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 /* 69 * Allow NOMMU mmap() to directly map the device (if not NULL) 70 * - return the address to which the offset maps 71 * - return -ENOSYS to indicate refusal to do the mapping 72 */ 73 static unsigned long ram_get_unmapped_area(struct mtd_info *mtd, 74 unsigned long len, 75 unsigned long offset, 76 unsigned long flags) 77 { 78 return (unsigned long) mtd->priv + offset; 79 } 80 81 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 82 size_t *retlen, u_char *buf) 83 { 84 if (from + len > mtd->size) 85 return -EINVAL; 86 87 memcpy(buf, mtd->priv + from, len); 88 89 *retlen = len; 90 return 0; 91 } 92 93 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 94 size_t *retlen, const u_char *buf) 95 { 96 if (to + len > mtd->size) 97 return -EINVAL; 98 99 memcpy((char *)mtd->priv + to, buf, len); 100 101 *retlen = len; 102 return 0; 103 } 104 105 static void __exit cleanup_mtdram(void) 106 { 107 if (mtd_info) { 108 del_mtd_device(mtd_info); 109 vfree(mtd_info->priv); 110 kfree(mtd_info); 111 } 112 } 113 114 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 115 unsigned long size, char *name) 116 { 117 memset(mtd, 0, sizeof(*mtd)); 118 119 /* Setup the MTD structure */ 120 mtd->name = name; 121 mtd->type = MTD_RAM; 122 mtd->flags = MTD_CAP_RAM; 123 mtd->size = size; 124 mtd->writesize = 1; 125 mtd->erasesize = MTDRAM_ERASE_SIZE; 126 mtd->priv = mapped_address; 127 128 mtd->owner = THIS_MODULE; 129 mtd->erase = ram_erase; 130 mtd->point = ram_point; 131 mtd->unpoint = ram_unpoint; 132 mtd->get_unmapped_area = ram_get_unmapped_area; 133 mtd->read = ram_read; 134 mtd->write = ram_write; 135 136 if (add_mtd_device(mtd)) { 137 return -EIO; 138 } 139 140 return 0; 141 } 142 143 static int __init init_mtdram(void) 144 { 145 void *addr; 146 int err; 147 148 if (!total_size) 149 return -EINVAL; 150 151 /* Allocate some memory */ 152 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 153 if (!mtd_info) 154 return -ENOMEM; 155 156 addr = vmalloc(MTDRAM_TOTAL_SIZE); 157 if (!addr) { 158 kfree(mtd_info); 159 mtd_info = NULL; 160 return -ENOMEM; 161 } 162 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 163 if (err) { 164 vfree(addr); 165 kfree(mtd_info); 166 mtd_info = NULL; 167 return err; 168 } 169 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 170 return err; 171 } 172 173 module_init(init_mtdram); 174 module_exit(cleanup_mtdram); 175 176 MODULE_LICENSE("GPL"); 177 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 178 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 179