/*
 * Generic NAND driver
 *
 * Author: Vitaly Wool <vitalywool@gmail.com>
 *
 * 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 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 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 = 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");