tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
fork
Configure Feed
Select the types of activity you want to include in your feed.
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/compatmac.h>
18#include <linux/mtd/mtd.h>
19#include <linux/mtd/mtdram.h>
20
21static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
22static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
23#define MTDRAM_TOTAL_SIZE (total_size * 1024)
24#define MTDRAM_ERASE_SIZE (erase_size * 1024)
25
26#ifdef MODULE
27module_param(total_size, ulong, 0);
28MODULE_PARM_DESC(total_size, "Total device size in KiB");
29module_param(erase_size, ulong, 0);
30MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
31#endif
32
33// We could store these in the mtd structure, but we only support 1 device..
34static struct mtd_info *mtd_info;
35
36static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
37{
38 if (instr->addr + instr->len > mtd->size)
39 return -EINVAL;
40
41 memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
42
43 instr->state = MTD_ERASE_DONE;
44 mtd_erase_callback(instr);
45
46 return 0;
47}
48
49static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
50 size_t *retlen, void **virt, resource_size_t *phys)
51{
52 if (from + len > mtd->size)
53 return -EINVAL;
54
55 /* can we return a physical address with this driver? */
56 if (phys)
57 return -EINVAL;
58
59 *virt = mtd->priv + from;
60 *retlen = len;
61 return 0;
62}
63
64static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
65{
66}
67
68static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
69 size_t *retlen, u_char *buf)
70{
71 if (from + len > mtd->size)
72 return -EINVAL;
73
74 memcpy(buf, mtd->priv + from, len);
75
76 *retlen = len;
77 return 0;
78}
79
80static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
81 size_t *retlen, const u_char *buf)
82{
83 if (to + len > mtd->size)
84 return -EINVAL;
85
86 memcpy((char *)mtd->priv + to, buf, len);
87
88 *retlen = len;
89 return 0;
90}
91
92static void __exit cleanup_mtdram(void)
93{
94 if (mtd_info) {
95 del_mtd_device(mtd_info);
96 vfree(mtd_info->priv);
97 kfree(mtd_info);
98 }
99}
100
101int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
102 unsigned long size, char *name)
103{
104 memset(mtd, 0, sizeof(*mtd));
105
106 /* Setup the MTD structure */
107 mtd->name = name;
108 mtd->type = MTD_RAM;
109 mtd->flags = MTD_CAP_RAM;
110 mtd->size = size;
111 mtd->writesize = 1;
112 mtd->erasesize = MTDRAM_ERASE_SIZE;
113 mtd->priv = mapped_address;
114
115 mtd->owner = THIS_MODULE;
116 mtd->erase = ram_erase;
117 mtd->point = ram_point;
118 mtd->unpoint = ram_unpoint;
119 mtd->read = ram_read;
120 mtd->write = ram_write;
121
122 if (add_mtd_device(mtd)) {
123 return -EIO;
124 }
125
126 return 0;
127}
128
129static int __init init_mtdram(void)
130{
131 void *addr;
132 int err;
133
134 if (!total_size)
135 return -EINVAL;
136
137 /* Allocate some memory */
138 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
139 if (!mtd_info)
140 return -ENOMEM;
141
142 addr = vmalloc(MTDRAM_TOTAL_SIZE);
143 if (!addr) {
144 kfree(mtd_info);
145 mtd_info = NULL;
146 return -ENOMEM;
147 }
148 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
149 if (err) {
150 vfree(addr);
151 kfree(mtd_info);
152 mtd_info = NULL;
153 return err;
154 }
155 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
156 return err;
157}
158
159module_init(init_mtdram);
160module_exit(cleanup_mtdram);
161
162MODULE_LICENSE("GPL");
163MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
164MODULE_DESCRIPTION("Simulated MTD driver for testing");