修改UBOOT支持NAND FLASH
1、把drivers\mtd\nand\s3c2410_nand.c複製爲s3c2440_nand.c
在之前移植uboot時去掉了#define CONFIG_CMD_NAND，現在需要打開。
修改：include/configs/smdk2440.h: #define CONFIG_CMD_NAND
編譯查看是否編譯通過。
根據打印信息分析，問題出現在s3c2410_nand.c文件。
s3c2410_hwcontrol->struct s3c2410_nand沒有定義， 把drivers\mtd\nand\s3c2410_nand.c複製爲s3c2440_nand.c
修改makefile：
COBJS-$(CONFIG_NAND_S3C2410) += s3c2410_nand.o
COBJS-$(CONFIG_NAND_S3C2440) += s3c2440_nand.o
修改include/configs/smdk2440.h:
#define CONFIG_NAND_S3C2440(makefile根據這個宏編譯s3c2440_nand.c)
2、根據數據手冊更改s3c2440_nand內容
分析過程：
nand_init
nand_init_chip
board_nand_init
設置nand_chip結構體, 提供底層的操作函數
nand_scan
nand_scan_ident
nand_set_defaults
chip->select_chip = nand_select_chip;
chip->cmdfunc = nand_command;
chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
nand_get_flash_type
chip->select_chip
chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
nand_command() // 即可以用來發命令，也可以用來發列地址(頁內地址)、行地址(哪一頁)
chip->cmd_ctrl
s3c2440_hwcontrol
chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
*maf_id = chip->read_byte(mtd);
*dev_id = chip->read_byte(mtd);
代碼修改如下：drivers\mtd\nand\s3c2440_nand.c
/*
* (C) Copyright 2006 OpenMoko, Inc.
* Author: Harald Welte <[email protected]>
*
* 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/arch/s3c24x0_cpu.h>
#include <asm/io.h>
#define S3C2440_NFCONF_EN (1<<15)
#define S3C2440_NFCONF_512BYTE (1<<14)
#define S3C2440_NFCONF_4STEP (1<<13)
#define S3C2440_NFCONF_INITECC (1<<12)
#define S3C2440_NFCONF_nFCE (1<<11)
#define S3C2440_NFCONF_TACLS(x) ((x)<<12)
#define S3C2440_NFCONF_TWRPH0(x) ((x)<<8)
#define S3C2440_NFCONF_TWRPH1(x) ((x)<<4)
#define S3C2440_ADDR_NALE 4
#define S3C2440_ADDR_NCLE 8
#ifdef CONFIG_NAND_SPL
/* in the early stage of NAND flash booting, printf() is not available */
#define printf(fmt, args...)
static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
int i;
struct nand_chip *this = mtd->priv;
for (i = 0; i < len; i++)
buf[i] = readb(this->IO_ADDR_R);
}
#endif
/* ctrl : 表示做什麼, 選中芯片/取消選中, 發命令還是發地址
*
* dat : 命令值或地址值
*/
static void s3c2440_hwcontrol(struct mtd_info *mtd, int dat, unsigned int ctrl)
{
struct s3c2440_nand *nand = s3c2440_get_base_nand();
if (ctrl & NAND_CLE)
{
/* 發命令 */
writeb(dat, &nand->nfcmd);
}
else if(ctrl & NAND_ALE)
{
/* 發地址 */
writeb(dat, &nand->nfaddr);
}
}
static void s3c2440_nand_select(struct mtd_info *mtd, int chipnr)
{
struct s3c2440_nand *nand = s3c2440_get_base_nand();
switch (chipnr) {
case -1: /* 取消選中 */
nand->nfcont |= (1<<1);
break;
case 0: /* 選中 */
nand->nfcont &= ~(1<<1);
break;
default:
BUG();
}
}
static int s3c2440_dev_ready(struct mtd_info *mtd)
{
struct s3c2440_nand *nand = s3c2440_get_base_nand();
debug("dev_ready\n");
return readl(&nand->nfstat) & 0x01;
}
#ifdef CONFIG_S3C2440_NAND_HWECC
void s3c2440_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
struct s3c2440_nand *nand = s3c2440_get_base_nand();
debug("s3c2440_nand_enable_hwecc(%p, %d)\n", mtd, mode);
writel(readl(&nand->nfconf) | S3C2440_NFCONF_INITECC, &nand->nfconf);
}
static int s3c2440_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
u_char *ecc_code)
{
struct s3c2440_nand *nand = s3c2440_get_base_nand();
ecc_code[0] = readb(&nand->nfecc);
ecc_code[1] = readb(&nand->nfecc + 1);
ecc_code[2] = readb(&nand->nfecc + 2);
debug("s3c2410_nand_calculate_hwecc(%p,): 0x%02x 0x%02x 0x%02x\n",
mtd , ecc_code[0], ecc_code[1], ecc_code[2]);
return 0;
}
static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *calc_ecc)
{
if (read_ecc[0] == calc_ecc[0] &&
read_ecc[1] == calc_ecc[1] &&
read_ecc[2] == calc_ecc[2])
return 0;
printf("s3c2410_nand_correct_data: not implemented\n");
return -1;
}
#endif
int board_nand_init(struct nand_chip *nand)
{
u_int32_t cfg;
u_int8_t tacls, twrph0, twrph1;
struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
struct s3c2440_nand *nand_reg = s3c2440_get_base_nand();
debug("board_nand_init()\n");
writel(readl(&clk_power->clkcon) | (1 << 4), &clk_power->clkcon);
/* initialize hardware */
#if defined(CONFIG_S3C24XX_CUSTOM_NAND_TIMING)
tacls = CONFIG_S3C24XX_TACLS;
twrph0 = CONFIG_S3C24XX_TWRPH0;
twrph1 = CONFIG_S3C24XX_TWRPH1;
#else
tacls = 4;
twrph0 = 8;
twrph1 = 8;
#endif
cfg = S3C2440_NFCONF_EN;
cfg |= S3C2440_NFCONF_TACLS(tacls - 1);
cfg |= S3C2440_NFCONF_TWRPH0(twrph0 - 1);
cfg |= S3C2440_NFCONF_TWRPH1(twrph1 - 1);
writel(cfg, &nand_reg->nfconf);
/* 使能NAND Flash控制器, 初始化ECC, 禁止片選 */
writel((1<<4)|(1<<1)|(1<<0), &nand_reg->nfcont);
/* initialize nand_chip data structure */
nand->IO_ADDR_R = (void *)&nand_reg->nfdata;
nand->IO_ADDR_W = (void *)&nand_reg->nfdata;
nand->select_chip = s3c2440_nand_select;
/* read_buf and write_buf are default */
/* read_byte and write_byte are default */
#ifdef CONFIG_NAND_SPL
nand->read_buf = nand_read_buf;
#endif
/* hwcontrol always must be implemented */
nand->cmd_ctrl = s3c2440_hwcontrol;
nand->dev_ready = s3c2440_dev_ready;
#ifdef CONFIG_S3C2410_NAND_HWECC
nand->ecc.hwctl = s3c2440_nand_enable_hwecc;
nand->ecc.calculate = s3c2440_nand_calculate_ecc;
nand->ecc.correct = s3c2410_nand_correct_data;
nand->ecc.mode = NAND_ECC_HW;
nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
#else
nand->ecc.mode = NAND_ECC_SOFT;
#endif
#ifdef CONFIG_S3C2410_NAND_BBT
nand->options = NAND_USE_FLASH_BBT;
#else
nand->options = 0;
#endif
debug("end of nand_init\n");
return 0;
}
重新編譯燒寫。
到此，uboot成功識別nandflash。