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>
17 #include <linux/mtd/mtd.h>
18 #include <linux/mtd/compatmac.h>
20 #include <asm/uaccess.h>
22 static struct class *mtd_class;
24 static void mtd_notify_add(struct mtd_info* mtd)
29 device_create_drvdata(mtd_class, NULL,
30 MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
31 NULL, "mtd%d", mtd->index);
33 device_create_drvdata(mtd_class, NULL,
34 MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
35 NULL, "mtd%dro", mtd->index);
38 static void mtd_notify_remove(struct mtd_info* mtd)
43 device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
44 device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
47 static struct mtd_notifier notifier = {
48 .add = mtd_notify_add,
49 .remove = mtd_notify_remove,
53 * Data structure to hold the pointer to the mtd device as well
54 * as mode information ofr various use cases.
56 struct mtd_file_info {
58 enum mtd_file_modes mode;
61 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
63 struct mtd_file_info *mfi = file->private_data;
64 struct mtd_info *mtd = mfi->mtd;
70 offset += file->f_pos;
79 if (offset >= 0 && offset <= mtd->size)
80 return file->f_pos = offset;
87 static int mtd_open(struct inode *inode, struct file *file)
89 int minor = iminor(inode);
90 int devnum = minor >> 1;
93 struct mtd_file_info *mfi;
95 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
97 if (devnum >= MAX_MTD_DEVICES)
100 /* You can't open the RO devices RW */
101 if ((file->f_mode & 2) && (minor & 1))
105 mtd = get_mtd_device(NULL, devnum);
112 if (MTD_ABSENT == mtd->type) {
118 /* You can't open it RW if it's not a writeable device */
119 if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
125 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
132 file->private_data = mfi;
139 /*====================================================================*/
141 static int mtd_close(struct inode *inode, struct file *file)
143 struct mtd_file_info *mfi = file->private_data;
144 struct mtd_info *mtd = mfi->mtd;
146 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
148 /* Only sync if opened RW */
149 if ((file->f_mode & 2) && mtd->sync)
153 file->private_data = NULL;
159 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
160 userspace buffer down and use it directly with readv/writev.
162 #define MAX_KMALLOC_SIZE 0x20000
164 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
166 struct mtd_file_info *mfi = file->private_data;
167 struct mtd_info *mtd = mfi->mtd;
169 size_t total_retlen=0;
174 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
176 if (*ppos + count > mtd->size)
177 count = mtd->size - *ppos;
182 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
183 and pass them directly to the MTD functions */
185 if (count > MAX_KMALLOC_SIZE)
186 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
188 kbuf=kmalloc(count, GFP_KERNEL);
195 if (count > MAX_KMALLOC_SIZE)
196 len = MAX_KMALLOC_SIZE;
201 case MTD_MODE_OTP_FACTORY:
202 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
204 case MTD_MODE_OTP_USER:
205 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
209 struct mtd_oob_ops ops;
211 ops.mode = MTD_OOB_RAW;
216 ret = mtd->read_oob(mtd, *ppos, &ops);
221 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
223 /* Nand returns -EBADMSG on ecc errors, but it returns
224 * the data. For our userspace tools it is important
225 * to dump areas with ecc errors !
226 * For kernel internal usage it also might return -EUCLEAN
227 * to signal the caller that a bitflip has occured and has
228 * been corrected by the ECC algorithm.
229 * Userspace software which accesses NAND this way
230 * must be aware of the fact that it deals with NAND
232 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
234 if (copy_to_user(buf, kbuf, retlen)) {
239 total_retlen += retlen;
257 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
259 struct mtd_file_info *mfi = file->private_data;
260 struct mtd_info *mtd = mfi->mtd;
263 size_t total_retlen=0;
267 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
269 if (*ppos == mtd->size)
272 if (*ppos + count > mtd->size)
273 count = mtd->size - *ppos;
278 if (count > MAX_KMALLOC_SIZE)
279 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
281 kbuf=kmalloc(count, GFP_KERNEL);
288 if (count > MAX_KMALLOC_SIZE)
289 len = MAX_KMALLOC_SIZE;
293 if (copy_from_user(kbuf, buf, len)) {
299 case MTD_MODE_OTP_FACTORY:
302 case MTD_MODE_OTP_USER:
303 if (!mtd->write_user_prot_reg) {
307 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
312 struct mtd_oob_ops ops;
314 ops.mode = MTD_OOB_RAW;
319 ret = mtd->write_oob(mtd, *ppos, &ops);
325 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
329 total_retlen += retlen;
343 /*======================================================================
345 IOCTL calls for getting device parameters.
347 ======================================================================*/
348 static void mtdchar_erase_callback (struct erase_info *instr)
350 wake_up((wait_queue_head_t *)instr->priv);
353 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
354 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
356 struct mtd_info *mtd = mfi->mtd;
360 case MTD_OTP_FACTORY:
361 if (!mtd->read_fact_prot_reg)
364 mfi->mode = MTD_MODE_OTP_FACTORY;
367 if (!mtd->read_fact_prot_reg)
370 mfi->mode = MTD_MODE_OTP_USER;
380 # define otp_select_filemode(f,m) -EOPNOTSUPP
383 static int mtd_ioctl(struct inode *inode, struct file *file,
384 u_int cmd, u_long arg)
386 struct mtd_file_info *mfi = file->private_data;
387 struct mtd_info *mtd = mfi->mtd;
388 void __user *argp = (void __user *)arg;
391 struct mtd_info_user info;
393 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
395 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
397 if (!access_ok(VERIFY_READ, argp, size))
401 if (!access_ok(VERIFY_WRITE, argp, size))
406 case MEMGETREGIONCOUNT:
407 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
411 case MEMGETREGIONINFO:
414 struct mtd_erase_region_info *kr;
415 struct region_info_user *ur = (struct region_info_user *) argp;
417 if (get_user(ur_idx, &(ur->regionindex)))
420 kr = &(mtd->eraseregions[ur_idx]);
422 if (put_user(kr->offset, &(ur->offset))
423 || put_user(kr->erasesize, &(ur->erasesize))
424 || put_user(kr->numblocks, &(ur->numblocks)))
431 info.type = mtd->type;
432 info.flags = mtd->flags;
433 info.size = mtd->size;
434 info.erasesize = mtd->erasesize;
435 info.writesize = mtd->writesize;
436 info.oobsize = mtd->oobsize;
437 /* The below fields are obsolete */
440 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
446 struct erase_info *erase;
448 if(!(file->f_mode & 2))
451 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
455 wait_queue_head_t waitq;
456 DECLARE_WAITQUEUE(wait, current);
458 init_waitqueue_head(&waitq);
460 if (copy_from_user(&erase->addr, argp,
461 sizeof(struct erase_info_user))) {
466 erase->callback = mtdchar_erase_callback;
467 erase->priv = (unsigned long)&waitq;
470 FIXME: Allow INTERRUPTIBLE. Which means
471 not having the wait_queue head on the stack.
473 If the wq_head is on the stack, and we
474 leave because we got interrupted, then the
475 wq_head is no longer there when the
476 callback routine tries to wake us up.
478 ret = mtd->erase(mtd, erase);
480 set_current_state(TASK_UNINTERRUPTIBLE);
481 add_wait_queue(&waitq, &wait);
482 if (erase->state != MTD_ERASE_DONE &&
483 erase->state != MTD_ERASE_FAILED)
485 remove_wait_queue(&waitq, &wait);
486 set_current_state(TASK_RUNNING);
488 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
497 struct mtd_oob_buf buf;
498 struct mtd_oob_ops ops;
499 struct mtd_oob_buf __user *user_buf = argp;
502 if(!(file->f_mode & 2))
505 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
508 if (buf.length > 4096)
514 ret = access_ok(VERIFY_READ, buf.ptr,
515 buf.length) ? 0 : EFAULT;
520 ops.ooblen = buf.length;
521 ops.ooboffs = buf.start & (mtd->oobsize - 1);
523 ops.mode = MTD_OOB_PLACE;
525 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
528 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
532 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
537 buf.start &= ~(mtd->oobsize - 1);
538 ret = mtd->write_oob(mtd, buf.start, &ops);
540 if (ops.oobretlen > 0xFFFFFFFFU)
542 retlen = ops.oobretlen;
543 if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
553 struct mtd_oob_buf buf;
554 struct mtd_oob_ops ops;
556 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
559 if (buf.length > 4096)
565 ret = access_ok(VERIFY_WRITE, buf.ptr,
566 buf.length) ? 0 : -EFAULT;
570 ops.ooblen = buf.length;
571 ops.ooboffs = buf.start & (mtd->oobsize - 1);
573 ops.mode = MTD_OOB_PLACE;
575 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
578 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
582 buf.start &= ~(mtd->oobsize - 1);
583 ret = mtd->read_oob(mtd, buf.start, &ops);
585 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
587 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
597 struct erase_info_user einfo;
599 if (copy_from_user(&einfo, argp, sizeof(einfo)))
605 ret = mtd->lock(mtd, einfo.start, einfo.length);
611 struct erase_info_user einfo;
613 if (copy_from_user(&einfo, argp, sizeof(einfo)))
619 ret = mtd->unlock(mtd, einfo.start, einfo.length);
623 /* Legacy interface */
626 struct nand_oobinfo oi;
630 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
633 oi.useecc = MTD_NANDECC_AUTOPLACE;
634 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
635 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
637 oi.eccbytes = mtd->ecclayout->eccbytes;
639 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
648 if (copy_from_user(&offs, argp, sizeof(loff_t)))
650 if (!mtd->block_isbad)
653 return mtd->block_isbad(mtd, offs);
661 if (copy_from_user(&offs, argp, sizeof(loff_t)))
663 if (!mtd->block_markbad)
666 return mtd->block_markbad(mtd, offs);
670 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
674 if (copy_from_user(&mode, argp, sizeof(int)))
677 mfi->mode = MTD_MODE_NORMAL;
679 ret = otp_select_filemode(mfi, mode);
685 case OTPGETREGIONCOUNT:
686 case OTPGETREGIONINFO:
688 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
693 case MTD_MODE_OTP_FACTORY:
694 if (mtd->get_fact_prot_info)
695 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
697 case MTD_MODE_OTP_USER:
698 if (mtd->get_user_prot_info)
699 ret = mtd->get_user_prot_info(mtd, buf, 4096);
705 if (cmd == OTPGETREGIONCOUNT) {
706 int nbr = ret / sizeof(struct otp_info);
707 ret = copy_to_user(argp, &nbr, sizeof(int));
709 ret = copy_to_user(argp, buf, ret);
719 struct otp_info oinfo;
721 if (mfi->mode != MTD_MODE_OTP_USER)
723 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
725 if (!mtd->lock_user_prot_reg)
727 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
737 if (copy_to_user(argp, mtd->ecclayout,
738 sizeof(struct nand_ecclayout)))
745 if (copy_to_user(argp, &mtd->ecc_stats,
746 sizeof(struct mtd_ecc_stats)))
756 case MTD_MODE_OTP_FACTORY:
757 case MTD_MODE_OTP_USER:
758 ret = otp_select_filemode(mfi, arg);
762 if (!mtd->read_oob || !mtd->write_oob)
766 case MTD_MODE_NORMAL:
782 static const struct file_operations mtd_fops = {
783 .owner = THIS_MODULE,
789 .release = mtd_close,
792 static int __init init_mtdchar(void)
794 if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
795 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
800 mtd_class = class_create(THIS_MODULE, "mtd");
802 if (IS_ERR(mtd_class)) {
803 printk(KERN_ERR "Error creating mtd class.\n");
804 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
805 return PTR_ERR(mtd_class);
808 register_mtd_user(¬ifier);
812 static void __exit cleanup_mtdchar(void)
814 unregister_mtd_user(¬ifier);
815 class_destroy(mtd_class);
816 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
819 module_init(init_mtdchar);
820 module_exit(cleanup_mtdchar);
823 MODULE_LICENSE("GPL");
824 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
825 MODULE_DESCRIPTION("Direct character-device access to MTD devices");