2 * Character-device access to raw MTD devices.
6 #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>
15 #include <linux/smp_lock.h>
16 #include <linux/backing-dev.h>
17 #include <linux/compat.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/compatmac.h>
22 #include <asm/uaccess.h>
26 * Data structure to hold the pointer to the mtd device as well
27 * as mode information ofr various use cases.
29 struct mtd_file_info {
31 enum mtd_file_modes mode;
34 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
36 struct mtd_file_info *mfi = file->private_data;
37 struct mtd_info *mtd = mfi->mtd;
43 offset += file->f_pos;
52 if (offset >= 0 && offset <= mtd->size)
53 return file->f_pos = offset;
60 static int mtd_open(struct inode *inode, struct file *file)
62 int minor = iminor(inode);
63 int devnum = minor >> 1;
66 struct mtd_file_info *mfi;
68 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
70 if (devnum >= MAX_MTD_DEVICES)
73 /* You can't open the RO devices RW */
74 if ((file->f_mode & FMODE_WRITE) && (minor & 1))
78 mtd = get_mtd_device(NULL, devnum);
85 if (mtd->type == MTD_ABSENT) {
91 if (mtd->backing_dev_info)
92 file->f_mapping->backing_dev_info = mtd->backing_dev_info;
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)) {
101 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
108 file->private_data = mfi;
115 /*====================================================================*/
117 static int mtd_close(struct inode *inode, struct file *file)
119 struct mtd_file_info *mfi = file->private_data;
120 struct mtd_info *mtd = mfi->mtd;
122 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
124 /* Only sync if opened RW */
125 if ((file->f_mode & FMODE_WRITE) && mtd->sync)
129 file->private_data = NULL;
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.
138 #define MAX_KMALLOC_SIZE 0x20000
140 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
142 struct mtd_file_info *mfi = file->private_data;
143 struct mtd_info *mtd = mfi->mtd;
145 size_t total_retlen=0;
150 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
152 if (*ppos + count > mtd->size)
153 count = mtd->size - *ppos;
158 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
159 and pass them directly to the MTD functions */
161 if (count > MAX_KMALLOC_SIZE)
162 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
164 kbuf=kmalloc(count, GFP_KERNEL);
171 if (count > MAX_KMALLOC_SIZE)
172 len = MAX_KMALLOC_SIZE;
177 case MTD_MODE_OTP_FACTORY:
178 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
180 case MTD_MODE_OTP_USER:
181 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
185 struct mtd_oob_ops ops;
187 ops.mode = MTD_OOB_RAW;
192 ret = mtd->read_oob(mtd, *ppos, &ops);
197 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
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
208 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
210 if (copy_to_user(buf, kbuf, retlen)) {
215 total_retlen += retlen;
233 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
235 struct mtd_file_info *mfi = file->private_data;
236 struct mtd_info *mtd = mfi->mtd;
239 size_t total_retlen=0;
243 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
245 if (*ppos == mtd->size)
248 if (*ppos + count > mtd->size)
249 count = mtd->size - *ppos;
254 if (count > MAX_KMALLOC_SIZE)
255 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
257 kbuf=kmalloc(count, GFP_KERNEL);
264 if (count > MAX_KMALLOC_SIZE)
265 len = MAX_KMALLOC_SIZE;
269 if (copy_from_user(kbuf, buf, len)) {
275 case MTD_MODE_OTP_FACTORY:
278 case MTD_MODE_OTP_USER:
279 if (!mtd->write_user_prot_reg) {
283 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
288 struct mtd_oob_ops ops;
290 ops.mode = MTD_OOB_RAW;
295 ret = mtd->write_oob(mtd, *ppos, &ops);
301 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
305 total_retlen += retlen;
319 /*======================================================================
321 IOCTL calls for getting device parameters.
323 ======================================================================*/
324 static void mtdchar_erase_callback (struct erase_info *instr)
326 wake_up((wait_queue_head_t *)instr->priv);
329 #ifdef CONFIG_HAVE_MTD_OTP
330 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
332 struct mtd_info *mtd = mfi->mtd;
336 case MTD_OTP_FACTORY:
337 if (!mtd->read_fact_prot_reg)
340 mfi->mode = MTD_MODE_OTP_FACTORY;
343 if (!mtd->read_fact_prot_reg)
346 mfi->mode = MTD_MODE_OTP_USER;
356 # define otp_select_filemode(f,m) -EOPNOTSUPP
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)
363 struct mtd_oob_ops ops;
367 if (!(file->f_mode & FMODE_WRITE))
376 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : EFAULT;
382 ops.ooboffs = start & (mtd->oobsize - 1);
384 ops.mode = MTD_OOB_PLACE;
386 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
389 ops.oobbuf = kmalloc(length, GFP_KERNEL);
393 if (copy_from_user(ops.oobbuf, ptr, length)) {
398 start &= ~((uint64_t)mtd->oobsize - 1);
399 ret = mtd->write_oob(mtd, start, &ops);
401 if (ops.oobretlen > 0xFFFFFFFFU)
403 retlen = ops.oobretlen;
404 if (copy_to_user(retp, &retlen, sizeof(length)))
411 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
412 uint32_t length, void __user *ptr, uint32_t __user *retp)
414 struct mtd_oob_ops ops;
423 ret = access_ok(VERIFY_WRITE, ptr,
424 length) ? 0 : -EFAULT;
429 ops.ooboffs = start & (mtd->oobsize - 1);
431 ops.mode = MTD_OOB_PLACE;
433 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
436 ops.oobbuf = kmalloc(length, GFP_KERNEL);
440 start &= ~((uint64_t)mtd->oobsize - 1);
441 ret = mtd->read_oob(mtd, start, &ops);
443 if (put_user(ops.oobretlen, retp))
445 else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
453 static int mtd_ioctl(struct inode *inode, struct file *file,
454 u_int cmd, u_long arg)
456 struct mtd_file_info *mfi = file->private_data;
457 struct mtd_info *mtd = mfi->mtd;
458 void __user *argp = (void __user *)arg;
461 struct mtd_info_user info;
463 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
465 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
467 if (!access_ok(VERIFY_READ, argp, size))
471 if (!access_ok(VERIFY_WRITE, argp, size))
476 case MEMGETREGIONCOUNT:
477 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
481 case MEMGETREGIONINFO:
484 struct mtd_erase_region_info *kr;
485 struct region_info_user *ur = (struct region_info_user *) argp;
487 if (get_user(ur_idx, &(ur->regionindex)))
490 kr = &(mtd->eraseregions[ur_idx]);
492 if (put_user(kr->offset, &(ur->offset))
493 || put_user(kr->erasesize, &(ur->erasesize))
494 || put_user(kr->numblocks, &(ur->numblocks)))
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 */
510 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
517 struct erase_info *erase;
519 if(!(file->f_mode & FMODE_WRITE))
522 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
526 wait_queue_head_t waitq;
527 DECLARE_WAITQUEUE(wait, current);
529 init_waitqueue_head(&waitq);
531 if (cmd == MEMERASE64) {
532 struct erase_info_user64 einfo64;
534 if (copy_from_user(&einfo64, argp,
535 sizeof(struct erase_info_user64))) {
539 erase->addr = einfo64.start;
540 erase->len = einfo64.length;
542 struct erase_info_user einfo32;
544 if (copy_from_user(&einfo32, argp,
545 sizeof(struct erase_info_user))) {
549 erase->addr = einfo32.start;
550 erase->len = einfo32.length;
553 erase->callback = mtdchar_erase_callback;
554 erase->priv = (unsigned long)&waitq;
557 FIXME: Allow INTERRUPTIBLE. Which means
558 not having the wait_queue head on the stack.
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.
565 ret = mtd->erase(mtd, erase);
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)
572 remove_wait_queue(&waitq, &wait);
573 set_current_state(TASK_RUNNING);
575 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
584 struct mtd_oob_buf buf;
585 struct mtd_oob_buf __user *buf_user = argp;
587 /* NOTE: writes return length to buf_user->length */
588 if (copy_from_user(&buf, argp, sizeof(buf)))
591 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
592 buf.ptr, &buf_user->length);
598 struct mtd_oob_buf buf;
599 struct mtd_oob_buf __user *buf_user = argp;
601 /* NOTE: writes return length to buf_user->start */
602 if (copy_from_user(&buf, argp, sizeof(buf)))
605 ret = mtd_do_readoob(mtd, buf.start, buf.length,
606 buf.ptr, &buf_user->start);
612 struct mtd_oob_buf64 buf;
613 struct mtd_oob_buf64 __user *buf_user = argp;
615 if (copy_from_user(&buf, argp, sizeof(buf)))
618 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
619 (void __user *)(uintptr_t)buf.usr_ptr,
626 struct mtd_oob_buf64 buf;
627 struct mtd_oob_buf64 __user *buf_user = argp;
629 if (copy_from_user(&buf, argp, sizeof(buf)))
632 ret = mtd_do_readoob(mtd, buf.start, buf.length,
633 (void __user *)(uintptr_t)buf.usr_ptr,
640 struct erase_info_user einfo;
642 if (copy_from_user(&einfo, argp, sizeof(einfo)))
648 ret = mtd->lock(mtd, einfo.start, einfo.length);
654 struct erase_info_user einfo;
656 if (copy_from_user(&einfo, argp, sizeof(einfo)))
662 ret = mtd->unlock(mtd, einfo.start, einfo.length);
666 /* Legacy interface */
669 struct nand_oobinfo oi;
673 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
676 oi.useecc = MTD_NANDECC_AUTOPLACE;
677 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
678 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
680 oi.eccbytes = mtd->ecclayout->eccbytes;
682 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
691 if (copy_from_user(&offs, argp, sizeof(loff_t)))
693 if (!mtd->block_isbad)
696 return mtd->block_isbad(mtd, offs);
704 if (copy_from_user(&offs, argp, sizeof(loff_t)))
706 if (!mtd->block_markbad)
709 return mtd->block_markbad(mtd, offs);
713 #ifdef CONFIG_HAVE_MTD_OTP
717 if (copy_from_user(&mode, argp, sizeof(int)))
720 mfi->mode = MTD_MODE_NORMAL;
722 ret = otp_select_filemode(mfi, mode);
728 case OTPGETREGIONCOUNT:
729 case OTPGETREGIONINFO:
731 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
736 case MTD_MODE_OTP_FACTORY:
737 if (mtd->get_fact_prot_info)
738 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
740 case MTD_MODE_OTP_USER:
741 if (mtd->get_user_prot_info)
742 ret = mtd->get_user_prot_info(mtd, buf, 4096);
748 if (cmd == OTPGETREGIONCOUNT) {
749 int nbr = ret / sizeof(struct otp_info);
750 ret = copy_to_user(argp, &nbr, sizeof(int));
752 ret = copy_to_user(argp, buf, ret);
762 struct otp_info oinfo;
764 if (mfi->mode != MTD_MODE_OTP_USER)
766 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
768 if (!mtd->lock_user_prot_reg)
770 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
780 if (copy_to_user(argp, mtd->ecclayout,
781 sizeof(struct nand_ecclayout)))
788 if (copy_to_user(argp, &mtd->ecc_stats,
789 sizeof(struct mtd_ecc_stats)))
799 case MTD_MODE_OTP_FACTORY:
800 case MTD_MODE_OTP_USER:
801 ret = otp_select_filemode(mfi, arg);
805 if (!mtd->read_oob || !mtd->write_oob)
809 case MTD_MODE_NORMAL:
827 struct mtd_oob_buf32 {
830 compat_caddr_t ptr; /* unsigned char* */
833 #define MEMWRITEOOB32 _IOWR('M', 3, struct mtd_oob_buf32)
834 #define MEMREADOOB32 _IOWR('M', 4, struct mtd_oob_buf32)
836 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
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);
850 struct mtd_oob_buf32 buf;
851 struct mtd_oob_buf32 __user *buf_user = argp;
853 if (copy_from_user(&buf, argp, sizeof(buf)))
856 ret = mtd_do_writeoob(file, mtd, buf.start,
857 buf.length, compat_ptr(buf.ptr),
864 struct mtd_oob_buf32 buf;
865 struct mtd_oob_buf32 __user *buf_user = argp;
867 /* NOTE: writes return length to buf->start */
868 if (copy_from_user(&buf, argp, sizeof(buf)))
871 ret = mtd_do_readoob(mtd, buf.start,
872 buf.length, compat_ptr(buf.ptr),
877 ret = mtd_ioctl(inode, file, cmd, (unsigned long)argp);
885 #endif /* CONFIG_COMPAT */
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
893 static unsigned long mtd_get_unmapped_area(struct file *file,
899 struct mtd_file_info *mfi = file->private_data;
900 struct mtd_info *mtd = mfi->mtd;
902 if (mtd->get_unmapped_area) {
903 unsigned long offset;
906 return (unsigned long) -EINVAL;
908 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
909 return (unsigned long) -EINVAL;
911 offset = pgoff << PAGE_SHIFT;
912 if (offset > mtd->size - len)
913 return (unsigned long) -EINVAL;
915 return mtd->get_unmapped_area(mtd, len, offset, flags);
918 /* can't map directly */
919 return (unsigned long) -ENOSYS;
924 * set up a mapping for shared memory segments
926 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
929 struct mtd_file_info *mfi = file->private_data;
930 struct mtd_info *mtd = mfi->mtd;
932 if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
936 return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
940 static const struct file_operations mtd_fops = {
941 .owner = THIS_MODULE,
947 .compat_ioctl = mtd_compat_ioctl,
950 .release = mtd_close,
953 .get_unmapped_area = mtd_get_unmapped_area,
957 static int __init init_mtdchar(void)
961 status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
963 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
970 static void __exit cleanup_mtdchar(void)
972 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
975 module_init(init_mtdchar);
976 module_exit(cleanup_mtdchar);
978 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
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);