[PATCH 6/9] MTD: common module for smartmedia/xD support

Maxim Levitsky
2010-01-12T19:34:39Z

>From 612ced620304d1991cca9c4f4f49b257d0931fdf Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <maximlevitsky@gmail.com>
Date: Tue, 12 Jan 2010 21:09:29 +0200
Subject: [PATCH 6/9] 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>
---
drivers/mtd/nand/Kconfig | 9 +++
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/sm_common.c | 126 ++++++++++++++++++++++++++++++++++++++++++
drivers/mtd/nand/sm_common.h | 46 +++++++++++++++
4 files changed, 182 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/nand/sm_common.c
create mode 100644 drivers/mtd/nand/sm_common.h

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 677cd53..13c1fb2 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -18,6 +18,10 @@ config MTD_NAND_VERIFY_WRITE
device thinks the write was successful, a bit could have been
flipped accidentally due to device wear or something else.

+config MTD_NAND_SMARTMEDIA
+ boolean
+ default n
+
config MTD_NAND_ECC_SMC
bool "NAND ECC Smart Media byte order"
default n
@@ -25,6 +29,11 @@ config MTD_NAND_ECC_SMC
Software ECC according to the Smart Media Specification.
The original Linux implementation had byte 0 and 1 swapped.

+config MTD_SM_COMMON
+ select MTD_NAND_SMARTMEDIA
+ tristate
+ default n
+
config MTD_NAND_MUSEUM_IDS
bool "Enable chip ids for obsolete ancient NAND devices"
depends on MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 1407bd1..09891f6 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -4,6 +4,7 @@

obj-$(CONFIG_MTD_NAND) += nand.o nand_ecc.o
obj-$(CONFIG_MTD_NAND_IDS) += nand_ids.o
+obj-$(CONFIG_MTD_SM_COMMON) += sm_common.o

obj-$(CONFIG_MTD_NAND_CAFE) += cafe_nand.o
obj-$(CONFIG_MTD_NAND_SPIA) += spia.o
diff --git a/drivers/mtd/nand/sm_common.c b/drivers/mtd/nand/sm_common.c
new file mode 100644
index 0000000..55ae3ff
--- /dev/null
+++ b/drivers/mtd/nand/sm_common.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2009 - Maxim Levitsky
+ * Common routines & support for 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/kernel.h>
+#include <linux/bitops.h>
+#include <linux/log2.h>
+#include "sm_common.h"
+
+static struct nand_ecclayout nand_oob_sm = {
+ .eccbytes = 6,
+ .eccpos = {8, 9, 10, 13, 14, 15},
+ .oobfree = {
+ {.offset = 0 , .length = 4}, /* reserved */
+ {.offset = 6 , .length = 2}, /* LBA1 */
+ {.offset = 11, .length = 2} /* LBA2 */
+ }
+};
+
+/* Tests if block (more correctly page) is bad */
+static int sm_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
+{
+ struct nand_chip *chip = (struct nand_chip *)mtd->priv;
+ struct mtd_oob_ops ops;
+ struct sm_oob_raw oob;
+ int bad = 1, ret;
+
+ ops.mode = MTD_OOB_RAW;
+ ops.ooboffs = 0;
+ ops.ooblen = SM_OOB_SIZE;
+ ops.oobbuf = (void *)&oob;
+ ops.datbuf = NULL;
+
+ if (getchip) {
+ nand_get_device(chip, mtd, FL_READING);
+ chip->select_chip(mtd, 0);
+ }
+
+ ret = nand_do_read_oob(mtd, ofs, &ops);
+ if (ret < 0 || ops.oobretlen != SM_OOB_SIZE)
+ goto out;
+
+ if (hweight16(oob.block_status) < 7 ||
+ hweight16(oob.data_status) < 5)
+ goto out;
+
+ bad = 0;
+out:
+ if (getchip)
+ nand_release_device(mtd);
+ return bad;
+}
+
+/* Marks block as bad */
+static int sm_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+ struct nand_chip *chip = (struct nand_chip *)mtd->priv;
+ struct mtd_oob_ops ops;
+ struct sm_oob_raw oob;
+ int ret, error = 0;
+
+ memset(&oob, -1, SM_OOB_SIZE);
+ oob.block_status = 0xF0;
+
+ ops.mode = MTD_OOB_RAW;
+ ops.ooboffs = 0;
+ ops.ooblen = SM_OOB_SIZE;
+ ops.oobbuf = (void *)&oob;
+ ops.datbuf = NULL;
+
+ nand_get_device(chip, mtd, FL_WRITING);
+
+ ret = nand_do_write_oob(mtd, ofs, &ops);
+ if (ret < 0 || ops.oobretlen != SM_OOB_SIZE) {
+ printk(KERN_NOTICE "sm_common: can't mark sector at %i as bad\n",
+ (int)ofs);
+ error = -EIO;
+ } else
+ mtd->ecc_stats.badblocks++;
+
+ nand_release_device(mtd);
+ return error;
+}
+
+int sm_register_device(struct mtd_info *mtd)
+{
+ struct nand_chip *chip = (struct nand_chip *)mtd->priv;
+ int ret;
+
+ chip->options |= NAND_SKIP_BBTSCAN;
+
+ /* Scan for card properties */
+ ret = nand_scan_ident(mtd, 1);
+
+ if (ret)
+ return ret;
+
+ /* Set oob handling functions. */
+ if (mtd->writesize == SM_SECTOR_SIZE) {
+ chip->block_bad = sm_block_bad;
+ chip->block_markbad = sm_block_markbad;
+ chip->ecc.layout = &nand_oob_sm;
+
+ /* SmartMedia on small page nand, has page depedent oob layout,
+ thus let FTL do that hard job */
+ } else if (mtd->writesize != SM_SMALL_PAGE)
+ return -ENODEV;
+
+ ret = nand_scan_tail(mtd);
+ if (ret)
+ return ret;
+
+ ret = add_mtd_device(mtd);
+ if (ret)
+ return ret;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(sm_register_device);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
+MODULE_DESCRIPTION("Common SmartMedia/xD functions");
diff --git a/drivers/mtd/nand/sm_common.h b/drivers/mtd/nand/sm_common.h
new file mode 100644
index 0000000..8f74a73
--- /dev/null
+++ b/drivers/mtd/nand/sm_common.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 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/mtd/nand.h>
+
+/* Full oob structure as written on the flash */
+struct sm_oob_raw {
+ u32 reserved;
+ u8 data_status;
+ u8 block_status;
+ u8 lba_copy1[2];
+ u8 ecc2[3];
+ u8 lba_copy2[2];
+ u8 ecc1[3];
+} __attribute__((packed));
+
+
+/* Oob structure , exposed to external interfaces */
+struct sm_oob {
+ u32 reserved;
+ u8 lba_copy1[2];
+ u8 lba_copy2[2];
+} __attribute__((packed));
+
+
+
+/* one sector is always 512 bytes, but it can consist of two nand pages */
+#define SM_SECTOR_SIZE 512
+
+/* minumum size of the page */
+#define SM_SMALL_PAGE 256
+
+/* 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
+
+extern int sm_register_device(struct mtd_info *mtd);
--
1.6.3.3