Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[linux-2.6.git] / 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 #include <linux/backing-dev.h>
17 #include <linux/compat.h>
18 #include <linux/mount.h>
19
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/compatmac.h>
22
23 #include <asm/uaccess.h>
24
25 #define MTD_INODE_FS_MAGIC 0x11307854
26 static struct vfsmount *mtd_inode_mnt __read_mostly;
27
28 /*
29  * Data structure to hold the pointer to the mtd device as well
30  * as mode information ofr various use cases.
31  */
32 struct mtd_file_info {
33         struct mtd_info *mtd;
34         struct inode *ino;
35         enum mtd_file_modes mode;
36 };
37
38 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
39 {
40         struct mtd_file_info *mfi = file->private_data;
41         struct mtd_info *mtd = mfi->mtd;
42
43         switch (orig) {
44         case SEEK_SET:
45                 break;
46         case SEEK_CUR:
47                 offset += file->f_pos;
48                 break;
49         case SEEK_END:
50                 offset += mtd->size;
51                 break;
52         default:
53                 return -EINVAL;
54         }
55
56         if (offset >= 0 && offset <= mtd->size)
57                 return file->f_pos = offset;
58
59         return -EINVAL;
60 }
61
62
63
64 static int mtd_open(struct inode *inode, struct file *file)
65 {
66         int minor = iminor(inode);
67         int devnum = minor >> 1;
68         int ret = 0;
69         struct mtd_info *mtd;
70         struct mtd_file_info *mfi;
71         struct inode *mtd_ino;
72
73         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
74
75         /* You can't open the RO devices RW */
76         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
77                 return -EACCES;
78
79         lock_kernel();
80         mtd = get_mtd_device(NULL, devnum);
81
82         if (IS_ERR(mtd)) {
83                 ret = PTR_ERR(mtd);
84                 goto out;
85         }
86
87         if (mtd->type == MTD_ABSENT) {
88                 put_mtd_device(mtd);
89                 ret = -ENODEV;
90                 goto out;
91         }
92
93         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
94         if (!mtd_ino) {
95                 put_mtd_device(mtd);
96                 ret = -ENOMEM;
97                 goto out;
98         }
99         if (mtd_ino->i_state & I_NEW) {
100                 mtd_ino->i_private = mtd;
101                 mtd_ino->i_mode = S_IFCHR;
102                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
103                 unlock_new_inode(mtd_ino);
104         }
105         file->f_mapping = mtd_ino->i_mapping;
106
107         /* You can't open it RW if it's not a writeable device */
108         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
109                 iput(mtd_ino);
110                 put_mtd_device(mtd);
111                 ret = -EACCES;
112                 goto out;
113         }
114
115         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
116         if (!mfi) {
117                 iput(mtd_ino);
118                 put_mtd_device(mtd);
119                 ret = -ENOMEM;
120                 goto out;
121         }
122         mfi->ino = mtd_ino;
123         mfi->mtd = mtd;
124         file->private_data = mfi;
125
126 out:
127         unlock_kernel();
128         return ret;
129 } /* mtd_open */
130
131 /*====================================================================*/
132
133 static int mtd_close(struct inode *inode, struct file *file)
134 {
135         struct mtd_file_info *mfi = file->private_data;
136         struct mtd_info *mtd = mfi->mtd;
137
138         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
139
140         /* Only sync if opened RW */
141         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
142                 mtd->sync(mtd);
143
144         iput(mfi->ino);
145
146         put_mtd_device(mtd);
147         file->private_data = NULL;
148         kfree(mfi);
149
150         return 0;
151 } /* mtd_close */
152
153 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
154    userspace buffer down and use it directly with readv/writev.
155 */
156 #define MAX_KMALLOC_SIZE 0x20000
157
158 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
159 {
160         struct mtd_file_info *mfi = file->private_data;
161         struct mtd_info *mtd = mfi->mtd;
162         size_t retlen=0;
163         size_t total_retlen=0;
164         int ret=0;
165         int len;
166         char *kbuf;
167
168         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
169
170         if (*ppos + count > mtd->size)
171                 count = mtd->size - *ppos;
172
173         if (!count)
174                 return 0;
175
176         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
177            and pass them directly to the MTD functions */
178
179         if (count > MAX_KMALLOC_SIZE)
180                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
181         else
182                 kbuf=kmalloc(count, GFP_KERNEL);
183
184         if (!kbuf)
185                 return -ENOMEM;
186
187         while (count) {
188
189                 if (count > MAX_KMALLOC_SIZE)
190                         len = MAX_KMALLOC_SIZE;
191                 else
192                         len = count;
193
194                 switch (mfi->mode) {
195                 case MTD_MODE_OTP_FACTORY:
196                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
197                         break;
198                 case MTD_MODE_OTP_USER:
199                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
200                         break;
201                 case MTD_MODE_RAW:
202                 {
203                         struct mtd_oob_ops ops;
204
205                         ops.mode = MTD_OOB_RAW;
206                         ops.datbuf = kbuf;
207                         ops.oobbuf = NULL;
208                         ops.len = len;
209
210                         ret = mtd->read_oob(mtd, *ppos, &ops);
211                         retlen = ops.retlen;
212                         break;
213                 }
214                 default:
215                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
216                 }
217                 /* Nand returns -EBADMSG on ecc errors, but it returns
218                  * the data. For our userspace tools it is important
219                  * to dump areas with ecc errors !
220                  * For kernel internal usage it also might return -EUCLEAN
221                  * to signal the caller that a bitflip has occured and has
222                  * been corrected by the ECC algorithm.
223                  * Userspace software which accesses NAND this way
224                  * must be aware of the fact that it deals with NAND
225                  */
226                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
227                         *ppos += retlen;
228                         if (copy_to_user(buf, kbuf, retlen)) {
229                                 kfree(kbuf);
230                                 return -EFAULT;
231                         }
232                         else
233                                 total_retlen += retlen;
234
235                         count -= retlen;
236                         buf += retlen;
237                         if (retlen == 0)
238                                 count = 0;
239                 }
240                 else {
241                         kfree(kbuf);
242                         return ret;
243                 }
244
245         }
246
247         kfree(kbuf);
248         return total_retlen;
249 } /* mtd_read */
250
251 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
252 {
253         struct mtd_file_info *mfi = file->private_data;
254         struct mtd_info *mtd = mfi->mtd;
255         char *kbuf;
256         size_t retlen;
257         size_t total_retlen=0;
258         int ret=0;
259         int len;
260
261         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
262
263         if (*ppos == mtd->size)
264                 return -ENOSPC;
265
266         if (*ppos + count > mtd->size)
267                 count = mtd->size - *ppos;
268
269         if (!count)
270                 return 0;
271
272         if (count > MAX_KMALLOC_SIZE)
273                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
274         else
275                 kbuf=kmalloc(count, GFP_KERNEL);
276
277         if (!kbuf)
278                 return -ENOMEM;
279
280         while (count) {
281
282                 if (count > MAX_KMALLOC_SIZE)
283                         len = MAX_KMALLOC_SIZE;
284                 else
285                         len = count;
286
287                 if (copy_from_user(kbuf, buf, len)) {
288                         kfree(kbuf);
289                         return -EFAULT;
290                 }
291
292                 switch (mfi->mode) {
293                 case MTD_MODE_OTP_FACTORY:
294                         ret = -EROFS;
295                         break;
296                 case MTD_MODE_OTP_USER:
297                         if (!mtd->write_user_prot_reg) {
298                                 ret = -EOPNOTSUPP;
299                                 break;
300                         }
301                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
302                         break;
303
304                 case MTD_MODE_RAW:
305                 {
306                         struct mtd_oob_ops ops;
307
308                         ops.mode = MTD_OOB_RAW;
309                         ops.datbuf = kbuf;
310                         ops.oobbuf = NULL;
311                         ops.len = len;
312
313                         ret = mtd->write_oob(mtd, *ppos, &ops);
314                         retlen = ops.retlen;
315                         break;
316                 }
317
318                 default:
319                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
320                 }
321                 if (!ret) {
322                         *ppos += retlen;
323                         total_retlen += retlen;
324                         count -= retlen;
325                         buf += retlen;
326                 }
327                 else {
328                         kfree(kbuf);
329                         return ret;
330                 }
331         }
332
333         kfree(kbuf);
334         return total_retlen;
335 } /* mtd_write */
336
337 /*======================================================================
338
339     IOCTL calls for getting device parameters.
340
341 ======================================================================*/
342 static void mtdchar_erase_callback (struct erase_info *instr)
343 {
344         wake_up((wait_queue_head_t *)instr->priv);
345 }
346
347 #ifdef CONFIG_HAVE_MTD_OTP
348 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
349 {
350         struct mtd_info *mtd = mfi->mtd;
351         int ret = 0;
352
353         switch (mode) {
354         case MTD_OTP_FACTORY:
355                 if (!mtd->read_fact_prot_reg)
356                         ret = -EOPNOTSUPP;
357                 else
358                         mfi->mode = MTD_MODE_OTP_FACTORY;
359                 break;
360         case MTD_OTP_USER:
361                 if (!mtd->read_fact_prot_reg)
362                         ret = -EOPNOTSUPP;
363                 else
364                         mfi->mode = MTD_MODE_OTP_USER;
365                 break;
366         default:
367                 ret = -EINVAL;
368         case MTD_OTP_OFF:
369                 break;
370         }
371         return ret;
372 }
373 #else
374 # define otp_select_filemode(f,m)       -EOPNOTSUPP
375 #endif
376
377 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
378         uint64_t start, uint32_t length, void __user *ptr,
379         uint32_t __user *retp)
380 {
381         struct mtd_oob_ops ops;
382         uint32_t retlen;
383         int ret = 0;
384
385         if (!(file->f_mode & FMODE_WRITE))
386                 return -EPERM;
387
388         if (length > 4096)
389                 return -EINVAL;
390
391         if (!mtd->write_oob)
392                 ret = -EOPNOTSUPP;
393         else
394                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
395
396         if (ret)
397                 return ret;
398
399         ops.ooblen = length;
400         ops.ooboffs = start & (mtd->oobsize - 1);
401         ops.datbuf = NULL;
402         ops.mode = MTD_OOB_PLACE;
403
404         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
405                 return -EINVAL;
406
407         ops.oobbuf = memdup_user(ptr, length);
408         if (IS_ERR(ops.oobbuf))
409                 return PTR_ERR(ops.oobbuf);
410
411         start &= ~((uint64_t)mtd->oobsize - 1);
412         ret = mtd->write_oob(mtd, start, &ops);
413
414         if (ops.oobretlen > 0xFFFFFFFFU)
415                 ret = -EOVERFLOW;
416         retlen = ops.oobretlen;
417         if (copy_to_user(retp, &retlen, sizeof(length)))
418                 ret = -EFAULT;
419
420         kfree(ops.oobbuf);
421         return ret;
422 }
423
424 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
425         uint32_t length, void __user *ptr, uint32_t __user *retp)
426 {
427         struct mtd_oob_ops ops;
428         int ret = 0;
429
430         if (length > 4096)
431                 return -EINVAL;
432
433         if (!mtd->read_oob)
434                 ret = -EOPNOTSUPP;
435         else
436                 ret = access_ok(VERIFY_WRITE, ptr,
437                                 length) ? 0 : -EFAULT;
438         if (ret)
439                 return ret;
440
441         ops.ooblen = length;
442         ops.ooboffs = start & (mtd->oobsize - 1);
443         ops.datbuf = NULL;
444         ops.mode = MTD_OOB_PLACE;
445
446         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
447                 return -EINVAL;
448
449         ops.oobbuf = kmalloc(length, GFP_KERNEL);
450         if (!ops.oobbuf)
451                 return -ENOMEM;
452
453         start &= ~((uint64_t)mtd->oobsize - 1);
454         ret = mtd->read_oob(mtd, start, &ops);
455
456         if (put_user(ops.oobretlen, retp))
457                 ret = -EFAULT;
458         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
459                                             ops.oobretlen))
460                 ret = -EFAULT;
461
462         kfree(ops.oobbuf);
463         return ret;
464 }
465
466 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
467 {
468         struct mtd_file_info *mfi = file->private_data;
469         struct mtd_info *mtd = mfi->mtd;
470         void __user *argp = (void __user *)arg;
471         int ret = 0;
472         u_long size;
473         struct mtd_info_user info;
474
475         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
476
477         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
478         if (cmd & IOC_IN) {
479                 if (!access_ok(VERIFY_READ, argp, size))
480                         return -EFAULT;
481         }
482         if (cmd & IOC_OUT) {
483                 if (!access_ok(VERIFY_WRITE, argp, size))
484                         return -EFAULT;
485         }
486
487         switch (cmd) {
488         case MEMGETREGIONCOUNT:
489                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
490                         return -EFAULT;
491                 break;
492
493         case MEMGETREGIONINFO:
494         {
495                 uint32_t ur_idx;
496                 struct mtd_erase_region_info *kr;
497                 struct region_info_user __user *ur = argp;
498
499                 if (get_user(ur_idx, &(ur->regionindex)))
500                         return -EFAULT;
501
502                 kr = &(mtd->eraseregions[ur_idx]);
503
504                 if (put_user(kr->offset, &(ur->offset))
505                     || put_user(kr->erasesize, &(ur->erasesize))
506                     || put_user(kr->numblocks, &(ur->numblocks)))
507                         return -EFAULT;
508
509                 break;
510         }
511
512         case MEMGETINFO:
513                 info.type       = mtd->type;
514                 info.flags      = mtd->flags;
515                 info.size       = mtd->size;
516                 info.erasesize  = mtd->erasesize;
517                 info.writesize  = mtd->writesize;
518                 info.oobsize    = mtd->oobsize;
519                 /* The below fields are obsolete */
520                 info.ecctype    = -1;
521                 info.eccsize    = 0;
522                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
523                         return -EFAULT;
524                 break;
525
526         case MEMERASE:
527         case MEMERASE64:
528         {
529                 struct erase_info *erase;
530
531                 if(!(file->f_mode & FMODE_WRITE))
532                         return -EPERM;
533
534                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
535                 if (!erase)
536                         ret = -ENOMEM;
537                 else {
538                         wait_queue_head_t waitq;
539                         DECLARE_WAITQUEUE(wait, current);
540
541                         init_waitqueue_head(&waitq);
542
543                         if (cmd == MEMERASE64) {
544                                 struct erase_info_user64 einfo64;
545
546                                 if (copy_from_user(&einfo64, argp,
547                                             sizeof(struct erase_info_user64))) {
548                                         kfree(erase);
549                                         return -EFAULT;
550                                 }
551                                 erase->addr = einfo64.start;
552                                 erase->len = einfo64.length;
553                         } else {
554                                 struct erase_info_user einfo32;
555
556                                 if (copy_from_user(&einfo32, argp,
557                                             sizeof(struct erase_info_user))) {
558                                         kfree(erase);
559                                         return -EFAULT;
560                                 }
561                                 erase->addr = einfo32.start;
562                                 erase->len = einfo32.length;
563                         }
564                         erase->mtd = mtd;
565                         erase->callback = mtdchar_erase_callback;
566                         erase->priv = (unsigned long)&waitq;
567
568                         /*
569                           FIXME: Allow INTERRUPTIBLE. Which means
570                           not having the wait_queue head on the stack.
571
572                           If the wq_head is on the stack, and we
573                           leave because we got interrupted, then the
574                           wq_head is no longer there when the
575                           callback routine tries to wake us up.
576                         */
577                         ret = mtd->erase(mtd, erase);
578                         if (!ret) {
579                                 set_current_state(TASK_UNINTERRUPTIBLE);
580                                 add_wait_queue(&waitq, &wait);
581                                 if (erase->state != MTD_ERASE_DONE &&
582                                     erase->state != MTD_ERASE_FAILED)
583                                         schedule();
584                                 remove_wait_queue(&waitq, &wait);
585                                 set_current_state(TASK_RUNNING);
586
587                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
588                         }
589                         kfree(erase);
590                 }
591                 break;
592         }
593
594         case MEMWRITEOOB:
595         {
596                 struct mtd_oob_buf buf;
597                 struct mtd_oob_buf __user *buf_user = argp;
598
599                 /* NOTE: writes return length to buf_user->length */
600                 if (copy_from_user(&buf, argp, sizeof(buf)))
601                         ret = -EFAULT;
602                 else
603                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
604                                 buf.ptr, &buf_user->length);
605                 break;
606         }
607
608         case MEMREADOOB:
609         {
610                 struct mtd_oob_buf buf;
611                 struct mtd_oob_buf __user *buf_user = argp;
612
613                 /* NOTE: writes return length to buf_user->start */
614                 if (copy_from_user(&buf, argp, sizeof(buf)))
615                         ret = -EFAULT;
616                 else
617                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
618                                 buf.ptr, &buf_user->start);
619                 break;
620         }
621
622         case MEMWRITEOOB64:
623         {
624                 struct mtd_oob_buf64 buf;
625                 struct mtd_oob_buf64 __user *buf_user = argp;
626
627                 if (copy_from_user(&buf, argp, sizeof(buf)))
628                         ret = -EFAULT;
629                 else
630                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
631                                 (void __user *)(uintptr_t)buf.usr_ptr,
632                                 &buf_user->length);
633                 break;
634         }
635
636         case MEMREADOOB64:
637         {
638                 struct mtd_oob_buf64 buf;
639                 struct mtd_oob_buf64 __user *buf_user = argp;
640
641                 if (copy_from_user(&buf, argp, sizeof(buf)))
642                         ret = -EFAULT;
643                 else
644                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
645                                 (void __user *)(uintptr_t)buf.usr_ptr,
646                                 &buf_user->length);
647                 break;
648         }
649
650         case MEMLOCK:
651         {
652                 struct erase_info_user einfo;
653
654                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
655                         return -EFAULT;
656
657                 if (!mtd->lock)
658                         ret = -EOPNOTSUPP;
659                 else
660                         ret = mtd->lock(mtd, einfo.start, einfo.length);
661                 break;
662         }
663
664         case MEMUNLOCK:
665         {
666                 struct erase_info_user einfo;
667
668                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
669                         return -EFAULT;
670
671                 if (!mtd->unlock)
672                         ret = -EOPNOTSUPP;
673                 else
674                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
675                 break;
676         }
677
678         /* Legacy interface */
679         case MEMGETOOBSEL:
680         {
681                 struct nand_oobinfo oi;
682
683                 if (!mtd->ecclayout)
684                         return -EOPNOTSUPP;
685                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
686                         return -EINVAL;
687
688                 oi.useecc = MTD_NANDECC_AUTOPLACE;
689                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
690                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
691                        sizeof(oi.oobfree));
692                 oi.eccbytes = mtd->ecclayout->eccbytes;
693
694                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
695                         return -EFAULT;
696                 break;
697         }
698
699         case MEMGETBADBLOCK:
700         {
701                 loff_t offs;
702
703                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
704                         return -EFAULT;
705                 if (!mtd->block_isbad)
706                         ret = -EOPNOTSUPP;
707                 else
708                         return mtd->block_isbad(mtd, offs);
709                 break;
710         }
711
712         case MEMSETBADBLOCK:
713         {
714                 loff_t offs;
715
716                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
717                         return -EFAULT;
718                 if (!mtd->block_markbad)
719                         ret = -EOPNOTSUPP;
720                 else
721                         return mtd->block_markbad(mtd, offs);
722                 break;
723         }
724
725 #ifdef CONFIG_HAVE_MTD_OTP
726         case OTPSELECT:
727         {
728                 int mode;
729                 if (copy_from_user(&mode, argp, sizeof(int)))
730                         return -EFAULT;
731
732                 mfi->mode = MTD_MODE_NORMAL;
733
734                 ret = otp_select_filemode(mfi, mode);
735
736                 file->f_pos = 0;
737                 break;
738         }
739
740         case OTPGETREGIONCOUNT:
741         case OTPGETREGIONINFO:
742         {
743                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
744                 if (!buf)
745                         return -ENOMEM;
746                 ret = -EOPNOTSUPP;
747                 switch (mfi->mode) {
748                 case MTD_MODE_OTP_FACTORY:
749                         if (mtd->get_fact_prot_info)
750                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
751                         break;
752                 case MTD_MODE_OTP_USER:
753                         if (mtd->get_user_prot_info)
754                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
755                         break;
756                 default:
757                         break;
758                 }
759                 if (ret >= 0) {
760                         if (cmd == OTPGETREGIONCOUNT) {
761                                 int nbr = ret / sizeof(struct otp_info);
762                                 ret = copy_to_user(argp, &nbr, sizeof(int));
763                         } else
764                                 ret = copy_to_user(argp, buf, ret);
765                         if (ret)
766                                 ret = -EFAULT;
767                 }
768                 kfree(buf);
769                 break;
770         }
771
772         case OTPLOCK:
773         {
774                 struct otp_info oinfo;
775
776                 if (mfi->mode != MTD_MODE_OTP_USER)
777                         return -EINVAL;
778                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
779                         return -EFAULT;
780                 if (!mtd->lock_user_prot_reg)
781                         return -EOPNOTSUPP;
782                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
783                 break;
784         }
785 #endif
786
787         case ECCGETLAYOUT:
788         {
789                 if (!mtd->ecclayout)
790                         return -EOPNOTSUPP;
791
792                 if (copy_to_user(argp, mtd->ecclayout,
793                                  sizeof(struct nand_ecclayout)))
794                         return -EFAULT;
795                 break;
796         }
797
798         case ECCGETSTATS:
799         {
800                 if (copy_to_user(argp, &mtd->ecc_stats,
801                                  sizeof(struct mtd_ecc_stats)))
802                         return -EFAULT;
803                 break;
804         }
805
806         case MTDFILEMODE:
807         {
808                 mfi->mode = 0;
809
810                 switch(arg) {
811                 case MTD_MODE_OTP_FACTORY:
812                 case MTD_MODE_OTP_USER:
813                         ret = otp_select_filemode(mfi, arg);
814                         break;
815
816                 case MTD_MODE_RAW:
817                         if (!mtd->read_oob || !mtd->write_oob)
818                                 return -EOPNOTSUPP;
819                         mfi->mode = arg;
820
821                 case MTD_MODE_NORMAL:
822                         break;
823                 default:
824                         ret = -EINVAL;
825                 }
826                 file->f_pos = 0;
827                 break;
828         }
829
830         default:
831                 ret = -ENOTTY;
832         }
833
834         return ret;
835 } /* memory_ioctl */
836
837 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
838 {
839         int ret;
840
841         lock_kernel();
842         ret = mtd_ioctl(file, cmd, arg);
843         unlock_kernel();
844
845         return ret;
846 }
847
848 #ifdef CONFIG_COMPAT
849
850 struct mtd_oob_buf32 {
851         u_int32_t start;
852         u_int32_t length;
853         compat_caddr_t ptr;     /* unsigned char* */
854 };
855
856 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
857 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
858
859 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
860         unsigned long arg)
861 {
862         struct mtd_file_info *mfi = file->private_data;
863         struct mtd_info *mtd = mfi->mtd;
864         void __user *argp = compat_ptr(arg);
865         int ret = 0;
866
867         lock_kernel();
868
869         switch (cmd) {
870         case MEMWRITEOOB32:
871         {
872                 struct mtd_oob_buf32 buf;
873                 struct mtd_oob_buf32 __user *buf_user = argp;
874
875                 if (copy_from_user(&buf, argp, sizeof(buf)))
876                         ret = -EFAULT;
877                 else
878                         ret = mtd_do_writeoob(file, mtd, buf.start,
879                                 buf.length, compat_ptr(buf.ptr),
880                                 &buf_user->length);
881                 break;
882         }
883
884         case MEMREADOOB32:
885         {
886                 struct mtd_oob_buf32 buf;
887                 struct mtd_oob_buf32 __user *buf_user = argp;
888
889                 /* NOTE: writes return length to buf->start */
890                 if (copy_from_user(&buf, argp, sizeof(buf)))
891                         ret = -EFAULT;
892                 else
893                         ret = mtd_do_readoob(mtd, buf.start,
894                                 buf.length, compat_ptr(buf.ptr),
895                                 &buf_user->start);
896                 break;
897         }
898         default:
899                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
900         }
901
902         unlock_kernel();
903
904         return ret;
905 }
906
907 #endif /* CONFIG_COMPAT */
908
909 /*
910  * try to determine where a shared mapping can be made
911  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
912  *   mappings)
913  */
914 #ifndef CONFIG_MMU
915 static unsigned long mtd_get_unmapped_area(struct file *file,
916                                            unsigned long addr,
917                                            unsigned long len,
918                                            unsigned long pgoff,
919                                            unsigned long flags)
920 {
921         struct mtd_file_info *mfi = file->private_data;
922         struct mtd_info *mtd = mfi->mtd;
923
924         if (mtd->get_unmapped_area) {
925                 unsigned long offset;
926
927                 if (addr != 0)
928                         return (unsigned long) -EINVAL;
929
930                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
931                         return (unsigned long) -EINVAL;
932
933                 offset = pgoff << PAGE_SHIFT;
934                 if (offset > mtd->size - len)
935                         return (unsigned long) -EINVAL;
936
937                 return mtd->get_unmapped_area(mtd, len, offset, flags);
938         }
939
940         /* can't map directly */
941         return (unsigned long) -ENOSYS;
942 }
943 #endif
944
945 /*
946  * set up a mapping for shared memory segments
947  */
948 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
949 {
950 #ifdef CONFIG_MMU
951         struct mtd_file_info *mfi = file->private_data;
952         struct mtd_info *mtd = mfi->mtd;
953
954         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
955                 return 0;
956         return -ENOSYS;
957 #else
958         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
959 #endif
960 }
961
962 static const struct file_operations mtd_fops = {
963         .owner          = THIS_MODULE,
964         .llseek         = mtd_lseek,
965         .read           = mtd_read,
966         .write          = mtd_write,
967         .unlocked_ioctl = mtd_unlocked_ioctl,
968 #ifdef CONFIG_COMPAT
969         .compat_ioctl   = mtd_compat_ioctl,
970 #endif
971         .open           = mtd_open,
972         .release        = mtd_close,
973         .mmap           = mtd_mmap,
974 #ifndef CONFIG_MMU
975         .get_unmapped_area = mtd_get_unmapped_area,
976 #endif
977 };
978
979 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
980                                const char *dev_name, void *data,
981                                struct vfsmount *mnt)
982 {
983         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
984                              mnt);
985 }
986
987 static struct file_system_type mtd_inodefs_type = {
988        .name = "mtd_inodefs",
989        .get_sb = mtd_inodefs_get_sb,
990        .kill_sb = kill_anon_super,
991 };
992
993 static void mtdchar_notify_add(struct mtd_info *mtd)
994 {
995 }
996
997 static void mtdchar_notify_remove(struct mtd_info *mtd)
998 {
999         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1000
1001         if (mtd_ino) {
1002                 /* Destroy the inode if it exists */
1003                 mtd_ino->i_nlink = 0;
1004                 iput(mtd_ino);
1005         }
1006 }
1007
1008 static struct mtd_notifier mtdchar_notifier = {
1009         .add = mtdchar_notify_add,
1010         .remove = mtdchar_notify_remove,
1011 };
1012
1013 static int __init init_mtdchar(void)
1014 {
1015         int ret;
1016
1017         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1018                                    "mtd", &mtd_fops);
1019         if (ret < 0) {
1020                 pr_notice("Can't allocate major number %d for "
1021                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1022                 return ret;
1023         }
1024
1025         ret = register_filesystem(&mtd_inodefs_type);
1026         if (ret) {
1027                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1028                 goto err_unregister_chdev;
1029         }
1030
1031         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1032         if (IS_ERR(mtd_inode_mnt)) {
1033                 ret = PTR_ERR(mtd_inode_mnt);
1034                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1035                 goto err_unregister_filesystem;
1036         }
1037         register_mtd_user(&mtdchar_notifier);
1038
1039         return ret;
1040
1041 err_unregister_filesystem:
1042         unregister_filesystem(&mtd_inodefs_type);
1043 err_unregister_chdev:
1044         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1045         return ret;
1046 }
1047
1048 static void __exit cleanup_mtdchar(void)
1049 {
1050         unregister_mtd_user(&mtdchar_notifier);
1051         mntput(mtd_inode_mnt);
1052         unregister_filesystem(&mtd_inodefs_type);
1053         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1054 }
1055
1056 module_init(init_mtdchar);
1057 module_exit(cleanup_mtdchar);
1058
1059 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1060
1061 MODULE_LICENSE("GPL");
1062 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1063 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1064 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);