Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc
[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
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/compatmac.h>
20
21 #include <asm/uaccess.h>
22
23 static struct class *mtd_class;
24
25 static void mtd_notify_add(struct mtd_info* mtd)
26 {
27         if (!mtd)
28                 return;
29
30         device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2), "mtd%d", mtd->index);
31
32         device_create(mtd_class, NULL,
33                       MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1), "mtd%dro", mtd->index);
34 }
35
36 static void mtd_notify_remove(struct mtd_info* mtd)
37 {
38         if (!mtd)
39                 return;
40
41         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
42         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
43 }
44
45 static struct mtd_notifier notifier = {
46         .add    = mtd_notify_add,
47         .remove = mtd_notify_remove,
48 };
49
50 /*
51  * Data structure to hold the pointer to the mtd device as well
52  * as mode information ofr various use cases.
53  */
54 struct mtd_file_info {
55         struct mtd_info *mtd;
56         enum mtd_file_modes mode;
57 };
58
59 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
60 {
61         struct mtd_file_info *mfi = file->private_data;
62         struct mtd_info *mtd = mfi->mtd;
63
64         switch (orig) {
65         case SEEK_SET:
66                 break;
67         case SEEK_CUR:
68                 offset += file->f_pos;
69                 break;
70         case SEEK_END:
71                 offset += mtd->size;
72                 break;
73         default:
74                 return -EINVAL;
75         }
76
77         if (offset >= 0 && offset <= mtd->size)
78                 return file->f_pos = offset;
79
80         return -EINVAL;
81 }
82
83
84
85 static int mtd_open(struct inode *inode, struct file *file)
86 {
87         int minor = iminor(inode);
88         int devnum = minor >> 1;
89         struct mtd_info *mtd;
90         struct mtd_file_info *mfi;
91
92         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
93
94         if (devnum >= MAX_MTD_DEVICES)
95                 return -ENODEV;
96
97         /* You can't open the RO devices RW */
98         if ((file->f_mode & 2) && (minor & 1))
99                 return -EACCES;
100
101         mtd = get_mtd_device(NULL, devnum);
102
103         if (IS_ERR(mtd))
104                 return PTR_ERR(mtd);
105
106         if (MTD_ABSENT == mtd->type) {
107                 put_mtd_device(mtd);
108                 return -ENODEV;
109         }
110
111         /* You can't open it RW if it's not a writeable device */
112         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
113                 put_mtd_device(mtd);
114                 return -EACCES;
115         }
116
117         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
118         if (!mfi) {
119                 put_mtd_device(mtd);
120                 return -ENOMEM;
121         }
122         mfi->mtd = mtd;
123         file->private_data = mfi;
124
125         return 0;
126 } /* mtd_open */
127
128 /*====================================================================*/
129
130 static int mtd_close(struct inode *inode, struct file *file)
131 {
132         struct mtd_file_info *mfi = file->private_data;
133         struct mtd_info *mtd = mfi->mtd;
134
135         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
136
137         /* Only sync if opened RW */
138         if ((file->f_mode & 2) && mtd->sync)
139                 mtd->sync(mtd);
140
141         put_mtd_device(mtd);
142         file->private_data = NULL;
143         kfree(mfi);
144
145         return 0;
146 } /* mtd_close */
147
148 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
149    userspace buffer down and use it directly with readv/writev.
150 */
151 #define MAX_KMALLOC_SIZE 0x20000
152
153 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
154 {
155         struct mtd_file_info *mfi = file->private_data;
156         struct mtd_info *mtd = mfi->mtd;
157         size_t retlen=0;
158         size_t total_retlen=0;
159         int ret=0;
160         int len;
161         char *kbuf;
162
163         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
164
165         if (*ppos + count > mtd->size)
166                 count = mtd->size - *ppos;
167
168         if (!count)
169                 return 0;
170
171         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
172            and pass them directly to the MTD functions */
173
174         if (count > MAX_KMALLOC_SIZE)
175                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
176         else
177                 kbuf=kmalloc(count, GFP_KERNEL);
178
179         if (!kbuf)
180                 return -ENOMEM;
181
182         while (count) {
183
184                 if (count > MAX_KMALLOC_SIZE)
185                         len = MAX_KMALLOC_SIZE;
186                 else
187                         len = count;
188
189                 switch (mfi->mode) {
190                 case MTD_MODE_OTP_FACTORY:
191                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
192                         break;
193                 case MTD_MODE_OTP_USER:
194                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
195                         break;
196                 case MTD_MODE_RAW:
197                 {
198                         struct mtd_oob_ops ops;
199
200                         ops.mode = MTD_OOB_RAW;
201                         ops.datbuf = kbuf;
202                         ops.oobbuf = NULL;
203                         ops.len = len;
204
205                         ret = mtd->read_oob(mtd, *ppos, &ops);
206                         retlen = ops.retlen;
207                         break;
208                 }
209                 default:
210                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
211                 }
212                 /* Nand returns -EBADMSG on ecc errors, but it returns
213                  * the data. For our userspace tools it is important
214                  * to dump areas with ecc errors !
215                  * For kernel internal usage it also might return -EUCLEAN
216                  * to signal the caller that a bitflip has occured and has
217                  * been corrected by the ECC algorithm.
218                  * Userspace software which accesses NAND this way
219                  * must be aware of the fact that it deals with NAND
220                  */
221                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
222                         *ppos += retlen;
223                         if (copy_to_user(buf, kbuf, retlen)) {
224                                 kfree(kbuf);
225                                 return -EFAULT;
226                         }
227                         else
228                                 total_retlen += retlen;
229
230                         count -= retlen;
231                         buf += retlen;
232                         if (retlen == 0)
233                                 count = 0;
234                 }
235                 else {
236                         kfree(kbuf);
237                         return ret;
238                 }
239
240         }
241
242         kfree(kbuf);
243         return total_retlen;
244 } /* mtd_read */
245
246 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
247 {
248         struct mtd_file_info *mfi = file->private_data;
249         struct mtd_info *mtd = mfi->mtd;
250         char *kbuf;
251         size_t retlen;
252         size_t total_retlen=0;
253         int ret=0;
254         int len;
255
256         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
257
258         if (*ppos == mtd->size)
259                 return -ENOSPC;
260
261         if (*ppos + count > mtd->size)
262                 count = mtd->size - *ppos;
263
264         if (!count)
265                 return 0;
266
267         if (count > MAX_KMALLOC_SIZE)
268                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
269         else
270                 kbuf=kmalloc(count, GFP_KERNEL);
271
272         if (!kbuf)
273                 return -ENOMEM;
274
275         while (count) {
276
277                 if (count > MAX_KMALLOC_SIZE)
278                         len = MAX_KMALLOC_SIZE;
279                 else
280                         len = count;
281
282                 if (copy_from_user(kbuf, buf, len)) {
283                         kfree(kbuf);
284                         return -EFAULT;
285                 }
286
287                 switch (mfi->mode) {
288                 case MTD_MODE_OTP_FACTORY:
289                         ret = -EROFS;
290                         break;
291                 case MTD_MODE_OTP_USER:
292                         if (!mtd->write_user_prot_reg) {
293                                 ret = -EOPNOTSUPP;
294                                 break;
295                         }
296                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
297                         break;
298
299                 case MTD_MODE_RAW:
300                 {
301                         struct mtd_oob_ops ops;
302
303                         ops.mode = MTD_OOB_RAW;
304                         ops.datbuf = kbuf;
305                         ops.oobbuf = NULL;
306                         ops.len = len;
307
308                         ret = mtd->write_oob(mtd, *ppos, &ops);
309                         retlen = ops.retlen;
310                         break;
311                 }
312
313                 default:
314                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
315                 }
316                 if (!ret) {
317                         *ppos += retlen;
318                         total_retlen += retlen;
319                         count -= retlen;
320                         buf += retlen;
321                 }
322                 else {
323                         kfree(kbuf);
324                         return ret;
325                 }
326         }
327
328         kfree(kbuf);
329         return total_retlen;
330 } /* mtd_write */
331
332 /*======================================================================
333
334     IOCTL calls for getting device parameters.
335
336 ======================================================================*/
337 static void mtdchar_erase_callback (struct erase_info *instr)
338 {
339         wake_up((wait_queue_head_t *)instr->priv);
340 }
341
342 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
343 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
344 {
345         struct mtd_info *mtd = mfi->mtd;
346         int ret = 0;
347
348         switch (mode) {
349         case MTD_OTP_FACTORY:
350                 if (!mtd->read_fact_prot_reg)
351                         ret = -EOPNOTSUPP;
352                 else
353                         mfi->mode = MTD_MODE_OTP_FACTORY;
354                 break;
355         case MTD_OTP_USER:
356                 if (!mtd->read_fact_prot_reg)
357                         ret = -EOPNOTSUPP;
358                 else
359                         mfi->mode = MTD_MODE_OTP_USER;
360                 break;
361         default:
362                 ret = -EINVAL;
363         case MTD_OTP_OFF:
364                 break;
365         }
366         return ret;
367 }
368 #else
369 # define otp_select_filemode(f,m)       -EOPNOTSUPP
370 #endif
371
372 static int mtd_ioctl(struct inode *inode, struct file *file,
373                      u_int cmd, u_long arg)
374 {
375         struct mtd_file_info *mfi = file->private_data;
376         struct mtd_info *mtd = mfi->mtd;
377         void __user *argp = (void __user *)arg;
378         int ret = 0;
379         u_long size;
380         struct mtd_info_user info;
381
382         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
383
384         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
385         if (cmd & IOC_IN) {
386                 if (!access_ok(VERIFY_READ, argp, size))
387                         return -EFAULT;
388         }
389         if (cmd & IOC_OUT) {
390                 if (!access_ok(VERIFY_WRITE, argp, size))
391                         return -EFAULT;
392         }
393
394         switch (cmd) {
395         case MEMGETREGIONCOUNT:
396                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
397                         return -EFAULT;
398                 break;
399
400         case MEMGETREGIONINFO:
401         {
402                 struct region_info_user ur;
403
404                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
405                         return -EFAULT;
406
407                 if (ur.regionindex >= mtd->numeraseregions)
408                         return -EINVAL;
409                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
410                                 sizeof(struct mtd_erase_region_info)))
411                         return -EFAULT;
412                 break;
413         }
414
415         case MEMGETINFO:
416                 info.type       = mtd->type;
417                 info.flags      = mtd->flags;
418                 info.size       = mtd->size;
419                 info.erasesize  = mtd->erasesize;
420                 info.writesize  = mtd->writesize;
421                 info.oobsize    = mtd->oobsize;
422                 /* The below fields are obsolete */
423                 info.ecctype    = -1;
424                 info.eccsize    = 0;
425                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
426                         return -EFAULT;
427                 break;
428
429         case MEMERASE:
430         {
431                 struct erase_info *erase;
432
433                 if(!(file->f_mode & 2))
434                         return -EPERM;
435
436                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
437                 if (!erase)
438                         ret = -ENOMEM;
439                 else {
440                         wait_queue_head_t waitq;
441                         DECLARE_WAITQUEUE(wait, current);
442
443                         init_waitqueue_head(&waitq);
444
445                         if (copy_from_user(&erase->addr, argp,
446                                     sizeof(struct erase_info_user))) {
447                                 kfree(erase);
448                                 return -EFAULT;
449                         }
450                         erase->mtd = mtd;
451                         erase->callback = mtdchar_erase_callback;
452                         erase->priv = (unsigned long)&waitq;
453
454                         /*
455                           FIXME: Allow INTERRUPTIBLE. Which means
456                           not having the wait_queue head on the stack.
457
458                           If the wq_head is on the stack, and we
459                           leave because we got interrupted, then the
460                           wq_head is no longer there when the
461                           callback routine tries to wake us up.
462                         */
463                         ret = mtd->erase(mtd, erase);
464                         if (!ret) {
465                                 set_current_state(TASK_UNINTERRUPTIBLE);
466                                 add_wait_queue(&waitq, &wait);
467                                 if (erase->state != MTD_ERASE_DONE &&
468                                     erase->state != MTD_ERASE_FAILED)
469                                         schedule();
470                                 remove_wait_queue(&waitq, &wait);
471                                 set_current_state(TASK_RUNNING);
472
473                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
474                         }
475                         kfree(erase);
476                 }
477                 break;
478         }
479
480         case MEMWRITEOOB:
481         {
482                 struct mtd_oob_buf buf;
483                 struct mtd_oob_ops ops;
484                 uint32_t retlen;
485
486                 if(!(file->f_mode & 2))
487                         return -EPERM;
488
489                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
490                         return -EFAULT;
491
492                 if (buf.length > 4096)
493                         return -EINVAL;
494
495                 if (!mtd->write_oob)
496                         ret = -EOPNOTSUPP;
497                 else
498                         ret = access_ok(VERIFY_READ, buf.ptr,
499                                         buf.length) ? 0 : EFAULT;
500
501                 if (ret)
502                         return ret;
503
504                 ops.ooblen = buf.length;
505                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
506                 ops.datbuf = NULL;
507                 ops.mode = MTD_OOB_PLACE;
508
509                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
510                         return -EINVAL;
511
512                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
513                 if (!ops.oobbuf)
514                         return -ENOMEM;
515
516                 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
517                         kfree(ops.oobbuf);
518                         return -EFAULT;
519                 }
520
521                 buf.start &= ~(mtd->oobsize - 1);
522                 ret = mtd->write_oob(mtd, buf.start, &ops);
523
524                 if (ops.oobretlen > 0xFFFFFFFFU)
525                         ret = -EOVERFLOW;
526                 retlen = ops.oobretlen;
527                 if (copy_to_user(&((struct mtd_oob_buf *)argp)->length,
528                                  &retlen, sizeof(buf.length)))
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.ooblen = buf.length;
556                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
557                 ops.datbuf = NULL;
558                 ops.mode = MTD_OOB_PLACE;
559
560                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
561                         return -EINVAL;
562
563                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
564                 if (!ops.oobbuf)
565                         return -ENOMEM;
566
567                 buf.start &= ~(mtd->oobsize - 1);
568                 ret = mtd->read_oob(mtd, buf.start, &ops);
569
570                 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
571                         ret = -EFAULT;
572                 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
573                                                     ops.oobretlen))
574                         ret = -EFAULT;
575
576                 kfree(ops.oobbuf);
577                 break;
578         }
579
580         case MEMLOCK:
581         {
582                 struct erase_info_user info;
583
584                 if (copy_from_user(&info, argp, sizeof(info)))
585                         return -EFAULT;
586
587                 if (!mtd->lock)
588                         ret = -EOPNOTSUPP;
589                 else
590                         ret = mtd->lock(mtd, info.start, info.length);
591                 break;
592         }
593
594         case MEMUNLOCK:
595         {
596                 struct erase_info_user info;
597
598                 if (copy_from_user(&info, argp, sizeof(info)))
599                         return -EFAULT;
600
601                 if (!mtd->unlock)
602                         ret = -EOPNOTSUPP;
603                 else
604                         ret = mtd->unlock(mtd, info.start, info.length);
605                 break;
606         }
607
608         /* Legacy interface */
609         case MEMGETOOBSEL:
610         {
611                 struct nand_oobinfo oi;
612
613                 if (!mtd->ecclayout)
614                         return -EOPNOTSUPP;
615                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
616                         return -EINVAL;
617
618                 oi.useecc = MTD_NANDECC_AUTOPLACE;
619                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
620                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
621                        sizeof(oi.oobfree));
622                 oi.eccbytes = mtd->ecclayout->eccbytes;
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 const 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");