[U-Boot] [PATCH 5/7] S3C24XX: Add NAND Flash driver

[Marek Vasut]

Dear José Miguel Gonçalves,

> NAND Flash driver with HW ECC for the S3C24XX SoCs.
> Currently it only supports SLC NAND chips.
> 
> Signed-off-by: José Miguel Gonçalves <jose.goncalves at inov.pt>
> ---
>  drivers/mtd/nand/Makefile       |    1 +
>  drivers/mtd/nand/s3c24xx_nand.c |  269
> +++++++++++++++++++++++++++++++++++++++ 2 files changed, 270 insertions(+)
>  create mode 100644 drivers/mtd/nand/s3c24xx_nand.c
> 
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index 29dc20e..791ec44 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -60,6 +60,7 @@ COBJS-$(CONFIG_NAND_MXS) += mxs_nand.o
>  COBJS-$(CONFIG_NAND_NDFC) += ndfc.o
>  COBJS-$(CONFIG_NAND_NOMADIK) += nomadik.o
>  COBJS-$(CONFIG_NAND_S3C2410) += s3c2410_nand.o
> +COBJS-$(CONFIG_NAND_S3C24XX) += s3c24xx_nand.o
>  COBJS-$(CONFIG_NAND_S3C64XX) += s3c64xx.o
>  COBJS-$(CONFIG_NAND_SPEAR) += spr_nand.o
>  COBJS-$(CONFIG_NAND_OMAP_GPMC) += omap_gpmc.o
> diff --git a/drivers/mtd/nand/s3c24xx_nand.c
> b/drivers/mtd/nand/s3c24xx_nand.c new file mode 100644
> index 0000000..eed72d5
> --- /dev/null
> +++ b/drivers/mtd/nand/s3c24xx_nand.c
> @@ -0,0 +1,269 @@
> +/*
> + * (C) Copyright 2012 INOV - INESC Inovacao
> + * Jose Goncalves <jose.goncalves at inov.pt>
> + *
> + * Based on drivers/mtd/nand/s3c64xx.c and U-Boot 1.3.4 from Samsung.
> + * Supports only SLC NAND Flash chips.
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * 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., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <nand.h>
> +#include <asm/io.h>
> +#include <asm/arch/s3c24xx_cpu.h>
> +#include <asm/errno.h>
> +
> +#define NFCONT_ECC_ENC	(1<<18)
> +#define NFCONT_WP	(1<<16)
> +#define NFCONT_MECCLOCK	(1<<7)
> +#define NFCONT_SECCLOCK	(1<<6)
> +#define NFCONT_INITMECC	(1<<5)
> +#define NFCONT_INITSECC	(1<<4)
> +#define NFCONT_NCE1	(1<<2)
> +#define NFCONT_NCE0	(1<<1)
> +#define NFCONT_ENABLE	(1<<0)
> +
> +#define NFSTAT_RNB	(1<<0)
> +
> +#define MAX_CHIPS	2
> +static int nand_cs[MAX_CHIPS] = { 0, 1 };
> +
> +#ifdef CONFIG_SPL_BUILD
> +#define printf(arg...) do {} while (0)
> +#endif
> +
> +static void s3c_nand_select_chip(struct mtd_info *mtd, int chip)
> +{
> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> +	u_long nfcont;
> +
> +	nfcont = readl(&nand->nfcont);
> +
> +	switch (chip) {
> +	case -1:
> +		nfcont |= NFCONT_NCE1 | NFCONT_NCE0;
> +		break;
> +	case 0:
> +		nfcont &= ~NFCONT_NCE0;
> +		break;
> +	case 1:
> +		nfcont &= ~NFCONT_NCE1;
> +		break;
> +	default:
> +		return;
> +	}
> +
> +	writel(nfcont, &nand->nfcont);
> +}
> +
> +/*
> + * Hardware specific access to control-lines function
> + */
> +static void s3c_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int
> ctrl) +{
> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> +	struct nand_chip *this = mtd->priv;
> +
> +	if (ctrl & NAND_CTRL_CHANGE) {
> +		if (ctrl & NAND_CLE)
> +			this->IO_ADDR_W = (void __iomem *)&nand->nfcmmd;
> +		else if (ctrl & NAND_ALE)
> +			this->IO_ADDR_W = (void __iomem *)&nand->nfaddr;
> +		else
> +			this->IO_ADDR_W = (void __iomem *)&nand->nfdata;

Do you need this cast ?

> +		if (ctrl & NAND_NCE)
> +			s3c_nand_select_chip(mtd, *(int *)this->priv);
> +		else
> +			s3c_nand_select_chip(mtd, -1);
> +	}
> +
> +	if (cmd != NAND_CMD_NONE)
> +		writeb(cmd, this->IO_ADDR_W);
> +}
> +
> +/*
> + * Function for checking device ready pin
> + */
> +static int s3c_nand_device_ready(struct mtd_info *mtdinfo)
> +{
> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> +
> +	return readl(&nand->nfstat) & NFSTAT_RNB;
> +}
> +
> +#ifdef CONFIG_S3C24XX_NAND_HWECC
> +/*
> + * This function is called before encoding ECC codes to ready ECC engine.
> + */
> +static void s3c_nand_enable_hwecc(struct mtd_info *mtd, int mode)
> +{
> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> +	u_long nfcont, nfconf;
> +
> +	/* Set 1-bit ECC */
> +	nfconf = readl(&nand->nfconf);
> +#if defined(CONFIG_S3C2412) || defined(CONFIG_S3C2413)
> +	nfconf &= ~(0x1 << 24);
> +#else
> +	nfconf &= ~(0x3 << 23);
> +#endif

Magic

> +	writel(nfconf, &nand->nfconf);
> +
> +	/* Initialize & unlock ECC */
> +	nfcont = readl(&nand->nfcont);
> +	nfcont |= NFCONT_INITMECC;
> +	nfcont &= ~NFCONT_MECCLOCK;
> +	writel(nfcont, &nand->nfcont);
> +}
> +
> +/*
> + * This function is called immediately after encoding ECC codes.
> + * This function returns encoded ECC codes.
> + */
> +static int s3c_nand_calculate_ecc(struct mtd_info *mtd, const u_char *
> dat, +				  u_char * ecc_code)
> +{
> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> +	u_long nfcont, nfmecc0;
> +
> +	/* Lock */
> +	nfcont = readl(&nand->nfcont);
> +	nfcont |= NFCONT_MECCLOCK;
> +	writel(nfcont, &nand->nfcont);
> +
> +	/* Return 1-bit ECC */
> +	nfmecc0 = readl(&nand->nfmecc[0]);
> +
> +	ecc_code[0] = nfmecc0 & 0xff;
> +	ecc_code[1] = (nfmecc0 >> 8) & 0xff;
> +	ecc_code[2] = (nfmecc0 >> 16) & 0xff;
> +	ecc_code[3] = (nfmecc0 >> 24) & 0xff;
> +
> +	return 0;
> +}
> +
> +/*
> + * This function determines whether read data is good or not.
> + * On SLC, must write ECC codes to controller before reading status bit.
> + * If status bit is good, return 0.
> + * If a correctable error occured, correct it and return 1.
> + * If an uncorrectable error occured, return -1.
> + */
> +static int s3c_nand_correct_data(struct mtd_info *mtd, u_char * dat,
> +				 u_char * read_ecc, u_char * calc_ecc)
> +{
> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> +	int ret;
> +	u_long nfeccerr0, nfmeccdata0, nfmeccdata1, err_byte_addr;
> +	u_char err_type, repaired;
> +
> +	/* SLC: Write ECC to compare */
> +	nfmeccdata0 = (((u_long) read_ecc[1]) << 16) | read_ecc[0];
> +	nfmeccdata1 = (((u_long) read_ecc[3]) << 16) | read_ecc[2];
> +	writel(nfmeccdata0, &nand->nfmeccd[0]);
> +	writel(nfmeccdata1, &nand->nfmeccd[1]);
> +
> +	/* Read ECC status */
> +	nfeccerr0 = readl(&nand->nfeccerr[0]);
> +	err_type = nfeccerr0 & 0x3;
> +
> +	switch (err_type) {
> +	case 0:		/* No error */
> +		ret = 0;
> +		break;
> +
> +	case 1:
> +		/*
> +		 * 1 bit error (Correctable)
> +		 * (nfeccerr0 >> 7) & 0x7ff     :error byte number
> +		 * (nfeccerr0 >> 4) & 0x7       :error bit number
> +		 */
> +		err_byte_addr = (nfeccerr0 >> 7) & 0x7ff;
> +		repaired = dat[err_byte_addr] ^ (1 << ((nfeccerr0 >> 4) & 0x7));
> +
> +		printf("S3C24XX NAND: 1 bit error detected at byte %ld. "
> +		       "Correcting from 0x%02x to 0x%02x\n",
> +		       err_byte_addr, dat[err_byte_addr], repaired);
> +
> +		dat[err_byte_addr] = repaired;
> +
> +		ret = 1;
> +		break;
> +
> +	case 2:		/* Multiple error */
> +	case 3:		/* ECC area error */
> +		printf("S3C24XX NAND: ECC uncorrectable error detected.\n");
> +		ret = -1;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +#endif /* CONFIG_S3C24XX_NAND_HWECC */
> +
> +/*
> + * Board-specific NAND initialization.
> + */
> +int board_nand_init(struct nand_chip *nand)
> +{
> +	static int chip_n = 0;
> +	s3c24xx_nand *const nand_reg = s3c24xx_get_base_nand();
> +	u_long nfconf, nfcont;
> +
> +	if (chip_n == 0) {
> +		/* Extend NAND timings to the maximum */
> +		nfconf = readl(&nand_reg->nfconf);
> +		nfconf |= 0x7770;

Magic

> +		writel(nfconf, &nand_reg->nfconf);
> +
> +		/* Disable chip selects and soft lock, enable controller */
> +		nfcont = readl(&nand_reg->nfcont);
> +		nfcont &= ~NFCONT_WP;
> +		nfcont |= NFCONT_NCE1 | NFCONT_NCE0 | NFCONT_ENABLE;
> +		writel(nfcont, &nand_reg->nfcont);

use clrsetbits_le32()

> +	} else if (chip_n >= MAX_CHIPS) {
> +		return -ENODEV;
> +	}
> +
> +	nand->IO_ADDR_R = (void __iomem *)&nand_reg->nfdata;
> +	nand->IO_ADDR_W = (void __iomem *)&nand_reg->nfdata;
> +	nand->cmd_ctrl = s3c_nand_hwcontrol;
> +	nand->dev_ready = s3c_nand_device_ready;
> +	nand->select_chip = s3c_nand_select_chip;
> +	nand->options = 0;
> +#ifdef CONFIG_SPL_BUILD
> +	nand->read_buf = nand_read_buf;
> +#endif
> +
> +#ifdef CONFIG_S3C24XX_NAND_HWECC
> +	nand->ecc.hwctl = s3c_nand_enable_hwecc;
> +	nand->ecc.calculate = s3c_nand_calculate_ecc;
> +	nand->ecc.correct = s3c_nand_correct_data;
> +	nand->ecc.mode = NAND_ECC_HW_OOB_FIRST;
> +	nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
> +	nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
> +#else
> +	nand->ecc.mode = NAND_ECC_SOFT;
> +#endif /* ! CONFIG_S3C24XX_NAND_HWECC */
> +
> +	nand->priv = nand_cs + chip_n++;
> +
> +	return 0;
> +}