2 * mtdram - a test mtd device
3 * Author: Alexander Larsson <alex@cendio.se>
5 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
6 * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
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>
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)
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)");
35 // We could store these in the mtd structure, but we only support 1 device..
36 static struct mtd_info *mtd_info;
38 static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
42 /* Start address must align on block boundary */
43 if (mtd_mod_by_eb(ofs, mtd)) {
44 pr_debug("%s: unaligned address\n", __func__);
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__);
57 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
59 if (check_offs_len(mtd, instr->addr, instr->len))
61 memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
62 instr->state = MTD_ERASE_DONE;
63 mtd_erase_callback(instr);
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)
70 *virt = mtd->priv + from;
75 static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
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
85 static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
90 return (unsigned long) mtd->priv + offset;
93 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
94 size_t *retlen, u_char *buf)
96 memcpy(buf, mtd->priv + from, len);
101 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
102 size_t *retlen, const u_char *buf)
104 memcpy((char *)mtd->priv + to, buf, len);
109 static void __exit cleanup_mtdram(void)
112 mtd_device_unregister(mtd_info);
113 vfree(mtd_info->priv);
118 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
119 unsigned long size, const char *name)
121 memset(mtd, 0, sizeof(*mtd));
123 /* Setup the MTD structure */
126 mtd->flags = MTD_CAP_RAM;
129 mtd->writebufsize = writebuf_size;
130 mtd->erasesize = MTDRAM_ERASE_SIZE;
131 mtd->priv = mapped_address;
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;
141 if (mtd_device_register(mtd, NULL, 0))
147 static int __init init_mtdram(void)
155 /* Allocate some memory */
156 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
160 addr = vmalloc(MTDRAM_TOTAL_SIZE);
166 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
173 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
177 module_init(init_mtdram);
178 module_exit(cleanup_mtdram);
180 MODULE_LICENSE("GPL");
181 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
182 MODULE_DESCRIPTION("Simulated MTD driver for testing");