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/mtd.h> 18 #include <linux/mtd/mtdram.h> 19 20 static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE; 21 static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE; 22 #define MTDRAM_TOTAL_SIZE (total_size * 1024) 23 #define MTDRAM_ERASE_SIZE (erase_size * 1024) 24 25 #ifdef MODULE 26 module_param(total_size, ulong, 0); 27 MODULE_PARM_DESC(total_size, "Total device size in KiB"); 28 module_param(erase_size, ulong, 0); 29 MODULE_PARM_DESC(erase_size, "Device erase block size in KiB"); 30 #endif 31 32 // We could store these in the mtd structure, but we only support 1 device.. 33 static struct mtd_info *mtd_info; 34 35 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) 36 { 37 if (instr->addr + instr->len > mtd->size) 38 return -EINVAL; 39 40 memset((char *)mtd->priv + instr->addr, 0xff, instr->len); 41 42 instr->state = MTD_ERASE_DONE; 43 mtd_erase_callback(instr); 44 45 return 0; 46 } 47 48 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len, 49 size_t *retlen, void **virt, resource_size_t *phys) 50 { 51 if (from + len > mtd->size) 52 return -EINVAL; 53 54 /* can we return a physical address with this driver? */ 55 if (phys) 56 return -EINVAL; 57 58 *virt = mtd->priv + from; 59 *retlen = len; 60 return 0; 61 } 62 63 static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 64 { 65 } 66 67 /* 68 * Allow NOMMU mmap() to directly map the device (if not NULL) 69 * - return the address to which the offset maps 70 * - return -ENOSYS to indicate refusal to do the mapping 71 */ 72 static unsigned long ram_get_unmapped_area(struct mtd_info *mtd, 73 unsigned long len, 74 unsigned long offset, 75 unsigned long flags) 76 { 77 return (unsigned long) mtd->priv + offset; 78 } 79 80 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 81 size_t *retlen, u_char *buf) 82 { 83 if (from + len > mtd->size) 84 return -EINVAL; 85 86 memcpy(buf, mtd->priv + from, len); 87 88 *retlen = len; 89 return 0; 90 } 91 92 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 93 size_t *retlen, const u_char *buf) 94 { 95 if (to + len > mtd->size) 96 return -EINVAL; 97 98 memcpy((char *)mtd->priv + to, buf, len); 99 100 *retlen = len; 101 return 0; 102 } 103 104 static void __exit cleanup_mtdram(void) 105 { 106 if (mtd_info) { 107 del_mtd_device(mtd_info); 108 vfree(mtd_info->priv); 109 kfree(mtd_info); 110 } 111 } 112 113 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 114 unsigned long size, char *name) 115 { 116 memset(mtd, 0, sizeof(*mtd)); 117 118 /* Setup the MTD structure */ 119 mtd->name = name; 120 mtd->type = MTD_RAM; 121 mtd->flags = MTD_CAP_RAM; 122 mtd->size = size; 123 mtd->writesize = 1; 124 mtd->erasesize = MTDRAM_ERASE_SIZE; 125 mtd->priv = mapped_address; 126 127 mtd->owner = THIS_MODULE; 128 mtd->erase = ram_erase; 129 mtd->point = ram_point; 130 mtd->unpoint = ram_unpoint; 131 mtd->get_unmapped_area = ram_get_unmapped_area; 132 mtd->read = ram_read; 133 mtd->write = ram_write; 134 135 if (add_mtd_device(mtd)) { 136 return -EIO; 137 } 138 139 return 0; 140 } 141 142 static int __init init_mtdram(void) 143 { 144 void *addr; 145 int err; 146 147 if (!total_size) 148 return -EINVAL; 149 150 /* Allocate some memory */ 151 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 152 if (!mtd_info) 153 return -ENOMEM; 154 155 addr = vmalloc(MTDRAM_TOTAL_SIZE); 156 if (!addr) { 157 kfree(mtd_info); 158 mtd_info = NULL; 159 return -ENOMEM; 160 } 161 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 162 if (err) { 163 vfree(addr); 164 kfree(mtd_info); 165 mtd_info = NULL; 166 return err; 167 } 168 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 169 return err; 170 } 171 172 module_init(init_mtdram); 173 module_exit(cleanup_mtdram); 174 175 MODULE_LICENSE("GPL"); 176 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 177 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 178