128 lines
3.1 KiB
C
128 lines
3.1 KiB
C
/*
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* NV-RAM memory access on autcpu12
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* (C) 2002 Thomas Gleixner (gleixner@autronix.de)
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*
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* $Id: autcpu12-nvram.c,v 1.9 2005/11/07 11:14:26 gleixner Exp $
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <asm/io.h>
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#include <asm/sizes.h>
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#include <asm/hardware.h>
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#include <asm/arch/autcpu12.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/map.h>
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#include <linux/mtd/partitions.h>
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static struct mtd_info *sram_mtd;
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struct map_info autcpu12_sram_map = {
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.name = "SRAM",
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.size = 32768,
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.bankwidth = 4,
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.phys = 0x12000000,
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};
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static int __init init_autcpu12_sram (void)
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{
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int err, save0, save1;
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autcpu12_sram_map.virt = ioremap(0x12000000, SZ_128K);
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if (!autcpu12_sram_map.virt) {
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printk("Failed to ioremap autcpu12 NV-RAM space\n");
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err = -EIO;
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goto out;
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}
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simple_map_init(&autcpu_sram_map);
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/*
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* Check for 32K/128K
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* read ofs 0
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* read ofs 0x10000
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* Write complement to ofs 0x100000
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* Read and check result on ofs 0x0
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* Restore contents
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*/
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save0 = map_read32(&autcpu12_sram_map,0);
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save1 = map_read32(&autcpu12_sram_map,0x10000);
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map_write32(&autcpu12_sram_map,~save0,0x10000);
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/* if we find this pattern on 0x0, we have 32K size
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* restore contents and exit
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*/
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if ( map_read32(&autcpu12_sram_map,0) != save0) {
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map_write32(&autcpu12_sram_map,save0,0x0);
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goto map;
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}
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/* We have a 128K found, restore 0x10000 and set size
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* to 128K
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*/
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map_write32(&autcpu12_sram_map,save1,0x10000);
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autcpu12_sram_map.size = SZ_128K;
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map:
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sram_mtd = do_map_probe("map_ram", &autcpu12_sram_map);
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if (!sram_mtd) {
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printk("NV-RAM probe failed\n");
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err = -ENXIO;
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goto out_ioremap;
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}
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sram_mtd->owner = THIS_MODULE;
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sram_mtd->erasesize = 16;
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if (add_mtd_device(sram_mtd)) {
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printk("NV-RAM device addition failed\n");
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err = -ENOMEM;
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goto out_probe;
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}
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printk("NV-RAM device size %ldKiB registered on AUTCPU12\n",autcpu12_sram_map.size/SZ_1K);
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return 0;
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out_probe:
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map_destroy(sram_mtd);
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sram_mtd = 0;
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out_ioremap:
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iounmap((void *)autcpu12_sram_map.virt);
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out:
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return err;
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}
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static void __exit cleanup_autcpu12_maps(void)
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{
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if (sram_mtd) {
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del_mtd_device(sram_mtd);
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map_destroy(sram_mtd);
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iounmap((void *)autcpu12_sram_map.virt);
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}
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}
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module_init(init_autcpu12_sram);
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module_exit(cleanup_autcpu12_maps);
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MODULE_AUTHOR("Thomas Gleixner");
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MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
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MODULE_LICENSE("GPL");
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