m68k: amiflop - Get rid of sleep_on calls
[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
58 #include <linux/fd.h>
59 #include <linux/hdreg.h>
60 #include <linux/delay.h>
61 #include <linux/init.h>
62 #include <linux/amifdreg.h>
63 #include <linux/amifd.h>
64 #include <linux/buffer_head.h>
65 #include <linux/blkdev.h>
66 #include <linux/elevator.h>
67 #include <linux/interrupt.h>
68
69 #include <asm/setup.h>
70 #include <asm/uaccess.h>
71 #include <asm/amigahw.h>
72 #include <asm/amigaints.h>
73 #include <asm/irq.h>
74
75 #undef DEBUG /* print _LOTS_ of infos */
76
77 #define RAW_IOCTL
78 #ifdef RAW_IOCTL
79 #define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
80 #endif
81
82 /*
83  *  Defines
84  */
85
86 /*
87  *  Error codes
88  */
89 #define FD_OK           0       /* operation succeeded */
90 #define FD_ERROR        -1      /* general error (seek, read, write, etc) */
91 #define FD_NOUNIT       1       /* unit does not exist */
92 #define FD_UNITBUSY     2       /* unit already active */
93 #define FD_NOTACTIVE    3       /* unit is not active */
94 #define FD_NOTREADY     4       /* unit is not ready (motor not on/no disk) */
95
96 #define MFM_NOSYNC      1
97 #define MFM_HEADER      2
98 #define MFM_DATA        3
99 #define MFM_TRACK       4
100
101 /*
102  *  Floppy ID values
103  */
104 #define FD_NODRIVE      0x00000000  /* response when no unit is present */
105 #define FD_DD_3         0xffffffff  /* double-density 3.5" (880K) drive */
106 #define FD_HD_3         0x55555555  /* high-density 3.5" (1760K) drive */
107 #define FD_DD_5         0xaaaaaaaa  /* double-density 5.25" (440K) drive */
108
109 static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
110
111 module_param(fd_def_df0, ulong, 0);
112 MODULE_LICENSE("GPL");
113
114 static struct request_queue *floppy_queue;
115 #define QUEUE (floppy_queue)
116 #define CURRENT elv_next_request(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         unsigned int cnt, block, track, sector;
1339         int drive;
1340         struct amiga_floppy_struct *floppy;
1341         char *data;
1342         unsigned long flags;
1343
1344  repeat:
1345         if (!CURRENT) {
1346                 /* Nothing left to do */
1347                 return;
1348         }
1349
1350         floppy = CURRENT->rq_disk->private_data;
1351         drive = floppy - unit;
1352
1353         /* Here someone could investigate to be more efficient */
1354         for (cnt = 0; cnt < CURRENT->current_nr_sectors; cnt++) { 
1355 #ifdef DEBUG
1356                 printk("fd: sector %ld + %d requested for %s\n",
1357                        CURRENT->sector,cnt,
1358                        (rq_data_dir(CURRENT) == READ) ? "read" : "write");
1359 #endif
1360                 block = CURRENT->sector + cnt;
1361                 if ((int)block > floppy->blocks) {
1362                         end_request(CURRENT, 0);
1363                         goto repeat;
1364                 }
1365
1366                 track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1367                 sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1368                 data = CURRENT->buffer + 512 * cnt;
1369 #ifdef DEBUG
1370                 printk("access to track %d, sector %d, with buffer at "
1371                        "0x%08lx\n", track, sector, data);
1372 #endif
1373
1374                 if ((rq_data_dir(CURRENT) != READ) && (rq_data_dir(CURRENT) != WRITE)) {
1375                         printk(KERN_WARNING "do_fd_request: unknown command\n");
1376                         end_request(CURRENT, 0);
1377                         goto repeat;
1378                 }
1379                 if (get_track(drive, track) == -1) {
1380                         end_request(CURRENT, 0);
1381                         goto repeat;
1382                 }
1383
1384                 switch (rq_data_dir(CURRENT)) {
1385                 case READ:
1386                         memcpy(data, floppy->trackbuf + sector * 512, 512);
1387                         break;
1388
1389                 case WRITE:
1390                         memcpy(floppy->trackbuf + sector * 512, data, 512);
1391
1392                         /* keep the drive spinning while writes are scheduled */
1393                         if (!fd_motor_on(drive)) {
1394                                 end_request(CURRENT, 0);
1395                                 goto repeat;
1396                         }
1397                         /*
1398                          * setup a callback to write the track buffer
1399                          * after a short (1 tick) delay.
1400                          */
1401                         local_irq_save(flags);
1402
1403                         floppy->dirty = 1;
1404                         /* reset the timer */
1405                         mod_timer (flush_track_timer + drive, jiffies + 1);
1406                         local_irq_restore(flags);
1407                         break;
1408                 }
1409         }
1410         CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
1411         CURRENT->sector += CURRENT->current_nr_sectors;
1412
1413         end_request(CURRENT, 1);
1414         goto repeat;
1415 }
1416
1417 static void do_fd_request(struct request_queue * q)
1418 {
1419         redo_fd_request();
1420 }
1421
1422 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1423 {
1424         int drive = MINOR(bdev->bd_dev) & 3;
1425
1426         geo->heads = unit[drive].type->heads;
1427         geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1428         geo->cylinders = unit[drive].type->tracks;
1429         return 0;
1430 }
1431
1432 static int fd_ioctl(struct block_device *bdev, fmode_t mode,
1433                     unsigned int cmd, unsigned long param)
1434 {
1435         struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1436         int drive = p - unit;
1437         static struct floppy_struct getprm;
1438         void __user *argp = (void __user *)param;
1439
1440         switch(cmd){
1441         case FDFMTBEG:
1442                 get_fdc(drive);
1443                 if (fd_ref[drive] > 1) {
1444                         rel_fdc();
1445                         return -EBUSY;
1446                 }
1447                 fsync_bdev(bdev);
1448                 if (fd_motor_on(drive) == 0) {
1449                         rel_fdc();
1450                         return -ENODEV;
1451                 }
1452                 if (fd_calibrate(drive) == 0) {
1453                         rel_fdc();
1454                         return -ENXIO;
1455                 }
1456                 floppy_off(drive);
1457                 rel_fdc();
1458                 break;
1459         case FDFMTTRK:
1460                 if (param < p->type->tracks * p->type->heads)
1461                 {
1462                         get_fdc(drive);
1463                         if (fd_seek(drive,param) != 0){
1464                                 memset(p->trackbuf, FD_FILL_BYTE,
1465                                        p->dtype->sects * p->type->sect_mult * 512);
1466                                 non_int_flush_track(drive);
1467                         }
1468                         floppy_off(drive);
1469                         rel_fdc();
1470                 }
1471                 else
1472                         return -EINVAL;
1473                 break;
1474         case FDFMTEND:
1475                 floppy_off(drive);
1476                 invalidate_bdev(bdev);
1477                 break;
1478         case FDGETPRM:
1479                 memset((void *)&getprm, 0, sizeof (getprm));
1480                 getprm.track=p->type->tracks;
1481                 getprm.head=p->type->heads;
1482                 getprm.sect=p->dtype->sects * p->type->sect_mult;
1483                 getprm.size=p->blocks;
1484                 if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1485                         return -EFAULT;
1486                 break;
1487         case FDSETPRM:
1488         case FDDEFPRM:
1489                 return -EINVAL;
1490         case FDFLUSH: /* unconditionally, even if not needed */
1491                 del_timer (flush_track_timer + drive);
1492                 non_int_flush_track(drive);
1493                 break;
1494 #ifdef RAW_IOCTL
1495         case IOCTL_RAW_TRACK:
1496                 if (copy_to_user(argp, raw_buf, p->type->read_size))
1497                         return -EFAULT;
1498                 else
1499                         return p->type->read_size;
1500 #endif
1501         default:
1502                 printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1503                        cmd, drive);
1504                 return -ENOSYS;
1505         }
1506         return 0;
1507 }
1508
1509 static void fd_probe(int dev)
1510 {
1511         unsigned long code;
1512         int type;
1513         int drive;
1514
1515         drive = dev & 3;
1516         code = fd_get_drive_id(drive);
1517
1518         /* get drive type */
1519         for (type = 0; type < num_dr_types; type++)
1520                 if (drive_types[type].code == code)
1521                         break;
1522
1523         if (type >= num_dr_types) {
1524                 printk(KERN_WARNING "fd_probe: unsupported drive type "
1525                        "%08lx found\n", code);
1526                 unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1527                 return;
1528         }
1529
1530         unit[drive].type = drive_types + type;
1531         unit[drive].track = -1;
1532
1533         unit[drive].disk = -1;
1534         unit[drive].motor = 0;
1535         unit[drive].busy = 0;
1536         unit[drive].status = -1;
1537 }
1538
1539 /*
1540  * floppy_open check for aliasing (/dev/fd0 can be the same as
1541  * /dev/PS0 etc), and disallows simultaneous access to the same
1542  * drive with different device numbers.
1543  */
1544 static int floppy_open(struct block_device *bdev, fmode_t mode)
1545 {
1546         int drive = MINOR(bdev->bd_dev) & 3;
1547         int system =  (MINOR(bdev->bd_dev) & 4) >> 2;
1548         int old_dev;
1549         unsigned long flags;
1550
1551         old_dev = fd_device[drive];
1552
1553         if (fd_ref[drive] && old_dev != system)
1554                 return -EBUSY;
1555
1556         if (mode & (FMODE_READ|FMODE_WRITE)) {
1557                 check_disk_change(bdev);
1558                 if (mode & FMODE_WRITE) {
1559                         int wrprot;
1560
1561                         get_fdc(drive);
1562                         fd_select (drive);
1563                         wrprot = !(ciaa.pra & DSKPROT);
1564                         fd_deselect (drive);
1565                         rel_fdc();
1566
1567                         if (wrprot)
1568                                 return -EROFS;
1569                 }
1570         }
1571
1572         local_irq_save(flags);
1573         fd_ref[drive]++;
1574         fd_device[drive] = system;
1575         local_irq_restore(flags);
1576
1577         unit[drive].dtype=&data_types[system];
1578         unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1579                 data_types[system].sects*unit[drive].type->sect_mult;
1580         set_capacity(unit[drive].gendisk, unit[drive].blocks);
1581
1582         printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1583                unit[drive].type->name, data_types[system].name);
1584
1585         return 0;
1586 }
1587
1588 static int floppy_release(struct gendisk *disk, fmode_t mode)
1589 {
1590         struct amiga_floppy_struct *p = disk->private_data;
1591         int drive = p - unit;
1592
1593         if (unit[drive].dirty == 1) {
1594                 del_timer (flush_track_timer + drive);
1595                 non_int_flush_track (drive);
1596         }
1597   
1598         if (!fd_ref[drive]--) {
1599                 printk(KERN_CRIT "floppy_release with fd_ref == 0");
1600                 fd_ref[drive] = 0;
1601         }
1602 #ifdef MODULE
1603 /* the mod_use counter is handled this way */
1604         floppy_off (drive | 0x40000000);
1605 #endif
1606         return 0;
1607 }
1608
1609 /*
1610  * floppy-change is never called from an interrupt, so we can relax a bit
1611  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1612  * to the desired drive, but it will probably not survive the sleep if
1613  * several floppies are used at the same time: thus the loop.
1614  */
1615 static int amiga_floppy_change(struct gendisk *disk)
1616 {
1617         struct amiga_floppy_struct *p = disk->private_data;
1618         int drive = p - unit;
1619         int changed;
1620         static int first_time = 1;
1621
1622         if (first_time)
1623                 changed = first_time--;
1624         else {
1625                 get_fdc(drive);
1626                 fd_select (drive);
1627                 changed = !(ciaa.pra & DSKCHANGE);
1628                 fd_deselect (drive);
1629                 rel_fdc();
1630         }
1631
1632         if (changed) {
1633                 fd_probe(drive);
1634                 p->track = -1;
1635                 p->dirty = 0;
1636                 writepending = 0; /* if this was true before, too bad! */
1637                 writefromint = 0;
1638                 return 1;
1639         }
1640         return 0;
1641 }
1642
1643 static struct block_device_operations floppy_fops = {
1644         .owner          = THIS_MODULE,
1645         .open           = floppy_open,
1646         .release        = floppy_release,
1647         .locked_ioctl   = fd_ioctl,
1648         .getgeo         = fd_getgeo,
1649         .media_changed  = amiga_floppy_change,
1650 };
1651
1652 static int __init fd_probe_drives(void)
1653 {
1654         int drive,drives,nomem;
1655
1656         printk(KERN_INFO "FD: probing units\n" KERN_INFO "found ");
1657         drives=0;
1658         nomem=0;
1659         for(drive=0;drive<FD_MAX_UNITS;drive++) {
1660                 struct gendisk *disk;
1661                 fd_probe(drive);
1662                 if (unit[drive].type->code == FD_NODRIVE)
1663                         continue;
1664                 disk = alloc_disk(1);
1665                 if (!disk) {
1666                         unit[drive].type->code = FD_NODRIVE;
1667                         continue;
1668                 }
1669                 unit[drive].gendisk = disk;
1670                 drives++;
1671                 if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1672                         printk("no mem for ");
1673                         unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1674                         drives--;
1675                         nomem = 1;
1676                 }
1677                 printk("fd%d ",drive);
1678                 disk->major = FLOPPY_MAJOR;
1679                 disk->first_minor = drive;
1680                 disk->fops = &floppy_fops;
1681                 sprintf(disk->disk_name, "fd%d", drive);
1682                 disk->private_data = &unit[drive];
1683                 disk->queue = floppy_queue;
1684                 set_capacity(disk, 880*2);
1685                 add_disk(disk);
1686         }
1687         if ((drives > 0) || (nomem == 0)) {
1688                 if (drives == 0)
1689                         printk("no drives");
1690                 printk("\n");
1691                 return drives;
1692         }
1693         printk("\n");
1694         return -ENOMEM;
1695 }
1696  
1697 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1698 {
1699         int drive = *part & 3;
1700         if (unit[drive].type->code == FD_NODRIVE)
1701                 return NULL;
1702         *part = 0;
1703         return get_disk(unit[drive].gendisk);
1704 }
1705
1706 static int __init amiga_floppy_init(void)
1707 {
1708         int i, ret;
1709
1710         if (!MACH_IS_AMIGA)
1711                 return -ENODEV;
1712
1713         if (!AMIGAHW_PRESENT(AMI_FLOPPY))
1714                 return -ENODEV;
1715
1716         if (register_blkdev(FLOPPY_MAJOR,"fd"))
1717                 return -EBUSY;
1718
1719         /*
1720          *  We request DSKPTR, DSKLEN and DSKDATA only, because the other
1721          *  floppy registers are too spreaded over the custom register space
1722          */
1723         ret = -EBUSY;
1724         if (!request_mem_region(CUSTOM_PHYSADDR+0x20, 8, "amiflop [Paula]")) {
1725                 printk("fd: cannot get floppy registers\n");
1726                 goto out_blkdev;
1727         }
1728
1729         ret = -ENOMEM;
1730         if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1731             NULL) {
1732                 printk("fd: cannot get chip mem buffer\n");
1733                 goto out_memregion;
1734         }
1735
1736         ret = -EBUSY;
1737         if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1738                 printk("fd: cannot get irq for dma\n");
1739                 goto out_irq;
1740         }
1741
1742         if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1743                 printk("fd: cannot get irq for timer\n");
1744                 goto out_irq2;
1745         }
1746
1747         ret = -ENOMEM;
1748         floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
1749         if (!floppy_queue)
1750                 goto out_queue;
1751
1752         ret = -ENODEV;
1753         if (fd_probe_drives() < 1) /* No usable drives */
1754                 goto out_probe;
1755
1756         blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1757                                 floppy_find, NULL, NULL);
1758
1759         /* initialize variables */
1760         init_timer(&motor_on_timer);
1761         motor_on_timer.expires = 0;
1762         motor_on_timer.data = 0;
1763         motor_on_timer.function = motor_on_callback;
1764         for (i = 0; i < FD_MAX_UNITS; i++) {
1765                 init_timer(&motor_off_timer[i]);
1766                 motor_off_timer[i].expires = 0;
1767                 motor_off_timer[i].data = i|0x80000000;
1768                 motor_off_timer[i].function = fd_motor_off;
1769                 init_timer(&flush_track_timer[i]);
1770                 flush_track_timer[i].expires = 0;
1771                 flush_track_timer[i].data = i;
1772                 flush_track_timer[i].function = flush_track_callback;
1773
1774                 unit[i].track = -1;
1775         }
1776
1777         init_timer(&post_write_timer);
1778         post_write_timer.expires = 0;
1779         post_write_timer.data = 0;
1780         post_write_timer.function = post_write;
1781   
1782         for (i = 0; i < 128; i++)
1783                 mfmdecode[i]=255;
1784         for (i = 0; i < 16; i++)
1785                 mfmdecode[mfmencode[i]]=i;
1786
1787         /* make sure that disk DMA is enabled */
1788         custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1789
1790         /* init ms timer */
1791         ciaa.crb = 8; /* one-shot, stop */
1792         return 0;
1793
1794 out_probe:
1795         blk_cleanup_queue(floppy_queue);
1796 out_queue:
1797         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1798 out_irq2:
1799         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1800 out_irq:
1801         amiga_chip_free(raw_buf);
1802 out_memregion:
1803         release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1804 out_blkdev:
1805         unregister_blkdev(FLOPPY_MAJOR,"fd");
1806         return ret;
1807 }
1808
1809 module_init(amiga_floppy_init);
1810 #ifdef MODULE
1811
1812 #if 0 /* not safe to unload */
1813 void cleanup_module(void)
1814 {
1815         int i;
1816
1817         for( i = 0; i < FD_MAX_UNITS; i++) {
1818                 if (unit[i].type->code != FD_NODRIVE) {
1819                         del_gendisk(unit[i].gendisk);
1820                         put_disk(unit[i].gendisk);
1821                         kfree(unit[i].trackbuf);
1822                 }
1823         }
1824         blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
1825         free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1826         free_irq(IRQ_AMIGA_DSKBLK, NULL);
1827         custom.dmacon = DMAF_DISK; /* disable DMA */
1828         amiga_chip_free(raw_buf);
1829         blk_cleanup_queue(floppy_queue);
1830         release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1831         unregister_blkdev(FLOPPY_MAJOR, "fd");
1832 }
1833 #endif
1834
1835 #else
1836 static int __init amiga_floppy_setup (char *str)
1837 {
1838         int n;
1839         if (!MACH_IS_AMIGA)
1840                 return 0;
1841         if (!get_option(&str, &n))
1842                 return 0;
1843         printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1844         fd_def_df0 = n;
1845         return 1;
1846 }
1847
1848 __setup("floppy=", amiga_floppy_setup);
1849 #endif