drivers/mtd/spi/sandbox.c

   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 #define STAT_BP_SHIFT   2
  61 #define STAT_BP_MASK    (7 << STAT_BP_SHIFT)
  62
  63 /* Assume all SPI flashes have 3 byte addresses since they do atm */
  64 #define SF_ADDR_LEN     3
  65
  66 #define IDCODE_LEN 3
  67
  68 /* Used to quickly bulk erase backing store */
  69 static u8 sandbox_sf_0xff[0x1000];
  70
  71 /* Internal state data for each SPI flash */
  72 struct sandbox_spi_flash {
  73         unsigned int cs;        /* Chip select we are attached to */
  74         /*
  75          * As we receive data over the SPI bus, our flash transitions
  76          * between states.  For example, we start off in the SF_CMD
  77          * state where the first byte tells us what operation to perform
  78          * (such as read or write the flash).  But the operation itself
  79          * can go through a few states such as first reading in the
  80          * offset in the flash to perform the requested operation.
  81          * Thus "state" stores the exact state that our machine is in
  82          * while "cmd" stores the overall command we're processing.
  83          */
  84         enum sandbox_sf_state state;
  85         uint cmd;
  86         /* Erase size of current erase command */
  87         uint erase_size;
  88         /* Current position in the flash; used when reading/writing/etc... */
  89         uint off;
  90         /* How many address bytes we've consumed */
  91         uint addr_bytes, pad_addr_bytes;
  92         /* The current flash status (see STAT_XXX defines above) */
  93         u16 status;
  94         /* Data describing the flash we're emulating */
  95         const struct flash_info *data;
  96         /* The file on disk to serv up data from */
  97         int fd;
  98 };
  99
 100 struct sandbox_spi_flash_plat_data {
 101         const char *filename;
 102         const char *device_name;
 103         int bus;
 104         int cs;
 105 };
 106
 107 void sandbox_sf_set_block_protect(struct udevice *dev, int bp_mask)
 108 {
 109         struct sandbox_spi_flash *sbsf = dev_get_priv(dev);
 110
 111         sbsf->status &= ~STAT_BP_MASK;
 112         sbsf->status |= bp_mask << STAT_BP_SHIFT;
 113 }
 114
 115 /**
 116  * This is a very strange probe function. If it has platform data (which may
 117  * have come from the device tree) then this function gets the filename and
 118  * device type from there.
 119  */
 120 static int sandbox_sf_probe(struct udevice *dev)
 121 {
 122         /* spec = idcode:file */
 123         struct sandbox_spi_flash *sbsf = dev_get_priv(dev);
 124         size_t len, idname_len;
 125         const struct flash_info *data;
 126         struct sandbox_spi_flash_plat_data *pdata = dev_get_platdata(dev);
 127         struct sandbox_state *state = state_get_current();
 128         struct dm_spi_slave_platdata *slave_plat;
 129         struct udevice *bus = dev->parent;
 130         const char *spec = NULL;
 131         struct udevice *emul;
 132         int ret = 0;
 133         int cs = -1;
 134
 135         debug("%s: bus %d, looking for emul=%p: ", __func__, bus->seq, dev);
 136         ret = sandbox_spi_get_emul(state, bus, dev, &emul);
 137         if (ret) {
 138                 printf("Error: Unknown chip select for device '%s'\n",
 139                         dev->name);
 140                 return ret;
 141         }
 142         slave_plat = dev_get_parent_platdata(dev);
 143         cs = slave_plat->cs;
 144         debug("found at cs %d\n", cs);
 145
 146         if (!pdata->filename) {
 147                 printf("Error: No filename available\n");
 148                 return -EINVAL;
 149         }
 150         spec = strchr(pdata->device_name, ',');
 151         if (spec)
 152                 spec++;
 153         else
 154                 spec = pdata->device_name;
 155         idname_len = strlen(spec);
 156         debug("%s: device='%s'\n", __func__, spec);
 157
 158         for (data = spi_nor_ids; data->name; data++) {
 159                 len = strlen(data->name);
 160                 if (idname_len != len)
 161                         continue;
 162                 if (!strncasecmp(spec, data->name, len))
 163                         break;
 164         }
 165         if (!data->name) {
 166                 printf("%s: unknown flash '%*s'\n", __func__, (int)idname_len,
 167                        spec);
 168                 ret = -EINVAL;
 169                 goto error;
 170         }
 171
 172         if (sandbox_sf_0xff[0] == 0x00)
 173                 memset(sandbox_sf_0xff, 0xff, sizeof(sandbox_sf_0xff));
 174
 175         sbsf->fd = os_open(pdata->filename, 02);
 176         if (sbsf->fd == -1) {
 177                 printf("%s: unable to open file '%s'\n", __func__,
 178                        pdata->filename);
 179                 ret = -EIO;
 180                 goto error;
 181         }
 182
 183         sbsf->data = data;
 184         sbsf->cs = cs;
 185
 186         return 0;
 187
 188  error:
 189         debug("%s: Got error %d\n", __func__, ret);
 190         return ret;
 191 }
 192
 193 static int sandbox_sf_remove(struct udevice *dev)
 194 {
 195         struct sandbox_spi_flash *sbsf = dev_get_priv(dev);
 196
 197         os_close(sbsf->fd);
 198
 199         return 0;
 200 }
 201
 202 static void sandbox_sf_cs_activate(struct udevice *dev)
 203 {
 204         struct sandbox_spi_flash *sbsf = dev_get_priv(dev);
 205
 206         log_content("sandbox_sf: CS activated; state is fresh!\n");
 207
 208         /* CS is asserted, so reset state */
 209         sbsf->off = 0;
 210         sbsf->addr_bytes = 0;
 211         sbsf->pad_addr_bytes = 0;
 212         sbsf->state = SF_CMD;
 213         sbsf->cmd = SF_CMD;
 214 }
 215
 216 static void sandbox_sf_cs_deactivate(struct udevice *dev)
 217 {
 218         log_content("sandbox_sf: CS deactivated; cmd done processing!\n");
 219 }
 220
 221 /*
 222  * There are times when the data lines are allowed to tristate.  What
 223  * is actually sensed on the line depends on the hardware.  It could
 224  * always be 0xFF/0x00 (if there are pull ups/downs), or things could
 225  * float and so we'd get garbage back.  This func encapsulates that
 226  * scenario so we can worry about the details here.
 227  */
 228 static void sandbox_spi_tristate(u8 *buf, uint len)
 229 {
 230         /* XXX: make this into a user config option ? */
 231         memset(buf, 0xff, len);
 232 }
 233
 234 /* Figure out what command this stream is telling us to do */
 235 static int sandbox_sf_process_cmd(struct sandbox_spi_flash *sbsf, const u8 *rx,
 236                                   u8 *tx)
 237 {
 238         enum sandbox_sf_state oldstate = sbsf->state;
 239
 240         /* We need to output a byte for the cmd byte we just ate */
 241         if (tx)
 242                 sandbox_spi_tristate(tx, 1);
 243
 244         sbsf->cmd = rx[0];
 245         switch (sbsf->cmd) {
 246         case SPINOR_OP_RDID:
 247                 sbsf->state = SF_ID;
 248                 sbsf->cmd = SF_ID;
 249                 break;
 250         case SPINOR_OP_READ_FAST:
 251                 sbsf->pad_addr_bytes = 1;
 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
 300 int 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
 316 static 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
 502 int sandbox_sf_ofdata_to_platdata(struct udevice *dev)
 503 {
 504         struct sandbox_spi_flash_plat_data *pdata = dev_get_platdata(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
 517 static const struct dm_spi_emul_ops sandbox_sf_emul_ops = {
 518         .xfer          = sandbox_sf_xfer,
 519 };
 520
 521 #ifdef CONFIG_SPI_FLASH
 522 int 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_ofnode(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
 554 void 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
 564 int 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 = bus->seq;
 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
 592 static const struct udevice_id sandbox_sf_ids[] = {
 593         { .compatible = "sandbox,spi-flash" },
 594         { }
 595 };
 596
 597 U_BOOT_DRIVER(sandbox_sf_emul) = {
 598         .name           = "sandbox_sf_emul",
 599         .id             = UCLASS_SPI_EMUL,
 600         .of_match       = sandbox_sf_ids,
 601         .ofdata_to_platdata = sandbox_sf_ofdata_to_platdata,
 602         .probe          = sandbox_sf_probe,
 603         .remove         = sandbox_sf_remove,
 604         .priv_auto_alloc_size = sizeof(struct sandbox_spi_flash),
 605         .platdata_auto_alloc_size = sizeof(struct sandbox_spi_flash_plat_data),
 606         .ops            = &sandbox_sf_emul_ops,
 607 };