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/sched.h>
59#include <linux/fs.h>
60#include <linux/fcntl.h>
61#include <linux/kernel.h>
62#include <linux/timer.h>
63#include <linux/fd.h>
64#include <linux/hdreg.h>
65#include <linux/errno.h>
66#include <linux/types.h>
67#include <linux/delay.h>
68#include <linux/string.h>
69#include <linux/slab.h>
70#include <linux/init.h>
71#include <linux/amifdreg.h>
72#include <linux/amifd.h>
73#include <linux/ioport.h>
74
75#include <asm/setup.h>
76#include <asm/uaccess.h>
77#include <asm/amigahw.h>
78#include <asm/amigaints.h>
79#include <asm/irq.h>
80
81#define MAJOR_NR FLOPPY_MAJOR
82#include <linux/blk.h>
83
84#undef DEBUG /* print _LOTS_ of infos */
85
86#define RAW_IOCTL
87#ifdef RAW_IOCTL
88#define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
89#endif
90
91/*
92 *  Defines
93 */
94
95/*
96 *  Error codes
97 */
98#define FD_OK		0	/* operation succeeded */
99#define FD_ERROR	-1	/* general error (seek, read, write, etc) */
100#define FD_NOUNIT	1	/* unit does not exist */
101#define FD_UNITBUSY	2	/* unit already active */
102#define FD_NOTACTIVE	3	/* unit is not active */
103#define FD_NOTREADY	4	/* unit is not ready (motor not on/no disk) */
104
105#define MFM_NOSYNC	1
106#define MFM_HEADER	2
107#define MFM_DATA	3
108#define MFM_TRACK	4
109
110/*
111 *  Floppy ID values
112 */
113#define FD_NODRIVE	0x00000000  /* response when no unit is present */
114#define FD_DD_3 	0xffffffff  /* double-density 3.5" (880K) drive */
115#define FD_HD_3 	0x55555555  /* high-density 3.5" (1760K) drive */
116#define FD_DD_5 	0xaaaaaaaa  /* double-density 5.25" (440K) drive */
117
118static long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
119
120MODULE_PARM(fd_def_df0,"l");
121MODULE_LICENSE("GPL");
122
123/*
124 *  Macros
125 */
126#define MOTOR_ON	(ciab.prb &= ~DSKMOTOR)
127#define MOTOR_OFF	(ciab.prb |= DSKMOTOR)
128#define SELECT(mask)    (ciab.prb &= ~mask)
129#define DESELECT(mask)  (ciab.prb |= mask)
130#define SELMASK(drive)  (1 << (3 + (drive & 3)))
131
132static struct fd_drive_type drive_types[] = {
133/*  code	name	   tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
134/*  warning: times are now in milliseconds (ms)                    */
135{ FD_DD_3,	"DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
136{ FD_HD_3,	"HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
137{ FD_DD_5,	"DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
138{ FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
139};
140static int num_dr_types = sizeof(drive_types) / sizeof(drive_types[0]);
141
142/* defaults for 3 1/2" HD-Disks */
143static int floppy_sizes[256]={880,880,880,880,720,720,720,720,};
144static int floppy_blocksizes[256];
145/* hardsector size assumed to be 512 */
146
147static int amiga_read(int), dos_read(int);
148static void amiga_write(int), dos_write(int);
149static struct fd_data_type data_types[] = {
150	{ "Amiga", 11 , amiga_read, amiga_write},
151	{ "MS-Dos", 9, dos_read, dos_write}
152};
153
154/* current info on each unit */
155static struct amiga_floppy_struct unit[FD_MAX_UNITS];
156
157static struct timer_list flush_track_timer[FD_MAX_UNITS];
158static struct timer_list post_write_timer;
159static struct timer_list motor_on_timer;
160static struct timer_list motor_off_timer[FD_MAX_UNITS];
161static int on_attempts;
162
163/* Synchronization of FDC access */
164/* request loop (trackbuffer) */
165static volatile int fdc_busy = -1;
166static volatile int fdc_nested;
167static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
168
169static DECLARE_WAIT_QUEUE_HEAD(motor_wait);
170
171static volatile int selected = -1;	/* currently selected drive */
172
173static int writepending;
174static int writefromint;
175static char *raw_buf;
176
177#define RAW_BUF_SIZE 30000  /* size of raw disk data */
178
179/*
180 * These are global variables, as that's the easiest way to give
181 * information to interrupts. They are the data used for the current
182 * request.
183 */
184static volatile char block_flag;
185static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
186
187/* MS-Dos MFM Coding tables (should go quick and easy) */
188static unsigned char mfmencode[16]={
189	0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
190	0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
191};
192static unsigned char mfmdecode[128];
193
194/* floppy internal millisecond timer stuff */
195static volatile int ms_busy = -1;
196static DECLARE_WAIT_QUEUE_HEAD(ms_wait);
197#define MS_TICKS ((amiga_eclock+50)/1000)
198
199/*
200 * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
201 * max X times - some types of errors increase the errorcount by 2 or
202 * even 3, so we might actually retry only X/2 times before giving up.
203 */
204#define MAX_ERRORS 12
205
206/* Prevent "aliased" accesses. */
207static int fd_ref[4] = { 0,0,0,0 };
208static int fd_device[4] = { 0,0,0,0 };
209
210/*
211 * Current device number. Taken either from the block header or from the
212 * format request descriptor.
213 */
214#define CURRENT_DEVICE (CURRENT->rq_dev)
215
216/* Current error count. */
217#define CURRENT_ERRORS (CURRENT->errors)
218
219
220
221/*
222 * Here come the actual hardware access and helper functions.
223 * They are not reentrant and single threaded because all drives
224 * share the same hardware and the same trackbuffer.
225 */
226
227/* Milliseconds timer */
228
229static void ms_isr(int irq, void *dummy, struct pt_regs *fp)
230{
231	ms_busy = -1;
232	wake_up(&ms_wait);
233}
234
235/* all waits are queued up
236   A more generic routine would do a schedule a la timer.device */
237static void ms_delay(int ms)
238{
239	unsigned long flags;
240	int ticks;
241	if (ms > 0) {
242		save_flags(flags);
243		cli();
244		while (ms_busy == 0)
245			sleep_on(&ms_wait);
246		ms_busy = 0;
247		restore_flags(flags);
248		ticks = MS_TICKS*ms-1;
249		ciaa.tblo=ticks%256;
250		ciaa.tbhi=ticks/256;
251		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
252		sleep_on(&ms_wait);
253	}
254}
255
256/* Hardware semaphore */
257
258/* returns true when we would get the semaphore */
259static inline int try_fdc(int drive)
260{
261	drive &= 3;
262	return ((fdc_busy < 0) || (fdc_busy == drive));
263}
264
265static void get_fdc(int drive)
266{
267	unsigned long flags;
268
269	drive &= 3;
270#ifdef DEBUG
271	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
272#endif
273	save_flags(flags);
274	cli();
275	while (!try_fdc(drive))
276		sleep_on(&fdc_wait);
277	fdc_busy = drive;
278	fdc_nested++;
279	restore_flags(flags);
280}
281
282static inline void rel_fdc(void)
283{
284#ifdef DEBUG
285	if (fdc_nested == 0)
286		printk("fd: unmatched rel_fdc\n");
287	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
288#endif
289	fdc_nested--;
290	if (fdc_nested == 0) {
291		fdc_busy = -1;
292		wake_up(&fdc_wait);
293	}
294}
295
296static void fd_select (int drive)
297{
298	unsigned char prb = ~0;
299
300	drive&=3;
301#ifdef DEBUG
302	printk("selecting %d\n",drive);
303#endif
304	if (drive == selected)
305		return;
306	get_fdc(drive);
307	selected = drive;
308
309	if (unit[drive].track % 2 != 0)
310		prb &= ~DSKSIDE;
311	if (unit[drive].motor == 1)
312		prb &= ~DSKMOTOR;
313	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
314	ciab.prb = prb;
315	prb &= ~SELMASK(drive);
316	ciab.prb = prb;
317	rel_fdc();
318}
319
320static void fd_deselect (int drive)
321{
322	unsigned char prb;
323	unsigned long flags;
324
325	drive&=3;
326#ifdef DEBUG
327	printk("deselecting %d\n",drive);
328#endif
329	if (drive != selected) {
330		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
331		return;
332	}
333
334	get_fdc(drive);
335	save_flags (flags);
336	sti();
337
338	selected = -1;
339
340	prb = ciab.prb;
341	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
342	ciab.prb = prb;
343
344	restore_flags (flags);
345	rel_fdc();
346
347}
348
349static void motor_on_callback(unsigned long nr)
350{
351	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
352		wake_up (&motor_wait);
353	} else {
354		motor_on_timer.expires = jiffies + HZ/10;
355		add_timer(&motor_on_timer);
356	}
357}
358
359static int fd_motor_on(int nr)
360{
361	nr &= 3;
362
363	del_timer(motor_off_timer + nr);
364
365	if (!unit[nr].motor) {
366		unit[nr].motor = 1;
367		fd_select(nr);
368
369		del_timer(&motor_on_timer);
370		motor_on_timer.data = nr;
371		motor_on_timer.expires = jiffies + HZ/2;
372		add_timer(&motor_on_timer);
373
374		on_attempts = 10;
375		sleep_on (&motor_wait);
376		fd_deselect(nr);
377	}
378
379	if (on_attempts == 0) {
380		on_attempts = -1;
381		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
382	}
383
384	return 1;
385}
386
387static void fd_motor_off(unsigned long drive)
388{
389	long calledfromint;
390#ifdef MODULE
391	long decusecount;
392
393	decusecount = drive & 0x40000000;
394#endif
395	calledfromint = drive & 0x80000000;
396	drive&=3;
397	if (calledfromint && !try_fdc(drive)) {
398		/* We would be blocked in an interrupt, so try again later */
399		motor_off_timer[drive].expires = jiffies + 1;
400		add_timer(motor_off_timer + drive);
401		return;
402	}
403	unit[drive].motor = 0;
404	fd_select(drive);
405	udelay (1);
406	fd_deselect(drive);
407
408#ifdef MODULE
409/*
410  this is the last interrupt for any drive access, happens after
411  release (from floppy_off). So we have to wait until now to decrease
412  the use count.
413*/
414	if (decusecount)
415		MOD_DEC_USE_COUNT;
416#endif
417}
418
419static void floppy_off (unsigned int nr)
420{
421	int drive;
422
423	drive = nr & 3;
424	del_timer(motor_off_timer + drive);
425	motor_off_timer[drive].expires = jiffies + 3*HZ;
426	/* called this way it is always from interrupt */
427	motor_off_timer[drive].data = nr | 0x80000000;
428	add_timer(motor_off_timer + nr);
429}
430
431static int fd_calibrate(int drive)
432{
433	unsigned char prb;
434	int n;
435
436	drive &= 3;
437	get_fdc(drive);
438	if (!fd_motor_on (drive))
439		return 0;
440	fd_select (drive);
441	prb = ciab.prb;
442	prb |= DSKSIDE;
443	prb &= ~DSKDIREC;
444	ciab.prb = prb;
445	for (n = unit[drive].type->tracks/2; n != 0; --n) {
446		if (ciaa.pra & DSKTRACK0)
447			break;
448		prb &= ~DSKSTEP;
449		ciab.prb = prb;
450		prb |= DSKSTEP;
451		udelay (2);
452		ciab.prb = prb;
453		ms_delay(unit[drive].type->step_delay);
454	}
455	ms_delay (unit[drive].type->settle_time);
456	prb |= DSKDIREC;
457	n = unit[drive].type->tracks + 20;
458	for (;;) {
459		prb &= ~DSKSTEP;
460		ciab.prb = prb;
461		prb |= DSKSTEP;
462		udelay (2);
463		ciab.prb = prb;
464		ms_delay(unit[drive].type->step_delay + 1);
465		if ((ciaa.pra & DSKTRACK0) == 0)
466			break;
467		if (--n == 0) {
468			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
469			fd_motor_off (drive);
470			unit[drive].track = -1;
471			rel_fdc();
472			return 0;
473		}
474	}
475	unit[drive].track = 0;
476	ms_delay(unit[drive].type->settle_time);
477
478	rel_fdc();
479	fd_deselect(drive);
480	return 1;
481}
482
483static int fd_seek(int drive, int track)
484{
485	unsigned char prb;
486	int cnt;
487
488#ifdef DEBUG
489	printk("seeking drive %d to track %d\n",drive,track);
490#endif
491	drive &= 3;
492	get_fdc(drive);
493	if (unit[drive].track == track) {
494		rel_fdc();
495		return 1;
496	}
497	if (!fd_motor_on(drive)) {
498		rel_fdc();
499		return 0;
500	}
501	if (unit[drive].track < 0 && !fd_calibrate(drive)) {
502		rel_fdc();
503		return 0;
504	}
505
506	fd_select (drive);
507	cnt = unit[drive].track/2 - track/2;
508	prb = ciab.prb;
509	prb |= DSKSIDE | DSKDIREC;
510	if (track % 2 != 0)
511		prb &= ~DSKSIDE;
512	if (cnt < 0) {
513		cnt = - cnt;
514		prb &= ~DSKDIREC;
515	}
516	ciab.prb = prb;
517	if (track % 2 != unit[drive].track % 2)
518		ms_delay (unit[drive].type->side_time);
519	unit[drive].track = track;
520	if (cnt == 0) {
521		rel_fdc();
522		fd_deselect(drive);
523		return 1;
524	}
525	do {
526		prb &= ~DSKSTEP;
527		ciab.prb = prb;
528		prb |= DSKSTEP;
529		udelay (1);
530		ciab.prb = prb;
531		ms_delay (unit[drive].type->step_delay);
532	} while (--cnt != 0);
533	ms_delay (unit[drive].type->settle_time);
534
535	rel_fdc();
536	fd_deselect(drive);
537	return 1;
538}
539
540static unsigned long fd_get_drive_id(int drive)
541{
542	int i;
543	ulong id = 0;
544
545  	drive&=3;
546  	get_fdc(drive);
547	/* set up for ID */
548	MOTOR_ON;
549	udelay(2);
550	SELECT(SELMASK(drive));
551	udelay(2);
552	DESELECT(SELMASK(drive));
553	udelay(2);
554	MOTOR_OFF;
555	udelay(2);
556	SELECT(SELMASK(drive));
557	udelay(2);
558	DESELECT(SELMASK(drive));
559	udelay(2);
560
561	/* loop and read disk ID */
562	for (i=0; i<32; i++) {
563		SELECT(SELMASK(drive));
564		udelay(2);
565
566		/* read and store value of DSKRDY */
567		id <<= 1;
568		id |= (ciaa.pra & DSKRDY) ? 0 : 1;	/* cia regs are low-active! */
569
570		DESELECT(SELMASK(drive));
571	}
572
573	rel_fdc();
574
575        /*
576         * RB: At least A500/A2000's df0: don't identify themselves.
577         * As every (real) Amiga has at least a 3.5" DD drive as df0:
578         * we default to that if df0: doesn't identify as a certain
579         * type.
580         */
581        if(drive == 0 && id == FD_NODRIVE)
582	{
583                id = fd_def_df0;
584                printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
585	}
586	/* return the ID value */
587	return (id);
588}
589
590static void fd_block_done(int irq, void *dummy, struct pt_regs *fp)
591{
592	if (block_flag)
593		custom.dsklen = 0x4000;
594
595	if (block_flag == 2) { /* writing */
596		writepending = 2;
597		post_write_timer.expires = jiffies + 1; /* at least 2 ms */
598		post_write_timer.data = selected;
599		add_timer(&post_write_timer);
600	}
601	else {                /* reading */
602		block_flag = 0;
603		wake_up (&wait_fd_block);
604	}
605}
606
607static void raw_read(int drive)
608{
609	drive&=3;
610	get_fdc(drive);
611	while (block_flag)
612		sleep_on(&wait_fd_block);
613	fd_select(drive);
614	/* setup adkcon bits correctly */
615	custom.adkcon = ADK_MSBSYNC;
616	custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
617
618	custom.dsksync = MFM_SYNC;
619
620	custom.dsklen = 0;
621	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
622	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
623	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
624
625	block_flag = 1;
626
627	while (block_flag)
628		sleep_on (&wait_fd_block);
629
630	custom.dsklen = 0;
631	fd_deselect(drive);
632	rel_fdc();
633}
634
635static int raw_write(int drive)
636{
637	ushort adk;
638
639	drive&=3;
640	get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
641	if ((ciaa.pra & DSKPROT) == 0) {
642		rel_fdc();
643		return 0;
644	}
645	while (block_flag)
646		sleep_on(&wait_fd_block);
647	fd_select(drive);
648	/* clear adkcon bits */
649	custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
650	/* set appropriate adkcon bits */
651	adk = ADK_SETCLR|ADK_FAST;
652	if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
653		adk |= ADK_PRECOMP1;
654	else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
655		adk |= ADK_PRECOMP0;
656	custom.adkcon = adk;
657
658	custom.dsklen = DSKLEN_WRITE;
659	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
660	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
661	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
662
663	block_flag = 2;
664	return 1;
665}
666
667/*
668 * to be called at least 2ms after the write has finished but before any
669 * other access to the hardware.
670 */
671static void post_write (unsigned long drive)
672{
673#ifdef DEBUG
674	printk("post_write for drive %ld\n",drive);
675#endif
676	drive &= 3;
677	custom.dsklen = 0;
678	block_flag = 0;
679	writepending = 0;
680	writefromint = 0;
681	unit[drive].dirty = 0;
682	wake_up(&wait_fd_block);
683	fd_deselect(drive);
684	rel_fdc(); /* corresponds to get_fdc() in raw_write */
685}
686
687
688/*
689 * The following functions are to convert the block contents into raw data
690 * written to disk and vice versa.
691 * (Add other formats here ;-))
692 */
693
694static unsigned long scan_sync(unsigned long raw, unsigned long end)
695{
696	ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
697
698	while (ptr < endp && *ptr++ != 0x4489)
699		;
700	if (ptr < endp) {
701		while (*ptr == 0x4489 && ptr < endp)
702			ptr++;
703		return (ulong)ptr;
704	}
705	return 0;
706}
707
708static inline unsigned long checksum(unsigned long *addr, int len)
709{
710	unsigned long csum = 0;
711
712	len /= sizeof(*addr);
713	while (len-- > 0)
714		csum ^= *addr++;
715	csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
716
717	return csum;
718}
719
720static unsigned long decode (unsigned long *data, unsigned long *raw,
721			     int len)
722{
723	ulong *odd, *even;
724
725	/* convert length from bytes to longwords */
726	len >>= 2;
727	odd = raw;
728	even = odd + len;
729
730	/* prepare return pointer */
731	raw += len * 2;
732
733	do {
734		*data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
735	} while (--len != 0);
736
737	return (ulong)raw;
738}
739
740struct header {
741	unsigned char magic;
742	unsigned char track;
743	unsigned char sect;
744	unsigned char ord;
745	unsigned char labels[16];
746	unsigned long hdrchk;
747	unsigned long datachk;
748};
749
750static int amiga_read(int drive)
751{
752	unsigned long raw;
753	unsigned long end;
754	int scnt;
755	unsigned long csum;
756	struct header hdr;
757
758	drive&=3;
759	raw = (long) raw_buf;
760	end = raw + unit[drive].type->read_size;
761
762	for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
763		if (!(raw = scan_sync(raw, end))) {
764			printk (KERN_INFO "can't find sync for sector %d\n", scnt);
765			return MFM_NOSYNC;
766		}
767
768		raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
769		raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
770		raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
771		raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
772		csum = checksum((ulong *)&hdr,
773				(char *)&hdr.hdrchk-(char *)&hdr);
774
775#ifdef DEBUG
776		printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
777			hdr.magic, hdr.track, hdr.sect, hdr.ord,
778			*(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
779			*(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
780			hdr.hdrchk, hdr.datachk);
781#endif
782
783		if (hdr.hdrchk != csum) {
784			printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
785			return MFM_HEADER;
786		}
787
788		/* verify track */
789		if (hdr.track != unit[drive].track) {
790			printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
791			return MFM_TRACK;
792		}
793
794		raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
795			      (ulong *)raw, 512);
796		csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
797
798		if (hdr.datachk != csum) {
799			printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
800			       hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
801			       hdr.datachk, csum);
802			printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
803				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
804				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
805				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
806				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
807			return MFM_DATA;
808		}
809	}
810
811	return 0;
812}
813
814static void encode(unsigned long data, unsigned long *dest)
815{
816	unsigned long data2;
817
818	data &= 0x55555555;
819	data2 = data ^ 0x55555555;
820	data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
821
822	if (*(dest - 1) & 0x00000001)
823		data &= 0x7FFFFFFF;
824
825	*dest = data;
826}
827
828static void encode_block(unsigned long *dest, unsigned long *src, int len)
829{
830	int cnt, to_cnt = 0;
831	unsigned long data;
832
833	/* odd bits */
834	for (cnt = 0; cnt < len / 4; cnt++) {
835		data = src[cnt] >> 1;
836		encode(data, dest + to_cnt++);
837	}
838
839	/* even bits */
840	for (cnt = 0; cnt < len / 4; cnt++) {
841		data = src[cnt];
842		encode(data, dest + to_cnt++);
843	}
844}
845
846static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
847{
848	struct header hdr;
849	int i;
850
851	disk&=3;
852	*raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
853	raw++;
854	*raw++ = 0x44894489;
855
856	hdr.magic = 0xFF;
857	hdr.track = unit[disk].track;
858	hdr.sect = cnt;
859	hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
860	for (i = 0; i < 16; i++)
861		hdr.labels[i] = 0;
862	hdr.hdrchk = checksum((ulong *)&hdr,
863			      (char *)&hdr.hdrchk-(char *)&hdr);
864	hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
865
866	encode_block(raw, (ulong *)&hdr.magic, 4);
867	raw += 2;
868	encode_block(raw, (ulong *)&hdr.labels, 16);
869	raw += 8;
870	encode_block(raw, (ulong *)&hdr.hdrchk, 4);
871	raw += 2;
872	encode_block(raw, (ulong *)&hdr.datachk, 4);
873	raw += 2;
874	encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
875	raw += 256;
876
877	return raw;
878}
879
880static void amiga_write(int disk)
881{
882	unsigned int cnt;
883	unsigned long *ptr = (unsigned long *)raw_buf;
884
885	disk&=3;
886	/* gap space */
887	for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
888		*ptr++ = 0xaaaaaaaa;
889
890	/* sectors */
891	for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
892		ptr = putsec (disk, ptr, cnt);
893	*(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
894}
895
896
897struct dos_header {
898	unsigned char track,   /* 0-80 */
899		side,    /* 0-1 */
900		sec,     /* 0-...*/
901		len_desc;/* 2 */
902	unsigned short crc;     /* on 68000 we got an alignment problem,
903				   but this compiler solves it  by adding silently
904				   adding a pad byte so data won't fit
905				   and this took about 3h to discover.... */
906	unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
907};
908
909/* crc routines are borrowed from the messydos-handler  */
910
911/* excerpt from the messydos-device
912; The CRC is computed not only over the actual data, but including
913; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
914; As we don't read or encode these fields into our buffers, we have to
915; preload the registers containing the CRC with the values they would have
916; after stepping over these fields.
917;
918; How CRCs "really" work:
919;
920; First, you should regard a bitstring as a series of coefficients of
921; polynomials. We calculate with these polynomials in modulo-2
922; arithmetic, in which both add and subtract are done the same as
923; exclusive-or. Now, we modify our data (a very long polynomial) in
924; such a way that it becomes divisible by the CCITT-standard 16-bit
925;		 16   12   5
926; polynomial:	x  + x	+ x + 1, represented by $11021. The easiest
927; way to do this would be to multiply (using proper arithmetic) our
928; datablock with $11021. So we have:
929;   data * $11021		 =
930;   data * ($10000 + $1021)      =
931;   data * $10000 + data * $1021
932; The left part of this is simple: Just add two 0 bytes. But then
933; the right part (data $1021) remains difficult and even could have
934; a carry into the left part. The solution is to use a modified
935; multiplication, which has a result that is not correct, but with
936; a difference of any multiple of $11021. We then only need to keep
937; the 16 least significant bits of the result.
938;
939; The following algorithm does this for us:
940;
941;   unsigned char *data, c, crclo, crchi;
942;   while (not done) {
943;	c = *data++ + crchi;
944;	crchi = (@ c) >> 8 + crclo;
945;	crclo = @ c;
946;   }
947;
948; Remember, + is done with EOR, the @ operator is in two tables (high
949; and low byte separately), which is calculated as
950;
951;      $1021 * (c & $F0)
952;  xor $1021 * (c & $0F)
953;  xor $1021 * (c >> 4)         (* is regular multiplication)
954;
955;
956; Anyway, the end result is the same as the remainder of the division of
957; the data by $11021. I am afraid I need to study theory a bit more...
958
959
960my only works was to code this from manx to C....
961
962*/
963
964static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
965{
966	static unsigned char CRCTable1[] = {
967		0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
968		0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
969		0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
970		0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
971		0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
972		0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
973		0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
974		0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
975		0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
976		0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
977		0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
978		0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
979		0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
980		0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
981		0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
982		0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
983	};
984
985	static unsigned char CRCTable2[] = {
986		0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
987		0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
988		0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
989		0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
990		0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
991		0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
992		0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
993		0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
994		0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
995		0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
996		0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
997		0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
998		0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
999		0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
1000		0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
1001		0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
1002	};
1003
1004/* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
1005	register int i;
1006	register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
1007
1008	CRCT1=CRCTable1;
1009	CRCT2=CRCTable2;
1010	data=data_a3;
1011	crcl=data_d1;
1012	crch=data_d0;
1013	for (i=data_d3; i>=0; i--) {
1014		c = (*data++) ^ crch;
1015		crch = CRCT1[c] ^ crcl;
1016		crcl = CRCT2[c];
1017	}
1018	return (crch<<8)|crcl;
1019}
1020
1021static inline ushort dos_hdr_crc (struct dos_header *hdr)
1022{
1023	return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
1024}
1025
1026static inline ushort dos_data_crc(unsigned char *data)
1027{
1028	return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
1029}
1030
1031static inline unsigned char dos_decode_byte(ushort word)
1032{
1033	register ushort w2;
1034	register unsigned char byte;
1035	register unsigned char *dec = mfmdecode;
1036
1037	w2=word;
1038	w2>>=8;
1039	w2&=127;
1040	byte = dec[w2];
1041	byte <<= 4;
1042	w2 = word & 127;
1043	byte |= dec[w2];
1044	return byte;
1045}
1046
1047static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1048{
1049	int i;
1050
1051	for (i = 0; i < len; i++)
1052		*data++=dos_decode_byte(*raw++);
1053	return ((ulong)raw);
1054}
1055
1056#ifdef DEBUG
1057static void dbg(unsigned long ptr)
1058{
1059	printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1060	       ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1061	       ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1062}
1063#endif
1064
1065static int dos_read(int drive)
1066{
1067	unsigned long end;
1068	unsigned long raw;
1069	int scnt;
1070	unsigned short crc,data_crc[2];
1071	struct dos_header hdr;
1072
1073	drive&=3;
1074	raw = (long) raw_buf;
1075	end = raw + unit[drive].type->read_size;
1076
1077	for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1078		do { /* search for the right sync of each sec-hdr */
1079			if (!(raw = scan_sync (raw, end))) {
1080				printk(KERN_INFO "dos_read: no hdr sync on "
1081				       "track %d, unit %d for sector %d\n",
1082				       unit[drive].track,drive,scnt);
1083				return MFM_NOSYNC;
1084			}
1085#ifdef DEBUG
1086			dbg(raw);
1087#endif
1088		} while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1089		raw+=2; /* skip over headermark */
1090		raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1091		crc = dos_hdr_crc(&hdr);
1092
1093#ifdef DEBUG
1094		printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1095		       hdr.sec, hdr.len_desc, hdr.crc);
1096#endif
1097
1098		if (crc != hdr.crc) {
1099			printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1100			       hdr.crc, crc);
1101			return MFM_HEADER;
1102		}
1103		if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1104			printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1105			       hdr.track,
1106			       unit[drive].track/unit[drive].type->heads);
1107			return MFM_TRACK;
1108		}
1109
1110		if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1111			printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1112			       hdr.side,
1113			       unit[drive].track%unit[drive].type->heads);
1114			return MFM_TRACK;
1115		}
1116
1117		if (hdr.len_desc != 2) {
1118			printk(KERN_INFO "dos_read: unknown sector len "
1119			       "descriptor %d\n", hdr.len_desc);
1120			return MFM_DATA;
1121		}
1122#ifdef DEBUG
1123		printk("hdr accepted\n");
1124#endif
1125		if (!(raw = scan_sync (raw, end))) {
1126			printk(KERN_INFO "dos_read: no data sync on track "
1127			       "%d, unit %d for sector%d, disk sector %d\n",
1128			       unit[drive].track, drive, scnt, hdr.sec);
1129			return MFM_NOSYNC;
1130		}
1131#ifdef DEBUG
1132		dbg(raw);
1133#endif
1134
1135		if (*((ushort *)raw)!=0x5545) {
1136			printk(KERN_INFO "dos_read: no data mark after "
1137			       "sync (%d,%d,%d,%d) sc=%d\n",
1138			       hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1139			return MFM_NOSYNC;
1140		}
1141
1142		raw+=2;  /* skip data mark (included in checksum) */
1143		raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1144		raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1145		crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1146
1147		if (crc != data_crc[0]) {
1148			printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1149			       "sc=%d, %x %x\n", hdr.track, hdr.side,
1150			       hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1151			printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1152			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1153			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1154			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1155			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1156			return MFM_DATA;
1157		}
1158	}
1159	return 0;
1160}
1161
1162static inline ushort dos_encode_byte(unsigned char byte)
1163{
1164	register unsigned char *enc, b2, b1;
1165	register ushort word;
1166
1167	enc=mfmencode;
1168	b1=byte;
1169	b2=b1>>4;
1170	b1&=15;
1171	word=enc[b2] <<8 | enc [b1];
1172	return (word|((word&(256|64)) ? 0: 128));
1173}
1174
1175static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1176{
1177	int i;
1178
1179	for (i = 0; i < len; i++) {
1180		*dest=dos_encode_byte(*src++);
1181		*dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1182		dest++;
1183	}
1184}
1185
1186static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1187{
1188	static struct dos_header hdr={0,0,0,2,0,
1189	  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1190	int i;
1191	static ushort crc[2]={0,0x4e4e};
1192
1193	drive&=3;
1194/* id gap 1 */
1195/* the MFM word before is always 9254 */
1196	for(i=0;i<6;i++)
1197		*raw++=0xaaaaaaaa;
1198/* 3 sync + 1 headermark */
1199	*raw++=0x44894489;
1200	*raw++=0x44895554;
1201
1202/* fill in the variable parts of the header */
1203	hdr.track=unit[drive].track/unit[drive].type->heads;
1204	hdr.side=unit[drive].track%unit[drive].type->heads;
1205	hdr.sec=cnt+1;
1206	hdr.crc=dos_hdr_crc(&hdr);
1207
1208/* header (without "magic") and id gap 2*/
1209	dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1210	raw+=14;
1211
1212/*id gap 3 */
1213	for(i=0;i<6;i++)
1214		*raw++=0xaaaaaaaa;
1215
1216/* 3 syncs and 1 datamark */
1217	*raw++=0x44894489;
1218	*raw++=0x44895545;
1219
1220/* data */
1221	dos_encode_block((ushort *)raw,
1222			 (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1223	raw+=256;
1224
1225/*data crc + jd's special gap (long words :-/) */
1226	crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1227	dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1228	raw+=2;
1229
1230/* data gap */
1231	for(i=0;i<38;i++)
1232		*raw++=0x92549254;
1233
1234	return raw; /* wrote 652 MFM words */
1235}
1236
1237static void dos_write(int disk)
1238{
1239	int cnt;
1240	unsigned long raw = (unsigned long) raw_buf;
1241	unsigned long *ptr=(unsigned long *)raw;
1242
1243	disk&=3;
1244/* really gap4 + indexgap , but we write it first and round it up */
1245	for (cnt=0;cnt<425;cnt++)
1246		*ptr++=0x92549254;
1247
1248/* the following is just guessed */
1249	if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1250		for(cnt=0;cnt<473;cnt++)
1251			*ptr++=0x92549254;
1252
1253/* now the index marks...*/
1254	for (cnt=0;cnt<20;cnt++)
1255		*ptr++=0x92549254;
1256	for (cnt=0;cnt<6;cnt++)
1257		*ptr++=0xaaaaaaaa;
1258	*ptr++=0x52245224;
1259	*ptr++=0x52245552;
1260	for (cnt=0;cnt<20;cnt++)
1261		*ptr++=0x92549254;
1262
1263/* sectors */
1264	for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1265		ptr=ms_putsec(disk,ptr,cnt);
1266
1267	*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1268}
1269
1270/*
1271 * Here comes the high level stuff (i.e. the filesystem interface)
1272 * and helper functions.
1273 * Normally this should be the only part that has to be adapted to
1274 * different kernel versions.
1275 */
1276
1277static void flush_track_callback(unsigned long nr)
1278{
1279	nr&=3;
1280	writefromint = 1;
1281	if (!try_fdc(nr)) {
1282		/* we might block in an interrupt, so try again later */
1283		flush_track_timer[nr].expires = jiffies + 1;
1284		add_timer(flush_track_timer + nr);
1285		return;
1286	}
1287	get_fdc(nr);
1288	(*unit[nr].dtype->write_fkt)(nr);
1289	if (!raw_write(nr)) {
1290		printk (KERN_NOTICE "floppy disk write protected\n");
1291		writefromint = 0;
1292		writepending = 0;
1293	}
1294	rel_fdc();
1295}
1296
1297static int non_int_flush_track (unsigned long nr)
1298{
1299	unsigned long flags;
1300
1301	nr&=3;
1302	writefromint = 0;
1303	del_timer(&post_write_timer);
1304	get_fdc(nr);
1305	if (!fd_motor_on(nr)) {
1306		writepending = 0;
1307		rel_fdc();
1308		return 0;
1309	}
1310	save_flags(flags);
1311	cli();
1312	if (writepending != 2) {
1313		restore_flags(flags);
1314		(*unit[nr].dtype->write_fkt)(nr);
1315		if (!raw_write(nr)) {
1316			printk (KERN_NOTICE "floppy disk write protected "
1317				"in write!\n");
1318			writepending = 0;
1319			return 0;
1320		}
1321		while (block_flag == 2)
1322			sleep_on (&wait_fd_block);
1323	}
1324	else {
1325		restore_flags(flags);
1326		ms_delay(2); /* 2 ms post_write delay */
1327		post_write(nr);
1328	}
1329	rel_fdc();
1330	return 1;
1331}
1332
1333static int get_track(int drive, int track)
1334{
1335	int error, errcnt;
1336
1337	drive&=3;
1338	if (unit[drive].track == track)
1339		return 0;
1340	get_fdc(drive);
1341	if (!fd_motor_on(drive)) {
1342		rel_fdc();
1343		return -1;
1344	}
1345
1346	if (unit[drive].dirty == 1) {
1347		del_timer (flush_track_timer + drive);
1348		non_int_flush_track (drive);
1349	}
1350	errcnt = 0;
1351	while (errcnt < MAX_ERRORS) {
1352		if (!fd_seek(drive, track))
1353			return -1;
1354		raw_read(drive);
1355		error = (*unit[drive].dtype->read_fkt)(drive);
1356		if (error == 0) {
1357			rel_fdc();
1358			return 0;
1359		}
1360		/* Read Error Handling: recalibrate and try again */
1361		unit[drive].track = -1;
1362		errcnt++;
1363	}
1364	rel_fdc();
1365	return -1;
1366}
1367
1368static void redo_fd_request(void)
1369{
1370	unsigned int cnt, block, track, sector;
1371	int device, drive;
1372	struct amiga_floppy_struct *floppy;
1373	char *data;
1374	unsigned long flags;
1375
1376	if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE){
1377		return;
1378	}
1379
1380 repeat:
1381	if (QUEUE_EMPTY) {
1382		/* Nothing left to do */
1383		return;
1384	}
1385
1386	if (MAJOR(CURRENT->rq_dev) != MAJOR_NR)
1387		panic(DEVICE_NAME ": request list destroyed");
1388
1389	if (CURRENT->bh && !buffer_locked(CURRENT->bh))
1390		panic(DEVICE_NAME ": block not locked");
1391
1392	device = MINOR(CURRENT_DEVICE);
1393	if (device < 8) {
1394		/* manual selection */
1395		drive = device & 3;
1396		floppy = unit + drive;
1397	} else {
1398		/* Auto-detection */
1399#ifdef DEBUG
1400		printk("redo_fd_request: can't handle auto detect\n");
1401		printk("redo_fd_request: default to normal\n");
1402#endif
1403		drive = device & 3;
1404		floppy = unit + drive;
1405	}
1406
1407	/* Here someone could investigate to be more efficient */
1408	for (cnt = 0; cnt < CURRENT->current_nr_sectors; cnt++) {
1409#ifdef DEBUG
1410		printk("fd: sector %ld + %d requested for %s\n",
1411		       CURRENT->sector,cnt,
1412		       (CURRENT->cmd==READ)?"read":"write");
1413#endif
1414		block = CURRENT->sector + cnt;
1415		if ((int)block > floppy->blocks) {
1416			end_request(0);
1417			goto repeat;
1418		}
1419
1420		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1421		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1422		data = CURRENT->buffer + 512 * cnt;
1423#ifdef DEBUG
1424		printk("access to track %d, sector %d, with buffer at "
1425		       "0x%08lx\n", track, sector, data);
1426#endif
1427
1428		if ((CURRENT->cmd != READ) && (CURRENT->cmd != WRITE)) {
1429			printk(KERN_WARNING "do_fd_request: unknown command\n");
1430			end_request(0);
1431			goto repeat;
1432		}
1433		if (get_track(drive, track) == -1) {
1434			end_request(0);
1435			goto repeat;
1436		}
1437
1438		switch (CURRENT->cmd) {
1439		case READ:
1440			memcpy(data, unit[drive].trackbuf + sector * 512, 512);
1441			break;
1442
1443		case WRITE:
1444			memcpy(unit[drive].trackbuf + sector * 512, data, 512);
1445
1446			/* keep the drive spinning while writes are scheduled */
1447			if (!fd_motor_on(drive)) {
1448				end_request(0);
1449				goto repeat;
1450			}
1451			/*
1452			 * setup a callback to write the track buffer
1453			 * after a short (1 tick) delay.
1454			 */
1455			save_flags (flags);
1456			cli();
1457
1458			unit[drive].dirty = 1;
1459		        /* reset the timer */
1460		        del_timer (flush_track_timer + drive);
1461
1462			flush_track_timer[drive].expires = jiffies + 1;
1463			add_timer (flush_track_timer + drive);
1464			restore_flags (flags);
1465			break;
1466		}
1467	}
1468	CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
1469	CURRENT->sector += CURRENT->current_nr_sectors;
1470
1471	end_request(1);
1472	goto repeat;
1473}
1474
1475static void do_fd_request(request_queue_t * q)
1476{
1477	redo_fd_request();
1478}
1479
1480static int fd_ioctl(struct inode *inode, struct file *filp,
1481		    unsigned int cmd, unsigned long param)
1482{
1483	int drive = inode->i_rdev & 3;
1484	static struct floppy_struct getprm;
1485
1486	switch(cmd){
1487	case HDIO_GETGEO:
1488	{
1489		struct hd_geometry loc;
1490		loc.heads = unit[drive].type->heads;
1491		loc.sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1492		loc.cylinders = unit[drive].type->tracks;
1493		loc.start = 0;
1494		if (copy_to_user((void *)param, (void *)&loc,
1495				 sizeof(struct hd_geometry)))
1496			return -EFAULT;
1497		break;
1498	}
1499	case FDFMTBEG:
1500		get_fdc(drive);
1501		if (fd_ref[drive] > 1) {
1502			rel_fdc();
1503			return -EBUSY;
1504		}
1505		fsync_dev(inode->i_rdev);
1506		if (fd_motor_on(drive) == 0) {
1507			rel_fdc();
1508			return -ENODEV;
1509		}
1510		if (fd_calibrate(drive) == 0) {
1511			rel_fdc();
1512			return -ENXIO;
1513		}
1514		floppy_off(drive);
1515		rel_fdc();
1516		break;
1517	case FDFMTTRK:
1518		if (param < unit[drive].type->tracks * unit[drive].type->heads)
1519		{
1520			get_fdc(drive);
1521			if (fd_seek(drive,param) != 0){
1522				memset(unit[drive].trackbuf, FD_FILL_BYTE,
1523				       unit[drive].dtype->sects * unit[drive].type->sect_mult * 512);
1524				non_int_flush_track(drive);
1525			}
1526			floppy_off(drive);
1527			rel_fdc();
1528		}
1529		else
1530			return -EINVAL;
1531		break;
1532	case FDFMTEND:
1533		floppy_off(drive);
1534		invalidate_device(inode->i_rdev, 0);
1535		break;
1536	case FDGETPRM:
1537		memset((void *)&getprm, 0, sizeof (getprm));
1538		getprm.track=unit[drive].type->tracks;
1539		getprm.head=unit[drive].type->heads;
1540		getprm.sect=unit[drive].dtype->sects * unit[drive].type->sect_mult;
1541		getprm.size=unit[drive].blocks;
1542		if (copy_to_user((void *)param,
1543				 (void *)&getprm,
1544				 sizeof(struct floppy_struct)))
1545			return -EFAULT;
1546		break;
1547	case BLKGETSIZE:
1548		return put_user(unit[drive].blocks,(unsigned long *)param);
1549		break;
1550	case BLKGETSIZE64:
1551		return put_user((u64)unit[drive].blocks << 9, (u64 *)param);
1552		break;
1553	case FDSETPRM:
1554	case FDDEFPRM:
1555		return -EINVAL;
1556	case FDFLUSH: /* unconditionally, even if not needed */
1557		del_timer (flush_track_timer + drive);
1558		non_int_flush_track(drive);
1559		break;
1560#ifdef RAW_IOCTL
1561	case IOCTL_RAW_TRACK:
1562		if (copy_to_user((void *)param, raw_buf,
1563				 unit[drive].type->read_size))
1564			return -EFAULT;
1565		else
1566			return unit[drive].type->read_size;
1567#endif
1568	default:
1569		printk(KERN_DEBUG "fd_ioctl: unknown cmd %d for drive %d.",
1570		       cmd, drive);
1571		return -ENOSYS;
1572	}
1573	return 0;
1574}
1575
1576static void fd_probe(int dev)
1577{
1578	unsigned long code;
1579	int type;
1580	int drive;
1581
1582	drive = dev & 3;
1583	code = fd_get_drive_id(drive);
1584
1585	/* get drive type */
1586	for (type = 0; type < num_dr_types; type++)
1587		if (drive_types[type].code == code)
1588			break;
1589
1590	if (type >= num_dr_types) {
1591		printk(KERN_WARNING "fd_probe: unsupported drive type "
1592		       "%08lx found\n", code);
1593		unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1594		return;
1595	}
1596
1597	unit[drive].type = drive_types + type;
1598	unit[drive].track = -1;
1599
1600	unit[drive].disk = -1;
1601	unit[drive].motor = 0;
1602	unit[drive].busy = 0;
1603	unit[drive].status = -1;
1604}
1605
1606/*
1607 * floppy_open check for aliasing (/dev/fd0 can be the same as
1608 * /dev/PS0 etc), and disallows simultaneous access to the same
1609 * drive with different device numbers.
1610 */
1611static int floppy_open(struct inode *inode, struct file *filp)
1612{
1613	int drive;
1614	int old_dev;
1615	int system;
1616	unsigned long flags;
1617
1618	drive = MINOR(inode->i_rdev) & 3;
1619	old_dev = fd_device[drive];
1620
1621	if (fd_ref[drive])
1622		if (old_dev != inode->i_rdev)
1623			return -EBUSY;
1624
1625	if (unit[drive].type->code == FD_NODRIVE)
1626		return -ENODEV;
1627
1628	if (filp && filp->f_mode & 3) {
1629		check_disk_change(inode->i_rdev);
1630		if (filp->f_mode & 2 ) {
1631			int wrprot;
1632
1633			get_fdc(drive);
1634			fd_select (drive);
1635			wrprot = !(ciaa.pra & DSKPROT);
1636			fd_deselect (drive);
1637			rel_fdc();
1638
1639			if (wrprot)
1640				return -EROFS;
1641		}
1642	}
1643
1644	save_flags(flags);
1645	cli();
1646	fd_ref[drive]++;
1647	fd_device[drive] = inode->i_rdev;
1648#ifdef MODULE
1649	if (unit[drive].motor == 0)
1650		MOD_INC_USE_COUNT;
1651#endif
1652	restore_flags(flags);
1653
1654	if (old_dev && old_dev != inode->i_rdev)
1655		invalidate_buffers(old_dev);
1656
1657	system=(inode->i_rdev & 4)>>2;
1658	unit[drive].dtype=&data_types[system];
1659	unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1660		data_types[system].sects*unit[drive].type->sect_mult;
1661	floppy_sizes[MINOR(inode->i_rdev)] = unit[drive].blocks >> 1;
1662
1663	printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1664	       unit[drive].type->name, data_types[system].name);
1665
1666	return 0;
1667}
1668
1669static int floppy_release(struct inode * inode, struct file * filp)
1670{
1671	int drive = MINOR(inode->i_rdev) & 3;
1672
1673	if (unit[drive].dirty == 1) {
1674		del_timer (flush_track_timer + drive);
1675		non_int_flush_track (drive);
1676	}
1677
1678	if (!fd_ref[drive]--) {
1679		printk(KERN_CRIT "floppy_release with fd_ref == 0");
1680		fd_ref[drive] = 0;
1681	}
1682#ifdef MODULE
1683/* the mod_use counter is handled this way */
1684	floppy_off (drive | 0x40000000);
1685#endif
1686	return 0;
1687}
1688
1689/*
1690 * floppy-change is never called from an interrupt, so we can relax a bit
1691 * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1692 * to the desired drive, but it will probably not survive the sleep if
1693 * several floppies are used at the same time: thus the loop.
1694 */
1695static int amiga_floppy_change(kdev_t dev)
1696{
1697	int drive = MINOR(dev) & 3;
1698	int changed;
1699	static int first_time = 1;
1700
1701	if (MAJOR(dev) != MAJOR_NR) {
1702		printk(KERN_CRIT "floppy_change: not a floppy\n");
1703		return 0;
1704	}
1705
1706	if (first_time)
1707		changed = first_time--;
1708	else {
1709		get_fdc(drive);
1710		fd_select (drive);
1711		changed = !(ciaa.pra & DSKCHANGE);
1712		fd_deselect (drive);
1713		rel_fdc();
1714	}
1715
1716	if (changed) {
1717		fd_probe(drive);
1718		unit[drive].track = -1;
1719		unit[drive].dirty = 0;
1720		writepending = 0; /* if this was true before, too bad! */
1721		writefromint = 0;
1722		return 1;
1723	}
1724	return 0;
1725}
1726
1727static struct block_device_operations floppy_fops = {
1728	owner:			THIS_MODULE,
1729	open:			floppy_open,
1730	release:		floppy_release,
1731	ioctl:			fd_ioctl,
1732	check_media_change:	amiga_floppy_change,
1733};
1734
1735void __init amiga_floppy_setup (char *str, int *ints)
1736{
1737	printk (KERN_INFO "amiflop: Setting default df0 to %x\n", ints[1]);
1738	fd_def_df0 = ints[1];
1739}
1740
1741static int __init fd_probe_drives(void)
1742{
1743	int drive,drives,nomem;
1744
1745	printk(KERN_INFO "FD: probing units\n" KERN_INFO "found ");
1746	drives=0;
1747	nomem=0;
1748	for(drive=0;drive<FD_MAX_UNITS;drive++) {
1749		fd_probe(drive);
1750		if (unit[drive].type->code != FD_NODRIVE) {
1751			drives++;
1752			if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
1753				printk("no mem for ");
1754				unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
1755				drives--;
1756				nomem = 1;
1757			}
1758			printk("fd%d ",drive);
1759		}
1760	}
1761	if ((drives > 0) || (nomem == 0)) {
1762		if (drives == 0)
1763			printk("no drives");
1764		printk("\n");
1765		return drives;
1766	}
1767	printk("\n");
1768	return -ENOMEM;
1769}
1770
1771int __init amiga_floppy_init(void)
1772{
1773	int i;
1774
1775	if (!AMIGAHW_PRESENT(AMI_FLOPPY))
1776		return -ENXIO;
1777
1778	if (register_blkdev(MAJOR_NR,"fd",&floppy_fops)) {
1779		printk("fd: Unable to get major %d for floppy\n",MAJOR_NR);
1780		return -EBUSY;
1781	}
1782	/*
1783	 *  We request DSKPTR, DSKLEN and DSKDATA only, because the other
1784	 *  floppy registers are too spreaded over the custom register space
1785	 */
1786	if (!request_mem_region(CUSTOM_PHYSADDR+0x20, 8, "amiflop [Paula]")) {
1787		printk("fd: cannot get floppy registers\n");
1788		unregister_blkdev(MAJOR_NR,"fd");
1789		return -EBUSY;
1790	}
1791	if ((raw_buf = (char *)amiga_chip_alloc (RAW_BUF_SIZE, "Floppy")) ==
1792	    NULL) {
1793		printk("fd: cannot get chip mem buffer\n");
1794		release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1795		unregister_blkdev(MAJOR_NR,"fd");
1796		return -ENOMEM;
1797	}
1798	if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1799		printk("fd: cannot get irq for dma\n");
1800		amiga_chip_free(raw_buf);
1801		release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1802		unregister_blkdev(MAJOR_NR,"fd");
1803		return -EBUSY;
1804	}
1805	if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1806		printk("fd: cannot get irq for timer\n");
1807		free_irq(IRQ_AMIGA_DSKBLK, NULL);
1808		amiga_chip_free(raw_buf);
1809		release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1810		unregister_blkdev(MAJOR_NR,"fd");
1811		return -EBUSY;
1812	}
1813	if (fd_probe_drives() < 1) { /* No usable drives */
1814		free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1815		free_irq(IRQ_AMIGA_DSKBLK, NULL);
1816		amiga_chip_free(raw_buf);
1817		release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1818		unregister_blkdev(MAJOR_NR,"fd");
1819		return -ENXIO;
1820	}
1821
1822	/* initialize variables */
1823	init_timer(&motor_on_timer);
1824	motor_on_timer.expires = 0;
1825	motor_on_timer.data = 0;
1826	motor_on_timer.function = motor_on_callback;
1827	for (i = 0; i < FD_MAX_UNITS; i++) {
1828		init_timer(&motor_off_timer[i]);
1829		motor_off_timer[i].expires = 0;
1830		motor_off_timer[i].data = i|0x80000000;
1831		motor_off_timer[i].function = fd_motor_off;
1832		init_timer(&flush_track_timer[i]);
1833		flush_track_timer[i].expires = 0;
1834		flush_track_timer[i].data = i;
1835		flush_track_timer[i].function = flush_track_callback;
1836
1837		unit[i].track = -1;
1838	}
1839
1840	init_timer(&post_write_timer);
1841	post_write_timer.expires = 0;
1842	post_write_timer.data = 0;
1843	post_write_timer.function = post_write;
1844
1845	blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
1846	blksize_size[MAJOR_NR] = floppy_blocksizes;
1847	blk_size[MAJOR_NR] = floppy_sizes;
1848
1849	for (i = 0; i < 128; i++)
1850		mfmdecode[i]=255;
1851	for (i = 0; i < 16; i++)
1852		mfmdecode[mfmencode[i]]=i;
1853
1854	/* make sure that disk DMA is enabled */
1855	custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1856
1857	/* init ms timer */
1858	ciaa.crb = 8; /* one-shot, stop */
1859
1860	(void)do_floppy; /* avoid warning about unused variable */
1861	return 0;
1862}
1863
1864#ifdef MODULE
1865#include <linux/version.h>
1866
1867int init_module(void)
1868{
1869	if (!MACH_IS_AMIGA)
1870		return -ENXIO;
1871	return amiga_floppy_init();
1872}
1873
1874void cleanup_module(void)
1875{
1876	int i;
1877
1878	for( i = 0; i < FD_MAX_UNITS; i++)
1879		if (unit[i].type->code != FD_NODRIVE)
1880			kfree(unit[i].trackbuf);
1881	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1882	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1883	custom.dmacon = DMAF_DISK; /* disable DMA */
1884	amiga_chip_free(raw_buf);
1885	blk_size[MAJOR_NR] = NULL;
1886	blksize_size[MAJOR_NR] = NULL;
1887	blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
1888	release_mem_region(CUSTOM_PHYSADDR+0x20, 8);
1889	unregister_blkdev(MAJOR_NR, "fd");
1890}
1891#endif
1892