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