release/src-rt-6.x/linux/linux-2.6/arch/cris/arch-v10/drivers/axisflashmap.c

   1 /*
   2  * Physical mapping layer for MTD using the Axis partitiontable format
   3  *
   4  * Copyright (c) 2001, 2002 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  * $Log: axisflashmap.c,v $
  14  * Revision 1.11  2004/11/15 10:27:14  starvik
  15  * Corrected typo (Thanks to Milton Miller <miltonm@bga.com>).
  16  *
  17  * Revision 1.10  2004/08/16 12:37:22  starvik
  18  * Merge of Linux 2.6.8
  19  *
  20  * Revision 1.8  2004/05/14 07:58:03  starvik
  21  * Merge of changes from 2.4
  22  *
  23  * Revision 1.6  2003/07/04 08:27:37  starvik
  24  * Merge of Linux 2.5.74
  25  *
  26  * Revision 1.5  2002/12/11 13:13:57  starvik
  27  * Added arch/ to v10 specific includes
  28  * Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
  29  *
  30  * Revision 1.4  2002/11/20 11:56:10  starvik
  31  * Merge of Linux 2.5.48
  32  *
  33  * Revision 1.3  2002/11/13 14:54:13  starvik
  34  * Copied from linux 2.4
  35  *
  36  * Revision 1.28  2002/10/01 08:08:43  jonashg
  37  * The first partition ends at the start of the partition table.
  38  *
  39  * Revision 1.27  2002/08/21 09:23:13  jonashg
  40  * Speling.
  41  *
  42  * Revision 1.26  2002/08/21 08:35:20  jonashg
  43  * Cosmetic change to printouts.
  44  *
  45  * Revision 1.25  2002/08/21 08:15:42  jonashg
  46  * Made it compile even without CONFIG_MTD_CONCAT defined.
  47  *
  48  * Revision 1.24  2002/08/20 13:12:35  jonashg
  49  * * New approach to probing. Probe cse0 and cse1 separately and (mtd)concat
  50  *   the results.
  51  * * Removed compile time tests concerning how the mtdram driver has been
  52  *   configured. The user will know about the misconfiguration at runtime
  53  *   instead. (The old approach made it impossible to use mtdram for anything
  54  *   else than RAM boot).
  55  *
  56  * Revision 1.23  2002/05/13 12:12:28  johana
  57  * Allow compile without CONFIG_MTD_MTDRAM but warn at compiletime and
  58  * be informative at runtime.
  59  *
  60  * Revision 1.22  2002/05/13 10:24:44  johana
  61  * Added #if checks on MTDRAM CONFIG
  62  *
  63  * Revision 1.21  2002/05/06 16:05:20  johana
  64  * Removed debug printout.
  65  *
  66  * Revision 1.20  2002/05/06 16:03:00  johana
  67  * No more cramfs as root hack in generic code.
  68  * It's handled by axisflashmap using mtdram.
  69  *
  70  * Revision 1.19  2002/03/15 17:10:28  bjornw
  71  * Changed comment about cached access since we changed this before
  72  *
  73  * Revision 1.18  2002/03/05 17:06:15  jonashg
  74  * Try amd_flash probe before cfi_probe since amd_flash driver can handle two
  75  * (or more) flash chips of different model and the cfi driver cannot.
  76  *
  77  * Revision 1.17  2001/11/12 19:42:38  pkj
  78  * Fixed compiler warnings.
  79  *
  80  * Revision 1.16  2001/11/08 11:18:58  jonashg
  81  * Always read from uncached address to avoid problems with flushing
  82  * cachelines after write and MTD-erase. No performance loss have been
  83  * seen yet.
  84  *
  85  * Revision 1.15  2001/10/19 12:41:04  jonashg
  86  * Name of probe has changed in MTD.
  87  *
  88  * Revision 1.14  2001/09/21 07:14:10  jonashg
  89  * Made root filesystem (cramfs) use mtdblock driver when booting from flash.
  90  *
  91  * Revision 1.13  2001/08/15 13:57:35  jonashg
  92  * Entire MTD updated to the linux 2.4.7 version.
  93  *
  94  * Revision 1.12  2001/06/11 09:50:30  jonashg
  95  * Oops, 2MB is 0x200000 bytes.
  96  *
  97  * Revision 1.11  2001/06/08 11:39:44  jonashg
  98  * Changed sizes and offsets in axis_default_partitions to use
  99  * CONFIG_ETRAX_PTABLE_SECTOR.
 100  *
 101  * Revision 1.10  2001/05/29 09:42:03  jonashg
 102  * Use macro for end marker length instead of sizeof.
 103  *
 104  * Revision 1.9  2001/05/29 08:52:52  jonashg
 105  * Gave names to the magic fours (size of the ptable end marker).
 106  *
 107  * Revision 1.8  2001/05/28 15:36:20  jonashg
 108  * * Removed old comment about ptable location in flash (it's a CONFIG_ option).
 109  * * Variable ptable was initialized twice to the same value.
 110  *
 111  * Revision 1.7  2001/04/05 13:41:46  markusl
 112  * Updated according to review remarks
 113  *
 114  * Revision 1.6  2001/03/07 09:21:21  bjornw
 115  * No need to waste .data
 116  *
 117  * Revision 1.5  2001/03/06 16:27:01  jonashg
 118  * Probe the entire flash area for flash devices.
 119  *
 120  * Revision 1.4  2001/02/23 12:47:15  bjornw
 121  * Uncached flash in LOW_MAP moved from 0xe to 0x8
 122  *
 123  * Revision 1.3  2001/02/16 12:11:45  jonashg
 124  * MTD driver amd_flash is now included in MTD CVS repository.
 125  * (It's now in drivers/mtd).
 126  *
 127  * Revision 1.2  2001/02/09 11:12:22  jonashg
 128  * Support for AMD compatible non-CFI flash chips.
 129  * Only tested with Toshiba TC58FVT160 so far.
 130  *
 131  * Revision 1.1  2001/01/12 17:01:18  bjornw
 132  * * Added axisflashmap.c, a physical mapping for MTD that reads and understands
 133  *   Axis partition-table format.
 134  *
 135  *
 136  */
 137
 138 #include <linux/module.h>
 139 #include <linux/types.h>
 140 #include <linux/kernel.h>
 141 #include <linux/init.h>
 142 #include <linux/slab.h>
 143
 144 #include <linux/mtd/concat.h>
 145 #include <linux/mtd/map.h>
 146 #include <linux/mtd/mtd.h>
 147 #include <linux/mtd/mtdram.h>
 148 #include <linux/mtd/partitions.h>
 149
 150 #include <asm/axisflashmap.h>
 151 #include <asm/mmu.h>
 152 #include <asm/arch/sv_addr_ag.h>
 153
 154 #ifdef CONFIG_CRIS_LOW_MAP
 155 #define FLASH_UNCACHED_ADDR  KSEG_8
 156 #define FLASH_CACHED_ADDR    KSEG_5
 157 #else
 158 #define FLASH_UNCACHED_ADDR  KSEG_E
 159 #define FLASH_CACHED_ADDR    KSEG_F
 160 #endif
 161
 162 #if CONFIG_ETRAX_FLASH_BUSWIDTH==1
 163 #define flash_data __u8
 164 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
 165 #define flash_data __u16
 166 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
 167 #define flash_data __u32
 168 #endif
 169
 170 /* From head.S */
 171 extern unsigned long romfs_start, romfs_length, romfs_in_flash;
 172
 173 /* The master mtd for the entire flash. */
 174 struct mtd_info* axisflash_mtd = NULL;
 175
 176 /* Map driver functions. */
 177
 178 static map_word flash_read(struct map_info *map, unsigned long ofs)
 179 {
 180         map_word tmp;
 181         tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
 182         return tmp;
 183 }
 184
 185 static void flash_copy_from(struct map_info *map, void *to,
 186                             unsigned long from, ssize_t len)
 187 {
 188         memcpy(to, (void *)(map->map_priv_1 + from), len);
 189 }
 190
 191 static void flash_write(struct map_info *map, map_word d, unsigned long adr)
 192 {
 193         *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
 194 }
 195
 196 /*
 197  * The map for chip select e0.
 198  *
 199  * We run into tricky coherence situations if we mix cached with uncached
 200  * accesses to we only use the uncached version here.
 201  *
 202  * The size field is the total size where the flash chips may be mapped on the
 203  * chip select. MTD probes should find all devices there and it does not matter
 204  * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
 205  * probes will ignore them.
 206  *
 207  * The start address in map_priv_1 is in virtual memory so we cannot use
 208  * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
 209  * address of cse0.
 210  */
 211 static struct map_info map_cse0 = {
 212         .name = "cse0",
 213         .size = MEM_CSE0_SIZE,
 214         .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
 215         .read = flash_read,
 216         .copy_from = flash_copy_from,
 217         .write = flash_write,
 218         .map_priv_1 = FLASH_UNCACHED_ADDR
 219 };
 220
 221 /*
 222  * The map for chip select e1.
 223  *
 224  * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
 225  * address, but there isn't.
 226  */
 227 static struct map_info map_cse1 = {
 228         .name = "cse1",
 229         .size = MEM_CSE1_SIZE,
 230         .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
 231         .read = flash_read,
 232         .copy_from = flash_copy_from,
 233         .write = flash_write,
 234         .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
 235 };
 236
 237 /* If no partition-table was found, we use this default-set. */
 238 #define MAX_PARTITIONS         7
 239 #define NUM_DEFAULT_PARTITIONS 3
 240
 241 /*
 242  * Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
 243  * size of one flash block and "filesystem"-partition needs 5 blocks to be able
 244  * to use JFFS.
 245  */
 246 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
 247         {
 248                 .name = "boot firmware",
 249                 .size = CONFIG_ETRAX_PTABLE_SECTOR,
 250                 .offset = 0
 251         },
 252         {
 253                 .name = "kernel",
 254                 .size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
 255                 .offset = CONFIG_ETRAX_PTABLE_SECTOR
 256         },
 257         {
 258                 .name = "filesystem",
 259                 .size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
 260                 .offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
 261         }
 262 };
 263
 264 /* Initialize the ones normally used. */
 265 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
 266         {
 267                 .name = "part0",
 268                 .size = CONFIG_ETRAX_PTABLE_SECTOR,
 269                 .offset = 0
 270         },
 271         {
 272                 .name = "part1",
 273                 .size = 0,
 274                 .offset = 0
 275         },
 276         {
 277                 .name = "part2",
 278                 .size = 0,
 279                 .offset = 0
 280         },
 281         {
 282                 .name = "part3",
 283                 .size = 0,
 284                 .offset = 0
 285         },
 286         {
 287                 .name = "part4",
 288                 .size = 0,
 289                 .offset = 0
 290         },
 291         {
 292                 .name = "part5",
 293                 .size = 0,
 294                 .offset = 0
 295         },
 296         {
 297                 .name = "part6",
 298                 .size = 0,
 299                 .offset = 0
 300         },
 301 };
 302
 303 /*
 304  * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
 305  * chips in that order (because the amd_flash-driver is faster).
 306  */
 307 static struct mtd_info *probe_cs(struct map_info *map_cs)
 308 {
 309         struct mtd_info *mtd_cs = NULL;
 310
 311         printk(KERN_INFO
 312                "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
 313                map_cs->name, map_cs->size, map_cs->map_priv_1);
 314
 315 #ifdef CONFIG_MTD_AMDSTD
 316         mtd_cs = do_map_probe("amd_flash", map_cs);
 317 #endif
 318 #ifdef CONFIG_MTD_CFI
 319         if (!mtd_cs) {
 320                 mtd_cs = do_map_probe("cfi_probe", map_cs);
 321         }
 322 #endif
 323
 324         return mtd_cs;
 325 }
 326
 327 /*
 328  * Probe each chip select individually for flash chips. If there are chips on
 329  * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
 330  * so that MTD partitions can cross chip boundries.
 331  *
 332  * The only known restriction to how you can mount your chips is that each
 333  * chip select must hold similar flash chips. But you need external hardware
 334  * to do that anyway and you can put totally different chips on cse0 and cse1
 335  * so it isn't really much of a restriction.
 336  */
 337 static struct mtd_info *flash_probe(void)
 338 {
 339         struct mtd_info *mtd_cse0;
 340         struct mtd_info *mtd_cse1;
 341         struct mtd_info *mtd_cse;
 342
 343         mtd_cse0 = probe_cs(&map_cse0);
 344         mtd_cse1 = probe_cs(&map_cse1);
 345
 346         if (!mtd_cse0 && !mtd_cse1) {
 347                 /* No chip found. */
 348                 return NULL;
 349         }
 350
 351         if (mtd_cse0 && mtd_cse1) {
 352 #ifdef CONFIG_MTD_CONCAT
 353                 struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };
 354
 355                 /* Since the concatenation layer adds a small overhead we
 356                  * could try to figure out if the chips in cse0 and cse1 are
 357                  * identical and reprobe the whole cse0+cse1 window. But since
 358                  * flash chips are slow, the overhead is relatively small.
 359                  * So we use the MTD concatenation layer instead of further
 360                  * complicating the probing procedure.
 361                  */
 362                 mtd_cse = mtd_concat_create(mtds, ARRAY_SIZE(mtds),
 363                                             "cse0+cse1");
 364 #else
 365                 printk(KERN_ERR "%s and %s: Cannot concatenate due to kernel "
 366                        "(mis)configuration!\n", map_cse0.name, map_cse1.name);
 367                 mtd_cse = NULL;
 368 #endif
 369                 if (!mtd_cse) {
 370                         printk(KERN_ERR "%s and %s: Concatenation failed!\n",
 371                                map_cse0.name, map_cse1.name);
 372
 373                         /* The best we can do now is to only use what we found
 374                          * at cse0.
 375                          */
 376                         mtd_cse = mtd_cse0;
 377                         map_destroy(mtd_cse1);
 378                 }
 379         } else {
 380                 mtd_cse = mtd_cse0? mtd_cse0 : mtd_cse1;
 381         }
 382
 383         return mtd_cse;
 384 }
 385
 386 /*
 387  * Probe the flash chip(s) and, if it succeeds, read the partition-table
 388  * and register the partitions with MTD.
 389  */
 390 static int __init init_axis_flash(void)
 391 {
 392         struct mtd_info *mymtd;
 393         int err = 0;
 394         int pidx = 0;
 395         struct partitiontable_head *ptable_head = NULL;
 396         struct partitiontable_entry *ptable;
 397         int use_default_ptable = 1; /* Until proven otherwise. */
 398         const char *pmsg = "  /dev/flash%d at 0x%08x, size 0x%08x\n";
 399
 400         if (!(mymtd = flash_probe())) {
 401                 /* There's no reason to use this module if no flash chip can
 402                  * be identified. Make sure that's understood.
 403                  */
 404                 printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
 405         } else {
 406                 printk(KERN_INFO "%s: 0x%08x bytes of flash memory.\n",
 407                        mymtd->name, mymtd->size);
 408                 axisflash_mtd = mymtd;
 409         }
 410
 411         if (mymtd) {
 412                 mymtd->owner = THIS_MODULE;
 413                 ptable_head = (struct partitiontable_head *)(FLASH_CACHED_ADDR +
 414                               CONFIG_ETRAX_PTABLE_SECTOR +
 415                               PARTITION_TABLE_OFFSET);
 416         }
 417         pidx++;  /* First partition is always set to the default. */
 418
 419         if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
 420             && (ptable_head->size <
 421                 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
 422                 PARTITIONTABLE_END_MARKER_SIZE))
 423             && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
 424                                   ptable_head->size -
 425                                   PARTITIONTABLE_END_MARKER_SIZE)
 426                 == PARTITIONTABLE_END_MARKER)) {
 427                 /* Looks like a start, sane length and end of a
 428                  * partition table, lets check csum etc.
 429                  */
 430                 int ptable_ok = 0;
 431                 struct partitiontable_entry *max_addr =
 432                         (struct partitiontable_entry *)
 433                         ((unsigned long)ptable_head + sizeof(*ptable_head) +
 434                          ptable_head->size);
 435                 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
 436                 unsigned char *p;
 437                 unsigned long csum = 0;
 438
 439                 ptable = (struct partitiontable_entry *)
 440                         ((unsigned long)ptable_head + sizeof(*ptable_head));
 441
 442                 /* Lets be PARANOID, and check the checksum. */
 443                 p = (unsigned char*) ptable;
 444
 445                 while (p <= (unsigned char*)max_addr) {
 446                         csum += *p++;
 447                         csum += *p++;
 448                         csum += *p++;
 449                         csum += *p++;
 450                 }
 451                 ptable_ok = (csum == ptable_head->checksum);
 452
 453                 /* Read the entries and use/show the info.  */
 454                 printk(KERN_INFO " Found a%s partition table at 0x%p-0x%p.\n",
 455                        (ptable_ok ? " valid" : "n invalid"), ptable_head,
 456                        max_addr);
 457
 458                 /* We have found a working bootblock.  Now read the
 459                  * partition table.  Scan the table.  It ends when
 460                  * there is 0xffffffff, that is, empty flash.
 461                  */
 462                 while (ptable_ok
 463                        && ptable->offset != 0xffffffff
 464                        && ptable < max_addr
 465                        && pidx < MAX_PARTITIONS) {
 466
 467                         axis_partitions[pidx].offset = offset + ptable->offset;
 468                         axis_partitions[pidx].size = ptable->size;
 469
 470                         printk(pmsg, pidx, axis_partitions[pidx].offset,
 471                                axis_partitions[pidx].size);
 472                         pidx++;
 473                         ptable++;
 474                 }
 475                 use_default_ptable = !ptable_ok;
 476         }
 477
 478         if (romfs_in_flash) {
 479                 /* Add an overlapping device for the root partition (romfs). */
 480
 481                 axis_partitions[pidx].name = "romfs";
 482                 axis_partitions[pidx].size = romfs_length;
 483                 axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
 484                 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
 485
 486                 printk(KERN_INFO
 487                        " Adding readonly flash partition for romfs image:\n");
 488                 printk(pmsg, pidx, axis_partitions[pidx].offset,
 489                        axis_partitions[pidx].size);
 490                 pidx++;
 491         }
 492
 493         if (mymtd) {
 494                 if (use_default_ptable) {
 495                         printk(KERN_INFO " Using default partition table.\n");
 496                         err = add_mtd_partitions(mymtd, axis_default_partitions,
 497                                                  NUM_DEFAULT_PARTITIONS);
 498                 } else {
 499                         err = add_mtd_partitions(mymtd, axis_partitions, pidx);
 500                 }
 501
 502                 if (err) {
 503                         panic("axisflashmap could not add MTD partitions!\n");
 504                 }
 505         }
 506
 507         if (!romfs_in_flash) {
 508                 /* Create an RAM device for the root partition (romfs). */
 509
 510 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
 511                 /* No use trying to boot this kernel from RAM. Panic! */
 512                 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
 513                        "device due to kernel (mis)configuration!\n");
 514                 panic("This kernel cannot boot from RAM!\n");
 515 #else
 516                 struct mtd_info *mtd_ram;
 517
 518                 mtd_ram = kmalloc(sizeof(struct mtd_info),
 519                                                      GFP_KERNEL);
 520                 if (!mtd_ram) {
 521                         panic("axisflashmap couldn't allocate memory for "
 522                               "mtd_info!\n");
 523                 }
 524
 525                 printk(KERN_INFO " Adding RAM partition for romfs image:\n");
 526                 printk(pmsg, pidx, romfs_start, romfs_length);
 527
 528                 err = mtdram_init_device(mtd_ram, (void*)romfs_start,
 529                                          romfs_length, "romfs");
 530                 if (err) {
 531                         panic("axisflashmap could not initialize MTD RAM "
 532                               "device!\n");
 533                 }
 534 #endif
 535         }
 536
 537         return err;
 538 }
 539
 540 /* This adds the above to the kernels init-call chain. */
 541 module_init(init_axis_flash);
 542
 543 EXPORT_SYMBOL(axisflash_mtd);