amiflop.c revision 786029ff810ff4a2fd52c0462713985a415417ab
1/*
2 *  linux/amiga/amiflop.c
3 *
4 *  Copyright (C) 1993  Greg Harp
5 *  Portions of this driver are based on code contributed by Brad Pepers
6 *
7 *  revised 28.5.95 by Joerg Dorchain
8 *  - now no bugs(?) any more for both HD & DD
9 *  - added support for 40 Track 5.25" drives, 80-track hopefully behaves
10 *    like 3.5" dd (no way to test - are there any 5.25" drives out there
11 *    that work on an A4000?)
12 *  - wrote formatting routine (maybe dirty, but works)
13 *
14 *  june/july 1995 added ms-dos support by Joerg Dorchain
15 *  (portions based on messydos.device and various contributors)
16 *  - currently only 9 and 18 sector disks
17 *
18 *  - fixed a bug with the internal trackbuffer when using multiple
19 *    disks the same time
20 *  - made formatting a bit safer
21 *  - added command line and machine based default for "silent" df0
22 *
23 *  december 1995 adapted for 1.2.13pl4 by Joerg Dorchain
24 *  - works but I think it's inefficient. (look in redo_fd_request)
25 *    But the changes were very efficient. (only three and a half lines)
26 *
27 *  january 1996 added special ioctl for tracking down read/write problems
28 *  - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data
29 *    is copied to area. (area should be large enough since no checking is
30 *    done - 30K is currently sufficient). return the actual size of the
31 *    trackbuffer
32 *  - replaced udelays() by a timer (CIAA timer B) for the waits
33 *    needed for the disk mechanic.
34 *
35 *  february 1996 fixed error recovery and multiple disk access
36 *  - both got broken the first time I tampered with the driver :-(
37 *  - still not safe, but better than before
38 *
39 *  revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.
40 *  - Minor changes to accept the kdev_t.
41 *  - Replaced some more udelays with ms_delays. Udelay is just a loop,
42 *    and so the delay will be different depending on the given
43 *    processor :-(
44 *  - The driver could use a major cleanup because of the new
45 *    major/minor handling that came with kdev_t. It seems to work for
46 *    the time being, but I can't guarantee that it will stay like
47 *    that when we start using 16 (24?) bit minors.
48 *
49 * restructured jan 1997 by Joerg Dorchain
50 * - Fixed Bug accessing multiple disks
51 * - some code cleanup
52 * - added trackbuffer for each drive to speed things up
53 * - fixed some race conditions (who finds the next may send it to me ;-)
54 */
55
56#include <linux/module.h>
57#include <linux/slab.h>
58
59#include <linux/fd.h>
60#include <linux/hdreg.h>
61#include <linux/delay.h>
62#include <linux/init.h>
63#include <linux/smp_lock.h>
64#include <linux/amifdreg.h>
65#include <linux/amifd.h>
66#include <linux/buffer_head.h>
67#include <linux/blkdev.h>
68#include <linux/elevator.h>
69#include <linux/interrupt.h>
70#include <linux/platform_device.h>
71
72#include <asm/setup.h>
73#include <asm/uaccess.h>
74#include <asm/amigahw.h>
75#include <asm/amigaints.h>
76#include <asm/irq.h>
77
78#undef DEBUG /* print _LOTS_ of infos */
79
80#define RAW_IOCTL
81#ifdef RAW_IOCTL
82#define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
83#endif
84
85/*
86 *  Defines
87 */
88
89/*
90 *  Error codes
91 */
92#define FD_OK		0	/* operation succeeded */
93#define FD_ERROR	-1	/* general error (seek, read, write, etc) */
94#define FD_NOUNIT	1	/* unit does not exist */
95#define FD_UNITBUSY	2	/* unit already active */
96#define FD_NOTACTIVE	3	/* unit is not active */
97#define FD_NOTREADY	4	/* unit is not ready (motor not on/no disk) */
98
99#define MFM_NOSYNC	1
100#define MFM_HEADER	2
101#define MFM_DATA	3
102#define MFM_TRACK	4
103
104/*
105 *  Floppy ID values
106 */
107#define FD_NODRIVE	0x00000000  /* response when no unit is present */
108#define FD_DD_3 	0xffffffff  /* double-density 3.5" (880K) drive */
109#define FD_HD_3 	0x55555555  /* high-density 3.5" (1760K) drive */
110#define FD_DD_5 	0xaaaaaaaa  /* double-density 5.25" (440K) drive */
111
112static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
113
114module_param(fd_def_df0, ulong, 0);
115MODULE_LICENSE("GPL");
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
126static 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};
134static int num_dr_types = ARRAY_SIZE(drive_types);
135
136static int amiga_read(int), dos_read(int);
137static void amiga_write(int), dos_write(int);
138static 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 */
144static struct amiga_floppy_struct unit[FD_MAX_UNITS];
145
146static struct timer_list flush_track_timer[FD_MAX_UNITS];
147static struct timer_list post_write_timer;
148static struct timer_list motor_on_timer;
149static struct timer_list motor_off_timer[FD_MAX_UNITS];
150static int on_attempts;
151
152/* Synchronization of FDC access */
153/* request loop (trackbuffer) */
154static volatile int fdc_busy = -1;
155static volatile int fdc_nested;
156static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
157
158static DECLARE_COMPLETION(motor_on_completion);
159
160static volatile int selected = -1;	/* currently selected drive */
161
162static int writepending;
163static int writefromint;
164static char *raw_buf;
165static int fdc_queue;
166
167static DEFINE_SPINLOCK(amiflop_lock);
168
169#define RAW_BUF_SIZE 30000  /* size of raw disk data */
170
171/*
172 * These are global variables, as that's the easiest way to give
173 * information to interrupts. They are the data used for the current
174 * request.
175 */
176static volatile char block_flag;
177static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
178
179/* MS-Dos MFM Coding tables (should go quick and easy) */
180static unsigned char mfmencode[16]={
181	0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
182	0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
183};
184static unsigned char mfmdecode[128];
185
186/* floppy internal millisecond timer stuff */
187static DECLARE_COMPLETION(ms_wait_completion);
188#define MS_TICKS ((amiga_eclock+50)/1000)
189
190/*
191 * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
192 * max X times - some types of errors increase the errorcount by 2 or
193 * even 3, so we might actually retry only X/2 times before giving up.
194 */
195#define MAX_ERRORS 12
196
197#define custom amiga_custom
198
199/* Prevent "aliased" accesses. */
200static int fd_ref[4] = { 0,0,0,0 };
201static 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
211static irqreturn_t ms_isr(int irq, void *dummy)
212{
213	complete(&ms_wait_completion);
214	return IRQ_HANDLED;
215}
216
217/* all waits are queued up
218   A more generic routine would do a schedule a la timer.device */
219static void ms_delay(int ms)
220{
221	int ticks;
222	static DEFINE_MUTEX(mutex);
223
224	if (ms > 0) {
225		mutex_lock(&mutex);
226		ticks = MS_TICKS*ms-1;
227		ciaa.tblo=ticks%256;
228		ciaa.tbhi=ticks/256;
229		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
230		wait_for_completion(&ms_wait_completion);
231		mutex_unlock(&mutex);
232	}
233}
234
235/* Hardware semaphore */
236
237/* returns true when we would get the semaphore */
238static inline int try_fdc(int drive)
239{
240	drive &= 3;
241	return ((fdc_busy < 0) || (fdc_busy == drive));
242}
243
244static void get_fdc(int drive)
245{
246	unsigned long flags;
247
248	drive &= 3;
249#ifdef DEBUG
250	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
251#endif
252	local_irq_save(flags);
253	wait_event(fdc_wait, try_fdc(drive));
254	fdc_busy = drive;
255	fdc_nested++;
256	local_irq_restore(flags);
257}
258
259static inline void rel_fdc(void)
260{
261#ifdef DEBUG
262	if (fdc_nested == 0)
263		printk("fd: unmatched rel_fdc\n");
264	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
265#endif
266	fdc_nested--;
267	if (fdc_nested == 0) {
268		fdc_busy = -1;
269		wake_up(&fdc_wait);
270	}
271}
272
273static void fd_select (int drive)
274{
275	unsigned char prb = ~0;
276
277	drive&=3;
278#ifdef DEBUG
279	printk("selecting %d\n",drive);
280#endif
281	if (drive == selected)
282		return;
283	get_fdc(drive);
284	selected = drive;
285
286	if (unit[drive].track % 2 != 0)
287		prb &= ~DSKSIDE;
288	if (unit[drive].motor == 1)
289		prb &= ~DSKMOTOR;
290	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
291	ciab.prb = prb;
292	prb &= ~SELMASK(drive);
293	ciab.prb = prb;
294	rel_fdc();
295}
296
297static void fd_deselect (int drive)
298{
299	unsigned char prb;
300	unsigned long flags;
301
302	drive&=3;
303#ifdef DEBUG
304	printk("deselecting %d\n",drive);
305#endif
306	if (drive != selected) {
307		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
308		return;
309	}
310
311	get_fdc(drive);
312	local_irq_save(flags);
313
314	selected = -1;
315
316	prb = ciab.prb;
317	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
318	ciab.prb = prb;
319
320	local_irq_restore (flags);
321	rel_fdc();
322
323}
324
325static void motor_on_callback(unsigned long nr)
326{
327	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
328		complete_all(&motor_on_completion);
329	} else {
330		motor_on_timer.expires = jiffies + HZ/10;
331		add_timer(&motor_on_timer);
332	}
333}
334
335static int fd_motor_on(int nr)
336{
337	nr &= 3;
338
339	del_timer(motor_off_timer + nr);
340
341	if (!unit[nr].motor) {
342		unit[nr].motor = 1;
343		fd_select(nr);
344
345		INIT_COMPLETION(motor_on_completion);
346		motor_on_timer.data = nr;
347		mod_timer(&motor_on_timer, jiffies + HZ/2);
348
349		on_attempts = 10;
350		wait_for_completion(&motor_on_completion);
351		fd_deselect(nr);
352	}
353
354	if (on_attempts == 0) {
355		on_attempts = -1;
356#if 0
357		printk (KERN_ERR "motor_on failed, turning motor off\n");
358		fd_motor_off (nr);
359		return 0;
360#else
361		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
362#endif
363	}
364
365	return 1;
366}
367
368static void fd_motor_off(unsigned long drive)
369{
370	long calledfromint;
371#ifdef MODULE
372	long decusecount;
373
374	decusecount = drive & 0x40000000;
375#endif
376	calledfromint = drive & 0x80000000;
377	drive&=3;
378	if (calledfromint && !try_fdc(drive)) {
379		/* We would be blocked in an interrupt, so try again later */
380		motor_off_timer[drive].expires = jiffies + 1;
381		add_timer(motor_off_timer + drive);
382		return;
383	}
384	unit[drive].motor = 0;
385	fd_select(drive);
386	udelay (1);
387	fd_deselect(drive);
388}
389
390static void floppy_off (unsigned int nr)
391{
392	int drive;
393
394	drive = nr & 3;
395	/* called this way it is always from interrupt */
396	motor_off_timer[drive].data = nr | 0x80000000;
397	mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
398}
399
400static int fd_calibrate(int drive)
401{
402	unsigned char prb;
403	int n;
404
405	drive &= 3;
406	get_fdc(drive);
407	if (!fd_motor_on (drive))
408		return 0;
409	fd_select (drive);
410	prb = ciab.prb;
411	prb |= DSKSIDE;
412	prb &= ~DSKDIREC;
413	ciab.prb = prb;
414	for (n = unit[drive].type->tracks/2; n != 0; --n) {
415		if (ciaa.pra & DSKTRACK0)
416			break;
417		prb &= ~DSKSTEP;
418		ciab.prb = prb;
419		prb |= DSKSTEP;
420		udelay (2);
421		ciab.prb = prb;
422		ms_delay(unit[drive].type->step_delay);
423	}
424	ms_delay (unit[drive].type->settle_time);
425	prb |= DSKDIREC;
426	n = unit[drive].type->tracks + 20;
427	for (;;) {
428		prb &= ~DSKSTEP;
429		ciab.prb = prb;
430		prb |= DSKSTEP;
431		udelay (2);
432		ciab.prb = prb;
433		ms_delay(unit[drive].type->step_delay + 1);
434		if ((ciaa.pra & DSKTRACK0) == 0)
435			break;
436		if (--n == 0) {
437			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
438			fd_motor_off (drive);
439			unit[drive].track = -1;
440			rel_fdc();
441			return 0;
442		}
443	}
444	unit[drive].track = 0;
445	ms_delay(unit[drive].type->settle_time);
446
447	rel_fdc();
448	fd_deselect(drive);
449	return 1;
450}
451
452static int fd_seek(int drive, int track)
453{
454	unsigned char prb;
455	int cnt;
456
457#ifdef DEBUG
458	printk("seeking drive %d to track %d\n",drive,track);
459#endif
460	drive &= 3;
461	get_fdc(drive);
462	if (unit[drive].track == track) {
463		rel_fdc();
464		return 1;
465	}
466	if (!fd_motor_on(drive)) {
467		rel_fdc();
468		return 0;
469	}
470	if (unit[drive].track < 0 && !fd_calibrate(drive)) {
471		rel_fdc();
472		return 0;
473	}
474
475	fd_select (drive);
476	cnt = unit[drive].track/2 - track/2;
477	prb = ciab.prb;
478	prb |= DSKSIDE | DSKDIREC;
479	if (track % 2 != 0)
480		prb &= ~DSKSIDE;
481	if (cnt < 0) {
482		cnt = - cnt;
483		prb &= ~DSKDIREC;
484	}
485	ciab.prb = prb;
486	if (track % 2 != unit[drive].track % 2)
487		ms_delay (unit[drive].type->side_time);
488	unit[drive].track = track;
489	if (cnt == 0) {
490		rel_fdc();
491		fd_deselect(drive);
492		return 1;
493	}
494	do {
495		prb &= ~DSKSTEP;
496		ciab.prb = prb;
497		prb |= DSKSTEP;
498		udelay (1);
499		ciab.prb = prb;
500		ms_delay (unit[drive].type->step_delay);
501	} while (--cnt != 0);
502	ms_delay (unit[drive].type->settle_time);
503
504	rel_fdc();
505	fd_deselect(drive);
506	return 1;
507}
508
509static unsigned long fd_get_drive_id(int drive)
510{
511	int i;
512	ulong id = 0;
513
514  	drive&=3;
515  	get_fdc(drive);
516	/* set up for ID */
517	MOTOR_ON;
518	udelay(2);
519	SELECT(SELMASK(drive));
520	udelay(2);
521	DESELECT(SELMASK(drive));
522	udelay(2);
523	MOTOR_OFF;
524	udelay(2);
525	SELECT(SELMASK(drive));
526	udelay(2);
527	DESELECT(SELMASK(drive));
528	udelay(2);
529
530	/* loop and read disk ID */
531	for (i=0; i<32; i++) {
532		SELECT(SELMASK(drive));
533		udelay(2);
534
535		/* read and store value of DSKRDY */
536		id <<= 1;
537		id |= (ciaa.pra & DSKRDY) ? 0 : 1;	/* cia regs are low-active! */
538
539		DESELECT(SELMASK(drive));
540	}
541
542	rel_fdc();
543
544        /*
545         * RB: At least A500/A2000's df0: don't identify themselves.
546         * As every (real) Amiga has at least a 3.5" DD drive as df0:
547         * we default to that if df0: doesn't identify as a certain
548         * type.
549         */
550        if(drive == 0 && id == FD_NODRIVE)
551	{
552                id = fd_def_df0;
553                printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
554	}
555	/* return the ID value */
556	return (id);
557}
558
559static irqreturn_t fd_block_done(int irq, void *dummy)
560{
561	if (block_flag)
562		custom.dsklen = 0x4000;
563
564	if (block_flag == 2) { /* writing */
565		writepending = 2;
566		post_write_timer.expires = jiffies + 1; /* at least 2 ms */
567		post_write_timer.data = selected;
568		add_timer(&post_write_timer);
569	}
570	else {                /* reading */
571		block_flag = 0;
572		wake_up (&wait_fd_block);
573	}
574	return IRQ_HANDLED;
575}
576
577static void raw_read(int drive)
578{
579	drive&=3;
580	get_fdc(drive);
581	wait_event(wait_fd_block, !block_flag);
582	fd_select(drive);
583	/* setup adkcon bits correctly */
584	custom.adkcon = ADK_MSBSYNC;
585	custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
586
587	custom.dsksync = MFM_SYNC;
588
589	custom.dsklen = 0;
590	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
591	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
592	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
593
594	block_flag = 1;
595
596	wait_event(wait_fd_block, !block_flag);
597
598	custom.dsklen = 0;
599	fd_deselect(drive);
600	rel_fdc();
601}
602
603static int raw_write(int drive)
604{
605	ushort adk;
606
607	drive&=3;
608	get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
609	if ((ciaa.pra & DSKPROT) == 0) {
610		rel_fdc();
611		return 0;
612	}
613	wait_event(wait_fd_block, !block_flag);
614	fd_select(drive);
615	/* clear adkcon bits */
616	custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
617	/* set appropriate adkcon bits */
618	adk = ADK_SETCLR|ADK_FAST;
619	if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
620		adk |= ADK_PRECOMP1;
621	else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
622		adk |= ADK_PRECOMP0;
623	custom.adkcon = adk;
624
625	custom.dsklen = DSKLEN_WRITE;
626	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
627	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
628	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
629
630	block_flag = 2;
631	return 1;
632}
633
634/*
635 * to be called at least 2ms after the write has finished but before any
636 * other access to the hardware.
637 */
638static void post_write (unsigned long drive)
639{
640#ifdef DEBUG
641	printk("post_write for drive %ld\n",drive);
642#endif
643	drive &= 3;
644	custom.dsklen = 0;
645	block_flag = 0;
646	writepending = 0;
647	writefromint = 0;
648	unit[drive].dirty = 0;
649	wake_up(&wait_fd_block);
650	fd_deselect(drive);
651	rel_fdc(); /* corresponds to get_fdc() in raw_write */
652}
653
654
655/*
656 * The following functions are to convert the block contents into raw data
657 * written to disk and vice versa.
658 * (Add other formats here ;-))
659 */
660
661static unsigned long scan_sync(unsigned long raw, unsigned long end)
662{
663	ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
664
665	while (ptr < endp && *ptr++ != 0x4489)
666		;
667	if (ptr < endp) {
668		while (*ptr == 0x4489 && ptr < endp)
669			ptr++;
670		return (ulong)ptr;
671	}
672	return 0;
673}
674
675static inline unsigned long checksum(unsigned long *addr, int len)
676{
677	unsigned long csum = 0;
678
679	len /= sizeof(*addr);
680	while (len-- > 0)
681		csum ^= *addr++;
682	csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
683
684	return csum;
685}
686
687static unsigned long decode (unsigned long *data, unsigned long *raw,
688			     int len)
689{
690	ulong *odd, *even;
691
692	/* convert length from bytes to longwords */
693	len >>= 2;
694	odd = raw;
695	even = odd + len;
696
697	/* prepare return pointer */
698	raw += len * 2;
699
700	do {
701		*data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
702	} while (--len != 0);
703
704	return (ulong)raw;
705}
706
707struct header {
708	unsigned char magic;
709	unsigned char track;
710	unsigned char sect;
711	unsigned char ord;
712	unsigned char labels[16];
713	unsigned long hdrchk;
714	unsigned long datachk;
715};
716
717static int amiga_read(int drive)
718{
719	unsigned long raw;
720	unsigned long end;
721	int scnt;
722	unsigned long csum;
723	struct header hdr;
724
725	drive&=3;
726	raw = (long) raw_buf;
727	end = raw + unit[drive].type->read_size;
728
729	for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
730		if (!(raw = scan_sync(raw, end))) {
731			printk (KERN_INFO "can't find sync for sector %d\n", scnt);
732			return MFM_NOSYNC;
733		}
734
735		raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
736		raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
737		raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
738		raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
739		csum = checksum((ulong *)&hdr,
740				(char *)&hdr.hdrchk-(char *)&hdr);
741
742#ifdef DEBUG
743		printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
744			hdr.magic, hdr.track, hdr.sect, hdr.ord,
745			*(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
746			*(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
747			hdr.hdrchk, hdr.datachk);
748#endif
749
750		if (hdr.hdrchk != csum) {
751			printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
752			return MFM_HEADER;
753		}
754
755		/* verify track */
756		if (hdr.track != unit[drive].track) {
757			printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
758			return MFM_TRACK;
759		}
760
761		raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
762			      (ulong *)raw, 512);
763		csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
764
765		if (hdr.datachk != csum) {
766			printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
767			       hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
768			       hdr.datachk, csum);
769			printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
770				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
771				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
772				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
773				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
774			return MFM_DATA;
775		}
776	}
777
778	return 0;
779}
780
781static void encode(unsigned long data, unsigned long *dest)
782{
783	unsigned long data2;
784
785	data &= 0x55555555;
786	data2 = data ^ 0x55555555;
787	data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
788
789	if (*(dest - 1) & 0x00000001)
790		data &= 0x7FFFFFFF;
791
792	*dest = data;
793}
794
795static void encode_block(unsigned long *dest, unsigned long *src, int len)
796{
797	int cnt, to_cnt = 0;
798	unsigned long data;
799
800	/* odd bits */
801	for (cnt = 0; cnt < len / 4; cnt++) {
802		data = src[cnt] >> 1;
803		encode(data, dest + to_cnt++);
804	}
805
806	/* even bits */
807	for (cnt = 0; cnt < len / 4; cnt++) {
808		data = src[cnt];
809		encode(data, dest + to_cnt++);
810	}
811}
812
813static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
814{
815	struct header hdr;
816	int i;
817
818	disk&=3;
819	*raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
820	raw++;
821	*raw++ = 0x44894489;
822
823	hdr.magic = 0xFF;
824	hdr.track = unit[disk].track;
825	hdr.sect = cnt;
826	hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
827	for (i = 0; i < 16; i++)
828		hdr.labels[i] = 0;
829	hdr.hdrchk = checksum((ulong *)&hdr,
830			      (char *)&hdr.hdrchk-(char *)&hdr);
831	hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
832
833	encode_block(raw, (ulong *)&hdr.magic, 4);
834	raw += 2;
835	encode_block(raw, (ulong *)&hdr.labels, 16);
836	raw += 8;
837	encode_block(raw, (ulong *)&hdr.hdrchk, 4);
838	raw += 2;
839	encode_block(raw, (ulong *)&hdr.datachk, 4);
840	raw += 2;
841	encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
842	raw += 256;
843
844	return raw;
845}
846
847static void amiga_write(int disk)
848{
849	unsigned int cnt;
850	unsigned long *ptr = (unsigned long *)raw_buf;
851
852	disk&=3;
853	/* gap space */
854	for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
855		*ptr++ = 0xaaaaaaaa;
856
857	/* sectors */
858	for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
859		ptr = putsec (disk, ptr, cnt);
860	*(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
861}
862
863
864struct dos_header {
865	unsigned char track,   /* 0-80 */
866		side,    /* 0-1 */
867		sec,     /* 0-...*/
868		len_desc;/* 2 */
869	unsigned short crc;     /* on 68000 we got an alignment problem,
870				   but this compiler solves it  by adding silently
871				   adding a pad byte so data won't fit
872				   and this took about 3h to discover.... */
873	unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
874};
875
876/* crc routines are borrowed from the messydos-handler  */
877
878/* excerpt from the messydos-device
879; The CRC is computed not only over the actual data, but including
880; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
881; As we don't read or encode these fields into our buffers, we have to
882; preload the registers containing the CRC with the values they would have
883; after stepping over these fields.
884;
885; How CRCs "really" work:
886;
887; First, you should regard a bitstring as a series of coefficients of
888; polynomials. We calculate with these polynomials in modulo-2
889; arithmetic, in which both add and subtract are done the same as
890; exclusive-or. Now, we modify our data (a very long polynomial) in
891; such a way that it becomes divisible by the CCITT-standard 16-bit
892;		 16   12   5
893; polynomial:	x  + x	+ x + 1, represented by $11021. The easiest
894; way to do this would be to multiply (using proper arithmetic) our
895; datablock with $11021. So we have:
896;   data * $11021		 =
897;   data * ($10000 + $1021)      =
898;   data * $10000 + data * $1021
899; The left part of this is simple: Just add two 0 bytes. But then
900; the right part (data $1021) remains difficult and even could have
901; a carry into the left part. The solution is to use a modified
902; multiplication, which has a result that is not correct, but with
903; a difference of any multiple of $11021. We then only need to keep
904; the 16 least significant bits of the result.
905;
906; The following algorithm does this for us:
907;
908;   unsigned char *data, c, crclo, crchi;
909;   while (not done) {
910;	c = *data++ + crchi;
911;	crchi = (@ c) >> 8 + crclo;
912;	crclo = @ c;
913;   }
914;
915; Remember, + is done with EOR, the @ operator is in two tables (high
916; and low byte separately), which is calculated as
917;
918;      $1021 * (c & $F0)
919;  xor $1021 * (c & $0F)
920;  xor $1021 * (c >> 4)         (* is regular multiplication)
921;
922;
923; Anyway, the end result is the same as the remainder of the division of
924; the data by $11021. I am afraid I need to study theory a bit more...
925
926
927my only works was to code this from manx to C....
928
929*/
930
931static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
932{
933	static unsigned char CRCTable1[] = {
934		0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
935		0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
936		0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
937		0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
938		0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
939		0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
940		0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
941		0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
942		0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
943		0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
944		0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
945		0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
946		0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
947		0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
948		0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
949		0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
950	};
951
952	static unsigned char CRCTable2[] = {
953		0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
954		0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
955		0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
956		0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
957		0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
958		0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
959		0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
960		0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
961		0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
962		0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
963		0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
964		0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
965		0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
966		0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
967		0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
968		0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
969	};
970
971/* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
972	register int i;
973	register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
974
975	CRCT1=CRCTable1;
976	CRCT2=CRCTable2;
977	data=data_a3;
978	crcl=data_d1;
979	crch=data_d0;
980	for (i=data_d3; i>=0; i--) {
981		c = (*data++) ^ crch;
982		crch = CRCT1[c] ^ crcl;
983		crcl = CRCT2[c];
984	}
985	return (crch<<8)|crcl;
986}
987
988static inline ushort dos_hdr_crc (struct dos_header *hdr)
989{
990	return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
991}
992
993static inline ushort dos_data_crc(unsigned char *data)
994{
995	return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
996}
997
998static inline unsigned char dos_decode_byte(ushort word)
999{
1000	register ushort w2;
1001	register unsigned char byte;
1002	register unsigned char *dec = mfmdecode;
1003
1004	w2=word;
1005	w2>>=8;
1006	w2&=127;
1007	byte = dec[w2];
1008	byte <<= 4;
1009	w2 = word & 127;
1010	byte |= dec[w2];
1011	return byte;
1012}
1013
1014static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1015{
1016	int i;
1017
1018	for (i = 0; i < len; i++)
1019		*data++=dos_decode_byte(*raw++);
1020	return ((ulong)raw);
1021}
1022
1023#ifdef DEBUG
1024static void dbg(unsigned long ptr)
1025{
1026	printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1027	       ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1028	       ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1029}
1030#endif
1031
1032static int dos_read(int drive)
1033{
1034	unsigned long end;
1035	unsigned long raw;
1036	int scnt;
1037	unsigned short crc,data_crc[2];
1038	struct dos_header hdr;
1039
1040	drive&=3;
1041	raw = (long) raw_buf;
1042	end = raw + unit[drive].type->read_size;
1043
1044	for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1045		do { /* search for the right sync of each sec-hdr */
1046			if (!(raw = scan_sync (raw, end))) {
1047				printk(KERN_INFO "dos_read: no hdr sync on "
1048				       "track %d, unit %d for sector %d\n",
1049				       unit[drive].track,drive,scnt);
1050				return MFM_NOSYNC;
1051			}
1052#ifdef DEBUG
1053			dbg(raw);
1054#endif
1055		} while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1056		raw+=2; /* skip over headermark */
1057		raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1058		crc = dos_hdr_crc(&hdr);
1059
1060#ifdef DEBUG
1061		printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1062		       hdr.sec, hdr.len_desc, hdr.crc);
1063#endif
1064
1065		if (crc != hdr.crc) {
1066			printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1067			       hdr.crc, crc);
1068			return MFM_HEADER;
1069		}
1070		if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1071			printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1072			       hdr.track,
1073			       unit[drive].track/unit[drive].type->heads);
1074			return MFM_TRACK;
1075		}
1076
1077		if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1078			printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1079			       hdr.side,
1080			       unit[drive].track%unit[drive].type->heads);
1081			return MFM_TRACK;
1082		}
1083
1084		if (hdr.len_desc != 2) {
1085			printk(KERN_INFO "dos_read: unknown sector len "
1086			       "descriptor %d\n", hdr.len_desc);
1087			return MFM_DATA;
1088		}
1089#ifdef DEBUG
1090		printk("hdr accepted\n");
1091#endif
1092		if (!(raw = scan_sync (raw, end))) {
1093			printk(KERN_INFO "dos_read: no data sync on track "
1094			       "%d, unit %d for sector%d, disk sector %d\n",
1095			       unit[drive].track, drive, scnt, hdr.sec);
1096			return MFM_NOSYNC;
1097		}
1098#ifdef DEBUG
1099		dbg(raw);
1100#endif
1101
1102		if (*((ushort *)raw)!=0x5545) {
1103			printk(KERN_INFO "dos_read: no data mark after "
1104			       "sync (%d,%d,%d,%d) sc=%d\n",
1105			       hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1106			return MFM_NOSYNC;
1107		}
1108
1109		raw+=2;  /* skip data mark (included in checksum) */
1110		raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1111		raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1112		crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1113
1114		if (crc != data_crc[0]) {
1115			printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1116			       "sc=%d, %x %x\n", hdr.track, hdr.side,
1117			       hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1118			printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1119			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1120			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1121			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1122			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1123			return MFM_DATA;
1124		}
1125	}
1126	return 0;
1127}
1128
1129static inline ushort dos_encode_byte(unsigned char byte)
1130{
1131	register unsigned char *enc, b2, b1;
1132	register ushort word;
1133
1134	enc=mfmencode;
1135	b1=byte;
1136	b2=b1>>4;
1137	b1&=15;
1138	word=enc[b2] <<8 | enc [b1];
1139	return (word|((word&(256|64)) ? 0: 128));
1140}
1141
1142static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1143{
1144	int i;
1145
1146	for (i = 0; i < len; i++) {
1147		*dest=dos_encode_byte(*src++);
1148		*dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1149		dest++;
1150	}
1151}
1152
1153static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1154{
1155	static struct dos_header hdr={0,0,0,2,0,
1156	  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1157	int i;
1158	static ushort crc[2]={0,0x4e4e};
1159
1160	drive&=3;
1161/* id gap 1 */
1162/* the MFM word before is always 9254 */
1163	for(i=0;i<6;i++)
1164		*raw++=0xaaaaaaaa;
1165/* 3 sync + 1 headermark */
1166	*raw++=0x44894489;
1167	*raw++=0x44895554;
1168
1169/* fill in the variable parts of the header */
1170	hdr.track=unit[drive].track/unit[drive].type->heads;
1171	hdr.side=unit[drive].track%unit[drive].type->heads;
1172	hdr.sec=cnt+1;
1173	hdr.crc=dos_hdr_crc(&hdr);
1174
1175/* header (without "magic") and id gap 2*/
1176	dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1177	raw+=14;
1178
1179/*id gap 3 */
1180	for(i=0;i<6;i++)
1181		*raw++=0xaaaaaaaa;
1182
1183/* 3 syncs and 1 datamark */
1184	*raw++=0x44894489;
1185	*raw++=0x44895545;
1186
1187/* data */
1188	dos_encode_block((ushort *)raw,
1189			 (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1190	raw+=256;
1191
1192/*data crc + jd's special gap (long words :-/) */
1193	crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1194	dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1195	raw+=2;
1196
1197/* data gap */
1198	for(i=0;i<38;i++)
1199		*raw++=0x92549254;
1200
1201	return raw; /* wrote 652 MFM words */
1202}
1203
1204static void dos_write(int disk)
1205{
1206	int cnt;
1207	unsigned long raw = (unsigned long) raw_buf;
1208	unsigned long *ptr=(unsigned long *)raw;
1209
1210	disk&=3;
1211/* really gap4 + indexgap , but we write it first and round it up */
1212	for (cnt=0;cnt<425;cnt++)
1213		*ptr++=0x92549254;
1214
1215/* the following is just guessed */
1216	if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1217		for(cnt=0;cnt<473;cnt++)
1218			*ptr++=0x92549254;
1219
1220/* now the index marks...*/
1221	for (cnt=0;cnt<20;cnt++)
1222		*ptr++=0x92549254;
1223	for (cnt=0;cnt<6;cnt++)
1224		*ptr++=0xaaaaaaaa;
1225	*ptr++=0x52245224;
1226	*ptr++=0x52245552;
1227	for (cnt=0;cnt<20;cnt++)
1228		*ptr++=0x92549254;
1229
1230/* sectors */
1231	for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1232		ptr=ms_putsec(disk,ptr,cnt);
1233
1234	*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1235}
1236
1237/*
1238 * Here comes the high level stuff (i.e. the filesystem interface)
1239 * and helper functions.
1240 * Normally this should be the only part that has to be adapted to
1241 * different kernel versions.
1242 */
1243
1244/* FIXME: this assumes the drive is still spinning -
1245 * which is only true if we complete writing a track within three seconds
1246 */
1247static void flush_track_callback(unsigned long nr)
1248{
1249	nr&=3;
1250	writefromint = 1;
1251	if (!try_fdc(nr)) {
1252		/* we might block in an interrupt, so try again later */
1253		flush_track_timer[nr].expires = jiffies + 1;
1254		add_timer(flush_track_timer + nr);
1255		return;
1256	}
1257	get_fdc(nr);
1258	(*unit[nr].dtype->write_fkt)(nr);
1259	if (!raw_write(nr)) {
1260		printk (KERN_NOTICE "floppy disk write protected\n");
1261		writefromint = 0;
1262		writepending = 0;
1263	}
1264	rel_fdc();
1265}
1266
1267static int non_int_flush_track (unsigned long nr)
1268{
1269	unsigned long flags;
1270
1271	nr&=3;
1272	writefromint = 0;
1273	del_timer(&post_write_timer);
1274	get_fdc(nr);
1275	if (!fd_motor_on(nr)) {
1276		writepending = 0;
1277		rel_fdc();
1278		return 0;
1279	}
1280	local_irq_save(flags);
1281	if (writepending != 2) {
1282		local_irq_restore(flags);
1283		(*unit[nr].dtype->write_fkt)(nr);
1284		if (!raw_write(nr)) {
1285			printk (KERN_NOTICE "floppy disk write protected "
1286				"in write!\n");
1287			writepending = 0;
1288			return 0;
1289		}
1290		wait_event(wait_fd_block, block_flag != 2);
1291	}
1292	else {
1293		local_irq_restore(flags);
1294		ms_delay(2); /* 2 ms post_write delay */
1295		post_write(nr);
1296	}
1297	rel_fdc();
1298	return 1;
1299}
1300
1301static int get_track(int drive, int track)
1302{
1303	int error, errcnt;
1304
1305	drive&=3;
1306	if (unit[drive].track == track)
1307		return 0;
1308	get_fdc(drive);
1309	if (!fd_motor_on(drive)) {
1310		rel_fdc();
1311		return -1;
1312	}
1313
1314	if (unit[drive].dirty == 1) {
1315		del_timer (flush_track_timer + drive);
1316		non_int_flush_track (drive);
1317	}
1318	errcnt = 0;
1319	while (errcnt < MAX_ERRORS) {
1320		if (!fd_seek(drive, track))
1321			return -1;
1322		raw_read(drive);
1323		error = (*unit[drive].dtype->read_fkt)(drive);
1324		if (error == 0) {
1325			rel_fdc();
1326			return 0;
1327		}
1328		/* Read Error Handling: recalibrate and try again */
1329		unit[drive].track = -1;
1330		errcnt++;
1331	}
1332	rel_fdc();
1333	return -1;
1334}
1335
1336/*
1337 * Round-robin between our available drives, doing one request from each
1338 */
1339static struct request *set_next_request(void)
1340{
1341	struct request_queue *q;
1342	int cnt = FD_MAX_UNITS;
1343	struct request *rq;
1344
1345	/* Find next queue we can dispatch from */
1346	fdc_queue = fdc_queue + 1;
1347	if (fdc_queue == FD_MAX_UNITS)
1348		fdc_queue = 0;
1349
1350	for(cnt = FD_MAX_UNITS; cnt > 0, cnt--) {
1351
1352		if (unit[fdc_queue].type->code == FD_NODRIVE) {
1353			if (++fdc_queue == FD_MAX_UNITS)
1354				fdc_queue = 0;
1355			cotinue;
1356		}
1357
1358		q = unit[fdc_queue].gendisk->queue;
1359		if (q) {
1360			rq = blk_fetch_request(q);
1361			if (rq)
1362				break;
1363		}
1364
1365		if (++fdc_queue == FD_MAX_UNITS)
1366			fdc_queue = 0;
1367	}
1368
1369	return rq;
1370}
1371
1372static void redo_fd_request(void)
1373{
1374	struct request *rq;
1375	unsigned int cnt, block, track, sector;
1376	int drive;
1377	struct amiga_floppy_struct *floppy;
1378	char *data;
1379	unsigned long flags;
1380	int err;
1381
1382next_req:
1383	rq = set_next_request();
1384	if (!rq) {
1385		/* Nothing left to do */
1386		return;
1387	}
1388
1389	floppy = rq->rq_disk->private_data;
1390	drive = floppy - unit;
1391
1392next_segment:
1393	/* Here someone could investigate to be more efficient */
1394	for (cnt = 0, err = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
1395#ifdef DEBUG
1396		printk("fd: sector %ld + %d requested for %s\n",
1397		       blk_rq_pos(rq), cnt,
1398		       (rq_data_dir(rq) == READ) ? "read" : "write");
1399#endif
1400		block = blk_rq_pos(rq) + cnt;
1401		if ((int)block > floppy->blocks) {
1402			err = -EIO;
1403			break;
1404		}
1405
1406		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1407		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1408		data = rq->buffer + 512 * cnt;
1409#ifdef DEBUG
1410		printk("access to track %d, sector %d, with buffer at "
1411		       "0x%08lx\n", track, sector, data);
1412#endif
1413
1414		if (get_track(drive, track) == -1) {
1415			err = -EIO;
1416			break;
1417		}
1418
1419		if (rq_data_dir(rq) == READ) {
1420			memcpy(data, floppy->trackbuf + sector * 512, 512);
1421		} else {
1422			memcpy(floppy->trackbuf + sector * 512, data, 512);
1423
1424			/* keep the drive spinning while writes are scheduled */
1425			if (!fd_motor_on(drive)) {
1426				err = -EIO;
1427				break;
1428			}
1429			/*
1430			 * setup a callback to write the track buffer
1431			 * after a short (1 tick) delay.
1432			 */
1433			local_irq_save(flags);
1434
1435			floppy->dirty = 1;
1436		        /* reset the timer */
1437			mod_timer (flush_track_timer + drive, jiffies + 1);
1438			local_irq_restore(flags);
1439		}
1440	}
1441
1442	if (__blk_end_request_cur(rq, err))
1443		goto next_segment;
1444	goto next_req;
1445}
1446
1447static void do_fd_request(struct request_queue * q)
1448{
1449	redo_fd_request();
1450}
1451
1452static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1453{
1454	int drive = MINOR(bdev->bd_dev) & 3;
1455
1456	geo->heads = unit[drive].type->heads;
1457	geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1458	geo->cylinders = unit[drive].type->tracks;
1459	return 0;
1460}
1461
1462static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
1463		    unsigned int cmd, unsigned long param)
1464{
1465	struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1466	int drive = p - unit;
1467	static struct floppy_struct getprm;
1468	void __user *argp = (void __user *)param;
1469
1470	switch(cmd){
1471	case FDFMTBEG:
1472		get_fdc(drive);
1473		if (fd_ref[drive] > 1) {
1474			rel_fdc();
1475			return -EBUSY;
1476		}
1477		fsync_bdev(bdev);
1478		if (fd_motor_on(drive) == 0) {
1479			rel_fdc();
1480			return -ENODEV;
1481		}
1482		if (fd_calibrate(drive) == 0) {
1483			rel_fdc();
1484			return -ENXIO;
1485		}
1486		floppy_off(drive);
1487		rel_fdc();
1488		break;
1489	case FDFMTTRK:
1490		if (param < p->type->tracks * p->type->heads)
1491		{
1492			get_fdc(drive);
1493			if (fd_seek(drive,param) != 0){
1494				memset(p->trackbuf, FD_FILL_BYTE,
1495				       p->dtype->sects * p->type->sect_mult * 512);
1496				non_int_flush_track(drive);
1497			}
1498			floppy_off(drive);
1499			rel_fdc();
1500		}
1501		else
1502			return -EINVAL;
1503		break;
1504	case FDFMTEND:
1505		floppy_off(drive);
1506		invalidate_bdev(bdev);
1507		break;
1508	case FDGETPRM:
1509		memset((void *)&getprm, 0, sizeof (getprm));
1510		getprm.track=p->type->tracks;
1511		getprm.head=p->type->heads;
1512		getprm.sect=p->dtype->sects * p->type->sect_mult;
1513		getprm.size=p->blocks;
1514		if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1515			return -EFAULT;
1516		break;
1517	case FDSETPRM:
1518	case FDDEFPRM:
1519		return -EINVAL;
1520	case FDFLUSH: /* unconditionally, even if not needed */
1521		del_timer (flush_track_timer + drive);
1522		non_int_flush_track(drive);
1523		break;
1524#ifdef RAW_IOCTL
1525	case IOCTL_RAW_TRACK:
1526		if (copy_to_user(argp, raw_buf, p->type->read_size))
1527			return -EFAULT;
1528		else
1529			return p->type->read_size;
1530#endif
1531	default:
1532		printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1533		       cmd, drive);
1534		return -ENOSYS;
1535	}
1536	return 0;
1537}
1538
1539static int fd_ioctl(struct block_device *bdev, fmode_t mode,
1540			     unsigned int cmd, unsigned long param)
1541{
1542	int ret;
1543
1544	lock_kernel();
1545	ret = fd_locked_ioctl(bdev, mode, cmd, param);
1546	unlock_kernel();
1547
1548	return ret;
1549}
1550
1551static void fd_probe(int dev)
1552{
1553	unsigned long code;
1554	int type;
1555	int drive;
1556
1557	drive = dev & 3;
1558	code = fd_get_drive_id(drive);
1559
1560	/* get drive type */
1561	for (type = 0; type < num_dr_types; type++)
1562		if (drive_types[type].code == code)
1563			break;
1564
1565	if (type >= num_dr_types) {
1566		printk(KERN_WARNING "fd_probe: unsupported drive type "
1567		       "%08lx found\n", code);
1568		unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1569		return;
1570	}
1571
1572	unit[drive].type = drive_types + type;
1573	unit[drive].track = -1;
1574
1575	unit[drive].disk = -1;
1576	unit[drive].motor = 0;
1577	unit[drive].busy = 0;
1578	unit[drive].status = -1;
1579}
1580
1581/*
1582 * floppy_open check for aliasing (/dev/fd0 can be the same as
1583 * /dev/PS0 etc), and disallows simultaneous access to the same
1584 * drive with different device numbers.
1585 */
1586static int floppy_open(struct block_device *bdev, fmode_t mode)
1587{
1588	int drive = MINOR(bdev->bd_dev) & 3;
1589	int system =  (MINOR(bdev->bd_dev) & 4) >> 2;
1590	int old_dev;
1591	unsigned long flags;
1592
1593	lock_kernel();
1594	old_dev = fd_device[drive];
1595
1596	if (fd_ref[drive] && old_dev != system) {
1597		unlock_kernel();
1598		return -EBUSY;
1599	}
1600
1601	if (mode & (FMODE_READ|FMODE_WRITE)) {
1602		check_disk_change(bdev);
1603		if (mode & FMODE_WRITE) {
1604			int wrprot;
1605
1606			get_fdc(drive);
1607			fd_select (drive);
1608			wrprot = !(ciaa.pra & DSKPROT);
1609			fd_deselect (drive);
1610			rel_fdc();
1611
1612			if (wrprot) {
1613				unlock_kernel();
1614				return -EROFS;
1615			}
1616		}
1617	}
1618
1619	local_irq_save(flags);
1620	fd_ref[drive]++;
1621	fd_device[drive] = system;
1622	local_irq_restore(flags);
1623
1624	unit[drive].dtype=&data_types[system];
1625	unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1626		data_types[system].sects*unit[drive].type->sect_mult;
1627	set_capacity(unit[drive].gendisk, unit[drive].blocks);
1628
1629	printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1630	       unit[drive].type->name, data_types[system].name);
1631
1632	unlock_kernel();
1633	return 0;
1634}
1635
1636static int floppy_release(struct gendisk *disk, fmode_t mode)
1637{
1638	struct amiga_floppy_struct *p = disk->private_data;
1639	int drive = p - unit;
1640
1641	lock_kernel();
1642	if (unit[drive].dirty == 1) {
1643		del_timer (flush_track_timer + drive);
1644		non_int_flush_track (drive);
1645	}
1646
1647	if (!fd_ref[drive]--) {
1648		printk(KERN_CRIT "floppy_release with fd_ref == 0");
1649		fd_ref[drive] = 0;
1650	}
1651#ifdef MODULE
1652/* the mod_use counter is handled this way */
1653	floppy_off (drive | 0x40000000);
1654#endif
1655	unlock_kernel();
1656	return 0;
1657}
1658
1659/*
1660 * floppy-change is never called from an interrupt, so we can relax a bit
1661 * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1662 * to the desired drive, but it will probably not survive the sleep if
1663 * several floppies are used at the same time: thus the loop.
1664 */
1665static int amiga_floppy_change(struct gendisk *disk)
1666{
1667	struct amiga_floppy_struct *p = disk->private_data;
1668	int drive = p - unit;
1669	int changed;
1670	static int first_time = 1;
1671
1672	if (first_time)
1673		changed = first_time--;
1674	else {
1675		get_fdc(drive);
1676		fd_select (drive);
1677		changed = !(ciaa.pra & DSKCHANGE);
1678		fd_deselect (drive);
1679		rel_fdc();
1680	}
1681
1682	if (changed) {
1683		fd_probe(drive);
1684		p->track = -1;
1685		p->dirty = 0;
1686		writepending = 0; /* if this was true before, too bad! */
1687		writefromint = 0;
1688		return 1;
1689	}
1690	return 0;
1691}
1692
1693static const struct block_device_operations floppy_fops = {
1694	.owner		= THIS_MODULE,
1695	.open		= floppy_open,
1696	.release	= floppy_release,
1697	.ioctl		= fd_ioctl,
1698	.getgeo		= fd_getgeo,
1699	.media_changed	= amiga_floppy_change,
1700};
1701
1702static int __init fd_probe_drives(void)
1703{
1704	int drive,drives,nomem;
1705
1706	printk(KERN_INFO "FD: probing units\nfound ");
1707	drives=0;
1708	nomem=0;
1709	for(drive=0;drive<FD_MAX_UNITS;drive++) {
1710		struct gendisk *disk;
1711		fd_probe(drive);
1712		if (unit[drive].type->code == FD_NODRIVE)
1713			continue;
1714		disk = alloc_disk(1);
1715		if (!disk) {
1716			unit[drive].type->code = FD_NODRIVE;
1717			continue;
1718		}
1719		unit[drive].gendisk = disk;
1720
1721		disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
1722		if (!disk->queue) {
1723			unit[drive].type->code = FD_NODRIVE;
1724			continue;
1725		}
1726
1727		drives++;
1728		if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1729			printk("no mem for ");
1730			unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1731			drives--;
1732			nomem = 1;
1733		}
1734		printk("fd%d ",drive);
1735		disk->major = FLOPPY_MAJOR;
1736		disk->first_minor = drive;
1737		disk->fops = &floppy_fops;
1738		sprintf(disk->disk_name, "fd%d", drive);
1739		disk->private_data = &unit[drive];
1740		set_capacity(disk, 880*2);
1741		add_disk(disk);
1742	}
1743	if ((drives > 0) || (nomem == 0)) {
1744		if (drives == 0)
1745			printk("no drives");
1746		printk("\n");
1747		return drives;
1748	}
1749	printk("\n");
1750	return -ENOMEM;
1751}
1752
1753static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1754{
1755	int drive = *part & 3;
1756	if (unit[drive].type->code == FD_NODRIVE)
1757		return NULL;
1758	*part = 0;
1759	return get_disk(unit[drive].gendisk);
1760}
1761
1762static int __init amiga_floppy_probe(struct platform_device *pdev)
1763{
1764	int i, ret;
1765
1766	if (register_blkdev(FLOPPY_MAJOR,"fd"))
1767		return -EBUSY;
1768
1769	ret = -ENOMEM;
1770	if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1771	    NULL) {
1772		printk("fd: cannot get chip mem buffer\n");
1773		goto out_blkdev;
1774	}
1775
1776	ret = -EBUSY;
1777	if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1778		printk("fd: cannot get irq for dma\n");
1779		goto out_irq;
1780	}
1781
1782	if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1783		printk("fd: cannot get irq for timer\n");
1784		goto out_irq2;
1785	}
1786
1787	ret = -ENODEV;
1788	if (fd_probe_drives() < 1) /* No usable drives */
1789		goto out_probe;
1790
1791	blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1792				floppy_find, NULL, NULL);
1793
1794	/* initialize variables */
1795	init_timer(&motor_on_timer);
1796	motor_on_timer.expires = 0;
1797	motor_on_timer.data = 0;
1798	motor_on_timer.function = motor_on_callback;
1799	for (i = 0; i < FD_MAX_UNITS; i++) {
1800		init_timer(&motor_off_timer[i]);
1801		motor_off_timer[i].expires = 0;
1802		motor_off_timer[i].data = i|0x80000000;
1803		motor_off_timer[i].function = fd_motor_off;
1804		init_timer(&flush_track_timer[i]);
1805		flush_track_timer[i].expires = 0;
1806		flush_track_timer[i].data = i;
1807		flush_track_timer[i].function = flush_track_callback;
1808
1809		unit[i].track = -1;
1810	}
1811
1812	init_timer(&post_write_timer);
1813	post_write_timer.expires = 0;
1814	post_write_timer.data = 0;
1815	post_write_timer.function = post_write;
1816
1817	for (i = 0; i < 128; i++)
1818		mfmdecode[i]=255;
1819	for (i = 0; i < 16; i++)
1820		mfmdecode[mfmencode[i]]=i;
1821
1822	/* make sure that disk DMA is enabled */
1823	custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1824
1825	/* init ms timer */
1826	ciaa.crb = 8; /* one-shot, stop */
1827	return 0;
1828
1829out_probe:
1830out_queue:
1831	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1832out_irq2:
1833	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1834out_irq:
1835	amiga_chip_free(raw_buf);
1836out_blkdev:
1837	unregister_blkdev(FLOPPY_MAJOR,"fd");
1838	return ret;
1839}
1840
1841#if 0 /* not safe to unload */
1842static int __exit amiga_floppy_remove(struct platform_device *pdev)
1843{
1844	int i;
1845
1846	for( i = 0; i < FD_MAX_UNITS; i++) {
1847		if (unit[i].type->code != FD_NODRIVE) {
1848			struct request_queue *q = unit[i].gendisk->queue;
1849			del_gendisk(unit[i].gendisk);
1850			put_disk(unit[i].gendisk);
1851			kfree(unit[i].trackbuf);
1852			if (q)
1853				blk_cleanup_queue(q);
1854		}
1855	}
1856	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
1857	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1858	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1859	custom.dmacon = DMAF_DISK; /* disable DMA */
1860	amiga_chip_free(raw_buf);
1861	unregister_blkdev(FLOPPY_MAJOR, "fd");
1862}
1863#endif
1864
1865static struct platform_driver amiga_floppy_driver = {
1866	.driver   = {
1867		.name	= "amiga-floppy",
1868		.owner	= THIS_MODULE,
1869	},
1870};
1871
1872static int __init amiga_floppy_init(void)
1873{
1874	return platform_driver_probe(&amiga_floppy_driver, amiga_floppy_probe);
1875}
1876
1877module_init(amiga_floppy_init);
1878
1879#ifndef MODULE
1880static int __init amiga_floppy_setup (char *str)
1881{
1882	int n;
1883	if (!MACH_IS_AMIGA)
1884		return 0;
1885	if (!get_option(&str, &n))
1886		return 0;
1887	printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1888	fd_def_df0 = n;
1889	return 1;
1890}
1891
1892__setup("floppy=", amiga_floppy_setup);
1893#endif
1894
1895MODULE_ALIAS("platform:amiga-floppy");
1896