aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/mtd/maps/vmu-flash.c
blob: 4afc167731ef5e980383d0f442c9417ab58494f4 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615









                                               
                       



























































































































































































































































































































































































































































































































































































































                                                                               


                                                               




                                                                           
                                















































































































































































































                                                                            
/* vmu-flash.c
 * Driver for SEGA Dreamcast Visual Memory Unit
 *
 * Copyright (c) Adrian McMenamin 2002 - 2009
 * Copyright (c) Paul Mundt 2001
 *
 * Licensed under version 2 of the
 * GNU General Public Licence
 */
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/maple.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>

struct vmu_cache {
	unsigned char *buffer;		/* Cache */
	unsigned int block;		/* Which block was cached */
	unsigned long jiffies_atc;	/* When was it cached? */
	int valid;
};

struct mdev_part {
	struct maple_device *mdev;
	int partition;
};

struct vmupart {
	u16 user_blocks;
	u16 root_block;
	u16 numblocks;
	char *name;
	struct vmu_cache *pcache;
};

struct memcard {
	u16 tempA;
	u16 tempB;
	u32 partitions;
	u32 blocklen;
	u32 writecnt;
	u32 readcnt;
	u32 removeable;
	int partition;
	int read;
	unsigned char *blockread;
	struct vmupart *parts;
	struct mtd_info *mtd;
};

struct vmu_block {
	unsigned int num; /* block number */
	unsigned int ofs; /* block offset */
};

static struct vmu_block *ofs_to_block(unsigned long src_ofs,
	struct mtd_info *mtd, int partition)
{
	struct vmu_block *vblock;
	struct maple_device *mdev;
	struct memcard *card;
	struct mdev_part *mpart;
	int num;

	mpart = mtd->priv;
	mdev = mpart->mdev;
	card = maple_get_drvdata(mdev);

	if (src_ofs >= card->parts[partition].numblocks * card->blocklen)
		goto failed;

	num = src_ofs / card->blocklen;
	if (num > card->parts[partition].numblocks)
		goto failed;

	vblock = kmalloc(sizeof(struct vmu_block), GFP_KERNEL);
	if (!vblock)
		goto failed;

	vblock->num = num;
	vblock->ofs = src_ofs % card->blocklen;
	return vblock;

failed:
	return NULL;
}

/* Maple bus callback function for reads */
static void vmu_blockread(struct mapleq *mq)
{
	struct maple_device *mdev;
	struct memcard *card;

	mdev = mq->dev;
	card = maple_get_drvdata(mdev);
	/* copy the read in data */

	if (unlikely(!card->blockread))
		return;

	memcpy(card->blockread, mq->recvbuf->buf + 12,
		card->blocklen/card->readcnt);

}

/* Interface with maple bus to read blocks
 * caching the results so that other parts
 * of the driver can access block reads */
static int maple_vmu_read_block(unsigned int num, unsigned char *buf,
	struct mtd_info *mtd)
{
	struct memcard *card;
	struct mdev_part *mpart;
	struct maple_device *mdev;
	int partition, error = 0, x, wait;
	unsigned char *blockread = NULL;
	struct vmu_cache *pcache;
	__be32 sendbuf;

	mpart = mtd->priv;
	mdev = mpart->mdev;
	partition = mpart->partition;
	card = maple_get_drvdata(mdev);
	pcache = card->parts[partition].pcache;
	pcache->valid = 0;

	/* prepare the cache for this block */
	if (!pcache->buffer) {
		pcache->buffer = kmalloc(card->blocklen, GFP_KERNEL);
		if (!pcache->buffer) {
			dev_err(&mdev->dev, "VMU at (%d, %d) - read fails due"
				" to lack of memory\n", mdev->port,
				mdev->unit);
			error = -ENOMEM;
			goto outB;
		}
	}

	/*
	* Reads may be phased - again the hardware spec
	* supports this - though may not be any devices in
	* the wild that implement it, but we will here
	*/
	for (x = 0; x < card->readcnt; x++) {
		sendbuf = cpu_to_be32(partition << 24 | x << 16 | num);

		if (atomic_read(&mdev->busy) == 1) {
			wait_event_interruptible_timeout(mdev->maple_wait,
				atomic_read(&mdev->busy) == 0, HZ);
			if (atomic_read(&mdev->busy) == 1) {
				dev_notice(&mdev->dev, "VMU at (%d, %d)"
					" is busy\n", mdev->port, mdev->unit);
				error = -EAGAIN;
				goto outB;
			}
		}

		atomic_set(&mdev->busy, 1);
		blockread = kmalloc(card->blocklen/card->readcnt, GFP_KERNEL);
		if (!blockread) {
			error = -ENOMEM;
			atomic_set(&mdev->busy, 0);
			goto outB;
		}
		card->blockread = blockread;

		maple_getcond_callback(mdev, vmu_blockread, 0,
			MAPLE_FUNC_MEMCARD);
		error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
				MAPLE_COMMAND_BREAD, 2, &sendbuf);
		/* Very long timeouts seem to be needed when box is stressed */
		wait = wait_event_interruptible_timeout(mdev->maple_wait,
			(atomic_read(&mdev->busy) == 0 ||
			atomic_read(&mdev->busy) == 2), HZ * 3);
		/*
		* MTD layer does not handle hotplugging well
		* so have to return errors when VMU is unplugged
		* in the middle of a read (busy == 2)
		*/
		if (error || atomic_read(&mdev->busy) == 2) {
			if (atomic_read(&mdev->busy) == 2)
				error = -ENXIO;
			atomic_set(&mdev->busy, 0);
			card->blockread = NULL;
			goto outA;
		}
		if (wait == 0 || wait == -ERESTARTSYS) {
			card->blockread = NULL;
			atomic_set(&mdev->busy, 0);
			error = -EIO;
			list_del_init(&(mdev->mq->list));
			kfree(mdev->mq->sendbuf);
			mdev->mq->sendbuf = NULL;
			if (wait == -ERESTARTSYS) {
				dev_warn(&mdev->dev, "VMU read on (%d, %d)"
					" interrupted on block 0x%X\n",
					mdev->port, mdev->unit, num);
			} else
				dev_notice(&mdev->dev, "VMU read on (%d, %d)"
					" timed out on block 0x%X\n",
					mdev->port, mdev->unit, num);
			goto outA;
		}

		memcpy(buf + (card->blocklen/card->readcnt) * x, blockread,
			card->blocklen/card->readcnt);

		memcpy(pcache->buffer + (card->blocklen/card->readcnt) * x,
			card->blockread, card->blocklen/card->readcnt);
		card->blockread = NULL;
		pcache->block = num;
		pcache->jiffies_atc = jiffies;
		pcache->valid = 1;
		kfree(blockread);
	}

	return error;

outA:
	kfree(blockread);
outB:
	return error;
}

/* communicate with maple bus for phased writing */
static int maple_vmu_write_block(unsigned int num, const unsigned char *buf,
	struct mtd_info *mtd)
{
	struct memcard *card;
	struct mdev_part *mpart;
	struct maple_device *mdev;
	int partition, error, locking, x, phaselen, wait;
	__be32 *sendbuf;

	mpart = mtd->priv;
	mdev = mpart->mdev;
	partition = mpart->partition;
	card = maple_get_drvdata(mdev);

	phaselen = card->blocklen/card->writecnt;

	sendbuf = kmalloc(phaselen + 4, GFP_KERNEL);
	if (!sendbuf) {
		error = -ENOMEM;
		goto fail_nosendbuf;
	}
	for (x = 0; x < card->writecnt; x++) {
		sendbuf[0] = cpu_to_be32(partition << 24 | x << 16 | num);
		memcpy(&sendbuf[1], buf + phaselen * x, phaselen);
		/* wait until the device is not busy doing something else
		* or 1 second - which ever is longer */
		if (atomic_read(&mdev->busy) == 1) {
			wait_event_interruptible_timeout(mdev->maple_wait,
				atomic_read(&mdev->busy) == 0, HZ);
			if (atomic_read(&mdev->busy) == 1) {
				error = -EBUSY;
				dev_notice(&mdev->dev, "VMU write at (%d, %d)"
					"failed - device is busy\n",
					mdev->port, mdev->unit);
				goto fail_nolock;
			}
		}
		atomic_set(&mdev->busy, 1);

		locking = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
			MAPLE_COMMAND_BWRITE, phaselen / 4 + 2, sendbuf);
		wait = wait_event_interruptible_timeout(mdev->maple_wait,
			atomic_read(&mdev->busy) == 0, HZ/10);
		if (locking) {
			error = -EIO;
			atomic_set(&mdev->busy, 0);
			goto fail_nolock;
		}
		if (atomic_read(&mdev->busy) == 2) {
			atomic_set(&mdev->busy, 0);
		} else if (wait == 0 || wait == -ERESTARTSYS) {
			error = -EIO;
			dev_warn(&mdev->dev, "Write at (%d, %d) of block"
				" 0x%X at phase %d failed: could not"
				" communicate with VMU", mdev->port,
				mdev->unit, num, x);
			atomic_set(&mdev->busy, 0);
			kfree(mdev->mq->sendbuf);
			mdev->mq->sendbuf = NULL;
			list_del_init(&(mdev->mq->list));
			goto fail_nolock;
		}
	}
	kfree(sendbuf);

	return card->blocklen;

fail_nolock:
	kfree(sendbuf);
fail_nosendbuf:
	dev_err(&mdev->dev, "VMU (%d, %d): write failed\n", mdev->port,
		mdev->unit);
	return error;
}

/* mtd function to simulate reading byte by byte */
static unsigned char vmu_flash_read_char(unsigned long ofs, int *retval,
	struct mtd_info *mtd)
{
	struct vmu_block *vblock;
	struct memcard *card;
	struct mdev_part *mpart;
	struct maple_device *mdev;
	unsigned char *buf, ret;
	int partition, error;

	mpart = mtd->priv;
	mdev = mpart->mdev;
	partition = mpart->partition;
	card = maple_get_drvdata(mdev);
	*retval =  0;

	buf = kmalloc(card->blocklen, GFP_KERNEL);
	if (!buf) {
		*retval = 1;
		ret = -ENOMEM;
		goto finish;
	}

	vblock = ofs_to_block(ofs, mtd, partition);
	if (!vblock) {
		*retval = 3;
		ret = -ENOMEM;
		goto out_buf;
	}

	error = maple_vmu_read_block(vblock->num, buf, mtd);
	if (error) {
		ret = error;
		*retval = 2;
		goto out_vblock;
	}

	ret = buf[vblock->ofs];

out_vblock:
	kfree(vblock);
out_buf:
	kfree(buf);
finish:
	return ret;
}

/* mtd higher order function to read flash */
static int vmu_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
	size_t *retlen,  u_char *buf)
{
	struct maple_device *mdev;
	struct memcard *card;
	struct mdev_part *mpart;
	struct vmu_cache *pcache;
	struct vmu_block *vblock;
	int index = 0, retval, partition, leftover, numblocks;
	unsigned char cx;

	if (len < 1)
		return -EIO;

	mpart = mtd->priv;
	mdev = mpart->mdev;
	partition = mpart->partition;
	card = maple_get_drvdata(mdev);

	numblocks = card->parts[partition].numblocks;
	if (from + len > numblocks * card->blocklen)
		len = numblocks * card->blocklen - from;
	if (len == 0)
		return -EIO;
	/* Have we cached this bit already? */
	pcache = card->parts[partition].pcache;
	do {
		vblock =  ofs_to_block(from + index, mtd, partition);
		if (!vblock)
			return -ENOMEM;
		/* Have we cached this and is the cache valid and timely? */
		if (pcache->valid &&
			time_before(jiffies, pcache->jiffies_atc + HZ) &&
			(pcache->block == vblock->num)) {
			/* we have cached it, so do necessary copying */
			leftover = card->blocklen - vblock->ofs;
			if (vblock->ofs + len - index < card->blocklen) {
				/* only a bit of this block to copy */
				memcpy(buf + index,
					pcache->buffer + vblock->ofs,
					len - index);
				index = len;
			} else {
				/* otherwise copy remainder of whole block */
				memcpy(buf + index, pcache->buffer +
					vblock->ofs, leftover);
				index += leftover;
			}
		} else {
			/*
			* Not cached so read one byte -
			* but cache the rest of the block
			*/
			cx = vmu_flash_read_char(from + index, &retval, mtd);
			if (retval) {
				*retlen = index;
				kfree(vblock);
				return cx;
			}
			memset(buf + index, cx, 1);
			index++;
		}
		kfree(vblock);
	} while (len > index);
	*retlen = index;

	return 0;
}

static int vmu_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
	size_t *retlen, const u_char *buf)
{
	struct maple_device *mdev;
	struct memcard *card;
	struct mdev_part *mpart;
	int index = 0, partition, error = 0, numblocks;
	struct vmu_cache *pcache;
	struct vmu_block *vblock;
	unsigned char *buffer;

	mpart = mtd->priv;
	mdev = mpart->mdev;
	partition = mpart->partition;
	card = maple_get_drvdata(mdev);

	/* simple sanity checks */
	if (len < 1) {
		error = -EIO;
		goto failed;
	}
	numblocks = card->parts[partition].numblocks;
	if (to + len > numblocks * card->blocklen)
		len = numblocks * card->blocklen - to;
	if (len == 0) {
		error = -EIO;
		goto failed;
	}

	vblock = ofs_to_block(to, mtd, partition);
	if (!vblock) {
		error = -ENOMEM;
		goto failed;
	}

	buffer = kmalloc(card->blocklen, GFP_KERNEL);
	if (!buffer) {
		error = -ENOMEM;
		goto fail_buffer;
	}

	do {
		/* Read in the block we are to write to */
		error = maple_vmu_read_block(vblock->num, buffer, mtd);
		if (error)
			goto fail_io;

		do {
			buffer[vblock->ofs] = buf[index];
			vblock->ofs++;
			index++;
			if (index >= len)
				break;
		} while (vblock->ofs < card->blocklen);

		/* write out new buffer */
		error = maple_vmu_write_block(vblock->num, buffer, mtd);
		/* invalidate the cache */
		pcache = card->parts[partition].pcache;
		pcache->valid = 0;

		if (error != card->blocklen)
			goto fail_io;

		vblock->num++;
		vblock->ofs = 0;
	} while (len > index);

	kfree(buffer);
	*retlen = index;
	kfree(vblock);
	return 0;

fail_io:
	kfree(buffer);
fail_buffer:
	kfree(vblock);
failed:
	dev_err(&mdev->dev, "VMU write failing with error %d\n", error);
	return error;
}

static void vmu_flash_sync(struct mtd_info *mtd)
{
	/* Do nothing here */
}

/* Maple bus callback function to recursively query hardware details */
static void vmu_queryblocks(struct mapleq *mq)
{
	struct maple_device *mdev;
	unsigned short *res;
	struct memcard *card;
	__be32 partnum;
	struct vmu_cache *pcache;
	struct mdev_part *mpart;
	struct mtd_info *mtd_cur;
	struct vmupart *part_cur;
	int error;

	mdev = mq->dev;
	card = maple_get_drvdata(mdev);
	res = (unsigned short *) (mq->recvbuf->buf);
	card->tempA = res[12];
	card->tempB = res[6];

	dev_info(&mdev->dev, "VMU device at partition %d has %d user "
		"blocks with a root block at %d\n", card->partition,
		card->tempA, card->tempB);

	part_cur = &card->parts[card->partition];
	part_cur->user_blocks = card->tempA;
	part_cur->root_block = card->tempB;
	part_cur->numblocks = card->tempB + 1;
	part_cur->name = kmalloc(12, GFP_KERNEL);
	if (!part_cur->name)
		goto fail_name;

	sprintf(part_cur->name, "vmu%d.%d.%d",
		mdev->port, mdev->unit, card->partition);
	mtd_cur = &card->mtd[card->partition];
	mtd_cur->name = part_cur->name;
	mtd_cur->type = 8;
	mtd_cur->flags = MTD_WRITEABLE|MTD_NO_ERASE;
	mtd_cur->size = part_cur->numblocks * card->blocklen;
	mtd_cur->erasesize = card->blocklen;
	mtd_cur->write = vmu_flash_write;
	mtd_cur->read = vmu_flash_read;
	mtd_cur->sync = vmu_flash_sync;
	mtd_cur->writesize = card->blocklen;

	mpart = kmalloc(sizeof(struct mdev_part), GFP_KERNEL);
	if (!mpart)
		goto fail_mpart;

	mpart->mdev = mdev;
	mpart->partition = card->partition;
	mtd_cur->priv = mpart;
	mtd_cur->owner = THIS_MODULE;

	pcache = kzalloc(sizeof(struct vmu_cache), GFP_KERNEL);
	if (!pcache)
		goto fail_cache_create;
	part_cur->pcache = pcache;

	error = add_mtd_device(mtd_cur);
	if (error)
		goto fail_mtd_register;

	maple_getcond_callback(mdev, NULL, 0,
		MAPLE_FUNC_MEMCARD);

	/*
	* Set up a recursive call to the (probably theoretical)
	* second or more partition
	*/
	if (++card->partition < card->partitions) {
		partnum = cpu_to_be32(card->partition << 24);
		maple_getcond_callback(mdev, vmu_queryblocks, 0,
			MAPLE_FUNC_MEMCARD);
		maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
			MAPLE_COMMAND_GETMINFO, 2, &partnum);
	}
	return;

fail_mtd_register:
	dev_err(&mdev->dev, "Could not register maple device at (%d, %d)"
		"error is 0x%X\n", mdev->port, mdev->unit, error);
	for (error = 0; error <= card->partition; error++) {
		kfree(((card->parts)[error]).pcache);
		((card->parts)[error]).pcache = NULL;
	}
fail_cache_create:
fail_mpart:
	for (error = 0; error <= card->partition; error++) {
		kfree(((card->mtd)[error]).priv);
		((card->mtd)[error]).priv = NULL;
	}
	maple_getcond_callback(mdev, NULL, 0,
		MAPLE_FUNC_MEMCARD);
	kfree(part_cur->name);
fail_name:
	return;
}

/* Handles very basic info about the flash, queries for details */
static int __devinit vmu_connect(struct maple_device *mdev)
{
	unsigned long test_flash_data, basic_flash_data;
	int c, error;
	struct memcard *card;
	u32 partnum = 0;

	test_flash_data = be32_to_cpu(mdev->devinfo.function);
	/* Need to count how many bits are set - to find out which
	 * function_data element has details of the memory card
	 */
	c = hweight_long(test_flash_data);

	basic_flash_data = be32_to_cpu(mdev->devinfo.function_data[c - 1]);

	card = kmalloc(sizeof(struct memcard), GFP_KERNEL);
	if (!card) {
		error = -ENOMEM;
		goto fail_nomem;
	}

	card->partitions = (basic_flash_data >> 24 & 0xFF) + 1;
	card->blocklen = ((basic_flash_data >> 16 & 0xFF) + 1) << 5;
	card->writecnt = basic_flash_data >> 12 & 0xF;
	card->readcnt = basic_flash_data >> 8 & 0xF;
	card->removeable = basic_flash_data >> 7 & 1;

	card->partition = 0;

	/*
	* Not sure there are actually any multi-partition devices in the
	* real world, but the hardware supports them, so, so will we
	*/
	card->parts = kmalloc(sizeof(struct vmupart) * card->partitions,
		GFP_KERNEL);
	if (!card->parts) {
		error = -ENOMEM;
		goto fail_partitions;
	}

	card->mtd = kmalloc(sizeof(struct mtd_info) * card->partitions,
		GFP_KERNEL);
	if (!card->mtd) {
		error = -ENOMEM;
		goto fail_mtd_info;
	}

	maple_set_drvdata(mdev, card);

	/*
	* We want to trap meminfo not get cond
	* so set interval to zero, but rely on maple bus
	* driver to pass back the results of the meminfo
	*/
	maple_getcond_callback(mdev, vmu_queryblocks, 0,
		MAPLE_FUNC_MEMCARD);

	/* Make sure we are clear to go */
	if (atomic_read(&mdev->busy) == 1) {
		wait_event_interruptible_timeout(mdev->maple_wait,
			atomic_read(&mdev->busy) == 0, HZ);
		if (atomic_read(&mdev->busy) == 1) {
			dev_notice(&mdev->dev, "VMU at (%d, %d) is busy\n",
				mdev->port, mdev->unit);
			error = -EAGAIN;
			goto fail_device_busy;
		}
	}

	atomic_set(&mdev->busy, 1);

	/*
	* Set up the minfo call: vmu_queryblocks will handle
	* the information passed back
	*/
	error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
		MAPLE_COMMAND_GETMINFO, 2, &partnum);
	if (error) {
		dev_err(&mdev->dev, "Could not lock VMU at (%d, %d)"
			" error is 0x%X\n", mdev->port, mdev->unit, error);
		goto fail_mtd_info;
	}
	return 0;

fail_device_busy:
	kfree(card->mtd);
fail_mtd_info:
	kfree(card->parts);
fail_partitions:
	kfree(card);
fail_nomem:
	return error;
}

static void __devexit vmu_disconnect(struct maple_device *mdev)
{
	struct memcard *card;
	struct mdev_part *mpart;
	int x;

	mdev->callback = NULL;
	card = maple_get_drvdata(mdev);
	for (x = 0; x < card->partitions; x++) {
		mpart = ((card->mtd)[x]).priv;
		mpart->mdev = NULL;
		del_mtd_device(&((card->mtd)[x]));
		kfree(((card->parts)[x]).name);
	}
	kfree(card->parts);
	kfree(card->mtd);
	kfree(card);
}

/* Callback to handle eccentricities of both mtd subsystem
 * and general flakyness of Dreamcast VMUs
 */
static int vmu_can_unload(struct maple_device *mdev)
{
	struct memcard *card;
	int x;
	struct mtd_info *mtd;

	card = maple_get_drvdata(mdev);
	for (x = 0; x < card->partitions; x++) {
		mtd = &((card->mtd)[x]);
		if (mtd->usecount > 0)
			return 0;
	}
	return 1;
}

#define ERRSTR "VMU at (%d, %d) file error -"

static void vmu_file_error(struct maple_device *mdev, void *recvbuf)
{
	enum maple_file_errors error = ((int *)recvbuf)[1];

	switch (error) {

	case MAPLE_FILEERR_INVALID_PARTITION:
		dev_notice(&mdev->dev, ERRSTR " invalid partition number\n",
			mdev->port, mdev->unit);
		break;

	case MAPLE_FILEERR_PHASE_ERROR:
		dev_notice(&mdev->dev, ERRSTR " phase error\n",
			mdev->port, mdev->unit);
		break;

	case MAPLE_FILEERR_INVALID_BLOCK:
		dev_notice(&mdev->dev, ERRSTR " invalid block number\n",
			mdev->port, mdev->unit);
		break;

	case MAPLE_FILEERR_WRITE_ERROR:
		dev_notice(&mdev->dev, ERRSTR " write error\n",
			mdev->port, mdev->unit);
		break;

	case MAPLE_FILEERR_INVALID_WRITE_LENGTH:
		dev_notice(&mdev->dev, ERRSTR " invalid write length\n",
			mdev->port, mdev->unit);
		break;

	case MAPLE_FILEERR_BAD_CRC:
		dev_notice(&mdev->dev, ERRSTR " bad CRC\n",
			mdev->port, mdev->unit);
		break;

	default:
		dev_notice(&mdev->dev, ERRSTR " 0x%X\n",
			mdev->port, mdev->unit, error);
	}
}


static int __devinit probe_maple_vmu(struct device *dev)
{
	int error;
	struct maple_device *mdev = to_maple_dev(dev);
	struct maple_driver *mdrv = to_maple_driver(dev->driver);

	mdev->can_unload = vmu_can_unload;
	mdev->fileerr_handler = vmu_file_error;
	mdev->driver = mdrv;

	error = vmu_connect(mdev);
	if (error)
		return error;

	return 0;
}

static int __devexit remove_maple_vmu(struct device *dev)
{
	struct maple_device *mdev = to_maple_dev(dev);

	vmu_disconnect(mdev);
	return 0;
}

static struct maple_driver vmu_flash_driver = {
	.function =	MAPLE_FUNC_MEMCARD,
	.drv = {
		.name =		"Dreamcast_visual_memory",
		.probe =	probe_maple_vmu,
		.remove = 	__devexit_p(remove_maple_vmu),
	},
};

static int __init vmu_flash_map_init(void)
{
	return maple_driver_register(&vmu_flash_driver);
}

static void __exit vmu_flash_map_exit(void)
{
	maple_driver_unregister(&vmu_flash_driver);
}

module_init(vmu_flash_map_init);
module_exit(vmu_flash_map_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Adrian McMenamin");
MODULE_DESCRIPTION("Flash mapping for Sega Dreamcast visual memory");