xref: /openbmc/linux/drivers/mtd/mtdchar.c (revision a09d2831)
1 /*
2  * Character-device access to raw MTD devices.
3  *
4  */
5 
6 #include <linux/device.h>
7 #include <linux/fs.h>
8 #include <linux/mm.h>
9 #include <linux/err.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/smp_lock.h>
16 #include <linux/backing-dev.h>
17 #include <linux/compat.h>
18 
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/compatmac.h>
21 
22 #include <asm/uaccess.h>
23 
24 
25 /*
26  * Data structure to hold the pointer to the mtd device as well
27  * as mode information ofr various use cases.
28  */
29 struct mtd_file_info {
30 	struct mtd_info *mtd;
31 	enum mtd_file_modes mode;
32 };
33 
34 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
35 {
36 	struct mtd_file_info *mfi = file->private_data;
37 	struct mtd_info *mtd = mfi->mtd;
38 
39 	switch (orig) {
40 	case SEEK_SET:
41 		break;
42 	case SEEK_CUR:
43 		offset += file->f_pos;
44 		break;
45 	case SEEK_END:
46 		offset += mtd->size;
47 		break;
48 	default:
49 		return -EINVAL;
50 	}
51 
52 	if (offset >= 0 && offset <= mtd->size)
53 		return file->f_pos = offset;
54 
55 	return -EINVAL;
56 }
57 
58 
59 
60 static int mtd_open(struct inode *inode, struct file *file)
61 {
62 	int minor = iminor(inode);
63 	int devnum = minor >> 1;
64 	int ret = 0;
65 	struct mtd_info *mtd;
66 	struct mtd_file_info *mfi;
67 
68 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
69 
70 	if (devnum >= MAX_MTD_DEVICES)
71 		return -ENODEV;
72 
73 	/* You can't open the RO devices RW */
74 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
75 		return -EACCES;
76 
77 	lock_kernel();
78 	mtd = get_mtd_device(NULL, devnum);
79 
80 	if (IS_ERR(mtd)) {
81 		ret = PTR_ERR(mtd);
82 		goto out;
83 	}
84 
85 	if (mtd->type == MTD_ABSENT) {
86 		put_mtd_device(mtd);
87 		ret = -ENODEV;
88 		goto out;
89 	}
90 
91 	if (mtd->backing_dev_info)
92 		file->f_mapping->backing_dev_info = mtd->backing_dev_info;
93 
94 	/* You can't open it RW if it's not a writeable device */
95 	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
96 		put_mtd_device(mtd);
97 		ret = -EACCES;
98 		goto out;
99 	}
100 
101 	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
102 	if (!mfi) {
103 		put_mtd_device(mtd);
104 		ret = -ENOMEM;
105 		goto out;
106 	}
107 	mfi->mtd = mtd;
108 	file->private_data = mfi;
109 
110 out:
111 	unlock_kernel();
112 	return ret;
113 } /* mtd_open */
114 
115 /*====================================================================*/
116 
117 static int mtd_close(struct inode *inode, struct file *file)
118 {
119 	struct mtd_file_info *mfi = file->private_data;
120 	struct mtd_info *mtd = mfi->mtd;
121 
122 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
123 
124 	/* Only sync if opened RW */
125 	if ((file->f_mode & FMODE_WRITE) && mtd->sync)
126 		mtd->sync(mtd);
127 
128 	put_mtd_device(mtd);
129 	file->private_data = NULL;
130 	kfree(mfi);
131 
132 	return 0;
133 } /* mtd_close */
134 
135 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
136    userspace buffer down and use it directly with readv/writev.
137 */
138 #define MAX_KMALLOC_SIZE 0x20000
139 
140 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
141 {
142 	struct mtd_file_info *mfi = file->private_data;
143 	struct mtd_info *mtd = mfi->mtd;
144 	size_t retlen=0;
145 	size_t total_retlen=0;
146 	int ret=0;
147 	int len;
148 	char *kbuf;
149 
150 	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
151 
152 	if (*ppos + count > mtd->size)
153 		count = mtd->size - *ppos;
154 
155 	if (!count)
156 		return 0;
157 
158 	/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
159 	   and pass them directly to the MTD functions */
160 
161 	if (count > MAX_KMALLOC_SIZE)
162 		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
163 	else
164 		kbuf=kmalloc(count, GFP_KERNEL);
165 
166 	if (!kbuf)
167 		return -ENOMEM;
168 
169 	while (count) {
170 
171 		if (count > MAX_KMALLOC_SIZE)
172 			len = MAX_KMALLOC_SIZE;
173 		else
174 			len = count;
175 
176 		switch (mfi->mode) {
177 		case MTD_MODE_OTP_FACTORY:
178 			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
179 			break;
180 		case MTD_MODE_OTP_USER:
181 			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
182 			break;
183 		case MTD_MODE_RAW:
184 		{
185 			struct mtd_oob_ops ops;
186 
187 			ops.mode = MTD_OOB_RAW;
188 			ops.datbuf = kbuf;
189 			ops.oobbuf = NULL;
190 			ops.len = len;
191 
192 			ret = mtd->read_oob(mtd, *ppos, &ops);
193 			retlen = ops.retlen;
194 			break;
195 		}
196 		default:
197 			ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
198 		}
199 		/* Nand returns -EBADMSG on ecc errors, but it returns
200 		 * the data. For our userspace tools it is important
201 		 * to dump areas with ecc errors !
202 		 * For kernel internal usage it also might return -EUCLEAN
203 		 * to signal the caller that a bitflip has occured and has
204 		 * been corrected by the ECC algorithm.
205 		 * Userspace software which accesses NAND this way
206 		 * must be aware of the fact that it deals with NAND
207 		 */
208 		if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
209 			*ppos += retlen;
210 			if (copy_to_user(buf, kbuf, retlen)) {
211 				kfree(kbuf);
212 				return -EFAULT;
213 			}
214 			else
215 				total_retlen += retlen;
216 
217 			count -= retlen;
218 			buf += retlen;
219 			if (retlen == 0)
220 				count = 0;
221 		}
222 		else {
223 			kfree(kbuf);
224 			return ret;
225 		}
226 
227 	}
228 
229 	kfree(kbuf);
230 	return total_retlen;
231 } /* mtd_read */
232 
233 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
234 {
235 	struct mtd_file_info *mfi = file->private_data;
236 	struct mtd_info *mtd = mfi->mtd;
237 	char *kbuf;
238 	size_t retlen;
239 	size_t total_retlen=0;
240 	int ret=0;
241 	int len;
242 
243 	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
244 
245 	if (*ppos == mtd->size)
246 		return -ENOSPC;
247 
248 	if (*ppos + count > mtd->size)
249 		count = mtd->size - *ppos;
250 
251 	if (!count)
252 		return 0;
253 
254 	if (count > MAX_KMALLOC_SIZE)
255 		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
256 	else
257 		kbuf=kmalloc(count, GFP_KERNEL);
258 
259 	if (!kbuf)
260 		return -ENOMEM;
261 
262 	while (count) {
263 
264 		if (count > MAX_KMALLOC_SIZE)
265 			len = MAX_KMALLOC_SIZE;
266 		else
267 			len = count;
268 
269 		if (copy_from_user(kbuf, buf, len)) {
270 			kfree(kbuf);
271 			return -EFAULT;
272 		}
273 
274 		switch (mfi->mode) {
275 		case MTD_MODE_OTP_FACTORY:
276 			ret = -EROFS;
277 			break;
278 		case MTD_MODE_OTP_USER:
279 			if (!mtd->write_user_prot_reg) {
280 				ret = -EOPNOTSUPP;
281 				break;
282 			}
283 			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
284 			break;
285 
286 		case MTD_MODE_RAW:
287 		{
288 			struct mtd_oob_ops ops;
289 
290 			ops.mode = MTD_OOB_RAW;
291 			ops.datbuf = kbuf;
292 			ops.oobbuf = NULL;
293 			ops.len = len;
294 
295 			ret = mtd->write_oob(mtd, *ppos, &ops);
296 			retlen = ops.retlen;
297 			break;
298 		}
299 
300 		default:
301 			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
302 		}
303 		if (!ret) {
304 			*ppos += retlen;
305 			total_retlen += retlen;
306 			count -= retlen;
307 			buf += retlen;
308 		}
309 		else {
310 			kfree(kbuf);
311 			return ret;
312 		}
313 	}
314 
315 	kfree(kbuf);
316 	return total_retlen;
317 } /* mtd_write */
318 
319 /*======================================================================
320 
321     IOCTL calls for getting device parameters.
322 
323 ======================================================================*/
324 static void mtdchar_erase_callback (struct erase_info *instr)
325 {
326 	wake_up((wait_queue_head_t *)instr->priv);
327 }
328 
329 #ifdef CONFIG_HAVE_MTD_OTP
330 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
331 {
332 	struct mtd_info *mtd = mfi->mtd;
333 	int ret = 0;
334 
335 	switch (mode) {
336 	case MTD_OTP_FACTORY:
337 		if (!mtd->read_fact_prot_reg)
338 			ret = -EOPNOTSUPP;
339 		else
340 			mfi->mode = MTD_MODE_OTP_FACTORY;
341 		break;
342 	case MTD_OTP_USER:
343 		if (!mtd->read_fact_prot_reg)
344 			ret = -EOPNOTSUPP;
345 		else
346 			mfi->mode = MTD_MODE_OTP_USER;
347 		break;
348 	default:
349 		ret = -EINVAL;
350 	case MTD_OTP_OFF:
351 		break;
352 	}
353 	return ret;
354 }
355 #else
356 # define otp_select_filemode(f,m)	-EOPNOTSUPP
357 #endif
358 
359 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
360 	uint64_t start, uint32_t length, void __user *ptr,
361 	uint32_t __user *retp)
362 {
363 	struct mtd_oob_ops ops;
364 	uint32_t retlen;
365 	int ret = 0;
366 
367 	if (!(file->f_mode & FMODE_WRITE))
368 		return -EPERM;
369 
370 	if (length > 4096)
371 		return -EINVAL;
372 
373 	if (!mtd->write_oob)
374 		ret = -EOPNOTSUPP;
375 	else
376 		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : EFAULT;
377 
378 	if (ret)
379 		return ret;
380 
381 	ops.ooblen = length;
382 	ops.ooboffs = start & (mtd->oobsize - 1);
383 	ops.datbuf = NULL;
384 	ops.mode = MTD_OOB_PLACE;
385 
386 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
387 		return -EINVAL;
388 
389 	ops.oobbuf = kmalloc(length, GFP_KERNEL);
390 	if (!ops.oobbuf)
391 		return -ENOMEM;
392 
393 	if (copy_from_user(ops.oobbuf, ptr, length)) {
394 		kfree(ops.oobbuf);
395 		return -EFAULT;
396 	}
397 
398 	start &= ~((uint64_t)mtd->oobsize - 1);
399 	ret = mtd->write_oob(mtd, start, &ops);
400 
401 	if (ops.oobretlen > 0xFFFFFFFFU)
402 		ret = -EOVERFLOW;
403 	retlen = ops.oobretlen;
404 	if (copy_to_user(retp, &retlen, sizeof(length)))
405 		ret = -EFAULT;
406 
407 	kfree(ops.oobbuf);
408 	return ret;
409 }
410 
411 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
412 	uint32_t length, void __user *ptr, uint32_t __user *retp)
413 {
414 	struct mtd_oob_ops ops;
415 	int ret = 0;
416 
417 	if (length > 4096)
418 		return -EINVAL;
419 
420 	if (!mtd->read_oob)
421 		ret = -EOPNOTSUPP;
422 	else
423 		ret = access_ok(VERIFY_WRITE, ptr,
424 				length) ? 0 : -EFAULT;
425 	if (ret)
426 		return ret;
427 
428 	ops.ooblen = length;
429 	ops.ooboffs = start & (mtd->oobsize - 1);
430 	ops.datbuf = NULL;
431 	ops.mode = MTD_OOB_PLACE;
432 
433 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
434 		return -EINVAL;
435 
436 	ops.oobbuf = kmalloc(length, GFP_KERNEL);
437 	if (!ops.oobbuf)
438 		return -ENOMEM;
439 
440 	start &= ~((uint64_t)mtd->oobsize - 1);
441 	ret = mtd->read_oob(mtd, start, &ops);
442 
443 	if (put_user(ops.oobretlen, retp))
444 		ret = -EFAULT;
445 	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
446 					    ops.oobretlen))
447 		ret = -EFAULT;
448 
449 	kfree(ops.oobbuf);
450 	return ret;
451 }
452 
453 static int mtd_ioctl(struct inode *inode, struct file *file,
454 		     u_int cmd, u_long arg)
455 {
456 	struct mtd_file_info *mfi = file->private_data;
457 	struct mtd_info *mtd = mfi->mtd;
458 	void __user *argp = (void __user *)arg;
459 	int ret = 0;
460 	u_long size;
461 	struct mtd_info_user info;
462 
463 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
464 
465 	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
466 	if (cmd & IOC_IN) {
467 		if (!access_ok(VERIFY_READ, argp, size))
468 			return -EFAULT;
469 	}
470 	if (cmd & IOC_OUT) {
471 		if (!access_ok(VERIFY_WRITE, argp, size))
472 			return -EFAULT;
473 	}
474 
475 	switch (cmd) {
476 	case MEMGETREGIONCOUNT:
477 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
478 			return -EFAULT;
479 		break;
480 
481 	case MEMGETREGIONINFO:
482 	{
483 		uint32_t ur_idx;
484 		struct mtd_erase_region_info *kr;
485 		struct region_info_user *ur = (struct region_info_user *) argp;
486 
487 		if (get_user(ur_idx, &(ur->regionindex)))
488 			return -EFAULT;
489 
490 		kr = &(mtd->eraseregions[ur_idx]);
491 
492 		if (put_user(kr->offset, &(ur->offset))
493 		    || put_user(kr->erasesize, &(ur->erasesize))
494 		    || put_user(kr->numblocks, &(ur->numblocks)))
495 			return -EFAULT;
496 
497 		break;
498 	}
499 
500 	case MEMGETINFO:
501 		info.type	= mtd->type;
502 		info.flags	= mtd->flags;
503 		info.size	= mtd->size;
504 		info.erasesize	= mtd->erasesize;
505 		info.writesize	= mtd->writesize;
506 		info.oobsize	= mtd->oobsize;
507 		/* The below fields are obsolete */
508 		info.ecctype	= -1;
509 		info.eccsize	= 0;
510 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
511 			return -EFAULT;
512 		break;
513 
514 	case MEMERASE:
515 	case MEMERASE64:
516 	{
517 		struct erase_info *erase;
518 
519 		if(!(file->f_mode & FMODE_WRITE))
520 			return -EPERM;
521 
522 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
523 		if (!erase)
524 			ret = -ENOMEM;
525 		else {
526 			wait_queue_head_t waitq;
527 			DECLARE_WAITQUEUE(wait, current);
528 
529 			init_waitqueue_head(&waitq);
530 
531 			if (cmd == MEMERASE64) {
532 				struct erase_info_user64 einfo64;
533 
534 				if (copy_from_user(&einfo64, argp,
535 					    sizeof(struct erase_info_user64))) {
536 					kfree(erase);
537 					return -EFAULT;
538 				}
539 				erase->addr = einfo64.start;
540 				erase->len = einfo64.length;
541 			} else {
542 				struct erase_info_user einfo32;
543 
544 				if (copy_from_user(&einfo32, argp,
545 					    sizeof(struct erase_info_user))) {
546 					kfree(erase);
547 					return -EFAULT;
548 				}
549 				erase->addr = einfo32.start;
550 				erase->len = einfo32.length;
551 			}
552 			erase->mtd = mtd;
553 			erase->callback = mtdchar_erase_callback;
554 			erase->priv = (unsigned long)&waitq;
555 
556 			/*
557 			  FIXME: Allow INTERRUPTIBLE. Which means
558 			  not having the wait_queue head on the stack.
559 
560 			  If the wq_head is on the stack, and we
561 			  leave because we got interrupted, then the
562 			  wq_head is no longer there when the
563 			  callback routine tries to wake us up.
564 			*/
565 			ret = mtd->erase(mtd, erase);
566 			if (!ret) {
567 				set_current_state(TASK_UNINTERRUPTIBLE);
568 				add_wait_queue(&waitq, &wait);
569 				if (erase->state != MTD_ERASE_DONE &&
570 				    erase->state != MTD_ERASE_FAILED)
571 					schedule();
572 				remove_wait_queue(&waitq, &wait);
573 				set_current_state(TASK_RUNNING);
574 
575 				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
576 			}
577 			kfree(erase);
578 		}
579 		break;
580 	}
581 
582 	case MEMWRITEOOB:
583 	{
584 		struct mtd_oob_buf buf;
585 		struct mtd_oob_buf __user *buf_user = argp;
586 
587 		/* NOTE: writes return length to buf_user->length */
588 		if (copy_from_user(&buf, argp, sizeof(buf)))
589 			ret = -EFAULT;
590 		else
591 			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
592 				buf.ptr, &buf_user->length);
593 		break;
594 	}
595 
596 	case MEMREADOOB:
597 	{
598 		struct mtd_oob_buf buf;
599 		struct mtd_oob_buf __user *buf_user = argp;
600 
601 		/* NOTE: writes return length to buf_user->start */
602 		if (copy_from_user(&buf, argp, sizeof(buf)))
603 			ret = -EFAULT;
604 		else
605 			ret = mtd_do_readoob(mtd, buf.start, buf.length,
606 				buf.ptr, &buf_user->start);
607 		break;
608 	}
609 
610 	case MEMWRITEOOB64:
611 	{
612 		struct mtd_oob_buf64 buf;
613 		struct mtd_oob_buf64 __user *buf_user = argp;
614 
615 		if (copy_from_user(&buf, argp, sizeof(buf)))
616 			ret = -EFAULT;
617 		else
618 			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
619 				(void __user *)(uintptr_t)buf.usr_ptr,
620 				&buf_user->length);
621 		break;
622 	}
623 
624 	case MEMREADOOB64:
625 	{
626 		struct mtd_oob_buf64 buf;
627 		struct mtd_oob_buf64 __user *buf_user = argp;
628 
629 		if (copy_from_user(&buf, argp, sizeof(buf)))
630 			ret = -EFAULT;
631 		else
632 			ret = mtd_do_readoob(mtd, buf.start, buf.length,
633 				(void __user *)(uintptr_t)buf.usr_ptr,
634 				&buf_user->length);
635 		break;
636 	}
637 
638 	case MEMLOCK:
639 	{
640 		struct erase_info_user einfo;
641 
642 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
643 			return -EFAULT;
644 
645 		if (!mtd->lock)
646 			ret = -EOPNOTSUPP;
647 		else
648 			ret = mtd->lock(mtd, einfo.start, einfo.length);
649 		break;
650 	}
651 
652 	case MEMUNLOCK:
653 	{
654 		struct erase_info_user einfo;
655 
656 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
657 			return -EFAULT;
658 
659 		if (!mtd->unlock)
660 			ret = -EOPNOTSUPP;
661 		else
662 			ret = mtd->unlock(mtd, einfo.start, einfo.length);
663 		break;
664 	}
665 
666 	/* Legacy interface */
667 	case MEMGETOOBSEL:
668 	{
669 		struct nand_oobinfo oi;
670 
671 		if (!mtd->ecclayout)
672 			return -EOPNOTSUPP;
673 		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
674 			return -EINVAL;
675 
676 		oi.useecc = MTD_NANDECC_AUTOPLACE;
677 		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
678 		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
679 		       sizeof(oi.oobfree));
680 		oi.eccbytes = mtd->ecclayout->eccbytes;
681 
682 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
683 			return -EFAULT;
684 		break;
685 	}
686 
687 	case MEMGETBADBLOCK:
688 	{
689 		loff_t offs;
690 
691 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
692 			return -EFAULT;
693 		if (!mtd->block_isbad)
694 			ret = -EOPNOTSUPP;
695 		else
696 			return mtd->block_isbad(mtd, offs);
697 		break;
698 	}
699 
700 	case MEMSETBADBLOCK:
701 	{
702 		loff_t offs;
703 
704 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
705 			return -EFAULT;
706 		if (!mtd->block_markbad)
707 			ret = -EOPNOTSUPP;
708 		else
709 			return mtd->block_markbad(mtd, offs);
710 		break;
711 	}
712 
713 #ifdef CONFIG_HAVE_MTD_OTP
714 	case OTPSELECT:
715 	{
716 		int mode;
717 		if (copy_from_user(&mode, argp, sizeof(int)))
718 			return -EFAULT;
719 
720 		mfi->mode = MTD_MODE_NORMAL;
721 
722 		ret = otp_select_filemode(mfi, mode);
723 
724 		file->f_pos = 0;
725 		break;
726 	}
727 
728 	case OTPGETREGIONCOUNT:
729 	case OTPGETREGIONINFO:
730 	{
731 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
732 		if (!buf)
733 			return -ENOMEM;
734 		ret = -EOPNOTSUPP;
735 		switch (mfi->mode) {
736 		case MTD_MODE_OTP_FACTORY:
737 			if (mtd->get_fact_prot_info)
738 				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
739 			break;
740 		case MTD_MODE_OTP_USER:
741 			if (mtd->get_user_prot_info)
742 				ret = mtd->get_user_prot_info(mtd, buf, 4096);
743 			break;
744 		default:
745 			break;
746 		}
747 		if (ret >= 0) {
748 			if (cmd == OTPGETREGIONCOUNT) {
749 				int nbr = ret / sizeof(struct otp_info);
750 				ret = copy_to_user(argp, &nbr, sizeof(int));
751 			} else
752 				ret = copy_to_user(argp, buf, ret);
753 			if (ret)
754 				ret = -EFAULT;
755 		}
756 		kfree(buf);
757 		break;
758 	}
759 
760 	case OTPLOCK:
761 	{
762 		struct otp_info oinfo;
763 
764 		if (mfi->mode != MTD_MODE_OTP_USER)
765 			return -EINVAL;
766 		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
767 			return -EFAULT;
768 		if (!mtd->lock_user_prot_reg)
769 			return -EOPNOTSUPP;
770 		ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
771 		break;
772 	}
773 #endif
774 
775 	case ECCGETLAYOUT:
776 	{
777 		if (!mtd->ecclayout)
778 			return -EOPNOTSUPP;
779 
780 		if (copy_to_user(argp, mtd->ecclayout,
781 				 sizeof(struct nand_ecclayout)))
782 			return -EFAULT;
783 		break;
784 	}
785 
786 	case ECCGETSTATS:
787 	{
788 		if (copy_to_user(argp, &mtd->ecc_stats,
789 				 sizeof(struct mtd_ecc_stats)))
790 			return -EFAULT;
791 		break;
792 	}
793 
794 	case MTDFILEMODE:
795 	{
796 		mfi->mode = 0;
797 
798 		switch(arg) {
799 		case MTD_MODE_OTP_FACTORY:
800 		case MTD_MODE_OTP_USER:
801 			ret = otp_select_filemode(mfi, arg);
802 			break;
803 
804 		case MTD_MODE_RAW:
805 			if (!mtd->read_oob || !mtd->write_oob)
806 				return -EOPNOTSUPP;
807 			mfi->mode = arg;
808 
809 		case MTD_MODE_NORMAL:
810 			break;
811 		default:
812 			ret = -EINVAL;
813 		}
814 		file->f_pos = 0;
815 		break;
816 	}
817 
818 	default:
819 		ret = -ENOTTY;
820 	}
821 
822 	return ret;
823 } /* memory_ioctl */
824 
825 #ifdef CONFIG_COMPAT
826 
827 struct mtd_oob_buf32 {
828 	u_int32_t start;
829 	u_int32_t length;
830 	compat_caddr_t ptr;	/* unsigned char* */
831 };
832 
833 #define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
834 #define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
835 
836 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
837 	unsigned long arg)
838 {
839 	struct inode *inode = file->f_path.dentry->d_inode;
840 	struct mtd_file_info *mfi = file->private_data;
841 	struct mtd_info *mtd = mfi->mtd;
842 	void __user *argp = compat_ptr(arg);
843 	int ret = 0;
844 
845 	lock_kernel();
846 
847 	switch (cmd) {
848 	case MEMWRITEOOB32:
849 	{
850 		struct mtd_oob_buf32 buf;
851 		struct mtd_oob_buf32 __user *buf_user = argp;
852 
853 		if (copy_from_user(&buf, argp, sizeof(buf)))
854 			ret = -EFAULT;
855 		else
856 			ret = mtd_do_writeoob(file, mtd, buf.start,
857 				buf.length, compat_ptr(buf.ptr),
858 				&buf_user->length);
859 		break;
860 	}
861 
862 	case MEMREADOOB32:
863 	{
864 		struct mtd_oob_buf32 buf;
865 		struct mtd_oob_buf32 __user *buf_user = argp;
866 
867 		/* NOTE: writes return length to buf->start */
868 		if (copy_from_user(&buf, argp, sizeof(buf)))
869 			ret = -EFAULT;
870 		else
871 			ret = mtd_do_readoob(mtd, buf.start,
872 				buf.length, compat_ptr(buf.ptr),
873 				&buf_user->start);
874 		break;
875 	}
876 	default:
877 		ret = mtd_ioctl(inode, file, cmd, (unsigned long)argp);
878 	}
879 
880 	unlock_kernel();
881 
882 	return ret;
883 }
884 
885 #endif /* CONFIG_COMPAT */
886 
887 /*
888  * try to determine where a shared mapping can be made
889  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
890  *   mappings)
891  */
892 #ifndef CONFIG_MMU
893 static unsigned long mtd_get_unmapped_area(struct file *file,
894 					   unsigned long addr,
895 					   unsigned long len,
896 					   unsigned long pgoff,
897 					   unsigned long flags)
898 {
899 	struct mtd_file_info *mfi = file->private_data;
900 	struct mtd_info *mtd = mfi->mtd;
901 
902 	if (mtd->get_unmapped_area) {
903 		unsigned long offset;
904 
905 		if (addr != 0)
906 			return (unsigned long) -EINVAL;
907 
908 		if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
909 			return (unsigned long) -EINVAL;
910 
911 		offset = pgoff << PAGE_SHIFT;
912 		if (offset > mtd->size - len)
913 			return (unsigned long) -EINVAL;
914 
915 		return mtd->get_unmapped_area(mtd, len, offset, flags);
916 	}
917 
918 	/* can't map directly */
919 	return (unsigned long) -ENOSYS;
920 }
921 #endif
922 
923 /*
924  * set up a mapping for shared memory segments
925  */
926 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
927 {
928 #ifdef CONFIG_MMU
929 	struct mtd_file_info *mfi = file->private_data;
930 	struct mtd_info *mtd = mfi->mtd;
931 
932 	if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
933 		return 0;
934 	return -ENOSYS;
935 #else
936 	return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
937 #endif
938 }
939 
940 static const struct file_operations mtd_fops = {
941 	.owner		= THIS_MODULE,
942 	.llseek		= mtd_lseek,
943 	.read		= mtd_read,
944 	.write		= mtd_write,
945 	.ioctl		= mtd_ioctl,
946 #ifdef CONFIG_COMPAT
947 	.compat_ioctl	= mtd_compat_ioctl,
948 #endif
949 	.open		= mtd_open,
950 	.release	= mtd_close,
951 	.mmap		= mtd_mmap,
952 #ifndef CONFIG_MMU
953 	.get_unmapped_area = mtd_get_unmapped_area,
954 #endif
955 };
956 
957 static int __init init_mtdchar(void)
958 {
959 	int status;
960 
961 	status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
962 	if (status < 0) {
963 		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
964 		       MTD_CHAR_MAJOR);
965 	}
966 
967 	return status;
968 }
969 
970 static void __exit cleanup_mtdchar(void)
971 {
972 	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
973 }
974 
975 module_init(init_mtdchar);
976 module_exit(cleanup_mtdchar);
977 
978 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
979 
980 MODULE_LICENSE("GPL");
981 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
982 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
983 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
984