1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/*
* mtdram - a test mtd device
* Author: Alexander Larsson <alex@cendio.se>
*
* Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
* Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
*
* This code is GPL
*
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/mtdram.h>
static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
#define MTDRAM_TOTAL_SIZE (total_size * 1024)
#define MTDRAM_ERASE_SIZE (erase_size * 1024)
#ifdef MODULE
module_param(total_size, ulong, 0);
MODULE_PARM_DESC(total_size, "Total device size in KiB");
module_param(erase_size, ulong, 0);
MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
#endif
// We could store these in the mtd structure, but we only support 1 device..
static struct mtd_info *mtd_info;
static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
{
if (instr->addr + instr->len > mtd->size)
return -EINVAL;
memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return 0;
}
static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, void **virt, resource_size_t *phys)
{
if (from + len > mtd->size)
return -EINVAL;
/* can we return a physical address with this driver? */
if (phys)
return -EINVAL;
*virt = mtd->priv + from;
*retlen = len;
return 0;
}
static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
}
/*
* Allow NOMMU mmap() to directly map the device (if not NULL)
* - return the address to which the offset maps
* - return -ENOSYS to indicate refusal to do the mapping
*/
static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
unsigned long len,
unsigned long offset,
unsigned long flags)
{
return (unsigned long) mtd->priv + offset;
}
static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
if (from + len > mtd->size)
return -EINVAL;
memcpy(buf, mtd->priv + from, len);
*retlen = len;
return 0;
}
static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
if (to + len > mtd->size)
return -EINVAL;
memcpy((char *)mtd->priv + to, buf, len);
*retlen = len;
return 0;
}
static void __exit cleanup_mtdram(void)
{
if (mtd_info) {
del_mtd_device(mtd_info);
vfree(mtd_info->priv);
kfree(mtd_info);
}
}
int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
unsigned long size, char *name)
{
memset(mtd, 0, sizeof(*mtd));
/* Setup the MTD structure */
mtd->name = name;
mtd->type = MTD_RAM;
mtd->flags = MTD_CAP_RAM;
mtd->size = size;
mtd->writesize = 1;
mtd->writebufsize = 64; /* Mimic CFI NOR flashes */
mtd->erasesize = MTDRAM_ERASE_SIZE;
mtd->priv = mapped_address;
mtd->owner = THIS_MODULE;
mtd->erase = ram_erase;
mtd->point = ram_point;
mtd->unpoint = ram_unpoint;
mtd->get_unmapped_area = ram_get_unmapped_area;
mtd->read = ram_read;
mtd->write = ram_write;
if (add_mtd_device(mtd)) {
return -EIO;
}
return 0;
}
static int __init init_mtdram(void)
{
void *addr;
int err;
if (!total_size)
return -EINVAL;
/* Allocate some memory */
mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
if (!mtd_info)
return -ENOMEM;
addr = vmalloc(MTDRAM_TOTAL_SIZE);
if (!addr) {
kfree(mtd_info);
mtd_info = NULL;
return -ENOMEM;
}
err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
if (err) {
vfree(addr);
kfree(mtd_info);
mtd_info = NULL;
return err;
}
memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
return err;
}
module_init(init_mtdram);
module_exit(cleanup_mtdram);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
MODULE_DESCRIPTION("Simulated MTD driver for testing");
|
