1 /* 2 * mtdram - a test mtd device 3 * $Id: mtdram.c,v 1.37 2005/04/21 03:42:11 joern Exp $ 4 * Author: Alexander Larsson <alex@cendio.se> 5 * 6 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se> 7 * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de> 8 * 9 * This code is GPL 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/ioport.h> 16 #include <linux/vmalloc.h> 17 #include <linux/init.h> 18 #include <linux/mtd/compatmac.h> 19 #include <linux/mtd/mtd.h> 20 21 static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE; 22 static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE; 23 #define MTDRAM_TOTAL_SIZE (total_size * 1024) 24 #define MTDRAM_ERASE_SIZE (erase_size * 1024) 25 26 #ifdef MODULE 27 module_param(total_size, ulong, 0); 28 MODULE_PARM_DESC(total_size, "Total device size in KiB"); 29 module_param(erase_size, ulong, 0); 30 MODULE_PARM_DESC(erase_size, "Device erase block size in KiB"); 31 #endif 32 33 // We could store these in the mtd structure, but we only support 1 device.. 34 static struct mtd_info *mtd_info; 35 36 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) 37 { 38 if (instr->addr + instr->len > mtd->size) 39 return -EINVAL; 40 41 memset((char *)mtd->priv + instr->addr, 0xff, instr->len); 42 43 instr->state = MTD_ERASE_DONE; 44 mtd_erase_callback(instr); 45 46 return 0; 47 } 48 49 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len, 50 size_t *retlen, u_char **mtdbuf) 51 { 52 if (from + len > mtd->size) 53 return -EINVAL; 54 55 *mtdbuf = mtd->priv + from; 56 *retlen = len; 57 return 0; 58 } 59 60 static void ram_unpoint(struct mtd_info *mtd, u_char * addr, loff_t from, 61 size_t len) 62 { 63 } 64 65 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 66 size_t *retlen, u_char *buf) 67 { 68 if (from + len > mtd->size) 69 return -EINVAL; 70 71 memcpy(buf, mtd->priv + from, len); 72 73 *retlen = len; 74 return 0; 75 } 76 77 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 78 size_t *retlen, const u_char *buf) 79 { 80 if (to + len > mtd->size) 81 return -EINVAL; 82 83 memcpy((char *)mtd->priv + to, buf, len); 84 85 *retlen = len; 86 return 0; 87 } 88 89 static void __exit cleanup_mtdram(void) 90 { 91 if (mtd_info) { 92 del_mtd_device(mtd_info); 93 vfree(mtd_info->priv); 94 kfree(mtd_info); 95 } 96 } 97 98 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 99 unsigned long size, char *name) 100 { 101 memset(mtd, 0, sizeof(*mtd)); 102 103 /* Setup the MTD structure */ 104 mtd->name = name; 105 mtd->type = MTD_RAM; 106 mtd->flags = MTD_CAP_RAM; 107 mtd->size = size; 108 mtd->writesize = 1; 109 mtd->erasesize = MTDRAM_ERASE_SIZE; 110 mtd->priv = mapped_address; 111 112 mtd->owner = THIS_MODULE; 113 mtd->erase = ram_erase; 114 mtd->point = ram_point; 115 mtd->unpoint = ram_unpoint; 116 mtd->read = ram_read; 117 mtd->write = ram_write; 118 119 if (add_mtd_device(mtd)) { 120 return -EIO; 121 } 122 123 return 0; 124 } 125 126 static int __init init_mtdram(void) 127 { 128 void *addr; 129 int err; 130 131 if (!total_size) 132 return -EINVAL; 133 134 /* Allocate some memory */ 135 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 136 if (!mtd_info) 137 return -ENOMEM; 138 139 addr = vmalloc(MTDRAM_TOTAL_SIZE); 140 if (!addr) { 141 kfree(mtd_info); 142 mtd_info = NULL; 143 return -ENOMEM; 144 } 145 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 146 if (err) { 147 vfree(addr); 148 kfree(mtd_info); 149 mtd_info = NULL; 150 return err; 151 } 152 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 153 return err; 154 } 155 156 module_init(init_mtdram); 157 module_exit(cleanup_mtdram); 158 159 MODULE_LICENSE("GPL"); 160 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 161 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 162