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