ixp2000.c

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/*
 * drivers/mtd/maps/ixp2000.c
 *
 * Mapping for the Intel XScale IXP2000 based systems
 *
 * Copyright (C) 2002 Intel Corp.
 * Copyright (C) 2003-2004 MontaVista Software, Inc.
 *
 * Original Author: Naeem M Afzal <[email protected]>
 * Maintainer: Deepak Saxena <[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/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/platform_device.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>

#include <asm/io.h>
#include <mach/hardware.h>
#include <asm/mach/flash.h>

#include <linux/reboot.h>

struct ixp2000_flash_info {
    struct      mtd_info *mtd;
    struct      map_info map;
    struct      resource *res;
};

static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
{
    unsigned long (*set_bank)(unsigned long) =
        (unsigned long(*)(unsigned long))map->map_priv_2;

    return (set_bank ? set_bank(ofs) : ofs);
}

#ifdef __ARMEB__
/*
 * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
 * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
 * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
 */
static int erratum44_workaround = 0;

static inline unsigned long address_fix8_write(unsigned long addr)
{
    if (erratum44_workaround) {
        return (addr ^ 3);
    }
    return addr;
}
#else

#define address_fix8_write(x)   (x)
#endif

static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
{
    map_word val;

    val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
    return val;
}

/*
 * We can't use the standard memcpy due to the broken SlowPort
 * address translation on rev A0 and A1 silicon and the fact that
 * we have banked flash.
 */
static void ixp2000_flash_copy_from(struct map_info *map, void *to,
                  unsigned long from, ssize_t len)
{
    from = flash_bank_setup(map, from);
    while(len--)
        *(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
}

static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
{
    *(__u8 *) (address_fix8_write(map->map_priv_1 +
                      flash_bank_setup(map, ofs))) = d.x[0];
}

static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
                const void *from, ssize_t len)
{
    to = flash_bank_setup(map, to);
    while(len--) {
        unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
        *(__u8 *)(tmp) = *(__u8 *)(from++);
    }
}


static int ixp2000_flash_remove(struct platform_device *dev)
{
    struct flash_platform_data *plat = dev->dev.platform_data;
    struct ixp2000_flash_info *info = platform_get_drvdata(dev);

    platform_set_drvdata(dev, NULL);

    if(!info)
        return 0;

    if (info->mtd) {
        mtd_device_unregister(info->mtd);
        map_destroy(info->mtd);
    }
    if (info->map.map_priv_1)
        iounmap((void *) info->map.map_priv_1);

    if (info->res) {
        release_resource(info->res);
        kfree(info->res);
    }

    if (plat->exit)
        plat->exit();

    return 0;
}


static int ixp2000_flash_probe(struct platform_device *dev)
{
    static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
    struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
    struct flash_platform_data *plat;
    struct ixp2000_flash_info *info;
    unsigned long window_size;
    int err = -1;

    if (!ixp_data)
        return -ENODEV;

    plat = ixp_data->platform_data;
    if (!plat)
        return -ENODEV;

    window_size = resource_size(dev->resource);
    dev_info(&dev->dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
         ixp_data->nr_banks, ((u32)window_size >> 20));

    if (plat->width != 1) {
        dev_err(&dev->dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
            plat->width * 8);
        return -EIO;
    }

    info = kzalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
    if(!info) {
        err = -ENOMEM;
        goto Error;
    }

    platform_set_drvdata(dev, info);

    /*
     * Tell the MTD layer we're not 1:1 mapped so that it does
     * not attempt to do a direct access on us.
     */
    info->map.phys = NO_XIP;

    info->map.size = ixp_data->nr_banks * window_size;
    info->map.bankwidth = 1;

    /*
     * map_priv_2 is used to store a ptr to the bank_setup routine
     */
    info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;

    info->map.name = dev_name(&dev->dev);
    info->map.read = ixp2000_flash_read8;
    info->map.write = ixp2000_flash_write8;
    info->map.copy_from = ixp2000_flash_copy_from;
    info->map.copy_to = ixp2000_flash_copy_to;

    info->res = request_mem_region(dev->resource->start,
                       resource_size(dev->resource),
                       dev_name(&dev->dev));
    if (!info->res) {
        dev_err(&dev->dev, "Could not reserve memory region\n");
        err = -ENOMEM;
        goto Error;
    }

    info->map.map_priv_1 =
        (unsigned long)ioremap(dev->resource->start,
                       resource_size(dev->resource));
    if (!info->map.map_priv_1) {
        dev_err(&dev->dev, "Failed to ioremap flash region\n");
        err = -EIO;
        goto Error;
    }

#if defined(__ARMEB__)
    /*
     * Enable erratum 44 workaround for NPUs with broken slowport
     */

    erratum44_workaround = ixp2000_has_broken_slowport();
    dev_info(&dev->dev, "Erratum 44 workaround %s\n",
           erratum44_workaround ? "enabled" : "disabled");
#endif

    info->mtd = do_map_probe(plat->map_name, &info->map);
    if (!info->mtd) {
        dev_err(&dev->dev, "map_probe failed\n");
        err = -ENXIO;
        goto Error;
    }
    info->mtd->owner = THIS_MODULE;

    err = mtd_device_parse_register(info->mtd, probes, NULL, NULL, 0);
    if (err)
        goto Error;

    return 0;

Error:
    ixp2000_flash_remove(dev);
    return err;
}

static struct platform_driver ixp2000_flash_driver = {
    .probe      = ixp2000_flash_probe,
    .remove     = ixp2000_flash_remove,
    .driver     = {
        .name   = "IXP2000-Flash",
        .owner  = THIS_MODULE,
    },
};

module_platform_driver(ixp2000_flash_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Deepak Saxena <[email protected]>");
MODULE_ALIAS("platform:IXP2000-Flash");