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/*
* Core registration and callback routines for MTD
* drivers and users.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/mtd/mtd.h>
#include <linux/mtd/compat.h>
#include <ubi_uboot.h>
struct mtd_info *mtd_table[MAX_MTD_DEVICES];
int add_mtd_device(struct mtd_info *mtd)
{
int i;
BUG_ON(mtd->writesize == 0);
for (i = 0; i < MAX_MTD_DEVICES; i++)
if (!mtd_table[i]) {
mtd_table[i] = mtd;
mtd->index = i;
mtd->usecount = 0;
/* No need to get a refcount on the module containing
the notifier, since we hold the 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. :) */
return 0;
}
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;
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 {
/* No need to get a refcount on the module containing
* the notifier, since we hold the mtd_table_mutex */
mtd_table[mtd->index] = NULL;
ret = 0;
}
return ret;
}
/**
* 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;
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;
ret->usecount++;
return ret;
out_unlock:
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;
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;
mtd->usecount++;
return mtd;
out_unlock:
return ERR_PTR(err);
}
void put_mtd_device(struct mtd_info *mtd)
{
int c;
c = --mtd->usecount;
BUG_ON(c < 0);
}
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