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
   9/****************************************************************************/
  10
  11#include <linux/module.h>
  12#include <linux/types.h>
  13#include <linux/init.h>
  14#include <linux/kernel.h>
  15#include <linux/fs.h>
  16#include <linux/mm.h>
  17#include <linux/major.h>
  18#include <linux/mtd/mtd.h>
  19#include <linux/mtd/map.h>
  20#include <linux/mtd/partitions.h>
  21#include <asm/io.h>
  22#include <asm/sections.h>
  23
  24/****************************************************************************/
  25
  26#ifdef CONFIG_MTD_ROM
  27#define MAP_NAME "rom"
  28#else
  29#define MAP_NAME "ram"
  30#endif
  31
  32/*
  33 * Blackfin uses uclinux_ram_map during startup, so it must not be static.
  34 * Provide a dummy declaration to make sparse happy.
  35 */
  36extern struct map_info uclinux_ram_map;
  37
  38struct map_info uclinux_ram_map = {
  39        .name = MAP_NAME,
  40        .size = 0,
  41};
  42
  43static unsigned long physaddr = -1;
  44module_param(physaddr, ulong, S_IRUGO);
  45
  46static struct mtd_info *uclinux_ram_mtdinfo;
  47
  48/****************************************************************************/
  49
  50static struct mtd_partition uclinux_romfs[] = {
  51        { .name = "ROMfs" }
  52};
  53
  54#define NUM_PARTITIONS  ARRAY_SIZE(uclinux_romfs)
  55
  56/****************************************************************************/
  57
  58static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  59        size_t *retlen, void **virt, resource_size_t *phys)
  60{
  61        struct map_info *map = mtd->priv;
  62        *virt = map->virt + from;
  63        if (phys)
  64                *phys = map->phys + from;
  65        *retlen = len;
  66        return(0);
  67}
  68
  69/****************************************************************************/
  70
  71static int __init uclinux_mtd_init(void)
  72{
  73        struct mtd_info *mtd;
  74        struct map_info *mapp;
  75
  76        mapp = &uclinux_ram_map;
  77
  78        if (physaddr == -1)
  79                mapp->phys = (resource_size_t)__bss_stop;
  80        else
  81                mapp->phys = physaddr;
  82
  83        if (!mapp->size)
  84                mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
  85        mapp->bankwidth = 4;
  86
  87        printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
  88                (int) mapp->phys, (int) mapp->size);
  89
  90        /*
  91         * The filesystem is guaranteed to be in direct mapped memory. It is
  92         * directly following the kernels own bss region. Following the same
  93         * mechanism used by architectures setting up traditional initrds we
  94         * use phys_to_virt to get the virtual address of its start.
  95         */
  96        mapp->virt = phys_to_virt(mapp->phys);
  97
  98        if (mapp->virt == 0) {
  99                printk("uclinux[mtd]: no virtual mapping?\n");
 100                return(-EIO);
 101        }
 102
 103        simple_map_init(mapp);
 104
 105        mtd = do_map_probe("map_" MAP_NAME, mapp);
 106        if (!mtd) {
 107                printk("uclinux[mtd]: failed to find a mapping?\n");
 108                return(-ENXIO);
 109        }
 110
 111        mtd->owner = THIS_MODULE;
 112        mtd->_point = uclinux_point;
 113        mtd->priv = mapp;
 114
 115        uclinux_ram_mtdinfo = mtd;
 116        mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
 117
 118        return(0);
 119}
 120
 121/****************************************************************************/
 122
 123static void __exit uclinux_mtd_cleanup(void)
 124{
 125        if (uclinux_ram_mtdinfo) {
 126                mtd_device_unregister(uclinux_ram_mtdinfo);
 127                map_destroy(uclinux_ram_mtdinfo);
 128                uclinux_ram_mtdinfo = NULL;
 129        }
 130        if (uclinux_ram_map.virt)
 131                uclinux_ram_map.virt = 0;
 132}
 133
 134/****************************************************************************/
 135
 136module_init(uclinux_mtd_init);
 137module_exit(uclinux_mtd_cleanup);
 138
 139MODULE_LICENSE("GPL");
 140MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 141MODULE_DESCRIPTION("Generic MTD for uClinux");
 142
 143/****************************************************************************/
 144