LXR linux/drivers/mtd/maps/uclinux.c

   1/****************************************************************************/
   2
   3/*
   4 *      uclinux.c -- generic memory mapped MTD driver for uclinux
   5 *
   6 *      (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
   7 *
   8 *      License: GPL
   9 */
  10
  11/****************************************************************************/
  12
  13#include <linux/moduleparam.h>
  14#include <linux/types.h>
  15#include <linux/init.h>
  16#include <linux/kernel.h>
  17#include <linux/fs.h>
  18#include <linux/mm.h>
  19#include <linux/major.h>
  20#include <linux/mtd/mtd.h>
  21#include <linux/mtd/map.h>
  22#include <linux/mtd/partitions.h>
  23#include <asm/io.h>
  24#include <asm/sections.h>
  25
  26/****************************************************************************/
  27
  28#ifdef CONFIG_MTD_ROM
  29#define MAP_NAME "rom"
  30#else
  31#define MAP_NAME "ram"
  32#endif
  33
  34static struct map_info uclinux_ram_map = {
  35        .name = MAP_NAME,
  36        .size = 0,
  37};
  38
  39static unsigned long physaddr = -1;
  40module_param(physaddr, ulong, S_IRUGO);
  41
  42static struct mtd_info *uclinux_ram_mtdinfo;
  43
  44/****************************************************************************/
  45
  46static const struct mtd_partition uclinux_romfs[] = {
  47        { .name = "ROMfs" }
  48};
  49
  50#define NUM_PARTITIONS  ARRAY_SIZE(uclinux_romfs)
  51
  52/****************************************************************************/
  53
  54static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  55        size_t *retlen, void **virt, resource_size_t *phys)
  56{
  57        struct map_info *map = mtd->priv;
  58        *virt = map->virt + from;
  59        if (phys)
  60                *phys = map->phys + from;
  61        *retlen = len;
  62        return(0);
  63}
  64
  65/****************************************************************************/
  66
  67static int __init uclinux_mtd_init(void)
  68{
  69        struct mtd_info *mtd;
  70        struct map_info *mapp;
  71
  72        mapp = &uclinux_ram_map;
  73
  74        if (physaddr == -1)
  75                mapp->phys = (resource_size_t)__bss_stop;
  76        else
  77                mapp->phys = physaddr;
  78
  79        if (!mapp->size)
  80                mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
  81        mapp->bankwidth = 4;
  82
  83        printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
  84                (int) mapp->phys, (int) mapp->size);
  85
  86        /*
  87         * The filesystem is guaranteed to be in direct mapped memory. It is
  88         * directly following the kernels own bss region. Following the same
  89         * mechanism used by architectures setting up traditional initrds we
  90         * use phys_to_virt to get the virtual address of its start.
  91         */
  92        mapp->virt = phys_to_virt(mapp->phys);
  93
  94        if (mapp->virt == 0) {
  95                printk("uclinux[mtd]: no virtual mapping?\n");
  96                return(-EIO);
  97        }
  98
  99        simple_map_init(mapp);
 100
 101        mtd = do_map_probe("map_" MAP_NAME, mapp);
 102        if (!mtd) {
 103                printk("uclinux[mtd]: failed to find a mapping?\n");
 104                return(-ENXIO);
 105        }
 106
 107        mtd->owner = THIS_MODULE;
 108        mtd->_point = uclinux_point;
 109        mtd->priv = mapp;
 110
 111        uclinux_ram_mtdinfo = mtd;
 112        mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
 113
 114        return(0);
 115}
 116device_initcall(uclinux_mtd_init);
 117
 118/****************************************************************************/
 119