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 1.8 2004/11/04 13:24:14 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
  37 static struct mtd_info *sram_mtd;
  38
  39 struct map_info autcpu12_sram_map = {
  40         .name = "SRAM",
  41         .size = 32768,
  42         .bankwidth = 4,
  43         .phys = 0x12000000,
  44 };
  45
  46 static 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
  82 map:
  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
 103 out_probe:
 104         map_destroy(sram_mtd);
 105         sram_mtd = 0;
 106
 107 out_ioremap:
 108         iounmap((void *)autcpu12_sram_map.virt);
 109 out:
 110         return err;
 111 }
 112
 113 static 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
 122 module_init(init_autcpu12_sram);
 123 module_exit(cleanup_autcpu12_maps);
 124
 125 MODULE_AUTHOR("Thomas Gleixner");
 126 MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
 127 MODULE_LICENSE("GPL");