patch-2.4.6 linux/drivers/mtd/chips/map_ram.c

• Lines: 137
• Date: Tue Jun 12 10:30:27 2001
• Orig file: v2.4.5/linux/drivers/mtd/chips/map_ram.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.5/linux/drivers/mtd/chips/map_ram.c linux/drivers/mtd/chips/map_ram.c
@@ -0,0 +1,136 @@
+/*
+ * Common code to handle map devices which are simple RAM
+ * (C) 2000 Red Hat. GPL'd.
+ * $Id: map_ram.c,v 1.11 2001/06/08 15:34:04 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/mtd/map.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: "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->erasesize = 0x10000;
+	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;
+
+	MOD_INC_USE_COUNT;
+	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 = (struct map_info *)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 = (struct map_info *)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 = (struct map_info *)mtd->priv;
+	unsigned long i;
+
+	for (i=0; i<instr->len; i++)
+		map->write8(map, 0xFF, instr->addr + i);
+
+	if (instr->callback)
+		instr->callback(instr);
+
+	return 0;
+}
+
+static void mapram_nop(struct mtd_info *mtd)
+{
+	/* Nothing to see here */
+}
+
+#if LINUX_VERSION_CODE < 0x20212 && defined(MODULE)
+#define map_ram_init init_module
+#define map_ram_exit cleanup_module
+#endif
+
+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);