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