1 files changed, 87 insertions, 0 deletions

diff --git a/drivers/mtd/mtdblock_ro.c b/drivers/mtd/mtdblock_ro.c
new file mode 100644
index 000000000000..0c830ba41ef0
--- /dev/null
+++ b/drivers/mtd/mtdblock_ro.c
@@ -0,0 +1,87 @@
+/*
+ * $Id: mtdblock_ro.c,v 1.19 2004/11/16 18:28:59 dwmw2 Exp $
+ *
+ * (C) 2003 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Simple read-only (writable only for RAM) mtdblock driver
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/blktrans.h>
+
+static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
+                              unsigned long block, char *buf)
+{
+        size_t retlen;
+
+        if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
+                return 1;
+        return 0;
+}
+
+static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
+                              unsigned long block, char *buf)
+{
+        size_t retlen;
+
+        if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
+                return 1;
+        return 0;
+}
+
+static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
+{
+        struct mtd_blktrans_dev *dev = kmalloc(sizeof(*dev), GFP_KERNEL);
+
+        if (!dev)
+                return;
+
+        memset(dev, 0, sizeof(*dev));
+
+        dev->mtd = mtd;
+        dev->devnum = mtd->index;
+        dev->blksize = 512;
+        dev->size = mtd->size >> 9;
+        dev->tr = tr;
+        if ((mtd->flags & (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE)) !=
+            (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE))
+                dev->readonly = 1;
+
+        add_mtd_blktrans_dev(dev);
+}
+
+static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
+{
+        del_mtd_blktrans_dev(dev);
+        kfree(dev);
+}
+
+static struct mtd_blktrans_ops mtdblock_tr = {
+        .name           = "mtdblock",
+        .major          = 31,
+        .part_bits      = 0,
+        .readsect       = mtdblock_readsect,
+        .writesect      = mtdblock_writesect,
+        .add_mtd        = mtdblock_add_mtd,
+        .remove_dev     = mtdblock_remove_dev,
+        .owner          = THIS_MODULE,
+};
+
+static int __init mtdblock_init(void)
+{
+        return register_mtd_blktrans(&mtdblock_tr);
+}
+
+static void __exit mtdblock_exit(void)
+{
+        deregister_mtd_blktrans(&mtdblock_tr);
+}
+
+module_init(mtdblock_init);
+module_exit(mtdblock_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");