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