Merge git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-2.6 into lvs-next-2.6
[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                 uint32_t ur_idx;
414                 struct mtd_erase_region_info *kr;
415                 struct region_info_user *ur = (struct region_info_user *) argp;
416
417                 if (get_user(ur_idx, &(ur->regionindex)))
418                         return -EFAULT;
419
420                 kr = &(mtd->eraseregions[ur_idx]);
421
422                 if (put_user(kr->offset, &(ur->offset))
423                     || put_user(kr->erasesize, &(ur->erasesize))
424                     || put_user(kr->numblocks, &(ur->numblocks)))
425                         return -EFAULT;
426
427                 break;
428         }
429
430         case MEMGETINFO:
431                 info.type       = mtd->type;
432                 info.flags      = mtd->flags;
433                 info.size       = mtd->size;
434                 info.erasesize  = mtd->erasesize;
435                 info.writesize  = mtd->writesize;
436                 info.oobsize    = mtd->oobsize;
437                 /* The below fields are obsolete */
438                 info.ecctype    = -1;
439                 info.eccsize    = 0;
440                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
441                         return -EFAULT;
442                 break;
443
444         case MEMERASE:
445         {
446                 struct erase_info *erase;
447
448                 if(!(file->f_mode & 2))
449                         return -EPERM;
450
451                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
452                 if (!erase)
453                         ret = -ENOMEM;
454                 else {
455                         wait_queue_head_t waitq;
456                         DECLARE_WAITQUEUE(wait, current);
457
458                         init_waitqueue_head(&waitq);
459
460                         if (copy_from_user(&erase->addr, argp,
461                                     sizeof(struct erase_info_user))) {
462                                 kfree(erase);
463                                 return -EFAULT;
464                         }
465                         erase->mtd = mtd;
466                         erase->callback = mtdchar_erase_callback;
467                         erase->priv = (unsigned long)&waitq;
468
469                         /*
470                           FIXME: Allow INTERRUPTIBLE. Which means
471                           not having the wait_queue head on the stack.
472
473                           If the wq_head is on the stack, and we
474                           leave because we got interrupted, then the
475                           wq_head is no longer there when the
476                           callback routine tries to wake us up.
477                         */
478                         ret = mtd->erase(mtd, erase);
479                         if (!ret) {
480                                 set_current_state(TASK_UNINTERRUPTIBLE);
481                                 add_wait_queue(&waitq, &wait);
482                                 if (erase->state != MTD_ERASE_DONE &&
483                                     erase->state != MTD_ERASE_FAILED)
484                                         schedule();
485                                 remove_wait_queue(&waitq, &wait);
486                                 set_current_state(TASK_RUNNING);
487
488                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
489                         }
490                         kfree(erase);
491                 }
492                 break;
493         }
494
495         case MEMWRITEOOB:
496         {
497                 struct mtd_oob_buf buf;
498                 struct mtd_oob_ops ops;
499                 struct mtd_oob_buf __user *user_buf = argp;
500                 uint32_t retlen;
501
502                 if(!(file->f_mode & 2))
503                         return -EPERM;
504
505                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
506                         return -EFAULT;
507
508                 if (buf.length > 4096)
509                         return -EINVAL;
510
511                 if (!mtd->write_oob)
512                         ret = -EOPNOTSUPP;
513                 else
514                         ret = access_ok(VERIFY_READ, buf.ptr,
515                                         buf.length) ? 0 : EFAULT;
516
517                 if (ret)
518                         return ret;
519
520                 ops.ooblen = buf.length;
521                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
522                 ops.datbuf = NULL;
523                 ops.mode = MTD_OOB_PLACE;
524
525                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
526                         return -EINVAL;
527
528                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
529                 if (!ops.oobbuf)
530                         return -ENOMEM;
531
532                 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
533                         kfree(ops.oobbuf);
534                         return -EFAULT;
535                 }
536
537                 buf.start &= ~(mtd->oobsize - 1);
538                 ret = mtd->write_oob(mtd, buf.start, &ops);
539
540                 if (ops.oobretlen > 0xFFFFFFFFU)
541                         ret = -EOVERFLOW;
542                 retlen = ops.oobretlen;
543                 if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
544                         ret = -EFAULT;
545
546                 kfree(ops.oobbuf);
547                 break;
548
549         }
550
551         case MEMREADOOB:
552         {
553                 struct mtd_oob_buf buf;
554                 struct mtd_oob_ops ops;
555
556                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
557                         return -EFAULT;
558
559                 if (buf.length > 4096)
560                         return -EINVAL;
561
562                 if (!mtd->read_oob)
563                         ret = -EOPNOTSUPP;
564                 else
565                         ret = access_ok(VERIFY_WRITE, buf.ptr,
566                                         buf.length) ? 0 : -EFAULT;
567                 if (ret)
568                         return ret;
569
570                 ops.ooblen = buf.length;
571                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
572                 ops.datbuf = NULL;
573                 ops.mode = MTD_OOB_PLACE;
574
575                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
576                         return -EINVAL;
577
578                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
579                 if (!ops.oobbuf)
580                         return -ENOMEM;
581
582                 buf.start &= ~(mtd->oobsize - 1);
583                 ret = mtd->read_oob(mtd, buf.start, &ops);
584
585                 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
586                         ret = -EFAULT;
587                 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
588                                                     ops.oobretlen))
589                         ret = -EFAULT;
590
591                 kfree(ops.oobbuf);
592                 break;
593         }
594
595         case MEMLOCK:
596         {
597                 struct erase_info_user einfo;
598
599                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
600                         return -EFAULT;
601
602                 if (!mtd->lock)
603                         ret = -EOPNOTSUPP;
604                 else
605                         ret = mtd->lock(mtd, einfo.start, einfo.length);
606                 break;
607         }
608
609         case MEMUNLOCK:
610         {
611                 struct erase_info_user einfo;
612
613                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
614                         return -EFAULT;
615
616                 if (!mtd->unlock)
617                         ret = -EOPNOTSUPP;
618                 else
619                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
620                 break;
621         }
622
623         /* Legacy interface */
624         case MEMGETOOBSEL:
625         {
626                 struct nand_oobinfo oi;
627
628                 if (!mtd->ecclayout)
629                         return -EOPNOTSUPP;
630                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
631                         return -EINVAL;
632
633                 oi.useecc = MTD_NANDECC_AUTOPLACE;
634                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
635                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
636                        sizeof(oi.oobfree));
637                 oi.eccbytes = mtd->ecclayout->eccbytes;
638
639                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
640                         return -EFAULT;
641                 break;
642         }
643
644         case MEMGETBADBLOCK:
645         {
646                 loff_t offs;
647
648                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
649                         return -EFAULT;
650                 if (!mtd->block_isbad)
651                         ret = -EOPNOTSUPP;
652                 else
653                         return mtd->block_isbad(mtd, offs);
654                 break;
655         }
656
657         case MEMSETBADBLOCK:
658         {
659                 loff_t offs;
660
661                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
662                         return -EFAULT;
663                 if (!mtd->block_markbad)
664                         ret = -EOPNOTSUPP;
665                 else
666                         return mtd->block_markbad(mtd, offs);
667                 break;
668         }
669
670 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
671         case OTPSELECT:
672         {
673                 int mode;
674                 if (copy_from_user(&mode, argp, sizeof(int)))
675                         return -EFAULT;
676
677                 mfi->mode = MTD_MODE_NORMAL;
678
679                 ret = otp_select_filemode(mfi, mode);
680
681                 file->f_pos = 0;
682                 break;
683         }
684
685         case OTPGETREGIONCOUNT:
686         case OTPGETREGIONINFO:
687         {
688                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
689                 if (!buf)
690                         return -ENOMEM;
691                 ret = -EOPNOTSUPP;
692                 switch (mfi->mode) {
693                 case MTD_MODE_OTP_FACTORY:
694                         if (mtd->get_fact_prot_info)
695                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
696                         break;
697                 case MTD_MODE_OTP_USER:
698                         if (mtd->get_user_prot_info)
699                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
700                         break;
701                 default:
702                         break;
703                 }
704                 if (ret >= 0) {
705                         if (cmd == OTPGETREGIONCOUNT) {
706                                 int nbr = ret / sizeof(struct otp_info);
707                                 ret = copy_to_user(argp, &nbr, sizeof(int));
708                         } else
709                                 ret = copy_to_user(argp, buf, ret);
710                         if (ret)
711                                 ret = -EFAULT;
712                 }
713                 kfree(buf);
714                 break;
715         }
716
717         case OTPLOCK:
718         {
719                 struct otp_info oinfo;
720
721                 if (mfi->mode != MTD_MODE_OTP_USER)
722                         return -EINVAL;
723                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
724                         return -EFAULT;
725                 if (!mtd->lock_user_prot_reg)
726                         return -EOPNOTSUPP;
727                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
728                 break;
729         }
730 #endif
731
732         case ECCGETLAYOUT:
733         {
734                 if (!mtd->ecclayout)
735                         return -EOPNOTSUPP;
736
737                 if (copy_to_user(argp, mtd->ecclayout,
738                                  sizeof(struct nand_ecclayout)))
739                         return -EFAULT;
740                 break;
741         }
742
743         case ECCGETSTATS:
744         {
745                 if (copy_to_user(argp, &mtd->ecc_stats,
746                                  sizeof(struct mtd_ecc_stats)))
747                         return -EFAULT;
748                 break;
749         }
750
751         case MTDFILEMODE:
752         {
753                 mfi->mode = 0;
754
755                 switch(arg) {
756                 case MTD_MODE_OTP_FACTORY:
757                 case MTD_MODE_OTP_USER:
758                         ret = otp_select_filemode(mfi, arg);
759                         break;
760
761                 case MTD_MODE_RAW:
762                         if (!mtd->read_oob || !mtd->write_oob)
763                                 return -EOPNOTSUPP;
764                         mfi->mode = arg;
765
766                 case MTD_MODE_NORMAL:
767                         break;
768                 default:
769                         ret = -EINVAL;
770                 }
771                 file->f_pos = 0;
772                 break;
773         }
774
775         default:
776                 ret = -ENOTTY;
777         }
778
779         return ret;
780 } /* memory_ioctl */
781
782 static const struct file_operations mtd_fops = {
783         .owner          = THIS_MODULE,
784         .llseek         = mtd_lseek,
785         .read           = mtd_read,
786         .write          = mtd_write,
787         .ioctl          = mtd_ioctl,
788         .open           = mtd_open,
789         .release        = mtd_close,
790 };
791
792 static int __init init_mtdchar(void)
793 {
794         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
795                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
796                        MTD_CHAR_MAJOR);
797                 return -EAGAIN;
798         }
799
800         mtd_class = class_create(THIS_MODULE, "mtd");
801
802         if (IS_ERR(mtd_class)) {
803                 printk(KERN_ERR "Error creating mtd class.\n");
804                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
805                 return PTR_ERR(mtd_class);
806         }
807
808         register_mtd_user(&notifier);
809         return 0;
810 }
811
812 static void __exit cleanup_mtdchar(void)
813 {
814         unregister_mtd_user(&notifier);
815         class_destroy(mtd_class);
816         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
817 }
818
819 module_init(init_mtdchar);
820 module_exit(cleanup_mtdchar);
821
822
823 MODULE_LICENSE("GPL");
824 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
825 MODULE_DESCRIPTION("Direct character-device access to MTD devices");