/*
* arch/cris/arch-v32/drivers/nandflash.c
*
* Copyright (c) 2004
*
* 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/gio_defs.h>
#include <hwregs/bif_core_defs.h>
#include <asm/io.h>
#define CE_BIT 4
#define CLE_BIT 5
#define ALE_BIT 6
#define BY_BIT 7
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))
/* Bitmask for mtd nand control bits */
#define CTRL_BITMASK (NAND_NCE | NAND_CLE | NAND_ALE)
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_gio_rw_pa_dout dout;
struct nand_chip *this = mtd->priv;
local_irq_save(flags);
/* control bits change */
if (ctrl & NAND_CTRL_CHANGE) {
dout = REG_RD(gio, regi_gio, rw_pa_dout);
dout.data &= ~PIN_BITMASK;
#if (CE_BIT == 4 && NAND_NCE == 1 && \
CLE_BIT == 5 && NAND_CLE == 2 && \
ALE_BIT == 6 && NAND_ALE == 4)
/* Pins in same order as control bits, but shifted.
* Optimize for this case; works for 2.6.18 */
dout.data |= ((ctrl & CTRL_BITMASK) ^ NAND_NCE) << CE_BIT;
#else
/* the slow way */
if (!(ctrl & NAND_NCE))
dout.data |= (1 << CE_BIT);
if (ctrl & NAND_CLE)
dout.data |= (1 << CLE_BIT);
if (ctrl & NAND_ALE)
dout.data |= (1 << ALE_BIT);
#endif
REG_WR(gio, regi_gio, rw_pa_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_gio_r_pa_din din = REG_RD(gio, regi_gio, r_pa_din);
return ((din.data & (1 << BY_BIT)) >> BY_BIT);
}
/*
* Main initialization routine
*/
struct mtd_info *__init crisv32_nand_flash_probe(void)
{
void __iomem *read_cs;
void __iomem *write_cs;
reg_bif_core_rw_grp3_cfg bif_cfg = REG_RD(bif_core, regi_bif_core,
rw_grp3_cfg);
reg_gio_rw_pa_oe pa_oe = REG_RD(gio, regi_gio, rw_pa_oe);
struct mtd_info_wrapper *wrapper;
struct nand_chip *this;
int err = 0;
/* 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 = ioremap(MEM_CSP0_START | MEM_NON_CACHEABLE, 8192);
write_cs = ioremap(MEM_CSP1_START | MEM_NON_CACHEABLE, 8192);
if (!read_cs || !write_cs) {
printk(KERN_ERR "CRISv32 NAND ioremap failed\n");
err = -EIO;
goto out_mtd;
}
/* Get pointer to private data */
this = &wrapper->chip;
crisv32_mtd = &wrapper->info;
pa_oe.oe |= 1 << CE_BIT;
pa_oe.oe |= 1 << ALE_BIT;
pa_oe.oe |= 1 << CLE_BIT;
pa_oe.oe &= ~(1 << BY_BIT);
REG_WR(gio, regi_gio, rw_pa_oe, pa_oe);
bif_cfg.gated_csp0 = regk_bif_core_rd;
bif_cfg.gated_csp1 = regk_bif_core_wr;
REG_WR(bif_core, regi_bif_core, rw_grp3_cfg, bif_cfg);
/* 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 existence of the device */
if (nand_scan(crisv32_mtd, 1)) {
err = -ENXIO;
goto out_ior;
}
return crisv32_mtd;
out_ior:
iounmap((void *)read_cs);
iounmap((void *)write_cs);
out_mtd:
kfree(wrapper);
return NULL;
}
