u-boot/drivers/mtd/nand/nand_spl_simple.c

/*
 * (C) Copyright 2006-2008
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <nand.h>
#include <asm/io.h>
#include <linux/mtd/nand_ecc.h>

static int nand_ecc_pos[] = CONFIG_SYS_NAND_ECCPOS;
static struct mtd_info *mtd;
static struct nand_chip nand_chip;

#define ECCSTEPS	(CONFIG_SYS_NAND_PAGE_SIZE / \
					CONFIG_SYS_NAND_ECCSIZE)
#define ECCTOTAL	(ECCSTEPS * CONFIG_SYS_NAND_ECCBYTES)


#if (CONFIG_SYS_NAND_PAGE_SIZE <= 512)
/*
 * NAND command for small page NAND devices (512)
 */
static int nand_command(int block, int page, uint32_t offs,
	u8 cmd)
{
	struct nand_chip *this = mtd_to_nand(mtd);
	int page_addr = page + block * CONFIG_SYS_NAND_PAGE_COUNT;

	while (!this->dev_ready(mtd))
		;

	/* Begin command latch cycle */
	this->cmd_ctrl(mtd, cmd, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
	/* Set ALE and clear CLE to start address cycle */
	/* Column address */
	this->cmd_ctrl(mtd, offs, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
	this->cmd_ctrl(mtd, page_addr & 0xff, NAND_CTRL_ALE); /* A[16:9] */
	this->cmd_ctrl(mtd, (page_addr >> 8) & 0xff,
		       NAND_CTRL_ALE); /* A[24:17] */
#ifdef CONFIG_SYS_NAND_4_ADDR_CYCLE
	/* One more address cycle for devices > 32MiB */
	this->cmd_ctrl(mtd, (page_addr >> 16) & 0x0f,
		       NAND_CTRL_ALE); /* A[28:25] */
#endif
	/* Latch in address */
	this->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);

	/*
	 * Wait a while for the data to be ready
	 */
	while (!this->dev_ready(mtd))
		;

	return 0;
}
#else
/*
 * NAND command for large page NAND devices (2k)
 */
static int nand_command(int block, int page, uint32_t offs,
	u8 cmd)
{
	struct nand_chip *this = mtd_to_nand(mtd);
	int page_addr = page + block * CONFIG_SYS_NAND_PAGE_COUNT;
	void (*hwctrl)(struct mtd_info *mtd, int cmd,
			unsigned int ctrl) = this->cmd_ctrl;

	while (!this->dev_ready(mtd))
		;

	/* Emulate NAND_CMD_READOOB */
	if (cmd == NAND_CMD_READOOB) {
		offs += CONFIG_SYS_NAND_PAGE_SIZE;
		cmd = NAND_CMD_READ0;
	}

	/* Shift the offset from byte addressing to word addressing. */
	if ((this->options & NAND_BUSWIDTH_16) && !nand_opcode_8bits(cmd))
		offs >>= 1;

	/* Begin command latch cycle */
	hwctrl(mtd, cmd, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
	/* Set ALE and clear CLE to start address cycle */
	/* Column address */
	hwctrl(mtd, offs & 0xff,
		    NAND_CTRL_ALE | NAND_CTRL_CHANGE); /* A[7:0] */
	hwctrl(mtd, (offs >> 8) & 0xff, NAND_CTRL_ALE); /* A[11:9] */
	/* Row address */
	hwctrl(mtd, (page_addr & 0xff), NAND_CTRL_ALE); /* A[19:12] */
	hwctrl(mtd, ((page_addr >> 8) & 0xff),
		    NAND_CTRL_ALE); /* A[27:20] */
#ifdef CONFIG_SYS_NAND_5_ADDR_CYCLE
	/* One more address cycle for devices > 128MiB */
	hwctrl(mtd, (page_addr >> 16) & 0x0f,
		       NAND_CTRL_ALE); /* A[31:28] */
#endif
	/* Latch in address */
	hwctrl(mtd, NAND_CMD_READSTART,
		    NAND_CTRL_CLE | NAND_CTRL_CHANGE);
	hwctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);

	/*
	 * Wait a while for the data to be ready
	 */
	while (!this->dev_ready(mtd))
		;

	return 0;
}
#endif

static int nand_is_bad_block(int block)
{
	struct nand_chip *this = mtd_to_nand(mtd);
	u_char bb_data[2];

	nand_command(block, 0, CONFIG_SYS_NAND_BAD_BLOCK_POS,
		NAND_CMD_READOOB);

	/*
	 * Read one byte (or two if it's a 16 bit chip).
	 */
	if (this->options & NAND_BUSWIDTH_16) {
		this->read_buf(mtd, bb_data, 2);
		if (bb_data[0] != 0xff || bb_data[1] != 0xff)
			return 1;
	} else {
		this->read_buf(mtd, bb_data, 1);
		if (bb_data[0] != 0xff)
			return 1;
	}

	return 0;
}

#if defined(CONFIG_SYS_NAND_HW_ECC_OOBFIRST)
static int nand_read_page(int block, int page, uchar *dst)
{
	struct nand_chip *this = mtd_to_nand(mtd);
	u_char ecc_calc[ECCTOTAL];
	u_char ecc_code[ECCTOTAL];
	u_char oob_data[CONFIG_SYS_NAND_OOBSIZE];
	int i;
	int eccsize = CONFIG_SYS_NAND_ECCSIZE;
	int eccbytes = CONFIG_SYS_NAND_ECCBYTES;
	int eccsteps = ECCSTEPS;
	uint8_t *p = dst;

	nand_command(block, page, 0, NAND_CMD_READOOB);
	this->read_buf(mtd, oob_data, CONFIG_SYS_NAND_OOBSIZE);
	nand_command(block, page, 0, NAND_CMD_READ0);

	/* Pick the ECC bytes out of the oob data */
	for (i = 0; i < ECCTOTAL; i++)
		ecc_code[i] = oob_data[nand_ecc_pos[i]];


	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
		this->ecc.hwctl(mtd, NAND_ECC_READ);
		this->read_buf(mtd, p, eccsize);
		this->ecc.calculate(mtd, p, &ecc_calc[i]);
		this->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
	}

	return 0;
}
#else
static int nand_read_page(int block, int page, void *dst)
{
	struct nand_chip *this = mtd_to_nand(mtd);
	u_char ecc_calc[ECCTOTAL];
	u_char ecc_code[ECCTOTAL];
	u_char oob_data[CONFIG_SYS_NAND_OOBSIZE];
	int i;
	int eccsize = CONFIG_SYS_NAND_ECCSIZE;
	int eccbytes = CONFIG_SYS_NAND_ECCBYTES;
	int eccsteps = ECCSTEPS;
	uint8_t *p = dst;

	nand_command(block, page, 0, NAND_CMD_READ0);

	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
		if (this->ecc.mode != NAND_ECC_SOFT)
			this->ecc.hwctl(mtd, NAND_ECC_READ);
		this->read_buf(mtd, p, eccsize);
		this->ecc.calculate(mtd, p, &ecc_calc[i]);
	}
	this->read_buf(mtd, oob_data, CONFIG_SYS_NAND_OOBSIZE);

	/* Pick the ECC bytes out of the oob data */
	for (i = 0; i < ECCTOTAL; i++)
		ecc_code[i] = oob_data[nand_ecc_pos[i]];

	eccsteps = ECCSTEPS;
	p = dst;

	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
		/* No chance to do something with the possible error message
		 * from correct_data(). We just hope that all possible errors
		 * are corrected by this routine.
		 */
		this->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
	}

	return 0;
}
#endif

#ifdef CONFIG_SPL_UBI
/*
 * Temporary storage for non NAND page aligned and non NAND page sized
 * reads. Note: This does not support runtime detected FLASH yet, but
 * that should be reasonably easy to fix by making the buffer large
 * enough :)
 */
static u8 scratch_buf[CONFIG_SYS_NAND_PAGE_SIZE];

/**
 * nand_spl_read_block - Read data from physical eraseblock into a buffer
 * @block:	Number of the physical eraseblock
 * @offset:	Data offset from the start of @peb
 * @len:	Data size to read
 * @dst:	Address of the destination buffer
 *
 * This could be further optimized if we'd have a subpage read
 * function in the simple code. On NAND which allows subpage reads
 * this would spare quite some time to readout e.g. the VID header of
 * UBI.
 *
 * Notes:
 *	@offset + @len are not allowed to be larger than a physical
 *	erase block. No sanity check done for simplicity reasons.
 *
 * To support runtime detected flash this needs to be extended by
 * information about the actual flash geometry, but thats beyond the
 * scope of this effort and for most applications where fast boot is
 * required it is not an issue anyway.
 */
int nand_spl_read_block(int block, int offset, int len, void *dst)
{
	int page, read;

	/* Calculate the page number */
	page = offset / CONFIG_SYS_NAND_PAGE_SIZE;

	/* Offset to the start of a flash page */
	offset = offset % CONFIG_SYS_NAND_PAGE_SIZE;

	while (len) {
		/*
		 * Non page aligned reads go to the scratch buffer.
		 * Page aligned reads go directly to the destination.
		 */
		if (offset || len < CONFIG_SYS_NAND_PAGE_SIZE) {
			nand_read_page(block, page, scratch_buf);
			read = min(len, CONFIG_SYS_NAND_PAGE_SIZE - offset);
			memcpy(dst, scratch_buf + offset, read);
			offset = 0;
		} else {
			nand_read_page(block, page, dst);
			read = CONFIG_SYS_NAND_PAGE_SIZE;
		}
		page++;
		len -= read;
		dst += read;
	}
	return 0;
}
#endif

int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst)
{
	unsigned int block, lastblock;
	unsigned int page;

	/*
	 * offs has to be aligned to a page address!
	 */
	block = offs / CONFIG_SYS_NAND_BLOCK_SIZE;
	lastblock = (offs + size - 1) / CONFIG_SYS_NAND_BLOCK_SIZE;
	page = (offs % CONFIG_SYS_NAND_BLOCK_SIZE) / CONFIG_SYS_NAND_PAGE_SIZE;

	while (block <= lastblock) {
		if (!nand_is_bad_block(block)) {
			/*
			 * Skip bad blocks
			 */
			while (page < CONFIG_SYS_NAND_PAGE_COUNT) {
				nand_read_page(block, page, dst);
				dst += CONFIG_SYS_NAND_PAGE_SIZE;
				page++;
			}

			page = 0;
		} else {
			lastblock++;
		}

		block++;
	}

	return 0;
}

/* nand_init() - initialize data to make nand usable by SPL */
void nand_init(void)
{
	/*
	 * Init board specific nand support
	 */
	mtd = nand_to_mtd(&nand_chip);
	nand_chip.IO_ADDR_R = nand_chip.IO_ADDR_W =
		(void  __iomem *)CONFIG_SYS_NAND_BASE;
	board_nand_init(&nand_chip);

#ifdef CONFIG_SPL_NAND_SOFTECC
	if (nand_chip.ecc.mode == NAND_ECC_SOFT) {
		nand_chip.ecc.calculate = nand_calculate_ecc;
		nand_chip.ecc.correct = nand_correct_data;
	}
#endif

	if (nand_chip.select_chip)
		nand_chip.select_chip(mtd, 0);
}

/* Unselect after operation */
void nand_deselect(void)
{
	if (nand_chip.select_chip)
		nand_chip.select_chip(mtd, -1);
}