nand.c

来自「最新版的u-boot,2008-10-18发布」· C语言 代码 · 共 563 行 · 第 1/2 页

/*
 * (C) Copyright 2006 DENX Software Engineering
 *
 * 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>

#if defined(CONFIG_CMD_NAND)
#ifdef CONFIG_NEW_NAND_CODE

#include <nand.h>
#include <asm/arch/pxa-regs.h>

#ifdef CFG_DFC_DEBUG1
# define DFC_DEBUG1(fmt, args...) printf(fmt, ##args)
#else
# define DFC_DEBUG1(fmt, args...)
#endif

#ifdef CFG_DFC_DEBUG2
# define DFC_DEBUG2(fmt, args...) printf(fmt, ##args)
#else
# define DFC_DEBUG2(fmt, args...)
#endif

#ifdef CFG_DFC_DEBUG3
# define DFC_DEBUG3(fmt, args...) printf(fmt, ##args)
#else
# define DFC_DEBUG3(fmt, args...)
#endif

#define MIN(x, y)		((x < y) ? x : y)

/* These really don't belong here, as they are specific to the NAND Model */
static uint8_t scan_ff_pattern[] = { 0xff, 0xff };

static struct nand_bbt_descr delta_bbt_descr = {
	.options = 0,
	.offs = 0,
	.len = 2,
	.pattern = scan_ff_pattern
};

static struct nand_ecclayout delta_oob = {
	.eccbytes = 6,
	.eccpos = {2, 3, 4, 5, 6, 7},
	.oobfree = { {8, 2}, {12, 4} }
};

/*
 * not required for Monahans DFC
 */
static void dfc_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	return;
}

#if 0
/* read device ready pin */
static int dfc_device_ready(struct mtd_info *mtdinfo)
{
	if(NDSR & NDSR_RDY)
		return 1;
	else
		return 0;
	return 0;
}
#endif

/*
 * Write buf to the DFC Controller Data Buffer
 */
static void dfc_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
	unsigned long bytes_multi = len & 0xfffffffc;
	unsigned long rest = len & 0x3;
	unsigned long *long_buf;
	int i;

	DFC_DEBUG2("dfc_write_buf: writing %d bytes starting with 0x%x.\n", len, *((unsigned long*) buf));
	if(bytes_multi) {
		for(i=0; i<bytes_multi; i+=4) {
			long_buf = (unsigned long*) &buf[i];
			NDDB = *long_buf;
		}
	}
	if(rest) {
		printf("dfc_write_buf: ERROR, writing non 4-byte aligned data.\n");
	}
	return;
}


/* The original:
 * static void dfc_read_buf(struct mtd_info *mtd, const u_char *buf, int len)
 *
 * Shouldn't this be "u_char * const buf" ?
 */
static void dfc_read_buf(struct mtd_info *mtd, u_char* const buf, int len)
{
	int i=0, j;

	/* we have to be carefull not to overflow the buffer if len is
	 * not a multiple of 4 */
	unsigned long bytes_multi = len & 0xfffffffc;
	unsigned long rest = len & 0x3;
	unsigned long *long_buf;

	DFC_DEBUG3("dfc_read_buf: reading %d bytes.\n", len);
	/* if there are any, first copy multiple of 4 bytes */
	if(bytes_multi) {
		for(i=0; i<bytes_multi; i+=4) {
			long_buf = (unsigned long*) &buf[i];
			*long_buf = NDDB;
		}
	}

	/* ...then the rest */
	if(rest) {
		unsigned long rest_data = NDDB;
		for(j=0;j<rest; j++)
			buf[i+j] = (u_char) ((rest_data>>j) & 0xff);
	}

	return;
}

/*
 * read a word. Not implemented as not used in NAND code.
 */
static u16 dfc_read_word(struct mtd_info *mtd)
{
	printf("dfc_read_word: UNIMPLEMENTED.\n");
	return 0;
}

/* global var, too bad: mk@tbd: move to ->priv pointer */
static unsigned long read_buf = 0;
static int bytes_read = -1;

/*
 * read a byte from NDDB Because we can only read 4 bytes from NDDB at
 * a time, we buffer the remaining bytes. The buffer is reset when a
 * new command is sent to the chip.
 *
 * WARNING:
 * This function is currently only used to read status and id
 * bytes. For these commands always 8 bytes need to be read from
 * NDDB. So we read and discard these bytes right now. In case this
 * function is used for anything else in the future, we must check
 * what was the last command issued and read the appropriate amount of
 * bytes respectively.
 */
static u_char dfc_read_byte(struct mtd_info *mtd)
{
	unsigned char byte;
	unsigned long dummy;

	if(bytes_read < 0) {
		read_buf = NDDB;
		dummy = NDDB;
		bytes_read = 0;
	}
	byte = (unsigned char) (read_buf>>(8 * bytes_read++));
	if(bytes_read >= 4)
		bytes_read = -1;

	DFC_DEBUG2("dfc_read_byte: byte %u: 0x%x of (0x%x).\n", bytes_read - 1, byte, read_buf);
	return byte;
}

/* calculate delta between OSCR values start and now  */
static unsigned long get_delta(unsigned long start)
{
	unsigned long cur = OSCR;

	if(cur < start) /* OSCR overflowed */
		return (cur + (start^0xffffffff));
	else
		return (cur - start);
}

/* delay function, this doesn't belong here */
static void wait_us(unsigned long us)
{
	unsigned long start = OSCR;
	us *= OSCR_CLK_FREQ;

	while (get_delta(start) < us) {
		/* do nothing */
	}
}

static void dfc_clear_nddb(void)
{
	NDCR &= ~NDCR_ND_RUN;
	wait_us(CFG_NAND_OTHER_TO);
}

/* wait_event with timeout */
static unsigned long dfc_wait_event(unsigned long event)
{
	unsigned long ndsr, timeout, start = OSCR;

	if(!event)
		return 0xff000000;
	else if(event & (NDSR_CS0_CMDD | NDSR_CS0_BBD))
		timeout = CFG_NAND_PROG_ERASE_TO * OSCR_CLK_FREQ;
	else
		timeout = CFG_NAND_OTHER_TO * OSCR_CLK_FREQ;

	while(1) {
		ndsr = NDSR;
		if(ndsr & event) {
			NDSR |= event;
			break;
		}
		if(get_delta(start) > timeout) {
			DFC_DEBUG1("dfc_wait_event: TIMEOUT waiting for event: 0x%lx.\n", event);
			return 0xff000000;
		}

	}
	return ndsr;
}

/* we don't always wan't to do this */
static void dfc_new_cmd(void)
{
	int retry = 0;
	unsigned long status;

	while(retry++ <= CFG_NAND_SENDCMD_RETRY) {
		/* Clear NDSR */
		NDSR = 0xFFF;

		/* set NDCR[NDRUN] */
		if(!(NDCR & NDCR_ND_RUN))
			NDCR |= NDCR_ND_RUN;

		status = dfc_wait_event(NDSR_WRCMDREQ);

		if(status & NDSR_WRCMDREQ)
			return;

		DFC_DEBUG2("dfc_new_cmd: FAILED to get WRITECMDREQ, retry: %d.\n", retry);
		dfc_clear_nddb();
	}
	DFC_DEBUG1("dfc_new_cmd: giving up after %d retries.\n", retry);
}

/* this function is called after Programm and Erase Operations to
 * check for success or failure */
static int dfc_wait(struct mtd_info *mtd, struct nand_chip *this)
{
	unsigned long ndsr=0, event=0;
	int state = this->state;

	if(state == FL_WRITING) {
		event = NDSR_CS0_CMDD | NDSR_CS0_BBD;
	} else if(state == FL_ERASING) {
		event = NDSR_CS0_CMDD | NDSR_CS0_BBD;
	}

	ndsr = dfc_wait_event(event);