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 #include <asm/sections.h>
  23
  24 /****************************************************************************/
  25
  26 struct map_info uclinux_ram_map = {
  27         .name = "RAM",
  28         .phys = (unsigned long)__bss_stop,
  29         .size = 0,
  30 };
  31
  32 static struct mtd_info *uclinux_ram_mtdinfo;
  33
  34 /****************************************************************************/
  35
  36 static struct mtd_partition uclinux_romfs[] = {
  37         { .name = "ROMfs" }
  38 };
  39
  40 #define NUM_PARTITIONS  ARRAY_SIZE(uclinux_romfs)
  41
  42 /****************************************************************************/
  43
  44 static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
  45         size_t *retlen, void **virt, resource_size_t *phys)
  46 {
  47         struct map_info *map = mtd->priv;
  48         *virt = map->virt + from;
  49         if (phys)
  50                 *phys = map->phys + from;
  51         *retlen = len;
  52         return(0);
  53 }
  54
  55 /****************************************************************************/
  56
  57 static int __init uclinux_mtd_init(void)
  58 {
  59         struct mtd_info *mtd;
  60         struct map_info *mapp;
  61
  62         mapp = &uclinux_ram_map;
  63         if (!mapp->size)
  64                 mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 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 == 0) {
  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         mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
  92
  93         return(0);
  94 }
  95
  96 /****************************************************************************/
  97
  98 static void __exit uclinux_mtd_cleanup(void)
  99 {
 100         if (uclinux_ram_mtdinfo) {
 101                 mtd_device_unregister(uclinux_ram_mtdinfo);
 102                 map_destroy(uclinux_ram_mtdinfo);
 103                 uclinux_ram_mtdinfo = NULL;
 104         }
 105         if (uclinux_ram_map.virt) {
 106                 iounmap((void *) uclinux_ram_map.virt);
 107                 uclinux_ram_map.virt = 0;
 108         }
 109 }
 110
 111 /****************************************************************************/
 112
 113 module_init(uclinux_mtd_init);
 114 module_exit(uclinux_mtd_cleanup);
 115
 116 MODULE_LICENSE("GPL");
 117 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 118 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
 119
 120 /****************************************************************************/