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 #include <linux/mtd/mtdram.h> 21 22 static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE; 23 static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE; 24 #define MTDRAM_TOTAL_SIZE (total_size * 1024) 25 #define MTDRAM_ERASE_SIZE (erase_size * 1024) 26 27 #ifdef MODULE 28 module_param(total_size, ulong, 0); 29 MODULE_PARM_DESC(total_size, "Total device size in KiB"); 30 module_param(erase_size, ulong, 0); 31 MODULE_PARM_DESC(erase_size, "Device erase block size in KiB"); 32 #endif 33 34 // We could store these in the mtd structure, but we only support 1 device.. 35 static struct mtd_info *mtd_info; 36 37 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) 38 { 39 if (instr->addr + instr->len > mtd->size) 40 return -EINVAL; 41 42 memset((char *)mtd->priv + instr->addr, 0xff, instr->len); 43 44 instr->state = MTD_ERASE_DONE; 45 mtd_erase_callback(instr); 46 47 return 0; 48 } 49 50 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len, 51 size_t *retlen, void **virt, resource_size_t *phys) 52 { 53 if (from + len > mtd->size) 54 return -EINVAL; 55 56 /* can we return a physical address with this driver? */ 57 if (phys) 58 return -EINVAL; 59 60 *virt = mtd->priv + from; 61 *retlen = len; 62 return 0; 63 } 64 65 static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 66 { 67 } 68 69 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 70 size_t *retlen, u_char *buf) 71 { 72 if (from + len > mtd->size) 73 return -EINVAL; 74 75 memcpy(buf, mtd->priv + from, len); 76 77 *retlen = len; 78 return 0; 79 } 80 81 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 82 size_t *retlen, const u_char *buf) 83 { 84 if (to + len > mtd->size) 85 return -EINVAL; 86 87 memcpy((char *)mtd->priv + to, buf, len); 88 89 *retlen = len; 90 return 0; 91 } 92 93 static void __exit cleanup_mtdram(void) 94 { 95 if (mtd_info) { 96 del_mtd_device(mtd_info); 97 vfree(mtd_info->priv); 98 kfree(mtd_info); 99 } 100 } 101 102 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 103 unsigned long size, char *name) 104 { 105 memset(mtd, 0, sizeof(*mtd)); 106 107 /* Setup the MTD structure */ 108 mtd->name = name; 109 mtd->type = MTD_RAM; 110 mtd->flags = MTD_CAP_RAM; 111 mtd->size = size; 112 mtd->writesize = 1; 113 mtd->erasesize = MTDRAM_ERASE_SIZE; 114 mtd->priv = mapped_address; 115 116 mtd->owner = THIS_MODULE; 117 mtd->erase = ram_erase; 118 mtd->point = ram_point; 119 mtd->unpoint = ram_unpoint; 120 mtd->read = ram_read; 121 mtd->write = ram_write; 122 123 if (add_mtd_device(mtd)) { 124 return -EIO; 125 } 126 127 return 0; 128 } 129 130 static int __init init_mtdram(void) 131 { 132 void *addr; 133 int err; 134 135 if (!total_size) 136 return -EINVAL; 137 138 /* Allocate some memory */ 139 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 140 if (!mtd_info) 141 return -ENOMEM; 142 143 addr = vmalloc(MTDRAM_TOTAL_SIZE); 144 if (!addr) { 145 kfree(mtd_info); 146 mtd_info = NULL; 147 return -ENOMEM; 148 } 149 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 150 if (err) { 151 vfree(addr); 152 kfree(mtd_info); 153 mtd_info = NULL; 154 return err; 155 } 156 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 157 return err; 158 } 159 160 module_init(init_mtdram); 161 module_exit(cleanup_mtdram); 162 163 MODULE_LICENSE("GPL"); 164 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 165 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 166