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 check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len) 36 { 37 int ret = 0; 38 39 /* Start address must align on block boundary */ 40 if (mtd_mod_by_eb(ofs, mtd)) { 41 pr_debug("%s: unaligned address\n", __func__); 42 ret = -EINVAL; 43 } 44 45 /* Length must align on block boundary */ 46 if (mtd_mod_by_eb(len, mtd)) { 47 pr_debug("%s: length not block aligned\n", __func__); 48 ret = -EINVAL; 49 } 50 51 return ret; 52 } 53 54 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) 55 { 56 if (check_offs_len(mtd, instr->addr, instr->len)) 57 return -EINVAL; 58 memset((char *)mtd->priv + instr->addr, 0xff, instr->len); 59 instr->state = MTD_ERASE_DONE; 60 mtd_erase_callback(instr); 61 return 0; 62 } 63 64 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len, 65 size_t *retlen, void **virt, resource_size_t *phys) 66 { 67 *virt = mtd->priv + from; 68 *retlen = len; 69 return 0; 70 } 71 72 static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 73 { 74 return 0; 75 } 76 77 /* 78 * Allow NOMMU mmap() to directly map the device (if not NULL) 79 * - return the address to which the offset maps 80 * - return -ENOSYS to indicate refusal to do the mapping 81 */ 82 static unsigned long ram_get_unmapped_area(struct mtd_info *mtd, 83 unsigned long len, 84 unsigned long offset, 85 unsigned long flags) 86 { 87 return (unsigned long) mtd->priv + offset; 88 } 89 90 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, 91 size_t *retlen, u_char *buf) 92 { 93 memcpy(buf, mtd->priv + from, len); 94 *retlen = len; 95 return 0; 96 } 97 98 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, 99 size_t *retlen, const u_char *buf) 100 { 101 memcpy((char *)mtd->priv + to, buf, len); 102 *retlen = len; 103 return 0; 104 } 105 106 static void __exit cleanup_mtdram(void) 107 { 108 if (mtd_info) { 109 mtd_device_unregister(mtd_info); 110 vfree(mtd_info->priv); 111 kfree(mtd_info); 112 } 113 } 114 115 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, 116 unsigned long size, const char *name) 117 { 118 memset(mtd, 0, sizeof(*mtd)); 119 120 /* Setup the MTD structure */ 121 mtd->name = name; 122 mtd->type = MTD_RAM; 123 mtd->flags = MTD_CAP_RAM; 124 mtd->size = size; 125 mtd->writesize = 1; 126 mtd->writebufsize = 64; /* Mimic CFI NOR flashes */ 127 mtd->erasesize = MTDRAM_ERASE_SIZE; 128 mtd->priv = mapped_address; 129 130 mtd->owner = THIS_MODULE; 131 mtd->_erase = ram_erase; 132 mtd->_point = ram_point; 133 mtd->_unpoint = ram_unpoint; 134 mtd->_get_unmapped_area = ram_get_unmapped_area; 135 mtd->_read = ram_read; 136 mtd->_write = ram_write; 137 138 if (mtd_device_register(mtd, NULL, 0)) 139 return -EIO; 140 141 return 0; 142 } 143 144 static int __init init_mtdram(void) 145 { 146 void *addr; 147 int err; 148 149 if (!total_size) 150 return -EINVAL; 151 152 /* Allocate some memory */ 153 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); 154 if (!mtd_info) 155 return -ENOMEM; 156 157 addr = vmalloc(MTDRAM_TOTAL_SIZE); 158 if (!addr) { 159 kfree(mtd_info); 160 mtd_info = NULL; 161 return -ENOMEM; 162 } 163 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); 164 if (err) { 165 vfree(addr); 166 kfree(mtd_info); 167 mtd_info = NULL; 168 return err; 169 } 170 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); 171 return err; 172 } 173 174 module_init(init_mtdram); 175 module_exit(cleanup_mtdram); 176 177 MODULE_LICENSE("GPL"); 178 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); 179 MODULE_DESCRIPTION("Simulated MTD driver for testing"); 180