Merge git://git.infradead.org/mtd-2.6
[linux-2.6.git] / drivers / mtd / mtdchar.c
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
17 #include <linux/mtd/mtd.h>
18 #include <linux/mtd/compatmac.h>
19
20 #include <asm/uaccess.h>
21
22 static struct class *mtd_class;
23
24 static void mtd_notify_add(struct mtd_info* mtd)
25 {
26         if (!mtd)
27                 return;
28
29         device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
30                       NULL, "mtd%d", mtd->index);
31
32         device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
33                       NULL, "mtd%dro", mtd->index);
34 }
35
36 static void mtd_notify_remove(struct mtd_info* mtd)
37 {
38         if (!mtd)
39                 return;
40
41         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
42         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
43 }
44
45 static struct mtd_notifier notifier = {
46         .add    = mtd_notify_add,
47         .remove = mtd_notify_remove,
48 };
49
50 /*
51  * Data structure to hold the pointer to the mtd device as well
52  * as mode information ofr various use cases.
53  */
54 struct mtd_file_info {
55         struct mtd_info *mtd;
56         enum mtd_file_modes mode;
57 };
58
59 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
60 {
61         struct mtd_file_info *mfi = file->private_data;
62         struct mtd_info *mtd = mfi->mtd;
63
64         switch (orig) {
65         case SEEK_SET:
66                 break;
67         case SEEK_CUR:
68                 offset += file->f_pos;
69                 break;
70         case SEEK_END:
71                 offset += mtd->size;
72                 break;
73         default:
74                 return -EINVAL;
75         }
76
77         if (offset >= 0 && offset <= mtd->size)
78                 return file->f_pos = offset;
79
80         return -EINVAL;
81 }
82
83
84
85 static int mtd_open(struct inode *inode, struct file *file)
86 {
87         int minor = iminor(inode);
88         int devnum = minor >> 1;
89         int ret = 0;
90         struct mtd_info *mtd;
91         struct mtd_file_info *mfi;
92
93         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
94
95         if (devnum >= MAX_MTD_DEVICES)
96                 return -ENODEV;
97
98         /* You can't open the RO devices RW */
99         if ((file->f_mode & 2) && (minor & 1))
100                 return -EACCES;
101
102         lock_kernel();
103         mtd = get_mtd_device(NULL, devnum);
104
105         if (IS_ERR(mtd)) {
106                 ret = PTR_ERR(mtd);
107                 goto out;
108         }
109
110         if (MTD_ABSENT == mtd->type) {
111                 put_mtd_device(mtd);
112                 ret = -ENODEV;
113                 goto out;
114         }
115
116         /* You can't open it RW if it's not a writeable device */
117         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
118                 put_mtd_device(mtd);
119                 ret = -EACCES;
120                 goto out;
121         }
122
123         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
124         if (!mfi) {
125                 put_mtd_device(mtd);
126                 ret = -ENOMEM;
127                 goto out;
128         }
129         mfi->mtd = mtd;
130         file->private_data = mfi;
131
132 out:
133         unlock_kernel();
134         return ret;
135 } /* mtd_open */
136
137 /*====================================================================*/
138
139 static int mtd_close(struct inode *inode, struct file *file)
140 {
141         struct mtd_file_info *mfi = file->private_data;
142         struct mtd_info *mtd = mfi->mtd;
143
144         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
145
146         /* Only sync if opened RW */
147         if ((file->f_mode & 2) && mtd->sync)
148                 mtd->sync(mtd);
149
150         put_mtd_device(mtd);
151         file->private_data = NULL;
152         kfree(mfi);
153
154         return 0;
155 } /* mtd_close */
156
157 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
158    userspace buffer down and use it directly with readv/writev.
159 */
160 #define MAX_KMALLOC_SIZE 0x20000
161
162 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
163 {
164         struct mtd_file_info *mfi = file->private_data;
165         struct mtd_info *mtd = mfi->mtd;
166         size_t retlen=0;
167         size_t total_retlen=0;
168         int ret=0;
169         int len;
170         char *kbuf;
171
172         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
173
174         if (*ppos + count > mtd->size)
175                 count = mtd->size - *ppos;
176
177         if (!count)
178                 return 0;
179
180         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
181            and pass them directly to the MTD functions */
182
183         if (count > MAX_KMALLOC_SIZE)
184                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
185         else
186                 kbuf=kmalloc(count, GFP_KERNEL);
187
188         if (!kbuf)
189                 return -ENOMEM;
190
191         while (count) {
192
193                 if (count > MAX_KMALLOC_SIZE)
194                         len = MAX_KMALLOC_SIZE;
195                 else
196                         len = count;
197
198                 switch (mfi->mode) {
199                 case MTD_MODE_OTP_FACTORY:
200                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
201                         break;
202                 case MTD_MODE_OTP_USER:
203                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
204                         break;
205                 case MTD_MODE_RAW:
206                 {
207                         struct mtd_oob_ops ops;
208
209                         ops.mode = MTD_OOB_RAW;
210                         ops.datbuf = kbuf;
211                         ops.oobbuf = NULL;
212                         ops.len = len;
213
214                         ret = mtd->read_oob(mtd, *ppos, &ops);
215                         retlen = ops.retlen;
216                         break;
217                 }
218                 default:
219                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
220                 }
221                 /* Nand returns -EBADMSG on ecc errors, but it returns
222                  * the data. For our userspace tools it is important
223                  * to dump areas with ecc errors !
224                  * For kernel internal usage it also might return -EUCLEAN
225                  * to signal the caller that a bitflip has occured and has
226                  * been corrected by the ECC algorithm.
227                  * Userspace software which accesses NAND this way
228                  * must be aware of the fact that it deals with NAND
229                  */
230                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
231                         *ppos += retlen;
232                         if (copy_to_user(buf, kbuf, retlen)) {
233                                 kfree(kbuf);
234                                 return -EFAULT;
235                         }
236                         else
237                                 total_retlen += retlen;
238
239                         count -= retlen;
240                         buf += retlen;
241                         if (retlen == 0)
242                                 count = 0;
243                 }
244                 else {
245                         kfree(kbuf);
246                         return ret;
247                 }
248
249         }
250
251         kfree(kbuf);
252         return total_retlen;
253 } /* mtd_read */
254
255 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
256 {
257         struct mtd_file_info *mfi = file->private_data;
258         struct mtd_info *mtd = mfi->mtd;
259         char *kbuf;
260         size_t retlen;
261         size_t total_retlen=0;
262         int ret=0;
263         int len;
264
265         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
266
267         if (*ppos == mtd->size)
268                 return -ENOSPC;
269
270         if (*ppos + count > mtd->size)
271                 count = mtd->size - *ppos;
272
273         if (!count)
274                 return 0;
275
276         if (count > MAX_KMALLOC_SIZE)
277                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
278         else
279                 kbuf=kmalloc(count, GFP_KERNEL);
280
281         if (!kbuf)
282                 return -ENOMEM;
283
284         while (count) {
285
286                 if (count > MAX_KMALLOC_SIZE)
287                         len = MAX_KMALLOC_SIZE;
288                 else
289                         len = count;
290
291                 if (copy_from_user(kbuf, buf, len)) {
292                         kfree(kbuf);
293                         return -EFAULT;
294                 }
295
296                 switch (mfi->mode) {
297                 case MTD_MODE_OTP_FACTORY:
298                         ret = -EROFS;
299                         break;
300                 case MTD_MODE_OTP_USER:
301                         if (!mtd->write_user_prot_reg) {
302                                 ret = -EOPNOTSUPP;
303                                 break;
304                         }
305                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
306                         break;
307
308                 case MTD_MODE_RAW:
309                 {
310                         struct mtd_oob_ops ops;
311
312                         ops.mode = MTD_OOB_RAW;
313                         ops.datbuf = kbuf;
314                         ops.oobbuf = NULL;
315                         ops.len = len;
316
317                         ret = mtd->write_oob(mtd, *ppos, &ops);
318                         retlen = ops.retlen;
319                         break;
320                 }
321
322                 default:
323                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
324                 }
325                 if (!ret) {
326                         *ppos += retlen;
327                         total_retlen += retlen;
328                         count -= retlen;
329                         buf += retlen;
330                 }
331                 else {
332                         kfree(kbuf);
333                         return ret;
334                 }
335         }
336
337         kfree(kbuf);
338         return total_retlen;
339 } /* mtd_write */
340
341 /*======================================================================
342
343     IOCTL calls for getting device parameters.
344
345 ======================================================================*/
346 static void mtdchar_erase_callback (struct erase_info *instr)
347 {
348         wake_up((wait_queue_head_t *)instr->priv);
349 }
350
351 #ifdef CONFIG_HAVE_MTD_OTP
352 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
353 {
354         struct mtd_info *mtd = mfi->mtd;
355         int ret = 0;
356
357         switch (mode) {
358         case MTD_OTP_FACTORY:
359                 if (!mtd->read_fact_prot_reg)
360                         ret = -EOPNOTSUPP;
361                 else
362                         mfi->mode = MTD_MODE_OTP_FACTORY;
363                 break;
364         case MTD_OTP_USER:
365                 if (!mtd->read_fact_prot_reg)
366                         ret = -EOPNOTSUPP;
367                 else
368                         mfi->mode = MTD_MODE_OTP_USER;
369                 break;
370         default:
371                 ret = -EINVAL;
372         case MTD_OTP_OFF:
373                 break;
374         }
375         return ret;
376 }
377 #else
378 # define otp_select_filemode(f,m)       -EOPNOTSUPP
379 #endif
380
381 static int mtd_ioctl(struct inode *inode, struct file *file,
382                      u_int cmd, u_long arg)
383 {
384         struct mtd_file_info *mfi = file->private_data;
385         struct mtd_info *mtd = mfi->mtd;
386         void __user *argp = (void __user *)arg;
387         int ret = 0;
388         u_long size;
389         struct mtd_info_user info;
390
391         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
392
393         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
394         if (cmd & IOC_IN) {
395                 if (!access_ok(VERIFY_READ, argp, size))
396                         return -EFAULT;
397         }
398         if (cmd & IOC_OUT) {
399                 if (!access_ok(VERIFY_WRITE, argp, size))
400                         return -EFAULT;
401         }
402
403         switch (cmd) {
404         case MEMGETREGIONCOUNT:
405                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
406                         return -EFAULT;
407                 break;
408
409         case MEMGETREGIONINFO:
410         {
411                 uint32_t ur_idx;
412                 struct mtd_erase_region_info *kr;
413                 struct region_info_user *ur = (struct region_info_user *) argp;
414
415                 if (get_user(ur_idx, &(ur->regionindex)))
416                         return -EFAULT;
417
418                 kr = &(mtd->eraseregions[ur_idx]);
419
420                 if (put_user(kr->offset, &(ur->offset))
421                     || put_user(kr->erasesize, &(ur->erasesize))
422                     || put_user(kr->numblocks, &(ur->numblocks)))
423                         return -EFAULT;
424
425                 break;
426         }
427
428         case MEMGETINFO:
429                 info.type       = mtd->type;
430                 info.flags      = mtd->flags;
431                 info.size       = mtd->size;
432                 info.erasesize  = mtd->erasesize;
433                 info.writesize  = mtd->writesize;
434                 info.oobsize    = mtd->oobsize;
435                 /* The below fields are obsolete */
436                 info.ecctype    = -1;
437                 info.eccsize    = 0;
438                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
439                         return -EFAULT;
440                 break;
441
442         case MEMERASE:
443         {
444                 struct erase_info *erase;
445
446                 if(!(file->f_mode & 2))
447                         return -EPERM;
448
449                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
450                 if (!erase)
451                         ret = -ENOMEM;
452                 else {
453                         wait_queue_head_t waitq;
454                         DECLARE_WAITQUEUE(wait, current);
455
456                         init_waitqueue_head(&waitq);
457
458                         if (copy_from_user(&erase->addr, argp,
459                                     sizeof(struct erase_info_user))) {
460                                 kfree(erase);
461                                 return -EFAULT;
462                         }
463                         erase->mtd = mtd;
464                         erase->callback = mtdchar_erase_callback;
465                         erase->priv = (unsigned long)&waitq;
466
467                         /*
468                           FIXME: Allow INTERRUPTIBLE. Which means
469                           not having the wait_queue head on the stack.
470
471                           If the wq_head is on the stack, and we
472                           leave because we got interrupted, then the
473                           wq_head is no longer there when the
474                           callback routine tries to wake us up.
475                         */
476                         ret = mtd->erase(mtd, erase);
477                         if (!ret) {
478                                 set_current_state(TASK_UNINTERRUPTIBLE);
479                                 add_wait_queue(&waitq, &wait);
480                                 if (erase->state != MTD_ERASE_DONE &&
481                                     erase->state != MTD_ERASE_FAILED)
482                                         schedule();
483                                 remove_wait_queue(&waitq, &wait);
484                                 set_current_state(TASK_RUNNING);
485
486                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
487                         }
488                         kfree(erase);
489                 }
490                 break;
491         }
492
493         case MEMWRITEOOB:
494         {
495                 struct mtd_oob_buf buf;
496                 struct mtd_oob_ops ops;
497                 struct mtd_oob_buf __user *user_buf = argp;
498                 uint32_t retlen;
499
500                 if(!(file->f_mode & 2))
501                         return -EPERM;
502
503                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
504                         return -EFAULT;
505
506                 if (buf.length > 4096)
507                         return -EINVAL;
508
509                 if (!mtd->write_oob)
510                         ret = -EOPNOTSUPP;
511                 else
512                         ret = access_ok(VERIFY_READ, buf.ptr,
513                                         buf.length) ? 0 : EFAULT;
514
515                 if (ret)
516                         return ret;
517
518                 ops.ooblen = buf.length;
519                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
520                 ops.datbuf = NULL;
521                 ops.mode = MTD_OOB_PLACE;
522
523                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
524                         return -EINVAL;
525
526                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
527                 if (!ops.oobbuf)
528                         return -ENOMEM;
529
530                 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
531                         kfree(ops.oobbuf);
532                         return -EFAULT;
533                 }
534
535                 buf.start &= ~(mtd->oobsize - 1);
536                 ret = mtd->write_oob(mtd, buf.start, &ops);
537
538                 if (ops.oobretlen > 0xFFFFFFFFU)
539                         ret = -EOVERFLOW;
540                 retlen = ops.oobretlen;
541                 if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
542                         ret = -EFAULT;
543
544                 kfree(ops.oobbuf);
545                 break;
546
547         }
548
549         case MEMREADOOB:
550         {
551                 struct mtd_oob_buf buf;
552                 struct mtd_oob_ops ops;
553
554                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
555                         return -EFAULT;
556
557                 if (buf.length > 4096)
558                         return -EINVAL;
559
560                 if (!mtd->read_oob)
561                         ret = -EOPNOTSUPP;
562                 else
563                         ret = access_ok(VERIFY_WRITE, buf.ptr,
564                                         buf.length) ? 0 : -EFAULT;
565                 if (ret)
566                         return ret;
567
568                 ops.ooblen = buf.length;
569                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
570                 ops.datbuf = NULL;
571                 ops.mode = MTD_OOB_PLACE;
572
573                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
574                         return -EINVAL;
575
576                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
577                 if (!ops.oobbuf)
578                         return -ENOMEM;
579
580                 buf.start &= ~(mtd->oobsize - 1);
581                 ret = mtd->read_oob(mtd, buf.start, &ops);
582
583                 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
584                         ret = -EFAULT;
585                 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
586                                                     ops.oobretlen))
587                         ret = -EFAULT;
588
589                 kfree(ops.oobbuf);
590                 break;
591         }
592
593         case MEMLOCK:
594         {
595                 struct erase_info_user einfo;
596
597                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
598                         return -EFAULT;
599
600                 if (!mtd->lock)
601                         ret = -EOPNOTSUPP;
602                 else
603                         ret = mtd->lock(mtd, einfo.start, einfo.length);
604                 break;
605         }
606
607         case MEMUNLOCK:
608         {
609                 struct erase_info_user einfo;
610
611                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
612                         return -EFAULT;
613
614                 if (!mtd->unlock)
615                         ret = -EOPNOTSUPP;
616                 else
617                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
618                 break;
619         }
620
621         /* Legacy interface */
622         case MEMGETOOBSEL:
623         {
624                 struct nand_oobinfo oi;
625
626                 if (!mtd->ecclayout)
627                         return -EOPNOTSUPP;
628                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
629                         return -EINVAL;
630
631                 oi.useecc = MTD_NANDECC_AUTOPLACE;
632                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
633                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
634                        sizeof(oi.oobfree));
635                 oi.eccbytes = mtd->ecclayout->eccbytes;
636
637                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
638                         return -EFAULT;
639                 break;
640         }
641
642         case MEMGETBADBLOCK:
643         {
644                 loff_t offs;
645
646                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
647                         return -EFAULT;
648                 if (!mtd->block_isbad)
649                         ret = -EOPNOTSUPP;
650                 else
651                         return mtd->block_isbad(mtd, offs);
652                 break;
653         }
654
655         case MEMSETBADBLOCK:
656         {
657                 loff_t offs;
658
659                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
660                         return -EFAULT;
661                 if (!mtd->block_markbad)
662                         ret = -EOPNOTSUPP;
663                 else
664                         return mtd->block_markbad(mtd, offs);
665                 break;
666         }
667
668 #ifdef CONFIG_HAVE_MTD_OTP
669         case OTPSELECT:
670         {
671                 int mode;
672                 if (copy_from_user(&mode, argp, sizeof(int)))
673                         return -EFAULT;
674
675                 mfi->mode = MTD_MODE_NORMAL;
676
677                 ret = otp_select_filemode(mfi, mode);
678
679                 file->f_pos = 0;
680                 break;
681         }
682
683         case OTPGETREGIONCOUNT:
684         case OTPGETREGIONINFO:
685         {
686                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
687                 if (!buf)
688                         return -ENOMEM;
689                 ret = -EOPNOTSUPP;
690                 switch (mfi->mode) {
691                 case MTD_MODE_OTP_FACTORY:
692                         if (mtd->get_fact_prot_info)
693                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
694                         break;
695                 case MTD_MODE_OTP_USER:
696                         if (mtd->get_user_prot_info)
697                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
698                         break;
699                 default:
700                         break;
701                 }
702                 if (ret >= 0) {
703                         if (cmd == OTPGETREGIONCOUNT) {
704                                 int nbr = ret / sizeof(struct otp_info);
705                                 ret = copy_to_user(argp, &nbr, sizeof(int));
706                         } else
707                                 ret = copy_to_user(argp, buf, ret);
708                         if (ret)
709                                 ret = -EFAULT;
710                 }
711                 kfree(buf);
712                 break;
713         }
714
715         case OTPLOCK:
716         {
717                 struct otp_info oinfo;
718
719                 if (mfi->mode != MTD_MODE_OTP_USER)
720                         return -EINVAL;
721                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
722                         return -EFAULT;
723                 if (!mtd->lock_user_prot_reg)
724                         return -EOPNOTSUPP;
725                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
726                 break;
727         }
728 #endif
729
730         case ECCGETLAYOUT:
731         {
732                 if (!mtd->ecclayout)
733                         return -EOPNOTSUPP;
734
735                 if (copy_to_user(argp, mtd->ecclayout,
736                                  sizeof(struct nand_ecclayout)))
737                         return -EFAULT;
738                 break;
739         }
740
741         case ECCGETSTATS:
742         {
743                 if (copy_to_user(argp, &mtd->ecc_stats,
744                                  sizeof(struct mtd_ecc_stats)))
745                         return -EFAULT;
746                 break;
747         }
748
749         case MTDFILEMODE:
750         {
751                 mfi->mode = 0;
752
753                 switch(arg) {
754                 case MTD_MODE_OTP_FACTORY:
755                 case MTD_MODE_OTP_USER:
756                         ret = otp_select_filemode(mfi, arg);
757                         break;
758
759                 case MTD_MODE_RAW:
760                         if (!mtd->read_oob || !mtd->write_oob)
761                                 return -EOPNOTSUPP;
762                         mfi->mode = arg;
763
764                 case MTD_MODE_NORMAL:
765                         break;
766                 default:
767                         ret = -EINVAL;
768                 }
769                 file->f_pos = 0;
770                 break;
771         }
772
773         default:
774                 ret = -ENOTTY;
775         }
776
777         return ret;
778 } /* memory_ioctl */
779
780 static const struct file_operations mtd_fops = {
781         .owner          = THIS_MODULE,
782         .llseek         = mtd_lseek,
783         .read           = mtd_read,
784         .write          = mtd_write,
785         .ioctl          = mtd_ioctl,
786         .open           = mtd_open,
787         .release        = mtd_close,
788 };
789
790 static int __init init_mtdchar(void)
791 {
792         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
793                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
794                        MTD_CHAR_MAJOR);
795                 return -EAGAIN;
796         }
797
798         mtd_class = class_create(THIS_MODULE, "mtd");
799
800         if (IS_ERR(mtd_class)) {
801                 printk(KERN_ERR "Error creating mtd class.\n");
802                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
803                 return PTR_ERR(mtd_class);
804         }
805
806         register_mtd_user(&notifier);
807         return 0;
808 }
809
810 static void __exit cleanup_mtdchar(void)
811 {
812         unregister_mtd_user(&notifier);
813         class_destroy(mtd_class);
814         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
815 }
816
817 module_init(init_mtdchar);
818 module_exit(cleanup_mtdchar);
819
820
821 MODULE_LICENSE("GPL");
822 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
823 MODULE_DESCRIPTION("Direct character-device access to MTD devices");