[deliverable/linux.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/slab.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 struct class *mtd_class;

/* 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)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	/* remove /dev/mtdXro node if needed */
	if (MTD_DEVT(mtd->index))
		device_destroy(mtd_class, MTD_DEVT(mtd->index) + 1);
}

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(mtd_type, S_IRUGO, mtd_type_show, NULL);

static struct attribute *mtd_attrs[] = {
	&dev_attr_mtd_type.attr,
	/* FIXME provide a /proc/mtd superset */
	NULL,
};

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

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);
			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;

		/* 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 < 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);

static int __init mtd_setup(void)
{
	mtd_class = class_create(THIS_MODULE, "mtd");

	if (IS_ERR(mtd_class)) {
		pr_err("Error creating mtd class.\n");
		return PTR_ERR(mtd_class);
	}
	return 0;
}
core_initcall(mtd_setup);

static void __exit mtd_teardown(void)
{
	class_destroy(mtd_class);
}
__exitcall(mtd_teardown);

#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);
}

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

static int __init init_mtd(void)
{
	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
		proc_mtd->read_proc = mtd_read_proc;
	return 0;
}

static void __exit cleanup_mtd(void)
{
        if (proc_mtd)
		remove_proc_entry( "mtd", NULL);
}

module_init(init_mtd);
module_exit(cleanup_mtd);

#endif /* CONFIG_PROC_FS */


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