Root/target/linux/ar7/files-3.3/drivers/mtd/ac49xpart.c

1/*
2 * AudioCodes AC49x PSPBoot-based flash partition table
3 * Copyright 2012 Daniel Golle <daniel.golle@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 */
20
21#include <linux/kernel.h>
22#include <linux/slab.h>
23
24#include <linux/mtd/mtd.h>
25#include <linux/mtd/partitions.h>
26#include <linux/bootmem.h>
27#include <linux/magic.h>
28#include <linux/module.h>
29
30#include <asm/mach-ar7/prom.h>
31
32#define AC49X_MAXENVPARTS 8
33
34#define AC49X_PARTTYPE_LOADER 0
35#define AC49X_PARTTYPE_BOOTENV 1
36#define AC49X_PARTTYPE_LINUX 2
37#define AC49X_PARTTYPE_ROOTFS 3
38#define AC49X_PARTTYPE_UNKNOWN 4
39#define AC49X_NUM_PARTTYPES 5
40
41#define AC49X_FLASH_ADDRMASK 0x00FFFFFF
42
43#define AC49X_LOADER_MAGIC 0x40809000
44#define AC49X_LINUX_MAGIC 0x464c457f /* ELF */
45#define AC49X_BOOTENV_MAGIC 0x4578614d /* MaxE */
46
47#define ROOTFS_MIN_OFFSET 0xC0000
48
49int parse_partvar(const unsigned char *partvar, struct mtd_partition *part)
50{
51    unsigned int partstart, partend;
52    unsigned int pnum;
53
54    pnum = sscanf(partvar, "0x%x,0x%x", &partstart, &partend);
55    if (pnum != 2)
56        return 1;
57
58    part->offset = partstart & AC49X_FLASH_ADDRMASK;
59    part->size = partend - partstart;
60
61    return 0;
62}
63
64int detect_parttype(struct mtd_info *master, struct mtd_partition part)
65{
66    unsigned int magic;
67    size_t len;
68
69    if (part.size < 4)
70        return -1;
71
72    mtd_read(master, part.offset, sizeof(magic), &len,
73         (uint8_t *)&magic);
74
75    if (len != sizeof(magic))
76        return -1;
77
78    switch (magic) {
79    case AC49X_LOADER_MAGIC:
80        return AC49X_PARTTYPE_LOADER;
81    case AC49X_LINUX_MAGIC:
82        return AC49X_PARTTYPE_LINUX;
83    case SQUASHFS_MAGIC:
84    case CRAMFS_MAGIC:
85    case CRAMFS_MAGIC_WEND:
86        return AC49X_PARTTYPE_ROOTFS;
87    case AC49X_BOOTENV_MAGIC:
88        return AC49X_PARTTYPE_BOOTENV;
89    default:
90        switch (magic & 0xFF) {
91        case JFFS2_SUPER_MAGIC:
92            return AC49X_PARTTYPE_ROOTFS;
93        }
94        switch (magic >> 8) {
95        case JFFS2_SUPER_MAGIC:
96            return AC49X_PARTTYPE_ROOTFS;
97        }
98        return AC49X_PARTTYPE_UNKNOWN;
99    }
100}
101
102const char *partnames[] = {
103    "loader",
104    "config",
105    "linux",
106    "rootfs",
107    "data"
108};
109
110void gen_partname(unsigned int type,
111          unsigned int *typenumeration,
112          struct mtd_partition *part)
113{
114    char *s = kzalloc(sizeof(char) * 8, GFP_KERNEL);
115
116    (typenumeration[type])++;
117    if (typenumeration[type] == 1)
118        sprintf(s, "%s", partnames[type]);
119    else
120        sprintf(s, "%s%d", partnames[type], typenumeration[type]);
121
122    part->name = s;
123}
124
125static int create_mtd_partitions(struct mtd_info *master,
126                 struct mtd_partition **pparts,
127                 struct mtd_part_parser_data *data)
128{
129    unsigned int envpartnum = 0, linuxpartnum = 0;
130    unsigned int typenumeration[5] = { 0, 0, 0, 0, 0 };
131    unsigned char evn[5];
132    const unsigned char *partvar = NULL;
133
134    struct mtd_partition *ac49x_parts;
135
136    ac49x_parts = kzalloc(sizeof(*ac49x_parts) * AC49X_MAXENVPARTS,
137                GFP_KERNEL);
138
139    if (!ac49x_parts)
140        return -ENOMEM;
141
142    linuxpartnum = 0;
143    for (envpartnum = 0; envpartnum < AC49X_MAXENVPARTS; envpartnum++) {
144        struct mtd_partition parsepart;
145        unsigned int offset, size, type;
146        int err;
147        sprintf(evn, "mtd%d", envpartnum);
148        partvar = prom_getenv(evn);
149        if (!partvar)
150            continue;
151        err = parse_partvar(partvar, &parsepart);
152        if (err)
153            continue;
154        offset = parsepart.offset;
155        size = parsepart.size;
156        type = detect_parttype(master, parsepart);
157        gen_partname(type, typenumeration, &parsepart);
158        /* protect loader */
159        if (type == AC49X_PARTTYPE_LOADER)
160            parsepart.mask_flags = MTD_WRITEABLE;
161        else
162            parsepart.mask_flags = 0;
163
164        memcpy(&(ac49x_parts[linuxpartnum]), &parsepart,
165            sizeof(struct mtd_partition));
166
167        /* scan for contained rootfs */
168        if (type == AC49X_PARTTYPE_LINUX) {
169            parsepart.offset += ROOTFS_MIN_OFFSET &
170                        ~(master->erasesize - 1);
171            parsepart.size -= ROOTFS_MIN_OFFSET &
172                        ~(master->erasesize - 1);
173            do {
174                unsigned int size, offset;
175                size = parsepart.size;
176                offset = parsepart.offset;
177
178                type = detect_parttype(master, parsepart);
179                if (type == AC49X_PARTTYPE_ROOTFS) {
180                    gen_partname(type, typenumeration,
181                            &parsepart);
182                    printk(KERN_INFO
183                        "%s %s: 0x%08x@0x%08x\n",
184                        "detected sub-partition",
185                        parsepart.name,
186                        (unsigned int)parsepart.size,
187                        (unsigned int)parsepart.offset);
188                    linuxpartnum++;
189                    memcpy(&(ac49x_parts[linuxpartnum]),
190                        &parsepart,
191                        sizeof(struct mtd_partition));
192                    break;
193                }
194                parsepart.offset += master->erasesize;
195                parsepart.size -= master->erasesize;
196            } while (parsepart.size >= master->erasesize);
197        }
198        linuxpartnum++;
199    }
200
201    *pparts = ac49x_parts;
202    return linuxpartnum;
203}
204
205static struct mtd_part_parser ac49x_parser = {
206    .owner = THIS_MODULE,
207    .parse_fn = create_mtd_partitions,
208    .name = "ac49xpart",
209};
210
211static int __init ac49x_parser_init(void)
212{
213    return register_mtd_parser(&ac49x_parser);
214}
215
216module_init(ac49x_parser_init);
217
218MODULE_LICENSE("GPL");
219MODULE_AUTHOR("Daniel Golle <daniel.golle@gmail.com>");
220MODULE_DESCRIPTION("MTD partitioning for AudioCodes AC49x");
221

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