mtdcore.c 15.1 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14
/*
 * Core registration and callback routines for MTD
 * drivers and users.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
15
#include <linux/err.h>
Linus Torvalds's avatar
Linus Torvalds committed
16 17 18 19
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/mtd/compatmac.h>
#include <linux/proc_fs.h>
20
#include <linux/idr.h>
Linus Torvalds's avatar
Linus Torvalds committed
21 22

#include <linux/mtd/mtd.h>
23
#include "internal.h"
Linus Torvalds's avatar
Linus Torvalds committed
24

25 26
#include "mtdcore.h"

27 28 29 30 31 32 33 34 35
static int mtd_cls_suspend(struct device *dev, pm_message_t state);
static int mtd_cls_resume(struct device *dev);

static struct class mtd_class = {
	.name = "mtd",
	.owner = THIS_MODULE,
	.suspend = mtd_cls_suspend,
	.resume = mtd_cls_resume,
};
David Brownell's avatar
David Brownell committed
36

37 38
static DEFINE_IDR(mtd_idr);

39
/* These are exported solely for the purpose of mtd_blkdevs.c. You
Linus Torvalds's avatar
Linus Torvalds committed
40
   should not use them for _anything_ else */
Ingo Molnar's avatar
Ingo Molnar committed
41
DEFINE_MUTEX(mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
42
EXPORT_SYMBOL_GPL(mtd_table_mutex);
43 44 45 46 47 48

struct mtd_info *__mtd_next_device(int i)
{
	return idr_get_next(&mtd_idr, &i);
}
EXPORT_SYMBOL_GPL(__mtd_next_device);
Linus Torvalds's avatar
Linus Torvalds committed
49 50 51

static LIST_HEAD(mtd_notifiers);

David Brownell's avatar
David Brownell committed
52 53 54 55 56 57 58 59 60 61 62 63

#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
#else
#define MTD_DEVT(index) 0
#endif

/* REVISIT once MTD uses the driver model better, whoever allocates
 * the mtd_info will probably want to use the release() hook...
 */
static void mtd_release(struct device *dev)
{
64
	dev_t index = MTD_DEVT(dev_to_mtd(dev)->index);
David Brownell's avatar
David Brownell committed
65 66

	/* remove /dev/mtdXro node if needed */
67
	if (index)
68 69 70 71 72 73
		device_destroy(&mtd_class, index + 1);
}

static int mtd_cls_suspend(struct device *dev, pm_message_t state)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
74 75

	if (mtd && mtd->suspend)
76 77 78 79 80 81 82 83 84
		return mtd->suspend(mtd);
	else
		return 0;
}

static int mtd_cls_resume(struct device *dev)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	
85
	if (mtd && mtd->resume)
86 87
		mtd->resume(mtd);
	return 0;
David Brownell's avatar
David Brownell committed
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
}

static ssize_t mtd_type_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	char *type;

	switch (mtd->type) {
	case MTD_ABSENT:
		type = "absent";
		break;
	case MTD_RAM:
		type = "ram";
		break;
	case MTD_ROM:
		type = "rom";
		break;
	case MTD_NORFLASH:
		type = "nor";
		break;
	case MTD_NANDFLASH:
		type = "nand";
		break;
	case MTD_DATAFLASH:
		type = "dataflash";
		break;
	case MTD_UBIVOLUME:
		type = "ubi";
		break;
	default:
		type = "unknown";
	}

	return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
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
static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);

static ssize_t mtd_flags_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);

}
static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);

static ssize_t mtd_size_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)mtd->size);

}
static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);

static ssize_t mtd_erasesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);

}
static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);

static ssize_t mtd_writesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);

}
static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);

167 168 169 170 171 172 173 174 175 176 177
static ssize_t mtd_subpagesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;

	return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);

}
static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);

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
static ssize_t mtd_oobsize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);

}
static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);

static ssize_t mtd_numeraseregions_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);

}
static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
	NULL);

static ssize_t mtd_name_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);

}
static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
David Brownell's avatar
David Brownell committed
208 209

static struct attribute *mtd_attrs[] = {
210 211 212 213 214
	&dev_attr_type.attr,
	&dev_attr_flags.attr,
	&dev_attr_size.attr,
	&dev_attr_erasesize.attr,
	&dev_attr_writesize.attr,
215
	&dev_attr_subpagesize.attr,
216 217 218
	&dev_attr_oobsize.attr,
	&dev_attr_numeraseregions.attr,
	&dev_attr_name.attr,
David Brownell's avatar
David Brownell committed
219 220 221
	NULL,
};

222
static struct attribute_group mtd_group = {
David Brownell's avatar
David Brownell committed
223 224 225
	.attrs		= mtd_attrs,
};

226
static const struct attribute_group *mtd_groups[] = {
David Brownell's avatar
David Brownell committed
227 228 229 230 231 232 233 234 235 236
	&mtd_group,
	NULL,
};

static struct device_type mtd_devtype = {
	.name		= "mtd",
	.groups		= mtd_groups,
	.release	= mtd_release,
};

Linus Torvalds's avatar
Linus Torvalds committed
237 238 239 240 241 242 243
/**
 *	add_mtd_device - register an MTD device
 *	@mtd: pointer to new MTD device info structure
 *
 *	Add a device to the list of MTD devices present in the system, and
 *	notify each currently active MTD 'user' of its arrival. Returns
 *	zero on success or 1 on failure, which currently will only happen
244
 *	if there is insufficient memory or a sysfs error.
Linus Torvalds's avatar
Linus Torvalds committed
245 246 247 248
 */

int add_mtd_device(struct mtd_info *mtd)
{
249 250
	struct mtd_notifier *not;
	int i, error;
Linus Torvalds's avatar
Linus Torvalds committed
251

252 253 254 255 256 257 258 259 260 261 262 263 264 265
	if (!mtd->backing_dev_info) {
		switch (mtd->type) {
		case MTD_RAM:
			mtd->backing_dev_info = &mtd_bdi_rw_mappable;
			break;
		case MTD_ROM:
			mtd->backing_dev_info = &mtd_bdi_ro_mappable;
			break;
		default:
			mtd->backing_dev_info = &mtd_bdi_unmappable;
			break;
		}
	}

266
	BUG_ON(mtd->writesize == 0);
Ingo Molnar's avatar
Ingo Molnar committed
267
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
268

269 270 271 272 273
	do {
		if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
			goto fail_locked;
		error = idr_get_new(&mtd_idr, mtd, &i);
	} while (error == -EAGAIN);
274

275 276
	if (error)
		goto fail_locked;
David Brownell's avatar
David Brownell committed
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
	mtd->index = i;
	mtd->usecount = 0;

	if (is_power_of_2(mtd->erasesize))
		mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
	else
		mtd->erasesize_shift = 0;

	if (is_power_of_2(mtd->writesize))
		mtd->writesize_shift = ffs(mtd->writesize) - 1;
	else
		mtd->writesize_shift = 0;

	mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
	mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;

	/* Some chips always power up locked. Unlock them now */
	if ((mtd->flags & MTD_WRITEABLE)
	    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
		if (mtd->unlock(mtd, 0, mtd->size))
			printk(KERN_WARNING
			       "%s: unlock failed, writes may not work\n",
			       mtd->name);
	}

	/* Caller should have set dev.parent to match the
	 * physical device.
	 */
	mtd->dev.type = &mtd_devtype;
	mtd->dev.class = &mtd_class;
	mtd->dev.devt = MTD_DEVT(i);
	dev_set_name(&mtd->dev, "mtd%d", i);
	dev_set_drvdata(&mtd->dev, mtd);
	if (device_register(&mtd->dev) != 0)
		goto fail_added;

	if (MTD_DEVT(i))
		device_create(&mtd_class, mtd->dev.parent,
			      MTD_DEVT(i) + 1,
			      NULL, "mtd%dro", i);

	DEBUG(0, "mtd: Giving out device %d to %s\n", i, mtd->name);
	/* No need to get a refcount on the module containing
	   the notifier, since we hold the mtd_table_mutex */
	list_for_each_entry(not, &mtd_notifiers, list)
		not->add(mtd);

	mutex_unlock(&mtd_table_mutex);
	/* We _know_ we aren't being removed, because
	   our caller is still holding us here. So none
	   of this try_ nonsense, and no bitching about it
	   either. :) */
	__module_get(THIS_MODULE);
	return 0;
332

333 334 335
fail_added:
	idr_remove(&mtd_idr, i);
fail_locked:
Ingo Molnar's avatar
Ingo Molnar committed
336
	mutex_unlock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352
	return 1;
}

/**
 *	del_mtd_device - unregister an MTD device
 *	@mtd: pointer to MTD device info structure
 *
 *	Remove a device from the list of MTD devices present in the system,
 *	and notify each currently active MTD 'user' of its departure.
 *	Returns zero on success or 1 on failure, which currently will happen
 *	if the requested device does not appear to be present in the list.
 */

int del_mtd_device (struct mtd_info *mtd)
{
	int ret;
353

Ingo Molnar's avatar
Ingo Molnar committed
354
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
355

356
	if (idr_find(&mtd_idr, mtd->index) != mtd) {
Linus Torvalds's avatar
Linus Torvalds committed
357 358
		ret = -ENODEV;
	} else if (mtd->usecount) {
359
		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
Linus Torvalds's avatar
Linus Torvalds committed
360 361 362
		       mtd->index, mtd->name, mtd->usecount);
		ret = -EBUSY;
	} else {
363
		struct mtd_notifier *not;
Linus Torvalds's avatar
Linus Torvalds committed
364

365 366
		device_unregister(&mtd->dev);

Linus Torvalds's avatar
Linus Torvalds committed
367 368
		/* No need to get a refcount on the module containing
		   the notifier, since we hold the mtd_table_mutex */
369
		list_for_each_entry(not, &mtd_notifiers, list)
Linus Torvalds's avatar
Linus Torvalds committed
370 371
			not->remove(mtd);

372
		idr_remove(&mtd_idr, mtd->index);
Linus Torvalds's avatar
Linus Torvalds committed
373 374 375 376 377

		module_put(THIS_MODULE);
		ret = 0;
	}

Ingo Molnar's avatar
Ingo Molnar committed
378
	mutex_unlock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
379 380 381 382 383 384 385 386 387 388 389 390 391 392
	return ret;
}

/**
 *	register_mtd_user - register a 'user' of MTD devices.
 *	@new: pointer to notifier info structure
 *
 *	Registers a pair of callbacks function to be called upon addition
 *	or removal of MTD devices. Causes the 'add' callback to be immediately
 *	invoked for each MTD device currently present in the system.
 */

void register_mtd_user (struct mtd_notifier *new)
{
393
	struct mtd_info *mtd;
Linus Torvalds's avatar
Linus Torvalds committed
394

Ingo Molnar's avatar
Ingo Molnar committed
395
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
396 397 398 399

	list_add(&new->list, &mtd_notifiers);

 	__module_get(THIS_MODULE);
400

401 402
	mtd_for_each_device(mtd)
		new->add(mtd);
Linus Torvalds's avatar
Linus Torvalds committed
403

Ingo Molnar's avatar
Ingo Molnar committed
404
	mutex_unlock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
405 406 407
}

/**
408 409
 *	unregister_mtd_user - unregister a 'user' of MTD devices.
 *	@old: pointer to notifier info structure
Linus Torvalds's avatar
Linus Torvalds committed
410 411 412 413 414 415 416 417 418
 *
 *	Removes a callback function pair from the list of 'users' to be
 *	notified upon addition or removal of MTD devices. Causes the
 *	'remove' callback to be immediately invoked for each MTD device
 *	currently present in the system.
 */

int unregister_mtd_user (struct mtd_notifier *old)
{
419
	struct mtd_info *mtd;
Linus Torvalds's avatar
Linus Torvalds committed
420

Ingo Molnar's avatar
Ingo Molnar committed
421
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
422 423 424

	module_put(THIS_MODULE);

425 426
	mtd_for_each_device(mtd)
		old->remove(mtd);
427

Linus Torvalds's avatar
Linus Torvalds committed
428
	list_del(&old->list);
Ingo Molnar's avatar
Ingo Molnar committed
429
	mutex_unlock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
430 431 432 433 434 435 436 437 438 439 440 441
	return 0;
}


/**
 *	get_mtd_device - obtain a validated handle for an MTD device
 *	@mtd: last known address of the required MTD device
 *	@num: internal device number of the required MTD device
 *
 *	Given a number and NULL address, return the num'th entry in the device
 *	table, if any.	Given an address and num == -1, search the device table
 *	for a device with that address and return if it's still present. Given
442 443
 *	both, return the num'th driver only if its address matches. Return
 *	error code if not.
Linus Torvalds's avatar
Linus Torvalds committed
444
 */
445

Linus Torvalds's avatar
Linus Torvalds committed
446 447
struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
448 449
	struct mtd_info *ret = NULL, *other;
	int err = -ENODEV;
Linus Torvalds's avatar
Linus Torvalds committed
450

Ingo Molnar's avatar
Ingo Molnar committed
451
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
452 453

	if (num == -1) {
454 455 456 457 458 459
		mtd_for_each_device(other) {
			if (other == mtd) {
				ret = mtd;
				break;
			}
		}
460 461
	} else if (num >= 0) {
		ret = idr_find(&mtd_idr, num);
Linus Torvalds's avatar
Linus Torvalds committed
462 463 464 465
		if (mtd && mtd != ret)
			ret = NULL;
	}

466 467 468
	if (!ret)
		goto out_unlock;

469
	if (!try_module_get(ret->owner))
470 471
		goto out_unlock;

472 473 474 475
	if (ret->get_device) {
		err = ret->get_device(ret);
		if (err)
			goto out_put;
476
	}
Linus Torvalds's avatar
Linus Torvalds committed
477

478
	ret->usecount++;
479 480
	mutex_unlock(&mtd_table_mutex);
	return ret;
Linus Torvalds's avatar
Linus Torvalds committed
481

482 483
out_put:
	module_put(ret->owner);
484
out_unlock:
Ingo Molnar's avatar
Ingo Molnar committed
485
	mutex_unlock(&mtd_table_mutex);
486
	return ERR_PTR(err);
Linus Torvalds's avatar
Linus Torvalds committed
487 488
}

489 490 491 492 493 494 495 496 497 498 499
/**
 *	get_mtd_device_nm - obtain a validated handle for an MTD device by
 *	device name
 *	@name: MTD device name to open
 *
 * 	This function returns MTD device description structure in case of
 * 	success and an error code in case of failure.
 */

struct mtd_info *get_mtd_device_nm(const char *name)
{
500 501
	int err = -ENODEV;
	struct mtd_info *mtd = NULL, *other;
502 503 504

	mutex_lock(&mtd_table_mutex);

505 506 507
	mtd_for_each_device(other) {
		if (!strcmp(name, other->name)) {
			mtd = other;
508 509 510 511
			break;
		}
	}

512
	if (!mtd)
513 514 515 516 517
		goto out_unlock;

	if (!try_module_get(mtd->owner))
		goto out_unlock;

518 519 520 521 522 523
	if (mtd->get_device) {
		err = mtd->get_device(mtd);
		if (err)
			goto out_put;
	}

524
	mtd->usecount++;
525 526
	mutex_unlock(&mtd_table_mutex);
	return mtd;
527

528 529
out_put:
	module_put(mtd->owner);
530 531
out_unlock:
	mutex_unlock(&mtd_table_mutex);
532
	return ERR_PTR(err);
533 534
}

Linus Torvalds's avatar
Linus Torvalds committed
535 536 537 538
void put_mtd_device(struct mtd_info *mtd)
{
	int c;

Ingo Molnar's avatar
Ingo Molnar committed
539
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
540
	c = --mtd->usecount;
541 542
	if (mtd->put_device)
		mtd->put_device(mtd);
Ingo Molnar's avatar
Ingo Molnar committed
543
	mutex_unlock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
544 545 546 547 548 549
	BUG_ON(c < 0);

	module_put(mtd->owner);
}

/* default_mtd_writev - default mtd writev method for MTD devices that
550
 *			don't implement their own
Linus Torvalds's avatar
Linus Torvalds committed
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
 */

int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
		       unsigned long count, loff_t to, size_t *retlen)
{
	unsigned long i;
	size_t totlen = 0, thislen;
	int ret = 0;

	if(!mtd->write) {
		ret = -EROFS;
	} else {
		for (i=0; i<count; i++) {
			if (!vecs[i].iov_len)
				continue;
			ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
			totlen += thislen;
			if (ret || thislen != vecs[i].iov_len)
				break;
			to += vecs[i].iov_len;
		}
	}
	if (retlen)
		*retlen = totlen;
	return ret;
}

578 579 580 581 582 583 584 585
EXPORT_SYMBOL_GPL(add_mtd_device);
EXPORT_SYMBOL_GPL(del_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
EXPORT_SYMBOL_GPL(put_mtd_device);
EXPORT_SYMBOL_GPL(register_mtd_user);
EXPORT_SYMBOL_GPL(unregister_mtd_user);
EXPORT_SYMBOL_GPL(default_mtd_writev);
Linus Torvalds's avatar
Linus Torvalds committed
586

587 588
#ifdef CONFIG_PROC_FS

Linus Torvalds's avatar
Linus Torvalds committed
589 590 591 592 593
/*====================================================================*/
/* Support for /proc/mtd */

static struct proc_dir_entry *proc_mtd;

594
static inline int mtd_proc_info(char *buf, struct mtd_info *this)
Linus Torvalds's avatar
Linus Torvalds committed
595
{
596
	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", this->index,
597
		       (unsigned long long)this->size,
Linus Torvalds's avatar
Linus Torvalds committed
598 599 600 601 602 603
		       this->erasesize, this->name);
}

static int mtd_read_proc (char *page, char **start, off_t off, int count,
			  int *eof, void *data_unused)
{
604 605
	struct mtd_info *mtd;
	int len, l;
Linus Torvalds's avatar
Linus Torvalds committed
606 607
        off_t   begin = 0;

Ingo Molnar's avatar
Ingo Molnar committed
608
	mutex_lock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
609 610

	len = sprintf(page, "dev:    size   erasesize  name\n");
611 612
	mtd_for_each_device(mtd) {
		l = mtd_proc_info(page + len, mtd);
Linus Torvalds's avatar
Linus Torvalds committed
613 614 615 616 617 618 619 620 621 622 623 624
                len += l;
                if (len+begin > off+count)
                        goto done;
                if (len+begin < off) {
                        begin += len;
                        len = 0;
                }
        }

        *eof = 1;

done:
Ingo Molnar's avatar
Ingo Molnar committed
625
	mutex_unlock(&mtd_table_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
626 627 628 629 630 631
        if (off >= len+begin)
                return 0;
        *start = page + (off-begin);
        return ((count < begin+len-off) ? count : begin+len-off);
}

632 633
#endif /* CONFIG_PROC_FS */

Linus Torvalds's avatar
Linus Torvalds committed
634 635 636 637 638
/*====================================================================*/
/* Init code */

static int __init init_mtd(void)
{
639 640
	int ret;
	ret = class_register(&mtd_class);
641

642 643 644
	if (ret) {
		pr_err("Error registering mtd class: %d\n", ret);
		return ret;
645
	}
646
#ifdef CONFIG_PROC_FS
Linus Torvalds's avatar
Linus Torvalds committed
647 648
	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
		proc_mtd->read_proc = mtd_read_proc;
649
#endif /* CONFIG_PROC_FS */
Linus Torvalds's avatar
Linus Torvalds committed
650 651 652 653 654
	return 0;
}

static void __exit cleanup_mtd(void)
{
655
#ifdef CONFIG_PROC_FS
Linus Torvalds's avatar
Linus Torvalds committed
656 657
        if (proc_mtd)
		remove_proc_entry( "mtd", NULL);
658
#endif /* CONFIG_PROC_FS */
659
	class_unregister(&mtd_class);
Linus Torvalds's avatar
Linus Torvalds committed
660 661 662 663 664 665 666 667
}

module_init(init_mtd);
module_exit(cleanup_mtd);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Core MTD registration and access routines");