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/uaccess.h>
21 static struct class *mtd_class;
23 static void mtd_notify_add(struct mtd_info* mtd)
28 class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
29 NULL, "mtd%d", mtd->index);
31 class_device_create(mtd_class, NULL,
32 MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
33 NULL, "mtd%dro", mtd->index);
36 static void mtd_notify_remove(struct mtd_info* mtd)
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));
45 static struct mtd_notifier notifier = {
46 .add = mtd_notify_add,
47 .remove = mtd_notify_remove,
51 * Data structure to hold the pointer to the mtd device as well
52 * as mode information ofr various use cases.
54 struct mtd_file_info {
56 enum mtd_file_modes mode;
59 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
61 struct mtd_file_info *mfi = file->private_data;
62 struct mtd_info *mtd = mfi->mtd;
68 offset += file->f_pos;
77 if (offset >= 0 && offset <= mtd->size)
78 return file->f_pos = offset;
85 static int mtd_open(struct inode *inode, struct file *file)
87 int minor = iminor(inode);
88 int devnum = minor >> 1;
90 struct mtd_file_info *mfi;
92 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
94 if (devnum >= MAX_MTD_DEVICES)
97 /* You can't open the RO devices RW */
98 if ((file->f_mode & 2) && (minor & 1))
101 mtd = get_mtd_device(NULL, devnum);
106 if (MTD_ABSENT == mtd->type) {
111 /* You can't open it RW if it's not a writeable device */
112 if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
117 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
123 file->private_data = mfi;
128 /*====================================================================*/
130 static int mtd_close(struct inode *inode, struct file *file)
132 struct mtd_file_info *mfi = file->private_data;
133 struct mtd_info *mtd = mfi->mtd;
135 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
141 file->private_data = NULL;
147 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
148 userspace buffer down and use it directly with readv/writev.
150 #define MAX_KMALLOC_SIZE 0x20000
152 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
154 struct mtd_file_info *mfi = file->private_data;
155 struct mtd_info *mtd = mfi->mtd;
157 size_t total_retlen=0;
162 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
164 if (*ppos + count > mtd->size)
165 count = mtd->size - *ppos;
170 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
171 and pass them directly to the MTD functions */
173 if (count > MAX_KMALLOC_SIZE)
174 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
176 kbuf=kmalloc(count, GFP_KERNEL);
183 if (count > MAX_KMALLOC_SIZE)
184 len = MAX_KMALLOC_SIZE;
189 case MTD_MODE_OTP_FACTORY:
190 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
192 case MTD_MODE_OTP_USER:
193 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
197 struct mtd_oob_ops ops;
199 ops.mode = MTD_OOB_RAW;
204 ret = mtd->read_oob(mtd, *ppos, &ops);
209 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
211 /* Nand returns -EBADMSG on ecc errors, but it returns
212 * the data. For our userspace tools it is important
213 * to dump areas with ecc errors !
214 * For kernel internal usage it also might return -EUCLEAN
215 * to signal the caller that a bitflip has occured and has
216 * been corrected by the ECC algorithm.
217 * Userspace software which accesses NAND this way
218 * must be aware of the fact that it deals with NAND
220 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
222 if (copy_to_user(buf, kbuf, retlen)) {
227 total_retlen += retlen;
245 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
247 struct mtd_file_info *mfi = file->private_data;
248 struct mtd_info *mtd = mfi->mtd;
251 size_t total_retlen=0;
255 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
257 if (*ppos == mtd->size)
260 if (*ppos + count > mtd->size)
261 count = mtd->size - *ppos;
266 if (count > MAX_KMALLOC_SIZE)
267 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
269 kbuf=kmalloc(count, GFP_KERNEL);
276 if (count > MAX_KMALLOC_SIZE)
277 len = MAX_KMALLOC_SIZE;
281 if (copy_from_user(kbuf, buf, len)) {
287 case MTD_MODE_OTP_FACTORY:
290 case MTD_MODE_OTP_USER:
291 if (!mtd->write_user_prot_reg) {
295 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
300 struct mtd_oob_ops ops;
302 ops.mode = MTD_OOB_RAW;
307 ret = mtd->write_oob(mtd, *ppos, &ops);
313 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
317 total_retlen += retlen;
331 /*======================================================================
333 IOCTL calls for getting device parameters.
335 ======================================================================*/
336 static void mtdchar_erase_callback (struct erase_info *instr)
338 wake_up((wait_queue_head_t *)instr->priv);
341 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
342 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
344 struct mtd_info *mtd = mfi->mtd;
348 case MTD_OTP_FACTORY:
349 if (!mtd->read_fact_prot_reg)
352 mfi->mode = MTD_MODE_OTP_FACTORY;
355 if (!mtd->read_fact_prot_reg)
358 mfi->mode = MTD_MODE_OTP_USER;
368 # define otp_select_filemode(f,m) -EOPNOTSUPP
371 static int mtd_ioctl(struct inode *inode, struct file *file,
372 u_int cmd, u_long arg)
374 struct mtd_file_info *mfi = file->private_data;
375 struct mtd_info *mtd = mfi->mtd;
376 void __user *argp = (void __user *)arg;
379 struct mtd_info_user info;
381 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
383 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
385 if (!access_ok(VERIFY_READ, argp, size))
389 if (!access_ok(VERIFY_WRITE, argp, size))
394 case MEMGETREGIONCOUNT:
395 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
399 case MEMGETREGIONINFO:
401 struct region_info_user ur;
403 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
406 if (ur.regionindex >= mtd->numeraseregions)
408 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
409 sizeof(struct mtd_erase_region_info)))
415 info.type = mtd->type;
416 info.flags = mtd->flags;
417 info.size = mtd->size;
418 info.erasesize = mtd->erasesize;
419 info.writesize = mtd->writesize;
420 info.oobsize = mtd->oobsize;
421 info.ecctype = mtd->ecctype;
422 info.eccsize = mtd->eccsize;
423 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
429 struct erase_info *erase;
431 if(!(file->f_mode & 2))
434 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
438 wait_queue_head_t waitq;
439 DECLARE_WAITQUEUE(wait, current);
441 init_waitqueue_head(&waitq);
443 memset (erase,0,sizeof(struct erase_info));
444 if (copy_from_user(&erase->addr, argp,
445 sizeof(struct erase_info_user))) {
450 erase->callback = mtdchar_erase_callback;
451 erase->priv = (unsigned long)&waitq;
454 FIXME: Allow INTERRUPTIBLE. Which means
455 not having the wait_queue head on the stack.
457 If the wq_head is on the stack, and we
458 leave because we got interrupted, then the
459 wq_head is no longer there when the
460 callback routine tries to wake us up.
462 ret = mtd->erase(mtd, erase);
464 set_current_state(TASK_UNINTERRUPTIBLE);
465 add_wait_queue(&waitq, &wait);
466 if (erase->state != MTD_ERASE_DONE &&
467 erase->state != MTD_ERASE_FAILED)
469 remove_wait_queue(&waitq, &wait);
470 set_current_state(TASK_RUNNING);
472 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
481 struct mtd_oob_buf buf;
482 struct mtd_oob_ops ops;
484 if(!(file->f_mode & 2))
487 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
490 if (buf.length > 4096)
496 ret = access_ok(VERIFY_READ, buf.ptr,
497 buf.length) ? 0 : EFAULT;
502 ops.len = buf.length;
503 ops.ooblen = buf.length;
504 ops.ooboffs = buf.start & (mtd->oobsize - 1);
506 ops.mode = MTD_OOB_PLACE;
508 if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
511 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
515 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
520 buf.start &= ~(mtd->oobsize - 1);
521 ret = mtd->write_oob(mtd, buf.start, &ops);
523 if (copy_to_user(argp + sizeof(uint32_t), &ops.retlen,
534 struct mtd_oob_buf buf;
535 struct mtd_oob_ops ops;
537 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
540 if (buf.length > 4096)
546 ret = access_ok(VERIFY_WRITE, buf.ptr,
547 buf.length) ? 0 : -EFAULT;
551 ops.len = buf.length;
552 ops.ooblen = buf.length;
553 ops.ooboffs = buf.start & (mtd->oobsize - 1);
555 ops.mode = MTD_OOB_PLACE;
557 if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
560 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
564 buf.start &= ~(mtd->oobsize - 1);
565 ret = mtd->read_oob(mtd, buf.start, &ops);
567 if (put_user(ops.retlen, (uint32_t __user *)argp))
569 else if (ops.retlen && copy_to_user(buf.ptr, ops.oobbuf,
579 struct erase_info_user info;
581 if (copy_from_user(&info, argp, sizeof(info)))
587 ret = mtd->lock(mtd, info.start, info.length);
593 struct erase_info_user info;
595 if (copy_from_user(&info, argp, sizeof(info)))
601 ret = mtd->unlock(mtd, info.start, info.length);
605 /* Legacy interface */
608 struct nand_oobinfo oi;
612 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
615 oi.useecc = MTD_NANDECC_AUTOPLACE;
616 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
617 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
620 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
629 if (copy_from_user(&offs, argp, sizeof(loff_t)))
631 if (!mtd->block_isbad)
634 return mtd->block_isbad(mtd, offs);
642 if (copy_from_user(&offs, argp, sizeof(loff_t)))
644 if (!mtd->block_markbad)
647 return mtd->block_markbad(mtd, offs);
651 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
655 if (copy_from_user(&mode, argp, sizeof(int)))
658 mfi->mode = MTD_MODE_NORMAL;
660 ret = otp_select_filemode(mfi, mode);
666 case OTPGETREGIONCOUNT:
667 case OTPGETREGIONINFO:
669 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
674 case MTD_MODE_OTP_FACTORY:
675 if (mtd->get_fact_prot_info)
676 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
678 case MTD_MODE_OTP_USER:
679 if (mtd->get_user_prot_info)
680 ret = mtd->get_user_prot_info(mtd, buf, 4096);
686 if (cmd == OTPGETREGIONCOUNT) {
687 int nbr = ret / sizeof(struct otp_info);
688 ret = copy_to_user(argp, &nbr, sizeof(int));
690 ret = copy_to_user(argp, buf, ret);
700 struct otp_info info;
702 if (mfi->mode != MTD_MODE_OTP_USER)
704 if (copy_from_user(&info, argp, sizeof(info)))
706 if (!mtd->lock_user_prot_reg)
708 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
718 if (copy_to_user(argp, &mtd->ecclayout,
719 sizeof(struct nand_ecclayout)))
726 if (copy_to_user(argp, &mtd->ecc_stats,
727 sizeof(struct mtd_ecc_stats)))
737 case MTD_MODE_OTP_FACTORY:
738 case MTD_MODE_OTP_USER:
739 ret = otp_select_filemode(mfi, arg);
743 if (!mtd->read_oob || !mtd->write_oob)
747 case MTD_MODE_NORMAL:
763 static struct file_operations mtd_fops = {
764 .owner = THIS_MODULE,
770 .release = mtd_close,
773 static int __init init_mtdchar(void)
775 if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
776 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
781 mtd_class = class_create(THIS_MODULE, "mtd");
783 if (IS_ERR(mtd_class)) {
784 printk(KERN_ERR "Error creating mtd class.\n");
785 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
786 return PTR_ERR(mtd_class);
789 register_mtd_user(¬ifier);
793 static void __exit cleanup_mtdchar(void)
795 unregister_mtd_user(¬ifier);
796 class_destroy(mtd_class);
797 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
800 module_init(init_mtdchar);
801 module_exit(cleanup_mtdchar);
804 MODULE_LICENSE("GPL");
805 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
806 MODULE_DESCRIPTION("Direct character-device access to MTD devices");