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>
17 #include <linux/init.h>
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/mtdram.h>
21 static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
22 static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
23 static unsigned long writebuf_size = 64;
24 #define MTDRAM_TOTAL_SIZE (total_size * 1024)
25 #define MTDRAM_ERASE_SIZE (erase_size * 1024)
28 module_param(total_size, ulong, 0);
29 MODULE_PARM_DESC(total_size, "Total device size in KiB");
30 module_param(erase_size, ulong, 0);
31 MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
32 module_param(writebuf_size, ulong, 0);
33 MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)");
36 // We could store these in the mtd structure, but we only support 1 device..
37 static struct mtd_info *mtd_info;
39 static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
43 /* Start address must align on block boundary */
44 if (mtd_mod_by_eb(ofs, mtd)) {
45 pr_debug("%s: unaligned address\n", __func__);
49 /* Length must align on block boundary */
50 if (mtd_mod_by_eb(len, mtd)) {
51 pr_debug("%s: length not block aligned\n", __func__);
58 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
60 if (check_offs_len(mtd, instr->addr, instr->len))
62 memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
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;
74 /* limit retlen to the number of contiguous physical pages */
75 unsigned long page_ofs = offset_in_page(*virt);
76 void *addr = *virt - page_ofs;
77 unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr);
79 *phys = __pfn_to_phys(pfn0) + page_ofs;
81 while (len > PAGE_SIZE) {
85 pfn1 = vmalloc_to_pfn(addr);
87 *retlen = addr - *virt;
96 static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
101 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
102 size_t *retlen, u_char *buf)
104 memcpy(buf, mtd->priv + from, len);
109 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
110 size_t *retlen, const u_char *buf)
112 memcpy((char *)mtd->priv + to, buf, len);
117 static void __exit cleanup_mtdram(void)
120 mtd_device_unregister(mtd_info);
121 vfree(mtd_info->priv);
126 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
127 unsigned long size, const char *name)
129 memset(mtd, 0, sizeof(*mtd));
131 /* Setup the MTD structure */
134 mtd->flags = MTD_CAP_RAM;
137 mtd->writebufsize = writebuf_size;
138 mtd->erasesize = MTDRAM_ERASE_SIZE;
139 mtd->priv = mapped_address;
141 mtd->owner = THIS_MODULE;
142 mtd->_erase = ram_erase;
143 mtd->_point = ram_point;
144 mtd->_unpoint = ram_unpoint;
145 mtd->_read = ram_read;
146 mtd->_write = ram_write;
148 if (mtd_device_register(mtd, NULL, 0))
154 static int __init init_mtdram(void)
162 /* Allocate some memory */
163 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
167 addr = vmalloc(MTDRAM_TOTAL_SIZE);
173 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
180 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
184 module_init(init_mtdram);
185 module_exit(cleanup_mtdram);
187 MODULE_LICENSE("GPL");
188 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
189 MODULE_DESCRIPTION("Simulated MTD driver for testing");