1 /* 2 * mtdram - a test mtd device 3 * Author: Alexander Larsson <alex@cendio.se> 4 * 5 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se> 6 * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de> 7 * 8 * This code is GPL 9 * 10 */ 11 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/ioport.h> 15 #include <linux/vmalloc.h> 16 #include <linux/init.h> 17 #include <linux/mtd/compatmac.h> 18 #include <linux/mtd/mtd.h> 19 #include <linux/mtd/mtdram.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, void **virt, resource_size_t *phys) 51 { 52 if (from + len > mtd->size) 53 return -EINVAL; 54 55 /* can we return a physical address with this driver? */ 56 if (phys) 57 return -EINVAL; 58 59 *virt = mtd->priv + from; 60 *retlen = len; 61 return 0; 62 } 63 64 static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 65 { 66 } 67 68 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 69 size_t *retlen, u_char *buf) 70 { 71 if (from + len > mtd->size) 72 return -EINVAL; 73 74 memcpy(buf, mtd->priv + from, len); 75 76 *retlen = len; 77 return 0; 78 } 79 80 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 81 size_t *retlen, const u_char *buf) 82 { 83 if (to + len > mtd->size) 84 return -EINVAL; 85 86 memcpy((char *)mtd->priv + to, buf, len); 87 88 *retlen = len; 89 return 0; 90 } 91 92 static void __exit cleanup_mtdram(void) 93 { 94 if (mtd_info) { 95 del_mtd_device(mtd_info); 96 vfree(mtd_info->priv); 97 kfree(mtd_info); 98 } 99 } 100 101 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 102 unsigned long size, char *name) 103 { 104 memset(mtd, 0, sizeof(*mtd)); 105 106 /* Setup the MTD structure */ 107 mtd->name = name; 108 mtd->type = MTD_RAM; 109 mtd->flags = MTD_CAP_RAM; 110 mtd->size = size; 111 mtd->writesize = 1; 112 mtd->erasesize = MTDRAM_ERASE_SIZE; 113 mtd->priv = mapped_address; 114 115 mtd->owner = THIS_MODULE; 116 mtd->erase = ram_erase; 117 mtd->point = ram_point; 118 mtd->unpoint = ram_unpoint; 119 mtd->read = ram_read; 120 mtd->write = ram_write; 121 122 if (add_mtd_device(mtd)) { 123 return -EIO; 124 } 125 126 return 0; 127 } 128 129 static int __init init_mtdram(void) 130 { 131 void *addr; 132 int err; 133 134 if (!total_size) 135 return -EINVAL; 136 137 /* Allocate some memory */ 138 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 139 if (!mtd_info) 140 return -ENOMEM; 141 142 addr = vmalloc(MTDRAM_TOTAL_SIZE); 143 if (!addr) { 144 kfree(mtd_info); 145 mtd_info = NULL; 146 return -ENOMEM; 147 } 148 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 149 if (err) { 150 vfree(addr); 151 kfree(mtd_info); 152 mtd_info = NULL; 153 return err; 154 } 155 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 156 return err; 157 } 158 159 module_init(init_mtdram); 160 module_exit(cleanup_mtdram); 161 162 MODULE_LICENSE("GPL"); 163 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 164 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 165