mtd: common module for smartmedia/xD support

This small module implements few helpers that are usefull
for nand drivers for SmartMedia/xD card readers.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/mtd/nand/sm_common.h b/drivers/mtd/nand/sm_common.h
new file mode 100644
index 000000000000..7c03314bdac5
--- /dev/null
+++ b/drivers/mtd/nand/sm_common.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright © 2009 - Maxim Levitsky
+ * Common routines & support for SmartMedia/xD format
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/bitops.h>
+#include <linux/mtd/mtd.h>
+
+/* Full oob structure as written on the flash */
+struct sm_oob {
+	uint32_t reserved;
+	uint8_t data_status;
+	uint8_t block_status;
+	uint8_t lba_copy1[2];
+	uint8_t ecc2[3];
+	uint8_t lba_copy2[2];
+	uint8_t ecc1[3];
+} __attribute__((packed));
+
+
+/* one sector is always 512 bytes, but it can consist of two nand pages */
+#define SM_SECTOR_SIZE		512
+
+/* oob area is also 16 bytes, but might be from two pages */
+#define SM_OOB_SIZE		16
+
+/* This is maximum zone size, and all devices that have more that one zone
+   have this size */
+#define SM_MAX_ZONE_SIZE 	1024
+
+/* support for small page nand */
+#define SM_SMALL_PAGE 		256
+#define SM_SMALL_OOB_SIZE	8
+
+
+extern int sm_register_device(struct mtd_info *mtd);
+
+
+inline int sm_sector_valid(struct sm_oob *oob)
+{
+	return hweight16(oob->data_status) >= 5;
+}
+
+inline int sm_block_valid(struct sm_oob *oob)
+{
+	return hweight16(oob->block_status) >= 7;
+}
+
+inline int sm_block_erased(struct sm_oob *oob)
+{
+	static const uint32_t erased_pattern[4] = {
+		0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+
+	/* First test for erased block */
+	if (!memcmp(oob, erased_pattern, sizeof(*oob)))
+		return 1;
+	return 0;
+}