u-boot/drivers/mtd/nand/kb9202_nand.c

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/*
* (C) Copyright 2006
* KwikByte <kb9200_dev@kwikbyte.com>
*
* (C) Copyright 2009
* Matthias Kaehlcke <matthias@kaehlcke.net>
*
* 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>
#include <asm/io.h>
#include <asm/arch/AT91RM9200.h>
#include <asm/arch/hardware.h>
#include <nand.h>
/*
* hardware specific access to control-lines
*/
#define MASK_ALE (1 << 22) /* our ALE is A22 */
#define MASK_CLE (1 << 21) /* our CLE is A21 */
#define KB9202_NAND_NCE (1 << 28) /* EN* on D28 */
#define KB9202_NAND_BUSY (1 << 29) /* RB* on D29 */
#define KB9202_SMC2_NWS (1 << 2)
#define KB9202_SMC2_TDF (1 << 8)
#define KB9202_SMC2_RWSETUP (1 << 24)
#define KB9202_SMC2_RWHOLD (1 << 29)
/*
* Board-specific function to access device control signals
*/
static void kb9202_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *this = mtd->priv;
if (ctrl & NAND_CTRL_CHANGE) {
ulong IO_ADDR_W = (ulong) this->IO_ADDR_W;
/* clear ALE and CLE bits */
IO_ADDR_W &= ~(MASK_ALE | MASK_CLE);
if (ctrl & NAND_CLE)
IO_ADDR_W |= MASK_CLE;
if (ctrl & NAND_ALE)
IO_ADDR_W |= MASK_ALE;
this->IO_ADDR_W = (void *) IO_ADDR_W;
if (ctrl & NAND_NCE)
writel(KB9202_NAND_NCE, AT91C_PIOC_CODR);
else
writel(KB9202_NAND_NCE, AT91C_PIOC_SODR);
}
if (cmd != NAND_CMD_NONE)
writeb(cmd, this->IO_ADDR_W);
}
/*
* Board-specific function to access the device ready signal.
*/
static int kb9202_nand_ready(struct mtd_info *mtd)
{
return readl(AT91C_PIOC_PDSR) & KB9202_NAND_BUSY;
}
/*
* Board-specific NAND init. Copied from include/linux/mtd/nand.h for reference.
*
* struct nand_chip - NAND Private Flash Chip Data
* @IO_ADDR_R: [BOARDSPECIFIC] address to read the 8 I/O lines of the flash device
* @IO_ADDR_W: [BOARDSPECIFIC] address to write the 8 I/O lines of the flash device
* @hwcontrol: [BOARDSPECIFIC] hardwarespecific function for accesing control-lines
* @dev_ready: [BOARDSPECIFIC] hardwarespecific function for accesing device ready/busy line
* If set to NULL no access to ready/busy is available and the ready/busy information
* is read from the chip status register
* @enable_hwecc: [BOARDSPECIFIC] function to enable (reset) hardware ecc generator. Must only
* be provided if a hardware ECC is available
* @eccmode: [BOARDSPECIFIC] mode of ecc, see defines
* @chip_delay: [BOARDSPECIFIC] chip dependent delay for transfering data from array to read regs (tR)
* @options: [BOARDSPECIFIC] various chip options. They can partly be set to inform nand_scan about
* special functionality. See the defines for further explanation
*/
/*
* This routine initializes controller and GPIOs.
*/
int board_nand_init(struct nand_chip *nand)
{
unsigned int value;
nand->ecc.mode = NAND_ECC_SOFT;
nand->cmd_ctrl = kb9202_nand_hwcontrol;
nand->dev_ready = kb9202_nand_ready;
/* in case running outside of bootloader */
writel(1 << AT91C_ID_PIOC, AT91C_PMC_PCER);
/* setup nand flash access (allow ample margin) */
/* 4 wait states, 1 setup, 1 hold, 1 float for 8-bit device */
writel(AT91C_SMC2_WSEN | KB9202_SMC2_NWS | KB9202_SMC2_TDF |
AT91C_SMC2_DBW_8 | KB9202_SMC2_RWSETUP | KB9202_SMC2_RWHOLD,
AT91C_SMC_CSR3);
/* enable internal NAND controller */
value = readl(AT91C_EBI_CSA);
value |= AT91C_EBI_CS3A_SMC_SmartMedia;
writel(value, AT91C_EBI_CSA);
/* enable SMOE/SMWE */
writel(AT91C_PC1_BFRDY_SMOE | AT91C_PC3_BFBAA_SMWE, AT91C_PIOC_ASR);
writel(AT91C_PC1_BFRDY_SMOE | AT91C_PC3_BFBAA_SMWE, AT91C_PIOC_PDR);
writel(AT91C_PC1_BFRDY_SMOE | AT91C_PC3_BFBAA_SMWE, AT91C_PIOC_OER);
/* set NCE to high */
writel(KB9202_NAND_NCE, AT91C_PIOC_SODR);
/* disable output on pin connected to the busy line of the NAND */
writel(KB9202_NAND_BUSY, AT91C_PIOC_ODR);
/* enable the PIO to control NCE and BUSY */
writel(KB9202_NAND_NCE | KB9202_NAND_BUSY, AT91C_PIOC_PER);
/* enable output for NCE */
writel(KB9202_NAND_NCE, AT91C_PIOC_OER);
return (0);
}