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
  23 /****************************************************************************/
  24
  25 extern char _ebss;
  26
  27 struct map_info uclinux_ram_map = {
  28         .name = "RAM",
  29         .phys = (unsigned long)&_ebss,
  30         .size = 0,
  31 };
  32
  33 static struct mtd_info *uclinux_ram_mtdinfo;
  34
  35 /****************************************************************************/
  36
  37 static struct mtd_partition uclinux_romfs[] = {
  38         { .name = "ROMfs" }
  39 };
  40
  41 #define NUM_PARTITIONS  ARRAY_SIZE(uclinux_romfs)
  42
  43 /****************************************************************************/
  44
  45 static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  46         size_t *retlen, void **virt, resource_size_t *phys)
  47 {
  48         struct map_info *map = mtd->priv;
  49         *virt = map->virt + from;
  50         if (phys)
  51                 *phys = map->phys + from;
  52         *retlen = len;
  53         return(0);
  54 }
  55
  56 /****************************************************************************/
  57
  58 static int __init uclinux_mtd_init(void)
  59 {
  60         struct mtd_info *mtd;
  61         struct map_info *mapp;
  62
  63         mapp = &uclinux_ram_map;
  64         if (!mapp->size)
  65                 mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
  66         mapp->bankwidth = 4;
  67
  68         printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
  69                 (int) mapp->phys, (int) mapp->size);
  70
  71         mapp->virt = ioremap_nocache(mapp->phys, mapp->size);
  72
  73         if (mapp->virt == 0) {
  74                 printk("uclinux[mtd]: ioremap_nocache() failed\n");
  75                 return(-EIO);
  76         }
  77
  78         simple_map_init(mapp);
  79
  80         mtd = do_map_probe("map_ram", mapp);
  81         if (!mtd) {
  82                 printk("uclinux[mtd]: failed to find a mapping?\n");
  83                 iounmap(mapp->virt);
  84                 return(-ENXIO);
  85         }
  86
  87         mtd->owner = THIS_MODULE;
  88         mtd->point = uclinux_point;
  89         mtd->priv = mapp;
  90
  91         uclinux_ram_mtdinfo = mtd;
  92         mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
  93
  94         return(0);
  95 }
  96
  97 /****************************************************************************/
  98
  99 static void __exit uclinux_mtd_cleanup(void)
 100 {
 101         if (uclinux_ram_mtdinfo) {
 102                 mtd_device_unregister(uclinux_ram_mtdinfo);
 103                 map_destroy(uclinux_ram_mtdinfo);
 104                 uclinux_ram_mtdinfo = NULL;
 105         }
 106         if (uclinux_ram_map.virt) {
 107                 iounmap((void *) uclinux_ram_map.virt);
 108                 uclinux_ram_map.virt = 0;
 109         }
 110 }
 111
 112 /****************************************************************************/
 113
 114 module_init(uclinux_mtd_init);
 115 module_exit(uclinux_mtd_cleanup);
 116
 117 MODULE_LICENSE("GPL");
 118 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 119 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
 120
 121 /****************************************************************************/