xref: /linux/drivers/block/amiflop.c (revision 7fcfa9a2d9a7c1b428d61992c2deaa9e37a437b0)
1 /*
2  *  linux/amiga/amiflop.c
3  *
4  *  Copyright (C) 1993  Greg Harp
5  *  Portions of this driver are based on code contributed by Brad Pepers
6  *
7  *  revised 28.5.95 by Joerg Dorchain
8  *  - now no bugs(?) any more for both HD & DD
9  *  - added support for 40 Track 5.25" drives, 80-track hopefully behaves
10  *    like 3.5" dd (no way to test - are there any 5.25" drives out there
11  *    that work on an A4000?)
12  *  - wrote formatting routine (maybe dirty, but works)
13  *
14  *  june/july 1995 added ms-dos support by Joerg Dorchain
15  *  (portions based on messydos.device and various contributors)
16  *  - currently only 9 and 18 sector disks
17  *
18  *  - fixed a bug with the internal trackbuffer when using multiple
19  *    disks the same time
20  *  - made formatting a bit safer
21  *  - added command line and machine based default for "silent" df0
22  *
23  *  december 1995 adapted for 1.2.13pl4 by Joerg Dorchain
24  *  - works but I think it's inefficient. (look in redo_fd_request)
25  *    But the changes were very efficient. (only three and a half lines)
26  *
27  *  january 1996 added special ioctl for tracking down read/write problems
28  *  - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data
29  *    is copied to area. (area should be large enough since no checking is
30  *    done - 30K is currently sufficient). return the actual size of the
31  *    trackbuffer
32  *  - replaced udelays() by a timer (CIAA timer B) for the waits
33  *    needed for the disk mechanic.
34  *
35  *  february 1996 fixed error recovery and multiple disk access
36  *  - both got broken the first time I tampered with the driver :-(
37  *  - still not safe, but better than before
38  *
39  *  revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.
40  *  - Minor changes to accept the kdev_t.
41  *  - Replaced some more udelays with ms_delays. Udelay is just a loop,
42  *    and so the delay will be different depending on the given
43  *    processor :-(
44  *  - The driver could use a major cleanup because of the new
45  *    major/minor handling that came with kdev_t. It seems to work for
46  *    the time being, but I can't guarantee that it will stay like
47  *    that when we start using 16 (24?) bit minors.
48  *
49  * restructured jan 1997 by Joerg Dorchain
50  * - Fixed Bug accessing multiple disks
51  * - some code cleanup
52  * - added trackbuffer for each drive to speed things up
53  * - fixed some race conditions (who finds the next may send it to me ;-)
54  */
55 
56 #include <linux/module.h>
57 #include <linux/slab.h>
58 
59 #include <linux/fd.h>
60 #include <linux/hdreg.h>
61 #include <linux/delay.h>
62 #include <linux/init.h>
63 #include <linux/mutex.h>
64 #include <linux/fs.h>
65 #include <linux/blk-mq.h>
66 #include <linux/elevator.h>
67 #include <linux/interrupt.h>
68 #include <linux/platform_device.h>
69 
70 #include <asm/setup.h>
71 #include <linux/uaccess.h>
72 #include <asm/amigahw.h>
73 #include <asm/amigaints.h>
74 #include <asm/irq.h>
75 
76 #undef DEBUG /* print _LOTS_ of infos */
77 
78 #define RAW_IOCTL
79 #ifdef RAW_IOCTL
80 #define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
81 #endif
82 
83 /*
84  *  Defines
85  */
86 
87 /*
88  * CIAAPRA bits (read only)
89  */
90 
91 #define DSKRDY      (0x1<<5)        /* disk ready when low */
92 #define DSKTRACK0   (0x1<<4)        /* head at track zero when low */
93 #define DSKPROT     (0x1<<3)        /* disk protected when low */
94 #define DSKCHANGE   (0x1<<2)        /* low when disk removed */
95 
96 /*
97  * CIAAPRB bits (read/write)
98  */
99 
100 #define DSKMOTOR    (0x1<<7)        /* motor on when low */
101 #define DSKSEL3     (0x1<<6)        /* select drive 3 when low */
102 #define DSKSEL2     (0x1<<5)        /* select drive 2 when low */
103 #define DSKSEL1     (0x1<<4)        /* select drive 1 when low */
104 #define DSKSEL0     (0x1<<3)        /* select drive 0 when low */
105 #define DSKSIDE     (0x1<<2)        /* side selection: 0 = upper, 1 = lower */
106 #define DSKDIREC    (0x1<<1)        /* step direction: 0=in, 1=out (to trk 0) */
107 #define DSKSTEP     (0x1)           /* pulse low to step head 1 track */
108 
109 /*
110  * DSKBYTR bits (read only)
111  */
112 
113 #define DSKBYT      (1<<15)         /* register contains valid byte when set */
114 #define DMAON       (1<<14)         /* disk DMA enabled */
115 #define DISKWRITE   (1<<13)         /* disk write bit in DSKLEN enabled */
116 #define WORDEQUAL   (1<<12)         /* DSKSYNC register match when true */
117 /* bits 7-0 are data */
118 
119 /*
120  * ADKCON/ADKCONR bits
121  */
122 
123 #ifndef SETCLR
124 #define ADK_SETCLR      (1<<15)     /* control bit */
125 #endif
126 #define ADK_PRECOMP1    (1<<14)     /* precompensation selection */
127 #define ADK_PRECOMP0    (1<<13)     /* 00=none, 01=140ns, 10=280ns, 11=500ns */
128 #define ADK_MFMPREC     (1<<12)     /* 0=GCR precomp., 1=MFM precomp. */
129 #define ADK_WORDSYNC    (1<<10)     /* enable DSKSYNC auto DMA */
130 #define ADK_MSBSYNC     (1<<9)      /* when 1, enable sync on MSbit (for GCR) */
131 #define ADK_FAST        (1<<8)      /* bit cell: 0=2us (GCR), 1=1us (MFM) */
132 
133 /*
134  * DSKLEN bits
135  */
136 
137 #define DSKLEN_DMAEN    (1<<15)
138 #define DSKLEN_WRITE    (1<<14)
139 
140 /*
141  * INTENA/INTREQ bits
142  */
143 
144 #define DSKINDEX    (0x1<<4)        /* DSKINDEX bit */
145 
146 /*
147  * Misc
148  */
149 
150 #define MFM_SYNC    0x4489          /* standard MFM sync value */
151 
152 /* Values for FD_COMMAND */
153 #define FD_RECALIBRATE		0x07	/* move to track 0 */
154 #define FD_SEEK			0x0F	/* seek track */
155 #define FD_READ			0xE6	/* read with MT, MFM, SKip deleted */
156 #define FD_WRITE		0xC5	/* write with MT, MFM */
157 #define FD_SENSEI		0x08	/* Sense Interrupt Status */
158 #define FD_SPECIFY		0x03	/* specify HUT etc */
159 #define FD_FORMAT		0x4D	/* format one track */
160 #define FD_VERSION		0x10	/* get version code */
161 #define FD_CONFIGURE		0x13	/* configure FIFO operation */
162 #define FD_PERPENDICULAR	0x12	/* perpendicular r/w mode */
163 
164 #define FD_MAX_UNITS    4	/* Max. Number of drives */
165 #define FLOPPY_MAX_SECTORS	22	/* Max. Number of sectors per track */
166 
167 struct fd_data_type {
168 	char *name;		/* description of data type */
169 	int sects;		/* sectors per track */
170 	int (*read_fkt)(int);	/* read whole track */
171 	void (*write_fkt)(int);	/* write whole track */
172 };
173 
174 struct fd_drive_type {
175 	unsigned long code;		/* code returned from drive */
176 	char *name;			/* description of drive */
177 	unsigned int tracks;	/* number of tracks */
178 	unsigned int heads;		/* number of heads */
179 	unsigned int read_size;	/* raw read size for one track */
180 	unsigned int write_size;	/* raw write size for one track */
181 	unsigned int sect_mult;	/* sectors and gap multiplier (HD = 2) */
182 	unsigned int precomp1;	/* start track for precomp 1 */
183 	unsigned int precomp2;	/* start track for precomp 2 */
184 	unsigned int step_delay;	/* time (in ms) for delay after step */
185 	unsigned int settle_time;	/* time to settle after dir change */
186 	unsigned int side_time;	/* time needed to change sides */
187 };
188 
189 struct amiga_floppy_struct {
190 	struct fd_drive_type *type;	/* type of floppy for this unit */
191 	struct fd_data_type *dtype;	/* type of floppy for this unit */
192 	int track;			/* current track (-1 == unknown) */
193 	unsigned char *trackbuf;	/* current track (kmaloc()'d */
194 
195 	int blocks;			/* total # blocks on disk */
196 
197 	int changed;			/* true when not known */
198 	int disk;			/* disk in drive (-1 == unknown) */
199 	int motor;			/* true when motor is at speed */
200 	int busy;			/* true when drive is active */
201 	int dirty;			/* true when trackbuf is not on disk */
202 	int status;			/* current error code for unit */
203 	struct gendisk *gendisk;
204 	struct blk_mq_tag_set tag_set;
205 };
206 
207 /*
208  *  Error codes
209  */
210 #define FD_OK		0	/* operation succeeded */
211 #define FD_ERROR	-1	/* general error (seek, read, write, etc) */
212 #define FD_NOUNIT	1	/* unit does not exist */
213 #define FD_UNITBUSY	2	/* unit already active */
214 #define FD_NOTACTIVE	3	/* unit is not active */
215 #define FD_NOTREADY	4	/* unit is not ready (motor not on/no disk) */
216 
217 #define MFM_NOSYNC	1
218 #define MFM_HEADER	2
219 #define MFM_DATA	3
220 #define MFM_TRACK	4
221 
222 /*
223  *  Floppy ID values
224  */
225 #define FD_NODRIVE	0x00000000  /* response when no unit is present */
226 #define FD_DD_3 	0xffffffff  /* double-density 3.5" (880K) drive */
227 #define FD_HD_3 	0x55555555  /* high-density 3.5" (1760K) drive */
228 #define FD_DD_5 	0xaaaaaaaa  /* double-density 5.25" (440K) drive */
229 
230 static DEFINE_MUTEX(amiflop_mutex);
231 static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
232 
233 module_param(fd_def_df0, ulong, 0);
234 MODULE_LICENSE("GPL");
235 
236 /*
237  *  Macros
238  */
239 #define MOTOR_ON	(ciab.prb &= ~DSKMOTOR)
240 #define MOTOR_OFF	(ciab.prb |= DSKMOTOR)
241 #define SELECT(mask)    (ciab.prb &= ~mask)
242 #define DESELECT(mask)  (ciab.prb |= mask)
243 #define SELMASK(drive)  (1 << (3 + (drive & 3)))
244 
245 static struct fd_drive_type drive_types[] = {
246 /*  code	name	   tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
247 /*  warning: times are now in milliseconds (ms)                    */
248 { FD_DD_3,	"DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
249 { FD_HD_3,	"HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
250 { FD_DD_5,	"DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
251 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
252 };
253 static int num_dr_types = ARRAY_SIZE(drive_types);
254 
255 static int amiga_read(int), dos_read(int);
256 static void amiga_write(int), dos_write(int);
257 static struct fd_data_type data_types[] = {
258 	{ "Amiga", 11 , amiga_read, amiga_write},
259 	{ "MS-Dos", 9, dos_read, dos_write}
260 };
261 
262 /* current info on each unit */
263 static struct amiga_floppy_struct unit[FD_MAX_UNITS];
264 
265 static struct timer_list flush_track_timer[FD_MAX_UNITS];
266 static struct timer_list post_write_timer;
267 static unsigned long post_write_timer_drive;
268 static struct timer_list motor_on_timer;
269 static struct timer_list motor_off_timer[FD_MAX_UNITS];
270 static int on_attempts;
271 
272 /* Synchronization of FDC access */
273 /* request loop (trackbuffer) */
274 static volatile int fdc_busy = -1;
275 static volatile int fdc_nested;
276 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
277 
278 static DECLARE_COMPLETION(motor_on_completion);
279 
280 static volatile int selected = -1;	/* currently selected drive */
281 
282 static int writepending;
283 static int writefromint;
284 static char *raw_buf;
285 
286 static DEFINE_SPINLOCK(amiflop_lock);
287 
288 #define RAW_BUF_SIZE 30000  /* size of raw disk data */
289 
290 /*
291  * These are global variables, as that's the easiest way to give
292  * information to interrupts. They are the data used for the current
293  * request.
294  */
295 static volatile char block_flag;
296 static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
297 
298 /* MS-Dos MFM Coding tables (should go quick and easy) */
299 static unsigned char mfmencode[16]={
300 	0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
301 	0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
302 };
303 static unsigned char mfmdecode[128];
304 
305 /* floppy internal millisecond timer stuff */
306 static DECLARE_COMPLETION(ms_wait_completion);
307 #define MS_TICKS ((amiga_eclock+50)/1000)
308 
309 /*
310  * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
311  * max X times - some types of errors increase the errorcount by 2 or
312  * even 3, so we might actually retry only X/2 times before giving up.
313  */
314 #define MAX_ERRORS 12
315 
316 #define custom amiga_custom
317 
318 /* Prevent "aliased" accesses. */
319 static int fd_ref[4] = { 0,0,0,0 };
320 static int fd_device[4] = { 0, 0, 0, 0 };
321 
322 /*
323  * Here come the actual hardware access and helper functions.
324  * They are not reentrant and single threaded because all drives
325  * share the same hardware and the same trackbuffer.
326  */
327 
328 /* Milliseconds timer */
329 
330 static irqreturn_t ms_isr(int irq, void *dummy)
331 {
332 	complete(&ms_wait_completion);
333 	return IRQ_HANDLED;
334 }
335 
336 /* all waits are queued up
337    A more generic routine would do a schedule a la timer.device */
338 static void ms_delay(int ms)
339 {
340 	int ticks;
341 	static DEFINE_MUTEX(mutex);
342 
343 	if (ms > 0) {
344 		mutex_lock(&mutex);
345 		ticks = MS_TICKS*ms-1;
346 		ciaa.tblo=ticks%256;
347 		ciaa.tbhi=ticks/256;
348 		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
349 		wait_for_completion(&ms_wait_completion);
350 		mutex_unlock(&mutex);
351 	}
352 }
353 
354 /* Hardware semaphore */
355 
356 /* returns true when we would get the semaphore */
357 static inline int try_fdc(int drive)
358 {
359 	drive &= 3;
360 	return ((fdc_busy < 0) || (fdc_busy == drive));
361 }
362 
363 static void get_fdc(int drive)
364 {
365 	unsigned long flags;
366 
367 	drive &= 3;
368 #ifdef DEBUG
369 	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
370 #endif
371 	local_irq_save(flags);
372 	wait_event(fdc_wait, try_fdc(drive));
373 	fdc_busy = drive;
374 	fdc_nested++;
375 	local_irq_restore(flags);
376 }
377 
378 static inline void rel_fdc(void)
379 {
380 #ifdef DEBUG
381 	if (fdc_nested == 0)
382 		printk("fd: unmatched rel_fdc\n");
383 	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
384 #endif
385 	fdc_nested--;
386 	if (fdc_nested == 0) {
387 		fdc_busy = -1;
388 		wake_up(&fdc_wait);
389 	}
390 }
391 
392 static void fd_select (int drive)
393 {
394 	unsigned char prb = ~0;
395 
396 	drive&=3;
397 #ifdef DEBUG
398 	printk("selecting %d\n",drive);
399 #endif
400 	if (drive == selected)
401 		return;
402 	get_fdc(drive);
403 	selected = drive;
404 
405 	if (unit[drive].track % 2 != 0)
406 		prb &= ~DSKSIDE;
407 	if (unit[drive].motor == 1)
408 		prb &= ~DSKMOTOR;
409 	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
410 	ciab.prb = prb;
411 	prb &= ~SELMASK(drive);
412 	ciab.prb = prb;
413 	rel_fdc();
414 }
415 
416 static void fd_deselect (int drive)
417 {
418 	unsigned char prb;
419 	unsigned long flags;
420 
421 	drive&=3;
422 #ifdef DEBUG
423 	printk("deselecting %d\n",drive);
424 #endif
425 	if (drive != selected) {
426 		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
427 		return;
428 	}
429 
430 	get_fdc(drive);
431 	local_irq_save(flags);
432 
433 	selected = -1;
434 
435 	prb = ciab.prb;
436 	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
437 	ciab.prb = prb;
438 
439 	local_irq_restore (flags);
440 	rel_fdc();
441 
442 }
443 
444 static void motor_on_callback(struct timer_list *unused)
445 {
446 	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
447 		complete_all(&motor_on_completion);
448 	} else {
449 		motor_on_timer.expires = jiffies + HZ/10;
450 		add_timer(&motor_on_timer);
451 	}
452 }
453 
454 static int fd_motor_on(int nr)
455 {
456 	nr &= 3;
457 
458 	del_timer(motor_off_timer + nr);
459 
460 	if (!unit[nr].motor) {
461 		unit[nr].motor = 1;
462 		fd_select(nr);
463 
464 		reinit_completion(&motor_on_completion);
465 		mod_timer(&motor_on_timer, jiffies + HZ/2);
466 
467 		on_attempts = 10;
468 		wait_for_completion(&motor_on_completion);
469 		fd_deselect(nr);
470 	}
471 
472 	if (on_attempts == 0) {
473 		on_attempts = -1;
474 #if 0
475 		printk (KERN_ERR "motor_on failed, turning motor off\n");
476 		fd_motor_off (motor_off_timer + nr);
477 		return 0;
478 #else
479 		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
480 #endif
481 	}
482 
483 	return 1;
484 }
485 
486 static void fd_motor_off(struct timer_list *timer)
487 {
488 	unsigned long drive = ((unsigned long)timer -
489 			       (unsigned long)&motor_off_timer[0]) /
490 					sizeof(motor_off_timer[0]);
491 
492 	drive&=3;
493 	if (!try_fdc(drive)) {
494 		/* We would be blocked in an interrupt, so try again later */
495 		timer->expires = jiffies + 1;
496 		add_timer(timer);
497 		return;
498 	}
499 	unit[drive].motor = 0;
500 	fd_select(drive);
501 	udelay (1);
502 	fd_deselect(drive);
503 }
504 
505 static void floppy_off (unsigned int nr)
506 {
507 	int drive;
508 
509 	drive = nr & 3;
510 	mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
511 }
512 
513 static int fd_calibrate(int drive)
514 {
515 	unsigned char prb;
516 	int n;
517 
518 	drive &= 3;
519 	get_fdc(drive);
520 	if (!fd_motor_on (drive))
521 		return 0;
522 	fd_select (drive);
523 	prb = ciab.prb;
524 	prb |= DSKSIDE;
525 	prb &= ~DSKDIREC;
526 	ciab.prb = prb;
527 	for (n = unit[drive].type->tracks/2; n != 0; --n) {
528 		if (ciaa.pra & DSKTRACK0)
529 			break;
530 		prb &= ~DSKSTEP;
531 		ciab.prb = prb;
532 		prb |= DSKSTEP;
533 		udelay (2);
534 		ciab.prb = prb;
535 		ms_delay(unit[drive].type->step_delay);
536 	}
537 	ms_delay (unit[drive].type->settle_time);
538 	prb |= DSKDIREC;
539 	n = unit[drive].type->tracks + 20;
540 	for (;;) {
541 		prb &= ~DSKSTEP;
542 		ciab.prb = prb;
543 		prb |= DSKSTEP;
544 		udelay (2);
545 		ciab.prb = prb;
546 		ms_delay(unit[drive].type->step_delay + 1);
547 		if ((ciaa.pra & DSKTRACK0) == 0)
548 			break;
549 		if (--n == 0) {
550 			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
551 			fd_motor_off (motor_off_timer + drive);
552 			unit[drive].track = -1;
553 			rel_fdc();
554 			return 0;
555 		}
556 	}
557 	unit[drive].track = 0;
558 	ms_delay(unit[drive].type->settle_time);
559 
560 	rel_fdc();
561 	fd_deselect(drive);
562 	return 1;
563 }
564 
565 static int fd_seek(int drive, int track)
566 {
567 	unsigned char prb;
568 	int cnt;
569 
570 #ifdef DEBUG
571 	printk("seeking drive %d to track %d\n",drive,track);
572 #endif
573 	drive &= 3;
574 	get_fdc(drive);
575 	if (unit[drive].track == track) {
576 		rel_fdc();
577 		return 1;
578 	}
579 	if (!fd_motor_on(drive)) {
580 		rel_fdc();
581 		return 0;
582 	}
583 	if (unit[drive].track < 0 && !fd_calibrate(drive)) {
584 		rel_fdc();
585 		return 0;
586 	}
587 
588 	fd_select (drive);
589 	cnt = unit[drive].track/2 - track/2;
590 	prb = ciab.prb;
591 	prb |= DSKSIDE | DSKDIREC;
592 	if (track % 2 != 0)
593 		prb &= ~DSKSIDE;
594 	if (cnt < 0) {
595 		cnt = - cnt;
596 		prb &= ~DSKDIREC;
597 	}
598 	ciab.prb = prb;
599 	if (track % 2 != unit[drive].track % 2)
600 		ms_delay (unit[drive].type->side_time);
601 	unit[drive].track = track;
602 	if (cnt == 0) {
603 		rel_fdc();
604 		fd_deselect(drive);
605 		return 1;
606 	}
607 	do {
608 		prb &= ~DSKSTEP;
609 		ciab.prb = prb;
610 		prb |= DSKSTEP;
611 		udelay (1);
612 		ciab.prb = prb;
613 		ms_delay (unit[drive].type->step_delay);
614 	} while (--cnt != 0);
615 	ms_delay (unit[drive].type->settle_time);
616 
617 	rel_fdc();
618 	fd_deselect(drive);
619 	return 1;
620 }
621 
622 static unsigned long fd_get_drive_id(int drive)
623 {
624 	int i;
625 	ulong id = 0;
626 
627   	drive&=3;
628   	get_fdc(drive);
629 	/* set up for ID */
630 	MOTOR_ON;
631 	udelay(2);
632 	SELECT(SELMASK(drive));
633 	udelay(2);
634 	DESELECT(SELMASK(drive));
635 	udelay(2);
636 	MOTOR_OFF;
637 	udelay(2);
638 	SELECT(SELMASK(drive));
639 	udelay(2);
640 	DESELECT(SELMASK(drive));
641 	udelay(2);
642 
643 	/* loop and read disk ID */
644 	for (i=0; i<32; i++) {
645 		SELECT(SELMASK(drive));
646 		udelay(2);
647 
648 		/* read and store value of DSKRDY */
649 		id <<= 1;
650 		id |= (ciaa.pra & DSKRDY) ? 0 : 1;	/* cia regs are low-active! */
651 
652 		DESELECT(SELMASK(drive));
653 	}
654 
655 	rel_fdc();
656 
657         /*
658          * RB: At least A500/A2000's df0: don't identify themselves.
659          * As every (real) Amiga has at least a 3.5" DD drive as df0:
660          * we default to that if df0: doesn't identify as a certain
661          * type.
662          */
663         if(drive == 0 && id == FD_NODRIVE)
664 	{
665                 id = fd_def_df0;
666                 printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
667 	}
668 	/* return the ID value */
669 	return (id);
670 }
671 
672 static irqreturn_t fd_block_done(int irq, void *dummy)
673 {
674 	if (block_flag)
675 		custom.dsklen = 0x4000;
676 
677 	if (block_flag == 2) { /* writing */
678 		writepending = 2;
679 		post_write_timer.expires = jiffies + 1; /* at least 2 ms */
680 		post_write_timer_drive = selected;
681 		add_timer(&post_write_timer);
682 	}
683 	else {                /* reading */
684 		block_flag = 0;
685 		wake_up (&wait_fd_block);
686 	}
687 	return IRQ_HANDLED;
688 }
689 
690 static void raw_read(int drive)
691 {
692 	drive&=3;
693 	get_fdc(drive);
694 	wait_event(wait_fd_block, !block_flag);
695 	fd_select(drive);
696 	/* setup adkcon bits correctly */
697 	custom.adkcon = ADK_MSBSYNC;
698 	custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
699 
700 	custom.dsksync = MFM_SYNC;
701 
702 	custom.dsklen = 0;
703 	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
704 	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
705 	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
706 
707 	block_flag = 1;
708 
709 	wait_event(wait_fd_block, !block_flag);
710 
711 	custom.dsklen = 0;
712 	fd_deselect(drive);
713 	rel_fdc();
714 }
715 
716 static int raw_write(int drive)
717 {
718 	ushort adk;
719 
720 	drive&=3;
721 	get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
722 	if ((ciaa.pra & DSKPROT) == 0) {
723 		rel_fdc();
724 		return 0;
725 	}
726 	wait_event(wait_fd_block, !block_flag);
727 	fd_select(drive);
728 	/* clear adkcon bits */
729 	custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
730 	/* set appropriate adkcon bits */
731 	adk = ADK_SETCLR|ADK_FAST;
732 	if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
733 		adk |= ADK_PRECOMP1;
734 	else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
735 		adk |= ADK_PRECOMP0;
736 	custom.adkcon = adk;
737 
738 	custom.dsklen = DSKLEN_WRITE;
739 	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
740 	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
741 	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
742 
743 	block_flag = 2;
744 	return 1;
745 }
746 
747 /*
748  * to be called at least 2ms after the write has finished but before any
749  * other access to the hardware.
750  */
751 static void post_write (unsigned long drive)
752 {
753 #ifdef DEBUG
754 	printk("post_write for drive %ld\n",drive);
755 #endif
756 	drive &= 3;
757 	custom.dsklen = 0;
758 	block_flag = 0;
759 	writepending = 0;
760 	writefromint = 0;
761 	unit[drive].dirty = 0;
762 	wake_up(&wait_fd_block);
763 	fd_deselect(drive);
764 	rel_fdc(); /* corresponds to get_fdc() in raw_write */
765 }
766 
767 static void post_write_callback(struct timer_list *timer)
768 {
769 	post_write(post_write_timer_drive);
770 }
771 
772 /*
773  * The following functions are to convert the block contents into raw data
774  * written to disk and vice versa.
775  * (Add other formats here ;-))
776  */
777 
778 static unsigned long scan_sync(unsigned long raw, unsigned long end)
779 {
780 	ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
781 
782 	while (ptr < endp && *ptr++ != 0x4489)
783 		;
784 	if (ptr < endp) {
785 		while (*ptr == 0x4489 && ptr < endp)
786 			ptr++;
787 		return (ulong)ptr;
788 	}
789 	return 0;
790 }
791 
792 static inline unsigned long checksum(unsigned long *addr, int len)
793 {
794 	unsigned long csum = 0;
795 
796 	len /= sizeof(*addr);
797 	while (len-- > 0)
798 		csum ^= *addr++;
799 	csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
800 
801 	return csum;
802 }
803 
804 static unsigned long decode (unsigned long *data, unsigned long *raw,
805 			     int len)
806 {
807 	ulong *odd, *even;
808 
809 	/* convert length from bytes to longwords */
810 	len >>= 2;
811 	odd = raw;
812 	even = odd + len;
813 
814 	/* prepare return pointer */
815 	raw += len * 2;
816 
817 	do {
818 		*data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
819 	} while (--len != 0);
820 
821 	return (ulong)raw;
822 }
823 
824 struct header {
825 	unsigned char magic;
826 	unsigned char track;
827 	unsigned char sect;
828 	unsigned char ord;
829 	unsigned char labels[16];
830 	unsigned long hdrchk;
831 	unsigned long datachk;
832 };
833 
834 static int amiga_read(int drive)
835 {
836 	unsigned long raw;
837 	unsigned long end;
838 	int scnt;
839 	unsigned long csum;
840 	struct header hdr;
841 
842 	drive&=3;
843 	raw = (long) raw_buf;
844 	end = raw + unit[drive].type->read_size;
845 
846 	for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
847 		if (!(raw = scan_sync(raw, end))) {
848 			printk (KERN_INFO "can't find sync for sector %d\n", scnt);
849 			return MFM_NOSYNC;
850 		}
851 
852 		raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
853 		raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
854 		raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
855 		raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
856 		csum = checksum((ulong *)&hdr,
857 				(char *)&hdr.hdrchk-(char *)&hdr);
858 
859 #ifdef DEBUG
860 		printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
861 			hdr.magic, hdr.track, hdr.sect, hdr.ord,
862 			*(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
863 			*(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
864 			hdr.hdrchk, hdr.datachk);
865 #endif
866 
867 		if (hdr.hdrchk != csum) {
868 			printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
869 			return MFM_HEADER;
870 		}
871 
872 		/* verify track */
873 		if (hdr.track != unit[drive].track) {
874 			printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
875 			return MFM_TRACK;
876 		}
877 
878 		raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
879 			      (ulong *)raw, 512);
880 		csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
881 
882 		if (hdr.datachk != csum) {
883 			printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
884 			       hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
885 			       hdr.datachk, csum);
886 			printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
887 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
888 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
889 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
890 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
891 			return MFM_DATA;
892 		}
893 	}
894 
895 	return 0;
896 }
897 
898 static void encode(unsigned long data, unsigned long *dest)
899 {
900 	unsigned long data2;
901 
902 	data &= 0x55555555;
903 	data2 = data ^ 0x55555555;
904 	data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
905 
906 	if (*(dest - 1) & 0x00000001)
907 		data &= 0x7FFFFFFF;
908 
909 	*dest = data;
910 }
911 
912 static void encode_block(unsigned long *dest, unsigned long *src, int len)
913 {
914 	int cnt, to_cnt = 0;
915 	unsigned long data;
916 
917 	/* odd bits */
918 	for (cnt = 0; cnt < len / 4; cnt++) {
919 		data = src[cnt] >> 1;
920 		encode(data, dest + to_cnt++);
921 	}
922 
923 	/* even bits */
924 	for (cnt = 0; cnt < len / 4; cnt++) {
925 		data = src[cnt];
926 		encode(data, dest + to_cnt++);
927 	}
928 }
929 
930 static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
931 {
932 	struct header hdr;
933 	int i;
934 
935 	disk&=3;
936 	*raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
937 	raw++;
938 	*raw++ = 0x44894489;
939 
940 	hdr.magic = 0xFF;
941 	hdr.track = unit[disk].track;
942 	hdr.sect = cnt;
943 	hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
944 	for (i = 0; i < 16; i++)
945 		hdr.labels[i] = 0;
946 	hdr.hdrchk = checksum((ulong *)&hdr,
947 			      (char *)&hdr.hdrchk-(char *)&hdr);
948 	hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
949 
950 	encode_block(raw, (ulong *)&hdr.magic, 4);
951 	raw += 2;
952 	encode_block(raw, (ulong *)&hdr.labels, 16);
953 	raw += 8;
954 	encode_block(raw, (ulong *)&hdr.hdrchk, 4);
955 	raw += 2;
956 	encode_block(raw, (ulong *)&hdr.datachk, 4);
957 	raw += 2;
958 	encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
959 	raw += 256;
960 
961 	return raw;
962 }
963 
964 static void amiga_write(int disk)
965 {
966 	unsigned int cnt;
967 	unsigned long *ptr = (unsigned long *)raw_buf;
968 
969 	disk&=3;
970 	/* gap space */
971 	for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
972 		*ptr++ = 0xaaaaaaaa;
973 
974 	/* sectors */
975 	for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
976 		ptr = putsec (disk, ptr, cnt);
977 	*(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
978 }
979 
980 
981 struct dos_header {
982 	unsigned char track,   /* 0-80 */
983 		side,    /* 0-1 */
984 		sec,     /* 0-...*/
985 		len_desc;/* 2 */
986 	unsigned short crc;     /* on 68000 we got an alignment problem,
987 				   but this compiler solves it  by adding silently
988 				   adding a pad byte so data won't fit
989 				   and this took about 3h to discover.... */
990 	unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
991 };
992 
993 /* crc routines are borrowed from the messydos-handler  */
994 
995 /* excerpt from the messydos-device
996 ; The CRC is computed not only over the actual data, but including
997 ; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
998 ; As we don't read or encode these fields into our buffers, we have to
999 ; preload the registers containing the CRC with the values they would have
1000 ; after stepping over these fields.
1001 ;
1002 ; How CRCs "really" work:
1003 ;
1004 ; First, you should regard a bitstring as a series of coefficients of
1005 ; polynomials. We calculate with these polynomials in modulo-2
1006 ; arithmetic, in which both add and subtract are done the same as
1007 ; exclusive-or. Now, we modify our data (a very long polynomial) in
1008 ; such a way that it becomes divisible by the CCITT-standard 16-bit
1009 ;		 16   12   5
1010 ; polynomial:	x  + x	+ x + 1, represented by $11021. The easiest
1011 ; way to do this would be to multiply (using proper arithmetic) our
1012 ; datablock with $11021. So we have:
1013 ;   data * $11021		 =
1014 ;   data * ($10000 + $1021)      =
1015 ;   data * $10000 + data * $1021
1016 ; The left part of this is simple: Just add two 0 bytes. But then
1017 ; the right part (data $1021) remains difficult and even could have
1018 ; a carry into the left part. The solution is to use a modified
1019 ; multiplication, which has a result that is not correct, but with
1020 ; a difference of any multiple of $11021. We then only need to keep
1021 ; the 16 least significant bits of the result.
1022 ;
1023 ; The following algorithm does this for us:
1024 ;
1025 ;   unsigned char *data, c, crclo, crchi;
1026 ;   while (not done) {
1027 ;	c = *data++ + crchi;
1028 ;	crchi = (@ c) >> 8 + crclo;
1029 ;	crclo = @ c;
1030 ;   }
1031 ;
1032 ; Remember, + is done with EOR, the @ operator is in two tables (high
1033 ; and low byte separately), which is calculated as
1034 ;
1035 ;      $1021 * (c & $F0)
1036 ;  xor $1021 * (c & $0F)
1037 ;  xor $1021 * (c >> 4)         (* is regular multiplication)
1038 ;
1039 ;
1040 ; Anyway, the end result is the same as the remainder of the division of
1041 ; the data by $11021. I am afraid I need to study theory a bit more...
1042 
1043 
1044 my only works was to code this from manx to C....
1045 
1046 */
1047 
1048 static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
1049 {
1050 	static unsigned char CRCTable1[] = {
1051 		0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
1052 		0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
1053 		0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
1054 		0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
1055 		0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
1056 		0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
1057 		0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
1058 		0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
1059 		0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
1060 		0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
1061 		0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
1062 		0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
1063 		0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
1064 		0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
1065 		0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
1066 		0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
1067 	};
1068 
1069 	static unsigned char CRCTable2[] = {
1070 		0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
1071 		0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
1072 		0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
1073 		0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
1074 		0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
1075 		0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
1076 		0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
1077 		0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
1078 		0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
1079 		0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
1080 		0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
1081 		0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
1082 		0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
1083 		0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
1084 		0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
1085 		0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
1086 	};
1087 
1088 /* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
1089 	register int i;
1090 	register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
1091 
1092 	CRCT1=CRCTable1;
1093 	CRCT2=CRCTable2;
1094 	data=data_a3;
1095 	crcl=data_d1;
1096 	crch=data_d0;
1097 	for (i=data_d3; i>=0; i--) {
1098 		c = (*data++) ^ crch;
1099 		crch = CRCT1[c] ^ crcl;
1100 		crcl = CRCT2[c];
1101 	}
1102 	return (crch<<8)|crcl;
1103 }
1104 
1105 static inline ushort dos_hdr_crc (struct dos_header *hdr)
1106 {
1107 	return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
1108 }
1109 
1110 static inline ushort dos_data_crc(unsigned char *data)
1111 {
1112 	return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
1113 }
1114 
1115 static inline unsigned char dos_decode_byte(ushort word)
1116 {
1117 	register ushort w2;
1118 	register unsigned char byte;
1119 	register unsigned char *dec = mfmdecode;
1120 
1121 	w2=word;
1122 	w2>>=8;
1123 	w2&=127;
1124 	byte = dec[w2];
1125 	byte <<= 4;
1126 	w2 = word & 127;
1127 	byte |= dec[w2];
1128 	return byte;
1129 }
1130 
1131 static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1132 {
1133 	int i;
1134 
1135 	for (i = 0; i < len; i++)
1136 		*data++=dos_decode_byte(*raw++);
1137 	return ((ulong)raw);
1138 }
1139 
1140 #ifdef DEBUG
1141 static void dbg(unsigned long ptr)
1142 {
1143 	printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1144 	       ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1145 	       ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1146 }
1147 #endif
1148 
1149 static int dos_read(int drive)
1150 {
1151 	unsigned long end;
1152 	unsigned long raw;
1153 	int scnt;
1154 	unsigned short crc,data_crc[2];
1155 	struct dos_header hdr;
1156 
1157 	drive&=3;
1158 	raw = (long) raw_buf;
1159 	end = raw + unit[drive].type->read_size;
1160 
1161 	for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1162 		do { /* search for the right sync of each sec-hdr */
1163 			if (!(raw = scan_sync (raw, end))) {
1164 				printk(KERN_INFO "dos_read: no hdr sync on "
1165 				       "track %d, unit %d for sector %d\n",
1166 				       unit[drive].track,drive,scnt);
1167 				return MFM_NOSYNC;
1168 			}
1169 #ifdef DEBUG
1170 			dbg(raw);
1171 #endif
1172 		} while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1173 		raw+=2; /* skip over headermark */
1174 		raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1175 		crc = dos_hdr_crc(&hdr);
1176 
1177 #ifdef DEBUG
1178 		printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1179 		       hdr.sec, hdr.len_desc, hdr.crc);
1180 #endif
1181 
1182 		if (crc != hdr.crc) {
1183 			printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1184 			       hdr.crc, crc);
1185 			return MFM_HEADER;
1186 		}
1187 		if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1188 			printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1189 			       hdr.track,
1190 			       unit[drive].track/unit[drive].type->heads);
1191 			return MFM_TRACK;
1192 		}
1193 
1194 		if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1195 			printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1196 			       hdr.side,
1197 			       unit[drive].track%unit[drive].type->heads);
1198 			return MFM_TRACK;
1199 		}
1200 
1201 		if (hdr.len_desc != 2) {
1202 			printk(KERN_INFO "dos_read: unknown sector len "
1203 			       "descriptor %d\n", hdr.len_desc);
1204 			return MFM_DATA;
1205 		}
1206 #ifdef DEBUG
1207 		printk("hdr accepted\n");
1208 #endif
1209 		if (!(raw = scan_sync (raw, end))) {
1210 			printk(KERN_INFO "dos_read: no data sync on track "
1211 			       "%d, unit %d for sector%d, disk sector %d\n",
1212 			       unit[drive].track, drive, scnt, hdr.sec);
1213 			return MFM_NOSYNC;
1214 		}
1215 #ifdef DEBUG
1216 		dbg(raw);
1217 #endif
1218 
1219 		if (*((ushort *)raw)!=0x5545) {
1220 			printk(KERN_INFO "dos_read: no data mark after "
1221 			       "sync (%d,%d,%d,%d) sc=%d\n",
1222 			       hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1223 			return MFM_NOSYNC;
1224 		}
1225 
1226 		raw+=2;  /* skip data mark (included in checksum) */
1227 		raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1228 		raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1229 		crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1230 
1231 		if (crc != data_crc[0]) {
1232 			printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1233 			       "sc=%d, %x %x\n", hdr.track, hdr.side,
1234 			       hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1235 			printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1236 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1237 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1238 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1239 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1240 			return MFM_DATA;
1241 		}
1242 	}
1243 	return 0;
1244 }
1245 
1246 static inline ushort dos_encode_byte(unsigned char byte)
1247 {
1248 	register unsigned char *enc, b2, b1;
1249 	register ushort word;
1250 
1251 	enc=mfmencode;
1252 	b1=byte;
1253 	b2=b1>>4;
1254 	b1&=15;
1255 	word=enc[b2] <<8 | enc [b1];
1256 	return (word|((word&(256|64)) ? 0: 128));
1257 }
1258 
1259 static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1260 {
1261 	int i;
1262 
1263 	for (i = 0; i < len; i++) {
1264 		*dest=dos_encode_byte(*src++);
1265 		*dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1266 		dest++;
1267 	}
1268 }
1269 
1270 static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1271 {
1272 	static struct dos_header hdr={0,0,0,2,0,
1273 	  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1274 	int i;
1275 	static ushort crc[2]={0,0x4e4e};
1276 
1277 	drive&=3;
1278 /* id gap 1 */
1279 /* the MFM word before is always 9254 */
1280 	for(i=0;i<6;i++)
1281 		*raw++=0xaaaaaaaa;
1282 /* 3 sync + 1 headermark */
1283 	*raw++=0x44894489;
1284 	*raw++=0x44895554;
1285 
1286 /* fill in the variable parts of the header */
1287 	hdr.track=unit[drive].track/unit[drive].type->heads;
1288 	hdr.side=unit[drive].track%unit[drive].type->heads;
1289 	hdr.sec=cnt+1;
1290 	hdr.crc=dos_hdr_crc(&hdr);
1291 
1292 /* header (without "magic") and id gap 2*/
1293 	dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1294 	raw+=14;
1295 
1296 /*id gap 3 */
1297 	for(i=0;i<6;i++)
1298 		*raw++=0xaaaaaaaa;
1299 
1300 /* 3 syncs and 1 datamark */
1301 	*raw++=0x44894489;
1302 	*raw++=0x44895545;
1303 
1304 /* data */
1305 	dos_encode_block((ushort *)raw,
1306 			 (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1307 	raw+=256;
1308 
1309 /*data crc + jd's special gap (long words :-/) */
1310 	crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1311 	dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1312 	raw+=2;
1313 
1314 /* data gap */
1315 	for(i=0;i<38;i++)
1316 		*raw++=0x92549254;
1317 
1318 	return raw; /* wrote 652 MFM words */
1319 }
1320 
1321 static void dos_write(int disk)
1322 {
1323 	int cnt;
1324 	unsigned long raw = (unsigned long) raw_buf;
1325 	unsigned long *ptr=(unsigned long *)raw;
1326 
1327 	disk&=3;
1328 /* really gap4 + indexgap , but we write it first and round it up */
1329 	for (cnt=0;cnt<425;cnt++)
1330 		*ptr++=0x92549254;
1331 
1332 /* the following is just guessed */
1333 	if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1334 		for(cnt=0;cnt<473;cnt++)
1335 			*ptr++=0x92549254;
1336 
1337 /* now the index marks...*/
1338 	for (cnt=0;cnt<20;cnt++)
1339 		*ptr++=0x92549254;
1340 	for (cnt=0;cnt<6;cnt++)
1341 		*ptr++=0xaaaaaaaa;
1342 	*ptr++=0x52245224;
1343 	*ptr++=0x52245552;
1344 	for (cnt=0;cnt<20;cnt++)
1345 		*ptr++=0x92549254;
1346 
1347 /* sectors */
1348 	for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1349 		ptr=ms_putsec(disk,ptr,cnt);
1350 
1351 	*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1352 }
1353 
1354 /*
1355  * Here comes the high level stuff (i.e. the filesystem interface)
1356  * and helper functions.
1357  * Normally this should be the only part that has to be adapted to
1358  * different kernel versions.
1359  */
1360 
1361 /* FIXME: this assumes the drive is still spinning -
1362  * which is only true if we complete writing a track within three seconds
1363  */
1364 static void flush_track_callback(struct timer_list *timer)
1365 {
1366 	unsigned long nr = ((unsigned long)timer -
1367 			       (unsigned long)&flush_track_timer[0]) /
1368 					sizeof(flush_track_timer[0]);
1369 
1370 	nr&=3;
1371 	writefromint = 1;
1372 	if (!try_fdc(nr)) {
1373 		/* we might block in an interrupt, so try again later */
1374 		flush_track_timer[nr].expires = jiffies + 1;
1375 		add_timer(flush_track_timer + nr);
1376 		return;
1377 	}
1378 	get_fdc(nr);
1379 	(*unit[nr].dtype->write_fkt)(nr);
1380 	if (!raw_write(nr)) {
1381 		printk (KERN_NOTICE "floppy disk write protected\n");
1382 		writefromint = 0;
1383 		writepending = 0;
1384 	}
1385 	rel_fdc();
1386 }
1387 
1388 static int non_int_flush_track (unsigned long nr)
1389 {
1390 	unsigned long flags;
1391 
1392 	nr&=3;
1393 	writefromint = 0;
1394 	del_timer(&post_write_timer);
1395 	get_fdc(nr);
1396 	if (!fd_motor_on(nr)) {
1397 		writepending = 0;
1398 		rel_fdc();
1399 		return 0;
1400 	}
1401 	local_irq_save(flags);
1402 	if (writepending != 2) {
1403 		local_irq_restore(flags);
1404 		(*unit[nr].dtype->write_fkt)(nr);
1405 		if (!raw_write(nr)) {
1406 			printk (KERN_NOTICE "floppy disk write protected "
1407 				"in write!\n");
1408 			writepending = 0;
1409 			return 0;
1410 		}
1411 		wait_event(wait_fd_block, block_flag != 2);
1412 	}
1413 	else {
1414 		local_irq_restore(flags);
1415 		ms_delay(2); /* 2 ms post_write delay */
1416 		post_write(nr);
1417 	}
1418 	rel_fdc();
1419 	return 1;
1420 }
1421 
1422 static int get_track(int drive, int track)
1423 {
1424 	int error, errcnt;
1425 
1426 	drive&=3;
1427 	if (unit[drive].track == track)
1428 		return 0;
1429 	get_fdc(drive);
1430 	if (!fd_motor_on(drive)) {
1431 		rel_fdc();
1432 		return -1;
1433 	}
1434 
1435 	if (unit[drive].dirty == 1) {
1436 		del_timer (flush_track_timer + drive);
1437 		non_int_flush_track (drive);
1438 	}
1439 	errcnt = 0;
1440 	while (errcnt < MAX_ERRORS) {
1441 		if (!fd_seek(drive, track))
1442 			return -1;
1443 		raw_read(drive);
1444 		error = (*unit[drive].dtype->read_fkt)(drive);
1445 		if (error == 0) {
1446 			rel_fdc();
1447 			return 0;
1448 		}
1449 		/* Read Error Handling: recalibrate and try again */
1450 		unit[drive].track = -1;
1451 		errcnt++;
1452 	}
1453 	rel_fdc();
1454 	return -1;
1455 }
1456 
1457 static blk_status_t amiflop_rw_cur_segment(struct amiga_floppy_struct *floppy,
1458 					   struct request *rq)
1459 {
1460 	int drive = floppy - unit;
1461 	unsigned int cnt, block, track, sector;
1462 	char *data;
1463 
1464 	for (cnt = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
1465 #ifdef DEBUG
1466 		printk("fd: sector %ld + %d requested for %s\n",
1467 		       blk_rq_pos(rq), cnt,
1468 		       (rq_data_dir(rq) == READ) ? "read" : "write");
1469 #endif
1470 		block = blk_rq_pos(rq) + cnt;
1471 		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1472 		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1473 		data = bio_data(rq->bio) + 512 * cnt;
1474 #ifdef DEBUG
1475 		printk("access to track %d, sector %d, with buffer at "
1476 		       "0x%08lx\n", track, sector, data);
1477 #endif
1478 
1479 		if (get_track(drive, track) == -1)
1480 			return BLK_STS_IOERR;
1481 
1482 		if (rq_data_dir(rq) == READ) {
1483 			memcpy(data, floppy->trackbuf + sector * 512, 512);
1484 		} else {
1485 			memcpy(floppy->trackbuf + sector * 512, data, 512);
1486 
1487 			/* keep the drive spinning while writes are scheduled */
1488 			if (!fd_motor_on(drive))
1489 				return BLK_STS_IOERR;
1490 			/*
1491 			 * setup a callback to write the track buffer
1492 			 * after a short (1 tick) delay.
1493 			 */
1494 			floppy->dirty = 1;
1495 		        /* reset the timer */
1496 			mod_timer (flush_track_timer + drive, jiffies + 1);
1497 		}
1498 	}
1499 
1500 	return BLK_STS_OK;
1501 }
1502 
1503 static blk_status_t amiflop_queue_rq(struct blk_mq_hw_ctx *hctx,
1504 				     const struct blk_mq_queue_data *bd)
1505 {
1506 	struct request *rq = bd->rq;
1507 	struct amiga_floppy_struct *floppy = rq->rq_disk->private_data;
1508 	blk_status_t err;
1509 
1510 	if (!spin_trylock_irq(&amiflop_lock))
1511 		return BLK_STS_DEV_RESOURCE;
1512 
1513 	blk_mq_start_request(rq);
1514 
1515 	do {
1516 		err = amiflop_rw_cur_segment(floppy, rq);
1517 	} while (blk_update_request(rq, err, blk_rq_cur_bytes(rq)));
1518 	blk_mq_end_request(rq, err);
1519 
1520 	spin_unlock_irq(&amiflop_lock);
1521 	return BLK_STS_OK;
1522 }
1523 
1524 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1525 {
1526 	int drive = MINOR(bdev->bd_dev) & 3;
1527 
1528 	geo->heads = unit[drive].type->heads;
1529 	geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1530 	geo->cylinders = unit[drive].type->tracks;
1531 	return 0;
1532 }
1533 
1534 static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
1535 		    unsigned int cmd, unsigned long param)
1536 {
1537 	struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1538 	int drive = p - unit;
1539 	static struct floppy_struct getprm;
1540 	void __user *argp = (void __user *)param;
1541 
1542 	switch(cmd){
1543 	case FDFMTBEG:
1544 		get_fdc(drive);
1545 		if (fd_ref[drive] > 1) {
1546 			rel_fdc();
1547 			return -EBUSY;
1548 		}
1549 		fsync_bdev(bdev);
1550 		if (fd_motor_on(drive) == 0) {
1551 			rel_fdc();
1552 			return -ENODEV;
1553 		}
1554 		if (fd_calibrate(drive) == 0) {
1555 			rel_fdc();
1556 			return -ENXIO;
1557 		}
1558 		floppy_off(drive);
1559 		rel_fdc();
1560 		break;
1561 	case FDFMTTRK:
1562 		if (param < p->type->tracks * p->type->heads)
1563 		{
1564 			get_fdc(drive);
1565 			if (fd_seek(drive,param) != 0){
1566 				memset(p->trackbuf, FD_FILL_BYTE,
1567 				       p->dtype->sects * p->type->sect_mult * 512);
1568 				non_int_flush_track(drive);
1569 			}
1570 			floppy_off(drive);
1571 			rel_fdc();
1572 		}
1573 		else
1574 			return -EINVAL;
1575 		break;
1576 	case FDFMTEND:
1577 		floppy_off(drive);
1578 		invalidate_bdev(bdev);
1579 		break;
1580 	case FDGETPRM:
1581 		memset((void *)&getprm, 0, sizeof (getprm));
1582 		getprm.track=p->type->tracks;
1583 		getprm.head=p->type->heads;
1584 		getprm.sect=p->dtype->sects * p->type->sect_mult;
1585 		getprm.size=p->blocks;
1586 		if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1587 			return -EFAULT;
1588 		break;
1589 	case FDSETPRM:
1590 	case FDDEFPRM:
1591 		return -EINVAL;
1592 	case FDFLUSH: /* unconditionally, even if not needed */
1593 		del_timer (flush_track_timer + drive);
1594 		non_int_flush_track(drive);
1595 		break;
1596 #ifdef RAW_IOCTL
1597 	case IOCTL_RAW_TRACK:
1598 		if (copy_to_user(argp, raw_buf, p->type->read_size))
1599 			return -EFAULT;
1600 		else
1601 			return p->type->read_size;
1602 #endif
1603 	default:
1604 		return -ENOSYS;
1605 	}
1606 	return 0;
1607 }
1608 
1609 static int fd_ioctl(struct block_device *bdev, fmode_t mode,
1610 			     unsigned int cmd, unsigned long param)
1611 {
1612 	int ret;
1613 
1614 	mutex_lock(&amiflop_mutex);
1615 	ret = fd_locked_ioctl(bdev, mode, cmd, param);
1616 	mutex_unlock(&amiflop_mutex);
1617 
1618 	return ret;
1619 }
1620 
1621 static void fd_probe(int dev)
1622 {
1623 	unsigned long code;
1624 	int type;
1625 	int drive;
1626 
1627 	drive = dev & 3;
1628 	code = fd_get_drive_id(drive);
1629 
1630 	/* get drive type */
1631 	for (type = 0; type < num_dr_types; type++)
1632 		if (drive_types[type].code == code)
1633 			break;
1634 
1635 	if (type >= num_dr_types) {
1636 		printk(KERN_WARNING "fd_probe: unsupported drive type "
1637 		       "%08lx found\n", code);
1638 		unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1639 		return;
1640 	}
1641 
1642 	unit[drive].type = drive_types + type;
1643 	unit[drive].track = -1;
1644 
1645 	unit[drive].disk = -1;
1646 	unit[drive].motor = 0;
1647 	unit[drive].busy = 0;
1648 	unit[drive].status = -1;
1649 }
1650 
1651 /*
1652  * floppy_open check for aliasing (/dev/fd0 can be the same as
1653  * /dev/PS0 etc), and disallows simultaneous access to the same
1654  * drive with different device numbers.
1655  */
1656 static int floppy_open(struct block_device *bdev, fmode_t mode)
1657 {
1658 	int drive = MINOR(bdev->bd_dev) & 3;
1659 	int system =  (MINOR(bdev->bd_dev) & 4) >> 2;
1660 	int old_dev;
1661 	unsigned long flags;
1662 
1663 	mutex_lock(&amiflop_mutex);
1664 	old_dev = fd_device[drive];
1665 
1666 	if (fd_ref[drive] && old_dev != system) {
1667 		mutex_unlock(&amiflop_mutex);
1668 		return -EBUSY;
1669 	}
1670 
1671 	if (mode & (FMODE_READ|FMODE_WRITE)) {
1672 		check_disk_change(bdev);
1673 		if (mode & FMODE_WRITE) {
1674 			int wrprot;
1675 
1676 			get_fdc(drive);
1677 			fd_select (drive);
1678 			wrprot = !(ciaa.pra & DSKPROT);
1679 			fd_deselect (drive);
1680 			rel_fdc();
1681 
1682 			if (wrprot) {
1683 				mutex_unlock(&amiflop_mutex);
1684 				return -EROFS;
1685 			}
1686 		}
1687 	}
1688 
1689 	local_irq_save(flags);
1690 	fd_ref[drive]++;
1691 	fd_device[drive] = system;
1692 	local_irq_restore(flags);
1693 
1694 	unit[drive].dtype=&data_types[system];
1695 	unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1696 		data_types[system].sects*unit[drive].type->sect_mult;
1697 	set_capacity(unit[drive].gendisk, unit[drive].blocks);
1698 
1699 	printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1700 	       unit[drive].type->name, data_types[system].name);
1701 
1702 	mutex_unlock(&amiflop_mutex);
1703 	return 0;
1704 }
1705 
1706 static void floppy_release(struct gendisk *disk, fmode_t mode)
1707 {
1708 	struct amiga_floppy_struct *p = disk->private_data;
1709 	int drive = p - unit;
1710 
1711 	mutex_lock(&amiflop_mutex);
1712 	if (unit[drive].dirty == 1) {
1713 		del_timer (flush_track_timer + drive);
1714 		non_int_flush_track (drive);
1715 	}
1716 
1717 	if (!fd_ref[drive]--) {
1718 		printk(KERN_CRIT "floppy_release with fd_ref == 0");
1719 		fd_ref[drive] = 0;
1720 	}
1721 #ifdef MODULE
1722 	floppy_off (drive);
1723 #endif
1724 	mutex_unlock(&amiflop_mutex);
1725 }
1726 
1727 /*
1728  * check_events is never called from an interrupt, so we can relax a bit
1729  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1730  * to the desired drive, but it will probably not survive the sleep if
1731  * several floppies are used at the same time: thus the loop.
1732  */
1733 static unsigned amiga_check_events(struct gendisk *disk, unsigned int clearing)
1734 {
1735 	struct amiga_floppy_struct *p = disk->private_data;
1736 	int drive = p - unit;
1737 	int changed;
1738 	static int first_time = 1;
1739 
1740 	if (first_time)
1741 		changed = first_time--;
1742 	else {
1743 		get_fdc(drive);
1744 		fd_select (drive);
1745 		changed = !(ciaa.pra & DSKCHANGE);
1746 		fd_deselect (drive);
1747 		rel_fdc();
1748 	}
1749 
1750 	if (changed) {
1751 		fd_probe(drive);
1752 		p->track = -1;
1753 		p->dirty = 0;
1754 		writepending = 0; /* if this was true before, too bad! */
1755 		writefromint = 0;
1756 		return DISK_EVENT_MEDIA_CHANGE;
1757 	}
1758 	return 0;
1759 }
1760 
1761 static const struct block_device_operations floppy_fops = {
1762 	.owner		= THIS_MODULE,
1763 	.open		= floppy_open,
1764 	.release	= floppy_release,
1765 	.ioctl		= fd_ioctl,
1766 	.getgeo		= fd_getgeo,
1767 	.check_events	= amiga_check_events,
1768 };
1769 
1770 static const struct blk_mq_ops amiflop_mq_ops = {
1771 	.queue_rq = amiflop_queue_rq,
1772 };
1773 
1774 static struct gendisk *fd_alloc_disk(int drive)
1775 {
1776 	struct gendisk *disk;
1777 
1778 	disk = alloc_disk(1);
1779 	if (!disk)
1780 		goto out;
1781 
1782 	disk->queue = blk_mq_init_sq_queue(&unit[drive].tag_set, &amiflop_mq_ops,
1783 						2, BLK_MQ_F_SHOULD_MERGE);
1784 	if (IS_ERR(disk->queue)) {
1785 		disk->queue = NULL;
1786 		goto out_put_disk;
1787 	}
1788 
1789 	unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL);
1790 	if (!unit[drive].trackbuf)
1791 		goto out_cleanup_queue;
1792 
1793 	return disk;
1794 
1795 out_cleanup_queue:
1796 	blk_cleanup_queue(disk->queue);
1797 	disk->queue = NULL;
1798 	blk_mq_free_tag_set(&unit[drive].tag_set);
1799 out_put_disk:
1800 	put_disk(disk);
1801 out:
1802 	unit[drive].type->code = FD_NODRIVE;
1803 	return NULL;
1804 }
1805 
1806 static int __init fd_probe_drives(void)
1807 {
1808 	int drive,drives,nomem;
1809 
1810 	pr_info("FD: probing units\nfound");
1811 	drives=0;
1812 	nomem=0;
1813 	for(drive=0;drive<FD_MAX_UNITS;drive++) {
1814 		struct gendisk *disk;
1815 		fd_probe(drive);
1816 		if (unit[drive].type->code == FD_NODRIVE)
1817 			continue;
1818 
1819 		disk = fd_alloc_disk(drive);
1820 		if (!disk) {
1821 			pr_cont(" no mem for fd%d", drive);
1822 			nomem = 1;
1823 			continue;
1824 		}
1825 		unit[drive].gendisk = disk;
1826 		drives++;
1827 
1828 		pr_cont(" fd%d",drive);
1829 		disk->major = FLOPPY_MAJOR;
1830 		disk->first_minor = drive;
1831 		disk->fops = &floppy_fops;
1832 		sprintf(disk->disk_name, "fd%d", drive);
1833 		disk->private_data = &unit[drive];
1834 		set_capacity(disk, 880*2);
1835 		add_disk(disk);
1836 	}
1837 	if ((drives > 0) || (nomem == 0)) {
1838 		if (drives == 0)
1839 			pr_cont(" no drives");
1840 		pr_cont("\n");
1841 		return drives;
1842 	}
1843 	pr_cont("\n");
1844 	return -ENOMEM;
1845 }
1846 
1847 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1848 {
1849 	int drive = *part & 3;
1850 	if (unit[drive].type->code == FD_NODRIVE)
1851 		return NULL;
1852 	*part = 0;
1853 	return get_disk_and_module(unit[drive].gendisk);
1854 }
1855 
1856 static int __init amiga_floppy_probe(struct platform_device *pdev)
1857 {
1858 	int i, ret;
1859 
1860 	if (register_blkdev(FLOPPY_MAJOR,"fd"))
1861 		return -EBUSY;
1862 
1863 	ret = -ENOMEM;
1864 	raw_buf = amiga_chip_alloc(RAW_BUF_SIZE, "Floppy");
1865 	if (!raw_buf) {
1866 		printk("fd: cannot get chip mem buffer\n");
1867 		goto out_blkdev;
1868 	}
1869 
1870 	ret = -EBUSY;
1871 	if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1872 		printk("fd: cannot get irq for dma\n");
1873 		goto out_irq;
1874 	}
1875 
1876 	if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1877 		printk("fd: cannot get irq for timer\n");
1878 		goto out_irq2;
1879 	}
1880 
1881 	ret = -ENODEV;
1882 	if (fd_probe_drives() < 1) /* No usable drives */
1883 		goto out_probe;
1884 
1885 	blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1886 				floppy_find, NULL, NULL);
1887 
1888 	/* initialize variables */
1889 	timer_setup(&motor_on_timer, motor_on_callback, 0);
1890 	motor_on_timer.expires = 0;
1891 	for (i = 0; i < FD_MAX_UNITS; i++) {
1892 		timer_setup(&motor_off_timer[i], fd_motor_off, 0);
1893 		motor_off_timer[i].expires = 0;
1894 		timer_setup(&flush_track_timer[i], flush_track_callback, 0);
1895 		flush_track_timer[i].expires = 0;
1896 
1897 		unit[i].track = -1;
1898 	}
1899 
1900 	timer_setup(&post_write_timer, post_write_callback, 0);
1901 	post_write_timer.expires = 0;
1902 
1903 	for (i = 0; i < 128; i++)
1904 		mfmdecode[i]=255;
1905 	for (i = 0; i < 16; i++)
1906 		mfmdecode[mfmencode[i]]=i;
1907 
1908 	/* make sure that disk DMA is enabled */
1909 	custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1910 
1911 	/* init ms timer */
1912 	ciaa.crb = 8; /* one-shot, stop */
1913 	return 0;
1914 
1915 out_probe:
1916 	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1917 out_irq2:
1918 	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1919 out_irq:
1920 	amiga_chip_free(raw_buf);
1921 out_blkdev:
1922 	unregister_blkdev(FLOPPY_MAJOR,"fd");
1923 	return ret;
1924 }
1925 
1926 static struct platform_driver amiga_floppy_driver = {
1927 	.driver   = {
1928 		.name	= "amiga-floppy",
1929 	},
1930 };
1931 
1932 static int __init amiga_floppy_init(void)
1933 {
1934 	return platform_driver_probe(&amiga_floppy_driver, amiga_floppy_probe);
1935 }
1936 
1937 module_init(amiga_floppy_init);
1938 
1939 #ifndef MODULE
1940 static int __init amiga_floppy_setup (char *str)
1941 {
1942 	int n;
1943 	if (!MACH_IS_AMIGA)
1944 		return 0;
1945 	if (!get_option(&str, &n))
1946 		return 0;
1947 	printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1948 	fd_def_df0 = n;
1949 	return 1;
1950 }
1951 
1952 __setup("floppy=", amiga_floppy_setup);
1953 #endif
1954 
1955 MODULE_ALIAS("platform:amiga-floppy");
1956