2 * $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $
4 * Character-device access to raw MTD devices.
8 #include <linux/device.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>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/compatmac.h>
19 #include <asm/semaphore.h>
20 #include <asm/uaccess.h>
22 static struct class *mtd_class
;
24 static void mtd_notify_add(struct mtd_info
* mtd
)
29 class_device_create(mtd_class
, NULL
, MKDEV(MTD_CHAR_MAJOR
, mtd
->index
*2),
30 NULL
, "mtd%d", mtd
->index
);
32 class_device_create(mtd_class
, NULL
,
33 MKDEV(MTD_CHAR_MAJOR
, mtd
->index
*2+1),
34 NULL
, "mtd%dro", mtd
->index
);
37 static void mtd_notify_remove(struct mtd_info
* mtd
)
42 class_device_destroy(mtd_class
, MKDEV(MTD_CHAR_MAJOR
, mtd
->index
*2));
43 class_device_destroy(mtd_class
, MKDEV(MTD_CHAR_MAJOR
, mtd
->index
*2+1));
46 static struct mtd_notifier notifier
= {
47 .add
= mtd_notify_add
,
48 .remove
= mtd_notify_remove
,
52 * Data structure to hold the pointer to the mtd device as well
53 * as mode information ofr various use cases.
55 struct mtd_file_info
{
57 enum mtd_file_modes mode
;
60 static loff_t
mtd_lseek (struct file
*file
, loff_t offset
, int orig
)
62 struct mtd_file_info
*mfi
= file
->private_data
;
63 struct mtd_info
*mtd
= mfi
->mtd
;
69 offset
+= file
->f_pos
;
78 if (offset
>= 0 && offset
<= mtd
->size
)
79 return file
->f_pos
= offset
;
86 static int mtd_open(struct inode
*inode
, struct file
*file
)
88 int minor
= iminor(inode
);
89 int devnum
= minor
>> 1;
91 struct mtd_file_info
*mfi
;
93 DEBUG(MTD_DEBUG_LEVEL0
, "MTD_open\n");
95 if (devnum
>= MAX_MTD_DEVICES
)
98 /* You can't open the RO devices RW */
99 if ((file
->f_mode
& 2) && (minor
& 1))
102 mtd
= get_mtd_device(NULL
, devnum
);
107 if (MTD_ABSENT
== mtd
->type
) {
112 /* You can't open it RW if it's not a writeable device */
113 if ((file
->f_mode
& 2) && !(mtd
->flags
& MTD_WRITEABLE
)) {
118 mfi
= kzalloc(sizeof(*mfi
), GFP_KERNEL
);
124 file
->private_data
= mfi
;
129 /*====================================================================*/
131 static int mtd_close(struct inode
*inode
, struct file
*file
)
133 struct mtd_file_info
*mfi
= file
->private_data
;
134 struct mtd_info
*mtd
= mfi
->mtd
;
136 DEBUG(MTD_DEBUG_LEVEL0
, "MTD_close\n");
142 file
->private_data
= NULL
;
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.
151 #define MAX_KMALLOC_SIZE 0x2000
153 static ssize_t
mtd_read(struct file
*file
, char __user
*buf
, size_t count
,loff_t
*ppos
)
155 struct mtd_file_info
*mfi
= file
->private_data
;
156 struct mtd_info
*mtd
= mfi
->mtd
;
158 size_t total_retlen
=0;
163 DEBUG(MTD_DEBUG_LEVEL0
,"MTD_read\n");
165 if (*ppos
+ count
> mtd
->size
)
166 count
= mtd
->size
- *ppos
;
171 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
172 and pass them directly to the MTD functions */
174 if (count
> MAX_KMALLOC_SIZE
)
175 kbuf
=kmalloc(MAX_KMALLOC_SIZE
, GFP_KERNEL
);
177 kbuf
=kmalloc(count
, GFP_KERNEL
);
184 if (count
> MAX_KMALLOC_SIZE
)
185 len
= MAX_KMALLOC_SIZE
;
190 case MTD_MODE_OTP_FACTORY
:
191 ret
= mtd
->read_fact_prot_reg(mtd
, *ppos
, len
, &retlen
, kbuf
);
193 case MTD_MODE_OTP_USER
:
194 ret
= mtd
->read_user_prot_reg(mtd
, *ppos
, len
, &retlen
, kbuf
);
198 struct mtd_oob_ops ops
;
200 ops
.mode
= MTD_OOB_RAW
;
205 ret
= mtd
->read_oob(mtd
, *ppos
, &ops
);
210 ret
= mtd
->read(mtd
, *ppos
, len
, &retlen
, kbuf
);
212 /* Nand returns -EBADMSG on ecc errors, but it returns
213 * the data. For our userspace tools it is important
214 * to dump areas with ecc errors !
215 * For kernel internal usage it also might return -EUCLEAN
216 * to signal the caller that a bitflip has occured and has
217 * been corrected by the ECC algorithm.
218 * Userspace software which accesses NAND this way
219 * must be aware of the fact that it deals with NAND
221 if (!ret
|| (ret
== -EUCLEAN
) || (ret
== -EBADMSG
)) {
223 if (copy_to_user(buf
, kbuf
, retlen
)) {
228 total_retlen
+= retlen
;
246 #define WRITE_KBUF_SIZE MAX_KMALLOC_SIZE
247 static DECLARE_MUTEX(write_kbuf_sem
);
248 static char *write_kbuf
;
250 static ssize_t
mtd_write(struct file
*file
, const char __user
*buf
, size_t count
,loff_t
*ppos
)
252 struct mtd_file_info
*mfi
= file
->private_data
;
253 struct mtd_info
*mtd
= mfi
->mtd
;
255 size_t total_retlen
=0;
259 DEBUG(MTD_DEBUG_LEVEL0
,"MTD_write\n");
261 if (*ppos
== mtd
->size
)
264 if (*ppos
+ count
> mtd
->size
)
265 count
= mtd
->size
- *ppos
;
270 down(&write_kbuf_sem
);
274 if (count
> WRITE_KBUF_SIZE
)
275 len
= WRITE_KBUF_SIZE
;
279 if (copy_from_user(write_kbuf
, buf
, len
)) {
285 case MTD_MODE_OTP_FACTORY
:
288 case MTD_MODE_OTP_USER
:
289 if (!mtd
->write_user_prot_reg
) {
293 ret
= mtd
->write_user_prot_reg(mtd
, *ppos
, len
, &retlen
, write_kbuf
);
298 struct mtd_oob_ops ops
;
300 ops
.mode
= MTD_OOB_RAW
;
301 ops
.datbuf
= write_kbuf
;
305 ret
= mtd
->write_oob(mtd
, *ppos
, &ops
);
311 ret
= (*(mtd
->write
))(mtd
, *ppos
, len
, &retlen
, write_kbuf
);
315 total_retlen
+= retlen
;
329 /*======================================================================
331 IOCTL calls for getting device parameters.
333 ======================================================================*/
334 static void mtdchar_erase_callback (struct erase_info
*instr
)
336 wake_up((wait_queue_head_t
*)instr
->priv
);
339 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
340 static int otp_select_filemode(struct mtd_file_info
*mfi
, int mode
)
342 struct mtd_info
*mtd
= mfi
->mtd
;
346 case MTD_OTP_FACTORY
:
347 if (!mtd
->read_fact_prot_reg
)
350 mfi
->mode
= MTD_MODE_OTP_FACTORY
;
353 if (!mtd
->read_fact_prot_reg
)
356 mfi
->mode
= MTD_MODE_OTP_USER
;
366 # define otp_select_filemode(f,m) -EOPNOTSUPP
369 static int mtd_ioctl(struct inode
*inode
, struct file
*file
,
370 u_int cmd
, u_long arg
)
372 struct mtd_file_info
*mfi
= file
->private_data
;
373 struct mtd_info
*mtd
= mfi
->mtd
;
374 void __user
*argp
= (void __user
*)arg
;
377 struct mtd_info_user info
;
379 DEBUG(MTD_DEBUG_LEVEL0
, "MTD_ioctl\n");
381 size
= (cmd
& IOCSIZE_MASK
) >> IOCSIZE_SHIFT
;
383 if (!access_ok(VERIFY_READ
, argp
, size
))
387 if (!access_ok(VERIFY_WRITE
, argp
, size
))
392 case MEMGETREGIONCOUNT
:
393 if (copy_to_user(argp
, &(mtd
->numeraseregions
), sizeof(int)))
397 case MEMGETREGIONINFO
:
399 struct region_info_user ur
;
401 if (copy_from_user(&ur
, argp
, sizeof(struct region_info_user
)))
404 if (ur
.regionindex
>= mtd
->numeraseregions
)
406 if (copy_to_user(argp
, &(mtd
->eraseregions
[ur
.regionindex
]),
407 sizeof(struct mtd_erase_region_info
)))
413 info
.type
= mtd
->type
;
414 info
.flags
= mtd
->flags
;
415 info
.size
= mtd
->size
;
416 info
.erasesize
= mtd
->erasesize
;
417 info
.writesize
= mtd
->writesize
;
418 info
.oobsize
= mtd
->oobsize
;
419 info
.ecctype
= mtd
->ecctype
;
420 info
.eccsize
= mtd
->eccsize
;
421 if (copy_to_user(argp
, &info
, sizeof(struct mtd_info_user
)))
427 struct erase_info
*erase
;
429 if(!(file
->f_mode
& 2))
432 erase
=kmalloc(sizeof(struct erase_info
),GFP_KERNEL
);
436 wait_queue_head_t waitq
;
437 DECLARE_WAITQUEUE(wait
, current
);
439 init_waitqueue_head(&waitq
);
441 memset (erase
,0,sizeof(struct erase_info
));
442 if (copy_from_user(&erase
->addr
, argp
,
443 sizeof(struct erase_info_user
))) {
448 erase
->callback
= mtdchar_erase_callback
;
449 erase
->priv
= (unsigned long)&waitq
;
452 FIXME: Allow INTERRUPTIBLE. Which means
453 not having the wait_queue head on the stack.
455 If the wq_head is on the stack, and we
456 leave because we got interrupted, then the
457 wq_head is no longer there when the
458 callback routine tries to wake us up.
460 ret
= mtd
->erase(mtd
, erase
);
462 set_current_state(TASK_UNINTERRUPTIBLE
);
463 add_wait_queue(&waitq
, &wait
);
464 if (erase
->state
!= MTD_ERASE_DONE
&&
465 erase
->state
!= MTD_ERASE_FAILED
)
467 remove_wait_queue(&waitq
, &wait
);
468 set_current_state(TASK_RUNNING
);
470 ret
= (erase
->state
== MTD_ERASE_FAILED
)?-EIO
:0;
479 struct mtd_oob_buf buf
;
480 struct mtd_oob_ops ops
;
482 if(!(file
->f_mode
& 2))
485 if (copy_from_user(&buf
, argp
, sizeof(struct mtd_oob_buf
)))
488 if (buf
.length
> 4096)
494 ret
= access_ok(VERIFY_READ
, buf
.ptr
,
495 buf
.length
) ? 0 : EFAULT
;
500 ops
.len
= buf
.length
;
501 ops
.ooblen
= buf
.length
;
502 ops
.ooboffs
= buf
.start
& (mtd
->oobsize
- 1);
504 ops
.mode
= MTD_OOB_PLACE
;
506 if (ops
.ooboffs
&& ops
.len
> (mtd
->oobsize
- ops
.ooboffs
))
509 ops
.oobbuf
= kmalloc(buf
.length
, GFP_KERNEL
);
513 if (copy_from_user(ops
.oobbuf
, buf
.ptr
, buf
.length
)) {
518 buf
.start
&= ~(mtd
->oobsize
- 1);
519 ret
= mtd
->write_oob(mtd
, buf
.start
, &ops
);
521 if (copy_to_user(argp
+ sizeof(uint32_t), &ops
.retlen
,
532 struct mtd_oob_buf buf
;
533 struct mtd_oob_ops ops
;
535 if (copy_from_user(&buf
, argp
, sizeof(struct mtd_oob_buf
)))
538 if (buf
.length
> 4096)
544 ret
= access_ok(VERIFY_WRITE
, buf
.ptr
,
545 buf
.length
) ? 0 : -EFAULT
;
549 ops
.len
= buf
.length
;
550 ops
.ooblen
= buf
.length
;
551 ops
.ooboffs
= buf
.start
& (mtd
->oobsize
- 1);
553 ops
.mode
= MTD_OOB_PLACE
;
555 if (ops
.ooboffs
&& ops
.len
> (mtd
->oobsize
- ops
.ooboffs
))
558 ops
.oobbuf
= kmalloc(buf
.length
, GFP_KERNEL
);
562 buf
.start
&= ~(mtd
->oobsize
- 1);
563 ret
= mtd
->read_oob(mtd
, buf
.start
, &ops
);
565 if (put_user(ops
.retlen
, (uint32_t __user
*)argp
))
567 else if (ops
.retlen
&& copy_to_user(buf
.ptr
, ops
.oobbuf
,
577 struct erase_info_user info
;
579 if (copy_from_user(&info
, argp
, sizeof(info
)))
585 ret
= mtd
->lock(mtd
, info
.start
, info
.length
);
591 struct erase_info_user info
;
593 if (copy_from_user(&info
, argp
, sizeof(info
)))
599 ret
= mtd
->unlock(mtd
, info
.start
, info
.length
);
603 /* Legacy interface */
606 struct nand_oobinfo oi
;
610 if (mtd
->ecclayout
->eccbytes
> ARRAY_SIZE(oi
.eccpos
))
613 oi
.useecc
= MTD_NANDECC_AUTOPLACE
;
614 memcpy(&oi
.eccpos
, mtd
->ecclayout
->eccpos
, sizeof(oi
.eccpos
));
615 memcpy(&oi
.oobfree
, mtd
->ecclayout
->oobfree
,
618 if (copy_to_user(argp
, &oi
, sizeof(struct nand_oobinfo
)))
627 if (copy_from_user(&offs
, argp
, sizeof(loff_t
)))
629 if (!mtd
->block_isbad
)
632 return mtd
->block_isbad(mtd
, offs
);
640 if (copy_from_user(&offs
, argp
, sizeof(loff_t
)))
642 if (!mtd
->block_markbad
)
645 return mtd
->block_markbad(mtd
, offs
);
649 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
653 if (copy_from_user(&mode
, argp
, sizeof(int)))
656 mfi
->mode
= MTD_MODE_NORMAL
;
658 ret
= otp_select_filemode(mfi
, mode
);
664 case OTPGETREGIONCOUNT
:
665 case OTPGETREGIONINFO
:
667 struct otp_info
*buf
= kmalloc(4096, GFP_KERNEL
);
672 case MTD_MODE_OTP_FACTORY
:
673 if (mtd
->get_fact_prot_info
)
674 ret
= mtd
->get_fact_prot_info(mtd
, buf
, 4096);
676 case MTD_MODE_OTP_USER
:
677 if (mtd
->get_user_prot_info
)
678 ret
= mtd
->get_user_prot_info(mtd
, buf
, 4096);
684 if (cmd
== OTPGETREGIONCOUNT
) {
685 int nbr
= ret
/ sizeof(struct otp_info
);
686 ret
= copy_to_user(argp
, &nbr
, sizeof(int));
688 ret
= copy_to_user(argp
, buf
, ret
);
698 struct otp_info info
;
700 if (mfi
->mode
!= MTD_MODE_OTP_USER
)
702 if (copy_from_user(&info
, argp
, sizeof(info
)))
704 if (!mtd
->lock_user_prot_reg
)
706 ret
= mtd
->lock_user_prot_reg(mtd
, info
.start
, info
.length
);
716 if (copy_to_user(argp
, &mtd
->ecclayout
,
717 sizeof(struct nand_ecclayout
)))
724 if (copy_to_user(argp
, &mtd
->ecc_stats
,
725 sizeof(struct mtd_ecc_stats
)))
735 case MTD_MODE_OTP_FACTORY
:
736 case MTD_MODE_OTP_USER
:
737 ret
= otp_select_filemode(mfi
, arg
);
741 if (!mtd
->read_oob
|| !mtd
->write_oob
)
745 case MTD_MODE_NORMAL
:
761 static struct file_operations mtd_fops
= {
762 .owner
= THIS_MODULE
,
768 .release
= mtd_close
,
771 static int __init
init_mtdchar(void)
773 if (register_chrdev(MTD_CHAR_MAJOR
, "mtd", &mtd_fops
)) {
774 printk(KERN_NOTICE
"Can't allocate major number %d for Memory Technology Devices.\n",
779 mtd_class
= class_create(THIS_MODULE
, "mtd");
781 if (IS_ERR(mtd_class
)) {
782 printk(KERN_ERR
"Error creating mtd class.\n");
783 unregister_chrdev(MTD_CHAR_MAJOR
, "mtd");
784 return PTR_ERR(mtd_class
);
787 /* Allocate write buffer. */
788 down(&write_kbuf_sem
);
789 write_kbuf
= kmalloc(WRITE_KBUF_SIZE
, GFP_KERNEL
);
790 if (write_kbuf
== NULL
) {
792 class_destroy(mtd_class
);
793 unregister_chrdev(MTD_CHAR_MAJOR
, "mtd");
798 register_mtd_user(¬ifier
);
802 static void __exit
cleanup_mtdchar(void)
804 unregister_mtd_user(¬ifier
);
805 class_destroy(mtd_class
);
806 unregister_chrdev(MTD_CHAR_MAJOR
, "mtd");
809 module_init(init_mtdchar
);
810 module_exit(cleanup_mtdchar
);
813 MODULE_LICENSE("GPL");
814 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
815 MODULE_DESCRIPTION("Direct character-device access to MTD devices");