plat_nand.c

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/*
 * Generic NAND driver
 *
 * Author: Vitaly Wool <[email protected]>
 *
 * 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/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>

struct plat_nand_data {
    struct nand_chip    chip;
    struct mtd_info     mtd;
    void __iomem        *io_base;
};

static const char *part_probe_types[] = { "cmdlinepart", NULL };

/*
 * Probe for the NAND device.
 */
static int __devinit plat_nand_probe(struct platform_device *pdev)
{
    struct platform_nand_data *pdata = pdev->dev.platform_data;
    struct mtd_part_parser_data ppdata;
    struct plat_nand_data *data;
    struct resource *res;
    const char **part_types;
    int err = 0;

    if (!pdata) {
        dev_err(&pdev->dev, "platform_nand_data is missing\n");
        return -EINVAL;
    }

    if (pdata->chip.nr_chips < 1) {
        dev_err(&pdev->dev, "invalid number of chips specified\n");
        return -EINVAL;
    }

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res)
        return -ENXIO;

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

    if (!request_mem_region(res->start, resource_size(res),
                dev_name(&pdev->dev))) {
        dev_err(&pdev->dev, "request_mem_region failed\n");
        err = -EBUSY;
        goto out_free;
    }

    data->io_base = ioremap(res->start, resource_size(res));
    if (data->io_base == NULL) {
        dev_err(&pdev->dev, "ioremap failed\n");
        err = -EIO;
        goto out_release_io;
    }

    data->chip.priv = &data;
    data->mtd.priv = &data->chip;
    data->mtd.owner = THIS_MODULE;
    data->mtd.name = dev_name(&pdev->dev);

    data->chip.IO_ADDR_R = data->io_base;
    data->chip.IO_ADDR_W = data->io_base;
    data->chip.cmd_ctrl = pdata->ctrl.cmd_ctrl;
    data->chip.dev_ready = pdata->ctrl.dev_ready;
    data->chip.select_chip = pdata->ctrl.select_chip;
    data->chip.write_buf = pdata->ctrl.write_buf;
    data->chip.read_buf = pdata->ctrl.read_buf;
    data->chip.read_byte = pdata->ctrl.read_byte;
    data->chip.chip_delay = pdata->chip.chip_delay;
    data->chip.options |= pdata->chip.options;
    data->chip.bbt_options |= pdata->chip.bbt_options;

    data->chip.ecc.hwctl = pdata->ctrl.hwcontrol;
    data->chip.ecc.layout = pdata->chip.ecclayout;
    data->chip.ecc.mode = NAND_ECC_SOFT;

    platform_set_drvdata(pdev, data);

    /* Handle any platform specific setup */
    if (pdata->ctrl.probe) {
        err = pdata->ctrl.probe(pdev);
        if (err)
            goto out;
    }

    /* Scan to find existence of the device */
    if (nand_scan(&data->mtd, pdata->chip.nr_chips)) {
        err = -ENXIO;
        goto out;
    }

    part_types = pdata->chip.part_probe_types ? : part_probe_types;

    ppdata.of_node = pdev->dev.of_node;
    err = mtd_device_parse_register(&data->mtd, part_types, &ppdata,
                    pdata->chip.partitions,
                    pdata->chip.nr_partitions);

    if (!err)
        return err;

    nand_release(&data->mtd);
out:
    if (pdata->ctrl.remove)
        pdata->ctrl.remove(pdev);
    platform_set_drvdata(pdev, NULL);
    iounmap(data->io_base);
out_release_io:
    release_mem_region(res->start, resource_size(res));
out_free:
    kfree(data);
    return err;
}

/*
 * Remove a NAND device.
 */
static int __devexit plat_nand_remove(struct platform_device *pdev)
{
    struct plat_nand_data *data = platform_get_drvdata(pdev);
    struct platform_nand_data *pdata = pdev->dev.platform_data;
    struct resource *res;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    nand_release(&data->mtd);
    if (pdata->ctrl.remove)
        pdata->ctrl.remove(pdev);
    iounmap(data->io_base);
    release_mem_region(res->start, resource_size(res));
    kfree(data);

    return 0;
}

static const struct of_device_id plat_nand_match[] = {
    { .compatible = "gen_nand" },
    {},
};
MODULE_DEVICE_TABLE(of, plat_nand_match);

static struct platform_driver plat_nand_driver = {
    .probe  = plat_nand_probe,
    .remove = __devexit_p(plat_nand_remove),
    .driver = {
        .name       = "gen_nand",
        .owner      = THIS_MODULE,
        .of_match_table = plat_nand_match,
    },
};

module_platform_driver(plat_nand_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vitaly Wool");
MODULE_DESCRIPTION("Simple generic NAND driver");
MODULE_ALIAS("platform:gen_nand");