nomadik_nand.c

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/*
 *  drivers/mtd/nand/nomadik_nand.c
 *
 *  Overview:
 *      Driver for on-board NAND flash on Nomadik Platforms
 *
 * Copyright © 2007 STMicroelectronics Pvt. Ltd.
 * Author: Sachin Verma <[email protected]>
 *
 * Copyright © 2009 Alessandro Rubini
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/platform_device.h>
#include <linux/mtd/partitions.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/platform_data/mtd-nomadik-nand.h>
#include <mach/fsmc.h>

#include <mtd/mtd-abi.h>

struct nomadik_nand_host {
    struct mtd_info     mtd;
    struct nand_chip    nand;
    void __iomem *data_va;
    void __iomem *cmd_va;
    void __iomem *addr_va;
    struct nand_bbt_descr *bbt_desc;
};

static struct nand_ecclayout nomadik_ecc_layout = {
    .eccbytes = 3 * 4,
    .eccpos = { /* each subpage has 16 bytes: pos 2,3,4 hosts ECC */
        0x02, 0x03, 0x04,
        0x12, 0x13, 0x14,
        0x22, 0x23, 0x24,
        0x32, 0x33, 0x34},
    /* let's keep bytes 5,6,7 for us, just in case we change ECC algo */
    .oobfree = { {0x08, 0x08}, {0x18, 0x08}, {0x28, 0x08}, {0x38, 0x08} },
};

static void nomadik_ecc_control(struct mtd_info *mtd, int mode)
{
    /* No need to enable hw ecc, it's on by default */
}

static void nomadik_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
    struct nand_chip *nand = mtd->priv;
    struct nomadik_nand_host *host = nand->priv;

    if (cmd == NAND_CMD_NONE)
        return;

    if (ctrl & NAND_CLE)
        writeb(cmd, host->cmd_va);
    else
        writeb(cmd, host->addr_va);
}

static int nomadik_nand_probe(struct platform_device *pdev)
{
    struct nomadik_nand_platform_data *pdata = pdev->dev.platform_data;
    struct nomadik_nand_host *host;
    struct mtd_info *mtd;
    struct nand_chip *nand;
    struct resource *res;
    int ret = 0;

    /* Allocate memory for the device structure (and zero it) */
    host = kzalloc(sizeof(struct nomadik_nand_host), GFP_KERNEL);
    if (!host) {
        dev_err(&pdev->dev, "Failed to allocate device structure.\n");
        return -ENOMEM;
    }

    /* Call the client's init function, if any */
    if (pdata->init)
        ret = pdata->init();
    if (ret < 0) {
        dev_err(&pdev->dev, "Init function failed\n");
        goto err;
    }

    /* ioremap three regions */
    res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_addr");
    if (!res) {
        ret = -EIO;
        goto err_unmap;
    }
    host->addr_va = ioremap(res->start, resource_size(res));

    res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_data");
    if (!res) {
        ret = -EIO;
        goto err_unmap;
    }
    host->data_va = ioremap(res->start, resource_size(res));

    res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_cmd");
    if (!res) {
        ret = -EIO;
        goto err_unmap;
    }
    host->cmd_va = ioremap(res->start, resource_size(res));

    if (!host->addr_va || !host->data_va || !host->cmd_va) {
        ret = -ENOMEM;
        goto err_unmap;
    }

    /* Link all private pointers */
    mtd = &host->mtd;
    nand = &host->nand;
    mtd->priv = nand;
    nand->priv = host;

    host->mtd.owner = THIS_MODULE;
    nand->IO_ADDR_R = host->data_va;
    nand->IO_ADDR_W = host->data_va;
    nand->cmd_ctrl = nomadik_cmd_ctrl;

    /*
     * This stanza declares ECC_HW but uses soft routines. It's because
     * HW claims to make the calculation but not the correction. However,
     * I haven't managed to get the desired data out of it until now.
     */
    nand->ecc.mode = NAND_ECC_SOFT;
    nand->ecc.layout = &nomadik_ecc_layout;
    nand->ecc.hwctl = nomadik_ecc_control;
    nand->ecc.size = 512;
    nand->ecc.bytes = 3;

    nand->options = pdata->options;

    /*
     * Scan to find existence of the device
     */
    if (nand_scan(&host->mtd, 1)) {
        ret = -ENXIO;
        goto err_unmap;
    }

    mtd_device_register(&host->mtd, pdata->parts, pdata->nparts);

    platform_set_drvdata(pdev, host);
    return 0;

 err_unmap:
    if (host->cmd_va)
        iounmap(host->cmd_va);
    if (host->data_va)
        iounmap(host->data_va);
    if (host->addr_va)
        iounmap(host->addr_va);
 err:
    kfree(host);
    return ret;
}

/*
 * Clean up routine
 */
static int nomadik_nand_remove(struct platform_device *pdev)
{
    struct nomadik_nand_host *host = platform_get_drvdata(pdev);
    struct nomadik_nand_platform_data *pdata = pdev->dev.platform_data;

    if (pdata->exit)
        pdata->exit();

    if (host) {
        nand_release(&host->mtd);
        iounmap(host->cmd_va);
        iounmap(host->data_va);
        iounmap(host->addr_va);
        kfree(host);
    }
    return 0;
}

static int nomadik_nand_suspend(struct device *dev)
{
    struct nomadik_nand_host *host = dev_get_drvdata(dev);
    int ret = 0;
    if (host)
        ret = mtd_suspend(&host->mtd);
    return ret;
}

static int nomadik_nand_resume(struct device *dev)
{
    struct nomadik_nand_host *host = dev_get_drvdata(dev);
    if (host)
        mtd_resume(&host->mtd);
    return 0;
}

static const struct dev_pm_ops nomadik_nand_pm_ops = {
    .suspend = nomadik_nand_suspend,
    .resume = nomadik_nand_resume,
};

static struct platform_driver nomadik_nand_driver = {
    .probe = nomadik_nand_probe,
    .remove = nomadik_nand_remove,
    .driver = {
        .owner = THIS_MODULE,
        .name = "nomadik_nand",
        .pm = &nomadik_nand_pm_ops,
    },
};

module_platform_driver(nomadik_nand_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("ST Microelectronics ([email protected])");
MODULE_DESCRIPTION("NAND driver for Nomadik Platform");