Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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         struct mtd_info_user info;
384
385         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
386
387         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
388         if (cmd & IOC_IN) {
389                 if (!access_ok(VERIFY_READ, argp, size))
390                         return -EFAULT;
391         }
392         if (cmd & IOC_OUT) {
393                 if (!access_ok(VERIFY_WRITE, argp, size))
394                         return -EFAULT;
395         }
396
397         switch (cmd) {
398         case MEMGETREGIONCOUNT:
399                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
400                         return -EFAULT;
401                 break;
402
403         case MEMGETREGIONINFO:
404         {
405                 struct region_info_user ur;
406
407                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
408                         return -EFAULT;
409
410                 if (ur.regionindex >= mtd->numeraseregions)
411                         return -EINVAL;
412                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
413                                 sizeof(struct mtd_erase_region_info)))
414                         return -EFAULT;
415                 break;
416         }
417
418         case MEMGETINFO:
419                 info.type       = mtd->type;
420                 info.flags      = mtd->flags;
421                 info.size       = mtd->size;
422                 info.erasesize  = mtd->erasesize;
423                 info.writesize  = mtd->writesize;
424                 info.oobsize    = mtd->oobsize;
425                 info.ecctype    = mtd->ecctype;
426                 info.eccsize    = mtd->eccsize;
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=kmalloc(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                         memset (erase,0,sizeof(struct erase_info));
448                         if (copy_from_user(&erase->addr, argp,
449                                     sizeof(struct erase_info_user))) {
450                                 kfree(erase);
451                                 return -EFAULT;
452                         }
453                         erase->mtd = mtd;
454                         erase->callback = mtdchar_erase_callback;
455                         erase->priv = (unsigned long)&waitq;
456
457                         /*
458                           FIXME: Allow INTERRUPTIBLE. Which means
459                           not having the wait_queue head on the stack.
460
461                           If the wq_head is on the stack, and we
462                           leave because we got interrupted, then the
463                           wq_head is no longer there when the
464                           callback routine tries to wake us up.
465                         */
466                         ret = mtd->erase(mtd, erase);
467                         if (!ret) {
468                                 set_current_state(TASK_UNINTERRUPTIBLE);
469                                 add_wait_queue(&waitq, &wait);
470                                 if (erase->state != MTD_ERASE_DONE &&
471                                     erase->state != MTD_ERASE_FAILED)
472                                         schedule();
473                                 remove_wait_queue(&waitq, &wait);
474                                 set_current_state(TASK_RUNNING);
475
476                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
477                         }
478                         kfree(erase);
479                 }
480                 break;
481         }
482
483         case MEMWRITEOOB:
484         {
485                 struct mtd_oob_buf buf;
486                 struct mtd_oob_ops ops;
487
488                 if(!(file->f_mode & 2))
489                         return -EPERM;
490
491                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
492                         return -EFAULT;
493
494                 if (buf.length > 4096)
495                         return -EINVAL;
496
497                 if (!mtd->write_oob)
498                         ret = -EOPNOTSUPP;
499                 else
500                         ret = access_ok(VERIFY_READ, buf.ptr,
501                                         buf.length) ? 0 : EFAULT;
502
503                 if (ret)
504                         return ret;
505
506                 ops.len = buf.length;
507                 ops.ooblen = buf.length;
508                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
509                 ops.datbuf = NULL;
510                 ops.mode = MTD_OOB_PLACE;
511
512                 if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
513                         return -EINVAL;
514
515                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
516                 if (!ops.oobbuf)
517                         return -ENOMEM;
518
519                 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
520                         kfree(ops.oobbuf);
521                         return -EFAULT;
522                 }
523
524                 buf.start &= ~(mtd->oobsize - 1);
525                 ret = mtd->write_oob(mtd, buf.start, &ops);
526
527                 if (copy_to_user(argp + sizeof(uint32_t), &ops.retlen,
528                                  sizeof(uint32_t)))
529                         ret = -EFAULT;
530
531                 kfree(ops.oobbuf);
532                 break;
533
534         }
535
536         case MEMREADOOB:
537         {
538                 struct mtd_oob_buf buf;
539                 struct mtd_oob_ops ops;
540
541                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
542                         return -EFAULT;
543
544                 if (buf.length > 4096)
545                         return -EINVAL;
546
547                 if (!mtd->read_oob)
548                         ret = -EOPNOTSUPP;
549                 else
550                         ret = access_ok(VERIFY_WRITE, buf.ptr,
551                                         buf.length) ? 0 : -EFAULT;
552                 if (ret)
553                         return ret;
554
555                 ops.len = buf.length;
556                 ops.ooblen = buf.length;
557                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
558                 ops.datbuf = NULL;
559                 ops.mode = MTD_OOB_PLACE;
560
561                 if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
562                         return -EINVAL;
563
564                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
565                 if (!ops.oobbuf)
566                         return -ENOMEM;
567
568                 buf.start &= ~(mtd->oobsize - 1);
569                 ret = mtd->read_oob(mtd, buf.start, &ops);
570
571                 if (put_user(ops.retlen, (uint32_t __user *)argp))
572                         ret = -EFAULT;
573                 else if (ops.retlen && copy_to_user(buf.ptr, ops.oobbuf,
574                                                     ops.retlen))
575                         ret = -EFAULT;
576
577                 kfree(ops.oobbuf);
578                 break;
579         }
580
581         case MEMLOCK:
582         {
583                 struct erase_info_user info;
584
585                 if (copy_from_user(&info, argp, sizeof(info)))
586                         return -EFAULT;
587
588                 if (!mtd->lock)
589                         ret = -EOPNOTSUPP;
590                 else
591                         ret = mtd->lock(mtd, info.start, info.length);
592                 break;
593         }
594
595         case MEMUNLOCK:
596         {
597                 struct erase_info_user info;
598
599                 if (copy_from_user(&info, argp, sizeof(info)))
600                         return -EFAULT;
601
602                 if (!mtd->unlock)
603                         ret = -EOPNOTSUPP;
604                 else
605                         ret = mtd->unlock(mtd, info.start, info.length);
606                 break;
607         }
608
609         /* Legacy interface */
610         case MEMGETOOBSEL:
611         {
612                 struct nand_oobinfo oi;
613
614                 if (!mtd->ecclayout)
615                         return -EOPNOTSUPP;
616                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
617                         return -EINVAL;
618
619                 oi.useecc = MTD_NANDECC_AUTOPLACE;
620                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
621                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
622                        sizeof(oi.oobfree));
623
624                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
625                         return -EFAULT;
626                 break;
627         }
628
629         case MEMGETBADBLOCK:
630         {
631                 loff_t offs;
632
633                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
634                         return -EFAULT;
635                 if (!mtd->block_isbad)
636                         ret = -EOPNOTSUPP;
637                 else
638                         return mtd->block_isbad(mtd, offs);
639                 break;
640         }
641
642         case MEMSETBADBLOCK:
643         {
644                 loff_t offs;
645
646                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
647                         return -EFAULT;
648                 if (!mtd->block_markbad)
649                         ret = -EOPNOTSUPP;
650                 else
651                         return mtd->block_markbad(mtd, offs);
652                 break;
653         }
654
655 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
656         case OTPSELECT:
657         {
658                 int mode;
659                 if (copy_from_user(&mode, argp, sizeof(int)))
660                         return -EFAULT;
661
662                 mfi->mode = MTD_MODE_NORMAL;
663
664                 ret = otp_select_filemode(mfi, mode);
665
666                 file->f_pos = 0;
667                 break;
668         }
669
670         case OTPGETREGIONCOUNT:
671         case OTPGETREGIONINFO:
672         {
673                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
674                 if (!buf)
675                         return -ENOMEM;
676                 ret = -EOPNOTSUPP;
677                 switch (mfi->mode) {
678                 case MTD_MODE_OTP_FACTORY:
679                         if (mtd->get_fact_prot_info)
680                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
681                         break;
682                 case MTD_MODE_OTP_USER:
683                         if (mtd->get_user_prot_info)
684                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
685                         break;
686                 default:
687                         break;
688                 }
689                 if (ret >= 0) {
690                         if (cmd == OTPGETREGIONCOUNT) {
691                                 int nbr = ret / sizeof(struct otp_info);
692                                 ret = copy_to_user(argp, &nbr, sizeof(int));
693                         } else
694                                 ret = copy_to_user(argp, buf, ret);
695                         if (ret)
696                                 ret = -EFAULT;
697                 }
698                 kfree(buf);
699                 break;
700         }
701
702         case OTPLOCK:
703         {
704                 struct otp_info info;
705
706                 if (mfi->mode != MTD_MODE_OTP_USER)
707                         return -EINVAL;
708                 if (copy_from_user(&info, argp, sizeof(info)))
709                         return -EFAULT;
710                 if (!mtd->lock_user_prot_reg)
711                         return -EOPNOTSUPP;
712                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
713                 break;
714         }
715 #endif
716
717         case ECCGETLAYOUT:
718         {
719                 if (!mtd->ecclayout)
720                         return -EOPNOTSUPP;
721
722                 if (copy_to_user(argp, &mtd->ecclayout,
723                                  sizeof(struct nand_ecclayout)))
724                         return -EFAULT;
725                 break;
726         }
727
728         case ECCGETSTATS:
729         {
730                 if (copy_to_user(argp, &mtd->ecc_stats,
731                                  sizeof(struct mtd_ecc_stats)))
732                         return -EFAULT;
733                 break;
734         }
735
736         case MTDFILEMODE:
737         {
738                 mfi->mode = 0;
739
740                 switch(arg) {
741                 case MTD_MODE_OTP_FACTORY:
742                 case MTD_MODE_OTP_USER:
743                         ret = otp_select_filemode(mfi, arg);
744                         break;
745
746                 case MTD_MODE_RAW:
747                         if (!mtd->read_oob || !mtd->write_oob)
748                                 return -EOPNOTSUPP;
749                         mfi->mode = arg;
750
751                 case MTD_MODE_NORMAL:
752                         break;
753                 default:
754                         ret = -EINVAL;
755                 }
756                 file->f_pos = 0;
757                 break;
758         }
759
760         default:
761                 ret = -ENOTTY;
762         }
763
764         return ret;
765 } /* memory_ioctl */
766
767 static struct file_operations mtd_fops = {
768         .owner          = THIS_MODULE,
769         .llseek         = mtd_lseek,
770         .read           = mtd_read,
771         .write          = mtd_write,
772         .ioctl          = mtd_ioctl,
773         .open           = mtd_open,
774         .release        = mtd_close,
775 };
776
777 static int __init init_mtdchar(void)
778 {
779         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
780                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
781                        MTD_CHAR_MAJOR);
782                 return -EAGAIN;
783         }
784
785         mtd_class = class_create(THIS_MODULE, "mtd");
786
787         if (IS_ERR(mtd_class)) {
788                 printk(KERN_ERR "Error creating mtd class.\n");
789                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
790                 return PTR_ERR(mtd_class);
791         }
792
793         register_mtd_user(&notifier);
794         return 0;
795 }
796
797 static void __exit cleanup_mtdchar(void)
798 {
799         unregister_mtd_user(&notifier);
800         class_destroy(mtd_class);
801         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
802 }
803
804 module_init(init_mtdchar);
805 module_exit(cleanup_mtdchar);
806
807
808 MODULE_LICENSE("GPL");
809 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
810 MODULE_DESCRIPTION("Direct character-device access to MTD devices");