xref: /openbmc/linux/drivers/block/swim3.c (revision e9e8bcb8)
1 /*
2  * Driver for the SWIM3 (Super Woz Integrated Machine 3)
3  * floppy controller found on Power Macintoshes.
4  *
5  * Copyright (C) 1996 Paul Mackerras.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12 
13 /*
14  * TODO:
15  * handle 2 drives
16  * handle GCR disks
17  */
18 
19 #include <linux/stddef.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/timer.h>
23 #include <linux/delay.h>
24 #include <linux/fd.h>
25 #include <linux/ioctl.h>
26 #include <linux/blkdev.h>
27 #include <linux/interrupt.h>
28 #include <linux/mutex.h>
29 #include <linux/module.h>
30 #include <linux/spinlock.h>
31 #include <asm/io.h>
32 #include <asm/dbdma.h>
33 #include <asm/prom.h>
34 #include <asm/uaccess.h>
35 #include <asm/mediabay.h>
36 #include <asm/machdep.h>
37 #include <asm/pmac_feature.h>
38 
39 static DEFINE_MUTEX(swim3_mutex);
40 static struct request_queue *swim3_queue;
41 static struct gendisk *disks[2];
42 static struct request *fd_req;
43 
44 #define MAX_FLOPPIES	2
45 
46 enum swim_state {
47 	idle,
48 	locating,
49 	seeking,
50 	settling,
51 	do_transfer,
52 	jogging,
53 	available,
54 	revalidating,
55 	ejecting
56 };
57 
58 #define REG(x)	unsigned char x; char x ## _pad[15];
59 
60 /*
61  * The names for these registers mostly represent speculation on my part.
62  * It will be interesting to see how close they are to the names Apple uses.
63  */
64 struct swim3 {
65 	REG(data);
66 	REG(timer);		/* counts down at 1MHz */
67 	REG(error);
68 	REG(mode);
69 	REG(select);		/* controls CA0, CA1, CA2 and LSTRB signals */
70 	REG(setup);
71 	REG(control);		/* writing bits clears them */
72 	REG(status);		/* writing bits sets them in control */
73 	REG(intr);
74 	REG(nseek);		/* # tracks to seek */
75 	REG(ctrack);		/* current track number */
76 	REG(csect);		/* current sector number */
77 	REG(gap3);		/* size of gap 3 in track format */
78 	REG(sector);		/* sector # to read or write */
79 	REG(nsect);		/* # sectors to read or write */
80 	REG(intr_enable);
81 };
82 
83 #define control_bic	control
84 #define control_bis	status
85 
86 /* Bits in select register */
87 #define CA_MASK		7
88 #define LSTRB		8
89 
90 /* Bits in control register */
91 #define DO_SEEK		0x80
92 #define FORMAT		0x40
93 #define SELECT		0x20
94 #define WRITE_SECTORS	0x10
95 #define DO_ACTION	0x08
96 #define DRIVE2_ENABLE	0x04
97 #define DRIVE_ENABLE	0x02
98 #define INTR_ENABLE	0x01
99 
100 /* Bits in status register */
101 #define FIFO_1BYTE	0x80
102 #define FIFO_2BYTE	0x40
103 #define ERROR		0x20
104 #define DATA		0x08
105 #define RDDATA		0x04
106 #define INTR_PENDING	0x02
107 #define MARK_BYTE	0x01
108 
109 /* Bits in intr and intr_enable registers */
110 #define ERROR_INTR	0x20
111 #define DATA_CHANGED	0x10
112 #define TRANSFER_DONE	0x08
113 #define SEEN_SECTOR	0x04
114 #define SEEK_DONE	0x02
115 #define TIMER_DONE	0x01
116 
117 /* Bits in error register */
118 #define ERR_DATA_CRC	0x80
119 #define ERR_ADDR_CRC	0x40
120 #define ERR_OVERRUN	0x04
121 #define ERR_UNDERRUN	0x01
122 
123 /* Bits in setup register */
124 #define S_SW_RESET	0x80
125 #define S_GCR_WRITE	0x40
126 #define S_IBM_DRIVE	0x20
127 #define S_TEST_MODE	0x10
128 #define S_FCLK_DIV2	0x08
129 #define S_GCR		0x04
130 #define S_COPY_PROT	0x02
131 #define S_INV_WDATA	0x01
132 
133 /* Select values for swim3_action */
134 #define SEEK_POSITIVE	0
135 #define SEEK_NEGATIVE	4
136 #define STEP		1
137 #define MOTOR_ON	2
138 #define MOTOR_OFF	6
139 #define INDEX		3
140 #define EJECT		7
141 #define SETMFM		9
142 #define SETGCR		13
143 
144 /* Select values for swim3_select and swim3_readbit */
145 #define STEP_DIR	0
146 #define STEPPING	1
147 #define MOTOR_ON	2
148 #define RELAX		3	/* also eject in progress */
149 #define READ_DATA_0	4
150 #define TWOMEG_DRIVE	5
151 #define SINGLE_SIDED	6	/* drive or diskette is 4MB type? */
152 #define DRIVE_PRESENT	7
153 #define DISK_IN		8
154 #define WRITE_PROT	9
155 #define TRACK_ZERO	10
156 #define TACHO		11
157 #define READ_DATA_1	12
158 #define MFM_MODE	13
159 #define SEEK_COMPLETE	14
160 #define ONEMEG_MEDIA	15
161 
162 /* Definitions of values used in writing and formatting */
163 #define DATA_ESCAPE	0x99
164 #define GCR_SYNC_EXC	0x3f
165 #define GCR_SYNC_CONV	0x80
166 #define GCR_FIRST_MARK	0xd5
167 #define GCR_SECOND_MARK	0xaa
168 #define GCR_ADDR_MARK	"\xd5\xaa\x00"
169 #define GCR_DATA_MARK	"\xd5\xaa\x0b"
170 #define GCR_SLIP_BYTE	"\x27\xaa"
171 #define GCR_SELF_SYNC	"\x3f\xbf\x1e\x34\x3c\x3f"
172 
173 #define DATA_99		"\x99\x99"
174 #define MFM_ADDR_MARK	"\x99\xa1\x99\xa1\x99\xa1\x99\xfe"
175 #define MFM_INDEX_MARK	"\x99\xc2\x99\xc2\x99\xc2\x99\xfc"
176 #define MFM_GAP_LEN	12
177 
178 struct floppy_state {
179 	enum swim_state	state;
180 	spinlock_t lock;
181 	struct swim3 __iomem *swim3;	/* hardware registers */
182 	struct dbdma_regs __iomem *dma;	/* DMA controller registers */
183 	int	swim3_intr;	/* interrupt number for SWIM3 */
184 	int	dma_intr;	/* interrupt number for DMA channel */
185 	int	cur_cyl;	/* cylinder head is on, or -1 */
186 	int	cur_sector;	/* last sector we saw go past */
187 	int	req_cyl;	/* the cylinder for the current r/w request */
188 	int	head;		/* head number ditto */
189 	int	req_sector;	/* sector number ditto */
190 	int	scount;		/* # sectors we're transferring at present */
191 	int	retries;
192 	int	settle_time;
193 	int	secpercyl;	/* disk geometry information */
194 	int	secpertrack;
195 	int	total_secs;
196 	int	write_prot;	/* 1 if write-protected, 0 if not, -1 dunno */
197 	struct dbdma_cmd *dma_cmd;
198 	int	ref_count;
199 	int	expect_cyl;
200 	struct timer_list timeout;
201 	int	timeout_pending;
202 	int	ejected;
203 	wait_queue_head_t wait;
204 	int	wanted;
205 	struct macio_dev *mdev;
206 	char	dbdma_cmd_space[5 * sizeof(struct dbdma_cmd)];
207 };
208 
209 static struct floppy_state floppy_states[MAX_FLOPPIES];
210 static int floppy_count = 0;
211 static DEFINE_SPINLOCK(swim3_lock);
212 
213 static unsigned short write_preamble[] = {
214 	0x4e4e, 0x4e4e, 0x4e4e, 0x4e4e, 0x4e4e,	/* gap field */
215 	0, 0, 0, 0, 0, 0,			/* sync field */
216 	0x99a1, 0x99a1, 0x99a1, 0x99fb,		/* data address mark */
217 	0x990f					/* no escape for 512 bytes */
218 };
219 
220 static unsigned short write_postamble[] = {
221 	0x9904,					/* insert CRC */
222 	0x4e4e, 0x4e4e,
223 	0x9908,					/* stop writing */
224 	0, 0, 0, 0, 0, 0
225 };
226 
227 static void swim3_select(struct floppy_state *fs, int sel);
228 static void swim3_action(struct floppy_state *fs, int action);
229 static int swim3_readbit(struct floppy_state *fs, int bit);
230 static void do_fd_request(struct request_queue * q);
231 static void start_request(struct floppy_state *fs);
232 static void set_timeout(struct floppy_state *fs, int nticks,
233 			void (*proc)(unsigned long));
234 static void scan_track(struct floppy_state *fs);
235 static void seek_track(struct floppy_state *fs, int n);
236 static void init_dma(struct dbdma_cmd *cp, int cmd, void *buf, int count);
237 static void setup_transfer(struct floppy_state *fs);
238 static void act(struct floppy_state *fs);
239 static void scan_timeout(unsigned long data);
240 static void seek_timeout(unsigned long data);
241 static void settle_timeout(unsigned long data);
242 static void xfer_timeout(unsigned long data);
243 static irqreturn_t swim3_interrupt(int irq, void *dev_id);
244 /*static void fd_dma_interrupt(int irq, void *dev_id);*/
245 static int grab_drive(struct floppy_state *fs, enum swim_state state,
246 		      int interruptible);
247 static void release_drive(struct floppy_state *fs);
248 static int fd_eject(struct floppy_state *fs);
249 static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
250 			unsigned int cmd, unsigned long param);
251 static int floppy_open(struct block_device *bdev, fmode_t mode);
252 static int floppy_release(struct gendisk *disk, fmode_t mode);
253 static unsigned int floppy_check_events(struct gendisk *disk,
254 					unsigned int clearing);
255 static int floppy_revalidate(struct gendisk *disk);
256 
257 static bool swim3_end_request(int err, unsigned int nr_bytes)
258 {
259 	if (__blk_end_request(fd_req, err, nr_bytes))
260 		return true;
261 
262 	fd_req = NULL;
263 	return false;
264 }
265 
266 static bool swim3_end_request_cur(int err)
267 {
268 	return swim3_end_request(err, blk_rq_cur_bytes(fd_req));
269 }
270 
271 static void swim3_select(struct floppy_state *fs, int sel)
272 {
273 	struct swim3 __iomem *sw = fs->swim3;
274 
275 	out_8(&sw->select, RELAX);
276 	if (sel & 8)
277 		out_8(&sw->control_bis, SELECT);
278 	else
279 		out_8(&sw->control_bic, SELECT);
280 	out_8(&sw->select, sel & CA_MASK);
281 }
282 
283 static void swim3_action(struct floppy_state *fs, int action)
284 {
285 	struct swim3 __iomem *sw = fs->swim3;
286 
287 	swim3_select(fs, action);
288 	udelay(1);
289 	out_8(&sw->select, sw->select | LSTRB);
290 	udelay(2);
291 	out_8(&sw->select, sw->select & ~LSTRB);
292 	udelay(1);
293 }
294 
295 static int swim3_readbit(struct floppy_state *fs, int bit)
296 {
297 	struct swim3 __iomem *sw = fs->swim3;
298 	int stat;
299 
300 	swim3_select(fs, bit);
301 	udelay(1);
302 	stat = in_8(&sw->status);
303 	return (stat & DATA) == 0;
304 }
305 
306 static void do_fd_request(struct request_queue * q)
307 {
308 	int i;
309 
310 	for(i=0; i<floppy_count; i++) {
311 		struct floppy_state *fs = &floppy_states[i];
312 		if (fs->mdev->media_bay &&
313 		    check_media_bay(fs->mdev->media_bay) != MB_FD)
314 			continue;
315 		start_request(fs);
316 	}
317 }
318 
319 static void start_request(struct floppy_state *fs)
320 {
321 	struct request *req;
322 	unsigned long x;
323 
324 	if (fs->state == idle && fs->wanted) {
325 		fs->state = available;
326 		wake_up(&fs->wait);
327 		return;
328 	}
329 	while (fs->state == idle) {
330 		if (!fd_req) {
331 			fd_req = blk_fetch_request(swim3_queue);
332 			if (!fd_req)
333 				break;
334 		}
335 		req = fd_req;
336 #if 0
337 		printk("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%u buf=%p\n",
338 		       req->rq_disk->disk_name, req->cmd,
339 		       (long)blk_rq_pos(req), blk_rq_sectors(req), req->buffer);
340 		printk("           errors=%d current_nr_sectors=%u\n",
341 		       req->errors, blk_rq_cur_sectors(req));
342 #endif
343 
344 		if (blk_rq_pos(req) >= fs->total_secs) {
345 			swim3_end_request_cur(-EIO);
346 			continue;
347 		}
348 		if (fs->ejected) {
349 			swim3_end_request_cur(-EIO);
350 			continue;
351 		}
352 
353 		if (rq_data_dir(req) == WRITE) {
354 			if (fs->write_prot < 0)
355 				fs->write_prot = swim3_readbit(fs, WRITE_PROT);
356 			if (fs->write_prot) {
357 				swim3_end_request_cur(-EIO);
358 				continue;
359 			}
360 		}
361 
362 		/* Do not remove the cast. blk_rq_pos(req) is now a
363 		 * sector_t and can be 64 bits, but it will never go
364 		 * past 32 bits for this driver anyway, so we can
365 		 * safely cast it down and not have to do a 64/32
366 		 * division
367 		 */
368 		fs->req_cyl = ((long)blk_rq_pos(req)) / fs->secpercyl;
369 		x = ((long)blk_rq_pos(req)) % fs->secpercyl;
370 		fs->head = x / fs->secpertrack;
371 		fs->req_sector = x % fs->secpertrack + 1;
372 		fd_req = req;
373 		fs->state = do_transfer;
374 		fs->retries = 0;
375 
376 		act(fs);
377 	}
378 }
379 
380 static void set_timeout(struct floppy_state *fs, int nticks,
381 			void (*proc)(unsigned long))
382 {
383 	unsigned long flags;
384 
385 	spin_lock_irqsave(&fs->lock, flags);
386 	if (fs->timeout_pending)
387 		del_timer(&fs->timeout);
388 	fs->timeout.expires = jiffies + nticks;
389 	fs->timeout.function = proc;
390 	fs->timeout.data = (unsigned long) fs;
391 	add_timer(&fs->timeout);
392 	fs->timeout_pending = 1;
393 	spin_unlock_irqrestore(&fs->lock, flags);
394 }
395 
396 static inline void scan_track(struct floppy_state *fs)
397 {
398 	struct swim3 __iomem *sw = fs->swim3;
399 
400 	swim3_select(fs, READ_DATA_0);
401 	in_8(&sw->intr);		/* clear SEEN_SECTOR bit */
402 	in_8(&sw->error);
403 	out_8(&sw->intr_enable, SEEN_SECTOR);
404 	out_8(&sw->control_bis, DO_ACTION);
405 	/* enable intr when track found */
406 	set_timeout(fs, HZ, scan_timeout);	/* enable timeout */
407 }
408 
409 static inline void seek_track(struct floppy_state *fs, int n)
410 {
411 	struct swim3 __iomem *sw = fs->swim3;
412 
413 	if (n >= 0) {
414 		swim3_action(fs, SEEK_POSITIVE);
415 		sw->nseek = n;
416 	} else {
417 		swim3_action(fs, SEEK_NEGATIVE);
418 		sw->nseek = -n;
419 	}
420 	fs->expect_cyl = (fs->cur_cyl >= 0)? fs->cur_cyl + n: -1;
421 	swim3_select(fs, STEP);
422 	in_8(&sw->error);
423 	/* enable intr when seek finished */
424 	out_8(&sw->intr_enable, SEEK_DONE);
425 	out_8(&sw->control_bis, DO_SEEK);
426 	set_timeout(fs, 3*HZ, seek_timeout);	/* enable timeout */
427 	fs->settle_time = 0;
428 }
429 
430 static inline void init_dma(struct dbdma_cmd *cp, int cmd,
431 			    void *buf, int count)
432 {
433 	st_le16(&cp->req_count, count);
434 	st_le16(&cp->command, cmd);
435 	st_le32(&cp->phy_addr, virt_to_bus(buf));
436 	cp->xfer_status = 0;
437 }
438 
439 static inline void setup_transfer(struct floppy_state *fs)
440 {
441 	int n;
442 	struct swim3 __iomem *sw = fs->swim3;
443 	struct dbdma_cmd *cp = fs->dma_cmd;
444 	struct dbdma_regs __iomem *dr = fs->dma;
445 
446 	if (blk_rq_cur_sectors(fd_req) <= 0) {
447 		printk(KERN_ERR "swim3: transfer 0 sectors?\n");
448 		return;
449 	}
450 	if (rq_data_dir(fd_req) == WRITE)
451 		n = 1;
452 	else {
453 		n = fs->secpertrack - fs->req_sector + 1;
454 		if (n > blk_rq_cur_sectors(fd_req))
455 			n = blk_rq_cur_sectors(fd_req);
456 	}
457 	fs->scount = n;
458 	swim3_select(fs, fs->head? READ_DATA_1: READ_DATA_0);
459 	out_8(&sw->sector, fs->req_sector);
460 	out_8(&sw->nsect, n);
461 	out_8(&sw->gap3, 0);
462 	out_le32(&dr->cmdptr, virt_to_bus(cp));
463 	if (rq_data_dir(fd_req) == WRITE) {
464 		/* Set up 3 dma commands: write preamble, data, postamble */
465 		init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));
466 		++cp;
467 		init_dma(cp, OUTPUT_MORE, fd_req->buffer, 512);
468 		++cp;
469 		init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));
470 	} else {
471 		init_dma(cp, INPUT_LAST, fd_req->buffer, n * 512);
472 	}
473 	++cp;
474 	out_le16(&cp->command, DBDMA_STOP);
475 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
476 	in_8(&sw->error);
477 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
478 	if (rq_data_dir(fd_req) == WRITE)
479 		out_8(&sw->control_bis, WRITE_SECTORS);
480 	in_8(&sw->intr);
481 	out_le32(&dr->control, (RUN << 16) | RUN);
482 	/* enable intr when transfer complete */
483 	out_8(&sw->intr_enable, TRANSFER_DONE);
484 	out_8(&sw->control_bis, DO_ACTION);
485 	set_timeout(fs, 2*HZ, xfer_timeout);	/* enable timeout */
486 }
487 
488 static void act(struct floppy_state *fs)
489 {
490 	for (;;) {
491 		switch (fs->state) {
492 		case idle:
493 			return;		/* XXX shouldn't get here */
494 
495 		case locating:
496 			if (swim3_readbit(fs, TRACK_ZERO)) {
497 				fs->cur_cyl = 0;
498 				if (fs->req_cyl == 0)
499 					fs->state = do_transfer;
500 				else
501 					fs->state = seeking;
502 				break;
503 			}
504 			scan_track(fs);
505 			return;
506 
507 		case seeking:
508 			if (fs->cur_cyl < 0) {
509 				fs->expect_cyl = -1;
510 				fs->state = locating;
511 				break;
512 			}
513 			if (fs->req_cyl == fs->cur_cyl) {
514 				printk("whoops, seeking 0\n");
515 				fs->state = do_transfer;
516 				break;
517 			}
518 			seek_track(fs, fs->req_cyl - fs->cur_cyl);
519 			return;
520 
521 		case settling:
522 			/* check for SEEK_COMPLETE after 30ms */
523 			fs->settle_time = (HZ + 32) / 33;
524 			set_timeout(fs, fs->settle_time, settle_timeout);
525 			return;
526 
527 		case do_transfer:
528 			if (fs->cur_cyl != fs->req_cyl) {
529 				if (fs->retries > 5) {
530 					swim3_end_request_cur(-EIO);
531 					fs->state = idle;
532 					return;
533 				}
534 				fs->state = seeking;
535 				break;
536 			}
537 			setup_transfer(fs);
538 			return;
539 
540 		case jogging:
541 			seek_track(fs, -5);
542 			return;
543 
544 		default:
545 			printk(KERN_ERR"swim3: unknown state %d\n", fs->state);
546 			return;
547 		}
548 	}
549 }
550 
551 static void scan_timeout(unsigned long data)
552 {
553 	struct floppy_state *fs = (struct floppy_state *) data;
554 	struct swim3 __iomem *sw = fs->swim3;
555 
556 	fs->timeout_pending = 0;
557 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
558 	out_8(&sw->select, RELAX);
559 	out_8(&sw->intr_enable, 0);
560 	fs->cur_cyl = -1;
561 	if (fs->retries > 5) {
562 		swim3_end_request_cur(-EIO);
563 		fs->state = idle;
564 		start_request(fs);
565 	} else {
566 		fs->state = jogging;
567 		act(fs);
568 	}
569 }
570 
571 static void seek_timeout(unsigned long data)
572 {
573 	struct floppy_state *fs = (struct floppy_state *) data;
574 	struct swim3 __iomem *sw = fs->swim3;
575 
576 	fs->timeout_pending = 0;
577 	out_8(&sw->control_bic, DO_SEEK);
578 	out_8(&sw->select, RELAX);
579 	out_8(&sw->intr_enable, 0);
580 	printk(KERN_ERR "swim3: seek timeout\n");
581 	swim3_end_request_cur(-EIO);
582 	fs->state = idle;
583 	start_request(fs);
584 }
585 
586 static void settle_timeout(unsigned long data)
587 {
588 	struct floppy_state *fs = (struct floppy_state *) data;
589 	struct swim3 __iomem *sw = fs->swim3;
590 
591 	fs->timeout_pending = 0;
592 	if (swim3_readbit(fs, SEEK_COMPLETE)) {
593 		out_8(&sw->select, RELAX);
594 		fs->state = locating;
595 		act(fs);
596 		return;
597 	}
598 	out_8(&sw->select, RELAX);
599 	if (fs->settle_time < 2*HZ) {
600 		++fs->settle_time;
601 		set_timeout(fs, 1, settle_timeout);
602 		return;
603 	}
604 	printk(KERN_ERR "swim3: seek settle timeout\n");
605 	swim3_end_request_cur(-EIO);
606 	fs->state = idle;
607 	start_request(fs);
608 }
609 
610 static void xfer_timeout(unsigned long data)
611 {
612 	struct floppy_state *fs = (struct floppy_state *) data;
613 	struct swim3 __iomem *sw = fs->swim3;
614 	struct dbdma_regs __iomem *dr = fs->dma;
615 	int n;
616 
617 	fs->timeout_pending = 0;
618 	out_le32(&dr->control, RUN << 16);
619 	/* We must wait a bit for dbdma to stop */
620 	for (n = 0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
621 		udelay(1);
622 	out_8(&sw->intr_enable, 0);
623 	out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
624 	out_8(&sw->select, RELAX);
625 	printk(KERN_ERR "swim3: timeout %sing sector %ld\n",
626 	       (rq_data_dir(fd_req)==WRITE? "writ": "read"),
627 	       (long)blk_rq_pos(fd_req));
628 	swim3_end_request_cur(-EIO);
629 	fs->state = idle;
630 	start_request(fs);
631 }
632 
633 static irqreturn_t swim3_interrupt(int irq, void *dev_id)
634 {
635 	struct floppy_state *fs = (struct floppy_state *) dev_id;
636 	struct swim3 __iomem *sw = fs->swim3;
637 	int intr, err, n;
638 	int stat, resid;
639 	struct dbdma_regs __iomem *dr;
640 	struct dbdma_cmd *cp;
641 
642 	intr = in_8(&sw->intr);
643 	err = (intr & ERROR_INTR)? in_8(&sw->error): 0;
644 	if ((intr & ERROR_INTR) && fs->state != do_transfer)
645 		printk(KERN_ERR "swim3_interrupt, state=%d, dir=%x, intr=%x, err=%x\n",
646 		       fs->state, rq_data_dir(fd_req), intr, err);
647 	switch (fs->state) {
648 	case locating:
649 		if (intr & SEEN_SECTOR) {
650 			out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
651 			out_8(&sw->select, RELAX);
652 			out_8(&sw->intr_enable, 0);
653 			del_timer(&fs->timeout);
654 			fs->timeout_pending = 0;
655 			if (sw->ctrack == 0xff) {
656 				printk(KERN_ERR "swim3: seen sector but cyl=ff?\n");
657 				fs->cur_cyl = -1;
658 				if (fs->retries > 5) {
659 					swim3_end_request_cur(-EIO);
660 					fs->state = idle;
661 					start_request(fs);
662 				} else {
663 					fs->state = jogging;
664 					act(fs);
665 				}
666 				break;
667 			}
668 			fs->cur_cyl = sw->ctrack;
669 			fs->cur_sector = sw->csect;
670 			if (fs->expect_cyl != -1 && fs->expect_cyl != fs->cur_cyl)
671 				printk(KERN_ERR "swim3: expected cyl %d, got %d\n",
672 				       fs->expect_cyl, fs->cur_cyl);
673 			fs->state = do_transfer;
674 			act(fs);
675 		}
676 		break;
677 	case seeking:
678 	case jogging:
679 		if (sw->nseek == 0) {
680 			out_8(&sw->control_bic, DO_SEEK);
681 			out_8(&sw->select, RELAX);
682 			out_8(&sw->intr_enable, 0);
683 			del_timer(&fs->timeout);
684 			fs->timeout_pending = 0;
685 			if (fs->state == seeking)
686 				++fs->retries;
687 			fs->state = settling;
688 			act(fs);
689 		}
690 		break;
691 	case settling:
692 		out_8(&sw->intr_enable, 0);
693 		del_timer(&fs->timeout);
694 		fs->timeout_pending = 0;
695 		act(fs);
696 		break;
697 	case do_transfer:
698 		if ((intr & (ERROR_INTR | TRANSFER_DONE)) == 0)
699 			break;
700 		out_8(&sw->intr_enable, 0);
701 		out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
702 		out_8(&sw->select, RELAX);
703 		del_timer(&fs->timeout);
704 		fs->timeout_pending = 0;
705 		dr = fs->dma;
706 		cp = fs->dma_cmd;
707 		if (rq_data_dir(fd_req) == WRITE)
708 			++cp;
709 		/*
710 		 * Check that the main data transfer has finished.
711 		 * On writing, the swim3 sometimes doesn't use
712 		 * up all the bytes of the postamble, so we can still
713 		 * see DMA active here.  That doesn't matter as long
714 		 * as all the sector data has been transferred.
715 		 */
716 		if ((intr & ERROR_INTR) == 0 && cp->xfer_status == 0) {
717 			/* wait a little while for DMA to complete */
718 			for (n = 0; n < 100; ++n) {
719 				if (cp->xfer_status != 0)
720 					break;
721 				udelay(1);
722 				barrier();
723 			}
724 		}
725 		/* turn off DMA */
726 		out_le32(&dr->control, (RUN | PAUSE) << 16);
727 		stat = ld_le16(&cp->xfer_status);
728 		resid = ld_le16(&cp->res_count);
729 		if (intr & ERROR_INTR) {
730 			n = fs->scount - 1 - resid / 512;
731 			if (n > 0) {
732 				blk_update_request(fd_req, 0, n << 9);
733 				fs->req_sector += n;
734 			}
735 			if (fs->retries < 5) {
736 				++fs->retries;
737 				act(fs);
738 			} else {
739 				printk("swim3: error %sing block %ld (err=%x)\n",
740 				       rq_data_dir(fd_req) == WRITE? "writ": "read",
741 				       (long)blk_rq_pos(fd_req), err);
742 				swim3_end_request_cur(-EIO);
743 				fs->state = idle;
744 			}
745 		} else {
746 			if ((stat & ACTIVE) == 0 || resid != 0) {
747 				/* musta been an error */
748 				printk(KERN_ERR "swim3: fd dma: stat=%x resid=%d\n", stat, resid);
749 				printk(KERN_ERR "  state=%d, dir=%x, intr=%x, err=%x\n",
750 				       fs->state, rq_data_dir(fd_req), intr, err);
751 				swim3_end_request_cur(-EIO);
752 				fs->state = idle;
753 				start_request(fs);
754 				break;
755 			}
756 			if (swim3_end_request(0, fs->scount << 9)) {
757 				fs->req_sector += fs->scount;
758 				if (fs->req_sector > fs->secpertrack) {
759 					fs->req_sector -= fs->secpertrack;
760 					if (++fs->head > 1) {
761 						fs->head = 0;
762 						++fs->req_cyl;
763 					}
764 				}
765 				act(fs);
766 			} else
767 				fs->state = idle;
768 		}
769 		if (fs->state == idle)
770 			start_request(fs);
771 		break;
772 	default:
773 		printk(KERN_ERR "swim3: don't know what to do in state %d\n", fs->state);
774 	}
775 	return IRQ_HANDLED;
776 }
777 
778 /*
779 static void fd_dma_interrupt(int irq, void *dev_id)
780 {
781 }
782 */
783 
784 static int grab_drive(struct floppy_state *fs, enum swim_state state,
785 		      int interruptible)
786 {
787 	unsigned long flags;
788 
789 	spin_lock_irqsave(&fs->lock, flags);
790 	if (fs->state != idle) {
791 		++fs->wanted;
792 		while (fs->state != available) {
793 			if (interruptible && signal_pending(current)) {
794 				--fs->wanted;
795 				spin_unlock_irqrestore(&fs->lock, flags);
796 				return -EINTR;
797 			}
798 			interruptible_sleep_on(&fs->wait);
799 		}
800 		--fs->wanted;
801 	}
802 	fs->state = state;
803 	spin_unlock_irqrestore(&fs->lock, flags);
804 	return 0;
805 }
806 
807 static void release_drive(struct floppy_state *fs)
808 {
809 	unsigned long flags;
810 
811 	spin_lock_irqsave(&fs->lock, flags);
812 	fs->state = idle;
813 	start_request(fs);
814 	spin_unlock_irqrestore(&fs->lock, flags);
815 }
816 
817 static int fd_eject(struct floppy_state *fs)
818 {
819 	int err, n;
820 
821 	err = grab_drive(fs, ejecting, 1);
822 	if (err)
823 		return err;
824 	swim3_action(fs, EJECT);
825 	for (n = 20; n > 0; --n) {
826 		if (signal_pending(current)) {
827 			err = -EINTR;
828 			break;
829 		}
830 		swim3_select(fs, RELAX);
831 		schedule_timeout_interruptible(1);
832 		if (swim3_readbit(fs, DISK_IN) == 0)
833 			break;
834 	}
835 	swim3_select(fs, RELAX);
836 	udelay(150);
837 	fs->ejected = 1;
838 	release_drive(fs);
839 	return err;
840 }
841 
842 static struct floppy_struct floppy_type =
843 	{ 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,NULL };	/*  7 1.44MB 3.5"   */
844 
845 static int floppy_locked_ioctl(struct block_device *bdev, fmode_t mode,
846 			unsigned int cmd, unsigned long param)
847 {
848 	struct floppy_state *fs = bdev->bd_disk->private_data;
849 	int err;
850 
851 	if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
852 		return -EPERM;
853 
854 	if (fs->mdev->media_bay &&
855 	    check_media_bay(fs->mdev->media_bay) != MB_FD)
856 		return -ENXIO;
857 
858 	switch (cmd) {
859 	case FDEJECT:
860 		if (fs->ref_count != 1)
861 			return -EBUSY;
862 		err = fd_eject(fs);
863 		return err;
864 	case FDGETPRM:
865 	        if (copy_to_user((void __user *) param, &floppy_type,
866 				 sizeof(struct floppy_struct)))
867 			return -EFAULT;
868 		return 0;
869 	}
870 	return -ENOTTY;
871 }
872 
873 static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
874 				 unsigned int cmd, unsigned long param)
875 {
876 	int ret;
877 
878 	mutex_lock(&swim3_mutex);
879 	ret = floppy_locked_ioctl(bdev, mode, cmd, param);
880 	mutex_unlock(&swim3_mutex);
881 
882 	return ret;
883 }
884 
885 static int floppy_open(struct block_device *bdev, fmode_t mode)
886 {
887 	struct floppy_state *fs = bdev->bd_disk->private_data;
888 	struct swim3 __iomem *sw = fs->swim3;
889 	int n, err = 0;
890 
891 	if (fs->ref_count == 0) {
892 		if (fs->mdev->media_bay &&
893 		    check_media_bay(fs->mdev->media_bay) != MB_FD)
894 			return -ENXIO;
895 		out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
896 		out_8(&sw->control_bic, 0xff);
897 		out_8(&sw->mode, 0x95);
898 		udelay(10);
899 		out_8(&sw->intr_enable, 0);
900 		out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
901 		swim3_action(fs, MOTOR_ON);
902 		fs->write_prot = -1;
903 		fs->cur_cyl = -1;
904 		for (n = 0; n < 2 * HZ; ++n) {
905 			if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
906 				break;
907 			if (signal_pending(current)) {
908 				err = -EINTR;
909 				break;
910 			}
911 			swim3_select(fs, RELAX);
912 			schedule_timeout_interruptible(1);
913 		}
914 		if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
915 				 || swim3_readbit(fs, DISK_IN) == 0))
916 			err = -ENXIO;
917 		swim3_action(fs, SETMFM);
918 		swim3_select(fs, RELAX);
919 
920 	} else if (fs->ref_count == -1 || mode & FMODE_EXCL)
921 		return -EBUSY;
922 
923 	if (err == 0 && (mode & FMODE_NDELAY) == 0
924 	    && (mode & (FMODE_READ|FMODE_WRITE))) {
925 		check_disk_change(bdev);
926 		if (fs->ejected)
927 			err = -ENXIO;
928 	}
929 
930 	if (err == 0 && (mode & FMODE_WRITE)) {
931 		if (fs->write_prot < 0)
932 			fs->write_prot = swim3_readbit(fs, WRITE_PROT);
933 		if (fs->write_prot)
934 			err = -EROFS;
935 	}
936 
937 	if (err) {
938 		if (fs->ref_count == 0) {
939 			swim3_action(fs, MOTOR_OFF);
940 			out_8(&sw->control_bic, DRIVE_ENABLE | INTR_ENABLE);
941 			swim3_select(fs, RELAX);
942 		}
943 		return err;
944 	}
945 
946 	if (mode & FMODE_EXCL)
947 		fs->ref_count = -1;
948 	else
949 		++fs->ref_count;
950 
951 	return 0;
952 }
953 
954 static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
955 {
956 	int ret;
957 
958 	mutex_lock(&swim3_mutex);
959 	ret = floppy_open(bdev, mode);
960 	mutex_unlock(&swim3_mutex);
961 
962 	return ret;
963 }
964 
965 static int floppy_release(struct gendisk *disk, fmode_t mode)
966 {
967 	struct floppy_state *fs = disk->private_data;
968 	struct swim3 __iomem *sw = fs->swim3;
969 	mutex_lock(&swim3_mutex);
970 	if (fs->ref_count > 0 && --fs->ref_count == 0) {
971 		swim3_action(fs, MOTOR_OFF);
972 		out_8(&sw->control_bic, 0xff);
973 		swim3_select(fs, RELAX);
974 	}
975 	mutex_unlock(&swim3_mutex);
976 	return 0;
977 }
978 
979 static unsigned int floppy_check_events(struct gendisk *disk,
980 					unsigned int clearing)
981 {
982 	struct floppy_state *fs = disk->private_data;
983 	return fs->ejected ? DISK_EVENT_MEDIA_CHANGE : 0;
984 }
985 
986 static int floppy_revalidate(struct gendisk *disk)
987 {
988 	struct floppy_state *fs = disk->private_data;
989 	struct swim3 __iomem *sw;
990 	int ret, n;
991 
992 	if (fs->mdev->media_bay &&
993 	    check_media_bay(fs->mdev->media_bay) != MB_FD)
994 		return -ENXIO;
995 
996 	sw = fs->swim3;
997 	grab_drive(fs, revalidating, 0);
998 	out_8(&sw->intr_enable, 0);
999 	out_8(&sw->control_bis, DRIVE_ENABLE);
1000 	swim3_action(fs, MOTOR_ON);	/* necessary? */
1001 	fs->write_prot = -1;
1002 	fs->cur_cyl = -1;
1003 	mdelay(1);
1004 	for (n = HZ; n > 0; --n) {
1005 		if (swim3_readbit(fs, SEEK_COMPLETE))
1006 			break;
1007 		if (signal_pending(current))
1008 			break;
1009 		swim3_select(fs, RELAX);
1010 		schedule_timeout_interruptible(1);
1011 	}
1012 	ret = swim3_readbit(fs, SEEK_COMPLETE) == 0
1013 		|| swim3_readbit(fs, DISK_IN) == 0;
1014 	if (ret)
1015 		swim3_action(fs, MOTOR_OFF);
1016 	else {
1017 		fs->ejected = 0;
1018 		swim3_action(fs, SETMFM);
1019 	}
1020 	swim3_select(fs, RELAX);
1021 
1022 	release_drive(fs);
1023 	return ret;
1024 }
1025 
1026 static const struct block_device_operations floppy_fops = {
1027 	.open		= floppy_unlocked_open,
1028 	.release	= floppy_release,
1029 	.ioctl		= floppy_ioctl,
1030 	.check_events	= floppy_check_events,
1031 	.revalidate_disk= floppy_revalidate,
1032 };
1033 
1034 static int swim3_add_device(struct macio_dev *mdev, int index)
1035 {
1036 	struct device_node *swim = mdev->ofdev.dev.of_node;
1037 	struct floppy_state *fs = &floppy_states[index];
1038 	int rc = -EBUSY;
1039 
1040 	/* Check & Request resources */
1041 	if (macio_resource_count(mdev) < 2) {
1042 		printk(KERN_WARNING "ifd%d: no address for %s\n",
1043 		       index, swim->full_name);
1044 		return -ENXIO;
1045 	}
1046 	if (macio_irq_count(mdev) < 2) {
1047 		printk(KERN_WARNING "fd%d: no intrs for device %s\n",
1048 			index, swim->full_name);
1049 	}
1050 	if (macio_request_resource(mdev, 0, "swim3 (mmio)")) {
1051 		printk(KERN_ERR "fd%d: can't request mmio resource for %s\n",
1052 		       index, swim->full_name);
1053 		return -EBUSY;
1054 	}
1055 	if (macio_request_resource(mdev, 1, "swim3 (dma)")) {
1056 		printk(KERN_ERR "fd%d: can't request dma resource for %s\n",
1057 		       index, swim->full_name);
1058 		macio_release_resource(mdev, 0);
1059 		return -EBUSY;
1060 	}
1061 	dev_set_drvdata(&mdev->ofdev.dev, fs);
1062 
1063 	if (mdev->media_bay == NULL)
1064 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 1);
1065 
1066 	memset(fs, 0, sizeof(*fs));
1067 	spin_lock_init(&fs->lock);
1068 	fs->state = idle;
1069 	fs->swim3 = (struct swim3 __iomem *)
1070 		ioremap(macio_resource_start(mdev, 0), 0x200);
1071 	if (fs->swim3 == NULL) {
1072 		printk("fd%d: couldn't map registers for %s\n",
1073 		       index, swim->full_name);
1074 		rc = -ENOMEM;
1075 		goto out_release;
1076 	}
1077 	fs->dma = (struct dbdma_regs __iomem *)
1078 		ioremap(macio_resource_start(mdev, 1), 0x200);
1079 	if (fs->dma == NULL) {
1080 		printk("fd%d: couldn't map DMA for %s\n",
1081 		       index, swim->full_name);
1082 		iounmap(fs->swim3);
1083 		rc = -ENOMEM;
1084 		goto out_release;
1085 	}
1086 	fs->swim3_intr = macio_irq(mdev, 0);
1087 	fs->dma_intr = macio_irq(mdev, 1);
1088 	fs->cur_cyl = -1;
1089 	fs->cur_sector = -1;
1090 	fs->secpercyl = 36;
1091 	fs->secpertrack = 18;
1092 	fs->total_secs = 2880;
1093 	fs->mdev = mdev;
1094 	init_waitqueue_head(&fs->wait);
1095 
1096 	fs->dma_cmd = (struct dbdma_cmd *) DBDMA_ALIGN(fs->dbdma_cmd_space);
1097 	memset(fs->dma_cmd, 0, 2 * sizeof(struct dbdma_cmd));
1098 	st_le16(&fs->dma_cmd[1].command, DBDMA_STOP);
1099 
1100 	if (request_irq(fs->swim3_intr, swim3_interrupt, 0, "SWIM3", fs)) {
1101 		printk(KERN_ERR "fd%d: couldn't request irq %d for %s\n",
1102 		       index, fs->swim3_intr, swim->full_name);
1103 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 0);
1104 		goto out_unmap;
1105 		return -EBUSY;
1106 	}
1107 /*
1108 	if (request_irq(fs->dma_intr, fd_dma_interrupt, 0, "SWIM3-dma", fs)) {
1109 		printk(KERN_ERR "Couldn't get irq %d for SWIM3 DMA",
1110 		       fs->dma_intr);
1111 		return -EBUSY;
1112 	}
1113 */
1114 
1115 	init_timer(&fs->timeout);
1116 
1117 	printk(KERN_INFO "fd%d: SWIM3 floppy controller %s\n", floppy_count,
1118 		mdev->media_bay ? "in media bay" : "");
1119 
1120 	return 0;
1121 
1122  out_unmap:
1123 	iounmap(fs->dma);
1124 	iounmap(fs->swim3);
1125 
1126  out_release:
1127 	macio_release_resource(mdev, 0);
1128 	macio_release_resource(mdev, 1);
1129 
1130 	return rc;
1131 }
1132 
1133 static int __devinit swim3_attach(struct macio_dev *mdev, const struct of_device_id *match)
1134 {
1135 	int i, rc;
1136 	struct gendisk *disk;
1137 
1138 	/* Add the drive */
1139 	rc = swim3_add_device(mdev, floppy_count);
1140 	if (rc)
1141 		return rc;
1142 
1143 	/* Now create the queue if not there yet */
1144 	if (swim3_queue == NULL) {
1145 		/* If we failed, there isn't much we can do as the driver is still
1146 		 * too dumb to remove the device, just bail out
1147 		 */
1148 		if (register_blkdev(FLOPPY_MAJOR, "fd"))
1149 			return 0;
1150 		swim3_queue = blk_init_queue(do_fd_request, &swim3_lock);
1151 		if (swim3_queue == NULL) {
1152 			unregister_blkdev(FLOPPY_MAJOR, "fd");
1153 			return 0;
1154 		}
1155 	}
1156 
1157 	/* Now register that disk. Same comment about failure handling */
1158 	i = floppy_count++;
1159 	disk = disks[i] = alloc_disk(1);
1160 	if (disk == NULL)
1161 		return 0;
1162 
1163 	disk->major = FLOPPY_MAJOR;
1164 	disk->first_minor = i;
1165 	disk->fops = &floppy_fops;
1166 	disk->private_data = &floppy_states[i];
1167 	disk->queue = swim3_queue;
1168 	disk->flags |= GENHD_FL_REMOVABLE;
1169 	sprintf(disk->disk_name, "fd%d", i);
1170 	set_capacity(disk, 2880);
1171 	add_disk(disk);
1172 
1173 	return 0;
1174 }
1175 
1176 static struct of_device_id swim3_match[] =
1177 {
1178 	{
1179 	.name		= "swim3",
1180 	},
1181 	{
1182 	.compatible	= "ohare-swim3"
1183 	},
1184 	{
1185 	.compatible	= "swim3"
1186 	},
1187 };
1188 
1189 static struct macio_driver swim3_driver =
1190 {
1191 	.driver = {
1192 		.name 		= "swim3",
1193 		.of_match_table	= swim3_match,
1194 	},
1195 	.probe		= swim3_attach,
1196 #if 0
1197 	.suspend	= swim3_suspend,
1198 	.resume		= swim3_resume,
1199 #endif
1200 };
1201 
1202 
1203 int swim3_init(void)
1204 {
1205 	macio_register_driver(&swim3_driver);
1206 	return 0;
1207 }
1208 
1209 module_init(swim3_init)
1210 
1211 MODULE_LICENSE("GPL");
1212 MODULE_AUTHOR("Paul Mackerras");
1213 MODULE_ALIAS_BLOCKDEV_MAJOR(FLOPPY_MAJOR);
1214