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>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
17 #include <linux/smp_lock.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/compatmac.h>
22 #include <asm/uaccess.h>
24 static struct class *mtd_class;
26 static void mtd_notify_add(struct mtd_info* mtd)
31 device_create_drvdata(mtd_class, NULL,
32 MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
33 NULL, "mtd%d", mtd->index);
35 device_create_drvdata(mtd_class, NULL,
36 MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
37 NULL, "mtd%dro", mtd->index);
40 static void mtd_notify_remove(struct mtd_info* mtd)
45 device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
46 device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
49 static struct mtd_notifier notifier = {
50 .add = mtd_notify_add,
51 .remove = mtd_notify_remove,
55 * Data structure to hold the pointer to the mtd device as well
56 * as mode information ofr various use cases.
58 struct mtd_file_info {
60 enum mtd_file_modes mode;
63 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
65 struct mtd_file_info *mfi = file->private_data;
66 struct mtd_info *mtd = mfi->mtd;
72 offset += file->f_pos;
81 if (offset >= 0 && offset <= mtd->size)
82 return file->f_pos = offset;
89 static int mtd_open(struct inode *inode, struct file *file)
91 int minor = iminor(inode);
92 int devnum = minor >> 1;
95 struct mtd_file_info *mfi;
97 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
99 if (devnum >= MAX_MTD_DEVICES)
102 /* You can't open the RO devices RW */
103 if ((file->f_mode & 2) && (minor & 1))
107 mtd = get_mtd_device(NULL, devnum);
114 if (MTD_ABSENT == mtd->type) {
120 /* You can't open it RW if it's not a writeable device */
121 if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
127 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
134 file->private_data = mfi;
141 /*====================================================================*/
143 static int mtd_close(struct inode *inode, struct file *file)
145 struct mtd_file_info *mfi = file->private_data;
146 struct mtd_info *mtd = mfi->mtd;
148 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
150 /* Only sync if opened RW */
151 if ((file->f_mode & 2) && mtd->sync)
155 file->private_data = NULL;
161 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
162 userspace buffer down and use it directly with readv/writev.
164 #define MAX_KMALLOC_SIZE 0x20000
166 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
168 struct mtd_file_info *mfi = file->private_data;
169 struct mtd_info *mtd = mfi->mtd;
171 size_t total_retlen=0;
176 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
178 if (*ppos + count > mtd->size)
179 count = mtd->size - *ppos;
184 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
185 and pass them directly to the MTD functions */
187 if (count > MAX_KMALLOC_SIZE)
188 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
190 kbuf=kmalloc(count, GFP_KERNEL);
197 if (count > MAX_KMALLOC_SIZE)
198 len = MAX_KMALLOC_SIZE;
203 case MTD_MODE_OTP_FACTORY:
204 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
206 case MTD_MODE_OTP_USER:
207 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
211 struct mtd_oob_ops ops;
213 ops.mode = MTD_OOB_RAW;
218 ret = mtd->read_oob(mtd, *ppos, &ops);
223 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
225 /* Nand returns -EBADMSG on ecc errors, but it returns
226 * the data. For our userspace tools it is important
227 * to dump areas with ecc errors !
228 * For kernel internal usage it also might return -EUCLEAN
229 * to signal the caller that a bitflip has occured and has
230 * been corrected by the ECC algorithm.
231 * Userspace software which accesses NAND this way
232 * must be aware of the fact that it deals with NAND
234 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
236 if (copy_to_user(buf, kbuf, retlen)) {
241 total_retlen += retlen;
259 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
261 struct mtd_file_info *mfi = file->private_data;
262 struct mtd_info *mtd = mfi->mtd;
265 size_t total_retlen=0;
269 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
271 if (*ppos == mtd->size)
274 if (*ppos + count > mtd->size)
275 count = mtd->size - *ppos;
280 if (count > MAX_KMALLOC_SIZE)
281 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
283 kbuf=kmalloc(count, GFP_KERNEL);
290 if (count > MAX_KMALLOC_SIZE)
291 len = MAX_KMALLOC_SIZE;
295 if (copy_from_user(kbuf, buf, len)) {
301 case MTD_MODE_OTP_FACTORY:
304 case MTD_MODE_OTP_USER:
305 if (!mtd->write_user_prot_reg) {
309 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
314 struct mtd_oob_ops ops;
316 ops.mode = MTD_OOB_RAW;
321 ret = mtd->write_oob(mtd, *ppos, &ops);
327 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
331 total_retlen += retlen;
345 /*======================================================================
347 IOCTL calls for getting device parameters.
349 ======================================================================*/
350 static void mtdchar_erase_callback (struct erase_info *instr)
352 wake_up((wait_queue_head_t *)instr->priv);
355 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
356 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
358 struct mtd_info *mtd = mfi->mtd;
362 case MTD_OTP_FACTORY:
363 if (!mtd->read_fact_prot_reg)
366 mfi->mode = MTD_MODE_OTP_FACTORY;
369 if (!mtd->read_fact_prot_reg)
372 mfi->mode = MTD_MODE_OTP_USER;
382 # define otp_select_filemode(f,m) -EOPNOTSUPP
385 static int mtd_ioctl(struct inode *inode, struct file *file,
386 u_int cmd, u_long arg)
388 struct mtd_file_info *mfi = file->private_data;
389 struct mtd_info *mtd = mfi->mtd;
390 void __user *argp = (void __user *)arg;
393 struct mtd_info_user info;
395 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
397 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
399 if (!access_ok(VERIFY_READ, argp, size))
403 if (!access_ok(VERIFY_WRITE, argp, size))
408 case MEMGETREGIONCOUNT:
409 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
413 case MEMGETREGIONINFO:
415 struct region_info_user ur;
417 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
420 if (ur.regionindex >= mtd->numeraseregions)
422 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
423 sizeof(struct mtd_erase_region_info)))
429 info.type = mtd->type;
430 info.flags = mtd->flags;
431 info.size = mtd->size;
432 info.erasesize = mtd->erasesize;
433 info.writesize = mtd->writesize;
434 info.oobsize = mtd->oobsize;
435 /* The below fields are obsolete */
438 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
444 struct erase_info *erase;
446 if(!(file->f_mode & 2))
449 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
453 wait_queue_head_t waitq;
454 DECLARE_WAITQUEUE(wait, current);
456 init_waitqueue_head(&waitq);
458 if (copy_from_user(&erase->addr, argp,
459 sizeof(struct erase_info_user))) {
464 erase->callback = mtdchar_erase_callback;
465 erase->priv = (unsigned long)&waitq;
468 FIXME: Allow INTERRUPTIBLE. Which means
469 not having the wait_queue head on the stack.
471 If the wq_head is on the stack, and we
472 leave because we got interrupted, then the
473 wq_head is no longer there when the
474 callback routine tries to wake us up.
476 ret = mtd->erase(mtd, erase);
478 set_current_state(TASK_UNINTERRUPTIBLE);
479 add_wait_queue(&waitq, &wait);
480 if (erase->state != MTD_ERASE_DONE &&
481 erase->state != MTD_ERASE_FAILED)
483 remove_wait_queue(&waitq, &wait);
484 set_current_state(TASK_RUNNING);
486 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
495 struct mtd_oob_buf buf;
496 struct mtd_oob_ops ops;
499 if(!(file->f_mode & 2))
502 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
505 if (buf.length > 4096)
511 ret = access_ok(VERIFY_READ, buf.ptr,
512 buf.length) ? 0 : EFAULT;
517 ops.ooblen = buf.length;
518 ops.ooboffs = buf.start & (mtd->oobsize - 1);
520 ops.mode = MTD_OOB_PLACE;
522 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
525 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
529 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
534 buf.start &= ~(mtd->oobsize - 1);
535 ret = mtd->write_oob(mtd, buf.start, &ops);
537 if (ops.oobretlen > 0xFFFFFFFFU)
539 retlen = ops.oobretlen;
540 if (copy_to_user(&((struct mtd_oob_buf *)argp)->length,
541 &retlen, sizeof(buf.length)))
551 struct mtd_oob_buf buf;
552 struct mtd_oob_ops ops;
554 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
557 if (buf.length > 4096)
563 ret = access_ok(VERIFY_WRITE, buf.ptr,
564 buf.length) ? 0 : -EFAULT;
568 ops.ooblen = buf.length;
569 ops.ooboffs = buf.start & (mtd->oobsize - 1);
571 ops.mode = MTD_OOB_PLACE;
573 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
576 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
580 buf.start &= ~(mtd->oobsize - 1);
581 ret = mtd->read_oob(mtd, buf.start, &ops);
583 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
585 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
595 struct erase_info_user info;
597 if (copy_from_user(&info, argp, sizeof(info)))
603 ret = mtd->lock(mtd, info.start, info.length);
609 struct erase_info_user info;
611 if (copy_from_user(&info, argp, sizeof(info)))
617 ret = mtd->unlock(mtd, info.start, info.length);
621 /* Legacy interface */
624 struct nand_oobinfo oi;
628 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
631 oi.useecc = MTD_NANDECC_AUTOPLACE;
632 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
633 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
635 oi.eccbytes = mtd->ecclayout->eccbytes;
637 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
646 if (copy_from_user(&offs, argp, sizeof(loff_t)))
648 if (!mtd->block_isbad)
651 return mtd->block_isbad(mtd, offs);
659 if (copy_from_user(&offs, argp, sizeof(loff_t)))
661 if (!mtd->block_markbad)
664 return mtd->block_markbad(mtd, offs);
668 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
672 if (copy_from_user(&mode, argp, sizeof(int)))
675 mfi->mode = MTD_MODE_NORMAL;
677 ret = otp_select_filemode(mfi, mode);
683 case OTPGETREGIONCOUNT:
684 case OTPGETREGIONINFO:
686 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
691 case MTD_MODE_OTP_FACTORY:
692 if (mtd->get_fact_prot_info)
693 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
695 case MTD_MODE_OTP_USER:
696 if (mtd->get_user_prot_info)
697 ret = mtd->get_user_prot_info(mtd, buf, 4096);
703 if (cmd == OTPGETREGIONCOUNT) {
704 int nbr = ret / sizeof(struct otp_info);
705 ret = copy_to_user(argp, &nbr, sizeof(int));
707 ret = copy_to_user(argp, buf, ret);
717 struct otp_info info;
719 if (mfi->mode != MTD_MODE_OTP_USER)
721 if (copy_from_user(&info, argp, sizeof(info)))
723 if (!mtd->lock_user_prot_reg)
725 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
735 if (copy_to_user(argp, mtd->ecclayout,
736 sizeof(struct nand_ecclayout)))
743 if (copy_to_user(argp, &mtd->ecc_stats,
744 sizeof(struct mtd_ecc_stats)))
754 case MTD_MODE_OTP_FACTORY:
755 case MTD_MODE_OTP_USER:
756 ret = otp_select_filemode(mfi, arg);
760 if (!mtd->read_oob || !mtd->write_oob)
764 case MTD_MODE_NORMAL:
780 static const struct file_operations mtd_fops = {
781 .owner = THIS_MODULE,
787 .release = mtd_close,
790 static int __init init_mtdchar(void)
792 if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
793 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
798 mtd_class = class_create(THIS_MODULE, "mtd");
800 if (IS_ERR(mtd_class)) {
801 printk(KERN_ERR "Error creating mtd class.\n");
802 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
803 return PTR_ERR(mtd_class);
806 register_mtd_user(¬ifier);
810 static void __exit cleanup_mtdchar(void)
812 unregister_mtd_user(¬ifier);
813 class_destroy(mtd_class);
814 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
817 module_init(init_mtdchar);
818 module_exit(cleanup_mtdchar);
821 MODULE_LICENSE("GPL");
822 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
823 MODULE_DESCRIPTION("Direct character-device access to MTD devices");