spi-nor.h

/*
 * Copyright (C) 2014 Freescale Semiconductor, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#ifndef __LINUX_MTD_SPI_NOR_H
#define __LINUX_MTD_SPI_NOR_H

#include <linux/bitops.h>
#include <linux/mtd/cfi.h>
#include <linux/mtd/mtd.h>

/*
 * Manufacturer IDs
 *
 * The first byte returned from the flash after sending opcode SPINOR_OP_RDID.
 * Sometimes these are the same as CFI IDs, but sometimes they aren't.
 */
#define SNOR_MFR_ATMEL		CFI_MFR_ATMEL
#define SNOR_MFR_GIGADEVICE	0xc8
#define SNOR_MFR_INTEL		CFI_MFR_INTEL
#define SNOR_MFR_MICRON		CFI_MFR_ST /* ST Micro <--> Micron */
#define SNOR_MFR_MACRONIX	CFI_MFR_MACRONIX
#define SNOR_MFR_SPANSION	CFI_MFR_AMD
#define SNOR_MFR_SST		CFI_MFR_SST
#define SNOR_MFR_WINBOND	0xef /* Also used by some Spansion */

/*
 * Note on opcode nomenclature: some opcodes have a format like
 * SPINOR_OP_FUNCTION{4,}_x_y_z. The numbers x, y, and z stand for the number
 * of I/O lines used for the opcode, address, and data (respectively). The
 * FUNCTION has an optional suffix of '4', to represent an opcode which
 * requires a 4-byte (32-bit) address.
 */

/* Flash opcodes. */
#define SPINOR_OP_WREN		0x06	/* Write enable */
#define SPINOR_OP_RDSR		0x05	/* Read status register */
#define SPINOR_OP_WRSR		0x01	/* Write status register 1 byte */
#define SPINOR_OP_RDSR2		0x3f	/* Read status register 2 */
#define SPINOR_OP_WRSR2		0x3e	/* Write status register 2 */
#define SPINOR_OP_READ		0x03	/* Read data bytes (low frequency) */
#define SPINOR_OP_READ_FAST	0x0b	/* Read data bytes (high frequency) */
#define SPINOR_OP_READ_1_1_2	0x3b	/* Read data bytes (Dual Output SPI) */
#define SPINOR_OP_READ_1_2_2	0xbb	/* Read data bytes (Dual I/O SPI) */
#define SPINOR_OP_READ_1_1_4	0x6b	/* Read data bytes (Quad Output SPI) */
#define SPINOR_OP_READ_1_4_4	0xeb	/* Read data bytes (Quad I/O SPI) */
#define SPINOR_OP_PP		0x02	/* Page program (up to 256 bytes) */
#define SPINOR_OP_PP_1_1_4	0x32	/* Quad page program */
#define SPINOR_OP_PP_1_4_4	0x38	/* Quad page program */
#define SPINOR_OP_BE_4K		0x20	/* Erase 4KiB block */
#define SPINOR_OP_BE_4K_PMC	0xd7	/* Erase 4KiB block on PMC chips */
#define SPINOR_OP_BE_32K	0x52	/* Erase 32KiB block */
#define SPINOR_OP_CHIP_ERASE	0xc7	/* Erase whole flash chip */
#define SPINOR_OP_SE		0xd8	/* Sector erase (usually 64KiB) */
#define SPINOR_OP_RDID		0x9f	/* Read JEDEC ID */
#define SPINOR_OP_RDSFDP	0x5a	/* Read SFDP */
#define SPINOR_OP_RDCR		0x35	/* Read configuration register */
#define SPINOR_OP_RDFSR		0x70	/* Read flag status register */
#define SPINOR_OP_CLFSR		0x50	/* Clear flag status register */
#define SPINOR_OP_RDEAR		0xc8	/* Read Extended Address Register */
#define SPINOR_OP_WREAR		0xc5	/* Write Extended Address Register */

/* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
#define SPINOR_OP_READ_4B	0x13	/* Read data bytes (low frequency) */
#define SPINOR_OP_READ_FAST_4B	0x0c	/* Read data bytes (high frequency) */
#define SPINOR_OP_READ_1_1_2_4B	0x3c	/* Read data bytes (Dual Output SPI) */
#define SPINOR_OP_READ_1_2_2_4B	0xbc	/* Read data bytes (Dual I/O SPI) */
#define SPINOR_OP_READ_1_1_4_4B	0x6c	/* Read data bytes (Quad Output SPI) */
#define SPINOR_OP_READ_1_4_4_4B	0xec	/* Read data bytes (Quad I/O SPI) */
#define SPINOR_OP_PP_4B		0x12	/* Page program (up to 256 bytes) */
#define SPINOR_OP_PP_1_1_4_4B	0x34	/* Quad page program */
#define SPINOR_OP_PP_1_4_4_4B	0x3e	/* Quad page program */
#define SPINOR_OP_BE_4K_4B	0x21	/* Erase 4KiB block */
#define SPINOR_OP_BE_32K_4B	0x5c	/* Erase 32KiB block */
#define SPINOR_OP_SE_4B		0xdc	/* Sector erase (usually 64KiB) */

/* Double Transfer Rate opcodes - defined in JEDEC JESD216B. */
#define SPINOR_OP_READ_1_1_1_DTR	0x0d
#define SPINOR_OP_READ_1_2_2_DTR	0xbd
#define SPINOR_OP_READ_1_4_4_DTR	0xed

#define SPINOR_OP_READ_1_1_1_DTR_4B	0x0e
#define SPINOR_OP_READ_1_2_2_DTR_4B	0xbe
#define SPINOR_OP_READ_1_4_4_DTR_4B	0xee

/* Used for SST flashes only. */
#define SPINOR_OP_BP		0x02	/* Byte program */
#define SPINOR_OP_WRDI		0x04	/* Write disable */
#define SPINOR_OP_AAI_WP	0xad	/* Auto address increment word program */

/* Used for S3AN flashes only */
#define SPINOR_OP_XSE		0x50	/* Sector erase */
#define SPINOR_OP_XPP		0x82	/* Page program */
#define SPINOR_OP_XRDSR		0xd7	/* Read status register */

#define XSR_PAGESIZE		BIT(0)	/* Page size in Po2 or Linear */
#define XSR_RDY			BIT(7)	/* Ready */


/* Used for Macronix and Winbond flashes. */
#define SPINOR_OP_EN4B		0xb7	/* Enter 4-byte mode */
#define SPINOR_OP_EX4B		0xe9	/* Exit 4-byte mode */

/* Used for Spansion flashes only. */
#define SPINOR_OP_BRWR		0x17	/* Bank register write */
#define SPINOR_OP_CLSR		0x30	/* Clear status register 1 */

/* Used for Micron flashes only. */
#define SPINOR_OP_RD_EVCR      0x65    /* Read EVCR register */
#define SPINOR_OP_WD_EVCR      0x61    /* Write EVCR register */

/* Status Register bits. */
#define SR_WIP			BIT(0)	/* Write in progress */
#define SR_WEL			BIT(1)	/* Write enable latch */
/* meaning of other SR_* bits may differ between vendors */
#define SR_BP0			BIT(2)	/* Block protect 0 */
#define SR_BP1			BIT(3)	/* Block protect 1 */
#define SR_BP2			BIT(4)	/* Block protect 2 */
#define SR_TB			BIT(5)	/* Top/Bottom protect */
#define SR_SRWD			BIT(7)	/* SR write protect */
/* Spansion/Cypress specific status bits */
#define SR_E_ERR		BIT(5)
#define SR_P_ERR		BIT(6)

#define SR_QUAD_EN_MX		BIT(6)	/* Macronix Quad I/O */

/* Enhanced Volatile Configuration Register bits */
#define EVCR_QUAD_EN_MICRON	BIT(7)	/* Micron Quad I/O */

/* Flag Status Register bits */
#define FSR_READY		BIT(7)	/* Device status, 0 = Busy, 1 = Ready */
#define FSR_E_ERR		BIT(5)	/* Erase operation status */
#define FSR_P_ERR		BIT(4)	/* Program operation status */
#define FSR_PT_ERR		BIT(1)	/* Protection error bit */

/* Configuration Register bits. */
#define CR_QUAD_EN_SPAN		BIT(1)	/* Spansion Quad I/O */

/* Status Register 2 bits. */
#define SR2_QUAD_EN_BIT7	BIT(7)

/* Supported SPI protocols */
#define SNOR_PROTO_INST_MASK	GENMASK(23, 16)
#define SNOR_PROTO_INST_SHIFT	16
#define SNOR_PROTO_INST(_nbits)	\
	((((unsigned long)(_nbits)) << SNOR_PROTO_INST_SHIFT) & \
	 SNOR_PROTO_INST_MASK)

#define SNOR_PROTO_ADDR_MASK	GENMASK(15, 8)
#define SNOR_PROTO_ADDR_SHIFT	8
#define SNOR_PROTO_ADDR(_nbits)	\
	((((unsigned long)(_nbits)) << SNOR_PROTO_ADDR_SHIFT) & \
	 SNOR_PROTO_ADDR_MASK)

#define SNOR_PROTO_DATA_MASK	GENMASK(7, 0)
#define SNOR_PROTO_DATA_SHIFT	0
#define SNOR_PROTO_DATA(_nbits)	\
	((((unsigned long)(_nbits)) << SNOR_PROTO_DATA_SHIFT) & \
	 SNOR_PROTO_DATA_MASK)

#define SNOR_PROTO_IS_DTR	BIT(24)	/* Double Transfer Rate */

#define SNOR_PROTO_STR(_inst_nbits, _addr_nbits, _data_nbits)	\
	(SNOR_PROTO_INST(_inst_nbits) |				\
	 SNOR_PROTO_ADDR(_addr_nbits) |				\
	 SNOR_PROTO_DATA(_data_nbits))
#define SNOR_PROTO_DTR(_inst_nbits, _addr_nbits, _data_nbits)	\
	(SNOR_PROTO_IS_DTR |					\
	 SNOR_PROTO_STR(_inst_nbits, _addr_nbits, _data_nbits))

enum spi_nor_protocol {
	SNOR_PROTO_1_1_1 = SNOR_PROTO_STR(1, 1, 1),
	SNOR_PROTO_1_1_2 = SNOR_PROTO_STR(1, 1, 2),
	SNOR_PROTO_1_1_4 = SNOR_PROTO_STR(1, 1, 4),
	SNOR_PROTO_1_1_8 = SNOR_PROTO_STR(1, 1, 8),
	SNOR_PROTO_1_2_2 = SNOR_PROTO_STR(1, 2, 2),
	SNOR_PROTO_1_4_4 = SNOR_PROTO_STR(1, 4, 4),
	SNOR_PROTO_1_8_8 = SNOR_PROTO_STR(1, 8, 8),
	SNOR_PROTO_2_2_2 = SNOR_PROTO_STR(2, 2, 2),
	SNOR_PROTO_4_4_4 = SNOR_PROTO_STR(4, 4, 4),
	SNOR_PROTO_8_8_8 = SNOR_PROTO_STR(8, 8, 8),

	SNOR_PROTO_1_1_1_DTR = SNOR_PROTO_DTR(1, 1, 1),
	SNOR_PROTO_1_2_2_DTR = SNOR_PROTO_DTR(1, 2, 2),
	SNOR_PROTO_1_4_4_DTR = SNOR_PROTO_DTR(1, 4, 4),
	SNOR_PROTO_1_8_8_DTR = SNOR_PROTO_DTR(1, 8, 8),
};

static inline bool spi_nor_protocol_is_dtr(enum spi_nor_protocol proto)
{
	return !!(proto & SNOR_PROTO_IS_DTR);
}

static inline u8 spi_nor_get_protocol_inst_nbits(enum spi_nor_protocol proto)
{
	return ((unsigned long)(proto & SNOR_PROTO_INST_MASK)) >>
		SNOR_PROTO_INST_SHIFT;
}

static inline u8 spi_nor_get_protocol_addr_nbits(enum spi_nor_protocol proto)
{
	return ((unsigned long)(proto & SNOR_PROTO_ADDR_MASK)) >>
		SNOR_PROTO_ADDR_SHIFT;
}

static inline u8 spi_nor_get_protocol_data_nbits(enum spi_nor_protocol proto)
{
	return ((unsigned long)(proto & SNOR_PROTO_DATA_MASK)) >>
		SNOR_PROTO_DATA_SHIFT;
}

static inline u8 spi_nor_get_protocol_width(enum spi_nor_protocol proto)
{
	return spi_nor_get_protocol_data_nbits(proto);
}

#define SPI_NOR_MAX_CMD_SIZE	8
enum spi_nor_ops {
	SPI_NOR_OPS_READ = 0,
	SPI_NOR_OPS_WRITE,
	SPI_NOR_OPS_ERASE,
	SPI_NOR_OPS_LOCK,
	SPI_NOR_OPS_UNLOCK,
};

enum spi_nor_option_flags {
	SNOR_F_USE_FSR		= BIT(0),
	SNOR_F_HAS_SR_TB	= BIT(1),
	SNOR_F_NO_OP_CHIP_ERASE	= BIT(2),
	SNOR_F_S3AN_ADDR_DEFAULT = BIT(3),
	SNOR_F_READY_XSR_RDY	= BIT(4),
	SNOR_F_USE_CLSR		= BIT(5),
	SNOR_F_BROKEN_RESET	= BIT(6),
};

/**
 * struct spi_nor_erase_type - Structure to describe a SPI NOR erase type
 * @size:		the size of the sector/block erased by the erase type.
 *			JEDEC JESD216B imposes erase sizes to be a power of 2.
 * @size_shift:		@size is a power of 2, the shift is stored in
 *			@size_shift.
 * @size_mask:		the size mask based on @size_shift.
 * @opcode:		the SPI command op code to erase the sector/block.
 * @idx:		Erase Type index as sorted in the Basic Flash Parameter
 *			Table. It will be used to synchronize the supported
 *			Erase Types with the ones identified in the SFDP
 *			optional tables.
 */
struct spi_nor_erase_type {
	u32	size;
	u32	size_shift;
	u32	size_mask;
	u8	opcode;
	u8	idx;
};

/**
 * struct spi_nor_erase_command - Used for non-uniform erases
 * The structure is used to describe a list of erase commands to be executed
 * once we validate that the erase can be performed. The elements in the list
 * are run-length encoded.
 * @list:		for inclusion into the list of erase commands.
 * @count:		how many times the same erase command should be
 *			consecutively used.
 * @size:		the size of the sector/block erased by the command.
 * @opcode:		the SPI command op code to erase the sector/block.
 */
struct spi_nor_erase_command {
	struct list_head	list;
	u32			count;
	u32			size;
	u8			opcode;
};

/**
 * struct spi_nor_erase_region - Structure to describe a SPI NOR erase region
 * @offset:		the offset in the data array of erase region start.
 *			LSB bits are used as a bitmask encoding flags to
 *			determine if this region is overlaid, if this region is
 *			the last in the SPI NOR flash memory and to indicate
 *			all the supported erase commands inside this region.
 *			The erase types are sorted in ascending order with the
 *			smallest Erase Type size being at BIT(0).
 * @size:		the size of the region in bytes.
 */
struct spi_nor_erase_region {
	u64		offset;
	u64		size;
};

#define SNOR_ERASE_TYPE_MAX	4
#define SNOR_ERASE_TYPE_MASK	GENMASK_ULL(SNOR_ERASE_TYPE_MAX - 1, 0)

#define SNOR_LAST_REGION	BIT(4)
#define SNOR_OVERLAID_REGION	BIT(5)

#define SNOR_ERASE_FLAGS_MAX	6
#define SNOR_ERASE_FLAGS_MASK	GENMASK_ULL(SNOR_ERASE_FLAGS_MAX - 1, 0)

/**
 * struct spi_nor_erase_map - Structure to describe the SPI NOR erase map
 * @regions:		array of erase regions. The regions are consecutive in
 *			address space. Walking through the regions is done
 *			incrementally.
 * @uniform_region:	a pre-allocated erase region for SPI NOR with a uniform
 *			sector size (legacy implementation).
 * @erase_type:		an array of erase types shared by all the regions.
 *			The erase types are sorted in ascending order, with the
 *			smallest Erase Type size being the first member in the
 *			erase_type array.
 * @uniform_erase_type:	bitmask encoding erase types that can erase the
 *			entire memory. This member is completed at init by
 *			uniform and non-uniform SPI NOR flash memories if they
 *			support at least one erase type that can erase the
 *			entire memory.
 */
struct spi_nor_erase_map {
	struct spi_nor_erase_region	*regions;
	struct spi_nor_erase_region	uniform_region;
	struct spi_nor_erase_type	erase_type[SNOR_ERASE_TYPE_MAX];
	u8				uniform_erase_type;
};

/**
 * struct flash_info - Forward declaration of a structure used internally by
 *		       spi_nor_scan()
 */
struct flash_info;

/**
 * struct spi_nor - Structure for defining a the SPI NOR layer
 * @mtd:		point to a mtd_info structure
 * @lock:		the lock for the read/write/erase/lock/unlock operations
 * @dev:		point to a spi device, or a spi nor controller device.
 * @info:		spi-nor part JDEC MFR id and other info
 * @page_size:		the page size of the SPI NOR
 * @addr_width:		number of address bytes
 * @erase_opcode:	the opcode for erasing a sector
 * @read_opcode:	the read opcode
 * @read_dummy:		the dummy needed by the read operation
 * @program_opcode:	the program opcode
 * @sst_write_second:	used by the SST write operation
 * @flags:		flag options for the current SPI-NOR (SNOR_F_*)
 * @read_proto:		the SPI protocol for read operations
 * @write_proto:	the SPI protocol for write operations
 * @reg_proto		the SPI protocol for read_reg/write_reg/erase operations
 * @cmd_buf:		used by the write_reg
 * @erase_map:		the erase map of the SPI NOR
 * @prepare:		[OPTIONAL] do some preparations for the
 *			read/write/erase/lock/unlock operations
 * @unprepare:		[OPTIONAL] do some post work after the
 *			read/write/erase/lock/unlock operations
 * @read_reg:		[DRIVER-SPECIFIC] read out the register
 * @write_reg:		[DRIVER-SPECIFIC] write data to the register
 * @read:		[DRIVER-SPECIFIC] read data from the SPI NOR
 * @write:		[DRIVER-SPECIFIC] write data to the SPI NOR
 * @erase:		[DRIVER-SPECIFIC] erase a sector of the SPI NOR
 *			at the offset @offs; if not provided by the driver,
 *			spi-nor will send the erase opcode via write_reg()
 * @flash_lock:		[FLASH-SPECIFIC] lock a region of the SPI NOR
 * @flash_unlock:	[FLASH-SPECIFIC] unlock a region of the SPI NOR
 * @flash_is_locked:	[FLASH-SPECIFIC] check if a region of the SPI NOR is
 * @quad_enable:	[FLASH-SPECIFIC] enables SPI NOR quad mode
 *			completely locked
 * @priv:		the private data
 */
struct spi_nor {
	struct mtd_info		mtd;
	struct mutex		lock;
	struct device		*dev;
	const struct flash_info	*info;
	u32			page_size;
	u8			addr_width;
	u8			erase_opcode;
	u8			read_opcode;
	u8			read_dummy;
	u8			program_opcode;
	enum spi_nor_protocol	read_proto;
	enum spi_nor_protocol	write_proto;
	enum spi_nor_protocol	reg_proto;
	bool			sst_write_second;
	u32			flags;
	u8			cmd_buf[SPI_NOR_MAX_CMD_SIZE];
	struct spi_nor_erase_map	erase_map;

	int (*prepare)(struct spi_nor *nor, enum spi_nor_ops ops);
	void (*unprepare)(struct spi_nor *nor, enum spi_nor_ops ops);
	int (*read_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
	int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);

	ssize_t (*read)(struct spi_nor *nor, loff_t from,
			size_t len, u_char *read_buf);
	ssize_t (*write)(struct spi_nor *nor, loff_t to,
			size_t len, const u_char *write_buf);
	int (*erase)(struct spi_nor *nor, loff_t offs);

	int (*flash_lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
	int (*flash_unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
	int (*flash_is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
	int (*quad_enable)(struct spi_nor *nor);

	void *priv;
};

static u64 __maybe_unused
spi_nor_region_is_last(const struct spi_nor_erase_region *region)
{
	return region->offset & SNOR_LAST_REGION;
}

static u64 __maybe_unused
spi_nor_region_end(const struct spi_nor_erase_region *region)
{
	return (region->offset & ~SNOR_ERASE_FLAGS_MASK) + region->size;
}

static bool __maybe_unused spi_nor_has_uniform_erase(const struct spi_nor *nor)
{
	return !!nor->erase_map.uniform_erase_type;
}

static inline void spi_nor_set_flash_node(struct spi_nor *nor,
					  struct device_node *np)
{
	mtd_set_of_node(&nor->mtd, np);
}

static inline struct device_node *spi_nor_get_flash_node(struct spi_nor *nor)
{
	return mtd_get_of_node(&nor->mtd);
}

/**
 * struct spi_nor_hwcaps - Structure for describing the hardware capabilies
 * supported by the SPI controller (bus master).
 * @mask:		the bitmask listing all the supported hw capabilies
 */
struct spi_nor_hwcaps {
	u32	mask;
};

/*
 *(Fast) Read capabilities.
 * MUST be ordered by priority: the higher bit position, the higher priority.
 * As a matter of performances, it is relevant to use Octo SPI protocols first,
 * then Quad SPI protocols before Dual SPI protocols, Fast Read and lastly
 * (Slow) Read.
 */
#define SNOR_HWCAPS_READ_MASK		GENMASK(14, 0)
#define SNOR_HWCAPS_READ		BIT(0)
#define SNOR_HWCAPS_READ_FAST		BIT(1)
#define SNOR_HWCAPS_READ_1_1_1_DTR	BIT(2)

#define SNOR_HWCAPS_READ_DUAL		GENMASK(6, 3)
#define SNOR_HWCAPS_READ_1_1_2		BIT(3)
#define SNOR_HWCAPS_READ_1_2_2		BIT(4)
#define SNOR_HWCAPS_READ_2_2_2		BIT(5)
#define SNOR_HWCAPS_READ_1_2_2_DTR	BIT(6)

#define SNOR_HWCAPS_READ_QUAD		GENMASK(10, 7)
#define SNOR_HWCAPS_READ_1_1_4		BIT(7)
#define SNOR_HWCAPS_READ_1_4_4		BIT(8)
#define SNOR_HWCAPS_READ_4_4_4		BIT(9)
#define SNOR_HWCAPS_READ_1_4_4_DTR	BIT(10)

#define SNOR_HWCPAS_READ_OCTO		GENMASK(14, 11)
#define SNOR_HWCAPS_READ_1_1_8		BIT(11)
#define SNOR_HWCAPS_READ_1_8_8		BIT(12)
#define SNOR_HWCAPS_READ_8_8_8		BIT(13)
#define SNOR_HWCAPS_READ_1_8_8_DTR	BIT(14)

/*
 * Page Program capabilities.
 * MUST be ordered by priority: the higher bit position, the higher priority.
 * Like (Fast) Read capabilities, Octo/Quad SPI protocols are preferred to the
 * legacy SPI 1-1-1 protocol.
 * Note that Dual Page Programs are not supported because there is no existing
 * JEDEC/SFDP standard to define them. Also at this moment no SPI flash memory
 * implements such commands.
 */
#define SNOR_HWCAPS_PP_MASK	GENMASK(22, 16)
#define SNOR_HWCAPS_PP		BIT(16)

#define SNOR_HWCAPS_PP_QUAD	GENMASK(19, 17)
#define SNOR_HWCAPS_PP_1_1_4	BIT(17)
#define SNOR_HWCAPS_PP_1_4_4	BIT(18)
#define SNOR_HWCAPS_PP_4_4_4	BIT(19)

#define SNOR_HWCAPS_PP_OCTO	GENMASK(22, 20)
#define SNOR_HWCAPS_PP_1_1_8	BIT(20)
#define SNOR_HWCAPS_PP_1_8_8	BIT(21)
#define SNOR_HWCAPS_PP_8_8_8	BIT(22)

/**
 * spi_nor_scan() - scan the SPI NOR
 * @nor:	the spi_nor structure
 * @name:	the chip type name
 * @hwcaps:	the hardware capabilities supported by the controller driver
 *
 * The drivers can use this fuction to scan the SPI NOR.
 * In the scanning, it will try to get all the necessary information to
 * fill the mtd_info{} and the spi_nor{}.
 *
 * The chip type name can be provided through the @name parameter.
 *
 * Return: 0 for success, others for failure.
 */
int spi_nor_scan(struct spi_nor *nor, const char *name,
		 const struct spi_nor_hwcaps *hwcaps);

/**
 * spi_nor_restore_addr_mode() - restore the status of SPI NOR
 * @nor:	the spi_nor structure
 */
void spi_nor_restore(struct spi_nor *nor);

#endif