1 // SPDX-License-Identifier: GPL-2.0-or-later 2 // SPI init/core code 3 // 4 // Copyright (C) 2005 David Brownell 5 // Copyright (C) 2008 Secret Lab Technologies Ltd. 6 7 #include <linux/acpi.h> 8 #include <linux/cache.h> 9 #include <linux/clk/clk-conf.h> 10 #include <linux/delay.h> 11 #include <linux/device.h> 12 #include <linux/dmaengine.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/export.h> 15 #include <linux/gpio/consumer.h> 16 #include <linux/highmem.h> 17 #include <linux/idr.h> 18 #include <linux/init.h> 19 #include <linux/ioport.h> 20 #include <linux/kernel.h> 21 #include <linux/kthread.h> 22 #include <linux/mod_devicetable.h> 23 #include <linux/mutex.h> 24 #include <linux/of_device.h> 25 #include <linux/of_irq.h> 26 #include <linux/percpu.h> 27 #include <linux/platform_data/x86/apple.h> 28 #include <linux/pm_domain.h> 29 #include <linux/pm_runtime.h> 30 #include <linux/property.h> 31 #include <linux/ptp_clock_kernel.h> 32 #include <linux/sched/rt.h> 33 #include <linux/slab.h> 34 #include <linux/spi/spi.h> 35 #include <linux/spi/spi-mem.h> 36 #include <uapi/linux/sched/types.h> 37 38 #define CREATE_TRACE_POINTS 39 #include <trace/events/spi.h> 40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start); 41 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop); 42 43 #include "internals.h" 44 45 static DEFINE_IDR(spi_master_idr); 46 47 static void spidev_release(struct device *dev) 48 { 49 struct spi_device *spi = to_spi_device(dev); 50 51 spi_controller_put(spi->controller); 52 kfree(spi->driver_override); 53 free_percpu(spi->pcpu_statistics); 54 kfree(spi); 55 } 56 57 static ssize_t 58 modalias_show(struct device *dev, struct device_attribute *a, char *buf) 59 { 60 const struct spi_device *spi = to_spi_device(dev); 61 int len; 62 63 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 64 if (len != -ENODEV) 65 return len; 66 67 return sysfs_emit(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); 68 } 69 static DEVICE_ATTR_RO(modalias); 70 71 static ssize_t driver_override_store(struct device *dev, 72 struct device_attribute *a, 73 const char *buf, size_t count) 74 { 75 struct spi_device *spi = to_spi_device(dev); 76 int ret; 77 78 ret = driver_set_override(dev, &spi->driver_override, buf, count); 79 if (ret) 80 return ret; 81 82 return count; 83 } 84 85 static ssize_t driver_override_show(struct device *dev, 86 struct device_attribute *a, char *buf) 87 { 88 const struct spi_device *spi = to_spi_device(dev); 89 ssize_t len; 90 91 device_lock(dev); 92 len = sysfs_emit(buf, "%s\n", spi->driver_override ? : ""); 93 device_unlock(dev); 94 return len; 95 } 96 static DEVICE_ATTR_RW(driver_override); 97 98 static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev) 99 { 100 struct spi_statistics __percpu *pcpu_stats; 101 102 if (dev) 103 pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics); 104 else 105 pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL); 106 107 if (pcpu_stats) { 108 int cpu; 109 110 for_each_possible_cpu(cpu) { 111 struct spi_statistics *stat; 112 113 stat = per_cpu_ptr(pcpu_stats, cpu); 114 u64_stats_init(&stat->syncp); 115 } 116 } 117 return pcpu_stats; 118 } 119 120 static ssize_t spi_emit_pcpu_stats(struct spi_statistics __percpu *stat, 121 char *buf, size_t offset) 122 { 123 u64 val = 0; 124 int i; 125 126 for_each_possible_cpu(i) { 127 const struct spi_statistics *pcpu_stats; 128 u64_stats_t *field; 129 unsigned int start; 130 u64 inc; 131 132 pcpu_stats = per_cpu_ptr(stat, i); 133 field = (void *)pcpu_stats + offset; 134 do { 135 start = u64_stats_fetch_begin(&pcpu_stats->syncp); 136 inc = u64_stats_read(field); 137 } while (u64_stats_fetch_retry(&pcpu_stats->syncp, start)); 138 val += inc; 139 } 140 return sysfs_emit(buf, "%llu\n", val); 141 } 142 143 #define SPI_STATISTICS_ATTRS(field, file) \ 144 static ssize_t spi_controller_##field##_show(struct device *dev, \ 145 struct device_attribute *attr, \ 146 char *buf) \ 147 { \ 148 struct spi_controller *ctlr = container_of(dev, \ 149 struct spi_controller, dev); \ 150 return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \ 151 } \ 152 static struct device_attribute dev_attr_spi_controller_##field = { \ 153 .attr = { .name = file, .mode = 0444 }, \ 154 .show = spi_controller_##field##_show, \ 155 }; \ 156 static ssize_t spi_device_##field##_show(struct device *dev, \ 157 struct device_attribute *attr, \ 158 char *buf) \ 159 { \ 160 struct spi_device *spi = to_spi_device(dev); \ 161 return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \ 162 } \ 163 static struct device_attribute dev_attr_spi_device_##field = { \ 164 .attr = { .name = file, .mode = 0444 }, \ 165 .show = spi_device_##field##_show, \ 166 } 167 168 #define SPI_STATISTICS_SHOW_NAME(name, file, field) \ 169 static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \ 170 char *buf) \ 171 { \ 172 return spi_emit_pcpu_stats(stat, buf, \ 173 offsetof(struct spi_statistics, field)); \ 174 } \ 175 SPI_STATISTICS_ATTRS(name, file) 176 177 #define SPI_STATISTICS_SHOW(field) \ 178 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ 179 field) 180 181 SPI_STATISTICS_SHOW(messages); 182 SPI_STATISTICS_SHOW(transfers); 183 SPI_STATISTICS_SHOW(errors); 184 SPI_STATISTICS_SHOW(timedout); 185 186 SPI_STATISTICS_SHOW(spi_sync); 187 SPI_STATISTICS_SHOW(spi_sync_immediate); 188 SPI_STATISTICS_SHOW(spi_async); 189 190 SPI_STATISTICS_SHOW(bytes); 191 SPI_STATISTICS_SHOW(bytes_rx); 192 SPI_STATISTICS_SHOW(bytes_tx); 193 194 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ 195 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ 196 "transfer_bytes_histo_" number, \ 197 transfer_bytes_histo[index]) 198 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); 199 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); 200 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); 201 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); 202 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); 203 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); 204 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); 205 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); 206 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); 207 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); 208 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); 209 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); 210 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); 211 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); 212 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); 213 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); 214 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); 215 216 SPI_STATISTICS_SHOW(transfers_split_maxsize); 217 218 static struct attribute *spi_dev_attrs[] = { 219 &dev_attr_modalias.attr, 220 &dev_attr_driver_override.attr, 221 NULL, 222 }; 223 224 static const struct attribute_group spi_dev_group = { 225 .attrs = spi_dev_attrs, 226 }; 227 228 static struct attribute *spi_device_statistics_attrs[] = { 229 &dev_attr_spi_device_messages.attr, 230 &dev_attr_spi_device_transfers.attr, 231 &dev_attr_spi_device_errors.attr, 232 &dev_attr_spi_device_timedout.attr, 233 &dev_attr_spi_device_spi_sync.attr, 234 &dev_attr_spi_device_spi_sync_immediate.attr, 235 &dev_attr_spi_device_spi_async.attr, 236 &dev_attr_spi_device_bytes.attr, 237 &dev_attr_spi_device_bytes_rx.attr, 238 &dev_attr_spi_device_bytes_tx.attr, 239 &dev_attr_spi_device_transfer_bytes_histo0.attr, 240 &dev_attr_spi_device_transfer_bytes_histo1.attr, 241 &dev_attr_spi_device_transfer_bytes_histo2.attr, 242 &dev_attr_spi_device_transfer_bytes_histo3.attr, 243 &dev_attr_spi_device_transfer_bytes_histo4.attr, 244 &dev_attr_spi_device_transfer_bytes_histo5.attr, 245 &dev_attr_spi_device_transfer_bytes_histo6.attr, 246 &dev_attr_spi_device_transfer_bytes_histo7.attr, 247 &dev_attr_spi_device_transfer_bytes_histo8.attr, 248 &dev_attr_spi_device_transfer_bytes_histo9.attr, 249 &dev_attr_spi_device_transfer_bytes_histo10.attr, 250 &dev_attr_spi_device_transfer_bytes_histo11.attr, 251 &dev_attr_spi_device_transfer_bytes_histo12.attr, 252 &dev_attr_spi_device_transfer_bytes_histo13.attr, 253 &dev_attr_spi_device_transfer_bytes_histo14.attr, 254 &dev_attr_spi_device_transfer_bytes_histo15.attr, 255 &dev_attr_spi_device_transfer_bytes_histo16.attr, 256 &dev_attr_spi_device_transfers_split_maxsize.attr, 257 NULL, 258 }; 259 260 static const struct attribute_group spi_device_statistics_group = { 261 .name = "statistics", 262 .attrs = spi_device_statistics_attrs, 263 }; 264 265 static const struct attribute_group *spi_dev_groups[] = { 266 &spi_dev_group, 267 &spi_device_statistics_group, 268 NULL, 269 }; 270 271 static struct attribute *spi_controller_statistics_attrs[] = { 272 &dev_attr_spi_controller_messages.attr, 273 &dev_attr_spi_controller_transfers.attr, 274 &dev_attr_spi_controller_errors.attr, 275 &dev_attr_spi_controller_timedout.attr, 276 &dev_attr_spi_controller_spi_sync.attr, 277 &dev_attr_spi_controller_spi_sync_immediate.attr, 278 &dev_attr_spi_controller_spi_async.attr, 279 &dev_attr_spi_controller_bytes.attr, 280 &dev_attr_spi_controller_bytes_rx.attr, 281 &dev_attr_spi_controller_bytes_tx.attr, 282 &dev_attr_spi_controller_transfer_bytes_histo0.attr, 283 &dev_attr_spi_controller_transfer_bytes_histo1.attr, 284 &dev_attr_spi_controller_transfer_bytes_histo2.attr, 285 &dev_attr_spi_controller_transfer_bytes_histo3.attr, 286 &dev_attr_spi_controller_transfer_bytes_histo4.attr, 287 &dev_attr_spi_controller_transfer_bytes_histo5.attr, 288 &dev_attr_spi_controller_transfer_bytes_histo6.attr, 289 &dev_attr_spi_controller_transfer_bytes_histo7.attr, 290 &dev_attr_spi_controller_transfer_bytes_histo8.attr, 291 &dev_attr_spi_controller_transfer_bytes_histo9.attr, 292 &dev_attr_spi_controller_transfer_bytes_histo10.attr, 293 &dev_attr_spi_controller_transfer_bytes_histo11.attr, 294 &dev_attr_spi_controller_transfer_bytes_histo12.attr, 295 &dev_attr_spi_controller_transfer_bytes_histo13.attr, 296 &dev_attr_spi_controller_transfer_bytes_histo14.attr, 297 &dev_attr_spi_controller_transfer_bytes_histo15.attr, 298 &dev_attr_spi_controller_transfer_bytes_histo16.attr, 299 &dev_attr_spi_controller_transfers_split_maxsize.attr, 300 NULL, 301 }; 302 303 static const struct attribute_group spi_controller_statistics_group = { 304 .name = "statistics", 305 .attrs = spi_controller_statistics_attrs, 306 }; 307 308 static const struct attribute_group *spi_master_groups[] = { 309 &spi_controller_statistics_group, 310 NULL, 311 }; 312 313 static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats, 314 struct spi_transfer *xfer, 315 struct spi_controller *ctlr) 316 { 317 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; 318 struct spi_statistics *stats; 319 320 if (l2len < 0) 321 l2len = 0; 322 323 get_cpu(); 324 stats = this_cpu_ptr(pcpu_stats); 325 u64_stats_update_begin(&stats->syncp); 326 327 u64_stats_inc(&stats->transfers); 328 u64_stats_inc(&stats->transfer_bytes_histo[l2len]); 329 330 u64_stats_add(&stats->bytes, xfer->len); 331 if ((xfer->tx_buf) && 332 (xfer->tx_buf != ctlr->dummy_tx)) 333 u64_stats_add(&stats->bytes_tx, xfer->len); 334 if ((xfer->rx_buf) && 335 (xfer->rx_buf != ctlr->dummy_rx)) 336 u64_stats_add(&stats->bytes_rx, xfer->len); 337 338 u64_stats_update_end(&stats->syncp); 339 put_cpu(); 340 } 341 342 /* 343 * modalias support makes "modprobe $MODALIAS" new-style hotplug work, 344 * and the sysfs version makes coldplug work too. 345 */ 346 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name) 347 { 348 while (id->name[0]) { 349 if (!strcmp(name, id->name)) 350 return id; 351 id++; 352 } 353 return NULL; 354 } 355 356 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) 357 { 358 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); 359 360 return spi_match_id(sdrv->id_table, sdev->modalias); 361 } 362 EXPORT_SYMBOL_GPL(spi_get_device_id); 363 364 const void *spi_get_device_match_data(const struct spi_device *sdev) 365 { 366 const void *match; 367 368 match = device_get_match_data(&sdev->dev); 369 if (match) 370 return match; 371 372 return (const void *)spi_get_device_id(sdev)->driver_data; 373 } 374 EXPORT_SYMBOL_GPL(spi_get_device_match_data); 375 376 static int spi_match_device(struct device *dev, struct device_driver *drv) 377 { 378 const struct spi_device *spi = to_spi_device(dev); 379 const struct spi_driver *sdrv = to_spi_driver(drv); 380 381 /* Check override first, and if set, only use the named driver */ 382 if (spi->driver_override) 383 return strcmp(spi->driver_override, drv->name) == 0; 384 385 /* Attempt an OF style match */ 386 if (of_driver_match_device(dev, drv)) 387 return 1; 388 389 /* Then try ACPI */ 390 if (acpi_driver_match_device(dev, drv)) 391 return 1; 392 393 if (sdrv->id_table) 394 return !!spi_match_id(sdrv->id_table, spi->modalias); 395 396 return strcmp(spi->modalias, drv->name) == 0; 397 } 398 399 static int spi_uevent(const struct device *dev, struct kobj_uevent_env *env) 400 { 401 const struct spi_device *spi = to_spi_device(dev); 402 int rc; 403 404 rc = acpi_device_uevent_modalias(dev, env); 405 if (rc != -ENODEV) 406 return rc; 407 408 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); 409 } 410 411 static int spi_probe(struct device *dev) 412 { 413 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 414 struct spi_device *spi = to_spi_device(dev); 415 int ret; 416 417 ret = of_clk_set_defaults(dev->of_node, false); 418 if (ret) 419 return ret; 420 421 if (dev->of_node) { 422 spi->irq = of_irq_get(dev->of_node, 0); 423 if (spi->irq == -EPROBE_DEFER) 424 return -EPROBE_DEFER; 425 if (spi->irq < 0) 426 spi->irq = 0; 427 } 428 429 ret = dev_pm_domain_attach(dev, true); 430 if (ret) 431 return ret; 432 433 if (sdrv->probe) { 434 ret = sdrv->probe(spi); 435 if (ret) 436 dev_pm_domain_detach(dev, true); 437 } 438 439 return ret; 440 } 441 442 static void spi_remove(struct device *dev) 443 { 444 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 445 446 if (sdrv->remove) 447 sdrv->remove(to_spi_device(dev)); 448 449 dev_pm_domain_detach(dev, true); 450 } 451 452 static void spi_shutdown(struct device *dev) 453 { 454 if (dev->driver) { 455 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 456 457 if (sdrv->shutdown) 458 sdrv->shutdown(to_spi_device(dev)); 459 } 460 } 461 462 const struct bus_type spi_bus_type = { 463 .name = "spi", 464 .dev_groups = spi_dev_groups, 465 .match = spi_match_device, 466 .uevent = spi_uevent, 467 .probe = spi_probe, 468 .remove = spi_remove, 469 .shutdown = spi_shutdown, 470 }; 471 EXPORT_SYMBOL_GPL(spi_bus_type); 472 473 /** 474 * __spi_register_driver - register a SPI driver 475 * @owner: owner module of the driver to register 476 * @sdrv: the driver to register 477 * Context: can sleep 478 * 479 * Return: zero on success, else a negative error code. 480 */ 481 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) 482 { 483 sdrv->driver.owner = owner; 484 sdrv->driver.bus = &spi_bus_type; 485 486 /* 487 * For Really Good Reasons we use spi: modaliases not of: 488 * modaliases for DT so module autoloading won't work if we 489 * don't have a spi_device_id as well as a compatible string. 490 */ 491 if (sdrv->driver.of_match_table) { 492 const struct of_device_id *of_id; 493 494 for (of_id = sdrv->driver.of_match_table; of_id->compatible[0]; 495 of_id++) { 496 const char *of_name; 497 498 /* Strip off any vendor prefix */ 499 of_name = strnchr(of_id->compatible, 500 sizeof(of_id->compatible), ','); 501 if (of_name) 502 of_name++; 503 else 504 of_name = of_id->compatible; 505 506 if (sdrv->id_table) { 507 const struct spi_device_id *spi_id; 508 509 spi_id = spi_match_id(sdrv->id_table, of_name); 510 if (spi_id) 511 continue; 512 } else { 513 if (strcmp(sdrv->driver.name, of_name) == 0) 514 continue; 515 } 516 517 pr_warn("SPI driver %s has no spi_device_id for %s\n", 518 sdrv->driver.name, of_id->compatible); 519 } 520 } 521 522 return driver_register(&sdrv->driver); 523 } 524 EXPORT_SYMBOL_GPL(__spi_register_driver); 525 526 /*-------------------------------------------------------------------------*/ 527 528 /* 529 * SPI devices should normally not be created by SPI device drivers; that 530 * would make them board-specific. Similarly with SPI controller drivers. 531 * Device registration normally goes into like arch/.../mach.../board-YYY.c 532 * with other readonly (flashable) information about mainboard devices. 533 */ 534 535 struct boardinfo { 536 struct list_head list; 537 struct spi_board_info board_info; 538 }; 539 540 static LIST_HEAD(board_list); 541 static LIST_HEAD(spi_controller_list); 542 543 /* 544 * Used to protect add/del operation for board_info list and 545 * spi_controller list, and their matching process also used 546 * to protect object of type struct idr. 547 */ 548 static DEFINE_MUTEX(board_lock); 549 550 /** 551 * spi_alloc_device - Allocate a new SPI device 552 * @ctlr: Controller to which device is connected 553 * Context: can sleep 554 * 555 * Allows a driver to allocate and initialize a spi_device without 556 * registering it immediately. This allows a driver to directly 557 * fill the spi_device with device parameters before calling 558 * spi_add_device() on it. 559 * 560 * Caller is responsible to call spi_add_device() on the returned 561 * spi_device structure to add it to the SPI controller. If the caller 562 * needs to discard the spi_device without adding it, then it should 563 * call spi_dev_put() on it. 564 * 565 * Return: a pointer to the new device, or NULL. 566 */ 567 struct spi_device *spi_alloc_device(struct spi_controller *ctlr) 568 { 569 struct spi_device *spi; 570 571 if (!spi_controller_get(ctlr)) 572 return NULL; 573 574 spi = kzalloc(sizeof(*spi), GFP_KERNEL); 575 if (!spi) { 576 spi_controller_put(ctlr); 577 return NULL; 578 } 579 580 spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL); 581 if (!spi->pcpu_statistics) { 582 kfree(spi); 583 spi_controller_put(ctlr); 584 return NULL; 585 } 586 587 spi->controller = ctlr; 588 spi->dev.parent = &ctlr->dev; 589 spi->dev.bus = &spi_bus_type; 590 spi->dev.release = spidev_release; 591 spi->mode = ctlr->buswidth_override_bits; 592 593 device_initialize(&spi->dev); 594 return spi; 595 } 596 EXPORT_SYMBOL_GPL(spi_alloc_device); 597 598 static void spi_dev_set_name(struct spi_device *spi) 599 { 600 struct acpi_device *adev = ACPI_COMPANION(&spi->dev); 601 602 if (adev) { 603 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); 604 return; 605 } 606 607 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev), 608 spi_get_chipselect(spi, 0)); 609 } 610 611 /* 612 * Zero(0) is a valid physical CS value and can be located at any 613 * logical CS in the spi->chip_select[]. If all the physical CS 614 * are initialized to 0 then It would be difficult to differentiate 615 * between a valid physical CS 0 & an unused logical CS whose physical 616 * CS can be 0. As a solution to this issue initialize all the CS to -1. 617 * Now all the unused logical CS will have -1 physical CS value & can be 618 * ignored while performing physical CS validity checks. 619 */ 620 #define SPI_INVALID_CS ((s8)-1) 621 622 static inline bool is_valid_cs(s8 chip_select) 623 { 624 return chip_select != SPI_INVALID_CS; 625 } 626 627 static inline int spi_dev_check_cs(struct device *dev, 628 struct spi_device *spi, u8 idx, 629 struct spi_device *new_spi, u8 new_idx) 630 { 631 u8 cs, cs_new; 632 u8 idx_new; 633 634 cs = spi_get_chipselect(spi, idx); 635 for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) { 636 cs_new = spi_get_chipselect(new_spi, idx_new); 637 if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) { 638 dev_err(dev, "chipselect %u already in use\n", cs_new); 639 return -EBUSY; 640 } 641 } 642 return 0; 643 } 644 645 static int spi_dev_check(struct device *dev, void *data) 646 { 647 struct spi_device *spi = to_spi_device(dev); 648 struct spi_device *new_spi = data; 649 int status, idx; 650 651 if (spi->controller == new_spi->controller) { 652 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { 653 status = spi_dev_check_cs(dev, spi, idx, new_spi, 0); 654 if (status) 655 return status; 656 } 657 } 658 return 0; 659 } 660 661 static void spi_cleanup(struct spi_device *spi) 662 { 663 if (spi->controller->cleanup) 664 spi->controller->cleanup(spi); 665 } 666 667 static int __spi_add_device(struct spi_device *spi) 668 { 669 struct spi_controller *ctlr = spi->controller; 670 struct device *dev = ctlr->dev.parent; 671 int status, idx; 672 u8 cs; 673 674 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { 675 /* Chipselects are numbered 0..max; validate. */ 676 cs = spi_get_chipselect(spi, idx); 677 if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) { 678 dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx), 679 ctlr->num_chipselect); 680 return -EINVAL; 681 } 682 } 683 684 /* 685 * Make sure that multiple logical CS doesn't map to the same physical CS. 686 * For example, spi->chip_select[0] != spi->chip_select[1] and so on. 687 */ 688 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { 689 status = spi_dev_check_cs(dev, spi, idx, spi, idx + 1); 690 if (status) 691 return status; 692 } 693 694 /* Set the bus ID string */ 695 spi_dev_set_name(spi); 696 697 /* 698 * We need to make sure there's no other device with this 699 * chipselect **BEFORE** we call setup(), else we'll trash 700 * its configuration. 701 */ 702 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); 703 if (status) 704 return status; 705 706 /* Controller may unregister concurrently */ 707 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && 708 !device_is_registered(&ctlr->dev)) { 709 return -ENODEV; 710 } 711 712 if (ctlr->cs_gpiods) { 713 u8 cs; 714 715 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { 716 cs = spi_get_chipselect(spi, idx); 717 if (is_valid_cs(cs)) 718 spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]); 719 } 720 } 721 722 /* 723 * Drivers may modify this initial i/o setup, but will 724 * normally rely on the device being setup. Devices 725 * using SPI_CS_HIGH can't coexist well otherwise... 726 */ 727 status = spi_setup(spi); 728 if (status < 0) { 729 dev_err(dev, "can't setup %s, status %d\n", 730 dev_name(&spi->dev), status); 731 return status; 732 } 733 734 /* Device may be bound to an active driver when this returns */ 735 status = device_add(&spi->dev); 736 if (status < 0) { 737 dev_err(dev, "can't add %s, status %d\n", 738 dev_name(&spi->dev), status); 739 spi_cleanup(spi); 740 } else { 741 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); 742 } 743 744 return status; 745 } 746 747 /** 748 * spi_add_device - Add spi_device allocated with spi_alloc_device 749 * @spi: spi_device to register 750 * 751 * Companion function to spi_alloc_device. Devices allocated with 752 * spi_alloc_device can be added onto the SPI bus with this function. 753 * 754 * Return: 0 on success; negative errno on failure 755 */ 756 int spi_add_device(struct spi_device *spi) 757 { 758 struct spi_controller *ctlr = spi->controller; 759 int status; 760 761 /* Set the bus ID string */ 762 spi_dev_set_name(spi); 763 764 mutex_lock(&ctlr->add_lock); 765 status = __spi_add_device(spi); 766 mutex_unlock(&ctlr->add_lock); 767 return status; 768 } 769 EXPORT_SYMBOL_GPL(spi_add_device); 770 771 static void spi_set_all_cs_unused(struct spi_device *spi) 772 { 773 u8 idx; 774 775 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) 776 spi_set_chipselect(spi, idx, SPI_INVALID_CS); 777 } 778 779 /** 780 * spi_new_device - instantiate one new SPI device 781 * @ctlr: Controller to which device is connected 782 * @chip: Describes the SPI device 783 * Context: can sleep 784 * 785 * On typical mainboards, this is purely internal; and it's not needed 786 * after board init creates the hard-wired devices. Some development 787 * platforms may not be able to use spi_register_board_info though, and 788 * this is exported so that for example a USB or parport based adapter 789 * driver could add devices (which it would learn about out-of-band). 790 * 791 * Return: the new device, or NULL. 792 */ 793 struct spi_device *spi_new_device(struct spi_controller *ctlr, 794 struct spi_board_info *chip) 795 { 796 struct spi_device *proxy; 797 int status; 798 799 /* 800 * NOTE: caller did any chip->bus_num checks necessary. 801 * 802 * Also, unless we change the return value convention to use 803 * error-or-pointer (not NULL-or-pointer), troubleshootability 804 * suggests syslogged diagnostics are best here (ugh). 805 */ 806 807 proxy = spi_alloc_device(ctlr); 808 if (!proxy) 809 return NULL; 810 811 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); 812 813 /* Use provided chip-select for proxy device */ 814 spi_set_all_cs_unused(proxy); 815 spi_set_chipselect(proxy, 0, chip->chip_select); 816 817 proxy->max_speed_hz = chip->max_speed_hz; 818 proxy->mode = chip->mode; 819 proxy->irq = chip->irq; 820 strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); 821 proxy->dev.platform_data = (void *) chip->platform_data; 822 proxy->controller_data = chip->controller_data; 823 proxy->controller_state = NULL; 824 /* 825 * spi->chip_select[i] gives the corresponding physical CS for logical CS i 826 * logical CS number is represented by setting the ith bit in spi->cs_index_mask 827 * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and 828 * spi->chip_select[0] will give the physical CS. 829 * By default spi->chip_select[0] will hold the physical CS number so, set 830 * spi->cs_index_mask as 0x01. 831 */ 832 proxy->cs_index_mask = 0x01; 833 834 if (chip->swnode) { 835 status = device_add_software_node(&proxy->dev, chip->swnode); 836 if (status) { 837 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n", 838 chip->modalias, status); 839 goto err_dev_put; 840 } 841 } 842 843 status = spi_add_device(proxy); 844 if (status < 0) 845 goto err_dev_put; 846 847 return proxy; 848 849 err_dev_put: 850 device_remove_software_node(&proxy->dev); 851 spi_dev_put(proxy); 852 return NULL; 853 } 854 EXPORT_SYMBOL_GPL(spi_new_device); 855 856 /** 857 * spi_unregister_device - unregister a single SPI device 858 * @spi: spi_device to unregister 859 * 860 * Start making the passed SPI device vanish. Normally this would be handled 861 * by spi_unregister_controller(). 862 */ 863 void spi_unregister_device(struct spi_device *spi) 864 { 865 if (!spi) 866 return; 867 868 if (spi->dev.of_node) { 869 of_node_clear_flag(spi->dev.of_node, OF_POPULATED); 870 of_node_put(spi->dev.of_node); 871 } 872 if (ACPI_COMPANION(&spi->dev)) 873 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); 874 device_remove_software_node(&spi->dev); 875 device_del(&spi->dev); 876 spi_cleanup(spi); 877 put_device(&spi->dev); 878 } 879 EXPORT_SYMBOL_GPL(spi_unregister_device); 880 881 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr, 882 struct spi_board_info *bi) 883 { 884 struct spi_device *dev; 885 886 if (ctlr->bus_num != bi->bus_num) 887 return; 888 889 dev = spi_new_device(ctlr, bi); 890 if (!dev) 891 dev_err(ctlr->dev.parent, "can't create new device for %s\n", 892 bi->modalias); 893 } 894 895 /** 896 * spi_register_board_info - register SPI devices for a given board 897 * @info: array of chip descriptors 898 * @n: how many descriptors are provided 899 * Context: can sleep 900 * 901 * Board-specific early init code calls this (probably during arch_initcall) 902 * with segments of the SPI device table. Any device nodes are created later, 903 * after the relevant parent SPI controller (bus_num) is defined. We keep 904 * this table of devices forever, so that reloading a controller driver will 905 * not make Linux forget about these hard-wired devices. 906 * 907 * Other code can also call this, e.g. a particular add-on board might provide 908 * SPI devices through its expansion connector, so code initializing that board 909 * would naturally declare its SPI devices. 910 * 911 * The board info passed can safely be __initdata ... but be careful of 912 * any embedded pointers (platform_data, etc), they're copied as-is. 913 * 914 * Return: zero on success, else a negative error code. 915 */ 916 int spi_register_board_info(struct spi_board_info const *info, unsigned n) 917 { 918 struct boardinfo *bi; 919 int i; 920 921 if (!n) 922 return 0; 923 924 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL); 925 if (!bi) 926 return -ENOMEM; 927 928 for (i = 0; i < n; i++, bi++, info++) { 929 struct spi_controller *ctlr; 930 931 memcpy(&bi->board_info, info, sizeof(*info)); 932 933 mutex_lock(&board_lock); 934 list_add_tail(&bi->list, &board_list); 935 list_for_each_entry(ctlr, &spi_controller_list, list) 936 spi_match_controller_to_boardinfo(ctlr, 937 &bi->board_info); 938 mutex_unlock(&board_lock); 939 } 940 941 return 0; 942 } 943 944 /*-------------------------------------------------------------------------*/ 945 946 /* Core methods for SPI resource management */ 947 948 /** 949 * spi_res_alloc - allocate a spi resource that is life-cycle managed 950 * during the processing of a spi_message while using 951 * spi_transfer_one 952 * @spi: the SPI device for which we allocate memory 953 * @release: the release code to execute for this resource 954 * @size: size to alloc and return 955 * @gfp: GFP allocation flags 956 * 957 * Return: the pointer to the allocated data 958 * 959 * This may get enhanced in the future to allocate from a memory pool 960 * of the @spi_device or @spi_controller to avoid repeated allocations. 961 */ 962 static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release, 963 size_t size, gfp_t gfp) 964 { 965 struct spi_res *sres; 966 967 sres = kzalloc(sizeof(*sres) + size, gfp); 968 if (!sres) 969 return NULL; 970 971 INIT_LIST_HEAD(&sres->entry); 972 sres->release = release; 973 974 return sres->data; 975 } 976 977 /** 978 * spi_res_free - free an SPI resource 979 * @res: pointer to the custom data of a resource 980 */ 981 static void spi_res_free(void *res) 982 { 983 struct spi_res *sres = container_of(res, struct spi_res, data); 984 985 if (!res) 986 return; 987 988 WARN_ON(!list_empty(&sres->entry)); 989 kfree(sres); 990 } 991 992 /** 993 * spi_res_add - add a spi_res to the spi_message 994 * @message: the SPI message 995 * @res: the spi_resource 996 */ 997 static void spi_res_add(struct spi_message *message, void *res) 998 { 999 struct spi_res *sres = container_of(res, struct spi_res, data); 1000 1001 WARN_ON(!list_empty(&sres->entry)); 1002 list_add_tail(&sres->entry, &message->resources); 1003 } 1004 1005 /** 1006 * spi_res_release - release all SPI resources for this message 1007 * @ctlr: the @spi_controller 1008 * @message: the @spi_message 1009 */ 1010 static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) 1011 { 1012 struct spi_res *res, *tmp; 1013 1014 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) { 1015 if (res->release) 1016 res->release(ctlr, message, res->data); 1017 1018 list_del(&res->entry); 1019 1020 kfree(res); 1021 } 1022 } 1023 1024 /*-------------------------------------------------------------------------*/ 1025 static inline bool spi_is_last_cs(struct spi_device *spi) 1026 { 1027 u8 idx; 1028 bool last = false; 1029 1030 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { 1031 if (spi->cs_index_mask & BIT(idx)) { 1032 if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx)) 1033 last = true; 1034 } 1035 } 1036 return last; 1037 } 1038 1039 1040 static void spi_set_cs(struct spi_device *spi, bool enable, bool force) 1041 { 1042 bool activate = enable; 1043 u8 idx; 1044 1045 /* 1046 * Avoid calling into the driver (or doing delays) if the chip select 1047 * isn't actually changing from the last time this was called. 1048 */ 1049 if (!force && ((enable && spi->controller->last_cs_index_mask == spi->cs_index_mask && 1050 spi_is_last_cs(spi)) || 1051 (!enable && spi->controller->last_cs_index_mask == spi->cs_index_mask && 1052 !spi_is_last_cs(spi))) && 1053 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) 1054 return; 1055 1056 trace_spi_set_cs(spi, activate); 1057 1058 spi->controller->last_cs_index_mask = spi->cs_index_mask; 1059 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) 1060 spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS; 1061 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; 1062 1063 if (spi->mode & SPI_CS_HIGH) 1064 enable = !enable; 1065 1066 if (spi_is_csgpiod(spi)) { 1067 if (!spi->controller->set_cs_timing && !activate) 1068 spi_delay_exec(&spi->cs_hold, NULL); 1069 1070 if (!(spi->mode & SPI_NO_CS)) { 1071 /* 1072 * Historically ACPI has no means of the GPIO polarity and 1073 * thus the SPISerialBus() resource defines it on the per-chip 1074 * basis. In order to avoid a chain of negations, the GPIO 1075 * polarity is considered being Active High. Even for the cases 1076 * when _DSD() is involved (in the updated versions of ACPI) 1077 * the GPIO CS polarity must be defined Active High to avoid 1078 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH 1079 * into account. 1080 */ 1081 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { 1082 if ((spi->cs_index_mask & BIT(idx)) && spi_get_csgpiod(spi, idx)) { 1083 if (has_acpi_companion(&spi->dev)) 1084 gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), 1085 !enable); 1086 else 1087 /* Polarity handled by GPIO library */ 1088 gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), 1089 activate); 1090 1091 if (activate) 1092 spi_delay_exec(&spi->cs_setup, NULL); 1093 else 1094 spi_delay_exec(&spi->cs_inactive, NULL); 1095 } 1096 } 1097 } 1098 /* Some SPI masters need both GPIO CS & slave_select */ 1099 if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) && 1100 spi->controller->set_cs) 1101 spi->controller->set_cs(spi, !enable); 1102 1103 if (!spi->controller->set_cs_timing) { 1104 if (activate) 1105 spi_delay_exec(&spi->cs_setup, NULL); 1106 else 1107 spi_delay_exec(&spi->cs_inactive, NULL); 1108 } 1109 } else if (spi->controller->set_cs) { 1110 spi->controller->set_cs(spi, !enable); 1111 } 1112 } 1113 1114 #ifdef CONFIG_HAS_DMA 1115 static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev, 1116 struct sg_table *sgt, void *buf, size_t len, 1117 enum dma_data_direction dir, unsigned long attrs) 1118 { 1119 const bool vmalloced_buf = is_vmalloc_addr(buf); 1120 unsigned int max_seg_size = dma_get_max_seg_size(dev); 1121 #ifdef CONFIG_HIGHMEM 1122 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && 1123 (unsigned long)buf < (PKMAP_BASE + 1124 (LAST_PKMAP * PAGE_SIZE))); 1125 #else 1126 const bool kmap_buf = false; 1127 #endif 1128 int desc_len; 1129 int sgs; 1130 struct page *vm_page; 1131 struct scatterlist *sg; 1132 void *sg_buf; 1133 size_t min; 1134 int i, ret; 1135 1136 if (vmalloced_buf || kmap_buf) { 1137 desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE); 1138 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); 1139 } else if (virt_addr_valid(buf)) { 1140 desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len); 1141 sgs = DIV_ROUND_UP(len, desc_len); 1142 } else { 1143 return -EINVAL; 1144 } 1145 1146 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); 1147 if (ret != 0) 1148 return ret; 1149 1150 sg = &sgt->sgl[0]; 1151 for (i = 0; i < sgs; i++) { 1152 1153 if (vmalloced_buf || kmap_buf) { 1154 /* 1155 * Next scatterlist entry size is the minimum between 1156 * the desc_len and the remaining buffer length that 1157 * fits in a page. 1158 */ 1159 min = min_t(size_t, desc_len, 1160 min_t(size_t, len, 1161 PAGE_SIZE - offset_in_page(buf))); 1162 if (vmalloced_buf) 1163 vm_page = vmalloc_to_page(buf); 1164 else 1165 vm_page = kmap_to_page(buf); 1166 if (!vm_page) { 1167 sg_free_table(sgt); 1168 return -ENOMEM; 1169 } 1170 sg_set_page(sg, vm_page, 1171 min, offset_in_page(buf)); 1172 } else { 1173 min = min_t(size_t, len, desc_len); 1174 sg_buf = buf; 1175 sg_set_buf(sg, sg_buf, min); 1176 } 1177 1178 buf += min; 1179 len -= min; 1180 sg = sg_next(sg); 1181 } 1182 1183 ret = dma_map_sgtable(dev, sgt, dir, attrs); 1184 if (ret < 0) { 1185 sg_free_table(sgt); 1186 return ret; 1187 } 1188 1189 return 0; 1190 } 1191 1192 int spi_map_buf(struct spi_controller *ctlr, struct device *dev, 1193 struct sg_table *sgt, void *buf, size_t len, 1194 enum dma_data_direction dir) 1195 { 1196 return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0); 1197 } 1198 1199 static void spi_unmap_buf_attrs(struct spi_controller *ctlr, 1200 struct device *dev, struct sg_table *sgt, 1201 enum dma_data_direction dir, 1202 unsigned long attrs) 1203 { 1204 if (sgt->orig_nents) { 1205 dma_unmap_sgtable(dev, sgt, dir, attrs); 1206 sg_free_table(sgt); 1207 sgt->orig_nents = 0; 1208 sgt->nents = 0; 1209 } 1210 } 1211 1212 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, 1213 struct sg_table *sgt, enum dma_data_direction dir) 1214 { 1215 spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0); 1216 } 1217 1218 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) 1219 { 1220 struct device *tx_dev, *rx_dev; 1221 struct spi_transfer *xfer; 1222 int ret; 1223 1224 if (!ctlr->can_dma) 1225 return 0; 1226 1227 if (ctlr->dma_tx) 1228 tx_dev = ctlr->dma_tx->device->dev; 1229 else if (ctlr->dma_map_dev) 1230 tx_dev = ctlr->dma_map_dev; 1231 else 1232 tx_dev = ctlr->dev.parent; 1233 1234 if (ctlr->dma_rx) 1235 rx_dev = ctlr->dma_rx->device->dev; 1236 else if (ctlr->dma_map_dev) 1237 rx_dev = ctlr->dma_map_dev; 1238 else 1239 rx_dev = ctlr->dev.parent; 1240 1241 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1242 /* The sync is done before each transfer. */ 1243 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; 1244 1245 if (!ctlr->can_dma(ctlr, msg->spi, xfer)) 1246 continue; 1247 1248 if (xfer->tx_buf != NULL) { 1249 ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, 1250 (void *)xfer->tx_buf, 1251 xfer->len, DMA_TO_DEVICE, 1252 attrs); 1253 if (ret != 0) 1254 return ret; 1255 } 1256 1257 if (xfer->rx_buf != NULL) { 1258 ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg, 1259 xfer->rx_buf, xfer->len, 1260 DMA_FROM_DEVICE, attrs); 1261 if (ret != 0) { 1262 spi_unmap_buf_attrs(ctlr, tx_dev, 1263 &xfer->tx_sg, DMA_TO_DEVICE, 1264 attrs); 1265 1266 return ret; 1267 } 1268 } 1269 } 1270 1271 ctlr->cur_rx_dma_dev = rx_dev; 1272 ctlr->cur_tx_dma_dev = tx_dev; 1273 ctlr->cur_msg_mapped = true; 1274 1275 return 0; 1276 } 1277 1278 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) 1279 { 1280 struct device *rx_dev = ctlr->cur_rx_dma_dev; 1281 struct device *tx_dev = ctlr->cur_tx_dma_dev; 1282 struct spi_transfer *xfer; 1283 1284 if (!ctlr->cur_msg_mapped || !ctlr->can_dma) 1285 return 0; 1286 1287 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1288 /* The sync has already been done after each transfer. */ 1289 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; 1290 1291 if (!ctlr->can_dma(ctlr, msg->spi, xfer)) 1292 continue; 1293 1294 spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg, 1295 DMA_FROM_DEVICE, attrs); 1296 spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, 1297 DMA_TO_DEVICE, attrs); 1298 } 1299 1300 ctlr->cur_msg_mapped = false; 1301 1302 return 0; 1303 } 1304 1305 static void spi_dma_sync_for_device(struct spi_controller *ctlr, 1306 struct spi_transfer *xfer) 1307 { 1308 struct device *rx_dev = ctlr->cur_rx_dma_dev; 1309 struct device *tx_dev = ctlr->cur_tx_dma_dev; 1310 1311 if (!ctlr->cur_msg_mapped) 1312 return; 1313 1314 if (xfer->tx_sg.orig_nents) 1315 dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); 1316 if (xfer->rx_sg.orig_nents) 1317 dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); 1318 } 1319 1320 static void spi_dma_sync_for_cpu(struct spi_controller *ctlr, 1321 struct spi_transfer *xfer) 1322 { 1323 struct device *rx_dev = ctlr->cur_rx_dma_dev; 1324 struct device *tx_dev = ctlr->cur_tx_dma_dev; 1325 1326 if (!ctlr->cur_msg_mapped) 1327 return; 1328 1329 if (xfer->rx_sg.orig_nents) 1330 dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); 1331 if (xfer->tx_sg.orig_nents) 1332 dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); 1333 } 1334 #else /* !CONFIG_HAS_DMA */ 1335 static inline int __spi_map_msg(struct spi_controller *ctlr, 1336 struct spi_message *msg) 1337 { 1338 return 0; 1339 } 1340 1341 static inline int __spi_unmap_msg(struct spi_controller *ctlr, 1342 struct spi_message *msg) 1343 { 1344 return 0; 1345 } 1346 1347 static void spi_dma_sync_for_device(struct spi_controller *ctrl, 1348 struct spi_transfer *xfer) 1349 { 1350 } 1351 1352 static void spi_dma_sync_for_cpu(struct spi_controller *ctrl, 1353 struct spi_transfer *xfer) 1354 { 1355 } 1356 #endif /* !CONFIG_HAS_DMA */ 1357 1358 static inline int spi_unmap_msg(struct spi_controller *ctlr, 1359 struct spi_message *msg) 1360 { 1361 struct spi_transfer *xfer; 1362 1363 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1364 /* 1365 * Restore the original value of tx_buf or rx_buf if they are 1366 * NULL. 1367 */ 1368 if (xfer->tx_buf == ctlr->dummy_tx) 1369 xfer->tx_buf = NULL; 1370 if (xfer->rx_buf == ctlr->dummy_rx) 1371 xfer->rx_buf = NULL; 1372 } 1373 1374 return __spi_unmap_msg(ctlr, msg); 1375 } 1376 1377 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) 1378 { 1379 struct spi_transfer *xfer; 1380 void *tmp; 1381 unsigned int max_tx, max_rx; 1382 1383 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) 1384 && !(msg->spi->mode & SPI_3WIRE)) { 1385 max_tx = 0; 1386 max_rx = 0; 1387 1388 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1389 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) && 1390 !xfer->tx_buf) 1391 max_tx = max(xfer->len, max_tx); 1392 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) && 1393 !xfer->rx_buf) 1394 max_rx = max(xfer->len, max_rx); 1395 } 1396 1397 if (max_tx) { 1398 tmp = krealloc(ctlr->dummy_tx, max_tx, 1399 GFP_KERNEL | GFP_DMA | __GFP_ZERO); 1400 if (!tmp) 1401 return -ENOMEM; 1402 ctlr->dummy_tx = tmp; 1403 } 1404 1405 if (max_rx) { 1406 tmp = krealloc(ctlr->dummy_rx, max_rx, 1407 GFP_KERNEL | GFP_DMA); 1408 if (!tmp) 1409 return -ENOMEM; 1410 ctlr->dummy_rx = tmp; 1411 } 1412 1413 if (max_tx || max_rx) { 1414 list_for_each_entry(xfer, &msg->transfers, 1415 transfer_list) { 1416 if (!xfer->len) 1417 continue; 1418 if (!xfer->tx_buf) 1419 xfer->tx_buf = ctlr->dummy_tx; 1420 if (!xfer->rx_buf) 1421 xfer->rx_buf = ctlr->dummy_rx; 1422 } 1423 } 1424 } 1425 1426 return __spi_map_msg(ctlr, msg); 1427 } 1428 1429 static int spi_transfer_wait(struct spi_controller *ctlr, 1430 struct spi_message *msg, 1431 struct spi_transfer *xfer) 1432 { 1433 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics; 1434 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics; 1435 u32 speed_hz = xfer->speed_hz; 1436 unsigned long long ms; 1437 1438 if (spi_controller_is_slave(ctlr)) { 1439 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) { 1440 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n"); 1441 return -EINTR; 1442 } 1443 } else { 1444 if (!speed_hz) 1445 speed_hz = 100000; 1446 1447 /* 1448 * For each byte we wait for 8 cycles of the SPI clock. 1449 * Since speed is defined in Hz and we want milliseconds, 1450 * use respective multiplier, but before the division, 1451 * otherwise we may get 0 for short transfers. 1452 */ 1453 ms = 8LL * MSEC_PER_SEC * xfer->len; 1454 do_div(ms, speed_hz); 1455 1456 /* 1457 * Increase it twice and add 200 ms tolerance, use 1458 * predefined maximum in case of overflow. 1459 */ 1460 ms += ms + 200; 1461 if (ms > UINT_MAX) 1462 ms = UINT_MAX; 1463 1464 ms = wait_for_completion_timeout(&ctlr->xfer_completion, 1465 msecs_to_jiffies(ms)); 1466 1467 if (ms == 0) { 1468 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout); 1469 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout); 1470 dev_err(&msg->spi->dev, 1471 "SPI transfer timed out\n"); 1472 return -ETIMEDOUT; 1473 } 1474 1475 if (xfer->error & SPI_TRANS_FAIL_IO) 1476 return -EIO; 1477 } 1478 1479 return 0; 1480 } 1481 1482 static void _spi_transfer_delay_ns(u32 ns) 1483 { 1484 if (!ns) 1485 return; 1486 if (ns <= NSEC_PER_USEC) { 1487 ndelay(ns); 1488 } else { 1489 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC); 1490 1491 if (us <= 10) 1492 udelay(us); 1493 else 1494 usleep_range(us, us + DIV_ROUND_UP(us, 10)); 1495 } 1496 } 1497 1498 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) 1499 { 1500 u32 delay = _delay->value; 1501 u32 unit = _delay->unit; 1502 u32 hz; 1503 1504 if (!delay) 1505 return 0; 1506 1507 switch (unit) { 1508 case SPI_DELAY_UNIT_USECS: 1509 delay *= NSEC_PER_USEC; 1510 break; 1511 case SPI_DELAY_UNIT_NSECS: 1512 /* Nothing to do here */ 1513 break; 1514 case SPI_DELAY_UNIT_SCK: 1515 /* Clock cycles need to be obtained from spi_transfer */ 1516 if (!xfer) 1517 return -EINVAL; 1518 /* 1519 * If there is unknown effective speed, approximate it 1520 * by underestimating with half of the requested Hz. 1521 */ 1522 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; 1523 if (!hz) 1524 return -EINVAL; 1525 1526 /* Convert delay to nanoseconds */ 1527 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz); 1528 break; 1529 default: 1530 return -EINVAL; 1531 } 1532 1533 return delay; 1534 } 1535 EXPORT_SYMBOL_GPL(spi_delay_to_ns); 1536 1537 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) 1538 { 1539 int delay; 1540 1541 might_sleep(); 1542 1543 if (!_delay) 1544 return -EINVAL; 1545 1546 delay = spi_delay_to_ns(_delay, xfer); 1547 if (delay < 0) 1548 return delay; 1549 1550 _spi_transfer_delay_ns(delay); 1551 1552 return 0; 1553 } 1554 EXPORT_SYMBOL_GPL(spi_delay_exec); 1555 1556 static void _spi_transfer_cs_change_delay(struct spi_message *msg, 1557 struct spi_transfer *xfer) 1558 { 1559 u32 default_delay_ns = 10 * NSEC_PER_USEC; 1560 u32 delay = xfer->cs_change_delay.value; 1561 u32 unit = xfer->cs_change_delay.unit; 1562 int ret; 1563 1564 /* Return early on "fast" mode - for everything but USECS */ 1565 if (!delay) { 1566 if (unit == SPI_DELAY_UNIT_USECS) 1567 _spi_transfer_delay_ns(default_delay_ns); 1568 return; 1569 } 1570 1571 ret = spi_delay_exec(&xfer->cs_change_delay, xfer); 1572 if (ret) { 1573 dev_err_once(&msg->spi->dev, 1574 "Use of unsupported delay unit %i, using default of %luus\n", 1575 unit, default_delay_ns / NSEC_PER_USEC); 1576 _spi_transfer_delay_ns(default_delay_ns); 1577 } 1578 } 1579 1580 void spi_transfer_cs_change_delay_exec(struct spi_message *msg, 1581 struct spi_transfer *xfer) 1582 { 1583 _spi_transfer_cs_change_delay(msg, xfer); 1584 } 1585 EXPORT_SYMBOL_GPL(spi_transfer_cs_change_delay_exec); 1586 1587 /* 1588 * spi_transfer_one_message - Default implementation of transfer_one_message() 1589 * 1590 * This is a standard implementation of transfer_one_message() for 1591 * drivers which implement a transfer_one() operation. It provides 1592 * standard handling of delays and chip select management. 1593 */ 1594 static int spi_transfer_one_message(struct spi_controller *ctlr, 1595 struct spi_message *msg) 1596 { 1597 struct spi_transfer *xfer; 1598 bool keep_cs = false; 1599 int ret = 0; 1600 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics; 1601 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics; 1602 1603 xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list); 1604 spi_set_cs(msg->spi, !xfer->cs_off, false); 1605 1606 SPI_STATISTICS_INCREMENT_FIELD(statm, messages); 1607 SPI_STATISTICS_INCREMENT_FIELD(stats, messages); 1608 1609 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1610 trace_spi_transfer_start(msg, xfer); 1611 1612 spi_statistics_add_transfer_stats(statm, xfer, ctlr); 1613 spi_statistics_add_transfer_stats(stats, xfer, ctlr); 1614 1615 if (!ctlr->ptp_sts_supported) { 1616 xfer->ptp_sts_word_pre = 0; 1617 ptp_read_system_prets(xfer->ptp_sts); 1618 } 1619 1620 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { 1621 reinit_completion(&ctlr->xfer_completion); 1622 1623 fallback_pio: 1624 spi_dma_sync_for_device(ctlr, xfer); 1625 ret = ctlr->transfer_one(ctlr, msg->spi, xfer); 1626 if (ret < 0) { 1627 spi_dma_sync_for_cpu(ctlr, xfer); 1628 1629 if (ctlr->cur_msg_mapped && 1630 (xfer->error & SPI_TRANS_FAIL_NO_START)) { 1631 __spi_unmap_msg(ctlr, msg); 1632 ctlr->fallback = true; 1633 xfer->error &= ~SPI_TRANS_FAIL_NO_START; 1634 goto fallback_pio; 1635 } 1636 1637 SPI_STATISTICS_INCREMENT_FIELD(statm, 1638 errors); 1639 SPI_STATISTICS_INCREMENT_FIELD(stats, 1640 errors); 1641 dev_err(&msg->spi->dev, 1642 "SPI transfer failed: %d\n", ret); 1643 goto out; 1644 } 1645 1646 if (ret > 0) { 1647 ret = spi_transfer_wait(ctlr, msg, xfer); 1648 if (ret < 0) 1649 msg->status = ret; 1650 } 1651 1652 spi_dma_sync_for_cpu(ctlr, xfer); 1653 } else { 1654 if (xfer->len) 1655 dev_err(&msg->spi->dev, 1656 "Bufferless transfer has length %u\n", 1657 xfer->len); 1658 } 1659 1660 if (!ctlr->ptp_sts_supported) { 1661 ptp_read_system_postts(xfer->ptp_sts); 1662 xfer->ptp_sts_word_post = xfer->len; 1663 } 1664 1665 trace_spi_transfer_stop(msg, xfer); 1666 1667 if (msg->status != -EINPROGRESS) 1668 goto out; 1669 1670 spi_transfer_delay_exec(xfer); 1671 1672 if (xfer->cs_change) { 1673 if (list_is_last(&xfer->transfer_list, 1674 &msg->transfers)) { 1675 keep_cs = true; 1676 } else { 1677 if (!xfer->cs_off) 1678 spi_set_cs(msg->spi, false, false); 1679 _spi_transfer_cs_change_delay(msg, xfer); 1680 if (!list_next_entry(xfer, transfer_list)->cs_off) 1681 spi_set_cs(msg->spi, true, false); 1682 } 1683 } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) && 1684 xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) { 1685 spi_set_cs(msg->spi, xfer->cs_off, false); 1686 } 1687 1688 msg->actual_length += xfer->len; 1689 } 1690 1691 out: 1692 if (ret != 0 || !keep_cs) 1693 spi_set_cs(msg->spi, false, false); 1694 1695 if (msg->status == -EINPROGRESS) 1696 msg->status = ret; 1697 1698 if (msg->status && ctlr->handle_err) 1699 ctlr->handle_err(ctlr, msg); 1700 1701 spi_finalize_current_message(ctlr); 1702 1703 return ret; 1704 } 1705 1706 /** 1707 * spi_finalize_current_transfer - report completion of a transfer 1708 * @ctlr: the controller reporting completion 1709 * 1710 * Called by SPI drivers using the core transfer_one_message() 1711 * implementation to notify it that the current interrupt driven 1712 * transfer has finished and the next one may be scheduled. 1713 */ 1714 void spi_finalize_current_transfer(struct spi_controller *ctlr) 1715 { 1716 complete(&ctlr->xfer_completion); 1717 } 1718 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); 1719 1720 static void spi_idle_runtime_pm(struct spi_controller *ctlr) 1721 { 1722 if (ctlr->auto_runtime_pm) { 1723 pm_runtime_mark_last_busy(ctlr->dev.parent); 1724 pm_runtime_put_autosuspend(ctlr->dev.parent); 1725 } 1726 } 1727 1728 static int __spi_pump_transfer_message(struct spi_controller *ctlr, 1729 struct spi_message *msg, bool was_busy) 1730 { 1731 struct spi_transfer *xfer; 1732 int ret; 1733 1734 if (!was_busy && ctlr->auto_runtime_pm) { 1735 ret = pm_runtime_get_sync(ctlr->dev.parent); 1736 if (ret < 0) { 1737 pm_runtime_put_noidle(ctlr->dev.parent); 1738 dev_err(&ctlr->dev, "Failed to power device: %d\n", 1739 ret); 1740 1741 msg->status = ret; 1742 spi_finalize_current_message(ctlr); 1743 1744 return ret; 1745 } 1746 } 1747 1748 if (!was_busy) 1749 trace_spi_controller_busy(ctlr); 1750 1751 if (!was_busy && ctlr->prepare_transfer_hardware) { 1752 ret = ctlr->prepare_transfer_hardware(ctlr); 1753 if (ret) { 1754 dev_err(&ctlr->dev, 1755 "failed to prepare transfer hardware: %d\n", 1756 ret); 1757 1758 if (ctlr->auto_runtime_pm) 1759 pm_runtime_put(ctlr->dev.parent); 1760 1761 msg->status = ret; 1762 spi_finalize_current_message(ctlr); 1763 1764 return ret; 1765 } 1766 } 1767 1768 trace_spi_message_start(msg); 1769 1770 if (ctlr->prepare_message) { 1771 ret = ctlr->prepare_message(ctlr, msg); 1772 if (ret) { 1773 dev_err(&ctlr->dev, "failed to prepare message: %d\n", 1774 ret); 1775 msg->status = ret; 1776 spi_finalize_current_message(ctlr); 1777 return ret; 1778 } 1779 msg->prepared = true; 1780 } 1781 1782 ret = spi_map_msg(ctlr, msg); 1783 if (ret) { 1784 msg->status = ret; 1785 spi_finalize_current_message(ctlr); 1786 return ret; 1787 } 1788 1789 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { 1790 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1791 xfer->ptp_sts_word_pre = 0; 1792 ptp_read_system_prets(xfer->ptp_sts); 1793 } 1794 } 1795 1796 /* 1797 * Drivers implementation of transfer_one_message() must arrange for 1798 * spi_finalize_current_message() to get called. Most drivers will do 1799 * this in the calling context, but some don't. For those cases, a 1800 * completion is used to guarantee that this function does not return 1801 * until spi_finalize_current_message() is done accessing 1802 * ctlr->cur_msg. 1803 * Use of the following two flags enable to opportunistically skip the 1804 * use of the completion since its use involves expensive spin locks. 1805 * In case of a race with the context that calls 1806 * spi_finalize_current_message() the completion will always be used, 1807 * due to strict ordering of these flags using barriers. 1808 */ 1809 WRITE_ONCE(ctlr->cur_msg_incomplete, true); 1810 WRITE_ONCE(ctlr->cur_msg_need_completion, false); 1811 reinit_completion(&ctlr->cur_msg_completion); 1812 smp_wmb(); /* Make these available to spi_finalize_current_message() */ 1813 1814 ret = ctlr->transfer_one_message(ctlr, msg); 1815 if (ret) { 1816 dev_err(&ctlr->dev, 1817 "failed to transfer one message from queue\n"); 1818 return ret; 1819 } 1820 1821 WRITE_ONCE(ctlr->cur_msg_need_completion, true); 1822 smp_mb(); /* See spi_finalize_current_message()... */ 1823 if (READ_ONCE(ctlr->cur_msg_incomplete)) 1824 wait_for_completion(&ctlr->cur_msg_completion); 1825 1826 return 0; 1827 } 1828 1829 /** 1830 * __spi_pump_messages - function which processes SPI message queue 1831 * @ctlr: controller to process queue for 1832 * @in_kthread: true if we are in the context of the message pump thread 1833 * 1834 * This function checks if there is any SPI message in the queue that 1835 * needs processing and if so call out to the driver to initialize hardware 1836 * and transfer each message. 1837 * 1838 * Note that it is called both from the kthread itself and also from 1839 * inside spi_sync(); the queue extraction handling at the top of the 1840 * function should deal with this safely. 1841 */ 1842 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) 1843 { 1844 struct spi_message *msg; 1845 bool was_busy = false; 1846 unsigned long flags; 1847 int ret; 1848 1849 /* Take the I/O mutex */ 1850 mutex_lock(&ctlr->io_mutex); 1851 1852 /* Lock queue */ 1853 spin_lock_irqsave(&ctlr->queue_lock, flags); 1854 1855 /* Make sure we are not already running a message */ 1856 if (ctlr->cur_msg) 1857 goto out_unlock; 1858 1859 /* Check if the queue is idle */ 1860 if (list_empty(&ctlr->queue) || !ctlr->running) { 1861 if (!ctlr->busy) 1862 goto out_unlock; 1863 1864 /* Defer any non-atomic teardown to the thread */ 1865 if (!in_kthread) { 1866 if (!ctlr->dummy_rx && !ctlr->dummy_tx && 1867 !ctlr->unprepare_transfer_hardware) { 1868 spi_idle_runtime_pm(ctlr); 1869 ctlr->busy = false; 1870 ctlr->queue_empty = true; 1871 trace_spi_controller_idle(ctlr); 1872 } else { 1873 kthread_queue_work(ctlr->kworker, 1874 &ctlr->pump_messages); 1875 } 1876 goto out_unlock; 1877 } 1878 1879 ctlr->busy = false; 1880 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1881 1882 kfree(ctlr->dummy_rx); 1883 ctlr->dummy_rx = NULL; 1884 kfree(ctlr->dummy_tx); 1885 ctlr->dummy_tx = NULL; 1886 if (ctlr->unprepare_transfer_hardware && 1887 ctlr->unprepare_transfer_hardware(ctlr)) 1888 dev_err(&ctlr->dev, 1889 "failed to unprepare transfer hardware\n"); 1890 spi_idle_runtime_pm(ctlr); 1891 trace_spi_controller_idle(ctlr); 1892 1893 spin_lock_irqsave(&ctlr->queue_lock, flags); 1894 ctlr->queue_empty = true; 1895 goto out_unlock; 1896 } 1897 1898 /* Extract head of queue */ 1899 msg = list_first_entry(&ctlr->queue, struct spi_message, queue); 1900 ctlr->cur_msg = msg; 1901 1902 list_del_init(&msg->queue); 1903 if (ctlr->busy) 1904 was_busy = true; 1905 else 1906 ctlr->busy = true; 1907 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1908 1909 ret = __spi_pump_transfer_message(ctlr, msg, was_busy); 1910 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 1911 1912 ctlr->cur_msg = NULL; 1913 ctlr->fallback = false; 1914 1915 mutex_unlock(&ctlr->io_mutex); 1916 1917 /* Prod the scheduler in case transfer_one() was busy waiting */ 1918 if (!ret) 1919 cond_resched(); 1920 return; 1921 1922 out_unlock: 1923 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1924 mutex_unlock(&ctlr->io_mutex); 1925 } 1926 1927 /** 1928 * spi_pump_messages - kthread work function which processes spi message queue 1929 * @work: pointer to kthread work struct contained in the controller struct 1930 */ 1931 static void spi_pump_messages(struct kthread_work *work) 1932 { 1933 struct spi_controller *ctlr = 1934 container_of(work, struct spi_controller, pump_messages); 1935 1936 __spi_pump_messages(ctlr, true); 1937 } 1938 1939 /** 1940 * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp 1941 * @ctlr: Pointer to the spi_controller structure of the driver 1942 * @xfer: Pointer to the transfer being timestamped 1943 * @progress: How many words (not bytes) have been transferred so far 1944 * @irqs_off: If true, will disable IRQs and preemption for the duration of the 1945 * transfer, for less jitter in time measurement. Only compatible 1946 * with PIO drivers. If true, must follow up with 1947 * spi_take_timestamp_post or otherwise system will crash. 1948 * WARNING: for fully predictable results, the CPU frequency must 1949 * also be under control (governor). 1950 * 1951 * This is a helper for drivers to collect the beginning of the TX timestamp 1952 * for the requested byte from the SPI transfer. The frequency with which this 1953 * function must be called (once per word, once for the whole transfer, once 1954 * per batch of words etc) is arbitrary as long as the @tx buffer offset is 1955 * greater than or equal to the requested byte at the time of the call. The 1956 * timestamp is only taken once, at the first such call. It is assumed that 1957 * the driver advances its @tx buffer pointer monotonically. 1958 */ 1959 void spi_take_timestamp_pre(struct spi_controller *ctlr, 1960 struct spi_transfer *xfer, 1961 size_t progress, bool irqs_off) 1962 { 1963 if (!xfer->ptp_sts) 1964 return; 1965 1966 if (xfer->timestamped) 1967 return; 1968 1969 if (progress > xfer->ptp_sts_word_pre) 1970 return; 1971 1972 /* Capture the resolution of the timestamp */ 1973 xfer->ptp_sts_word_pre = progress; 1974 1975 if (irqs_off) { 1976 local_irq_save(ctlr->irq_flags); 1977 preempt_disable(); 1978 } 1979 1980 ptp_read_system_prets(xfer->ptp_sts); 1981 } 1982 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); 1983 1984 /** 1985 * spi_take_timestamp_post - helper to collect the end of the TX timestamp 1986 * @ctlr: Pointer to the spi_controller structure of the driver 1987 * @xfer: Pointer to the transfer being timestamped 1988 * @progress: How many words (not bytes) have been transferred so far 1989 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. 1990 * 1991 * This is a helper for drivers to collect the end of the TX timestamp for 1992 * the requested byte from the SPI transfer. Can be called with an arbitrary 1993 * frequency: only the first call where @tx exceeds or is equal to the 1994 * requested word will be timestamped. 1995 */ 1996 void spi_take_timestamp_post(struct spi_controller *ctlr, 1997 struct spi_transfer *xfer, 1998 size_t progress, bool irqs_off) 1999 { 2000 if (!xfer->ptp_sts) 2001 return; 2002 2003 if (xfer->timestamped) 2004 return; 2005 2006 if (progress < xfer->ptp_sts_word_post) 2007 return; 2008 2009 ptp_read_system_postts(xfer->ptp_sts); 2010 2011 if (irqs_off) { 2012 local_irq_restore(ctlr->irq_flags); 2013 preempt_enable(); 2014 } 2015 2016 /* Capture the resolution of the timestamp */ 2017 xfer->ptp_sts_word_post = progress; 2018 2019 xfer->timestamped = 1; 2020 } 2021 EXPORT_SYMBOL_GPL(spi_take_timestamp_post); 2022 2023 /** 2024 * spi_set_thread_rt - set the controller to pump at realtime priority 2025 * @ctlr: controller to boost priority of 2026 * 2027 * This can be called because the controller requested realtime priority 2028 * (by setting the ->rt value before calling spi_register_controller()) or 2029 * because a device on the bus said that its transfers needed realtime 2030 * priority. 2031 * 2032 * NOTE: at the moment if any device on a bus says it needs realtime then 2033 * the thread will be at realtime priority for all transfers on that 2034 * controller. If this eventually becomes a problem we may see if we can 2035 * find a way to boost the priority only temporarily during relevant 2036 * transfers. 2037 */ 2038 static void spi_set_thread_rt(struct spi_controller *ctlr) 2039 { 2040 dev_info(&ctlr->dev, 2041 "will run message pump with realtime priority\n"); 2042 sched_set_fifo(ctlr->kworker->task); 2043 } 2044 2045 static int spi_init_queue(struct spi_controller *ctlr) 2046 { 2047 ctlr->running = false; 2048 ctlr->busy = false; 2049 ctlr->queue_empty = true; 2050 2051 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev)); 2052 if (IS_ERR(ctlr->kworker)) { 2053 dev_err(&ctlr->dev, "failed to create message pump kworker\n"); 2054 return PTR_ERR(ctlr->kworker); 2055 } 2056 2057 kthread_init_work(&ctlr->pump_messages, spi_pump_messages); 2058 2059 /* 2060 * Controller config will indicate if this controller should run the 2061 * message pump with high (realtime) priority to reduce the transfer 2062 * latency on the bus by minimising the delay between a transfer 2063 * request and the scheduling of the message pump thread. Without this 2064 * setting the message pump thread will remain at default priority. 2065 */ 2066 if (ctlr->rt) 2067 spi_set_thread_rt(ctlr); 2068 2069 return 0; 2070 } 2071 2072 /** 2073 * spi_get_next_queued_message() - called by driver to check for queued 2074 * messages 2075 * @ctlr: the controller to check for queued messages 2076 * 2077 * If there are more messages in the queue, the next message is returned from 2078 * this call. 2079 * 2080 * Return: the next message in the queue, else NULL if the queue is empty. 2081 */ 2082 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) 2083 { 2084 struct spi_message *next; 2085 unsigned long flags; 2086 2087 /* Get a pointer to the next message, if any */ 2088 spin_lock_irqsave(&ctlr->queue_lock, flags); 2089 next = list_first_entry_or_null(&ctlr->queue, struct spi_message, 2090 queue); 2091 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2092 2093 return next; 2094 } 2095 EXPORT_SYMBOL_GPL(spi_get_next_queued_message); 2096 2097 /* 2098 * __spi_unoptimize_message - shared implementation of spi_unoptimize_message() 2099 * and spi_maybe_unoptimize_message() 2100 * @msg: the message to unoptimize 2101 * 2102 * Peripheral drivers should use spi_unoptimize_message() and callers inside 2103 * core should use spi_maybe_unoptimize_message() rather than calling this 2104 * function directly. 2105 * 2106 * It is not valid to call this on a message that is not currently optimized. 2107 */ 2108 static void __spi_unoptimize_message(struct spi_message *msg) 2109 { 2110 struct spi_controller *ctlr = msg->spi->controller; 2111 2112 if (ctlr->unoptimize_message) 2113 ctlr->unoptimize_message(msg); 2114 2115 spi_res_release(ctlr, msg); 2116 2117 msg->optimized = false; 2118 msg->opt_state = NULL; 2119 } 2120 2121 /* 2122 * spi_maybe_unoptimize_message - unoptimize msg not managed by a peripheral 2123 * @msg: the message to unoptimize 2124 * 2125 * This function is used to unoptimize a message if and only if it was 2126 * optimized by the core (via spi_maybe_optimize_message()). 2127 */ 2128 static void spi_maybe_unoptimize_message(struct spi_message *msg) 2129 { 2130 if (!msg->pre_optimized && msg->optimized) 2131 __spi_unoptimize_message(msg); 2132 } 2133 2134 /** 2135 * spi_finalize_current_message() - the current message is complete 2136 * @ctlr: the controller to return the message to 2137 * 2138 * Called by the driver to notify the core that the message in the front of the 2139 * queue is complete and can be removed from the queue. 2140 */ 2141 void spi_finalize_current_message(struct spi_controller *ctlr) 2142 { 2143 struct spi_transfer *xfer; 2144 struct spi_message *mesg; 2145 int ret; 2146 2147 mesg = ctlr->cur_msg; 2148 2149 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { 2150 list_for_each_entry(xfer, &mesg->transfers, transfer_list) { 2151 ptp_read_system_postts(xfer->ptp_sts); 2152 xfer->ptp_sts_word_post = xfer->len; 2153 } 2154 } 2155 2156 if (unlikely(ctlr->ptp_sts_supported)) 2157 list_for_each_entry(xfer, &mesg->transfers, transfer_list) 2158 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped); 2159 2160 spi_unmap_msg(ctlr, mesg); 2161 2162 if (mesg->prepared && ctlr->unprepare_message) { 2163 ret = ctlr->unprepare_message(ctlr, mesg); 2164 if (ret) { 2165 dev_err(&ctlr->dev, "failed to unprepare message: %d\n", 2166 ret); 2167 } 2168 } 2169 2170 mesg->prepared = false; 2171 2172 spi_maybe_unoptimize_message(mesg); 2173 2174 WRITE_ONCE(ctlr->cur_msg_incomplete, false); 2175 smp_mb(); /* See __spi_pump_transfer_message()... */ 2176 if (READ_ONCE(ctlr->cur_msg_need_completion)) 2177 complete(&ctlr->cur_msg_completion); 2178 2179 trace_spi_message_done(mesg); 2180 2181 mesg->state = NULL; 2182 if (mesg->complete) 2183 mesg->complete(mesg->context); 2184 } 2185 EXPORT_SYMBOL_GPL(spi_finalize_current_message); 2186 2187 static int spi_start_queue(struct spi_controller *ctlr) 2188 { 2189 unsigned long flags; 2190 2191 spin_lock_irqsave(&ctlr->queue_lock, flags); 2192 2193 if (ctlr->running || ctlr->busy) { 2194 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2195 return -EBUSY; 2196 } 2197 2198 ctlr->running = true; 2199 ctlr->cur_msg = NULL; 2200 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2201 2202 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 2203 2204 return 0; 2205 } 2206 2207 static int spi_stop_queue(struct spi_controller *ctlr) 2208 { 2209 unsigned long flags; 2210 unsigned limit = 500; 2211 int ret = 0; 2212 2213 spin_lock_irqsave(&ctlr->queue_lock, flags); 2214 2215 /* 2216 * This is a bit lame, but is optimized for the common execution path. 2217 * A wait_queue on the ctlr->busy could be used, but then the common 2218 * execution path (pump_messages) would be required to call wake_up or 2219 * friends on every SPI message. Do this instead. 2220 */ 2221 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) { 2222 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2223 usleep_range(10000, 11000); 2224 spin_lock_irqsave(&ctlr->queue_lock, flags); 2225 } 2226 2227 if (!list_empty(&ctlr->queue) || ctlr->busy) 2228 ret = -EBUSY; 2229 else 2230 ctlr->running = false; 2231 2232 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2233 2234 return ret; 2235 } 2236 2237 static int spi_destroy_queue(struct spi_controller *ctlr) 2238 { 2239 int ret; 2240 2241 ret = spi_stop_queue(ctlr); 2242 2243 /* 2244 * kthread_flush_worker will block until all work is done. 2245 * If the reason that stop_queue timed out is that the work will never 2246 * finish, then it does no good to call flush/stop thread, so 2247 * return anyway. 2248 */ 2249 if (ret) { 2250 dev_err(&ctlr->dev, "problem destroying queue\n"); 2251 return ret; 2252 } 2253 2254 kthread_destroy_worker(ctlr->kworker); 2255 2256 return 0; 2257 } 2258 2259 static int __spi_queued_transfer(struct spi_device *spi, 2260 struct spi_message *msg, 2261 bool need_pump) 2262 { 2263 struct spi_controller *ctlr = spi->controller; 2264 unsigned long flags; 2265 2266 spin_lock_irqsave(&ctlr->queue_lock, flags); 2267 2268 if (!ctlr->running) { 2269 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2270 return -ESHUTDOWN; 2271 } 2272 msg->actual_length = 0; 2273 msg->status = -EINPROGRESS; 2274 2275 list_add_tail(&msg->queue, &ctlr->queue); 2276 ctlr->queue_empty = false; 2277 if (!ctlr->busy && need_pump) 2278 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 2279 2280 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 2281 return 0; 2282 } 2283 2284 /** 2285 * spi_queued_transfer - transfer function for queued transfers 2286 * @spi: SPI device which is requesting transfer 2287 * @msg: SPI message which is to handled is queued to driver queue 2288 * 2289 * Return: zero on success, else a negative error code. 2290 */ 2291 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) 2292 { 2293 return __spi_queued_transfer(spi, msg, true); 2294 } 2295 2296 static int spi_controller_initialize_queue(struct spi_controller *ctlr) 2297 { 2298 int ret; 2299 2300 ctlr->transfer = spi_queued_transfer; 2301 if (!ctlr->transfer_one_message) 2302 ctlr->transfer_one_message = spi_transfer_one_message; 2303 2304 /* Initialize and start queue */ 2305 ret = spi_init_queue(ctlr); 2306 if (ret) { 2307 dev_err(&ctlr->dev, "problem initializing queue\n"); 2308 goto err_init_queue; 2309 } 2310 ctlr->queued = true; 2311 ret = spi_start_queue(ctlr); 2312 if (ret) { 2313 dev_err(&ctlr->dev, "problem starting queue\n"); 2314 goto err_start_queue; 2315 } 2316 2317 return 0; 2318 2319 err_start_queue: 2320 spi_destroy_queue(ctlr); 2321 err_init_queue: 2322 return ret; 2323 } 2324 2325 /** 2326 * spi_flush_queue - Send all pending messages in the queue from the callers' 2327 * context 2328 * @ctlr: controller to process queue for 2329 * 2330 * This should be used when one wants to ensure all pending messages have been 2331 * sent before doing something. Is used by the spi-mem code to make sure SPI 2332 * memory operations do not preempt regular SPI transfers that have been queued 2333 * before the spi-mem operation. 2334 */ 2335 void spi_flush_queue(struct spi_controller *ctlr) 2336 { 2337 if (ctlr->transfer == spi_queued_transfer) 2338 __spi_pump_messages(ctlr, false); 2339 } 2340 2341 /*-------------------------------------------------------------------------*/ 2342 2343 #if defined(CONFIG_OF) 2344 static void of_spi_parse_dt_cs_delay(struct device_node *nc, 2345 struct spi_delay *delay, const char *prop) 2346 { 2347 u32 value; 2348 2349 if (!of_property_read_u32(nc, prop, &value)) { 2350 if (value > U16_MAX) { 2351 delay->value = DIV_ROUND_UP(value, 1000); 2352 delay->unit = SPI_DELAY_UNIT_USECS; 2353 } else { 2354 delay->value = value; 2355 delay->unit = SPI_DELAY_UNIT_NSECS; 2356 } 2357 } 2358 } 2359 2360 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, 2361 struct device_node *nc) 2362 { 2363 u32 value, cs[SPI_CS_CNT_MAX]; 2364 int rc, idx; 2365 2366 /* Mode (clock phase/polarity/etc.) */ 2367 if (of_property_read_bool(nc, "spi-cpha")) 2368 spi->mode |= SPI_CPHA; 2369 if (of_property_read_bool(nc, "spi-cpol")) 2370 spi->mode |= SPI_CPOL; 2371 if (of_property_read_bool(nc, "spi-3wire")) 2372 spi->mode |= SPI_3WIRE; 2373 if (of_property_read_bool(nc, "spi-lsb-first")) 2374 spi->mode |= SPI_LSB_FIRST; 2375 if (of_property_read_bool(nc, "spi-cs-high")) 2376 spi->mode |= SPI_CS_HIGH; 2377 2378 /* Device DUAL/QUAD mode */ 2379 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { 2380 switch (value) { 2381 case 0: 2382 spi->mode |= SPI_NO_TX; 2383 break; 2384 case 1: 2385 break; 2386 case 2: 2387 spi->mode |= SPI_TX_DUAL; 2388 break; 2389 case 4: 2390 spi->mode |= SPI_TX_QUAD; 2391 break; 2392 case 8: 2393 spi->mode |= SPI_TX_OCTAL; 2394 break; 2395 default: 2396 dev_warn(&ctlr->dev, 2397 "spi-tx-bus-width %d not supported\n", 2398 value); 2399 break; 2400 } 2401 } 2402 2403 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { 2404 switch (value) { 2405 case 0: 2406 spi->mode |= SPI_NO_RX; 2407 break; 2408 case 1: 2409 break; 2410 case 2: 2411 spi->mode |= SPI_RX_DUAL; 2412 break; 2413 case 4: 2414 spi->mode |= SPI_RX_QUAD; 2415 break; 2416 case 8: 2417 spi->mode |= SPI_RX_OCTAL; 2418 break; 2419 default: 2420 dev_warn(&ctlr->dev, 2421 "spi-rx-bus-width %d not supported\n", 2422 value); 2423 break; 2424 } 2425 } 2426 2427 if (spi_controller_is_slave(ctlr)) { 2428 if (!of_node_name_eq(nc, "slave")) { 2429 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n", 2430 nc); 2431 return -EINVAL; 2432 } 2433 return 0; 2434 } 2435 2436 if (ctlr->num_chipselect > SPI_CS_CNT_MAX) { 2437 dev_err(&ctlr->dev, "No. of CS is more than max. no. of supported CS\n"); 2438 return -EINVAL; 2439 } 2440 2441 spi_set_all_cs_unused(spi); 2442 2443 /* Device address */ 2444 rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1, 2445 SPI_CS_CNT_MAX); 2446 if (rc < 0) { 2447 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", 2448 nc, rc); 2449 return rc; 2450 } 2451 if (rc > ctlr->num_chipselect) { 2452 dev_err(&ctlr->dev, "%pOF has number of CS > ctlr->num_chipselect (%d)\n", 2453 nc, rc); 2454 return rc; 2455 } 2456 if ((of_property_read_bool(nc, "parallel-memories")) && 2457 (!(ctlr->flags & SPI_CONTROLLER_MULTI_CS))) { 2458 dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n"); 2459 return -EINVAL; 2460 } 2461 for (idx = 0; idx < rc; idx++) 2462 spi_set_chipselect(spi, idx, cs[idx]); 2463 2464 /* 2465 * By default spi->chip_select[0] will hold the physical CS number, 2466 * so set bit 0 in spi->cs_index_mask. 2467 */ 2468 spi->cs_index_mask = BIT(0); 2469 2470 /* Device speed */ 2471 if (!of_property_read_u32(nc, "spi-max-frequency", &value)) 2472 spi->max_speed_hz = value; 2473 2474 /* Device CS delays */ 2475 of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns"); 2476 of_spi_parse_dt_cs_delay(nc, &spi->cs_hold, "spi-cs-hold-delay-ns"); 2477 of_spi_parse_dt_cs_delay(nc, &spi->cs_inactive, "spi-cs-inactive-delay-ns"); 2478 2479 return 0; 2480 } 2481 2482 static struct spi_device * 2483 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) 2484 { 2485 struct spi_device *spi; 2486 int rc; 2487 2488 /* Alloc an spi_device */ 2489 spi = spi_alloc_device(ctlr); 2490 if (!spi) { 2491 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc); 2492 rc = -ENOMEM; 2493 goto err_out; 2494 } 2495 2496 /* Select device driver */ 2497 rc = of_alias_from_compatible(nc, spi->modalias, 2498 sizeof(spi->modalias)); 2499 if (rc < 0) { 2500 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc); 2501 goto err_out; 2502 } 2503 2504 rc = of_spi_parse_dt(ctlr, spi, nc); 2505 if (rc) 2506 goto err_out; 2507 2508 /* Store a pointer to the node in the device structure */ 2509 of_node_get(nc); 2510 2511 device_set_node(&spi->dev, of_fwnode_handle(nc)); 2512 2513 /* Register the new device */ 2514 rc = spi_add_device(spi); 2515 if (rc) { 2516 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc); 2517 goto err_of_node_put; 2518 } 2519 2520 return spi; 2521 2522 err_of_node_put: 2523 of_node_put(nc); 2524 err_out: 2525 spi_dev_put(spi); 2526 return ERR_PTR(rc); 2527 } 2528 2529 /** 2530 * of_register_spi_devices() - Register child devices onto the SPI bus 2531 * @ctlr: Pointer to spi_controller device 2532 * 2533 * Registers an spi_device for each child node of controller node which 2534 * represents a valid SPI slave. 2535 */ 2536 static void of_register_spi_devices(struct spi_controller *ctlr) 2537 { 2538 struct spi_device *spi; 2539 struct device_node *nc; 2540 2541 for_each_available_child_of_node(ctlr->dev.of_node, nc) { 2542 if (of_node_test_and_set_flag(nc, OF_POPULATED)) 2543 continue; 2544 spi = of_register_spi_device(ctlr, nc); 2545 if (IS_ERR(spi)) { 2546 dev_warn(&ctlr->dev, 2547 "Failed to create SPI device for %pOF\n", nc); 2548 of_node_clear_flag(nc, OF_POPULATED); 2549 } 2550 } 2551 } 2552 #else 2553 static void of_register_spi_devices(struct spi_controller *ctlr) { } 2554 #endif 2555 2556 /** 2557 * spi_new_ancillary_device() - Register ancillary SPI device 2558 * @spi: Pointer to the main SPI device registering the ancillary device 2559 * @chip_select: Chip Select of the ancillary device 2560 * 2561 * Register an ancillary SPI device; for example some chips have a chip-select 2562 * for normal device usage and another one for setup/firmware upload. 2563 * 2564 * This may only be called from main SPI device's probe routine. 2565 * 2566 * Return: 0 on success; negative errno on failure 2567 */ 2568 struct spi_device *spi_new_ancillary_device(struct spi_device *spi, 2569 u8 chip_select) 2570 { 2571 struct spi_controller *ctlr = spi->controller; 2572 struct spi_device *ancillary; 2573 int rc = 0; 2574 2575 /* Alloc an spi_device */ 2576 ancillary = spi_alloc_device(ctlr); 2577 if (!ancillary) { 2578 rc = -ENOMEM; 2579 goto err_out; 2580 } 2581 2582 strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); 2583 2584 /* Use provided chip-select for ancillary device */ 2585 spi_set_all_cs_unused(ancillary); 2586 spi_set_chipselect(ancillary, 0, chip_select); 2587 2588 /* Take over SPI mode/speed from SPI main device */ 2589 ancillary->max_speed_hz = spi->max_speed_hz; 2590 ancillary->mode = spi->mode; 2591 /* 2592 * By default spi->chip_select[0] will hold the physical CS number, 2593 * so set bit 0 in spi->cs_index_mask. 2594 */ 2595 ancillary->cs_index_mask = BIT(0); 2596 2597 WARN_ON(!mutex_is_locked(&ctlr->add_lock)); 2598 2599 /* Register the new device */ 2600 rc = __spi_add_device(ancillary); 2601 if (rc) { 2602 dev_err(&spi->dev, "failed to register ancillary device\n"); 2603 goto err_out; 2604 } 2605 2606 return ancillary; 2607 2608 err_out: 2609 spi_dev_put(ancillary); 2610 return ERR_PTR(rc); 2611 } 2612 EXPORT_SYMBOL_GPL(spi_new_ancillary_device); 2613 2614 #ifdef CONFIG_ACPI 2615 struct acpi_spi_lookup { 2616 struct spi_controller *ctlr; 2617 u32 max_speed_hz; 2618 u32 mode; 2619 int irq; 2620 u8 bits_per_word; 2621 u8 chip_select; 2622 int n; 2623 int index; 2624 }; 2625 2626 static int acpi_spi_count(struct acpi_resource *ares, void *data) 2627 { 2628 struct acpi_resource_spi_serialbus *sb; 2629 int *count = data; 2630 2631 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) 2632 return 1; 2633 2634 sb = &ares->data.spi_serial_bus; 2635 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI) 2636 return 1; 2637 2638 *count = *count + 1; 2639 2640 return 1; 2641 } 2642 2643 /** 2644 * acpi_spi_count_resources - Count the number of SpiSerialBus resources 2645 * @adev: ACPI device 2646 * 2647 * Return: the number of SpiSerialBus resources in the ACPI-device's 2648 * resource-list; or a negative error code. 2649 */ 2650 int acpi_spi_count_resources(struct acpi_device *adev) 2651 { 2652 LIST_HEAD(r); 2653 int count = 0; 2654 int ret; 2655 2656 ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count); 2657 if (ret < 0) 2658 return ret; 2659 2660 acpi_dev_free_resource_list(&r); 2661 2662 return count; 2663 } 2664 EXPORT_SYMBOL_GPL(acpi_spi_count_resources); 2665 2666 static void acpi_spi_parse_apple_properties(struct acpi_device *dev, 2667 struct acpi_spi_lookup *lookup) 2668 { 2669 const union acpi_object *obj; 2670 2671 if (!x86_apple_machine) 2672 return; 2673 2674 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) 2675 && obj->buffer.length >= 4) 2676 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; 2677 2678 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) 2679 && obj->buffer.length == 8) 2680 lookup->bits_per_word = *(u64 *)obj->buffer.pointer; 2681 2682 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) 2683 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) 2684 lookup->mode |= SPI_LSB_FIRST; 2685 2686 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) 2687 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) 2688 lookup->mode |= SPI_CPOL; 2689 2690 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) 2691 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) 2692 lookup->mode |= SPI_CPHA; 2693 } 2694 2695 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) 2696 { 2697 struct acpi_spi_lookup *lookup = data; 2698 struct spi_controller *ctlr = lookup->ctlr; 2699 2700 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { 2701 struct acpi_resource_spi_serialbus *sb; 2702 acpi_handle parent_handle; 2703 acpi_status status; 2704 2705 sb = &ares->data.spi_serial_bus; 2706 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { 2707 2708 if (lookup->index != -1 && lookup->n++ != lookup->index) 2709 return 1; 2710 2711 status = acpi_get_handle(NULL, 2712 sb->resource_source.string_ptr, 2713 &parent_handle); 2714 2715 if (ACPI_FAILURE(status)) 2716 return -ENODEV; 2717 2718 if (ctlr) { 2719 if (ACPI_HANDLE(ctlr->dev.parent) != parent_handle) 2720 return -ENODEV; 2721 } else { 2722 struct acpi_device *adev; 2723 2724 adev = acpi_fetch_acpi_dev(parent_handle); 2725 if (!adev) 2726 return -ENODEV; 2727 2728 ctlr = acpi_spi_find_controller_by_adev(adev); 2729 if (!ctlr) 2730 return -EPROBE_DEFER; 2731 2732 lookup->ctlr = ctlr; 2733 } 2734 2735 /* 2736 * ACPI DeviceSelection numbering is handled by the 2737 * host controller driver in Windows and can vary 2738 * from driver to driver. In Linux we always expect 2739 * 0 .. max - 1 so we need to ask the driver to 2740 * translate between the two schemes. 2741 */ 2742 if (ctlr->fw_translate_cs) { 2743 int cs = ctlr->fw_translate_cs(ctlr, 2744 sb->device_selection); 2745 if (cs < 0) 2746 return cs; 2747 lookup->chip_select = cs; 2748 } else { 2749 lookup->chip_select = sb->device_selection; 2750 } 2751 2752 lookup->max_speed_hz = sb->connection_speed; 2753 lookup->bits_per_word = sb->data_bit_length; 2754 2755 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) 2756 lookup->mode |= SPI_CPHA; 2757 if (sb->clock_polarity == ACPI_SPI_START_HIGH) 2758 lookup->mode |= SPI_CPOL; 2759 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) 2760 lookup->mode |= SPI_CS_HIGH; 2761 } 2762 } else if (lookup->irq < 0) { 2763 struct resource r; 2764 2765 if (acpi_dev_resource_interrupt(ares, 0, &r)) 2766 lookup->irq = r.start; 2767 } 2768 2769 /* Always tell the ACPI core to skip this resource */ 2770 return 1; 2771 } 2772 2773 /** 2774 * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information 2775 * @ctlr: controller to which the spi device belongs 2776 * @adev: ACPI Device for the spi device 2777 * @index: Index of the spi resource inside the ACPI Node 2778 * 2779 * This should be used to allocate a new SPI device from and ACPI Device node. 2780 * The caller is responsible for calling spi_add_device to register the SPI device. 2781 * 2782 * If ctlr is set to NULL, the Controller for the SPI device will be looked up 2783 * using the resource. 2784 * If index is set to -1, index is not used. 2785 * Note: If index is -1, ctlr must be set. 2786 * 2787 * Return: a pointer to the new device, or ERR_PTR on error. 2788 */ 2789 struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, 2790 struct acpi_device *adev, 2791 int index) 2792 { 2793 acpi_handle parent_handle = NULL; 2794 struct list_head resource_list; 2795 struct acpi_spi_lookup lookup = {}; 2796 struct spi_device *spi; 2797 int ret; 2798 2799 if (!ctlr && index == -1) 2800 return ERR_PTR(-EINVAL); 2801 2802 lookup.ctlr = ctlr; 2803 lookup.irq = -1; 2804 lookup.index = index; 2805 lookup.n = 0; 2806 2807 INIT_LIST_HEAD(&resource_list); 2808 ret = acpi_dev_get_resources(adev, &resource_list, 2809 acpi_spi_add_resource, &lookup); 2810 acpi_dev_free_resource_list(&resource_list); 2811 2812 if (ret < 0) 2813 /* Found SPI in _CRS but it points to another controller */ 2814 return ERR_PTR(ret); 2815 2816 if (!lookup.max_speed_hz && 2817 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) && 2818 ACPI_HANDLE(lookup.ctlr->dev.parent) == parent_handle) { 2819 /* Apple does not use _CRS but nested devices for SPI slaves */ 2820 acpi_spi_parse_apple_properties(adev, &lookup); 2821 } 2822 2823 if (!lookup.max_speed_hz) 2824 return ERR_PTR(-ENODEV); 2825 2826 spi = spi_alloc_device(lookup.ctlr); 2827 if (!spi) { 2828 dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n", 2829 dev_name(&adev->dev)); 2830 return ERR_PTR(-ENOMEM); 2831 } 2832 2833 spi_set_all_cs_unused(spi); 2834 spi_set_chipselect(spi, 0, lookup.chip_select); 2835 2836 ACPI_COMPANION_SET(&spi->dev, adev); 2837 spi->max_speed_hz = lookup.max_speed_hz; 2838 spi->mode |= lookup.mode; 2839 spi->irq = lookup.irq; 2840 spi->bits_per_word = lookup.bits_per_word; 2841 /* 2842 * By default spi->chip_select[0] will hold the physical CS number, 2843 * so set bit 0 in spi->cs_index_mask. 2844 */ 2845 spi->cs_index_mask = BIT(0); 2846 2847 return spi; 2848 } 2849 EXPORT_SYMBOL_GPL(acpi_spi_device_alloc); 2850 2851 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 2852 struct acpi_device *adev) 2853 { 2854 struct spi_device *spi; 2855 2856 if (acpi_bus_get_status(adev) || !adev->status.present || 2857 acpi_device_enumerated(adev)) 2858 return AE_OK; 2859 2860 spi = acpi_spi_device_alloc(ctlr, adev, -1); 2861 if (IS_ERR(spi)) { 2862 if (PTR_ERR(spi) == -ENOMEM) 2863 return AE_NO_MEMORY; 2864 else 2865 return AE_OK; 2866 } 2867 2868 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias, 2869 sizeof(spi->modalias)); 2870 2871 if (spi->irq < 0) 2872 spi->irq = acpi_dev_gpio_irq_get(adev, 0); 2873 2874 acpi_device_set_enumerated(adev); 2875 2876 adev->power.flags.ignore_parent = true; 2877 if (spi_add_device(spi)) { 2878 adev->power.flags.ignore_parent = false; 2879 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n", 2880 dev_name(&adev->dev)); 2881 spi_dev_put(spi); 2882 } 2883 2884 return AE_OK; 2885 } 2886 2887 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, 2888 void *data, void **return_value) 2889 { 2890 struct acpi_device *adev = acpi_fetch_acpi_dev(handle); 2891 struct spi_controller *ctlr = data; 2892 2893 if (!adev) 2894 return AE_OK; 2895 2896 return acpi_register_spi_device(ctlr, adev); 2897 } 2898 2899 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32 2900 2901 static void acpi_register_spi_devices(struct spi_controller *ctlr) 2902 { 2903 acpi_status status; 2904 acpi_handle handle; 2905 2906 handle = ACPI_HANDLE(ctlr->dev.parent); 2907 if (!handle) 2908 return; 2909 2910 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 2911 SPI_ACPI_ENUMERATE_MAX_DEPTH, 2912 acpi_spi_add_device, NULL, ctlr, NULL); 2913 if (ACPI_FAILURE(status)) 2914 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n"); 2915 } 2916 #else 2917 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {} 2918 #endif /* CONFIG_ACPI */ 2919 2920 static void spi_controller_release(struct device *dev) 2921 { 2922 struct spi_controller *ctlr; 2923 2924 ctlr = container_of(dev, struct spi_controller, dev); 2925 kfree(ctlr); 2926 } 2927 2928 static struct class spi_master_class = { 2929 .name = "spi_master", 2930 .dev_release = spi_controller_release, 2931 .dev_groups = spi_master_groups, 2932 }; 2933 2934 #ifdef CONFIG_SPI_SLAVE 2935 /** 2936 * spi_slave_abort - abort the ongoing transfer request on an SPI slave 2937 * controller 2938 * @spi: device used for the current transfer 2939 */ 2940 int spi_slave_abort(struct spi_device *spi) 2941 { 2942 struct spi_controller *ctlr = spi->controller; 2943 2944 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort) 2945 return ctlr->slave_abort(ctlr); 2946 2947 return -ENOTSUPP; 2948 } 2949 EXPORT_SYMBOL_GPL(spi_slave_abort); 2950 2951 int spi_target_abort(struct spi_device *spi) 2952 { 2953 struct spi_controller *ctlr = spi->controller; 2954 2955 if (spi_controller_is_target(ctlr) && ctlr->target_abort) 2956 return ctlr->target_abort(ctlr); 2957 2958 return -ENOTSUPP; 2959 } 2960 EXPORT_SYMBOL_GPL(spi_target_abort); 2961 2962 static ssize_t slave_show(struct device *dev, struct device_attribute *attr, 2963 char *buf) 2964 { 2965 struct spi_controller *ctlr = container_of(dev, struct spi_controller, 2966 dev); 2967 struct device *child; 2968 2969 child = device_find_any_child(&ctlr->dev); 2970 return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); 2971 } 2972 2973 static ssize_t slave_store(struct device *dev, struct device_attribute *attr, 2974 const char *buf, size_t count) 2975 { 2976 struct spi_controller *ctlr = container_of(dev, struct spi_controller, 2977 dev); 2978 struct spi_device *spi; 2979 struct device *child; 2980 char name[32]; 2981 int rc; 2982 2983 rc = sscanf(buf, "%31s", name); 2984 if (rc != 1 || !name[0]) 2985 return -EINVAL; 2986 2987 child = device_find_any_child(&ctlr->dev); 2988 if (child) { 2989 /* Remove registered slave */ 2990 device_unregister(child); 2991 put_device(child); 2992 } 2993 2994 if (strcmp(name, "(null)")) { 2995 /* Register new slave */ 2996 spi = spi_alloc_device(ctlr); 2997 if (!spi) 2998 return -ENOMEM; 2999 3000 strscpy(spi->modalias, name, sizeof(spi->modalias)); 3001 3002 rc = spi_add_device(spi); 3003 if (rc) { 3004 spi_dev_put(spi); 3005 return rc; 3006 } 3007 } 3008 3009 return count; 3010 } 3011 3012 static DEVICE_ATTR_RW(slave); 3013 3014 static struct attribute *spi_slave_attrs[] = { 3015 &dev_attr_slave.attr, 3016 NULL, 3017 }; 3018 3019 static const struct attribute_group spi_slave_group = { 3020 .attrs = spi_slave_attrs, 3021 }; 3022 3023 static const struct attribute_group *spi_slave_groups[] = { 3024 &spi_controller_statistics_group, 3025 &spi_slave_group, 3026 NULL, 3027 }; 3028 3029 static struct class spi_slave_class = { 3030 .name = "spi_slave", 3031 .dev_release = spi_controller_release, 3032 .dev_groups = spi_slave_groups, 3033 }; 3034 #else 3035 extern struct class spi_slave_class; /* dummy */ 3036 #endif 3037 3038 /** 3039 * __spi_alloc_controller - allocate an SPI master or slave controller 3040 * @dev: the controller, possibly using the platform_bus 3041 * @size: how much zeroed driver-private data to allocate; the pointer to this 3042 * memory is in the driver_data field of the returned device, accessible 3043 * with spi_controller_get_devdata(); the memory is cacheline aligned; 3044 * drivers granting DMA access to portions of their private data need to 3045 * round up @size using ALIGN(size, dma_get_cache_alignment()). 3046 * @slave: flag indicating whether to allocate an SPI master (false) or SPI 3047 * slave (true) controller 3048 * Context: can sleep 3049 * 3050 * This call is used only by SPI controller drivers, which are the 3051 * only ones directly touching chip registers. It's how they allocate 3052 * an spi_controller structure, prior to calling spi_register_controller(). 3053 * 3054 * This must be called from context that can sleep. 3055 * 3056 * The caller is responsible for assigning the bus number and initializing the 3057 * controller's methods before calling spi_register_controller(); and (after 3058 * errors adding the device) calling spi_controller_put() to prevent a memory 3059 * leak. 3060 * 3061 * Return: the SPI controller structure on success, else NULL. 3062 */ 3063 struct spi_controller *__spi_alloc_controller(struct device *dev, 3064 unsigned int size, bool slave) 3065 { 3066 struct spi_controller *ctlr; 3067 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment()); 3068 3069 if (!dev) 3070 return NULL; 3071 3072 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL); 3073 if (!ctlr) 3074 return NULL; 3075 3076 device_initialize(&ctlr->dev); 3077 INIT_LIST_HEAD(&ctlr->queue); 3078 spin_lock_init(&ctlr->queue_lock); 3079 spin_lock_init(&ctlr->bus_lock_spinlock); 3080 mutex_init(&ctlr->bus_lock_mutex); 3081 mutex_init(&ctlr->io_mutex); 3082 mutex_init(&ctlr->add_lock); 3083 ctlr->bus_num = -1; 3084 ctlr->num_chipselect = 1; 3085 ctlr->slave = slave; 3086 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave) 3087 ctlr->dev.class = &spi_slave_class; 3088 else 3089 ctlr->dev.class = &spi_master_class; 3090 ctlr->dev.parent = dev; 3091 pm_suspend_ignore_children(&ctlr->dev, true); 3092 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size); 3093 3094 return ctlr; 3095 } 3096 EXPORT_SYMBOL_GPL(__spi_alloc_controller); 3097 3098 static void devm_spi_release_controller(struct device *dev, void *ctlr) 3099 { 3100 spi_controller_put(*(struct spi_controller **)ctlr); 3101 } 3102 3103 /** 3104 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller() 3105 * @dev: physical device of SPI controller 3106 * @size: how much zeroed driver-private data to allocate 3107 * @slave: whether to allocate an SPI master (false) or SPI slave (true) 3108 * Context: can sleep 3109 * 3110 * Allocate an SPI controller and automatically release a reference on it 3111 * when @dev is unbound from its driver. Drivers are thus relieved from 3112 * having to call spi_controller_put(). 3113 * 3114 * The arguments to this function are identical to __spi_alloc_controller(). 3115 * 3116 * Return: the SPI controller structure on success, else NULL. 3117 */ 3118 struct spi_controller *__devm_spi_alloc_controller(struct device *dev, 3119 unsigned int size, 3120 bool slave) 3121 { 3122 struct spi_controller **ptr, *ctlr; 3123 3124 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr), 3125 GFP_KERNEL); 3126 if (!ptr) 3127 return NULL; 3128 3129 ctlr = __spi_alloc_controller(dev, size, slave); 3130 if (ctlr) { 3131 ctlr->devm_allocated = true; 3132 *ptr = ctlr; 3133 devres_add(dev, ptr); 3134 } else { 3135 devres_free(ptr); 3136 } 3137 3138 return ctlr; 3139 } 3140 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller); 3141 3142 /** 3143 * spi_get_gpio_descs() - grab chip select GPIOs for the master 3144 * @ctlr: The SPI master to grab GPIO descriptors for 3145 */ 3146 static int spi_get_gpio_descs(struct spi_controller *ctlr) 3147 { 3148 int nb, i; 3149 struct gpio_desc **cs; 3150 struct device *dev = &ctlr->dev; 3151 unsigned long native_cs_mask = 0; 3152 unsigned int num_cs_gpios = 0; 3153 3154 nb = gpiod_count(dev, "cs"); 3155 if (nb < 0) { 3156 /* No GPIOs at all is fine, else return the error */ 3157 if (nb == -ENOENT) 3158 return 0; 3159 return nb; 3160 } 3161 3162 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); 3163 3164 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs), 3165 GFP_KERNEL); 3166 if (!cs) 3167 return -ENOMEM; 3168 ctlr->cs_gpiods = cs; 3169 3170 for (i = 0; i < nb; i++) { 3171 /* 3172 * Most chipselects are active low, the inverted 3173 * semantics are handled by special quirks in gpiolib, 3174 * so initializing them GPIOD_OUT_LOW here means 3175 * "unasserted", in most cases this will drive the physical 3176 * line high. 3177 */ 3178 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, 3179 GPIOD_OUT_LOW); 3180 if (IS_ERR(cs[i])) 3181 return PTR_ERR(cs[i]); 3182 3183 if (cs[i]) { 3184 /* 3185 * If we find a CS GPIO, name it after the device and 3186 * chip select line. 3187 */ 3188 char *gpioname; 3189 3190 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d", 3191 dev_name(dev), i); 3192 if (!gpioname) 3193 return -ENOMEM; 3194 gpiod_set_consumer_name(cs[i], gpioname); 3195 num_cs_gpios++; 3196 continue; 3197 } 3198 3199 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { 3200 dev_err(dev, "Invalid native chip select %d\n", i); 3201 return -EINVAL; 3202 } 3203 native_cs_mask |= BIT(i); 3204 } 3205 3206 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; 3207 3208 if ((ctlr->flags & SPI_CONTROLLER_GPIO_SS) && num_cs_gpios && 3209 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) { 3210 dev_err(dev, "No unused native chip select available\n"); 3211 return -EINVAL; 3212 } 3213 3214 return 0; 3215 } 3216 3217 static int spi_controller_check_ops(struct spi_controller *ctlr) 3218 { 3219 /* 3220 * The controller may implement only the high-level SPI-memory like 3221 * operations if it does not support regular SPI transfers, and this is 3222 * valid use case. 3223 * If ->mem_ops or ->mem_ops->exec_op is NULL, we request that at least 3224 * one of the ->transfer_xxx() method be implemented. 3225 */ 3226 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) { 3227 if (!ctlr->transfer && !ctlr->transfer_one && 3228 !ctlr->transfer_one_message) { 3229 return -EINVAL; 3230 } 3231 } 3232 3233 return 0; 3234 } 3235 3236 /* Allocate dynamic bus number using Linux idr */ 3237 static int spi_controller_id_alloc(struct spi_controller *ctlr, int start, int end) 3238 { 3239 int id; 3240 3241 mutex_lock(&board_lock); 3242 id = idr_alloc(&spi_master_idr, ctlr, start, end, GFP_KERNEL); 3243 mutex_unlock(&board_lock); 3244 if (WARN(id < 0, "couldn't get idr")) 3245 return id == -ENOSPC ? -EBUSY : id; 3246 ctlr->bus_num = id; 3247 return 0; 3248 } 3249 3250 /** 3251 * spi_register_controller - register SPI master or slave controller 3252 * @ctlr: initialized master, originally from spi_alloc_master() or 3253 * spi_alloc_slave() 3254 * Context: can sleep 3255 * 3256 * SPI controllers connect to their drivers using some non-SPI bus, 3257 * such as the platform bus. The final stage of probe() in that code 3258 * includes calling spi_register_controller() to hook up to this SPI bus glue. 3259 * 3260 * SPI controllers use board specific (often SOC specific) bus numbers, 3261 * and board-specific addressing for SPI devices combines those numbers 3262 * with chip select numbers. Since SPI does not directly support dynamic 3263 * device identification, boards need configuration tables telling which 3264 * chip is at which address. 3265 * 3266 * This must be called from context that can sleep. It returns zero on 3267 * success, else a negative error code (dropping the controller's refcount). 3268 * After a successful return, the caller is responsible for calling 3269 * spi_unregister_controller(). 3270 * 3271 * Return: zero on success, else a negative error code. 3272 */ 3273 int spi_register_controller(struct spi_controller *ctlr) 3274 { 3275 struct device *dev = ctlr->dev.parent; 3276 struct boardinfo *bi; 3277 int first_dynamic; 3278 int status; 3279 int idx; 3280 3281 if (!dev) 3282 return -ENODEV; 3283 3284 /* 3285 * Make sure all necessary hooks are implemented before registering 3286 * the SPI controller. 3287 */ 3288 status = spi_controller_check_ops(ctlr); 3289 if (status) 3290 return status; 3291 3292 if (ctlr->bus_num < 0) 3293 ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi"); 3294 if (ctlr->bus_num >= 0) { 3295 /* Devices with a fixed bus num must check-in with the num */ 3296 status = spi_controller_id_alloc(ctlr, ctlr->bus_num, ctlr->bus_num + 1); 3297 if (status) 3298 return status; 3299 } 3300 if (ctlr->bus_num < 0) { 3301 first_dynamic = of_alias_get_highest_id("spi"); 3302 if (first_dynamic < 0) 3303 first_dynamic = 0; 3304 else 3305 first_dynamic++; 3306 3307 status = spi_controller_id_alloc(ctlr, first_dynamic, 0); 3308 if (status) 3309 return status; 3310 } 3311 ctlr->bus_lock_flag = 0; 3312 init_completion(&ctlr->xfer_completion); 3313 init_completion(&ctlr->cur_msg_completion); 3314 if (!ctlr->max_dma_len) 3315 ctlr->max_dma_len = INT_MAX; 3316 3317 /* 3318 * Register the device, then userspace will see it. 3319 * Registration fails if the bus ID is in use. 3320 */ 3321 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num); 3322 3323 if (!spi_controller_is_slave(ctlr) && ctlr->use_gpio_descriptors) { 3324 status = spi_get_gpio_descs(ctlr); 3325 if (status) 3326 goto free_bus_id; 3327 /* 3328 * A controller using GPIO descriptors always 3329 * supports SPI_CS_HIGH if need be. 3330 */ 3331 ctlr->mode_bits |= SPI_CS_HIGH; 3332 } 3333 3334 /* 3335 * Even if it's just one always-selected device, there must 3336 * be at least one chipselect. 3337 */ 3338 if (!ctlr->num_chipselect) { 3339 status = -EINVAL; 3340 goto free_bus_id; 3341 } 3342 3343 /* Setting last_cs to SPI_INVALID_CS means no chip selected */ 3344 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) 3345 ctlr->last_cs[idx] = SPI_INVALID_CS; 3346 3347 status = device_add(&ctlr->dev); 3348 if (status < 0) 3349 goto free_bus_id; 3350 dev_dbg(dev, "registered %s %s\n", 3351 spi_controller_is_slave(ctlr) ? "slave" : "master", 3352 dev_name(&ctlr->dev)); 3353 3354 /* 3355 * If we're using a queued driver, start the queue. Note that we don't 3356 * need the queueing logic if the driver is only supporting high-level 3357 * memory operations. 3358 */ 3359 if (ctlr->transfer) { 3360 dev_info(dev, "controller is unqueued, this is deprecated\n"); 3361 } else if (ctlr->transfer_one || ctlr->transfer_one_message) { 3362 status = spi_controller_initialize_queue(ctlr); 3363 if (status) { 3364 device_del(&ctlr->dev); 3365 goto free_bus_id; 3366 } 3367 } 3368 /* Add statistics */ 3369 ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev); 3370 if (!ctlr->pcpu_statistics) { 3371 dev_err(dev, "Error allocating per-cpu statistics\n"); 3372 status = -ENOMEM; 3373 goto destroy_queue; 3374 } 3375 3376 mutex_lock(&board_lock); 3377 list_add_tail(&ctlr->list, &spi_controller_list); 3378 list_for_each_entry(bi, &board_list, list) 3379 spi_match_controller_to_boardinfo(ctlr, &bi->board_info); 3380 mutex_unlock(&board_lock); 3381 3382 /* Register devices from the device tree and ACPI */ 3383 of_register_spi_devices(ctlr); 3384 acpi_register_spi_devices(ctlr); 3385 return status; 3386 3387 destroy_queue: 3388 spi_destroy_queue(ctlr); 3389 free_bus_id: 3390 mutex_lock(&board_lock); 3391 idr_remove(&spi_master_idr, ctlr->bus_num); 3392 mutex_unlock(&board_lock); 3393 return status; 3394 } 3395 EXPORT_SYMBOL_GPL(spi_register_controller); 3396 3397 static void devm_spi_unregister(struct device *dev, void *res) 3398 { 3399 spi_unregister_controller(*(struct spi_controller **)res); 3400 } 3401 3402 /** 3403 * devm_spi_register_controller - register managed SPI master or slave 3404 * controller 3405 * @dev: device managing SPI controller 3406 * @ctlr: initialized controller, originally from spi_alloc_master() or 3407 * spi_alloc_slave() 3408 * Context: can sleep 3409 * 3410 * Register a SPI device as with spi_register_controller() which will 3411 * automatically be unregistered and freed. 3412 * 3413 * Return: zero on success, else a negative error code. 3414 */ 3415 int devm_spi_register_controller(struct device *dev, 3416 struct spi_controller *ctlr) 3417 { 3418 struct spi_controller **ptr; 3419 int ret; 3420 3421 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); 3422 if (!ptr) 3423 return -ENOMEM; 3424 3425 ret = spi_register_controller(ctlr); 3426 if (!ret) { 3427 *ptr = ctlr; 3428 devres_add(dev, ptr); 3429 } else { 3430 devres_free(ptr); 3431 } 3432 3433 return ret; 3434 } 3435 EXPORT_SYMBOL_GPL(devm_spi_register_controller); 3436 3437 static int __unregister(struct device *dev, void *null) 3438 { 3439 spi_unregister_device(to_spi_device(dev)); 3440 return 0; 3441 } 3442 3443 /** 3444 * spi_unregister_controller - unregister SPI master or slave controller 3445 * @ctlr: the controller being unregistered 3446 * Context: can sleep 3447 * 3448 * This call is used only by SPI controller drivers, which are the 3449 * only ones directly touching chip registers. 3450 * 3451 * This must be called from context that can sleep. 3452 * 3453 * Note that this function also drops a reference to the controller. 3454 */ 3455 void spi_unregister_controller(struct spi_controller *ctlr) 3456 { 3457 struct spi_controller *found; 3458 int id = ctlr->bus_num; 3459 3460 /* Prevent addition of new devices, unregister existing ones */ 3461 if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) 3462 mutex_lock(&ctlr->add_lock); 3463 3464 device_for_each_child(&ctlr->dev, NULL, __unregister); 3465 3466 /* First make sure that this controller was ever added */ 3467 mutex_lock(&board_lock); 3468 found = idr_find(&spi_master_idr, id); 3469 mutex_unlock(&board_lock); 3470 if (ctlr->queued) { 3471 if (spi_destroy_queue(ctlr)) 3472 dev_err(&ctlr->dev, "queue remove failed\n"); 3473 } 3474 mutex_lock(&board_lock); 3475 list_del(&ctlr->list); 3476 mutex_unlock(&board_lock); 3477 3478 device_del(&ctlr->dev); 3479 3480 /* Free bus id */ 3481 mutex_lock(&board_lock); 3482 if (found == ctlr) 3483 idr_remove(&spi_master_idr, id); 3484 mutex_unlock(&board_lock); 3485 3486 if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) 3487 mutex_unlock(&ctlr->add_lock); 3488 3489 /* 3490 * Release the last reference on the controller if its driver 3491 * has not yet been converted to devm_spi_alloc_master/slave(). 3492 */ 3493 if (!ctlr->devm_allocated) 3494 put_device(&ctlr->dev); 3495 } 3496 EXPORT_SYMBOL_GPL(spi_unregister_controller); 3497 3498 static inline int __spi_check_suspended(const struct spi_controller *ctlr) 3499 { 3500 return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0; 3501 } 3502 3503 static inline void __spi_mark_suspended(struct spi_controller *ctlr) 3504 { 3505 mutex_lock(&ctlr->bus_lock_mutex); 3506 ctlr->flags |= SPI_CONTROLLER_SUSPENDED; 3507 mutex_unlock(&ctlr->bus_lock_mutex); 3508 } 3509 3510 static inline void __spi_mark_resumed(struct spi_controller *ctlr) 3511 { 3512 mutex_lock(&ctlr->bus_lock_mutex); 3513 ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED; 3514 mutex_unlock(&ctlr->bus_lock_mutex); 3515 } 3516 3517 int spi_controller_suspend(struct spi_controller *ctlr) 3518 { 3519 int ret = 0; 3520 3521 /* Basically no-ops for non-queued controllers */ 3522 if (ctlr->queued) { 3523 ret = spi_stop_queue(ctlr); 3524 if (ret) 3525 dev_err(&ctlr->dev, "queue stop failed\n"); 3526 } 3527 3528 __spi_mark_suspended(ctlr); 3529 return ret; 3530 } 3531 EXPORT_SYMBOL_GPL(spi_controller_suspend); 3532 3533 int spi_controller_resume(struct spi_controller *ctlr) 3534 { 3535 int ret = 0; 3536 3537 __spi_mark_resumed(ctlr); 3538 3539 if (ctlr->queued) { 3540 ret = spi_start_queue(ctlr); 3541 if (ret) 3542 dev_err(&ctlr->dev, "queue restart failed\n"); 3543 } 3544 return ret; 3545 } 3546 EXPORT_SYMBOL_GPL(spi_controller_resume); 3547 3548 /*-------------------------------------------------------------------------*/ 3549 3550 /* Core methods for spi_message alterations */ 3551 3552 static void __spi_replace_transfers_release(struct spi_controller *ctlr, 3553 struct spi_message *msg, 3554 void *res) 3555 { 3556 struct spi_replaced_transfers *rxfer = res; 3557 size_t i; 3558 3559 /* Call extra callback if requested */ 3560 if (rxfer->release) 3561 rxfer->release(ctlr, msg, res); 3562 3563 /* Insert replaced transfers back into the message */ 3564 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); 3565 3566 /* Remove the formerly inserted entries */ 3567 for (i = 0; i < rxfer->inserted; i++) 3568 list_del(&rxfer->inserted_transfers[i].transfer_list); 3569 } 3570 3571 /** 3572 * spi_replace_transfers - replace transfers with several transfers 3573 * and register change with spi_message.resources 3574 * @msg: the spi_message we work upon 3575 * @xfer_first: the first spi_transfer we want to replace 3576 * @remove: number of transfers to remove 3577 * @insert: the number of transfers we want to insert instead 3578 * @release: extra release code necessary in some circumstances 3579 * @extradatasize: extra data to allocate (with alignment guarantees 3580 * of struct @spi_transfer) 3581 * @gfp: gfp flags 3582 * 3583 * Returns: pointer to @spi_replaced_transfers, 3584 * PTR_ERR(...) in case of errors. 3585 */ 3586 static struct spi_replaced_transfers *spi_replace_transfers( 3587 struct spi_message *msg, 3588 struct spi_transfer *xfer_first, 3589 size_t remove, 3590 size_t insert, 3591 spi_replaced_release_t release, 3592 size_t extradatasize, 3593 gfp_t gfp) 3594 { 3595 struct spi_replaced_transfers *rxfer; 3596 struct spi_transfer *xfer; 3597 size_t i; 3598 3599 /* Allocate the structure using spi_res */ 3600 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release, 3601 struct_size(rxfer, inserted_transfers, insert) 3602 + extradatasize, 3603 gfp); 3604 if (!rxfer) 3605 return ERR_PTR(-ENOMEM); 3606 3607 /* The release code to invoke before running the generic release */ 3608 rxfer->release = release; 3609 3610 /* Assign extradata */ 3611 if (extradatasize) 3612 rxfer->extradata = 3613 &rxfer->inserted_transfers[insert]; 3614 3615 /* Init the replaced_transfers list */ 3616 INIT_LIST_HEAD(&rxfer->replaced_transfers); 3617 3618 /* 3619 * Assign the list_entry after which we should reinsert 3620 * the @replaced_transfers - it may be spi_message.messages! 3621 */ 3622 rxfer->replaced_after = xfer_first->transfer_list.prev; 3623 3624 /* Remove the requested number of transfers */ 3625 for (i = 0; i < remove; i++) { 3626 /* 3627 * If the entry after replaced_after it is msg->transfers 3628 * then we have been requested to remove more transfers 3629 * than are in the list. 3630 */ 3631 if (rxfer->replaced_after->next == &msg->transfers) { 3632 dev_err(&msg->spi->dev, 3633 "requested to remove more spi_transfers than are available\n"); 3634 /* Insert replaced transfers back into the message */ 3635 list_splice(&rxfer->replaced_transfers, 3636 rxfer->replaced_after); 3637 3638 /* Free the spi_replace_transfer structure... */ 3639 spi_res_free(rxfer); 3640 3641 /* ...and return with an error */ 3642 return ERR_PTR(-EINVAL); 3643 } 3644 3645 /* 3646 * Remove the entry after replaced_after from list of 3647 * transfers and add it to list of replaced_transfers. 3648 */ 3649 list_move_tail(rxfer->replaced_after->next, 3650 &rxfer->replaced_transfers); 3651 } 3652 3653 /* 3654 * Create copy of the given xfer with identical settings 3655 * based on the first transfer to get removed. 3656 */ 3657 for (i = 0; i < insert; i++) { 3658 /* We need to run in reverse order */ 3659 xfer = &rxfer->inserted_transfers[insert - 1 - i]; 3660 3661 /* Copy all spi_transfer data */ 3662 memcpy(xfer, xfer_first, sizeof(*xfer)); 3663 3664 /* Add to list */ 3665 list_add(&xfer->transfer_list, rxfer->replaced_after); 3666 3667 /* Clear cs_change and delay for all but the last */ 3668 if (i) { 3669 xfer->cs_change = false; 3670 xfer->delay.value = 0; 3671 } 3672 } 3673 3674 /* Set up inserted... */ 3675 rxfer->inserted = insert; 3676 3677 /* ...and register it with spi_res/spi_message */ 3678 spi_res_add(msg, rxfer); 3679 3680 return rxfer; 3681 } 3682 3683 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, 3684 struct spi_message *msg, 3685 struct spi_transfer **xferp, 3686 size_t maxsize) 3687 { 3688 struct spi_transfer *xfer = *xferp, *xfers; 3689 struct spi_replaced_transfers *srt; 3690 size_t offset; 3691 size_t count, i; 3692 3693 /* Calculate how many we have to replace */ 3694 count = DIV_ROUND_UP(xfer->len, maxsize); 3695 3696 /* Create replacement */ 3697 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, GFP_KERNEL); 3698 if (IS_ERR(srt)) 3699 return PTR_ERR(srt); 3700 xfers = srt->inserted_transfers; 3701 3702 /* 3703 * Now handle each of those newly inserted spi_transfers. 3704 * Note that the replacements spi_transfers all are preset 3705 * to the same values as *xferp, so tx_buf, rx_buf and len 3706 * are all identical (as well as most others) 3707 * so we just have to fix up len and the pointers. 3708 * 3709 * This also includes support for the depreciated 3710 * spi_message.is_dma_mapped interface. 3711 */ 3712 3713 /* 3714 * The first transfer just needs the length modified, so we 3715 * run it outside the loop. 3716 */ 3717 xfers[0].len = min_t(size_t, maxsize, xfer[0].len); 3718 3719 /* All the others need rx_buf/tx_buf also set */ 3720 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { 3721 /* Update rx_buf, tx_buf and DMA */ 3722 if (xfers[i].rx_buf) 3723 xfers[i].rx_buf += offset; 3724 if (xfers[i].rx_dma) 3725 xfers[i].rx_dma += offset; 3726 if (xfers[i].tx_buf) 3727 xfers[i].tx_buf += offset; 3728 if (xfers[i].tx_dma) 3729 xfers[i].tx_dma += offset; 3730 3731 /* Update length */ 3732 xfers[i].len = min(maxsize, xfers[i].len - offset); 3733 } 3734 3735 /* 3736 * We set up xferp to the last entry we have inserted, 3737 * so that we skip those already split transfers. 3738 */ 3739 *xferp = &xfers[count - 1]; 3740 3741 /* Increment statistics counters */ 3742 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, 3743 transfers_split_maxsize); 3744 SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics, 3745 transfers_split_maxsize); 3746 3747 return 0; 3748 } 3749 3750 /** 3751 * spi_split_transfers_maxsize - split spi transfers into multiple transfers 3752 * when an individual transfer exceeds a 3753 * certain size 3754 * @ctlr: the @spi_controller for this transfer 3755 * @msg: the @spi_message to transform 3756 * @maxsize: the maximum when to apply this 3757 * 3758 * This function allocates resources that are automatically freed during the 3759 * spi message unoptimize phase so this function should only be called from 3760 * optimize_message callbacks. 3761 * 3762 * Return: status of transformation 3763 */ 3764 int spi_split_transfers_maxsize(struct spi_controller *ctlr, 3765 struct spi_message *msg, 3766 size_t maxsize) 3767 { 3768 struct spi_transfer *xfer; 3769 int ret; 3770 3771 /* 3772 * Iterate over the transfer_list, 3773 * but note that xfer is advanced to the last transfer inserted 3774 * to avoid checking sizes again unnecessarily (also xfer does 3775 * potentially belong to a different list by the time the 3776 * replacement has happened). 3777 */ 3778 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 3779 if (xfer->len > maxsize) { 3780 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, 3781 maxsize); 3782 if (ret) 3783 return ret; 3784 } 3785 } 3786 3787 return 0; 3788 } 3789 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); 3790 3791 3792 /** 3793 * spi_split_transfers_maxwords - split SPI transfers into multiple transfers 3794 * when an individual transfer exceeds a 3795 * certain number of SPI words 3796 * @ctlr: the @spi_controller for this transfer 3797 * @msg: the @spi_message to transform 3798 * @maxwords: the number of words to limit each transfer to 3799 * 3800 * This function allocates resources that are automatically freed during the 3801 * spi message unoptimize phase so this function should only be called from 3802 * optimize_message callbacks. 3803 * 3804 * Return: status of transformation 3805 */ 3806 int spi_split_transfers_maxwords(struct spi_controller *ctlr, 3807 struct spi_message *msg, 3808 size_t maxwords) 3809 { 3810 struct spi_transfer *xfer; 3811 3812 /* 3813 * Iterate over the transfer_list, 3814 * but note that xfer is advanced to the last transfer inserted 3815 * to avoid checking sizes again unnecessarily (also xfer does 3816 * potentially belong to a different list by the time the 3817 * replacement has happened). 3818 */ 3819 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 3820 size_t maxsize; 3821 int ret; 3822 3823 maxsize = maxwords * roundup_pow_of_two(BITS_TO_BYTES(xfer->bits_per_word)); 3824 if (xfer->len > maxsize) { 3825 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, 3826 maxsize); 3827 if (ret) 3828 return ret; 3829 } 3830 } 3831 3832 return 0; 3833 } 3834 EXPORT_SYMBOL_GPL(spi_split_transfers_maxwords); 3835 3836 /*-------------------------------------------------------------------------*/ 3837 3838 /* 3839 * Core methods for SPI controller protocol drivers. Some of the 3840 * other core methods are currently defined as inline functions. 3841 */ 3842 3843 static int __spi_validate_bits_per_word(struct spi_controller *ctlr, 3844 u8 bits_per_word) 3845 { 3846 if (ctlr->bits_per_word_mask) { 3847 /* Only 32 bits fit in the mask */ 3848 if (bits_per_word > 32) 3849 return -EINVAL; 3850 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word))) 3851 return -EINVAL; 3852 } 3853 3854 return 0; 3855 } 3856 3857 /** 3858 * spi_set_cs_timing - configure CS setup, hold, and inactive delays 3859 * @spi: the device that requires specific CS timing configuration 3860 * 3861 * Return: zero on success, else a negative error code. 3862 */ 3863 static int spi_set_cs_timing(struct spi_device *spi) 3864 { 3865 struct device *parent = spi->controller->dev.parent; 3866 int status = 0; 3867 3868 if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) { 3869 if (spi->controller->auto_runtime_pm) { 3870 status = pm_runtime_get_sync(parent); 3871 if (status < 0) { 3872 pm_runtime_put_noidle(parent); 3873 dev_err(&spi->controller->dev, "Failed to power device: %d\n", 3874 status); 3875 return status; 3876 } 3877 3878 status = spi->controller->set_cs_timing(spi); 3879 pm_runtime_mark_last_busy(parent); 3880 pm_runtime_put_autosuspend(parent); 3881 } else { 3882 status = spi->controller->set_cs_timing(spi); 3883 } 3884 } 3885 return status; 3886 } 3887 3888 /** 3889 * spi_setup - setup SPI mode and clock rate 3890 * @spi: the device whose settings are being modified 3891 * Context: can sleep, and no requests are queued to the device 3892 * 3893 * SPI protocol drivers may need to update the transfer mode if the 3894 * device doesn't work with its default. They may likewise need 3895 * to update clock rates or word sizes from initial values. This function 3896 * changes those settings, and must be called from a context that can sleep. 3897 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take 3898 * effect the next time the device is selected and data is transferred to 3899 * or from it. When this function returns, the SPI device is deselected. 3900 * 3901 * Note that this call will fail if the protocol driver specifies an option 3902 * that the underlying controller or its driver does not support. For 3903 * example, not all hardware supports wire transfers using nine bit words, 3904 * LSB-first wire encoding, or active-high chipselects. 3905 * 3906 * Return: zero on success, else a negative error code. 3907 */ 3908 int spi_setup(struct spi_device *spi) 3909 { 3910 unsigned bad_bits, ugly_bits; 3911 int status = 0; 3912 3913 /* 3914 * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO 3915 * are set at the same time. 3916 */ 3917 if ((hweight_long(spi->mode & 3918 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) || 3919 (hweight_long(spi->mode & 3920 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) { 3921 dev_err(&spi->dev, 3922 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n"); 3923 return -EINVAL; 3924 } 3925 /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */ 3926 if ((spi->mode & SPI_3WIRE) && (spi->mode & 3927 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | 3928 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) 3929 return -EINVAL; 3930 /* 3931 * Help drivers fail *cleanly* when they need options 3932 * that aren't supported with their current controller. 3933 * SPI_CS_WORD has a fallback software implementation, 3934 * so it is ignored here. 3935 */ 3936 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | 3937 SPI_NO_TX | SPI_NO_RX); 3938 ugly_bits = bad_bits & 3939 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | 3940 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL); 3941 if (ugly_bits) { 3942 dev_warn(&spi->dev, 3943 "setup: ignoring unsupported mode bits %x\n", 3944 ugly_bits); 3945 spi->mode &= ~ugly_bits; 3946 bad_bits &= ~ugly_bits; 3947 } 3948 if (bad_bits) { 3949 dev_err(&spi->dev, "setup: unsupported mode bits %x\n", 3950 bad_bits); 3951 return -EINVAL; 3952 } 3953 3954 if (!spi->bits_per_word) { 3955 spi->bits_per_word = 8; 3956 } else { 3957 /* 3958 * Some controllers may not support the default 8 bits-per-word 3959 * so only perform the check when this is explicitly provided. 3960 */ 3961 status = __spi_validate_bits_per_word(spi->controller, 3962 spi->bits_per_word); 3963 if (status) 3964 return status; 3965 } 3966 3967 if (spi->controller->max_speed_hz && 3968 (!spi->max_speed_hz || 3969 spi->max_speed_hz > spi->controller->max_speed_hz)) 3970 spi->max_speed_hz = spi->controller->max_speed_hz; 3971 3972 mutex_lock(&spi->controller->io_mutex); 3973 3974 if (spi->controller->setup) { 3975 status = spi->controller->setup(spi); 3976 if (status) { 3977 mutex_unlock(&spi->controller->io_mutex); 3978 dev_err(&spi->controller->dev, "Failed to setup device: %d\n", 3979 status); 3980 return status; 3981 } 3982 } 3983 3984 status = spi_set_cs_timing(spi); 3985 if (status) { 3986 mutex_unlock(&spi->controller->io_mutex); 3987 return status; 3988 } 3989 3990 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { 3991 status = pm_runtime_resume_and_get(spi->controller->dev.parent); 3992 if (status < 0) { 3993 mutex_unlock(&spi->controller->io_mutex); 3994 dev_err(&spi->controller->dev, "Failed to power device: %d\n", 3995 status); 3996 return status; 3997 } 3998 3999 /* 4000 * We do not want to return positive value from pm_runtime_get, 4001 * there are many instances of devices calling spi_setup() and 4002 * checking for a non-zero return value instead of a negative 4003 * return value. 4004 */ 4005 status = 0; 4006 4007 spi_set_cs(spi, false, true); 4008 pm_runtime_mark_last_busy(spi->controller->dev.parent); 4009 pm_runtime_put_autosuspend(spi->controller->dev.parent); 4010 } else { 4011 spi_set_cs(spi, false, true); 4012 } 4013 4014 mutex_unlock(&spi->controller->io_mutex); 4015 4016 if (spi->rt && !spi->controller->rt) { 4017 spi->controller->rt = true; 4018 spi_set_thread_rt(spi->controller); 4019 } 4020 4021 trace_spi_setup(spi, status); 4022 4023 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n", 4024 spi->mode & SPI_MODE_X_MASK, 4025 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", 4026 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", 4027 (spi->mode & SPI_3WIRE) ? "3wire, " : "", 4028 (spi->mode & SPI_LOOP) ? "loopback, " : "", 4029 spi->bits_per_word, spi->max_speed_hz, 4030 status); 4031 4032 return status; 4033 } 4034 EXPORT_SYMBOL_GPL(spi_setup); 4035 4036 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, 4037 struct spi_device *spi) 4038 { 4039 int delay1, delay2; 4040 4041 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); 4042 if (delay1 < 0) 4043 return delay1; 4044 4045 delay2 = spi_delay_to_ns(&spi->word_delay, xfer); 4046 if (delay2 < 0) 4047 return delay2; 4048 4049 if (delay1 < delay2) 4050 memcpy(&xfer->word_delay, &spi->word_delay, 4051 sizeof(xfer->word_delay)); 4052 4053 return 0; 4054 } 4055 4056 static int __spi_validate(struct spi_device *spi, struct spi_message *message) 4057 { 4058 struct spi_controller *ctlr = spi->controller; 4059 struct spi_transfer *xfer; 4060 int w_size; 4061 4062 if (list_empty(&message->transfers)) 4063 return -EINVAL; 4064 4065 message->spi = spi; 4066 4067 /* 4068 * Half-duplex links include original MicroWire, and ones with 4069 * only one data pin like SPI_3WIRE (switches direction) or where 4070 * either MOSI or MISO is missing. They can also be caused by 4071 * software limitations. 4072 */ 4073 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) || 4074 (spi->mode & SPI_3WIRE)) { 4075 unsigned flags = ctlr->flags; 4076 4077 list_for_each_entry(xfer, &message->transfers, transfer_list) { 4078 if (xfer->rx_buf && xfer->tx_buf) 4079 return -EINVAL; 4080 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf) 4081 return -EINVAL; 4082 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf) 4083 return -EINVAL; 4084 } 4085 } 4086 4087 /* 4088 * Set transfer bits_per_word and max speed as spi device default if 4089 * it is not set for this transfer. 4090 * Set transfer tx_nbits and rx_nbits as single transfer default 4091 * (SPI_NBITS_SINGLE) if it is not set for this transfer. 4092 * Ensure transfer word_delay is at least as long as that required by 4093 * device itself. 4094 */ 4095 message->frame_length = 0; 4096 list_for_each_entry(xfer, &message->transfers, transfer_list) { 4097 xfer->effective_speed_hz = 0; 4098 message->frame_length += xfer->len; 4099 if (!xfer->bits_per_word) 4100 xfer->bits_per_word = spi->bits_per_word; 4101 4102 if (!xfer->speed_hz) 4103 xfer->speed_hz = spi->max_speed_hz; 4104 4105 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz) 4106 xfer->speed_hz = ctlr->max_speed_hz; 4107 4108 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word)) 4109 return -EINVAL; 4110 4111 /* 4112 * SPI transfer length should be multiple of SPI word size 4113 * where SPI word size should be power-of-two multiple. 4114 */ 4115 if (xfer->bits_per_word <= 8) 4116 w_size = 1; 4117 else if (xfer->bits_per_word <= 16) 4118 w_size = 2; 4119 else 4120 w_size = 4; 4121 4122 /* No partial transfers accepted */ 4123 if (xfer->len % w_size) 4124 return -EINVAL; 4125 4126 if (xfer->speed_hz && ctlr->min_speed_hz && 4127 xfer->speed_hz < ctlr->min_speed_hz) 4128 return -EINVAL; 4129 4130 if (xfer->tx_buf && !xfer->tx_nbits) 4131 xfer->tx_nbits = SPI_NBITS_SINGLE; 4132 if (xfer->rx_buf && !xfer->rx_nbits) 4133 xfer->rx_nbits = SPI_NBITS_SINGLE; 4134 /* 4135 * Check transfer tx/rx_nbits: 4136 * 1. check the value matches one of single, dual and quad 4137 * 2. check tx/rx_nbits match the mode in spi_device 4138 */ 4139 if (xfer->tx_buf) { 4140 if (spi->mode & SPI_NO_TX) 4141 return -EINVAL; 4142 if (xfer->tx_nbits != SPI_NBITS_SINGLE && 4143 xfer->tx_nbits != SPI_NBITS_DUAL && 4144 xfer->tx_nbits != SPI_NBITS_QUAD) 4145 return -EINVAL; 4146 if ((xfer->tx_nbits == SPI_NBITS_DUAL) && 4147 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) 4148 return -EINVAL; 4149 if ((xfer->tx_nbits == SPI_NBITS_QUAD) && 4150 !(spi->mode & SPI_TX_QUAD)) 4151 return -EINVAL; 4152 } 4153 /* Check transfer rx_nbits */ 4154 if (xfer->rx_buf) { 4155 if (spi->mode & SPI_NO_RX) 4156 return -EINVAL; 4157 if (xfer->rx_nbits != SPI_NBITS_SINGLE && 4158 xfer->rx_nbits != SPI_NBITS_DUAL && 4159 xfer->rx_nbits != SPI_NBITS_QUAD) 4160 return -EINVAL; 4161 if ((xfer->rx_nbits == SPI_NBITS_DUAL) && 4162 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) 4163 return -EINVAL; 4164 if ((xfer->rx_nbits == SPI_NBITS_QUAD) && 4165 !(spi->mode & SPI_RX_QUAD)) 4166 return -EINVAL; 4167 } 4168 4169 if (_spi_xfer_word_delay_update(xfer, spi)) 4170 return -EINVAL; 4171 } 4172 4173 message->status = -EINPROGRESS; 4174 4175 return 0; 4176 } 4177 4178 /* 4179 * spi_split_transfers - generic handling of transfer splitting 4180 * @msg: the message to split 4181 * 4182 * Under certain conditions, a SPI controller may not support arbitrary 4183 * transfer sizes or other features required by a peripheral. This function 4184 * will split the transfers in the message into smaller transfers that are 4185 * supported by the controller. 4186 * 4187 * Controllers with special requirements not covered here can also split 4188 * transfers in the optimize_message() callback. 4189 * 4190 * Context: can sleep 4191 * Return: zero on success, else a negative error code 4192 */ 4193 static int spi_split_transfers(struct spi_message *msg) 4194 { 4195 struct spi_controller *ctlr = msg->spi->controller; 4196 struct spi_transfer *xfer; 4197 int ret; 4198 4199 /* 4200 * If an SPI controller does not support toggling the CS line on each 4201 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO 4202 * for the CS line, we can emulate the CS-per-word hardware function by 4203 * splitting transfers into one-word transfers and ensuring that 4204 * cs_change is set for each transfer. 4205 */ 4206 if ((msg->spi->mode & SPI_CS_WORD) && 4207 (!(ctlr->mode_bits & SPI_CS_WORD) || spi_is_csgpiod(msg->spi))) { 4208 ret = spi_split_transfers_maxwords(ctlr, msg, 1); 4209 if (ret) 4210 return ret; 4211 4212 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 4213 /* Don't change cs_change on the last entry in the list */ 4214 if (list_is_last(&xfer->transfer_list, &msg->transfers)) 4215 break; 4216 4217 xfer->cs_change = 1; 4218 } 4219 } else { 4220 ret = spi_split_transfers_maxsize(ctlr, msg, 4221 spi_max_transfer_size(msg->spi)); 4222 if (ret) 4223 return ret; 4224 } 4225 4226 return 0; 4227 } 4228 4229 /* 4230 * __spi_optimize_message - shared implementation for spi_optimize_message() 4231 * and spi_maybe_optimize_message() 4232 * @spi: the device that will be used for the message 4233 * @msg: the message to optimize 4234 * 4235 * Peripheral drivers will call spi_optimize_message() and the spi core will 4236 * call spi_maybe_optimize_message() instead of calling this directly. 4237 * 4238 * It is not valid to call this on a message that has already been optimized. 4239 * 4240 * Return: zero on success, else a negative error code 4241 */ 4242 static int __spi_optimize_message(struct spi_device *spi, 4243 struct spi_message *msg) 4244 { 4245 struct spi_controller *ctlr = spi->controller; 4246 int ret; 4247 4248 ret = __spi_validate(spi, msg); 4249 if (ret) 4250 return ret; 4251 4252 ret = spi_split_transfers(msg); 4253 if (ret) 4254 return ret; 4255 4256 if (ctlr->optimize_message) { 4257 ret = ctlr->optimize_message(msg); 4258 if (ret) { 4259 spi_res_release(ctlr, msg); 4260 return ret; 4261 } 4262 } 4263 4264 msg->optimized = true; 4265 4266 return 0; 4267 } 4268 4269 /* 4270 * spi_maybe_optimize_message - optimize message if it isn't already pre-optimized 4271 * @spi: the device that will be used for the message 4272 * @msg: the message to optimize 4273 * Return: zero on success, else a negative error code 4274 */ 4275 static int spi_maybe_optimize_message(struct spi_device *spi, 4276 struct spi_message *msg) 4277 { 4278 if (msg->pre_optimized) 4279 return 0; 4280 4281 return __spi_optimize_message(spi, msg); 4282 } 4283 4284 /** 4285 * spi_optimize_message - do any one-time validation and setup for a SPI message 4286 * @spi: the device that will be used for the message 4287 * @msg: the message to optimize 4288 * 4289 * Peripheral drivers that reuse the same message repeatedly may call this to 4290 * perform as much message prep as possible once, rather than repeating it each 4291 * time a message transfer is performed to improve throughput and reduce CPU 4292 * usage. 4293 * 4294 * Once a message has been optimized, it cannot be modified with the exception 4295 * of updating the contents of any xfer->tx_buf (the pointer can't be changed, 4296 * only the data in the memory it points to). 4297 * 4298 * Calls to this function must be balanced with calls to spi_unoptimize_message() 4299 * to avoid leaking resources. 4300 * 4301 * Context: can sleep 4302 * Return: zero on success, else a negative error code 4303 */ 4304 int spi_optimize_message(struct spi_device *spi, struct spi_message *msg) 4305 { 4306 int ret; 4307 4308 ret = __spi_optimize_message(spi, msg); 4309 if (ret) 4310 return ret; 4311 4312 /* 4313 * This flag indicates that the peripheral driver called spi_optimize_message() 4314 * and therefore we shouldn't unoptimize message automatically when finalizing 4315 * the message but rather wait until spi_unoptimize_message() is called 4316 * by the peripheral driver. 4317 */ 4318 msg->pre_optimized = true; 4319 4320 return 0; 4321 } 4322 EXPORT_SYMBOL_GPL(spi_optimize_message); 4323 4324 /** 4325 * spi_unoptimize_message - releases any resources allocated by spi_optimize_message() 4326 * @msg: the message to unoptimize 4327 * 4328 * Calls to this function must be balanced with calls to spi_optimize_message(). 4329 * 4330 * Context: can sleep 4331 */ 4332 void spi_unoptimize_message(struct spi_message *msg) 4333 { 4334 __spi_unoptimize_message(msg); 4335 msg->pre_optimized = false; 4336 } 4337 EXPORT_SYMBOL_GPL(spi_unoptimize_message); 4338 4339 static int __spi_async(struct spi_device *spi, struct spi_message *message) 4340 { 4341 struct spi_controller *ctlr = spi->controller; 4342 struct spi_transfer *xfer; 4343 4344 /* 4345 * Some controllers do not support doing regular SPI transfers. Return 4346 * ENOTSUPP when this is the case. 4347 */ 4348 if (!ctlr->transfer) 4349 return -ENOTSUPP; 4350 4351 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async); 4352 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async); 4353 4354 trace_spi_message_submit(message); 4355 4356 if (!ctlr->ptp_sts_supported) { 4357 list_for_each_entry(xfer, &message->transfers, transfer_list) { 4358 xfer->ptp_sts_word_pre = 0; 4359 ptp_read_system_prets(xfer->ptp_sts); 4360 } 4361 } 4362 4363 return ctlr->transfer(spi, message); 4364 } 4365 4366 /** 4367 * spi_async - asynchronous SPI transfer 4368 * @spi: device with which data will be exchanged 4369 * @message: describes the data transfers, including completion callback 4370 * Context: any (IRQs may be blocked, etc) 4371 * 4372 * This call may be used in_irq and other contexts which can't sleep, 4373 * as well as from task contexts which can sleep. 4374 * 4375 * The completion callback is invoked in a context which can't sleep. 4376 * Before that invocation, the value of message->status is undefined. 4377 * When the callback is issued, message->status holds either zero (to 4378 * indicate complete success) or a negative error code. After that 4379 * callback returns, the driver which issued the transfer request may 4380 * deallocate the associated memory; it's no longer in use by any SPI 4381 * core or controller driver code. 4382 * 4383 * Note that although all messages to a spi_device are handled in 4384 * FIFO order, messages may go to different devices in other orders. 4385 * Some device might be higher priority, or have various "hard" access 4386 * time requirements, for example. 4387 * 4388 * On detection of any fault during the transfer, processing of 4389 * the entire message is aborted, and the device is deselected. 4390 * Until returning from the associated message completion callback, 4391 * no other spi_message queued to that device will be processed. 4392 * (This rule applies equally to all the synchronous transfer calls, 4393 * which are wrappers around this core asynchronous primitive.) 4394 * 4395 * Return: zero on success, else a negative error code. 4396 */ 4397 int spi_async(struct spi_device *spi, struct spi_message *message) 4398 { 4399 struct spi_controller *ctlr = spi->controller; 4400 int ret; 4401 unsigned long flags; 4402 4403 ret = spi_maybe_optimize_message(spi, message); 4404 if (ret) 4405 return ret; 4406 4407 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 4408 4409 if (ctlr->bus_lock_flag) 4410 ret = -EBUSY; 4411 else 4412 ret = __spi_async(spi, message); 4413 4414 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 4415 4416 spi_maybe_unoptimize_message(message); 4417 4418 return ret; 4419 } 4420 EXPORT_SYMBOL_GPL(spi_async); 4421 4422 static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg) 4423 { 4424 bool was_busy; 4425 int ret; 4426 4427 mutex_lock(&ctlr->io_mutex); 4428 4429 was_busy = ctlr->busy; 4430 4431 ctlr->cur_msg = msg; 4432 ret = __spi_pump_transfer_message(ctlr, msg, was_busy); 4433 if (ret) 4434 dev_err(&ctlr->dev, "noqueue transfer failed\n"); 4435 ctlr->cur_msg = NULL; 4436 ctlr->fallback = false; 4437 4438 if (!was_busy) { 4439 kfree(ctlr->dummy_rx); 4440 ctlr->dummy_rx = NULL; 4441 kfree(ctlr->dummy_tx); 4442 ctlr->dummy_tx = NULL; 4443 if (ctlr->unprepare_transfer_hardware && 4444 ctlr->unprepare_transfer_hardware(ctlr)) 4445 dev_err(&ctlr->dev, 4446 "failed to unprepare transfer hardware\n"); 4447 spi_idle_runtime_pm(ctlr); 4448 } 4449 4450 mutex_unlock(&ctlr->io_mutex); 4451 } 4452 4453 /*-------------------------------------------------------------------------*/ 4454 4455 /* 4456 * Utility methods for SPI protocol drivers, layered on 4457 * top of the core. Some other utility methods are defined as 4458 * inline functions. 4459 */ 4460 4461 static void spi_complete(void *arg) 4462 { 4463 complete(arg); 4464 } 4465 4466 static int __spi_sync(struct spi_device *spi, struct spi_message *message) 4467 { 4468 DECLARE_COMPLETION_ONSTACK(done); 4469 unsigned long flags; 4470 int status; 4471 struct spi_controller *ctlr = spi->controller; 4472 4473 if (__spi_check_suspended(ctlr)) { 4474 dev_warn_once(&spi->dev, "Attempted to sync while suspend\n"); 4475 return -ESHUTDOWN; 4476 } 4477 4478 status = spi_maybe_optimize_message(spi, message); 4479 if (status) 4480 return status; 4481 4482 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync); 4483 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync); 4484 4485 /* 4486 * Checking queue_empty here only guarantees async/sync message 4487 * ordering when coming from the same context. It does not need to 4488 * guard against reentrancy from a different context. The io_mutex 4489 * will catch those cases. 4490 */ 4491 if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) { 4492 message->actual_length = 0; 4493 message->status = -EINPROGRESS; 4494 4495 trace_spi_message_submit(message); 4496 4497 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate); 4498 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate); 4499 4500 __spi_transfer_message_noqueue(ctlr, message); 4501 4502 return message->status; 4503 } 4504 4505 /* 4506 * There are messages in the async queue that could have originated 4507 * from the same context, so we need to preserve ordering. 4508 * Therefor we send the message to the async queue and wait until they 4509 * are completed. 4510 */ 4511 message->complete = spi_complete; 4512 message->context = &done; 4513 4514 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 4515 status = __spi_async(spi, message); 4516 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 4517 4518 if (status == 0) { 4519 wait_for_completion(&done); 4520 status = message->status; 4521 } 4522 message->context = NULL; 4523 4524 return status; 4525 } 4526 4527 /** 4528 * spi_sync - blocking/synchronous SPI data transfers 4529 * @spi: device with which data will be exchanged 4530 * @message: describes the data transfers 4531 * Context: can sleep 4532 * 4533 * This call may only be used from a context that may sleep. The sleep 4534 * is non-interruptible, and has no timeout. Low-overhead controller 4535 * drivers may DMA directly into and out of the message buffers. 4536 * 4537 * Note that the SPI device's chip select is active during the message, 4538 * and then is normally disabled between messages. Drivers for some 4539 * frequently-used devices may want to minimize costs of selecting a chip, 4540 * by leaving it selected in anticipation that the next message will go 4541 * to the same chip. (That may increase power usage.) 4542 * 4543 * Also, the caller is guaranteeing that the memory associated with the 4544 * message will not be freed before this call returns. 4545 * 4546 * Return: zero on success, else a negative error code. 4547 */ 4548 int spi_sync(struct spi_device *spi, struct spi_message *message) 4549 { 4550 int ret; 4551 4552 mutex_lock(&spi->controller->bus_lock_mutex); 4553 ret = __spi_sync(spi, message); 4554 mutex_unlock(&spi->controller->bus_lock_mutex); 4555 4556 return ret; 4557 } 4558 EXPORT_SYMBOL_GPL(spi_sync); 4559 4560 /** 4561 * spi_sync_locked - version of spi_sync with exclusive bus usage 4562 * @spi: device with which data will be exchanged 4563 * @message: describes the data transfers 4564 * Context: can sleep 4565 * 4566 * This call may only be used from a context that may sleep. The sleep 4567 * is non-interruptible, and has no timeout. Low-overhead controller 4568 * drivers may DMA directly into and out of the message buffers. 4569 * 4570 * This call should be used by drivers that require exclusive access to the 4571 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must 4572 * be released by a spi_bus_unlock call when the exclusive access is over. 4573 * 4574 * Return: zero on success, else a negative error code. 4575 */ 4576 int spi_sync_locked(struct spi_device *spi, struct spi_message *message) 4577 { 4578 return __spi_sync(spi, message); 4579 } 4580 EXPORT_SYMBOL_GPL(spi_sync_locked); 4581 4582 /** 4583 * spi_bus_lock - obtain a lock for exclusive SPI bus usage 4584 * @ctlr: SPI bus master that should be locked for exclusive bus access 4585 * Context: can sleep 4586 * 4587 * This call may only be used from a context that may sleep. The sleep 4588 * is non-interruptible, and has no timeout. 4589 * 4590 * This call should be used by drivers that require exclusive access to the 4591 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the 4592 * exclusive access is over. Data transfer must be done by spi_sync_locked 4593 * and spi_async_locked calls when the SPI bus lock is held. 4594 * 4595 * Return: always zero. 4596 */ 4597 int spi_bus_lock(struct spi_controller *ctlr) 4598 { 4599 unsigned long flags; 4600 4601 mutex_lock(&ctlr->bus_lock_mutex); 4602 4603 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 4604 ctlr->bus_lock_flag = 1; 4605 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 4606 4607 /* Mutex remains locked until spi_bus_unlock() is called */ 4608 4609 return 0; 4610 } 4611 EXPORT_SYMBOL_GPL(spi_bus_lock); 4612 4613 /** 4614 * spi_bus_unlock - release the lock for exclusive SPI bus usage 4615 * @ctlr: SPI bus master that was locked for exclusive bus access 4616 * Context: can sleep 4617 * 4618 * This call may only be used from a context that may sleep. The sleep 4619 * is non-interruptible, and has no timeout. 4620 * 4621 * This call releases an SPI bus lock previously obtained by an spi_bus_lock 4622 * call. 4623 * 4624 * Return: always zero. 4625 */ 4626 int spi_bus_unlock(struct spi_controller *ctlr) 4627 { 4628 ctlr->bus_lock_flag = 0; 4629 4630 mutex_unlock(&ctlr->bus_lock_mutex); 4631 4632 return 0; 4633 } 4634 EXPORT_SYMBOL_GPL(spi_bus_unlock); 4635 4636 /* Portable code must never pass more than 32 bytes */ 4637 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) 4638 4639 static u8 *buf; 4640 4641 /** 4642 * spi_write_then_read - SPI synchronous write followed by read 4643 * @spi: device with which data will be exchanged 4644 * @txbuf: data to be written (need not be DMA-safe) 4645 * @n_tx: size of txbuf, in bytes 4646 * @rxbuf: buffer into which data will be read (need not be DMA-safe) 4647 * @n_rx: size of rxbuf, in bytes 4648 * Context: can sleep 4649 * 4650 * This performs a half duplex MicroWire style transaction with the 4651 * device, sending txbuf and then reading rxbuf. The return value 4652 * is zero for success, else a negative errno status code. 4653 * This call may only be used from a context that may sleep. 4654 * 4655 * Parameters to this routine are always copied using a small buffer. 4656 * Performance-sensitive or bulk transfer code should instead use 4657 * spi_{async,sync}() calls with DMA-safe buffers. 4658 * 4659 * Return: zero on success, else a negative error code. 4660 */ 4661 int spi_write_then_read(struct spi_device *spi, 4662 const void *txbuf, unsigned n_tx, 4663 void *rxbuf, unsigned n_rx) 4664 { 4665 static DEFINE_MUTEX(lock); 4666 4667 int status; 4668 struct spi_message message; 4669 struct spi_transfer x[2]; 4670 u8 *local_buf; 4671 4672 /* 4673 * Use preallocated DMA-safe buffer if we can. We can't avoid 4674 * copying here, (as a pure convenience thing), but we can 4675 * keep heap costs out of the hot path unless someone else is 4676 * using the pre-allocated buffer or the transfer is too large. 4677 */ 4678 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { 4679 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), 4680 GFP_KERNEL | GFP_DMA); 4681 if (!local_buf) 4682 return -ENOMEM; 4683 } else { 4684 local_buf = buf; 4685 } 4686 4687 spi_message_init(&message); 4688 memset(x, 0, sizeof(x)); 4689 if (n_tx) { 4690 x[0].len = n_tx; 4691 spi_message_add_tail(&x[0], &message); 4692 } 4693 if (n_rx) { 4694 x[1].len = n_rx; 4695 spi_message_add_tail(&x[1], &message); 4696 } 4697 4698 memcpy(local_buf, txbuf, n_tx); 4699 x[0].tx_buf = local_buf; 4700 x[1].rx_buf = local_buf + n_tx; 4701 4702 /* Do the I/O */ 4703 status = spi_sync(spi, &message); 4704 if (status == 0) 4705 memcpy(rxbuf, x[1].rx_buf, n_rx); 4706 4707 if (x[0].tx_buf == buf) 4708 mutex_unlock(&lock); 4709 else 4710 kfree(local_buf); 4711 4712 return status; 4713 } 4714 EXPORT_SYMBOL_GPL(spi_write_then_read); 4715 4716 /*-------------------------------------------------------------------------*/ 4717 4718 #if IS_ENABLED(CONFIG_OF_DYNAMIC) 4719 /* Must call put_device() when done with returned spi_device device */ 4720 static struct spi_device *of_find_spi_device_by_node(struct device_node *node) 4721 { 4722 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node); 4723 4724 return dev ? to_spi_device(dev) : NULL; 4725 } 4726 4727 /* The spi controllers are not using spi_bus, so we find it with another way */ 4728 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node) 4729 { 4730 struct device *dev; 4731 4732 dev = class_find_device_by_of_node(&spi_master_class, node); 4733 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) 4734 dev = class_find_device_by_of_node(&spi_slave_class, node); 4735 if (!dev) 4736 return NULL; 4737 4738 /* Reference got in class_find_device */ 4739 return container_of(dev, struct spi_controller, dev); 4740 } 4741 4742 static int of_spi_notify(struct notifier_block *nb, unsigned long action, 4743 void *arg) 4744 { 4745 struct of_reconfig_data *rd = arg; 4746 struct spi_controller *ctlr; 4747 struct spi_device *spi; 4748 4749 switch (of_reconfig_get_state_change(action, arg)) { 4750 case OF_RECONFIG_CHANGE_ADD: 4751 ctlr = of_find_spi_controller_by_node(rd->dn->parent); 4752 if (ctlr == NULL) 4753 return NOTIFY_OK; /* Not for us */ 4754 4755 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { 4756 put_device(&ctlr->dev); 4757 return NOTIFY_OK; 4758 } 4759 4760 /* 4761 * Clear the flag before adding the device so that fw_devlink 4762 * doesn't skip adding consumers to this device. 4763 */ 4764 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE; 4765 spi = of_register_spi_device(ctlr, rd->dn); 4766 put_device(&ctlr->dev); 4767 4768 if (IS_ERR(spi)) { 4769 pr_err("%s: failed to create for '%pOF'\n", 4770 __func__, rd->dn); 4771 of_node_clear_flag(rd->dn, OF_POPULATED); 4772 return notifier_from_errno(PTR_ERR(spi)); 4773 } 4774 break; 4775 4776 case OF_RECONFIG_CHANGE_REMOVE: 4777 /* Already depopulated? */ 4778 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 4779 return NOTIFY_OK; 4780 4781 /* Find our device by node */ 4782 spi = of_find_spi_device_by_node(rd->dn); 4783 if (spi == NULL) 4784 return NOTIFY_OK; /* No? not meant for us */ 4785 4786 /* Unregister takes one ref away */ 4787 spi_unregister_device(spi); 4788 4789 /* And put the reference of the find */ 4790 put_device(&spi->dev); 4791 break; 4792 } 4793 4794 return NOTIFY_OK; 4795 } 4796 4797 static struct notifier_block spi_of_notifier = { 4798 .notifier_call = of_spi_notify, 4799 }; 4800 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ 4801 extern struct notifier_block spi_of_notifier; 4802 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ 4803 4804 #if IS_ENABLED(CONFIG_ACPI) 4805 static int spi_acpi_controller_match(struct device *dev, const void *data) 4806 { 4807 return ACPI_COMPANION(dev->parent) == data; 4808 } 4809 4810 struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev) 4811 { 4812 struct device *dev; 4813 4814 dev = class_find_device(&spi_master_class, NULL, adev, 4815 spi_acpi_controller_match); 4816 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) 4817 dev = class_find_device(&spi_slave_class, NULL, adev, 4818 spi_acpi_controller_match); 4819 if (!dev) 4820 return NULL; 4821 4822 return container_of(dev, struct spi_controller, dev); 4823 } 4824 EXPORT_SYMBOL_GPL(acpi_spi_find_controller_by_adev); 4825 4826 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) 4827 { 4828 struct device *dev; 4829 4830 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev); 4831 return to_spi_device(dev); 4832 } 4833 4834 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, 4835 void *arg) 4836 { 4837 struct acpi_device *adev = arg; 4838 struct spi_controller *ctlr; 4839 struct spi_device *spi; 4840 4841 switch (value) { 4842 case ACPI_RECONFIG_DEVICE_ADD: 4843 ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev)); 4844 if (!ctlr) 4845 break; 4846 4847 acpi_register_spi_device(ctlr, adev); 4848 put_device(&ctlr->dev); 4849 break; 4850 case ACPI_RECONFIG_DEVICE_REMOVE: 4851 if (!acpi_device_enumerated(adev)) 4852 break; 4853 4854 spi = acpi_spi_find_device_by_adev(adev); 4855 if (!spi) 4856 break; 4857 4858 spi_unregister_device(spi); 4859 put_device(&spi->dev); 4860 break; 4861 } 4862 4863 return NOTIFY_OK; 4864 } 4865 4866 static struct notifier_block spi_acpi_notifier = { 4867 .notifier_call = acpi_spi_notify, 4868 }; 4869 #else 4870 extern struct notifier_block spi_acpi_notifier; 4871 #endif 4872 4873 static int __init spi_init(void) 4874 { 4875 int status; 4876 4877 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); 4878 if (!buf) { 4879 status = -ENOMEM; 4880 goto err0; 4881 } 4882 4883 status = bus_register(&spi_bus_type); 4884 if (status < 0) 4885 goto err1; 4886 4887 status = class_register(&spi_master_class); 4888 if (status < 0) 4889 goto err2; 4890 4891 if (IS_ENABLED(CONFIG_SPI_SLAVE)) { 4892 status = class_register(&spi_slave_class); 4893 if (status < 0) 4894 goto err3; 4895 } 4896 4897 if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 4898 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); 4899 if (IS_ENABLED(CONFIG_ACPI)) 4900 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); 4901 4902 return 0; 4903 4904 err3: 4905 class_unregister(&spi_master_class); 4906 err2: 4907 bus_unregister(&spi_bus_type); 4908 err1: 4909 kfree(buf); 4910 buf = NULL; 4911 err0: 4912 return status; 4913 } 4914 4915 /* 4916 * A board_info is normally registered in arch_initcall(), 4917 * but even essential drivers wait till later. 4918 * 4919 * REVISIT only boardinfo really needs static linking. The rest (device and 4920 * driver registration) _could_ be dynamically linked (modular) ... Costs 4921 * include needing to have boardinfo data structures be much more public. 4922 */ 4923 postcore_initcall(spi_init); 4924