sharpsl.c

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/*
 * drivers/mtd/nand/sharpsl.c
 *
 *  Copyright (C) 2004 Richard Purdie
 *  Copyright (C) 2008 Dmitry Baryshkov
 *
 *  Based on Sharp's NAND driver sharp_sl.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.
 *
 */

#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/sharpsl.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <asm/io.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>

struct sharpsl_nand {
    struct mtd_info     mtd;
    struct nand_chip    chip;

    void __iomem        *io;
};

#define mtd_to_sharpsl(_mtd)    container_of(_mtd, struct sharpsl_nand, mtd)

/* register offset */
#define ECCLPLB     0x00    /* line parity 7 - 0 bit */
#define ECCLPUB     0x04    /* line parity 15 - 8 bit */
#define ECCCP       0x08    /* column parity 5 - 0 bit */
#define ECCCNTR     0x0C    /* ECC byte counter */
#define ECCCLRR     0x10    /* cleare ECC */
#define FLASHIO     0x14    /* Flash I/O */
#define FLASHCTL    0x18    /* Flash Control */

/* Flash control bit */
#define FLRYBY      (1 << 5)
#define FLCE1       (1 << 4)
#define FLWP        (1 << 3)
#define FLALE       (1 << 2)
#define FLCLE       (1 << 1)
#define FLCE0       (1 << 0)

/*
 *  hardware specific access to control-lines
 *  ctrl:
 *  NAND_CNE: bit 0 -> ! bit 0 & 4
 *  NAND_CLE: bit 1 -> bit 1
 *  NAND_ALE: bit 2 -> bit 2
 *
 */
static void sharpsl_nand_hwcontrol(struct mtd_info *mtd, int cmd,
                   unsigned int ctrl)
{
    struct sharpsl_nand *sharpsl = mtd_to_sharpsl(mtd);
    struct nand_chip *chip = mtd->priv;

    if (ctrl & NAND_CTRL_CHANGE) {
        unsigned char bits = ctrl & 0x07;

        bits |= (ctrl & 0x01) << 4;

        bits ^= 0x11;

        writeb((readb(sharpsl->io + FLASHCTL) & ~0x17) | bits, sharpsl->io + FLASHCTL);
    }

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

static int sharpsl_nand_dev_ready(struct mtd_info *mtd)
{
    struct sharpsl_nand *sharpsl = mtd_to_sharpsl(mtd);
    return !((readb(sharpsl->io + FLASHCTL) & FLRYBY) == 0);
}

static void sharpsl_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
    struct sharpsl_nand *sharpsl = mtd_to_sharpsl(mtd);
    writeb(0, sharpsl->io + ECCCLRR);
}

static int sharpsl_nand_calculate_ecc(struct mtd_info *mtd, const u_char * dat, u_char * ecc_code)
{
    struct sharpsl_nand *sharpsl = mtd_to_sharpsl(mtd);
    ecc_code[0] = ~readb(sharpsl->io + ECCLPUB);
    ecc_code[1] = ~readb(sharpsl->io + ECCLPLB);
    ecc_code[2] = (~readb(sharpsl->io + ECCCP) << 2) | 0x03;
    return readb(sharpsl->io + ECCCNTR) != 0;
}

/*
 * Main initialization routine
 */
static int __devinit sharpsl_nand_probe(struct platform_device *pdev)
{
    struct nand_chip *this;
    struct resource *r;
    int err = 0;
    struct sharpsl_nand *sharpsl;
    struct sharpsl_nand_platform_data *data = pdev->dev.platform_data;

    if (!data) {
        dev_err(&pdev->dev, "no platform data!\n");
        return -EINVAL;
    }

    /* Allocate memory for MTD device structure and private data */
    sharpsl = kzalloc(sizeof(struct sharpsl_nand), GFP_KERNEL);
    if (!sharpsl) {
        printk("Unable to allocate SharpSL NAND MTD device structure.\n");
        return -ENOMEM;
    }

    r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!r) {
        dev_err(&pdev->dev, "no io memory resource defined!\n");
        err = -ENODEV;
        goto err_get_res;
    }

    /* map physical address */
    sharpsl->io = ioremap(r->start, resource_size(r));
    if (!sharpsl->io) {
        printk("ioremap to access Sharp SL NAND chip failed\n");
        err = -EIO;
        goto err_ioremap;
    }

    /* Get pointer to private data */
    this = (struct nand_chip *)(&sharpsl->chip);

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

    platform_set_drvdata(pdev, sharpsl);

    /*
     * PXA initialize
     */
    writeb(readb(sharpsl->io + FLASHCTL) | FLWP, sharpsl->io + FLASHCTL);

    /* Set address of NAND IO lines */
    this->IO_ADDR_R = sharpsl->io + FLASHIO;
    this->IO_ADDR_W = sharpsl->io + FLASHIO;
    /* Set address of hardware control function */
    this->cmd_ctrl = sharpsl_nand_hwcontrol;
    this->dev_ready = sharpsl_nand_dev_ready;
    /* 15 us command delay time */
    this->chip_delay = 15;
    /* set eccmode using hardware ECC */
    this->ecc.mode = NAND_ECC_HW;
    this->ecc.size = 256;
    this->ecc.bytes = 3;
    this->ecc.strength = 1;
    this->badblock_pattern = data->badblock_pattern;
    this->ecc.layout = data->ecc_layout;
    this->ecc.hwctl = sharpsl_nand_enable_hwecc;
    this->ecc.calculate = sharpsl_nand_calculate_ecc;
    this->ecc.correct = nand_correct_data;

    /* Scan to find existence of the device */
    err = nand_scan(&sharpsl->mtd, 1);
    if (err)
        goto err_scan;

    /* Register the partitions */
    sharpsl->mtd.name = "sharpsl-nand";

    err = mtd_device_parse_register(&sharpsl->mtd, NULL, NULL,
                    data->partitions, data->nr_partitions);
    if (err)
        goto err_add;

    /* Return happy */
    return 0;

err_add:
    nand_release(&sharpsl->mtd);

err_scan:
    platform_set_drvdata(pdev, NULL);
    iounmap(sharpsl->io);
err_ioremap:
err_get_res:
    kfree(sharpsl);
    return err;
}

/*
 * Clean up routine
 */
static int __devexit sharpsl_nand_remove(struct platform_device *pdev)
{
    struct sharpsl_nand *sharpsl = platform_get_drvdata(pdev);

    /* Release resources, unregister device */
    nand_release(&sharpsl->mtd);

    platform_set_drvdata(pdev, NULL);

    iounmap(sharpsl->io);

    /* Free the MTD device structure */
    kfree(sharpsl);

    return 0;
}

static struct platform_driver sharpsl_nand_driver = {
    .driver = {
        .name   = "sharpsl-nand",
        .owner  = THIS_MODULE,
    },
    .probe      = sharpsl_nand_probe,
    .remove     = __devexit_p(sharpsl_nand_remove),
};

module_platform_driver(sharpsl_nand_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Richard Purdie <[email protected]>");
MODULE_DESCRIPTION("Device specific logic for NAND flash on Sharp SL-C7xx Series");