xref: /linux/drivers/mtd/mtdchar.c (revision 42fda66387daa53538ae13a2c858396aaf037158)
1 /*
2  * $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $
3  *
4  * Character-device access to raw MTD devices.
5  *
6  */
7 
8 #include <linux/device.h>
9 #include <linux/fs.h>
10 #include <linux/mm.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
17 
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/compatmac.h>
20 
21 #include <asm/uaccess.h>
22 
23 static struct class *mtd_class;
24 
25 static void mtd_notify_add(struct mtd_info* mtd)
26 {
27 	if (!mtd)
28 		return;
29 
30 	class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
31 			    NULL, "mtd%d", mtd->index);
32 
33 	class_device_create(mtd_class, NULL,
34 			    MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
35 			    NULL, "mtd%dro", mtd->index);
36 }
37 
38 static void mtd_notify_remove(struct mtd_info* mtd)
39 {
40 	if (!mtd)
41 		return;
42 
43 	class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
44 	class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
45 }
46 
47 static struct mtd_notifier notifier = {
48 	.add	= mtd_notify_add,
49 	.remove	= mtd_notify_remove,
50 };
51 
52 /*
53  * Data structure to hold the pointer to the mtd device as well
54  * as mode information ofr various use cases.
55  */
56 struct mtd_file_info {
57 	struct mtd_info *mtd;
58 	enum mtd_file_modes mode;
59 };
60 
61 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
62 {
63 	struct mtd_file_info *mfi = file->private_data;
64 	struct mtd_info *mtd = mfi->mtd;
65 
66 	switch (orig) {
67 	case SEEK_SET:
68 		break;
69 	case SEEK_CUR:
70 		offset += file->f_pos;
71 		break;
72 	case SEEK_END:
73 		offset += mtd->size;
74 		break;
75 	default:
76 		return -EINVAL;
77 	}
78 
79 	if (offset >= 0 && offset <= mtd->size)
80 		return file->f_pos = offset;
81 
82 	return -EINVAL;
83 }
84 
85 
86 
87 static int mtd_open(struct inode *inode, struct file *file)
88 {
89 	int minor = iminor(inode);
90 	int devnum = minor >> 1;
91 	struct mtd_info *mtd;
92 	struct mtd_file_info *mfi;
93 
94 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
95 
96 	if (devnum >= MAX_MTD_DEVICES)
97 		return -ENODEV;
98 
99 	/* You can't open the RO devices RW */
100 	if ((file->f_mode & 2) && (minor & 1))
101 		return -EACCES;
102 
103 	mtd = get_mtd_device(NULL, devnum);
104 
105 	if (IS_ERR(mtd))
106 		return PTR_ERR(mtd);
107 
108 	if (MTD_ABSENT == mtd->type) {
109 		put_mtd_device(mtd);
110 		return -ENODEV;
111 	}
112 
113 	/* You can't open it RW if it's not a writeable device */
114 	if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
115 		put_mtd_device(mtd);
116 		return -EACCES;
117 	}
118 
119 	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
120 	if (!mfi) {
121 		put_mtd_device(mtd);
122 		return -ENOMEM;
123 	}
124 	mfi->mtd = mtd;
125 	file->private_data = mfi;
126 
127 	return 0;
128 } /* mtd_open */
129 
130 /*====================================================================*/
131 
132 static int mtd_close(struct inode *inode, struct file *file)
133 {
134 	struct mtd_file_info *mfi = file->private_data;
135 	struct mtd_info *mtd = mfi->mtd;
136 
137 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
138 
139 	/* Only sync if opened RW */
140 	if ((file->f_mode & 2) && mtd->sync)
141 		mtd->sync(mtd);
142 
143 	put_mtd_device(mtd);
144 	file->private_data = NULL;
145 	kfree(mfi);
146 
147 	return 0;
148 } /* mtd_close */
149 
150 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
151    userspace buffer down and use it directly with readv/writev.
152 */
153 #define MAX_KMALLOC_SIZE 0x20000
154 
155 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
156 {
157 	struct mtd_file_info *mfi = file->private_data;
158 	struct mtd_info *mtd = mfi->mtd;
159 	size_t retlen=0;
160 	size_t total_retlen=0;
161 	int ret=0;
162 	int len;
163 	char *kbuf;
164 
165 	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
166 
167 	if (*ppos + count > mtd->size)
168 		count = mtd->size - *ppos;
169 
170 	if (!count)
171 		return 0;
172 
173 	/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
174 	   and pass them directly to the MTD functions */
175 
176 	if (count > MAX_KMALLOC_SIZE)
177 		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
178 	else
179 		kbuf=kmalloc(count, GFP_KERNEL);
180 
181 	if (!kbuf)
182 		return -ENOMEM;
183 
184 	while (count) {
185 
186 		if (count > MAX_KMALLOC_SIZE)
187 			len = MAX_KMALLOC_SIZE;
188 		else
189 			len = count;
190 
191 		switch (mfi->mode) {
192 		case MTD_MODE_OTP_FACTORY:
193 			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
194 			break;
195 		case MTD_MODE_OTP_USER:
196 			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
197 			break;
198 		case MTD_MODE_RAW:
199 		{
200 			struct mtd_oob_ops ops;
201 
202 			ops.mode = MTD_OOB_RAW;
203 			ops.datbuf = kbuf;
204 			ops.oobbuf = NULL;
205 			ops.len = len;
206 
207 			ret = mtd->read_oob(mtd, *ppos, &ops);
208 			retlen = ops.retlen;
209 			break;
210 		}
211 		default:
212 			ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
213 		}
214 		/* Nand returns -EBADMSG on ecc errors, but it returns
215 		 * the data. For our userspace tools it is important
216 		 * to dump areas with ecc errors !
217 		 * For kernel internal usage it also might return -EUCLEAN
218 		 * to signal the caller that a bitflip has occured and has
219 		 * been corrected by the ECC algorithm.
220 		 * Userspace software which accesses NAND this way
221 		 * must be aware of the fact that it deals with NAND
222 		 */
223 		if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
224 			*ppos += retlen;
225 			if (copy_to_user(buf, kbuf, retlen)) {
226 				kfree(kbuf);
227 				return -EFAULT;
228 			}
229 			else
230 				total_retlen += retlen;
231 
232 			count -= retlen;
233 			buf += retlen;
234 			if (retlen == 0)
235 				count = 0;
236 		}
237 		else {
238 			kfree(kbuf);
239 			return ret;
240 		}
241 
242 	}
243 
244 	kfree(kbuf);
245 	return total_retlen;
246 } /* mtd_read */
247 
248 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
249 {
250 	struct mtd_file_info *mfi = file->private_data;
251 	struct mtd_info *mtd = mfi->mtd;
252 	char *kbuf;
253 	size_t retlen;
254 	size_t total_retlen=0;
255 	int ret=0;
256 	int len;
257 
258 	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
259 
260 	if (*ppos == mtd->size)
261 		return -ENOSPC;
262 
263 	if (*ppos + count > mtd->size)
264 		count = mtd->size - *ppos;
265 
266 	if (!count)
267 		return 0;
268 
269 	if (count > MAX_KMALLOC_SIZE)
270 		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
271 	else
272 		kbuf=kmalloc(count, GFP_KERNEL);
273 
274 	if (!kbuf)
275 		return -ENOMEM;
276 
277 	while (count) {
278 
279 		if (count > MAX_KMALLOC_SIZE)
280 			len = MAX_KMALLOC_SIZE;
281 		else
282 			len = count;
283 
284 		if (copy_from_user(kbuf, buf, len)) {
285 			kfree(kbuf);
286 			return -EFAULT;
287 		}
288 
289 		switch (mfi->mode) {
290 		case MTD_MODE_OTP_FACTORY:
291 			ret = -EROFS;
292 			break;
293 		case MTD_MODE_OTP_USER:
294 			if (!mtd->write_user_prot_reg) {
295 				ret = -EOPNOTSUPP;
296 				break;
297 			}
298 			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
299 			break;
300 
301 		case MTD_MODE_RAW:
302 		{
303 			struct mtd_oob_ops ops;
304 
305 			ops.mode = MTD_OOB_RAW;
306 			ops.datbuf = kbuf;
307 			ops.oobbuf = NULL;
308 			ops.len = len;
309 
310 			ret = mtd->write_oob(mtd, *ppos, &ops);
311 			retlen = ops.retlen;
312 			break;
313 		}
314 
315 		default:
316 			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
317 		}
318 		if (!ret) {
319 			*ppos += retlen;
320 			total_retlen += retlen;
321 			count -= retlen;
322 			buf += retlen;
323 		}
324 		else {
325 			kfree(kbuf);
326 			return ret;
327 		}
328 	}
329 
330 	kfree(kbuf);
331 	return total_retlen;
332 } /* mtd_write */
333 
334 /*======================================================================
335 
336     IOCTL calls for getting device parameters.
337 
338 ======================================================================*/
339 static void mtdchar_erase_callback (struct erase_info *instr)
340 {
341 	wake_up((wait_queue_head_t *)instr->priv);
342 }
343 
344 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
345 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
346 {
347 	struct mtd_info *mtd = mfi->mtd;
348 	int ret = 0;
349 
350 	switch (mode) {
351 	case MTD_OTP_FACTORY:
352 		if (!mtd->read_fact_prot_reg)
353 			ret = -EOPNOTSUPP;
354 		else
355 			mfi->mode = MTD_MODE_OTP_FACTORY;
356 		break;
357 	case MTD_OTP_USER:
358 		if (!mtd->read_fact_prot_reg)
359 			ret = -EOPNOTSUPP;
360 		else
361 			mfi->mode = MTD_MODE_OTP_USER;
362 		break;
363 	default:
364 		ret = -EINVAL;
365 	case MTD_OTP_OFF:
366 		break;
367 	}
368 	return ret;
369 }
370 #else
371 # define otp_select_filemode(f,m)	-EOPNOTSUPP
372 #endif
373 
374 static int mtd_ioctl(struct inode *inode, struct file *file,
375 		     u_int cmd, u_long arg)
376 {
377 	struct mtd_file_info *mfi = file->private_data;
378 	struct mtd_info *mtd = mfi->mtd;
379 	void __user *argp = (void __user *)arg;
380 	int ret = 0;
381 	u_long size;
382 	struct mtd_info_user info;
383 
384 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
385 
386 	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
387 	if (cmd & IOC_IN) {
388 		if (!access_ok(VERIFY_READ, argp, size))
389 			return -EFAULT;
390 	}
391 	if (cmd & IOC_OUT) {
392 		if (!access_ok(VERIFY_WRITE, argp, size))
393 			return -EFAULT;
394 	}
395 
396 	switch (cmd) {
397 	case MEMGETREGIONCOUNT:
398 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
399 			return -EFAULT;
400 		break;
401 
402 	case MEMGETREGIONINFO:
403 	{
404 		struct region_info_user ur;
405 
406 		if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
407 			return -EFAULT;
408 
409 		if (ur.regionindex >= mtd->numeraseregions)
410 			return -EINVAL;
411 		if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
412 				sizeof(struct mtd_erase_region_info)))
413 			return -EFAULT;
414 		break;
415 	}
416 
417 	case MEMGETINFO:
418 		info.type	= mtd->type;
419 		info.flags	= mtd->flags;
420 		info.size	= mtd->size;
421 		info.erasesize	= mtd->erasesize;
422 		info.writesize	= mtd->writesize;
423 		info.oobsize	= mtd->oobsize;
424 		/* The below fields are obsolete */
425 		info.ecctype	= -1;
426 		info.eccsize	= 0;
427 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
428 			return -EFAULT;
429 		break;
430 
431 	case MEMERASE:
432 	{
433 		struct erase_info *erase;
434 
435 		if(!(file->f_mode & 2))
436 			return -EPERM;
437 
438 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
439 		if (!erase)
440 			ret = -ENOMEM;
441 		else {
442 			wait_queue_head_t waitq;
443 			DECLARE_WAITQUEUE(wait, current);
444 
445 			init_waitqueue_head(&waitq);
446 
447 			if (copy_from_user(&erase->addr, argp,
448 				    sizeof(struct erase_info_user))) {
449 				kfree(erase);
450 				return -EFAULT;
451 			}
452 			erase->mtd = mtd;
453 			erase->callback = mtdchar_erase_callback;
454 			erase->priv = (unsigned long)&waitq;
455 
456 			/*
457 			  FIXME: Allow INTERRUPTIBLE. Which means
458 			  not having the wait_queue head on the stack.
459 
460 			  If the wq_head is on the stack, and we
461 			  leave because we got interrupted, then the
462 			  wq_head is no longer there when the
463 			  callback routine tries to wake us up.
464 			*/
465 			ret = mtd->erase(mtd, erase);
466 			if (!ret) {
467 				set_current_state(TASK_UNINTERRUPTIBLE);
468 				add_wait_queue(&waitq, &wait);
469 				if (erase->state != MTD_ERASE_DONE &&
470 				    erase->state != MTD_ERASE_FAILED)
471 					schedule();
472 				remove_wait_queue(&waitq, &wait);
473 				set_current_state(TASK_RUNNING);
474 
475 				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
476 			}
477 			kfree(erase);
478 		}
479 		break;
480 	}
481 
482 	case MEMWRITEOOB:
483 	{
484 		struct mtd_oob_buf buf;
485 		struct mtd_oob_ops ops;
486 
487 		if(!(file->f_mode & 2))
488 			return -EPERM;
489 
490 		if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
491 			return -EFAULT;
492 
493 		if (buf.length > 4096)
494 			return -EINVAL;
495 
496 		if (!mtd->write_oob)
497 			ret = -EOPNOTSUPP;
498 		else
499 			ret = access_ok(VERIFY_READ, buf.ptr,
500 					buf.length) ? 0 : EFAULT;
501 
502 		if (ret)
503 			return ret;
504 
505 		ops.ooblen = buf.length;
506 		ops.ooboffs = buf.start & (mtd->oobsize - 1);
507 		ops.datbuf = NULL;
508 		ops.mode = MTD_OOB_PLACE;
509 
510 		if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
511 			return -EINVAL;
512 
513 		ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
514 		if (!ops.oobbuf)
515 			return -ENOMEM;
516 
517 		if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
518 			kfree(ops.oobbuf);
519 			return -EFAULT;
520 		}
521 
522 		buf.start &= ~(mtd->oobsize - 1);
523 		ret = mtd->write_oob(mtd, buf.start, &ops);
524 
525 		if (copy_to_user(argp + sizeof(uint32_t), &ops.oobretlen,
526 				 sizeof(uint32_t)))
527 			ret = -EFAULT;
528 
529 		kfree(ops.oobbuf);
530 		break;
531 
532 	}
533 
534 	case MEMREADOOB:
535 	{
536 		struct mtd_oob_buf buf;
537 		struct mtd_oob_ops ops;
538 
539 		if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
540 			return -EFAULT;
541 
542 		if (buf.length > 4096)
543 			return -EINVAL;
544 
545 		if (!mtd->read_oob)
546 			ret = -EOPNOTSUPP;
547 		else
548 			ret = access_ok(VERIFY_WRITE, buf.ptr,
549 					buf.length) ? 0 : -EFAULT;
550 		if (ret)
551 			return ret;
552 
553 		ops.ooblen = buf.length;
554 		ops.ooboffs = buf.start & (mtd->oobsize - 1);
555 		ops.datbuf = NULL;
556 		ops.mode = MTD_OOB_PLACE;
557 
558 		if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
559 			return -EINVAL;
560 
561 		ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
562 		if (!ops.oobbuf)
563 			return -ENOMEM;
564 
565 		buf.start &= ~(mtd->oobsize - 1);
566 		ret = mtd->read_oob(mtd, buf.start, &ops);
567 
568 		if (put_user(ops.oobretlen, (uint32_t __user *)argp))
569 			ret = -EFAULT;
570 		else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
571 						    ops.oobretlen))
572 			ret = -EFAULT;
573 
574 		kfree(ops.oobbuf);
575 		break;
576 	}
577 
578 	case MEMLOCK:
579 	{
580 		struct erase_info_user info;
581 
582 		if (copy_from_user(&info, argp, sizeof(info)))
583 			return -EFAULT;
584 
585 		if (!mtd->lock)
586 			ret = -EOPNOTSUPP;
587 		else
588 			ret = mtd->lock(mtd, info.start, info.length);
589 		break;
590 	}
591 
592 	case MEMUNLOCK:
593 	{
594 		struct erase_info_user info;
595 
596 		if (copy_from_user(&info, argp, sizeof(info)))
597 			return -EFAULT;
598 
599 		if (!mtd->unlock)
600 			ret = -EOPNOTSUPP;
601 		else
602 			ret = mtd->unlock(mtd, info.start, info.length);
603 		break;
604 	}
605 
606 	/* Legacy interface */
607 	case MEMGETOOBSEL:
608 	{
609 		struct nand_oobinfo oi;
610 
611 		if (!mtd->ecclayout)
612 			return -EOPNOTSUPP;
613 		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
614 			return -EINVAL;
615 
616 		oi.useecc = MTD_NANDECC_AUTOPLACE;
617 		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
618 		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
619 		       sizeof(oi.oobfree));
620 		oi.eccbytes = mtd->ecclayout->eccbytes;
621 
622 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
623 			return -EFAULT;
624 		break;
625 	}
626 
627 	case MEMGETBADBLOCK:
628 	{
629 		loff_t offs;
630 
631 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
632 			return -EFAULT;
633 		if (!mtd->block_isbad)
634 			ret = -EOPNOTSUPP;
635 		else
636 			return mtd->block_isbad(mtd, offs);
637 		break;
638 	}
639 
640 	case MEMSETBADBLOCK:
641 	{
642 		loff_t offs;
643 
644 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
645 			return -EFAULT;
646 		if (!mtd->block_markbad)
647 			ret = -EOPNOTSUPP;
648 		else
649 			return mtd->block_markbad(mtd, offs);
650 		break;
651 	}
652 
653 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
654 	case OTPSELECT:
655 	{
656 		int mode;
657 		if (copy_from_user(&mode, argp, sizeof(int)))
658 			return -EFAULT;
659 
660 		mfi->mode = MTD_MODE_NORMAL;
661 
662 		ret = otp_select_filemode(mfi, mode);
663 
664 		file->f_pos = 0;
665 		break;
666 	}
667 
668 	case OTPGETREGIONCOUNT:
669 	case OTPGETREGIONINFO:
670 	{
671 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
672 		if (!buf)
673 			return -ENOMEM;
674 		ret = -EOPNOTSUPP;
675 		switch (mfi->mode) {
676 		case MTD_MODE_OTP_FACTORY:
677 			if (mtd->get_fact_prot_info)
678 				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
679 			break;
680 		case MTD_MODE_OTP_USER:
681 			if (mtd->get_user_prot_info)
682 				ret = mtd->get_user_prot_info(mtd, buf, 4096);
683 			break;
684 		default:
685 			break;
686 		}
687 		if (ret >= 0) {
688 			if (cmd == OTPGETREGIONCOUNT) {
689 				int nbr = ret / sizeof(struct otp_info);
690 				ret = copy_to_user(argp, &nbr, sizeof(int));
691 			} else
692 				ret = copy_to_user(argp, buf, ret);
693 			if (ret)
694 				ret = -EFAULT;
695 		}
696 		kfree(buf);
697 		break;
698 	}
699 
700 	case OTPLOCK:
701 	{
702 		struct otp_info info;
703 
704 		if (mfi->mode != MTD_MODE_OTP_USER)
705 			return -EINVAL;
706 		if (copy_from_user(&info, argp, sizeof(info)))
707 			return -EFAULT;
708 		if (!mtd->lock_user_prot_reg)
709 			return -EOPNOTSUPP;
710 		ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
711 		break;
712 	}
713 #endif
714 
715 	case ECCGETLAYOUT:
716 	{
717 		if (!mtd->ecclayout)
718 			return -EOPNOTSUPP;
719 
720 		if (copy_to_user(argp, mtd->ecclayout,
721 				 sizeof(struct nand_ecclayout)))
722 			return -EFAULT;
723 		break;
724 	}
725 
726 	case ECCGETSTATS:
727 	{
728 		if (copy_to_user(argp, &mtd->ecc_stats,
729 				 sizeof(struct mtd_ecc_stats)))
730 			return -EFAULT;
731 		break;
732 	}
733 
734 	case MTDFILEMODE:
735 	{
736 		mfi->mode = 0;
737 
738 		switch(arg) {
739 		case MTD_MODE_OTP_FACTORY:
740 		case MTD_MODE_OTP_USER:
741 			ret = otp_select_filemode(mfi, arg);
742 			break;
743 
744 		case MTD_MODE_RAW:
745 			if (!mtd->read_oob || !mtd->write_oob)
746 				return -EOPNOTSUPP;
747 			mfi->mode = arg;
748 
749 		case MTD_MODE_NORMAL:
750 			break;
751 		default:
752 			ret = -EINVAL;
753 		}
754 		file->f_pos = 0;
755 		break;
756 	}
757 
758 	default:
759 		ret = -ENOTTY;
760 	}
761 
762 	return ret;
763 } /* memory_ioctl */
764 
765 static const struct file_operations mtd_fops = {
766 	.owner		= THIS_MODULE,
767 	.llseek		= mtd_lseek,
768 	.read		= mtd_read,
769 	.write		= mtd_write,
770 	.ioctl		= mtd_ioctl,
771 	.open		= mtd_open,
772 	.release	= mtd_close,
773 };
774 
775 static int __init init_mtdchar(void)
776 {
777 	if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
778 		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
779 		       MTD_CHAR_MAJOR);
780 		return -EAGAIN;
781 	}
782 
783 	mtd_class = class_create(THIS_MODULE, "mtd");
784 
785 	if (IS_ERR(mtd_class)) {
786 		printk(KERN_ERR "Error creating mtd class.\n");
787 		unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
788 		return PTR_ERR(mtd_class);
789 	}
790 
791 	register_mtd_user(&notifier);
792 	return 0;
793 }
794 
795 static void __exit cleanup_mtdchar(void)
796 {
797 	unregister_mtd_user(&notifier);
798 	class_destroy(mtd_class);
799 	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
800 }
801 
802 module_init(init_mtdchar);
803 module_exit(cleanup_mtdchar);
804 
805 
806 MODULE_LICENSE("GPL");
807 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
808 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
809