/*
* drivers/mtd/nand/ams-delta.c
*
* Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
*
* Derived from drivers/mtd/toto.c
*
* 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.
*
* Overview:
* This is a device driver for the NAND flash device found on the
* Amstrad E3 (Delta).
*/
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <asm/sizes.h>
#include <asm/arch/gpio.h>
#include <asm/arch/board-ams-delta.h>
/*
* MTD structure for E3 (Delta)
*/
static struct mtd_info *ams_delta_mtd = NULL;
#define NAND_MASK (AMS_DELTA_LATCH2_NAND_NRE | AMS_DELTA_LATCH2_NAND_NWE | AMS_DELTA_LATCH2_NAND_CLE | AMS_DELTA_LATCH2_NAND_ALE | AMS_DELTA_LATCH2_NAND_NCE | AMS_DELTA_LATCH2_NAND_NWP)
/*
* Define partitions for flash devices
*/
static struct mtd_partition partition_info[] = {
{ .name = "Kernel",
.offset = 0,
.size = 3 * SZ_1M + SZ_512K },
{ .name = "u-boot",
.offset = 3 * SZ_1M + SZ_512K,
.size = SZ_256K },
{ .name = "u-boot params",
.offset = 3 * SZ_1M + SZ_512K + SZ_256K,
.size = SZ_256K },
{ .name = "Amstrad LDR",
.offset = 4 * SZ_1M,
.size = SZ_256K },
{ .name = "File system",
.offset = 4 * SZ_1M + 1 * SZ_256K,
.size = 27 * SZ_1M },
{ .name = "PBL reserved",
.offset = 32 * SZ_1M - 3 * SZ_256K,
.size = 3 * SZ_256K },
};
static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
{
struct nand_chip *this = mtd->priv;
omap_writew(0, (OMAP_MPUIO_BASE + OMAP_MPUIO_IO_CNTL));
omap_writew(byte, this->IO_ADDR_W);
ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE, 0);
ndelay(40);
ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE,
AMS_DELTA_LATCH2_NAND_NWE);
}
static u_char ams_delta_read_byte(struct mtd_info *mtd)
{
u_char res;
struct nand_chip *this = mtd->priv;
ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE, 0);
ndelay(40);
omap_writew(~0, (OMAP_MPUIO_BASE + OMAP_MPUIO_IO_CNTL));
res = omap_readw(this->IO_ADDR_R);
ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE,
AMS_DELTA_LATCH2_NAND_NRE);
return res;
}
static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf,
int len)
{
int i;
for (i=0; i<len; i++)
ams_delta_write_byte(mtd, buf[i]);
}
static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
int i;
for (i=0; i<len; i++)
buf[i] = ams_delta_read_byte(mtd);
}
static int ams_delta_verify_buf(struct mtd_info *mtd, const u_char *buf,
int len)
{
int i;
for (i=0; i<len; i++)
if (buf[i] != ams_delta_read_byte(mtd))
return -EFAULT;
return 0;
}
/*
* Command control function
*
* ctrl:
* NAND_NCE: bit 0 -> bit 2
* NAND_CLE: bit 1 -> bit 7
* NAND_ALE: bit 2 -> bit 6
*/
static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
unsigned int ctrl)
{
if (ctrl & NAND_CTRL_CHANGE) {
unsigned long bits;
bits = (~ctrl & NAND_NCE) << 2;
bits |= (ctrl & NAND_CLE) << 7;
bits |= (ctrl & NAND_ALE) << 6;
ams_delta_latch2_write(0xC2, bits);
}
if (cmd != NAND_CMD_NONE)
ams_delta_write_byte(mtd, cmd);
}
static int ams_delta_nand_ready(struct mtd_info *mtd)
{
return omap_get_gpio_datain(AMS_DELTA_GPIO_PIN_NAND_RB);
}
/*
* Main initialization routine
*/
static int __init ams_delta_init(void)
{
struct nand_chip *this;
int err = 0;
/* Allocate memory for MTD device structure and private data */
ams_delta_mtd = kmalloc(sizeof(struct mtd_info) +
sizeof(struct nand_chip), GFP_KERNEL);
if (!ams_delta_mtd) {
printk (KERN_WARNING "Unable to allocate E3 NAND MTD device structure.\n");
err = -ENOMEM;
goto out;
}
ams_delta_mtd->owner = THIS_MODULE;
/* Get pointer to private data */
this = (struct nand_chip *) (&ams_delta_mtd[1]);
/* Initialize structures */
memset(ams_delta_mtd, 0, sizeof(struct mtd_info));
memset(this, 0, sizeof(struct nand_chip));
/* Link the private data with the MTD structure */
ams_delta_mtd->priv = this;
/* Set address of NAND IO lines */
this->IO_ADDR_R = (OMAP_MPUIO_BASE + OMAP_MPUIO_INPUT_LATCH);
this->IO_ADDR_W = (OMAP_MPUIO_BASE + OMAP_MPUIO_OUTPUT);
this->read_byte = ams_delta_read_byte;
this->write_byte = ams_delta_write_byte;
this->write_buf = ams_delta_write_buf;
this->read_buf = ams_delta_read_buf;
this->verify_buf = ams_delta_verify_buf;
this->cmd_ctrl = ams_delta_hwcontrol;
if (!omap_request_gpio(AMS_DELTA_GPIO_PIN_NAND_RB)) {
this->dev_ready = ams_delta_nand_ready;
} else {
this->dev_ready = NULL;
printk(KERN_NOTICE "Couldn't request gpio for Delta NAND ready.\n");
}
/* 25 us command delay time */
this->chip_delay = 30;
this->ecc.mode = NAND_ECC_SOFT;
/* Set chip enabled, but */
ams_delta_latch2_write(NAND_MASK, AMS_DELTA_LATCH2_NAND_NRE |
AMS_DELTA_LATCH2_NAND_NWE |
AMS_DELTA_LATCH2_NAND_NCE |
AMS_DELTA_LATCH2_NAND_NWP);
/* Scan to find existance of the device */
if (nand_scan(ams_delta_mtd, 1)) {
err = -ENXIO;
goto out_mtd;
}
/* Register the partitions */
add_mtd_partitions(ams_delta_mtd, partition_info,
ARRAY_SIZE(partition_info));
goto out;
out_mtd:
kfree(ams_delta_mtd);
out:
return err;
}
module_init(ams_delta_init);
/*
* Clean up routine
*/
static void __exit ams_delta_cleanup(void)
{
/* Release resources, unregister device */
nand_release(ams_delta_mtd);
/* Free the MTD device structure */
kfree(ams_delta_mtd);
}
module_exit(ams_delta_cleanup);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");
