[linux-block.git] / drivers / mtd / mtdcore.c

/*
 * Core registration and callback routines for MTD
 * drivers and users.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/mtd/compatmac.h>
#include <linux/proc_fs.h>

#include <linux/mtd/mtd.h>
#include "internal.h"

#include "mtdcore.h"

static int mtd_cls_suspend(struct device *dev, pm_message_t state);
static int mtd_cls_resume(struct device *dev);

static struct class mtd_class = {
	.name = "mtd",
	.owner = THIS_MODULE,
	.suspend = mtd_cls_suspend,
	.resume = mtd_cls_resume,
};

/* These are exported solely for the purpose of mtd_blkdevs.c. You
   should not use them for _anything_ else */
DEFINE_MUTEX(mtd_table_mutex);
struct mtd_info *mtd_table[MAX_MTD_DEVICES];

EXPORT_SYMBOL_GPL(mtd_table_mutex);
EXPORT_SYMBOL_GPL(mtd_table);

static LIST_HEAD(mtd_notifiers);


#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
#else
#define MTD_DEVT(index) 0
#endif

/* REVISIT once MTD uses the driver model better, whoever allocates
 * the mtd_info will probably want to use the release() hook...
 */
static void mtd_release(struct device *dev)
{
	dev_t index = MTD_DEVT(dev_to_mtd(dev)->index);

	/* remove /dev/mtdXro node if needed */
	if (index)
		device_destroy(&mtd_class, index + 1);
}

static int mtd_cls_suspend(struct device *dev, pm_message_t state)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	if (mtd && mtd->suspend)
		return mtd->suspend(mtd);
	else
		return 0;
}

static int mtd_cls_resume(struct device *dev)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	
	if (mtd && mtd->resume)
		mtd->resume(mtd);
	return 0;
}

static ssize_t mtd_type_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	char *type;

	switch (mtd->type) {
	case MTD_ABSENT:
		type = "absent";
		break;
	case MTD_RAM:
		type = "ram";
		break;
	case MTD_ROM:
		type = "rom";
		break;
	case MTD_NORFLASH:
		type = "nor";
		break;
	case MTD_NANDFLASH:
		type = "nand";
		break;
	case MTD_DATAFLASH:
		type = "dataflash";
		break;
	case MTD_UBIVOLUME:
		type = "ubi";
		break;
	default:
		type = "unknown";
	}

	return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);

static ssize_t mtd_flags_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);

}
static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);

static ssize_t mtd_size_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)mtd->size);

}
static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);

static ssize_t mtd_erasesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);

}
static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);

static ssize_t mtd_writesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);

}
static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);

static ssize_t mtd_subpagesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;

	return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);

}
static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);

static ssize_t mtd_oobsize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);

}
static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);

static ssize_t mtd_numeraseregions_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);

}
static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
	NULL);

static ssize_t mtd_name_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);

}
static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);

static struct attribute *mtd_attrs[] = {
	&dev_attr_type.attr,
	&dev_attr_flags.attr,
	&dev_attr_size.attr,
	&dev_attr_erasesize.attr,
	&dev_attr_writesize.attr,
	&dev_attr_subpagesize.attr,
	&dev_attr_oobsize.attr,
	&dev_attr_numeraseregions.attr,
	&dev_attr_name.attr,
	NULL,
};

static struct attribute_group mtd_group = {
	.attrs		= mtd_attrs,
};

static const struct attribute_group *mtd_groups[] = {
	&mtd_group,
	NULL,
};

static struct device_type mtd_devtype = {
	.name		= "mtd",
	.groups		= mtd_groups,
	.release	= mtd_release,
};

/**
 *	add_mtd_device - register an MTD device
 *	@mtd: pointer to new MTD device info structure
 *
 *	Add a device to the list of MTD devices present in the system, and
 *	notify each currently active MTD 'user' of its arrival. Returns
 *	zero on success or 1 on failure, which currently will only happen
 *	if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
 *	or there's a sysfs error.
 */

int add_mtd_device(struct mtd_info *mtd)
{
	int i;

	if (!mtd->backing_dev_info) {
		switch (mtd->type) {
		case MTD_RAM:
			mtd->backing_dev_info = &mtd_bdi_rw_mappable;
			break;
		case MTD_ROM:
			mtd->backing_dev_info = &mtd_bdi_ro_mappable;
			break;
		default:
			mtd->backing_dev_info = &mtd_bdi_unmappable;
			break;
		}
	}

	BUG_ON(mtd->writesize == 0);
	mutex_lock(&mtd_table_mutex);

	for (i=0; i < MAX_MTD_DEVICES; i++)
		if (!mtd_table[i]) {
			struct mtd_notifier *not;

			mtd_table[i] = mtd;
			mtd->index = i;
			mtd->usecount = 0;

			if (is_power_of_2(mtd->erasesize))
				mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
			else
				mtd->erasesize_shift = 0;

			if (is_power_of_2(mtd->writesize))
				mtd->writesize_shift = ffs(mtd->writesize) - 1;
			else
				mtd->writesize_shift = 0;

			mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
			mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;

			/* Some chips always power up locked. Unlock them now */
			if ((mtd->flags & MTD_WRITEABLE)
			    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
				if (mtd->unlock(mtd, 0, mtd->size))
					printk(KERN_WARNING
					       "%s: unlock failed, "
					       "writes may not work\n",
					       mtd->name);
			}

			/* Caller should have set dev.parent to match the
			 * physical device.
			 */
			mtd->dev.type = &mtd_devtype;
			mtd->dev.class = &mtd_class;
			mtd->dev.devt = MTD_DEVT(i);
			dev_set_name(&mtd->dev, "mtd%d", i);
			dev_set_drvdata(&mtd->dev, mtd);
			if (device_register(&mtd->dev) != 0) {
				mtd_table[i] = NULL;
				break;
			}

			if (MTD_DEVT(i))
				device_create(&mtd_class, mtd->dev.parent,
						MTD_DEVT(i) + 1,
						NULL, "mtd%dro", i);

			DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
			/* No need to get a refcount on the module containing
			   the notifier, since we hold the mtd_table_mutex */
			list_for_each_entry(not, &mtd_notifiers, list)
				not->add(mtd);

			mutex_unlock(&mtd_table_mutex);
			/* We _know_ we aren't being removed, because
			   our caller is still holding us here. So none
			   of this try_ nonsense, and no bitching about it
			   either. :) */
			__module_get(THIS_MODULE);
			return 0;
		}

	mutex_unlock(&mtd_table_mutex);
	return 1;
}

/**
 *	del_mtd_device - unregister an MTD device
 *	@mtd: pointer to MTD device info structure
 *
 *	Remove a device from the list of MTD devices present in the system,
 *	and notify each currently active MTD 'user' of its departure.
 *	Returns zero on success or 1 on failure, which currently will happen
 *	if the requested device does not appear to be present in the list.
 */

int del_mtd_device (struct mtd_info *mtd)
{
	int ret;

	mutex_lock(&mtd_table_mutex);

	if (mtd_table[mtd->index] != mtd) {
		ret = -ENODEV;
	} else if (mtd->usecount) {
		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
		       mtd->index, mtd->name, mtd->usecount);
		ret = -EBUSY;
	} else {
		struct mtd_notifier *not;

		device_unregister(&mtd->dev);

		/* No need to get a refcount on the module containing
		   the notifier, since we hold the mtd_table_mutex */
		list_for_each_entry(not, &mtd_notifiers, list)
			not->remove(mtd);

		mtd_table[mtd->index] = NULL;

		module_put(THIS_MODULE);
		ret = 0;
	}

	mutex_unlock(&mtd_table_mutex);
	return ret;
}

/**
 *	register_mtd_user - register a 'user' of MTD devices.
 *	@new: pointer to notifier info structure
 *
 *	Registers a pair of callbacks function to be called upon addition
 *	or removal of MTD devices. Causes the 'add' callback to be immediately
 *	invoked for each MTD device currently present in the system.
 */

void register_mtd_user (struct mtd_notifier *new)
{
	int i;

	mutex_lock(&mtd_table_mutex);

	list_add(&new->list, &mtd_notifiers);

 	__module_get(THIS_MODULE);

	for (i=0; i< MAX_MTD_DEVICES; i++)
		if (mtd_table[i])
			new->add(mtd_table[i]);

	mutex_unlock(&mtd_table_mutex);
}

/**
 *	unregister_mtd_user - unregister a 'user' of MTD devices.
 *	@old: pointer to notifier info structure
 *
 *	Removes a callback function pair from the list of 'users' to be
 *	notified upon addition or removal of MTD devices. Causes the
 *	'remove' callback to be immediately invoked for each MTD device
 *	currently present in the system.
 */

int unregister_mtd_user (struct mtd_notifier *old)
{
	int i;

	mutex_lock(&mtd_table_mutex);

	module_put(THIS_MODULE);

	for (i=0; i< MAX_MTD_DEVICES; i++)
		if (mtd_table[i])
			old->remove(mtd_table[i]);

	list_del(&old->list);
	mutex_unlock(&mtd_table_mutex);
	return 0;
}


/**
 *	get_mtd_device - obtain a validated handle for an MTD device
 *	@mtd: last known address of the required MTD device
 *	@num: internal device number of the required MTD device
 *
 *	Given a number and NULL address, return the num'th entry in the device
 *	table, if any.	Given an address and num == -1, search the device table
 *	for a device with that address and return if it's still present. Given
 *	both, return the num'th driver only if its address matches. Return
 *	error code if not.
 */

struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
	struct mtd_info *ret = NULL;
	int i, err = -ENODEV;

	mutex_lock(&mtd_table_mutex);

	if (num == -1) {
		for (i=0; i< MAX_MTD_DEVICES; i++)
			if (mtd_table[i] == mtd)
				ret = mtd_table[i];
	} else if (num >= 0 && num < MAX_MTD_DEVICES) {
		ret = mtd_table[num];
		if (mtd && mtd != ret)
			ret = NULL;
	}

	if (!ret)
		goto out_unlock;

	if (!try_module_get(ret->owner))
		goto out_unlock;

	if (ret->get_device) {
		err = ret->get_device(ret);
		if (err)
			goto out_put;
	}

	ret->usecount++;
	mutex_unlock(&mtd_table_mutex);
	return ret;

out_put:
	module_put(ret->owner);
out_unlock:
	mutex_unlock(&mtd_table_mutex);
	return ERR_PTR(err);
}

/**
 *	get_mtd_device_nm - obtain a validated handle for an MTD device by
 *	device name
 *	@name: MTD device name to open
 *
 * 	This function returns MTD device description structure in case of
 * 	success and an error code in case of failure.
 */

struct mtd_info *get_mtd_device_nm(const char *name)
{
	int i, err = -ENODEV;
	struct mtd_info *mtd = NULL;

	mutex_lock(&mtd_table_mutex);

	for (i = 0; i < MAX_MTD_DEVICES; i++) {
		if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
			mtd = mtd_table[i];
			break;
		}
	}

	if (!mtd)
		goto out_unlock;

	if (!try_module_get(mtd->owner))
		goto out_unlock;

	if (mtd->get_device) {
		err = mtd->get_device(mtd);
		if (err)
			goto out_put;
	}

	mtd->usecount++;
	mutex_unlock(&mtd_table_mutex);
	return mtd;

out_put:
	module_put(mtd->owner);
out_unlock:
	mutex_unlock(&mtd_table_mutex);
	return ERR_PTR(err);
}

void put_mtd_device(struct mtd_info *mtd)
{
	int c;

	mutex_lock(&mtd_table_mutex);
	c = --mtd->usecount;
	if (mtd->put_device)
		mtd->put_device(mtd);
	mutex_unlock(&mtd_table_mutex);
	BUG_ON(c < 0);

	module_put(mtd->owner);
}

/* default_mtd_writev - default mtd writev method for MTD devices that
 *			don't implement their own
 */

int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
		       unsigned long count, loff_t to, size_t *retlen)
{
	unsigned long i;
	size_t totlen = 0, thislen;
	int ret = 0;

	if(!mtd->write) {
		ret = -EROFS;
	} else {
		for (i=0; i<count; i++) {
			if (!vecs[i].iov_len)
				continue;
			ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
			totlen += thislen;
			if (ret || thislen != vecs[i].iov_len)
				break;
			to += vecs[i].iov_len;
		}
	}
	if (retlen)
		*retlen = totlen;
	return ret;
}

EXPORT_SYMBOL_GPL(add_mtd_device);
EXPORT_SYMBOL_GPL(del_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
EXPORT_SYMBOL_GPL(put_mtd_device);
EXPORT_SYMBOL_GPL(register_mtd_user);
EXPORT_SYMBOL_GPL(unregister_mtd_user);
EXPORT_SYMBOL_GPL(default_mtd_writev);

#ifdef CONFIG_PROC_FS

/*====================================================================*/
/* Support for /proc/mtd */

static struct proc_dir_entry *proc_mtd;

static inline int mtd_proc_info (char *buf, int i)
{
	struct mtd_info *this = mtd_table[i];

	if (!this)
		return 0;

	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", i,
		       (unsigned long long)this->size,
		       this->erasesize, this->name);
}

static int mtd_read_proc (char *page, char **start, off_t off, int count,
			  int *eof, void *data_unused)
{
	int len, l, i;
        off_t   begin = 0;

	mutex_lock(&mtd_table_mutex);

	len = sprintf(page, "dev:    size   erasesize  name\n");
        for (i=0; i< MAX_MTD_DEVICES; i++) {

                l = mtd_proc_info(page + len, i);
                len += l;
                if (len+begin > off+count)
                        goto done;
                if (len+begin < off) {
                        begin += len;
                        len = 0;
                }
        }

        *eof = 1;

done:
	mutex_unlock(&mtd_table_mutex);
        if (off >= len+begin)
                return 0;
        *start = page + (off-begin);
        return ((count < begin+len-off) ? count : begin+len-off);
}

#endif /* CONFIG_PROC_FS */

/*====================================================================*/
/* Init code */

static int __init init_mtd(void)
{
	int ret;
	ret = class_register(&mtd_class);

	if (ret) {
		pr_err("Error registering mtd class: %d\n", ret);
		return ret;
	}
#ifdef CONFIG_PROC_FS
	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
		proc_mtd->read_proc = mtd_read_proc;
#endif /* CONFIG_PROC_FS */
	return 0;
}

static void __exit cleanup_mtd(void)
{
#ifdef CONFIG_PROC_FS
        if (proc_mtd)
		remove_proc_entry( "mtd", NULL);
#endif /* CONFIG_PROC_FS */
	class_unregister(&mtd_class);
}

module_init(init_mtd);
module_exit(cleanup_mtd);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Core MTD registration and access routines");
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* Core registration and callback routines for MTD
	3	* drivers and users.
	4	*
	5	*/
	6
1da177e4 LT	7	#include <linux/module.h>
1da177e4 LT	8	#include <linux/kernel.h>
1da177e4	9	#include <linux/ptrace.h>
1da177e4 LT	10	#include <linux/string.h>
	11	#include <linux/timer.h>
	12	#include <linux/major.h>
	13	#include <linux/fs.h>
7799308f	14	#include <linux/err.h>
1da177e4 LT	15	#include <linux/ioctl.h>
	16	#include <linux/init.h>
	17	#include <linux/mtd/compatmac.h>
1da177e4	18	#include <linux/proc_fs.h>
1da177e4 LT	19
1da177e4 LT	20	#include <linux/mtd/mtd.h>
402d3265	21	#include "internal.h"
1da177e4	22
356d70f1 BD	23	#include "mtdcore.h"
356d70f1 BD	24
15bce40c DW	25	static int mtd_cls_suspend(struct device *dev, pm_message_t state);
	26	static int mtd_cls_resume(struct device *dev);
	27
	28	static struct class mtd_class = {
	29	.name = "mtd",
	30	.owner = THIS_MODULE,
	31	.suspend = mtd_cls_suspend,
	32	.resume = mtd_cls_resume,
	33	};
1f24b5a8	34
97894cda	35	/* These are exported solely for the purpose of mtd_blkdevs.c. You
1da177e4	36	should not use them for _anything_ else */
48b19268	37	DEFINE_MUTEX(mtd_table_mutex);
1da177e4 LT	38	struct mtd_info *mtd_table[MAX_MTD_DEVICES];
	39
	40	EXPORT_SYMBOL_GPL(mtd_table_mutex);
	41	EXPORT_SYMBOL_GPL(mtd_table);
	42
	43	static LIST_HEAD(mtd_notifiers);
	44
1f24b5a8 DB	45
	46	#if defined(CONFIG_MTD_CHAR) \|\| defined(CONFIG_MTD_CHAR_MODULE)
	47	#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
	48	#else
	49	#define MTD_DEVT(index) 0
	50	#endif
	51
	52	/* REVISIT once MTD uses the driver model better, whoever allocates
	53	* the mtd_info will probably want to use the release() hook...
	54	*/
	55	static void mtd_release(struct device *dev)
	56	{
2fdb1144	57	dev_t index = MTD_DEVT(dev_to_mtd(dev)->index);
1f24b5a8 DB	58
1f24b5a8 DB	59	/* remove /dev/mtdXro node if needed */
2fdb1144	60	if (index)
15bce40c DW	61	device_destroy(&mtd_class, index + 1);
	62	}
	63
	64	static int mtd_cls_suspend(struct device *dev, pm_message_t state)
	65	{
	66	struct mtd_info *mtd = dev_to_mtd(dev);
6afc4fdb SB	67
6afc4fdb SB	68	if (mtd && mtd->suspend)
15bce40c DW	69	return mtd->suspend(mtd);
	70	else
	71	return 0;
	72	}
	73
	74	static int mtd_cls_resume(struct device *dev)
	75	{
	76	struct mtd_info *mtd = dev_to_mtd(dev);
	77
6afc4fdb	78	if (mtd && mtd->resume)
15bce40c DW	79	mtd->resume(mtd);
15bce40c DW	80	return 0;
1f24b5a8 DB	81	}
	82
	83	static ssize_t mtd_type_show(struct device *dev,
	84	struct device_attribute attr, char buf)
	85	{
	86	struct mtd_info *mtd = dev_to_mtd(dev);
	87	char *type;
	88
	89	switch (mtd->type) {
	90	case MTD_ABSENT:
	91	type = "absent";
	92	break;
	93	case MTD_RAM:
	94	type = "ram";
	95	break;
	96	case MTD_ROM:
	97	type = "rom";
	98	break;
	99	case MTD_NORFLASH:
	100	type = "nor";
	101	break;
	102	case MTD_NANDFLASH:
	103	type = "nand";
	104	break;
	105	case MTD_DATAFLASH:
	106	type = "dataflash";
	107	break;
	108	case MTD_UBIVOLUME:
	109	type = "ubi";
	110	break;
	111	default:
	112	type = "unknown";
	113	}
	114
	115	return snprintf(buf, PAGE_SIZE, "%s\n", type);
	116	}
694bb7fc KC	117	static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
	118
	119	static ssize_t mtd_flags_show(struct device *dev,
	120	struct device_attribute attr, char buf)
	121	{
	122	struct mtd_info *mtd = dev_to_mtd(dev);
	123
	124	return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
	125
	126	}
	127	static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
	128
	129	static ssize_t mtd_size_show(struct device *dev,
	130	struct device_attribute attr, char buf)
	131	{
	132	struct mtd_info *mtd = dev_to_mtd(dev);
	133
	134	return snprintf(buf, PAGE_SIZE, "%llu\n",
	135	(unsigned long long)mtd->size);
	136
	137	}
	138	static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
	139
	140	static ssize_t mtd_erasesize_show(struct device *dev,
	141	struct device_attribute attr, char buf)
	142	{
	143	struct mtd_info *mtd = dev_to_mtd(dev);
	144
	145	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
	146
	147	}
	148	static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
	149
	150	static ssize_t mtd_writesize_show(struct device *dev,
	151	struct device_attribute attr, char buf)
	152	{
	153	struct mtd_info *mtd = dev_to_mtd(dev);
	154
	155	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
	156
	157	}
	158	static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
	159
e7693548 AB	160	static ssize_t mtd_subpagesize_show(struct device *dev,
	161	struct device_attribute attr, char buf)
	162	{
	163	struct mtd_info *mtd = dev_to_mtd(dev);
	164	unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
	165
	166	return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
	167
	168	}
	169	static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
	170
694bb7fc KC	171	static ssize_t mtd_oobsize_show(struct device *dev,
	172	struct device_attribute attr, char buf)
	173	{
	174	struct mtd_info *mtd = dev_to_mtd(dev);
	175
	176	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
	177
	178	}
	179	static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
	180
	181	static ssize_t mtd_numeraseregions_show(struct device *dev,
	182	struct device_attribute attr, char buf)
	183	{
	184	struct mtd_info *mtd = dev_to_mtd(dev);
	185
	186	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
	187
	188	}
	189	static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
	190	NULL);
	191
	192	static ssize_t mtd_name_show(struct device *dev,
	193	struct device_attribute attr, char buf)
	194	{
	195	struct mtd_info *mtd = dev_to_mtd(dev);
	196
	197	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
	198
	199	}
	200	static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
1f24b5a8 DB	201
1f24b5a8 DB	202	static struct attribute *mtd_attrs[] = {
694bb7fc KC	203	&dev_attr_type.attr,
	204	&dev_attr_flags.attr,
	205	&dev_attr_size.attr,
	206	&dev_attr_erasesize.attr,
	207	&dev_attr_writesize.attr,
e7693548	208	&dev_attr_subpagesize.attr,
694bb7fc KC	209	&dev_attr_oobsize.attr,
	210	&dev_attr_numeraseregions.attr,
	211	&dev_attr_name.attr,
1f24b5a8 DB	212	NULL,
	213	};
	214
fca91088	215	static struct attribute_group mtd_group = {
1f24b5a8 DB	216	.attrs = mtd_attrs,
	217	};
	218
6469f540	219	static const struct attribute_group *mtd_groups[] = {
1f24b5a8 DB	220	&mtd_group,
	221	NULL,
	222	};
	223
	224	static struct device_type mtd_devtype = {
	225	.name = "mtd",
	226	.groups = mtd_groups,
	227	.release = mtd_release,
	228	};
	229
1da177e4 LT	230	/**
	231	* add_mtd_device - register an MTD device
	232	* @mtd: pointer to new MTD device info structure
	233	*
	234	* Add a device to the list of MTD devices present in the system, and
	235	* notify each currently active MTD 'user' of its arrival. Returns
	236	* zero on success or 1 on failure, which currently will only happen
	237	* if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
1f24b5a8	238	* or there's a sysfs error.
1da177e4 LT	239	*/
	240
	241	int add_mtd_device(struct mtd_info *mtd)
	242	{
	243	int i;
	244
402d3265 DH	245	if (!mtd->backing_dev_info) {
	246	switch (mtd->type) {
	247	case MTD_RAM:
	248	mtd->backing_dev_info = &mtd_bdi_rw_mappable;
	249	break;
	250	case MTD_ROM:
	251	mtd->backing_dev_info = &mtd_bdi_ro_mappable;
	252	break;
	253	default:
	254	mtd->backing_dev_info = &mtd_bdi_unmappable;
	255	break;
	256	}
	257	}
	258
783ed81f	259	BUG_ON(mtd->writesize == 0);
48b19268	260	mutex_lock(&mtd_table_mutex);
1da177e4 LT	261
	262	for (i=0; i < MAX_MTD_DEVICES; i++)
	263	if (!mtd_table[i]) {
2606c797	264	struct mtd_notifier *not;
1da177e4 LT	265
	266	mtd_table[i] = mtd;
	267	mtd->index = i;
	268	mtd->usecount = 0;
	269
69423d99 AH	270	if (is_power_of_2(mtd->erasesize))
	271	mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
	272	else
	273	mtd->erasesize_shift = 0;
	274
	275	if (is_power_of_2(mtd->writesize))
	276	mtd->writesize_shift = ffs(mtd->writesize) - 1;
	277	else
	278	mtd->writesize_shift = 0;
	279
	280	mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
	281	mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
	282
187ef152 HS	283	/* Some chips always power up locked. Unlock them now */
187ef152 HS	284	if ((mtd->flags & MTD_WRITEABLE)
e619a75f	285	&& (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
187ef152 HS	286	if (mtd->unlock(mtd, 0, mtd->size))
	287	printk(KERN_WARNING
	288	"%s: unlock failed, "
	289	"writes may not work\n",
	290	mtd->name);
	291	}
	292
1f24b5a8 DB	293	/* Caller should have set dev.parent to match the
	294	* physical device.
	295	*/
	296	mtd->dev.type = &mtd_devtype;
15bce40c	297	mtd->dev.class = &mtd_class;
1f24b5a8 DB	298	mtd->dev.devt = MTD_DEVT(i);
1f24b5a8 DB	299	dev_set_name(&mtd->dev, "mtd%d", i);
6afc4fdb	300	dev_set_drvdata(&mtd->dev, mtd);
1f24b5a8 DB	301	if (device_register(&mtd->dev) != 0) {
	302	mtd_table[i] = NULL;
	303	break;
	304	}
	305
	306	if (MTD_DEVT(i))
15bce40c	307	device_create(&mtd_class, mtd->dev.parent,
1f24b5a8 DB	308	MTD_DEVT(i) + 1,
	309	NULL, "mtd%dro", i);
	310
1da177e4 LT	311	DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
	312	/* No need to get a refcount on the module containing
	313	the notifier, since we hold the mtd_table_mutex */
71a928c0	314	list_for_each_entry(not, &mtd_notifiers, list)
1da177e4	315	not->add(mtd);
97894cda	316
48b19268	317	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	318	/* We _know_ we aren't being removed, because
	319	our caller is still holding us here. So none
	320	of this try_ nonsense, and no bitching about it
	321	either. :) */
	322	__module_get(THIS_MODULE);
	323	return 0;
	324	}
97894cda	325
48b19268	326	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	327	return 1;
	328	}
	329
	330	/**
	331	* del_mtd_device - unregister an MTD device
	332	* @mtd: pointer to MTD device info structure
	333	*
	334	* Remove a device from the list of MTD devices present in the system,
	335	* and notify each currently active MTD 'user' of its departure.
	336	* Returns zero on success or 1 on failure, which currently will happen
	337	* if the requested device does not appear to be present in the list.
	338	*/
	339
	340	int del_mtd_device (struct mtd_info *mtd)
	341	{
	342	int ret;
97894cda	343
48b19268	344	mutex_lock(&mtd_table_mutex);
1da177e4 LT	345
	346	if (mtd_table[mtd->index] != mtd) {
	347	ret = -ENODEV;
	348	} else if (mtd->usecount) {
97894cda	349	printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
1da177e4 LT	350	mtd->index, mtd->name, mtd->usecount);
	351	ret = -EBUSY;
	352	} else {
856613c9	353	struct mtd_notifier *not;
1da177e4	354
694bb7fc KC	355	device_unregister(&mtd->dev);
694bb7fc KC	356
1da177e4 LT	357	/* No need to get a refcount on the module containing
1da177e4 LT	358	the notifier, since we hold the mtd_table_mutex */
71a928c0	359	list_for_each_entry(not, &mtd_notifiers, list)
1da177e4	360	not->remove(mtd);
1da177e4 LT	361
	362	mtd_table[mtd->index] = NULL;
	363
	364	module_put(THIS_MODULE);
	365	ret = 0;
	366	}
	367
48b19268	368	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	369	return ret;
	370	}
	371
	372	/**
	373	* register_mtd_user - register a 'user' of MTD devices.
	374	* @new: pointer to notifier info structure
	375	*
	376	* Registers a pair of callbacks function to be called upon addition
	377	* or removal of MTD devices. Causes the 'add' callback to be immediately
	378	* invoked for each MTD device currently present in the system.
	379	*/
	380
	381	void register_mtd_user (struct mtd_notifier *new)
	382	{
	383	int i;
	384
48b19268	385	mutex_lock(&mtd_table_mutex);
1da177e4 LT	386
	387	list_add(&new->list, &mtd_notifiers);
	388
	389	__module_get(THIS_MODULE);
97894cda	390
1da177e4 LT	391	for (i=0; i< MAX_MTD_DEVICES; i++)
	392	if (mtd_table[i])
	393	new->add(mtd_table[i]);
	394
48b19268	395	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	396	}
	397
	398	/**
49450795 AB	399	* unregister_mtd_user - unregister a 'user' of MTD devices.
49450795 AB	400	* @old: pointer to notifier info structure
1da177e4 LT	401	*
	402	* Removes a callback function pair from the list of 'users' to be
	403	* notified upon addition or removal of MTD devices. Causes the
	404	* 'remove' callback to be immediately invoked for each MTD device
	405	* currently present in the system.
	406	*/
	407
	408	int unregister_mtd_user (struct mtd_notifier *old)
	409	{
	410	int i;
	411
48b19268	412	mutex_lock(&mtd_table_mutex);
1da177e4 LT	413
	414	module_put(THIS_MODULE);
	415
	416	for (i=0; i< MAX_MTD_DEVICES; i++)
	417	if (mtd_table[i])
	418	old->remove(mtd_table[i]);
97894cda	419
1da177e4	420	list_del(&old->list);
48b19268	421	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	422	return 0;
	423	}
	424
	425
	426	/**
	427	* get_mtd_device - obtain a validated handle for an MTD device
	428	* @mtd: last known address of the required MTD device
	429	* @num: internal device number of the required MTD device
	430	*
	431	* Given a number and NULL address, return the num'th entry in the device
	432	* table, if any. Given an address and num == -1, search the device table
	433	* for a device with that address and return if it's still present. Given
9c74034f AB	434	* both, return the num'th driver only if its address matches. Return
9c74034f AB	435	* error code if not.
1da177e4	436	*/
97894cda	437
1da177e4 LT	438	struct mtd_info get_mtd_device(struct mtd_info mtd, int num)
	439	{
	440	struct mtd_info *ret = NULL;
9c74034f	441	int i, err = -ENODEV;
1da177e4	442
48b19268	443	mutex_lock(&mtd_table_mutex);
1da177e4 LT	444
	445	if (num == -1) {
	446	for (i=0; i< MAX_MTD_DEVICES; i++)
	447	if (mtd_table[i] == mtd)
	448	ret = mtd_table[i];
35016dd7	449	} else if (num >= 0 && num < MAX_MTD_DEVICES) {
1da177e4 LT	450	ret = mtd_table[num];
	451	if (mtd && mtd != ret)
	452	ret = NULL;
	453	}
	454
9fe912ce AB	455	if (!ret)
	456	goto out_unlock;
	457
9c74034f	458	if (!try_module_get(ret->owner))
9fe912ce	459	goto out_unlock;
9fe912ce	460
9c74034f AB	461	if (ret->get_device) {
	462	err = ret->get_device(ret);
	463	if (err)
	464	goto out_put;
9fe912ce	465	}
1da177e4	466
9fe912ce	467	ret->usecount++;
9c74034f AB	468	mutex_unlock(&mtd_table_mutex);
9c74034f AB	469	return ret;
1da177e4	470
9c74034f AB	471	out_put:
9c74034f AB	472	module_put(ret->owner);
9fe912ce	473	out_unlock:
48b19268	474	mutex_unlock(&mtd_table_mutex);
9c74034f	475	return ERR_PTR(err);
1da177e4 LT	476	}
1da177e4 LT	477
7799308f AB	478	/**
	479	* get_mtd_device_nm - obtain a validated handle for an MTD device by
	480	* device name
	481	* @name: MTD device name to open
	482	*
	483	* This function returns MTD device description structure in case of
	484	* success and an error code in case of failure.
	485	*/
	486
	487	struct mtd_info get_mtd_device_nm(const char name)
	488	{
9fe912ce AB	489	int i, err = -ENODEV;
9fe912ce AB	490	struct mtd_info *mtd = NULL;
7799308f AB	491
	492	mutex_lock(&mtd_table_mutex);
	493
	494	for (i = 0; i < MAX_MTD_DEVICES; i++) {
	495	if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
	496	mtd = mtd_table[i];
	497	break;
	498	}
	499	}
	500
9fe912ce	501	if (!mtd)
7799308f AB	502	goto out_unlock;
	503
	504	if (!try_module_get(mtd->owner))
	505	goto out_unlock;
	506
9fe912ce AB	507	if (mtd->get_device) {
	508	err = mtd->get_device(mtd);
	509	if (err)
	510	goto out_put;
	511	}
	512
7799308f	513	mtd->usecount++;
9fe912ce AB	514	mutex_unlock(&mtd_table_mutex);
9fe912ce AB	515	return mtd;
7799308f	516
9fe912ce AB	517	out_put:
9fe912ce AB	518	module_put(mtd->owner);
7799308f AB	519	out_unlock:
7799308f AB	520	mutex_unlock(&mtd_table_mutex);
9fe912ce	521	return ERR_PTR(err);
7799308f AB	522	}
7799308f AB	523
1da177e4 LT	524	void put_mtd_device(struct mtd_info *mtd)
	525	{
	526	int c;
	527
48b19268	528	mutex_lock(&mtd_table_mutex);
1da177e4	529	c = --mtd->usecount;
9fe912ce AB	530	if (mtd->put_device)
9fe912ce AB	531	mtd->put_device(mtd);
48b19268	532	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	533	BUG_ON(c < 0);
	534
	535	module_put(mtd->owner);
	536	}
	537
	538	/* default_mtd_writev - default mtd writev method for MTD devices that
dd36f267	539	* don't implement their own
1da177e4 LT	540	*/
	541
	542	int default_mtd_writev(struct mtd_info mtd, const struct kvec vecs,
	543	unsigned long count, loff_t to, size_t *retlen)
	544	{
	545	unsigned long i;
	546	size_t totlen = 0, thislen;
	547	int ret = 0;
	548
	549	if(!mtd->write) {
	550	ret = -EROFS;
	551	} else {
	552	for (i=0; i<count; i++) {
	553	if (!vecs[i].iov_len)
	554	continue;
	555	ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
	556	totlen += thislen;
	557	if (ret \|\| thislen != vecs[i].iov_len)
	558	break;
	559	to += vecs[i].iov_len;
	560	}
	561	}
	562	if (retlen)
	563	*retlen = totlen;
	564	return ret;
	565	}
	566
dd36f267 DW	567	EXPORT_SYMBOL_GPL(add_mtd_device);
	568	EXPORT_SYMBOL_GPL(del_mtd_device);
	569	EXPORT_SYMBOL_GPL(get_mtd_device);
	570	EXPORT_SYMBOL_GPL(get_mtd_device_nm);
	571	EXPORT_SYMBOL_GPL(put_mtd_device);
	572	EXPORT_SYMBOL_GPL(register_mtd_user);
	573	EXPORT_SYMBOL_GPL(unregister_mtd_user);
	574	EXPORT_SYMBOL_GPL(default_mtd_writev);
1da177e4	575
2d2dce0e PM	576	#ifdef CONFIG_PROC_FS
2d2dce0e PM	577
1da177e4 LT	578	/====================================================================/
	579	/* Support for /proc/mtd */
	580
1da177e4 LT	581	static struct proc_dir_entry *proc_mtd;
	582
	583	static inline int mtd_proc_info (char *buf, int i)
	584	{
	585	struct mtd_info *this = mtd_table[i];
	586
	587	if (!this)
	588	return 0;
	589
69423d99 AH	590	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", i,
69423d99 AH	591	(unsigned long long)this->size,
1da177e4 LT	592	this->erasesize, this->name);
	593	}
	594
	595	static int mtd_read_proc (char page, char *start, off_t off, int count,
	596	int eof, void data_unused)
	597	{
	598	int len, l, i;
	599	off_t begin = 0;
	600
48b19268	601	mutex_lock(&mtd_table_mutex);
1da177e4 LT	602
	603	len = sprintf(page, "dev: size erasesize name\n");
	604	for (i=0; i< MAX_MTD_DEVICES; i++) {
	605
	606	l = mtd_proc_info(page + len, i);
	607	len += l;
	608	if (len+begin > off+count)
	609	goto done;
	610	if (len+begin < off) {
	611	begin += len;
	612	len = 0;
	613	}
	614	}
	615
	616	*eof = 1;
	617
	618	done:
48b19268	619	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	620	if (off >= len+begin)
	621	return 0;
	622	*start = page + (off-begin);
	623	return ((count < begin+len-off) ? count : begin+len-off);
	624	}
	625
45b09076 KC	626	#endif /* CONFIG_PROC_FS */
45b09076 KC	627
1da177e4 LT	628	/====================================================================/
	629	/* Init code */
	630
	631	static int __init init_mtd(void)
	632	{
15bce40c DW	633	int ret;
15bce40c DW	634	ret = class_register(&mtd_class);
694bb7fc	635
15bce40c DW	636	if (ret) {
	637	pr_err("Error registering mtd class: %d\n", ret);
	638	return ret;
694bb7fc	639	}
45b09076	640	#ifdef CONFIG_PROC_FS
1da177e4 LT	641	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
1da177e4 LT	642	proc_mtd->read_proc = mtd_read_proc;
45b09076	643	#endif /* CONFIG_PROC_FS */
1da177e4 LT	644	return 0;
	645	}
	646
	647	static void __exit cleanup_mtd(void)
	648	{
45b09076	649	#ifdef CONFIG_PROC_FS
1da177e4 LT	650	if (proc_mtd)
1da177e4 LT	651	remove_proc_entry( "mtd", NULL);
45b09076	652	#endif /* CONFIG_PROC_FS */
15bce40c	653	class_unregister(&mtd_class);
1da177e4 LT	654	}
	655
	656	module_init(init_mtd);
	657	module_exit(cleanup_mtd);
	658
1da177e4 LT	659	MODULE_LICENSE("GPL");
	660	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	661	MODULE_DESCRIPTION("Core MTD registration and access routines");