1 /* 2 * Simulate a SPI flash 3 * 4 * Copyright (c) 2011-2013 The Chromium OS Authors. 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * Licensed under the GPL-2 or later. 9 */ 10 11 #define LOG_CATEGORY UCLASS_SPI_FLASH 12 13 #include <common.h> 14 #include <dm.h> 15 #include <malloc.h> 16 #include <spi.h> 17 #include <os.h> 18 19 #include <spi_flash.h> 20 #include "sf_internal.h" 21 22 #include <asm/getopt.h> 23 #include <asm/spi.h> 24 #include <asm/state.h> 25 #include <dm/device-internal.h> 26 #include <dm/lists.h> 27 #include <dm/uclass-internal.h> 28 29 /* 30 * The different states that our SPI flash transitions between. 31 * We need to keep track of this across multiple xfer calls since 32 * the SPI bus could possibly call down into us multiple times. 33 */ 34 enum sandbox_sf_state { 35 SF_CMD, /* default state -- we're awaiting a command */ 36 SF_ID, /* read the flash's (jedec) ID code */ 37 SF_ADDR, /* processing the offset in the flash to read/etc... */ 38 SF_READ, /* reading data from the flash */ 39 SF_WRITE, /* writing data to the flash, i.e. page programming */ 40 SF_ERASE, /* erase the flash */ 41 SF_READ_STATUS, /* read the flash's status register */ 42 SF_READ_STATUS1, /* read the flash's status register upper 8 bits*/ 43 SF_WRITE_STATUS, /* write the flash's status register */ 44 }; 45 46 #if CONFIG_IS_ENABLED(LOG) 47 static const char *sandbox_sf_state_name(enum sandbox_sf_state state) 48 { 49 static const char * const states[] = { 50 "CMD", "ID", "ADDR", "READ", "WRITE", "ERASE", "READ_STATUS", 51 "READ_STATUS1", "WRITE_STATUS", 52 }; 53 return states[state]; 54 } 55 #endif /* LOG */ 56 57 /* Bits for the status register */ 58 #define STAT_WIP (1 << 0) 59 #define STAT_WEL (1 << 1) 60 61 /* Assume all SPI flashes have 3 byte addresses since they do atm */ 62 #define SF_ADDR_LEN 3 63 64 #define IDCODE_LEN 3 65 66 /* Used to quickly bulk erase backing store */ 67 static u8 sandbox_sf_0xff[0x1000]; 68 69 /* Internal state data for each SPI flash */ 70 struct sandbox_spi_flash { 71 unsigned int cs; /* Chip select we are attached to */ 72 /* 73 * As we receive data over the SPI bus, our flash transitions 74 * between states. For example, we start off in the SF_CMD 75 * state where the first byte tells us what operation to perform 76 * (such as read or write the flash). But the operation itself 77 * can go through a few states such as first reading in the 78 * offset in the flash to perform the requested operation. 79 * Thus "state" stores the exact state that our machine is in 80 * while "cmd" stores the overall command we're processing. 81 */ 82 enum sandbox_sf_state state; 83 uint cmd; 84 /* Erase size of current erase command */ 85 uint erase_size; 86 /* Current position in the flash; used when reading/writing/etc... */ 87 uint off; 88 /* How many address bytes we've consumed */ 89 uint addr_bytes, pad_addr_bytes; 90 /* The current flash status (see STAT_XXX defines above) */ 91 u16 status; 92 /* Data describing the flash we're emulating */ 93 const struct spi_flash_info *data; 94 /* The file on disk to serv up data from */ 95 int fd; 96 }; 97 98 struct sandbox_spi_flash_plat_data { 99 const char *filename; 100 const char *device_name; 101 int bus; 102 int cs; 103 }; 104 105 /** 106 * This is a very strange probe function. If it has platform data (which may 107 * have come from the device tree) then this function gets the filename and 108 * device type from there. 109 */ 110 static int sandbox_sf_probe(struct udevice *dev) 111 { 112 /* spec = idcode:file */ 113 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 114 size_t len, idname_len; 115 const struct spi_flash_info *data; 116 struct sandbox_spi_flash_plat_data *pdata = dev_get_platdata(dev); 117 struct sandbox_state *state = state_get_current(); 118 struct dm_spi_slave_platdata *slave_plat; 119 struct udevice *bus = dev->parent; 120 const char *spec = NULL; 121 struct udevice *emul; 122 int ret = 0; 123 int cs = -1; 124 125 debug("%s: bus %d, looking for emul=%p: ", __func__, bus->seq, dev); 126 ret = sandbox_spi_get_emul(state, bus, dev, &emul); 127 if (ret) { 128 printf("Error: Unknown chip select for device '%s'\n", 129 dev->name); 130 return ret; 131 } 132 slave_plat = dev_get_parent_platdata(dev); 133 cs = slave_plat->cs; 134 debug("found at cs %d\n", cs); 135 136 if (!pdata->filename) { 137 printf("Error: No filename available\n"); 138 return -EINVAL; 139 } 140 spec = strchr(pdata->device_name, ','); 141 if (spec) 142 spec++; 143 else 144 spec = pdata->device_name; 145 idname_len = strlen(spec); 146 debug("%s: device='%s'\n", __func__, spec); 147 148 for (data = spi_flash_ids; data->name; data++) { 149 len = strlen(data->name); 150 if (idname_len != len) 151 continue; 152 if (!strncasecmp(spec, data->name, len)) 153 break; 154 } 155 if (!data->name) { 156 printf("%s: unknown flash '%*s'\n", __func__, (int)idname_len, 157 spec); 158 ret = -EINVAL; 159 goto error; 160 } 161 162 if (sandbox_sf_0xff[0] == 0x00) 163 memset(sandbox_sf_0xff, 0xff, sizeof(sandbox_sf_0xff)); 164 165 sbsf->fd = os_open(pdata->filename, 02); 166 if (sbsf->fd == -1) { 167 printf("%s: unable to open file '%s'\n", __func__, 168 pdata->filename); 169 ret = -EIO; 170 goto error; 171 } 172 173 sbsf->data = data; 174 sbsf->cs = cs; 175 176 return 0; 177 178 error: 179 debug("%s: Got error %d\n", __func__, ret); 180 return ret; 181 } 182 183 static int sandbox_sf_remove(struct udevice *dev) 184 { 185 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 186 187 os_close(sbsf->fd); 188 189 return 0; 190 } 191 192 static void sandbox_sf_cs_activate(struct udevice *dev) 193 { 194 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 195 196 log_content("sandbox_sf: CS activated; state is fresh!\n"); 197 198 /* CS is asserted, so reset state */ 199 sbsf->off = 0; 200 sbsf->addr_bytes = 0; 201 sbsf->pad_addr_bytes = 0; 202 sbsf->state = SF_CMD; 203 sbsf->cmd = SF_CMD; 204 } 205 206 static void sandbox_sf_cs_deactivate(struct udevice *dev) 207 { 208 log_content("sandbox_sf: CS deactivated; cmd done processing!\n"); 209 } 210 211 /* 212 * There are times when the data lines are allowed to tristate. What 213 * is actually sensed on the line depends on the hardware. It could 214 * always be 0xFF/0x00 (if there are pull ups/downs), or things could 215 * float and so we'd get garbage back. This func encapsulates that 216 * scenario so we can worry about the details here. 217 */ 218 static void sandbox_spi_tristate(u8 *buf, uint len) 219 { 220 /* XXX: make this into a user config option ? */ 221 memset(buf, 0xff, len); 222 } 223 224 /* Figure out what command this stream is telling us to do */ 225 static int sandbox_sf_process_cmd(struct sandbox_spi_flash *sbsf, const u8 *rx, 226 u8 *tx) 227 { 228 enum sandbox_sf_state oldstate = sbsf->state; 229 230 /* We need to output a byte for the cmd byte we just ate */ 231 if (tx) 232 sandbox_spi_tristate(tx, 1); 233 234 sbsf->cmd = rx[0]; 235 switch (sbsf->cmd) { 236 case CMD_READ_ID: 237 sbsf->state = SF_ID; 238 sbsf->cmd = SF_ID; 239 break; 240 case CMD_READ_ARRAY_FAST: 241 sbsf->pad_addr_bytes = 1; 242 case CMD_READ_ARRAY_SLOW: 243 case CMD_PAGE_PROGRAM: 244 sbsf->state = SF_ADDR; 245 break; 246 case CMD_WRITE_DISABLE: 247 debug(" write disabled\n"); 248 sbsf->status &= ~STAT_WEL; 249 break; 250 case CMD_READ_STATUS: 251 sbsf->state = SF_READ_STATUS; 252 break; 253 case CMD_READ_STATUS1: 254 sbsf->state = SF_READ_STATUS1; 255 break; 256 case CMD_WRITE_ENABLE: 257 debug(" write enabled\n"); 258 sbsf->status |= STAT_WEL; 259 break; 260 case CMD_WRITE_STATUS: 261 sbsf->state = SF_WRITE_STATUS; 262 break; 263 default: { 264 int flags = sbsf->data->flags; 265 266 /* we only support erase here */ 267 if (sbsf->cmd == CMD_ERASE_CHIP) { 268 sbsf->erase_size = sbsf->data->sector_size * 269 sbsf->data->n_sectors; 270 } else if (sbsf->cmd == CMD_ERASE_4K && (flags & SECT_4K)) { 271 sbsf->erase_size = 4 << 10; 272 } else if (sbsf->cmd == CMD_ERASE_64K && !(flags & SECT_4K)) { 273 sbsf->erase_size = 64 << 10; 274 } else { 275 debug(" cmd unknown: %#x\n", sbsf->cmd); 276 return -EIO; 277 } 278 sbsf->state = SF_ADDR; 279 break; 280 } 281 } 282 283 if (oldstate != sbsf->state) 284 log_content(" cmd: transition to %s state\n", 285 sandbox_sf_state_name(sbsf->state)); 286 287 return 0; 288 } 289 290 int sandbox_erase_part(struct sandbox_spi_flash *sbsf, int size) 291 { 292 int todo; 293 int ret; 294 295 while (size > 0) { 296 todo = min(size, (int)sizeof(sandbox_sf_0xff)); 297 ret = os_write(sbsf->fd, sandbox_sf_0xff, todo); 298 if (ret != todo) 299 return ret; 300 size -= todo; 301 } 302 303 return 0; 304 } 305 306 static int sandbox_sf_xfer(struct udevice *dev, unsigned int bitlen, 307 const void *rxp, void *txp, unsigned long flags) 308 { 309 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 310 const uint8_t *rx = rxp; 311 uint8_t *tx = txp; 312 uint cnt, pos = 0; 313 int bytes = bitlen / 8; 314 int ret; 315 316 log_content("sandbox_sf: state:%x(%s) bytes:%u\n", sbsf->state, 317 sandbox_sf_state_name(sbsf->state), bytes); 318 319 if ((flags & SPI_XFER_BEGIN)) 320 sandbox_sf_cs_activate(dev); 321 322 if (sbsf->state == SF_CMD) { 323 /* Figure out the initial state */ 324 ret = sandbox_sf_process_cmd(sbsf, rx, tx); 325 if (ret) 326 return ret; 327 ++pos; 328 } 329 330 /* Process the remaining data */ 331 while (pos < bytes) { 332 switch (sbsf->state) { 333 case SF_ID: { 334 u8 id; 335 336 log_content(" id: off:%u tx:", sbsf->off); 337 if (sbsf->off < IDCODE_LEN) { 338 /* Extract correct byte from ID 0x00aabbcc */ 339 id = ((JEDEC_MFR(sbsf->data) << 16) | 340 JEDEC_ID(sbsf->data)) >> 341 (8 * (IDCODE_LEN - 1 - sbsf->off)); 342 } else { 343 id = 0; 344 } 345 log_content("%d %02x\n", sbsf->off, id); 346 tx[pos++] = id; 347 ++sbsf->off; 348 break; 349 } 350 case SF_ADDR: 351 log_content(" addr: bytes:%u rx:%02x ", 352 sbsf->addr_bytes, rx[pos]); 353 354 if (sbsf->addr_bytes++ < SF_ADDR_LEN) 355 sbsf->off = (sbsf->off << 8) | rx[pos]; 356 log_content("addr:%06x\n", sbsf->off); 357 358 if (tx) 359 sandbox_spi_tristate(&tx[pos], 1); 360 pos++; 361 362 /* See if we're done processing */ 363 if (sbsf->addr_bytes < 364 SF_ADDR_LEN + sbsf->pad_addr_bytes) 365 break; 366 367 /* Next state! */ 368 if (os_lseek(sbsf->fd, sbsf->off, OS_SEEK_SET) < 0) { 369 puts("sandbox_sf: os_lseek() failed"); 370 return -EIO; 371 } 372 switch (sbsf->cmd) { 373 case CMD_READ_ARRAY_FAST: 374 case CMD_READ_ARRAY_SLOW: 375 sbsf->state = SF_READ; 376 break; 377 case CMD_PAGE_PROGRAM: 378 sbsf->state = SF_WRITE; 379 break; 380 default: 381 /* assume erase state ... */ 382 sbsf->state = SF_ERASE; 383 goto case_sf_erase; 384 } 385 log_content(" cmd: transition to %s state\n", 386 sandbox_sf_state_name(sbsf->state)); 387 break; 388 case SF_READ: 389 /* 390 * XXX: need to handle exotic behavior: 391 * - reading past end of device 392 */ 393 394 cnt = bytes - pos; 395 log_content(" tx: read(%u)\n", cnt); 396 assert(tx); 397 ret = os_read(sbsf->fd, tx + pos, cnt); 398 if (ret < 0) { 399 puts("sandbox_sf: os_read() failed\n"); 400 return -EIO; 401 } 402 pos += ret; 403 break; 404 case SF_READ_STATUS: 405 log_content(" read status: %#x\n", sbsf->status); 406 cnt = bytes - pos; 407 memset(tx + pos, sbsf->status, cnt); 408 pos += cnt; 409 break; 410 case SF_READ_STATUS1: 411 log_content(" read status: %#x\n", sbsf->status); 412 cnt = bytes - pos; 413 memset(tx + pos, sbsf->status >> 8, cnt); 414 pos += cnt; 415 break; 416 case SF_WRITE_STATUS: 417 log_content(" write status: %#x (ignored)\n", rx[pos]); 418 pos = bytes; 419 break; 420 case SF_WRITE: 421 /* 422 * XXX: need to handle exotic behavior: 423 * - unaligned addresses 424 * - more than a page (256) worth of data 425 * - reading past end of device 426 */ 427 if (!(sbsf->status & STAT_WEL)) { 428 puts("sandbox_sf: write enable not set before write\n"); 429 goto done; 430 } 431 432 cnt = bytes - pos; 433 log_content(" rx: write(%u)\n", cnt); 434 if (tx) 435 sandbox_spi_tristate(&tx[pos], cnt); 436 ret = os_write(sbsf->fd, rx + pos, cnt); 437 if (ret < 0) { 438 puts("sandbox_spi: os_write() failed\n"); 439 return -EIO; 440 } 441 pos += ret; 442 sbsf->status &= ~STAT_WEL; 443 break; 444 case SF_ERASE: 445 case_sf_erase: { 446 if (!(sbsf->status & STAT_WEL)) { 447 puts("sandbox_sf: write enable not set before erase\n"); 448 goto done; 449 } 450 451 /* verify address is aligned */ 452 if (sbsf->off & (sbsf->erase_size - 1)) { 453 log_content(" sector erase: cmd:%#x needs align:%#x, but we got %#x\n", 454 sbsf->cmd, sbsf->erase_size, 455 sbsf->off); 456 sbsf->status &= ~STAT_WEL; 457 goto done; 458 } 459 460 log_content(" sector erase addr: %u, size: %u\n", 461 sbsf->off, sbsf->erase_size); 462 463 cnt = bytes - pos; 464 if (tx) 465 sandbox_spi_tristate(&tx[pos], cnt); 466 pos += cnt; 467 468 /* 469 * TODO(vapier@gentoo.org): latch WIP in status, and 470 * delay before clearing it ? 471 */ 472 ret = sandbox_erase_part(sbsf, sbsf->erase_size); 473 sbsf->status &= ~STAT_WEL; 474 if (ret) { 475 log_content("sandbox_sf: Erase failed\n"); 476 goto done; 477 } 478 goto done; 479 } 480 default: 481 log_content(" ??? no idea what to do ???\n"); 482 goto done; 483 } 484 } 485 486 done: 487 if (flags & SPI_XFER_END) 488 sandbox_sf_cs_deactivate(dev); 489 return pos == bytes ? 0 : -EIO; 490 } 491 492 int sandbox_sf_ofdata_to_platdata(struct udevice *dev) 493 { 494 struct sandbox_spi_flash_plat_data *pdata = dev_get_platdata(dev); 495 496 pdata->filename = dev_read_string(dev, "sandbox,filename"); 497 pdata->device_name = dev_read_string(dev, "compatible"); 498 if (!pdata->filename || !pdata->device_name) { 499 debug("%s: Missing properties, filename=%s, device_name=%s\n", 500 __func__, pdata->filename, pdata->device_name); 501 return -EINVAL; 502 } 503 504 return 0; 505 } 506 507 static const struct dm_spi_emul_ops sandbox_sf_emul_ops = { 508 .xfer = sandbox_sf_xfer, 509 }; 510 511 #ifdef CONFIG_SPI_FLASH 512 int sandbox_sf_bind_emul(struct sandbox_state *state, int busnum, int cs, 513 struct udevice *bus, ofnode node, const char *spec) 514 { 515 struct udevice *emul; 516 char name[20], *str; 517 struct driver *drv; 518 int ret; 519 520 /* now the emulator */ 521 strncpy(name, spec, sizeof(name) - 6); 522 name[sizeof(name) - 6] = '\0'; 523 strcat(name, "-emul"); 524 drv = lists_driver_lookup_name("sandbox_sf_emul"); 525 if (!drv) { 526 puts("Cannot find sandbox_sf_emul driver\n"); 527 return -ENOENT; 528 } 529 str = strdup(name); 530 if (!str) 531 return -ENOMEM; 532 ret = device_bind_ofnode(bus, drv, str, NULL, node, &emul); 533 if (ret) { 534 free(str); 535 printf("Cannot create emul device for spec '%s' (err=%d)\n", 536 spec, ret); 537 return ret; 538 } 539 state->spi[busnum][cs].emul = emul; 540 541 return 0; 542 } 543 544 void sandbox_sf_unbind_emul(struct sandbox_state *state, int busnum, int cs) 545 { 546 struct udevice *dev; 547 548 dev = state->spi[busnum][cs].emul; 549 device_remove(dev, DM_REMOVE_NORMAL); 550 device_unbind(dev); 551 state->spi[busnum][cs].emul = NULL; 552 } 553 554 int sandbox_spi_get_emul(struct sandbox_state *state, 555 struct udevice *bus, struct udevice *slave, 556 struct udevice **emulp) 557 { 558 struct sandbox_spi_info *info; 559 int busnum = bus->seq; 560 int cs = spi_chip_select(slave); 561 int ret; 562 563 info = &state->spi[busnum][cs]; 564 if (!info->emul) { 565 /* Use the same device tree node as the SPI flash device */ 566 debug("%s: busnum=%u, cs=%u: binding SPI flash emulation: ", 567 __func__, busnum, cs); 568 ret = sandbox_sf_bind_emul(state, busnum, cs, bus, 569 dev_ofnode(slave), slave->name); 570 if (ret) { 571 debug("failed (err=%d)\n", ret); 572 return ret; 573 } 574 debug("OK\n"); 575 } 576 *emulp = info->emul; 577 578 return 0; 579 } 580 #endif 581 582 static const struct udevice_id sandbox_sf_ids[] = { 583 { .compatible = "sandbox,spi-flash" }, 584 { } 585 }; 586 587 U_BOOT_DRIVER(sandbox_sf_emul) = { 588 .name = "sandbox_sf_emul", 589 .id = UCLASS_SPI_EMUL, 590 .of_match = sandbox_sf_ids, 591 .ofdata_to_platdata = sandbox_sf_ofdata_to_platdata, 592 .probe = sandbox_sf_probe, 593 .remove = sandbox_sf_remove, 594 .priv_auto_alloc_size = sizeof(struct sandbox_spi_flash), 595 .platdata_auto_alloc_size = sizeof(struct sandbox_spi_flash_plat_data), 596 .ops = &sandbox_sf_emul_ops, 597 }; 598