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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [mtd/] [devices/] [phram.c] - Blame information for rev 62

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Line No. Rev Author Line
1 62 marcus.erl
/**
2
 * $Id: phram.c,v 1.16 2005/11/07 11:14:25 gleixner Exp $
3
 *
4
 * Copyright (c) ????           Jochen Schäuble <psionic@psionic.de>
5
 * Copyright (c) 2003-2004      Jörn Engel <joern@wh.fh-wedel.de>
6
 *
7
 * Usage:
8
 *
9
 * one commend line parameter per device, each in the form:
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 *   phram=<name>,<start>,<len>
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 * <name> may be up to 63 characters.
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 * <start> and <len> can be octal, decimal or hexadecimal.  If followed
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 * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
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 * gigabytes.
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 *
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 * Example:
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 *      phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
18
 */
19
#include <asm/io.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/slab.h>
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#include <linux/mtd/mtd.h>
27
 
28
#define ERROR(fmt, args...) printk(KERN_ERR "phram: " fmt , ## args)
29
 
30
struct phram_mtd_list {
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        struct mtd_info mtd;
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        struct list_head list;
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};
34
 
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static LIST_HEAD(phram_list);
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37
 
38
static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
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{
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        u_char *start = mtd->priv;
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42
        if (instr->addr + instr->len > mtd->size)
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                return -EINVAL;
44
 
45
        memset(start + instr->addr, 0xff, instr->len);
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47
        /* This'll catch a few races. Free the thing before returning :)
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         * I don't feel at all ashamed. This kind of thing is possible anyway
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         * with flash, but unlikely.
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         */
51
 
52
        instr->state = MTD_ERASE_DONE;
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54
        mtd_erase_callback(instr);
55
 
56
        return 0;
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}
58
 
59
static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
60
                size_t *retlen, u_char **mtdbuf)
61
{
62
        u_char *start = mtd->priv;
63
 
64
        if (from + len > mtd->size)
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                return -EINVAL;
66
 
67
        *mtdbuf = start + from;
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        *retlen = len;
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        return 0;
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}
71
 
72
static void phram_unpoint(struct mtd_info *mtd, u_char *addr, loff_t from,
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                size_t len)
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{
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}
76
 
77
static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
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                size_t *retlen, u_char *buf)
79
{
80
        u_char *start = mtd->priv;
81
 
82
        if (from >= mtd->size)
83
                return -EINVAL;
84
 
85
        if (len > mtd->size - from)
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                len = mtd->size - from;
87
 
88
        memcpy(buf, start + from, len);
89
 
90
        *retlen = len;
91
        return 0;
92
}
93
 
94
static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
95
                size_t *retlen, const u_char *buf)
96
{
97
        u_char *start = mtd->priv;
98
 
99
        if (to >= mtd->size)
100
                return -EINVAL;
101
 
102
        if (len > mtd->size - to)
103
                len = mtd->size - to;
104
 
105
        memcpy(start + to, buf, len);
106
 
107
        *retlen = len;
108
        return 0;
109
}
110
 
111
 
112
 
113
static void unregister_devices(void)
114
{
115
        struct phram_mtd_list *this, *safe;
116
 
117
        list_for_each_entry_safe(this, safe, &phram_list, list) {
118
                del_mtd_device(&this->mtd);
119
                iounmap(this->mtd.priv);
120
                kfree(this);
121
        }
122
}
123
 
124
static int register_device(char *name, unsigned long start, unsigned long len)
125
{
126
        struct phram_mtd_list *new;
127
        int ret = -ENOMEM;
128
 
129
        new = kzalloc(sizeof(*new), GFP_KERNEL);
130
        if (!new)
131
                goto out0;
132
 
133
        ret = -EIO;
134
        new->mtd.priv = ioremap(start, len);
135
        if (!new->mtd.priv) {
136
                ERROR("ioremap failed\n");
137
                goto out1;
138
        }
139
 
140
 
141
        new->mtd.name = name;
142
        new->mtd.size = len;
143
        new->mtd.flags = MTD_CAP_RAM;
144
        new->mtd.erase = phram_erase;
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        new->mtd.point = phram_point;
146
        new->mtd.unpoint = phram_unpoint;
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        new->mtd.read = phram_read;
148
        new->mtd.write = phram_write;
149
        new->mtd.owner = THIS_MODULE;
150
        new->mtd.type = MTD_RAM;
151
        new->mtd.erasesize = PAGE_SIZE;
152
        new->mtd.writesize = 1;
153
 
154
        ret = -EAGAIN;
155
        if (add_mtd_device(&new->mtd)) {
156
                ERROR("Failed to register new device\n");
157
                goto out2;
158
        }
159
 
160
        list_add_tail(&new->list, &phram_list);
161
        return 0;
162
 
163
out2:
164
        iounmap(new->mtd.priv);
165
out1:
166
        kfree(new);
167
out0:
168
        return ret;
169
}
170
 
171
static int ustrtoul(const char *cp, char **endp, unsigned int base)
172
{
173
        unsigned long result = simple_strtoul(cp, endp, base);
174
 
175
        switch (**endp) {
176
        case 'G':
177
                result *= 1024;
178
        case 'M':
179
                result *= 1024;
180
        case 'k':
181
                result *= 1024;
182
        /* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
183
                if ((*endp)[1] == 'i')
184
                        (*endp) += 2;
185
        }
186
        return result;
187
}
188
 
189
static int parse_num32(uint32_t *num32, const char *token)
190
{
191
        char *endp;
192
        unsigned long n;
193
 
194
        n = ustrtoul(token, &endp, 0);
195
        if (*endp)
196
                return -EINVAL;
197
 
198
        *num32 = n;
199
        return 0;
200
}
201
 
202
static int parse_name(char **pname, const char *token)
203
{
204
        size_t len;
205
        char *name;
206
 
207
        len = strlen(token) + 1;
208
        if (len > 64)
209
                return -ENOSPC;
210
 
211
        name = kmalloc(len, GFP_KERNEL);
212
        if (!name)
213
                return -ENOMEM;
214
 
215
        strcpy(name, token);
216
 
217
        *pname = name;
218
        return 0;
219
}
220
 
221
 
222
static inline void kill_final_newline(char *str)
223
{
224
        char *newline = strrchr(str, '\n');
225
        if (newline && !newline[1])
226
                *newline = 0;
227
}
228
 
229
 
230
#define parse_err(fmt, args...) do {    \
231
        ERROR(fmt , ## args);   \
232
        return 0;                \
233
} while (0)
234
 
235
static int phram_setup(const char *val, struct kernel_param *kp)
236
{
237
        char buf[64+12+12], *str = buf;
238
        char *token[3];
239
        char *name;
240
        uint32_t start;
241
        uint32_t len;
242
        int i, ret;
243
 
244
        if (strnlen(val, sizeof(buf)) >= sizeof(buf))
245
                parse_err("parameter too long\n");
246
 
247
        strcpy(str, val);
248
        kill_final_newline(str);
249
 
250
        for (i=0; i<3; i++)
251
                token[i] = strsep(&str, ",");
252
 
253
        if (str)
254
                parse_err("too many arguments\n");
255
 
256
        if (!token[2])
257
                parse_err("not enough arguments\n");
258
 
259
        ret = parse_name(&name, token[0]);
260
        if (ret == -ENOMEM)
261
                parse_err("out of memory\n");
262
        if (ret == -ENOSPC)
263
                parse_err("name too long\n");
264
        if (ret)
265
                return 0;
266
 
267
        ret = parse_num32(&start, token[1]);
268
        if (ret) {
269
                kfree(name);
270
                parse_err("illegal start address\n");
271
        }
272
 
273
        ret = parse_num32(&len, token[2]);
274
        if (ret) {
275
                kfree(name);
276
                parse_err("illegal device length\n");
277
        }
278
 
279
        register_device(name, start, len);
280
 
281
        return 0;
282
}
283
 
284
module_param_call(phram, phram_setup, NULL, NULL, 000);
285
MODULE_PARM_DESC(phram,"Memory region to map. \"map=<name>,<start>,<length>\"");
286
 
287
 
288
static int __init init_phram(void)
289
{
290
        return 0;
291
}
292
 
293
static void __exit cleanup_phram(void)
294
{
295
        unregister_devices();
296
}
297
 
298
module_init(init_phram);
299
module_exit(cleanup_phram);
300
 
301
MODULE_LICENSE("GPL");
302
MODULE_AUTHOR("Jörn Engel <joern@wh.fh-wedel.de>");
303
MODULE_DESCRIPTION("MTD driver for physical RAM");

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