xref: /linux/drivers/block/amiflop.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 
68 #include <asm/setup.h>
69 #include <asm/uaccess.h>
70 #include <asm/amigahw.h>
71 #include <asm/amigaints.h>
72 #include <asm/irq.h>
73 
74 #undef DEBUG /* print _LOTS_ of infos */
75 
76 #define RAW_IOCTL
77 #ifdef RAW_IOCTL
78 #define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
79 #endif
80 
81 /*
82  *  Defines
83  */
84 
85 /*
86  *  Error codes
87  */
88 #define FD_OK		0	/* operation succeeded */
89 #define FD_ERROR	-1	/* general error (seek, read, write, etc) */
90 #define FD_NOUNIT	1	/* unit does not exist */
91 #define FD_UNITBUSY	2	/* unit already active */
92 #define FD_NOTACTIVE	3	/* unit is not active */
93 #define FD_NOTREADY	4	/* unit is not ready (motor not on/no disk) */
94 
95 #define MFM_NOSYNC	1
96 #define MFM_HEADER	2
97 #define MFM_DATA	3
98 #define MFM_TRACK	4
99 
100 /*
101  *  Floppy ID values
102  */
103 #define FD_NODRIVE	0x00000000  /* response when no unit is present */
104 #define FD_DD_3 	0xffffffff  /* double-density 3.5" (880K) drive */
105 #define FD_HD_3 	0x55555555  /* high-density 3.5" (1760K) drive */
106 #define FD_DD_5 	0xaaaaaaaa  /* double-density 5.25" (440K) drive */
107 
108 static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
109 
110 module_param(fd_def_df0, ulong, 0);
111 MODULE_LICENSE("GPL");
112 
113 static struct request_queue *floppy_queue;
114 #define QUEUE (floppy_queue)
115 #define CURRENT elv_next_request(floppy_queue)
116 
117 /*
118  *  Macros
119  */
120 #define MOTOR_ON	(ciab.prb &= ~DSKMOTOR)
121 #define MOTOR_OFF	(ciab.prb |= DSKMOTOR)
122 #define SELECT(mask)    (ciab.prb &= ~mask)
123 #define DESELECT(mask)  (ciab.prb |= mask)
124 #define SELMASK(drive)  (1 << (3 + (drive & 3)))
125 
126 static struct fd_drive_type drive_types[] = {
127 /*  code	name	   tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
128 /*  warning: times are now in milliseconds (ms)                    */
129 { FD_DD_3,	"DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
130 { FD_HD_3,	"HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
131 { FD_DD_5,	"DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
132 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
133 };
134 static int num_dr_types = ARRAY_SIZE(drive_types);
135 
136 static int amiga_read(int), dos_read(int);
137 static void amiga_write(int), dos_write(int);
138 static struct fd_data_type data_types[] = {
139 	{ "Amiga", 11 , amiga_read, amiga_write},
140 	{ "MS-Dos", 9, dos_read, dos_write}
141 };
142 
143 /* current info on each unit */
144 static struct amiga_floppy_struct unit[FD_MAX_UNITS];
145 
146 static struct timer_list flush_track_timer[FD_MAX_UNITS];
147 static struct timer_list post_write_timer;
148 static struct timer_list motor_on_timer;
149 static struct timer_list motor_off_timer[FD_MAX_UNITS];
150 static int on_attempts;
151 
152 /* Synchronization of FDC access */
153 /* request loop (trackbuffer) */
154 static volatile int fdc_busy = -1;
155 static volatile int fdc_nested;
156 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
157 
158 static DECLARE_WAIT_QUEUE_HEAD(motor_wait);
159 
160 static volatile int selected = -1;	/* currently selected drive */
161 
162 static int writepending;
163 static int writefromint;
164 static char *raw_buf;
165 
166 static DEFINE_SPINLOCK(amiflop_lock);
167 
168 #define RAW_BUF_SIZE 30000  /* size of raw disk data */
169 
170 /*
171  * These are global variables, as that's the easiest way to give
172  * information to interrupts. They are the data used for the current
173  * request.
174  */
175 static volatile char block_flag;
176 static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
177 
178 /* MS-Dos MFM Coding tables (should go quick and easy) */
179 static unsigned char mfmencode[16]={
180 	0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
181 	0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
182 };
183 static unsigned char mfmdecode[128];
184 
185 /* floppy internal millisecond timer stuff */
186 static volatile int ms_busy = -1;
187 static DECLARE_WAIT_QUEUE_HEAD(ms_wait);
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, struct pt_regs *fp)
212 {
213 	ms_busy = -1;
214 	wake_up(&ms_wait);
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 	unsigned long flags;
223 	int ticks;
224 	if (ms > 0) {
225 		local_irq_save(flags);
226 		while (ms_busy == 0)
227 			sleep_on(&ms_wait);
228 		ms_busy = 0;
229 		local_irq_restore(flags);
230 		ticks = MS_TICKS*ms-1;
231 		ciaa.tblo=ticks%256;
232 		ciaa.tbhi=ticks/256;
233 		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
234 		sleep_on(&ms_wait);
235 	}
236 }
237 
238 /* Hardware semaphore */
239 
240 /* returns true when we would get the semaphore */
241 static inline int try_fdc(int drive)
242 {
243 	drive &= 3;
244 	return ((fdc_busy < 0) || (fdc_busy == drive));
245 }
246 
247 static void get_fdc(int drive)
248 {
249 	unsigned long flags;
250 
251 	drive &= 3;
252 #ifdef DEBUG
253 	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
254 #endif
255 	local_irq_save(flags);
256 	while (!try_fdc(drive))
257 		sleep_on(&fdc_wait);
258 	fdc_busy = drive;
259 	fdc_nested++;
260 	local_irq_restore(flags);
261 }
262 
263 static inline void rel_fdc(void)
264 {
265 #ifdef DEBUG
266 	if (fdc_nested == 0)
267 		printk("fd: unmatched rel_fdc\n");
268 	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
269 #endif
270 	fdc_nested--;
271 	if (fdc_nested == 0) {
272 		fdc_busy = -1;
273 		wake_up(&fdc_wait);
274 	}
275 }
276 
277 static void fd_select (int drive)
278 {
279 	unsigned char prb = ~0;
280 
281 	drive&=3;
282 #ifdef DEBUG
283 	printk("selecting %d\n",drive);
284 #endif
285 	if (drive == selected)
286 		return;
287 	get_fdc(drive);
288 	selected = drive;
289 
290 	if (unit[drive].track % 2 != 0)
291 		prb &= ~DSKSIDE;
292 	if (unit[drive].motor == 1)
293 		prb &= ~DSKMOTOR;
294 	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
295 	ciab.prb = prb;
296 	prb &= ~SELMASK(drive);
297 	ciab.prb = prb;
298 	rel_fdc();
299 }
300 
301 static void fd_deselect (int drive)
302 {
303 	unsigned char prb;
304 	unsigned long flags;
305 
306 	drive&=3;
307 #ifdef DEBUG
308 	printk("deselecting %d\n",drive);
309 #endif
310 	if (drive != selected) {
311 		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
312 		return;
313 	}
314 
315 	get_fdc(drive);
316 	local_irq_save(flags);
317 
318 	selected = -1;
319 
320 	prb = ciab.prb;
321 	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
322 	ciab.prb = prb;
323 
324 	local_irq_restore (flags);
325 	rel_fdc();
326 
327 }
328 
329 static void motor_on_callback(unsigned long nr)
330 {
331 	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
332 		wake_up (&motor_wait);
333 	} else {
334 		motor_on_timer.expires = jiffies + HZ/10;
335 		add_timer(&motor_on_timer);
336 	}
337 }
338 
339 static int fd_motor_on(int nr)
340 {
341 	nr &= 3;
342 
343 	del_timer(motor_off_timer + nr);
344 
345 	if (!unit[nr].motor) {
346 		unit[nr].motor = 1;
347 		fd_select(nr);
348 
349 		motor_on_timer.data = nr;
350 		mod_timer(&motor_on_timer, jiffies + HZ/2);
351 
352 		on_attempts = 10;
353 		sleep_on (&motor_wait);
354 		fd_deselect(nr);
355 	}
356 
357 	if (on_attempts == 0) {
358 		on_attempts = -1;
359 #if 0
360 		printk (KERN_ERR "motor_on failed, turning motor off\n");
361 		fd_motor_off (nr);
362 		return 0;
363 #else
364 		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
365 #endif
366 	}
367 
368 	return 1;
369 }
370 
371 static void fd_motor_off(unsigned long drive)
372 {
373 	long calledfromint;
374 #ifdef MODULE
375 	long decusecount;
376 
377 	decusecount = drive & 0x40000000;
378 #endif
379 	calledfromint = drive & 0x80000000;
380 	drive&=3;
381 	if (calledfromint && !try_fdc(drive)) {
382 		/* We would be blocked in an interrupt, so try again later */
383 		motor_off_timer[drive].expires = jiffies + 1;
384 		add_timer(motor_off_timer + drive);
385 		return;
386 	}
387 	unit[drive].motor = 0;
388 	fd_select(drive);
389 	udelay (1);
390 	fd_deselect(drive);
391 }
392 
393 static void floppy_off (unsigned int nr)
394 {
395 	int drive;
396 
397 	drive = nr & 3;
398 	/* called this way it is always from interrupt */
399 	motor_off_timer[drive].data = nr | 0x80000000;
400 	mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
401 }
402 
403 static int fd_calibrate(int drive)
404 {
405 	unsigned char prb;
406 	int n;
407 
408 	drive &= 3;
409 	get_fdc(drive);
410 	if (!fd_motor_on (drive))
411 		return 0;
412 	fd_select (drive);
413 	prb = ciab.prb;
414 	prb |= DSKSIDE;
415 	prb &= ~DSKDIREC;
416 	ciab.prb = prb;
417 	for (n = unit[drive].type->tracks/2; n != 0; --n) {
418 		if (ciaa.pra & DSKTRACK0)
419 			break;
420 		prb &= ~DSKSTEP;
421 		ciab.prb = prb;
422 		prb |= DSKSTEP;
423 		udelay (2);
424 		ciab.prb = prb;
425 		ms_delay(unit[drive].type->step_delay);
426 	}
427 	ms_delay (unit[drive].type->settle_time);
428 	prb |= DSKDIREC;
429 	n = unit[drive].type->tracks + 20;
430 	for (;;) {
431 		prb &= ~DSKSTEP;
432 		ciab.prb = prb;
433 		prb |= DSKSTEP;
434 		udelay (2);
435 		ciab.prb = prb;
436 		ms_delay(unit[drive].type->step_delay + 1);
437 		if ((ciaa.pra & DSKTRACK0) == 0)
438 			break;
439 		if (--n == 0) {
440 			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
441 			fd_motor_off (drive);
442 			unit[drive].track = -1;
443 			rel_fdc();
444 			return 0;
445 		}
446 	}
447 	unit[drive].track = 0;
448 	ms_delay(unit[drive].type->settle_time);
449 
450 	rel_fdc();
451 	fd_deselect(drive);
452 	return 1;
453 }
454 
455 static int fd_seek(int drive, int track)
456 {
457 	unsigned char prb;
458 	int cnt;
459 
460 #ifdef DEBUG
461 	printk("seeking drive %d to track %d\n",drive,track);
462 #endif
463 	drive &= 3;
464 	get_fdc(drive);
465 	if (unit[drive].track == track) {
466 		rel_fdc();
467 		return 1;
468 	}
469 	if (!fd_motor_on(drive)) {
470 		rel_fdc();
471 		return 0;
472 	}
473 	if (unit[drive].track < 0 && !fd_calibrate(drive)) {
474 		rel_fdc();
475 		return 0;
476 	}
477 
478 	fd_select (drive);
479 	cnt = unit[drive].track/2 - track/2;
480 	prb = ciab.prb;
481 	prb |= DSKSIDE | DSKDIREC;
482 	if (track % 2 != 0)
483 		prb &= ~DSKSIDE;
484 	if (cnt < 0) {
485 		cnt = - cnt;
486 		prb &= ~DSKDIREC;
487 	}
488 	ciab.prb = prb;
489 	if (track % 2 != unit[drive].track % 2)
490 		ms_delay (unit[drive].type->side_time);
491 	unit[drive].track = track;
492 	if (cnt == 0) {
493 		rel_fdc();
494 		fd_deselect(drive);
495 		return 1;
496 	}
497 	do {
498 		prb &= ~DSKSTEP;
499 		ciab.prb = prb;
500 		prb |= DSKSTEP;
501 		udelay (1);
502 		ciab.prb = prb;
503 		ms_delay (unit[drive].type->step_delay);
504 	} while (--cnt != 0);
505 	ms_delay (unit[drive].type->settle_time);
506 
507 	rel_fdc();
508 	fd_deselect(drive);
509 	return 1;
510 }
511 
512 static unsigned long fd_get_drive_id(int drive)
513 {
514 	int i;
515 	ulong id = 0;
516 
517   	drive&=3;
518   	get_fdc(drive);
519 	/* set up for ID */
520 	MOTOR_ON;
521 	udelay(2);
522 	SELECT(SELMASK(drive));
523 	udelay(2);
524 	DESELECT(SELMASK(drive));
525 	udelay(2);
526 	MOTOR_OFF;
527 	udelay(2);
528 	SELECT(SELMASK(drive));
529 	udelay(2);
530 	DESELECT(SELMASK(drive));
531 	udelay(2);
532 
533 	/* loop and read disk ID */
534 	for (i=0; i<32; i++) {
535 		SELECT(SELMASK(drive));
536 		udelay(2);
537 
538 		/* read and store value of DSKRDY */
539 		id <<= 1;
540 		id |= (ciaa.pra & DSKRDY) ? 0 : 1;	/* cia regs are low-active! */
541 
542 		DESELECT(SELMASK(drive));
543 	}
544 
545 	rel_fdc();
546 
547         /*
548          * RB: At least A500/A2000's df0: don't identify themselves.
549          * As every (real) Amiga has at least a 3.5" DD drive as df0:
550          * we default to that if df0: doesn't identify as a certain
551          * type.
552          */
553         if(drive == 0 && id == FD_NODRIVE)
554 	{
555                 id = fd_def_df0;
556                 printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
557 	}
558 	/* return the ID value */
559 	return (id);
560 }
561 
562 static irqreturn_t fd_block_done(int irq, void *dummy, struct pt_regs *fp)
563 {
564 	if (block_flag)
565 		custom.dsklen = 0x4000;
566 
567 	if (block_flag == 2) { /* writing */
568 		writepending = 2;
569 		post_write_timer.expires = jiffies + 1; /* at least 2 ms */
570 		post_write_timer.data = selected;
571 		add_timer(&post_write_timer);
572 	}
573 	else {                /* reading */
574 		block_flag = 0;
575 		wake_up (&wait_fd_block);
576 	}
577 	return IRQ_HANDLED;
578 }
579 
580 static void raw_read(int drive)
581 {
582 	drive&=3;
583 	get_fdc(drive);
584 	while (block_flag)
585 		sleep_on(&wait_fd_block);
586 	fd_select(drive);
587 	/* setup adkcon bits correctly */
588 	custom.adkcon = ADK_MSBSYNC;
589 	custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
590 
591 	custom.dsksync = MFM_SYNC;
592 
593 	custom.dsklen = 0;
594 	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
595 	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
596 	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
597 
598 	block_flag = 1;
599 
600 	while (block_flag)
601 		sleep_on (&wait_fd_block);
602 
603 	custom.dsklen = 0;
604 	fd_deselect(drive);
605 	rel_fdc();
606 }
607 
608 static int raw_write(int drive)
609 {
610 	ushort adk;
611 
612 	drive&=3;
613 	get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
614 	if ((ciaa.pra & DSKPROT) == 0) {
615 		rel_fdc();
616 		return 0;
617 	}
618 	while (block_flag)
619 		sleep_on(&wait_fd_block);
620 	fd_select(drive);
621 	/* clear adkcon bits */
622 	custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
623 	/* set appropriate adkcon bits */
624 	adk = ADK_SETCLR|ADK_FAST;
625 	if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
626 		adk |= ADK_PRECOMP1;
627 	else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
628 		adk |= ADK_PRECOMP0;
629 	custom.adkcon = adk;
630 
631 	custom.dsklen = DSKLEN_WRITE;
632 	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
633 	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
634 	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
635 
636 	block_flag = 2;
637 	return 1;
638 }
639 
640 /*
641  * to be called at least 2ms after the write has finished but before any
642  * other access to the hardware.
643  */
644 static void post_write (unsigned long drive)
645 {
646 #ifdef DEBUG
647 	printk("post_write for drive %ld\n",drive);
648 #endif
649 	drive &= 3;
650 	custom.dsklen = 0;
651 	block_flag = 0;
652 	writepending = 0;
653 	writefromint = 0;
654 	unit[drive].dirty = 0;
655 	wake_up(&wait_fd_block);
656 	fd_deselect(drive);
657 	rel_fdc(); /* corresponds to get_fdc() in raw_write */
658 }
659 
660 
661 /*
662  * The following functions are to convert the block contents into raw data
663  * written to disk and vice versa.
664  * (Add other formats here ;-))
665  */
666 
667 static unsigned long scan_sync(unsigned long raw, unsigned long end)
668 {
669 	ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
670 
671 	while (ptr < endp && *ptr++ != 0x4489)
672 		;
673 	if (ptr < endp) {
674 		while (*ptr == 0x4489 && ptr < endp)
675 			ptr++;
676 		return (ulong)ptr;
677 	}
678 	return 0;
679 }
680 
681 static inline unsigned long checksum(unsigned long *addr, int len)
682 {
683 	unsigned long csum = 0;
684 
685 	len /= sizeof(*addr);
686 	while (len-- > 0)
687 		csum ^= *addr++;
688 	csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
689 
690 	return csum;
691 }
692 
693 static unsigned long decode (unsigned long *data, unsigned long *raw,
694 			     int len)
695 {
696 	ulong *odd, *even;
697 
698 	/* convert length from bytes to longwords */
699 	len >>= 2;
700 	odd = raw;
701 	even = odd + len;
702 
703 	/* prepare return pointer */
704 	raw += len * 2;
705 
706 	do {
707 		*data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
708 	} while (--len != 0);
709 
710 	return (ulong)raw;
711 }
712 
713 struct header {
714 	unsigned char magic;
715 	unsigned char track;
716 	unsigned char sect;
717 	unsigned char ord;
718 	unsigned char labels[16];
719 	unsigned long hdrchk;
720 	unsigned long datachk;
721 };
722 
723 static int amiga_read(int drive)
724 {
725 	unsigned long raw;
726 	unsigned long end;
727 	int scnt;
728 	unsigned long csum;
729 	struct header hdr;
730 
731 	drive&=3;
732 	raw = (long) raw_buf;
733 	end = raw + unit[drive].type->read_size;
734 
735 	for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
736 		if (!(raw = scan_sync(raw, end))) {
737 			printk (KERN_INFO "can't find sync for sector %d\n", scnt);
738 			return MFM_NOSYNC;
739 		}
740 
741 		raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
742 		raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
743 		raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
744 		raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
745 		csum = checksum((ulong *)&hdr,
746 				(char *)&hdr.hdrchk-(char *)&hdr);
747 
748 #ifdef DEBUG
749 		printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
750 			hdr.magic, hdr.track, hdr.sect, hdr.ord,
751 			*(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
752 			*(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
753 			hdr.hdrchk, hdr.datachk);
754 #endif
755 
756 		if (hdr.hdrchk != csum) {
757 			printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
758 			return MFM_HEADER;
759 		}
760 
761 		/* verify track */
762 		if (hdr.track != unit[drive].track) {
763 			printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
764 			return MFM_TRACK;
765 		}
766 
767 		raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
768 			      (ulong *)raw, 512);
769 		csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
770 
771 		if (hdr.datachk != csum) {
772 			printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
773 			       hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
774 			       hdr.datachk, csum);
775 			printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
776 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
777 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
778 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
779 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
780 			return MFM_DATA;
781 		}
782 	}
783 
784 	return 0;
785 }
786 
787 static void encode(unsigned long data, unsigned long *dest)
788 {
789 	unsigned long data2;
790 
791 	data &= 0x55555555;
792 	data2 = data ^ 0x55555555;
793 	data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
794 
795 	if (*(dest - 1) & 0x00000001)
796 		data &= 0x7FFFFFFF;
797 
798 	*dest = data;
799 }
800 
801 static void encode_block(unsigned long *dest, unsigned long *src, int len)
802 {
803 	int cnt, to_cnt = 0;
804 	unsigned long data;
805 
806 	/* odd bits */
807 	for (cnt = 0; cnt < len / 4; cnt++) {
808 		data = src[cnt] >> 1;
809 		encode(data, dest + to_cnt++);
810 	}
811 
812 	/* even bits */
813 	for (cnt = 0; cnt < len / 4; cnt++) {
814 		data = src[cnt];
815 		encode(data, dest + to_cnt++);
816 	}
817 }
818 
819 static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
820 {
821 	struct header hdr;
822 	int i;
823 
824 	disk&=3;
825 	*raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
826 	raw++;
827 	*raw++ = 0x44894489;
828 
829 	hdr.magic = 0xFF;
830 	hdr.track = unit[disk].track;
831 	hdr.sect = cnt;
832 	hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
833 	for (i = 0; i < 16; i++)
834 		hdr.labels[i] = 0;
835 	hdr.hdrchk = checksum((ulong *)&hdr,
836 			      (char *)&hdr.hdrchk-(char *)&hdr);
837 	hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
838 
839 	encode_block(raw, (ulong *)&hdr.magic, 4);
840 	raw += 2;
841 	encode_block(raw, (ulong *)&hdr.labels, 16);
842 	raw += 8;
843 	encode_block(raw, (ulong *)&hdr.hdrchk, 4);
844 	raw += 2;
845 	encode_block(raw, (ulong *)&hdr.datachk, 4);
846 	raw += 2;
847 	encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
848 	raw += 256;
849 
850 	return raw;
851 }
852 
853 static void amiga_write(int disk)
854 {
855 	unsigned int cnt;
856 	unsigned long *ptr = (unsigned long *)raw_buf;
857 
858 	disk&=3;
859 	/* gap space */
860 	for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
861 		*ptr++ = 0xaaaaaaaa;
862 
863 	/* sectors */
864 	for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
865 		ptr = putsec (disk, ptr, cnt);
866 	*(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
867 }
868 
869 
870 struct dos_header {
871 	unsigned char track,   /* 0-80 */
872 		side,    /* 0-1 */
873 		sec,     /* 0-...*/
874 		len_desc;/* 2 */
875 	unsigned short crc;     /* on 68000 we got an alignment problem,
876 				   but this compiler solves it  by adding silently
877 				   adding a pad byte so data won't fit
878 				   and this took about 3h to discover.... */
879 	unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
880 };
881 
882 /* crc routines are borrowed from the messydos-handler  */
883 
884 /* excerpt from the messydos-device
885 ; The CRC is computed not only over the actual data, but including
886 ; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
887 ; As we don't read or encode these fields into our buffers, we have to
888 ; preload the registers containing the CRC with the values they would have
889 ; after stepping over these fields.
890 ;
891 ; How CRCs "really" work:
892 ;
893 ; First, you should regard a bitstring as a series of coefficients of
894 ; polynomials. We calculate with these polynomials in modulo-2
895 ; arithmetic, in which both add and subtract are done the same as
896 ; exclusive-or. Now, we modify our data (a very long polynomial) in
897 ; such a way that it becomes divisible by the CCITT-standard 16-bit
898 ;		 16   12   5
899 ; polynomial:	x  + x	+ x + 1, represented by $11021. The easiest
900 ; way to do this would be to multiply (using proper arithmetic) our
901 ; datablock with $11021. So we have:
902 ;   data * $11021		 =
903 ;   data * ($10000 + $1021)      =
904 ;   data * $10000 + data * $1021
905 ; The left part of this is simple: Just add two 0 bytes. But then
906 ; the right part (data $1021) remains difficult and even could have
907 ; a carry into the left part. The solution is to use a modified
908 ; multiplication, which has a result that is not correct, but with
909 ; a difference of any multiple of $11021. We then only need to keep
910 ; the 16 least significant bits of the result.
911 ;
912 ; The following algorithm does this for us:
913 ;
914 ;   unsigned char *data, c, crclo, crchi;
915 ;   while (not done) {
916 ;	c = *data++ + crchi;
917 ;	crchi = (@ c) >> 8 + crclo;
918 ;	crclo = @ c;
919 ;   }
920 ;
921 ; Remember, + is done with EOR, the @ operator is in two tables (high
922 ; and low byte separately), which is calculated as
923 ;
924 ;      $1021 * (c & $F0)
925 ;  xor $1021 * (c & $0F)
926 ;  xor $1021 * (c >> 4)         (* is regular multiplication)
927 ;
928 ;
929 ; Anyway, the end result is the same as the remainder of the division of
930 ; the data by $11021. I am afraid I need to study theory a bit more...
931 
932 
933 my only works was to code this from manx to C....
934 
935 */
936 
937 static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
938 {
939 	static unsigned char CRCTable1[] = {
940 		0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
941 		0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
942 		0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
943 		0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
944 		0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
945 		0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
946 		0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
947 		0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
948 		0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
949 		0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
950 		0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
951 		0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
952 		0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
953 		0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
954 		0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
955 		0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
956 	};
957 
958 	static unsigned char CRCTable2[] = {
959 		0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
960 		0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
961 		0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
962 		0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
963 		0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
964 		0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
965 		0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
966 		0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
967 		0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
968 		0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
969 		0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
970 		0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
971 		0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
972 		0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
973 		0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
974 		0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
975 	};
976 
977 /* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
978 	register int i;
979 	register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
980 
981 	CRCT1=CRCTable1;
982 	CRCT2=CRCTable2;
983 	data=data_a3;
984 	crcl=data_d1;
985 	crch=data_d0;
986 	for (i=data_d3; i>=0; i--) {
987 		c = (*data++) ^ crch;
988 		crch = CRCT1[c] ^ crcl;
989 		crcl = CRCT2[c];
990 	}
991 	return (crch<<8)|crcl;
992 }
993 
994 static inline ushort dos_hdr_crc (struct dos_header *hdr)
995 {
996 	return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
997 }
998 
999 static inline ushort dos_data_crc(unsigned char *data)
1000 {
1001 	return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
1002 }
1003 
1004 static inline unsigned char dos_decode_byte(ushort word)
1005 {
1006 	register ushort w2;
1007 	register unsigned char byte;
1008 	register unsigned char *dec = mfmdecode;
1009 
1010 	w2=word;
1011 	w2>>=8;
1012 	w2&=127;
1013 	byte = dec[w2];
1014 	byte <<= 4;
1015 	w2 = word & 127;
1016 	byte |= dec[w2];
1017 	return byte;
1018 }
1019 
1020 static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1021 {
1022 	int i;
1023 
1024 	for (i = 0; i < len; i++)
1025 		*data++=dos_decode_byte(*raw++);
1026 	return ((ulong)raw);
1027 }
1028 
1029 #ifdef DEBUG
1030 static void dbg(unsigned long ptr)
1031 {
1032 	printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1033 	       ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1034 	       ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1035 }
1036 #endif
1037 
1038 static int dos_read(int drive)
1039 {
1040 	unsigned long end;
1041 	unsigned long raw;
1042 	int scnt;
1043 	unsigned short crc,data_crc[2];
1044 	struct dos_header hdr;
1045 
1046 	drive&=3;
1047 	raw = (long) raw_buf;
1048 	end = raw + unit[drive].type->read_size;
1049 
1050 	for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1051 		do { /* search for the right sync of each sec-hdr */
1052 			if (!(raw = scan_sync (raw, end))) {
1053 				printk(KERN_INFO "dos_read: no hdr sync on "
1054 				       "track %d, unit %d for sector %d\n",
1055 				       unit[drive].track,drive,scnt);
1056 				return MFM_NOSYNC;
1057 			}
1058 #ifdef DEBUG
1059 			dbg(raw);
1060 #endif
1061 		} while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1062 		raw+=2; /* skip over headermark */
1063 		raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1064 		crc = dos_hdr_crc(&hdr);
1065 
1066 #ifdef DEBUG
1067 		printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1068 		       hdr.sec, hdr.len_desc, hdr.crc);
1069 #endif
1070 
1071 		if (crc != hdr.crc) {
1072 			printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1073 			       hdr.crc, crc);
1074 			return MFM_HEADER;
1075 		}
1076 		if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1077 			printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1078 			       hdr.track,
1079 			       unit[drive].track/unit[drive].type->heads);
1080 			return MFM_TRACK;
1081 		}
1082 
1083 		if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1084 			printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1085 			       hdr.side,
1086 			       unit[drive].track%unit[drive].type->heads);
1087 			return MFM_TRACK;
1088 		}
1089 
1090 		if (hdr.len_desc != 2) {
1091 			printk(KERN_INFO "dos_read: unknown sector len "
1092 			       "descriptor %d\n", hdr.len_desc);
1093 			return MFM_DATA;
1094 		}
1095 #ifdef DEBUG
1096 		printk("hdr accepted\n");
1097 #endif
1098 		if (!(raw = scan_sync (raw, end))) {
1099 			printk(KERN_INFO "dos_read: no data sync on track "
1100 			       "%d, unit %d for sector%d, disk sector %d\n",
1101 			       unit[drive].track, drive, scnt, hdr.sec);
1102 			return MFM_NOSYNC;
1103 		}
1104 #ifdef DEBUG
1105 		dbg(raw);
1106 #endif
1107 
1108 		if (*((ushort *)raw)!=0x5545) {
1109 			printk(KERN_INFO "dos_read: no data mark after "
1110 			       "sync (%d,%d,%d,%d) sc=%d\n",
1111 			       hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1112 			return MFM_NOSYNC;
1113 		}
1114 
1115 		raw+=2;  /* skip data mark (included in checksum) */
1116 		raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1117 		raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1118 		crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1119 
1120 		if (crc != data_crc[0]) {
1121 			printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1122 			       "sc=%d, %x %x\n", hdr.track, hdr.side,
1123 			       hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1124 			printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1125 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1126 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1127 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1128 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1129 			return MFM_DATA;
1130 		}
1131 	}
1132 	return 0;
1133 }
1134 
1135 static inline ushort dos_encode_byte(unsigned char byte)
1136 {
1137 	register unsigned char *enc, b2, b1;
1138 	register ushort word;
1139 
1140 	enc=mfmencode;
1141 	b1=byte;
1142 	b2=b1>>4;
1143 	b1&=15;
1144 	word=enc[b2] <<8 | enc [b1];
1145 	return (word|((word&(256|64)) ? 0: 128));
1146 }
1147 
1148 static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1149 {
1150 	int i;
1151 
1152 	for (i = 0; i < len; i++) {
1153 		*dest=dos_encode_byte(*src++);
1154 		*dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1155 		dest++;
1156 	}
1157 }
1158 
1159 static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1160 {
1161 	static struct dos_header hdr={0,0,0,2,0,
1162 	  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1163 	int i;
1164 	static ushort crc[2]={0,0x4e4e};
1165 
1166 	drive&=3;
1167 /* id gap 1 */
1168 /* the MFM word before is always 9254 */
1169 	for(i=0;i<6;i++)
1170 		*raw++=0xaaaaaaaa;
1171 /* 3 sync + 1 headermark */
1172 	*raw++=0x44894489;
1173 	*raw++=0x44895554;
1174 
1175 /* fill in the variable parts of the header */
1176 	hdr.track=unit[drive].track/unit[drive].type->heads;
1177 	hdr.side=unit[drive].track%unit[drive].type->heads;
1178 	hdr.sec=cnt+1;
1179 	hdr.crc=dos_hdr_crc(&hdr);
1180 
1181 /* header (without "magic") and id gap 2*/
1182 	dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1183 	raw+=14;
1184 
1185 /*id gap 3 */
1186 	for(i=0;i<6;i++)
1187 		*raw++=0xaaaaaaaa;
1188 
1189 /* 3 syncs and 1 datamark */
1190 	*raw++=0x44894489;
1191 	*raw++=0x44895545;
1192 
1193 /* data */
1194 	dos_encode_block((ushort *)raw,
1195 			 (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1196 	raw+=256;
1197 
1198 /*data crc + jd's special gap (long words :-/) */
1199 	crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1200 	dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1201 	raw+=2;
1202 
1203 /* data gap */
1204 	for(i=0;i<38;i++)
1205 		*raw++=0x92549254;
1206 
1207 	return raw; /* wrote 652 MFM words */
1208 }
1209 
1210 static void dos_write(int disk)
1211 {
1212 	int cnt;
1213 	unsigned long raw = (unsigned long) raw_buf;
1214 	unsigned long *ptr=(unsigned long *)raw;
1215 
1216 	disk&=3;
1217 /* really gap4 + indexgap , but we write it first and round it up */
1218 	for (cnt=0;cnt<425;cnt++)
1219 		*ptr++=0x92549254;
1220 
1221 /* the following is just guessed */
1222 	if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1223 		for(cnt=0;cnt<473;cnt++)
1224 			*ptr++=0x92549254;
1225 
1226 /* now the index marks...*/
1227 	for (cnt=0;cnt<20;cnt++)
1228 		*ptr++=0x92549254;
1229 	for (cnt=0;cnt<6;cnt++)
1230 		*ptr++=0xaaaaaaaa;
1231 	*ptr++=0x52245224;
1232 	*ptr++=0x52245552;
1233 	for (cnt=0;cnt<20;cnt++)
1234 		*ptr++=0x92549254;
1235 
1236 /* sectors */
1237 	for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1238 		ptr=ms_putsec(disk,ptr,cnt);
1239 
1240 	*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1241 }
1242 
1243 /*
1244  * Here comes the high level stuff (i.e. the filesystem interface)
1245  * and helper functions.
1246  * Normally this should be the only part that has to be adapted to
1247  * different kernel versions.
1248  */
1249 
1250 /* FIXME: this assumes the drive is still spinning -
1251  * which is only true if we complete writing a track within three seconds
1252  */
1253 static void flush_track_callback(unsigned long nr)
1254 {
1255 	nr&=3;
1256 	writefromint = 1;
1257 	if (!try_fdc(nr)) {
1258 		/* we might block in an interrupt, so try again later */
1259 		flush_track_timer[nr].expires = jiffies + 1;
1260 		add_timer(flush_track_timer + nr);
1261 		return;
1262 	}
1263 	get_fdc(nr);
1264 	(*unit[nr].dtype->write_fkt)(nr);
1265 	if (!raw_write(nr)) {
1266 		printk (KERN_NOTICE "floppy disk write protected\n");
1267 		writefromint = 0;
1268 		writepending = 0;
1269 	}
1270 	rel_fdc();
1271 }
1272 
1273 static int non_int_flush_track (unsigned long nr)
1274 {
1275 	unsigned long flags;
1276 
1277 	nr&=3;
1278 	writefromint = 0;
1279 	del_timer(&post_write_timer);
1280 	get_fdc(nr);
1281 	if (!fd_motor_on(nr)) {
1282 		writepending = 0;
1283 		rel_fdc();
1284 		return 0;
1285 	}
1286 	local_irq_save(flags);
1287 	if (writepending != 2) {
1288 		local_irq_restore(flags);
1289 		(*unit[nr].dtype->write_fkt)(nr);
1290 		if (!raw_write(nr)) {
1291 			printk (KERN_NOTICE "floppy disk write protected "
1292 				"in write!\n");
1293 			writepending = 0;
1294 			return 0;
1295 		}
1296 		while (block_flag == 2)
1297 			sleep_on (&wait_fd_block);
1298 	}
1299 	else {
1300 		local_irq_restore(flags);
1301 		ms_delay(2); /* 2 ms post_write delay */
1302 		post_write(nr);
1303 	}
1304 	rel_fdc();
1305 	return 1;
1306 }
1307 
1308 static int get_track(int drive, int track)
1309 {
1310 	int error, errcnt;
1311 
1312 	drive&=3;
1313 	if (unit[drive].track == track)
1314 		return 0;
1315 	get_fdc(drive);
1316 	if (!fd_motor_on(drive)) {
1317 		rel_fdc();
1318 		return -1;
1319 	}
1320 
1321 	if (unit[drive].dirty == 1) {
1322 		del_timer (flush_track_timer + drive);
1323 		non_int_flush_track (drive);
1324 	}
1325 	errcnt = 0;
1326 	while (errcnt < MAX_ERRORS) {
1327 		if (!fd_seek(drive, track))
1328 			return -1;
1329 		raw_read(drive);
1330 		error = (*unit[drive].dtype->read_fkt)(drive);
1331 		if (error == 0) {
1332 			rel_fdc();
1333 			return 0;
1334 		}
1335 		/* Read Error Handling: recalibrate and try again */
1336 		unit[drive].track = -1;
1337 		errcnt++;
1338 	}
1339 	rel_fdc();
1340 	return -1;
1341 }
1342 
1343 static void redo_fd_request(void)
1344 {
1345 	unsigned int cnt, block, track, sector;
1346 	int drive;
1347 	struct amiga_floppy_struct *floppy;
1348 	char *data;
1349 	unsigned long flags;
1350 
1351  repeat:
1352 	if (!CURRENT) {
1353 		/* Nothing left to do */
1354 		return;
1355 	}
1356 
1357 	floppy = CURRENT->rq_disk->private_data;
1358 	drive = floppy - unit;
1359 
1360 	/* Here someone could investigate to be more efficient */
1361 	for (cnt = 0; cnt < CURRENT->current_nr_sectors; cnt++) {
1362 #ifdef DEBUG
1363 		printk("fd: sector %ld + %d requested for %s\n",
1364 		       CURRENT->sector,cnt,
1365 		       (CURRENT->cmd==READ)?"read":"write");
1366 #endif
1367 		block = CURRENT->sector + cnt;
1368 		if ((int)block > floppy->blocks) {
1369 			end_request(CURRENT, 0);
1370 			goto repeat;
1371 		}
1372 
1373 		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1374 		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1375 		data = CURRENT->buffer + 512 * cnt;
1376 #ifdef DEBUG
1377 		printk("access to track %d, sector %d, with buffer at "
1378 		       "0x%08lx\n", track, sector, data);
1379 #endif
1380 
1381 		if ((rq_data_dir(CURRENT) != READ) && (rq_data_dir(CURRENT) != WRITE)) {
1382 			printk(KERN_WARNING "do_fd_request: unknown command\n");
1383 			end_request(CURRENT, 0);
1384 			goto repeat;
1385 		}
1386 		if (get_track(drive, track) == -1) {
1387 			end_request(CURRENT, 0);
1388 			goto repeat;
1389 		}
1390 
1391 		switch (rq_data_dir(CURRENT)) {
1392 		case READ:
1393 			memcpy(data, floppy->trackbuf + sector * 512, 512);
1394 			break;
1395 
1396 		case WRITE:
1397 			memcpy(floppy->trackbuf + sector * 512, data, 512);
1398 
1399 			/* keep the drive spinning while writes are scheduled */
1400 			if (!fd_motor_on(drive)) {
1401 				end_request(CURRENT, 0);
1402 				goto repeat;
1403 			}
1404 			/*
1405 			 * setup a callback to write the track buffer
1406 			 * after a short (1 tick) delay.
1407 			 */
1408 			local_irq_save(flags);
1409 
1410 			floppy->dirty = 1;
1411 		        /* reset the timer */
1412 			mod_timer (flush_track_timer + drive, jiffies + 1);
1413 			local_irq_restore(flags);
1414 			break;
1415 		}
1416 	}
1417 	CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
1418 	CURRENT->sector += CURRENT->current_nr_sectors;
1419 
1420 	end_request(CURRENT, 1);
1421 	goto repeat;
1422 }
1423 
1424 static void do_fd_request(request_queue_t * q)
1425 {
1426 	redo_fd_request();
1427 }
1428 
1429 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1430 {
1431 	int drive = MINOR(bdev->bd_dev) & 3;
1432 
1433 	geo->heads = unit[drive].type->heads;
1434 	geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1435 	geo->cylinders = unit[drive].type->tracks;
1436 	return 0;
1437 }
1438 
1439 static int fd_ioctl(struct inode *inode, struct file *filp,
1440 		    unsigned int cmd, unsigned long param)
1441 {
1442 	int drive = iminor(inode) & 3;
1443 	static struct floppy_struct getprm;
1444 	void __user *argp = (void __user *)param;
1445 
1446 	switch(cmd){
1447 	case FDFMTBEG:
1448 		get_fdc(drive);
1449 		if (fd_ref[drive] > 1) {
1450 			rel_fdc();
1451 			return -EBUSY;
1452 		}
1453 		fsync_bdev(inode->i_bdev);
1454 		if (fd_motor_on(drive) == 0) {
1455 			rel_fdc();
1456 			return -ENODEV;
1457 		}
1458 		if (fd_calibrate(drive) == 0) {
1459 			rel_fdc();
1460 			return -ENXIO;
1461 		}
1462 		floppy_off(drive);
1463 		rel_fdc();
1464 		break;
1465 	case FDFMTTRK:
1466 		if (param < unit[drive].type->tracks * unit[drive].type->heads)
1467 		{
1468 			get_fdc(drive);
1469 			if (fd_seek(drive,param) != 0){
1470 				memset(unit[drive].trackbuf, FD_FILL_BYTE,
1471 				       unit[drive].dtype->sects * unit[drive].type->sect_mult * 512);
1472 				non_int_flush_track(drive);
1473 			}
1474 			floppy_off(drive);
1475 			rel_fdc();
1476 		}
1477 		else
1478 			return -EINVAL;
1479 		break;
1480 	case FDFMTEND:
1481 		floppy_off(drive);
1482 		invalidate_bdev(inode->i_bdev, 0);
1483 		break;
1484 	case FDGETPRM:
1485 		memset((void *)&getprm, 0, sizeof (getprm));
1486 		getprm.track=unit[drive].type->tracks;
1487 		getprm.head=unit[drive].type->heads;
1488 		getprm.sect=unit[drive].dtype->sects * unit[drive].type->sect_mult;
1489 		getprm.size=unit[drive].blocks;
1490 		if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1491 			return -EFAULT;
1492 		break;
1493 	case FDSETPRM:
1494 	case FDDEFPRM:
1495 		return -EINVAL;
1496 	case FDFLUSH: /* unconditionally, even if not needed */
1497 		del_timer (flush_track_timer + drive);
1498 		non_int_flush_track(drive);
1499 		break;
1500 #ifdef RAW_IOCTL
1501 	case IOCTL_RAW_TRACK:
1502 		if (copy_to_user(argp, raw_buf, unit[drive].type->read_size))
1503 			return -EFAULT;
1504 		else
1505 			return unit[drive].type->read_size;
1506 #endif
1507 	default:
1508 		printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1509 		       cmd, drive);
1510 		return -ENOSYS;
1511 	}
1512 	return 0;
1513 }
1514 
1515 static void fd_probe(int dev)
1516 {
1517 	unsigned long code;
1518 	int type;
1519 	int drive;
1520 
1521 	drive = dev & 3;
1522 	code = fd_get_drive_id(drive);
1523 
1524 	/* get drive type */
1525 	for (type = 0; type < num_dr_types; type++)
1526 		if (drive_types[type].code == code)
1527 			break;
1528 
1529 	if (type >= num_dr_types) {
1530 		printk(KERN_WARNING "fd_probe: unsupported drive type "
1531 		       "%08lx found\n", code);
1532 		unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1533 		return;
1534 	}
1535 
1536 	unit[drive].type = drive_types + type;
1537 	unit[drive].track = -1;
1538 
1539 	unit[drive].disk = -1;
1540 	unit[drive].motor = 0;
1541 	unit[drive].busy = 0;
1542 	unit[drive].status = -1;
1543 }
1544 
1545 /*
1546  * floppy_open check for aliasing (/dev/fd0 can be the same as
1547  * /dev/PS0 etc), and disallows simultaneous access to the same
1548  * drive with different device numbers.
1549  */
1550 static int floppy_open(struct inode *inode, struct file *filp)
1551 {
1552 	int drive = iminor(inode) & 3;
1553 	int system =  (iminor(inode) & 4) >> 2;
1554 	int old_dev;
1555 	unsigned long flags;
1556 
1557 	old_dev = fd_device[drive];
1558 
1559 	if (fd_ref[drive] && old_dev != system)
1560 		return -EBUSY;
1561 
1562 	if (filp && filp->f_mode & 3) {
1563 		check_disk_change(inode->i_bdev);
1564 		if (filp->f_mode & 2 ) {
1565 			int wrprot;
1566 
1567 			get_fdc(drive);
1568 			fd_select (drive);
1569 			wrprot = !(ciaa.pra & DSKPROT);
1570 			fd_deselect (drive);
1571 			rel_fdc();
1572 
1573 			if (wrprot)
1574 				return -EROFS;
1575 		}
1576 	}
1577 
1578 	local_irq_save(flags);
1579 	fd_ref[drive]++;
1580 	fd_device[drive] = system;
1581 	local_irq_restore(flags);
1582 
1583 	unit[drive].dtype=&data_types[system];
1584 	unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1585 		data_types[system].sects*unit[drive].type->sect_mult;
1586 	set_capacity(unit[drive].gendisk, unit[drive].blocks);
1587 
1588 	printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1589 	       unit[drive].type->name, data_types[system].name);
1590 
1591 	return 0;
1592 }
1593 
1594 static int floppy_release(struct inode * inode, struct file * filp)
1595 {
1596 	int drive = iminor(inode) & 3;
1597 
1598 	if (unit[drive].dirty == 1) {
1599 		del_timer (flush_track_timer + drive);
1600 		non_int_flush_track (drive);
1601 	}
1602 
1603 	if (!fd_ref[drive]--) {
1604 		printk(KERN_CRIT "floppy_release with fd_ref == 0");
1605 		fd_ref[drive] = 0;
1606 	}
1607 #ifdef MODULE
1608 /* the mod_use counter is handled this way */
1609 	floppy_off (drive | 0x40000000);
1610 #endif
1611 	return 0;
1612 }
1613 
1614 /*
1615  * floppy-change is never called from an interrupt, so we can relax a bit
1616  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1617  * to the desired drive, but it will probably not survive the sleep if
1618  * several floppies are used at the same time: thus the loop.
1619  */
1620 static int amiga_floppy_change(struct gendisk *disk)
1621 {
1622 	struct amiga_floppy_struct *p = disk->private_data;
1623 	int drive = p - unit;
1624 	int changed;
1625 	static int first_time = 1;
1626 
1627 	if (first_time)
1628 		changed = first_time--;
1629 	else {
1630 		get_fdc(drive);
1631 		fd_select (drive);
1632 		changed = !(ciaa.pra & DSKCHANGE);
1633 		fd_deselect (drive);
1634 		rel_fdc();
1635 	}
1636 
1637 	if (changed) {
1638 		fd_probe(drive);
1639 		p->track = -1;
1640 		p->dirty = 0;
1641 		writepending = 0; /* if this was true before, too bad! */
1642 		writefromint = 0;
1643 		return 1;
1644 	}
1645 	return 0;
1646 }
1647 
1648 static struct block_device_operations floppy_fops = {
1649 	.owner		= THIS_MODULE,
1650 	.open		= floppy_open,
1651 	.release	= floppy_release,
1652 	.ioctl		= fd_ioctl,
1653 	.getgeo		= fd_getgeo,
1654 	.media_changed	= amiga_floppy_change,
1655 };
1656 
1657 static int __init fd_probe_drives(void)
1658 {
1659 	int drive,drives,nomem;
1660 
1661 	printk(KERN_INFO "FD: probing units\n" KERN_INFO "found ");
1662 	drives=0;
1663 	nomem=0;
1664 	for(drive=0;drive<FD_MAX_UNITS;drive++) {
1665 		struct gendisk *disk;
1666 		fd_probe(drive);
1667 		if (unit[drive].type->code == FD_NODRIVE)
1668 			continue;
1669 		disk = alloc_disk(1);
1670 		if (!disk) {
1671 			unit[drive].type->code = FD_NODRIVE;
1672 			continue;
1673 		}
1674 		unit[drive].gendisk = disk;
1675 		drives++;
1676 		if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1677 			printk("no mem for ");
1678 			unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1679 			drives--;
1680 			nomem = 1;
1681 		}
1682 		printk("fd%d ",drive);
1683 		disk->major = FLOPPY_MAJOR;
1684 		disk->first_minor = drive;
1685 		disk->fops = &floppy_fops;
1686 		sprintf(disk->disk_name, "fd%d", drive);
1687 		disk->private_data = &unit[drive];
1688 		disk->queue = floppy_queue;
1689 		set_capacity(disk, 880*2);
1690 		add_disk(disk);
1691 	}
1692 	if ((drives > 0) || (nomem == 0)) {
1693 		if (drives == 0)
1694 			printk("no drives");
1695 		printk("\n");
1696 		return drives;
1697 	}
1698 	printk("\n");
1699 	return -ENOMEM;
1700 }
1701 
1702 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1703 {
1704 	int drive = *part & 3;
1705 	if (unit[drive].type->code == FD_NODRIVE)
1706 		return NULL;
1707 	*part = 0;
1708 	return get_disk(unit[drive].gendisk);
1709 }
1710 
1711 int __init amiga_floppy_init(void)
1712 {
1713 	int i, ret;
1714 
1715 	if (!AMIGAHW_PRESENT(AMI_FLOPPY))
1716 		return -ENXIO;
1717 
1718 	if (register_blkdev(FLOPPY_MAJOR,"fd"))
1719 		return -EBUSY;
1720 
1721 	/*
1722 	 *  We request DSKPTR, DSKLEN and DSKDATA only, because the other
1723 	 *  floppy registers are too spreaded over the custom register space
1724 	 */
1725 	ret = -EBUSY;
1726 	if (!request_mem_region(CUSTOM_PHYSADDR+0x20, 8, "amiflop [Paula]")) {
1727 		printk("fd: cannot get floppy registers\n");
1728 		goto out_blkdev;
1729 	}
1730 
1731 	ret = -ENOMEM;
1732 	if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1733 	    NULL) {
1734 		printk("fd: cannot get chip mem buffer\n");
1735 		goto out_memregion;
1736 	}
1737 
1738 	ret = -EBUSY;
1739 	if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1740 		printk("fd: cannot get irq for dma\n");
1741 		goto out_irq;
1742 	}
1743 
1744 	if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1745 		printk("fd: cannot get irq for timer\n");
1746 		goto out_irq2;
1747 	}
1748 
1749 	ret = -ENOMEM;
1750 	floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
1751 	if (!floppy_queue)
1752 		goto out_queue;
1753 
1754 	ret = -ENXIO;
1755 	if (fd_probe_drives() < 1) /* No usable drives */
1756 		goto out_probe;
1757 
1758 	blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1759 				floppy_find, NULL, NULL);
1760 
1761 	/* initialize variables */
1762 	init_timer(&motor_on_timer);
1763 	motor_on_timer.expires = 0;
1764 	motor_on_timer.data = 0;
1765 	motor_on_timer.function = motor_on_callback;
1766 	for (i = 0; i < FD_MAX_UNITS; i++) {
1767 		init_timer(&motor_off_timer[i]);
1768 		motor_off_timer[i].expires = 0;
1769 		motor_off_timer[i].data = i|0x80000000;
1770 		motor_off_timer[i].function = fd_motor_off;
1771 		init_timer(&flush_track_timer[i]);
1772 		flush_track_timer[i].expires = 0;
1773 		flush_track_timer[i].data = i;
1774 		flush_track_timer[i].function = flush_track_callback;
1775 
1776 		unit[i].track = -1;
1777 	}
1778 
1779 	init_timer(&post_write_timer);
1780 	post_write_timer.expires = 0;
1781 	post_write_timer.data = 0;
1782 	post_write_timer.function = post_write;
1783 
1784 	for (i = 0; i < 128; i++)
1785 		mfmdecode[i]=255;
1786 	for (i = 0; i < 16; i++)
1787 		mfmdecode[mfmencode[i]]=i;
1788 
1789 	/* make sure that disk DMA is enabled */
1790 	custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1791 
1792 	/* init ms timer */
1793 	ciaa.crb = 8; /* one-shot, stop */
1794 	return 0;
1795 
1796 out_probe:
1797 	blk_cleanup_queue(floppy_queue);
1798 out_queue:
1799 	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1800 out_irq2:
1801 	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1802 out_irq:
1803 	amiga_chip_free(raw_buf);
1804 out_memregion:
1805 	release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1806 out_blkdev:
1807 	unregister_blkdev(FLOPPY_MAJOR,"fd");
1808 	return ret;
1809 }
1810 
1811 #ifdef MODULE
1812 
1813 int init_module(void)
1814 {
1815 	if (!MACH_IS_AMIGA)
1816 		return -ENXIO;
1817 	return amiga_floppy_init();
1818 }
1819 
1820 #if 0 /* not safe to unload */
1821 void cleanup_module(void)
1822 {
1823 	int i;
1824 
1825 	for( i = 0; i < FD_MAX_UNITS; i++) {
1826 		if (unit[i].type->code != FD_NODRIVE) {
1827 			del_gendisk(unit[i].gendisk);
1828 			put_disk(unit[i].gendisk);
1829 			kfree(unit[i].trackbuf);
1830 		}
1831 	}
1832 	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
1833 	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1834 	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1835 	custom.dmacon = DMAF_DISK; /* disable DMA */
1836 	amiga_chip_free(raw_buf);
1837 	blk_cleanup_queue(floppy_queue);
1838 	release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1839 	unregister_blkdev(FLOPPY_MAJOR, "fd");
1840 }
1841 #endif
1842 
1843 #else
1844 static int __init amiga_floppy_setup (char *str)
1845 {
1846 	int n;
1847 	if (!MACH_IS_AMIGA)
1848 		return 0;
1849 	if (!get_option(&str, &n))
1850 		return 0;
1851 	printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1852 	fd_def_df0 = n;
1853 	return 1;
1854 }
1855 
1856 __setup("floppy=", amiga_floppy_setup);
1857 #endif
1858