xref: /linux/drivers/block/swim3.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
20 #include <linux/stddef.h>
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/timer.h>
24 #include <linux/delay.h>
25 #include <linux/fd.h>
26 #include <linux/ioctl.h>
27 #include <linux/blkdev.h>
28 #include <linux/devfs_fs_kernel.h>
29 #include <linux/interrupt.h>
30 #include <linux/module.h>
31 #include <linux/spinlock.h>
32 #include <asm/io.h>
33 #include <asm/dbdma.h>
34 #include <asm/prom.h>
35 #include <asm/uaccess.h>
36 #include <asm/mediabay.h>
37 #include <asm/machdep.h>
38 #include <asm/pmac_feature.h>
39 
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 device_node*	media_bay; /* NULL when not in bay */
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(request_queue_t * 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, struct pt_regs *regs);
244 /*static void fd_dma_interrupt(int irq, void *dev_id, struct pt_regs *regs);*/
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 inode *inode, struct file *filp,
250 			unsigned int cmd, unsigned long param);
251 static int floppy_open(struct inode *inode, struct file *filp);
252 static int floppy_release(struct inode *inode, struct file *filp);
253 static int floppy_check_change(struct gendisk *disk);
254 static int floppy_revalidate(struct gendisk *disk);
255 static int swim3_add_device(struct device_node *swims);
256 int swim3_init(void);
257 
258 #ifndef CONFIG_PMAC_MEDIABAY
259 #define check_media_bay(which, what)	1
260 #endif
261 
262 static void swim3_select(struct floppy_state *fs, int sel)
263 {
264 	struct swim3 __iomem *sw = fs->swim3;
265 
266 	out_8(&sw->select, RELAX);
267 	if (sel & 8)
268 		out_8(&sw->control_bis, SELECT);
269 	else
270 		out_8(&sw->control_bic, SELECT);
271 	out_8(&sw->select, sel & CA_MASK);
272 }
273 
274 static void swim3_action(struct floppy_state *fs, int action)
275 {
276 	struct swim3 __iomem *sw = fs->swim3;
277 
278 	swim3_select(fs, action);
279 	udelay(1);
280 	out_8(&sw->select, sw->select | LSTRB);
281 	udelay(2);
282 	out_8(&sw->select, sw->select & ~LSTRB);
283 	udelay(1);
284 }
285 
286 static int swim3_readbit(struct floppy_state *fs, int bit)
287 {
288 	struct swim3 __iomem *sw = fs->swim3;
289 	int stat;
290 
291 	swim3_select(fs, bit);
292 	udelay(1);
293 	stat = in_8(&sw->status);
294 	return (stat & DATA) == 0;
295 }
296 
297 static void do_fd_request(request_queue_t * q)
298 {
299 	int i;
300 	for(i=0;i<floppy_count;i++)
301 	{
302 #ifdef CONFIG_PMAC_MEDIABAY
303 		if (floppy_states[i].media_bay &&
304 			check_media_bay(floppy_states[i].media_bay, MB_FD))
305 			continue;
306 #endif /* CONFIG_PMAC_MEDIABAY */
307 		start_request(&floppy_states[i]);
308 	}
309 }
310 
311 static void start_request(struct floppy_state *fs)
312 {
313 	struct request *req;
314 	unsigned long x;
315 
316 	if (fs->state == idle && fs->wanted) {
317 		fs->state = available;
318 		wake_up(&fs->wait);
319 		return;
320 	}
321 	while (fs->state == idle && (req = elv_next_request(swim3_queue))) {
322 #if 0
323 		printk("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%ld buf=%p\n",
324 		       req->rq_disk->disk_name, req->cmd,
325 		       (long)req->sector, req->nr_sectors, req->buffer);
326 		printk("           rq_status=%d errors=%d current_nr_sectors=%ld\n",
327 		       req->rq_status, req->errors, req->current_nr_sectors);
328 #endif
329 
330 		if (req->sector < 0 || req->sector >= fs->total_secs) {
331 			end_request(req, 0);
332 			continue;
333 		}
334 		if (req->current_nr_sectors == 0) {
335 			end_request(req, 1);
336 			continue;
337 		}
338 		if (fs->ejected) {
339 			end_request(req, 0);
340 			continue;
341 		}
342 
343 		if (rq_data_dir(req) == WRITE) {
344 			if (fs->write_prot < 0)
345 				fs->write_prot = swim3_readbit(fs, WRITE_PROT);
346 			if (fs->write_prot) {
347 				end_request(req, 0);
348 				continue;
349 			}
350 		}
351 
352 		/* Do not remove the cast. req->sector is now a sector_t and
353 		 * can be 64 bits, but it will never go past 32 bits for this
354 		 * driver anyway, so we can safely cast it down and not have
355 		 * to do a 64/32 division
356 		 */
357 		fs->req_cyl = ((long)req->sector) / fs->secpercyl;
358 		x = ((long)req->sector) % fs->secpercyl;
359 		fs->head = x / fs->secpertrack;
360 		fs->req_sector = x % fs->secpertrack + 1;
361 		fd_req = req;
362 		fs->state = do_transfer;
363 		fs->retries = 0;
364 
365 		act(fs);
366 	}
367 }
368 
369 static void set_timeout(struct floppy_state *fs, int nticks,
370 			void (*proc)(unsigned long))
371 {
372 	unsigned long flags;
373 
374 	spin_lock_irqsave(&fs->lock, flags);
375 	if (fs->timeout_pending)
376 		del_timer(&fs->timeout);
377 	fs->timeout.expires = jiffies + nticks;
378 	fs->timeout.function = proc;
379 	fs->timeout.data = (unsigned long) fs;
380 	add_timer(&fs->timeout);
381 	fs->timeout_pending = 1;
382 	spin_unlock_irqrestore(&fs->lock, flags);
383 }
384 
385 static inline void scan_track(struct floppy_state *fs)
386 {
387 	struct swim3 __iomem *sw = fs->swim3;
388 
389 	swim3_select(fs, READ_DATA_0);
390 	in_8(&sw->intr);		/* clear SEEN_SECTOR bit */
391 	in_8(&sw->error);
392 	out_8(&sw->intr_enable, SEEN_SECTOR);
393 	out_8(&sw->control_bis, DO_ACTION);
394 	/* enable intr when track found */
395 	set_timeout(fs, HZ, scan_timeout);	/* enable timeout */
396 }
397 
398 static inline void seek_track(struct floppy_state *fs, int n)
399 {
400 	struct swim3 __iomem *sw = fs->swim3;
401 
402 	if (n >= 0) {
403 		swim3_action(fs, SEEK_POSITIVE);
404 		sw->nseek = n;
405 	} else {
406 		swim3_action(fs, SEEK_NEGATIVE);
407 		sw->nseek = -n;
408 	}
409 	fs->expect_cyl = (fs->cur_cyl >= 0)? fs->cur_cyl + n: -1;
410 	swim3_select(fs, STEP);
411 	in_8(&sw->error);
412 	/* enable intr when seek finished */
413 	out_8(&sw->intr_enable, SEEK_DONE);
414 	out_8(&sw->control_bis, DO_SEEK);
415 	set_timeout(fs, 3*HZ, seek_timeout);	/* enable timeout */
416 	fs->settle_time = 0;
417 }
418 
419 static inline void init_dma(struct dbdma_cmd *cp, int cmd,
420 			    void *buf, int count)
421 {
422 	st_le16(&cp->req_count, count);
423 	st_le16(&cp->command, cmd);
424 	st_le32(&cp->phy_addr, virt_to_bus(buf));
425 	cp->xfer_status = 0;
426 }
427 
428 static inline void setup_transfer(struct floppy_state *fs)
429 {
430 	int n;
431 	struct swim3 __iomem *sw = fs->swim3;
432 	struct dbdma_cmd *cp = fs->dma_cmd;
433 	struct dbdma_regs __iomem *dr = fs->dma;
434 
435 	if (fd_req->current_nr_sectors <= 0) {
436 		printk(KERN_ERR "swim3: transfer 0 sectors?\n");
437 		return;
438 	}
439 	if (rq_data_dir(fd_req) == WRITE)
440 		n = 1;
441 	else {
442 		n = fs->secpertrack - fs->req_sector + 1;
443 		if (n > fd_req->current_nr_sectors)
444 			n = fd_req->current_nr_sectors;
445 	}
446 	fs->scount = n;
447 	swim3_select(fs, fs->head? READ_DATA_1: READ_DATA_0);
448 	out_8(&sw->sector, fs->req_sector);
449 	out_8(&sw->nsect, n);
450 	out_8(&sw->gap3, 0);
451 	out_le32(&dr->cmdptr, virt_to_bus(cp));
452 	if (rq_data_dir(fd_req) == WRITE) {
453 		/* Set up 3 dma commands: write preamble, data, postamble */
454 		init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));
455 		++cp;
456 		init_dma(cp, OUTPUT_MORE, fd_req->buffer, 512);
457 		++cp;
458 		init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));
459 	} else {
460 		init_dma(cp, INPUT_LAST, fd_req->buffer, n * 512);
461 	}
462 	++cp;
463 	out_le16(&cp->command, DBDMA_STOP);
464 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
465 	in_8(&sw->error);
466 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
467 	if (rq_data_dir(fd_req) == WRITE)
468 		out_8(&sw->control_bis, WRITE_SECTORS);
469 	in_8(&sw->intr);
470 	out_le32(&dr->control, (RUN << 16) | RUN);
471 	/* enable intr when transfer complete */
472 	out_8(&sw->intr_enable, TRANSFER_DONE);
473 	out_8(&sw->control_bis, DO_ACTION);
474 	set_timeout(fs, 2*HZ, xfer_timeout);	/* enable timeout */
475 }
476 
477 static void act(struct floppy_state *fs)
478 {
479 	for (;;) {
480 		switch (fs->state) {
481 		case idle:
482 			return;		/* XXX shouldn't get here */
483 
484 		case locating:
485 			if (swim3_readbit(fs, TRACK_ZERO)) {
486 				fs->cur_cyl = 0;
487 				if (fs->req_cyl == 0)
488 					fs->state = do_transfer;
489 				else
490 					fs->state = seeking;
491 				break;
492 			}
493 			scan_track(fs);
494 			return;
495 
496 		case seeking:
497 			if (fs->cur_cyl < 0) {
498 				fs->expect_cyl = -1;
499 				fs->state = locating;
500 				break;
501 			}
502 			if (fs->req_cyl == fs->cur_cyl) {
503 				printk("whoops, seeking 0\n");
504 				fs->state = do_transfer;
505 				break;
506 			}
507 			seek_track(fs, fs->req_cyl - fs->cur_cyl);
508 			return;
509 
510 		case settling:
511 			/* check for SEEK_COMPLETE after 30ms */
512 			fs->settle_time = (HZ + 32) / 33;
513 			set_timeout(fs, fs->settle_time, settle_timeout);
514 			return;
515 
516 		case do_transfer:
517 			if (fs->cur_cyl != fs->req_cyl) {
518 				if (fs->retries > 5) {
519 					end_request(fd_req, 0);
520 					fs->state = idle;
521 					return;
522 				}
523 				fs->state = seeking;
524 				break;
525 			}
526 			setup_transfer(fs);
527 			return;
528 
529 		case jogging:
530 			seek_track(fs, -5);
531 			return;
532 
533 		default:
534 			printk(KERN_ERR"swim3: unknown state %d\n", fs->state);
535 			return;
536 		}
537 	}
538 }
539 
540 static void scan_timeout(unsigned long data)
541 {
542 	struct floppy_state *fs = (struct floppy_state *) data;
543 	struct swim3 __iomem *sw = fs->swim3;
544 
545 	fs->timeout_pending = 0;
546 	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
547 	out_8(&sw->select, RELAX);
548 	out_8(&sw->intr_enable, 0);
549 	fs->cur_cyl = -1;
550 	if (fs->retries > 5) {
551 		end_request(fd_req, 0);
552 		fs->state = idle;
553 		start_request(fs);
554 	} else {
555 		fs->state = jogging;
556 		act(fs);
557 	}
558 }
559 
560 static void seek_timeout(unsigned long data)
561 {
562 	struct floppy_state *fs = (struct floppy_state *) data;
563 	struct swim3 __iomem *sw = fs->swim3;
564 
565 	fs->timeout_pending = 0;
566 	out_8(&sw->control_bic, DO_SEEK);
567 	out_8(&sw->select, RELAX);
568 	out_8(&sw->intr_enable, 0);
569 	printk(KERN_ERR "swim3: seek timeout\n");
570 	end_request(fd_req, 0);
571 	fs->state = idle;
572 	start_request(fs);
573 }
574 
575 static void settle_timeout(unsigned long data)
576 {
577 	struct floppy_state *fs = (struct floppy_state *) data;
578 	struct swim3 __iomem *sw = fs->swim3;
579 
580 	fs->timeout_pending = 0;
581 	if (swim3_readbit(fs, SEEK_COMPLETE)) {
582 		out_8(&sw->select, RELAX);
583 		fs->state = locating;
584 		act(fs);
585 		return;
586 	}
587 	out_8(&sw->select, RELAX);
588 	if (fs->settle_time < 2*HZ) {
589 		++fs->settle_time;
590 		set_timeout(fs, 1, settle_timeout);
591 		return;
592 	}
593 	printk(KERN_ERR "swim3: seek settle timeout\n");
594 	end_request(fd_req, 0);
595 	fs->state = idle;
596 	start_request(fs);
597 }
598 
599 static void xfer_timeout(unsigned long data)
600 {
601 	struct floppy_state *fs = (struct floppy_state *) data;
602 	struct swim3 __iomem *sw = fs->swim3;
603 	struct dbdma_regs __iomem *dr = fs->dma;
604 	struct dbdma_cmd *cp = fs->dma_cmd;
605 	unsigned long s;
606 	int n;
607 
608 	fs->timeout_pending = 0;
609 	out_le32(&dr->control, RUN << 16);
610 	/* We must wait a bit for dbdma to stop */
611 	for (n = 0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
612 		udelay(1);
613 	out_8(&sw->intr_enable, 0);
614 	out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
615 	out_8(&sw->select, RELAX);
616 	if (rq_data_dir(fd_req) == WRITE)
617 		++cp;
618 	if (ld_le16(&cp->xfer_status) != 0)
619 		s = fs->scount - ((ld_le16(&cp->res_count) + 511) >> 9);
620 	else
621 		s = 0;
622 	fd_req->sector += s;
623 	fd_req->current_nr_sectors -= s;
624 	printk(KERN_ERR "swim3: timeout %sing sector %ld\n",
625 	       (rq_data_dir(fd_req)==WRITE? "writ": "read"), (long)fd_req->sector);
626 	end_request(fd_req, 0);
627 	fs->state = idle;
628 	start_request(fs);
629 }
630 
631 static irqreturn_t swim3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
632 {
633 	struct floppy_state *fs = (struct floppy_state *) dev_id;
634 	struct swim3 __iomem *sw = fs->swim3;
635 	int intr, err, n;
636 	int stat, resid;
637 	struct dbdma_regs __iomem *dr;
638 	struct dbdma_cmd *cp;
639 
640 	intr = in_8(&sw->intr);
641 	err = (intr & ERROR_INTR)? in_8(&sw->error): 0;
642 	if ((intr & ERROR_INTR) && fs->state != do_transfer)
643 		printk(KERN_ERR "swim3_interrupt, state=%d, dir=%lx, intr=%x, err=%x\n",
644 		       fs->state, rq_data_dir(fd_req), intr, err);
645 	switch (fs->state) {
646 	case locating:
647 		if (intr & SEEN_SECTOR) {
648 			out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
649 			out_8(&sw->select, RELAX);
650 			out_8(&sw->intr_enable, 0);
651 			del_timer(&fs->timeout);
652 			fs->timeout_pending = 0;
653 			if (sw->ctrack == 0xff) {
654 				printk(KERN_ERR "swim3: seen sector but cyl=ff?\n");
655 				fs->cur_cyl = -1;
656 				if (fs->retries > 5) {
657 					end_request(fd_req, 0);
658 					fs->state = idle;
659 					start_request(fs);
660 				} else {
661 					fs->state = jogging;
662 					act(fs);
663 				}
664 				break;
665 			}
666 			fs->cur_cyl = sw->ctrack;
667 			fs->cur_sector = sw->csect;
668 			if (fs->expect_cyl != -1 && fs->expect_cyl != fs->cur_cyl)
669 				printk(KERN_ERR "swim3: expected cyl %d, got %d\n",
670 				       fs->expect_cyl, fs->cur_cyl);
671 			fs->state = do_transfer;
672 			act(fs);
673 		}
674 		break;
675 	case seeking:
676 	case jogging:
677 		if (sw->nseek == 0) {
678 			out_8(&sw->control_bic, DO_SEEK);
679 			out_8(&sw->select, RELAX);
680 			out_8(&sw->intr_enable, 0);
681 			del_timer(&fs->timeout);
682 			fs->timeout_pending = 0;
683 			if (fs->state == seeking)
684 				++fs->retries;
685 			fs->state = settling;
686 			act(fs);
687 		}
688 		break;
689 	case settling:
690 		out_8(&sw->intr_enable, 0);
691 		del_timer(&fs->timeout);
692 		fs->timeout_pending = 0;
693 		act(fs);
694 		break;
695 	case do_transfer:
696 		if ((intr & (ERROR_INTR | TRANSFER_DONE)) == 0)
697 			break;
698 		out_8(&sw->intr_enable, 0);
699 		out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
700 		out_8(&sw->select, RELAX);
701 		del_timer(&fs->timeout);
702 		fs->timeout_pending = 0;
703 		dr = fs->dma;
704 		cp = fs->dma_cmd;
705 		if (rq_data_dir(fd_req) == WRITE)
706 			++cp;
707 		/*
708 		 * Check that the main data transfer has finished.
709 		 * On writing, the swim3 sometimes doesn't use
710 		 * up all the bytes of the postamble, so we can still
711 		 * see DMA active here.  That doesn't matter as long
712 		 * as all the sector data has been transferred.
713 		 */
714 		if ((intr & ERROR_INTR) == 0 && cp->xfer_status == 0) {
715 			/* wait a little while for DMA to complete */
716 			for (n = 0; n < 100; ++n) {
717 				if (cp->xfer_status != 0)
718 					break;
719 				udelay(1);
720 				barrier();
721 			}
722 		}
723 		/* turn off DMA */
724 		out_le32(&dr->control, (RUN | PAUSE) << 16);
725 		stat = ld_le16(&cp->xfer_status);
726 		resid = ld_le16(&cp->res_count);
727 		if (intr & ERROR_INTR) {
728 			n = fs->scount - 1 - resid / 512;
729 			if (n > 0) {
730 				fd_req->sector += n;
731 				fd_req->current_nr_sectors -= n;
732 				fd_req->buffer += n * 512;
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)fd_req->sector, err);
742 				end_request(fd_req, 0);
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=%lx, intr=%x, err=%x\n",
750 				       fs->state, rq_data_dir(fd_req), intr, err);
751 				end_request(fd_req, 0);
752 				fs->state = idle;
753 				start_request(fs);
754 				break;
755 			}
756 			fd_req->sector += fs->scount;
757 			fd_req->current_nr_sectors -= fs->scount;
758 			fd_req->buffer += fs->scount * 512;
759 			if (fd_req->current_nr_sectors <= 0) {
760 				end_request(fd_req, 1);
761 				fs->state = idle;
762 			} else {
763 				fs->req_sector += fs->scount;
764 				if (fs->req_sector > fs->secpertrack) {
765 					fs->req_sector -= fs->secpertrack;
766 					if (++fs->head > 1) {
767 						fs->head = 0;
768 						++fs->req_cyl;
769 					}
770 				}
771 				act(fs);
772 			}
773 		}
774 		if (fs->state == idle)
775 			start_request(fs);
776 		break;
777 	default:
778 		printk(KERN_ERR "swim3: don't know what to do in state %d\n", fs->state);
779 	}
780 	return IRQ_HANDLED;
781 }
782 
783 /*
784 static void fd_dma_interrupt(int irq, void *dev_id, struct pt_regs *regs)
785 {
786 }
787 */
788 
789 static int grab_drive(struct floppy_state *fs, enum swim_state state,
790 		      int interruptible)
791 {
792 	unsigned long flags;
793 
794 	spin_lock_irqsave(&fs->lock, flags);
795 	if (fs->state != idle) {
796 		++fs->wanted;
797 		while (fs->state != available) {
798 			if (interruptible && signal_pending(current)) {
799 				--fs->wanted;
800 				spin_unlock_irqrestore(&fs->lock, flags);
801 				return -EINTR;
802 			}
803 			interruptible_sleep_on(&fs->wait);
804 		}
805 		--fs->wanted;
806 	}
807 	fs->state = state;
808 	spin_unlock_irqrestore(&fs->lock, flags);
809 	return 0;
810 }
811 
812 static void release_drive(struct floppy_state *fs)
813 {
814 	unsigned long flags;
815 
816 	spin_lock_irqsave(&fs->lock, flags);
817 	fs->state = idle;
818 	start_request(fs);
819 	spin_unlock_irqrestore(&fs->lock, flags);
820 }
821 
822 static int fd_eject(struct floppy_state *fs)
823 {
824 	int err, n;
825 
826 	err = grab_drive(fs, ejecting, 1);
827 	if (err)
828 		return err;
829 	swim3_action(fs, EJECT);
830 	for (n = 20; n > 0; --n) {
831 		if (signal_pending(current)) {
832 			err = -EINTR;
833 			break;
834 		}
835 		swim3_select(fs, RELAX);
836 		schedule_timeout_interruptible(1);
837 		if (swim3_readbit(fs, DISK_IN) == 0)
838 			break;
839 	}
840 	swim3_select(fs, RELAX);
841 	udelay(150);
842 	fs->ejected = 1;
843 	release_drive(fs);
844 	return err;
845 }
846 
847 static struct floppy_struct floppy_type =
848 	{ 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,NULL };	/*  7 1.44MB 3.5"   */
849 
850 static int floppy_ioctl(struct inode *inode, struct file *filp,
851 			unsigned int cmd, unsigned long param)
852 {
853 	struct floppy_state *fs = inode->i_bdev->bd_disk->private_data;
854 	int err;
855 
856 	if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
857 		return -EPERM;
858 
859 #ifdef CONFIG_PMAC_MEDIABAY
860 	if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
861 		return -ENXIO;
862 #endif
863 
864 	switch (cmd) {
865 	case FDEJECT:
866 		if (fs->ref_count != 1)
867 			return -EBUSY;
868 		err = fd_eject(fs);
869 		return err;
870 	case FDGETPRM:
871 	        if (copy_to_user((void __user *) param, &floppy_type,
872 				 sizeof(struct floppy_struct)))
873 			return -EFAULT;
874 		return 0;
875 	}
876 	return -ENOTTY;
877 }
878 
879 static int floppy_open(struct inode *inode, struct file *filp)
880 {
881 	struct floppy_state *fs = inode->i_bdev->bd_disk->private_data;
882 	struct swim3 __iomem *sw = fs->swim3;
883 	int n, err = 0;
884 
885 	if (fs->ref_count == 0) {
886 #ifdef CONFIG_PMAC_MEDIABAY
887 		if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
888 			return -ENXIO;
889 #endif
890 		out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
891 		out_8(&sw->control_bic, 0xff);
892 		out_8(&sw->mode, 0x95);
893 		udelay(10);
894 		out_8(&sw->intr_enable, 0);
895 		out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
896 		swim3_action(fs, MOTOR_ON);
897 		fs->write_prot = -1;
898 		fs->cur_cyl = -1;
899 		for (n = 0; n < 2 * HZ; ++n) {
900 			if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
901 				break;
902 			if (signal_pending(current)) {
903 				err = -EINTR;
904 				break;
905 			}
906 			swim3_select(fs, RELAX);
907 			schedule_timeout_interruptible(1);
908 		}
909 		if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
910 				 || swim3_readbit(fs, DISK_IN) == 0))
911 			err = -ENXIO;
912 		swim3_action(fs, SETMFM);
913 		swim3_select(fs, RELAX);
914 
915 	} else if (fs->ref_count == -1 || filp->f_flags & O_EXCL)
916 		return -EBUSY;
917 
918 	if (err == 0 && (filp->f_flags & O_NDELAY) == 0
919 	    && (filp->f_mode & 3)) {
920 		check_disk_change(inode->i_bdev);
921 		if (fs->ejected)
922 			err = -ENXIO;
923 	}
924 
925 	if (err == 0 && (filp->f_mode & 2)) {
926 		if (fs->write_prot < 0)
927 			fs->write_prot = swim3_readbit(fs, WRITE_PROT);
928 		if (fs->write_prot)
929 			err = -EROFS;
930 	}
931 
932 	if (err) {
933 		if (fs->ref_count == 0) {
934 			swim3_action(fs, MOTOR_OFF);
935 			out_8(&sw->control_bic, DRIVE_ENABLE | INTR_ENABLE);
936 			swim3_select(fs, RELAX);
937 		}
938 		return err;
939 	}
940 
941 	if (filp->f_flags & O_EXCL)
942 		fs->ref_count = -1;
943 	else
944 		++fs->ref_count;
945 
946 	return 0;
947 }
948 
949 static int floppy_release(struct inode *inode, struct file *filp)
950 {
951 	struct floppy_state *fs = inode->i_bdev->bd_disk->private_data;
952 	struct swim3 __iomem *sw = fs->swim3;
953 	if (fs->ref_count > 0 && --fs->ref_count == 0) {
954 		swim3_action(fs, MOTOR_OFF);
955 		out_8(&sw->control_bic, 0xff);
956 		swim3_select(fs, RELAX);
957 	}
958 	return 0;
959 }
960 
961 static int floppy_check_change(struct gendisk *disk)
962 {
963 	struct floppy_state *fs = disk->private_data;
964 	return fs->ejected;
965 }
966 
967 static int floppy_revalidate(struct gendisk *disk)
968 {
969 	struct floppy_state *fs = disk->private_data;
970 	struct swim3 __iomem *sw;
971 	int ret, n;
972 
973 #ifdef CONFIG_PMAC_MEDIABAY
974 	if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
975 		return -ENXIO;
976 #endif
977 
978 	sw = fs->swim3;
979 	grab_drive(fs, revalidating, 0);
980 	out_8(&sw->intr_enable, 0);
981 	out_8(&sw->control_bis, DRIVE_ENABLE);
982 	swim3_action(fs, MOTOR_ON);	/* necessary? */
983 	fs->write_prot = -1;
984 	fs->cur_cyl = -1;
985 	mdelay(1);
986 	for (n = HZ; n > 0; --n) {
987 		if (swim3_readbit(fs, SEEK_COMPLETE))
988 			break;
989 		if (signal_pending(current))
990 			break;
991 		swim3_select(fs, RELAX);
992 		schedule_timeout_interruptible(1);
993 	}
994 	ret = swim3_readbit(fs, SEEK_COMPLETE) == 0
995 		|| swim3_readbit(fs, DISK_IN) == 0;
996 	if (ret)
997 		swim3_action(fs, MOTOR_OFF);
998 	else {
999 		fs->ejected = 0;
1000 		swim3_action(fs, SETMFM);
1001 	}
1002 	swim3_select(fs, RELAX);
1003 
1004 	release_drive(fs);
1005 	return ret;
1006 }
1007 
1008 static struct block_device_operations floppy_fops = {
1009 	.open		= floppy_open,
1010 	.release	= floppy_release,
1011 	.ioctl		= floppy_ioctl,
1012 	.media_changed	= floppy_check_change,
1013 	.revalidate_disk= floppy_revalidate,
1014 };
1015 
1016 int swim3_init(void)
1017 {
1018 	struct device_node *swim;
1019 	int err = -ENOMEM;
1020 	int i;
1021 
1022 	devfs_mk_dir("floppy");
1023 
1024 	swim = find_devices("floppy");
1025 	while (swim && (floppy_count < MAX_FLOPPIES))
1026 	{
1027 		swim3_add_device(swim);
1028 		swim = swim->next;
1029 	}
1030 
1031 	swim = find_devices("swim3");
1032 	while (swim && (floppy_count < MAX_FLOPPIES))
1033 	{
1034 		swim3_add_device(swim);
1035 		swim = swim->next;
1036 	}
1037 
1038 	if (!floppy_count)
1039 		return -ENODEV;
1040 
1041 	for (i = 0; i < floppy_count; i++) {
1042 		disks[i] = alloc_disk(1);
1043 		if (!disks[i])
1044 			goto out;
1045 	}
1046 
1047 	if (register_blkdev(FLOPPY_MAJOR, "fd")) {
1048 		err = -EBUSY;
1049 		goto out;
1050 	}
1051 
1052 	swim3_queue = blk_init_queue(do_fd_request, &swim3_lock);
1053 	if (!swim3_queue) {
1054 		err = -ENOMEM;
1055 		goto out_queue;
1056 	}
1057 
1058 	for (i = 0; i < floppy_count; i++) {
1059 		struct gendisk *disk = disks[i];
1060 		disk->major = FLOPPY_MAJOR;
1061 		disk->first_minor = i;
1062 		disk->fops = &floppy_fops;
1063 		disk->private_data = &floppy_states[i];
1064 		disk->queue = swim3_queue;
1065 		disk->flags |= GENHD_FL_REMOVABLE;
1066 		sprintf(disk->disk_name, "fd%d", i);
1067 		sprintf(disk->devfs_name, "floppy/%d", i);
1068 		set_capacity(disk, 2880);
1069 		add_disk(disk);
1070 	}
1071 	return 0;
1072 
1073 out_queue:
1074 	unregister_blkdev(FLOPPY_MAJOR, "fd");
1075 out:
1076 	while (i--)
1077 		put_disk(disks[i]);
1078 	/* shouldn't we do something with results of swim_add_device()? */
1079 	return err;
1080 }
1081 
1082 static int swim3_add_device(struct device_node *swim)
1083 {
1084 	struct device_node *mediabay;
1085 	struct floppy_state *fs = &floppy_states[floppy_count];
1086 	struct resource res_reg, res_dma;
1087 
1088 	if (of_address_to_resource(swim, 0, &res_reg) ||
1089 	    of_address_to_resource(swim, 1, &res_dma)) {
1090 		printk(KERN_ERR "swim3: Can't get addresses\n");
1091 		return -EINVAL;
1092 	}
1093 	if (request_mem_region(res_reg.start, res_reg.end - res_reg.start + 1,
1094 			       " (reg)") == NULL) {
1095 		printk(KERN_ERR "swim3: Can't request register space\n");
1096 		return -EINVAL;
1097 	}
1098 	if (request_mem_region(res_dma.start, res_dma.end - res_dma.start + 1,
1099 			       " (dma)") == NULL) {
1100 		release_mem_region(res_reg.start,
1101 				   res_reg.end - res_reg.start + 1);
1102 		printk(KERN_ERR "swim3: Can't request DMA space\n");
1103 		return -EINVAL;
1104 	}
1105 
1106 	if (swim->n_intrs < 2) {
1107 		printk(KERN_INFO "swim3: expecting 2 intrs (n_intrs:%d)\n",
1108 		       swim->n_intrs);
1109 		release_mem_region(res_reg.start,
1110 				   res_reg.end - res_reg.start + 1);
1111 		release_mem_region(res_dma.start,
1112 				   res_dma.end - res_dma.start + 1);
1113 		return -EINVAL;
1114 	}
1115 
1116 	mediabay = (strcasecmp(swim->parent->type, "media-bay") == 0) ? swim->parent : NULL;
1117 	if (mediabay == NULL)
1118 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 1);
1119 
1120 	memset(fs, 0, sizeof(*fs));
1121 	spin_lock_init(&fs->lock);
1122 	fs->state = idle;
1123 	fs->swim3 = (struct swim3 __iomem *)ioremap(res_reg.start, 0x200);
1124 	fs->dma = (struct dbdma_regs __iomem *)ioremap(res_dma.start, 0x200);
1125 	fs->swim3_intr = swim->intrs[0].line;
1126 	fs->dma_intr = swim->intrs[1].line;
1127 	fs->cur_cyl = -1;
1128 	fs->cur_sector = -1;
1129 	fs->secpercyl = 36;
1130 	fs->secpertrack = 18;
1131 	fs->total_secs = 2880;
1132 	fs->media_bay = mediabay;
1133 	init_waitqueue_head(&fs->wait);
1134 
1135 	fs->dma_cmd = (struct dbdma_cmd *) DBDMA_ALIGN(fs->dbdma_cmd_space);
1136 	memset(fs->dma_cmd, 0, 2 * sizeof(struct dbdma_cmd));
1137 	st_le16(&fs->dma_cmd[1].command, DBDMA_STOP);
1138 
1139 	if (request_irq(fs->swim3_intr, swim3_interrupt, 0, "SWIM3", fs)) {
1140 		printk(KERN_ERR "Couldn't get irq %d for SWIM3\n", fs->swim3_intr);
1141 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 0);
1142 		return -EBUSY;
1143 	}
1144 /*
1145 	if (request_irq(fs->dma_intr, fd_dma_interrupt, 0, "SWIM3-dma", fs)) {
1146 		printk(KERN_ERR "Couldn't get irq %d for SWIM3 DMA",
1147 		       fs->dma_intr);
1148 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 0);
1149 		return -EBUSY;
1150 	}
1151 */
1152 
1153 	init_timer(&fs->timeout);
1154 
1155 	printk(KERN_INFO "fd%d: SWIM3 floppy controller %s\n", floppy_count,
1156 		mediabay ? "in media bay" : "");
1157 
1158 	floppy_count++;
1159 
1160 	return 0;
1161 }
1162 
1163 module_init(swim3_init)
1164 
1165 MODULE_LICENSE("GPL");
1166 MODULE_AUTHOR("Paul Mackerras");
1167 MODULE_ALIAS_BLOCKDEV_MAJOR(FLOPPY_MAJOR);
1168