1 /*
2 * Physical mapping layer for MTD using the Axis partitiontable format
3 *
4 * Copyright (c) 2001-2007 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 */
14
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20
21 #include <linux/mtd/concat.h>
22 #include <linux/mtd/map.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/mtdram.h>
25 #include <linux/mtd/partitions.h>
26
27 #include <linux/cramfs_fs.h>
28
29 #include <asm/axisflashmap.h>
30 #include <asm/mmu.h>
31
32 #define MEM_CSE0_SIZE (0x04000000)
33 #define MEM_CSE1_SIZE (0x04000000)
34
35 #define FLASH_UNCACHED_ADDR KSEG_E
36 #define FLASH_CACHED_ADDR KSEG_F
37
38 #define PAGESIZE (512)
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 __u32
46 #endif
47
48 /* From head.S */
49 extern unsigned long romfs_in_flash; /* 1 when romfs_start, _length in flash */
50 extern unsigned long romfs_start, romfs_length;
51 extern unsigned long nand_boot; /* 1 when booted from nand flash */
52
53 struct partition_name {
54 char name[6];
55 };
56
57 /* The master mtd for the entire flash. */
58 struct mtd_info* axisflash_mtd = NULL;
59
60 /* Map driver functions. */
61
flash_read(struct map_info * map,unsigned long ofs)62 static map_word flash_read(struct map_info *map, unsigned long ofs)
63 {
64 map_word tmp;
65 tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
66 return tmp;
67 }
68
flash_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)69 static void flash_copy_from(struct map_info *map, void *to,
70 unsigned long from, ssize_t len)
71 {
72 memcpy(to, (void *)(map->map_priv_1 + from), len);
73 }
74
flash_write(struct map_info * map,map_word d,unsigned long adr)75 static void flash_write(struct map_info *map, map_word d, unsigned long adr)
76 {
77 *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
78 }
79
80 /*
81 * The map for chip select e0.
82 *
83 * We run into tricky coherence situations if we mix cached with uncached
84 * accesses to we only use the uncached version here.
85 *
86 * The size field is the total size where the flash chips may be mapped on the
87 * chip select. MTD probes should find all devices there and it does not matter
88 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
89 * probes will ignore them.
90 *
91 * The start address in map_priv_1 is in virtual memory so we cannot use
92 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
93 * address of cse0.
94 */
95 static struct map_info map_cse0 = {
96 .name = "cse0",
97 .size = MEM_CSE0_SIZE,
98 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
99 .read = flash_read,
100 .copy_from = flash_copy_from,
101 .write = flash_write,
102 .map_priv_1 = FLASH_UNCACHED_ADDR
103 };
104
105 /*
106 * The map for chip select e1.
107 *
108 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
109 * address, but there isn't.
110 */
111 static struct map_info map_cse1 = {
112 .name = "cse1",
113 .size = MEM_CSE1_SIZE,
114 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
115 .read = flash_read,
116 .copy_from = flash_copy_from,
117 .write = flash_write,
118 .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
119 };
120
121 #define MAX_PARTITIONS 7
122 #ifdef CONFIG_ETRAX_NANDBOOT
123 #define NUM_DEFAULT_PARTITIONS 4
124 #define DEFAULT_ROOTFS_PARTITION_NO 2
125 #define DEFAULT_MEDIA_SIZE 0x2000000 /* 32 megs */
126 #else
127 #define NUM_DEFAULT_PARTITIONS 3
128 #define DEFAULT_ROOTFS_PARTITION_NO (-1)
129 #define DEFAULT_MEDIA_SIZE 0x800000 /* 8 megs */
130 #endif
131
132 #if (MAX_PARTITIONS < NUM_DEFAULT_PARTITIONS)
133 #error MAX_PARTITIONS must be >= than NUM_DEFAULT_PARTITIONS
134 #endif
135
136 /* Initialize the ones normally used. */
137 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
138 {
139 .name = "part0",
140 .size = CONFIG_ETRAX_PTABLE_SECTOR,
141 .offset = 0
142 },
143 {
144 .name = "part1",
145 .size = 0,
146 .offset = 0
147 },
148 {
149 .name = "part2",
150 .size = 0,
151 .offset = 0
152 },
153 {
154 .name = "part3",
155 .size = 0,
156 .offset = 0
157 },
158 {
159 .name = "part4",
160 .size = 0,
161 .offset = 0
162 },
163 {
164 .name = "part5",
165 .size = 0,
166 .offset = 0
167 },
168 {
169 .name = "part6",
170 .size = 0,
171 .offset = 0
172 },
173 };
174
175
176 /* If no partition-table was found, we use this default-set.
177 * Default flash size is 8MB (NOR). CONFIG_ETRAX_PTABLE_SECTOR is most
178 * likely the size of one flash block and "filesystem"-partition needs
179 * to be >=5 blocks to be able to use JFFS.
180 */
181 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
182 {
183 .name = "boot firmware",
184 .size = CONFIG_ETRAX_PTABLE_SECTOR,
185 .offset = 0
186 },
187 {
188 .name = "kernel",
189 .size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
190 .offset = CONFIG_ETRAX_PTABLE_SECTOR
191 },
192 #define FILESYSTEM_SECTOR (11 * CONFIG_ETRAX_PTABLE_SECTOR)
193 #ifdef CONFIG_ETRAX_NANDBOOT
194 {
195 .name = "rootfs",
196 .size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
197 .offset = FILESYSTEM_SECTOR
198 },
199 #undef FILESYSTEM_SECTOR
200 #define FILESYSTEM_SECTOR (21 * CONFIG_ETRAX_PTABLE_SECTOR)
201 #endif
202 {
203 .name = "rwfs",
204 .size = DEFAULT_MEDIA_SIZE - FILESYSTEM_SECTOR,
205 .offset = FILESYSTEM_SECTOR
206 }
207 };
208
209 #ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
210 /* Main flash device */
211 static struct mtd_partition main_partition = {
212 .name = "main",
213 .size = 0,
214 .offset = 0
215 };
216 #endif
217
218 /* Auxiliary partition if we find another flash */
219 static struct mtd_partition aux_partition = {
220 .name = "aux",
221 .size = 0,
222 .offset = 0
223 };
224
225 /*
226 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
227 * chips in that order (because the amd_flash-driver is faster).
228 */
probe_cs(struct map_info * map_cs)229 static struct mtd_info *probe_cs(struct map_info *map_cs)
230 {
231 struct mtd_info *mtd_cs = NULL;
232
233 printk(KERN_INFO
234 "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
235 map_cs->name, map_cs->size, map_cs->map_priv_1);
236
237 #ifdef CONFIG_MTD_CFI
238 mtd_cs = do_map_probe("cfi_probe", map_cs);
239 #endif
240 #ifdef CONFIG_MTD_JEDECPROBE
241 if (!mtd_cs)
242 mtd_cs = do_map_probe("jedec_probe", map_cs);
243 #endif
244
245 return mtd_cs;
246 }
247
248 /*
249 * Probe each chip select individually for flash chips. If there are chips on
250 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
251 * so that MTD partitions can cross chip boundries.
252 *
253 * The only known restriction to how you can mount your chips is that each
254 * chip select must hold similar flash chips. But you need external hardware
255 * to do that anyway and you can put totally different chips on cse0 and cse1
256 * so it isn't really much of a restriction.
257 */
258 extern struct mtd_info* __init crisv32_nand_flash_probe (void);
flash_probe(void)259 static struct mtd_info *flash_probe(void)
260 {
261 struct mtd_info *mtd_cse0;
262 struct mtd_info *mtd_cse1;
263 struct mtd_info *mtd_total;
264 struct mtd_info *mtds[2];
265 int count = 0;
266
267 if ((mtd_cse0 = probe_cs(&map_cse0)) != NULL)
268 mtds[count++] = mtd_cse0;
269 if ((mtd_cse1 = probe_cs(&map_cse1)) != NULL)
270 mtds[count++] = mtd_cse1;
271
272 if (!mtd_cse0 && !mtd_cse1) {
273 /* No chip found. */
274 return NULL;
275 }
276
277 if (count > 1) {
278 /* Since the concatenation layer adds a small overhead we
279 * could try to figure out if the chips in cse0 and cse1 are
280 * identical and reprobe the whole cse0+cse1 window. But since
281 * flash chips are slow, the overhead is relatively small.
282 * So we use the MTD concatenation layer instead of further
283 * complicating the probing procedure.
284 */
285 mtd_total = mtd_concat_create(mtds, count, "cse0+cse1");
286 if (!mtd_total) {
287 printk(KERN_ERR "%s and %s: Concatenation failed!\n",
288 map_cse0.name, map_cse1.name);
289
290 /* The best we can do now is to only use what we found
291 * at cse0. */
292 mtd_total = mtd_cse0;
293 map_destroy(mtd_cse1);
294 }
295 } else
296 mtd_total = mtd_cse0 ? mtd_cse0 : mtd_cse1;
297
298 return mtd_total;
299 }
300
301 /*
302 * Probe the flash chip(s) and, if it succeeds, read the partition-table
303 * and register the partitions with MTD.
304 */
init_axis_flash(void)305 static int __init init_axis_flash(void)
306 {
307 struct mtd_info *main_mtd;
308 struct mtd_info *aux_mtd = NULL;
309 int err = 0;
310 int pidx = 0;
311 struct partitiontable_head *ptable_head = NULL;
312 struct partitiontable_entry *ptable;
313 int ptable_ok = 0;
314 static char page[PAGESIZE];
315 size_t len;
316 int ram_rootfs_partition = -1; /* -1 => no RAM rootfs partition */
317 int part;
318
319 /* We need a root fs. If it resides in RAM, we need to use an
320 * MTDRAM device, so it must be enabled in the kernel config,
321 * but its size must be configured as 0 so as not to conflict
322 * with our usage.
323 */
324 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
325 if (!romfs_in_flash && !nand_boot) {
326 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
327 "device; configure CONFIG_MTD_MTDRAM with size = 0!\n");
328 panic("This kernel cannot boot from RAM!\n");
329 }
330 #endif
331
332 main_mtd = flash_probe();
333 if (main_mtd)
334 printk(KERN_INFO "%s: 0x%08x bytes of NOR flash memory.\n",
335 main_mtd->name, main_mtd->size);
336
337 #ifdef CONFIG_ETRAX_NANDFLASH
338 aux_mtd = crisv32_nand_flash_probe();
339 if (aux_mtd)
340 printk(KERN_INFO "%s: 0x%08x bytes of NAND flash memory.\n",
341 aux_mtd->name, aux_mtd->size);
342
343 #ifdef CONFIG_ETRAX_NANDBOOT
344 {
345 struct mtd_info *tmp_mtd;
346
347 printk(KERN_INFO "axisflashmap: Set to boot from NAND flash, "
348 "making NAND flash primary device.\n");
349 tmp_mtd = main_mtd;
350 main_mtd = aux_mtd;
351 aux_mtd = tmp_mtd;
352 }
353 #endif /* CONFIG_ETRAX_NANDBOOT */
354 #endif /* CONFIG_ETRAX_NANDFLASH */
355
356 if (!main_mtd && !aux_mtd) {
357 /* There's no reason to use this module if no flash chip can
358 * be identified. Make sure that's understood.
359 */
360 printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
361 }
362
363 #if 0 /* Dump flash memory so we can see what is going on */
364 if (main_mtd) {
365 int sectoraddr, i;
366 for (sectoraddr = 0; sectoraddr < 2*65536+4096;
367 sectoraddr += PAGESIZE) {
368 main_mtd->read(main_mtd, sectoraddr, PAGESIZE, &len,
369 page);
370 printk(KERN_INFO
371 "Sector at %d (length %d):\n",
372 sectoraddr, len);
373 for (i = 0; i < PAGESIZE; i += 16) {
374 printk(KERN_INFO
375 "%02x %02x %02x %02x "
376 "%02x %02x %02x %02x "
377 "%02x %02x %02x %02x "
378 "%02x %02x %02x %02x\n",
379 page[i] & 255, page[i+1] & 255,
380 page[i+2] & 255, page[i+3] & 255,
381 page[i+4] & 255, page[i+5] & 255,
382 page[i+6] & 255, page[i+7] & 255,
383 page[i+8] & 255, page[i+9] & 255,
384 page[i+10] & 255, page[i+11] & 255,
385 page[i+12] & 255, page[i+13] & 255,
386 page[i+14] & 255, page[i+15] & 255);
387 }
388 }
389 }
390 #endif
391
392 if (main_mtd) {
393 main_mtd->owner = THIS_MODULE;
394 axisflash_mtd = main_mtd;
395
396 loff_t ptable_sector = CONFIG_ETRAX_PTABLE_SECTOR;
397
398 /* First partition (rescue) is always set to the default. */
399 pidx++;
400 #ifdef CONFIG_ETRAX_NANDBOOT
401 /* We know where the partition table should be located,
402 * it will be in first good block after that.
403 */
404 int blockstat;
405 do {
406 blockstat = mtd_block_isbad(main_mtd, ptable_sector);
407 if (blockstat < 0)
408 ptable_sector = 0; /* read error */
409 else if (blockstat)
410 ptable_sector += main_mtd->erasesize;
411 } while (blockstat && ptable_sector);
412 #endif
413 if (ptable_sector) {
414 mtd_read(main_mtd, ptable_sector, PAGESIZE, &len,
415 page);
416 ptable_head = &((struct partitiontable *) page)->head;
417 }
418
419 #if 0 /* Dump partition table so we can see what is going on */
420 printk(KERN_INFO
421 "axisflashmap: flash read %d bytes at 0x%08x, data: "
422 "%02x %02x %02x %02x %02x %02x %02x %02x\n",
423 len, CONFIG_ETRAX_PTABLE_SECTOR,
424 page[0] & 255, page[1] & 255,
425 page[2] & 255, page[3] & 255,
426 page[4] & 255, page[5] & 255,
427 page[6] & 255, page[7] & 255);
428 printk(KERN_INFO
429 "axisflashmap: partition table offset %d, data: "
430 "%02x %02x %02x %02x %02x %02x %02x %02x\n",
431 PARTITION_TABLE_OFFSET,
432 page[PARTITION_TABLE_OFFSET+0] & 255,
433 page[PARTITION_TABLE_OFFSET+1] & 255,
434 page[PARTITION_TABLE_OFFSET+2] & 255,
435 page[PARTITION_TABLE_OFFSET+3] & 255,
436 page[PARTITION_TABLE_OFFSET+4] & 255,
437 page[PARTITION_TABLE_OFFSET+5] & 255,
438 page[PARTITION_TABLE_OFFSET+6] & 255,
439 page[PARTITION_TABLE_OFFSET+7] & 255);
440 #endif
441 }
442
443 if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
444 && (ptable_head->size <
445 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
446 PARTITIONTABLE_END_MARKER_SIZE))
447 && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
448 ptable_head->size -
449 PARTITIONTABLE_END_MARKER_SIZE)
450 == PARTITIONTABLE_END_MARKER)) {
451 /* Looks like a start, sane length and end of a
452 * partition table, lets check csum etc.
453 */
454 struct partitiontable_entry *max_addr =
455 (struct partitiontable_entry *)
456 ((unsigned long)ptable_head + sizeof(*ptable_head) +
457 ptable_head->size);
458 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
459 unsigned char *p;
460 unsigned long csum = 0;
461
462 ptable = (struct partitiontable_entry *)
463 ((unsigned long)ptable_head + sizeof(*ptable_head));
464
465 /* Lets be PARANOID, and check the checksum. */
466 p = (unsigned char*) ptable;
467
468 while (p <= (unsigned char*)max_addr) {
469 csum += *p++;
470 csum += *p++;
471 csum += *p++;
472 csum += *p++;
473 }
474 ptable_ok = (csum == ptable_head->checksum);
475
476 /* Read the entries and use/show the info. */
477 printk(KERN_INFO "axisflashmap: "
478 "Found a%s partition table at 0x%p-0x%p.\n",
479 (ptable_ok ? " valid" : "n invalid"), ptable_head,
480 max_addr);
481
482 /* We have found a working bootblock. Now read the
483 * partition table. Scan the table. It ends with 0xffffffff.
484 */
485 while (ptable_ok
486 && ptable->offset != PARTITIONTABLE_END_MARKER
487 && ptable < max_addr
488 && pidx < MAX_PARTITIONS - 1) {
489
490 axis_partitions[pidx].offset = offset + ptable->offset;
491 #ifdef CONFIG_ETRAX_NANDFLASH
492 if (main_mtd->type == MTD_NANDFLASH) {
493 axis_partitions[pidx].size =
494 (((ptable+1)->offset ==
495 PARTITIONTABLE_END_MARKER) ?
496 main_mtd->size :
497 ((ptable+1)->offset + offset)) -
498 (ptable->offset + offset);
499
500 } else
501 #endif /* CONFIG_ETRAX_NANDFLASH */
502 axis_partitions[pidx].size = ptable->size;
503 #ifdef CONFIG_ETRAX_NANDBOOT
504 /* Save partition number of jffs2 ro partition.
505 * Needed if RAM booting or root file system in RAM.
506 */
507 if (!nand_boot &&
508 ram_rootfs_partition < 0 && /* not already set */
509 ptable->type == PARTITION_TYPE_JFFS2 &&
510 (ptable->flags & PARTITION_FLAGS_READONLY_MASK) ==
511 PARTITION_FLAGS_READONLY)
512 ram_rootfs_partition = pidx;
513 #endif /* CONFIG_ETRAX_NANDBOOT */
514 pidx++;
515 ptable++;
516 }
517 }
518
519 /* Decide whether to use default partition table. */
520 /* Only use default table if we actually have a device (main_mtd) */
521
522 struct mtd_partition *partition = &axis_partitions[0];
523 if (main_mtd && !ptable_ok) {
524 memcpy(axis_partitions, axis_default_partitions,
525 sizeof(axis_default_partitions));
526 pidx = NUM_DEFAULT_PARTITIONS;
527 ram_rootfs_partition = DEFAULT_ROOTFS_PARTITION_NO;
528 }
529
530 /* Add artificial partitions for rootfs if necessary */
531 if (romfs_in_flash) {
532 /* rootfs is in directly accessible flash memory = NOR flash.
533 Add an overlapping device for the rootfs partition. */
534 printk(KERN_INFO "axisflashmap: Adding partition for "
535 "overlapping root file system image\n");
536 axis_partitions[pidx].size = romfs_length;
537 axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
538 axis_partitions[pidx].name = "romfs";
539 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
540 ram_rootfs_partition = -1;
541 pidx++;
542 } else if (romfs_length && !nand_boot) {
543 /* romfs exists in memory, but not in flash, so must be in RAM.
544 * Configure an MTDRAM partition. */
545 if (ram_rootfs_partition < 0) {
546 /* None set yet, put it at the end */
547 ram_rootfs_partition = pidx;
548 pidx++;
549 }
550 printk(KERN_INFO "axisflashmap: Adding partition for "
551 "root file system image in RAM\n");
552 axis_partitions[ram_rootfs_partition].size = romfs_length;
553 axis_partitions[ram_rootfs_partition].offset = romfs_start;
554 axis_partitions[ram_rootfs_partition].name = "romfs";
555 axis_partitions[ram_rootfs_partition].mask_flags |=
556 MTD_WRITEABLE;
557 }
558
559 #ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
560 if (main_mtd) {
561 main_partition.size = main_mtd->size;
562 err = mtd_device_register(main_mtd, &main_partition, 1);
563 if (err)
564 panic("axisflashmap: Could not initialize "
565 "partition for whole main mtd device!\n");
566 }
567 #endif
568
569 /* Now, register all partitions with mtd.
570 * We do this one at a time so we can slip in an MTDRAM device
571 * in the proper place if required. */
572
573 for (part = 0; part < pidx; part++) {
574 if (part == ram_rootfs_partition) {
575 /* add MTDRAM partition here */
576 struct mtd_info *mtd_ram;
577
578 mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
579 if (!mtd_ram)
580 panic("axisflashmap: Couldn't allocate memory "
581 "for mtd_info!\n");
582 printk(KERN_INFO "axisflashmap: Adding RAM partition "
583 "for rootfs image.\n");
584 err = mtdram_init_device(mtd_ram,
585 (void *)partition[part].offset,
586 partition[part].size,
587 partition[part].name);
588 if (err)
589 panic("axisflashmap: Could not initialize "
590 "MTD RAM device!\n");
591 /* JFFS2 likes to have an erasesize. Keep potential
592 * JFFS2 rootfs happy by providing one. Since image
593 * was most likely created for main mtd, use that
594 * erasesize, if available. Otherwise, make a guess. */
595 mtd_ram->erasesize = (main_mtd ? main_mtd->erasesize :
596 CONFIG_ETRAX_PTABLE_SECTOR);
597 } else {
598 err = mtd_device_register(main_mtd, &partition[part],
599 1);
600 if (err)
601 panic("axisflashmap: Could not add mtd "
602 "partition %d\n", part);
603 }
604 }
605
606 if (aux_mtd) {
607 aux_partition.size = aux_mtd->size;
608 err = mtd_device_register(aux_mtd, &aux_partition, 1);
609 if (err)
610 panic("axisflashmap: Could not initialize "
611 "aux mtd device!\n");
612
613 }
614
615 return err;
616 }
617
618 /* This adds the above to the kernels init-call chain. */
619 module_init(init_axis_flash);
620
621 EXPORT_SYMBOL(axisflash_mtd);
622