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 1.10 2005/01/05 18:05:13 dwmw2 Exp $
   9  */
  10
  11 /****************************************************************************/
  12
  13 #include <linux/config.h>
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/fs.h>
  19 #include <linux/major.h>
  20 #include <linux/root_dev.h>
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/map.h>
  23 #include <linux/mtd/partitions.h>
  24 #include <asm/io.h>
  25
  26 /****************************************************************************/
  27
  28
  29 /****************************************************************************/
  30
  31 struct map_info uclinux_ram_map = {
  32         .name = "RAM",
  33 };
  34
  35 struct mtd_info *uclinux_ram_mtdinfo;
  36
  37 /****************************************************************************/
  38
  39 struct mtd_partition uclinux_romfs[] = {
  40         { .name = "ROMfs" }
  41 };
  42
  43 #define NUM_PARTITIONS  (sizeof(uclinux_romfs) / sizeof(uclinux_romfs[0]))
  44
  45 /****************************************************************************/
  46
  47 int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  48         size_t *retlen, u_char **mtdbuf)
  49 {
  50         struct map_info *map = mtd->priv;
  51         *mtdbuf = (u_char *) (map->virt + ((int) from));
  52         *retlen = len;
  53         return(0);
  54 }
  55
  56 /****************************************************************************/
  57
  58 int __init uclinux_mtd_init(void)
  59 {
  60         struct mtd_info *mtd;
  61         struct map_info *mapp;
  62         extern char _ebss;
  63
  64         mapp = &uclinux_ram_map;
  65         mapp->phys = (unsigned long) &_ebss;
  66         mapp->size = PAGE_ALIGN(*((unsigned long *)((&_ebss) + 8)));
  67         mapp->bankwidth = 4;
  68
  69         printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
  70                 (int) mapp->map_priv_2, (int) mapp->size);
  71
  72         mapp->virt = ioremap_nocache(mapp->phys, mapp->size);
  73
  74         if (mapp->virt == 0) {
  75                 printk("uclinux[mtd]: ioremap_nocache() failed\n");
  76                 return(-EIO);
  77         }
  78
  79         simple_map_init(mapp);
  80
  81         mtd = do_map_probe("map_ram", mapp);
  82         if (!mtd) {
  83                 printk("uclinux[mtd]: failed to find a mapping?\n");
  84                 iounmap(mapp->virt);
  85                 return(-ENXIO);
  86         }
  87
  88         mtd->owner = THIS_MODULE;
  89         mtd->point = uclinux_point;
  90         mtd->priv = mapp;
  91
  92         uclinux_ram_mtdinfo = mtd;
  93         add_mtd_partitions(mtd, uclinux_romfs, NUM_PARTITIONS);
  94
  95         printk("uclinux[mtd]: set %s to be root filesystem\n",
  96                 uclinux_romfs[0].name);
  97         ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, 0);
  98         put_mtd_device(mtd);
  99
 100         return(0);
 101 }
 102
 103 /****************************************************************************/
 104
 105 void __exit uclinux_mtd_cleanup(void)
 106 {
 107         if (uclinux_ram_mtdinfo) {
 108                 del_mtd_partitions(uclinux_ram_mtdinfo);
 109                 map_destroy(uclinux_ram_mtdinfo);
 110                 uclinux_ram_mtdinfo = NULL;
 111         }
 112         if (uclinux_ram_map.map_priv_1) {
 113                 iounmap((void *) uclinux_ram_map.virt);
 114                 uclinux_ram_map.virt = 0;
 115         }
 116 }
 117
 118 /****************************************************************************/
 119
 120 module_init(uclinux_mtd_init);
 121 module_exit(uclinux_mtd_cleanup);
 122
 123 MODULE_LICENSE("GPL");
 124 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 125 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
 126
 127 /****************************************************************************/