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