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