drivers/mtd/nand/jz4740_nand.c

/*
 * Platform independend driver for JZ4740.
 *
 * Copyright (c) 2007 Ingenic Semiconductor Inc.
 * Author: <jlwei@ingenic.cn>
 *
 * 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.
 */
#include <common.h>

#include <nand.h>
#include <asm/io.h>
#include <asm/jz4740.h>

#define JZ_NAND_DATA_ADDR ((void __iomem *)0xB8000000)
#define JZ_NAND_CMD_ADDR (JZ_NAND_DATA_ADDR + 0x8000)
#define JZ_NAND_ADDR_ADDR (JZ_NAND_DATA_ADDR + 0x10000)

#define BIT(x) (1 << (x))
#define JZ_NAND_ECC_CTRL_ENCODING	BIT(3)
#define JZ_NAND_ECC_CTRL_RS		BIT(2)
#define JZ_NAND_ECC_CTRL_RESET		BIT(1)
#define JZ_NAND_ECC_CTRL_ENABLE		BIT(0)

#define EMC_SMCR1_OPT_NAND	0x094c4400
/* Optimize the timing of nand */

static struct jz4740_emc * emc = (struct jz4740_emc *)JZ4740_EMC_BASE;

static struct nand_ecclayout qi_lb60_ecclayout_2gb = {
	.eccbytes = 72,
	.eccpos = {
		12, 13, 14, 15, 16, 17, 18, 19,
		20, 21, 22, 23, 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, 64, 65, 66, 67,
		68, 69, 70, 71, 72, 73, 74, 75,
		76, 77, 78, 79, 80, 81, 82, 83 },
	.oobfree = {
		{.offset = 2,
		 .length = 10 },
		{.offset = 84,
		 .length = 44 } }
};

static int is_reading;

static void jz_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	struct nand_chip *this = mtd->priv;
	uint32_t reg;

	if (ctrl & NAND_CTRL_CHANGE) {
		if (ctrl & NAND_ALE)
			this->IO_ADDR_W = JZ_NAND_ADDR_ADDR;
		else if (ctrl & NAND_CLE)
			this->IO_ADDR_W = JZ_NAND_CMD_ADDR;
		else
			this->IO_ADDR_W = JZ_NAND_DATA_ADDR;

		reg = readl(&emc->nfcsr);
		if (ctrl & NAND_NCE)
			reg |= EMC_NFCSR_NFCE1;
		else
			reg &= ~EMC_NFCSR_NFCE1;
		writel(reg, &emc->nfcsr);
	}

	if (cmd != NAND_CMD_NONE)
		writeb(cmd, this->IO_ADDR_W);
}

static int jz_nand_device_ready(struct mtd_info *mtd)
{
	return (readl(GPIO_PXPIN(2)) & 0x40000000) ? 1 : 0;
}

void board_nand_select_device(struct nand_chip *nand, int chip)
{
	/*
	 * Don't use "chip" to address the NAND device,
	 * generate the cs from the address where it is encoded.
	 */
}

static int jz_nand_rs_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
				u_char *ecc_code)
{
	uint32_t status;
	int i;

	if (is_reading)
		return 0;

	do {
		status = readl(&emc->nfints);
	} while (!(status & EMC_NFINTS_ENCF));

	/* disable ecc */
	writel(readl(&emc->nfecr) & ~EMC_NFECR_ECCE, &emc->nfecr);

	for (i = 0; i < 9; i++)
		ecc_code[i] = readb(&emc->nfpar[i]);

	return 0;
}

static void jz_nand_hwctl(struct mtd_info *mtd, int mode)
{
	uint32_t reg;

	writel(0, &emc->nfints);
	reg = readl(&emc->nfecr);
	reg |= JZ_NAND_ECC_CTRL_RESET;
	reg |= JZ_NAND_ECC_CTRL_ENABLE;
	reg |= JZ_NAND_ECC_CTRL_RS;

	switch (mode) {
	case NAND_ECC_READ:
		reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
		is_reading = 1;
		break;
	case NAND_ECC_WRITE:
		reg |= JZ_NAND_ECC_CTRL_ENCODING;
		is_reading = 0;
		break;
	default:
		break;
	}

	writel(reg, &emc->nfecr);
}

/* Correct 1~9-bit errors in 512-bytes data */
static void jz_rs_correct(unsigned char *dat, int idx, int mask)
{
	int i;

	idx--;

	i = idx + (idx >> 3);
	if (i >= 512)
		return;

	mask <<= (idx & 0x7);

	dat[i] ^= mask & 0xff;
	if (i < 511)
		dat[i + 1] ^= (mask >> 8) & 0xff;
}

static int jz_nand_rs_correct_data(struct mtd_info *mtd, u_char *dat,
				   u_char *read_ecc, u_char *calc_ecc)
{
	int k;
	uint32_t errcnt, index, mask, status;

	/* Set PAR values */
	const uint8_t all_ff_ecc[] = {
		0xcd, 0x9d, 0x90, 0x58, 0xf4, 0x8b, 0xff, 0xb7, 0x6f };

	if (read_ecc[0] == 0xff && read_ecc[1] == 0xff &&
	    read_ecc[2] == 0xff && read_ecc[3] == 0xff &&
	    read_ecc[4] == 0xff && read_ecc[5] == 0xff &&
	    read_ecc[6] == 0xff && read_ecc[7] == 0xff &&
	    read_ecc[8] == 0xff) {
		for (k = 0; k < 9; k++)
			writeb(all_ff_ecc[k], &emc->nfpar[k]);
	} else {
		for (k = 0; k < 9; k++)
			writeb(read_ecc[k], &emc->nfpar[k]);
	}
	/* Set PRDY */
	writel(readl(&emc->nfecr) | EMC_NFECR_PRDY, &emc->nfecr);

	/* Wait for completion */
	do {
		status = readl(&emc->nfints);
	} while (!(status & EMC_NFINTS_DECF));

	/* disable ecc */
	writel(readl(&emc->nfecr) & ~EMC_NFECR_ECCE, &emc->nfecr);

	/* Check decoding */
	if (!(status & EMC_NFINTS_ERR))
		return 0;

	if (status & EMC_NFINTS_UNCOR) {
		printf("uncorrectable ecc\n");
		return -1;
	}

	errcnt = (status & EMC_NFINTS_ERRCNT_MASK) >> EMC_NFINTS_ERRCNT_BIT;

	switch (errcnt) {
	case 4:
		index = (readl(&emc->nferr[3]) & EMC_NFERR_INDEX_MASK) >>
			EMC_NFERR_INDEX_BIT;
		mask = (readl(&emc->nferr[3]) & EMC_NFERR_MASK_MASK) >>
			EMC_NFERR_MASK_BIT;
		jz_rs_correct(dat, index, mask);
	case 3:
		index = (readl(&emc->nferr[2]) & EMC_NFERR_INDEX_MASK) >>
			EMC_NFERR_INDEX_BIT;
		mask = (readl(&emc->nferr[2]) & EMC_NFERR_MASK_MASK) >>
			EMC_NFERR_MASK_BIT;
		jz_rs_correct(dat, index, mask);
	case 2:
		index = (readl(&emc->nferr[1]) & EMC_NFERR_INDEX_MASK) >>
			EMC_NFERR_INDEX_BIT;
		mask = (readl(&emc->nferr[1]) & EMC_NFERR_MASK_MASK) >>
			EMC_NFERR_MASK_BIT;
		jz_rs_correct(dat, index, mask);
	case 1:
		index = (readl(&emc->nferr[0]) & EMC_NFERR_INDEX_MASK) >>
			EMC_NFERR_INDEX_BIT;
		mask = (readl(&emc->nferr[0]) & EMC_NFERR_MASK_MASK) >>
			EMC_NFERR_MASK_BIT;
		jz_rs_correct(dat, index, mask);
	default:
		break;
	}

	return errcnt;
}

/*
 * Main initialization routine
 */
int board_nand_init(struct nand_chip *nand)
{
	uint32_t reg;

	reg = readl(&emc->nfcsr);
	reg |= EMC_NFCSR_NFE1;	/* EMC setup, Set NFE bit */
	writel(reg, &emc->nfcsr);

	writel(EMC_SMCR1_OPT_NAND, &emc->smcr[1]);

	nand->IO_ADDR_R		= JZ_NAND_DATA_ADDR;
	nand->IO_ADDR_W		= JZ_NAND_DATA_ADDR;
	nand->cmd_ctrl		= jz_nand_cmd_ctrl;
	nand->dev_ready		= jz_nand_device_ready;
	nand->ecc.hwctl		= jz_nand_hwctl;
	nand->ecc.correct	= jz_nand_rs_correct_data;
	nand->ecc.calculate	= jz_nand_rs_calculate_ecc;
	nand->ecc.mode		= NAND_ECC_HW_OOB_FIRST;
	nand->ecc.size		= CONFIG_SYS_NAND_ECCSIZE;
	nand->ecc.bytes		= CONFIG_SYS_NAND_ECCBYTES;
	nand->ecc.layout	= &qi_lb60_ecclayout_2gb;
	nand->chip_delay	= 50;
	nand->options		= NAND_USE_FLASH_BBT;

	return 0;
}