                         return MFM_TRACK;
1083                 }
1084
1085                 if (hdr.len_desc != 2) {
1086                         printk(KERN_INFO "dos_read: unknown sector len "
1087                                "descriptor %d\n", hdr.len_desc);
1088                         return MFM_DATA;
1089                 }
1090 #ifdef DEBUG
1091                 printk("hdr accepted\n");
1092 #endif
1093                 if (!(raw = scan_sync (raw, end))) {
1094                         printk(KERN_INFO "dos_read: no data sync on track "
1095                                "%d, unit %d for sector%d, disk sector %d\n",
1096                                unit[drive].track, drive, scnt, hdr.sec);
1097                         return MFM_NOSYNC;
1098                 }
1099 #ifdef DEBUG
1100                 dbg(raw);
1101 #endif
1102
1103                 if (*((ushort *)raw)!=0x5545) {
1104                         printk(KERN_INFO "dos_read: no data mark after "
1105                                "sync (%d,%d,%d,%d) sc=%d\n",
1106                                hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1107                         return MFM_NOSYNC;
1108                 }
1109
1110                 raw+=2;  /* skip data mark (included in checksum) */
1111                 raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1112                 raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1113                 crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1114
1115                 if (crc != data_crc[0]) {
1116                         printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1117                                "sc=%d, %x %x\n", hdr.track, hdr.side,
1118                                hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1119                         printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1120                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1121                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1122                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1123                                ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1124                         return MFM_DATA;
1125                 }
1126         }
1127         return 0;
1128 }
1129
1130 static inline ushort dos_encode_byte(unsigned char byte)
1131 {
1132         register unsigned char *enc, b2, b1;
1133         register ushort word;
1134
1135         enc=mfmencode;
1136         b1=byte;
1137         b2=b1>>4;
1138         b1&=15;
1139         word=enc[b2] <<8 | enc [b1];
1140         return (word|((word&(256|64)) ? 0: 128));
1141 }
1142
1143 static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1144 {
1145         int i;
1146
1147         for (i = 0; i < len; i++) {
1148                 *dest=dos_encode_byte(*src++);
1149                 *dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1150                 dest++;
1151         }
1152 }
1153
1154 static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1155 {
1156         static struct dos_header hdr={0,0,0,2,0,
1157           {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1158         int i;
1159         static ushort crc[2]={0,0x4e4e};
1160
1161         drive&=3;
1162 /* id gap 1 */
1163 /* the MFM word before is always 9254 */
1164         for(i=0;i<6;i++)
1165                 *raw++=0xaaaaaaaa;
1166 /* 3 sync + 1 headermark */
1167         *raw++=0x44894489;
1168         *raw++=0x44895554;
1169
1170 /* fill in the variable parts of the header */
1171         hdr.track=unit[drive].track/unit[drive].type->heads;
1172         hdr.side=unit[drive].track%unit[drive].type->heads;
1173         hdr.sec=cnt+1;
1174         hdr.crc=dos_hdr_crc(&hdr);
1175
1176 /* header (without "magic") and id gap 2*/
1177         dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1178         raw+=14;
1179
1180 /*id gap 3 */
1181         for(i=0;i<6;i++)
1182                 *raw++=0xaaaaaaaa;
1183
1184 /* 3 syncs and 1 datamark */
1185         *raw++=0x44894489;
1186         *raw++=0x44895545;
1187
1188 /* data */
1189         dos_encode_block((ushort *)raw,
1190                          (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1191         raw+=256;
1192
1193 /*data crc + jd's special gap (long words :-/) */
1194         crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1195         dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1196         raw+=2;
1197
1198 /* data gap */
1199         for(i=0;i<38;i++)
1200                 *raw++=0x92549254;
1201
1202         return raw; /* wrote 652 MFM words */
1203 }
1204
1205 static void dos_write(int disk)
1206 {
1207         int cnt;
1208         unsigned long raw = (unsigned long) raw_buf;
1209         unsigned long *ptr=(unsigned long *)raw;
1210
1211         disk&=3;
1212 /* really gap4 + indexgap , but we write it first and round it up */
1213         for (cnt=0;cnt<425;cnt++)
1214                 *ptr++=0x92549254;
1215
1216 /* the following is just guessed */
1217         if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1218                 for(cnt=0;cnt<473;cnt++)
1219                         *ptr++=0x92549254;
1220
1221 /* now the index marks...*/
1222         for (cnt=0;cnt<20;cnt++)
1223                 *ptr++=0x92549254;
1224         for (cnt=0;cnt<6;cnt++)
1225                 *ptr++=0xaaaaaaaa;
1226         *ptr++=0x52245224;
1227         *ptr++=0x52245552;
1228         for (cnt=0;cnt<20;cnt++)
1229                 *ptr++=0x92549254;
1230
1231 /* sectors */
1232         for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1233                 ptr=ms_putsec(disk,ptr,cnt);
1234
1235         *(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1236 }
1237
1238 /*
1239  * Here comes the high level stuff (i.e. the filesystem interface)
1240  * and helper functions.
1241  * Normally this should be the only part that has to be adapted to
1242  * different kernel versions.
1243  */
1244
1245 /* FIXME: this assumes the drive is still spinning -
1246  * which is only true if we complete writing a track within three seconds
1247  */
1248 static void flush_track_callback(unsigned long nr)
1249 {
1250         nr&=3;
1251         writefromint = 1;
1252         if (!try_fdc(nr)) {
1253                 /* we might block in an interrupt, so try again later */
1254                 flush_track_timer[nr].expires = jiffies + 1;
1255                 add_timer(flush_track_timer + nr);
1256                 return;
1257         }
1258         get_fdc(nr);
1259         (*unit[nr].dtype->write_fkt)(nr);
1260         if (!raw_write(nr)) {
1261                 printk (KERN_NOTICE "floppy disk write protected\n");
1262                 writefromint = 0;
1263                 writepending = 0;
1264         }
1265         rel_fdc();
1266 }
1267
1268 static int non_int_flush_track (unsigned long nr)
1269 {
1270         unsigned long flags;
1271
1272         nr&=3;
1273         writefromint = 0;
1274         del_timer(&post_write_timer);
1275         get_fdc(nr);
1276         if (!fd_motor_on(nr)) {
1277                 writepending = 0;
1278                 rel_fdc();
1279                 return 0;
1280         }
1281         local_irq_save(flags);
1282         if (writepending != 2) {
1283                 local_irq_restore(flags);
1284                 (*unit[nr].dtype->write_fkt)(nr);
1285                 if (!raw_write(nr)) {
1286                         printk (KERN_NOTICE "floppy disk write protected "
1287                                 "in write!\n");
1288                         writepending = 0;
1289                         return 0;
1290                 }
1291                 wait_event(wait_fd_block, block_flag != 2);
1292         }
1293         else {
1294                 local_irq_restore(flags);
1295                 ms_delay(2); /* 2 ms post_write delay */
1296                 post_write(nr);
1297         }
1298         rel_fdc();
1299         return 1;
1300 }
1301
1302 static int get_track(int drive, int track)
1303 {
1304         int error, errcnt;
1305
1306         drive&=3;
1307         if (unit[drive].track == track)
1308                 return 0;
1309         get_fdc(drive);
1310         if (!fd_motor_on(drive)) {
1311                 rel_fdc();
1312                 return -1;
1313         }
1314
1315         if (unit[drive].dirty == 1) {
1316                 del_timer (flush_track_timer + drive);
1317                 non_int_flush_track (drive);
1318         }
1319         errcnt = 0;
1320         while (errcnt < MAX_ERRORS) {
1321                 if (!fd_seek(drive, track))
1322                         return -1;
1323                 raw_read(drive);
1324                 error = (*unit[drive].dtype->read_fkt)(drive);
1325                 if (error == 0) {
1326                         rel_fdc();
1327                         return 0;
1328                 }
1329                 /* Read Error Handling: recalibrate and try again */
1330                 unit[drive].track = -1;
1331                 errcnt++;
1332         }
1333         rel_fdc();
1334         return -1;
1335 }
1336
1337 static void redo_fd_request(void)
1338 {
1339         struct request *rq;
1340         unsigned int cnt, block, track, sector;
1341         int drive;
1342         struct amiga_floppy_struct *floppy;
1343         char *data;
1344         unsigned long flags;
1345         int err;
1346
1347 next_req:
1348         rq = blk_fetch_request(floppy_queue);
1349         if (!rq) {
1350                 /* Nothing left to do */
1351                 return;
1352         }
1353
1354         floppy = rq->rq_disk->private_data;
1355         drive = floppy - unit;
1356
1357 next_segment:
1358         /* Here someone could investigate to be more efficient */
1359         for (cnt = 0, err = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
1360 #ifdef DEBUG
1361                 printk("fd: sector %ld + %d requested for %s\n",
1362                        blk_rq_pos(rq), cnt,
1363                        (rq_data_dir(rq) == READ) ? "read" : "write");
1364 #endif
1365                 block = blk_rq_pos(rq) + cnt;
1366                 if ((int)block > floppy->blocks) {
1367                         err = -EIO;
1368                         break;
1369                 }
1370
1371                 track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1372                 sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1373                 data = rq->buffer + 512 * cnt;
1374 #ifdef DEBUG
1375                 printk("access to track %d, sector %d, with buffer at "
1376                        "0x%08lx\n", track, sector, data);
1377 #endif
1378
1379                 if (get_track(drive, track) == -1) {
1380                         err = -EIO;
1381                         break;
1382                 }
1383
1384                 if (rq_data_dir(rq) == READ) {
1385                         memcpy(data, floppy->trackbuf + sector * 512, 512);
1386                 } else {
1387                         memcpy(floppy->trackbuf + sector * 512, data, 512);
1388
1389                         /* keep the drive spinning while writes are scheduled */
1390                         if (!fd_motor_on(drive)) {
1391                                 err = -EIO;
1392                                 break;
1393                         }
1394                         /*
1395                          * setup a callback to write the track buffer
1396                          * after a short (1 tick) delay.
1397                          */
1398                         local_irq_save(flags);
1399
1400                         floppy->dirty = 1;
1401                         /* reset the timer */
1402                         mod_timer (flush_track_timer + drive, jiffies + 1);
1403                         local_irq_restore(flags);
1404                 }
1405         }
1406
1407         if (__blk_end_request_cur(rq, err))
1408                 goto next_segment;
1409         goto next_req;
1410 }
1411
1412 static void do_fd_request(struct request_queue * q)
1413 {
1414         redo_fd_request();
1415 }
1416
1417 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1418 {
1419         int drive = MINOR(bdev->bd_dev) & 3;
1420
1421         geo->heads = unit[drive].type->heads;
1422         geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1423         geo->cylinders = unit[drive].type->tracks;
1424         return 0;
1425 }
1426
1427 static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
1428                     unsigned int cmd, unsigned long param)
1429 {
1430         struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1431         int drive = p - unit;
1432         static struct floppy_struct getprm;
1433         void __user *argp = (void __user *)param;
1434
1435         switch(cmd){
1436         case FDFMTBEG:
1437                 get_fdc(drive);
1438                 if (fd_ref[drive] > 1) {
1439                         rel_fdc();
1440                         return -EBUSY;
1441                 }
1442                 fsync_bdev(bdev);
1443                 if (fd_motor_on(drive) == 0) {
1444                         rel_fdc();
1445                         return -ENODEV;
1446                 }
1447                 if (fd_calibrate(drive) == 0) {
1448                         rel_fdc();
1449                         return -ENXIO;
1450                 }
1451                 floppy_off(drive);
1452                 rel_fdc();
1453                 break;
1454         case FDFMTTRK:
1455                 if (param < p->type->tracks * p->type->heads)
1456                 {
1457                         get_fdc(drive);
1458                         if (fd_seek(drive,param) != 0){
1459                                 memset(p->trackbuf, FD_FILL_BYTE,
1460                                        p->dtype->sects * p->type->sect_mult * 512);
1461                                 non_int_flush_track(drive);
1462                         }
1463                         floppy_off(drive);
1464                         rel_fdc();
1465                 }
1466                 else
1467                         return -EINVAL;
1468                 break;
1469         case FDFMTEND:
1470                 floppy_off(drive);
1471                 invalidate_bdev(bdev);
1472                 break;
1473         case FDGETPRM:
1474                 memset((void *)&getprm, 0, sizeof (getprm));
1475                 getprm.track=p->type->tracks;
1476                 getprm.head=p->type->heads;
1477                 getprm.sect=p->dtype->sects * p->type->sect_mult;
1478                 getprm.size=p->blocks;
1479                 if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1480                         return -EFAULT;
1481                 break;
1482         case FDSETPRM:
1483         case FDDEFPRM:
1484                 return -EINVAL;
1485         case FDFLUSH: /* unconditionally, even if not needed */
1486                 del_timer (flush_track_timer + drive);
1487                 non_int_flush_track(drive);
1488                 break;
1489 #ifdef RAW_IOCTL
1490         case IOCTL_RAW_TRACK:
1491                 if (copy_to_user(argp, raw_buf, p->type->read_size))
1492                         return -EFAULT;
1493                 else
1494                         return p->type->read_size;
1495 #endif
1496         default:
1497                 printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1498                        cmd, drive);
1499                 return -ENOSYS;
1500         }
1501         return 0;
1502 }
1503
1504 static int fd_ioctl(struct block_device *bdev, fmode_t mode,
1505                              unsigned int cmd, unsigned long param)
1506 {
1507         int ret;
1508
1509         lock_kernel();
1510         ret = fd_locked_ioctl(bdev, mode, cmd, param);
1511         unlock_kernel();
1512
1513         return ret;
1514 }
1515
1516 static void fd_probe(int dev)
1517 {
1518         unsigned long code;
1519         int type;
1520         int drive;
1521
1522         drive = dev & 3;
1523         code = fd_get_drive_id(drive);
1524
1525         /* get drive type */
1526         for (type = 0; type < num_dr_types; type++)
1527                 if (drive_types[type].code == code)
1528                         break;
1529
1530         if (type >= num_dr_types) {
1531                 printk(KERN_WARNING "fd_probe: unsupported drive type "
1532                        "%08lx found\n", code);
1533                 unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1534                 return;
1535         }
1536
1537         unit[drive].type = drive_types + type;
1538         unit[drive].track = -1;
1539
1540         unit[drive].disk = -1;
1541         unit[drive].motor = 0;
1542         unit[drive].busy = 0;
1543         unit[drive].status = -1;
1544 }
1545
1546 /*
1547  * floppy_open check for aliasing (/dev/fd0 can be the same as
1548  * /dev/PS0 etc), and disallows simultaneous access to the same
1549  * drive with different device numbers.
1550  */
1551 static int floppy_open(struct block_device *bdev, fmode_t mode)
1552 {
1553         int drive = MINOR(bdev->bd_dev) & 3;
1554         int system =  (MINOR(bdev->bd_dev) & 4) >> 2;
1555         int old_dev;
1556         unsigned long flags;
1557
1558         lock_kernel();
1559         old_dev = fd_device[drive];
1560
1561         if (fd_ref[drive] && old_dev != system) {
1562                 unlock_kernel();
1563                 return -EBUSY;
1564         }
1565
1566         if (mode & (FMODE_READ|FMODE_WRITE)) {
1567                 check_disk_change(bdev);
1568                 if (mode & FMODE_WRITE) {
1569                         int wrprot;
1570
1571                         get_fdc(drive);
1572                         fd_select (drive);
1573                         wrprot = !(ciaa.pra & DSKPROT);
1574                         fd_deselect (drive);
1575                         rel_fdc();
1576
1577                         if (wrprot) {
1578                                 unlock_kernel();
1579                                 return -EROFS;
1580                         }
1581                 }
1582         }
1583
1584         local_irq_save(flags);
1585         fd_ref[drive]++;
1586         fd_device[drive] = system;
1587         local_irq_restore(flags);
1588
1589         unit[drive].dtype=&data_types[system];
1590         unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1591                 data_types[system].sects*unit[drive].type->sect_mult;
1592         set_capacity(unit[drive].gendisk, unit[drive].blocks);
1593
1594         printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1595                unit[drive].type->name, data_types[system].name);
1596
1597         unlock_kernel();
1598         return 0;
1599 }
1600
1601 static int floppy_release(struct gendisk *disk, fmode_t mode)
1602 {
1603         struct amiga_floppy_struct *p = disk->private_data;
1604         int drive = p - unit;
1605
1606         lock_kernel();
1607         if (unit[drive].dirty == 1) {
1608                 del_timer (flush_track_timer + drive);
1609                 non_int_flush_track (drive);
1610         }
1611   
1612         if (!fd_ref[drive]--) {
1613                 printk(KERN_CRIT "floppy_release with fd_ref == 0");
1614                 fd_ref[drive] = 0;
1615         }
1616 #ifdef MODULE
1617 /* the mod_use counter is handled this way */
1618         floppy_off (drive | 0x40000000);
1619 #endif
1620         unlock_kernel();
1621         return 0;
1622 }
1623
1624 /*
1625  * floppy-change is never called from an interrupt, so we can relax a bit
1626  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1627  * to the desired drive, but it will probably not survive the sleep if
1628  * several floppies are used at the same time: thus the loop.
1629  */
1630 static int amiga_floppy_change(struct gendisk *disk)
1631 {
1632         struct amiga_floppy_struct *p = disk->private_data;
1633         int drive = p - unit;
1634         int changed;
1635         static int first_time = 1;
1636
1637         if (first_time)
1638                 changed = first_time--;
1639         else {
1640                 get_fdc(drive);
1641                 fd_select (drive);
1642                 changed = !(ciaa.pra & DSKCHANGE);
1643                 fd_deselect (drive);
1644                 rel_fdc();
1645         }
1646
1647         if (changed) {
1648                 fd_probe(drive);
1649                 p->track = -1;
1650                 p->dirty = 0;
1651                 writepending = 0; /* if this was true before, too bad! */
1652                 writefromint = 0;
1653                 return 1;
1654         }
1655         return 0;
1656 }
1657
1658 static const struct block_device_operations floppy_fops = {
1659         .owner          = THIS_MODULE,
1660         .open           = floppy_open,
1661         .release        = floppy_release,
1662         .ioctl          = fd_ioctl,
1663         .getgeo         = fd_getgeo,
1664         .media_changed  = amiga_floppy_change,
1665 };
1666
1667 static int __init fd_probe_drives(void)
1668 {
1669         int drive,drives,nomem;
1670
1671         printk(KERN_INFO "FD: probing units\nfound ");
1672         drives=0;
1673         nomem=0;
1674         for(drive=0;drive<FD_MAX_UNITS;drive++) {
1675                 struct gendisk *disk;
1676                 fd_probe(drive);
1677                 if (unit[drive].type->code == FD_NODRIVE)
1678                         continue;
1679                 disk = alloc_disk(1);
1680                 if (!disk) {
1681                         unit[drive].type->code = FD_NODRIVE;
1682                         continue;
1683                 }
1684                 unit[drive].gendisk = disk;
1685                 drives++;
1686                 if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1687                         printk("no mem for ");
1688                         unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1689                         drives--;
1690                         nomem = 1;
1691                 }
1692                 printk("fd%d ",drive);
1693                 disk->major = FLOPPY_MAJOR;
1694                 disk->first_minor = drive;
1695                 disk->fops = &floppy_fops;
1696                 sprintf(disk->disk_name, "fd%d", drive);
1697                 disk->private_data = &unit[drive];
1698                 disk->queue = floppy_queue;
1699                 set_capacity(disk, 880*2);
1700                 add_disk(disk);
1701         }
1702         if ((drives > 0) || (nomem == 0)) {
1703                 if (drives == 0)
1704                         printk("no drives");
1705                 printk("\n");
1706                 return drives;
1707         }
1708         printk("\n");
1709         return -ENOMEM;
1710 }
1711  
1712 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1713 {
1714         int drive = *part & 3;
1715         if (unit[drive].type->code == FD_NODRIVE)
1716                 return NULL;
1717         *part = 0;
1718         return get_disk(unit[drive].gendisk);
1719 }
1720
1721 static int __init amiga_floppy_probe(struct platform_device *pdev)
1722 {
1723         int i, ret;
1724
1725         if (register_blkdev(FLOPPY_MAJOR,"fd"))
1726                 return -EBUSY;
1727
1728         ret = -ENOMEM;
1729         if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1730             NULL) {
1731                 printk("fd: cannot get chip mem buffer\n");
1732                 goto out_blkdev;
1733         }
1734
1735         ret = -EBUSY;
1736         if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1737                 printk("fd: cannot get irq for dma\n");
1738                 goto out_irq;
1739         }
1740
1741         if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1742                 printk("fd: cannot get irq for timer\n");
1743                 goto out_irq2;
1744         }
1745
1746         ret = -ENOMEM;
1747         floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
1748         if (!floppy_queue)
1749                 goto out_queue;
1750
1751         ret = -ENODEV;
1752         if (fd_probe_drives() < 1) /* No usable drives */
1753                 goto out_probe;
1754
1755         blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1756                                 floppy_find, NULL, NULL);
1757
1758         /* initialize variables */
1759         init_timer(&motor_on_timer);
1760         motor_on_timer.expires = 0;
1761         motor_on_timer.data = 0;
1762         motor_on_timer.function = motor_on_callback;
1763         for (i = 0; i < FD_MAX_UNITS; i++) {
1764                 init_timer(&motor_off_timer[i]);
1765                 motor_off_timer[i].expires = 0;
1766                 motor_off_timer[i].data = i|0x80000000;
1767                 motor_off_timer[i].function = fd_motor_off;
1768                 init_timer(&flush_track_timer[i]);
1769                 flush_track_timer[i].expires = 0;
1770                 flush_track_timer[i].data = i;
1771                 flush_track_timer[i].function = flush_track_callback;
1772
1773                 unit[i].track = -1;
1774         }
1775
1776         init_timer(&post_write_timer);
1777         post_write_timer.expires = 0;
1778         post_write_timer.data = 0;
1779         post_write_timer.function = post_write;
1780   
1781         for (i = 0; i < 128; i++)
1782                 mfmdecode[i]=255;
1783         for (i = 0; i < 16; i++)
1784                 mfmdecode[mfmencode[i]]=i;
1785
1786         /* make sure that disk DMA is enabled */
1787         custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1788
1789         /* init ms timer */
1790         ciaa.crb = 8; /* one-shot, stop */
1791         return 0;
1792
1793 out_probe:
1794         blk_cleanup_queue(floppy_queue);
1795 out_queue:
1796         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1797 out_irq2:
1798         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1799 out_irq:
1800         amiga_chip_free(raw_buf);
1801 out_blkdev:
1802         unregister_blkdev(FLOPPY_MAJOR,"fd");
1803         return ret;
1804 }
1805
1806 #if 0 /* not safe to unload */
1807 static int __exit amiga_floppy_remove(struct platform_device *pdev)
1808 {
1809         int i;
1810
1811         for( i = 0; i < FD_MAX_UNITS; i++) {
1812                 if (unit[i].type->code != FD_NODRIVE) {
1813                         del_gendisk(unit[i].gendisk);
1814                         put_disk(unit[i].gendisk);
1815                         kfree(unit[i].trackbuf);
1816                 }
1817         }
1818         blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
1819         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1820         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1821         custom.dmacon = DMAF_DISK; /* disable DMA */
1822         amiga_chip_free(raw_buf);
1823         blk_cleanup_queue(floppy_queue);
1824         unregister_blkdev(FLOPPY_MAJOR, "fd");
1825 }
1826 #endif
1827
1828 static struct platform_driver amiga_floppy_driver = {
1829         .driver   = {
1830                 .name   = "amiga-floppy",
1831                 .owner  = THIS_MODULE,
1832         },
1833 };
1834
1835 static int __init amiga_floppy_init(void)
1836 {
1837         return platform_driver_probe(&amiga_floppy_driver, amiga_floppy_probe);
1838 }
1839
1840 module_init(amiga_floppy_init);
1841
1842 #ifndef MODULE
1843 static int __init amiga_floppy_setup (char *str)
1844 {
1845         int n;
1846         if (!MACH_IS_AMIGA)
1847                 return 0;
1848         if (!get_option(&str, &n))
1849                 return 0;
1850         printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1851         fd_def_df0 = n;
1852         return 1;
1853 }
1854
1855 __setup("floppy=", amiga_floppy_setup);
1856 #endif
1857
1858 MODULE_ALIAS("platform:amiga-floppy");