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| 2 | |
| 3 | * Simple read-only (writable only for RAM) mtdblock driver
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| 4 | *
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| 5 | * Copyright © 2001-2010 David Woodhouse <[email protected]>
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| 6 |
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| 7 |
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| 8 | #include <linux/init.h>
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| 9 | #include <linux/slab.h>
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| 10 | #include <linux/mtd/mtd.h>
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| 11 | #include <linux/mtd/blktrans.h>
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| 12 | #include <linux/module.h>
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| 13 | #include <linux/major.h>
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| 14 |
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| 15 | static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
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| 16 | unsigned long block, char *buf)
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| 17 | {
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| 18 | size_t retlen;
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| 19 | int err;
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| 20 |
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| 21 | err = mtd_read(dev->mtd, (block * 512), 512, &retlen, buf);
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| 22 | if (err && !mtd_is_bitflip(err))
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| 23 | return 1;
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| 24 | return 0;
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| 25 | }
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| 26 |
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| 27 | static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
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| 28 | unsigned long block, char *buf)
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| 29 | {
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| 30 | size_t retlen;
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| 31 |
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| 32 | if (mtd_write(dev->mtd, (block * 512), 512, &retlen, buf))
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| 33 | return 1;
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| 34 | return 0;
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| 35 | }
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| 36 |
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| 37 | static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
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| 38 | {
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| 39 | struct mtd_blktrans_dev *dev = kzalloc_obj(*dev);
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| 40 |
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| 41 | if (!dev)
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| 42 | return;
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| 43 |
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| 44 | dev->mtd = mtd;
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| 45 | dev->devnum = mtd->index;
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| 46 |
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| 47 | dev->size = mtd->size >> 9;
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| 48 | dev->tr = tr;
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| 49 | dev->readonly = 1;
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| 50 |
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| 51 | if (mtd_type_is_nand(mtd))
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| 52 | pr_warn_ratelimited("%s: MTD device '%s' is NAND, please consider using UBI block devices instead.\n",
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| 53 | tr->name, mtd->name);
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| 54 |
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| 55 | if (add_mtd_blktrans_dev(dev))
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| 56 | kfree(dev);
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| 57 | }
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| 58 |
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| 59 | static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
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| 60 | {
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| 61 | del_mtd_blktrans_dev(dev);
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| 62 | }
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| 63 |
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| 64 | static struct mtd_blktrans_ops mtdblock_tr = {
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| 65 | .name = "mtdblock",
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| 66 | .major = MTD_BLOCK_MAJOR,
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| 67 | .part_bits = 0,
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| 68 | .blksize = 512,
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| 69 | .readsect = mtdblock_readsect,
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| 70 | .writesect = mtdblock_writesect,
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| 71 | .add_mtd = mtdblock_add_mtd,
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| 72 | .remove_dev = mtdblock_remove_dev,
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| 73 | .owner = THIS_MODULE,
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| 74 | };
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| 75 |
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| 76 | module_mtd_blktrans(mtdblock_tr);
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| 77 |
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| 78 | MODULE_LICENSE("GPL");
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| 79 | MODULE_AUTHOR("David Woodhouse <[email protected]>");
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| 80 | MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");
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