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 <log.h> 16#include <malloc.h> 17#include <spi.h> 18#include <os.h> 19 20#include <spi_flash.h> 21#include "sf_internal.h" 22 23#include <asm/getopt.h> 24#include <asm/spi.h> 25#include <asm/state.h> 26#include <dm/device-internal.h> 27#include <dm/lists.h> 28#include <dm/uclass-internal.h> 29 30/* 31 * The different states that our SPI flash transitions between. 32 * We need to keep track of this across multiple xfer calls since 33 * the SPI bus could possibly call down into us multiple times. 34 */ 35enum sandbox_sf_state { 36 SF_CMD, /* default state -- we're awaiting a command */ 37 SF_ID, /* read the flash's (jedec) ID code */ 38 SF_ADDR, /* processing the offset in the flash to read/etc... */ 39 SF_READ, /* reading data from the flash */ 40 SF_WRITE, /* writing data to the flash, i.e. page programming */ 41 SF_ERASE, /* erase the flash */ 42 SF_READ_STATUS, /* read the flash's status register */ 43 SF_READ_STATUS1, /* read the flash's status register upper 8 bits*/ 44 SF_WRITE_STATUS, /* write the flash's status register */ 45}; 46 47static 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 56/* Bits for the status register */ 57#define STAT_WIP (1 << 0) 58#define STAT_WEL (1 << 1) 59#define STAT_BP_SHIFT 2 60#define STAT_BP_MASK (7 << STAT_BP_SHIFT) 61 62/* Assume all SPI flashes have 3 byte addresses since they do atm */ 63#define SF_ADDR_LEN 3 64 65#define IDCODE_LEN 3 66 67/* Used to quickly bulk erase backing store */ 68static u8 sandbox_sf_0xff[0x1000]; 69 70/* Internal state data for each SPI flash */ 71struct sandbox_spi_flash { 72 unsigned int cs; /* Chip select we are attached to */ 73 /* 74 * As we receive data over the SPI bus, our flash transitions 75 * between states. For example, we start off in the SF_CMD 76 * state where the first byte tells us what operation to perform 77 * (such as read or write the flash). But the operation itself 78 * can go through a few states such as first reading in the 79 * offset in the flash to perform the requested operation. 80 * Thus "state" stores the exact state that our machine is in 81 * while "cmd" stores the overall command we're processing. 82 */ 83 enum sandbox_sf_state state; 84 uint cmd; 85 /* Erase size of current erase command */ 86 uint erase_size; 87 /* Current position in the flash; used when reading/writing/etc... */ 88 uint off; 89 /* How many address bytes we've consumed */ 90 uint addr_bytes, pad_addr_bytes; 91 /* The current flash status (see STAT_XXX defines above) */ 92 u16 status; 93 /* Data describing the flash we're emulating */ 94 const struct flash_info *data; 95 /* The file on disk to serv up data from */ 96 int fd; 97}; 98 99struct sandbox_spi_flash_plat_data { 100 const char *filename; 101 const char *device_name; 102 int bus; 103 int cs; 104}; 105 106void sandbox_sf_set_block_protect(struct udevice *dev, int bp_mask) 107{ 108 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 109 110 sbsf->status &= ~STAT_BP_MASK; 111 sbsf->status |= bp_mask << STAT_BP_SHIFT; 112} 113 114/** 115 * This is a very strange probe function. If it has platform data (which may 116 * have come from the device tree) then this function gets the filename and 117 * device type from there. 118 */ 119static int sandbox_sf_probe(struct udevice *dev) 120{ 121 /* spec = idcode:file */ 122 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 123 size_t len, idname_len; 124 const struct flash_info *data; 125 struct sandbox_spi_flash_plat_data *pdata = dev_get_plat(dev); 126 struct sandbox_state *state = state_get_current(); 127 struct dm_spi_slave_plat *slave_plat; 128 struct udevice *bus = dev->parent; 129 const char *spec = NULL; 130 struct udevice *emul; 131 int ret = 0; 132 int cs = -1; 133 134 debug("%s: bus %d, looking for emul=%p: ", __func__, dev_seq(bus), dev); 135 ret = sandbox_spi_get_emul(state, bus, dev, &emul); 136 if (ret) { 137 printf("Error: Unknown chip select for device '%s'\n", 138 dev->name); 139 return ret; 140 } 141 slave_plat = dev_get_parent_plat(dev); 142 cs = slave_plat->cs; 143 debug("found at cs %d\n", cs); 144 145 if (!pdata->filename) { 146 printf("Error: No filename available\n"); 147 return -EINVAL; 148 } 149 spec = strchr(pdata->device_name, ','); 150 if (spec) 151 spec++; 152 else 153 spec = pdata->device_name; 154 idname_len = strlen(spec); 155 debug("%s: device='%s'\n", __func__, spec); 156 157 for (data = spi_nor_ids; data->name; data++) { 158 len = strlen(data->name); 159 if (idname_len != len) 160 continue; 161 if (!strncasecmp(spec, data->name, len)) 162 break; 163 } 164 if (!data->name) { 165 printf("%s: unknown flash '%*s'\n", __func__, (int)idname_len, 166 spec); 167 ret = -EINVAL; 168 goto error; 169 } 170 171 if (sandbox_sf_0xff[0] == 0x00) 172 memset(sandbox_sf_0xff, 0xff, sizeof(sandbox_sf_0xff)); 173 174 sbsf->fd = os_open(pdata->filename, 02); 175 if (sbsf->fd == -1) { 176 printf("%s: unable to open file '%s'\n", __func__, 177 pdata->filename); 178 ret = -EIO; 179 goto error; 180 } 181 182 sbsf->data = data; 183 sbsf->cs = cs; 184 185 return 0; 186 187 error: 188 debug("%s: Got error %d\n", __func__, ret); 189 return ret; 190} 191 192static int sandbox_sf_remove(struct udevice *dev) 193{ 194 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 195 196 os_close(sbsf->fd); 197 198 return 0; 199} 200 201static void sandbox_sf_cs_activate(struct udevice *dev) 202{ 203 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 204 205 log_content("sandbox_sf: CS activated; state is fresh!\n"); 206 207 /* CS is asserted, so reset state */ 208 sbsf->off = 0; 209 sbsf->addr_bytes = 0; 210 sbsf->pad_addr_bytes = 0; 211 sbsf->state = SF_CMD; 212 sbsf->cmd = SF_CMD; 213} 214 215static void sandbox_sf_cs_deactivate(struct udevice *dev) 216{ 217 log_content("sandbox_sf: CS deactivated; cmd done processing!\n"); 218} 219 220/* 221 * There are times when the data lines are allowed to tristate. What 222 * is actually sensed on the line depends on the hardware. It could 223 * always be 0xFF/0x00 (if there are pull ups/downs), or things could 224 * float and so we'd get garbage back. This func encapsulates that 225 * scenario so we can worry about the details here. 226 */ 227static void sandbox_spi_tristate(u8 *buf, uint len) 228{ 229 /* XXX: make this into a user config option ? */ 230 memset(buf, 0xff, len); 231} 232 233/* Figure out what command this stream is telling us to do */ 234static int sandbox_sf_process_cmd(struct sandbox_spi_flash *sbsf, const u8 *rx, 235 u8 *tx) 236{ 237 enum sandbox_sf_state oldstate = sbsf->state; 238 239 /* We need to output a byte for the cmd byte we just ate */ 240 if (tx) 241 sandbox_spi_tristate(tx, 1); 242 243 sbsf->cmd = rx[0]; 244 switch (sbsf->cmd) { 245 case SPINOR_OP_RDID: 246 sbsf->state = SF_ID; 247 sbsf->cmd = SF_ID; 248 break; 249 case SPINOR_OP_READ_FAST: 250 sbsf->pad_addr_bytes = 1; 251 fallthrough; 252 case SPINOR_OP_READ: 253 case SPINOR_OP_PP: 254 sbsf->state = SF_ADDR; 255 break; 256 case SPINOR_OP_WRDI: 257 debug(" write disabled\n"); 258 sbsf->status &= ~STAT_WEL; 259 break; 260 case SPINOR_OP_RDSR: 261 sbsf->state = SF_READ_STATUS; 262 break; 263 case SPINOR_OP_RDSR2: 264 sbsf->state = SF_READ_STATUS1; 265 break; 266 case SPINOR_OP_WREN: 267 debug(" write enabled\n"); 268 sbsf->status |= STAT_WEL; 269 break; 270 case SPINOR_OP_WRSR: 271 sbsf->state = SF_WRITE_STATUS; 272 break; 273 default: { 274 int flags = sbsf->data->flags; 275 276 /* we only support erase here */ 277 if (sbsf->cmd == SPINOR_OP_CHIP_ERASE) { 278 sbsf->erase_size = sbsf->data->sector_size * 279 sbsf->data->n_sectors; 280 } else if (sbsf->cmd == SPINOR_OP_BE_4K && (flags & SECT_4K)) { 281 sbsf->erase_size = 4 << 10; 282 } else if (sbsf->cmd == SPINOR_OP_SE && !(flags & SECT_4K)) { 283 sbsf->erase_size = 64 << 10; 284 } else { 285 debug(" cmd unknown: %#x\n", sbsf->cmd); 286 return -EIO; 287 } 288 sbsf->state = SF_ADDR; 289 break; 290 } 291 } 292 293 if (oldstate != sbsf->state) 294 log_content(" cmd: transition to %s state\n", 295 sandbox_sf_state_name(sbsf->state)); 296 297 return 0; 298} 299 300int sandbox_erase_part(struct sandbox_spi_flash *sbsf, int size) 301{ 302 int todo; 303 int ret; 304 305 while (size > 0) { 306 todo = min(size, (int)sizeof(sandbox_sf_0xff)); 307 ret = os_write(sbsf->fd, sandbox_sf_0xff, todo); 308 if (ret != todo) 309 return ret; 310 size -= todo; 311 } 312 313 return 0; 314} 315 316static int sandbox_sf_xfer(struct udevice *dev, unsigned int bitlen, 317 const void *rxp, void *txp, unsigned long flags) 318{ 319 struct sandbox_spi_flash *sbsf = dev_get_priv(dev); 320 const uint8_t *rx = rxp; 321 uint8_t *tx = txp; 322 uint cnt, pos = 0; 323 int bytes = bitlen / 8; 324 int ret; 325 326 log_content("sandbox_sf: state:%x(%s) bytes:%u\n", sbsf->state, 327 sandbox_sf_state_name(sbsf->state), bytes); 328 329 if ((flags & SPI_XFER_BEGIN)) 330 sandbox_sf_cs_activate(dev); 331 332 if (sbsf->state == SF_CMD) { 333 /* Figure out the initial state */ 334 ret = sandbox_sf_process_cmd(sbsf, rx, tx); 335 if (ret) 336 return ret; 337 ++pos; 338 } 339 340 /* Process the remaining data */ 341 while (pos < bytes) { 342 switch (sbsf->state) { 343 case SF_ID: { 344 u8 id; 345 346 log_content(" id: off:%u tx:", sbsf->off); 347 if (sbsf->off < IDCODE_LEN) { 348 /* Extract correct byte from ID 0x00aabbcc */ 349 id = ((JEDEC_MFR(sbsf->data) << 16) | 350 JEDEC_ID(sbsf->data)) >> 351 (8 * (IDCODE_LEN - 1 - sbsf->off)); 352 } else { 353 id = 0; 354 } 355 log_content("%d %02x\n", sbsf->off, id); 356 tx[pos++] = id; 357 ++sbsf->off; 358 break; 359 } 360 case SF_ADDR: 361 log_content(" addr: bytes:%u rx:%02x ", 362 sbsf->addr_bytes, rx[pos]); 363 364 if (sbsf->addr_bytes++ < SF_ADDR_LEN) 365 sbsf->off = (sbsf->off << 8) | rx[pos]; 366 log_content("addr:%06x\n", sbsf->off); 367 368 if (tx) 369 sandbox_spi_tristate(&tx[pos], 1); 370 pos++; 371 372 /* See if we're done processing */ 373 if (sbsf->addr_bytes < 374 SF_ADDR_LEN + sbsf->pad_addr_bytes) 375 break; 376 377 /* Next state! */ 378 if (os_lseek(sbsf->fd, sbsf->off, OS_SEEK_SET) < 0) { 379 puts("sandbox_sf: os_lseek() failed"); 380 return -EIO; 381 } 382 switch (sbsf->cmd) { 383 case SPINOR_OP_READ_FAST: 384 case SPINOR_OP_READ: 385 sbsf->state = SF_READ; 386 break; 387 case SPINOR_OP_PP: 388 sbsf->state = SF_WRITE; 389 break; 390 default: 391 /* assume erase state ... */ 392 sbsf->state = SF_ERASE; 393 goto case_sf_erase; 394 } 395 log_content(" cmd: transition to %s state\n", 396 sandbox_sf_state_name(sbsf->state)); 397 break; 398 case SF_READ: 399 /* 400 * XXX: need to handle exotic behavior: 401 * - reading past end of device 402 */ 403 404 cnt = bytes - pos; 405 log_content(" tx: read(%u)\n", cnt); 406 assert(tx); 407 ret = os_read(sbsf->fd, tx + pos, cnt); 408 if (ret < 0) { 409 puts("sandbox_sf: os_read() failed\n"); 410 return -EIO; 411 } 412 pos += ret; 413 break; 414 case SF_READ_STATUS: 415 log_content(" read status: %#x\n", sbsf->status); 416 cnt = bytes - pos; 417 memset(tx + pos, sbsf->status, cnt); 418 pos += cnt; 419 break; 420 case SF_READ_STATUS1: 421 log_content(" read status: %#x\n", sbsf->status); 422 cnt = bytes - pos; 423 memset(tx + pos, sbsf->status >> 8, cnt); 424 pos += cnt; 425 break; 426 case SF_WRITE_STATUS: 427 log_content(" write status: %#x (ignored)\n", rx[pos]); 428 pos = bytes; 429 break; 430 case SF_WRITE: 431 /* 432 * XXX: need to handle exotic behavior: 433 * - unaligned addresses 434 * - more than a page (256) worth of data 435 * - reading past end of device 436 */ 437 if (!(sbsf->status & STAT_WEL)) { 438 puts("sandbox_sf: write enable not set before write\n"); 439 goto done; 440 } 441 442 cnt = bytes - pos; 443 log_content(" rx: write(%u)\n", cnt); 444 if (tx) 445 sandbox_spi_tristate(&tx[pos], cnt); 446 ret = os_write(sbsf->fd, rx + pos, cnt); 447 if (ret < 0) { 448 puts("sandbox_spi: os_write() failed\n"); 449 return -EIO; 450 } 451 pos += ret; 452 sbsf->status &= ~STAT_WEL; 453 break; 454 case SF_ERASE: 455 case_sf_erase: { 456 if (!(sbsf->status & STAT_WEL)) { 457 puts("sandbox_sf: write enable not set before erase\n"); 458 goto done; 459 } 460 461 /* verify address is aligned */ 462 if (sbsf->off & (sbsf->erase_size - 1)) { 463 log_content(" sector erase: cmd:%#x needs align:%#x, but we got %#x\n", 464 sbsf->cmd, sbsf->erase_size, 465 sbsf->off); 466 sbsf->status &= ~STAT_WEL; 467 goto done; 468 } 469 470 log_content(" sector erase addr: %u, size: %u\n", 471 sbsf->off, sbsf->erase_size); 472 473 cnt = bytes - pos; 474 if (tx) 475 sandbox_spi_tristate(&tx[pos], cnt); 476 pos += cnt; 477 478 /* 479 * TODO(vapier@gentoo.org): latch WIP in status, and 480 * delay before clearing it ? 481 */ 482 ret = sandbox_erase_part(sbsf, sbsf->erase_size); 483 sbsf->status &= ~STAT_WEL; 484 if (ret) { 485 log_content("sandbox_sf: Erase failed\n"); 486 goto done; 487 } 488 goto done; 489 } 490 default: 491 log_content(" ??? no idea what to do ???\n"); 492 goto done; 493 } 494 } 495 496 done: 497 if (flags & SPI_XFER_END) 498 sandbox_sf_cs_deactivate(dev); 499 return pos == bytes ? 0 : -EIO; 500} 501 502int sandbox_sf_of_to_plat(struct udevice *dev) 503{ 504 struct sandbox_spi_flash_plat_data *pdata = dev_get_plat(dev); 505 506 pdata->filename = dev_read_string(dev, "sandbox,filename"); 507 pdata->device_name = dev_read_string(dev, "compatible"); 508 if (!pdata->filename || !pdata->device_name) { 509 debug("%s: Missing properties, filename=%s, device_name=%s\n", 510 __func__, pdata->filename, pdata->device_name); 511 return -EINVAL; 512 } 513 514 return 0; 515} 516 517static const struct dm_spi_emul_ops sandbox_sf_emul_ops = { 518 .xfer = sandbox_sf_xfer, 519}; 520 521#ifdef CONFIG_SPI_FLASH 522int sandbox_sf_bind_emul(struct sandbox_state *state, int busnum, int cs, 523 struct udevice *bus, ofnode node, const char *spec) 524{ 525 struct udevice *emul; 526 char name[20], *str; 527 struct driver *drv; 528 int ret; 529 530 /* now the emulator */ 531 strncpy(name, spec, sizeof(name) - 6); 532 name[sizeof(name) - 6] = '\0'; 533 strcat(name, "-emul"); 534 drv = lists_driver_lookup_name("sandbox_sf_emul"); 535 if (!drv) { 536 puts("Cannot find sandbox_sf_emul driver\n"); 537 return -ENOENT; 538 } 539 str = strdup(name); 540 if (!str) 541 return -ENOMEM; 542 ret = device_bind(bus, drv, str, NULL, node, &emul); 543 if (ret) { 544 free(str); 545 printf("Cannot create emul device for spec '%s' (err=%d)\n", 546 spec, ret); 547 return ret; 548 } 549 state->spi[busnum][cs].emul = emul; 550 551 return 0; 552} 553 554void sandbox_sf_unbind_emul(struct sandbox_state *state, int busnum, int cs) 555{ 556 struct udevice *dev; 557 558 dev = state->spi[busnum][cs].emul; 559 device_remove(dev, DM_REMOVE_NORMAL); 560 device_unbind(dev); 561 state->spi[busnum][cs].emul = NULL; 562} 563 564int sandbox_spi_get_emul(struct sandbox_state *state, 565 struct udevice *bus, struct udevice *slave, 566 struct udevice **emulp) 567{ 568 struct sandbox_spi_info *info; 569 int busnum = dev_seq(bus); 570 int cs = spi_chip_select(slave); 571 int ret; 572 573 info = &state->spi[busnum][cs]; 574 if (!info->emul) { 575 /* Use the same device tree node as the SPI flash device */ 576 debug("%s: busnum=%u, cs=%u: binding SPI flash emulation: ", 577 __func__, busnum, cs); 578 ret = sandbox_sf_bind_emul(state, busnum, cs, bus, 579 dev_ofnode(slave), slave->name); 580 if (ret) { 581 debug("failed (err=%d)\n", ret); 582 return ret; 583 } 584 debug("OK\n"); 585 } 586 *emulp = info->emul; 587 588 return 0; 589} 590#endif 591 592static const struct udevice_id sandbox_sf_ids[] = { 593 { .compatible = "sandbox,spi-flash" }, 594 { } 595}; 596 597U_BOOT_DRIVER(sandbox_sf_emul) = { 598 .name = "sandbox_sf_emul", 599 .id = UCLASS_SPI_EMUL, 600 .of_match = sandbox_sf_ids, 601 .of_to_plat = sandbox_sf_of_to_plat, 602 .probe = sandbox_sf_probe, 603 .remove = sandbox_sf_remove, 604 .priv_auto = sizeof(struct sandbox_spi_flash), 605 .plat_auto = sizeof(struct sandbox_spi_flash_plat_data), 606 .ops = &sandbox_sf_emul_ops, 607}; 608