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  *      $Id: uclinux.c,v 1.12 2005/11/07 11:14:29 gleixner Exp $
   9  */
  10
  11 /****************************************************************************/
  12
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/fs.h>
  18 #include <linux/major.h>
  19 #include <linux/root_dev.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
  25 /****************************************************************************/
  26
  27 #ifdef CONFIG_MTD_UCLINUX_EBSS
  28         #define MAP_TYPE        "map_ram"
  29         #define MAP_NAME        "RAM"
  30         #define  CONFIG_MTD_UCLINUX_ADDRESS &_ebss
  31         extern char _ebss;
  32 #elif CONFIG_MTD_UCLINUX_RAM
  33         #define MAP_TYPE        "map_ram"
  34         #define MAP_NAME        "RAM"
  35 #elif CONFIG_MTD_UCLINUX_ROM
  36         #define MAP_TYPE        "map_rom"
  37         #define MAP_NAME        "ROM"
  38 #else
  39         #error "Unknown uClinux map type"
  40 #endif
  41
  42 /****************************************************************************/
  43
  44 struct map_info uclinux_map = {
  45         .name = MAP_NAME,
  46 };
  47
  48 struct mtd_info *uclinux_mtdinfo;
  49
  50 /****************************************************************************/
  51
  52 struct mtd_partition uclinux_fs[] = {
  53         { .name = "ROMfs" }
  54 };
  55
  56 #define NUM_PARTITIONS  ARRAY_SIZE(uclinux_fs)
  57
  58 /****************************************************************************/
  59
  60 int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  61         size_t *retlen, u_char **mtdbuf)
  62 {
  63         struct map_info *map = mtd->priv;
  64         *mtdbuf = (u_char *) (map->virt + ((int) from));
  65         *retlen = len;
  66         return(0);
  67 }
  68
  69 /****************************************************************************/
  70
  71 int __init uclinux_mtd_init(void)
  72 {
  73         struct mtd_info *mtd;
  74         struct map_info *mapp;
  75         unsigned long addr = (unsigned long) CONFIG_MTD_UCLINUX_ADDRESS;
  76
  77         mapp = &uclinux_map;
  78         mapp->phys = addr;
  79         mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(addr + 8))));
  80         mapp->bankwidth = 4;
  81
  82         printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
  83                 (int) mapp->phys, (int) mapp->size);
  84
  85         mapp->virt = ioremap_nocache(mapp->phys, mapp->size);
  86
  87         if (mapp->virt == 0) {
  88                 printk("uclinux[mtd]: ioremap_nocache() failed\n");
  89                 return(-EIO);
  90         }
  91
  92         simple_map_init(mapp);
  93
  94         mtd = do_map_probe(MAP_TYPE, mapp);
  95         if (!mtd) {
  96                 printk("uclinux[mtd]: failed to find a mapping?\n");
  97                 iounmap(mapp->virt);
  98                 return(-ENXIO);
  99         }
 100
 101         mtd->owner = THIS_MODULE;
 102         mtd->point = uclinux_point;
 103         mtd->priv = mapp;
 104
 105         uclinux_mtdinfo = mtd;
 106         add_mtd_partitions(mtd, uclinux_fs, NUM_PARTITIONS);
 107
 108         printk("uclinux[mtd]: set %s to be root filesystem\n",
 109                 uclinux_fs[0].name);
 110         ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, 0);
 111
 112         return(0);
 113 }
 114
 115 /****************************************************************************/
 116
 117 void __exit uclinux_mtd_cleanup(void)
 118 {
 119         if (uclinux_mtdinfo) {
 120                 del_mtd_partitions(uclinux_mtdinfo);
 121                 map_destroy(uclinux_mtdinfo);
 122                 uclinux_mtdinfo = NULL;
 123         }
 124         if (uclinux_map.virt) {
 125                 iounmap((void *) uclinux_map.virt);
 126                 uclinux_map.virt = 0;
 127         }
 128 }
 129
 130 /****************************************************************************/
 131
 132 module_init(uclinux_mtd_init);
 133 module_exit(uclinux_mtd_cleanup);
 134
 135 MODULE_LICENSE("GPL");
 136 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 137 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
 138
 139 /****************************************************************************/