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