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
35 static struct mtd_info *sram_mtd;
36
37 struct map_info autcpu12_sram_map = {
38 .name = "SRAM",
39 .size = 32768,
40 .bankwidth = 4,
41 .phys = 0x12000000,
42 };
43
init_autcpu12_sram(void)44 static 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
80 map:
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
101 out_probe:
102 map_destroy(sram_mtd);
103 sram_mtd = 0;
104
105 out_ioremap:
106 iounmap((void *)autcpu12_sram_map.virt);
107 out:
108 return err;
109 }
110
cleanup_autcpu12_maps(void)111 static 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
120 module_init(init_autcpu12_sram);
121 module_exit(cleanup_autcpu12_maps);
122
123 MODULE_AUTHOR("Thomas Gleixner");
124 MODULE_DESCRIPTION("autcpu12 NV-RAM map driver");
125 MODULE_LICENSE("GPL");
126