1/*
2 *  linux/amiga/amiflop.c
3 *
4 *  Copyright (C) 1993  Greg Harp
5 *  Portions of this driver are based on code contributed by Brad Pepers
6 *
7 *  revised 28.5.95 by Joerg Dorchain
8 *  - now no bugs(?) any more for both HD & DD
9 *  - added support for 40 Track 5.25" drives, 80-track hopefully behaves
10 *    like 3.5" dd (no way to test - are there any 5.25" drives out there
11 *    that work on an A4000?)
12 *  - wrote formatting routine (maybe dirty, but works)
13 *
14 *  june/july 1995 added ms-dos support by Joerg Dorchain
15 *  (portions based on messydos.device and various contributors)
16 *  - currently only 9 and 18 sector disks
17 *
18 *  - fixed a bug with the internal trackbuffer when using multiple
19 *    disks the same time
20 *  - made formatting a bit safer
21 *  - added command line and machine based default for "silent" df0
22 *
23 *  december 1995 adapted for 1.2.13pl4 by Joerg Dorchain
24 *  - works but I think it's inefficient. (look in redo_fd_request)
25 *    But the changes were very efficient. (only three and a half lines)
26 *
27 *  january 1996 added special ioctl for tracking down read/write problems
28 *  - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data
29 *    is copied to area. (area should be large enough since no checking is
30 *    done - 30K is currently sufficient). return the actual size of the
31 *    trackbuffer
32 *  - replaced udelays() by a timer (CIAA timer B) for the waits
33 *    needed for the disk mechanic.
34 *
35 *  february 1996 fixed error recovery and multiple disk access
36 *  - both got broken the first time I tampered with the driver :-(
37 *  - still not safe, but better than before
38 *
39 *  revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.
40 *  - Minor changes to accept the kdev_t.
41 *  - Replaced some more udelays with ms_delays. Udelay is just a loop,
42 *    and so the delay will be different depending on the given
43 *    processor :-(
44 *  - The driver could use a major cleanup because of the new
45 *    major/minor handling that came with kdev_t. It seems to work for
46 *    the time being, but I can't guarantee that it will stay like
47 *    that when we start using 16 (24?) bit minors.
48 *
49 * restructured jan 1997 by Joerg Dorchain
50 * - Fixed Bug accessing multiple disks
51 * - some code cleanup
52 * - added trackbuffer for each drive to speed things up
53 * - fixed some race conditions (who finds the next may send it to me ;-)
54 */
55
56#include <linux/module.h>
57
58#include <linux/fd.h>
59#include <linux/hdreg.h>
60#include <linux/delay.h>
61#include <linux/init.h>
62#include <linux/amifdreg.h>
63#include <linux/amifd.h>
64#include <linux/buffer_head.h>
65#include <linux/blkdev.h>
66#include <linux/elevator.h>
67#include <linux/interrupt.h>
68
69#include <asm/setup.h>
70#include <asm/uaccess.h>
71#include <asm/amigahw.h>
72#include <asm/amigaints.h>
73#include <asm/irq.h>
74
75#undef DEBUG /* print _LOTS_ of infos */
76
77#define RAW_IOCTL
78#ifdef RAW_IOCTL
79#define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
80#endif
81
82/*
83 *  Defines
84 */
85
86/*
87 *  Error codes
88 */
89#define FD_OK		0	/* operation succeeded */
90#define FD_ERROR	-1	/* general error (seek, read, write, etc) */
91#define FD_NOUNIT	1	/* unit does not exist */
92#define FD_UNITBUSY	2	/* unit already active */
93#define FD_NOTACTIVE	3	/* unit is not active */
94#define FD_NOTREADY	4	/* unit is not ready (motor not on/no disk) */
95
96#define MFM_NOSYNC	1
97#define MFM_HEADER	2
98#define MFM_DATA	3
99#define MFM_TRACK	4
100
101/*
102 *  Floppy ID values
103 */
104#define FD_NODRIVE	0x00000000  /* response when no unit is present */
105#define FD_DD_3 	0xffffffff  /* double-density 3.5" (880K) drive */
106#define FD_HD_3 	0x55555555  /* high-density 3.5" (1760K) drive */
107#define FD_DD_5 	0xaaaaaaaa  /* double-density 5.25" (440K) drive */
108
109static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
110
111module_param(fd_def_df0, ulong, 0);
112MODULE_LICENSE("GPL");
113
114static struct request_queue *floppy_queue;
115#define QUEUE (floppy_queue)
116#define CURRENT elv_next_request(floppy_queue)
117
118/*
119 *  Macros
120 */
121#define MOTOR_ON	(ciab.prb &= ~DSKMOTOR)
122#define MOTOR_OFF	(ciab.prb |= DSKMOTOR)
123#define SELECT(mask)    (ciab.prb &= ~mask)
124#define DESELECT(mask)  (ciab.prb |= mask)
125#define SELMASK(drive)  (1 << (3 + (drive & 3)))
126
127static struct fd_drive_type drive_types[] = {
128/*  code	name	   tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
129/*  warning: times are now in milliseconds (ms)                    */
130{ FD_DD_3,	"DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
131{ FD_HD_3,	"HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
132{ FD_DD_5,	"DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
133{ FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
134};
135static int num_dr_types = ARRAY_SIZE(drive_types);
136
137static int amiga_read(int), dos_read(int);
138static void amiga_write(int), dos_write(int);
139static struct fd_data_type data_types[] = {
140	{ "Amiga", 11 , amiga_read, amiga_write},
141	{ "MS-Dos", 9, dos_read, dos_write}
142};
143
144/* current info on each unit */
145static struct amiga_floppy_struct unit[FD_MAX_UNITS];
146
147static struct timer_list flush_track_timer[FD_MAX_UNITS];
148static struct timer_list post_write_timer;
149static struct timer_list motor_on_timer;
150static struct timer_list motor_off_timer[FD_MAX_UNITS];
151static int on_attempts;
152
153/* Synchronization of FDC access */
154/* request loop (trackbuffer) */
155static volatile int fdc_busy = -1;
156static volatile int fdc_nested;
157static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
158
159static DECLARE_WAIT_QUEUE_HEAD(motor_wait);
160
161static volatile int selected = -1;	/* currently selected drive */
162
163static int writepending;
164static int writefromint;
165static char *raw_buf;
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 volatile int ms_busy = -1;
188static DECLARE_WAIT_QUEUE_HEAD(ms_wait);
189#define MS_TICKS ((amiga_eclock+50)/1000)
190
191/*
192 * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
193 * max X times - some types of errors increase the errorcount by 2 or
194 * even 3, so we might actually retry only X/2 times before giving up.
195 */
196#define MAX_ERRORS 12
197
198#define custom amiga_custom
199
200/* Prevent "aliased" accesses. */
201static int fd_ref[4] = { 0,0,0,0 };
202static int fd_device[4] = { 0, 0, 0, 0 };
203
204/*
205 * Here come the actual hardware access and helper functions.
206 * They are not reentrant and single threaded because all drives
207 * share the same hardware and the same trackbuffer.
208 */
209
210/* Milliseconds timer */
211
212static irqreturn_t ms_isr(int irq, void *dummy)
213{
214	ms_busy = -1;
215	wake_up(&ms_wait);
216	return IRQ_HANDLED;
217}
218
219/* all waits are queued up
220   A more generic routine would do a schedule a la timer.device */
221static void ms_delay(int ms)
222{
223	unsigned long flags;
224	int ticks;
225	if (ms > 0) {
226		local_irq_save(flags);
227		while (ms_busy == 0)
228			sleep_on(&ms_wait);
229		ms_busy = 0;
230		local_irq_restore(flags);
231		ticks = MS_TICKS*ms-1;
232		ciaa.tblo=ticks%256;
233		ciaa.tbhi=ticks/256;
234		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
235		sleep_on(&ms_wait);
236	}
237}
238
239/* Hardware semaphore */
240
241/* returns true when we would get the semaphore */
242static inline int try_fdc(int drive)
243{
244	drive &= 3;
245	return ((fdc_busy < 0) || (fdc_busy == drive));
246}
247
248static void get_fdc(int drive)
249{
250	unsigned long flags;
251
252	drive &= 3;
253#ifdef DEBUG
254	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
255#endif
256	local_irq_save(flags);
257	while (!try_fdc(drive))
258		sleep_on(&fdc_wait);
259	fdc_busy = drive;
260	fdc_nested++;
261	local_irq_restore(flags);
262}
263
264static inline void rel_fdc(void)
265{
266#ifdef DEBUG
267	if (fdc_nested == 0)
268		printk("fd: unmatched rel_fdc\n");
269	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
270#endif
271	fdc_nested--;
272	if (fdc_nested == 0) {
273		fdc_busy = -1;
274		wake_up(&fdc_wait);
275	}
276}
277
278static void fd_select (int drive)
279{
280	unsigned char prb = ~0;
281
282	drive&=3;
283#ifdef DEBUG
284	printk("selecting %d\n",drive);
285#endif
286	if (drive == selected)
287		return;
288	get_fdc(drive);
289	selected = drive;
290
291	if (unit[drive].track % 2 != 0)
292		prb &= ~DSKSIDE;
293	if (unit[drive].motor == 1)
294		prb &= ~DSKMOTOR;
295	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
296	ciab.prb = prb;
297	prb &= ~SELMASK(drive);
298	ciab.prb = prb;
299	rel_fdc();
300}
301
302static void fd_deselect (int drive)
303{
304	unsigned char prb;
305	unsigned long flags;
306
307	drive&=3;
308#ifdef DEBUG
309	printk("deselecting %d\n",drive);
310#endif
311	if (drive != selected) {
312		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
313		return;
314	}
315
316	get_fdc(drive);
317	local_irq_save(flags);
318
319	selected = -1;
320
321	prb = ciab.prb;
322	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
323	ciab.prb = prb;
324
325	local_irq_restore (flags);
326	rel_fdc();
327
328}
329
330static void motor_on_callback(unsigned long nr)
331{
332	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
333		wake_up (&motor_wait);
334	} else {
335		motor_on_timer.expires = jiffies + HZ/10;
336		add_timer(&motor_on_timer);
337	}
338}
339
340static int fd_motor_on(int nr)
341{
342	nr &= 3;
343
344	del_timer(motor_off_timer + nr);
345
346	if (!unit[nr].motor) {
347		unit[nr].motor = 1;
348		fd_select(nr);
349
350		motor_on_timer.data = nr;
351		mod_timer(&motor_on_timer, jiffies + HZ/2);
352
353		on_attempts = 10;
354		sleep_on (&motor_wait);
355		fd_deselect(nr);
356	}
357
358	if (on_attempts == 0) {
359		on_attempts = -1;
360		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
361	}
362
363	return 1;
364}
365
366static void fd_motor_off(unsigned long drive)
367{
368	long calledfromint;
369#ifdef MODULE
370	long decusecount;
371
372	decusecount = drive & 0x40000000;
373#endif
374	calledfromint = drive & 0x80000000;
375	drive&=3;
376	if (calledfromint && !try_fdc(drive)) {
377		/* We would be blocked in an interrupt, so try again later */
378		motor_off_timer[drive].expires = jiffies + 1;
379		add_timer(motor_off_timer + drive);
380		return;
381	}
382	unit[drive].motor = 0;
383	fd_select(drive);
384	udelay (1);
385	fd_deselect(drive);
386}
387
388static void floppy_off (unsigned int nr)
389{
390	int drive;
391
392	drive = nr & 3;
393	/* called this way it is always from interrupt */
394	motor_off_timer[drive].data = nr | 0x80000000;
395	mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
396}
397
398static int fd_calibrate(int drive)
399{
400	unsigned char prb;
401	int n;
402
403	drive &= 3;
404	get_fdc(drive);
405	if (!fd_motor_on (drive))
406		return 0;
407	fd_select (drive);
408	prb = ciab.prb;
409	prb |= DSKSIDE;
410	prb &= ~DSKDIREC;
411	ciab.prb = prb;
412	for (n = unit[drive].type->tracks/2; n != 0; --n) {
413		if (ciaa.pra & DSKTRACK0)
414			break;
415		prb &= ~DSKSTEP;
416		ciab.prb = prb;
417		prb |= DSKSTEP;
418		udelay (2);
419		ciab.prb = prb;
420		ms_delay(unit[drive].type->step_delay);
421	}
422	ms_delay (unit[drive].type->settle_time);
423	prb |= DSKDIREC;
424	n = unit[drive].type->tracks + 20;
425	for (;;) {
426		prb &= ~DSKSTEP;
427		ciab.prb = prb;
428		prb |= DSKSTEP;
429		udelay (2);
430		ciab.prb = prb;
431		ms_delay(unit[drive].type->step_delay + 1);
432		if ((ciaa.pra & DSKTRACK0) == 0)
433			break;
434		if (--n == 0) {
435			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
436			fd_motor_off (drive);
437			unit[drive].track = -1;
438			rel_fdc();
439			return 0;
440		}
441	}
442	unit[drive].track = 0;
443	ms_delay(unit[drive].type->settle_time);
444
445	rel_fdc();
446	fd_deselect(drive);
447	return 1;
448}
449
450static int fd_seek(int drive, int track)
451{
452	unsigned char prb;
453	int cnt;
454
455#ifdef DEBUG
456	printk("seeking drive %d to track %d\n",drive,track);
457#endif
458	drive &= 3;
459	get_fdc(drive);
460	if (unit[drive].track == track) {
461		rel_fdc();
462		return 1;
463	}
464	if (!fd_motor_on(drive)) {
465		rel_fdc();
466		return 0;
467	}
468	if (unit[drive].track < 0 && !fd_calibrate(drive)) {
469		rel_fdc();
470		return 0;
471	}
472
473	fd_select (drive);
474	cnt = unit[drive].track/2 - track/2;
475	prb = ciab.prb;
476	prb |= DSKSIDE | DSKDIREC;
477	if (track % 2 != 0)
478		prb &= ~DSKSIDE;
479	if (cnt < 0) {
480		cnt = - cnt;
481		prb &= ~DSKDIREC;
482	}
483	ciab.prb = prb;
484	if (track % 2 != unit[drive].track % 2)
485		ms_delay (unit[drive].type->side_time);
486	unit[drive].track = track;
487	if (cnt == 0) {
488		rel_fdc();
489		fd_deselect(drive);
490		return 1;
491	}
492	do {
493		prb &= ~DSKSTEP;
494		ciab.prb = prb;
495		prb |= DSKSTEP;
496		udelay (1);
497		ciab.prb = prb;
498		ms_delay (unit[drive].type->step_delay);
499	} while (--cnt != 0);
500	ms_delay (unit[drive].type->settle_time);
501
502	rel_fdc();
503	fd_deselect(drive);
504	return 1;
505}
506
507static unsigned long fd_get_drive_id(int drive)
508{
509	int i;
510	ulong id = 0;
511
512  	drive&=3;
513  	get_fdc(drive);
514	/* set up for ID */
515	MOTOR_ON;
516	udelay(2);
517	SELECT(SELMASK(drive));
518	udelay(2);
519	DESELECT(SELMASK(drive));
520	udelay(2);
521	MOTOR_OFF;
522	udelay(2);
523	SELECT(SELMASK(drive));
524	udelay(2);
525	DESELECT(SELMASK(drive));
526	udelay(2);
527
528	/* loop and read disk ID */
529	for (i=0; i<32; i++) {
530		SELECT(SELMASK(drive));
531		udelay(2);
532
533		/* read and store value of DSKRDY */
534		id <<= 1;
535		id |= (ciaa.pra & DSKRDY) ? 0 : 1;	/* cia regs are low-active! */
536
537		DESELECT(SELMASK(drive));
538	}
539
540	rel_fdc();
541
542        /*
543         * RB: At least A500/A2000's df0: don't identify themselves.
544         * As every (real) Amiga has at least a 3.5" DD drive as df0:
545         * we default to that if df0: doesn't identify as a certain
546         * type.
547         */
548        if(drive == 0 && id == FD_NODRIVE)
549	{
550                id = fd_def_df0;
551                printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
552	}
553	/* return the ID value */
554	return (id);
555}
556
557static irqreturn_t fd_block_done(int irq, void *dummy)
558{
559	if (block_flag)
560		custom.dsklen = 0x4000;
561
562	if (block_flag == 2) { /* writing */
563		writepending = 2;
564		post_write_timer.expires = jiffies + 1; /* at least 2 ms */
565		post_write_timer.data = selected;
566		add_timer(&post_write_timer);
567	}
568	else {                /* reading */
569		block_flag = 0;
570		wake_up (&wait_fd_block);
571	}
572	return IRQ_HANDLED;
573}
574
575static void raw_read(int drive)
576{
577	drive&=3;
578	get_fdc(drive);
579	while (block_flag)
580		sleep_on(&wait_fd_block);
581	fd_select(drive);
582	/* setup adkcon bits correctly */
583	custom.adkcon = ADK_MSBSYNC;
584	custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
585
586	custom.dsksync = MFM_SYNC;
587
588	custom.dsklen = 0;
589	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
590	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
591	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
592
593	block_flag = 1;
594
595	while (block_flag)
596		sleep_on (&wait_fd_block);
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	while (block_flag)
614		sleep_on(&wait_fd_block);
615	fd_select(drive);
616	/* clear adkcon bits */
617	custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
618	/* set appropriate adkcon bits */
619	adk = ADK_SETCLR|ADK_FAST;
620	if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
621		adk |= ADK_PRECOMP1;
622	else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
623		adk |= ADK_PRECOMP0;
624	custom.adkcon = adk;
625
626	custom.dsklen = DSKLEN_WRITE;
627	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
628	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
629	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
630
631	block_flag = 2;
632	return 1;
633}
634
635/*
636 * to be called at least 2ms after the write has finished but before any
637 * other access to the hardware.
638 */
639static void post_write (unsigned long drive)
640{
641#ifdef DEBUG
642	printk("post_write for drive %ld\n",drive);
643#endif
644	drive &= 3;
645	custom.dsklen = 0;
646	block_flag = 0;
647	writepending = 0;
648	writefromint = 0;
649	unit[drive].dirty = 0;
650	wake_up(&wait_fd_block);
651	fd_deselect(drive);
652	rel_fdc(); /* corresponds to get_fdc() in raw_write */
653}
654
655
656/*
657 * The following functions are to convert the block contents into raw data
658 * written to disk and vice versa.
659 * (Add other formats here ;-))
660 */
661
662static unsigned long scan_sync(unsigned long raw, unsigned long end)
663{
664	ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
665
666	while (ptr < endp && *ptr++ != 0x4489)
667		;
668	if (ptr < endp) {
669		while (*ptr == 0x4489 && ptr < endp)
670			ptr++;
671		return (ulong)ptr;
672	}
673	return 0;
674}
675
676static inline unsigned long checksum(unsigned long *addr, int len)
677{
678	unsigned long csum = 0;
679
680	len /= sizeof(*addr);
681	while (len-- > 0)
682		csum ^= *addr++;
683	csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
684
685	return csum;
686}
687
688static unsigned long decode (unsigned long *data, unsigned long *raw,
689			     int len)
690{
691	ulong *odd, *even;
692
693	/* convert length from bytes to longwords */
694	len >>= 2;
695	odd = raw;
696	even = odd + len;
697
698	/* prepare return pointer */
699	raw += len * 2;
700
701	do {
702		*data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
703	} while (--len != 0);
704
705	return (ulong)raw;
706}
707
708struct header {
709	unsigned char magic;
710	unsigned char track;
711	unsigned char sect;
712	unsigned char ord;
713	unsigned char labels[16];
714	unsigned long hdrchk;
715	unsigned long datachk;
716};
717
718static int amiga_read(int drive)
719{
720	unsigned long raw;
721	unsigned long end;
722	int scnt;
723	unsigned long csum;
724	struct header hdr;
725
726	drive&=3;
727	raw = (long) raw_buf;
728	end = raw + unit[drive].type->read_size;
729
730	for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
731		if (!(raw = scan_sync(raw, end))) {
732			printk (KERN_INFO "can't find sync for sector %d\n", scnt);
733			return MFM_NOSYNC;
734		}
735
736		raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
737		raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
738		raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
739		raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
740		csum = checksum((ulong *)&hdr,
741				(char *)&hdr.hdrchk-(char *)&hdr);
742
743#ifdef DEBUG
744		printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
745			hdr.magic, hdr.track, hdr.sect, hdr.ord,
746			*(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
747			*(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
748			hdr.hdrchk, hdr.datachk);
749#endif
750
751		if (hdr.hdrchk != csum) {
752			printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
753			return MFM_HEADER;
754		}
755
756		/* verify track */
757		if (hdr.track != unit[drive].track) {
758			printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
759			return MFM_TRACK;
760		}
761
762		raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
763			      (ulong *)raw, 512);
764		csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
765
766		if (hdr.datachk != csum) {
767			printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
768			       hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
769			       hdr.datachk, csum);
770			printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
771				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
772				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
773				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
774				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
775			return MFM_DATA;
776		}
777	}
778
779	return 0;
780}
781
782static void encode(unsigned long data, unsigned long *dest)
783{
784	unsigned long data2;
785
786	data &= 0x55555555;
787	data2 = data ^ 0x55555555;
788	data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
789
790	if (*(dest - 1) & 0x00000001)
791		data &= 0x7FFFFFFF;
792
793	*dest = data;
794}
795
796static void encode_block(unsigned long *dest, unsigned long *src, int len)
797{
798	int cnt, to_cnt = 0;
799	unsigned long data;
800
801	/* odd bits */
802	for (cnt = 0; cnt < len / 4; cnt++) {
803		data = src[cnt] >> 1;
804		encode(data, dest + to_cnt++);
805	}
806
807	/* even bits */
808	for (cnt = 0; cnt < len / 4; cnt++) {
809		data = src[cnt];
810		encode(data, dest + to_cnt++);
811	}
812}
813
814static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
815{
816	struct header hdr;
817	int i;
818
819	disk&=3;
820	*raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
821	raw++;
822	*raw++ = 0x44894489;
823
824	hdr.magic = 0xFF;
825	hdr.track = unit[disk].track;
826	hdr.sect = cnt;
827	hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
828	for (i = 0; i < 16; i++)
829		hdr.labels[i] = 0;
830	hdr.hdrchk = checksum((ulong *)&hdr,
831			      (char *)&hdr.hdrchk-(char *)&hdr);
832	hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
833
834	encode_block(raw, (ulong *)&hdr.magic, 4);
835	raw += 2;
836	encode_block(raw, (ulong *)&hdr.labels, 16);
837	raw += 8;
838	encode_block(raw, (ulong *)&hdr.hdrchk, 4);
839	raw += 2;
840	encode_block(raw, (ulong *)&hdr.datachk, 4);
841	raw += 2;
842	encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
843	raw += 256;
844
845	return raw;
846}
847
848static void amiga_write(int disk)
849{
850	unsigned int cnt;
851	unsigned long *ptr = (unsigned long *)raw_buf;
852
853	disk&=3;
854	/* gap space */
855	for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
856		*ptr++ = 0xaaaaaaaa;
857
858	/* sectors */
859	for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
860		ptr = putsec (disk, ptr, cnt);
861	*(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
862}
863
864
865struct dos_header {
866	unsigned char track,   /* 0-80 */
867		side,    /* 0-1 */
868		sec,     /* 0-...*/
869		len_desc;/* 2 */
870	unsigned short crc;     /* on 68000 we got an alignment problem,
871				   but this compiler solves it  by adding silently
872				   adding a pad byte so data won't fit
873				   and this took about 3h to discover.... */
874	unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
875};
876
877/* crc routines are borrowed from the messydos-handler  */
878
879/* excerpt from the messydos-device
880; The CRC is computed not only over the actual data, but including
881; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
882; As we don't read or encode these fields into our buffers, we have to
883; preload the registers containing the CRC with the values they would have
884; after stepping over these fields.
885;
886; How CRCs "really" work:
887;
888; First, you should regard a bitstring as a series of coefficients of
889; polynomials. We calculate with these polynomials in modulo-2
890; arithmetic, in which both add and subtract are done the same as
891; exclusive-or. Now, we modify our data (a very long polynomial) in
892; such a way that it becomes divisible by the CCITT-standard 16-bit
893;		 16   12   5
894; polynomial:	x  + x	+ x + 1, represented by $11021. The easiest
895; way to do this would be to multiply (using proper arithmetic) our
896; datablock with $11021. So we have:
897;   data * $11021		 =
898;   data * ($10000 + $1021)      =
899;   data * $10000 + data * $1021
900; The left part of this is simple: Just add two 0 bytes. But then
901; the right part (data $1021) remains difficult and even could have
902; a carry into the left part. The solution is to use a modified
903; multiplication, which has a result that is not correct, but with
904; a difference of any multiple of $11021. We then only need to keep
905; the 16 least significant bits of the result.
906;
907; The following algorithm does this for us:
908;
909;   unsigned char *data, c, crclo, crchi;
910;   while (not done) {
911;	c = *data++ + crchi;
912;	crchi = (@ c) >> 8 + crclo;
913;	crclo = @ c;
914;   }
915;
916; Remember, + is done with EOR, the @ operator is in two tables (high
917; and low byte separately), which is calculated as
918;
919;      $1021 * (c & $F0)
920;  xor $1021 * (c & $0F)
921;  xor $1021 * (c >> 4)         (* is regular multiplication)
922;
923;
924; Anyway, the end result is the same as the remainder of the division of
925; the data by $11021. I am afraid I need to study theory a bit more...
926
927
928my only works was to code this from manx to C....
929
930*/
931
932static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
933{
934	static unsigned char CRCTable1[] = {
935		0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
936		0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
937		0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
938		0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
939		0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
940		0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
941		0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
942		0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
943		0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
944		0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
945		0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
946		0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
947		0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
948		0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
949		0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
950		0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
951	};
952
953	static unsigned char CRCTable2[] = {
954		0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
955		0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
956		0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
957		0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
958		0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
959		0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
960		0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
961		0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
962		0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
963		0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
964		0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
965		0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
966		0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
967		0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
968		0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
969		0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
970	};
971
972/* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
973	register int i;
974	register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
975
976	CRCT1=CRCTable1;
977	CRCT2=CRCTable2;
978	data=data_a3;
979	crcl=data_d1;
980	crch=data_d0;
981	for (i=data_d3; i>=0; i--) {
982		c = (*data++) ^ crch;
983		crch = CRCT1[c] ^ crcl;
984		crcl = CRCT2[c];
985	}
986	return (crch<<8)|crcl;
987}
988
989static inline ushort dos_hdr_crc (struct dos_header *hdr)
990{
991	return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
992}
993
994static inline ushort dos_data_crc(unsigned char *data)
995{
996	return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
997}
998
999static inline unsigned char dos_decode_byte(ushort word)
1000{
1001	register ushort w2;
1002	register unsigned char byte;
1003	register unsigned char *dec = mfmdecode;
1004
1005	w2=word;
1006	w2>>=8;
1007	w2&=127;
1008	byte = dec[w2];
1009	byte <<= 4;
1010	w2 = word & 127;
1011	byte |= dec[w2];
1012	return byte;
1013}
1014
1015static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1016{
1017	int i;
1018
1019	for (i = 0; i < len; i++)
1020		*data++=dos_decode_byte(*raw++);
1021	return ((ulong)raw);
1022}
1023
1024#ifdef DEBUG
1025static void dbg(unsigned long ptr)
1026{
1027	printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1028	       ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1029	       ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1030}
1031#endif
1032
1033static int dos_read(int drive)
1034{
1035	unsigned long end;
1036	unsigned long raw;
1037	int scnt;
1038	unsigned short crc,data_crc[2];
1039	struct dos_header hdr;
1040
1041	drive&=3;
1042	raw = (long) raw_buf;
1043	end = raw + unit[drive].type->read_size;
1044
1045	for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1046		do { /* search for the right sync of each sec-hdr */
1047			if (!(raw = scan_sync (raw, end))) {
1048				printk(KERN_INFO "dos_read: no hdr sync on "
1049				       "track %d, unit %d for sector %d\n",
1050				       unit[drive].track,drive,scnt);
1051				return MFM_NOSYNC;
1052			}
1053#ifdef DEBUG
1054			dbg(raw);
1055#endif
1056		} while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1057		raw+=2; /* skip over headermark */
1058		raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1059		crc = dos_hdr_crc(&hdr);
1060
1061#ifdef DEBUG
1062		printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1063		       hdr.sec, hdr.len_desc, hdr.crc);
1064#endif
1065
1066		if (crc != hdr.crc) {
1067			printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1068			       hdr.crc, crc);
1069			return MFM_HEADER;
1070		}
1071		if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1072			printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1073			       hdr.track,
1074			       unit[drive].track/unit[drive].type->heads);
1075			return MFM_TRACK;
1076		}
1077
1078		if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1079			printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1080			       hdr.side,
1081			       unit[drive].track%unit[drive].type->heads);
1082			return MFM_TRACK;
1083		}
1084
1085		if (hdr.len_desc != 2) {
1086			printk(KERN_INFO "dos_read: unknown sector len "
1087			       "descriptor %d\n", hdr.len_desc);
1088			return MFM_DATA;
1089		}
1090#ifdef DEBUG
1091		printk("hdr accepted\n");
1092#endif
1093		if (!(raw = scan_sync (raw, end))) {
1094			printk(KERN_INFO "dos_read: no data sync on track "
1095			       "%d, unit %d for sector%d, disk sector %d\n",
1096			       unit[drive].track, drive, scnt, hdr.sec);
1097			return MFM_NOSYNC;
1098		}
1099#ifdef DEBUG
1100		dbg(raw);
1101#endif
1102
1103		if (*((ushort *)raw)!=0x5545) {
1104			printk(KERN_INFO "dos_read: no data mark after "
1105			       "sync (%d,%d,%d,%d) sc=%d\n",
1106			       hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1107			return MFM_NOSYNC;
1108		}
1109
1110		raw+=2;  /* skip data mark (included in checksum) */
1111		raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1112		raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1113		crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1114
1115		if (crc != data_crc[0]) {
1116			printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1117			       "sc=%d, %x %x\n", hdr.track, hdr.side,
1118			       hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1119			printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1120			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1121			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1122			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1123			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1124			return MFM_DATA;
1125		}
1126	}
1127	return 0;
1128}
1129
1130static inline ushort dos_encode_byte(unsigned char byte)
1131{
1132	register unsigned char *enc, b2, b1;
1133	register ushort word;
1134
1135	enc=mfmencode;
1136	b1=byte;
1137	b2=b1>>4;
1138	b1&=15;
1139	word=enc[b2] <<8 | enc [b1];
1140	return (word|((word&(256|64)) ? 0: 128));
1141}
1142
1143static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1144{
1145	int i;
1146
1147	for (i = 0; i < len; i++) {
1148		*dest=dos_encode_byte(*src++);
1149		*dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1150		dest++;
1151	}
1152}
1153
1154static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1155{
1156	static struct dos_header hdr={0,0,0,2,0,
1157	  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1158	int i;
1159	static ushort crc[2]={0,0x4e4e};
1160
1161	drive&=3;
1162/* id gap 1 */
1163/* the MFM word before is always 9254 */
1164	for(i=0;i<6;i++)
1165		*raw++=0xaaaaaaaa;
1166/* 3 sync + 1 headermark */
1167	*raw++=0x44894489;
1168	*raw++=0x44895554;
1169
1170/* fill in the variable parts of the header */
1171	hdr.track=unit[drive].track/unit[drive].type->heads;
1172	hdr.side=unit[drive].track%unit[drive].type->heads;
1173	hdr.sec=cnt+1;
1174	hdr.crc=dos_hdr_crc(&hdr);
1175
1176/* header (without "magic") and id gap 2*/
1177	dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1178	raw+=14;
1179
1180/*id gap 3 */
1181	for(i=0;i<6;i++)
1182		*raw++=0xaaaaaaaa;
1183
1184/* 3 syncs and 1 datamark */
1185	*raw++=0x44894489;
1186	*raw++=0x44895545;
1187
1188/* data */
1189	dos_encode_block((ushort *)raw,
1190			 (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1191	raw+=256;
1192
1193/*data crc + jd's special gap (long words :-/) */
1194	crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1195	dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1196	raw+=2;
1197
1198/* data gap */
1199	for(i=0;i<38;i++)
1200		*raw++=0x92549254;
1201
1202	return raw; /* wrote 652 MFM words */
1203}
1204
1205static void dos_write(int disk)
1206{
1207	int cnt;
1208	unsigned long raw = (unsigned long) raw_buf;
1209	unsigned long *ptr=(unsigned long *)raw;
1210
1211	disk&=3;
1212/* really gap4 + indexgap , but we write it first and round it up */
1213	for (cnt=0;cnt<425;cnt++)
1214		*ptr++=0x92549254;
1215
1216/* the following is just guessed */
1217	if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1218		for(cnt=0;cnt<473;cnt++)
1219			*ptr++=0x92549254;
1220
1221/* now the index marks...*/
1222	for (cnt=0;cnt<20;cnt++)
1223		*ptr++=0x92549254;
1224	for (cnt=0;cnt<6;cnt++)
1225		*ptr++=0xaaaaaaaa;
1226	*ptr++=0x52245224;
1227	*ptr++=0x52245552;
1228	for (cnt=0;cnt<20;cnt++)
1229		*ptr++=0x92549254;
1230
1231/* sectors */
1232	for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1233		ptr=ms_putsec(disk,ptr,cnt);
1234
1235	*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1236}
1237
1238/*
1239 * Here comes the high level stuff (i.e. the filesystem interface)
1240 * and helper functions.
1241 * Normally this should be the only part that has to be adapted to
1242 * different kernel versions.
1243 */
1244
1245static void flush_track_callback(unsigned long nr)
1246{
1247	nr&=3;
1248	writefromint = 1;
1249	if (!try_fdc(nr)) {
1250		/* we might block in an interrupt, so try again later */
1251		flush_track_timer[nr].expires = jiffies + 1;
1252		add_timer(flush_track_timer + nr);
1253		return;
1254	}
1255	get_fdc(nr);
1256	(*unit[nr].dtype->write_fkt)(nr);
1257	if (!raw_write(nr)) {
1258		printk (KERN_NOTICE "floppy disk write protected\n");
1259		writefromint = 0;
1260		writepending = 0;
1261	}
1262	rel_fdc();
1263}
1264
1265static int non_int_flush_track (unsigned long nr)
1266{
1267	unsigned long flags;
1268
1269	nr&=3;
1270	writefromint = 0;
1271	del_timer(&post_write_timer);
1272	get_fdc(nr);
1273	if (!fd_motor_on(nr)) {
1274		writepending = 0;
1275		rel_fdc();
1276		return 0;
1277	}
1278	local_irq_save(flags);
1279	if (writepending != 2) {
1280		local_irq_restore(flags);
1281		(*unit[nr].dtype->write_fkt)(nr);
1282		if (!raw_write(nr)) {
1283			printk (KERN_NOTICE "floppy disk write protected "
1284				"in write!\n");
1285			writepending = 0;
1286			return 0;
1287		}
1288		while (block_flag == 2)
1289			sleep_on (&wait_fd_block);
1290	}
1291	else {
1292		local_irq_restore(flags);
1293		ms_delay(2); /* 2 ms post_write delay */
1294		post_write(nr);
1295	}
1296	rel_fdc();
1297	return 1;
1298}
1299
1300static int get_track(int drive, int track)
1301{
1302	int error, errcnt;
1303
1304	drive&=3;
1305	if (unit[drive].track == track)
1306		return 0;
1307	get_fdc(drive);
1308	if (!fd_motor_on(drive)) {
1309		rel_fdc();
1310		return -1;
1311	}
1312
1313	if (unit[drive].dirty == 1) {
1314		del_timer (flush_track_timer + drive);
1315		non_int_flush_track (drive);
1316	}
1317	errcnt = 0;
1318	while (errcnt < MAX_ERRORS) {
1319		if (!fd_seek(drive, track))
1320			return -1;
1321		raw_read(drive);
1322		error = (*unit[drive].dtype->read_fkt)(drive);
1323		if (error == 0) {
1324			rel_fdc();
1325			return 0;
1326		}
1327		/* Read Error Handling: recalibrate and try again */
1328		unit[drive].track = -1;
1329		errcnt++;
1330	}
1331	rel_fdc();
1332	return -1;
1333}
1334
1335static void redo_fd_request(void)
1336{
1337	unsigned int cnt, block, track, sector;
1338	int drive;
1339	struct amiga_floppy_struct *floppy;
1340	char *data;
1341	unsigned long flags;
1342
1343 repeat:
1344	if (!CURRENT) {
1345		/* Nothing left to do */
1346		return;
1347	}
1348
1349	floppy = CURRENT->rq_disk->private_data;
1350	drive = floppy - unit;
1351
1352	/* Here someone could investigate to be more efficient */
1353	for (cnt = 0; cnt < CURRENT->current_nr_sectors; cnt++) {
1354#ifdef DEBUG
1355		printk("fd: sector %ld + %d requested for %s\n",
1356		       CURRENT->sector,cnt,
1357		       (CURRENT->cmd==READ)?"read":"write");
1358#endif
1359		block = CURRENT->sector + cnt;
1360		if ((int)block > floppy->blocks) {
1361			end_request(CURRENT, 0);
1362			goto repeat;
1363		}
1364
1365		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1366		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1367		data = CURRENT->buffer + 512 * cnt;
1368#ifdef DEBUG
1369		printk("access to track %d, sector %d, with buffer at "
1370		       "0x%08lx\n", track, sector, data);
1371#endif
1372
1373		if ((rq_data_dir(CURRENT) != READ) && (rq_data_dir(CURRENT) != WRITE)) {
1374			printk(KERN_WARNING "do_fd_request: unknown command\n");
1375			end_request(CURRENT, 0);
1376			goto repeat;
1377		}
1378		if (get_track(drive, track) == -1) {
1379			end_request(CURRENT, 0);
1380			goto repeat;
1381		}
1382
1383		switch (rq_data_dir(CURRENT)) {
1384		case READ:
1385			memcpy(data, floppy->trackbuf + sector * 512, 512);
1386			break;
1387
1388		case WRITE:
1389			memcpy(floppy->trackbuf + sector * 512, data, 512);
1390
1391			/* keep the drive spinning while writes are scheduled */
1392			if (!fd_motor_on(drive)) {
1393				end_request(CURRENT, 0);
1394				goto repeat;
1395			}
1396			/*
1397			 * setup a callback to write the track buffer
1398			 * after a short (1 tick) delay.
1399			 */
1400			local_irq_save(flags);
1401
1402			floppy->dirty = 1;
1403		        /* reset the timer */
1404			mod_timer (flush_track_timer + drive, jiffies + 1);
1405			local_irq_restore(flags);
1406			break;
1407		}
1408	}
1409	CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
1410	CURRENT->sector += CURRENT->current_nr_sectors;
1411
1412	end_request(CURRENT, 1);
1413	goto repeat;
1414}
1415
1416static void do_fd_request(request_queue_t * q)
1417{
1418	redo_fd_request();
1419}
1420
1421static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1422{
1423	int drive = MINOR(bdev->bd_dev) & 3;
1424
1425	geo->heads = unit[drive].type->heads;
1426	geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1427	geo->cylinders = unit[drive].type->tracks;
1428	return 0;
1429}
1430
1431static int fd_ioctl(struct inode *inode, struct file *filp,
1432		    unsigned int cmd, unsigned long param)
1433{
1434	int drive = iminor(inode) & 3;
1435	static struct floppy_struct getprm;
1436	void __user *argp = (void __user *)param;
1437
1438	switch(cmd){
1439	case FDFMTBEG:
1440		get_fdc(drive);
1441		if (fd_ref[drive] > 1) {
1442			rel_fdc();
1443			return -EBUSY;
1444		}
1445		fsync_bdev(inode->i_bdev);
1446		if (fd_motor_on(drive) == 0) {
1447			rel_fdc();
1448			return -ENODEV;
1449		}
1450		if (fd_calibrate(drive) == 0) {
1451			rel_fdc();
1452			return -ENXIO;
1453		}
1454		floppy_off(drive);
1455		rel_fdc();
1456		break;
1457	case FDFMTTRK:
1458		if (param < unit[drive].type->tracks * unit[drive].type->heads)
1459		{
1460			get_fdc(drive);
1461			if (fd_seek(drive,param) != 0){
1462				memset(unit[drive].trackbuf, FD_FILL_BYTE,
1463				       unit[drive].dtype->sects * unit[drive].type->sect_mult * 512);
1464				non_int_flush_track(drive);
1465			}
1466			floppy_off(drive);
1467			rel_fdc();
1468		}
1469		else
1470			return -EINVAL;
1471		break;
1472	case FDFMTEND:
1473		floppy_off(drive);
1474		invalidate_bdev(inode->i_bdev);
1475		break;
1476	case FDGETPRM:
1477		memset((void *)&getprm, 0, sizeof (getprm));
1478		getprm.track=unit[drive].type->tracks;
1479		getprm.head=unit[drive].type->heads;
1480		getprm.sect=unit[drive].dtype->sects * unit[drive].type->sect_mult;
1481		getprm.size=unit[drive].blocks;
1482		if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1483			return -EFAULT;
1484		break;
1485	case FDSETPRM:
1486	case FDDEFPRM:
1487		return -EINVAL;
1488	case FDFLUSH: /* unconditionally, even if not needed */
1489		del_timer (flush_track_timer + drive);
1490		non_int_flush_track(drive);
1491		break;
1492#ifdef RAW_IOCTL
1493	case IOCTL_RAW_TRACK:
1494		if (copy_to_user(argp, raw_buf, unit[drive].type->read_size))
1495			return -EFAULT;
1496		else
1497			return unit[drive].type->read_size;
1498#endif
1499	default:
1500		printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1501		       cmd, drive);
1502		return -ENOSYS;
1503	}
1504	return 0;
1505}
1506
1507static void fd_probe(int dev)
1508{
1509	unsigned long code;
1510	int type;
1511	int drive;
1512
1513	drive = dev & 3;
1514	code = fd_get_drive_id(drive);
1515
1516	/* get drive type */
1517	for (type = 0; type < num_dr_types; type++)
1518		if (drive_types[type].code == code)
1519			break;
1520
1521	if (type >= num_dr_types) {
1522		printk(KERN_WARNING "fd_probe: unsupported drive type "
1523		       "%08lx found\n", code);
1524		unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1525		return;
1526	}
1527
1528	unit[drive].type = drive_types + type;
1529	unit[drive].track = -1;
1530
1531	unit[drive].disk = -1;
1532	unit[drive].motor = 0;
1533	unit[drive].busy = 0;
1534	unit[drive].status = -1;
1535}
1536
1537/*
1538 * floppy_open check for aliasing (/dev/fd0 can be the same as
1539 * /dev/PS0 etc), and disallows simultaneous access to the same
1540 * drive with different device numbers.
1541 */
1542static int floppy_open(struct inode *inode, struct file *filp)
1543{
1544	int drive = iminor(inode) & 3;
1545	int system =  (iminor(inode) & 4) >> 2;
1546	int old_dev;
1547	unsigned long flags;
1548
1549	old_dev = fd_device[drive];
1550
1551	if (fd_ref[drive] && old_dev != system)
1552		return -EBUSY;
1553
1554	if (filp && filp->f_mode & 3) {
1555		check_disk_change(inode->i_bdev);
1556		if (filp->f_mode & 2 ) {
1557			int wrprot;
1558
1559			get_fdc(drive);
1560			fd_select (drive);
1561			wrprot = !(ciaa.pra & DSKPROT);
1562			fd_deselect (drive);
1563			rel_fdc();
1564
1565			if (wrprot)
1566				return -EROFS;
1567		}
1568	}
1569
1570	local_irq_save(flags);
1571	fd_ref[drive]++;
1572	fd_device[drive] = system;
1573	local_irq_restore(flags);
1574
1575	unit[drive].dtype=&data_types[system];
1576	unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1577		data_types[system].sects*unit[drive].type->sect_mult;
1578	set_capacity(unit[drive].gendisk, unit[drive].blocks);
1579
1580	printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1581	       unit[drive].type->name, data_types[system].name);
1582
1583	return 0;
1584}
1585
1586static int floppy_release(struct inode * inode, struct file * filp)
1587{
1588	int drive = iminor(inode) & 3;
1589
1590	if (unit[drive].dirty == 1) {
1591		del_timer (flush_track_timer + drive);
1592		non_int_flush_track (drive);
1593	}
1594
1595	if (!fd_ref[drive]--) {
1596		printk(KERN_CRIT "floppy_release with fd_ref == 0");
1597		fd_ref[drive] = 0;
1598	}
1599#ifdef MODULE
1600/* the mod_use counter is handled this way */
1601	floppy_off (drive | 0x40000000);
1602#endif
1603	return 0;
1604}
1605
1606/*
1607 * floppy-change is never called from an interrupt, so we can relax a bit
1608 * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1609 * to the desired drive, but it will probably not survive the sleep if
1610 * several floppies are used at the same time: thus the loop.
1611 */
1612static int amiga_floppy_change(struct gendisk *disk)
1613{
1614	struct amiga_floppy_struct *p = disk->private_data;
1615	int drive = p - unit;
1616	int changed;
1617	static int first_time = 1;
1618
1619	if (first_time)
1620		changed = first_time--;
1621	else {
1622		get_fdc(drive);
1623		fd_select (drive);
1624		changed = !(ciaa.pra & DSKCHANGE);
1625		fd_deselect (drive);
1626		rel_fdc();
1627	}
1628
1629	if (changed) {
1630		fd_probe(drive);
1631		p->track = -1;
1632		p->dirty = 0;
1633		writepending = 0; /* if this was true before, too bad! */
1634		writefromint = 0;
1635		return 1;
1636	}
1637	return 0;
1638}
1639
1640static struct block_device_operations floppy_fops = {
1641	.owner		= THIS_MODULE,
1642	.open		= floppy_open,
1643	.release	= floppy_release,
1644	.ioctl		= fd_ioctl,
1645	.getgeo		= fd_getgeo,
1646	.media_changed	= amiga_floppy_change,
1647};
1648
1649static int __init fd_probe_drives(void)
1650{
1651	int drive,drives,nomem;
1652
1653	printk(KERN_INFO "FD: probing units\n" KERN_INFO "found ");
1654	drives=0;
1655	nomem=0;
1656	for(drive=0;drive<FD_MAX_UNITS;drive++) {
1657		struct gendisk *disk;
1658		fd_probe(drive);
1659		if (unit[drive].type->code == FD_NODRIVE)
1660			continue;
1661		disk = alloc_disk(1);
1662		if (!disk) {
1663			unit[drive].type->code = FD_NODRIVE;
1664			continue;
1665		}
1666		unit[drive].gendisk = disk;
1667		drives++;
1668		if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1669			printk("no mem for ");
1670			unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1671			drives--;
1672			nomem = 1;
1673		}
1674		printk("fd%d ",drive);
1675		disk->major = FLOPPY_MAJOR;
1676		disk->first_minor = drive;
1677		disk->fops = &floppy_fops;
1678		sprintf(disk->disk_name, "fd%d", drive);
1679		disk->private_data = &unit[drive];
1680		disk->queue = floppy_queue;
1681		set_capacity(disk, 880*2);
1682		add_disk(disk);
1683	}
1684	if ((drives > 0) || (nomem == 0)) {
1685		if (drives == 0)
1686			printk("no drives");
1687		printk("\n");
1688		return drives;
1689	}
1690	printk("\n");
1691	return -ENOMEM;
1692}
1693
1694static struct kobject *floppy_find(dev_t dev, int *part, void *data)
1695{
1696	int drive = *part & 3;
1697	if (unit[drive].type->code == FD_NODRIVE)
1698		return NULL;
1699	*part = 0;
1700	return get_disk(unit[drive].gendisk);
1701}
1702
1703static int __init amiga_floppy_init(void)
1704{
1705	int i, ret;
1706
1707	if (!MACH_IS_AMIGA)
1708		return -ENXIO;
1709
1710	if (!AMIGAHW_PRESENT(AMI_FLOPPY))
1711		return -ENXIO;
1712
1713	if (register_blkdev(FLOPPY_MAJOR,"fd"))
1714		return -EBUSY;
1715
1716	/*
1717	 *  We request DSKPTR, DSKLEN and DSKDATA only, because the other
1718	 *  floppy registers are too spreaded over the custom register space
1719	 */
1720	ret = -EBUSY;
1721	if (!request_mem_region(CUSTOM_PHYSADDR+0x20, 8, "amiflop [Paula]")) {
1722		printk("fd: cannot get floppy registers\n");
1723		goto out_blkdev;
1724	}
1725
1726	ret = -ENOMEM;
1727	if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1728	    NULL) {
1729		printk("fd: cannot get chip mem buffer\n");
1730		goto out_memregion;
1731	}
1732
1733	ret = -EBUSY;
1734	if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1735		printk("fd: cannot get irq for dma\n");
1736		goto out_irq;
1737	}
1738
1739	if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1740		printk("fd: cannot get irq for timer\n");
1741		goto out_irq2;
1742	}
1743
1744	ret = -ENOMEM;
1745	floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
1746	if (!floppy_queue)
1747		goto out_queue;
1748
1749	ret = -ENXIO;
1750	if (fd_probe_drives() < 1) /* No usable drives */
1751		goto out_probe;
1752
1753	blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
1754				floppy_find, NULL, NULL);
1755
1756	/* initialize variables */
1757	init_timer(&motor_on_timer);
1758	motor_on_timer.expires = 0;
1759	motor_on_timer.data = 0;
1760	motor_on_timer.function = motor_on_callback;
1761	for (i = 0; i < FD_MAX_UNITS; i++) {
1762		init_timer(&motor_off_timer[i]);
1763		motor_off_timer[i].expires = 0;
1764		motor_off_timer[i].data = i|0x80000000;
1765		motor_off_timer[i].function = fd_motor_off;
1766		init_timer(&flush_track_timer[i]);
1767		flush_track_timer[i].expires = 0;
1768		flush_track_timer[i].data = i;
1769		flush_track_timer[i].function = flush_track_callback;
1770
1771		unit[i].track = -1;
1772	}
1773
1774	init_timer(&post_write_timer);
1775	post_write_timer.expires = 0;
1776	post_write_timer.data = 0;
1777	post_write_timer.function = post_write;
1778
1779	for (i = 0; i < 128; i++)
1780		mfmdecode[i]=255;
1781	for (i = 0; i < 16; i++)
1782		mfmdecode[mfmencode[i]]=i;
1783
1784	/* make sure that disk DMA is enabled */
1785	custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1786
1787	/* init ms timer */
1788	ciaa.crb = 8; /* one-shot, stop */
1789	return 0;
1790
1791out_probe:
1792	blk_cleanup_queue(floppy_queue);
1793out_queue:
1794	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1795out_irq2:
1796	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1797out_irq:
1798	amiga_chip_free(raw_buf);
1799out_memregion:
1800	release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1801out_blkdev:
1802	unregister_blkdev(FLOPPY_MAJOR,"fd");
1803	return ret;
1804}
1805
1806module_init(amiga_floppy_init);
1807#ifdef MODULE
1808
1809
1810#else
1811static int __init amiga_floppy_setup (char *str)
1812{
1813	int n;
1814	if (!MACH_IS_AMIGA)
1815		return 0;
1816	if (!get_option(&str, &n))
1817		return 0;
1818	printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1819	fd_def_df0 = n;
1820	return 1;
1821}
1822
1823__setup("floppy=", amiga_floppy_setup);
1824#endif
1825