[mirror_ubuntu-hirsute-kernel.git] / drivers / mtd / mtdchar.c

/*
 * $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $
 *
 * Character-device access to raw MTD devices.
 *
 */

#include <linux/config.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/compatmac.h>

#include <asm/uaccess.h>

static struct class *mtd_class;

static void mtd_notify_add(struct mtd_info* mtd)
{
	if (!mtd)
		return;

	class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
			    NULL, "mtd%d", mtd->index);

	class_device_create(mtd_class, NULL,
			    MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
			    NULL, "mtd%dro", mtd->index);
}

static void mtd_notify_remove(struct mtd_info* mtd)
{
	if (!mtd)
		return;

	class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
	class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
}

static struct mtd_notifier notifier = {
	.add	= mtd_notify_add,
	.remove	= mtd_notify_remove,
};

/*
 * We use file->private_data to store a pointer to the MTDdevice.
 * Since alighment is at least 32 bits, we have 2 bits free for OTP
 * modes as well.
 */

#define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)

#define MTD_MODE_OTP_FACT	1
#define MTD_MODE_OTP_USER	2
#define MTD_MODE(file)		((long)((file)->private_data) & 3)

#define SET_MTD_MODE(file, mode) \
	do { long __p = (long)((file)->private_data); \
	     (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)

static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
{
	struct mtd_info *mtd = TO_MTD(file);

	switch (orig) {
	case 0:
		/* SEEK_SET */
		break;
	case 1:
		/* SEEK_CUR */
		offset += file->f_pos;
		break;
	case 2:
		/* SEEK_END */
		offset += mtd->size;
		break;
	default:
		return -EINVAL;
	}

	if (offset >= 0 && offset < mtd->size)
		return file->f_pos = offset;

	return -EINVAL;
}


static int mtd_open(struct inode *inode, struct file *file)
{
	int minor = iminor(inode);
	int devnum = minor >> 1;
	struct mtd_info *mtd;

	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");

	if (devnum >= MAX_MTD_DEVICES)
		return -ENODEV;

	/* You can't open the RO devices RW */
	if ((file->f_mode & 2) && (minor & 1))
		return -EACCES;

	mtd = get_mtd_device(NULL, devnum);

	if (!mtd)
		return -ENODEV;

	if (MTD_ABSENT == mtd->type) {
		put_mtd_device(mtd);
		return -ENODEV;
	}

	file->private_data = mtd;

	/* You can't open it RW if it's not a writeable device */
	if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
		put_mtd_device(mtd);
		return -EACCES;
	}

	return 0;
} /* mtd_open */

/*====================================================================*/

static int mtd_close(struct inode *inode, struct file *file)
{
	struct mtd_info *mtd;

	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");

	mtd = TO_MTD(file);

	if (mtd->sync)
		mtd->sync(mtd);

	put_mtd_device(mtd);

	return 0;
} /* mtd_close */

/* FIXME: This _really_ needs to die. In 2.5, we should lock the
   userspace buffer down and use it directly with readv/writev.
*/
#define MAX_KMALLOC_SIZE 0x20000

static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
{
	struct mtd_info *mtd = TO_MTD(file);
	size_t retlen=0;
	size_t total_retlen=0;
	int ret=0;
	int len;
	char *kbuf;

	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");

	if (*ppos + count > mtd->size)
		count = mtd->size - *ppos;

	if (!count)
		return 0;

	/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
	   and pass them directly to the MTD functions */

	if (count > MAX_KMALLOC_SIZE)
		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
	else
		kbuf=kmalloc(count, GFP_KERNEL);

	if (!kbuf)
		return -ENOMEM;

	while (count) {

		if (count > MAX_KMALLOC_SIZE)
			len = MAX_KMALLOC_SIZE;
		else
			len = count;

		switch (MTD_MODE(file)) {
		case MTD_MODE_OTP_FACT:
			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
			break;
		case MTD_MODE_OTP_USER:
			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
			break;
		default:
			ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
		}
		/* Nand returns -EBADMSG on ecc errors, but it returns
		 * the data. For our userspace tools it is important
		 * to dump areas with ecc errors !
		 * Userspace software which accesses NAND this way
		 * must be aware of the fact that it deals with NAND
		 */
		if (!ret || (ret == -EBADMSG)) {
			*ppos += retlen;
			if (copy_to_user(buf, kbuf, retlen)) {
			        kfree(kbuf);
				return -EFAULT;
			}
			else
				total_retlen += retlen;

			count -= retlen;
			buf += retlen;
			if (retlen == 0)
				count = 0;
		}
		else {
			kfree(kbuf);
			return ret;
		}

	}

	kfree(kbuf);
	return total_retlen;
} /* mtd_read */

static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
{
	struct mtd_info *mtd = TO_MTD(file);
	char *kbuf;
	size_t retlen;
	size_t total_retlen=0;
	int ret=0;
	int len;

	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");

	if (*ppos == mtd->size)
		return -ENOSPC;

	if (*ppos + count > mtd->size)
		count = mtd->size - *ppos;

	if (!count)
		return 0;

	if (count > MAX_KMALLOC_SIZE)
		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
	else
		kbuf=kmalloc(count, GFP_KERNEL);

	if (!kbuf)
		return -ENOMEM;

	while (count) {

		if (count > MAX_KMALLOC_SIZE)
			len = MAX_KMALLOC_SIZE;
		else
			len = count;

		if (copy_from_user(kbuf, buf, len)) {
			kfree(kbuf);
			return -EFAULT;
		}

		switch (MTD_MODE(file)) {
		case MTD_MODE_OTP_FACT:
			ret = -EROFS;
			break;
		case MTD_MODE_OTP_USER:
			if (!mtd->write_user_prot_reg) {
				ret = -EOPNOTSUPP;
				break;
			}
			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
			break;
		default:
			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
		}
		if (!ret) {
			*ppos += retlen;
			total_retlen += retlen;
			count -= retlen;
			buf += retlen;
		}
		else {
			kfree(kbuf);
			return ret;
		}
	}

	kfree(kbuf);
	return total_retlen;
} /* mtd_write */

/*======================================================================

    IOCTL calls for getting device parameters.

======================================================================*/
static void mtdchar_erase_callback (struct erase_info *instr)
{
	wake_up((wait_queue_head_t *)instr->priv);
}

static int mtd_ioctl(struct inode *inode, struct file *file,
		     u_int cmd, u_long arg)
{
	struct mtd_info *mtd = TO_MTD(file);
	void __user *argp = (void __user *)arg;
	int ret = 0;
	u_long size;

	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");

	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
	if (cmd & IOC_IN) {
		if (!access_ok(VERIFY_READ, argp, size))
			return -EFAULT;
	}
	if (cmd & IOC_OUT) {
		if (!access_ok(VERIFY_WRITE, argp, size))
			return -EFAULT;
	}

	switch (cmd) {
	case MEMGETREGIONCOUNT:
		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
			return -EFAULT;
		break;

	case MEMGETREGIONINFO:
	{
		struct region_info_user ur;

		if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
			return -EFAULT;

		if (ur.regionindex >= mtd->numeraseregions)
			return -EINVAL;
		if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
				sizeof(struct mtd_erase_region_info)))
			return -EFAULT;
		break;
	}

	case MEMGETINFO:
		if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
			return -EFAULT;
		break;

	case MEMERASE:
	{
		struct erase_info *erase;

		if(!(file->f_mode & 2))
			return -EPERM;

		erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
		if (!erase)
			ret = -ENOMEM;
		else {
			wait_queue_head_t waitq;
			DECLARE_WAITQUEUE(wait, current);

			init_waitqueue_head(&waitq);

			memset (erase,0,sizeof(struct erase_info));
			if (copy_from_user(&erase->addr, argp,
				    sizeof(struct erase_info_user))) {
				kfree(erase);
				return -EFAULT;
			}
			erase->mtd = mtd;
			erase->callback = mtdchar_erase_callback;
			erase->priv = (unsigned long)&waitq;

			/*
			  FIXME: Allow INTERRUPTIBLE. Which means
			  not having the wait_queue head on the stack.

			  If the wq_head is on the stack, and we
			  leave because we got interrupted, then the
			  wq_head is no longer there when the
			  callback routine tries to wake us up.
			*/
			ret = mtd->erase(mtd, erase);
			if (!ret) {
				set_current_state(TASK_UNINTERRUPTIBLE);
				add_wait_queue(&waitq, &wait);
				if (erase->state != MTD_ERASE_DONE &&
				    erase->state != MTD_ERASE_FAILED)
					schedule();
				remove_wait_queue(&waitq, &wait);
				set_current_state(TASK_RUNNING);

				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
			}
			kfree(erase);
		}
		break;
	}

	case MEMWRITEOOB:
	{
		struct mtd_oob_buf buf;
		void *databuf;
		ssize_t retlen;

		if(!(file->f_mode & 2))
			return -EPERM;

		if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
			return -EFAULT;

		if (buf.length > 0x4096)
			return -EINVAL;

		if (!mtd->write_oob)
			ret = -EOPNOTSUPP;
		else
			ret = access_ok(VERIFY_READ, buf.ptr,
					buf.length) ? 0 : EFAULT;

		if (ret)
			return ret;

		databuf = kmalloc(buf.length, GFP_KERNEL);
		if (!databuf)
			return -ENOMEM;

		if (copy_from_user(databuf, buf.ptr, buf.length)) {
			kfree(databuf);
			return -EFAULT;
		}

		ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);

		if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
			ret = -EFAULT;

		kfree(databuf);
		break;

	}

	case MEMREADOOB:
	{
		struct mtd_oob_buf buf;
		void *databuf;
		ssize_t retlen;

		if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
			return -EFAULT;

		if (buf.length > 0x4096)
			return -EINVAL;

		if (!mtd->read_oob)
			ret = -EOPNOTSUPP;
		else
			ret = access_ok(VERIFY_WRITE, buf.ptr,
					buf.length) ? 0 : -EFAULT;

		if (ret)
			return ret;

		databuf = kmalloc(buf.length, GFP_KERNEL);
		if (!databuf)
			return -ENOMEM;

		ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);

		if (put_user(retlen, (uint32_t __user *)argp))
			ret = -EFAULT;
		else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
			ret = -EFAULT;

		kfree(databuf);
		break;
	}

	case MEMLOCK:
	{
		struct erase_info_user info;

		if (copy_from_user(&info, argp, sizeof(info)))
			return -EFAULT;

		if (!mtd->lock)
			ret = -EOPNOTSUPP;
		else
			ret = mtd->lock(mtd, info.start, info.length);
		break;
	}

	case MEMUNLOCK:
	{
		struct erase_info_user info;

		if (copy_from_user(&info, argp, sizeof(info)))
			return -EFAULT;

		if (!mtd->unlock)
			ret = -EOPNOTSUPP;
		else
			ret = mtd->unlock(mtd, info.start, info.length);
		break;
	}

	case MEMSETOOBSEL:
	{
		if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
			return -EFAULT;
		break;
	}

	case MEMGETOOBSEL:
	{
		if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
			return -EFAULT;
		break;
	}

	case MEMGETBADBLOCK:
	{
		loff_t offs;

		if (copy_from_user(&offs, argp, sizeof(loff_t)))
			return -EFAULT;
		if (!mtd->block_isbad)
			ret = -EOPNOTSUPP;
		else
			return mtd->block_isbad(mtd, offs);
		break;
	}

	case MEMSETBADBLOCK:
	{
		loff_t offs;

		if (copy_from_user(&offs, argp, sizeof(loff_t)))
			return -EFAULT;
		if (!mtd->block_markbad)
			ret = -EOPNOTSUPP;
		else
			return mtd->block_markbad(mtd, offs);
		break;
	}

#ifdef CONFIG_MTD_OTP
	case OTPSELECT:
	{
		int mode;
		if (copy_from_user(&mode, argp, sizeof(int)))
			return -EFAULT;
		SET_MTD_MODE(file, 0);
		switch (mode) {
		case MTD_OTP_FACTORY:
			if (!mtd->read_fact_prot_reg)
				ret = -EOPNOTSUPP;
			else
				SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
			break;
		case MTD_OTP_USER:
			if (!mtd->read_fact_prot_reg)
				ret = -EOPNOTSUPP;
			else
				SET_MTD_MODE(file, MTD_MODE_OTP_USER);
			break;
		default:
			ret = -EINVAL;
		case MTD_OTP_OFF:
			break;
		}
		file->f_pos = 0;
		break;
	}

	case OTPGETREGIONCOUNT:
	case OTPGETREGIONINFO:
	{
		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
		ret = -EOPNOTSUPP;
		switch (MTD_MODE(file)) {
		case MTD_MODE_OTP_FACT:
			if (mtd->get_fact_prot_info)
				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
			break;
		case MTD_MODE_OTP_USER:
			if (mtd->get_user_prot_info)
				ret = mtd->get_user_prot_info(mtd, buf, 4096);
			break;
		}
		if (ret >= 0) {
			if (cmd == OTPGETREGIONCOUNT) {
				int nbr = ret / sizeof(struct otp_info);
				ret = copy_to_user(argp, &nbr, sizeof(int));
			} else
				ret = copy_to_user(argp, buf, ret);
			if (ret)
				ret = -EFAULT;
		}
		kfree(buf);
		break;
	}

	case OTPLOCK:
	{
		struct otp_info info;

		if (MTD_MODE(file) != MTD_MODE_OTP_USER)
			return -EINVAL;
		if (copy_from_user(&info, argp, sizeof(info)))
			return -EFAULT;
		if (!mtd->lock_user_prot_reg)
			return -EOPNOTSUPP;
		ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
		break;
	}
#endif

	default:
		ret = -ENOTTY;
	}

	return ret;
} /* memory_ioctl */

static struct file_operations mtd_fops = {
	.owner		= THIS_MODULE,
	.llseek		= mtd_lseek,
	.read		= mtd_read,
	.write		= mtd_write,
	.ioctl		= mtd_ioctl,
	.open		= mtd_open,
	.release	= mtd_close,
};

static int __init init_mtdchar(void)
{
	if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
		       MTD_CHAR_MAJOR);
		return -EAGAIN;
	}

	mtd_class = class_create(THIS_MODULE, "mtd");

	if (IS_ERR(mtd_class)) {
		printk(KERN_ERR "Error creating mtd class.\n");
		unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
		return PTR_ERR(mtd_class);
	}

	register_mtd_user(&notifier);
	return 0;
}

static void __exit cleanup_mtdchar(void)
{
	unregister_mtd_user(&notifier);
	class_destroy(mtd_class);
	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
}

module_init(init_mtdchar);
module_exit(cleanup_mtdchar);


MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Direct character-device access to MTD devices");
Commit	Line	Data
1da177e4	1	/*
97894cda	2	* $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $
1da177e4 LT	3	*
	4	* Character-device access to raw MTD devices.
	5	*
	6	*/
	7
	8	#include <linux/config.h>
15fdc52f TG	9	#include <linux/device.h>
	10	#include <linux/fs.h>
	11	#include <linux/init.h>
1da177e4 LT	12	#include <linux/kernel.h>
1da177e4 LT	13	#include <linux/module.h>
15fdc52f TG	14	#include <linux/slab.h>
	15	#include <linux/sched.h>
	16
1da177e4 LT	17	#include <linux/mtd/mtd.h>
1da177e4 LT	18	#include <linux/mtd/compatmac.h>
1da177e4	19
15fdc52f	20	#include <asm/uaccess.h>
9bc7b387 TP	21
9bc7b387 TP	22	static struct class *mtd_class;
1da177e4 LT	23
	24	static void mtd_notify_add(struct mtd_info* mtd)
	25	{
	26	if (!mtd)
	27	return;
	28
53f46542	29	class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
9bc7b387	30	NULL, "mtd%d", mtd->index);
97894cda	31
53f46542	32	class_device_create(mtd_class, NULL,
9bc7b387 TP	33	MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
9bc7b387 TP	34	NULL, "mtd%dro", mtd->index);
1da177e4 LT	35	}
	36
	37	static void mtd_notify_remove(struct mtd_info* mtd)
	38	{
	39	if (!mtd)
	40	return;
9bc7b387 TP	41
	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));
1da177e4 LT	44	}
	45
	46	static struct mtd_notifier notifier = {
	47	.add = mtd_notify_add,
	48	.remove = mtd_notify_remove,
	49	};
	50
045e9a5d NP	51	/*
	52	* We use file->private_data to store a pointer to the MTDdevice.
	53	* Since alighment is at least 32 bits, we have 2 bits free for OTP
	54	* modes as well.
	55	*/
	56
	57	#define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
31f4233b	58
045e9a5d NP	59	#define MTD_MODE_OTP_FACT 1
	60	#define MTD_MODE_OTP_USER 2
	61	#define MTD_MODE(file) ((long)((file)->private_data) & 3)
	62
	63	#define SET_MTD_MODE(file, mode) \
	64	do { long __p = (long)((file)->private_data); \
	65	(file)->private_data = (void *)((__p & ~3L) \| mode); } while (0)
31f4233b	66
1da177e4 LT	67	static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
1da177e4 LT	68	{
045e9a5d	69	struct mtd_info *mtd = TO_MTD(file);
1da177e4 LT	70
	71	switch (orig) {
	72	case 0:
	73	/* SEEK_SET */
1da177e4 LT	74	break;
	75	case 1:
	76	/* SEEK_CUR */
8b491d75	77	offset += file->f_pos;
1da177e4 LT	78	break;
	79	case 2:
	80	/* SEEK_END */
8b491d75	81	offset += mtd->size;
1da177e4 LT	82	break;
	83	default:
	84	return -EINVAL;
	85	}
	86
8b491d75 TP	87	if (offset >= 0 && offset < mtd->size)
8b491d75 TP	88	return file->f_pos = offset;
1da177e4	89
8b491d75	90	return -EINVAL;
1da177e4 LT	91	}
	92
	93
	94
	95	static int mtd_open(struct inode inode, struct file file)
	96	{
	97	int minor = iminor(inode);
	98	int devnum = minor >> 1;
	99	struct mtd_info *mtd;
	100
	101	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
	102
	103	if (devnum >= MAX_MTD_DEVICES)
	104	return -ENODEV;
	105
	106	/* You can't open the RO devices RW */
	107	if ((file->f_mode & 2) && (minor & 1))
	108	return -EACCES;
	109
	110	mtd = get_mtd_device(NULL, devnum);
97894cda	111
1da177e4 LT	112	if (!mtd)
1da177e4 LT	113	return -ENODEV;
97894cda	114
1da177e4 LT	115	if (MTD_ABSENT == mtd->type) {
	116	put_mtd_device(mtd);
	117	return -ENODEV;
	118	}
	119
	120	file->private_data = mtd;
97894cda	121
1da177e4 LT	122	/* You can't open it RW if it's not a writeable device */
	123	if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
	124	put_mtd_device(mtd);
	125	return -EACCES;
	126	}
97894cda	127
1da177e4 LT	128	return 0;
	129	} /* mtd_open */
	130
	131	/====================================================================/
	132
	133	static int mtd_close(struct inode inode, struct file file)
	134	{
	135	struct mtd_info *mtd;
	136
	137	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
	138
045e9a5d	139	mtd = TO_MTD(file);
97894cda	140
1da177e4 LT	141	if (mtd->sync)
1da177e4 LT	142	mtd->sync(mtd);
97894cda	143
1da177e4 LT	144	put_mtd_device(mtd);
	145
	146	return 0;
	147	} /* mtd_close */
	148
	149	/* FIXME: This _really_ needs to die. In 2.5, we should lock the
	150	userspace buffer down and use it directly with readv/writev.
	151	*/
	152	#define MAX_KMALLOC_SIZE 0x20000
	153
	154	static ssize_t mtd_read(struct file file, char __user buf, size_t count,loff_t *ppos)
	155	{
045e9a5d	156	struct mtd_info *mtd = TO_MTD(file);
1da177e4 LT	157	size_t retlen=0;
	158	size_t total_retlen=0;
	159	int ret=0;
	160	int len;
	161	char *kbuf;
97894cda	162
1da177e4 LT	163	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
	164
	165	if (*ppos + count > mtd->size)
	166	count = mtd->size - *ppos;
	167
	168	if (!count)
	169	return 0;
97894cda	170
1da177e4 LT	171	/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
1da177e4 LT	172	and pass them directly to the MTD functions */
b802c074 TG	173
	174	if (count > MAX_KMALLOC_SIZE)
	175	kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
	176	else
	177	kbuf=kmalloc(count, GFP_KERNEL);
	178
	179	if (!kbuf)
	180	return -ENOMEM;
	181
1da177e4	182	while (count) {
b802c074	183
97894cda	184	if (count > MAX_KMALLOC_SIZE)
1da177e4 LT	185	len = MAX_KMALLOC_SIZE;
	186	else
	187	len = count;
	188
045e9a5d	189	switch (MTD_MODE(file)) {
31f4233b NP	190	case MTD_MODE_OTP_FACT:
	191	ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
	192	break;
	193	case MTD_MODE_OTP_USER:
	194	ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
	195	break;
	196	default:
	197	ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
	198	}
1da177e4 LT	199	/* Nand returns -EBADMSG on ecc errors, but it returns
1da177e4 LT	200	* the data. For our userspace tools it is important
97894cda	201	* to dump areas with ecc errors !
1da177e4 LT	202	* Userspace software which accesses NAND this way
	203	* must be aware of the fact that it deals with NAND
	204	*/
	205	if (!ret \|\| (ret == -EBADMSG)) {
	206	*ppos += retlen;
	207	if (copy_to_user(buf, kbuf, retlen)) {
	208	kfree(kbuf);
	209	return -EFAULT;
	210	}
	211	else
	212	total_retlen += retlen;
	213
	214	count -= retlen;
	215	buf += retlen;
31f4233b NP	216	if (retlen == 0)
31f4233b NP	217	count = 0;
1da177e4 LT	218	}
	219	else {
	220	kfree(kbuf);
	221	return ret;
	222	}
97894cda	223
1da177e4 LT	224	}
1da177e4 LT	225
b802c074	226	kfree(kbuf);
1da177e4 LT	227	return total_retlen;
	228	} /* mtd_read */
	229
	230	static ssize_t mtd_write(struct file file, const char __user buf, size_t count,loff_t *ppos)
	231	{
045e9a5d	232	struct mtd_info *mtd = TO_MTD(file);
1da177e4 LT	233	char *kbuf;
	234	size_t retlen;
	235	size_t total_retlen=0;
	236	int ret=0;
	237	int len;
	238
	239	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
97894cda	240
1da177e4 LT	241	if (*ppos == mtd->size)
1da177e4 LT	242	return -ENOSPC;
97894cda	243
1da177e4 LT	244	if (*ppos + count > mtd->size)
	245	count = mtd->size - *ppos;
	246
	247	if (!count)
	248	return 0;
	249
b802c074 TG	250	if (count > MAX_KMALLOC_SIZE)
	251	kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
	252	else
	253	kbuf=kmalloc(count, GFP_KERNEL);
	254
	255	if (!kbuf)
	256	return -ENOMEM;
	257
1da177e4	258	while (count) {
b802c074	259
97894cda	260	if (count > MAX_KMALLOC_SIZE)
1da177e4 LT	261	len = MAX_KMALLOC_SIZE;
	262	else
	263	len = count;
	264
1da177e4 LT	265	if (copy_from_user(kbuf, buf, len)) {
	266	kfree(kbuf);
	267	return -EFAULT;
	268	}
97894cda	269
045e9a5d	270	switch (MTD_MODE(file)) {
31f4233b NP	271	case MTD_MODE_OTP_FACT:
	272	ret = -EROFS;
	273	break;
	274	case MTD_MODE_OTP_USER:
	275	if (!mtd->write_user_prot_reg) {
	276	ret = -EOPNOTSUPP;
	277	break;
	278	}
	279	ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
	280	break;
	281	default:
	282	ret = ((mtd->write))(mtd, ppos, len, &retlen, kbuf);
	283	}
1da177e4 LT	284	if (!ret) {
	285	*ppos += retlen;
	286	total_retlen += retlen;
	287	count -= retlen;
	288	buf += retlen;
	289	}
	290	else {
	291	kfree(kbuf);
	292	return ret;
	293	}
1da177e4 LT	294	}
1da177e4 LT	295
b802c074	296	kfree(kbuf);
1da177e4 LT	297	return total_retlen;
	298	} /* mtd_write */
	299
	300	/*======================================================================
	301
	302	IOCTL calls for getting device parameters.
	303
	304	======================================================================*/
	305	static void mtdchar_erase_callback (struct erase_info *instr)
	306	{
	307	wake_up((wait_queue_head_t *)instr->priv);
	308	}
	309
	310	static int mtd_ioctl(struct inode inode, struct file file,
	311	u_int cmd, u_long arg)
	312	{
045e9a5d	313	struct mtd_info *mtd = TO_MTD(file);
1da177e4 LT	314	void __user argp = (void __user )arg;
	315	int ret = 0;
	316	u_long size;
97894cda	317
1da177e4 LT	318	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
	319
	320	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
	321	if (cmd & IOC_IN) {
	322	if (!access_ok(VERIFY_READ, argp, size))
	323	return -EFAULT;
	324	}
	325	if (cmd & IOC_OUT) {
	326	if (!access_ok(VERIFY_WRITE, argp, size))
	327	return -EFAULT;
	328	}
97894cda	329
1da177e4 LT	330	switch (cmd) {
	331	case MEMGETREGIONCOUNT:
	332	if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
	333	return -EFAULT;
	334	break;
	335
	336	case MEMGETREGIONINFO:
	337	{
	338	struct region_info_user ur;
	339
	340	if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
	341	return -EFAULT;
	342
	343	if (ur.regionindex >= mtd->numeraseregions)
	344	return -EINVAL;
	345	if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
	346	sizeof(struct mtd_erase_region_info)))
	347	return -EFAULT;
	348	break;
	349	}
	350
	351	case MEMGETINFO:
	352	if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
	353	return -EFAULT;
	354	break;
	355
	356	case MEMERASE:
	357	{
	358	struct erase_info *erase;
	359
	360	if(!(file->f_mode & 2))
	361	return -EPERM;
	362
	363	erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
	364	if (!erase)
	365	ret = -ENOMEM;
	366	else {
	367	wait_queue_head_t waitq;
	368	DECLARE_WAITQUEUE(wait, current);
	369
	370	init_waitqueue_head(&waitq);
	371
	372	memset (erase,0,sizeof(struct erase_info));
	373	if (copy_from_user(&erase->addr, argp,
	374	sizeof(struct erase_info_user))) {
	375	kfree(erase);
	376	return -EFAULT;
	377	}
	378	erase->mtd = mtd;
	379	erase->callback = mtdchar_erase_callback;
	380	erase->priv = (unsigned long)&waitq;
97894cda	381
1da177e4 LT	382	/*
	383	FIXME: Allow INTERRUPTIBLE. Which means
	384	not having the wait_queue head on the stack.
97894cda	385
1da177e4 LT	386	If the wq_head is on the stack, and we
	387	leave because we got interrupted, then the
	388	wq_head is no longer there when the
	389	callback routine tries to wake us up.
	390	*/
	391	ret = mtd->erase(mtd, erase);
	392	if (!ret) {
	393	set_current_state(TASK_UNINTERRUPTIBLE);
	394	add_wait_queue(&waitq, &wait);
	395	if (erase->state != MTD_ERASE_DONE &&
	396	erase->state != MTD_ERASE_FAILED)
	397	schedule();
	398	remove_wait_queue(&waitq, &wait);
	399	set_current_state(TASK_RUNNING);
	400
	401	ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
	402	}
	403	kfree(erase);
	404	}
	405	break;
	406	}
	407
	408	case MEMWRITEOOB:
	409	{
	410	struct mtd_oob_buf buf;
	411	void *databuf;
	412	ssize_t retlen;
97894cda	413
1da177e4 LT	414	if(!(file->f_mode & 2))
	415	return -EPERM;
	416
	417	if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
	418	return -EFAULT;
97894cda	419
1da177e4 LT	420	if (buf.length > 0x4096)
	421	return -EINVAL;
	422
	423	if (!mtd->write_oob)
	424	ret = -EOPNOTSUPP;
	425	else
	426	ret = access_ok(VERIFY_READ, buf.ptr,
	427	buf.length) ? 0 : EFAULT;
	428
	429	if (ret)
	430	return ret;
	431
	432	databuf = kmalloc(buf.length, GFP_KERNEL);
	433	if (!databuf)
	434	return -ENOMEM;
97894cda	435
1da177e4 LT	436	if (copy_from_user(databuf, buf.ptr, buf.length)) {
	437	kfree(databuf);
	438	return -EFAULT;
	439	}
	440
	441	ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
	442
	443	if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
	444	ret = -EFAULT;
	445
	446	kfree(databuf);
	447	break;
	448
	449	}
	450
	451	case MEMREADOOB:
	452	{
	453	struct mtd_oob_buf buf;
	454	void *databuf;
	455	ssize_t retlen;
	456
	457	if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
	458	return -EFAULT;
97894cda	459
1da177e4 LT	460	if (buf.length > 0x4096)
	461	return -EINVAL;
	462
	463	if (!mtd->read_oob)
	464	ret = -EOPNOTSUPP;
	465	else
	466	ret = access_ok(VERIFY_WRITE, buf.ptr,
	467	buf.length) ? 0 : -EFAULT;
	468
	469	if (ret)
	470	return ret;
	471
	472	databuf = kmalloc(buf.length, GFP_KERNEL);
	473	if (!databuf)
	474	return -ENOMEM;
97894cda	475
1da177e4 LT	476	ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
	477
	478	if (put_user(retlen, (uint32_t __user *)argp))
	479	ret = -EFAULT;
	480	else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
	481	ret = -EFAULT;
97894cda	482
1da177e4 LT	483	kfree(databuf);
	484	break;
	485	}
	486
	487	case MEMLOCK:
	488	{
	489	struct erase_info_user info;
	490
	491	if (copy_from_user(&info, argp, sizeof(info)))
	492	return -EFAULT;
	493
	494	if (!mtd->lock)
	495	ret = -EOPNOTSUPP;
	496	else
	497	ret = mtd->lock(mtd, info.start, info.length);
	498	break;
	499	}
	500
	501	case MEMUNLOCK:
	502	{
	503	struct erase_info_user info;
	504
	505	if (copy_from_user(&info, argp, sizeof(info)))
	506	return -EFAULT;
	507
	508	if (!mtd->unlock)
	509	ret = -EOPNOTSUPP;
	510	else
	511	ret = mtd->unlock(mtd, info.start, info.length);
	512	break;
	513	}
	514
	515	case MEMSETOOBSEL:
	516	{
	517	if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
	518	return -EFAULT;
	519	break;
	520	}
	521
	522	case MEMGETOOBSEL:
	523	{
	524	if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
	525	return -EFAULT;
	526	break;
	527	}
	528
	529	case MEMGETBADBLOCK:
	530	{
	531	loff_t offs;
97894cda	532
1da177e4 LT	533	if (copy_from_user(&offs, argp, sizeof(loff_t)))
	534	return -EFAULT;
	535	if (!mtd->block_isbad)
	536	ret = -EOPNOTSUPP;
	537	else
	538	return mtd->block_isbad(mtd, offs);
	539	break;
	540	}
	541
	542	case MEMSETBADBLOCK:
	543	{
	544	loff_t offs;
	545
	546	if (copy_from_user(&offs, argp, sizeof(loff_t)))
	547	return -EFAULT;
	548	if (!mtd->block_markbad)
	549	ret = -EOPNOTSUPP;
	550	else
	551	return mtd->block_markbad(mtd, offs);
	552	break;
	553	}
	554
31f4233b NP	555	#ifdef CONFIG_MTD_OTP
	556	case OTPSELECT:
	557	{
	558	int mode;
	559	if (copy_from_user(&mode, argp, sizeof(int)))
	560	return -EFAULT;
045e9a5d	561	SET_MTD_MODE(file, 0);
31f4233b NP	562	switch (mode) {
	563	case MTD_OTP_FACTORY:
	564	if (!mtd->read_fact_prot_reg)
	565	ret = -EOPNOTSUPP;
	566	else
045e9a5d	567	SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
31f4233b NP	568	break;
	569	case MTD_OTP_USER:
	570	if (!mtd->read_fact_prot_reg)
	571	ret = -EOPNOTSUPP;
	572	else
045e9a5d	573	SET_MTD_MODE(file, MTD_MODE_OTP_USER);
31f4233b NP	574	break;
	575	default:
	576	ret = -EINVAL;
	577	case MTD_OTP_OFF:
	578	break;
	579	}
81dba488	580	file->f_pos = 0;
31f4233b NP	581	break;
	582	}
	583
	584	case OTPGETREGIONCOUNT:
	585	case OTPGETREGIONINFO:
	586	{
	587	struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
	588	if (!buf)
	589	return -ENOMEM;
	590	ret = -EOPNOTSUPP;
045e9a5d	591	switch (MTD_MODE(file)) {
31f4233b NP	592	case MTD_MODE_OTP_FACT:
	593	if (mtd->get_fact_prot_info)
	594	ret = mtd->get_fact_prot_info(mtd, buf, 4096);
	595	break;
	596	case MTD_MODE_OTP_USER:
	597	if (mtd->get_user_prot_info)
	598	ret = mtd->get_user_prot_info(mtd, buf, 4096);
	599	break;
	600	}
	601	if (ret >= 0) {
	602	if (cmd == OTPGETREGIONCOUNT) {
	603	int nbr = ret / sizeof(struct otp_info);
	604	ret = copy_to_user(argp, &nbr, sizeof(int));
	605	} else
	606	ret = copy_to_user(argp, buf, ret);
	607	if (ret)
	608	ret = -EFAULT;
	609	}
	610	kfree(buf);
	611	break;
	612	}
	613
	614	case OTPLOCK:
	615	{
	616	struct otp_info info;
	617
045e9a5d	618	if (MTD_MODE(file) != MTD_MODE_OTP_USER)
31f4233b NP	619	return -EINVAL;
	620	if (copy_from_user(&info, argp, sizeof(info)))
	621	return -EFAULT;
	622	if (!mtd->lock_user_prot_reg)
	623	return -EOPNOTSUPP;
	624	ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
	625	break;
	626	}
	627	#endif
	628
1da177e4 LT	629	default:
	630	ret = -ENOTTY;
	631	}
	632
	633	return ret;
	634	} /* memory_ioctl */
	635
	636	static struct file_operations mtd_fops = {
	637	.owner = THIS_MODULE,
	638	.llseek = mtd_lseek,
	639	.read = mtd_read,
	640	.write = mtd_write,
	641	.ioctl = mtd_ioctl,
	642	.open = mtd_open,
	643	.release = mtd_close,
	644	};
	645
	646	static int __init init_mtdchar(void)
	647	{
	648	if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
	649	printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
	650	MTD_CHAR_MAJOR);
	651	return -EAGAIN;
	652	}
	653
9bc7b387 TP	654	mtd_class = class_create(THIS_MODULE, "mtd");
	655
	656	if (IS_ERR(mtd_class)) {
	657	printk(KERN_ERR "Error creating mtd class.\n");
	658	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
3a7a8824	659	return PTR_ERR(mtd_class);
9bc7b387 TP	660	}
	661
	662	register_mtd_user(&notifier);
1da177e4 LT	663	return 0;
	664	}
	665
	666	static void __exit cleanup_mtdchar(void)
	667	{
9bc7b387 TP	668	unregister_mtd_user(&notifier);
9bc7b387 TP	669	class_destroy(mtd_class);
1da177e4 LT	670	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
	671	}
	672
	673	module_init(init_mtdchar);
	674	module_exit(cleanup_mtdchar);
	675
	676
	677	MODULE_LICENSE("GPL");
	678	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	679	MODULE_DESCRIPTION("Direct character-device access to MTD devices");