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/*
* Driver for Blackfin on-chip NAND controller.
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Copyright (c) 2007-2008 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
/* TODO:
* - move bit defines into mach-common/bits/nand.h
* - try and replace all IRQSTAT usage with STAT polling
* - have software ecc mode use same algo as hw ecc ?
*/
#include <common.h>
#include <console.h>
#include <asm/io.h>
#ifdef DEBUG
# define pr_stamp() printf("%s:%s:%i: here i am\n", __FILE__, __func__, __LINE__)
#else
# define pr_stamp()
#endif
#include <nand.h>
#include <asm/blackfin.h>
#include <asm/portmux.h>
/* Bit masks for NFC_CTL */
#define WR_DLY 0xf /* Write Strobe Delay */
#define RD_DLY 0xf0 /* Read Strobe Delay */
#define NWIDTH 0x100 /* NAND Data Width */
#define PG_SIZE 0x200 /* Page Size */
/* Bit masks for NFC_STAT */
#define NBUSY 0x1 /* Not Busy */
#define WB_FULL 0x2 /* Write Buffer Full */
#define PG_WR_STAT 0x4 /* Page Write Pending */
#define PG_RD_STAT 0x8 /* Page Read Pending */
#define WB_EMPTY 0x10 /* Write Buffer Empty */
/* Bit masks for NFC_IRQSTAT */
#define NBUSYIRQ 0x1 /* Not Busy IRQ */
#define WB_OVF 0x2 /* Write Buffer Overflow */
#define WB_EDGE 0x4 /* Write Buffer Edge Detect */
#define RD_RDY 0x8 /* Read Data Ready */
#define WR_DONE 0x10 /* Page Write Done */
#define NAND_IS_512() (CONFIG_BFIN_NFC_CTL_VAL & 0x200)
/*
* hardware specific access to control-lines
*/
static void bfin_nfc_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
pr_stamp();
if (cmd == NAND_CMD_NONE)
return;
while (bfin_read_NFC_STAT() & WB_FULL)
continue;
if (ctrl & NAND_CLE)
bfin_write_NFC_CMD(cmd);
else
bfin_write_NFC_ADDR(cmd);
SSYNC();
}
static int bfin_nfc_devready(struct mtd_info *mtd)
{
pr_stamp();
return (bfin_read_NFC_STAT() & NBUSY) ? 1 : 0;
}
/*
* PIO mode for buffer writing and reading
*/
static void bfin_nfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
pr_stamp();
int i;
/*
* Data reads are requested by first writing to NFC_DATA_RD
* and then reading back from NFC_READ.
*/
for (i = 0; i < len; ++i) {
while (bfin_read_NFC_STAT() & WB_FULL)
if (ctrlc())
return;
/* Contents do not matter */
bfin_write_NFC_DATA_RD(0x0000);
SSYNC();
while (!(bfin_read_NFC_IRQSTAT() & RD_RDY))
if (ctrlc())
return;
buf[i] = bfin_read_NFC_READ();
bfin_write_NFC_IRQSTAT(RD_RDY);
}
}
static uint8_t bfin_nfc_read_byte(struct mtd_info *mtd)
{
pr_stamp();
uint8_t val;
bfin_nfc_read_buf(mtd, &val, 1);
return val;
}
static void bfin_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
{
pr_stamp();
int i;
for (i = 0; i < len; ++i) {
while (bfin_read_NFC_STAT() & WB_FULL)
if (ctrlc())
return;
bfin_write_NFC_DATA_WR(buf[i]);
}
/* Wait for the buffer to drain before we return */
while (!(bfin_read_NFC_STAT() & WB_EMPTY))
if (ctrlc())
return;
}
/*
* ECC functions
* These allow the bfin to use the controller's ECC
* generator block to ECC the data as it passes through
*/
/*
* ECC error correction function
*/
static int bfin_nfc_correct_data_256(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *calc_ecc)
{
u32 syndrome[5];
u32 calced, stored;
unsigned short failing_bit, failing_byte;
u_char data;
pr_stamp();
calced = calc_ecc[0] | (calc_ecc[1] << 8) | (calc_ecc[2] << 16);
stored = read_ecc[0] | (read_ecc[1] << 8) | (read_ecc[2] << 16);
syndrome[0] = (calced ^ stored);
/*
* syndrome 0: all zero
* No error in data
* No action
*/
if (!syndrome[0] || !calced || !stored)
return 0;
/*
* sysdrome 0: only one bit is one
* ECC data was incorrect
* No action
*/
if (hweight32(syndrome[0]) == 1)
return 1;
syndrome[1] = (calced & 0x7FF) ^ (stored & 0x7FF);
syndrome[2] = (calced & 0x7FF) ^ ((calced >> 11) & 0x7FF);
syndrome[3] = (stored & 0x7FF) ^ ((stored >> 11) & 0x7FF);
syndrome[4] = syndrome[2] ^ syndrome[3];
/*
* sysdrome 0: exactly 11 bits are one, each parity
* and parity' pair is 1 & 0 or 0 & 1.
* 1-bit correctable error
* Correct the error
*/
if (hweight32(syndrome[0]) == 11 && syndrome[4] == 0x7FF) {
failing_bit = syndrome[1] & 0x7;
failing_byte = syndrome[1] >> 0x3;
data = *(dat + failing_byte);
data = data ^ (0x1 << failing_bit);
*(dat + failing_byte) = data;
return 0;
}
/*
* sysdrome 0: random data
* More than 1-bit error, non-correctable error
* Discard data, mark bad block
*/
return 1;
}
static int bfin_nfc_correct_data(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *calc_ecc)
{
int ret;
pr_stamp();
ret = bfin_nfc_correct_data_256(mtd, dat, read_ecc, calc_ecc);
/* If page size is 512, correct second 256 bytes */
if (NAND_IS_512()) {
dat += 256;
read_ecc += 8;
calc_ecc += 8;
ret |= bfin_nfc_correct_data_256(mtd, dat, read_ecc, calc_ecc);
}
return ret;
}
static void reset_ecc(void)
{
bfin_write_NFC_RST(0x1);
while (bfin_read_NFC_RST() & 1)
continue;
}
static void bfin_nfc_enable_hwecc(struct mtd_info *mtd, int mode)
{
reset_ecc();
}
static int bfin_nfc_calculate_ecc(struct mtd_info *mtd,
const u_char *dat, u_char *ecc_code)
{
u16 ecc0, ecc1;
u32 code[2];
u8 *p;
pr_stamp();
/* first 4 bytes ECC code for 256 page size */
ecc0 = bfin_read_NFC_ECC0();
ecc1 = bfin_read_NFC_ECC1();
code[0] = (ecc0 & 0x7FF) | ((ecc1 & 0x7FF) << 11);
/* first 3 bytes in ecc_code for 256 page size */
p = (u8 *) code;
memcpy(ecc_code, p, 3);
/* second 4 bytes ECC code for 512 page size */
if (NAND_IS_512()) {
ecc0 = bfin_read_NFC_ECC2();
ecc1 = bfin_read_NFC_ECC3();
code[1] = (ecc0 & 0x7FF) | ((ecc1 & 0x7FF) << 11);
/* second 3 bytes in ecc_code for second 256
* bytes of 512 page size
*/
p = (u8 *) (code + 1);
memcpy((ecc_code + 3), p, 3);
}
reset_ecc();
return 0;
}
#ifdef CONFIG_BFIN_NFC_BOOTROM_ECC
# define BOOTROM_ECC 1
#else
# define BOOTROM_ECC 0
#endif
static uint8_t bbt_pattern[] = { 0xff };
static struct nand_bbt_descr bootrom_bbt = {
.options = 0,
.offs = 63,
.len = 1,
.pattern = bbt_pattern,
};
static struct nand_ecclayout bootrom_ecclayout = {
.eccbytes = 24,
.eccpos = {
0x8 * 0, 0x8 * 0 + 1, 0x8 * 0 + 2,
0x8 * 1, 0x8 * 1 + 1, 0x8 * 1 + 2,
0x8 * 2, 0x8 * 2 + 1, 0x8 * 2 + 2,
0x8 * 3, 0x8 * 3 + 1, 0x8 * 3 + 2,
0x8 * 4, 0x8 * 4 + 1, 0x8 * 4 + 2,
0x8 * 5, 0x8 * 5 + 1, 0x8 * 5 + 2,
0x8 * 6, 0x8 * 6 + 1, 0x8 * 6 + 2,
0x8 * 7, 0x8 * 7 + 1, 0x8 * 7 + 2
},
.oobfree = {
{ 0x8 * 0 + 3, 5 },
{ 0x8 * 1 + 3, 5 },
{ 0x8 * 2 + 3, 5 },
{ 0x8 * 3 + 3, 5 },
{ 0x8 * 4 + 3, 5 },
{ 0x8 * 5 + 3, 5 },
{ 0x8 * 6 + 3, 5 },
{ 0x8 * 7 + 3, 5 },
}
};
/*
* Board-specific NAND initialization. The following members of the
* argument are board-specific (per include/linux/mtd/nand.h):
* - 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
* - cmd_ctrl: hardwarespecific function for accesing control-lines
* - dev_ready: hardwarespecific function for accesing device ready/busy line
* - enable_hwecc?: function to enable (reset) hardware ecc generator. Must
* only be provided if a hardware ECC is available
* - ecc.mode: mode of ecc, see defines
* - chip_delay: chip dependent delay for transfering data from array to
* read regs (tR)
* - options: various chip options. They can partly be set to inform
* nand_scan about special functionality. See the defines for further
* explanation
* Members with a "?" were not set in the merged testing-NAND branch,
* so they are not set here either.
*/
int board_nand_init(struct nand_chip *chip)
{
const unsigned short pins[] = {
P_NAND_CE, P_NAND_RB, P_NAND_D0, P_NAND_D1, P_NAND_D2,
P_NAND_D3, P_NAND_D4, P_NAND_D5, P_NAND_D6, P_NAND_D7,
P_NAND_WE, P_NAND_RE, P_NAND_CLE, P_NAND_ALE, 0,
};
pr_stamp();
/* set width/ecc/timings/etc... */
bfin_write_NFC_CTL(CONFIG_BFIN_NFC_CTL_VAL);
/* clear interrupt status */
bfin_write_NFC_IRQMASK(0x0);
bfin_write_NFC_IRQSTAT(0xffff);
/* enable GPIO function enable register */
peripheral_request_list(pins, "bfin_nand");
chip->cmd_ctrl = bfin_nfc_cmd_ctrl;
chip->read_buf = bfin_nfc_read_buf;
chip->write_buf = bfin_nfc_write_buf;
chip->read_byte = bfin_nfc_read_byte;
#ifdef CONFIG_BFIN_NFC_NO_HW_ECC
# define ECC_HW 0
#else
# define ECC_HW 1
#endif
if (ECC_HW) {
if (BOOTROM_ECC) {
chip->badblock_pattern = &bootrom_bbt;
chip->ecc.layout = &bootrom_ecclayout;
}
if (!NAND_IS_512()) {
chip->ecc.bytes = 3;
chip->ecc.size = 256;
chip->ecc.strength = 1;
} else {
chip->ecc.bytes = 6;
chip->ecc.size = 512;
chip->ecc.strength = 2;
}
chip->ecc.mode = NAND_ECC_HW;
chip->ecc.calculate = bfin_nfc_calculate_ecc;
chip->ecc.correct = bfin_nfc_correct_data;
chip->ecc.hwctl = bfin_nfc_enable_hwecc;
} else
chip->ecc.mode = NAND_ECC_SOFT;
chip->dev_ready = bfin_nfc_devready;
chip->chip_delay = 0;
return 0;
}