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#include <linux/err.h>
  20#include <linux/sizes.h>
  21
  22#include <linux/types.h>
  23#include <linux/kernel.h>
  24#include <linux/init.h>
  25#include <linux/device.h>
  26#include <linux/module.h>
  27#include <linux/platform_device.h>
  28
  29#include <linux/mtd/mtd.h>
  30#include <linux/mtd/map.h>
  31
  32struct autcpu12_nvram_priv {
  33        struct mtd_info *mtd;
  34        struct map_info map;
  35};
  36
  37static int autcpu12_nvram_probe(struct platform_device *pdev)
  38{
  39        map_word tmp, save0, save1;
  40        struct resource *res;
  41        struct autcpu12_nvram_priv *priv;
  42
  43        priv = devm_kzalloc(&pdev->dev,
  44                            sizeof(struct autcpu12_nvram_priv), GFP_KERNEL);
  45        if (!priv)
  46                return -ENOMEM;
  47
  48        platform_set_drvdata(pdev, priv);
  49
  50        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  51        if (!res) {
  52                dev_err(&pdev->dev, "failed to get memory resource\n");
  53                return -ENOENT;
  54        }
  55
  56        priv->map.bankwidth     = 4;
  57        priv->map.phys          = res->start;
  58        priv->map.size          = resource_size(res);
  59        priv->map.virt = devm_ioremap_resource(&pdev->dev, res);
  60        strcpy((char *)priv->map.name, res->name);
  61        if (IS_ERR(priv->map.virt))
  62                return PTR_ERR(priv->map.virt);
  63
  64        simple_map_init(&priv->map);
  65
  66        /*
  67         * Check for 32K/128K
  68         * read ofs 0
  69         * read ofs 0x10000
  70         * Write complement to ofs 0x100000
  71         * Read and check result on ofs 0x0
  72         * Restore contents
  73         */
  74        save0 = map_read(&priv->map, 0);
  75        save1 = map_read(&priv->map, 0x10000);
  76        tmp.x[0] = ~save0.x[0];
  77        map_write(&priv->map, tmp, 0x10000);
  78        tmp = map_read(&priv->map, 0);
  79        /* if we find this pattern on 0x0, we have 32K size */
  80        if (!map_word_equal(&priv->map, tmp, save0)) {
  81                map_write(&priv->map, save0, 0x0);
  82                priv->map.size = SZ_32K;
  83        } else
  84                map_write(&priv->map, save1, 0x10000);
  85
  86        priv->mtd = do_map_probe("map_ram", &priv->map);
  87        if (!priv->mtd) {
  88                dev_err(&pdev->dev, "probing failed\n");
  89                return -ENXIO;
  90        }
  91
  92        priv->mtd->owner        = THIS_MODULE;
  93        priv->mtd->erasesize    = 16;
  94        priv->mtd->dev.parent   = &pdev->dev;
  95        if (!mtd_device_register(priv->mtd, NULL, 0)) {
  96                dev_info(&pdev->dev,
  97                         "NV-RAM device size %ldKiB registered on AUTCPU12\n",
  98                         priv->map.size / SZ_1K);
  99                return 0;
 100        }
 101
 102        map_destroy(priv->mtd);
 103        dev_err(&pdev->dev, "NV-RAM device addition failed\n");
 104        return -ENOMEM;
 105}
 106
 107static int autcpu12_nvram_remove(struct platform_device *pdev)
 108{
 109        struct autcpu12_nvram_priv *priv = platform_get_drvdata(pdev);
 110
 111        mtd_device_unregister(priv->mtd);
 112        map_destroy(priv->mtd);
 113
 114        return 0;
 115}
 116
 117static struct platform_driver autcpu12_nvram_driver = {
 118        .driver         = {
 119                .name   = "autcpu12_nvram",
 120                .owner  = THIS_MODULE,
 121        },
 122        .probe          = autcpu12_nvram_probe,
 123        .remove         = autcpu12_nvram_remove,
 124};
 125module_platform_driver(autcpu12_nvram_driver);
 126
 127MODULE_AUTHOR("Thomas Gleixner");
 128MODULE_DESCRIPTION("autcpu12 NVRAM map driver");
 129MODULE_LICENSE("GPL");
 130