mtdram.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac 
1/*
2 * mtdram - a test mtd device
3 * $Id: mtdram.c,v 1.35 2005/01/05 18:05:12 dwmw2 Exp $
4 * Author: Alexander Larsson <alex@cendio.se>
5 *
6 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
7 *
8 * This code is GPL
9 *
10 */
11
12#include <linux/config.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/ioport.h>
16#include <linux/vmalloc.h>
17#include <linux/init.h>
18#include <linux/mtd/compatmac.h>
19#include <linux/mtd/mtd.h>
20
21#ifndef CONFIG_MTDRAM_ABS_POS
22  #define CONFIG_MTDRAM_ABS_POS 0
23#endif
24
25#if CONFIG_MTDRAM_ABS_POS > 0
26  #include <asm/io.h>
27#endif
28
29#ifdef MODULE
30static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
31static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
32module_param(total_size,ulong,0);
33MODULE_PARM_DESC(total_size, "Total device size in KiB");
34module_param(erase_size,ulong,0);
35MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
36#define MTDRAM_TOTAL_SIZE (total_size * 1024)
37#define MTDRAM_ERASE_SIZE (erase_size * 1024)
38#else
39#define MTDRAM_TOTAL_SIZE (CONFIG_MTDRAM_TOTAL_SIZE * 1024)
40#define MTDRAM_ERASE_SIZE (CONFIG_MTDRAM_ERASE_SIZE * 1024)
41#endif
42
43
44// We could store these in the mtd structure, but we only support 1 device..
45static struct mtd_info *mtd_info;
46
47
48static int
49ram_erase(struct mtd_info *mtd, struct erase_info *instr)
50{
51  DEBUG(MTD_DEBUG_LEVEL2, "ram_erase(pos:%ld, len:%ld)\n", (long)instr->addr, (long)instr->len);
52  if (instr->addr + instr->len > mtd->size) {
53    DEBUG(MTD_DEBUG_LEVEL1, "ram_erase() out of bounds (%ld > %ld)\n", (long)(instr->addr + instr->len), (long)mtd->size);
54    return -EINVAL;
55  }
56
57  memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
58
59  instr->state = MTD_ERASE_DONE;
60  mtd_erase_callback(instr);
61
62  return 0;
63}
64
65static int ram_point (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char **mtdbuf)
66{
67  if (from + len > mtd->size)
68    return -EINVAL;
69
70  *mtdbuf = mtd->priv + from;
71  *retlen = len;
72  return 0;
73}
74
75static void ram_unpoint (struct mtd_info *mtd, u_char *addr, loff_t from,
76			 size_t len)
77{
78  DEBUG(MTD_DEBUG_LEVEL2, "ram_unpoint\n");
79}
80
81static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
82	     size_t *retlen, u_char *buf)
83{
84  DEBUG(MTD_DEBUG_LEVEL2, "ram_read(pos:%ld, len:%ld)\n", (long)from, (long)len);
85  if (from + len > mtd->size) {
86    DEBUG(MTD_DEBUG_LEVEL1, "ram_read() out of bounds (%ld > %ld)\n", (long)(from + len), (long)mtd->size);
87    return -EINVAL;
88  }
89
90  memcpy(buf, mtd->priv + from, len);
91
92  *retlen=len;
93  return 0;
94}
95
96static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
97	      size_t *retlen, const u_char *buf)
98{
99  DEBUG(MTD_DEBUG_LEVEL2, "ram_write(pos:%ld, len:%ld)\n", (long)to, (long)len);
100  if (to + len > mtd->size) {
101    DEBUG(MTD_DEBUG_LEVEL1, "ram_write() out of bounds (%ld > %ld)\n", (long)(to + len), (long)mtd->size);
102    return -EINVAL;
103  }
104
105  memcpy ((char *)mtd->priv + to, buf, len);
106
107  *retlen=len;
108  return 0;
109}
110
111static void __exit cleanup_mtdram(void)
112{
113  if (mtd_info) {
114    del_mtd_device(mtd_info);
115#if CONFIG_MTDRAM_TOTAL_SIZE > 0
116    if (mtd_info->priv)
117#if CONFIG_MTDRAM_ABS_POS > 0
118      iounmap(mtd_info->priv);
119#else
120      vfree(mtd_info->priv);
121#endif
122#endif
123    kfree(mtd_info);
124  }
125}
126
127int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
128                       unsigned long size, char *name)
129{
130   memset(mtd, 0, sizeof(*mtd));
131
132   /* Setup the MTD structure */
133   mtd->name = name;
134   mtd->type = MTD_RAM;
135   mtd->flags = MTD_CAP_RAM;
136   mtd->size = size;
137   mtd->erasesize = MTDRAM_ERASE_SIZE;
138   mtd->priv = mapped_address;
139
140   mtd->owner = THIS_MODULE;
141   mtd->erase = ram_erase;
142   mtd->point = ram_point;
143   mtd->unpoint = ram_unpoint;
144   mtd->read = ram_read;
145   mtd->write = ram_write;
146
147   if (add_mtd_device(mtd)) {
148     return -EIO;
149   }
150
151   return 0;
152}
153
154#if CONFIG_MTDRAM_TOTAL_SIZE > 0
155#if CONFIG_MTDRAM_ABS_POS > 0
156static int __init init_mtdram(void)
157{
158  void *addr;
159  int err;
160  /* Allocate some memory */
161   mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
162   if (!mtd_info)
163     return -ENOMEM;
164
165  addr = ioremap(CONFIG_MTDRAM_ABS_POS, MTDRAM_TOTAL_SIZE);
166  if (!addr) {
167    DEBUG(MTD_DEBUG_LEVEL1,
168          "Failed to ioremap) memory region of size %ld at ABS_POS:%ld\n",
169          (long)MTDRAM_TOTAL_SIZE, (long)CONFIG_MTDRAM_ABS_POS);
170    kfree(mtd_info);
171    mtd_info = NULL;
172    return -ENOMEM;
173  }
174  err = mtdram_init_device(mtd_info, addr,
175                           MTDRAM_TOTAL_SIZE, "mtdram test device");
176  if (err)
177  {
178    iounmap(addr);
179    kfree(mtd_info);
180    mtd_info = NULL;
181    return err;
182  }
183  memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
184  return err;
185}
186
187#else /* CONFIG_MTDRAM_ABS_POS > 0 */
188
189static int __init init_mtdram(void)
190{
191  void *addr;
192  int err;
193  /* Allocate some memory */
194   mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
195   if (!mtd_info)
196     return -ENOMEM;
197
198  addr = vmalloc(MTDRAM_TOTAL_SIZE);
199  if (!addr) {
200    DEBUG(MTD_DEBUG_LEVEL1,
201          "Failed to vmalloc memory region of size %ld\n",
202          (long)MTDRAM_TOTAL_SIZE);
203    kfree(mtd_info);
204    mtd_info = NULL;
205    return -ENOMEM;
206  }
207  err = mtdram_init_device(mtd_info, addr,
208                           MTDRAM_TOTAL_SIZE, "mtdram test device");
209  if (err)
210  {
211    vfree(addr);
212    kfree(mtd_info);
213    mtd_info = NULL;
214    return err;
215  }
216  memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
217  return err;
218}
219#endif /* !(CONFIG_MTDRAM_ABS_POS > 0) */
220
221#else /* CONFIG_MTDRAM_TOTAL_SIZE > 0 */
222
223static int __init init_mtdram(void)
224{
225  return 0;
226}
227#endif /* !(CONFIG_MTDRAM_TOTAL_SIZE > 0) */
228
229module_init(init_mtdram);
230module_exit(cleanup_mtdram);
231
232MODULE_LICENSE("GPL");
233MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
234MODULE_DESCRIPTION("Simulated MTD driver for testing");
235
236