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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/mtd/chips/map_ram.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/mtd/chips/map_ram.c')
-rw-r--r--drivers/mtd/chips/map_ram.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/mtd/chips/map_ram.c b/drivers/mtd/chips/map_ram.c
new file mode 100644
index 00000000000..bd2e876a814
--- /dev/null
+++ b/drivers/mtd/chips/map_ram.c
@@ -0,0 +1,143 @@
+/*
+ * Common code to handle map devices which are simple RAM
+ * (C) 2000 Red Hat. GPL'd.
+ * $Id: map_ram.c,v 1.22 2005/01/05 18:05:12 dwmw2 Exp $
+ */
+
+#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/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/compatmac.h>
+
+
+static int mapram_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+static int mapram_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+static int mapram_erase (struct mtd_info *, struct erase_info *);
+static void mapram_nop (struct mtd_info *);
+static struct mtd_info *map_ram_probe(struct map_info *map);
+
+
+static struct mtd_chip_driver mapram_chipdrv = {
+ .probe = map_ram_probe,
+ .name = "map_ram",
+ .module = THIS_MODULE
+};
+
+static struct mtd_info *map_ram_probe(struct map_info *map)
+{
+ struct mtd_info *mtd;
+
+ /* Check the first byte is RAM */
+#if 0
+ map_write8(map, 0x55, 0);
+ if (map_read8(map, 0) != 0x55)
+ return NULL;
+
+ map_write8(map, 0xAA, 0);
+ if (map_read8(map, 0) != 0xAA)
+ return NULL;
+
+ /* Check the last byte is RAM */
+ map_write8(map, 0x55, map->size-1);
+ if (map_read8(map, map->size-1) != 0x55)
+ return NULL;
+
+ map_write8(map, 0xAA, map->size-1);
+ if (map_read8(map, map->size-1) != 0xAA)
+ return NULL;
+#endif
+ /* OK. It seems to be RAM. */
+
+ mtd = kmalloc(sizeof(*mtd), GFP_KERNEL);
+ if (!mtd)
+ return NULL;
+
+ memset(mtd, 0, sizeof(*mtd));
+
+ map->fldrv = &mapram_chipdrv;
+ mtd->priv = map;
+ mtd->name = map->name;
+ mtd->type = MTD_RAM;
+ mtd->size = map->size;
+ mtd->erase = mapram_erase;
+ mtd->read = mapram_read;
+ mtd->write = mapram_write;
+ mtd->sync = mapram_nop;
+ mtd->flags = MTD_CAP_RAM | MTD_VOLATILE;
+
+ mtd->erasesize = PAGE_SIZE;
+ while(mtd->size & (mtd->erasesize - 1))
+ mtd->erasesize >>= 1;
+
+ __module_get(THIS_MODULE);
+ return mtd;
+}
+
+
+static int mapram_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 int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
+{
+ struct map_info *map = mtd->priv;
+
+ map_copy_to(map, to, buf, len);
+ *retlen = len;
+ return 0;
+}
+
+static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr)
+{
+ /* Yeah, it's inefficient. Who cares? It's faster than a _real_
+ flash erase. */
+ struct map_info *map = mtd->priv;
+ map_word allff;
+ unsigned long i;
+
+ allff = map_word_ff(map);
+
+ for (i=0; i<instr->len; i += map_bankwidth(map))
+ map_write(map, allff, instr->addr + i);
+
+ instr->state = MTD_ERASE_DONE;
+
+ mtd_erase_callback(instr);
+
+ return 0;
+}
+
+static void mapram_nop(struct mtd_info *mtd)
+{
+ /* Nothing to see here */
+}
+
+static int __init map_ram_init(void)
+{
+ register_mtd_chip_driver(&mapram_chipdrv);
+ return 0;
+}
+
+static void __exit map_ram_exit(void)
+{
+ unregister_mtd_chip_driver(&mapram_chipdrv);
+}
+
+module_init(map_ram_init);
+module_exit(map_ram_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("MTD chip driver for RAM chips");