path: root/include/linux/mtd/nand.h

/*
 *  linux/include/linux/mtd/nand.h
 *
 *  Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
 *                        Steven J. Hill <sjhill@realitydiluted.com>
 *		          Thomas Gleixner <tglx@linutronix.de>
 *
 * 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.
 *
 * Info:
 *	Contains standard defines and IDs for NAND flash devices
 *
 * Changelog:
 *	See git changelog.
 */
#ifndef __LINUX_MTD_NAND_H
#define __LINUX_MTD_NAND_H

#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/flashchip.h>
#include <linux/mtd/bbm.h>

struct mtd_info;
struct nand_flash_dev;
struct device_node;

/* Scan and identify a NAND device */
int nand_scan(struct mtd_info *mtd, int max_chips);
/*
 * Separate phases of nand_scan(), allowing board driver to intervene
 * and override command or ECC setup according to flash type.
 */
int nand_scan_ident(struct mtd_info *mtd, int max_chips,
			   struct nand_flash_dev *table);
int nand_scan_tail(struct mtd_info *mtd);

/* Unregister the MTD device and free resources held by the NAND device */
void nand_release(struct mtd_info *mtd);

/* Internal helper for board drivers which need to override command function */
void nand_wait_ready(struct mtd_info *mtd);

/* locks all blocks present in the device */
int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);

/* unlocks specified locked blocks */
int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);

/* The maximum number of NAND chips in an array */
#define NAND_MAX_CHIPS		8

/*
 * Constants for hardware specific CLE/ALE/NCE function
 *
 * These are bits which can be or'ed to set/clear multiple
 * bits in one go.
 */
/* Select the chip by setting nCE to low */
#define NAND_NCE		0x01
/* Select the command latch by setting CLE to high */
#define NAND_CLE		0x02
/* Select the address latch by setting ALE to high */
#define NAND_ALE		0x04

#define NAND_CTRL_CLE		(NAND_NCE | NAND_CLE)
#define NAND_CTRL_ALE		(NAND_NCE | NAND_ALE)
#define NAND_CTRL_CHANGE	0x80

/*
 * Standard NAND flash commands
 */
#define NAND_CMD_READ0		0
#define NAND_CMD_READ1		1
#define NAND_CMD_RNDOUT		5
#define NAND_CMD_PAGEPROG	0x10
#define NAND_CMD_READOOB	0x50
#define NAND_CMD_ERASE1		0x60
#define NAND_CMD_STATUS		0x70
#define NAND_CMD_SEQIN		0x80
#define NAND_CMD_RNDIN		0x85
#define NAND_CMD_READID		0x90
#define NAND_CMD_ERASE2		0xd0
#define NAND_CMD_PARAM		0xec
#define NAND_CMD_GET_FEATURES	0xee
#define NAND_CMD_SET_FEATURES	0xef
#define NAND_CMD_RESET		0xff

#define NAND_CMD_LOCK		0x2a
#define NAND_CMD_UNLOCK1	0x23
#define NAND_CMD_UNLOCK2	0x24

/* Extended commands for large page devices */
#define NAND_CMD_READSTART	0x30
#define NAND_CMD_RNDOUTSTART	0xE0
#define NAND_CMD_CACHEDPROG	0x15

#define NAND_CMD_NONE		-1

/* Status bits */
#define NAND_STATUS_FAIL	0x01
#define NAND_STATUS_FAIL_N1	0x02
#define NAND_STATUS_TRUE_READY	0x20
#define NAND_STATUS_READY	0x40
#define NAND_STATUS_WP		0x80

/*
 * Constants for ECC_MODES
 */
typedef enum {
	NAND_ECC_NONE,
	NAND_ECC_SOFT,
	NAND_ECC_HW,
	NAND_ECC_HW_SYNDROME,
	NAND_ECC_HW_OOB_FIRST,
} nand_ecc_modes_t;

enum nand_ecc_algo {
	NAND_ECC_UNKNOWN,
	NAND_ECC_HAMMING,
	NAND_ECC_BCH,
};

/*
 * Constants for Hardware ECC
 */
/* Reset Hardware ECC for read */
#define NAND_ECC_READ		0
/* Reset Hardware ECC for write */
#define NAND_ECC_WRITE		1
/* Enable Hardware ECC before syndrome is read back from flash */
#define NAND_ECC_READSYN	2

/*
 * Enable generic NAND 'page erased' check. This check is only done when
 * ecc.correct() returns -EBADMSG.
 * Set this flag if your implementation does not fix bitflips in erased
 * pages and you want to rely on the default implementation.
 */
#define NAND_ECC_GENERIC_ERASED_CHECK	BIT(0)
#define NAND_ECC_MAXIMIZE		BIT(1)
/*
 * If your controller already sends the required NAND commands when
 * reading or writing a page, then the framework is not supposed to
 * send READ0 and SEQIN/PAGEPROG respectively.
 */
#define NAND_ECC_CUSTOM_PAGE_ACCESS	BIT(2)

/* Bit mask for flags passed to do_nand_read_ecc */
#define NAND_GET_DEVICE		0x80


/*
 * Option constants for bizarre disfunctionality and real
 * features.
 */
/* Buswidth is 16 bit */
#define NAND_BUSWIDTH_16	0x00000002
/* Chip has cache program function */
#define NAND_CACHEPRG		0x00000008
/*
 * Chip requires ready check on read (for auto-incremented sequential read).
 * True only for small page devices; large page devices do not support
 * autoincrement.
 */
#define NAND_NEED_READRDY	0x00000100

/* Chip does not allow subpage writes */
#define NAND_NO_SUBPAGE_WRITE	0x00000200

/* Device is one of 'new' xD cards that expose fake nand command set */
#define NAND_BROKEN_XD		0x00000400

/* Device behaves just like nand, but is readonly */
#define NAND_ROM		0x00000800

/* Device supports subpage reads */
#define NAND_SUBPAGE_READ	0x00001000

/*
 * Some MLC NANDs need data scrambling to limit bitflips caused by repeated
 * patterns.
 */
#define NAND_NEED_SCRAMBLING	0x00002000

/* Options valid for Samsung large page devices */
#define NAND_SAMSUNG_LP_OPTIONS NAND_CACHEPRG

/* Macros to identify the above */
#define NAND_HAS_CACHEPROG(chip) ((chip->options & NAND_CACHEPRG))
#define NAND_HAS_SUBPAGE_READ(chip) ((chip->options & NAND_SUBPAGE_READ))
#define NAND_HAS_SUBPAGE_WRITE(chip) !((chip)->options & NAND_NO_SUBPAGE_WRITE)

/* Non chip related options */
/* This option skips the bbt scan during initialization. */
#define NAND_SKIP_BBTSCAN	0x00010000
/*
 * This option is defined if the board driver allocates its own buffers
 * (e.g. because it needs them DMA-coherent).
 */
#define NAND_OWN_BUFFERS	0x00020000
/* Chip may not exist, so silence any errors in scan */
#define NAND_SCAN_SILENT_NODEV	0x00040000
/*
 * Autodetect nand buswidth with readid/onfi.
 * This suppose the driver will configure the hardware in 8 bits mode