16df1e4fb0e94d2efec9542e6114f0593c3ad3bf
[sfrench/cifs-2.6.git] / drivers / mtd / mtdchar.c
1 /*
2  * $Id: mtdchar.c,v 1.73 2005/07/04 17:36:41 gleixner 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 <linux/sched.h>        /* TASK_* */
17 #include <asm/uaccess.h>
18
19 #include <linux/device.h>
20
21 static struct class *mtd_class;
22
23 static void mtd_notify_add(struct mtd_info* mtd)
24 {
25         if (!mtd)
26                 return;
27
28         class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
29                             NULL, "mtd%d", mtd->index);
30         
31         class_device_create(mtd_class, NULL,
32                             MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
33                             NULL, "mtd%dro", mtd->index);
34 }
35
36 static void mtd_notify_remove(struct mtd_info* mtd)
37 {
38         if (!mtd)
39                 return;
40
41         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
42         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
43 }
44
45 static struct mtd_notifier notifier = {
46         .add    = mtd_notify_add,
47         .remove = mtd_notify_remove,
48 };
49
50 /*
51  * We use file->private_data to store a pointer to the MTDdevice.
52  * Since alighment is at least 32 bits, we have 2 bits free for OTP
53  * modes as well.
54  */
55
56 #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
57
58 #define MTD_MODE_OTP_FACT       1
59 #define MTD_MODE_OTP_USER       2
60 #define MTD_MODE(file)          ((long)((file)->private_data) & 3)
61
62 #define SET_MTD_MODE(file, mode) \
63         do { long __p = (long)((file)->private_data); \
64              (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
65
66 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
67 {
68         struct mtd_info *mtd = TO_MTD(file);
69
70         switch (orig) {
71         case 0:
72                 /* SEEK_SET */
73                 file->f_pos = offset;
74                 break;
75         case 1:
76                 /* SEEK_CUR */
77                 file->f_pos += offset;
78                 break;
79         case 2:
80                 /* SEEK_END */
81                 file->f_pos =mtd->size + offset;
82                 break;
83         default:
84                 return -EINVAL;
85         }
86
87         if (file->f_pos < 0)
88                 file->f_pos = 0;
89         else if (file->f_pos >= mtd->size)
90                 file->f_pos = mtd->size - 1;
91
92         return file->f_pos;
93 }
94
95
96
97 static int mtd_open(struct inode *inode, struct file *file)
98 {
99         int minor = iminor(inode);
100         int devnum = minor >> 1;
101         struct mtd_info *mtd;
102
103         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
104
105         if (devnum >= MAX_MTD_DEVICES)
106                 return -ENODEV;
107
108         /* You can't open the RO devices RW */
109         if ((file->f_mode & 2) && (minor & 1))
110                 return -EACCES;
111
112         mtd = get_mtd_device(NULL, devnum);
113         
114         if (!mtd)
115                 return -ENODEV;
116         
117         if (MTD_ABSENT == mtd->type) {
118                 put_mtd_device(mtd);
119                 return -ENODEV;
120         }
121
122         file->private_data = mtd;
123                 
124         /* You can't open it RW if it's not a writeable device */
125         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
126                 put_mtd_device(mtd);
127                 return -EACCES;
128         }
129                 
130         return 0;
131 } /* mtd_open */
132
133 /*====================================================================*/
134
135 static int mtd_close(struct inode *inode, struct file *file)
136 {
137         struct mtd_info *mtd;
138
139         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
140
141         mtd = TO_MTD(file);
142         
143         if (mtd->sync)
144                 mtd->sync(mtd);
145         
146         put_mtd_device(mtd);
147
148         return 0;
149 } /* mtd_close */
150
151 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
152    userspace buffer down and use it directly with readv/writev.
153 */
154 #define MAX_KMALLOC_SIZE 0x20000
155
156 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
157 {
158         struct mtd_info *mtd = TO_MTD(file);
159         size_t retlen=0;
160         size_t total_retlen=0;
161         int ret=0;
162         int len;
163         char *kbuf;
164         
165         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
166
167         if (*ppos + count > mtd->size)
168                 count = mtd->size - *ppos;
169
170         if (!count)
171                 return 0;
172         
173         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
174            and pass them directly to the MTD functions */
175         while (count) {
176                 if (count > MAX_KMALLOC_SIZE) 
177                         len = MAX_KMALLOC_SIZE;
178                 else
179                         len = count;
180
181                 kbuf=kmalloc(len,GFP_KERNEL);
182                 if (!kbuf)
183                         return -ENOMEM;
184                 
185                 switch (MTD_MODE(file)) {
186                 case MTD_MODE_OTP_FACT:
187                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
188                         break;
189                 case MTD_MODE_OTP_USER:
190                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
191                         break;
192                 default:
193                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
194                 }
195                 /* Nand returns -EBADMSG on ecc errors, but it returns
196                  * the data. For our userspace tools it is important
197                  * to dump areas with ecc errors ! 
198                  * Userspace software which accesses NAND this way
199                  * must be aware of the fact that it deals with NAND
200                  */
201                 if (!ret || (ret == -EBADMSG)) {
202                         *ppos += retlen;
203                         if (copy_to_user(buf, kbuf, retlen)) {
204                                 kfree(kbuf);
205                                 return -EFAULT;
206                         }
207                         else
208                                 total_retlen += retlen;
209
210                         count -= retlen;
211                         buf += retlen;
212                         if (retlen == 0)
213                                 count = 0;
214                 }
215                 else {
216                         kfree(kbuf);
217                         return ret;
218                 }
219                 
220                 kfree(kbuf);
221         }
222
223         return total_retlen;
224 } /* mtd_read */
225
226 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
227 {
228         struct mtd_info *mtd = TO_MTD(file);
229         char *kbuf;
230         size_t retlen;
231         size_t total_retlen=0;
232         int ret=0;
233         int len;
234
235         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
236         
237         if (*ppos == mtd->size)
238                 return -ENOSPC;
239         
240         if (*ppos + count > mtd->size)
241                 count = mtd->size - *ppos;
242
243         if (!count)
244                 return 0;
245
246         while (count) {
247                 if (count > MAX_KMALLOC_SIZE) 
248                         len = MAX_KMALLOC_SIZE;
249                 else
250                         len = count;
251
252                 kbuf=kmalloc(len,GFP_KERNEL);
253                 if (!kbuf) {
254                         printk("kmalloc is null\n");
255                         return -ENOMEM;
256                 }
257
258                 if (copy_from_user(kbuf, buf, len)) {
259                         kfree(kbuf);
260                         return -EFAULT;
261                 }
262                 
263                 switch (MTD_MODE(file)) {
264                 case MTD_MODE_OTP_FACT:
265                         ret = -EROFS;
266                         break;
267                 case MTD_MODE_OTP_USER:
268                         if (!mtd->write_user_prot_reg) {
269                                 ret = -EOPNOTSUPP;
270                                 break;
271                         }
272                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
273                         break;
274                 default:
275                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
276                 }
277                 if (!ret) {
278                         *ppos += retlen;
279                         total_retlen += retlen;
280                         count -= retlen;
281                         buf += retlen;
282                 }
283                 else {
284                         kfree(kbuf);
285                         return ret;
286                 }
287                 
288                 kfree(kbuf);
289         }
290
291         return total_retlen;
292 } /* mtd_write */
293
294 /*======================================================================
295
296     IOCTL calls for getting device parameters.
297
298 ======================================================================*/
299 static void mtdchar_erase_callback (struct erase_info *instr)
300 {
301         wake_up((wait_queue_head_t *)instr->priv);
302 }
303
304 static int mtd_ioctl(struct inode *inode, struct file *file,
305                      u_int cmd, u_long arg)
306 {
307         struct mtd_info *mtd = TO_MTD(file);
308         void __user *argp = (void __user *)arg;
309         int ret = 0;
310         u_long size;
311         
312         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
313
314         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
315         if (cmd & IOC_IN) {
316                 if (!access_ok(VERIFY_READ, argp, size))
317                         return -EFAULT;
318         }
319         if (cmd & IOC_OUT) {
320                 if (!access_ok(VERIFY_WRITE, argp, size))
321                         return -EFAULT;
322         }
323         
324         switch (cmd) {
325         case MEMGETREGIONCOUNT:
326                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
327                         return -EFAULT;
328                 break;
329
330         case MEMGETREGIONINFO:
331         {
332                 struct region_info_user ur;
333
334                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
335                         return -EFAULT;
336
337                 if (ur.regionindex >= mtd->numeraseregions)
338                         return -EINVAL;
339                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
340                                 sizeof(struct mtd_erase_region_info)))
341                         return -EFAULT;
342                 break;
343         }
344
345         case MEMGETINFO:
346                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
347                         return -EFAULT;
348                 break;
349
350         case MEMERASE:
351         {
352                 struct erase_info *erase;
353
354                 if(!(file->f_mode & 2))
355                         return -EPERM;
356
357                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
358                 if (!erase)
359                         ret = -ENOMEM;
360                 else {
361                         wait_queue_head_t waitq;
362                         DECLARE_WAITQUEUE(wait, current);
363
364                         init_waitqueue_head(&waitq);
365
366                         memset (erase,0,sizeof(struct erase_info));
367                         if (copy_from_user(&erase->addr, argp,
368                                     sizeof(struct erase_info_user))) {
369                                 kfree(erase);
370                                 return -EFAULT;
371                         }
372                         erase->mtd = mtd;
373                         erase->callback = mtdchar_erase_callback;
374                         erase->priv = (unsigned long)&waitq;
375                         
376                         /*
377                           FIXME: Allow INTERRUPTIBLE. Which means
378                           not having the wait_queue head on the stack.
379                           
380                           If the wq_head is on the stack, and we
381                           leave because we got interrupted, then the
382                           wq_head is no longer there when the
383                           callback routine tries to wake us up.
384                         */
385                         ret = mtd->erase(mtd, erase);
386                         if (!ret) {
387                                 set_current_state(TASK_UNINTERRUPTIBLE);
388                                 add_wait_queue(&waitq, &wait);
389                                 if (erase->state != MTD_ERASE_DONE &&
390                                     erase->state != MTD_ERASE_FAILED)
391                                         schedule();
392                                 remove_wait_queue(&waitq, &wait);
393                                 set_current_state(TASK_RUNNING);
394
395                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
396                         }
397                         kfree(erase);
398                 }
399                 break;
400         }
401
402         case MEMWRITEOOB:
403         {
404                 struct mtd_oob_buf buf;
405                 void *databuf;
406                 ssize_t retlen;
407                 
408                 if(!(file->f_mode & 2))
409                         return -EPERM;
410
411                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
412                         return -EFAULT;
413                 
414                 if (buf.length > 0x4096)
415                         return -EINVAL;
416
417                 if (!mtd->write_oob)
418                         ret = -EOPNOTSUPP;
419                 else
420                         ret = access_ok(VERIFY_READ, buf.ptr,
421                                         buf.length) ? 0 : EFAULT;
422
423                 if (ret)
424                         return ret;
425
426                 databuf = kmalloc(buf.length, GFP_KERNEL);
427                 if (!databuf)
428                         return -ENOMEM;
429                 
430                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
431                         kfree(databuf);
432                         return -EFAULT;
433                 }
434
435                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
436
437                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
438                         ret = -EFAULT;
439
440                 kfree(databuf);
441                 break;
442
443         }
444
445         case MEMREADOOB:
446         {
447                 struct mtd_oob_buf buf;
448                 void *databuf;
449                 ssize_t retlen;
450
451                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
452                         return -EFAULT;
453                 
454                 if (buf.length > 0x4096)
455                         return -EINVAL;
456
457                 if (!mtd->read_oob)
458                         ret = -EOPNOTSUPP;
459                 else
460                         ret = access_ok(VERIFY_WRITE, buf.ptr,
461                                         buf.length) ? 0 : -EFAULT;
462
463                 if (ret)
464                         return ret;
465
466                 databuf = kmalloc(buf.length, GFP_KERNEL);
467                 if (!databuf)
468                         return -ENOMEM;
469                 
470                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
471
472                 if (put_user(retlen, (uint32_t __user *)argp))
473                         ret = -EFAULT;
474                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
475                         ret = -EFAULT;
476                 
477                 kfree(databuf);
478                 break;
479         }
480
481         case MEMLOCK:
482         {
483                 struct erase_info_user info;
484
485                 if (copy_from_user(&info, argp, sizeof(info)))
486                         return -EFAULT;
487
488                 if (!mtd->lock)
489                         ret = -EOPNOTSUPP;
490                 else
491                         ret = mtd->lock(mtd, info.start, info.length);
492                 break;
493         }
494
495         case MEMUNLOCK:
496         {
497                 struct erase_info_user info;
498
499                 if (copy_from_user(&info, argp, sizeof(info)))
500                         return -EFAULT;
501
502                 if (!mtd->unlock)
503                         ret = -EOPNOTSUPP;
504                 else
505                         ret = mtd->unlock(mtd, info.start, info.length);
506                 break;
507         }
508
509         case MEMSETOOBSEL:
510         {
511                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
512                         return -EFAULT;
513                 break;
514         }
515
516         case MEMGETOOBSEL:
517         {
518                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
519                         return -EFAULT;
520                 break;
521         }
522
523         case MEMGETBADBLOCK:
524         {
525                 loff_t offs;
526                 
527                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
528                         return -EFAULT;
529                 if (!mtd->block_isbad)
530                         ret = -EOPNOTSUPP;
531                 else
532                         return mtd->block_isbad(mtd, offs);
533                 break;
534         }
535
536         case MEMSETBADBLOCK:
537         {
538                 loff_t offs;
539
540                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
541                         return -EFAULT;
542                 if (!mtd->block_markbad)
543                         ret = -EOPNOTSUPP;
544                 else
545                         return mtd->block_markbad(mtd, offs);
546                 break;
547         }
548
549 #ifdef CONFIG_MTD_OTP
550         case OTPSELECT:
551         {
552                 int mode;
553                 if (copy_from_user(&mode, argp, sizeof(int)))
554                         return -EFAULT;
555                 SET_MTD_MODE(file, 0);
556                 switch (mode) {
557                 case MTD_OTP_FACTORY:
558                         if (!mtd->read_fact_prot_reg)
559                                 ret = -EOPNOTSUPP;
560                         else
561                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
562                         break;
563                 case MTD_OTP_USER:
564                         if (!mtd->read_fact_prot_reg)
565                                 ret = -EOPNOTSUPP;
566                         else
567                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
568                         break;
569                 default:
570                         ret = -EINVAL;
571                 case MTD_OTP_OFF:
572                         break;
573                 }
574                 file->f_pos = 0;
575                 break;
576         }
577
578         case OTPGETREGIONCOUNT:
579         case OTPGETREGIONINFO:
580         {
581                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
582                 if (!buf)
583                         return -ENOMEM;
584                 ret = -EOPNOTSUPP;
585                 switch (MTD_MODE(file)) {
586                 case MTD_MODE_OTP_FACT:
587                         if (mtd->get_fact_prot_info)
588                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
589                         break;
590                 case MTD_MODE_OTP_USER:
591                         if (mtd->get_user_prot_info)
592                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
593                         break;
594                 }
595                 if (ret >= 0) {
596                         if (cmd == OTPGETREGIONCOUNT) {
597                                 int nbr = ret / sizeof(struct otp_info);
598                                 ret = copy_to_user(argp, &nbr, sizeof(int));
599                         } else
600                                 ret = copy_to_user(argp, buf, ret);
601                         if (ret)
602                                 ret = -EFAULT;
603                 }
604                 kfree(buf);
605                 break;
606         }
607
608         case OTPLOCK:
609         {
610                 struct otp_info info;
611
612                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
613                         return -EINVAL;
614                 if (copy_from_user(&info, argp, sizeof(info)))
615                         return -EFAULT;
616                 if (!mtd->lock_user_prot_reg)
617                         return -EOPNOTSUPP;
618                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
619                 break;
620         }
621 #endif
622
623         default:
624                 ret = -ENOTTY;
625         }
626
627         return ret;
628 } /* memory_ioctl */
629
630 static struct file_operations mtd_fops = {
631         .owner          = THIS_MODULE,
632         .llseek         = mtd_lseek,
633         .read           = mtd_read,
634         .write          = mtd_write,
635         .ioctl          = mtd_ioctl,
636         .open           = mtd_open,
637         .release        = mtd_close,
638 };
639
640 static int __init init_mtdchar(void)
641 {
642         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
643                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
644                        MTD_CHAR_MAJOR);
645                 return -EAGAIN;
646         }
647
648         mtd_class = class_create(THIS_MODULE, "mtd");
649
650         if (IS_ERR(mtd_class)) {
651                 printk(KERN_ERR "Error creating mtd class.\n");
652                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
653                 return PTR_ERR(mtd_class);
654         }
655
656         register_mtd_user(&notifier);
657         return 0;
658 }
659
660 static void __exit cleanup_mtdchar(void)
661 {
662         unregister_mtd_user(&notifier);
663         class_destroy(mtd_class);
664         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
665 }
666
667 module_init(init_mtdchar);
668 module_exit(cleanup_mtdchar);
669
670
671 MODULE_LICENSE("GPL");
672 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
673 MODULE_DESCRIPTION("Direct character-device access to MTD devices");