88 lines
1.9 KiB
C
88 lines
1.9 KiB
C
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/*
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* $Id: mtdblock_ro.c,v 1.19 2004/11/16 18:28:59 dwmw2 Exp $
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*
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* (C) 2003 David Woodhouse <dwmw2@infradead.org>
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*
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* Simple read-only (writable only for RAM) mtdblock driver
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*/
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/blktrans.h>
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static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
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unsigned long block, char *buf)
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{
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size_t retlen;
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if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
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return 1;
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return 0;
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}
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static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
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unsigned long block, char *buf)
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{
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size_t retlen;
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if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
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return 1;
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return 0;
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}
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static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
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{
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struct mtd_blktrans_dev *dev = kmalloc(sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return;
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memset(dev, 0, sizeof(*dev));
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dev->mtd = mtd;
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dev->devnum = mtd->index;
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dev->blksize = 512;
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dev->size = mtd->size >> 9;
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dev->tr = tr;
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if ((mtd->flags & (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE)) !=
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(MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE))
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dev->readonly = 1;
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add_mtd_blktrans_dev(dev);
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}
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static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
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{
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del_mtd_blktrans_dev(dev);
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kfree(dev);
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}
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static struct mtd_blktrans_ops mtdblock_tr = {
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.name = "mtdblock",
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.major = 31,
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.part_bits = 0,
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.readsect = mtdblock_readsect,
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.writesect = mtdblock_writesect,
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.add_mtd = mtdblock_add_mtd,
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.remove_dev = mtdblock_remove_dev,
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.owner = THIS_MODULE,
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};
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static int __init mtdblock_init(void)
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{
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return register_mtd_blktrans(&mtdblock_tr);
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}
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static void __exit mtdblock_exit(void)
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{
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deregister_mtd_blktrans(&mtdblock_tr);
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}
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module_init(mtdblock_init);
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module_exit(mtdblock_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
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MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");
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