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 static unsigned long writebuf_size = 64; 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 module_param(writebuf_size, ulong, 0); 32 MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)"); 33 #endif 34 35 // We could store these in the mtd structure, but we only support 1 device.. 36 static struct mtd_info *mtd_info; 37 38 static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len) 39 { 40 int ret = 0; 41 42 /* Start address must align on block boundary */ 43 if (mtd_mod_by_eb(ofs, mtd)) { 44 pr_debug("%s: unaligned address\n", __func__); 45 ret = -EINVAL; 46 } 47 48 /* Length must align on block boundary */ 49 if (mtd_mod_by_eb(len, mtd)) { 50 pr_debug("%s: length not block aligned\n", __func__); 51 ret = -EINVAL; 52 } 53 54 return ret; 55 } 56 57 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) 58 { 59 if (check_offs_len(mtd, instr->addr, instr->len)) 60 return -EINVAL; 61 memset((char *)mtd->priv + instr->addr, 0xff, instr->len); 62 instr->state = MTD_ERASE_DONE; 63 mtd_erase_callback(instr); 64 return 0; 65 } 66 67 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len, 68 size_t *retlen, void **virt, resource_size_t *phys) 69 { 70 *virt = mtd->priv + from; 71 *retlen = len; 72 return 0; 73 } 74 75 static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 76 { 77 return 0; 78 } 79 80 /* 81 * Allow NOMMU mmap() to directly map the device (if not NULL) 82 * - return the address to which the offset maps 83 * - return -ENOSYS to indicate refusal to do the mapping 84 */ 85 static unsigned long ram_get_unmapped_area(struct mtd_info *mtd, 86 unsigned long len, 87 unsigned long offset, 88 unsigned long flags) 89 { 90 return (unsigned long) mtd->priv + offset; 91 } 92 93 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 94 size_t *retlen, u_char *buf) 95 { 96 memcpy(buf, mtd->priv + from, len); 97 *retlen = len; 98 return 0; 99 } 100 101 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 102 size_t *retlen, const u_char *buf) 103 { 104 memcpy((char *)mtd->priv + to, buf, len); 105 *retlen = len; 106 return 0; 107 } 108 109 static void __exit cleanup_mtdram(void) 110 { 111 if (mtd_info) { 112 mtd_device_unregister(mtd_info); 113 vfree(mtd_info->priv); 114 kfree(mtd_info); 115 } 116 } 117 118 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 119 unsigned long size, const char *name) 120 { 121 memset(mtd, 0, sizeof(*mtd)); 122 123 /* Setup the MTD structure */ 124 mtd->name = name; 125 mtd->type = MTD_RAM; 126 mtd->flags = MTD_CAP_RAM; 127 mtd->size = size; 128 mtd->writesize = 1; 129 mtd->writebufsize = writebuf_size; 130 mtd->erasesize = MTDRAM_ERASE_SIZE; 131 mtd->priv = mapped_address; 132 133 mtd->owner = THIS_MODULE; 134 mtd->_erase = ram_erase; 135 mtd->_point = ram_point; 136 mtd->_unpoint = ram_unpoint; 137 mtd->_get_unmapped_area = ram_get_unmapped_area; 138 mtd->_read = ram_read; 139 mtd->_write = ram_write; 140 141 if (mtd_device_register(mtd, NULL, 0)) 142 return -EIO; 143 144 return 0; 145 } 146 147 static int __init init_mtdram(void) 148 { 149 void *addr; 150 int err; 151 152 if (!total_size) 153 return -EINVAL; 154 155 /* Allocate some memory */ 156 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 157 if (!mtd_info) 158 return -ENOMEM; 159 160 addr = vmalloc(MTDRAM_TOTAL_SIZE); 161 if (!addr) { 162 kfree(mtd_info); 163 mtd_info = NULL; 164 return -ENOMEM; 165 } 166 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 167 if (err) { 168 vfree(addr); 169 kfree(mtd_info); 170 mtd_info = NULL; 171 return err; 172 } 173 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 174 return err; 175 } 176 177 module_init(init_mtdram); 178 module_exit(cleanup_mtdram); 179 180 MODULE_LICENSE("GPL"); 181 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 182 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 183