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 */
 20
 21#include <linux/module.h>
 22#include <linux/types.h>
 23#include <linux/kernel.h>
 24#include <linux/ioport.h>
 25#include <linux/init.h>
 26#include <asm/io.h>
 27#include <asm/sizes.h>
 28#include <mach/hardware.h>
 29#include <mach/autcpu12.h>
 30#include <linux/mtd/mtd.h>
 31#include <linux/mtd/map.h>
 32#include <linux/mtd/partitions.h>
 33
 34
 35static struct mtd_info *sram_mtd;
 36
 37struct map_info autcpu12_sram_map = {
 38	.name = "SRAM",
 39	.size = 32768,
 40	.bankwidth = 4,
 41	.phys = 0x12000000,
 42};
 43
 44static int __init init_autcpu12_sram (void)
 45{
 46	int err, save0, save1;
 47
 48	autcpu12_sram_map.virt = ioremap(0x12000000, SZ_128K);
 49	if (!autcpu12_sram_map.virt) {
 50		printk("Failed to ioremap autcpu12 NV-RAM space\n");
 51		err = -EIO;
 52		goto out;
 53	}
 54	simple_map_init(&autcpu_sram_map);
 55
 56	/*
 57	 * Check for 32K/128K
 58	 * read ofs 0
 59	 * read ofs 0x10000
 60	 * Write complement to ofs 0x100000
 61	 * Read	and check result on ofs 0x0
 62	 * Restore contents
 63	 */
 64	save0 = map_read32(&autcpu12_sram_map,0);
 65	save1 = map_read32(&autcpu12_sram_map,0x10000);
 66	map_write32(&autcpu12_sram_map,~save0,0x10000);
 67	/* if we find this pattern on 0x0, we have 32K size
 68	 * restore contents and exit
 69	 */
 70	if ( map_read32(&autcpu12_sram_map,0) != save0) {
 71		map_write32(&autcpu12_sram_map,save0,0x0);
 72		goto map;
 73	}
 74	/* We have a 128K found, restore 0x10000 and set size
 75	 * to 128K
 76	 */
 77	map_write32(&autcpu12_sram_map,save1,0x10000);
 78	autcpu12_sram_map.size = SZ_128K;
 79
 80map:
 81	sram_mtd = do_map_probe("map_ram", &autcpu12_sram_map);
 82	if (!sram_mtd) {
 83		printk("NV-RAM probe failed\n");
 84		err = -ENXIO;
 85		goto out_ioremap;
 86	}
 87
 88	sram_mtd->owner = THIS_MODULE;
 89	sram_mtd->erasesize = 16;
 90
 91	if (mtd_device_register(sram_mtd, NULL, 0)) {
 92		printk("NV-RAM device addition failed\n");
 93		err = -ENOMEM;
 94		goto out_probe;
 95	}
 96
 97	printk("NV-RAM device size %ldKiB registered on AUTCPU12\n",autcpu12_sram_map.size/SZ_1K);
 98
 99	return 0;
100
101out_probe:
102	map_destroy(sram_mtd);
103	sram_mtd = 0;
104
105out_ioremap:
106	iounmap((void *)autcpu12_sram_map.virt);
107out:
108	return err;
109}
110
111static void __exit cleanup_autcpu12_maps(void)
112{
113	if (sram_mtd) {
114		mtd_device_unregister(sram_mtd);
115		map_destroy(sram_mtd);
116		iounmap((void *)autcpu12_sram_map.virt);
117	}
118}
119
120module_init(init_autcpu12_sram);
121module_exit(cleanup_autcpu12_maps);
122
123MODULE_AUTHOR("Thomas Gleixner");
124MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
125MODULE_LICENSE("GPL");