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: not supported by cvs2svn $ 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 */ 171extern unsigned long romfs_start, romfs_length, romfs_in_flash; 172 173/* The master mtd for the entire flash. */ 174struct mtd_info* axisflash_mtd = NULL; 175 176/* Map driver functions. */ 177 178static 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 185static 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 191static 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 */ 211static 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 */ 227static 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 */ 246static 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. */ 265static 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 */ 307static 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 */ 337static 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 */ 390static 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) || \ 511 (CONFIG_MTDRAM_ABS_POS != 0) 512 /* No use trying to boot this kernel from RAM. Panic! */ 513 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM " 514 "device due to kernel (mis)configuration!\n"); 515 panic("This kernel cannot boot from RAM!\n"); 516#else 517 struct mtd_info *mtd_ram; 518 519 mtd_ram = kmalloc(sizeof(struct mtd_info), 520 GFP_KERNEL); 521 if (!mtd_ram) { 522 panic("axisflashmap couldn't allocate memory for " 523 "mtd_info!\n"); 524 } 525 526 printk(KERN_INFO " Adding RAM partition for romfs image:\n"); 527 printk(pmsg, pidx, romfs_start, romfs_length); 528 529 err = mtdram_init_device(mtd_ram, (void*)romfs_start, 530 romfs_length, "romfs"); 531 if (err) { 532 panic("axisflashmap could not initialize MTD RAM " 533 "device!\n"); 534 } 535#endif 536 } 537 538 return err; 539} 540 541/* This adds the above to the kernels init-call chain. */ 542module_init(init_axis_flash); 543 544EXPORT_SYMBOL(axisflash_mtd); 545