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 1.13 2004/12/12 12:11:10 gerg 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 struct map_info uclinux_ram_map = {
  29         .name = "RAM",
  30 };
  31
  32 struct mtd_info *uclinux_ram_mtdinfo;
  33
  34 /****************************************************************************/
  35
  36 struct mtd_partition uclinux_romfs[] = {
  37         { .name = "ROMfs" }
  38 };
  39
  40 #define NUM_PARTITIONS  (sizeof(uclinux_romfs) / sizeof(uclinux_romfs[0]))
  41
  42 /****************************************************************************/
  43
  44 int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  45         size_t *retlen, u_char **mtdbuf)
  46 {
  47         struct map_info *map = (struct map_info *) mtd->priv;
  48         *mtdbuf = (u_char *) (map->virt + ((int) from));
  49         *retlen = len;
  50         return(0);
  51 }
  52
  53 /****************************************************************************/
  54
  55 int __init uclinux_mtd_init(void)
  56 {
  57         struct mtd_info *mtd;
  58         struct map_info *mapp;
  59         extern char _ebss;
  60         unsigned long addr = (unsigned long) &_ebss;
  61
  62         mapp = &uclinux_ram_map;
  63         mapp->phys = addr;
  64         mapp->size = PAGE_ALIGN(*((unsigned long *)(addr + 8)));
  65         mapp->bankwidth = 4;
  66
  67         printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
  68                 (int) mapp->phys, (int) mapp->size);
  69
  70         mapp->virt = ioremap_nocache(mapp->phys, mapp->size);
  71
  72         if (!mapp->virt) {
  73                 printk("uclinux[mtd]: ioremap_nocache() failed\n");
  74                 return(-EIO);
  75         }
  76
  77         simple_map_init(mapp);
  78
  79         mtd = do_map_probe("map_ram", mapp);
  80         if (!mtd) {
  81                 printk("uclinux[mtd]: failed to find a mapping?\n");
  82                 iounmap(mapp->virt);
  83                 return(-ENXIO);
  84         }
  85
  86         mtd->owner = THIS_MODULE;
  87         mtd->point = uclinux_point;
  88         mtd->priv = mapp;
  89
  90         uclinux_ram_mtdinfo = mtd;
  91         add_mtd_partitions(mtd, uclinux_romfs, NUM_PARTITIONS);
  92
  93         printk("uclinux[mtd]: set %s to be root filesystem\n",
  94                 uclinux_romfs[0].name);
  95         ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, 0);
  96
  97         return(0);
  98 }
  99
 100 /****************************************************************************/
 101
 102 void __exit uclinux_mtd_cleanup(void)
 103 {
 104         if (uclinux_ram_mtdinfo) {
 105                 del_mtd_partitions(uclinux_ram_mtdinfo);
 106                 map_destroy(uclinux_ram_mtdinfo);
 107                 uclinux_ram_mtdinfo = NULL;
 108         }
 109         if (uclinux_ram_map.virt) {
 110                 iounmap((void *) uclinux_ram_map.virt);
 111                 uclinux_ram_map.virt = 0;
 112         }
 113 }
 114
 115 /****************************************************************************/
 116
 117 module_init(uclinux_mtd_init);
 118 module_exit(uclinux_mtd_cleanup);
 119
 120 MODULE_LICENSE("GPL");
 121 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 122 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
 123
 124 /****************************************************************************/