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