target/linux/ar7/files/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
  49 int 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
  64 int 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
 102 const char *partnames[] = {
 103         "loader",
 104         "config",
 105         "linux",
 106         "rootfs",
 107         "data"
 108 };
 109
 110 void 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
 125 static 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
 205 static struct mtd_part_parser ac49x_parser = {
 206         .owner = THIS_MODULE,
 207         .parse_fn = create_mtd_partitions,
 208         .name = "ac49xpart",
 209 };
 210
 211 static int __init ac49x_parser_init(void)
 212 {
 213         return register_mtd_parser(&ac49x_parser);
 214 }
 215
 216 module_init(ac49x_parser_init);
 217
 218 MODULE_LICENSE("GPL");
 219 MODULE_AUTHOR("Daniel Golle <daniel.golle@gmail.com>");
 220 MODULE_DESCRIPTION("MTD partitioning for AudioCodes AC49x");