smdk24a0_nand.c

ARM的著名的启动代码 vivi s3c2440部分已测试通过

/*
 * vivi/drivers/mtd/maps/s3c24a0-flash.c: 
 *   Flash memory access on SA11x0 based devices
 *
 * Copyright (C) 2002 MIZI Research, Inc.
 * 
 * Based on linux/drivers/mtd/maps/s3c24a0-flash.c
 *
 * This code is GPL.
 * 
 * Author: Janghoon Lyu <[e-mail]>
 * Date  : $Date: 2003/08/19 05:12:11 $
 *
 * $Revision: 1.2 $
 * $Id: smdk24a0_nand.c,v 1.2 2003/08/19 05:12:11 nandy Exp $
 *
 * History
 *
 * 2002-06-26: Janghoon Lyu <[e-mail]>
 *    - Created this code
 *
 */

#include <config.h>
#include <machine.h>
#include <mtd/mtd.h>
#include <mtd/map.h>
#include <mtd/nand.h>
//#include <io.h>
#include <vstring.h>
#include <time.h>
#include <vmalloc.h>
#include <types.h>
#include <errno.h>

//extern struct mtd_info *mymtd;

static void smc_hwcontrol(int cmd) {
	switch (cmd) {
	case NAND_CTL_SETNCE:		NANDCONT &= ~(1 << 7); break;
	case NAND_CTL_CLRNCE:		NANDCONT |= (1 << 7); break;
	case NAND_CTL_SETCLE:		break;
	case NAND_CTL_CLRCLE:		break;
	case NAND_CTL_SETALE:		break;
	case NAND_CTL_CLRALE:		break;
	case NAND_CTL_DAT_IN:		break;
	case NAND_CTL_DAT_OUT:		break;
	}
}

static void
write_cmd(u_char val) 
{
	NFCMD = (u_char)val;
}

static void
write_addr(u_char val) 
{
	NFADDR = (u_char)val;
}

static u_char
read_data(void) 
{
	return (u_char)NFDATA;
}

static void
write_data(u_char val) 
{
	NFDATA = (u_char)val;
}

static void
wait_for_ready(void) 
{
	while (!(NFSTAT & NFSTAT_RnB)) {
		/* Busy */
		udelay(10);
	}
}

inline int
smc_insert(struct nand_chip *this) {
	/* Scan to find existance of the device */
    if (smc_scan(mymtd)) {
		return -ENXIO;
    }
    /* Allocate memory for internal data buffer */
    this->data_buf = vmalloc(sizeof(u_char) *
			     (mymtd->oobblock + mymtd->oobsize));

    if (!this->data_buf) {
		printk("Unable to allocate NAND data buffer for S3C24a0.\n");
		this->data_buf = NULL;
		return -ENOMEM;
    }

    return 0;
}

extern int bon_part_parser(void *);
static int
smc_init(void)
{
	struct nand_chip *this;
	//u_int16_t nfconf;

	/* Allocate memory for MTD device structure and private data */
	mymtd = vmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip));

	if (!mymtd) {
		printk("Unable to allocate S3C24a0 NAND MTD device structure.\n");
		return -ENOMEM;
	}

	/* Get pointer to private data */
	this = (struct nand_chip *)(&mymtd[1]);

	/* Initialize structures */
	memset((char *)mymtd, 0, sizeof(struct mtd_info));
	memset((char *)this, 0, sizeof(struct nand_chip));

	/* Link the private data with the MTD structure */
	mymtd->priv = this;

	NANDCONF = ((7 << 12) | (7 << 8) | (7 << 4) | (0 << 0) | (1 << 3)) ;
	NANDCONT = ((3 << 0));		/* Active chip */

	/* Disable write protect */
	GPCON_M &= ~(0x3 << 8);
	GPCON_M |= (0x1 << 8);	/* to set as output */
	GPDAT |= (0x1 << 15);	/* Disable write protect */

	/* Set address of NAND IO lines */
	this->hwcontrol = smc_hwcontrol;
	this->write_cmd = write_cmd;
	this->write_addr = write_addr;
	this->read_data = read_data;
	this->write_data = write_data;
	this->wait_for_ready = wait_for_ready;

	/* Chip Enable -> RESET -> Wait for Ready -> Chip Disable */
	this->hwcontrol(NAND_CTL_SETNCE);
	this->write_cmd(NAND_CMD_RESET);
	this->wait_for_ready();
	this->hwcontrol(NAND_CTL_CLRNCE);

	smc_insert(this);

	mymtd->mtd_part_parser = bon_part_parser;

	return 0;
}


int mtd_arch_init(void)
{
	int ret;

	if ((ret = smc_init())) {
		mymtd = NULL;
		return ret;
	}

#ifdef CONFIG_MTD_BON
	bon_init();
#endif

	return 0;
}