pasemi_nand.c

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/*
 * Copyright (C) 2006-2007 PA Semi, Inc
 *
 * Author: Egor Martovetsky <[email protected]>
 * Maintained by: Olof Johansson <[email protected]>
 *
 * Driver for the PWRficient onchip NAND flash interface
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#undef DEBUG

#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/nand_ecc.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pci.h>

#include <asm/io.h>

#define LBICTRL_LPCCTL_NR       0x00004000
#define CLE_PIN_CTL         15
#define ALE_PIN_CTL         14

static unsigned int lpcctl;
static struct mtd_info *pasemi_nand_mtd;
static const char driver_name[] = "pasemi-nand";

static void pasemi_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
    struct nand_chip *chip = mtd->priv;

    while (len > 0x800) {
        memcpy_fromio(buf, chip->IO_ADDR_R, 0x800);
        buf += 0x800;
        len -= 0x800;
    }
    memcpy_fromio(buf, chip->IO_ADDR_R, len);
}

static void pasemi_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
    struct nand_chip *chip = mtd->priv;

    while (len > 0x800) {
        memcpy_toio(chip->IO_ADDR_R, buf, 0x800);
        buf += 0x800;
        len -= 0x800;
    }
    memcpy_toio(chip->IO_ADDR_R, buf, len);
}

static void pasemi_hwcontrol(struct mtd_info *mtd, int cmd,
                 unsigned int ctrl)
{
    struct nand_chip *chip = mtd->priv;

    if (cmd == NAND_CMD_NONE)
        return;

    if (ctrl & NAND_CLE)
        out_8(chip->IO_ADDR_W + (1 << CLE_PIN_CTL), cmd);
    else
        out_8(chip->IO_ADDR_W + (1 << ALE_PIN_CTL), cmd);

    /* Push out posted writes */
    eieio();
    inl(lpcctl);
}

int pasemi_device_ready(struct mtd_info *mtd)
{
    return !!(inl(lpcctl) & LBICTRL_LPCCTL_NR);
}

static int __devinit pasemi_nand_probe(struct platform_device *ofdev)
{
    struct pci_dev *pdev;
    struct device_node *np = ofdev->dev.of_node;
    struct resource res;
    struct nand_chip *chip;
    int err = 0;

    err = of_address_to_resource(np, 0, &res);

    if (err)
        return -EINVAL;

    /* We only support one device at the moment */
    if (pasemi_nand_mtd)
        return -ENODEV;

    pr_debug("pasemi_nand at %pR\n", &res);

    /* Allocate memory for MTD device structure and private data */
    pasemi_nand_mtd = kzalloc(sizeof(struct mtd_info) +
                  sizeof(struct nand_chip), GFP_KERNEL);
    if (!pasemi_nand_mtd) {
        printk(KERN_WARNING
               "Unable to allocate PASEMI NAND MTD device structure\n");
        err = -ENOMEM;
        goto out;
    }

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

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

    chip->IO_ADDR_R = of_iomap(np, 0);
    chip->IO_ADDR_W = chip->IO_ADDR_R;

    if (!chip->IO_ADDR_R) {
        err = -EIO;
        goto out_mtd;
    }

    pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa008, NULL);
    if (!pdev) {
        err = -ENODEV;
        goto out_ior;
    }

    lpcctl = pci_resource_start(pdev, 0);
    pci_dev_put(pdev);

    if (!request_region(lpcctl, 4, driver_name)) {
        err = -EBUSY;
        goto out_ior;
    }

    chip->cmd_ctrl = pasemi_hwcontrol;
    chip->dev_ready = pasemi_device_ready;
    chip->read_buf = pasemi_read_buf;
    chip->write_buf = pasemi_write_buf;
    chip->chip_delay = 0;
    chip->ecc.mode = NAND_ECC_SOFT;

    /* Enable the following for a flash based bad block table */
    chip->bbt_options = NAND_BBT_USE_FLASH;

    /* Scan to find existence of the device */
    if (nand_scan(pasemi_nand_mtd, 1)) {
        err = -ENXIO;
        goto out_lpc;
    }

    if (mtd_device_register(pasemi_nand_mtd, NULL, 0)) {
        printk(KERN_ERR "pasemi_nand: Unable to register MTD device\n");
        err = -ENODEV;
        goto out_lpc;
    }

    printk(KERN_INFO "PA Semi NAND flash at %08llx, control at I/O %x\n",
           res.start, lpcctl);

    return 0;

 out_lpc:
    release_region(lpcctl, 4);
 out_ior:
    iounmap(chip->IO_ADDR_R);
 out_mtd:
    kfree(pasemi_nand_mtd);
 out:
    return err;
}

static int __devexit pasemi_nand_remove(struct platform_device *ofdev)
{
    struct nand_chip *chip;

    if (!pasemi_nand_mtd)
        return 0;

    chip = pasemi_nand_mtd->priv;

    /* Release resources, unregister device */
    nand_release(pasemi_nand_mtd);

    release_region(lpcctl, 4);

    iounmap(chip->IO_ADDR_R);

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

    pasemi_nand_mtd = NULL;

    return 0;
}

static const struct of_device_id pasemi_nand_match[] =
{
    {
        .compatible   = "pasemi,localbus-nand",
    },
    {},
};

MODULE_DEVICE_TABLE(of, pasemi_nand_match);

static struct platform_driver pasemi_nand_driver =
{
    .driver = {
        .name = (char*)driver_name,
        .owner = THIS_MODULE,
        .of_match_table = pasemi_nand_match,
    },
    .probe      = pasemi_nand_probe,
    .remove     = pasemi_nand_remove,
};

module_platform_driver(pasemi_nand_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Egor Martovetsky <[email protected]>");
MODULE_DESCRIPTION("NAND flash interface driver for PA Semi PWRficient");