spia.c

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/*
 *  drivers/mtd/nand/spia.c
 *
 *  Copyright (C) 2000 Steven J. Hill ([email protected])
 *
 *
 *  10-29-2001 TG   change to support hardwarespecific access
 *          to controllines (due to change in nand.c)
 *          page_cache added
 *
 * 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
 *   SPIA board which utilizes the Toshiba TC58V64AFT part. This is
 *   a 64Mibit (8MiB x 8 bits) NAND flash device.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>

/*
 * MTD structure for SPIA board
 */
static struct mtd_info *spia_mtd = NULL;

/*
 * Values specific to the SPIA board (used with EP7212 processor)
 */
#define SPIA_IO_BASE    0xd0000000  /* Start of EP7212 IO address space */
#define SPIA_FIO_BASE   0xf0000000  /* Address where flash is mapped */
#define SPIA_PEDR   0x0080  /*
                 * IO offset to Port E data register
                 * where the CLE, ALE and NCE pins
                 * are wired to.
                 */
#define SPIA_PEDDR  0x00c0  /*
                 * IO offset to Port E data direction
                 * register so we can control the IO
                 * lines.
                 */

/*
 * Module stuff
 */

static int spia_io_base = SPIA_IO_BASE;
static int spia_fio_base = SPIA_FIO_BASE;
static int spia_pedr = SPIA_PEDR;
static int spia_peddr = SPIA_PEDDR;

module_param(spia_io_base, int, 0);
module_param(spia_fio_base, int, 0);
module_param(spia_pedr, int, 0);
module_param(spia_peddr, int, 0);

/*
 * Define partitions for flash device
 */
static const struct mtd_partition partition_info[] = {
    {
     .name = "SPIA flash partition 1",
     .offset = 0,
     .size = 2 * 1024 * 1024},
    {
     .name = "SPIA flash partition 2",
     .offset = 2 * 1024 * 1024,
     .size = 6 * 1024 * 1024}
};

#define NUM_PARTITIONS 2

/*
 *  hardware specific access to control-lines
 *
 *  ctrl:
 *  NAND_CNE: bit 0 -> bit 2
 *  NAND_CLE: bit 1 -> bit 0
 *  NAND_ALE: bit 2 -> bit 1
 */
static void spia_hwcontrol(struct mtd_info *mtd, int cmd)
{
    struct nand_chip *chip = mtd->priv;

    if (ctrl & NAND_CTRL_CHANGE) {
        void __iomem *addr = spia_io_base + spia_pedr;
        unsigned char bits;

        bits = (ctrl & NAND_CNE) << 2;
        bits |= (ctrl & NAND_CLE | NAND_ALE) >> 1;
        writeb((readb(addr) & ~0x7) | bits, addr);
    }

    if (cmd != NAND_CMD_NONE)
        writeb(cmd, chip->IO_ADDR_W);
}

/*
 * Main initialization routine
 */
static int __init spia_init(void)
{
    struct nand_chip *this;

    /* Allocate memory for MTD device structure and private data */
    spia_mtd = kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
    if (!spia_mtd) {
        printk("Unable to allocate SPIA NAND MTD device structure.\n");
        return -ENOMEM;
    }

    /* Get pointer to private data */
    this = (struct nand_chip *)(&spia_mtd[1]);

    /* Initialize structures */
    memset(spia_mtd, 0, sizeof(struct mtd_info));
    memset(this, 0, sizeof(struct nand_chip));

    /* Link the private data with the MTD structure */
    spia_mtd->priv = this;
    spia_mtd->owner = THIS_MODULE;

    /*
     * Set GPIO Port E control register so that the pins are configured
     * to be outputs for controlling the NAND flash.
     */
    (*(volatile unsigned char *)(spia_io_base + spia_peddr)) = 0x07;

    /* Set address of NAND IO lines */
    this->IO_ADDR_R = (void __iomem *)spia_fio_base;
    this->IO_ADDR_W = (void __iomem *)spia_fio_base;
    /* Set address of hardware control function */
    this->cmd_ctrl = spia_hwcontrol;
    /* 15 us command delay time */
    this->chip_delay = 15;

    /* Scan to find existence of the device */
    if (nand_scan(spia_mtd, 1)) {
        kfree(spia_mtd);
        return -ENXIO;
    }

    /* Register the partitions */
    mtd_device_register(spia_mtd, partition_info, NUM_PARTITIONS);

    /* Return happy */
    return 0;
}

module_init(spia_init);

/*
 * Clean up routine
 */
static void __exit spia_cleanup(void)
{
    /* Release resources, unregister device */
    nand_release(spia_mtd);

    /* Free the MTD device structure */
    kfree(spia_mtd);
}

module_exit(spia_cleanup);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steven J. Hill <[email protected]");
MODULE_DESCRIPTION("Board-specific glue layer for NAND flash on SPIA board");