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 #define MTDRAM_TOTAL_SIZE (total_size * 1024)
23 #define MTDRAM_ERASE_SIZE (erase_size * 1024)
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");
32 // We could store these in the mtd structure, but we only support 1 device..
33 static struct mtd_info *mtd_info;
35 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
37 memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
38 instr->state = MTD_ERASE_DONE;
39 mtd_erase_callback(instr);
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)
46 /* can we return a physical address with this driver? */
49 *virt = mtd->priv + from;
54 static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
60 * Allow NOMMU mmap() to directly map the device (if not NULL)
61 * - return the address to which the offset maps
62 * - return -ENOSYS to indicate refusal to do the mapping
64 static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
69 return (unsigned long) mtd->priv + offset;
72 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
73 size_t *retlen, u_char *buf)
75 memcpy(buf, mtd->priv + from, len);
80 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
81 size_t *retlen, const u_char *buf)
83 memcpy((char *)mtd->priv + to, buf, len);
88 static void __exit cleanup_mtdram(void)
91 mtd_device_unregister(mtd_info);
92 vfree(mtd_info->priv);
97 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
98 unsigned long size, char *name)
100 memset(mtd, 0, sizeof(*mtd));
102 /* Setup the MTD structure */
105 mtd->flags = MTD_CAP_RAM;
108 mtd->writebufsize = 64; /* Mimic CFI NOR flashes */
109 mtd->erasesize = MTDRAM_ERASE_SIZE;
110 mtd->priv = mapped_address;
112 mtd->owner = THIS_MODULE;
113 mtd->_erase = ram_erase;
114 mtd->_point = ram_point;
115 mtd->_unpoint = ram_unpoint;
116 mtd->_get_unmapped_area = ram_get_unmapped_area;
117 mtd->_read = ram_read;
118 mtd->_write = ram_write;
120 if (mtd_device_register(mtd, NULL, 0))
126 static int __init init_mtdram(void)
134 /* Allocate some memory */
135 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
139 addr = vmalloc(MTDRAM_TOTAL_SIZE);
145 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
152 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
156 module_init(init_mtdram);
157 module_exit(cleanup_mtdram);
159 MODULE_LICENSE("GPL");
160 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
161 MODULE_DESCRIPTION("Simulated MTD driver for testing");