xref: /openbmc/linux/drivers/block/swim3.c (revision 565d76cb)
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 int floppy_check_change(struct gendisk *disk);
254 static int floppy_revalidate(struct gendisk *disk);
255 
256 static bool swim3_end_request(int err, unsigned int nr_bytes)
257 {
258 	if (__blk_end_request(fd_req, err, nr_bytes))
259 		return true;
260 
261 	fd_req = NULL;
262 	return false;
263 }
264 
265 static bool swim3_end_request_cur(int err)
266 {
267 	return swim3_end_request(err, blk_rq_cur_bytes(fd_req));
268 }
269 
270 static void swim3_select(struct floppy_state *fs, int sel)
271 {
272 	struct swim3 __iomem *sw = fs->swim3;
273 
274 	out_8(&sw->select, RELAX);
275 	if (sel & 8)
276 		out_8(&sw->control_bis, SELECT);
277 	else
278 		out_8(&sw->control_bic, SELECT);
279 	out_8(&sw->select, sel & CA_MASK);
280 }
281 
282 static void swim3_action(struct floppy_state *fs, int action)
283 {
284 	struct swim3 __iomem *sw = fs->swim3;
285 
286 	swim3_select(fs, action);
287 	udelay(1);
288 	out_8(&sw->select, sw->select | LSTRB);
289 	udelay(2);
290 	out_8(&sw->select, sw->select & ~LSTRB);
291 	udelay(1);
292 }
293 
294 static int swim3_readbit(struct floppy_state *fs, int bit)
295 {
296 	struct swim3 __iomem *sw = fs->swim3;
297 	int stat;
298 
299 	swim3_select(fs, bit);
300 	udelay(1);
301 	stat = in_8(&sw->status);
302 	return (stat & DATA) == 0;
303 }
304 
305 static void do_fd_request(struct request_queue * q)
306 {
307 	int i;
308 
309 	for(i=0; i<floppy_count; i++) {
310 		struct floppy_state *fs = &floppy_states[i];
311 		if (fs->mdev->media_bay &&
312 		    check_media_bay(fs->mdev->media_bay) != MB_FD)
313 			continue;
314 		start_request(fs);
315 	}
316 }
317 
318 static void start_request(struct floppy_state *fs)
319 {
320 	struct request *req;
321 	unsigned long x;
322 
323 	if (fs->state == idle && fs->wanted) {
324 		fs->state = available;
325 		wake_up(&fs->wait);
326 		return;
327 	}
328 	while (fs->state == idle) {
329 		if (!fd_req) {
330 			fd_req = blk_fetch_request(swim3_queue);
331 			if (!fd_req)
332 				break;
333 		}
334 		req = fd_req;
335 #if 0
336 		printk("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%u buf=%p\n",
337 		       req->rq_disk->disk_name, req->cmd,
338 		       (long)blk_rq_pos(req), blk_rq_sectors(req), req->buffer);
339 		printk("           errors=%d current_nr_sectors=%u\n",
340 		       req->errors, blk_rq_cur_sectors(req));
341 #endif
342 
343 		if (blk_rq_pos(req) >= fs->total_secs) {
344 			swim3_end_request_cur(-EIO);
345 			continue;
346 		}
347 		if (fs->ejected) {
348 			swim3_end_request_cur(-EIO);
349 			continue;
350 		}
351 
352 		if (rq_data_dir(req) == WRITE) {
353 			if (fs->write_prot < 0)
354 				fs->write_prot = swim3_readbit(fs, WRITE_PROT);
355 			if (fs->write_prot) {
356 				swim3_end_request_cur(-EIO);
357 				continue;
358 			}
359 		}
360 
361 		/* Do not remove the cast. blk_rq_pos(req) is now a
362 		 * sector_t and can be 64 bits, but it will never go
363 		 * past 32 bits for this driver anyway, so we can
364 		 * safely cast it down and not have to do a 64/32
365 		 * division
366 		 */
367 		fs->req_cyl = ((long)blk_rq_pos(req)) / fs->secpercyl;
368 		x = ((long)blk_rq_pos(req)) % fs->secpercyl;
369 		fs->head = x / fs->secpertrack;
370 		fs->req_sector = x % fs->secpertrack + 1;
371 		fd_req = req;
372 		fs->state = do_transfer;
373 		fs->retries = 0;
374 
375 		act(fs);
376 	}
377 }
378 
379 static void set_timeout(struct floppy_state *fs, int nticks,
380 			void (*proc)(unsigned long))
381 {
382 	unsigned long flags;
383 
384 	spin_lock_irqsave(&fs->lock, flags);
385 	if (fs->timeout_pending)
386 		del_timer(&fs->timeout);
387 	fs->timeout.expires = jiffies + nticks;
388 	fs->timeout.function = proc;
389 	fs->timeout.data = (unsigned long) fs;
390 	add_timer(&fs->timeout);
391 	fs->timeout_pending = 1;
392 	spin_unlock_irqrestore(&fs->lock, flags);
393 }
394 
395 static inline void scan_track(struct floppy_state *fs)
396 {
397 	struct swim3 __iomem *sw = fs->swim3;
398 
399 	swim3_select(fs, READ_DATA_0);
400 	in_8(&sw->intr);		/* clear SEEN_SECTOR bit */
401 	in_8(&sw->error);
402 	out_8(&sw->intr_enable, SEEN_SECTOR);
403 	out_8(&sw->control_bis, DO_ACTION);
404 	/* enable intr when track found */
405 	set_timeout(fs, HZ, scan_timeout);	/* enable timeout */
406 }
407 
408 static inline void seek_track(struct floppy_state *fs, int n)
409 {
410 	struct swim3 __iomem *sw = fs->swim3;
411 
412 	if (n >= 0) {
413 		swim3_action(fs, SEEK_POSITIVE);
414 		sw->nseek = n;
415 	} else {
416 		swim3_action(fs, SEEK_NEGATIVE);
417 		sw->nseek = -n;
418 	}
419 	fs->expect_cyl = (fs->cur_cyl >= 0)? fs->cur_cyl + n: -1;
420 	swim3_select(fs, STEP);
421 	in_8(&sw->error);
422 	/* enable intr when seek finished */
423 	out_8(&sw->intr_enable, SEEK_DONE);
424 	out_8(&sw->control_bis, DO_SEEK);
425 	set_timeout(fs, 3*HZ, seek_timeout);	/* enable timeout */
426 	fs->settle_time = 0;
427 }
428 
429 static inline void init_dma(struct dbdma_cmd *cp, int cmd,
430 			    void *buf, int count)
431 {
432 	st_le16(&cp->req_count, count);
433 	st_le16(&cp->command, cmd);
434 	st_le32(&cp->phy_addr, virt_to_bus(buf));
435 	cp->xfer_status = 0;
436 }
437 
438 static inline void setup_transfer(struct floppy_state *fs)
439 {
440 	int n;
441 	struct swim3 __iomem *sw = fs->swim3;
442 	struct dbdma_cmd *cp = fs->dma_cmd;
443 	struct dbdma_regs __iomem *dr = fs->dma;
444 
445 	if (blk_rq_cur_sectors(fd_req) <= 0) {
446 		printk(KERN_ERR "swim3: transfer 0 sectors?\n");
447 		return;
448 	}
449 	if (rq_data_dir(fd_req) == WRITE)
450 		n = 1;
451 	else {
452 		n = fs->secpertrack - fs->req_sector + 1;
453 		if (n > blk_rq_cur_sectors(fd_req))
454 			n = blk_rq_cur_sectors(fd_req);
455 	}
456 	fs->scount = n;
457 	swim3_select(fs, fs->head? READ_DATA_1: READ_DATA_0);
458 	out_8(&sw->sector, fs->req_sector);
459 	out_8(&sw->nsect, n);
460 	out_8(&sw->gap3, 0);
461 	out_le32(&dr->cmdptr, virt_to_bus(cp));
462 	if (rq_data_dir(fd_req) == WRITE) {
463 		/* Set up 3 dma commands: write preamble, data, postamble */
464 		init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));
465 		++cp;
466 		init_dma(cp, OUTPUT_MORE, fd_req->buffer, 512);
467 		++cp;
468 		init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));
469 	} else {
470 		init_dma(cp, INPUT_LAST, fd_req->buffer, n * 512);
471 	}
472 	++cp;
473 	out_le16(&cp->command, DBDMA_STOP);
474 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
475 	in_8(&sw->error);
476 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
477 	if (rq_data_dir(fd_req) == WRITE)
478 		out_8(&sw->control_bis, WRITE_SECTORS);
479 	in_8(&sw->intr);
480 	out_le32(&dr->control, (RUN << 16) | RUN);
481 	/* enable intr when transfer complete */
482 	out_8(&sw->intr_enable, TRANSFER_DONE);
483 	out_8(&sw->control_bis, DO_ACTION);
484 	set_timeout(fs, 2*HZ, xfer_timeout);	/* enable timeout */
485 }
486 
487 static void act(struct floppy_state *fs)
488 {
489 	for (;;) {
490 		switch (fs->state) {
491 		case idle:
492 			return;		/* XXX shouldn't get here */
493 
494 		case locating:
495 			if (swim3_readbit(fs, TRACK_ZERO)) {
496 				fs->cur_cyl = 0;
497 				if (fs->req_cyl == 0)
498 					fs->state = do_transfer;
499 				else
500 					fs->state = seeking;
501 				break;
502 			}
503 			scan_track(fs);
504 			return;
505 
506 		case seeking:
507 			if (fs->cur_cyl < 0) {
508 				fs->expect_cyl = -1;
509 				fs->state = locating;
510 				break;
511 			}
512 			if (fs->req_cyl == fs->cur_cyl) {
513 				printk("whoops, seeking 0\n");
514 				fs->state = do_transfer;
515 				break;
516 			}
517 			seek_track(fs, fs->req_cyl - fs->cur_cyl);
518 			return;
519 
520 		case settling:
521 			/* check for SEEK_COMPLETE after 30ms */
522 			fs->settle_time = (HZ + 32) / 33;
523 			set_timeout(fs, fs->settle_time, settle_timeout);
524 			return;
525 
526 		case do_transfer:
527 			if (fs->cur_cyl != fs->req_cyl) {
528 				if (fs->retries > 5) {
529 					swim3_end_request_cur(-EIO);
530 					fs->state = idle;
531 					return;
532 				}
533 				fs->state = seeking;
534 				break;
535 			}
536 			setup_transfer(fs);
537 			return;
538 
539 		case jogging:
540 			seek_track(fs, -5);
541 			return;
542 
543 		default:
544 			printk(KERN_ERR"swim3: unknown state %d\n", fs->state);
545 			return;
546 		}
547 	}
548 }
549 
550 static void scan_timeout(unsigned long data)
551 {
552 	struct floppy_state *fs = (struct floppy_state *) data;
553 	struct swim3 __iomem *sw = fs->swim3;
554 
555 	fs->timeout_pending = 0;
556 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
557 	out_8(&sw->select, RELAX);
558 	out_8(&sw->intr_enable, 0);
559 	fs->cur_cyl = -1;
560 	if (fs->retries > 5) {
561 		swim3_end_request_cur(-EIO);
562 		fs->state = idle;
563 		start_request(fs);
564 	} else {
565 		fs->state = jogging;
566 		act(fs);
567 	}
568 }
569 
570 static void seek_timeout(unsigned long data)
571 {
572 	struct floppy_state *fs = (struct floppy_state *) data;
573 	struct swim3 __iomem *sw = fs->swim3;
574 
575 	fs->timeout_pending = 0;
576 	out_8(&sw->control_bic, DO_SEEK);
577 	out_8(&sw->select, RELAX);
578 	out_8(&sw->intr_enable, 0);
579 	printk(KERN_ERR "swim3: seek timeout\n");
580 	swim3_end_request_cur(-EIO);
581 	fs->state = idle;
582 	start_request(fs);
583 }
584 
585 static void settle_timeout(unsigned long data)
586 {
587 	struct floppy_state *fs = (struct floppy_state *) data;
588 	struct swim3 __iomem *sw = fs->swim3;
589 
590 	fs->timeout_pending = 0;
591 	if (swim3_readbit(fs, SEEK_COMPLETE)) {
592 		out_8(&sw->select, RELAX);
593 		fs->state = locating;
594 		act(fs);
595 		return;
596 	}
597 	out_8(&sw->select, RELAX);
598 	if (fs->settle_time < 2*HZ) {
599 		++fs->settle_time;
600 		set_timeout(fs, 1, settle_timeout);
601 		return;
602 	}
603 	printk(KERN_ERR "swim3: seek settle timeout\n");
604 	swim3_end_request_cur(-EIO);
605 	fs->state = idle;
606 	start_request(fs);
607 }
608 
609 static void xfer_timeout(unsigned long data)
610 {
611 	struct floppy_state *fs = (struct floppy_state *) data;
612 	struct swim3 __iomem *sw = fs->swim3;
613 	struct dbdma_regs __iomem *dr = fs->dma;
614 	int n;
615 
616 	fs->timeout_pending = 0;
617 	out_le32(&dr->control, RUN << 16);
618 	/* We must wait a bit for dbdma to stop */
619 	for (n = 0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
620 		udelay(1);
621 	out_8(&sw->intr_enable, 0);
622 	out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
623 	out_8(&sw->select, RELAX);
624 	printk(KERN_ERR "swim3: timeout %sing sector %ld\n",
625 	       (rq_data_dir(fd_req)==WRITE? "writ": "read"),
626 	       (long)blk_rq_pos(fd_req));
627 	swim3_end_request_cur(-EIO);
628 	fs->state = idle;
629 	start_request(fs);
630 }
631 
632 static irqreturn_t swim3_interrupt(int irq, void *dev_id)
633 {
634 	struct floppy_state *fs = (struct floppy_state *) dev_id;
635 	struct swim3 __iomem *sw = fs->swim3;
636 	int intr, err, n;
637 	int stat, resid;
638 	struct dbdma_regs __iomem *dr;
639 	struct dbdma_cmd *cp;
640 
641 	intr = in_8(&sw->intr);
642 	err = (intr & ERROR_INTR)? in_8(&sw->error): 0;
643 	if ((intr & ERROR_INTR) && fs->state != do_transfer)
644 		printk(KERN_ERR "swim3_interrupt, state=%d, dir=%x, intr=%x, err=%x\n",
645 		       fs->state, rq_data_dir(fd_req), intr, err);
646 	switch (fs->state) {
647 	case locating:
648 		if (intr & SEEN_SECTOR) {
649 			out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
650 			out_8(&sw->select, RELAX);
651 			out_8(&sw->intr_enable, 0);
652 			del_timer(&fs->timeout);
653 			fs->timeout_pending = 0;
654 			if (sw->ctrack == 0xff) {
655 				printk(KERN_ERR "swim3: seen sector but cyl=ff?\n");
656 				fs->cur_cyl = -1;
657 				if (fs->retries > 5) {
658 					swim3_end_request_cur(-EIO);
659 					fs->state = idle;
660 					start_request(fs);
661 				} else {
662 					fs->state = jogging;
663 					act(fs);
664 				}
665 				break;
666 			}
667 			fs->cur_cyl = sw->ctrack;
668 			fs->cur_sector = sw->csect;
669 			if (fs->expect_cyl != -1 && fs->expect_cyl != fs->cur_cyl)
670 				printk(KERN_ERR "swim3: expected cyl %d, got %d\n",
671 				       fs->expect_cyl, fs->cur_cyl);
672 			fs->state = do_transfer;
673 			act(fs);
674 		}
675 		break;
676 	case seeking:
677 	case jogging:
678 		if (sw->nseek == 0) {
679 			out_8(&sw->control_bic, DO_SEEK);
680 			out_8(&sw->select, RELAX);
681 			out_8(&sw->intr_enable, 0);
682 			del_timer(&fs->timeout);
683 			fs->timeout_pending = 0;
684 			if (fs->state == seeking)
685 				++fs->retries;
686 			fs->state = settling;
687 			act(fs);
688 		}
689 		break;
690 	case settling:
691 		out_8(&sw->intr_enable, 0);
692 		del_timer(&fs->timeout);
693 		fs->timeout_pending = 0;
694 		act(fs);
695 		break;
696 	case do_transfer:
697 		if ((intr & (ERROR_INTR | TRANSFER_DONE)) == 0)
698 			break;
699 		out_8(&sw->intr_enable, 0);
700 		out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
701 		out_8(&sw->select, RELAX);
702 		del_timer(&fs->timeout);
703 		fs->timeout_pending = 0;
704 		dr = fs->dma;
705 		cp = fs->dma_cmd;
706 		if (rq_data_dir(fd_req) == WRITE)
707 			++cp;
708 		/*
709 		 * Check that the main data transfer has finished.
710 		 * On writing, the swim3 sometimes doesn't use
711 		 * up all the bytes of the postamble, so we can still
712 		 * see DMA active here.  That doesn't matter as long
713 		 * as all the sector data has been transferred.
714 		 */
715 		if ((intr & ERROR_INTR) == 0 && cp->xfer_status == 0) {
716 			/* wait a little while for DMA to complete */
717 			for (n = 0; n < 100; ++n) {
718 				if (cp->xfer_status != 0)
719 					break;
720 				udelay(1);
721 				barrier();
722 			}
723 		}
724 		/* turn off DMA */
725 		out_le32(&dr->control, (RUN | PAUSE) << 16);
726 		stat = ld_le16(&cp->xfer_status);
727 		resid = ld_le16(&cp->res_count);
728 		if (intr & ERROR_INTR) {
729 			n = fs->scount - 1 - resid / 512;
730 			if (n > 0) {
731 				blk_update_request(fd_req, 0, n << 9);
732 				fs->req_sector += n;
733 			}
734 			if (fs->retries < 5) {
735 				++fs->retries;
736 				act(fs);
737 			} else {
738 				printk("swim3: error %sing block %ld (err=%x)\n",
739 				       rq_data_dir(fd_req) == WRITE? "writ": "read",
740 				       (long)blk_rq_pos(fd_req), err);
741 				swim3_end_request_cur(-EIO);
742 				fs->state = idle;
743 			}
744 		} else {
745 			if ((stat & ACTIVE) == 0 || resid != 0) {
746 				/* musta been an error */
747 				printk(KERN_ERR "swim3: fd dma: stat=%x resid=%d\n", stat, resid);
748 				printk(KERN_ERR "  state=%d, dir=%x, intr=%x, err=%x\n",
749 				       fs->state, rq_data_dir(fd_req), intr, err);
750 				swim3_end_request_cur(-EIO);
751 				fs->state = idle;
752 				start_request(fs);
753 				break;
754 			}
755 			if (swim3_end_request(0, fs->scount << 9)) {
756 				fs->req_sector += fs->scount;
757 				if (fs->req_sector > fs->secpertrack) {
758 					fs->req_sector -= fs->secpertrack;
759 					if (++fs->head > 1) {
760 						fs->head = 0;
761 						++fs->req_cyl;
762 					}
763 				}
764 				act(fs);
765 			} else
766 				fs->state = idle;
767 		}
768 		if (fs->state == idle)
769 			start_request(fs);
770 		break;
771 	default:
772 		printk(KERN_ERR "swim3: don't know what to do in state %d\n", fs->state);
773 	}
774 	return IRQ_HANDLED;
775 }
776 
777 /*
778 static void fd_dma_interrupt(int irq, void *dev_id)
779 {
780 }
781 */
782 
783 static int grab_drive(struct floppy_state *fs, enum swim_state state,
784 		      int interruptible)
785 {
786 	unsigned long flags;
787 
788 	spin_lock_irqsave(&fs->lock, flags);
789 	if (fs->state != idle) {
790 		++fs->wanted;
791 		while (fs->state != available) {
792 			if (interruptible && signal_pending(current)) {
793 				--fs->wanted;
794 				spin_unlock_irqrestore(&fs->lock, flags);
795 				return -EINTR;
796 			}
797 			interruptible_sleep_on(&fs->wait);
798 		}
799 		--fs->wanted;
800 	}
801 	fs->state = state;
802 	spin_unlock_irqrestore(&fs->lock, flags);
803 	return 0;
804 }
805 
806 static void release_drive(struct floppy_state *fs)
807 {
808 	unsigned long flags;
809 
810 	spin_lock_irqsave(&fs->lock, flags);
811 	fs->state = idle;
812 	start_request(fs);
813 	spin_unlock_irqrestore(&fs->lock, flags);
814 }
815 
816 static int fd_eject(struct floppy_state *fs)
817 {
818 	int err, n;
819 
820 	err = grab_drive(fs, ejecting, 1);
821 	if (err)
822 		return err;
823 	swim3_action(fs, EJECT);
824 	for (n = 20; n > 0; --n) {
825 		if (signal_pending(current)) {
826 			err = -EINTR;
827 			break;
828 		}
829 		swim3_select(fs, RELAX);
830 		schedule_timeout_interruptible(1);
831 		if (swim3_readbit(fs, DISK_IN) == 0)
832 			break;
833 	}
834 	swim3_select(fs, RELAX);
835 	udelay(150);
836 	fs->ejected = 1;
837 	release_drive(fs);
838 	return err;
839 }
840 
841 static struct floppy_struct floppy_type =
842 	{ 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,NULL };	/*  7 1.44MB 3.5"   */
843 
844 static int floppy_locked_ioctl(struct block_device *bdev, fmode_t mode,
845 			unsigned int cmd, unsigned long param)
846 {
847 	struct floppy_state *fs = bdev->bd_disk->private_data;
848 	int err;
849 
850 	if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
851 		return -EPERM;
852 
853 	if (fs->mdev->media_bay &&
854 	    check_media_bay(fs->mdev->media_bay) != MB_FD)
855 		return -ENXIO;
856 
857 	switch (cmd) {
858 	case FDEJECT:
859 		if (fs->ref_count != 1)
860 			return -EBUSY;
861 		err = fd_eject(fs);
862 		return err;
863 	case FDGETPRM:
864 	        if (copy_to_user((void __user *) param, &floppy_type,
865 				 sizeof(struct floppy_struct)))
866 			return -EFAULT;
867 		return 0;
868 	}
869 	return -ENOTTY;
870 }
871 
872 static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
873 				 unsigned int cmd, unsigned long param)
874 {
875 	int ret;
876 
877 	mutex_lock(&swim3_mutex);
878 	ret = floppy_locked_ioctl(bdev, mode, cmd, param);
879 	mutex_unlock(&swim3_mutex);
880 
881 	return ret;
882 }
883 
884 static int floppy_open(struct block_device *bdev, fmode_t mode)
885 {
886 	struct floppy_state *fs = bdev->bd_disk->private_data;
887 	struct swim3 __iomem *sw = fs->swim3;
888 	int n, err = 0;
889 
890 	if (fs->ref_count == 0) {
891 		if (fs->mdev->media_bay &&
892 		    check_media_bay(fs->mdev->media_bay) != MB_FD)
893 			return -ENXIO;
894 		out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
895 		out_8(&sw->control_bic, 0xff);
896 		out_8(&sw->mode, 0x95);
897 		udelay(10);
898 		out_8(&sw->intr_enable, 0);
899 		out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
900 		swim3_action(fs, MOTOR_ON);
901 		fs->write_prot = -1;
902 		fs->cur_cyl = -1;
903 		for (n = 0; n < 2 * HZ; ++n) {
904 			if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
905 				break;
906 			if (signal_pending(current)) {
907 				err = -EINTR;
908 				break;
909 			}
910 			swim3_select(fs, RELAX);
911 			schedule_timeout_interruptible(1);
912 		}
913 		if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
914 				 || swim3_readbit(fs, DISK_IN) == 0))
915 			err = -ENXIO;
916 		swim3_action(fs, SETMFM);
917 		swim3_select(fs, RELAX);
918 
919 	} else if (fs->ref_count == -1 || mode & FMODE_EXCL)
920 		return -EBUSY;
921 
922 	if (err == 0 && (mode & FMODE_NDELAY) == 0
923 	    && (mode & (FMODE_READ|FMODE_WRITE))) {
924 		check_disk_change(bdev);
925 		if (fs->ejected)
926 			err = -ENXIO;
927 	}
928 
929 	if (err == 0 && (mode & FMODE_WRITE)) {
930 		if (fs->write_prot < 0)
931 			fs->write_prot = swim3_readbit(fs, WRITE_PROT);
932 		if (fs->write_prot)
933 			err = -EROFS;
934 	}
935 
936 	if (err) {
937 		if (fs->ref_count == 0) {
938 			swim3_action(fs, MOTOR_OFF);
939 			out_8(&sw->control_bic, DRIVE_ENABLE | INTR_ENABLE);
940 			swim3_select(fs, RELAX);
941 		}
942 		return err;
943 	}
944 
945 	if (mode & FMODE_EXCL)
946 		fs->ref_count = -1;
947 	else
948 		++fs->ref_count;
949 
950 	return 0;
951 }
952 
953 static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
954 {
955 	int ret;
956 
957 	mutex_lock(&swim3_mutex);
958 	ret = floppy_open(bdev, mode);
959 	mutex_unlock(&swim3_mutex);
960 
961 	return ret;
962 }
963 
964 static int floppy_release(struct gendisk *disk, fmode_t mode)
965 {
966 	struct floppy_state *fs = disk->private_data;
967 	struct swim3 __iomem *sw = fs->swim3;
968 	mutex_lock(&swim3_mutex);
969 	if (fs->ref_count > 0 && --fs->ref_count == 0) {
970 		swim3_action(fs, MOTOR_OFF);
971 		out_8(&sw->control_bic, 0xff);
972 		swim3_select(fs, RELAX);
973 	}
974 	mutex_unlock(&swim3_mutex);
975 	return 0;
976 }
977 
978 static int floppy_check_change(struct gendisk *disk)
979 {
980 	struct floppy_state *fs = disk->private_data;
981 	return fs->ejected;
982 }
983 
984 static int floppy_revalidate(struct gendisk *disk)
985 {
986 	struct floppy_state *fs = disk->private_data;
987 	struct swim3 __iomem *sw;
988 	int ret, n;
989 
990 	if (fs->mdev->media_bay &&
991 	    check_media_bay(fs->mdev->media_bay) != MB_FD)
992 		return -ENXIO;
993 
994 	sw = fs->swim3;
995 	grab_drive(fs, revalidating, 0);
996 	out_8(&sw->intr_enable, 0);
997 	out_8(&sw->control_bis, DRIVE_ENABLE);
998 	swim3_action(fs, MOTOR_ON);	/* necessary? */
999 	fs->write_prot = -1;
1000 	fs->cur_cyl = -1;
1001 	mdelay(1);
1002 	for (n = HZ; n > 0; --n) {
1003 		if (swim3_readbit(fs, SEEK_COMPLETE))
1004 			break;
1005 		if (signal_pending(current))
1006 			break;
1007 		swim3_select(fs, RELAX);
1008 		schedule_timeout_interruptible(1);
1009 	}
1010 	ret = swim3_readbit(fs, SEEK_COMPLETE) == 0
1011 		|| swim3_readbit(fs, DISK_IN) == 0;
1012 	if (ret)
1013 		swim3_action(fs, MOTOR_OFF);
1014 	else {
1015 		fs->ejected = 0;
1016 		swim3_action(fs, SETMFM);
1017 	}
1018 	swim3_select(fs, RELAX);
1019 
1020 	release_drive(fs);
1021 	return ret;
1022 }
1023 
1024 static const struct block_device_operations floppy_fops = {
1025 	.open		= floppy_unlocked_open,
1026 	.release	= floppy_release,
1027 	.ioctl		= floppy_ioctl,
1028 	.media_changed	= floppy_check_change,
1029 	.revalidate_disk= floppy_revalidate,
1030 };
1031 
1032 static int swim3_add_device(struct macio_dev *mdev, int index)
1033 {
1034 	struct device_node *swim = mdev->ofdev.dev.of_node;
1035 	struct floppy_state *fs = &floppy_states[index];
1036 	int rc = -EBUSY;
1037 
1038 	/* Check & Request resources */
1039 	if (macio_resource_count(mdev) < 2) {
1040 		printk(KERN_WARNING "ifd%d: no address for %s\n",
1041 		       index, swim->full_name);
1042 		return -ENXIO;
1043 	}
1044 	if (macio_irq_count(mdev) < 2) {
1045 		printk(KERN_WARNING "fd%d: no intrs for device %s\n",
1046 			index, swim->full_name);
1047 	}
1048 	if (macio_request_resource(mdev, 0, "swim3 (mmio)")) {
1049 		printk(KERN_ERR "fd%d: can't request mmio resource for %s\n",
1050 		       index, swim->full_name);
1051 		return -EBUSY;
1052 	}
1053 	if (macio_request_resource(mdev, 1, "swim3 (dma)")) {
1054 		printk(KERN_ERR "fd%d: can't request dma resource for %s\n",
1055 		       index, swim->full_name);
1056 		macio_release_resource(mdev, 0);
1057 		return -EBUSY;
1058 	}
1059 	dev_set_drvdata(&mdev->ofdev.dev, fs);
1060 
1061 	if (mdev->media_bay == NULL)
1062 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 1);
1063 
1064 	memset(fs, 0, sizeof(*fs));
1065 	spin_lock_init(&fs->lock);
1066 	fs->state = idle;
1067 	fs->swim3 = (struct swim3 __iomem *)
1068 		ioremap(macio_resource_start(mdev, 0), 0x200);
1069 	if (fs->swim3 == NULL) {
1070 		printk("fd%d: couldn't map registers for %s\n",
1071 		       index, swim->full_name);
1072 		rc = -ENOMEM;
1073 		goto out_release;
1074 	}
1075 	fs->dma = (struct dbdma_regs __iomem *)
1076 		ioremap(macio_resource_start(mdev, 1), 0x200);
1077 	if (fs->dma == NULL) {
1078 		printk("fd%d: couldn't map DMA for %s\n",
1079 		       index, swim->full_name);
1080 		iounmap(fs->swim3);
1081 		rc = -ENOMEM;
1082 		goto out_release;
1083 	}
1084 	fs->swim3_intr = macio_irq(mdev, 0);
1085 	fs->dma_intr = macio_irq(mdev, 1);
1086 	fs->cur_cyl = -1;
1087 	fs->cur_sector = -1;
1088 	fs->secpercyl = 36;
1089 	fs->secpertrack = 18;
1090 	fs->total_secs = 2880;
1091 	fs->mdev = mdev;
1092 	init_waitqueue_head(&fs->wait);
1093 
1094 	fs->dma_cmd = (struct dbdma_cmd *) DBDMA_ALIGN(fs->dbdma_cmd_space);
1095 	memset(fs->dma_cmd, 0, 2 * sizeof(struct dbdma_cmd));
1096 	st_le16(&fs->dma_cmd[1].command, DBDMA_STOP);
1097 
1098 	if (request_irq(fs->swim3_intr, swim3_interrupt, 0, "SWIM3", fs)) {
1099 		printk(KERN_ERR "fd%d: couldn't request irq %d for %s\n",
1100 		       index, fs->swim3_intr, swim->full_name);
1101 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 0);
1102 		goto out_unmap;
1103 		return -EBUSY;
1104 	}
1105 /*
1106 	if (request_irq(fs->dma_intr, fd_dma_interrupt, 0, "SWIM3-dma", fs)) {
1107 		printk(KERN_ERR "Couldn't get irq %d for SWIM3 DMA",
1108 		       fs->dma_intr);
1109 		return -EBUSY;
1110 	}
1111 */
1112 
1113 	init_timer(&fs->timeout);
1114 
1115 	printk(KERN_INFO "fd%d: SWIM3 floppy controller %s\n", floppy_count,
1116 		mdev->media_bay ? "in media bay" : "");
1117 
1118 	return 0;
1119 
1120  out_unmap:
1121 	iounmap(fs->dma);
1122 	iounmap(fs->swim3);
1123 
1124  out_release:
1125 	macio_release_resource(mdev, 0);
1126 	macio_release_resource(mdev, 1);
1127 
1128 	return rc;
1129 }
1130 
1131 static int __devinit swim3_attach(struct macio_dev *mdev, const struct of_device_id *match)
1132 {
1133 	int i, rc;
1134 	struct gendisk *disk;
1135 
1136 	/* Add the drive */
1137 	rc = swim3_add_device(mdev, floppy_count);
1138 	if (rc)
1139 		return rc;
1140 
1141 	/* Now create the queue if not there yet */
1142 	if (swim3_queue == NULL) {
1143 		/* If we failed, there isn't much we can do as the driver is still
1144 		 * too dumb to remove the device, just bail out
1145 		 */
1146 		if (register_blkdev(FLOPPY_MAJOR, "fd"))
1147 			return 0;
1148 		swim3_queue = blk_init_queue(do_fd_request, &swim3_lock);
1149 		if (swim3_queue == NULL) {
1150 			unregister_blkdev(FLOPPY_MAJOR, "fd");
1151 			return 0;
1152 		}
1153 	}
1154 
1155 	/* Now register that disk. Same comment about failure handling */
1156 	i = floppy_count++;
1157 	disk = disks[i] = alloc_disk(1);
1158 	if (disk == NULL)
1159 		return 0;
1160 
1161 	disk->major = FLOPPY_MAJOR;
1162 	disk->first_minor = i;
1163 	disk->fops = &floppy_fops;
1164 	disk->private_data = &floppy_states[i];
1165 	disk->queue = swim3_queue;
1166 	disk->flags |= GENHD_FL_REMOVABLE;
1167 	sprintf(disk->disk_name, "fd%d", i);
1168 	set_capacity(disk, 2880);
1169 	add_disk(disk);
1170 
1171 	return 0;
1172 }
1173 
1174 static struct of_device_id swim3_match[] =
1175 {
1176 	{
1177 	.name		= "swim3",
1178 	},
1179 	{
1180 	.compatible	= "ohare-swim3"
1181 	},
1182 	{
1183 	.compatible	= "swim3"
1184 	},
1185 };
1186 
1187 static struct macio_driver swim3_driver =
1188 {
1189 	.driver = {
1190 		.name 		= "swim3",
1191 		.of_match_table	= swim3_match,
1192 	},
1193 	.probe		= swim3_attach,
1194 #if 0
1195 	.suspend	= swim3_suspend,
1196 	.resume		= swim3_resume,
1197 #endif
1198 };
1199 
1200 
1201 int swim3_init(void)
1202 {
1203 	macio_register_driver(&swim3_driver);
1204 	return 0;
1205 }
1206 
1207 module_init(swim3_init)
1208 
1209 MODULE_LICENSE("GPL");
1210 MODULE_AUTHOR("Paul Mackerras");
1211 MODULE_ALIAS_BLOCKDEV_MAJOR(FLOPPY_MAJOR);
1212