u-boot/board/prodrive/alpr/nand.c

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/*
* (C) Copyright 2006
* Heiko Schocher, DENX Software Engineering, hs@denx.de
*
* (C) Copyright 2006
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
* 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)
#include <asm/processor.h>
#include <nand.h>
struct alpr_ndfc_regs {
u8 cmd[4];
u8 addr_wait;
u8 term;
u8 dummy;
u8 dummy2;
u8 data;
};
static u8 hwctl;
static struct alpr_ndfc_regs *alpr_ndfc = NULL;
#define readb(addr) (u8)(*(volatile u8 *)(addr))
#define writeb(d,addr) *(volatile u8 *)(addr) = ((u8)(d))
/*
* The ALPR has a NAND Flash Controller (NDFC) that handles all accesses to
* the NAND devices. The NDFC has command, address and data registers that
* when accessed will set up the NAND flash pins appropriately. We'll use the
* hwcontrol function to save the configuration in a global variable.
* We can then use this information in the read and write functions to
* determine which NDFC register to access.
*
* There are 2 NAND devices on the board, a Hynix HY27US08561A (1 GByte).
*/
static void alpr_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *this = mtd->priv;
if (ctrl & NAND_CTRL_CHANGE) {
if ( ctrl & NAND_CLE )
hwctl |= 0x1;
else
hwctl &= ~0x1;
if ( ctrl & NAND_ALE )
hwctl |= 0x2;
else
hwctl &= ~0x2;
if ( (ctrl & NAND_NCE) != NAND_NCE)
writeb(0x00, &(alpr_ndfc->term));
}
if (cmd != NAND_CMD_NONE)
writeb(cmd, this->IO_ADDR_W);
}
static u_char alpr_nand_read_byte(struct mtd_info *mtd)
{
return readb(&(alpr_ndfc->data));
}
static void alpr_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
struct nand_chip *nand = mtd->priv;
int i;
for (i = 0; i < len; i++) {
if (hwctl & 0x1)
/*
* IO_ADDR_W used as CMD[i] reg to support multiple NAND
* chips.
*/
writeb(buf[i], nand->IO_ADDR_W);
else if (hwctl & 0x2)
writeb(buf[i], &(alpr_ndfc->addr_wait));
else
writeb(buf[i], &(alpr_ndfc->data));
}
}
static void alpr_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
int i;
for (i = 0; i < len; i++) {
buf[i] = readb(&(alpr_ndfc->data));
}
}
static int alpr_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
int i;
for (i = 0; i < len; i++)
if (buf[i] != readb(&(alpr_ndfc->data)))
return i;
return 0;
}
static int alpr_nand_dev_ready(struct mtd_info *mtd)
{
volatile u_char val;
/*
* Blocking read to wait for NAND to be ready
*/
val = readb(&(alpr_ndfc->addr_wait));
/*
* Return always true
*/
return 1;
}
int board_nand_init(struct nand_chip *nand)
{
alpr_ndfc = (struct alpr_ndfc_regs *)CONFIG_SYS_NAND_BASE;
nand->ecc.mode = NAND_ECC_SOFT;
/* Reference hardware control function */
nand->cmd_ctrl = alpr_nand_hwcontrol;
nand->read_byte = alpr_nand_read_byte;
nand->write_buf = alpr_nand_write_buf;
nand->read_buf = alpr_nand_read_buf;
nand->verify_buf = alpr_nand_verify_buf;
nand->dev_ready = alpr_nand_dev_ready;
return 0;
}
#endif