1/*
2 * NV-RAM memory access on autcpu12
3 * (C) 2002 Thomas Gleixner (gleixner@autronix.de)
4 *
5 * $Id: autcpu12-nvram.c,v 1.1.1.1 2007/08/03 18:52:43 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
37static struct mtd_info *sram_mtd;
38
39struct map_info autcpu12_sram_map = {
40	.name = "SRAM",
41	.size = 32768,
42	.bankwidth = 4,
43	.phys = 0x12000000,
44};
45
46static 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
82map:
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
103out_probe:
104	map_destroy(sram_mtd);
105	sram_mtd = 0;
106
107out_ioremap:
108	iounmap((void *)autcpu12_sram_map.virt);
109out:
110	return err;
111}
112
113static 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
122module_init(init_autcpu12_sram);
123module_exit(cleanup_autcpu12_maps);
124
125MODULE_AUTHOR("Thomas Gleixner");
126MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
127MODULE_LICENSE("GPL");
128