/*
* arch/cris/arch-v32/drivers/nandflash.c
*
* Copyright (c) 2007
*
* Derived from drivers/mtd/nand/spia.c
* Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <arch/memmap.h>
#include <hwregs/reg_map.h>
#include <hwregs/reg_rdwr.h>
#include <hwregs/pio_defs.h>
#include <pinmux.h>
#include <asm/io.h>
#define MANUAL_ALE_CLE_CONTROL 1
#define regf_ALE a0
#define regf_CLE a1
#define regf_NCE ce0_n
#define CLE_BIT 10
#define ALE_BIT 11
#define CE_BIT 12
struct mtd_info_wrapper {
struct mtd_info info;
struct nand_chip chip;
};
/* Bitmask for control pins */
#define PIN_BITMASK ((1 << CE_BIT) | (1 << CLE_BIT) | (1 << ALE_BIT))
static struct mtd_info *crisv32_mtd;
/*
* hardware specific access to control-lines
*/
static void crisv32_hwcontrol(struct mtd_info *mtd, int cmd,
unsigned int ctrl)
{
unsigned long flags;
reg_pio_rw_dout dout;
struct nand_chip *this = mtd->priv;
local_irq_save(flags);
/* control bits change */
if (ctrl & NAND_CTRL_CHANGE) {
dout = REG_RD(pio, regi_pio, rw_dout);
dout.regf_NCE = (ctrl & NAND_NCE) ? 0 : 1;
#if !MANUAL_ALE_CLE_CONTROL
if (ctrl & NAND_ALE) {
/* A0 = ALE high */
this->IO_ADDR_W = (void __iomem *)REG_ADDR(pio,
regi_pio, rw_io_access1);
} else if (ctrl & NAND_CLE) {
/* A1 = CLE high */
this->IO_ADDR_W = (void __iomem *)REG_ADDR(pio,
regi_pio, rw_io_access2);
} else {
/* A1 = CLE and A0 = ALE low */
this->IO_ADDR_W = (void __iomem *)REG_ADDR(pio,
regi_pio, rw_io_access0);
}
#else
dout.regf_CLE = (ctrl & NAND_CLE) ? 1 : 0;
dout.regf_ALE = (ctrl & NAND_ALE) ? 1 : 0;
#endif
REG_WR(pio, regi_pio, rw_dout, dout);
}
/* command to chip */
if (cmd != NAND_CMD_NONE)
writeb(cmd, this->IO_ADDR_W);
local_irq_restore(flags);
}
/*
* read device ready pin
*/
static int crisv32_device_ready(struct mtd_info *mtd)
{
reg_pio_r_din din = REG_RD(pio, regi_pio, r_din);
return din.rdy;
}
/*
* Main initialization routine
*/
struct mtd_info *__init crisv32_nand_flash_probe(void)
{
void __iomem *read_cs;
void __iomem *write_cs;
struct mtd_info_wrapper *wrapper;
struct nand_chip *this;
int err = 0;
reg_pio_rw_man_ctrl man_ctrl = {
.regf_NCE = regk_pio_yes,
#if MANUAL_ALE_CLE_CONTROL
.regf_ALE = regk_pio_yes,
.regf_CLE = regk_pio_yes
#endif
};
reg_pio_rw_oe oe = {
.regf_NCE = regk_pio_yes,
#if MANUAL_ALE_CLE_CONTROL
.regf_ALE = regk_pio_yes,
.regf_CLE = regk_pio_yes
#endif
};
reg_pio_rw_dout dout = { .regf_NCE = 1 };
/* Allocate pio pins to pio */
crisv32_pinmux_alloc_fixed(pinmux_pio);
/* Set up CE, ALE, CLE (ce0_n, a0, a1) for manual control and output */
REG_WR(pio, regi_pio, rw_man_ctrl, man_ctrl);
REG_WR(pio, regi_pio, rw_dout, dout);
REG_WR(pio, regi_pio, rw_oe, oe);
/* Allocate memory for MTD device structure and private data */
wrapper = kzalloc(sizeof(struct mtd_info_wrapper), GFP_KERNEL);
if (!wrapper) {
printk(KERN_ERR "Unable to allocate CRISv32 NAND MTD "
"device structure.\n");
err = -ENOMEM;
return NULL;
}
read_cs = write_cs = (void __iomem *)REG_ADDR(pio, regi_pio,
rw_io_access0);
/* Get pointer to private data */
this = &wrapper->chip;
crisv32_mtd = &wrapper->info;
/* Link the private data with the MTD structure */
crisv32_mtd->priv = this;
/* Set address of NAND IO lines */
this->IO_ADDR_R = read_cs;
this->IO_ADDR_W = write_cs;
this->cmd_ctrl = crisv32_hwcontrol;
this->dev_ready = crisv32_device_ready;
/* 20 us command delay time */
this->chip_delay = 20;
this->ecc.mode = NAND_ECC_SOFT;
/* Enable the following for a flash based bad block table */
/* this->options = NAND_USE_FLASH_BBT; */
/* Scan to find existance of the device */
if (nand_scan(crisv32_mtd, 1)) {
err = -ENXIO;
goto out_mtd;
}
return crisv32_mtd;
out_mtd:
kfree(wrapper);
return NULL;
}
