release/src-rt-6.x/linux/linux-2.6/arch/cris/arch-v32/drivers/axisflashmap.c

   1 /*
   2  * Physical mapping layer for MTD using the Axis partitiontable format
   3  *
   4  * Copyright (c) 2001, 2002, 2003 Axis Communications AB
   5  *
   6  * This file is under the GPL.
   7  *
   8  * First partition is always sector 0 regardless of if we find a partitiontable
   9  * or not. In the start of the next sector, there can be a partitiontable that
  10  * tells us what other partitions to define. If there isn't, we use a default
  11  * partition split defined below.
  12  *
  13  * Copy of os/lx25/arch/cris/arch-v10/drivers/axisflashmap.c 1.5
  14  * with minor changes.
  15  *
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/types.h>
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/slab.h>
  23
  24 #include <linux/mtd/concat.h>
  25 #include <linux/mtd/map.h>
  26 #include <linux/mtd/mtd.h>
  27 #include <linux/mtd/mtdram.h>
  28 #include <linux/mtd/partitions.h>
  29
  30 #include <asm/arch/hwregs/config_defs.h>
  31 #include <asm/axisflashmap.h>
  32 #include <asm/mmu.h>
  33
  34 #define MEM_CSE0_SIZE (0x04000000)
  35 #define MEM_CSE1_SIZE (0x04000000)
  36
  37 #define FLASH_UNCACHED_ADDR  KSEG_E
  38 #define FLASH_CACHED_ADDR    KSEG_F
  39
  40 #if CONFIG_ETRAX_FLASH_BUSWIDTH==1
  41 #define flash_data __u8
  42 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
  43 #define flash_data __u16
  44 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
  45 #define flash_data __u16
  46 #endif
  47
  48 /* From head.S */
  49 extern unsigned long romfs_start, romfs_length, romfs_in_flash;
  50
  51 /* The master mtd for the entire flash. */
  52 struct mtd_info* axisflash_mtd = NULL;
  53
  54 /* Map driver functions. */
  55
  56 static map_word flash_read(struct map_info *map, unsigned long ofs)
  57 {
  58         map_word tmp;
  59         tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
  60         return tmp;
  61 }
  62
  63 static void flash_copy_from(struct map_info *map, void *to,
  64                             unsigned long from, ssize_t len)
  65 {
  66         memcpy(to, (void *)(map->map_priv_1 + from), len);
  67 }
  68
  69 static void flash_write(struct map_info *map, map_word d, unsigned long adr)
  70 {
  71         *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
  72 }
  73
  74 /*
  75  * The map for chip select e0.
  76  *
  77  * We run into tricky coherence situations if we mix cached with uncached
  78  * accesses to we only use the uncached version here.
  79  *
  80  * The size field is the total size where the flash chips may be mapped on the
  81  * chip select. MTD probes should find all devices there and it does not matter
  82  * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
  83  * probes will ignore them.
  84  *
  85  * The start address in map_priv_1 is in virtual memory so we cannot use
  86  * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
  87  * address of cse0.
  88  */
  89 static struct map_info map_cse0 = {
  90         .name = "cse0",
  91         .size = MEM_CSE0_SIZE,
  92         .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
  93         .read = flash_read,
  94         .copy_from = flash_copy_from,
  95         .write = flash_write,
  96         .map_priv_1 = FLASH_UNCACHED_ADDR
  97 };
  98
  99 /*
 100  * The map for chip select e1.
 101  *
 102  * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
 103  * address, but there isn't.
 104  */
 105 static struct map_info map_cse1 = {
 106         .name = "cse1",
 107         .size = MEM_CSE1_SIZE,
 108         .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
 109         .read = flash_read,
 110         .copy_from = flash_copy_from,
 111         .write = flash_write,
 112         .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
 113 };
 114
 115 /* If no partition-table was found, we use this default-set. */
 116 #define MAX_PARTITIONS         7
 117 #define NUM_DEFAULT_PARTITIONS 3
 118
 119 /*
 120  * Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
 121  * size of one flash block and "filesystem"-partition needs 5 blocks to be able
 122  * to use JFFS.
 123  */
 124 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
 125         {
 126                 .name = "boot firmware",
 127                 .size = CONFIG_ETRAX_PTABLE_SECTOR,
 128                 .offset = 0
 129         },
 130         {
 131                 .name = "kernel",
 132                 .size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
 133                 .offset = CONFIG_ETRAX_PTABLE_SECTOR
 134         },
 135         {
 136                 .name = "filesystem",
 137                 .size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
 138                 .offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
 139         }
 140 };
 141
 142 /* Initialize the ones normally used. */
 143 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
 144         {
 145                 .name = "part0",
 146                 .size = CONFIG_ETRAX_PTABLE_SECTOR,
 147                 .offset = 0
 148         },
 149         {
 150                 .name = "part1",
 151                 .size = 0,
 152                 .offset = 0
 153         },
 154         {
 155                 .name = "part2",
 156                 .size = 0,
 157                 .offset = 0
 158         },
 159         {
 160                 .name = "part3",
 161                 .size = 0,
 162                 .offset = 0
 163         },
 164         {
 165                 .name = "part4",
 166                 .size = 0,
 167                 .offset = 0
 168         },
 169         {
 170                 .name = "part5",
 171                 .size = 0,
 172                 .offset = 0
 173         },
 174         {
 175                 .name = "part6",
 176                 .size = 0,
 177                 .offset = 0
 178         },
 179 };
 180
 181 /*
 182  * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
 183  * chips in that order (because the amd_flash-driver is faster).
 184  */
 185 static struct mtd_info *probe_cs(struct map_info *map_cs)
 186 {
 187         struct mtd_info *mtd_cs = NULL;
 188
 189         printk(KERN_INFO
 190                "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
 191                map_cs->name, map_cs->size, map_cs->map_priv_1);
 192
 193 #ifdef CONFIG_MTD_AMDSTD
 194         mtd_cs = do_map_probe("amd_flash", map_cs);
 195 #endif
 196 #ifdef CONFIG_MTD_CFI
 197         if (!mtd_cs) {
 198                 mtd_cs = do_map_probe("cfi_probe", map_cs);
 199         }
 200 #endif
 201
 202         return mtd_cs;
 203 }
 204
 205 /*
 206  * Probe each chip select individually for flash chips. If there are chips on
 207  * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
 208  * so that MTD partitions can cross chip boundries.
 209  *
 210  * The only known restriction to how you can mount your chips is that each
 211  * chip select must hold similar flash chips. But you need external hardware
 212  * to do that anyway and you can put totally different chips on cse0 and cse1
 213  * so it isn't really much of a restriction.
 214  */
 215 extern struct mtd_info* __init crisv32_nand_flash_probe (void);
 216 static struct mtd_info *flash_probe(void)
 217 {
 218         struct mtd_info *mtd_cse0;
 219         struct mtd_info *mtd_cse1;
 220         struct mtd_info *mtd_nand = NULL;
 221         struct mtd_info *mtd_total;
 222         struct mtd_info *mtds[3];
 223         int count = 0;
 224
 225         if ((mtd_cse0 = probe_cs(&map_cse0)) != NULL)
 226                 mtds[count++] = mtd_cse0;
 227         if ((mtd_cse1 = probe_cs(&map_cse1)) != NULL)
 228                 mtds[count++] = mtd_cse1;
 229
 230 #ifdef CONFIG_ETRAX_NANDFLASH
 231         if ((mtd_nand = crisv32_nand_flash_probe()) != NULL)
 232                 mtds[count++] = mtd_nand;
 233 #endif
 234
 235         if (!mtd_cse0 && !mtd_cse1 && !mtd_nand) {
 236                 /* No chip found. */
 237                 return NULL;
 238         }
 239
 240         if (count > 1) {
 241 #ifdef CONFIG_MTD_CONCAT
 242                 /* Since the concatenation layer adds a small overhead we
 243                  * could try to figure out if the chips in cse0 and cse1 are
 244                  * identical and reprobe the whole cse0+cse1 window. But since
 245                  * flash chips are slow, the overhead is relatively small.
 246                  * So we use the MTD concatenation layer instead of further
 247                  * complicating the probing procedure.
 248                  */
 249                 mtd_total = mtd_concat_create(mtds,
 250                                               count,
 251                                               "cse0+cse1+nand");
 252 #else
 253                 printk(KERN_ERR "%s and %s: Cannot concatenate due to kernel "
 254                        "(mis)configuration!\n", map_cse0.name, map_cse1.name);
 255                 mtd_toal = NULL;
 256 #endif
 257                 if (!mtd_total) {
 258                         printk(KERN_ERR "%s and %s: Concatenation failed!\n",
 259                                map_cse0.name, map_cse1.name);
 260
 261                         /* The best we can do now is to only use what we found
 262                          * at cse0.
 263                          */
 264                         mtd_total = mtd_cse0;
 265                         map_destroy(mtd_cse1);
 266                 }
 267         } else {
 268                 mtd_total = mtd_cse0? mtd_cse0 : mtd_cse1 ? mtd_cse1 : mtd_nand;
 269
 270         }
 271
 272         return mtd_total;
 273 }
 274
 275 extern unsigned long crisv32_nand_boot;
 276 extern unsigned long crisv32_nand_cramfs_offset;
 277
 278 /*
 279  * Probe the flash chip(s) and, if it succeeds, read the partition-table
 280  * and register the partitions with MTD.
 281  */
 282 static int __init init_axis_flash(void)
 283 {
 284         struct mtd_info *mymtd;
 285         int err = 0;
 286         int pidx = 0;
 287         struct partitiontable_head *ptable_head = NULL;
 288         struct partitiontable_entry *ptable;
 289         int use_default_ptable = 1; /* Until proven otherwise. */
 290         const char *pmsg = KERN_INFO "  /dev/flash%d at 0x%08x, size 0x%08x\n";
 291         static char page[512];
 292         size_t len;
 293
 294 #ifndef CONFIG_ETRAXFS_SIM
 295         mymtd = flash_probe();
 296         mymtd->read(mymtd, CONFIG_ETRAX_PTABLE_SECTOR, 512, &len, page);
 297         ptable_head = (struct partitiontable_head *)(page + PARTITION_TABLE_OFFSET);
 298
 299         if (!mymtd) {
 300                 /* There's no reason to use this module if no flash chip can
 301                  * be identified. Make sure that's understood.
 302                  */
 303                 printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
 304         } else {
 305                 printk(KERN_INFO "%s: 0x%08x bytes of flash memory.\n",
 306                        mymtd->name, mymtd->size);
 307                 axisflash_mtd = mymtd;
 308         }
 309
 310         if (mymtd) {
 311                 mymtd->owner = THIS_MODULE;
 312         }
 313         pidx++;  /* First partition is always set to the default. */
 314
 315         if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
 316             && (ptable_head->size <
 317                 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
 318                 PARTITIONTABLE_END_MARKER_SIZE))
 319             && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
 320                                   ptable_head->size -
 321                                   PARTITIONTABLE_END_MARKER_SIZE)
 322                 == PARTITIONTABLE_END_MARKER)) {
 323                 /* Looks like a start, sane length and end of a
 324                  * partition table, lets check csum etc.
 325                  */
 326                 int ptable_ok = 0;
 327                 struct partitiontable_entry *max_addr =
 328                         (struct partitiontable_entry *)
 329                         ((unsigned long)ptable_head + sizeof(*ptable_head) +
 330                          ptable_head->size);
 331                 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
 332                 unsigned char *p;
 333                 unsigned long csum = 0;
 334
 335                 ptable = (struct partitiontable_entry *)
 336                         ((unsigned long)ptable_head + sizeof(*ptable_head));
 337
 338                 /* Lets be PARANOID, and check the checksum. */
 339                 p = (unsigned char*) ptable;
 340
 341                 while (p <= (unsigned char*)max_addr) {
 342                         csum += *p++;
 343                         csum += *p++;
 344                         csum += *p++;
 345                         csum += *p++;
 346                 }
 347                 ptable_ok = (csum == ptable_head->checksum);
 348
 349                 /* Read the entries and use/show the info.  */
 350                 printk(KERN_INFO " Found a%s partition table at 0x%p-0x%p.\n",
 351                        (ptable_ok ? " valid" : "n invalid"), ptable_head,
 352                        max_addr);
 353
 354                 /* We have found a working bootblock.  Now read the
 355                  * partition table.  Scan the table.  It ends when
 356                  * there is 0xffffffff, that is, empty flash.
 357                  */
 358                 while (ptable_ok
 359                        && ptable->offset != 0xffffffff
 360                        && ptable < max_addr
 361                        && pidx < MAX_PARTITIONS) {
 362
 363                         axis_partitions[pidx].offset = offset + ptable->offset + (crisv32_nand_boot ? 16384 : 0);
 364                         axis_partitions[pidx].size = ptable->size;
 365
 366                         printk(pmsg, pidx, axis_partitions[pidx].offset,
 367                                axis_partitions[pidx].size);
 368                         pidx++;
 369                         ptable++;
 370                 }
 371                 use_default_ptable = !ptable_ok;
 372         }
 373
 374         if (romfs_in_flash) {
 375                 /* Add an overlapping device for the root partition (romfs). */
 376
 377                 axis_partitions[pidx].name = "romfs";
 378                 if (crisv32_nand_boot) {
 379                         char* data = kmalloc(1024, GFP_KERNEL);
 380                         int len;
 381                         int offset = crisv32_nand_cramfs_offset & ~(1024-1);
 382                         char* tmp;
 383
 384                         mymtd->read(mymtd, offset, 1024, &len, data);
 385                         tmp = &data[crisv32_nand_cramfs_offset % 512];
 386                         axis_partitions[pidx].size = *(unsigned*)(tmp + 4);
 387                         axis_partitions[pidx].offset = crisv32_nand_cramfs_offset;
 388                         kfree(data);
 389                 } else {
 390                         axis_partitions[pidx].size = romfs_length;
 391                         axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
 392                 }
 393
 394                 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
 395
 396                 printk(KERN_INFO
 397                        " Adding readonly flash partition for romfs image:\n");
 398                 printk(pmsg, pidx, axis_partitions[pidx].offset,
 399                        axis_partitions[pidx].size);
 400                 pidx++;
 401         }
 402
 403         if (mymtd) {
 404                 if (use_default_ptable) {
 405                         printk(KERN_INFO " Using default partition table.\n");
 406                         err = add_mtd_partitions(mymtd, axis_default_partitions,
 407                                                  NUM_DEFAULT_PARTITIONS);
 408                 } else {
 409                         err = add_mtd_partitions(mymtd, axis_partitions, pidx);
 410                 }
 411
 412                 if (err) {
 413                         panic("axisflashmap could not add MTD partitions!\n");
 414                 }
 415         }
 416 /* CONFIG_EXTRAXFS_SIM */
 417 #endif
 418
 419         if (!romfs_in_flash) {
 420                 /* Create an RAM device for the root partition (romfs). */
 421
 422 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
 423                 /* No use trying to boot this kernel from RAM. Panic! */
 424                 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
 425                        "device due to kernel (mis)configuration!\n");
 426                 panic("This kernel cannot boot from RAM!\n");
 427 #else
 428                 struct mtd_info *mtd_ram;
 429
 430                 mtd_ram = kmalloc(sizeof(struct mtd_info),
 431                                                      GFP_KERNEL);
 432                 if (!mtd_ram) {
 433                         panic("axisflashmap couldn't allocate memory for "
 434                               "mtd_info!\n");
 435                 }
 436
 437                 printk(KERN_INFO " Adding RAM partition for romfs image:\n");
 438                 printk(pmsg, pidx, romfs_start, romfs_length);
 439
 440                 err = mtdram_init_device(mtd_ram, (void*)romfs_start,
 441                                          romfs_length, "romfs");
 442                 if (err) {
 443                         panic("axisflashmap could not initialize MTD RAM "
 444                               "device!\n");
 445                 }
 446 #endif
 447         }
 448
 449         return err;
 450 }
 451
 452 /* This adds the above to the kernels init-call chain. */
 453 module_init(init_axis_flash);
 454
 455 EXPORT_SYMBOL(axisflash_mtd);