Merge commit 'v2.6.27-rc1' into for-linus
[linux-2.6] / 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_drvdata(mtd_class, NULL,
30                               MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
31                               NULL, "mtd%d", mtd->index);
32
33         device_create_drvdata(mtd_class, NULL,
34                               MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
35                               NULL, "mtd%dro", mtd->index);
36 }
37
38 static void mtd_notify_remove(struct mtd_info* mtd)
39 {
40         if (!mtd)
41                 return;
42
43         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
44         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
45 }
46
47 static struct mtd_notifier notifier = {
48         .add    = mtd_notify_add,
49         .remove = mtd_notify_remove,
50 };
51
52 /*
53  * Data structure to hold the pointer to the mtd device as well
54  * as mode information ofr various use cases.
55  */
56 struct mtd_file_info {
57         struct mtd_info *mtd;
58         enum mtd_file_modes mode;
59 };
60
61 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
62 {
63         struct mtd_file_info *mfi = file->private_data;
64         struct mtd_info *mtd = mfi->mtd;
65
66         switch (orig) {
67         case SEEK_SET:
68                 break;
69         case SEEK_CUR:
70                 offset += file->f_pos;
71                 break;
72         case SEEK_END:
73                 offset += mtd->size;
74                 break;
75         default:
76                 return -EINVAL;
77         }
78
79         if (offset >= 0 && offset <= mtd->size)
80                 return file->f_pos = offset;
81
82         return -EINVAL;
83 }
84
85
86
87 static int mtd_open(struct inode *inode, struct file *file)
88 {
89         int minor = iminor(inode);
90         int devnum = minor >> 1;
91         int ret = 0;
92         struct mtd_info *mtd;
93         struct mtd_file_info *mfi;
94
95         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
96
97         if (devnum >= MAX_MTD_DEVICES)
98                 return -ENODEV;
99
100         /* You can't open the RO devices RW */
101         if ((file->f_mode & 2) && (minor & 1))
102                 return -EACCES;
103
104         lock_kernel();
105         mtd = get_mtd_device(NULL, devnum);
106
107         if (IS_ERR(mtd)) {
108                 ret = PTR_ERR(mtd);
109                 goto out;
110         }
111
112         if (MTD_ABSENT == mtd->type) {
113                 put_mtd_device(mtd);
114                 ret = -ENODEV;
115                 goto out;
116         }
117
118         /* You can't open it RW if it's not a writeable device */
119         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
120                 put_mtd_device(mtd);
121                 ret = -EACCES;
122                 goto out;
123         }
124
125         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
126         if (!mfi) {
127                 put_mtd_device(mtd);
128                 ret = -ENOMEM;
129                 goto out;
130         }
131         mfi->mtd = mtd;
132         file->private_data = mfi;
133
134 out:
135         unlock_kernel();
136         return ret;
137 } /* mtd_open */
138
139 /*====================================================================*/
140
141 static int mtd_close(struct inode *inode, struct file *file)
142 {
143         struct mtd_file_info *mfi = file->private_data;
144         struct mtd_info *mtd = mfi->mtd;
145
146         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
147
148         /* Only sync if opened RW */
149         if ((file->f_mode & 2) && mtd->sync)
150                 mtd->sync(mtd);
151
152         put_mtd_device(mtd);
153         file->private_data = NULL;
154         kfree(mfi);
155
156         return 0;
157 } /* mtd_close */
158
159 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
160    userspace buffer down and use it directly with readv/writev.
161 */
162 #define MAX_KMALLOC_SIZE 0x20000
163
164 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
165 {
166         struct mtd_file_info *mfi = file->private_data;
167         struct mtd_info *mtd = mfi->mtd;
168         size_t retlen=0;
169         size_t total_retlen=0;
170         int ret=0;
171         int len;
172         char *kbuf;
173
174         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
175
176         if (*ppos + count > mtd->size)
177                 count = mtd->size - *ppos;
178
179         if (!count)
180                 return 0;
181
182         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
183            and pass them directly to the MTD functions */
184
185         if (count > MAX_KMALLOC_SIZE)
186                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
187         else
188                 kbuf=kmalloc(count, GFP_KERNEL);
189
190         if (!kbuf)
191                 return -ENOMEM;
192
193         while (count) {
194
195                 if (count > MAX_KMALLOC_SIZE)
196                         len = MAX_KMALLOC_SIZE;
197                 else
198                         len = count;
199
200                 switch (mfi->mode) {
201                 case MTD_MODE_OTP_FACTORY:
202                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
203                         break;
204                 case MTD_MODE_OTP_USER:
205                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
206                         break;
207                 case MTD_MODE_RAW:
208                 {
209                         struct mtd_oob_ops ops;
210
211                         ops.mode = MTD_OOB_RAW;
212                         ops.datbuf = kbuf;
213                         ops.oobbuf = NULL;
214                         ops.len = len;
215
216                         ret = mtd->read_oob(mtd, *ppos, &ops);
217                         retlen = ops.retlen;
218                         break;
219                 }
220                 default:
221                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
222                 }
223                 /* Nand returns -EBADMSG on ecc errors, but it returns
224                  * the data. For our userspace tools it is important
225                  * to dump areas with ecc errors !
226                  * For kernel internal usage it also might return -EUCLEAN
227                  * to signal the caller that a bitflip has occured and has
228                  * been corrected by the ECC algorithm.
229                  * Userspace software which accesses NAND this way
230                  * must be aware of the fact that it deals with NAND
231                  */
232                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
233                         *ppos += retlen;
234                         if (copy_to_user(buf, kbuf, retlen)) {
235                                 kfree(kbuf);
236                                 return -EFAULT;
237                         }
238                         else
239                                 total_retlen += retlen;
240
241                         count -= retlen;
242                         buf += retlen;
243                         if (retlen == 0)
244                                 count = 0;
245                 }
246                 else {
247                         kfree(kbuf);
248                         return ret;
249                 }
250
251         }
252
253         kfree(kbuf);
254         return total_retlen;
255 } /* mtd_read */
256
257 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
258 {
259         struct mtd_file_info *mfi = file->private_data;
260         struct mtd_info *mtd = mfi->mtd;
261         char *kbuf;
262         size_t retlen;
263         size_t total_retlen=0;
264         int ret=0;
265         int len;
266
267         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
268
269         if (*ppos == mtd->size)
270                 return -ENOSPC;
271
272         if (*ppos + count > mtd->size)
273                 count = mtd->size - *ppos;
274
275         if (!count)
276                 return 0;
277
278         if (count > MAX_KMALLOC_SIZE)
279                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
280         else
281                 kbuf=kmalloc(count, GFP_KERNEL);
282
283         if (!kbuf)
284                 return -ENOMEM;
285
286         while (count) {
287
288                 if (count > MAX_KMALLOC_SIZE)
289                         len = MAX_KMALLOC_SIZE;
290                 else
291                         len = count;
292
293                 if (copy_from_user(kbuf, buf, len)) {
294                         kfree(kbuf);
295                         return -EFAULT;
296                 }
297
298                 switch (mfi->mode) {
299                 case MTD_MODE_OTP_FACTORY:
300                         ret = -EROFS;
301                         break;
302                 case MTD_MODE_OTP_USER:
303                         if (!mtd->write_user_prot_reg) {
304                                 ret = -EOPNOTSUPP;
305                                 break;
306                         }
307                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
308                         break;
309
310                 case MTD_MODE_RAW:
311                 {
312                         struct mtd_oob_ops ops;
313
314                         ops.mode = MTD_OOB_RAW;
315                         ops.datbuf = kbuf;
316                         ops.oobbuf = NULL;
317                         ops.len = len;
318
319                         ret = mtd->write_oob(mtd, *ppos, &ops);
320                         retlen = ops.retlen;
321                         break;
322                 }
323
324                 default:
325                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
326                 }
327                 if (!ret) {
328                         *ppos += retlen;
329                         total_retlen += retlen;
330                         count -= retlen;
331                         buf += retlen;
332                 }
333                 else {
334                         kfree(kbuf);
335                         return ret;
336                 }
337         }
338
339         kfree(kbuf);
340         return total_retlen;
341 } /* mtd_write */
342
343 /*======================================================================
344
345     IOCTL calls for getting device parameters.
346
347 ======================================================================*/
348 static void mtdchar_erase_callback (struct erase_info *instr)
349 {
350         wake_up((wait_queue_head_t *)instr->priv);
351 }
352
353 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
354 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
355 {
356         struct mtd_info *mtd = mfi->mtd;
357         int ret = 0;
358
359         switch (mode) {
360         case MTD_OTP_FACTORY:
361                 if (!mtd->read_fact_prot_reg)
362                         ret = -EOPNOTSUPP;
363                 else
364                         mfi->mode = MTD_MODE_OTP_FACTORY;
365                 break;
366         case MTD_OTP_USER:
367                 if (!mtd->read_fact_prot_reg)
368                         ret = -EOPNOTSUPP;
369                 else
370                         mfi->mode = MTD_MODE_OTP_USER;
371                 break;
372         default:
373                 ret = -EINVAL;
374         case MTD_OTP_OFF:
375                 break;
376         }
377         return ret;
378 }
379 #else
380 # define otp_select_filemode(f,m)       -EOPNOTSUPP
381 #endif
382
383 static int mtd_ioctl(struct inode *inode, struct file *file,
384                      u_int cmd, u_long arg)
385 {
386         struct mtd_file_info *mfi = file->private_data;
387         struct mtd_info *mtd = mfi->mtd;
388         void __user *argp = (void __user *)arg;
389         int ret = 0;
390         u_long size;
391         struct mtd_info_user info;
392
393         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
394
395         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
396         if (cmd & IOC_IN) {
397                 if (!access_ok(VERIFY_READ, argp, size))
398                         return -EFAULT;
399         }
400         if (cmd & IOC_OUT) {
401                 if (!access_ok(VERIFY_WRITE, argp, size))
402                         return -EFAULT;
403         }
404
405         switch (cmd) {
406         case MEMGETREGIONCOUNT:
407                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
408                         return -EFAULT;
409                 break;
410
411         case MEMGETREGIONINFO:
412         {
413                 struct region_info_user ur;
414
415                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
416                         return -EFAULT;
417
418                 if (ur.regionindex >= mtd->numeraseregions)
419                         return -EINVAL;
420                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
421                                 sizeof(struct mtd_erase_region_info)))
422                         return -EFAULT;
423                 break;
424         }
425
426         case MEMGETINFO:
427                 info.type       = mtd->type;
428                 info.flags      = mtd->flags;
429                 info.size       = mtd->size;
430                 info.erasesize  = mtd->erasesize;
431                 info.writesize  = mtd->writesize;
432                 info.oobsize    = mtd->oobsize;
433                 /* The below fields are obsolete */
434                 info.ecctype    = -1;
435                 info.eccsize    = 0;
436                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
437                         return -EFAULT;
438                 break;
439
440         case MEMERASE:
441         {
442                 struct erase_info *erase;
443
444                 if(!(file->f_mode & 2))
445                         return -EPERM;
446
447                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
448                 if (!erase)
449                         ret = -ENOMEM;
450                 else {
451                         wait_queue_head_t waitq;
452                         DECLARE_WAITQUEUE(wait, current);
453
454                         init_waitqueue_head(&waitq);
455
456                         if (copy_from_user(&erase->addr, argp,
457                                     sizeof(struct erase_info_user))) {
458                                 kfree(erase);
459                                 return -EFAULT;
460                         }
461                         erase->mtd = mtd;
462                         erase->callback = mtdchar_erase_callback;
463                         erase->priv = (unsigned long)&waitq;
464
465                         /*
466                           FIXME: Allow INTERRUPTIBLE. Which means
467                           not having the wait_queue head on the stack.
468
469                           If the wq_head is on the stack, and we
470                           leave because we got interrupted, then the
471                           wq_head is no longer there when the
472                           callback routine tries to wake us up.
473                         */
474                         ret = mtd->erase(mtd, erase);
475                         if (!ret) {
476                                 set_current_state(TASK_UNINTERRUPTIBLE);
477                                 add_wait_queue(&waitq, &wait);
478                                 if (erase->state != MTD_ERASE_DONE &&
479                                     erase->state != MTD_ERASE_FAILED)
480                                         schedule();
481                                 remove_wait_queue(&waitq, &wait);
482                                 set_current_state(TASK_RUNNING);
483
484                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
485                         }
486                         kfree(erase);
487                 }
488                 break;
489         }
490
491         case MEMWRITEOOB:
492         {
493                 struct mtd_oob_buf buf;
494                 struct mtd_oob_ops ops;
495                 struct mtd_oob_buf __user *user_buf = argp;
496                 uint32_t retlen;
497
498                 if(!(file->f_mode & 2))
499                         return -EPERM;
500
501                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
502                         return -EFAULT;
503
504                 if (buf.length > 4096)
505                         return -EINVAL;
506
507                 if (!mtd->write_oob)
508                         ret = -EOPNOTSUPP;
509                 else
510                         ret = access_ok(VERIFY_READ, buf.ptr,
511                                         buf.length) ? 0 : EFAULT;
512
513                 if (ret)
514                         return ret;
515
516                 ops.ooblen = buf.length;
517                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
518                 ops.datbuf = NULL;
519                 ops.mode = MTD_OOB_PLACE;
520
521                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
522                         return -EINVAL;
523
524                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
525                 if (!ops.oobbuf)
526                         return -ENOMEM;
527
528                 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
529                         kfree(ops.oobbuf);
530                         return -EFAULT;
531                 }
532
533                 buf.start &= ~(mtd->oobsize - 1);
534                 ret = mtd->write_oob(mtd, buf.start, &ops);
535
536                 if (ops.oobretlen > 0xFFFFFFFFU)
537                         ret = -EOVERFLOW;
538                 retlen = ops.oobretlen;
539                 if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
540                         ret = -EFAULT;
541
542                 kfree(ops.oobbuf);
543                 break;
544
545         }
546
547         case MEMREADOOB:
548         {
549                 struct mtd_oob_buf buf;
550                 struct mtd_oob_ops ops;
551
552                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
553                         return -EFAULT;
554
555                 if (buf.length > 4096)
556                         return -EINVAL;
557
558                 if (!mtd->read_oob)
559                         ret = -EOPNOTSUPP;
560                 else
561                         ret = access_ok(VERIFY_WRITE, buf.ptr,
562                                         buf.length) ? 0 : -EFAULT;
563                 if (ret)
564                         return ret;
565
566                 ops.ooblen = buf.length;
567                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
568                 ops.datbuf = NULL;
569                 ops.mode = MTD_OOB_PLACE;
570
571                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
572                         return -EINVAL;
573
574                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
575                 if (!ops.oobbuf)
576                         return -ENOMEM;
577
578                 buf.start &= ~(mtd->oobsize - 1);
579                 ret = mtd->read_oob(mtd, buf.start, &ops);
580
581                 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
582                         ret = -EFAULT;
583                 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
584                                                     ops.oobretlen))
585                         ret = -EFAULT;
586
587                 kfree(ops.oobbuf);
588                 break;
589         }
590
591         case MEMLOCK:
592         {
593                 struct erase_info_user einfo;
594
595                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
596                         return -EFAULT;
597
598                 if (!mtd->lock)
599                         ret = -EOPNOTSUPP;
600                 else
601                         ret = mtd->lock(mtd, einfo.start, einfo.length);
602                 break;
603         }
604
605         case MEMUNLOCK:
606         {
607                 struct erase_info_user einfo;
608
609                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
610                         return -EFAULT;
611
612                 if (!mtd->unlock)
613                         ret = -EOPNOTSUPP;
614                 else
615                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
616                 break;
617         }
618
619         /* Legacy interface */
620         case MEMGETOOBSEL:
621         {
622                 struct nand_oobinfo oi;
623
624                 if (!mtd->ecclayout)
625                         return -EOPNOTSUPP;
626                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
627                         return -EINVAL;
628
629                 oi.useecc = MTD_NANDECC_AUTOPLACE;
630                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
631                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
632                        sizeof(oi.oobfree));
633                 oi.eccbytes = mtd->ecclayout->eccbytes;
634
635                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
636                         return -EFAULT;
637                 break;
638         }
639
640         case MEMGETBADBLOCK:
641         {
642                 loff_t offs;
643
644                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
645                         return -EFAULT;
646                 if (!mtd->block_isbad)
647                         ret = -EOPNOTSUPP;
648                 else
649                         return mtd->block_isbad(mtd, offs);
650                 break;
651         }
652
653         case MEMSETBADBLOCK:
654         {
655                 loff_t offs;
656
657                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
658                         return -EFAULT;
659                 if (!mtd->block_markbad)
660                         ret = -EOPNOTSUPP;
661                 else
662                         return mtd->block_markbad(mtd, offs);
663                 break;
664         }
665
666 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
667         case OTPSELECT:
668         {
669                 int mode;
670                 if (copy_from_user(&mode, argp, sizeof(int)))
671                         return -EFAULT;
672
673                 mfi->mode = MTD_MODE_NORMAL;
674
675                 ret = otp_select_filemode(mfi, mode);
676
677                 file->f_pos = 0;
678                 break;
679         }
680
681         case OTPGETREGIONCOUNT:
682         case OTPGETREGIONINFO:
683         {
684                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
685                 if (!buf)
686                         return -ENOMEM;
687                 ret = -EOPNOTSUPP;
688                 switch (mfi->mode) {
689                 case MTD_MODE_OTP_FACTORY:
690                         if (mtd->get_fact_prot_info)
691                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
692                         break;
693                 case MTD_MODE_OTP_USER:
694                         if (mtd->get_user_prot_info)
695                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
696                         break;
697                 default:
698                         break;
699                 }
700                 if (ret >= 0) {
701                         if (cmd == OTPGETREGIONCOUNT) {
702                                 int nbr = ret / sizeof(struct otp_info);
703                                 ret = copy_to_user(argp, &nbr, sizeof(int));
704                         } else
705                                 ret = copy_to_user(argp, buf, ret);
706                         if (ret)
707                                 ret = -EFAULT;
708                 }
709                 kfree(buf);
710                 break;
711         }
712
713         case OTPLOCK:
714         {
715                 struct otp_info oinfo;
716
717                 if (mfi->mode != MTD_MODE_OTP_USER)
718                         return -EINVAL;
719                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
720                         return -EFAULT;
721                 if (!mtd->lock_user_prot_reg)
722                         return -EOPNOTSUPP;
723                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
724                 break;
725         }
726 #endif
727
728         case ECCGETLAYOUT:
729         {
730                 if (!mtd->ecclayout)
731                         return -EOPNOTSUPP;
732
733                 if (copy_to_user(argp, mtd->ecclayout,
734                                  sizeof(struct nand_ecclayout)))
735                         return -EFAULT;
736                 break;
737         }
738
739         case ECCGETSTATS:
740         {
741                 if (copy_to_user(argp, &mtd->ecc_stats,
742                                  sizeof(struct mtd_ecc_stats)))
743                         return -EFAULT;
744                 break;
745         }
746
747         case MTDFILEMODE:
748         {
749                 mfi->mode = 0;
750
751                 switch(arg) {
752                 case MTD_MODE_OTP_FACTORY:
753                 case MTD_MODE_OTP_USER:
754                         ret = otp_select_filemode(mfi, arg);
755                         break;
756
757                 case MTD_MODE_RAW:
758                         if (!mtd->read_oob || !mtd->write_oob)
759                                 return -EOPNOTSUPP;
760                         mfi->mode = arg;
761
762                 case MTD_MODE_NORMAL:
763                         break;
764                 default:
765                         ret = -EINVAL;
766                 }
767                 file->f_pos = 0;
768                 break;
769         }
770
771         default:
772                 ret = -ENOTTY;
773         }
774
775         return ret;
776 } /* memory_ioctl */
777
778 static const struct file_operations mtd_fops = {
779         .owner          = THIS_MODULE,
780         .llseek         = mtd_lseek,
781         .read           = mtd_read,
782         .write          = mtd_write,
783         .ioctl          = mtd_ioctl,
784         .open           = mtd_open,
785         .release        = mtd_close,
786 };
787
788 static int __init init_mtdchar(void)
789 {
790         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
791                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
792                        MTD_CHAR_MAJOR);
793                 return -EAGAIN;
794         }
795
796         mtd_class = class_create(THIS_MODULE, "mtd");
797
798         if (IS_ERR(mtd_class)) {
799                 printk(KERN_ERR "Error creating mtd class.\n");
800                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
801                 return PTR_ERR(mtd_class);
802         }
803
804         register_mtd_user(&notifier);
805         return 0;
806 }
807
808 static void __exit cleanup_mtdchar(void)
809 {
810         unregister_mtd_user(&notifier);
811         class_destroy(mtd_class);
812         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
813 }
814
815 module_init(init_mtdchar);
816 module_exit(cleanup_mtdchar);
817
818
819 MODULE_LICENSE("GPL");
820 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
821 MODULE_DESCRIPTION("Direct character-device access to MTD devices");