1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/mtd/chips/map_rom.c b/drivers/mtd/chips/map_rom.c
new file mode 100644
index 000000000..e67f73ab4
--- /dev/null
+++ b/drivers/mtd/chips/map_rom.c
@@ -0,0 +1,124 @@
+/*
+ * Common code to handle map devices which are simple ROM
+ * (C) 2000 Red Hat. GPL'd.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/io.h>
+#include <asm/byteorder.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+
+static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+static void maprom_nop (struct mtd_info *);
+static struct mtd_info *map_rom_probe(struct map_info *map);
+static int maprom_erase (struct mtd_info *mtd, struct erase_info *info);
+static unsigned long maprom_unmapped_area(struct mtd_info *, unsigned long,
+					  unsigned long, unsigned long);
+
+static struct mtd_chip_driver maprom_chipdrv = {
+	.probe	= map_rom_probe,
+	.name	= "map_rom",
+	.module	= THIS_MODULE
+};
+
+static unsigned int default_erasesize(struct map_info *map)
+{
+	const __be32 *erase_size = NULL;
+
+	erase_size = of_get_property(map->device_node, "erase-size", NULL);
+
+	return !erase_size ? map->size : be32_to_cpu(*erase_size);
+}
+
+static struct mtd_info *map_rom_probe(struct map_info *map)
+{
+	struct mtd_info *mtd;
+
+	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
+	if (!mtd)
+		return NULL;
+
+	map->fldrv = &maprom_chipdrv;
+	mtd->priv = map;
+	mtd->name = map->name;
+	mtd->type = MTD_ROM;
+	mtd->size = map->size;
+	mtd->_get_unmapped_area = maprom_unmapped_area;
+	mtd->_read = maprom_read;
+	mtd->_write = maprom_write;
+	mtd->_sync = maprom_nop;
+	mtd->_erase = maprom_erase;
+	mtd->flags = MTD_CAP_ROM;
+	mtd->erasesize = default_erasesize(map);
+	mtd->writesize = 1;
+	mtd->writebufsize = 1;
+
+	__module_get(THIS_MODULE);
+	return mtd;
+}
+
+
+/*
+ * Allow NOMMU mmap() to directly map the device (if not NULL)
+ * - return the address to which the offset maps
+ * - return -ENOSYS to indicate refusal to do the mapping
+ */
+static unsigned long maprom_unmapped_area(struct mtd_info *mtd,
+					  unsigned long len,
+					  unsigned long offset,
+					  unsigned long flags)
+{
+	struct map_info *map = mtd->priv;
+	return (unsigned long) map->virt + offset;
+}
+
+static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
+{
+	struct map_info *map = mtd->priv;
+
+	map_copy_from(map, buf, from, len);
+	*retlen = len;
+	return 0;
+}
+
+static void maprom_nop(struct mtd_info *mtd)
+{
+	/* Nothing to see here */
+}
+
+static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
+{
+	return -EROFS;
+}
+
+static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
+{
+	/* We do our best 8) */
+	return -EROFS;
+}
+
+static int __init map_rom_init(void)
+{
+	register_mtd_chip_driver(&maprom_chipdrv);
+	return 0;
+}
+
+static void __exit map_rom_exit(void)
+{
+	unregister_mtd_chip_driver(&maprom_chipdrv);
+}
+
+module_init(map_rom_init);
+module_exit(map_rom_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("MTD chip driver for ROM chips");