1 // SPDX-License-Identifier: GPL-2.0-or-later 2 // Copyright (C) IBM Corporation 2020 3 4 #include <linux/bitfield.h> 5 #include <linux/bits.h> 6 #include <linux/fsi.h> 7 #include <linux/jiffies.h> 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/spi/spi.h> 12 13 #define FSI_ENGID_SPI 0x23 14 #define FSI_MBOX_ROOT_CTRL_8 0x2860 15 #define FSI_MBOX_ROOT_CTRL_8_SPI_MUX 0xf0000000 16 17 #define FSI2SPI_DATA0 0x00 18 #define FSI2SPI_DATA1 0x04 19 #define FSI2SPI_CMD 0x08 20 #define FSI2SPI_CMD_WRITE BIT(31) 21 #define FSI2SPI_RESET 0x18 22 #define FSI2SPI_STATUS 0x1c 23 #define FSI2SPI_STATUS_ANY_ERROR BIT(31) 24 #define FSI2SPI_IRQ 0x20 25 26 #define SPI_FSI_BASE 0x70000 27 #define SPI_FSI_INIT_TIMEOUT_MS 1000 28 #define SPI_FSI_MAX_RX_SIZE 8 29 #define SPI_FSI_MAX_TX_SIZE 40 30 31 #define SPI_FSI_ERROR 0x0 32 #define SPI_FSI_COUNTER_CFG 0x1 33 #define SPI_FSI_CFG1 0x2 34 #define SPI_FSI_CLOCK_CFG 0x3 35 #define SPI_FSI_CLOCK_CFG_MM_ENABLE BIT_ULL(32) 36 #define SPI_FSI_CLOCK_CFG_ECC_DISABLE (BIT_ULL(35) | BIT_ULL(33)) 37 #define SPI_FSI_CLOCK_CFG_RESET1 (BIT_ULL(36) | BIT_ULL(38)) 38 #define SPI_FSI_CLOCK_CFG_RESET2 (BIT_ULL(37) | BIT_ULL(39)) 39 #define SPI_FSI_CLOCK_CFG_MODE (BIT_ULL(41) | BIT_ULL(42)) 40 #define SPI_FSI_CLOCK_CFG_SCK_RECV_DEL GENMASK_ULL(51, 44) 41 #define SPI_FSI_CLOCK_CFG_SCK_NO_DEL BIT_ULL(51) 42 #define SPI_FSI_CLOCK_CFG_SCK_DIV GENMASK_ULL(63, 52) 43 #define SPI_FSI_MMAP 0x4 44 #define SPI_FSI_DATA_TX 0x5 45 #define SPI_FSI_DATA_RX 0x6 46 #define SPI_FSI_SEQUENCE 0x7 47 #define SPI_FSI_SEQUENCE_STOP 0x00 48 #define SPI_FSI_SEQUENCE_SEL_SLAVE(x) (0x10 | ((x) & 0xf)) 49 #define SPI_FSI_SEQUENCE_SHIFT_OUT(x) (0x30 | ((x) & 0xf)) 50 #define SPI_FSI_SEQUENCE_SHIFT_IN(x) (0x40 | ((x) & 0xf)) 51 #define SPI_FSI_SEQUENCE_COPY_DATA_TX 0xc0 52 #define SPI_FSI_SEQUENCE_BRANCH(x) (0xe0 | ((x) & 0xf)) 53 #define SPI_FSI_STATUS 0x8 54 #define SPI_FSI_STATUS_ERROR \ 55 (GENMASK_ULL(31, 21) | GENMASK_ULL(15, 12)) 56 #define SPI_FSI_STATUS_SEQ_STATE GENMASK_ULL(55, 48) 57 #define SPI_FSI_STATUS_SEQ_STATE_IDLE BIT_ULL(48) 58 #define SPI_FSI_STATUS_TDR_UNDERRUN BIT_ULL(57) 59 #define SPI_FSI_STATUS_TDR_OVERRUN BIT_ULL(58) 60 #define SPI_FSI_STATUS_TDR_FULL BIT_ULL(59) 61 #define SPI_FSI_STATUS_RDR_UNDERRUN BIT_ULL(61) 62 #define SPI_FSI_STATUS_RDR_OVERRUN BIT_ULL(62) 63 #define SPI_FSI_STATUS_RDR_FULL BIT_ULL(63) 64 #define SPI_FSI_STATUS_ANY_ERROR \ 65 (SPI_FSI_STATUS_ERROR | \ 66 SPI_FSI_STATUS_TDR_OVERRUN | SPI_FSI_STATUS_RDR_UNDERRUN | \ 67 SPI_FSI_STATUS_RDR_OVERRUN) 68 #define SPI_FSI_PORT_CTRL 0x9 69 70 struct fsi2spi { 71 struct fsi_device *fsi; /* FSI2SPI CFAM engine device */ 72 struct mutex lock; /* lock access to the device */ 73 }; 74 75 struct fsi_spi { 76 struct device *dev; /* SPI controller device */ 77 struct fsi2spi *bridge; /* FSI2SPI device */ 78 u32 base; 79 }; 80 81 struct fsi_spi_sequence { 82 int bit; 83 u64 data; 84 }; 85 86 static int fsi_spi_check_mux(struct fsi_device *fsi, struct device *dev) 87 { 88 int rc; 89 u32 root_ctrl_8; 90 __be32 root_ctrl_8_be; 91 92 rc = fsi_slave_read(fsi->slave, FSI_MBOX_ROOT_CTRL_8, &root_ctrl_8_be, 93 sizeof(root_ctrl_8_be)); 94 if (rc) 95 return rc; 96 97 root_ctrl_8 = be32_to_cpu(root_ctrl_8_be); 98 dev_dbg(dev, "Root control register 8: %08x\n", root_ctrl_8); 99 if ((root_ctrl_8 & FSI_MBOX_ROOT_CTRL_8_SPI_MUX) == 100 FSI_MBOX_ROOT_CTRL_8_SPI_MUX) 101 return 0; 102 103 return -ENOLINK; 104 } 105 106 static int fsi_spi_check_status(struct fsi_spi *ctx) 107 { 108 int rc; 109 u32 sts; 110 __be32 sts_be; 111 112 rc = fsi_device_read(ctx->bridge->fsi, FSI2SPI_STATUS, &sts_be, 113 sizeof(sts_be)); 114 if (rc) 115 return rc; 116 117 sts = be32_to_cpu(sts_be); 118 if (sts & FSI2SPI_STATUS_ANY_ERROR) { 119 dev_err(ctx->dev, "Error with FSI2SPI interface: %08x.\n", sts); 120 return -EIO; 121 } 122 123 return 0; 124 } 125 126 static int fsi_spi_read_reg(struct fsi_spi *ctx, u32 offset, u64 *value) 127 { 128 int rc = 0; 129 __be32 cmd_be; 130 __be32 data_be; 131 u32 cmd = offset + ctx->base; 132 struct fsi2spi *bridge = ctx->bridge; 133 134 *value = 0ULL; 135 136 if (cmd & FSI2SPI_CMD_WRITE) 137 return -EINVAL; 138 139 rc = mutex_lock_interruptible(&bridge->lock); 140 if (rc) 141 return rc; 142 143 cmd_be = cpu_to_be32(cmd); 144 rc = fsi_device_write(bridge->fsi, FSI2SPI_CMD, &cmd_be, 145 sizeof(cmd_be)); 146 if (rc) 147 goto unlock; 148 149 rc = fsi_spi_check_status(ctx); 150 if (rc) 151 goto unlock; 152 153 rc = fsi_device_read(bridge->fsi, FSI2SPI_DATA0, &data_be, 154 sizeof(data_be)); 155 if (rc) 156 goto unlock; 157 158 *value |= (u64)be32_to_cpu(data_be) << 32; 159 160 rc = fsi_device_read(bridge->fsi, FSI2SPI_DATA1, &data_be, 161 sizeof(data_be)); 162 if (rc) 163 goto unlock; 164 165 *value |= (u64)be32_to_cpu(data_be); 166 dev_dbg(ctx->dev, "Read %02x[%016llx].\n", offset, *value); 167 168 unlock: 169 mutex_unlock(&bridge->lock); 170 return rc; 171 } 172 173 static int fsi_spi_write_reg(struct fsi_spi *ctx, u32 offset, u64 value) 174 { 175 int rc = 0; 176 __be32 cmd_be; 177 __be32 data_be; 178 u32 cmd = offset + ctx->base; 179 struct fsi2spi *bridge = ctx->bridge; 180 181 if (cmd & FSI2SPI_CMD_WRITE) 182 return -EINVAL; 183 184 rc = mutex_lock_interruptible(&bridge->lock); 185 if (rc) 186 return rc; 187 188 dev_dbg(ctx->dev, "Write %02x[%016llx].\n", offset, value); 189 190 data_be = cpu_to_be32(upper_32_bits(value)); 191 rc = fsi_device_write(bridge->fsi, FSI2SPI_DATA0, &data_be, 192 sizeof(data_be)); 193 if (rc) 194 goto unlock; 195 196 data_be = cpu_to_be32(lower_32_bits(value)); 197 rc = fsi_device_write(bridge->fsi, FSI2SPI_DATA1, &data_be, 198 sizeof(data_be)); 199 if (rc) 200 goto unlock; 201 202 cmd_be = cpu_to_be32(cmd | FSI2SPI_CMD_WRITE); 203 rc = fsi_device_write(bridge->fsi, FSI2SPI_CMD, &cmd_be, 204 sizeof(cmd_be)); 205 if (rc) 206 goto unlock; 207 208 rc = fsi_spi_check_status(ctx); 209 210 unlock: 211 mutex_unlock(&bridge->lock); 212 return rc; 213 } 214 215 static int fsi_spi_data_in(u64 in, u8 *rx, int len) 216 { 217 int i; 218 int num_bytes = min(len, 8); 219 220 for (i = 0; i < num_bytes; ++i) 221 rx[i] = (u8)(in >> (8 * ((num_bytes - 1) - i))); 222 223 return num_bytes; 224 } 225 226 static int fsi_spi_data_out(u64 *out, const u8 *tx, int len) 227 { 228 int i; 229 int num_bytes = min(len, 8); 230 u8 *out_bytes = (u8 *)out; 231 232 /* Unused bytes of the tx data should be 0. */ 233 *out = 0ULL; 234 235 for (i = 0; i < num_bytes; ++i) 236 out_bytes[8 - (i + 1)] = tx[i]; 237 238 return num_bytes; 239 } 240 241 static int fsi_spi_reset(struct fsi_spi *ctx) 242 { 243 int rc; 244 245 dev_dbg(ctx->dev, "Resetting SPI controller.\n"); 246 247 rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, 248 SPI_FSI_CLOCK_CFG_RESET1); 249 if (rc) 250 return rc; 251 252 rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, 253 SPI_FSI_CLOCK_CFG_RESET2); 254 if (rc) 255 return rc; 256 257 return fsi_spi_write_reg(ctx, SPI_FSI_STATUS, 0ULL); 258 } 259 260 static int fsi_spi_status(struct fsi_spi *ctx, u64 *status, const char *dir) 261 { 262 int rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS, status); 263 264 if (rc) 265 return rc; 266 267 if (*status & SPI_FSI_STATUS_ANY_ERROR) { 268 dev_err(ctx->dev, "%s error: %016llx\n", dir, *status); 269 270 rc = fsi_spi_reset(ctx); 271 if (rc) 272 return rc; 273 274 return -EREMOTEIO; 275 } 276 277 return 0; 278 } 279 280 static void fsi_spi_sequence_add(struct fsi_spi_sequence *seq, u8 val) 281 { 282 /* 283 * Add the next byte of instruction to the 8-byte sequence register. 284 * Then decrement the counter so that the next instruction will go in 285 * the right place. Return the index of the slot we just filled in the 286 * sequence register. 287 */ 288 seq->data |= (u64)val << seq->bit; 289 seq->bit -= 8; 290 } 291 292 static void fsi_spi_sequence_init(struct fsi_spi_sequence *seq) 293 { 294 seq->bit = 56; 295 seq->data = 0ULL; 296 } 297 298 static int fsi_spi_transfer_data(struct fsi_spi *ctx, 299 struct spi_transfer *transfer) 300 { 301 int rc = 0; 302 u64 status = 0ULL; 303 304 if (transfer->tx_buf) { 305 int nb; 306 int sent = 0; 307 u64 out = 0ULL; 308 const u8 *tx = transfer->tx_buf; 309 310 while (transfer->len > sent) { 311 nb = fsi_spi_data_out(&out, &tx[sent], 312 (int)transfer->len - sent); 313 314 rc = fsi_spi_write_reg(ctx, SPI_FSI_DATA_TX, out); 315 if (rc) 316 return rc; 317 318 do { 319 rc = fsi_spi_status(ctx, &status, "TX"); 320 if (rc) 321 return rc; 322 } while (status & SPI_FSI_STATUS_TDR_FULL); 323 324 sent += nb; 325 } 326 } else if (transfer->rx_buf) { 327 int recv = 0; 328 u64 in = 0ULL; 329 u8 *rx = transfer->rx_buf; 330 331 while (transfer->len > recv) { 332 do { 333 rc = fsi_spi_status(ctx, &status, "RX"); 334 if (rc) 335 return rc; 336 } while (!(status & SPI_FSI_STATUS_RDR_FULL)); 337 338 rc = fsi_spi_read_reg(ctx, SPI_FSI_DATA_RX, &in); 339 if (rc) 340 return rc; 341 342 recv += fsi_spi_data_in(in, &rx[recv], 343 (int)transfer->len - recv); 344 } 345 } 346 347 return 0; 348 } 349 350 static int fsi_spi_transfer_init(struct fsi_spi *ctx) 351 { 352 int rc; 353 bool reset = false; 354 unsigned long end; 355 u64 seq_state; 356 u64 clock_cfg = 0ULL; 357 u64 status = 0ULL; 358 u64 wanted_clock_cfg = SPI_FSI_CLOCK_CFG_ECC_DISABLE | 359 SPI_FSI_CLOCK_CFG_SCK_NO_DEL | 360 FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 19); 361 362 end = jiffies + msecs_to_jiffies(SPI_FSI_INIT_TIMEOUT_MS); 363 do { 364 if (time_after(jiffies, end)) 365 return -ETIMEDOUT; 366 367 rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS, &status); 368 if (rc) 369 return rc; 370 371 seq_state = status & SPI_FSI_STATUS_SEQ_STATE; 372 373 if (status & (SPI_FSI_STATUS_ANY_ERROR | 374 SPI_FSI_STATUS_TDR_FULL | 375 SPI_FSI_STATUS_RDR_FULL)) { 376 if (reset) { 377 dev_err(ctx->dev, 378 "Initialization error: %08llx\n", 379 status); 380 return -EIO; 381 } 382 383 rc = fsi_spi_reset(ctx); 384 if (rc) 385 return rc; 386 387 reset = true; 388 continue; 389 } 390 } while (seq_state && (seq_state != SPI_FSI_STATUS_SEQ_STATE_IDLE)); 391 392 rc = fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, 0ULL); 393 if (rc) 394 return rc; 395 396 rc = fsi_spi_read_reg(ctx, SPI_FSI_CLOCK_CFG, &clock_cfg); 397 if (rc) 398 return rc; 399 400 if ((clock_cfg & (SPI_FSI_CLOCK_CFG_MM_ENABLE | 401 SPI_FSI_CLOCK_CFG_ECC_DISABLE | 402 SPI_FSI_CLOCK_CFG_MODE | 403 SPI_FSI_CLOCK_CFG_SCK_RECV_DEL | 404 SPI_FSI_CLOCK_CFG_SCK_DIV)) != wanted_clock_cfg) 405 rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG, 406 wanted_clock_cfg); 407 408 return rc; 409 } 410 411 static int fsi_spi_transfer_one_message(struct spi_controller *ctlr, 412 struct spi_message *mesg) 413 { 414 int rc; 415 u8 seq_slave = SPI_FSI_SEQUENCE_SEL_SLAVE(mesg->spi->chip_select + 1); 416 unsigned int len; 417 struct spi_transfer *transfer; 418 struct fsi_spi *ctx = spi_controller_get_devdata(ctlr); 419 420 rc = fsi_spi_check_mux(ctx->bridge->fsi, ctx->dev); 421 if (rc) 422 goto error; 423 424 list_for_each_entry(transfer, &mesg->transfers, transfer_list) { 425 struct fsi_spi_sequence seq; 426 struct spi_transfer *next = NULL; 427 428 /* Sequencer must do shift out (tx) first. */ 429 if (!transfer->tx_buf || transfer->len > SPI_FSI_MAX_TX_SIZE) { 430 rc = -EINVAL; 431 goto error; 432 } 433 434 dev_dbg(ctx->dev, "Start tx of %d bytes.\n", transfer->len); 435 436 rc = fsi_spi_transfer_init(ctx); 437 if (rc < 0) 438 goto error; 439 440 fsi_spi_sequence_init(&seq); 441 fsi_spi_sequence_add(&seq, seq_slave); 442 443 len = transfer->len; 444 while (len > 8) { 445 fsi_spi_sequence_add(&seq, 446 SPI_FSI_SEQUENCE_SHIFT_OUT(8)); 447 len -= 8; 448 } 449 fsi_spi_sequence_add(&seq, SPI_FSI_SEQUENCE_SHIFT_OUT(len)); 450 451 if (!list_is_last(&transfer->transfer_list, 452 &mesg->transfers)) { 453 next = list_next_entry(transfer, transfer_list); 454 455 /* Sequencer can only do shift in (rx) after tx. */ 456 if (next->rx_buf) { 457 u8 shift; 458 459 if (next->len > SPI_FSI_MAX_RX_SIZE) { 460 rc = -EINVAL; 461 goto error; 462 } 463 464 dev_dbg(ctx->dev, "Sequence rx of %d bytes.\n", 465 next->len); 466 467 shift = SPI_FSI_SEQUENCE_SHIFT_IN(next->len); 468 fsi_spi_sequence_add(&seq, shift); 469 } else { 470 next = NULL; 471 } 472 } 473 474 fsi_spi_sequence_add(&seq, SPI_FSI_SEQUENCE_SEL_SLAVE(0)); 475 476 rc = fsi_spi_write_reg(ctx, SPI_FSI_SEQUENCE, seq.data); 477 if (rc) 478 goto error; 479 480 rc = fsi_spi_transfer_data(ctx, transfer); 481 if (rc) 482 goto error; 483 484 if (next) { 485 rc = fsi_spi_transfer_data(ctx, next); 486 if (rc) 487 goto error; 488 489 transfer = next; 490 } 491 } 492 493 error: 494 mesg->status = rc; 495 spi_finalize_current_message(ctlr); 496 497 return rc; 498 } 499 500 static size_t fsi_spi_max_transfer_size(struct spi_device *spi) 501 { 502 return SPI_FSI_MAX_RX_SIZE; 503 } 504 505 static int fsi_spi_probe(struct device *dev) 506 { 507 int rc; 508 struct device_node *np; 509 int num_controllers_registered = 0; 510 struct fsi2spi *bridge; 511 struct fsi_device *fsi = to_fsi_dev(dev); 512 513 rc = fsi_spi_check_mux(fsi, dev); 514 if (rc) 515 return -ENODEV; 516 517 bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL); 518 if (!bridge) 519 return -ENOMEM; 520 521 bridge->fsi = fsi; 522 mutex_init(&bridge->lock); 523 524 for_each_available_child_of_node(dev->of_node, np) { 525 u32 base; 526 struct fsi_spi *ctx; 527 struct spi_controller *ctlr; 528 529 if (of_property_read_u32(np, "reg", &base)) 530 continue; 531 532 ctlr = spi_alloc_master(dev, sizeof(*ctx)); 533 if (!ctlr) { 534 of_node_put(np); 535 break; 536 } 537 538 ctlr->dev.of_node = np; 539 ctlr->num_chipselect = of_get_available_child_count(np) ?: 1; 540 ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX; 541 ctlr->max_transfer_size = fsi_spi_max_transfer_size; 542 ctlr->transfer_one_message = fsi_spi_transfer_one_message; 543 544 ctx = spi_controller_get_devdata(ctlr); 545 ctx->dev = &ctlr->dev; 546 ctx->bridge = bridge; 547 ctx->base = base + SPI_FSI_BASE; 548 549 rc = devm_spi_register_controller(dev, ctlr); 550 if (rc) 551 spi_controller_put(ctlr); 552 else 553 num_controllers_registered++; 554 } 555 556 if (!num_controllers_registered) 557 return -ENODEV; 558 559 return 0; 560 } 561 562 static const struct fsi_device_id fsi_spi_ids[] = { 563 { FSI_ENGID_SPI, FSI_VERSION_ANY }, 564 { } 565 }; 566 MODULE_DEVICE_TABLE(fsi, fsi_spi_ids); 567 568 static struct fsi_driver fsi_spi_driver = { 569 .id_table = fsi_spi_ids, 570 .drv = { 571 .name = "spi-fsi", 572 .bus = &fsi_bus_type, 573 .probe = fsi_spi_probe, 574 }, 575 }; 576 module_fsi_driver(fsi_spi_driver); 577 578 MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>"); 579 MODULE_DESCRIPTION("FSI attached SPI controller"); 580 MODULE_LICENSE("GPL"); 581