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OpenCloudOS-Kernel/include/linux/mtd/rawnand.h

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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
* Steven J. Hill <sjhill@realitydiluted.com>
* Thomas Gleixner <tglx@linutronix.de>
*
* Info:
* Contains standard defines and IDs for NAND flash devices
*
* Changelog:
* See git changelog.
*/
#ifndef __LINUX_MTD_RAWNAND_H
#define __LINUX_MTD_RAWNAND_H
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/flashchip.h>
#include <linux/mtd/bbm.h>
#include <linux/mtd/jedec.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/onfi.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/types.h>
struct nand_chip;
/* 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
/* 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
#define NAND_DATA_IFACE_CHECK_ONLY -1
/*
* 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)
/*
* Option constants for bizarre disfunctionality and real
* features.
*/
/* Buswidth is 16 bit */
#define NAND_BUSWIDTH_16 BIT(1)
/*
* When using software implementation of Hamming, we can specify which byte
* ordering should be used.
*/
#define NAND_ECC_SOFT_HAMMING_SM_ORDER BIT(2)
/* Chip has cache program function */
#define NAND_CACHEPRG BIT(3)
/* Options valid for Samsung large page devices */
#define NAND_SAMSUNG_LP_OPTIONS NAND_CACHEPRG
/*
* 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 BIT(8)
/* Chip does not allow subpage writes */
#define NAND_NO_SUBPAGE_WRITE BIT(9)
/* Device is one of 'new' xD cards that expose fake nand command set */
#define NAND_BROKEN_XD BIT(10)
/* Device behaves just like nand, but is readonly */
#define NAND_ROM BIT(11)
/* Device supports subpage reads */
#define NAND_SUBPAGE_READ BIT(12)
/* Macros to identify the above */
#define NAND_HAS_SUBPAGE_READ(chip) ((chip->options & NAND_SUBPAGE_READ))
/*
* Some MLC NANDs need data scrambling to limit bitflips caused by repeated
* patterns.
*/
#define NAND_NEED_SCRAMBLING BIT(13)
/* Device needs 3rd row address cycle */
#define NAND_ROW_ADDR_3 BIT(14)
/* Non chip related options */
/* This option skips the bbt scan during initialization. */
#define NAND_SKIP_BBTSCAN BIT(16)
/* Chip may not exist, so silence any errors in scan */
#define NAND_SCAN_SILENT_NODEV BIT(18)
/*
* Autodetect nand buswidth with readid/onfi.
* This suppose the driver will configure the hardware in 8 bits mode
* when calling nand_scan_ident, and update its configuration
* before calling nand_scan_tail.
*/
#define NAND_BUSWIDTH_AUTO BIT(19)
/*
* This option could be defined by controller drivers to protect against
* kmap'ed, vmalloc'ed highmem buffers being passed from upper layers
*/
#define NAND_USES_DMA BIT(20)
/*
* In case your controller is implementing ->legacy.cmd_ctrl() and is relying
* on the default ->cmdfunc() implementation, you may want to let the core
* handle the tCCS delay which is required when a column change (RNDIN or
* RNDOUT) is requested.
* If your controller already takes care of this delay, you don't need to set
* this flag.
*/
#define NAND_WAIT_TCCS BIT(21)
/*
* Whether the NAND chip is a boot medium. Drivers might use this information
* to select ECC algorithms supported by the boot ROM or similar restrictions.
*/
#define NAND_IS_BOOT_MEDIUM BIT(22)
/*
* Do not try to tweak the timings at runtime. This is needed when the
* controller initializes the timings on itself or when it relies on
* configuration done by the bootloader.
*/
#define NAND_KEEP_TIMINGS BIT(23)
/*
* There are different places where the manufacturer stores the factory bad
* block markers.
*
* Position within the block: Each of these pages needs to be checked for a
* bad block marking pattern.
*/
#define NAND_BBM_FIRSTPAGE BIT(24)
#define NAND_BBM_SECONDPAGE BIT(25)
#define NAND_BBM_LASTPAGE BIT(26)
/*
* Some controllers with pipelined ECC engines override the BBM marker with
* data or ECC bytes, thus making bad block detection through bad block marker
* impossible. Let's flag those chips so the core knows it shouldn't check the
* BBM and consider all blocks good.
*/
#define NAND_NO_BBM_QUIRK BIT(27)
/* Cell info constants */
#define NAND_CI_CHIPNR_MSK 0x03
#define NAND_CI_CELLTYPE_MSK 0x0C
#define NAND_CI_CELLTYPE_SHIFT 2
/* Position within the OOB data of the page */
#define NAND_BBM_POS_SMALL 5
#define NAND_BBM_POS_LARGE 0
/**
* struct nand_parameters - NAND generic parameters from the parameter page
* @model: Model name
* @supports_set_get_features: The NAND chip supports setting/getting features
* @set_feature_list: Bitmap of features that can be set
* @get_feature_list: Bitmap of features that can be get
* @onfi: ONFI specific parameters
*/
struct nand_parameters {
/* Generic parameters */
const char *model;
bool supports_set_get_features;
DECLARE_BITMAP(set_feature_list, ONFI_FEATURE_NUMBER);
DECLARE_BITMAP(get_feature_list, ONFI_FEATURE_NUMBER);
/* ONFI parameters */
struct onfi_params *onfi;
};
/* The maximum expected count of bytes in the NAND ID sequence */
#define NAND_MAX_ID_LEN 8
/**
* struct nand_id - NAND id structure
* @data: buffer containing the id bytes.
* @len: ID length.
*/
struct nand_id {
u8 data[NAND_MAX_ID_LEN];
int len;
};
/**
* struct nand_ecc_step_info - ECC step information of ECC engine
* @stepsize: data bytes per ECC step
* @strengths: array of supported strengths
* @nstrengths: number of supported strengths
*/
struct nand_ecc_step_info {
int stepsize;
const int *strengths;
int nstrengths;
};
/**
* struct nand_ecc_caps - capability of ECC engine
* @stepinfos: array of ECC step information
* @nstepinfos: number of ECC step information
* @calc_ecc_bytes: driver's hook to calculate ECC bytes per step
*/
struct nand_ecc_caps {
const struct nand_ecc_step_info *stepinfos;
int nstepinfos;
int (*calc_ecc_bytes)(int step_size, int strength);
};
/* a shorthand to generate struct nand_ecc_caps with only one ECC stepsize */
#define NAND_ECC_CAPS_SINGLE(__name, __calc, __step, ...) \
static const int __name##_strengths[] = { __VA_ARGS__ }; \
static const struct nand_ecc_step_info __name##_stepinfo = { \
.stepsize = __step, \
.strengths = __name##_strengths, \
.nstrengths = ARRAY_SIZE(__name##_strengths), \
}; \
static const struct nand_ecc_caps __name = { \
.stepinfos = &__name##_stepinfo, \
.nstepinfos = 1, \
.calc_ecc_bytes = __calc, \
}
/**
* struct nand_ecc_ctrl - Control structure for ECC
* @engine_type: ECC engine type
* @placement: OOB bytes placement
* @algo: ECC algorithm
* @steps: number of ECC steps per page
* @size: data bytes per ECC step
* @bytes: ECC bytes per step
* @strength: max number of correctible bits per ECC step
* @total: total number of ECC bytes per page
* @prepad: padding information for syndrome based ECC generators
* @postpad: padding information for syndrome based ECC generators
* @options: ECC specific options (see NAND_ECC_XXX flags defined above)
* @calc_buf: buffer for calculated ECC, size is oobsize.
* @code_buf: buffer for ECC read from flash, size is oobsize.
* @hwctl: function to control hardware ECC generator. Must only
* be provided if an hardware ECC is available
* @calculate: function for ECC calculation or readback from ECC hardware
* @correct: function for ECC correction, matching to ECC generator (sw/hw).
* Should return a positive number representing the number of
* corrected bitflips, -EBADMSG if the number of bitflips exceed
* ECC strength, or any other error code if the error is not
* directly related to correction.
* If -EBADMSG is returned the input buffers should be left
* untouched.
* @read_page_raw: function to read a raw page without ECC. This function
* should hide the specific layout used by the ECC
* controller and always return contiguous in-band and
* out-of-band data even if they're not stored
* contiguously on the NAND chip (e.g.
* NAND_ECC_PLACEMENT_INTERLEAVED interleaves in-band and
* out-of-band data).
* @write_page_raw: function to write a raw page without ECC. This function
* should hide the specific layout used by the ECC
* controller and consider the passed data as contiguous
* in-band and out-of-band data. ECC controller is
* responsible for doing the appropriate transformations
* to adapt to its specific layout (e.g.
* NAND_ECC_PLACEMENT_INTERLEAVED interleaves in-band and
* out-of-band data).
* @read_page: function to read a page according to the ECC generator
* requirements; returns maximum number of bitflips corrected in
* any single ECC step, -EIO hw error
* @read_subpage: function to read parts of the page covered by ECC;
* returns same as read_page()
* @write_subpage: function to write parts of the page covered by ECC.
* @write_page: function to write a page according to the ECC generator
* requirements.
* @write_oob_raw: function to write chip OOB data without ECC
* @read_oob_raw: function to read chip OOB data without ECC
* @read_oob: function to read chip OOB data
* @write_oob: function to write chip OOB data
*/
struct nand_ecc_ctrl {
enum nand_ecc_engine_type engine_type;
enum nand_ecc_placement placement;
enum nand_ecc_algo algo;
int steps;
int size;
int bytes;
int total;
int strength;
int prepad;
int postpad;
unsigned int options;
u8 *calc_buf;
u8 *code_buf;
void (*hwctl)(struct nand_chip *chip, int mode);
int (*calculate)(struct nand_chip *chip, const uint8_t *dat,
uint8_t *ecc_code);
int (*correct)(struct nand_chip *chip, uint8_t *dat, uint8_t *read_ecc,
uint8_t *calc_ecc);
int (*read_page_raw)(struct nand_chip *chip, uint8_t *buf,
int oob_required, int page);
int (*write_page_raw)(struct nand_chip *chip, const uint8_t *buf,
int oob_required, int page);
int (*read_page)(struct nand_chip *chip, uint8_t *buf,
int oob_required, int page);
int (*read_subpage)(struct nand_chip *chip, uint32_t offs,
uint32_t len, uint8_t *buf, int page);
int (*write_subpage)(struct nand_chip *chip, uint32_t offset,
uint32_t data_len, const uint8_t *data_buf,
int oob_required, int page);
int (*write_page)(struct nand_chip *chip, const uint8_t *buf,
int oob_required, int page);
int (*write_oob_raw)(struct nand_chip *chip, int page);
int (*read_oob_raw)(struct nand_chip *chip, int page);
int (*read_oob)(struct nand_chip *chip, int page);
int (*write_oob)(struct nand_chip *chip, int page);
};
/**
* struct nand_sdr_timings - SDR NAND chip timings
*
* This struct defines the timing requirements of a SDR NAND chip.
* These information can be found in every NAND datasheets and the timings
* meaning are described in the ONFI specifications:
* www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf (chapter 4.15 Timing
* Parameters)
*
* All these timings are expressed in picoseconds.
*
* @tBERS_max: Block erase time
* @tCCS_min: Change column setup time
* @tPROG_max: Page program time
* @tR_max: Page read time
* @tALH_min: ALE hold time
* @tADL_min: ALE to data loading time
* @tALS_min: ALE setup time
* @tAR_min: ALE to RE# delay
* @tCEA_max: CE# access time
* @tCEH_min: CE# high hold time
* @tCH_min: CE# hold time
* @tCHZ_max: CE# high to output hi-Z
* @tCLH_min: CLE hold time
* @tCLR_min: CLE to RE# delay
* @tCLS_min: CLE setup time
* @tCOH_min: CE# high to output hold
* @tCS_min: CE# setup time
* @tDH_min: Data hold time
* @tDS_min: Data setup time
* @tFEAT_max: Busy time for Set Features and Get Features
* @tIR_min: Output hi-Z to RE# low
* @tITC_max: Interface and Timing Mode Change time
* @tRC_min: RE# cycle time
* @tREA_max: RE# access time
* @tREH_min: RE# high hold time
* @tRHOH_min: RE# high to output hold
* @tRHW_min: RE# high to WE# low
* @tRHZ_max: RE# high to output hi-Z
* @tRLOH_min: RE# low to output hold
* @tRP_min: RE# pulse width
* @tRR_min: Ready to RE# low (data only)
* @tRST_max: Device reset time, measured from the falling edge of R/B# to the
* rising edge of R/B#.
* @tWB_max: WE# high to SR[6] low
* @tWC_min: WE# cycle time
* @tWH_min: WE# high hold time
* @tWHR_min: WE# high to RE# low
* @tWP_min: WE# pulse width
* @tWW_min: WP# transition to WE# low
*/
struct nand_sdr_timings {
u64 tBERS_max;
u32 tCCS_min;
u64 tPROG_max;
u64 tR_max;
u32 tALH_min;
u32 tADL_min;
u32 tALS_min;
u32 tAR_min;
u32 tCEA_max;
u32 tCEH_min;
u32 tCH_min;
u32 tCHZ_max;
u32 tCLH_min;
u32 tCLR_min;
u32 tCLS_min;
u32 tCOH_min;
u32 tCS_min;
u32 tDH_min;
u32 tDS_min;
u32 tFEAT_max;
u32 tIR_min;
u32 tITC_max;
u32 tRC_min;
u32 tREA_max;
u32 tREH_min;
u32 tRHOH_min;
u32 tRHW_min;
u32 tRHZ_max;
u32 tRLOH_min;
u32 tRP_min;
u32 tRR_min;
u64 tRST_max;
u32 tWB_max;
u32 tWC_min;
u32 tWH_min;
u32 tWHR_min;
u32 tWP_min;
u32 tWW_min;
};
/**
* enum nand_interface_type - NAND interface type
* @NAND_SDR_IFACE: Single Data Rate interface
*/
enum nand_interface_type {
NAND_SDR_IFACE,
};
/**
* struct nand_interface_config - NAND interface timing
* @type: type of the timing
* @timings: The timing information
* @timings.mode: Timing mode as defined in the specification
* @timings.sdr: Use it when @type is %NAND_SDR_IFACE.
*/
struct nand_interface_config {
enum nand_interface_type type;
struct nand_timings {
unsigned int mode;
union {
struct nand_sdr_timings sdr;
};
} timings;
};
/**
* nand_get_sdr_timings - get SDR timing from data interface
* @conf: The data interface
*/
static inline const struct nand_sdr_timings *
nand_get_sdr_timings(const struct nand_interface_config *conf)
{
if (conf->type != NAND_SDR_IFACE)
return ERR_PTR(-EINVAL);
return &conf->timings.sdr;
}
/**
* struct nand_op_cmd_instr - Definition of a command instruction
* @opcode: the command to issue in one cycle
*/
struct nand_op_cmd_instr {
u8 opcode;
};
/**
* struct nand_op_addr_instr - Definition of an address instruction
* @naddrs: length of the @addrs array
* @addrs: array containing the address cycles to issue
*/
struct nand_op_addr_instr {
unsigned int naddrs;
const u8 *addrs;
};
/**
* struct nand_op_data_instr - Definition of a data instruction
* @len: number of data bytes to move
* @buf: buffer to fill
* @buf.in: buffer to fill when reading from the NAND chip
* @buf.out: buffer to read from when writing to the NAND chip
* @force_8bit: force 8-bit access
*
* Please note that "in" and "out" are inverted from the ONFI specification
* and are from the controller perspective, so a "in" is a read from the NAND
* chip while a "out" is a write to the NAND chip.
*/
struct nand_op_data_instr {
unsigned int len;
union {
void *in;
const void *out;
} buf;
bool force_8bit;
};
/**
* struct nand_op_waitrdy_instr - Definition of a wait ready instruction
* @timeout_ms: maximum delay while waiting for the ready/busy pin in ms
*/
struct nand_op_waitrdy_instr {
unsigned int timeout_ms;
};
/**
* enum nand_op_instr_type - Definition of all instruction types
* @NAND_OP_CMD_INSTR: command instruction
* @NAND_OP_ADDR_INSTR: address instruction
* @NAND_OP_DATA_IN_INSTR: data in instruction
* @NAND_OP_DATA_OUT_INSTR: data out instruction
* @NAND_OP_WAITRDY_INSTR: wait ready instruction
*/
enum nand_op_instr_type {
NAND_OP_CMD_INSTR,
NAND_OP_ADDR_INSTR,
NAND_OP_DATA_IN_INSTR,
NAND_OP_DATA_OUT_INSTR,
NAND_OP_WAITRDY_INSTR,
};
/**
* struct nand_op_instr - Instruction object
* @type: the instruction type
* @ctx: extra data associated to the instruction. You'll have to use the
* appropriate element depending on @type
* @ctx.cmd: use it if @type is %NAND_OP_CMD_INSTR
* @ctx.addr: use it if @type is %NAND_OP_ADDR_INSTR
* @ctx.data: use it if @type is %NAND_OP_DATA_IN_INSTR
* or %NAND_OP_DATA_OUT_INSTR
* @ctx.waitrdy: use it if @type is %NAND_OP_WAITRDY_INSTR
* @delay_ns: delay the controller should apply after the instruction has been
* issued on the bus. Most modern controllers have internal timings
* control logic, and in this case, the controller driver can ignore
* this field.
*/
struct nand_op_instr {
enum nand_op_instr_type type;
union {
struct nand_op_cmd_instr cmd;
struct nand_op_addr_instr addr;
struct nand_op_data_instr data;
struct nand_op_waitrdy_instr waitrdy;
} ctx;
unsigned int delay_ns;
};
/*
* Special handling must be done for the WAITRDY timeout parameter as it usually
* is either tPROG (after a prog), tR (before a read), tRST (during a reset) or
* tBERS (during an erase) which all of them are u64 values that cannot be
* divided by usual kernel macros and must be handled with the special
* DIV_ROUND_UP_ULL() macro.
*
* Cast to type of dividend is needed here to guarantee that the result won't
* be an unsigned long long when the dividend is an unsigned long (or smaller),
* which is what the compiler does when it sees ternary operator with 2
* different return types (picks the largest type to make sure there's no
* loss).
*/
#define __DIVIDE(dividend, divisor) ({ \
(__typeof__(dividend))(sizeof(dividend) <= sizeof(unsigned long) ? \
DIV_ROUND_UP(dividend, divisor) : \
DIV_ROUND_UP_ULL(dividend, divisor)); \
})
#define PSEC_TO_NSEC(x) __DIVIDE(x, 1000)
#define PSEC_TO_MSEC(x) __DIVIDE(x, 1000000000)
#define NAND_OP_CMD(id, ns) \
{ \
.type = NAND_OP_CMD_INSTR, \
.ctx.cmd.opcode = id, \
.delay_ns = ns, \
}
#define NAND_OP_ADDR(ncycles, cycles, ns) \
{ \
.type = NAND_OP_ADDR_INSTR, \
.ctx.addr = { \
.naddrs = ncycles, \
.addrs = cycles, \
}, \
.delay_ns = ns, \
}
#define NAND_OP_DATA_IN(l, b, ns) \
{ \
.type = NAND_OP_DATA_IN_INSTR, \
.ctx.data = { \
.len = l, \
.buf.in = b, \
.force_8bit = false, \
}, \
.delay_ns = ns, \
}
#define NAND_OP_DATA_OUT(l, b, ns) \
{ \
.type = NAND_OP_DATA_OUT_INSTR, \
.ctx.data = { \
.len = l, \
.buf.out = b, \
.force_8bit = false, \
}, \
.delay_ns = ns, \
}
#define NAND_OP_8BIT_DATA_IN(l, b, ns) \
{ \
.type = NAND_OP_DATA_IN_INSTR, \
.ctx.data = { \
.len = l, \
.buf.in = b, \
.force_8bit = true, \
}, \
.delay_ns = ns, \
}
#define NAND_OP_8BIT_DATA_OUT(l, b, ns) \
{ \
.type = NAND_OP_DATA_OUT_INSTR, \
.ctx.data = { \
.len = l, \
.buf.out = b, \
.force_8bit = true, \
}, \
.delay_ns = ns, \
}
#define NAND_OP_WAIT_RDY(tout_ms, ns) \
{ \
.type = NAND_OP_WAITRDY_INSTR, \
.ctx.waitrdy.timeout_ms = tout_ms, \
.delay_ns = ns, \
}
/**
* struct nand_subop - a sub operation
* @cs: the CS line to select for this NAND sub-operation
* @instrs: array of instructions
* @ninstrs: length of the @instrs array
* @first_instr_start_off: offset to start from for the first instruction
* of the sub-operation
* @last_instr_end_off: offset to end at (excluded) for the last instruction
* of the sub-operation
*
* Both @first_instr_start_off and @last_instr_end_off only apply to data or
* address instructions.
*
* When an operation cannot be handled as is by the NAND controller, it will
* be split by the parser into sub-operations which will be passed to the
* controller driver.
*/
struct nand_subop {
unsigned int cs;
const struct nand_op_instr *instrs;
unsigned int ninstrs;
unsigned int first_instr_start_off;
unsigned int last_instr_end_off;
};
unsigned int nand_subop_get_addr_start_off(const struct nand_subop *subop,
unsigned int op_id);
unsigned int nand_subop_get_num_addr_cyc(const struct nand_subop *subop,
unsigned int op_id);
unsigned int nand_subop_get_data_start_off(const struct nand_subop *subop,
unsigned int op_id);
unsigned int nand_subop_get_data_len(const struct nand_subop *subop,
unsigned int op_id);
/**
* struct nand_op_parser_addr_constraints - Constraints for address instructions
* @maxcycles: maximum number of address cycles the controller can issue in a
* single step
*/
struct nand_op_parser_addr_constraints {
unsigned int maxcycles;
};
/**
* struct nand_op_parser_data_constraints - Constraints for data instructions
* @maxlen: maximum data length that the controller can handle in a single step
*/
struct nand_op_parser_data_constraints {
unsigned int maxlen;
};
/**
* struct nand_op_parser_pattern_elem - One element of a pattern
* @type: the instructuction type
* @optional: whether this element of the pattern is optional or mandatory
* @ctx: address or data constraint
* @ctx.addr: address constraint (number of cycles)
* @ctx.data: data constraint (data length)
*/
struct nand_op_parser_pattern_elem {
enum nand_op_instr_type type;
bool optional;
union {
struct nand_op_parser_addr_constraints addr;
struct nand_op_parser_data_constraints data;
} ctx;
};
#define NAND_OP_PARSER_PAT_CMD_ELEM(_opt) \
{ \
.type = NAND_OP_CMD_INSTR, \
.optional = _opt, \
}
#define NAND_OP_PARSER_PAT_ADDR_ELEM(_opt, _maxcycles) \
{ \
.type = NAND_OP_ADDR_INSTR, \
.optional = _opt, \
.ctx.addr.maxcycles = _maxcycles, \
}
#define NAND_OP_PARSER_PAT_DATA_IN_ELEM(_opt, _maxlen) \
{ \
.type = NAND_OP_DATA_IN_INSTR, \
.optional = _opt, \
.ctx.data.maxlen = _maxlen, \
}
#define NAND_OP_PARSER_PAT_DATA_OUT_ELEM(_opt, _maxlen) \
{ \
.type = NAND_OP_DATA_OUT_INSTR, \
.optional = _opt, \
.ctx.data.maxlen = _maxlen, \
}
#define NAND_OP_PARSER_PAT_WAITRDY_ELEM(_opt) \
{ \
.type = NAND_OP_WAITRDY_INSTR, \
.optional = _opt, \
}
/**
* struct nand_op_parser_pattern - NAND sub-operation pattern descriptor
* @elems: array of pattern elements
* @nelems: number of pattern elements in @elems array
* @exec: the function that will issue a sub-operation
*
* A pattern is a list of elements, each element reprensenting one instruction
* with its constraints. The pattern itself is used by the core to match NAND
* chip operation with NAND controller operations.
* Once a match between a NAND controller operation pattern and a NAND chip
* operation (or a sub-set of a NAND operation) is found, the pattern ->exec()
* hook is called so that the controller driver can issue the operation on the
* bus.
*
* Controller drivers should declare as many patterns as they support and pass
* this list of patterns (created with the help of the following macro) to
* the nand_op_parser_exec_op() helper.
*/
struct nand_op_parser_pattern {
const struct nand_op_parser_pattern_elem *elems;
unsigned int nelems;
int (*exec)(struct nand_chip *chip, const struct nand_subop *subop);
};
#define NAND_OP_PARSER_PATTERN(_exec, ...) \
{ \
.exec = _exec, \
.elems = (const struct nand_op_parser_pattern_elem[]) { __VA_ARGS__ }, \
.nelems = sizeof((struct nand_op_parser_pattern_elem[]) { __VA_ARGS__ }) / \
sizeof(struct nand_op_parser_pattern_elem), \
}
/**
* struct nand_op_parser - NAND controller operation parser descriptor
* @patterns: array of supported patterns
* @npatterns: length of the @patterns array
*
* The parser descriptor is just an array of supported patterns which will be
* iterated by nand_op_parser_exec_op() everytime it tries to execute an
* NAND operation (or tries to determine if a specific operation is supported).
*
* It is worth mentioning that patterns will be tested in their declaration
* order, and the first match will be taken, so it's important to order patterns
* appropriately so that simple/inefficient patterns are placed at the end of
* the list. Usually, this is where you put single instruction patterns.
*/
struct nand_op_parser {
const struct nand_op_parser_pattern *patterns;
unsigned int npatterns;
};
#define NAND_OP_PARSER(...) \
{ \
.patterns = (const struct nand_op_parser_pattern[]) { __VA_ARGS__ }, \
.npatterns = sizeof((struct nand_op_parser_pattern[]) { __VA_ARGS__ }) / \
sizeof(struct nand_op_parser_pattern), \
}
/**
* struct nand_operation - NAND operation descriptor
* @cs: the CS line to select for this NAND operation
* @instrs: array of instructions to execute
* @ninstrs: length of the @instrs array
*
* The actual operation structure that will be passed to chip->exec_op().
*/
struct nand_operation {
unsigned int cs;
const struct nand_op_instr *instrs;
unsigned int ninstrs;
};
#define NAND_OPERATION(_cs, _instrs) \
{ \
.cs = _cs, \
.instrs = _instrs, \
.ninstrs = ARRAY_SIZE(_instrs), \
}
int nand_op_parser_exec_op(struct nand_chip *chip,
const struct nand_op_parser *parser,
const struct nand_operation *op, bool check_only);
static inline void nand_op_trace(const char *prefix,
const struct nand_op_instr *instr)
{
#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) || defined(DEBUG)
switch (instr->type) {
case NAND_OP_CMD_INSTR:
pr_debug("%sCMD [0x%02x]\n", prefix,
instr->ctx.cmd.opcode);
break;
case NAND_OP_ADDR_INSTR:
pr_debug("%sADDR [%d cyc: %*ph]\n", prefix,
instr->ctx.addr.naddrs,
instr->ctx.addr.naddrs < 64 ?
instr->ctx.addr.naddrs : 64,
instr->ctx.addr.addrs);
break;
case NAND_OP_DATA_IN_INSTR:
pr_debug("%sDATA_IN [%d B%s]\n", prefix,
instr->ctx.data.len,
instr->ctx.data.force_8bit ?
", force 8-bit" : "");
break;
case NAND_OP_DATA_OUT_INSTR:
pr_debug("%sDATA_OUT [%d B%s]\n", prefix,
instr->ctx.data.len,
instr->ctx.data.force_8bit ?
", force 8-bit" : "");
break;
case NAND_OP_WAITRDY_INSTR:
pr_debug("%sWAITRDY [max %d ms]\n", prefix,
instr->ctx.waitrdy.timeout_ms);
break;
}
#endif
}
/**
* struct nand_controller_ops - Controller operations
*
* @attach_chip: this method is called after the NAND detection phase after
* flash ID and MTD fields such as erase size, page size and OOB
* size have been set up. ECC requirements are available if
* provided by the NAND chip or device tree. Typically used to
* choose the appropriate ECC configuration and allocate
* associated resources.
* This hook is optional.
* @detach_chip: free all resources allocated/claimed in
* nand_controller_ops->attach_chip().
* This hook is optional.
* @exec_op: controller specific method to execute NAND operations.
* This method replaces chip->legacy.cmdfunc(),
* chip->legacy.{read,write}_{buf,byte,word}(),
* chip->legacy.dev_ready() and chip->legacy.waifunc().
* @setup_interface: setup the data interface and timing. If chipnr is set to
* %NAND_DATA_IFACE_CHECK_ONLY this means the configuration
* should not be applied but only checked.
* This hook is optional.
*/
struct nand_controller_ops {
int (*attach_chip)(struct nand_chip *chip);
void (*detach_chip)(struct nand_chip *chip);
int (*exec_op)(struct nand_chip *chip,
const struct nand_operation *op,
bool check_only);
int (*setup_interface)(struct nand_chip *chip, int chipnr,
const struct nand_interface_config *conf);
};
/**
* struct nand_controller - Structure used to describe a NAND controller
*
* @lock: lock used to serialize accesses to the NAND controller
* @ops: NAND controller operations.
*/
struct nand_controller {
struct mutex lock;
const struct nand_controller_ops *ops;
};
static inline void nand_controller_init(struct nand_controller *nfc)
{
mutex_init(&nfc->lock);
}
/**
* struct nand_legacy - NAND chip legacy fields/hooks
* @IO_ADDR_R: address to read the 8 I/O lines of the flash device
* @IO_ADDR_W: address to write the 8 I/O lines of the flash device
* @select_chip: select/deselect a specific target/die
* @read_byte: read one byte from the chip
* @write_byte: write a single byte to the chip on the low 8 I/O lines
* @write_buf: write data from the buffer to the chip
* @read_buf: read data from the chip into the buffer
* @cmd_ctrl: hardware specific function for controlling ALE/CLE/nCE. Also used
* to write command and address
* @cmdfunc: hardware specific function for writing commands to the chip.
* @dev_ready: hardware specific function for accessing device ready/busy line.
* If set to NULL no access to ready/busy is available and the
* ready/busy information is read from the chip status register.
* @waitfunc: hardware specific function for wait on ready.
* @block_bad: check if a block is bad, using OOB markers
* @block_markbad: mark a block bad
* @set_features: set the NAND chip features
* @get_features: get the NAND chip features
* @chip_delay: chip dependent delay for transferring data from array to read
* regs (tR).
* @dummy_controller: dummy controller implementation for drivers that can
* only control a single chip
*
* If you look at this structure you're already wrong. These fields/hooks are
* all deprecated.
*/
struct nand_legacy {
void __iomem *IO_ADDR_R;
void __iomem *IO_ADDR_W;
void (*select_chip)(struct nand_chip *chip, int cs);
u8 (*read_byte)(struct nand_chip *chip);
void (*write_byte)(struct nand_chip *chip, u8 byte);
void (*write_buf)(struct nand_chip *chip, const u8 *buf, int len);
void (*read_buf)(struct nand_chip *chip, u8 *buf, int len);
void (*cmd_ctrl)(struct nand_chip *chip, int dat, unsigned int ctrl);
void (*cmdfunc)(struct nand_chip *chip, unsigned command, int column,
int page_addr);
int (*dev_ready)(struct nand_chip *chip);
int (*waitfunc)(struct nand_chip *chip);
int (*block_bad)(struct nand_chip *chip, loff_t ofs);
int (*block_markbad)(struct nand_chip *chip, loff_t ofs);
int (*set_features)(struct nand_chip *chip, int feature_addr,
u8 *subfeature_para);
int (*get_features)(struct nand_chip *chip, int feature_addr,
u8 *subfeature_para);
int chip_delay;
struct nand_controller dummy_controller;
};
/**
* struct nand_chip_ops - NAND chip operations
* @suspend: Suspend operation
* @resume: Resume operation
* @lock_area: Lock operation
* @unlock_area: Unlock operation
* @setup_read_retry: Set the read-retry mode (mostly needed for MLC NANDs)
* @choose_interface_config: Choose the best interface configuration
*/
struct nand_chip_ops {
int (*suspend)(struct nand_chip *chip);
void (*resume)(struct nand_chip *chip);
int (*lock_area)(struct nand_chip *chip, loff_t ofs, uint64_t len);
int (*unlock_area)(struct nand_chip *chip, loff_t ofs, uint64_t len);
int (*setup_read_retry)(struct nand_chip *chip, int retry_mode);
int (*choose_interface_config)(struct nand_chip *chip,
struct nand_interface_config *iface);
};
/**
* struct nand_manufacturer - NAND manufacturer structure
* @desc: The manufacturer description
* @priv: Private information for the manufacturer driver
*/
struct nand_manufacturer {
const struct nand_manufacturer_desc *desc;
void *priv;
};
/**
* struct nand_chip - NAND Private Flash Chip Data
* @base: Inherit from the generic NAND device
* @id: Holds NAND ID
* @parameters: Holds generic parameters under an easily readable form
* @manufacturer: Manufacturer information
* @ops: NAND chip operations
* @legacy: All legacy fields/hooks. If you develop a new driver, don't even try
* to use any of these fields/hooks, and if you're modifying an
* existing driver that is using those fields/hooks, you should
* consider reworking the driver and avoid using them.
* @options: Various chip options. They can partly be set to inform nand_scan
* about special functionality. See the defines for further
* explanation.
* @current_interface_config: The currently used NAND interface configuration
* @best_interface_config: The best NAND interface configuration which fits both
* the NAND chip and NAND controller constraints. If
* unset, the default reset interface configuration must
* be used.
* @bbt_erase_shift: Number of address bits in a bbt entry
* @bbt_options: Bad block table specific options. All options used here must
* come from bbm.h. By default, these options will be copied to
* the appropriate nand_bbt_descr's.
* @badblockpos: Bad block marker position in the oob area
* @badblockbits: Minimum number of set bits in a good block's bad block marker
* position; i.e., BBM = 11110111b is good when badblockbits = 7
* @bbt_td: Bad block table descriptor for flash lookup
* @bbt_md: Bad block table mirror descriptor
* @badblock_pattern: Bad block scan pattern used for initial bad block scan
* @bbt: Bad block table pointer
* @page_shift: Number of address bits in a page (column address bits)
* @phys_erase_shift: Number of address bits in a physical eraseblock
* @chip_shift: Number of address bits in one chip
* @pagemask: Page number mask = number of (pages / chip) - 1
* @subpagesize: Holds the subpagesize
* @data_buf: Buffer for data, size is (page size + oobsize)
* @oob_poi: pointer on the OOB area covered by data_buf
* @pagecache: Structure containing page cache related fields
* @pagecache.bitflips: Number of bitflips of the cached page
* @pagecache.page: Page number currently in the cache. -1 means no page is
* currently cached
* @buf_align: Minimum buffer alignment required by a platform
* @lock: Lock protecting the suspended field. Also used to serialize accesses
* to the NAND device
* @suspended: Set to 1 when the device is suspended, 0 when it's not
* @cur_cs: Currently selected target. -1 means no target selected, otherwise we
* should always have cur_cs >= 0 && cur_cs < nanddev_ntargets().
* NAND Controller drivers should not modify this value, but they're
* allowed to read it.
* @read_retries: The number of read retry modes supported
* @controller: The hardware controller structure which is shared among multiple
* independent devices
* @ecc: The ECC controller structure
* @priv: Chip private data
*/
struct nand_chip {
struct nand_device base;
struct nand_id id;
struct nand_parameters parameters;
struct nand_manufacturer manufacturer;
struct nand_chip_ops ops;
struct nand_legacy legacy;
unsigned int options;
/* Data interface */
const struct nand_interface_config *current_interface_config;
struct nand_interface_config *best_interface_config;
/* Bad block information */
unsigned int bbt_erase_shift;
unsigned int bbt_options;
unsigned int badblockpos;
unsigned int badblockbits;
struct nand_bbt_descr *bbt_td;
struct nand_bbt_descr *bbt_md;
struct nand_bbt_descr *badblock_pattern;
u8 *bbt;
/* Device internal layout */
unsigned int page_shift;
unsigned int phys_erase_shift;
unsigned int chip_shift;
unsigned int pagemask;
unsigned int subpagesize;
/* Buffers */
u8 *data_buf;
u8 *oob_poi;
struct {
unsigned int bitflips;
int page;
} pagecache;
unsigned long buf_align;
/* Internals */
struct mutex lock;
unsigned int suspended : 1;
int cur_cs;
int read_retries;
/* Externals */
struct nand_controller *controller;
struct nand_ecc_ctrl ecc;
void *priv;
};
static inline struct nand_chip *mtd_to_nand(struct mtd_info *mtd)
{
return container_of(mtd, struct nand_chip, base.mtd);
}
static inline struct mtd_info *nand_to_mtd(struct nand_chip *chip)
{
return &chip->base.mtd;
}
static inline void *nand_get_controller_data(struct nand_chip *chip)
{
return chip->priv;
}
static inline void nand_set_controller_data(struct nand_chip *chip, void *priv)
{
chip->priv = priv;
}
static inline void nand_set_manufacturer_data(struct nand_chip *chip,
void *priv)
{
chip->manufacturer.priv = priv;
}
static inline void *nand_get_manufacturer_data(struct nand_chip *chip)
{
return chip->manufacturer.priv;
}
static inline void nand_set_flash_node(struct nand_chip *chip,
struct device_node *np)
{
mtd_set_of_node(nand_to_mtd(chip), np);
}
static inline struct device_node *nand_get_flash_node(struct nand_chip *chip)
{
return mtd_get_of_node(nand_to_mtd(chip));
}
/**
* nand_get_interface_config - Retrieve the current interface configuration
* of a NAND chip
* @chip: The NAND chip
*/
static inline const struct nand_interface_config *
nand_get_interface_config(struct nand_chip *chip)
{
return chip->current_interface_config;
}
/*
* A helper for defining older NAND chips where the second ID byte fully
* defined the chip, including the geometry (chip size, eraseblock size, page
* size). All these chips have 512 bytes NAND page size.
*/
#define LEGACY_ID_NAND(nm, devid, chipsz, erasesz, opts) \
{ .name = (nm), {{ .dev_id = (devid) }}, .pagesize = 512, \
.chipsize = (chipsz), .erasesize = (erasesz), .options = (opts) }
/*
* A helper for defining newer chips which report their page size and
* eraseblock size via the extended ID bytes.
*
* The real difference between LEGACY_ID_NAND and EXTENDED_ID_NAND is that with
* EXTENDED_ID_NAND, manufacturers overloaded the same device ID so that the
* device ID now only represented a particular total chip size (and voltage,
* buswidth), and the page size, eraseblock size, and OOB size could vary while
* using the same device ID.
*/
#define EXTENDED_ID_NAND(nm, devid, chipsz, opts) \
{ .name = (nm), {{ .dev_id = (devid) }}, .chipsize = (chipsz), \
.options = (opts) }
#define NAND_ECC_INFO(_strength, _step) \
{ .strength_ds = (_strength), .step_ds = (_step) }
#define NAND_ECC_STRENGTH(type) ((type)->ecc.strength_ds)
#define NAND_ECC_STEP(type) ((type)->ecc.step_ds)
/**
* struct nand_flash_dev - NAND Flash Device ID Structure
* @name: a human-readable name of the NAND chip
* @dev_id: the device ID (the second byte of the full chip ID array)
* @mfr_id: manufacturer ID part of the full chip ID array (refers the same
* memory address as ``id[0]``)
* @dev_id: device ID part of the full chip ID array (refers the same memory
* address as ``id[1]``)
* @id: full device ID array
* @pagesize: size of the NAND page in bytes; if 0, then the real page size (as
* well as the eraseblock size) is determined from the extended NAND
* chip ID array)
* @chipsize: total chip size in MiB
* @erasesize: eraseblock size in bytes (determined from the extended ID if 0)
* @options: stores various chip bit options
* @id_len: The valid length of the @id.
* @oobsize: OOB size
* @ecc: ECC correctability and step information from the datasheet.
* @ecc.strength_ds: The ECC correctability from the datasheet, same as the
* @ecc_strength_ds in nand_chip{}.
* @ecc.step_ds: The ECC step required by the @ecc.strength_ds, same as the
* @ecc_step_ds in nand_chip{}, also from the datasheet.
* For example, the "4bit ECC for each 512Byte" can be set with
* NAND_ECC_INFO(4, 512).
*/
struct nand_flash_dev {
char *name;
union {
struct {
uint8_t mfr_id;
uint8_t dev_id;
};
uint8_t id[NAND_MAX_ID_LEN];
};
unsigned int pagesize;
unsigned int chipsize;
unsigned int erasesize;
unsigned int options;
uint16_t id_len;
uint16_t oobsize;
struct {
uint16_t strength_ds;
uint16_t step_ds;
} ecc;
};
int nand_create_bbt(struct nand_chip *chip);
/*
* Check if it is a SLC nand.
* The !nand_is_slc() can be used to check the MLC/TLC nand chips.
* We do not distinguish the MLC and TLC now.
*/
static inline bool nand_is_slc(struct nand_chip *chip)
{
WARN(nanddev_bits_per_cell(&chip->base) == 0,
"chip->bits_per_cell is used uninitialized\n");
return nanddev_bits_per_cell(&chip->base) == 1;
}
/**
* nand_opcode_8bits - Check if the opcode's address should be sent only on the
* lower 8 bits
* @command: opcode to check
*/
static inline int nand_opcode_8bits(unsigned int command)
{
switch (command) {
case NAND_CMD_READID:
case NAND_CMD_PARAM:
case NAND_CMD_GET_FEATURES:
case NAND_CMD_SET_FEATURES:
return 1;
default:
break;
}
return 0;
}
int rawnand_sw_hamming_init(struct nand_chip *chip);
int rawnand_sw_hamming_calculate(struct nand_chip *chip,
const unsigned char *buf,
unsigned char *code);
int rawnand_sw_hamming_correct(struct nand_chip *chip,
unsigned char *buf,
unsigned char *read_ecc,
unsigned char *calc_ecc);
void rawnand_sw_hamming_cleanup(struct nand_chip *chip);
int rawnand_sw_bch_init(struct nand_chip *chip);
int rawnand_sw_bch_correct(struct nand_chip *chip, unsigned char *buf,
unsigned char *read_ecc, unsigned char *calc_ecc);
void rawnand_sw_bch_cleanup(struct nand_chip *chip);
int nand_check_erased_ecc_chunk(void *data, int datalen,
void *ecc, int ecclen,
void *extraoob, int extraooblen,
int threshold);
int nand_ecc_choose_conf(struct nand_chip *chip,
const struct nand_ecc_caps *caps, int oobavail);
/* Default write_oob implementation */
int nand_write_oob_std(struct nand_chip *chip, int page);
/* Default read_oob implementation */
int nand_read_oob_std(struct nand_chip *chip, int page);
/* Stub used by drivers that do not support GET/SET FEATURES operations */
int nand_get_set_features_notsupp(struct nand_chip *chip, int addr,
u8 *subfeature_param);
/* read_page_raw implementations */
int nand_read_page_raw(struct nand_chip *chip, uint8_t *buf, int oob_required,
int page);
int nand_monolithic_read_page_raw(struct nand_chip *chip, uint8_t *buf,
int oob_required, int page);
/* write_page_raw implementations */
int nand_write_page_raw(struct nand_chip *chip, const uint8_t *buf,
int oob_required, int page);
int nand_monolithic_write_page_raw(struct nand_chip *chip, const uint8_t *buf,
int oob_required, int page);
/* Reset and initialize a NAND device */
int nand_reset(struct nand_chip *chip, int chipnr);
/* NAND operation helpers */
int nand_reset_op(struct nand_chip *chip);
int nand_readid_op(struct nand_chip *chip, u8 addr, void *buf,
unsigned int len);
int nand_status_op(struct nand_chip *chip, u8 *status);
int nand_erase_op(struct nand_chip *chip, unsigned int eraseblock);
int nand_read_page_op(struct nand_chip *chip, unsigned int page,
unsigned int offset_in_page, void *buf, unsigned int len);
int nand_change_read_column_op(struct nand_chip *chip,
unsigned int offset_in_page, void *buf,
unsigned int len, bool force_8bit);
int nand_read_oob_op(struct nand_chip *chip, unsigned int page,
unsigned int offset_in_page, void *buf, unsigned int len);
int nand_prog_page_begin_op(struct nand_chip *chip, unsigned int page,
unsigned int offset_in_page, const void *buf,
unsigned int len);
int nand_prog_page_end_op(struct nand_chip *chip);
int nand_prog_page_op(struct nand_chip *chip, unsigned int page,
unsigned int offset_in_page, const void *buf,
unsigned int len);
int nand_change_write_column_op(struct nand_chip *chip,
unsigned int offset_in_page, const void *buf,
unsigned int len, bool force_8bit);
int nand_read_data_op(struct nand_chip *chip, void *buf, unsigned int len,
bool force_8bit, bool check_only);
int nand_write_data_op(struct nand_chip *chip, const void *buf,
unsigned int len, bool force_8bit);
/* Scan and identify a NAND device */
int nand_scan_with_ids(struct nand_chip *chip, unsigned int max_chips,
struct nand_flash_dev *ids);
static inline int nand_scan(struct nand_chip *chip, unsigned int max_chips)
{
return nand_scan_with_ids(chip, max_chips, NULL);
}
/* Internal helper for board drivers which need to override command function */
void nand_wait_ready(struct nand_chip *chip);
/*
* Free resources held by the NAND device, must be called on error after a
* sucessful nand_scan().
*/
void nand_cleanup(struct nand_chip *chip);
/*
* External helper for controller drivers that have to implement the WAITRDY
* instruction and have no physical pin to check it.
*/
int nand_soft_waitrdy(struct nand_chip *chip, unsigned long timeout_ms);
struct gpio_desc;
int nand_gpio_waitrdy(struct nand_chip *chip, struct gpio_desc *gpiod,
unsigned long timeout_ms);
/* Select/deselect a NAND target. */
void nand_select_target(struct nand_chip *chip, unsigned int cs);
void nand_deselect_target(struct nand_chip *chip);
/* Bitops */
void nand_extract_bits(u8 *dst, unsigned int dst_off, const u8 *src,
unsigned int src_off, unsigned int nbits);
/**
* nand_get_data_buf() - Get the internal page buffer
* @chip: NAND chip object
*
* Returns the pre-allocated page buffer after invalidating the cache. This
* function should be used by drivers that do not want to allocate their own
* bounce buffer and still need such a buffer for specific operations (most
* commonly when reading OOB data only).
*
* Be careful to never call this function in the write/write_oob path, because
* the core may have placed the data to be written out in this buffer.
*
* Return: pointer to the page cache buffer
*/
static inline void *nand_get_data_buf(struct nand_chip *chip)
{
chip->pagecache.page = -1;
return chip->data_buf;
}
#endif /* __LINUX_MTD_RAWNAND_H */
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