/****************************************************************************/

/*
 *      uclinux.c -- generic memory mapped MTD driver for uclinux
 *
 *      (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
 *
 *      License: GPL
 */

/****************************************************************************/

#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/major.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
#include <asm/sections.h>

/****************************************************************************/

#ifdef CONFIG_MTD_ROM
#define MAP_NAME "rom"
#else
#define MAP_NAME "ram"
#endif

static struct map_info uclinux_ram_map = {
        .name = MAP_NAME,
        .size = 0,
};

static unsigned long physaddr = -1;
module_param(physaddr, ulong, S_IRUGO);

static struct mtd_info *uclinux_ram_mtdinfo;

/****************************************************************************/

static const struct mtd_partition uclinux_romfs[] = {
        { .name = "ROMfs" }
};

#define NUM_PARTITIONS  ARRAY_SIZE(uclinux_romfs)

/****************************************************************************/

static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
        size_t *retlen, void **virt, resource_size_t *phys)
{
        struct map_info *map = mtd->priv;
        *virt = map->virt + from;
        if (phys)
                *phys = map->phys + from;
        *retlen = len;
        return(0);
}

/****************************************************************************/

static int __init uclinux_mtd_init(void)
{
        struct mtd_info *mtd;
        struct map_info *mapp;

        mapp = &uclinux_ram_map;

        if (physaddr == -1)
                mapp->phys = (resource_size_t)__bss_stop;
        else
                mapp->phys = physaddr;

        if (!mapp->size)
                mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
        mapp->bankwidth = 4;

        printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
                (int) mapp->phys, (int) mapp->size);

        /*
         * The filesystem is guaranteed to be in direct mapped memory. It is
         * directly following the kernels own bss region. Following the same
         * mechanism used by architectures setting up traditional initrds we
         * use phys_to_virt to get the virtual address of its start.
         */
        mapp->virt = phys_to_virt(mapp->phys);

        if (mapp->virt == 0) {
                printk("uclinux[mtd]: no virtual mapping?\n");
                return(-EIO);
        }

        simple_map_init(mapp);

        mtd = do_map_probe("map_" MAP_NAME, mapp);
        if (!mtd) {
                printk("uclinux[mtd]: failed to find a mapping?\n");
                return(-ENXIO);
        }

        mtd->owner = THIS_MODULE;
        mtd->_point = uclinux_point;
        mtd->priv = mapp;

        uclinux_ram_mtdinfo = mtd;
        mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);

        return(0);
}
device_initcall(uclinux_mtd_init);

/****************************************************************************/