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 * $Id: autcpu12-nvram.c,v 1.9 2005/11/07 11:14:26 gleixner Exp $
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 *
  21 */
  22
  23#include <linux/module.h>
  24#include <linux/types.h>
  25#include <linux/kernel.h>
  26#include <linux/ioport.h>
  27#include <linux/init.h>
  28#include <asm/io.h>
  29#include <asm/sizes.h>
  30#include <asm/hardware.h>
  31#include <asm/arch/autcpu12.h>
  32#include <linux/mtd/mtd.h>
  33#include <linux/mtd/map.h>
  34#include <linux/mtd/partitions.h>
  35
  36
  37static struct mtd_info *sram_mtd;
  38
  39struct map_info autcpu12_sram_map = {
  40        .name = "SRAM",
  41        .size = 32768,
  42        .bankwidth = 4,
  43        .phys = 0x12000000,
  44};
  45
  46static int __init init_autcpu12_sram (void)
  47{
  48        int err, save0, save1;
  49
  50        autcpu12_sram_map.virt = ioremap(0x12000000, SZ_128K);
  51        if (!autcpu12_sram_map.virt) {
  52                printk("Failed to ioremap autcpu12 NV-RAM space\n");
  53                err = -EIO;
  54                goto out;
  55        }
  56        simple_map_init(&autcpu_sram_map);
  57
  58        /*
  59         * Check for 32K/128K
  60         * read ofs 0
  61         * read ofs 0x10000
  62         * Write complement to ofs 0x100000
  63         * Read and check result on ofs 0x0
  64         * Restore contents
  65         */
  66        save0 = map_read32(&autcpu12_sram_map,0);
  67        save1 = map_read32(&autcpu12_sram_map,0x10000);
  68        map_write32(&autcpu12_sram_map,~save0,0x10000);
  69        /* if we find this pattern on 0x0, we have 32K size
  70         * restore contents and exit
  71         */
  72        if ( map_read32(&autcpu12_sram_map,0) != save0) {
  73                map_write32(&autcpu12_sram_map,save0,0x0);
  74                goto map;
  75        }
  76        /* We have a 128K found, restore 0x10000 and set size
  77         * to 128K
  78         */
  79        map_write32(&autcpu12_sram_map,save1,0x10000);
  80        autcpu12_sram_map.size = SZ_128K;
  81
  82map:
  83        sram_mtd = do_map_probe("map_ram", &autcpu12_sram_map);
  84        if (!sram_mtd) {
  85                printk("NV-RAM probe failed\n");
  86                err = -ENXIO;
  87                goto out_ioremap;
  88        }
  89
  90        sram_mtd->owner = THIS_MODULE;
  91        sram_mtd->erasesize = 16;
  92
  93        if (add_mtd_device(sram_mtd)) {
  94                printk("NV-RAM device addition failed\n");
  95                err = -ENOMEM;
  96                goto out_probe;
  97        }
  98
  99        printk("NV-RAM device size %ldKiB registered on AUTCPU12\n",autcpu12_sram_map.size/SZ_1K);
 100
 101        return 0;
 102
 103out_probe:
 104        map_destroy(sram_mtd);
 105        sram_mtd = 0;
 106
 107out_ioremap:
 108        iounmap((void *)autcpu12_sram_map.virt);
 109out:
 110        return err;
 111}
 112
 113static void __exit cleanup_autcpu12_maps(void)
 114{
 115        if (sram_mtd) {
 116                del_mtd_device(sram_mtd);
 117                map_destroy(sram_mtd);
 118                iounmap((void *)autcpu12_sram_map.virt);
 119        }
 120}
 121
 122module_init(init_autcpu12_sram);
 123module_exit(cleanup_autcpu12_maps);
 124
 125MODULE_AUTHOR("Thomas Gleixner");
 126MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
 127MODULE_LICENSE("GPL");
 128