/*
* NV-RAM memory access on autcpu12
* (C) 2002 Thomas Gleixner (gleixner@autronix.de)
*
* $Id: autcpu12-nvram.c,v 1.8 2004/11/04 13:24:14 gleixner Exp $
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/sizes.h>
#include <asm/hardware.h>
#include <asm/arch/autcpu12.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
static struct mtd_info *sram_mtd;
struct map_info autcpu12_sram_map = {
.name = "SRAM",
.size = 32768,
.bankwidth = 4,
.phys = 0x12000000,
};
static int __init init_autcpu12_sram (void)
{
int err, save0, save1;
autcpu12_sram_map.virt = ioremap(0x12000000, SZ_128K);
if (!autcpu12_sram_map.virt) {
printk("Failed to ioremap autcpu12 NV-RAM space\n");
err = -EIO;
goto out;
}
simple_map_init(&autcpu_sram_map);
/*
* Check for 32K/128K
* read ofs 0
* read ofs 0x10000
* Write complement to ofs 0x100000
* Read and check result on ofs 0x0
* Restore contents
*/
save0 = map_read32(&autcpu12_sram_map,0);
save1 = map_read32(&autcpu12_sram_map,0x10000);
map_write32(&autcpu12_sram_map,~save0,0x10000);
/* if we find this pattern on 0x0, we have 32K size
* restore contents and exit
*/
if ( map_read32(&autcpu12_sram_map,0) != save0) {
map_write32(&autcpu12_sram_map,save0,0x0);
goto map;
}
/* We have a 128K found, restore 0x10000 and set size
* to 128K
*/
map_write32(&autcpu12_sram_map,save1,0x10000);
autcpu12_sram_map.size = SZ_128K;
map:
sram_mtd = do_map_probe("map_ram", &autcpu12_sram_map);
if (!sram_mtd) {
printk("NV-RAM probe failed\n");
err = -ENXIO;
goto out_ioremap;
}
sram_mtd->owner = THIS_MODULE;
sram_mtd->erasesize = 16;
if (add_mtd_device(sram_mtd)) {
printk("NV-RAM device addition failed\n");
err = -ENOMEM;
goto out_probe;
}
printk("NV-RAM device size %ldKiB registered on AUTCPU12\n",autcpu12_sram_map.size/SZ_1K);
return 0;
out_probe:
map_destroy(sram_mtd);
sram_mtd = 0;
out_ioremap:
iounmap((void *)autcpu12_sram_map.virt);
out:
return err;
}
static void __exit cleanup_autcpu12_maps(void)
{
if (sram_mtd) {
del_mtd_device(sram_mtd);
map_destroy(sram_mtd);
iounmap((void *)autcpu12_sram_map.virt);
}
}
module_init(init_autcpu12_sram);
module_exit(cleanup_autcpu12_maps);
MODULE_AUTHOR("Thomas Gleixner");
MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
MODULE_LICENSE("GPL");
