openocd/src/flash/nand/davinci.c

796 lines
22 KiB
C

/***************************************************************************
* Copyright (C) 2009 by David Brownell *
* *
* 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. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
***************************************************************************/
/*
* DaVinci family NAND controller support for OpenOCD.
*
* This driver uses hardware ECC (1-bit or 4-bit) unless
* the chip is accessed in "raw" mode.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "imp.h"
#include "arm_io.h"
#include <target/target.h>
enum ecc {
HWECC1, /* all controllers support 1-bit ECC */
HWECC4, /* newer chips also have 4-bit ECC hardware */
HWECC4_INFIX, /* avoid this layout, except maybe for boot code */
};
struct davinci_nand {
uint8_t chipsel; /* chipselect 0..3 == CS2..CS5 */
uint8_t eccmode;
/* Async EMIF controller base */
uint32_t aemif;
/* NAND chip addresses */
uint32_t data; /* without CLE or ALE */
uint32_t cmd; /* with CLE */
uint32_t addr; /* with ALE */
/* write acceleration */
struct arm_nand_data io;
/* page i/o for the relevant flavor of hardware ECC */
int (*read_page)(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size);
int (*write_page)(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size);
};
#define NANDFCR 0x60 /* flash control register */
#define NANDFSR 0x64 /* flash status register */
#define NANDFECC 0x70 /* 1-bit ECC data, CS0, 1st of 4 */
#define NAND4BITECCLOAD 0xbc /* 4-bit ECC, load saved values */
#define NAND4BITECC 0xc0 /* 4-bit ECC data, 1st of 4 */
#define NANDERRADDR 0xd0 /* 4-bit ECC err addr, 1st of 2 */
#define NANDERRVAL 0xd8 /* 4-bit ECC err value, 1st of 2 */
static int halted(struct target *target, const char *label)
{
if (target->state == TARGET_HALTED)
return true;
LOG_ERROR("Target must be halted to use NAND controller (%s)", label);
return false;
}
static int davinci_init(struct nand_device *nand)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
uint32_t nandfcr;
if (!halted(target, "init"))
return ERROR_NAND_OPERATION_FAILED;
/* We require something else to have configured AEMIF to talk
* to NAND chip in this range (including timings and width).
*/
target_read_u32(target, info->aemif + NANDFCR, &nandfcr);
if (!(nandfcr & (1 << info->chipsel))) {
LOG_ERROR("chip address %08" PRIx32 " not NAND-enabled?", info->data);
return ERROR_NAND_OPERATION_FAILED;
}
/* REVISIT verify: AxCR must be in 8-bit mode, since that's all we
* tested. 16 bit support should work too; but not with 4-bit ECC.
*/
return ERROR_OK;
}
static int davinci_reset(struct nand_device *nand)
{
return ERROR_OK;
}
static int davinci_nand_ready(struct nand_device *nand, int timeout)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
uint32_t nandfsr;
/* NOTE: return code is zero/error, else success; not ERROR_* */
if (!halted(target, "ready"))
return 0;
do {
target_read_u32(target, info->aemif + NANDFSR, &nandfsr);
if (nandfsr & 0x01)
return 1;
alive_sleep(1);
} while (timeout-- > 0);
return 0;
}
static int davinci_command(struct nand_device *nand, uint8_t command)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
if (!halted(target, "command"))
return ERROR_NAND_OPERATION_FAILED;
target_write_u8(target, info->cmd, command);
return ERROR_OK;
}
static int davinci_address(struct nand_device *nand, uint8_t address)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
if (!halted(target, "address"))
return ERROR_NAND_OPERATION_FAILED;
target_write_u8(target, info->addr, address);
return ERROR_OK;
}
static int davinci_write_data(struct nand_device *nand, uint16_t data)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
if (!halted(target, "write_data"))
return ERROR_NAND_OPERATION_FAILED;
target_write_u8(target, info->data, data);
return ERROR_OK;
}
static int davinci_read_data(struct nand_device *nand, void *data)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
if (!halted(target, "read_data"))
return ERROR_NAND_OPERATION_FAILED;
target_read_u8(target, info->data, data);
return ERROR_OK;
}
/* REVISIT a bit of native code should let block reads be MUCH faster */
static int davinci_read_block_data(struct nand_device *nand,
uint8_t *data, int data_size)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
uint32_t nfdata = info->data;
uint32_t tmp;
if (!halted(target, "read_block"))
return ERROR_NAND_OPERATION_FAILED;
while (data_size >= 4) {
target_read_u32(target, nfdata, &tmp);
data[0] = tmp;
data[1] = tmp >> 8;
data[2] = tmp >> 16;
data[3] = tmp >> 24;
data_size -= 4;
data += 4;
}
while (data_size > 0) {
target_read_u8(target, nfdata, data);
data_size -= 1;
data += 1;
}
return ERROR_OK;
}
static int davinci_write_block_data(struct nand_device *nand,
uint8_t *data, int data_size)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
uint32_t nfdata = info->data;
uint32_t tmp;
int status;
if (!halted(target, "write_block"))
return ERROR_NAND_OPERATION_FAILED;
/* try the fast way first */
status = arm_nandwrite(&info->io, data, data_size);
if (status != ERROR_NAND_NO_BUFFER)
return status;
/* else do it slowly */
while (data_size >= 4) {
tmp = le_to_h_u32(data);
target_write_u32(target, nfdata, tmp);
data_size -= 4;
data += 4;
}
while (data_size > 0) {
target_write_u8(target, nfdata, *data);
data_size -= 1;
data += 1;
}
return ERROR_OK;
}
static int davinci_write_page(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size)
{
struct davinci_nand *info = nand->controller_priv;
uint8_t *ooballoc = NULL;
int status;
if (!nand->device)
return ERROR_NAND_DEVICE_NOT_PROBED;
if (!halted(nand->target, "write_page"))
return ERROR_NAND_OPERATION_FAILED;
/* Always write both data and OOB ... we are not "raw" I/O! */
if (!data) {
LOG_ERROR("Missing NAND data; try 'nand raw_access enable'");
return ERROR_NAND_OPERATION_FAILED;
}
/* If we're not given OOB, write 0xff where we don't write ECC codes. */
switch (nand->page_size) {
case 512:
oob_size = 16;
break;
case 2048:
oob_size = 64;
break;
case 4096:
oob_size = 128;
break;
default:
return ERROR_NAND_OPERATION_FAILED;
}
if (!oob) {
ooballoc = malloc(oob_size);
if (!ooballoc)
return ERROR_NAND_OPERATION_FAILED;
oob = ooballoc;
memset(oob, 0x0ff, oob_size);
}
/* REVISIT avoid wasting SRAM: unless nand->use_raw is set,
* use 512 byte chunks. Read side support will often want
* to include oob_size ...
*/
info->io.chunk_size = nand->page_size;
status = info->write_page(nand, page, data, data_size, oob, oob_size);
free(ooballoc);
return status;
}
static int davinci_read_page(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size)
{
struct davinci_nand *info = nand->controller_priv;
if (!nand->device)
return ERROR_NAND_DEVICE_NOT_PROBED;
if (!halted(nand->target, "read_page"))
return ERROR_NAND_OPERATION_FAILED;
return info->read_page(nand, page, data, data_size, oob, oob_size);
}
static void davinci_write_pagecmd(struct nand_device *nand, uint8_t cmd, uint32_t page)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
int page3 = nand->address_cycles - (nand->page_size == 512);
/* write command ({page,otp}x{read,program} */
target_write_u8(target, info->cmd, cmd);
/* column address (beginning-of-page) */
target_write_u8(target, info->addr, 0);
if (nand->page_size > 512)
target_write_u8(target, info->addr, 0);
/* page address */
target_write_u8(target, info->addr, page);
target_write_u8(target, info->addr, page >> 8);
if (page3)
target_write_u8(target, info->addr, page >> 16);
if (page3 == 2)
target_write_u8(target, info->addr, page >> 24);
}
static int davinci_seek_column(struct nand_device *nand, uint16_t column)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
/* Random read, we must have issued a page read already */
target_write_u8(target, info->cmd, NAND_CMD_RNDOUT);
target_write_u8(target, info->addr, column);
if (nand->page_size > 512) {
target_write_u8(target, info->addr, column >> 8);
target_write_u8(target, info->cmd, NAND_CMD_RNDOUTSTART);
}
if (!davinci_nand_ready(nand, 100))
return ERROR_NAND_OPERATION_TIMEOUT;
return ERROR_OK;
}
static int davinci_writepage_tail(struct nand_device *nand,
uint8_t *oob, uint32_t oob_size)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
uint8_t status;
if (oob_size)
davinci_write_block_data(nand, oob, oob_size);
/* non-cachemode page program */
target_write_u8(target, info->cmd, NAND_CMD_PAGEPROG);
if (!davinci_nand_ready(nand, 100))
return ERROR_NAND_OPERATION_TIMEOUT;
if (nand_read_status(nand, &status) != ERROR_OK) {
LOG_ERROR("couldn't read status");
return ERROR_NAND_OPERATION_FAILED;
}
if (status & NAND_STATUS_FAIL) {
LOG_ERROR("write operation failed, status: 0x%02x", status);
return ERROR_NAND_OPERATION_FAILED;
}
return ERROR_OK;
}
/*
* All DaVinci family chips support 1-bit ECC on a per-chipselect basis.
*/
static int davinci_write_page_ecc1(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size)
{
unsigned oob_offset;
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
const uint32_t fcr_addr = info->aemif + NANDFCR;
const uint32_t ecc1_addr = info->aemif + NANDFECC + (4 * info->chipsel);
uint32_t fcr, ecc1;
/* Write contiguous ECC bytes starting at specified offset.
* NOTE: Linux reserves twice as many bytes as we need; and
* for 16-bit OOB, those extra bytes are discontiguous.
*/
switch (nand->page_size) {
case 512:
oob_offset = 0;
break;
case 2048:
oob_offset = 40;
break;
default:
oob_offset = 80;
break;
}
davinci_write_pagecmd(nand, NAND_CMD_SEQIN, page);
/* scrub any old ECC state */
target_read_u32(target, ecc1_addr, &ecc1);
target_read_u32(target, fcr_addr, &fcr);
fcr |= 1 << (8 + info->chipsel);
do {
/* set "start csX 1bit ecc" bit */
target_write_u32(target, fcr_addr, fcr);
/* write 512 bytes */
davinci_write_block_data(nand, data, 512);
data += 512;
data_size -= 512;
/* read the ecc, pack to 3 bytes, and invert so the ecc
* in an erased block is correct
*/
target_read_u32(target, ecc1_addr, &ecc1);
ecc1 = (ecc1 & 0x0fff) | ((ecc1 & 0x0fff0000) >> 4);
ecc1 = ~ecc1;
/* save correct ECC code into oob data */
oob[oob_offset++] = (uint8_t)(ecc1);
oob[oob_offset++] = (uint8_t)(ecc1 >> 8);
oob[oob_offset++] = (uint8_t)(ecc1 >> 16);
} while (data_size);
/* write OOB into spare area */
return davinci_writepage_tail(nand, oob, oob_size);
}
/*
* Preferred "new style" ECC layout for use with 4-bit ECC. This somewhat
* slows down large page reads done with error correction (since the OOB
* is read first, so its ECC data can be used incrementally), but the
* manufacturer bad block markers are safe. Contrast: old "infix" style.
*/
static int davinci_write_page_ecc4(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size)
{
static const uint8_t ecc512[] = {
0, 1, 2, 3, 4, /* 5== mfr badblock */
6, 7, /* 8..12 for BBT or JFFS2 */ 13, 14, 15,
};
static const uint8_t ecc2048[] = {
24, 25, 26, 27, 28, 29, 30, 31, 32, 33,
34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
};
static const uint8_t ecc4096[] = {
48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
58, 59, 60, 61, 62, 63, 64, 65, 66, 67,
68, 69, 70, 71, 72, 73, 74, 75, 76, 77,
78, 79, 80, 81, 82, 83, 84, 85, 86, 87,
88, 89, 90, 91, 92, 93, 94, 95, 96, 97,
98, 99, 100, 101, 102, 103, 104, 105, 106, 107,
108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
};
struct davinci_nand *info = nand->controller_priv;
const uint8_t *l;
struct target *target = nand->target;
const uint32_t fcr_addr = info->aemif + NANDFCR;
const uint32_t ecc4_addr = info->aemif + NAND4BITECC;
uint32_t fcr, ecc4;
/* Use the same ECC layout Linux uses. For small page chips
* it's a bit cramped.
*
* NOTE: at this writing, 4KB pages have issues in Linux
* because they need more than 64 bytes of ECC data, which
* the standard ECC logic can't handle.
*/
switch (nand->page_size) {
case 512:
l = ecc512;
break;
case 2048:
l = ecc2048;
break;
default:
l = ecc4096;
break;
}
davinci_write_pagecmd(nand, NAND_CMD_SEQIN, page);
/* scrub any old ECC state */
target_read_u32(target, info->aemif + NANDERRVAL, &ecc4);
target_read_u32(target, fcr_addr, &fcr);
fcr &= ~(0x03 << 4);
fcr |= (1 << 12) | (info->chipsel << 4);
do {
uint32_t raw_ecc[4], *p;
int i;
/* start 4bit ecc on csX */
target_write_u32(target, fcr_addr, fcr);
/* write 512 bytes */
davinci_write_block_data(nand, data, 512);
data += 512;
data_size -= 512;
/* read the ecc, then save it into 10 bytes in the oob */
for (i = 0; i < 4; i++) {
target_read_u32(target, ecc4_addr + 4 * i, &raw_ecc[i]);
raw_ecc[i] &= 0x03ff03ff;
}
for (i = 0, p = raw_ecc; i < 2; i++, p += 2) {
oob[*l++] = p[0] & 0xff;
oob[*l++] = ((p[0] >> 8) & 0x03) | ((p[0] >> 14) & 0xfc);
oob[*l++] = ((p[0] >> 22) & 0x0f) | ((p[1] << 4) & 0xf0);
oob[*l++] = ((p[1] >> 4) & 0x3f) | ((p[1] >> 10) & 0xc0);
oob[*l++] = (p[1] >> 18) & 0xff;
}
} while (data_size);
/* write OOB into spare area */
return davinci_writepage_tail(nand, oob, oob_size);
}
/*
* "Infix" OOB ... like Linux ECC_HW_SYNDROME. Avoided because it trashes
* manufacturer bad block markers, except on small page chips. Once you
* write to a page using this scheme, you need specialized code to update
* it (code which ignores now-invalid bad block markers).
*
* This is needed *only* to support older firmware. Older ROM Boot Loaders
* need it to read their second stage loader (UBL) into SRAM, but from then
* on the whole system can use the cleaner non-infix layouts. Systems with
* older second stage loaders (ABL/U-Boot, etc) or other system software
* (MVL 4.x/5.x kernels, filesystems, etc) may need it more generally.
*/
static int davinci_write_page_ecc4infix(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size)
{
struct davinci_nand *info = nand->controller_priv;
struct target *target = nand->target;
const uint32_t fcr_addr = info->aemif + NANDFCR;
const uint32_t ecc4_addr = info->aemif + NAND4BITECC;
uint32_t fcr, ecc4;
davinci_write_pagecmd(nand, NAND_CMD_SEQIN, page);
/* scrub any old ECC state */
target_read_u32(target, info->aemif + NANDERRVAL, &ecc4);
target_read_u32(target, fcr_addr, &fcr);
fcr &= ~(0x03 << 4);
fcr |= (1 << 12) | (info->chipsel << 4);
do {
uint32_t raw_ecc[4], *p;
uint8_t *l;
int i;
/* start 4bit ecc on csX */
target_write_u32(target, fcr_addr, fcr);
/* write 512 bytes */
davinci_write_block_data(nand, data, 512);
data += 512;
data_size -= 512;
/* read the ecc */
for (i = 0; i < 4; i++) {
target_read_u32(target, ecc4_addr + 4 * i, &raw_ecc[i]);
raw_ecc[i] &= 0x03ff03ff;
}
/* skip 6 bytes of prepad, then pack 10 packed ecc bytes */
for (i = 0, l = oob + 6, p = raw_ecc; i < 2; i++, p += 2) {
*l++ = p[0] & 0xff;
*l++ = ((p[0] >> 8) & 0x03) | ((p[0] >> 14) & 0xfc);
*l++ = ((p[0] >> 22) & 0x0f) | ((p[1] << 4) & 0xf0);
*l++ = ((p[1] >> 4) & 0x3f) | ((p[1] >> 10) & 0xc0);
*l++ = (p[1] >> 18) & 0xff;
}
/* write this "out-of-band" data -- infix */
davinci_write_block_data(nand, oob, 16);
oob += 16;
oob_size -= 16;
} while (data_size);
/* the last data and OOB writes included the spare area */
return davinci_writepage_tail(nand, NULL, 0);
}
static int davinci_read_page_ecc4infix(struct nand_device *nand, uint32_t page,
uint8_t *data, uint32_t data_size, uint8_t *oob, uint32_t oob_size)
{
int read_size;
int want_col, at_col;
int ret;
davinci_write_pagecmd(nand, NAND_CMD_READ0, page);
/* large page devices need a start command */
if (nand->page_size > 512)
davinci_command(nand, NAND_CMD_READSTART);
if (!davinci_nand_ready(nand, 100))
return ERROR_NAND_OPERATION_TIMEOUT;
/* NOTE: not bothering to compute and use ECC data for now */
want_col = 0;
at_col = 0;
while ((data && data_size) || (oob && oob_size)) {
if (data && data_size) {
if (want_col != at_col) {
/* Reads are slow, so seek past them when we can */
ret = davinci_seek_column(nand, want_col);
if (ret != ERROR_OK)
return ret;
at_col = want_col;
}
/* read 512 bytes or data_size, whichever is smaller*/
read_size = data_size > 512 ? 512 : data_size;
davinci_read_block_data(nand, data, read_size);
data += read_size;
data_size -= read_size;
at_col += read_size;
}
want_col += 512;
if (oob && oob_size) {
if (want_col != at_col) {
ret = davinci_seek_column(nand, want_col);
if (ret != ERROR_OK)
return ret;
at_col = want_col;
}
/* read this "out-of-band" data -- infix */
read_size = oob_size > 16 ? 16 : oob_size;
davinci_read_block_data(nand, oob, read_size);
oob += read_size;
oob_size -= read_size;
at_col += read_size;
}
want_col += 16;
}
return ERROR_OK;
}
NAND_DEVICE_COMMAND_HANDLER(davinci_nand_device_command)
{
struct davinci_nand *info;
unsigned long chip, aemif;
enum ecc eccmode;
int chipsel;
/* arguments:
* - "davinci"
* - target
* - nand chip address
* - ecc mode
* - aemif address
* Plus someday, optionally, ALE and CLE masks.
*/
if (CMD_ARGC < 5)
return ERROR_COMMAND_SYNTAX_ERROR;
COMMAND_PARSE_NUMBER(ulong, CMD_ARGV[2], chip);
if (chip == 0) {
LOG_ERROR("Invalid NAND chip address %s", CMD_ARGV[2]);
goto fail;
}
if (strcmp(CMD_ARGV[3], "hwecc1") == 0)
eccmode = HWECC1;
else if (strcmp(CMD_ARGV[3], "hwecc4") == 0)
eccmode = HWECC4;
else if (strcmp(CMD_ARGV[3], "hwecc4_infix") == 0)
eccmode = HWECC4_INFIX;
else {
LOG_ERROR("Invalid ecc mode %s", CMD_ARGV[3]);
goto fail;
}
COMMAND_PARSE_NUMBER(ulong, CMD_ARGV[4], aemif);
if (aemif == 0) {
LOG_ERROR("Invalid AEMIF controller address %s", CMD_ARGV[4]);
goto fail;
}
/* REVISIT what we'd *like* to do is look up valid ranges using
* target-specific declarations, and not even need to pass the
* AEMIF controller address.
*/
if (aemif == 0x01e00000 /* dm6446, dm357 */
|| aemif == 0x01e10000 /* dm335, dm355 */
|| aemif == 0x01d10000 /* dm365 */
) {
if (chip < 0x02000000 || chip >= 0x0a000000) {
LOG_ERROR("NAND address %08lx out of range?", chip);
goto fail;
}
chipsel = (chip - 0x02000000) >> 25;
} else {
LOG_ERROR("unrecognized AEMIF controller address %08lx", aemif);
goto fail;
}
info = calloc(1, sizeof *info);
if (info == NULL)
goto fail;
info->eccmode = eccmode;
info->chipsel = chipsel;
info->aemif = aemif;
info->data = chip;
info->cmd = chip | 0x10;
info->addr = chip | 0x08;
nand->controller_priv = info;
info->io.target = nand->target;
info->io.data = info->data;
info->io.op = ARM_NAND_NONE;
/* NOTE: for now we don't do any error correction on read.
* Nothing else in OpenOCD currently corrects read errors,
* and in any case it's *writing* that we care most about.
*/
info->read_page = nand_read_page_raw;
switch (eccmode) {
case HWECC1:
/* ECC_HW, 1-bit corrections, 3 bytes ECC per 512 data bytes */
info->write_page = davinci_write_page_ecc1;
break;
case HWECC4:
/* ECC_HW, 4-bit corrections, 10 bytes ECC per 512 data bytes */
info->write_page = davinci_write_page_ecc4;
break;
case HWECC4_INFIX:
/* Same 4-bit ECC HW, with problematic page/ecc layout */
info->read_page = davinci_read_page_ecc4infix;
info->write_page = davinci_write_page_ecc4infix;
break;
}
return ERROR_OK;
fail:
return ERROR_NAND_OPERATION_FAILED;
}
struct nand_flash_controller davinci_nand_controller = {
.name = "davinci",
.usage = "chip_addr hwecc_mode aemif_addr",
.nand_device_command = davinci_nand_device_command,
.init = davinci_init,
.reset = davinci_reset,
.command = davinci_command,
.address = davinci_address,
.write_data = davinci_write_data,
.read_data = davinci_read_data,
.write_page = davinci_write_page,
.read_page = davinci_read_page,
.write_block_data = davinci_write_block_data,
.read_block_data = davinci_read_block_data,
.nand_ready = davinci_nand_ready,
};