LXR linux/drivers/mtd/maps/autcpu12-nvram.c

   1/*
   2 * NV-RAM memory access on autcpu12
   3 * (C) 2002 Thomas Gleixner (gleixner@autronix.de)
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 *
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/types.h>
  23#include <linux/kernel.h>
  24#include <linux/ioport.h>
  25#include <linux/init.h>
  26#include <asm/io.h>
  27#include <asm/sizes.h>
  28#include <mach/hardware.h>
  29#include <mach/autcpu12.h>
  30#include <linux/mtd/mtd.h>
  31#include <linux/mtd/map.h>
  32#include <linux/mtd/partitions.h>
  33
  34
  35static struct mtd_info *sram_mtd;
  36
  37struct map_info autcpu12_sram_map = {
  38        .name = "SRAM",
  39        .size = 32768,
  40        .bankwidth = 4,
  41        .phys = 0x12000000,
  42};
  43
  44static int __init init_autcpu12_sram (void)
  45{
  46        int err, save0, save1;
  47
  48        autcpu12_sram_map.virt = ioremap(0x12000000, SZ_128K);
  49        if (!autcpu12_sram_map.virt) {
  50                printk("Failed to ioremap autcpu12 NV-RAM space\n");
  51                err = -EIO;
  52                goto out;
  53        }
  54        simple_map_init(&autcpu_sram_map);
  55
  56        /*
  57         * Check for 32K/128K
  58         * read ofs 0
  59         * read ofs 0x10000
  60         * Write complement to ofs 0x100000
  61         * Read and check result on ofs 0x0
  62         * Restore contents
  63         */
  64        save0 = map_read32(&autcpu12_sram_map,0);
  65        save1 = map_read32(&autcpu12_sram_map,0x10000);
  66        map_write32(&autcpu12_sram_map,~save0,0x10000);
  67        /* if we find this pattern on 0x0, we have 32K size
  68         * restore contents and exit
  69         */
  70        if ( map_read32(&autcpu12_sram_map,0) != save0) {
  71                map_write32(&autcpu12_sram_map,save0,0x0);
  72                goto map;
  73        }
  74        /* We have a 128K found, restore 0x10000 and set size
  75         * to 128K
  76         */
  77        map_write32(&autcpu12_sram_map,save1,0x10000);
  78        autcpu12_sram_map.size = SZ_128K;
  79
  80map:
  81        sram_mtd = do_map_probe("map_ram", &autcpu12_sram_map);
  82        if (!sram_mtd) {
  83                printk("NV-RAM probe failed\n");
  84                err = -ENXIO;
  85                goto out_ioremap;
  86        }
  87
  88        sram_mtd->owner = THIS_MODULE;
  89        sram_mtd->erasesize = 16;
  90
  91        if (mtd_device_register(sram_mtd, NULL, 0)) {
  92                printk("NV-RAM device addition failed\n");
  93                err = -ENOMEM;
  94                goto out_probe;
  95        }
  96
  97        printk("NV-RAM device size %ldKiB registered on AUTCPU12\n",autcpu12_sram_map.size/SZ_1K);
  98
  99        return 0;
 100
 101out_probe:
 102        map_destroy(sram_mtd);
 103        sram_mtd = 0;
 104
 105out_ioremap:
 106        iounmap((void *)autcpu12_sram_map.virt);
 107out:
 108        return err;
 109}
 110
 111static void __exit cleanup_autcpu12_maps(void)
 112{
 113        if (sram_mtd) {
 114                mtd_device_unregister(sram_mtd);
 115                map_destroy(sram_mtd);
 116                iounmap((void *)autcpu12_sram_map.virt);
 117        }
 118}
 119
 120module_init(init_autcpu12_sram);
 121module_exit(cleanup_autcpu12_maps);
 122
 123MODULE_AUTHOR("Thomas Gleixner");
 124MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
 125MODULE_LICENSE("GPL");
 126