1 /* 2 * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework 3 * 4 * Largely derived from at91_dataflash.c: 5 * Copyright (C) 2003-2005 SAN People (Pty) Ltd 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/slab.h> 15 #include <linux/delay.h> 16 #include <linux/device.h> 17 #include <linux/mutex.h> 18 #include <linux/spi/spi.h> 19 #include <linux/spi/flash.h> 20 21 #include <linux/mtd/mtd.h> 22 #include <linux/mtd/partitions.h> 23 24 25 /* 26 * DataFlash is a kind of SPI flash. Most AT45 chips have two buffers in 27 * each chip, which may be used for double buffered I/O; but this driver 28 * doesn't (yet) use these for any kind of i/o overlap or prefetching. 29 * 30 * Sometimes DataFlash is packaged in MMC-format cards, although the 31 * MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash 32 * protocols during enumeration. 33 */ 34 35 #define CONFIG_DATAFLASH_WRITE_VERIFY 36 37 /* reads can bypass the buffers */ 38 #define OP_READ_CONTINUOUS 0xE8 39 #define OP_READ_PAGE 0xD2 40 41 /* group B requests can run even while status reports "busy" */ 42 #define OP_READ_STATUS 0xD7 /* group B */ 43 44 /* move data between host and buffer */ 45 #define OP_READ_BUFFER1 0xD4 /* group B */ 46 #define OP_READ_BUFFER2 0xD6 /* group B */ 47 #define OP_WRITE_BUFFER1 0x84 /* group B */ 48 #define OP_WRITE_BUFFER2 0x87 /* group B */ 49 50 /* erasing flash */ 51 #define OP_ERASE_PAGE 0x81 52 #define OP_ERASE_BLOCK 0x50 53 54 /* move data between buffer and flash */ 55 #define OP_TRANSFER_BUF1 0x53 56 #define OP_TRANSFER_BUF2 0x55 57 #define OP_MREAD_BUFFER1 0xD4 58 #define OP_MREAD_BUFFER2 0xD6 59 #define OP_MWERASE_BUFFER1 0x83 60 #define OP_MWERASE_BUFFER2 0x86 61 #define OP_MWRITE_BUFFER1 0x88 /* sector must be pre-erased */ 62 #define OP_MWRITE_BUFFER2 0x89 /* sector must be pre-erased */ 63 64 /* write to buffer, then write-erase to flash */ 65 #define OP_PROGRAM_VIA_BUF1 0x82 66 #define OP_PROGRAM_VIA_BUF2 0x85 67 68 /* compare buffer to flash */ 69 #define OP_COMPARE_BUF1 0x60 70 #define OP_COMPARE_BUF2 0x61 71 72 /* read flash to buffer, then write-erase to flash */ 73 #define OP_REWRITE_VIA_BUF1 0x58 74 #define OP_REWRITE_VIA_BUF2 0x59 75 76 /* newer chips report JEDEC manufacturer and device IDs; chip 77 * serial number and OTP bits; and per-sector writeprotect. 78 */ 79 #define OP_READ_ID 0x9F 80 #define OP_READ_SECURITY 0x77 81 #define OP_WRITE_SECURITY 0x9A /* OTP bits */ 82 83 84 struct dataflash { 85 u8 command[4]; 86 char name[24]; 87 88 unsigned partitioned:1; 89 90 unsigned short page_offset; /* offset in flash address */ 91 unsigned int page_size; /* of bytes per page */ 92 93 struct mutex lock; 94 struct spi_device *spi; 95 96 struct mtd_info mtd; 97 }; 98 99 #ifdef CONFIG_MTD_PARTITIONS 100 #define mtd_has_partitions() (1) 101 #else 102 #define mtd_has_partitions() (0) 103 #endif 104 105 /* ......................................................................... */ 106 107 /* 108 * Return the status of the DataFlash device. 109 */ 110 static inline int dataflash_status(struct spi_device *spi) 111 { 112 /* NOTE: at45db321c over 25 MHz wants to write 113 * a dummy byte after the opcode... 114 */ 115 return spi_w8r8(spi, OP_READ_STATUS); 116 } 117 118 /* 119 * Poll the DataFlash device until it is READY. 120 * This usually takes 5-20 msec or so; more for sector erase. 121 */ 122 static int dataflash_waitready(struct spi_device *spi) 123 { 124 int status; 125 126 for (;;) { 127 status = dataflash_status(spi); 128 if (status < 0) { 129 DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n", 130 spi->dev.bus_id, status); 131 status = 0; 132 } 133 134 if (status & (1 << 7)) /* RDY/nBSY */ 135 return status; 136 137 msleep(3); 138 } 139 } 140 141 /* ......................................................................... */ 142 143 /* 144 * Erase pages of flash. 145 */ 146 static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr) 147 { 148 struct dataflash *priv = (struct dataflash *)mtd->priv; 149 struct spi_device *spi = priv->spi; 150 struct spi_transfer x = { .tx_dma = 0, }; 151 struct spi_message msg; 152 unsigned blocksize = priv->page_size << 3; 153 u8 *command; 154 155 DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%x len 0x%x\n", 156 spi->dev.bus_id, 157 instr->addr, instr->len); 158 159 /* Sanity checks */ 160 if ((instr->addr + instr->len) > mtd->size 161 || (instr->len % priv->page_size) != 0 162 || (instr->addr % priv->page_size) != 0) 163 return -EINVAL; 164 165 spi_message_init(&msg); 166 167 x.tx_buf = command = priv->command; 168 x.len = 4; 169 spi_message_add_tail(&x, &msg); 170 171 mutex_lock(&priv->lock); 172 while (instr->len > 0) { 173 unsigned int pageaddr; 174 int status; 175 int do_block; 176 177 /* Calculate flash page address; use block erase (for speed) if 178 * we're at a block boundary and need to erase the whole block. 179 */ 180 pageaddr = instr->addr / priv->page_size; 181 do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize; 182 pageaddr = pageaddr << priv->page_offset; 183 184 command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE; 185 command[1] = (u8)(pageaddr >> 16); 186 command[2] = (u8)(pageaddr >> 8); 187 command[3] = 0; 188 189 DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n", 190 do_block ? "block" : "page", 191 command[0], command[1], command[2], command[3], 192 pageaddr); 193 194 status = spi_sync(spi, &msg); 195 (void) dataflash_waitready(spi); 196 197 if (status < 0) { 198 printk(KERN_ERR "%s: erase %x, err %d\n", 199 spi->dev.bus_id, pageaddr, status); 200 /* REVISIT: can retry instr->retries times; or 201 * giveup and instr->fail_addr = instr->addr; 202 */ 203 continue; 204 } 205 206 if (do_block) { 207 instr->addr += blocksize; 208 instr->len -= blocksize; 209 } else { 210 instr->addr += priv->page_size; 211 instr->len -= priv->page_size; 212 } 213 } 214 mutex_unlock(&priv->lock); 215 216 /* Inform MTD subsystem that erase is complete */ 217 instr->state = MTD_ERASE_DONE; 218 mtd_erase_callback(instr); 219 220 return 0; 221 } 222 223 /* 224 * Read from the DataFlash device. 225 * from : Start offset in flash device 226 * len : Amount to read 227 * retlen : About of data actually read 228 * buf : Buffer containing the data 229 */ 230 static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len, 231 size_t *retlen, u_char *buf) 232 { 233 struct dataflash *priv = (struct dataflash *)mtd->priv; 234 struct spi_transfer x[2] = { { .tx_dma = 0, }, }; 235 struct spi_message msg; 236 unsigned int addr; 237 u8 *command; 238 int status; 239 240 DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n", 241 priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len)); 242 243 *retlen = 0; 244 245 /* Sanity checks */ 246 if (!len) 247 return 0; 248 if (from + len > mtd->size) 249 return -EINVAL; 250 251 /* Calculate flash page/byte address */ 252 addr = (((unsigned)from / priv->page_size) << priv->page_offset) 253 + ((unsigned)from % priv->page_size); 254 255 command = priv->command; 256 257 DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n", 258 command[0], command[1], command[2], command[3]); 259 260 spi_message_init(&msg); 261 262 x[0].tx_buf = command; 263 x[0].len = 8; 264 spi_message_add_tail(&x[0], &msg); 265 266 x[1].rx_buf = buf; 267 x[1].len = len; 268 spi_message_add_tail(&x[1], &msg); 269 270 mutex_lock(&priv->lock); 271 272 /* Continuous read, max clock = f(car) which may be less than 273 * the peak rate available. Some chips support commands with 274 * fewer "don't care" bytes. Both buffers stay unchanged. 275 */ 276 command[0] = OP_READ_CONTINUOUS; 277 command[1] = (u8)(addr >> 16); 278 command[2] = (u8)(addr >> 8); 279 command[3] = (u8)(addr >> 0); 280 /* plus 4 "don't care" bytes */ 281 282 status = spi_sync(priv->spi, &msg); 283 mutex_unlock(&priv->lock); 284 285 if (status >= 0) { 286 *retlen = msg.actual_length - 8; 287 status = 0; 288 } else 289 DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n", 290 priv->spi->dev.bus_id, 291 (unsigned)from, (unsigned)(from + len), 292 status); 293 return status; 294 } 295 296 /* 297 * Write to the DataFlash device. 298 * to : Start offset in flash device 299 * len : Amount to write 300 * retlen : Amount of data actually written 301 * buf : Buffer containing the data 302 */ 303 static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len, 304 size_t * retlen, const u_char * buf) 305 { 306 struct dataflash *priv = (struct dataflash *)mtd->priv; 307 struct spi_device *spi = priv->spi; 308 struct spi_transfer x[2] = { { .tx_dma = 0, }, }; 309 struct spi_message msg; 310 unsigned int pageaddr, addr, offset, writelen; 311 size_t remaining = len; 312 u_char *writebuf = (u_char *) buf; 313 int status = -EINVAL; 314 u8 *command; 315 316 DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n", 317 spi->dev.bus_id, (unsigned)to, (unsigned)(to + len)); 318 319 *retlen = 0; 320 321 /* Sanity checks */ 322 if (!len) 323 return 0; 324 if ((to + len) > mtd->size) 325 return -EINVAL; 326 327 spi_message_init(&msg); 328 329 x[0].tx_buf = command = priv->command; 330 x[0].len = 4; 331 spi_message_add_tail(&x[0], &msg); 332 333 pageaddr = ((unsigned)to / priv->page_size); 334 offset = ((unsigned)to % priv->page_size); 335 if (offset + len > priv->page_size) 336 writelen = priv->page_size - offset; 337 else 338 writelen = len; 339 340 mutex_lock(&priv->lock); 341 while (remaining > 0) { 342 DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n", 343 pageaddr, offset, writelen); 344 345 /* REVISIT: 346 * (a) each page in a sector must be rewritten at least 347 * once every 10K sibling erase/program operations. 348 * (b) for pages that are already erased, we could 349 * use WRITE+MWRITE not PROGRAM for ~30% speedup. 350 * (c) WRITE to buffer could be done while waiting for 351 * a previous MWRITE/MWERASE to complete ... 352 * (d) error handling here seems to be mostly missing. 353 * 354 * Two persistent bits per page, plus a per-sector counter, 355 * could support (a) and (b) ... we might consider using 356 * the second half of sector zero, which is just one block, 357 * to track that state. (On AT91, that sector should also 358 * support boot-from-DataFlash.) 359 */ 360 361 addr = pageaddr << priv->page_offset; 362 363 /* (1) Maybe transfer partial page to Buffer1 */ 364 if (writelen != priv->page_size) { 365 command[0] = OP_TRANSFER_BUF1; 366 command[1] = (addr & 0x00FF0000) >> 16; 367 command[2] = (addr & 0x0000FF00) >> 8; 368 command[3] = 0; 369 370 DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n", 371 command[0], command[1], command[2], command[3]); 372 373 status = spi_sync(spi, &msg); 374 if (status < 0) 375 DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n", 376 spi->dev.bus_id, addr, status); 377 378 (void) dataflash_waitready(priv->spi); 379 } 380 381 /* (2) Program full page via Buffer1 */ 382 addr += offset; 383 command[0] = OP_PROGRAM_VIA_BUF1; 384 command[1] = (addr & 0x00FF0000) >> 16; 385 command[2] = (addr & 0x0000FF00) >> 8; 386 command[3] = (addr & 0x000000FF); 387 388 DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n", 389 command[0], command[1], command[2], command[3]); 390 391 x[1].tx_buf = writebuf; 392 x[1].len = writelen; 393 spi_message_add_tail(x + 1, &msg); 394 status = spi_sync(spi, &msg); 395 spi_transfer_del(x + 1); 396 if (status < 0) 397 DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n", 398 spi->dev.bus_id, addr, writelen, status); 399 400 (void) dataflash_waitready(priv->spi); 401 402 403 #ifdef CONFIG_DATAFLASH_WRITE_VERIFY 404 405 /* (3) Compare to Buffer1 */ 406 addr = pageaddr << priv->page_offset; 407 command[0] = OP_COMPARE_BUF1; 408 command[1] = (addr & 0x00FF0000) >> 16; 409 command[2] = (addr & 0x0000FF00) >> 8; 410 command[3] = 0; 411 412 DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n", 413 command[0], command[1], command[2], command[3]); 414 415 status = spi_sync(spi, &msg); 416 if (status < 0) 417 DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n", 418 spi->dev.bus_id, addr, status); 419 420 status = dataflash_waitready(priv->spi); 421 422 /* Check result of the compare operation */ 423 if (status & (1 << 6)) { 424 printk(KERN_ERR "%s: compare page %u, err %d\n", 425 spi->dev.bus_id, pageaddr, status); 426 remaining = 0; 427 status = -EIO; 428 break; 429 } else 430 status = 0; 431 432 #endif /* CONFIG_DATAFLASH_WRITE_VERIFY */ 433 434 remaining = remaining - writelen; 435 pageaddr++; 436 offset = 0; 437 writebuf += writelen; 438 *retlen += writelen; 439 440 if (remaining > priv->page_size) 441 writelen = priv->page_size; 442 else 443 writelen = remaining; 444 } 445 mutex_unlock(&priv->lock); 446 447 return status; 448 } 449 450 /* ......................................................................... */ 451 452 /* 453 * Register DataFlash device with MTD subsystem. 454 */ 455 static int __devinit 456 add_dataflash(struct spi_device *spi, char *name, 457 int nr_pages, int pagesize, int pageoffset) 458 { 459 struct dataflash *priv; 460 struct mtd_info *device; 461 struct flash_platform_data *pdata = spi->dev.platform_data; 462 463 priv = kzalloc(sizeof *priv, GFP_KERNEL); 464 if (!priv) 465 return -ENOMEM; 466 467 mutex_init(&priv->lock); 468 priv->spi = spi; 469 priv->page_size = pagesize; 470 priv->page_offset = pageoffset; 471 472 /* name must be usable with cmdlinepart */ 473 sprintf(priv->name, "spi%d.%d-%s", 474 spi->master->bus_num, spi->chip_select, 475 name); 476 477 device = &priv->mtd; 478 device->name = (pdata && pdata->name) ? pdata->name : priv->name; 479 device->size = nr_pages * pagesize; 480 device->erasesize = pagesize; 481 device->writesize = pagesize; 482 device->owner = THIS_MODULE; 483 device->type = MTD_DATAFLASH; 484 device->flags = MTD_WRITEABLE; 485 device->erase = dataflash_erase; 486 device->read = dataflash_read; 487 device->write = dataflash_write; 488 device->priv = priv; 489 490 dev_info(&spi->dev, "%s (%d KBytes)\n", name, device->size/1024); 491 dev_set_drvdata(&spi->dev, priv); 492 493 if (mtd_has_partitions()) { 494 struct mtd_partition *parts; 495 int nr_parts = 0; 496 497 #ifdef CONFIG_MTD_CMDLINE_PARTS 498 static const char *part_probes[] = { "cmdlinepart", NULL, }; 499 500 nr_parts = parse_mtd_partitions(device, part_probes, &parts, 0); 501 #endif 502 503 if (nr_parts <= 0 && pdata && pdata->parts) { 504 parts = pdata->parts; 505 nr_parts = pdata->nr_parts; 506 } 507 508 if (nr_parts > 0) { 509 priv->partitioned = 1; 510 return add_mtd_partitions(device, parts, nr_parts); 511 } 512 } else if (pdata && pdata->nr_parts) 513 dev_warn(&spi->dev, "ignoring %d default partitions on %s\n", 514 pdata->nr_parts, device->name); 515 516 return add_mtd_device(device) == 1 ? -ENODEV : 0; 517 } 518 519 /* 520 * Detect and initialize DataFlash device: 521 * 522 * Device Density ID code #Pages PageSize Offset 523 * AT45DB011B 1Mbit (128K) xx0011xx (0x0c) 512 264 9 524 * AT45DB021B 2Mbit (256K) xx0101xx (0x14) 1025 264 9 525 * AT45DB041B 4Mbit (512K) xx0111xx (0x1c) 2048 264 9 526 * AT45DB081B 8Mbit (1M) xx1001xx (0x24) 4096 264 9 527 * AT45DB0161B 16Mbit (2M) xx1011xx (0x2c) 4096 528 10 528 * AT45DB0321B 32Mbit (4M) xx1101xx (0x34) 8192 528 10 529 * AT45DB0642 64Mbit (8M) xx111xxx (0x3c) 8192 1056 11 530 * AT45DB1282 128Mbit (16M) xx0100xx (0x10) 16384 1056 11 531 */ 532 static int __devinit dataflash_probe(struct spi_device *spi) 533 { 534 int status; 535 536 status = dataflash_status(spi); 537 if (status <= 0 || status == 0xff) { 538 DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n", 539 spi->dev.bus_id, status); 540 if (status == 0 || status == 0xff) 541 status = -ENODEV; 542 return status; 543 } 544 545 /* if there's a device there, assume it's dataflash. 546 * board setup should have set spi->max_speed_max to 547 * match f(car) for continuous reads, mode 0 or 3. 548 */ 549 switch (status & 0x3c) { 550 case 0x0c: /* 0 0 1 1 x x */ 551 status = add_dataflash(spi, "AT45DB011B", 512, 264, 9); 552 break; 553 case 0x14: /* 0 1 0 1 x x */ 554 status = add_dataflash(spi, "AT45DB021B", 1025, 264, 9); 555 break; 556 case 0x1c: /* 0 1 1 1 x x */ 557 status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9); 558 break; 559 case 0x24: /* 1 0 0 1 x x */ 560 status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9); 561 break; 562 case 0x2c: /* 1 0 1 1 x x */ 563 status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10); 564 break; 565 case 0x34: /* 1 1 0 1 x x */ 566 status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10); 567 break; 568 case 0x38: /* 1 1 1 x x x */ 569 case 0x3c: 570 status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11); 571 break; 572 /* obsolete AT45DB1282 not (yet?) supported */ 573 default: 574 DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n", 575 spi->dev.bus_id, status & 0x3c); 576 status = -ENODEV; 577 } 578 579 if (status < 0) 580 DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n", 581 spi->dev.bus_id, status); 582 583 return status; 584 } 585 586 static int __devexit dataflash_remove(struct spi_device *spi) 587 { 588 struct dataflash *flash = dev_get_drvdata(&spi->dev); 589 int status; 590 591 DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", spi->dev.bus_id); 592 593 if (mtd_has_partitions() && flash->partitioned) 594 status = del_mtd_partitions(&flash->mtd); 595 else 596 status = del_mtd_device(&flash->mtd); 597 if (status == 0) 598 kfree(flash); 599 return status; 600 } 601 602 static struct spi_driver dataflash_driver = { 603 .driver = { 604 .name = "mtd_dataflash", 605 .bus = &spi_bus_type, 606 .owner = THIS_MODULE, 607 }, 608 609 .probe = dataflash_probe, 610 .remove = __devexit_p(dataflash_remove), 611 612 /* FIXME: investigate suspend and resume... */ 613 }; 614 615 static int __init dataflash_init(void) 616 { 617 return spi_register_driver(&dataflash_driver); 618 } 619 module_init(dataflash_init); 620 621 static void __exit dataflash_exit(void) 622 { 623 spi_unregister_driver(&dataflash_driver); 624 } 625 module_exit(dataflash_exit); 626 627 628 MODULE_LICENSE("GPL"); 629 MODULE_AUTHOR("Andrew Victor, David Brownell"); 630 MODULE_DESCRIPTION("MTD DataFlash driver"); 631