4b3c6263e7fcdcf22a3481f1b3e096179a71d7fe
[sfrench/cifs-2.6.git] / drivers / mtd / mtdchar.c
1 /*
2  * $Id: mtdchar.c,v 1.74 2005/08/04 01:05:48 tpoynor Exp $
3  *
4  * Character-device access to raw MTD devices.
5  *
6  */
7
8 #include <linux/config.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/mtd/mtd.h>
12 #include <linux/mtd/compatmac.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/fs.h>
16 #include <asm/uaccess.h>
17
18 #include <linux/device.h>
19
20 static struct class *mtd_class;
21
22 static void mtd_notify_add(struct mtd_info* mtd)
23 {
24         if (!mtd)
25                 return;
26
27         class_device_create(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
28                             NULL, "mtd%d", mtd->index);
29         
30         class_device_create(mtd_class, 
31                             MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
32                             NULL, "mtd%dro", mtd->index);
33 }
34
35 static void mtd_notify_remove(struct mtd_info* mtd)
36 {
37         if (!mtd)
38                 return;
39
40         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
41         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
42 }
43
44 static struct mtd_notifier notifier = {
45         .add    = mtd_notify_add,
46         .remove = mtd_notify_remove,
47 };
48
49 /*
50  * We use file->private_data to store a pointer to the MTDdevice.
51  * Since alighment is at least 32 bits, we have 2 bits free for OTP
52  * modes as well.
53  */
54
55 #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
56
57 #define MTD_MODE_OTP_FACT       1
58 #define MTD_MODE_OTP_USER       2
59 #define MTD_MODE(file)          ((long)((file)->private_data) & 3)
60
61 #define SET_MTD_MODE(file, mode) \
62         do { long __p = (long)((file)->private_data); \
63              (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
64
65 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
66 {
67         struct mtd_info *mtd = TO_MTD(file);
68
69         switch (orig) {
70         case 0:
71                 /* SEEK_SET */
72                 break;
73         case 1:
74                 /* SEEK_CUR */
75                 offset += file->f_pos;
76                 break;
77         case 2:
78                 /* SEEK_END */
79                 offset += mtd->size;
80                 break;
81         default:
82                 return -EINVAL;
83         }
84
85         if (offset >= 0 && offset < mtd->size)
86                 return file->f_pos = offset;
87
88         return -EINVAL;
89 }
90
91
92
93 static int mtd_open(struct inode *inode, struct file *file)
94 {
95         int minor = iminor(inode);
96         int devnum = minor >> 1;
97         struct mtd_info *mtd;
98
99         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
100
101         if (devnum >= MAX_MTD_DEVICES)
102                 return -ENODEV;
103
104         /* You can't open the RO devices RW */
105         if ((file->f_mode & 2) && (minor & 1))
106                 return -EACCES;
107
108         mtd = get_mtd_device(NULL, devnum);
109         
110         if (!mtd)
111                 return -ENODEV;
112         
113         if (MTD_ABSENT == mtd->type) {
114                 put_mtd_device(mtd);
115                 return -ENODEV;
116         }
117
118         file->private_data = mtd;
119                 
120         /* You can't open it RW if it's not a writeable device */
121         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
122                 put_mtd_device(mtd);
123                 return -EACCES;
124         }
125                 
126         return 0;
127 } /* mtd_open */
128
129 /*====================================================================*/
130
131 static int mtd_close(struct inode *inode, struct file *file)
132 {
133         struct mtd_info *mtd;
134
135         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
136
137         mtd = TO_MTD(file);
138         
139         if (mtd->sync)
140                 mtd->sync(mtd);
141         
142         put_mtd_device(mtd);
143
144         return 0;
145 } /* mtd_close */
146
147 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
148    userspace buffer down and use it directly with readv/writev.
149 */
150 #define MAX_KMALLOC_SIZE 0x20000
151
152 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
153 {
154         struct mtd_info *mtd = TO_MTD(file);
155         size_t retlen=0;
156         size_t total_retlen=0;
157         int ret=0;
158         int len;
159         char *kbuf;
160         
161         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
162
163         if (*ppos + count > mtd->size)
164                 count = mtd->size - *ppos;
165
166         if (!count)
167                 return 0;
168         
169         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
170            and pass them directly to the MTD functions */
171         while (count) {
172                 if (count > MAX_KMALLOC_SIZE) 
173                         len = MAX_KMALLOC_SIZE;
174                 else
175                         len = count;
176
177                 kbuf=kmalloc(len,GFP_KERNEL);
178                 if (!kbuf)
179                         return -ENOMEM;
180                 
181                 switch (MTD_MODE(file)) {
182                 case MTD_MODE_OTP_FACT:
183                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
184                         break;
185                 case MTD_MODE_OTP_USER:
186                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
187                         break;
188                 default:
189                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
190                 }
191                 /* Nand returns -EBADMSG on ecc errors, but it returns
192                  * the data. For our userspace tools it is important
193                  * to dump areas with ecc errors ! 
194                  * Userspace software which accesses NAND this way
195                  * must be aware of the fact that it deals with NAND
196                  */
197                 if (!ret || (ret == -EBADMSG)) {
198                         *ppos += retlen;
199                         if (copy_to_user(buf, kbuf, retlen)) {
200                                 kfree(kbuf);
201                                 return -EFAULT;
202                         }
203                         else
204                                 total_retlen += retlen;
205
206                         count -= retlen;
207                         buf += retlen;
208                         if (retlen == 0)
209                                 count = 0;
210                 }
211                 else {
212                         kfree(kbuf);
213                         return ret;
214                 }
215                 
216                 kfree(kbuf);
217         }
218
219         return total_retlen;
220 } /* mtd_read */
221
222 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
223 {
224         struct mtd_info *mtd = TO_MTD(file);
225         char *kbuf;
226         size_t retlen;
227         size_t total_retlen=0;
228         int ret=0;
229         int len;
230
231         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
232         
233         if (*ppos == mtd->size)
234                 return -ENOSPC;
235         
236         if (*ppos + count > mtd->size)
237                 count = mtd->size - *ppos;
238
239         if (!count)
240                 return 0;
241
242         while (count) {
243                 if (count > MAX_KMALLOC_SIZE) 
244                         len = MAX_KMALLOC_SIZE;
245                 else
246                         len = count;
247
248                 kbuf=kmalloc(len,GFP_KERNEL);
249                 if (!kbuf) {
250                         printk("kmalloc is null\n");
251                         return -ENOMEM;
252                 }
253
254                 if (copy_from_user(kbuf, buf, len)) {
255                         kfree(kbuf);
256                         return -EFAULT;
257                 }
258                 
259                 switch (MTD_MODE(file)) {
260                 case MTD_MODE_OTP_FACT:
261                         ret = -EROFS;
262                         break;
263                 case MTD_MODE_OTP_USER:
264                         if (!mtd->write_user_prot_reg) {
265                                 ret = -EOPNOTSUPP;
266                                 break;
267                         }
268                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
269                         break;
270                 default:
271                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
272                 }
273                 if (!ret) {
274                         *ppos += retlen;
275                         total_retlen += retlen;
276                         count -= retlen;
277                         buf += retlen;
278                 }
279                 else {
280                         kfree(kbuf);
281                         return ret;
282                 }
283                 
284                 kfree(kbuf);
285         }
286
287         return total_retlen;
288 } /* mtd_write */
289
290 /*======================================================================
291
292     IOCTL calls for getting device parameters.
293
294 ======================================================================*/
295 static void mtdchar_erase_callback (struct erase_info *instr)
296 {
297         wake_up((wait_queue_head_t *)instr->priv);
298 }
299
300 static int mtd_ioctl(struct inode *inode, struct file *file,
301                      u_int cmd, u_long arg)
302 {
303         struct mtd_info *mtd = TO_MTD(file);
304         void __user *argp = (void __user *)arg;
305         int ret = 0;
306         u_long size;
307         
308         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
309
310         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
311         if (cmd & IOC_IN) {
312                 if (!access_ok(VERIFY_READ, argp, size))
313                         return -EFAULT;
314         }
315         if (cmd & IOC_OUT) {
316                 if (!access_ok(VERIFY_WRITE, argp, size))
317                         return -EFAULT;
318         }
319         
320         switch (cmd) {
321         case MEMGETREGIONCOUNT:
322                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
323                         return -EFAULT;
324                 break;
325
326         case MEMGETREGIONINFO:
327         {
328                 struct region_info_user ur;
329
330                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
331                         return -EFAULT;
332
333                 if (ur.regionindex >= mtd->numeraseregions)
334                         return -EINVAL;
335                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
336                                 sizeof(struct mtd_erase_region_info)))
337                         return -EFAULT;
338                 break;
339         }
340
341         case MEMGETINFO:
342                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
343                         return -EFAULT;
344                 break;
345
346         case MEMERASE:
347         {
348                 struct erase_info *erase;
349
350                 if(!(file->f_mode & 2))
351                         return -EPERM;
352
353                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
354                 if (!erase)
355                         ret = -ENOMEM;
356                 else {
357                         wait_queue_head_t waitq;
358                         DECLARE_WAITQUEUE(wait, current);
359
360                         init_waitqueue_head(&waitq);
361
362                         memset (erase,0,sizeof(struct erase_info));
363                         if (copy_from_user(&erase->addr, argp,
364                                     sizeof(struct erase_info_user))) {
365                                 kfree(erase);
366                                 return -EFAULT;
367                         }
368                         erase->mtd = mtd;
369                         erase->callback = mtdchar_erase_callback;
370                         erase->priv = (unsigned long)&waitq;
371                         
372                         /*
373                           FIXME: Allow INTERRUPTIBLE. Which means
374                           not having the wait_queue head on the stack.
375                           
376                           If the wq_head is on the stack, and we
377                           leave because we got interrupted, then the
378                           wq_head is no longer there when the
379                           callback routine tries to wake us up.
380                         */
381                         ret = mtd->erase(mtd, erase);
382                         if (!ret) {
383                                 set_current_state(TASK_UNINTERRUPTIBLE);
384                                 add_wait_queue(&waitq, &wait);
385                                 if (erase->state != MTD_ERASE_DONE &&
386                                     erase->state != MTD_ERASE_FAILED)
387                                         schedule();
388                                 remove_wait_queue(&waitq, &wait);
389                                 set_current_state(TASK_RUNNING);
390
391                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
392                         }
393                         kfree(erase);
394                 }
395                 break;
396         }
397
398         case MEMWRITEOOB:
399         {
400                 struct mtd_oob_buf buf;
401                 void *databuf;
402                 ssize_t retlen;
403                 
404                 if(!(file->f_mode & 2))
405                         return -EPERM;
406
407                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
408                         return -EFAULT;
409                 
410                 if (buf.length > 0x4096)
411                         return -EINVAL;
412
413                 if (!mtd->write_oob)
414                         ret = -EOPNOTSUPP;
415                 else
416                         ret = access_ok(VERIFY_READ, buf.ptr,
417                                         buf.length) ? 0 : EFAULT;
418
419                 if (ret)
420                         return ret;
421
422                 databuf = kmalloc(buf.length, GFP_KERNEL);
423                 if (!databuf)
424                         return -ENOMEM;
425                 
426                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
427                         kfree(databuf);
428                         return -EFAULT;
429                 }
430
431                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
432
433                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
434                         ret = -EFAULT;
435
436                 kfree(databuf);
437                 break;
438
439         }
440
441         case MEMREADOOB:
442         {
443                 struct mtd_oob_buf buf;
444                 void *databuf;
445                 ssize_t retlen;
446
447                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
448                         return -EFAULT;
449                 
450                 if (buf.length > 0x4096)
451                         return -EINVAL;
452
453                 if (!mtd->read_oob)
454                         ret = -EOPNOTSUPP;
455                 else
456                         ret = access_ok(VERIFY_WRITE, buf.ptr,
457                                         buf.length) ? 0 : -EFAULT;
458
459                 if (ret)
460                         return ret;
461
462                 databuf = kmalloc(buf.length, GFP_KERNEL);
463                 if (!databuf)
464                         return -ENOMEM;
465                 
466                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
467
468                 if (put_user(retlen, (uint32_t __user *)argp))
469                         ret = -EFAULT;
470                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
471                         ret = -EFAULT;
472                 
473                 kfree(databuf);
474                 break;
475         }
476
477         case MEMLOCK:
478         {
479                 struct erase_info_user info;
480
481                 if (copy_from_user(&info, argp, sizeof(info)))
482                         return -EFAULT;
483
484                 if (!mtd->lock)
485                         ret = -EOPNOTSUPP;
486                 else
487                         ret = mtd->lock(mtd, info.start, info.length);
488                 break;
489         }
490
491         case MEMUNLOCK:
492         {
493                 struct erase_info_user info;
494
495                 if (copy_from_user(&info, argp, sizeof(info)))
496                         return -EFAULT;
497
498                 if (!mtd->unlock)
499                         ret = -EOPNOTSUPP;
500                 else
501                         ret = mtd->unlock(mtd, info.start, info.length);
502                 break;
503         }
504
505         case MEMSETOOBSEL:
506         {
507                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
508                         return -EFAULT;
509                 break;
510         }
511
512         case MEMGETOOBSEL:
513         {
514                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
515                         return -EFAULT;
516                 break;
517         }
518
519         case MEMGETBADBLOCK:
520         {
521                 loff_t offs;
522                 
523                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
524                         return -EFAULT;
525                 if (!mtd->block_isbad)
526                         ret = -EOPNOTSUPP;
527                 else
528                         return mtd->block_isbad(mtd, offs);
529                 break;
530         }
531
532         case MEMSETBADBLOCK:
533         {
534                 loff_t offs;
535
536                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
537                         return -EFAULT;
538                 if (!mtd->block_markbad)
539                         ret = -EOPNOTSUPP;
540                 else
541                         return mtd->block_markbad(mtd, offs);
542                 break;
543         }
544
545 #ifdef CONFIG_MTD_OTP
546         case OTPSELECT:
547         {
548                 int mode;
549                 if (copy_from_user(&mode, argp, sizeof(int)))
550                         return -EFAULT;
551                 SET_MTD_MODE(file, 0);
552                 switch (mode) {
553                 case MTD_OTP_FACTORY:
554                         if (!mtd->read_fact_prot_reg)
555                                 ret = -EOPNOTSUPP;
556                         else
557                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
558                         break;
559                 case MTD_OTP_USER:
560                         if (!mtd->read_fact_prot_reg)
561                                 ret = -EOPNOTSUPP;
562                         else
563                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
564                         break;
565                 default:
566                         ret = -EINVAL;
567                 case MTD_OTP_OFF:
568                         break;
569                 }
570                 file->f_pos = 0;
571                 break;
572         }
573
574         case OTPGETREGIONCOUNT:
575         case OTPGETREGIONINFO:
576         {
577                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
578                 if (!buf)
579                         return -ENOMEM;
580                 ret = -EOPNOTSUPP;
581                 switch (MTD_MODE(file)) {
582                 case MTD_MODE_OTP_FACT:
583                         if (mtd->get_fact_prot_info)
584                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
585                         break;
586                 case MTD_MODE_OTP_USER:
587                         if (mtd->get_user_prot_info)
588                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
589                         break;
590                 }
591                 if (ret >= 0) {
592                         if (cmd == OTPGETREGIONCOUNT) {
593                                 int nbr = ret / sizeof(struct otp_info);
594                                 ret = copy_to_user(argp, &nbr, sizeof(int));
595                         } else
596                                 ret = copy_to_user(argp, buf, ret);
597                         if (ret)
598                                 ret = -EFAULT;
599                 }
600                 kfree(buf);
601                 break;
602         }
603
604         case OTPLOCK:
605         {
606                 struct otp_info info;
607
608                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
609                         return -EINVAL;
610                 if (copy_from_user(&info, argp, sizeof(info)))
611                         return -EFAULT;
612                 if (!mtd->lock_user_prot_reg)
613                         return -EOPNOTSUPP;
614                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
615                 break;
616         }
617 #endif
618
619         default:
620                 ret = -ENOTTY;
621         }
622
623         return ret;
624 } /* memory_ioctl */
625
626 static struct file_operations mtd_fops = {
627         .owner          = THIS_MODULE,
628         .llseek         = mtd_lseek,
629         .read           = mtd_read,
630         .write          = mtd_write,
631         .ioctl          = mtd_ioctl,
632         .open           = mtd_open,
633         .release        = mtd_close,
634 };
635
636 static int __init init_mtdchar(void)
637 {
638         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
639                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
640                        MTD_CHAR_MAJOR);
641                 return -EAGAIN;
642         }
643
644         mtd_class = class_create(THIS_MODULE, "mtd");
645
646         if (IS_ERR(mtd_class)) {
647                 printk(KERN_ERR "Error creating mtd class.\n");
648                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
649                 return PTR_ERR(mtd_class);
650         }
651
652         register_mtd_user(&notifier);
653         return 0;
654 }
655
656 static void __exit cleanup_mtdchar(void)
657 {
658         unregister_mtd_user(&notifier);
659         class_destroy(mtd_class);
660         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
661 }
662
663 module_init(init_mtdchar);
664 module_exit(cleanup_mtdchar);
665
666
667 MODULE_LICENSE("GPL");
668 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
669 MODULE_DESCRIPTION("Direct character-device access to MTD devices");