xref: /openbmc/linux/drivers/mtd/maps/vmu-flash.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* vmu-flash.c
3  * Driver for SEGA Dreamcast Visual Memory Unit
4  *
5  * Copyright (c) Adrian McMenamin 2002 - 2009
6  * Copyright (c) Paul Mundt 2001
7  */
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/sched.h>
11 #include <linux/delay.h>
12 #include <linux/maple.h>
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/map.h>
15 
16 struct vmu_cache {
17 	unsigned char *buffer;		/* Cache */
18 	unsigned int block;		/* Which block was cached */
19 	unsigned long jiffies_atc;	/* When was it cached? */
20 	int valid;
21 };
22 
23 struct mdev_part {
24 	struct maple_device *mdev;
25 	int partition;
26 };
27 
28 struct vmupart {
29 	u16 user_blocks;
30 	u16 root_block;
31 	u16 numblocks;
32 	char *name;
33 	struct vmu_cache *pcache;
34 };
35 
36 struct memcard {
37 	u16 tempA;
38 	u16 tempB;
39 	u32 partitions;
40 	u32 blocklen;
41 	u32 writecnt;
42 	u32 readcnt;
43 	u32 removeable;
44 	int partition;
45 	int read;
46 	unsigned char *blockread;
47 	struct vmupart *parts;
48 	struct mtd_info *mtd;
49 };
50 
51 struct vmu_block {
52 	unsigned int num; /* block number */
53 	unsigned int ofs; /* block offset */
54 };
55 
56 static struct vmu_block *ofs_to_block(unsigned long src_ofs,
57 	struct mtd_info *mtd, int partition)
58 {
59 	struct vmu_block *vblock;
60 	struct maple_device *mdev;
61 	struct memcard *card;
62 	struct mdev_part *mpart;
63 	int num;
64 
65 	mpart = mtd->priv;
66 	mdev = mpart->mdev;
67 	card = maple_get_drvdata(mdev);
68 
69 	if (src_ofs >= card->parts[partition].numblocks * card->blocklen)
70 		goto failed;
71 
72 	num = src_ofs / card->blocklen;
73 	if (num > card->parts[partition].numblocks)
74 		goto failed;
75 
76 	vblock = kmalloc(sizeof(struct vmu_block), GFP_KERNEL);
77 	if (!vblock)
78 		goto failed;
79 
80 	vblock->num = num;
81 	vblock->ofs = src_ofs % card->blocklen;
82 	return vblock;
83 
84 failed:
85 	return NULL;
86 }
87 
88 /* Maple bus callback function for reads */
89 static void vmu_blockread(struct mapleq *mq)
90 {
91 	struct maple_device *mdev;
92 	struct memcard *card;
93 
94 	mdev = mq->dev;
95 	card = maple_get_drvdata(mdev);
96 	/* copy the read in data */
97 
98 	if (unlikely(!card->blockread))
99 		return;
100 
101 	memcpy(card->blockread, mq->recvbuf->buf + 12,
102 		card->blocklen/card->readcnt);
103 
104 }
105 
106 /* Interface with maple bus to read blocks
107  * caching the results so that other parts
108  * of the driver can access block reads */
109 static int maple_vmu_read_block(unsigned int num, unsigned char *buf,
110 	struct mtd_info *mtd)
111 {
112 	struct memcard *card;
113 	struct mdev_part *mpart;
114 	struct maple_device *mdev;
115 	int partition, error = 0, x, wait;
116 	unsigned char *blockread = NULL;
117 	struct vmu_cache *pcache;
118 	__be32 sendbuf;
119 
120 	mpart = mtd->priv;
121 	mdev = mpart->mdev;
122 	partition = mpart->partition;
123 	card = maple_get_drvdata(mdev);
124 	pcache = card->parts[partition].pcache;
125 	pcache->valid = 0;
126 
127 	/* prepare the cache for this block */
128 	if (!pcache->buffer) {
129 		pcache->buffer = kmalloc(card->blocklen, GFP_KERNEL);
130 		if (!pcache->buffer) {
131 			dev_err(&mdev->dev, "VMU at (%d, %d) - read fails due"
132 				" to lack of memory\n", mdev->port,
133 				mdev->unit);
134 			error = -ENOMEM;
135 			goto outB;
136 		}
137 	}
138 
139 	/*
140 	* Reads may be phased - again the hardware spec
141 	* supports this - though may not be any devices in
142 	* the wild that implement it, but we will here
143 	*/
144 	for (x = 0; x < card->readcnt; x++) {
145 		sendbuf = cpu_to_be32(partition << 24 | x << 16 | num);
146 
147 		if (atomic_read(&mdev->busy) == 1) {
148 			wait_event_interruptible_timeout(mdev->maple_wait,
149 				atomic_read(&mdev->busy) == 0, HZ);
150 			if (atomic_read(&mdev->busy) == 1) {
151 				dev_notice(&mdev->dev, "VMU at (%d, %d)"
152 					" is busy\n", mdev->port, mdev->unit);
153 				error = -EAGAIN;
154 				goto outB;
155 			}
156 		}
157 
158 		atomic_set(&mdev->busy, 1);
159 		blockread = kmalloc(card->blocklen/card->readcnt, GFP_KERNEL);
160 		if (!blockread) {
161 			error = -ENOMEM;
162 			atomic_set(&mdev->busy, 0);
163 			goto outB;
164 		}
165 		card->blockread = blockread;
166 
167 		maple_getcond_callback(mdev, vmu_blockread, 0,
168 			MAPLE_FUNC_MEMCARD);
169 		error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
170 				MAPLE_COMMAND_BREAD, 2, &sendbuf);
171 		/* Very long timeouts seem to be needed when box is stressed */
172 		wait = wait_event_interruptible_timeout(mdev->maple_wait,
173 			(atomic_read(&mdev->busy) == 0 ||
174 			atomic_read(&mdev->busy) == 2), HZ * 3);
175 		/*
176 		* MTD layer does not handle hotplugging well
177 		* so have to return errors when VMU is unplugged
178 		* in the middle of a read (busy == 2)
179 		*/
180 		if (error || atomic_read(&mdev->busy) == 2) {
181 			if (atomic_read(&mdev->busy) == 2)
182 				error = -ENXIO;
183 			atomic_set(&mdev->busy, 0);
184 			card->blockread = NULL;
185 			goto outA;
186 		}
187 		if (wait == 0 || wait == -ERESTARTSYS) {
188 			card->blockread = NULL;
189 			atomic_set(&mdev->busy, 0);
190 			error = -EIO;
191 			list_del_init(&(mdev->mq->list));
192 			kfree(mdev->mq->sendbuf);
193 			mdev->mq->sendbuf = NULL;
194 			if (wait == -ERESTARTSYS) {
195 				dev_warn(&mdev->dev, "VMU read on (%d, %d)"
196 					" interrupted on block 0x%X\n",
197 					mdev->port, mdev->unit, num);
198 			} else
199 				dev_notice(&mdev->dev, "VMU read on (%d, %d)"
200 					" timed out on block 0x%X\n",
201 					mdev->port, mdev->unit, num);
202 			goto outA;
203 		}
204 
205 		memcpy(buf + (card->blocklen/card->readcnt) * x, blockread,
206 			card->blocklen/card->readcnt);
207 
208 		memcpy(pcache->buffer + (card->blocklen/card->readcnt) * x,
209 			card->blockread, card->blocklen/card->readcnt);
210 		card->blockread = NULL;
211 		pcache->block = num;
212 		pcache->jiffies_atc = jiffies;
213 		pcache->valid = 1;
214 		kfree(blockread);
215 	}
216 
217 	return error;
218 
219 outA:
220 	kfree(blockread);
221 outB:
222 	return error;
223 }
224 
225 /* communicate with maple bus for phased writing */
226 static int maple_vmu_write_block(unsigned int num, const unsigned char *buf,
227 	struct mtd_info *mtd)
228 {
229 	struct memcard *card;
230 	struct mdev_part *mpart;
231 	struct maple_device *mdev;
232 	int partition, error, locking, x, phaselen, wait;
233 	__be32 *sendbuf;
234 
235 	mpart = mtd->priv;
236 	mdev = mpart->mdev;
237 	partition = mpart->partition;
238 	card = maple_get_drvdata(mdev);
239 
240 	phaselen = card->blocklen/card->writecnt;
241 
242 	sendbuf = kmalloc(phaselen + 4, GFP_KERNEL);
243 	if (!sendbuf) {
244 		error = -ENOMEM;
245 		goto fail_nosendbuf;
246 	}
247 	for (x = 0; x < card->writecnt; x++) {
248 		sendbuf[0] = cpu_to_be32(partition << 24 | x << 16 | num);
249 		memcpy(&sendbuf[1], buf + phaselen * x, phaselen);
250 		/* wait until the device is not busy doing something else
251 		* or 1 second - which ever is longer */
252 		if (atomic_read(&mdev->busy) == 1) {
253 			wait_event_interruptible_timeout(mdev->maple_wait,
254 				atomic_read(&mdev->busy) == 0, HZ);
255 			if (atomic_read(&mdev->busy) == 1) {
256 				error = -EBUSY;
257 				dev_notice(&mdev->dev, "VMU write at (%d, %d)"
258 					"failed - device is busy\n",
259 					mdev->port, mdev->unit);
260 				goto fail_nolock;
261 			}
262 		}
263 		atomic_set(&mdev->busy, 1);
264 
265 		locking = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
266 			MAPLE_COMMAND_BWRITE, phaselen / 4 + 2, sendbuf);
267 		wait = wait_event_interruptible_timeout(mdev->maple_wait,
268 			atomic_read(&mdev->busy) == 0, HZ/10);
269 		if (locking) {
270 			error = -EIO;
271 			atomic_set(&mdev->busy, 0);
272 			goto fail_nolock;
273 		}
274 		if (atomic_read(&mdev->busy) == 2) {
275 			atomic_set(&mdev->busy, 0);
276 		} else if (wait == 0 || wait == -ERESTARTSYS) {
277 			error = -EIO;
278 			dev_warn(&mdev->dev, "Write at (%d, %d) of block"
279 				" 0x%X at phase %d failed: could not"
280 				" communicate with VMU", mdev->port,
281 				mdev->unit, num, x);
282 			atomic_set(&mdev->busy, 0);
283 			kfree(mdev->mq->sendbuf);
284 			mdev->mq->sendbuf = NULL;
285 			list_del_init(&(mdev->mq->list));
286 			goto fail_nolock;
287 		}
288 	}
289 	kfree(sendbuf);
290 
291 	return card->blocklen;
292 
293 fail_nolock:
294 	kfree(sendbuf);
295 fail_nosendbuf:
296 	dev_err(&mdev->dev, "VMU (%d, %d): write failed\n", mdev->port,
297 		mdev->unit);
298 	return error;
299 }
300 
301 /* mtd function to simulate reading byte by byte */
302 static unsigned char vmu_flash_read_char(unsigned long ofs, int *retval,
303 	struct mtd_info *mtd)
304 {
305 	struct vmu_block *vblock;
306 	struct memcard *card;
307 	struct mdev_part *mpart;
308 	struct maple_device *mdev;
309 	unsigned char *buf, ret;
310 	int partition, error;
311 
312 	mpart = mtd->priv;
313 	mdev = mpart->mdev;
314 	partition = mpart->partition;
315 	card = maple_get_drvdata(mdev);
316 	*retval =  0;
317 
318 	buf = kmalloc(card->blocklen, GFP_KERNEL);
319 	if (!buf) {
320 		*retval = 1;
321 		ret = -ENOMEM;
322 		goto finish;
323 	}
324 
325 	vblock = ofs_to_block(ofs, mtd, partition);
326 	if (!vblock) {
327 		*retval = 3;
328 		ret = -ENOMEM;
329 		goto out_buf;
330 	}
331 
332 	error = maple_vmu_read_block(vblock->num, buf, mtd);
333 	if (error) {
334 		ret = error;
335 		*retval = 2;
336 		goto out_vblock;
337 	}
338 
339 	ret = buf[vblock->ofs];
340 
341 out_vblock:
342 	kfree(vblock);
343 out_buf:
344 	kfree(buf);
345 finish:
346 	return ret;
347 }
348 
349 /* mtd higher order function to read flash */
350 static int vmu_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
351 	size_t *retlen,  u_char *buf)
352 {
353 	struct maple_device *mdev;
354 	struct memcard *card;
355 	struct mdev_part *mpart;
356 	struct vmu_cache *pcache;
357 	struct vmu_block *vblock;
358 	int index = 0, retval, partition, leftover, numblocks;
359 	unsigned char cx;
360 
361 	mpart = mtd->priv;
362 	mdev = mpart->mdev;
363 	partition = mpart->partition;
364 	card = maple_get_drvdata(mdev);
365 
366 	numblocks = card->parts[partition].numblocks;
367 	if (from + len > numblocks * card->blocklen)
368 		len = numblocks * card->blocklen - from;
369 	if (len == 0)
370 		return -EIO;
371 	/* Have we cached this bit already? */
372 	pcache = card->parts[partition].pcache;
373 	do {
374 		vblock =  ofs_to_block(from + index, mtd, partition);
375 		if (!vblock)
376 			return -ENOMEM;
377 		/* Have we cached this and is the cache valid and timely? */
378 		if (pcache->valid &&
379 			time_before(jiffies, pcache->jiffies_atc + HZ) &&
380 			(pcache->block == vblock->num)) {
381 			/* we have cached it, so do necessary copying */
382 			leftover = card->blocklen - vblock->ofs;
383 			if (vblock->ofs + len - index < card->blocklen) {
384 				/* only a bit of this block to copy */
385 				memcpy(buf + index,
386 					pcache->buffer + vblock->ofs,
387 					len - index);
388 				index = len;
389 			} else {
390 				/* otherwise copy remainder of whole block */
391 				memcpy(buf + index, pcache->buffer +
392 					vblock->ofs, leftover);
393 				index += leftover;
394 			}
395 		} else {
396 			/*
397 			* Not cached so read one byte -
398 			* but cache the rest of the block
399 			*/
400 			cx = vmu_flash_read_char(from + index, &retval, mtd);
401 			if (retval) {
402 				*retlen = index;
403 				kfree(vblock);
404 				return cx;
405 			}
406 			memset(buf + index, cx, 1);
407 			index++;
408 		}
409 		kfree(vblock);
410 	} while (len > index);
411 	*retlen = index;
412 
413 	return 0;
414 }
415 
416 static int vmu_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
417 	size_t *retlen, const u_char *buf)
418 {
419 	struct maple_device *mdev;
420 	struct memcard *card;
421 	struct mdev_part *mpart;
422 	int index = 0, partition, error = 0, numblocks;
423 	struct vmu_cache *pcache;
424 	struct vmu_block *vblock;
425 	unsigned char *buffer;
426 
427 	mpart = mtd->priv;
428 	mdev = mpart->mdev;
429 	partition = mpart->partition;
430 	card = maple_get_drvdata(mdev);
431 
432 	numblocks = card->parts[partition].numblocks;
433 	if (to + len > numblocks * card->blocklen)
434 		len = numblocks * card->blocklen - to;
435 	if (len == 0) {
436 		error = -EIO;
437 		goto failed;
438 	}
439 
440 	vblock = ofs_to_block(to, mtd, partition);
441 	if (!vblock) {
442 		error = -ENOMEM;
443 		goto failed;
444 	}
445 
446 	buffer = kmalloc(card->blocklen, GFP_KERNEL);
447 	if (!buffer) {
448 		error = -ENOMEM;
449 		goto fail_buffer;
450 	}
451 
452 	do {
453 		/* Read in the block we are to write to */
454 		error = maple_vmu_read_block(vblock->num, buffer, mtd);
455 		if (error)
456 			goto fail_io;
457 
458 		do {
459 			buffer[vblock->ofs] = buf[index];
460 			vblock->ofs++;
461 			index++;
462 			if (index >= len)
463 				break;
464 		} while (vblock->ofs < card->blocklen);
465 
466 		/* write out new buffer */
467 		error = maple_vmu_write_block(vblock->num, buffer, mtd);
468 		/* invalidate the cache */
469 		pcache = card->parts[partition].pcache;
470 		pcache->valid = 0;
471 
472 		if (error != card->blocklen)
473 			goto fail_io;
474 
475 		vblock->num++;
476 		vblock->ofs = 0;
477 	} while (len > index);
478 
479 	kfree(buffer);
480 	*retlen = index;
481 	kfree(vblock);
482 	return 0;
483 
484 fail_io:
485 	kfree(buffer);
486 fail_buffer:
487 	kfree(vblock);
488 failed:
489 	dev_err(&mdev->dev, "VMU write failing with error %d\n", error);
490 	return error;
491 }
492 
493 static void vmu_flash_sync(struct mtd_info *mtd)
494 {
495 	/* Do nothing here */
496 }
497 
498 /* Maple bus callback function to recursively query hardware details */
499 static void vmu_queryblocks(struct mapleq *mq)
500 {
501 	struct maple_device *mdev;
502 	unsigned short *res;
503 	struct memcard *card;
504 	__be32 partnum;
505 	struct vmu_cache *pcache;
506 	struct mdev_part *mpart;
507 	struct mtd_info *mtd_cur;
508 	struct vmupart *part_cur;
509 	int error;
510 
511 	mdev = mq->dev;
512 	card = maple_get_drvdata(mdev);
513 	res = (unsigned short *) (mq->recvbuf->buf);
514 	card->tempA = res[12];
515 	card->tempB = res[6];
516 
517 	dev_info(&mdev->dev, "VMU device at partition %d has %d user "
518 		"blocks with a root block at %d\n", card->partition,
519 		card->tempA, card->tempB);
520 
521 	part_cur = &card->parts[card->partition];
522 	part_cur->user_blocks = card->tempA;
523 	part_cur->root_block = card->tempB;
524 	part_cur->numblocks = card->tempB + 1;
525 	part_cur->name = kmalloc(12, GFP_KERNEL);
526 	if (!part_cur->name)
527 		goto fail_name;
528 
529 	sprintf(part_cur->name, "vmu%d.%d.%d",
530 		mdev->port, mdev->unit, card->partition);
531 	mtd_cur = &card->mtd[card->partition];
532 	mtd_cur->name = part_cur->name;
533 	mtd_cur->type = 8;
534 	mtd_cur->flags = MTD_WRITEABLE|MTD_NO_ERASE;
535 	mtd_cur->size = part_cur->numblocks * card->blocklen;
536 	mtd_cur->erasesize = card->blocklen;
537 	mtd_cur->_write = vmu_flash_write;
538 	mtd_cur->_read = vmu_flash_read;
539 	mtd_cur->_sync = vmu_flash_sync;
540 	mtd_cur->writesize = card->blocklen;
541 
542 	mpart = kmalloc(sizeof(struct mdev_part), GFP_KERNEL);
543 	if (!mpart)
544 		goto fail_mpart;
545 
546 	mpart->mdev = mdev;
547 	mpart->partition = card->partition;
548 	mtd_cur->priv = mpart;
549 	mtd_cur->owner = THIS_MODULE;
550 
551 	pcache = kzalloc(sizeof(struct vmu_cache), GFP_KERNEL);
552 	if (!pcache)
553 		goto fail_cache_create;
554 	part_cur->pcache = pcache;
555 
556 	error = mtd_device_register(mtd_cur, NULL, 0);
557 	if (error)
558 		goto fail_mtd_register;
559 
560 	maple_getcond_callback(mdev, NULL, 0,
561 		MAPLE_FUNC_MEMCARD);
562 
563 	/*
564 	* Set up a recursive call to the (probably theoretical)
565 	* second or more partition
566 	*/
567 	if (++card->partition < card->partitions) {
568 		partnum = cpu_to_be32(card->partition << 24);
569 		maple_getcond_callback(mdev, vmu_queryblocks, 0,
570 			MAPLE_FUNC_MEMCARD);
571 		maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
572 			MAPLE_COMMAND_GETMINFO, 2, &partnum);
573 	}
574 	return;
575 
576 fail_mtd_register:
577 	dev_err(&mdev->dev, "Could not register maple device at (%d, %d)"
578 		"error is 0x%X\n", mdev->port, mdev->unit, error);
579 	for (error = 0; error <= card->partition; error++) {
580 		kfree(((card->parts)[error]).pcache);
581 		((card->parts)[error]).pcache = NULL;
582 	}
583 fail_cache_create:
584 fail_mpart:
585 	for (error = 0; error <= card->partition; error++) {
586 		kfree(((card->mtd)[error]).priv);
587 		((card->mtd)[error]).priv = NULL;
588 	}
589 	maple_getcond_callback(mdev, NULL, 0,
590 		MAPLE_FUNC_MEMCARD);
591 	kfree(part_cur->name);
592 fail_name:
593 	return;
594 }
595 
596 /* Handles very basic info about the flash, queries for details */
597 static int vmu_connect(struct maple_device *mdev)
598 {
599 	unsigned long test_flash_data, basic_flash_data;
600 	int c, error;
601 	struct memcard *card;
602 	u32 partnum = 0;
603 
604 	test_flash_data = be32_to_cpu(mdev->devinfo.function);
605 	/* Need to count how many bits are set - to find out which
606 	 * function_data element has details of the memory card
607 	 */
608 	c = hweight_long(test_flash_data);
609 
610 	basic_flash_data = be32_to_cpu(mdev->devinfo.function_data[c - 1]);
611 
612 	card = kmalloc(sizeof(struct memcard), GFP_KERNEL);
613 	if (!card) {
614 		error = -ENOMEM;
615 		goto fail_nomem;
616 	}
617 
618 	card->partitions = (basic_flash_data >> 24 & 0xFF) + 1;
619 	card->blocklen = ((basic_flash_data >> 16 & 0xFF) + 1) << 5;
620 	card->writecnt = basic_flash_data >> 12 & 0xF;
621 	card->readcnt = basic_flash_data >> 8 & 0xF;
622 	card->removeable = basic_flash_data >> 7 & 1;
623 
624 	card->partition = 0;
625 
626 	/*
627 	* Not sure there are actually any multi-partition devices in the
628 	* real world, but the hardware supports them, so, so will we
629 	*/
630 	card->parts = kmalloc_array(card->partitions, sizeof(struct vmupart),
631 				    GFP_KERNEL);
632 	if (!card->parts) {
633 		error = -ENOMEM;
634 		goto fail_partitions;
635 	}
636 
637 	card->mtd = kmalloc_array(card->partitions, sizeof(struct mtd_info),
638 				  GFP_KERNEL);
639 	if (!card->mtd) {
640 		error = -ENOMEM;
641 		goto fail_mtd_info;
642 	}
643 
644 	maple_set_drvdata(mdev, card);
645 
646 	/*
647 	* We want to trap meminfo not get cond
648 	* so set interval to zero, but rely on maple bus
649 	* driver to pass back the results of the meminfo
650 	*/
651 	maple_getcond_callback(mdev, vmu_queryblocks, 0,
652 		MAPLE_FUNC_MEMCARD);
653 
654 	/* Make sure we are clear to go */
655 	if (atomic_read(&mdev->busy) == 1) {
656 		wait_event_interruptible_timeout(mdev->maple_wait,
657 			atomic_read(&mdev->busy) == 0, HZ);
658 		if (atomic_read(&mdev->busy) == 1) {
659 			dev_notice(&mdev->dev, "VMU at (%d, %d) is busy\n",
660 				mdev->port, mdev->unit);
661 			error = -EAGAIN;
662 			goto fail_device_busy;
663 		}
664 	}
665 
666 	atomic_set(&mdev->busy, 1);
667 
668 	/*
669 	* Set up the minfo call: vmu_queryblocks will handle
670 	* the information passed back
671 	*/
672 	error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
673 		MAPLE_COMMAND_GETMINFO, 2, &partnum);
674 	if (error) {
675 		dev_err(&mdev->dev, "Could not lock VMU at (%d, %d)"
676 			" error is 0x%X\n", mdev->port, mdev->unit, error);
677 		goto fail_mtd_info;
678 	}
679 	return 0;
680 
681 fail_device_busy:
682 	kfree(card->mtd);
683 fail_mtd_info:
684 	kfree(card->parts);
685 fail_partitions:
686 	kfree(card);
687 fail_nomem:
688 	return error;
689 }
690 
691 static void vmu_disconnect(struct maple_device *mdev)
692 {
693 	struct memcard *card;
694 	struct mdev_part *mpart;
695 	int x;
696 
697 	mdev->callback = NULL;
698 	card = maple_get_drvdata(mdev);
699 	for (x = 0; x < card->partitions; x++) {
700 		mpart = ((card->mtd)[x]).priv;
701 		mpart->mdev = NULL;
702 		mtd_device_unregister(&((card->mtd)[x]));
703 		kfree(((card->parts)[x]).name);
704 	}
705 	kfree(card->parts);
706 	kfree(card->mtd);
707 	kfree(card);
708 }
709 
710 /* Callback to handle eccentricities of both mtd subsystem
711  * and general flakyness of Dreamcast VMUs
712  */
713 static int vmu_can_unload(struct maple_device *mdev)
714 {
715 	struct memcard *card;
716 	int x;
717 	struct mtd_info *mtd;
718 
719 	card = maple_get_drvdata(mdev);
720 	for (x = 0; x < card->partitions; x++) {
721 		mtd = &((card->mtd)[x]);
722 		if (mtd->usecount > 0)
723 			return 0;
724 	}
725 	return 1;
726 }
727 
728 #define ERRSTR "VMU at (%d, %d) file error -"
729 
730 static void vmu_file_error(struct maple_device *mdev, void *recvbuf)
731 {
732 	enum maple_file_errors error = ((int *)recvbuf)[1];
733 
734 	switch (error) {
735 
736 	case MAPLE_FILEERR_INVALID_PARTITION:
737 		dev_notice(&mdev->dev, ERRSTR " invalid partition number\n",
738 			mdev->port, mdev->unit);
739 		break;
740 
741 	case MAPLE_FILEERR_PHASE_ERROR:
742 		dev_notice(&mdev->dev, ERRSTR " phase error\n",
743 			mdev->port, mdev->unit);
744 		break;
745 
746 	case MAPLE_FILEERR_INVALID_BLOCK:
747 		dev_notice(&mdev->dev, ERRSTR " invalid block number\n",
748 			mdev->port, mdev->unit);
749 		break;
750 
751 	case MAPLE_FILEERR_WRITE_ERROR:
752 		dev_notice(&mdev->dev, ERRSTR " write error\n",
753 			mdev->port, mdev->unit);
754 		break;
755 
756 	case MAPLE_FILEERR_INVALID_WRITE_LENGTH:
757 		dev_notice(&mdev->dev, ERRSTR " invalid write length\n",
758 			mdev->port, mdev->unit);
759 		break;
760 
761 	case MAPLE_FILEERR_BAD_CRC:
762 		dev_notice(&mdev->dev, ERRSTR " bad CRC\n",
763 			mdev->port, mdev->unit);
764 		break;
765 
766 	default:
767 		dev_notice(&mdev->dev, ERRSTR " 0x%X\n",
768 			mdev->port, mdev->unit, error);
769 	}
770 }
771 
772 
773 static int probe_maple_vmu(struct device *dev)
774 {
775 	int error;
776 	struct maple_device *mdev = to_maple_dev(dev);
777 	struct maple_driver *mdrv = to_maple_driver(dev->driver);
778 
779 	mdev->can_unload = vmu_can_unload;
780 	mdev->fileerr_handler = vmu_file_error;
781 	mdev->driver = mdrv;
782 
783 	error = vmu_connect(mdev);
784 	if (error)
785 		return error;
786 
787 	return 0;
788 }
789 
790 static int remove_maple_vmu(struct device *dev)
791 {
792 	struct maple_device *mdev = to_maple_dev(dev);
793 
794 	vmu_disconnect(mdev);
795 	return 0;
796 }
797 
798 static struct maple_driver vmu_flash_driver = {
799 	.function =	MAPLE_FUNC_MEMCARD,
800 	.drv = {
801 		.name =		"Dreamcast_visual_memory",
802 		.probe =	probe_maple_vmu,
803 		.remove =	remove_maple_vmu,
804 	},
805 };
806 
807 static int __init vmu_flash_map_init(void)
808 {
809 	return maple_driver_register(&vmu_flash_driver);
810 }
811 
812 static void __exit vmu_flash_map_exit(void)
813 {
814 	maple_driver_unregister(&vmu_flash_driver);
815 }
816 
817 module_init(vmu_flash_map_init);
818 module_exit(vmu_flash_map_exit);
819 
820 MODULE_LICENSE("GPL");
821 MODULE_AUTHOR("Adrian McMenamin");
822 MODULE_DESCRIPTION("Flash mapping for Sega Dreamcast visual memory");
823