/*
 * 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

/*
 * 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_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 SPI) */
#define SPINOR_OP_READ_1_1_4	0x6b	/* Read data bytes (Quad SPI) */
#define SPINOR_OP_PP		0x02	/* Page program (up to 256 bytes) */
#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_RDCR		0x35	/* Read configuration register */
#define SPINOR_OP_RDFSR		0x70	/* Read flag status register */

/* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
#define SPINOR_OP_READ4		0x13	/* Read data bytes (low frequency) */
#define SPINOR_OP_READ4_FAST	0x0c	/* Read data bytes (high frequency) */
#define SPINOR_OP_READ4_1_1_2	0x3c	/* Read data bytes (Dual SPI) */
#define SPINOR_OP_READ4_1_1_4	0x6c	/* Read data bytes (Quad SPI) */
#define SPINOR_OP_PP_4B		0x12	/* Page program (up to 256 bytes) */
#define SPINOR_OP_SE_4B		0xdc	/* Sector erase (usually 64KiB) */

/* 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 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 */

/* Status Register bits. */
#define SR_WIP			1	/* Write in progress */
#define SR_WEL			2	/* Write enable latch */
/* meaning of other SR_* bits may differ between vendors */
#define SR_BP0			4	/* Block protect 0 */
#define SR_BP1			8	/* Block protect 1 */
#define SR_BP2			0x10	/* Block protect 2 */
#define SR_SRWD			0x80	/* SR write protect */

#define SR_QUAD_EN_MX		0x40	/* Macronix Quad I/O */

/* Flag Status Register bits */
#define FSR_READY		0x80

/* Configuration Register bits. */
#define CR_QUAD_EN_SPAN		0x2	/* Spansion Quad I/O */

enum read_mode {
	SPI_NOR_NORMAL = 0,
	SPI_NOR_FAST,
	SPI_NOR_DUAL,
	SPI_NOR_QUAD,
};

/**
 * struct spi_nor_xfer_cfg - Structure for defining a Serial Flash transfer
 * @wren:		command for "Write Enable", or 0x00 for not required
 * @cmd:		command for operation
 * @cmd_pins:		number of pins to send @cmd (1, 2, 4)
 * @addr:		address for operation
 * @addr_pins:		number of pins to send @addr (1, 2, 4)
 * @addr_width:		number of address bytes
 *			(3,4, or 0 for address not required)
 * @mode:		mode data
 * @mode_pins:		number of pins to send @mode (1, 2, 4)
 * @mode_cycles:	number of mode cycles (0 for mode not required)
 * @dummy_cycles:	number of dummy cycles (0 for dummy not required)
 */
struct spi_nor_xfer_cfg {
	u8		wren;
	u8		cmd;
	u8		cmd_pins;
	u32		addr;
	u8		addr_pins;
	u8		addr_width;
	u8		mode;
	u8		mode_pins;
	u8		mode_cycles;
	u8		dummy_cycles;
};

#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),
};

/**
 * 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.
 * @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
 * @flash_read:		the mode of the read
 * @sst_write_second:	used by the SST write operation
 * @flags:		flag options for the current SPI-NOR (SNOR_F_*)
 * @cfg:		used by the read_xfer/write_xfer
 * @cmd_buf:		used by the write_reg
 * @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_xfer:		[OPTIONAL] the read fundamental primitive
 * @write_xfer:		[OPTIONAL] the writefundamental primitive
 * @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
 * @priv:		the private data
 */
struct spi_nor {
	struct mtd_info		*mtd;
	struct mutex		lock;
	struct device		*dev;
	u32			page_size;
	u8			addr_width;
	u8			erase_opcode;
	u8			read_opcode;
	u8			read_dummy;
	u8			program_opcode;
	enum read_mode		flash_read;
	bool			sst_write_second;
	u32			flags;
	struct spi_nor_xfer_cfg	cfg;
	u8			cmd_buf[SPI_NOR_MAX_CMD_SIZE];

	int (*prepare)(struct spi_nor *nor, enum spi_nor_ops ops);
	void (*unprepare)(struct spi_nor *nor, enum spi_nor_ops ops);
	int (*read_xfer)(struct spi_nor *nor, struct spi_nor_xfer_cfg *cfg,
			 u8 *buf, size_t len);
	int (*write_xfer)(struct spi_nor *nor, struct spi_nor_xfer_cfg *cfg,
			  u8 *buf, size_t len);
	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,
			int write_enable);

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

	void *priv;
};

/**
 * spi_nor_scan() - scan the SPI NOR
 * @nor:	the spi_nor structure
 * @name:	the chip type name
 * @mode:	the read mode supported by the 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, enum read_mode mode);

#endif