mtd: common module for smartmedia/xD support (9fc51a37) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/mtd/nand/Kconfig

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		@@ -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

drivers/mtd/nand/Makefile

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		@@ -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

drivers/mtd/nand/sm_common.c

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		/*
		* Copyright © 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/mtd/nand.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 */
		}
		};

		/* NOTE: This layout is is not compatabable with SmartMedia, */
		/* because the 256 byte devices have page depenent oob layout */
		/* However it does preserve the bad block markers */
		/* If you use smftl, it will bypass this and work correctly */
		/* If you not, then you break SmartMedia compliance anyway */

		static struct nand_ecclayout nand_oob_sm_small = {
		.eccbytes = 3,
		.eccpos = {0, 1, 2},
		.oobfree = {
		{.offset = 3 , .length = 2}, /* reserved */
		{.offset = 6 , .length = 2}, /* LBA1 */
		}
		};


		static int sm_block_markbad(struct mtd_info *mtd, loff_t ofs)
		{
		struct mtd_oob_ops ops;
		struct sm_oob oob;
		int ret, error = 0;

		memset(&oob, -1, SM_OOB_SIZE);
		oob.block_status = 0x0F;

		/* As long as this function is called on erase block boundaries
		it will work correctly for 256 byte nand */
		ops.mode = MTD_OOB_PLACE;
		ops.ooboffs = 0;
		ops.ooblen = mtd->oobsize;
		ops.oobbuf = (void *)&oob;
		ops.datbuf = NULL;


		ret = mtd->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++;

		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 \| NAND_SMARTMEDIA;

		/* Scan for card properties */
		ret = nand_scan_ident(mtd, 1);

		if (ret)
		return ret;

		/* Bad block marker postion */
		chip->badblockpos = 0x05;
		chip->badblockbits = 7;
		chip->block_markbad = sm_block_markbad;

		/* ECC layout */
		if (mtd->writesize == SM_SECTOR_SIZE)
		chip->ecc.layout = &nand_oob_sm;
		else if (mtd->writesize == SM_SMALL_PAGE)
		chip->ecc.layout = &nand_oob_sm_small;
		else
		return -ENODEV;

		ret = nand_scan_tail(mtd);

		if (ret)
		return ret;

		return add_mtd_device(mtd);
		}
		EXPORT_SYMBOL_GPL(sm_register_device);

		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
		MODULE_DESCRIPTION("Common SmartMedia/xD functions");

drivers/mtd/nand/sm_common.h

0 → 100644

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		/*
		* 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;
		}