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
  34/*
  35 * Blackfin uses uclinux_ram_map during startup, so it must not be static.
  36 * Provide a dummy declaration to make sparse happy.
  37 */
  38extern struct map_info uclinux_ram_map;
  39
  40struct map_info uclinux_ram_map = {
  41        .name = MAP_NAME,
  42        .size = 0,
  43};
  44
  45static unsigned long physaddr = -1;
  46module_param(physaddr, ulong, S_IRUGO);
  47
  48static struct mtd_info *uclinux_ram_mtdinfo;
  49
  50/****************************************************************************/
  51
  52static struct mtd_partition uclinux_romfs[] = {
  53        { .name = "ROMfs" }
  54};
  55
  56#define NUM_PARTITIONS  ARRAY_SIZE(uclinux_romfs)
  57
  58/****************************************************************************/
  59
  60static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  61        size_t *retlen, void **virt, resource_size_t *phys)
  62{
  63        struct map_info *map = mtd->priv;
  64        *virt = map->virt + from;
  65        if (phys)
  66                *phys = map->phys + from;
  67        *retlen = len;
  68        return(0);
  69}
  70
  71/****************************************************************************/
  72
  73static int __init uclinux_mtd_init(void)
  74{
  75        struct mtd_info *mtd;
  76        struct map_info *mapp;
  77
  78        mapp = &uclinux_ram_map;
  79
  80        if (physaddr == -1)
  81                mapp->phys = (resource_size_t)__bss_stop;
  82        else
  83                mapp->phys = physaddr;
  84
  85        if (!mapp->size)
  86                mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
  87        mapp->bankwidth = 4;
  88
  89        printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
  90                (int) mapp->phys, (int) mapp->size);
  91
  92        /*
  93         * The filesystem is guaranteed to be in direct mapped memory. It is
  94         * directly following the kernels own bss region. Following the same
  95         * mechanism used by architectures setting up traditional initrds we
  96         * use phys_to_virt to get the virtual address of its start.
  97         */
  98        mapp->virt = phys_to_virt(mapp->phys);
  99
 100        if (mapp->virt == 0) {
 101                printk("uclinux[mtd]: no virtual mapping?\n");
 102                return(-EIO);
 103        }
 104
 105        simple_map_init(mapp);
 106
 107        mtd = do_map_probe("map_" MAP_NAME, mapp);
 108        if (!mtd) {
 109                printk("uclinux[mtd]: failed to find a mapping?\n");
 110                return(-ENXIO);
 111        }
 112
 113        mtd->owner = THIS_MODULE;
 114        mtd->_point = uclinux_point;
 115        mtd->priv = mapp;
 116
 117        uclinux_ram_mtdinfo = mtd;
 118        mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
 119
 120        return(0);
 121}
 122device_initcall(uclinux_mtd_init);
 123
 124/****************************************************************************/
 125