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