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/kernel.h> 8 #include <linux/device.h> 9 #include <linux/init.h> 10 #include <linux/cache.h> 11 #include <linux/dma-mapping.h> 12 #include <linux/dmaengine.h> 13 #include <linux/mutex.h> 14 #include <linux/of_device.h> 15 #include <linux/of_irq.h> 16 #include <linux/clk/clk-conf.h> 17 #include <linux/slab.h> 18 #include <linux/mod_devicetable.h> 19 #include <linux/spi/spi.h> 20 #include <linux/spi/spi-mem.h> 21 #include <linux/of_gpio.h> 22 #include <linux/gpio/consumer.h> 23 #include <linux/pm_runtime.h> 24 #include <linux/pm_domain.h> 25 #include <linux/property.h> 26 #include <linux/export.h> 27 #include <linux/sched/rt.h> 28 #include <uapi/linux/sched/types.h> 29 #include <linux/delay.h> 30 #include <linux/kthread.h> 31 #include <linux/ioport.h> 32 #include <linux/acpi.h> 33 #include <linux/highmem.h> 34 #include <linux/idr.h> 35 #include <linux/platform_data/x86/apple.h> 36 37 #define CREATE_TRACE_POINTS 38 #include <trace/events/spi.h> 39 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start); 40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop); 41 42 #include "internals.h" 43 44 static DEFINE_IDR(spi_master_idr); 45 46 static void spidev_release(struct device *dev) 47 { 48 struct spi_device *spi = to_spi_device(dev); 49 50 spi_controller_put(spi->controller); 51 kfree(spi->driver_override); 52 kfree(spi); 53 } 54 55 static ssize_t 56 modalias_show(struct device *dev, struct device_attribute *a, char *buf) 57 { 58 const struct spi_device *spi = to_spi_device(dev); 59 int len; 60 61 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 62 if (len != -ENODEV) 63 return len; 64 65 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); 66 } 67 static DEVICE_ATTR_RO(modalias); 68 69 static ssize_t driver_override_store(struct device *dev, 70 struct device_attribute *a, 71 const char *buf, size_t count) 72 { 73 struct spi_device *spi = to_spi_device(dev); 74 const char *end = memchr(buf, '\n', count); 75 const size_t len = end ? end - buf : count; 76 const char *driver_override, *old; 77 78 /* We need to keep extra room for a newline when displaying value */ 79 if (len >= (PAGE_SIZE - 1)) 80 return -EINVAL; 81 82 driver_override = kstrndup(buf, len, GFP_KERNEL); 83 if (!driver_override) 84 return -ENOMEM; 85 86 device_lock(dev); 87 old = spi->driver_override; 88 if (len) { 89 spi->driver_override = driver_override; 90 } else { 91 /* Empty string, disable driver override */ 92 spi->driver_override = NULL; 93 kfree(driver_override); 94 } 95 device_unlock(dev); 96 kfree(old); 97 98 return count; 99 } 100 101 static ssize_t driver_override_show(struct device *dev, 102 struct device_attribute *a, char *buf) 103 { 104 const struct spi_device *spi = to_spi_device(dev); 105 ssize_t len; 106 107 device_lock(dev); 108 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : ""); 109 device_unlock(dev); 110 return len; 111 } 112 static DEVICE_ATTR_RW(driver_override); 113 114 #define SPI_STATISTICS_ATTRS(field, file) \ 115 static ssize_t spi_controller_##field##_show(struct device *dev, \ 116 struct device_attribute *attr, \ 117 char *buf) \ 118 { \ 119 struct spi_controller *ctlr = container_of(dev, \ 120 struct spi_controller, dev); \ 121 return spi_statistics_##field##_show(&ctlr->statistics, buf); \ 122 } \ 123 static struct device_attribute dev_attr_spi_controller_##field = { \ 124 .attr = { .name = file, .mode = 0444 }, \ 125 .show = spi_controller_##field##_show, \ 126 }; \ 127 static ssize_t spi_device_##field##_show(struct device *dev, \ 128 struct device_attribute *attr, \ 129 char *buf) \ 130 { \ 131 struct spi_device *spi = to_spi_device(dev); \ 132 return spi_statistics_##field##_show(&spi->statistics, buf); \ 133 } \ 134 static struct device_attribute dev_attr_spi_device_##field = { \ 135 .attr = { .name = file, .mode = 0444 }, \ 136 .show = spi_device_##field##_show, \ 137 } 138 139 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \ 140 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \ 141 char *buf) \ 142 { \ 143 unsigned long flags; \ 144 ssize_t len; \ 145 spin_lock_irqsave(&stat->lock, flags); \ 146 len = sprintf(buf, format_string, stat->field); \ 147 spin_unlock_irqrestore(&stat->lock, flags); \ 148 return len; \ 149 } \ 150 SPI_STATISTICS_ATTRS(name, file) 151 152 #define SPI_STATISTICS_SHOW(field, format_string) \ 153 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ 154 field, format_string) 155 156 SPI_STATISTICS_SHOW(messages, "%lu"); 157 SPI_STATISTICS_SHOW(transfers, "%lu"); 158 SPI_STATISTICS_SHOW(errors, "%lu"); 159 SPI_STATISTICS_SHOW(timedout, "%lu"); 160 161 SPI_STATISTICS_SHOW(spi_sync, "%lu"); 162 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu"); 163 SPI_STATISTICS_SHOW(spi_async, "%lu"); 164 165 SPI_STATISTICS_SHOW(bytes, "%llu"); 166 SPI_STATISTICS_SHOW(bytes_rx, "%llu"); 167 SPI_STATISTICS_SHOW(bytes_tx, "%llu"); 168 169 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ 170 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ 171 "transfer_bytes_histo_" number, \ 172 transfer_bytes_histo[index], "%lu") 173 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); 174 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); 175 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); 176 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); 177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); 178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); 179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); 180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); 181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); 182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); 183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); 184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); 185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); 186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); 187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); 188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); 189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); 190 191 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu"); 192 193 static struct attribute *spi_dev_attrs[] = { 194 &dev_attr_modalias.attr, 195 &dev_attr_driver_override.attr, 196 NULL, 197 }; 198 199 static const struct attribute_group spi_dev_group = { 200 .attrs = spi_dev_attrs, 201 }; 202 203 static struct attribute *spi_device_statistics_attrs[] = { 204 &dev_attr_spi_device_messages.attr, 205 &dev_attr_spi_device_transfers.attr, 206 &dev_attr_spi_device_errors.attr, 207 &dev_attr_spi_device_timedout.attr, 208 &dev_attr_spi_device_spi_sync.attr, 209 &dev_attr_spi_device_spi_sync_immediate.attr, 210 &dev_attr_spi_device_spi_async.attr, 211 &dev_attr_spi_device_bytes.attr, 212 &dev_attr_spi_device_bytes_rx.attr, 213 &dev_attr_spi_device_bytes_tx.attr, 214 &dev_attr_spi_device_transfer_bytes_histo0.attr, 215 &dev_attr_spi_device_transfer_bytes_histo1.attr, 216 &dev_attr_spi_device_transfer_bytes_histo2.attr, 217 &dev_attr_spi_device_transfer_bytes_histo3.attr, 218 &dev_attr_spi_device_transfer_bytes_histo4.attr, 219 &dev_attr_spi_device_transfer_bytes_histo5.attr, 220 &dev_attr_spi_device_transfer_bytes_histo6.attr, 221 &dev_attr_spi_device_transfer_bytes_histo7.attr, 222 &dev_attr_spi_device_transfer_bytes_histo8.attr, 223 &dev_attr_spi_device_transfer_bytes_histo9.attr, 224 &dev_attr_spi_device_transfer_bytes_histo10.attr, 225 &dev_attr_spi_device_transfer_bytes_histo11.attr, 226 &dev_attr_spi_device_transfer_bytes_histo12.attr, 227 &dev_attr_spi_device_transfer_bytes_histo13.attr, 228 &dev_attr_spi_device_transfer_bytes_histo14.attr, 229 &dev_attr_spi_device_transfer_bytes_histo15.attr, 230 &dev_attr_spi_device_transfer_bytes_histo16.attr, 231 &dev_attr_spi_device_transfers_split_maxsize.attr, 232 NULL, 233 }; 234 235 static const struct attribute_group spi_device_statistics_group = { 236 .name = "statistics", 237 .attrs = spi_device_statistics_attrs, 238 }; 239 240 static const struct attribute_group *spi_dev_groups[] = { 241 &spi_dev_group, 242 &spi_device_statistics_group, 243 NULL, 244 }; 245 246 static struct attribute *spi_controller_statistics_attrs[] = { 247 &dev_attr_spi_controller_messages.attr, 248 &dev_attr_spi_controller_transfers.attr, 249 &dev_attr_spi_controller_errors.attr, 250 &dev_attr_spi_controller_timedout.attr, 251 &dev_attr_spi_controller_spi_sync.attr, 252 &dev_attr_spi_controller_spi_sync_immediate.attr, 253 &dev_attr_spi_controller_spi_async.attr, 254 &dev_attr_spi_controller_bytes.attr, 255 &dev_attr_spi_controller_bytes_rx.attr, 256 &dev_attr_spi_controller_bytes_tx.attr, 257 &dev_attr_spi_controller_transfer_bytes_histo0.attr, 258 &dev_attr_spi_controller_transfer_bytes_histo1.attr, 259 &dev_attr_spi_controller_transfer_bytes_histo2.attr, 260 &dev_attr_spi_controller_transfer_bytes_histo3.attr, 261 &dev_attr_spi_controller_transfer_bytes_histo4.attr, 262 &dev_attr_spi_controller_transfer_bytes_histo5.attr, 263 &dev_attr_spi_controller_transfer_bytes_histo6.attr, 264 &dev_attr_spi_controller_transfer_bytes_histo7.attr, 265 &dev_attr_spi_controller_transfer_bytes_histo8.attr, 266 &dev_attr_spi_controller_transfer_bytes_histo9.attr, 267 &dev_attr_spi_controller_transfer_bytes_histo10.attr, 268 &dev_attr_spi_controller_transfer_bytes_histo11.attr, 269 &dev_attr_spi_controller_transfer_bytes_histo12.attr, 270 &dev_attr_spi_controller_transfer_bytes_histo13.attr, 271 &dev_attr_spi_controller_transfer_bytes_histo14.attr, 272 &dev_attr_spi_controller_transfer_bytes_histo15.attr, 273 &dev_attr_spi_controller_transfer_bytes_histo16.attr, 274 &dev_attr_spi_controller_transfers_split_maxsize.attr, 275 NULL, 276 }; 277 278 static const struct attribute_group spi_controller_statistics_group = { 279 .name = "statistics", 280 .attrs = spi_controller_statistics_attrs, 281 }; 282 283 static const struct attribute_group *spi_master_groups[] = { 284 &spi_controller_statistics_group, 285 NULL, 286 }; 287 288 void spi_statistics_add_transfer_stats(struct spi_statistics *stats, 289 struct spi_transfer *xfer, 290 struct spi_controller *ctlr) 291 { 292 unsigned long flags; 293 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; 294 295 if (l2len < 0) 296 l2len = 0; 297 298 spin_lock_irqsave(&stats->lock, flags); 299 300 stats->transfers++; 301 stats->transfer_bytes_histo[l2len]++; 302 303 stats->bytes += xfer->len; 304 if ((xfer->tx_buf) && 305 (xfer->tx_buf != ctlr->dummy_tx)) 306 stats->bytes_tx += xfer->len; 307 if ((xfer->rx_buf) && 308 (xfer->rx_buf != ctlr->dummy_rx)) 309 stats->bytes_rx += xfer->len; 310 311 spin_unlock_irqrestore(&stats->lock, flags); 312 } 313 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats); 314 315 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, 316 * and the sysfs version makes coldplug work too. 317 */ 318 319 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, 320 const struct spi_device *sdev) 321 { 322 while (id->name[0]) { 323 if (!strcmp(sdev->modalias, id->name)) 324 return id; 325 id++; 326 } 327 return NULL; 328 } 329 330 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) 331 { 332 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); 333 334 return spi_match_id(sdrv->id_table, sdev); 335 } 336 EXPORT_SYMBOL_GPL(spi_get_device_id); 337 338 static int spi_match_device(struct device *dev, struct device_driver *drv) 339 { 340 const struct spi_device *spi = to_spi_device(dev); 341 const struct spi_driver *sdrv = to_spi_driver(drv); 342 343 /* Check override first, and if set, only use the named driver */ 344 if (spi->driver_override) 345 return strcmp(spi->driver_override, drv->name) == 0; 346 347 /* Attempt an OF style match */ 348 if (of_driver_match_device(dev, drv)) 349 return 1; 350 351 /* Then try ACPI */ 352 if (acpi_driver_match_device(dev, drv)) 353 return 1; 354 355 if (sdrv->id_table) 356 return !!spi_match_id(sdrv->id_table, spi); 357 358 return strcmp(spi->modalias, drv->name) == 0; 359 } 360 361 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) 362 { 363 const struct spi_device *spi = to_spi_device(dev); 364 int rc; 365 366 rc = acpi_device_uevent_modalias(dev, env); 367 if (rc != -ENODEV) 368 return rc; 369 370 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); 371 } 372 373 static int spi_probe(struct device *dev) 374 { 375 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 376 struct spi_device *spi = to_spi_device(dev); 377 int ret; 378 379 ret = of_clk_set_defaults(dev->of_node, false); 380 if (ret) 381 return ret; 382 383 if (dev->of_node) { 384 spi->irq = of_irq_get(dev->of_node, 0); 385 if (spi->irq == -EPROBE_DEFER) 386 return -EPROBE_DEFER; 387 if (spi->irq < 0) 388 spi->irq = 0; 389 } 390 391 ret = dev_pm_domain_attach(dev, true); 392 if (ret) 393 return ret; 394 395 if (sdrv->probe) { 396 ret = sdrv->probe(spi); 397 if (ret) 398 dev_pm_domain_detach(dev, true); 399 } 400 401 return ret; 402 } 403 404 static void spi_remove(struct device *dev) 405 { 406 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 407 408 if (sdrv->remove) { 409 int ret; 410 411 ret = sdrv->remove(to_spi_device(dev)); 412 if (ret) 413 dev_warn(dev, 414 "Failed to unbind driver (%pe), ignoring\n", 415 ERR_PTR(ret)); 416 } 417 418 dev_pm_domain_detach(dev, true); 419 } 420 421 static void spi_shutdown(struct device *dev) 422 { 423 if (dev->driver) { 424 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 425 426 if (sdrv->shutdown) 427 sdrv->shutdown(to_spi_device(dev)); 428 } 429 } 430 431 struct bus_type spi_bus_type = { 432 .name = "spi", 433 .dev_groups = spi_dev_groups, 434 .match = spi_match_device, 435 .uevent = spi_uevent, 436 .probe = spi_probe, 437 .remove = spi_remove, 438 .shutdown = spi_shutdown, 439 }; 440 EXPORT_SYMBOL_GPL(spi_bus_type); 441 442 /** 443 * __spi_register_driver - register a SPI driver 444 * @owner: owner module of the driver to register 445 * @sdrv: the driver to register 446 * Context: can sleep 447 * 448 * Return: zero on success, else a negative error code. 449 */ 450 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) 451 { 452 sdrv->driver.owner = owner; 453 sdrv->driver.bus = &spi_bus_type; 454 return driver_register(&sdrv->driver); 455 } 456 EXPORT_SYMBOL_GPL(__spi_register_driver); 457 458 /*-------------------------------------------------------------------------*/ 459 460 /* SPI devices should normally not be created by SPI device drivers; that 461 * would make them board-specific. Similarly with SPI controller drivers. 462 * Device registration normally goes into like arch/.../mach.../board-YYY.c 463 * with other readonly (flashable) information about mainboard devices. 464 */ 465 466 struct boardinfo { 467 struct list_head list; 468 struct spi_board_info board_info; 469 }; 470 471 static LIST_HEAD(board_list); 472 static LIST_HEAD(spi_controller_list); 473 474 /* 475 * Used to protect add/del operation for board_info list and 476 * spi_controller list, and their matching process 477 * also used to protect object of type struct idr 478 */ 479 static DEFINE_MUTEX(board_lock); 480 481 /** 482 * spi_alloc_device - Allocate a new SPI device 483 * @ctlr: Controller to which device is connected 484 * Context: can sleep 485 * 486 * Allows a driver to allocate and initialize a spi_device without 487 * registering it immediately. This allows a driver to directly 488 * fill the spi_device with device parameters before calling 489 * spi_add_device() on it. 490 * 491 * Caller is responsible to call spi_add_device() on the returned 492 * spi_device structure to add it to the SPI controller. If the caller 493 * needs to discard the spi_device without adding it, then it should 494 * call spi_dev_put() on it. 495 * 496 * Return: a pointer to the new device, or NULL. 497 */ 498 struct spi_device *spi_alloc_device(struct spi_controller *ctlr) 499 { 500 struct spi_device *spi; 501 502 if (!spi_controller_get(ctlr)) 503 return NULL; 504 505 spi = kzalloc(sizeof(*spi), GFP_KERNEL); 506 if (!spi) { 507 spi_controller_put(ctlr); 508 return NULL; 509 } 510 511 spi->master = spi->controller = ctlr; 512 spi->dev.parent = &ctlr->dev; 513 spi->dev.bus = &spi_bus_type; 514 spi->dev.release = spidev_release; 515 spi->cs_gpio = -ENOENT; 516 spi->mode = ctlr->buswidth_override_bits; 517 518 spin_lock_init(&spi->statistics.lock); 519 520 device_initialize(&spi->dev); 521 return spi; 522 } 523 EXPORT_SYMBOL_GPL(spi_alloc_device); 524 525 static void spi_dev_set_name(struct spi_device *spi) 526 { 527 struct acpi_device *adev = ACPI_COMPANION(&spi->dev); 528 529 if (adev) { 530 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); 531 return; 532 } 533 534 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev), 535 spi->chip_select); 536 } 537 538 static int spi_dev_check(struct device *dev, void *data) 539 { 540 struct spi_device *spi = to_spi_device(dev); 541 struct spi_device *new_spi = data; 542 543 if (spi->controller == new_spi->controller && 544 spi->chip_select == new_spi->chip_select) 545 return -EBUSY; 546 return 0; 547 } 548 549 static void spi_cleanup(struct spi_device *spi) 550 { 551 if (spi->controller->cleanup) 552 spi->controller->cleanup(spi); 553 } 554 555 static int __spi_add_device(struct spi_device *spi) 556 { 557 struct spi_controller *ctlr = spi->controller; 558 struct device *dev = ctlr->dev.parent; 559 int status; 560 561 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); 562 if (status) { 563 dev_err(dev, "chipselect %d already in use\n", 564 spi->chip_select); 565 return status; 566 } 567 568 /* Controller may unregister concurrently */ 569 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && 570 !device_is_registered(&ctlr->dev)) { 571 return -ENODEV; 572 } 573 574 /* Descriptors take precedence */ 575 if (ctlr->cs_gpiods) 576 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select]; 577 else if (ctlr->cs_gpios) 578 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select]; 579 580 /* Drivers may modify this initial i/o setup, but will 581 * normally rely on the device being setup. Devices 582 * using SPI_CS_HIGH can't coexist well otherwise... 583 */ 584 status = spi_setup(spi); 585 if (status < 0) { 586 dev_err(dev, "can't setup %s, status %d\n", 587 dev_name(&spi->dev), status); 588 return status; 589 } 590 591 /* Device may be bound to an active driver when this returns */ 592 status = device_add(&spi->dev); 593 if (status < 0) { 594 dev_err(dev, "can't add %s, status %d\n", 595 dev_name(&spi->dev), status); 596 spi_cleanup(spi); 597 } else { 598 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); 599 } 600 601 return status; 602 } 603 604 /** 605 * spi_add_device - Add spi_device allocated with spi_alloc_device 606 * @spi: spi_device to register 607 * 608 * Companion function to spi_alloc_device. Devices allocated with 609 * spi_alloc_device can be added onto the spi bus with this function. 610 * 611 * Return: 0 on success; negative errno on failure 612 */ 613 int spi_add_device(struct spi_device *spi) 614 { 615 struct spi_controller *ctlr = spi->controller; 616 struct device *dev = ctlr->dev.parent; 617 int status; 618 619 /* Chipselects are numbered 0..max; validate. */ 620 if (spi->chip_select >= ctlr->num_chipselect) { 621 dev_err(dev, "cs%d >= max %d\n", spi->chip_select, 622 ctlr->num_chipselect); 623 return -EINVAL; 624 } 625 626 /* Set the bus ID string */ 627 spi_dev_set_name(spi); 628 629 /* We need to make sure there's no other device with this 630 * chipselect **BEFORE** we call setup(), else we'll trash 631 * its configuration. Lock against concurrent add() calls. 632 */ 633 mutex_lock(&ctlr->add_lock); 634 status = __spi_add_device(spi); 635 mutex_unlock(&ctlr->add_lock); 636 return status; 637 } 638 EXPORT_SYMBOL_GPL(spi_add_device); 639 640 static int spi_add_device_locked(struct spi_device *spi) 641 { 642 struct spi_controller *ctlr = spi->controller; 643 struct device *dev = ctlr->dev.parent; 644 645 /* Chipselects are numbered 0..max; validate. */ 646 if (spi->chip_select >= ctlr->num_chipselect) { 647 dev_err(dev, "cs%d >= max %d\n", spi->chip_select, 648 ctlr->num_chipselect); 649 return -EINVAL; 650 } 651 652 /* Set the bus ID string */ 653 spi_dev_set_name(spi); 654 655 WARN_ON(!mutex_is_locked(&ctlr->add_lock)); 656 return __spi_add_device(spi); 657 } 658 659 /** 660 * spi_new_device - instantiate one new SPI device 661 * @ctlr: Controller to which device is connected 662 * @chip: Describes the SPI device 663 * Context: can sleep 664 * 665 * On typical mainboards, this is purely internal; and it's not needed 666 * after board init creates the hard-wired devices. Some development 667 * platforms may not be able to use spi_register_board_info though, and 668 * this is exported so that for example a USB or parport based adapter 669 * driver could add devices (which it would learn about out-of-band). 670 * 671 * Return: the new device, or NULL. 672 */ 673 struct spi_device *spi_new_device(struct spi_controller *ctlr, 674 struct spi_board_info *chip) 675 { 676 struct spi_device *proxy; 677 int status; 678 679 /* NOTE: caller did any chip->bus_num checks necessary. 680 * 681 * Also, unless we change the return value convention to use 682 * error-or-pointer (not NULL-or-pointer), troubleshootability 683 * suggests syslogged diagnostics are best here (ugh). 684 */ 685 686 proxy = spi_alloc_device(ctlr); 687 if (!proxy) 688 return NULL; 689 690 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); 691 692 proxy->chip_select = chip->chip_select; 693 proxy->max_speed_hz = chip->max_speed_hz; 694 proxy->mode = chip->mode; 695 proxy->irq = chip->irq; 696 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); 697 proxy->dev.platform_data = (void *) chip->platform_data; 698 proxy->controller_data = chip->controller_data; 699 proxy->controller_state = NULL; 700 701 if (chip->swnode) { 702 status = device_add_software_node(&proxy->dev, chip->swnode); 703 if (status) { 704 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n", 705 chip->modalias, status); 706 goto err_dev_put; 707 } 708 } 709 710 status = spi_add_device(proxy); 711 if (status < 0) 712 goto err_dev_put; 713 714 return proxy; 715 716 err_dev_put: 717 device_remove_software_node(&proxy->dev); 718 spi_dev_put(proxy); 719 return NULL; 720 } 721 EXPORT_SYMBOL_GPL(spi_new_device); 722 723 /** 724 * spi_unregister_device - unregister a single SPI device 725 * @spi: spi_device to unregister 726 * 727 * Start making the passed SPI device vanish. Normally this would be handled 728 * by spi_unregister_controller(). 729 */ 730 void spi_unregister_device(struct spi_device *spi) 731 { 732 if (!spi) 733 return; 734 735 if (spi->dev.of_node) { 736 of_node_clear_flag(spi->dev.of_node, OF_POPULATED); 737 of_node_put(spi->dev.of_node); 738 } 739 if (ACPI_COMPANION(&spi->dev)) 740 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); 741 device_remove_software_node(&spi->dev); 742 device_del(&spi->dev); 743 spi_cleanup(spi); 744 put_device(&spi->dev); 745 } 746 EXPORT_SYMBOL_GPL(spi_unregister_device); 747 748 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr, 749 struct spi_board_info *bi) 750 { 751 struct spi_device *dev; 752 753 if (ctlr->bus_num != bi->bus_num) 754 return; 755 756 dev = spi_new_device(ctlr, bi); 757 if (!dev) 758 dev_err(ctlr->dev.parent, "can't create new device for %s\n", 759 bi->modalias); 760 } 761 762 /** 763 * spi_register_board_info - register SPI devices for a given board 764 * @info: array of chip descriptors 765 * @n: how many descriptors are provided 766 * Context: can sleep 767 * 768 * Board-specific early init code calls this (probably during arch_initcall) 769 * with segments of the SPI device table. Any device nodes are created later, 770 * after the relevant parent SPI controller (bus_num) is defined. We keep 771 * this table of devices forever, so that reloading a controller driver will 772 * not make Linux forget about these hard-wired devices. 773 * 774 * Other code can also call this, e.g. a particular add-on board might provide 775 * SPI devices through its expansion connector, so code initializing that board 776 * would naturally declare its SPI devices. 777 * 778 * The board info passed can safely be __initdata ... but be careful of 779 * any embedded pointers (platform_data, etc), they're copied as-is. 780 * 781 * Return: zero on success, else a negative error code. 782 */ 783 int spi_register_board_info(struct spi_board_info const *info, unsigned n) 784 { 785 struct boardinfo *bi; 786 int i; 787 788 if (!n) 789 return 0; 790 791 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL); 792 if (!bi) 793 return -ENOMEM; 794 795 for (i = 0; i < n; i++, bi++, info++) { 796 struct spi_controller *ctlr; 797 798 memcpy(&bi->board_info, info, sizeof(*info)); 799 800 mutex_lock(&board_lock); 801 list_add_tail(&bi->list, &board_list); 802 list_for_each_entry(ctlr, &spi_controller_list, list) 803 spi_match_controller_to_boardinfo(ctlr, 804 &bi->board_info); 805 mutex_unlock(&board_lock); 806 } 807 808 return 0; 809 } 810 811 /*-------------------------------------------------------------------------*/ 812 813 static void spi_set_cs(struct spi_device *spi, bool enable, bool force) 814 { 815 bool activate = enable; 816 817 /* 818 * Avoid calling into the driver (or doing delays) if the chip select 819 * isn't actually changing from the last time this was called. 820 */ 821 if (!force && (spi->controller->last_cs_enable == enable) && 822 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) 823 return; 824 825 trace_spi_set_cs(spi, activate); 826 827 spi->controller->last_cs_enable = enable; 828 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; 829 830 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) || 831 !spi->controller->set_cs_timing) { 832 if (activate) 833 spi_delay_exec(&spi->cs_setup, NULL); 834 else 835 spi_delay_exec(&spi->cs_hold, NULL); 836 } 837 838 if (spi->mode & SPI_CS_HIGH) 839 enable = !enable; 840 841 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) { 842 if (!(spi->mode & SPI_NO_CS)) { 843 if (spi->cs_gpiod) { 844 /* 845 * Historically ACPI has no means of the GPIO polarity and 846 * thus the SPISerialBus() resource defines it on the per-chip 847 * basis. In order to avoid a chain of negations, the GPIO 848 * polarity is considered being Active High. Even for the cases 849 * when _DSD() is involved (in the updated versions of ACPI) 850 * the GPIO CS polarity must be defined Active High to avoid 851 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH 852 * into account. 853 */ 854 if (has_acpi_companion(&spi->dev)) 855 gpiod_set_value_cansleep(spi->cs_gpiod, !enable); 856 else 857 /* Polarity handled by GPIO library */ 858 gpiod_set_value_cansleep(spi->cs_gpiod, activate); 859 } else { 860 /* 861 * invert the enable line, as active low is 862 * default for SPI. 863 */ 864 gpio_set_value_cansleep(spi->cs_gpio, !enable); 865 } 866 } 867 /* Some SPI masters need both GPIO CS & slave_select */ 868 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && 869 spi->controller->set_cs) 870 spi->controller->set_cs(spi, !enable); 871 } else if (spi->controller->set_cs) { 872 spi->controller->set_cs(spi, !enable); 873 } 874 875 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) || 876 !spi->controller->set_cs_timing) { 877 if (!activate) 878 spi_delay_exec(&spi->cs_inactive, NULL); 879 } 880 } 881 882 #ifdef CONFIG_HAS_DMA 883 int spi_map_buf(struct spi_controller *ctlr, struct device *dev, 884 struct sg_table *sgt, void *buf, size_t len, 885 enum dma_data_direction dir) 886 { 887 const bool vmalloced_buf = is_vmalloc_addr(buf); 888 unsigned int max_seg_size = dma_get_max_seg_size(dev); 889 #ifdef CONFIG_HIGHMEM 890 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && 891 (unsigned long)buf < (PKMAP_BASE + 892 (LAST_PKMAP * PAGE_SIZE))); 893 #else 894 const bool kmap_buf = false; 895 #endif 896 int desc_len; 897 int sgs; 898 struct page *vm_page; 899 struct scatterlist *sg; 900 void *sg_buf; 901 size_t min; 902 int i, ret; 903 904 if (vmalloced_buf || kmap_buf) { 905 desc_len = min_t(int, max_seg_size, PAGE_SIZE); 906 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); 907 } else if (virt_addr_valid(buf)) { 908 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len); 909 sgs = DIV_ROUND_UP(len, desc_len); 910 } else { 911 return -EINVAL; 912 } 913 914 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); 915 if (ret != 0) 916 return ret; 917 918 sg = &sgt->sgl[0]; 919 for (i = 0; i < sgs; i++) { 920 921 if (vmalloced_buf || kmap_buf) { 922 /* 923 * Next scatterlist entry size is the minimum between 924 * the desc_len and the remaining buffer length that 925 * fits in a page. 926 */ 927 min = min_t(size_t, desc_len, 928 min_t(size_t, len, 929 PAGE_SIZE - offset_in_page(buf))); 930 if (vmalloced_buf) 931 vm_page = vmalloc_to_page(buf); 932 else 933 vm_page = kmap_to_page(buf); 934 if (!vm_page) { 935 sg_free_table(sgt); 936 return -ENOMEM; 937 } 938 sg_set_page(sg, vm_page, 939 min, offset_in_page(buf)); 940 } else { 941 min = min_t(size_t, len, desc_len); 942 sg_buf = buf; 943 sg_set_buf(sg, sg_buf, min); 944 } 945 946 buf += min; 947 len -= min; 948 sg = sg_next(sg); 949 } 950 951 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); 952 if (!ret) 953 ret = -ENOMEM; 954 if (ret < 0) { 955 sg_free_table(sgt); 956 return ret; 957 } 958 959 sgt->nents = ret; 960 961 return 0; 962 } 963 964 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, 965 struct sg_table *sgt, enum dma_data_direction dir) 966 { 967 if (sgt->orig_nents) { 968 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); 969 sg_free_table(sgt); 970 } 971 } 972 973 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) 974 { 975 struct device *tx_dev, *rx_dev; 976 struct spi_transfer *xfer; 977 int ret; 978 979 if (!ctlr->can_dma) 980 return 0; 981 982 if (ctlr->dma_tx) 983 tx_dev = ctlr->dma_tx->device->dev; 984 else if (ctlr->dma_map_dev) 985 tx_dev = ctlr->dma_map_dev; 986 else 987 tx_dev = ctlr->dev.parent; 988 989 if (ctlr->dma_rx) 990 rx_dev = ctlr->dma_rx->device->dev; 991 else if (ctlr->dma_map_dev) 992 rx_dev = ctlr->dma_map_dev; 993 else 994 rx_dev = ctlr->dev.parent; 995 996 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 997 if (!ctlr->can_dma(ctlr, msg->spi, xfer)) 998 continue; 999 1000 if (xfer->tx_buf != NULL) { 1001 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg, 1002 (void *)xfer->tx_buf, xfer->len, 1003 DMA_TO_DEVICE); 1004 if (ret != 0) 1005 return ret; 1006 } 1007 1008 if (xfer->rx_buf != NULL) { 1009 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg, 1010 xfer->rx_buf, xfer->len, 1011 DMA_FROM_DEVICE); 1012 if (ret != 0) { 1013 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, 1014 DMA_TO_DEVICE); 1015 return ret; 1016 } 1017 } 1018 } 1019 1020 ctlr->cur_msg_mapped = true; 1021 1022 return 0; 1023 } 1024 1025 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) 1026 { 1027 struct spi_transfer *xfer; 1028 struct device *tx_dev, *rx_dev; 1029 1030 if (!ctlr->cur_msg_mapped || !ctlr->can_dma) 1031 return 0; 1032 1033 if (ctlr->dma_tx) 1034 tx_dev = ctlr->dma_tx->device->dev; 1035 else 1036 tx_dev = ctlr->dev.parent; 1037 1038 if (ctlr->dma_rx) 1039 rx_dev = ctlr->dma_rx->device->dev; 1040 else 1041 rx_dev = ctlr->dev.parent; 1042 1043 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1044 if (!ctlr->can_dma(ctlr, msg->spi, xfer)) 1045 continue; 1046 1047 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); 1048 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); 1049 } 1050 1051 ctlr->cur_msg_mapped = false; 1052 1053 return 0; 1054 } 1055 #else /* !CONFIG_HAS_DMA */ 1056 static inline int __spi_map_msg(struct spi_controller *ctlr, 1057 struct spi_message *msg) 1058 { 1059 return 0; 1060 } 1061 1062 static inline int __spi_unmap_msg(struct spi_controller *ctlr, 1063 struct spi_message *msg) 1064 { 1065 return 0; 1066 } 1067 #endif /* !CONFIG_HAS_DMA */ 1068 1069 static inline int spi_unmap_msg(struct spi_controller *ctlr, 1070 struct spi_message *msg) 1071 { 1072 struct spi_transfer *xfer; 1073 1074 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1075 /* 1076 * Restore the original value of tx_buf or rx_buf if they are 1077 * NULL. 1078 */ 1079 if (xfer->tx_buf == ctlr->dummy_tx) 1080 xfer->tx_buf = NULL; 1081 if (xfer->rx_buf == ctlr->dummy_rx) 1082 xfer->rx_buf = NULL; 1083 } 1084 1085 return __spi_unmap_msg(ctlr, msg); 1086 } 1087 1088 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) 1089 { 1090 struct spi_transfer *xfer; 1091 void *tmp; 1092 unsigned int max_tx, max_rx; 1093 1094 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) 1095 && !(msg->spi->mode & SPI_3WIRE)) { 1096 max_tx = 0; 1097 max_rx = 0; 1098 1099 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1100 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) && 1101 !xfer->tx_buf) 1102 max_tx = max(xfer->len, max_tx); 1103 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) && 1104 !xfer->rx_buf) 1105 max_rx = max(xfer->len, max_rx); 1106 } 1107 1108 if (max_tx) { 1109 tmp = krealloc(ctlr->dummy_tx, max_tx, 1110 GFP_KERNEL | GFP_DMA); 1111 if (!tmp) 1112 return -ENOMEM; 1113 ctlr->dummy_tx = tmp; 1114 memset(tmp, 0, max_tx); 1115 } 1116 1117 if (max_rx) { 1118 tmp = krealloc(ctlr->dummy_rx, max_rx, 1119 GFP_KERNEL | GFP_DMA); 1120 if (!tmp) 1121 return -ENOMEM; 1122 ctlr->dummy_rx = tmp; 1123 } 1124 1125 if (max_tx || max_rx) { 1126 list_for_each_entry(xfer, &msg->transfers, 1127 transfer_list) { 1128 if (!xfer->len) 1129 continue; 1130 if (!xfer->tx_buf) 1131 xfer->tx_buf = ctlr->dummy_tx; 1132 if (!xfer->rx_buf) 1133 xfer->rx_buf = ctlr->dummy_rx; 1134 } 1135 } 1136 } 1137 1138 return __spi_map_msg(ctlr, msg); 1139 } 1140 1141 static int spi_transfer_wait(struct spi_controller *ctlr, 1142 struct spi_message *msg, 1143 struct spi_transfer *xfer) 1144 { 1145 struct spi_statistics *statm = &ctlr->statistics; 1146 struct spi_statistics *stats = &msg->spi->statistics; 1147 u32 speed_hz = xfer->speed_hz; 1148 unsigned long long ms; 1149 1150 if (spi_controller_is_slave(ctlr)) { 1151 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) { 1152 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n"); 1153 return -EINTR; 1154 } 1155 } else { 1156 if (!speed_hz) 1157 speed_hz = 100000; 1158 1159 /* 1160 * For each byte we wait for 8 cycles of the SPI clock. 1161 * Since speed is defined in Hz and we want milliseconds, 1162 * use respective multiplier, but before the division, 1163 * otherwise we may get 0 for short transfers. 1164 */ 1165 ms = 8LL * MSEC_PER_SEC * xfer->len; 1166 do_div(ms, speed_hz); 1167 1168 /* 1169 * Increase it twice and add 200 ms tolerance, use 1170 * predefined maximum in case of overflow. 1171 */ 1172 ms += ms + 200; 1173 if (ms > UINT_MAX) 1174 ms = UINT_MAX; 1175 1176 ms = wait_for_completion_timeout(&ctlr->xfer_completion, 1177 msecs_to_jiffies(ms)); 1178 1179 if (ms == 0) { 1180 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout); 1181 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout); 1182 dev_err(&msg->spi->dev, 1183 "SPI transfer timed out\n"); 1184 return -ETIMEDOUT; 1185 } 1186 } 1187 1188 return 0; 1189 } 1190 1191 static void _spi_transfer_delay_ns(u32 ns) 1192 { 1193 if (!ns) 1194 return; 1195 if (ns <= NSEC_PER_USEC) { 1196 ndelay(ns); 1197 } else { 1198 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC); 1199 1200 if (us <= 10) 1201 udelay(us); 1202 else 1203 usleep_range(us, us + DIV_ROUND_UP(us, 10)); 1204 } 1205 } 1206 1207 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) 1208 { 1209 u32 delay = _delay->value; 1210 u32 unit = _delay->unit; 1211 u32 hz; 1212 1213 if (!delay) 1214 return 0; 1215 1216 switch (unit) { 1217 case SPI_DELAY_UNIT_USECS: 1218 delay *= NSEC_PER_USEC; 1219 break; 1220 case SPI_DELAY_UNIT_NSECS: 1221 /* Nothing to do here */ 1222 break; 1223 case SPI_DELAY_UNIT_SCK: 1224 /* clock cycles need to be obtained from spi_transfer */ 1225 if (!xfer) 1226 return -EINVAL; 1227 /* 1228 * If there is unknown effective speed, approximate it 1229 * by underestimating with half of the requested hz. 1230 */ 1231 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; 1232 if (!hz) 1233 return -EINVAL; 1234 1235 /* Convert delay to nanoseconds */ 1236 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz); 1237 break; 1238 default: 1239 return -EINVAL; 1240 } 1241 1242 return delay; 1243 } 1244 EXPORT_SYMBOL_GPL(spi_delay_to_ns); 1245 1246 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) 1247 { 1248 int delay; 1249 1250 might_sleep(); 1251 1252 if (!_delay) 1253 return -EINVAL; 1254 1255 delay = spi_delay_to_ns(_delay, xfer); 1256 if (delay < 0) 1257 return delay; 1258 1259 _spi_transfer_delay_ns(delay); 1260 1261 return 0; 1262 } 1263 EXPORT_SYMBOL_GPL(spi_delay_exec); 1264 1265 static void _spi_transfer_cs_change_delay(struct spi_message *msg, 1266 struct spi_transfer *xfer) 1267 { 1268 u32 default_delay_ns = 10 * NSEC_PER_USEC; 1269 u32 delay = xfer->cs_change_delay.value; 1270 u32 unit = xfer->cs_change_delay.unit; 1271 int ret; 1272 1273 /* return early on "fast" mode - for everything but USECS */ 1274 if (!delay) { 1275 if (unit == SPI_DELAY_UNIT_USECS) 1276 _spi_transfer_delay_ns(default_delay_ns); 1277 return; 1278 } 1279 1280 ret = spi_delay_exec(&xfer->cs_change_delay, xfer); 1281 if (ret) { 1282 dev_err_once(&msg->spi->dev, 1283 "Use of unsupported delay unit %i, using default of %luus\n", 1284 unit, default_delay_ns / NSEC_PER_USEC); 1285 _spi_transfer_delay_ns(default_delay_ns); 1286 } 1287 } 1288 1289 /* 1290 * spi_transfer_one_message - Default implementation of transfer_one_message() 1291 * 1292 * This is a standard implementation of transfer_one_message() for 1293 * drivers which implement a transfer_one() operation. It provides 1294 * standard handling of delays and chip select management. 1295 */ 1296 static int spi_transfer_one_message(struct spi_controller *ctlr, 1297 struct spi_message *msg) 1298 { 1299 struct spi_transfer *xfer; 1300 bool keep_cs = false; 1301 int ret = 0; 1302 struct spi_statistics *statm = &ctlr->statistics; 1303 struct spi_statistics *stats = &msg->spi->statistics; 1304 1305 spi_set_cs(msg->spi, true, false); 1306 1307 SPI_STATISTICS_INCREMENT_FIELD(statm, messages); 1308 SPI_STATISTICS_INCREMENT_FIELD(stats, messages); 1309 1310 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1311 trace_spi_transfer_start(msg, xfer); 1312 1313 spi_statistics_add_transfer_stats(statm, xfer, ctlr); 1314 spi_statistics_add_transfer_stats(stats, xfer, ctlr); 1315 1316 if (!ctlr->ptp_sts_supported) { 1317 xfer->ptp_sts_word_pre = 0; 1318 ptp_read_system_prets(xfer->ptp_sts); 1319 } 1320 1321 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { 1322 reinit_completion(&ctlr->xfer_completion); 1323 1324 fallback_pio: 1325 ret = ctlr->transfer_one(ctlr, msg->spi, xfer); 1326 if (ret < 0) { 1327 if (ctlr->cur_msg_mapped && 1328 (xfer->error & SPI_TRANS_FAIL_NO_START)) { 1329 __spi_unmap_msg(ctlr, msg); 1330 ctlr->fallback = true; 1331 xfer->error &= ~SPI_TRANS_FAIL_NO_START; 1332 goto fallback_pio; 1333 } 1334 1335 SPI_STATISTICS_INCREMENT_FIELD(statm, 1336 errors); 1337 SPI_STATISTICS_INCREMENT_FIELD(stats, 1338 errors); 1339 dev_err(&msg->spi->dev, 1340 "SPI transfer failed: %d\n", ret); 1341 goto out; 1342 } 1343 1344 if (ret > 0) { 1345 ret = spi_transfer_wait(ctlr, msg, xfer); 1346 if (ret < 0) 1347 msg->status = ret; 1348 } 1349 } else { 1350 if (xfer->len) 1351 dev_err(&msg->spi->dev, 1352 "Bufferless transfer has length %u\n", 1353 xfer->len); 1354 } 1355 1356 if (!ctlr->ptp_sts_supported) { 1357 ptp_read_system_postts(xfer->ptp_sts); 1358 xfer->ptp_sts_word_post = xfer->len; 1359 } 1360 1361 trace_spi_transfer_stop(msg, xfer); 1362 1363 if (msg->status != -EINPROGRESS) 1364 goto out; 1365 1366 spi_transfer_delay_exec(xfer); 1367 1368 if (xfer->cs_change) { 1369 if (list_is_last(&xfer->transfer_list, 1370 &msg->transfers)) { 1371 keep_cs = true; 1372 } else { 1373 spi_set_cs(msg->spi, false, false); 1374 _spi_transfer_cs_change_delay(msg, xfer); 1375 spi_set_cs(msg->spi, true, false); 1376 } 1377 } 1378 1379 msg->actual_length += xfer->len; 1380 } 1381 1382 out: 1383 if (ret != 0 || !keep_cs) 1384 spi_set_cs(msg->spi, false, false); 1385 1386 if (msg->status == -EINPROGRESS) 1387 msg->status = ret; 1388 1389 if (msg->status && ctlr->handle_err) 1390 ctlr->handle_err(ctlr, msg); 1391 1392 spi_finalize_current_message(ctlr); 1393 1394 return ret; 1395 } 1396 1397 /** 1398 * spi_finalize_current_transfer - report completion of a transfer 1399 * @ctlr: the controller reporting completion 1400 * 1401 * Called by SPI drivers using the core transfer_one_message() 1402 * implementation to notify it that the current interrupt driven 1403 * transfer has finished and the next one may be scheduled. 1404 */ 1405 void spi_finalize_current_transfer(struct spi_controller *ctlr) 1406 { 1407 complete(&ctlr->xfer_completion); 1408 } 1409 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); 1410 1411 static void spi_idle_runtime_pm(struct spi_controller *ctlr) 1412 { 1413 if (ctlr->auto_runtime_pm) { 1414 pm_runtime_mark_last_busy(ctlr->dev.parent); 1415 pm_runtime_put_autosuspend(ctlr->dev.parent); 1416 } 1417 } 1418 1419 /** 1420 * __spi_pump_messages - function which processes spi message queue 1421 * @ctlr: controller to process queue for 1422 * @in_kthread: true if we are in the context of the message pump thread 1423 * 1424 * This function checks if there is any spi message in the queue that 1425 * needs processing and if so call out to the driver to initialize hardware 1426 * and transfer each message. 1427 * 1428 * Note that it is called both from the kthread itself and also from 1429 * inside spi_sync(); the queue extraction handling at the top of the 1430 * function should deal with this safely. 1431 */ 1432 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) 1433 { 1434 struct spi_transfer *xfer; 1435 struct spi_message *msg; 1436 bool was_busy = false; 1437 unsigned long flags; 1438 int ret; 1439 1440 /* Lock queue */ 1441 spin_lock_irqsave(&ctlr->queue_lock, flags); 1442 1443 /* Make sure we are not already running a message */ 1444 if (ctlr->cur_msg) { 1445 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1446 return; 1447 } 1448 1449 /* If another context is idling the device then defer */ 1450 if (ctlr->idling) { 1451 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 1452 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1453 return; 1454 } 1455 1456 /* Check if the queue is idle */ 1457 if (list_empty(&ctlr->queue) || !ctlr->running) { 1458 if (!ctlr->busy) { 1459 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1460 return; 1461 } 1462 1463 /* Defer any non-atomic teardown to the thread */ 1464 if (!in_kthread) { 1465 if (!ctlr->dummy_rx && !ctlr->dummy_tx && 1466 !ctlr->unprepare_transfer_hardware) { 1467 spi_idle_runtime_pm(ctlr); 1468 ctlr->busy = false; 1469 trace_spi_controller_idle(ctlr); 1470 } else { 1471 kthread_queue_work(ctlr->kworker, 1472 &ctlr->pump_messages); 1473 } 1474 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1475 return; 1476 } 1477 1478 ctlr->busy = false; 1479 ctlr->idling = true; 1480 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1481 1482 kfree(ctlr->dummy_rx); 1483 ctlr->dummy_rx = NULL; 1484 kfree(ctlr->dummy_tx); 1485 ctlr->dummy_tx = NULL; 1486 if (ctlr->unprepare_transfer_hardware && 1487 ctlr->unprepare_transfer_hardware(ctlr)) 1488 dev_err(&ctlr->dev, 1489 "failed to unprepare transfer hardware\n"); 1490 spi_idle_runtime_pm(ctlr); 1491 trace_spi_controller_idle(ctlr); 1492 1493 spin_lock_irqsave(&ctlr->queue_lock, flags); 1494 ctlr->idling = false; 1495 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1496 return; 1497 } 1498 1499 /* Extract head of queue */ 1500 msg = list_first_entry(&ctlr->queue, struct spi_message, queue); 1501 ctlr->cur_msg = msg; 1502 1503 list_del_init(&msg->queue); 1504 if (ctlr->busy) 1505 was_busy = true; 1506 else 1507 ctlr->busy = true; 1508 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1509 1510 mutex_lock(&ctlr->io_mutex); 1511 1512 if (!was_busy && ctlr->auto_runtime_pm) { 1513 ret = pm_runtime_get_sync(ctlr->dev.parent); 1514 if (ret < 0) { 1515 pm_runtime_put_noidle(ctlr->dev.parent); 1516 dev_err(&ctlr->dev, "Failed to power device: %d\n", 1517 ret); 1518 mutex_unlock(&ctlr->io_mutex); 1519 return; 1520 } 1521 } 1522 1523 if (!was_busy) 1524 trace_spi_controller_busy(ctlr); 1525 1526 if (!was_busy && ctlr->prepare_transfer_hardware) { 1527 ret = ctlr->prepare_transfer_hardware(ctlr); 1528 if (ret) { 1529 dev_err(&ctlr->dev, 1530 "failed to prepare transfer hardware: %d\n", 1531 ret); 1532 1533 if (ctlr->auto_runtime_pm) 1534 pm_runtime_put(ctlr->dev.parent); 1535 1536 msg->status = ret; 1537 spi_finalize_current_message(ctlr); 1538 1539 mutex_unlock(&ctlr->io_mutex); 1540 return; 1541 } 1542 } 1543 1544 trace_spi_message_start(msg); 1545 1546 if (ctlr->prepare_message) { 1547 ret = ctlr->prepare_message(ctlr, msg); 1548 if (ret) { 1549 dev_err(&ctlr->dev, "failed to prepare message: %d\n", 1550 ret); 1551 msg->status = ret; 1552 spi_finalize_current_message(ctlr); 1553 goto out; 1554 } 1555 ctlr->cur_msg_prepared = true; 1556 } 1557 1558 ret = spi_map_msg(ctlr, msg); 1559 if (ret) { 1560 msg->status = ret; 1561 spi_finalize_current_message(ctlr); 1562 goto out; 1563 } 1564 1565 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { 1566 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 1567 xfer->ptp_sts_word_pre = 0; 1568 ptp_read_system_prets(xfer->ptp_sts); 1569 } 1570 } 1571 1572 ret = ctlr->transfer_one_message(ctlr, msg); 1573 if (ret) { 1574 dev_err(&ctlr->dev, 1575 "failed to transfer one message from queue\n"); 1576 goto out; 1577 } 1578 1579 out: 1580 mutex_unlock(&ctlr->io_mutex); 1581 1582 /* Prod the scheduler in case transfer_one() was busy waiting */ 1583 if (!ret) 1584 cond_resched(); 1585 } 1586 1587 /** 1588 * spi_pump_messages - kthread work function which processes spi message queue 1589 * @work: pointer to kthread work struct contained in the controller struct 1590 */ 1591 static void spi_pump_messages(struct kthread_work *work) 1592 { 1593 struct spi_controller *ctlr = 1594 container_of(work, struct spi_controller, pump_messages); 1595 1596 __spi_pump_messages(ctlr, true); 1597 } 1598 1599 /** 1600 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the 1601 * TX timestamp for the requested byte from the SPI 1602 * transfer. The frequency with which this function 1603 * must be called (once per word, once for the whole 1604 * transfer, once per batch of words etc) is arbitrary 1605 * as long as the @tx buffer offset is greater than or 1606 * equal to the requested byte at the time of the 1607 * call. The timestamp is only taken once, at the 1608 * first such call. It is assumed that the driver 1609 * advances its @tx buffer pointer monotonically. 1610 * @ctlr: Pointer to the spi_controller structure of the driver 1611 * @xfer: Pointer to the transfer being timestamped 1612 * @progress: How many words (not bytes) have been transferred so far 1613 * @irqs_off: If true, will disable IRQs and preemption for the duration of the 1614 * transfer, for less jitter in time measurement. Only compatible 1615 * with PIO drivers. If true, must follow up with 1616 * spi_take_timestamp_post or otherwise system will crash. 1617 * WARNING: for fully predictable results, the CPU frequency must 1618 * also be under control (governor). 1619 */ 1620 void spi_take_timestamp_pre(struct spi_controller *ctlr, 1621 struct spi_transfer *xfer, 1622 size_t progress, bool irqs_off) 1623 { 1624 if (!xfer->ptp_sts) 1625 return; 1626 1627 if (xfer->timestamped) 1628 return; 1629 1630 if (progress > xfer->ptp_sts_word_pre) 1631 return; 1632 1633 /* Capture the resolution of the timestamp */ 1634 xfer->ptp_sts_word_pre = progress; 1635 1636 if (irqs_off) { 1637 local_irq_save(ctlr->irq_flags); 1638 preempt_disable(); 1639 } 1640 1641 ptp_read_system_prets(xfer->ptp_sts); 1642 } 1643 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); 1644 1645 /** 1646 * spi_take_timestamp_post - helper for drivers to collect the end of the 1647 * TX timestamp for the requested byte from the SPI 1648 * transfer. Can be called with an arbitrary 1649 * frequency: only the first call where @tx exceeds 1650 * or is equal to the requested word will be 1651 * timestamped. 1652 * @ctlr: Pointer to the spi_controller structure of the driver 1653 * @xfer: Pointer to the transfer being timestamped 1654 * @progress: How many words (not bytes) have been transferred so far 1655 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. 1656 */ 1657 void spi_take_timestamp_post(struct spi_controller *ctlr, 1658 struct spi_transfer *xfer, 1659 size_t progress, bool irqs_off) 1660 { 1661 if (!xfer->ptp_sts) 1662 return; 1663 1664 if (xfer->timestamped) 1665 return; 1666 1667 if (progress < xfer->ptp_sts_word_post) 1668 return; 1669 1670 ptp_read_system_postts(xfer->ptp_sts); 1671 1672 if (irqs_off) { 1673 local_irq_restore(ctlr->irq_flags); 1674 preempt_enable(); 1675 } 1676 1677 /* Capture the resolution of the timestamp */ 1678 xfer->ptp_sts_word_post = progress; 1679 1680 xfer->timestamped = true; 1681 } 1682 EXPORT_SYMBOL_GPL(spi_take_timestamp_post); 1683 1684 /** 1685 * spi_set_thread_rt - set the controller to pump at realtime priority 1686 * @ctlr: controller to boost priority of 1687 * 1688 * This can be called because the controller requested realtime priority 1689 * (by setting the ->rt value before calling spi_register_controller()) or 1690 * because a device on the bus said that its transfers needed realtime 1691 * priority. 1692 * 1693 * NOTE: at the moment if any device on a bus says it needs realtime then 1694 * the thread will be at realtime priority for all transfers on that 1695 * controller. If this eventually becomes a problem we may see if we can 1696 * find a way to boost the priority only temporarily during relevant 1697 * transfers. 1698 */ 1699 static void spi_set_thread_rt(struct spi_controller *ctlr) 1700 { 1701 dev_info(&ctlr->dev, 1702 "will run message pump with realtime priority\n"); 1703 sched_set_fifo(ctlr->kworker->task); 1704 } 1705 1706 static int spi_init_queue(struct spi_controller *ctlr) 1707 { 1708 ctlr->running = false; 1709 ctlr->busy = false; 1710 1711 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev)); 1712 if (IS_ERR(ctlr->kworker)) { 1713 dev_err(&ctlr->dev, "failed to create message pump kworker\n"); 1714 return PTR_ERR(ctlr->kworker); 1715 } 1716 1717 kthread_init_work(&ctlr->pump_messages, spi_pump_messages); 1718 1719 /* 1720 * Controller config will indicate if this controller should run the 1721 * message pump with high (realtime) priority to reduce the transfer 1722 * latency on the bus by minimising the delay between a transfer 1723 * request and the scheduling of the message pump thread. Without this 1724 * setting the message pump thread will remain at default priority. 1725 */ 1726 if (ctlr->rt) 1727 spi_set_thread_rt(ctlr); 1728 1729 return 0; 1730 } 1731 1732 /** 1733 * spi_get_next_queued_message() - called by driver to check for queued 1734 * messages 1735 * @ctlr: the controller to check for queued messages 1736 * 1737 * If there are more messages in the queue, the next message is returned from 1738 * this call. 1739 * 1740 * Return: the next message in the queue, else NULL if the queue is empty. 1741 */ 1742 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) 1743 { 1744 struct spi_message *next; 1745 unsigned long flags; 1746 1747 /* get a pointer to the next message, if any */ 1748 spin_lock_irqsave(&ctlr->queue_lock, flags); 1749 next = list_first_entry_or_null(&ctlr->queue, struct spi_message, 1750 queue); 1751 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1752 1753 return next; 1754 } 1755 EXPORT_SYMBOL_GPL(spi_get_next_queued_message); 1756 1757 /** 1758 * spi_finalize_current_message() - the current message is complete 1759 * @ctlr: the controller to return the message to 1760 * 1761 * Called by the driver to notify the core that the message in the front of the 1762 * queue is complete and can be removed from the queue. 1763 */ 1764 void spi_finalize_current_message(struct spi_controller *ctlr) 1765 { 1766 struct spi_transfer *xfer; 1767 struct spi_message *mesg; 1768 unsigned long flags; 1769 int ret; 1770 1771 spin_lock_irqsave(&ctlr->queue_lock, flags); 1772 mesg = ctlr->cur_msg; 1773 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1774 1775 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { 1776 list_for_each_entry(xfer, &mesg->transfers, transfer_list) { 1777 ptp_read_system_postts(xfer->ptp_sts); 1778 xfer->ptp_sts_word_post = xfer->len; 1779 } 1780 } 1781 1782 if (unlikely(ctlr->ptp_sts_supported)) 1783 list_for_each_entry(xfer, &mesg->transfers, transfer_list) 1784 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped); 1785 1786 spi_unmap_msg(ctlr, mesg); 1787 1788 /* In the prepare_messages callback the spi bus has the opportunity to 1789 * split a transfer to smaller chunks. 1790 * Release splited transfers here since spi_map_msg is done on the 1791 * splited transfers. 1792 */ 1793 spi_res_release(ctlr, mesg); 1794 1795 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { 1796 ret = ctlr->unprepare_message(ctlr, mesg); 1797 if (ret) { 1798 dev_err(&ctlr->dev, "failed to unprepare message: %d\n", 1799 ret); 1800 } 1801 } 1802 1803 spin_lock_irqsave(&ctlr->queue_lock, flags); 1804 ctlr->cur_msg = NULL; 1805 ctlr->cur_msg_prepared = false; 1806 ctlr->fallback = false; 1807 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 1808 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1809 1810 trace_spi_message_done(mesg); 1811 1812 mesg->state = NULL; 1813 if (mesg->complete) 1814 mesg->complete(mesg->context); 1815 } 1816 EXPORT_SYMBOL_GPL(spi_finalize_current_message); 1817 1818 static int spi_start_queue(struct spi_controller *ctlr) 1819 { 1820 unsigned long flags; 1821 1822 spin_lock_irqsave(&ctlr->queue_lock, flags); 1823 1824 if (ctlr->running || ctlr->busy) { 1825 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1826 return -EBUSY; 1827 } 1828 1829 ctlr->running = true; 1830 ctlr->cur_msg = NULL; 1831 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1832 1833 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 1834 1835 return 0; 1836 } 1837 1838 static int spi_stop_queue(struct spi_controller *ctlr) 1839 { 1840 unsigned long flags; 1841 unsigned limit = 500; 1842 int ret = 0; 1843 1844 spin_lock_irqsave(&ctlr->queue_lock, flags); 1845 1846 /* 1847 * This is a bit lame, but is optimized for the common execution path. 1848 * A wait_queue on the ctlr->busy could be used, but then the common 1849 * execution path (pump_messages) would be required to call wake_up or 1850 * friends on every SPI message. Do this instead. 1851 */ 1852 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) { 1853 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1854 usleep_range(10000, 11000); 1855 spin_lock_irqsave(&ctlr->queue_lock, flags); 1856 } 1857 1858 if (!list_empty(&ctlr->queue) || ctlr->busy) 1859 ret = -EBUSY; 1860 else 1861 ctlr->running = false; 1862 1863 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1864 1865 if (ret) { 1866 dev_warn(&ctlr->dev, "could not stop message queue\n"); 1867 return ret; 1868 } 1869 return ret; 1870 } 1871 1872 static int spi_destroy_queue(struct spi_controller *ctlr) 1873 { 1874 int ret; 1875 1876 ret = spi_stop_queue(ctlr); 1877 1878 /* 1879 * kthread_flush_worker will block until all work is done. 1880 * If the reason that stop_queue timed out is that the work will never 1881 * finish, then it does no good to call flush/stop thread, so 1882 * return anyway. 1883 */ 1884 if (ret) { 1885 dev_err(&ctlr->dev, "problem destroying queue\n"); 1886 return ret; 1887 } 1888 1889 kthread_destroy_worker(ctlr->kworker); 1890 1891 return 0; 1892 } 1893 1894 static int __spi_queued_transfer(struct spi_device *spi, 1895 struct spi_message *msg, 1896 bool need_pump) 1897 { 1898 struct spi_controller *ctlr = spi->controller; 1899 unsigned long flags; 1900 1901 spin_lock_irqsave(&ctlr->queue_lock, flags); 1902 1903 if (!ctlr->running) { 1904 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1905 return -ESHUTDOWN; 1906 } 1907 msg->actual_length = 0; 1908 msg->status = -EINPROGRESS; 1909 1910 list_add_tail(&msg->queue, &ctlr->queue); 1911 if (!ctlr->busy && need_pump) 1912 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); 1913 1914 spin_unlock_irqrestore(&ctlr->queue_lock, flags); 1915 return 0; 1916 } 1917 1918 /** 1919 * spi_queued_transfer - transfer function for queued transfers 1920 * @spi: spi device which is requesting transfer 1921 * @msg: spi message which is to handled is queued to driver queue 1922 * 1923 * Return: zero on success, else a negative error code. 1924 */ 1925 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) 1926 { 1927 return __spi_queued_transfer(spi, msg, true); 1928 } 1929 1930 static int spi_controller_initialize_queue(struct spi_controller *ctlr) 1931 { 1932 int ret; 1933 1934 ctlr->transfer = spi_queued_transfer; 1935 if (!ctlr->transfer_one_message) 1936 ctlr->transfer_one_message = spi_transfer_one_message; 1937 1938 /* Initialize and start queue */ 1939 ret = spi_init_queue(ctlr); 1940 if (ret) { 1941 dev_err(&ctlr->dev, "problem initializing queue\n"); 1942 goto err_init_queue; 1943 } 1944 ctlr->queued = true; 1945 ret = spi_start_queue(ctlr); 1946 if (ret) { 1947 dev_err(&ctlr->dev, "problem starting queue\n"); 1948 goto err_start_queue; 1949 } 1950 1951 return 0; 1952 1953 err_start_queue: 1954 spi_destroy_queue(ctlr); 1955 err_init_queue: 1956 return ret; 1957 } 1958 1959 /** 1960 * spi_flush_queue - Send all pending messages in the queue from the callers' 1961 * context 1962 * @ctlr: controller to process queue for 1963 * 1964 * This should be used when one wants to ensure all pending messages have been 1965 * sent before doing something. Is used by the spi-mem code to make sure SPI 1966 * memory operations do not preempt regular SPI transfers that have been queued 1967 * before the spi-mem operation. 1968 */ 1969 void spi_flush_queue(struct spi_controller *ctlr) 1970 { 1971 if (ctlr->transfer == spi_queued_transfer) 1972 __spi_pump_messages(ctlr, false); 1973 } 1974 1975 /*-------------------------------------------------------------------------*/ 1976 1977 #if defined(CONFIG_OF) 1978 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, 1979 struct device_node *nc) 1980 { 1981 u32 value; 1982 int rc; 1983 1984 /* Mode (clock phase/polarity/etc.) */ 1985 if (of_property_read_bool(nc, "spi-cpha")) 1986 spi->mode |= SPI_CPHA; 1987 if (of_property_read_bool(nc, "spi-cpol")) 1988 spi->mode |= SPI_CPOL; 1989 if (of_property_read_bool(nc, "spi-3wire")) 1990 spi->mode |= SPI_3WIRE; 1991 if (of_property_read_bool(nc, "spi-lsb-first")) 1992 spi->mode |= SPI_LSB_FIRST; 1993 if (of_property_read_bool(nc, "spi-cs-high")) 1994 spi->mode |= SPI_CS_HIGH; 1995 1996 /* Device DUAL/QUAD mode */ 1997 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { 1998 switch (value) { 1999 case 0: 2000 spi->mode |= SPI_NO_TX; 2001 break; 2002 case 1: 2003 break; 2004 case 2: 2005 spi->mode |= SPI_TX_DUAL; 2006 break; 2007 case 4: 2008 spi->mode |= SPI_TX_QUAD; 2009 break; 2010 case 8: 2011 spi->mode |= SPI_TX_OCTAL; 2012 break; 2013 default: 2014 dev_warn(&ctlr->dev, 2015 "spi-tx-bus-width %d not supported\n", 2016 value); 2017 break; 2018 } 2019 } 2020 2021 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { 2022 switch (value) { 2023 case 0: 2024 spi->mode |= SPI_NO_RX; 2025 break; 2026 case 1: 2027 break; 2028 case 2: 2029 spi->mode |= SPI_RX_DUAL; 2030 break; 2031 case 4: 2032 spi->mode |= SPI_RX_QUAD; 2033 break; 2034 case 8: 2035 spi->mode |= SPI_RX_OCTAL; 2036 break; 2037 default: 2038 dev_warn(&ctlr->dev, 2039 "spi-rx-bus-width %d not supported\n", 2040 value); 2041 break; 2042 } 2043 } 2044 2045 if (spi_controller_is_slave(ctlr)) { 2046 if (!of_node_name_eq(nc, "slave")) { 2047 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n", 2048 nc); 2049 return -EINVAL; 2050 } 2051 return 0; 2052 } 2053 2054 /* Device address */ 2055 rc = of_property_read_u32(nc, "reg", &value); 2056 if (rc) { 2057 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", 2058 nc, rc); 2059 return rc; 2060 } 2061 spi->chip_select = value; 2062 2063 /* Device speed */ 2064 if (!of_property_read_u32(nc, "spi-max-frequency", &value)) 2065 spi->max_speed_hz = value; 2066 2067 return 0; 2068 } 2069 2070 static struct spi_device * 2071 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) 2072 { 2073 struct spi_device *spi; 2074 int rc; 2075 2076 /* Alloc an spi_device */ 2077 spi = spi_alloc_device(ctlr); 2078 if (!spi) { 2079 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc); 2080 rc = -ENOMEM; 2081 goto err_out; 2082 } 2083 2084 /* Select device driver */ 2085 rc = of_modalias_node(nc, spi->modalias, 2086 sizeof(spi->modalias)); 2087 if (rc < 0) { 2088 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc); 2089 goto err_out; 2090 } 2091 2092 rc = of_spi_parse_dt(ctlr, spi, nc); 2093 if (rc) 2094 goto err_out; 2095 2096 /* Store a pointer to the node in the device structure */ 2097 of_node_get(nc); 2098 spi->dev.of_node = nc; 2099 spi->dev.fwnode = of_fwnode_handle(nc); 2100 2101 /* Register the new device */ 2102 rc = spi_add_device(spi); 2103 if (rc) { 2104 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc); 2105 goto err_of_node_put; 2106 } 2107 2108 return spi; 2109 2110 err_of_node_put: 2111 of_node_put(nc); 2112 err_out: 2113 spi_dev_put(spi); 2114 return ERR_PTR(rc); 2115 } 2116 2117 /** 2118 * of_register_spi_devices() - Register child devices onto the SPI bus 2119 * @ctlr: Pointer to spi_controller device 2120 * 2121 * Registers an spi_device for each child node of controller node which 2122 * represents a valid SPI slave. 2123 */ 2124 static void of_register_spi_devices(struct spi_controller *ctlr) 2125 { 2126 struct spi_device *spi; 2127 struct device_node *nc; 2128 2129 if (!ctlr->dev.of_node) 2130 return; 2131 2132 for_each_available_child_of_node(ctlr->dev.of_node, nc) { 2133 if (of_node_test_and_set_flag(nc, OF_POPULATED)) 2134 continue; 2135 spi = of_register_spi_device(ctlr, nc); 2136 if (IS_ERR(spi)) { 2137 dev_warn(&ctlr->dev, 2138 "Failed to create SPI device for %pOF\n", nc); 2139 of_node_clear_flag(nc, OF_POPULATED); 2140 } 2141 } 2142 } 2143 #else 2144 static void of_register_spi_devices(struct spi_controller *ctlr) { } 2145 #endif 2146 2147 /** 2148 * spi_new_ancillary_device() - Register ancillary SPI device 2149 * @spi: Pointer to the main SPI device registering the ancillary device 2150 * @chip_select: Chip Select of the ancillary device 2151 * 2152 * Register an ancillary SPI device; for example some chips have a chip-select 2153 * for normal device usage and another one for setup/firmware upload. 2154 * 2155 * This may only be called from main SPI device's probe routine. 2156 * 2157 * Return: 0 on success; negative errno on failure 2158 */ 2159 struct spi_device *spi_new_ancillary_device(struct spi_device *spi, 2160 u8 chip_select) 2161 { 2162 struct spi_device *ancillary; 2163 int rc = 0; 2164 2165 /* Alloc an spi_device */ 2166 ancillary = spi_alloc_device(spi->controller); 2167 if (!ancillary) { 2168 rc = -ENOMEM; 2169 goto err_out; 2170 } 2171 2172 strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); 2173 2174 /* Use provided chip-select for ancillary device */ 2175 ancillary->chip_select = chip_select; 2176 2177 /* Take over SPI mode/speed from SPI main device */ 2178 ancillary->max_speed_hz = spi->max_speed_hz; 2179 ancillary->mode = spi->mode; 2180 2181 /* Register the new device */ 2182 rc = spi_add_device_locked(ancillary); 2183 if (rc) { 2184 dev_err(&spi->dev, "failed to register ancillary device\n"); 2185 goto err_out; 2186 } 2187 2188 return ancillary; 2189 2190 err_out: 2191 spi_dev_put(ancillary); 2192 return ERR_PTR(rc); 2193 } 2194 EXPORT_SYMBOL_GPL(spi_new_ancillary_device); 2195 2196 #ifdef CONFIG_ACPI 2197 struct acpi_spi_lookup { 2198 struct spi_controller *ctlr; 2199 u32 max_speed_hz; 2200 u32 mode; 2201 int irq; 2202 u8 bits_per_word; 2203 u8 chip_select; 2204 }; 2205 2206 static void acpi_spi_parse_apple_properties(struct acpi_device *dev, 2207 struct acpi_spi_lookup *lookup) 2208 { 2209 const union acpi_object *obj; 2210 2211 if (!x86_apple_machine) 2212 return; 2213 2214 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) 2215 && obj->buffer.length >= 4) 2216 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; 2217 2218 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) 2219 && obj->buffer.length == 8) 2220 lookup->bits_per_word = *(u64 *)obj->buffer.pointer; 2221 2222 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) 2223 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) 2224 lookup->mode |= SPI_LSB_FIRST; 2225 2226 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) 2227 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) 2228 lookup->mode |= SPI_CPOL; 2229 2230 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) 2231 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) 2232 lookup->mode |= SPI_CPHA; 2233 } 2234 2235 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) 2236 { 2237 struct acpi_spi_lookup *lookup = data; 2238 struct spi_controller *ctlr = lookup->ctlr; 2239 2240 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { 2241 struct acpi_resource_spi_serialbus *sb; 2242 acpi_handle parent_handle; 2243 acpi_status status; 2244 2245 sb = &ares->data.spi_serial_bus; 2246 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { 2247 2248 status = acpi_get_handle(NULL, 2249 sb->resource_source.string_ptr, 2250 &parent_handle); 2251 2252 if (ACPI_FAILURE(status) || 2253 ACPI_HANDLE(ctlr->dev.parent) != parent_handle) 2254 return -ENODEV; 2255 2256 /* 2257 * ACPI DeviceSelection numbering is handled by the 2258 * host controller driver in Windows and can vary 2259 * from driver to driver. In Linux we always expect 2260 * 0 .. max - 1 so we need to ask the driver to 2261 * translate between the two schemes. 2262 */ 2263 if (ctlr->fw_translate_cs) { 2264 int cs = ctlr->fw_translate_cs(ctlr, 2265 sb->device_selection); 2266 if (cs < 0) 2267 return cs; 2268 lookup->chip_select = cs; 2269 } else { 2270 lookup->chip_select = sb->device_selection; 2271 } 2272 2273 lookup->max_speed_hz = sb->connection_speed; 2274 lookup->bits_per_word = sb->data_bit_length; 2275 2276 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) 2277 lookup->mode |= SPI_CPHA; 2278 if (sb->clock_polarity == ACPI_SPI_START_HIGH) 2279 lookup->mode |= SPI_CPOL; 2280 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) 2281 lookup->mode |= SPI_CS_HIGH; 2282 } 2283 } else if (lookup->irq < 0) { 2284 struct resource r; 2285 2286 if (acpi_dev_resource_interrupt(ares, 0, &r)) 2287 lookup->irq = r.start; 2288 } 2289 2290 /* Always tell the ACPI core to skip this resource */ 2291 return 1; 2292 } 2293 2294 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 2295 struct acpi_device *adev) 2296 { 2297 acpi_handle parent_handle = NULL; 2298 struct list_head resource_list; 2299 struct acpi_spi_lookup lookup = {}; 2300 struct spi_device *spi; 2301 int ret; 2302 2303 if (acpi_bus_get_status(adev) || !adev->status.present || 2304 acpi_device_enumerated(adev)) 2305 return AE_OK; 2306 2307 lookup.ctlr = ctlr; 2308 lookup.irq = -1; 2309 2310 INIT_LIST_HEAD(&resource_list); 2311 ret = acpi_dev_get_resources(adev, &resource_list, 2312 acpi_spi_add_resource, &lookup); 2313 acpi_dev_free_resource_list(&resource_list); 2314 2315 if (ret < 0) 2316 /* found SPI in _CRS but it points to another controller */ 2317 return AE_OK; 2318 2319 if (!lookup.max_speed_hz && 2320 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) && 2321 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) { 2322 /* Apple does not use _CRS but nested devices for SPI slaves */ 2323 acpi_spi_parse_apple_properties(adev, &lookup); 2324 } 2325 2326 if (!lookup.max_speed_hz) 2327 return AE_OK; 2328 2329 spi = spi_alloc_device(ctlr); 2330 if (!spi) { 2331 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n", 2332 dev_name(&adev->dev)); 2333 return AE_NO_MEMORY; 2334 } 2335 2336 2337 ACPI_COMPANION_SET(&spi->dev, adev); 2338 spi->max_speed_hz = lookup.max_speed_hz; 2339 spi->mode |= lookup.mode; 2340 spi->irq = lookup.irq; 2341 spi->bits_per_word = lookup.bits_per_word; 2342 spi->chip_select = lookup.chip_select; 2343 2344 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias, 2345 sizeof(spi->modalias)); 2346 2347 if (spi->irq < 0) 2348 spi->irq = acpi_dev_gpio_irq_get(adev, 0); 2349 2350 acpi_device_set_enumerated(adev); 2351 2352 adev->power.flags.ignore_parent = true; 2353 if (spi_add_device(spi)) { 2354 adev->power.flags.ignore_parent = false; 2355 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n", 2356 dev_name(&adev->dev)); 2357 spi_dev_put(spi); 2358 } 2359 2360 return AE_OK; 2361 } 2362 2363 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, 2364 void *data, void **return_value) 2365 { 2366 struct spi_controller *ctlr = data; 2367 struct acpi_device *adev; 2368 2369 if (acpi_bus_get_device(handle, &adev)) 2370 return AE_OK; 2371 2372 return acpi_register_spi_device(ctlr, adev); 2373 } 2374 2375 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32 2376 2377 static void acpi_register_spi_devices(struct spi_controller *ctlr) 2378 { 2379 acpi_status status; 2380 acpi_handle handle; 2381 2382 handle = ACPI_HANDLE(ctlr->dev.parent); 2383 if (!handle) 2384 return; 2385 2386 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 2387 SPI_ACPI_ENUMERATE_MAX_DEPTH, 2388 acpi_spi_add_device, NULL, ctlr, NULL); 2389 if (ACPI_FAILURE(status)) 2390 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n"); 2391 } 2392 #else 2393 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {} 2394 #endif /* CONFIG_ACPI */ 2395 2396 static void spi_controller_release(struct device *dev) 2397 { 2398 struct spi_controller *ctlr; 2399 2400 ctlr = container_of(dev, struct spi_controller, dev); 2401 kfree(ctlr); 2402 } 2403 2404 static struct class spi_master_class = { 2405 .name = "spi_master", 2406 .owner = THIS_MODULE, 2407 .dev_release = spi_controller_release, 2408 .dev_groups = spi_master_groups, 2409 }; 2410 2411 #ifdef CONFIG_SPI_SLAVE 2412 /** 2413 * spi_slave_abort - abort the ongoing transfer request on an SPI slave 2414 * controller 2415 * @spi: device used for the current transfer 2416 */ 2417 int spi_slave_abort(struct spi_device *spi) 2418 { 2419 struct spi_controller *ctlr = spi->controller; 2420 2421 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort) 2422 return ctlr->slave_abort(ctlr); 2423 2424 return -ENOTSUPP; 2425 } 2426 EXPORT_SYMBOL_GPL(spi_slave_abort); 2427 2428 static int match_true(struct device *dev, void *data) 2429 { 2430 return 1; 2431 } 2432 2433 static ssize_t slave_show(struct device *dev, struct device_attribute *attr, 2434 char *buf) 2435 { 2436 struct spi_controller *ctlr = container_of(dev, struct spi_controller, 2437 dev); 2438 struct device *child; 2439 2440 child = device_find_child(&ctlr->dev, NULL, match_true); 2441 return sprintf(buf, "%s\n", 2442 child ? to_spi_device(child)->modalias : NULL); 2443 } 2444 2445 static ssize_t slave_store(struct device *dev, struct device_attribute *attr, 2446 const char *buf, size_t count) 2447 { 2448 struct spi_controller *ctlr = container_of(dev, struct spi_controller, 2449 dev); 2450 struct spi_device *spi; 2451 struct device *child; 2452 char name[32]; 2453 int rc; 2454 2455 rc = sscanf(buf, "%31s", name); 2456 if (rc != 1 || !name[0]) 2457 return -EINVAL; 2458 2459 child = device_find_child(&ctlr->dev, NULL, match_true); 2460 if (child) { 2461 /* Remove registered slave */ 2462 device_unregister(child); 2463 put_device(child); 2464 } 2465 2466 if (strcmp(name, "(null)")) { 2467 /* Register new slave */ 2468 spi = spi_alloc_device(ctlr); 2469 if (!spi) 2470 return -ENOMEM; 2471 2472 strlcpy(spi->modalias, name, sizeof(spi->modalias)); 2473 2474 rc = spi_add_device(spi); 2475 if (rc) { 2476 spi_dev_put(spi); 2477 return rc; 2478 } 2479 } 2480 2481 return count; 2482 } 2483 2484 static DEVICE_ATTR_RW(slave); 2485 2486 static struct attribute *spi_slave_attrs[] = { 2487 &dev_attr_slave.attr, 2488 NULL, 2489 }; 2490 2491 static const struct attribute_group spi_slave_group = { 2492 .attrs = spi_slave_attrs, 2493 }; 2494 2495 static const struct attribute_group *spi_slave_groups[] = { 2496 &spi_controller_statistics_group, 2497 &spi_slave_group, 2498 NULL, 2499 }; 2500 2501 static struct class spi_slave_class = { 2502 .name = "spi_slave", 2503 .owner = THIS_MODULE, 2504 .dev_release = spi_controller_release, 2505 .dev_groups = spi_slave_groups, 2506 }; 2507 #else 2508 extern struct class spi_slave_class; /* dummy */ 2509 #endif 2510 2511 /** 2512 * __spi_alloc_controller - allocate an SPI master or slave controller 2513 * @dev: the controller, possibly using the platform_bus 2514 * @size: how much zeroed driver-private data to allocate; the pointer to this 2515 * memory is in the driver_data field of the returned device, accessible 2516 * with spi_controller_get_devdata(); the memory is cacheline aligned; 2517 * drivers granting DMA access to portions of their private data need to 2518 * round up @size using ALIGN(size, dma_get_cache_alignment()). 2519 * @slave: flag indicating whether to allocate an SPI master (false) or SPI 2520 * slave (true) controller 2521 * Context: can sleep 2522 * 2523 * This call is used only by SPI controller drivers, which are the 2524 * only ones directly touching chip registers. It's how they allocate 2525 * an spi_controller structure, prior to calling spi_register_controller(). 2526 * 2527 * This must be called from context that can sleep. 2528 * 2529 * The caller is responsible for assigning the bus number and initializing the 2530 * controller's methods before calling spi_register_controller(); and (after 2531 * errors adding the device) calling spi_controller_put() to prevent a memory 2532 * leak. 2533 * 2534 * Return: the SPI controller structure on success, else NULL. 2535 */ 2536 struct spi_controller *__spi_alloc_controller(struct device *dev, 2537 unsigned int size, bool slave) 2538 { 2539 struct spi_controller *ctlr; 2540 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment()); 2541 2542 if (!dev) 2543 return NULL; 2544 2545 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL); 2546 if (!ctlr) 2547 return NULL; 2548 2549 device_initialize(&ctlr->dev); 2550 INIT_LIST_HEAD(&ctlr->queue); 2551 spin_lock_init(&ctlr->queue_lock); 2552 spin_lock_init(&ctlr->bus_lock_spinlock); 2553 mutex_init(&ctlr->bus_lock_mutex); 2554 mutex_init(&ctlr->io_mutex); 2555 mutex_init(&ctlr->add_lock); 2556 ctlr->bus_num = -1; 2557 ctlr->num_chipselect = 1; 2558 ctlr->slave = slave; 2559 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave) 2560 ctlr->dev.class = &spi_slave_class; 2561 else 2562 ctlr->dev.class = &spi_master_class; 2563 ctlr->dev.parent = dev; 2564 pm_suspend_ignore_children(&ctlr->dev, true); 2565 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size); 2566 2567 return ctlr; 2568 } 2569 EXPORT_SYMBOL_GPL(__spi_alloc_controller); 2570 2571 static void devm_spi_release_controller(struct device *dev, void *ctlr) 2572 { 2573 spi_controller_put(*(struct spi_controller **)ctlr); 2574 } 2575 2576 /** 2577 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller() 2578 * @dev: physical device of SPI controller 2579 * @size: how much zeroed driver-private data to allocate 2580 * @slave: whether to allocate an SPI master (false) or SPI slave (true) 2581 * Context: can sleep 2582 * 2583 * Allocate an SPI controller and automatically release a reference on it 2584 * when @dev is unbound from its driver. Drivers are thus relieved from 2585 * having to call spi_controller_put(). 2586 * 2587 * The arguments to this function are identical to __spi_alloc_controller(). 2588 * 2589 * Return: the SPI controller structure on success, else NULL. 2590 */ 2591 struct spi_controller *__devm_spi_alloc_controller(struct device *dev, 2592 unsigned int size, 2593 bool slave) 2594 { 2595 struct spi_controller **ptr, *ctlr; 2596 2597 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr), 2598 GFP_KERNEL); 2599 if (!ptr) 2600 return NULL; 2601 2602 ctlr = __spi_alloc_controller(dev, size, slave); 2603 if (ctlr) { 2604 ctlr->devm_allocated = true; 2605 *ptr = ctlr; 2606 devres_add(dev, ptr); 2607 } else { 2608 devres_free(ptr); 2609 } 2610 2611 return ctlr; 2612 } 2613 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller); 2614 2615 #ifdef CONFIG_OF 2616 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr) 2617 { 2618 int nb, i, *cs; 2619 struct device_node *np = ctlr->dev.of_node; 2620 2621 if (!np) 2622 return 0; 2623 2624 nb = of_gpio_named_count(np, "cs-gpios"); 2625 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); 2626 2627 /* Return error only for an incorrectly formed cs-gpios property */ 2628 if (nb == 0 || nb == -ENOENT) 2629 return 0; 2630 else if (nb < 0) 2631 return nb; 2632 2633 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int), 2634 GFP_KERNEL); 2635 ctlr->cs_gpios = cs; 2636 2637 if (!ctlr->cs_gpios) 2638 return -ENOMEM; 2639 2640 for (i = 0; i < ctlr->num_chipselect; i++) 2641 cs[i] = -ENOENT; 2642 2643 for (i = 0; i < nb; i++) 2644 cs[i] = of_get_named_gpio(np, "cs-gpios", i); 2645 2646 return 0; 2647 } 2648 #else 2649 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr) 2650 { 2651 return 0; 2652 } 2653 #endif 2654 2655 /** 2656 * spi_get_gpio_descs() - grab chip select GPIOs for the master 2657 * @ctlr: The SPI master to grab GPIO descriptors for 2658 */ 2659 static int spi_get_gpio_descs(struct spi_controller *ctlr) 2660 { 2661 int nb, i; 2662 struct gpio_desc **cs; 2663 struct device *dev = &ctlr->dev; 2664 unsigned long native_cs_mask = 0; 2665 unsigned int num_cs_gpios = 0; 2666 2667 nb = gpiod_count(dev, "cs"); 2668 if (nb < 0) { 2669 /* No GPIOs at all is fine, else return the error */ 2670 if (nb == -ENOENT) 2671 return 0; 2672 return nb; 2673 } 2674 2675 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); 2676 2677 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs), 2678 GFP_KERNEL); 2679 if (!cs) 2680 return -ENOMEM; 2681 ctlr->cs_gpiods = cs; 2682 2683 for (i = 0; i < nb; i++) { 2684 /* 2685 * Most chipselects are active low, the inverted 2686 * semantics are handled by special quirks in gpiolib, 2687 * so initializing them GPIOD_OUT_LOW here means 2688 * "unasserted", in most cases this will drive the physical 2689 * line high. 2690 */ 2691 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, 2692 GPIOD_OUT_LOW); 2693 if (IS_ERR(cs[i])) 2694 return PTR_ERR(cs[i]); 2695 2696 if (cs[i]) { 2697 /* 2698 * If we find a CS GPIO, name it after the device and 2699 * chip select line. 2700 */ 2701 char *gpioname; 2702 2703 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d", 2704 dev_name(dev), i); 2705 if (!gpioname) 2706 return -ENOMEM; 2707 gpiod_set_consumer_name(cs[i], gpioname); 2708 num_cs_gpios++; 2709 continue; 2710 } 2711 2712 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { 2713 dev_err(dev, "Invalid native chip select %d\n", i); 2714 return -EINVAL; 2715 } 2716 native_cs_mask |= BIT(i); 2717 } 2718 2719 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; 2720 2721 if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios && 2722 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) { 2723 dev_err(dev, "No unused native chip select available\n"); 2724 return -EINVAL; 2725 } 2726 2727 return 0; 2728 } 2729 2730 static int spi_controller_check_ops(struct spi_controller *ctlr) 2731 { 2732 /* 2733 * The controller may implement only the high-level SPI-memory like 2734 * operations if it does not support regular SPI transfers, and this is 2735 * valid use case. 2736 * If ->mem_ops is NULL, we request that at least one of the 2737 * ->transfer_xxx() method be implemented. 2738 */ 2739 if (ctlr->mem_ops) { 2740 if (!ctlr->mem_ops->exec_op) 2741 return -EINVAL; 2742 } else if (!ctlr->transfer && !ctlr->transfer_one && 2743 !ctlr->transfer_one_message) { 2744 return -EINVAL; 2745 } 2746 2747 return 0; 2748 } 2749 2750 /** 2751 * spi_register_controller - register SPI master or slave controller 2752 * @ctlr: initialized master, originally from spi_alloc_master() or 2753 * spi_alloc_slave() 2754 * Context: can sleep 2755 * 2756 * SPI controllers connect to their drivers using some non-SPI bus, 2757 * such as the platform bus. The final stage of probe() in that code 2758 * includes calling spi_register_controller() to hook up to this SPI bus glue. 2759 * 2760 * SPI controllers use board specific (often SOC specific) bus numbers, 2761 * and board-specific addressing for SPI devices combines those numbers 2762 * with chip select numbers. Since SPI does not directly support dynamic 2763 * device identification, boards need configuration tables telling which 2764 * chip is at which address. 2765 * 2766 * This must be called from context that can sleep. It returns zero on 2767 * success, else a negative error code (dropping the controller's refcount). 2768 * After a successful return, the caller is responsible for calling 2769 * spi_unregister_controller(). 2770 * 2771 * Return: zero on success, else a negative error code. 2772 */ 2773 int spi_register_controller(struct spi_controller *ctlr) 2774 { 2775 struct device *dev = ctlr->dev.parent; 2776 struct boardinfo *bi; 2777 int status; 2778 int id, first_dynamic; 2779 2780 if (!dev) 2781 return -ENODEV; 2782 2783 /* 2784 * Make sure all necessary hooks are implemented before registering 2785 * the SPI controller. 2786 */ 2787 status = spi_controller_check_ops(ctlr); 2788 if (status) 2789 return status; 2790 2791 if (ctlr->bus_num >= 0) { 2792 /* devices with a fixed bus num must check-in with the num */ 2793 mutex_lock(&board_lock); 2794 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, 2795 ctlr->bus_num + 1, GFP_KERNEL); 2796 mutex_unlock(&board_lock); 2797 if (WARN(id < 0, "couldn't get idr")) 2798 return id == -ENOSPC ? -EBUSY : id; 2799 ctlr->bus_num = id; 2800 } else if (ctlr->dev.of_node) { 2801 /* allocate dynamic bus number using Linux idr */ 2802 id = of_alias_get_id(ctlr->dev.of_node, "spi"); 2803 if (id >= 0) { 2804 ctlr->bus_num = id; 2805 mutex_lock(&board_lock); 2806 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, 2807 ctlr->bus_num + 1, GFP_KERNEL); 2808 mutex_unlock(&board_lock); 2809 if (WARN(id < 0, "couldn't get idr")) 2810 return id == -ENOSPC ? -EBUSY : id; 2811 } 2812 } 2813 if (ctlr->bus_num < 0) { 2814 first_dynamic = of_alias_get_highest_id("spi"); 2815 if (first_dynamic < 0) 2816 first_dynamic = 0; 2817 else 2818 first_dynamic++; 2819 2820 mutex_lock(&board_lock); 2821 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, 2822 0, GFP_KERNEL); 2823 mutex_unlock(&board_lock); 2824 if (WARN(id < 0, "couldn't get idr")) 2825 return id; 2826 ctlr->bus_num = id; 2827 } 2828 ctlr->bus_lock_flag = 0; 2829 init_completion(&ctlr->xfer_completion); 2830 if (!ctlr->max_dma_len) 2831 ctlr->max_dma_len = INT_MAX; 2832 2833 /* register the device, then userspace will see it. 2834 * registration fails if the bus ID is in use. 2835 */ 2836 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num); 2837 2838 if (!spi_controller_is_slave(ctlr)) { 2839 if (ctlr->use_gpio_descriptors) { 2840 status = spi_get_gpio_descs(ctlr); 2841 if (status) 2842 goto free_bus_id; 2843 /* 2844 * A controller using GPIO descriptors always 2845 * supports SPI_CS_HIGH if need be. 2846 */ 2847 ctlr->mode_bits |= SPI_CS_HIGH; 2848 } else { 2849 /* Legacy code path for GPIOs from DT */ 2850 status = of_spi_get_gpio_numbers(ctlr); 2851 if (status) 2852 goto free_bus_id; 2853 } 2854 } 2855 2856 /* 2857 * Even if it's just one always-selected device, there must 2858 * be at least one chipselect. 2859 */ 2860 if (!ctlr->num_chipselect) { 2861 status = -EINVAL; 2862 goto free_bus_id; 2863 } 2864 2865 status = device_add(&ctlr->dev); 2866 if (status < 0) 2867 goto free_bus_id; 2868 dev_dbg(dev, "registered %s %s\n", 2869 spi_controller_is_slave(ctlr) ? "slave" : "master", 2870 dev_name(&ctlr->dev)); 2871 2872 /* 2873 * If we're using a queued driver, start the queue. Note that we don't 2874 * need the queueing logic if the driver is only supporting high-level 2875 * memory operations. 2876 */ 2877 if (ctlr->transfer) { 2878 dev_info(dev, "controller is unqueued, this is deprecated\n"); 2879 } else if (ctlr->transfer_one || ctlr->transfer_one_message) { 2880 status = spi_controller_initialize_queue(ctlr); 2881 if (status) { 2882 device_del(&ctlr->dev); 2883 goto free_bus_id; 2884 } 2885 } 2886 /* add statistics */ 2887 spin_lock_init(&ctlr->statistics.lock); 2888 2889 mutex_lock(&board_lock); 2890 list_add_tail(&ctlr->list, &spi_controller_list); 2891 list_for_each_entry(bi, &board_list, list) 2892 spi_match_controller_to_boardinfo(ctlr, &bi->board_info); 2893 mutex_unlock(&board_lock); 2894 2895 /* Register devices from the device tree and ACPI */ 2896 of_register_spi_devices(ctlr); 2897 acpi_register_spi_devices(ctlr); 2898 return status; 2899 2900 free_bus_id: 2901 mutex_lock(&board_lock); 2902 idr_remove(&spi_master_idr, ctlr->bus_num); 2903 mutex_unlock(&board_lock); 2904 return status; 2905 } 2906 EXPORT_SYMBOL_GPL(spi_register_controller); 2907 2908 static void devm_spi_unregister(void *ctlr) 2909 { 2910 spi_unregister_controller(ctlr); 2911 } 2912 2913 /** 2914 * devm_spi_register_controller - register managed SPI master or slave 2915 * controller 2916 * @dev: device managing SPI controller 2917 * @ctlr: initialized controller, originally from spi_alloc_master() or 2918 * spi_alloc_slave() 2919 * Context: can sleep 2920 * 2921 * Register a SPI device as with spi_register_controller() which will 2922 * automatically be unregistered and freed. 2923 * 2924 * Return: zero on success, else a negative error code. 2925 */ 2926 int devm_spi_register_controller(struct device *dev, 2927 struct spi_controller *ctlr) 2928 { 2929 int ret; 2930 2931 ret = spi_register_controller(ctlr); 2932 if (ret) 2933 return ret; 2934 2935 return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr); 2936 } 2937 EXPORT_SYMBOL_GPL(devm_spi_register_controller); 2938 2939 static int __unregister(struct device *dev, void *null) 2940 { 2941 spi_unregister_device(to_spi_device(dev)); 2942 return 0; 2943 } 2944 2945 /** 2946 * spi_unregister_controller - unregister SPI master or slave controller 2947 * @ctlr: the controller being unregistered 2948 * Context: can sleep 2949 * 2950 * This call is used only by SPI controller drivers, which are the 2951 * only ones directly touching chip registers. 2952 * 2953 * This must be called from context that can sleep. 2954 * 2955 * Note that this function also drops a reference to the controller. 2956 */ 2957 void spi_unregister_controller(struct spi_controller *ctlr) 2958 { 2959 struct spi_controller *found; 2960 int id = ctlr->bus_num; 2961 2962 /* Prevent addition of new devices, unregister existing ones */ 2963 if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) 2964 mutex_lock(&ctlr->add_lock); 2965 2966 device_for_each_child(&ctlr->dev, NULL, __unregister); 2967 2968 /* First make sure that this controller was ever added */ 2969 mutex_lock(&board_lock); 2970 found = idr_find(&spi_master_idr, id); 2971 mutex_unlock(&board_lock); 2972 if (ctlr->queued) { 2973 if (spi_destroy_queue(ctlr)) 2974 dev_err(&ctlr->dev, "queue remove failed\n"); 2975 } 2976 mutex_lock(&board_lock); 2977 list_del(&ctlr->list); 2978 mutex_unlock(&board_lock); 2979 2980 device_del(&ctlr->dev); 2981 2982 /* Release the last reference on the controller if its driver 2983 * has not yet been converted to devm_spi_alloc_master/slave(). 2984 */ 2985 if (!ctlr->devm_allocated) 2986 put_device(&ctlr->dev); 2987 2988 /* free bus id */ 2989 mutex_lock(&board_lock); 2990 if (found == ctlr) 2991 idr_remove(&spi_master_idr, id); 2992 mutex_unlock(&board_lock); 2993 2994 if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) 2995 mutex_unlock(&ctlr->add_lock); 2996 } 2997 EXPORT_SYMBOL_GPL(spi_unregister_controller); 2998 2999 int spi_controller_suspend(struct spi_controller *ctlr) 3000 { 3001 int ret; 3002 3003 /* Basically no-ops for non-queued controllers */ 3004 if (!ctlr->queued) 3005 return 0; 3006 3007 ret = spi_stop_queue(ctlr); 3008 if (ret) 3009 dev_err(&ctlr->dev, "queue stop failed\n"); 3010 3011 return ret; 3012 } 3013 EXPORT_SYMBOL_GPL(spi_controller_suspend); 3014 3015 int spi_controller_resume(struct spi_controller *ctlr) 3016 { 3017 int ret; 3018 3019 if (!ctlr->queued) 3020 return 0; 3021 3022 ret = spi_start_queue(ctlr); 3023 if (ret) 3024 dev_err(&ctlr->dev, "queue restart failed\n"); 3025 3026 return ret; 3027 } 3028 EXPORT_SYMBOL_GPL(spi_controller_resume); 3029 3030 static int __spi_controller_match(struct device *dev, const void *data) 3031 { 3032 struct spi_controller *ctlr; 3033 const u16 *bus_num = data; 3034 3035 ctlr = container_of(dev, struct spi_controller, dev); 3036 return ctlr->bus_num == *bus_num; 3037 } 3038 3039 /** 3040 * spi_busnum_to_master - look up master associated with bus_num 3041 * @bus_num: the master's bus number 3042 * Context: can sleep 3043 * 3044 * This call may be used with devices that are registered after 3045 * arch init time. It returns a refcounted pointer to the relevant 3046 * spi_controller (which the caller must release), or NULL if there is 3047 * no such master registered. 3048 * 3049 * Return: the SPI master structure on success, else NULL. 3050 */ 3051 struct spi_controller *spi_busnum_to_master(u16 bus_num) 3052 { 3053 struct device *dev; 3054 struct spi_controller *ctlr = NULL; 3055 3056 dev = class_find_device(&spi_master_class, NULL, &bus_num, 3057 __spi_controller_match); 3058 if (dev) 3059 ctlr = container_of(dev, struct spi_controller, dev); 3060 /* reference got in class_find_device */ 3061 return ctlr; 3062 } 3063 EXPORT_SYMBOL_GPL(spi_busnum_to_master); 3064 3065 /*-------------------------------------------------------------------------*/ 3066 3067 /* Core methods for SPI resource management */ 3068 3069 /** 3070 * spi_res_alloc - allocate a spi resource that is life-cycle managed 3071 * during the processing of a spi_message while using 3072 * spi_transfer_one 3073 * @spi: the spi device for which we allocate memory 3074 * @release: the release code to execute for this resource 3075 * @size: size to alloc and return 3076 * @gfp: GFP allocation flags 3077 * 3078 * Return: the pointer to the allocated data 3079 * 3080 * This may get enhanced in the future to allocate from a memory pool 3081 * of the @spi_device or @spi_controller to avoid repeated allocations. 3082 */ 3083 void *spi_res_alloc(struct spi_device *spi, 3084 spi_res_release_t release, 3085 size_t size, gfp_t gfp) 3086 { 3087 struct spi_res *sres; 3088 3089 sres = kzalloc(sizeof(*sres) + size, gfp); 3090 if (!sres) 3091 return NULL; 3092 3093 INIT_LIST_HEAD(&sres->entry); 3094 sres->release = release; 3095 3096 return sres->data; 3097 } 3098 EXPORT_SYMBOL_GPL(spi_res_alloc); 3099 3100 /** 3101 * spi_res_free - free an spi resource 3102 * @res: pointer to the custom data of a resource 3103 * 3104 */ 3105 void spi_res_free(void *res) 3106 { 3107 struct spi_res *sres = container_of(res, struct spi_res, data); 3108 3109 if (!res) 3110 return; 3111 3112 WARN_ON(!list_empty(&sres->entry)); 3113 kfree(sres); 3114 } 3115 EXPORT_SYMBOL_GPL(spi_res_free); 3116 3117 /** 3118 * spi_res_add - add a spi_res to the spi_message 3119 * @message: the spi message 3120 * @res: the spi_resource 3121 */ 3122 void spi_res_add(struct spi_message *message, void *res) 3123 { 3124 struct spi_res *sres = container_of(res, struct spi_res, data); 3125 3126 WARN_ON(!list_empty(&sres->entry)); 3127 list_add_tail(&sres->entry, &message->resources); 3128 } 3129 EXPORT_SYMBOL_GPL(spi_res_add); 3130 3131 /** 3132 * spi_res_release - release all spi resources for this message 3133 * @ctlr: the @spi_controller 3134 * @message: the @spi_message 3135 */ 3136 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) 3137 { 3138 struct spi_res *res, *tmp; 3139 3140 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) { 3141 if (res->release) 3142 res->release(ctlr, message, res->data); 3143 3144 list_del(&res->entry); 3145 3146 kfree(res); 3147 } 3148 } 3149 EXPORT_SYMBOL_GPL(spi_res_release); 3150 3151 /*-------------------------------------------------------------------------*/ 3152 3153 /* Core methods for spi_message alterations */ 3154 3155 static void __spi_replace_transfers_release(struct spi_controller *ctlr, 3156 struct spi_message *msg, 3157 void *res) 3158 { 3159 struct spi_replaced_transfers *rxfer = res; 3160 size_t i; 3161 3162 /* call extra callback if requested */ 3163 if (rxfer->release) 3164 rxfer->release(ctlr, msg, res); 3165 3166 /* insert replaced transfers back into the message */ 3167 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); 3168 3169 /* remove the formerly inserted entries */ 3170 for (i = 0; i < rxfer->inserted; i++) 3171 list_del(&rxfer->inserted_transfers[i].transfer_list); 3172 } 3173 3174 /** 3175 * spi_replace_transfers - replace transfers with several transfers 3176 * and register change with spi_message.resources 3177 * @msg: the spi_message we work upon 3178 * @xfer_first: the first spi_transfer we want to replace 3179 * @remove: number of transfers to remove 3180 * @insert: the number of transfers we want to insert instead 3181 * @release: extra release code necessary in some circumstances 3182 * @extradatasize: extra data to allocate (with alignment guarantees 3183 * of struct @spi_transfer) 3184 * @gfp: gfp flags 3185 * 3186 * Returns: pointer to @spi_replaced_transfers, 3187 * PTR_ERR(...) in case of errors. 3188 */ 3189 struct spi_replaced_transfers *spi_replace_transfers( 3190 struct spi_message *msg, 3191 struct spi_transfer *xfer_first, 3192 size_t remove, 3193 size_t insert, 3194 spi_replaced_release_t release, 3195 size_t extradatasize, 3196 gfp_t gfp) 3197 { 3198 struct spi_replaced_transfers *rxfer; 3199 struct spi_transfer *xfer; 3200 size_t i; 3201 3202 /* allocate the structure using spi_res */ 3203 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release, 3204 struct_size(rxfer, inserted_transfers, insert) 3205 + extradatasize, 3206 gfp); 3207 if (!rxfer) 3208 return ERR_PTR(-ENOMEM); 3209 3210 /* the release code to invoke before running the generic release */ 3211 rxfer->release = release; 3212 3213 /* assign extradata */ 3214 if (extradatasize) 3215 rxfer->extradata = 3216 &rxfer->inserted_transfers[insert]; 3217 3218 /* init the replaced_transfers list */ 3219 INIT_LIST_HEAD(&rxfer->replaced_transfers); 3220 3221 /* assign the list_entry after which we should reinsert 3222 * the @replaced_transfers - it may be spi_message.messages! 3223 */ 3224 rxfer->replaced_after = xfer_first->transfer_list.prev; 3225 3226 /* remove the requested number of transfers */ 3227 for (i = 0; i < remove; i++) { 3228 /* if the entry after replaced_after it is msg->transfers 3229 * then we have been requested to remove more transfers 3230 * than are in the list 3231 */ 3232 if (rxfer->replaced_after->next == &msg->transfers) { 3233 dev_err(&msg->spi->dev, 3234 "requested to remove more spi_transfers than are available\n"); 3235 /* insert replaced transfers back into the message */ 3236 list_splice(&rxfer->replaced_transfers, 3237 rxfer->replaced_after); 3238 3239 /* free the spi_replace_transfer structure */ 3240 spi_res_free(rxfer); 3241 3242 /* and return with an error */ 3243 return ERR_PTR(-EINVAL); 3244 } 3245 3246 /* remove the entry after replaced_after from list of 3247 * transfers and add it to list of replaced_transfers 3248 */ 3249 list_move_tail(rxfer->replaced_after->next, 3250 &rxfer->replaced_transfers); 3251 } 3252 3253 /* create copy of the given xfer with identical settings 3254 * based on the first transfer to get removed 3255 */ 3256 for (i = 0; i < insert; i++) { 3257 /* we need to run in reverse order */ 3258 xfer = &rxfer->inserted_transfers[insert - 1 - i]; 3259 3260 /* copy all spi_transfer data */ 3261 memcpy(xfer, xfer_first, sizeof(*xfer)); 3262 3263 /* add to list */ 3264 list_add(&xfer->transfer_list, rxfer->replaced_after); 3265 3266 /* clear cs_change and delay for all but the last */ 3267 if (i) { 3268 xfer->cs_change = false; 3269 xfer->delay.value = 0; 3270 } 3271 } 3272 3273 /* set up inserted */ 3274 rxfer->inserted = insert; 3275 3276 /* and register it with spi_res/spi_message */ 3277 spi_res_add(msg, rxfer); 3278 3279 return rxfer; 3280 } 3281 EXPORT_SYMBOL_GPL(spi_replace_transfers); 3282 3283 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, 3284 struct spi_message *msg, 3285 struct spi_transfer **xferp, 3286 size_t maxsize, 3287 gfp_t gfp) 3288 { 3289 struct spi_transfer *xfer = *xferp, *xfers; 3290 struct spi_replaced_transfers *srt; 3291 size_t offset; 3292 size_t count, i; 3293 3294 /* calculate how many we have to replace */ 3295 count = DIV_ROUND_UP(xfer->len, maxsize); 3296 3297 /* create replacement */ 3298 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp); 3299 if (IS_ERR(srt)) 3300 return PTR_ERR(srt); 3301 xfers = srt->inserted_transfers; 3302 3303 /* now handle each of those newly inserted spi_transfers 3304 * note that the replacements spi_transfers all are preset 3305 * to the same values as *xferp, so tx_buf, rx_buf and len 3306 * are all identical (as well as most others) 3307 * so we just have to fix up len and the pointers. 3308 * 3309 * this also includes support for the depreciated 3310 * spi_message.is_dma_mapped interface 3311 */ 3312 3313 /* the first transfer just needs the length modified, so we 3314 * run it outside the loop 3315 */ 3316 xfers[0].len = min_t(size_t, maxsize, xfer[0].len); 3317 3318 /* all the others need rx_buf/tx_buf also set */ 3319 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { 3320 /* update rx_buf, tx_buf and dma */ 3321 if (xfers[i].rx_buf) 3322 xfers[i].rx_buf += offset; 3323 if (xfers[i].rx_dma) 3324 xfers[i].rx_dma += offset; 3325 if (xfers[i].tx_buf) 3326 xfers[i].tx_buf += offset; 3327 if (xfers[i].tx_dma) 3328 xfers[i].tx_dma += offset; 3329 3330 /* update length */ 3331 xfers[i].len = min(maxsize, xfers[i].len - offset); 3332 } 3333 3334 /* we set up xferp to the last entry we have inserted, 3335 * so that we skip those already split transfers 3336 */ 3337 *xferp = &xfers[count - 1]; 3338 3339 /* increment statistics counters */ 3340 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, 3341 transfers_split_maxsize); 3342 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics, 3343 transfers_split_maxsize); 3344 3345 return 0; 3346 } 3347 3348 /** 3349 * spi_split_transfers_maxsize - split spi transfers into multiple transfers 3350 * when an individual transfer exceeds a 3351 * certain size 3352 * @ctlr: the @spi_controller for this transfer 3353 * @msg: the @spi_message to transform 3354 * @maxsize: the maximum when to apply this 3355 * @gfp: GFP allocation flags 3356 * 3357 * Return: status of transformation 3358 */ 3359 int spi_split_transfers_maxsize(struct spi_controller *ctlr, 3360 struct spi_message *msg, 3361 size_t maxsize, 3362 gfp_t gfp) 3363 { 3364 struct spi_transfer *xfer; 3365 int ret; 3366 3367 /* iterate over the transfer_list, 3368 * but note that xfer is advanced to the last transfer inserted 3369 * to avoid checking sizes again unnecessarily (also xfer does 3370 * potentiall belong to a different list by the time the 3371 * replacement has happened 3372 */ 3373 list_for_each_entry(xfer, &msg->transfers, transfer_list) { 3374 if (xfer->len > maxsize) { 3375 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, 3376 maxsize, gfp); 3377 if (ret) 3378 return ret; 3379 } 3380 } 3381 3382 return 0; 3383 } 3384 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); 3385 3386 /*-------------------------------------------------------------------------*/ 3387 3388 /* Core methods for SPI controller protocol drivers. Some of the 3389 * other core methods are currently defined as inline functions. 3390 */ 3391 3392 static int __spi_validate_bits_per_word(struct spi_controller *ctlr, 3393 u8 bits_per_word) 3394 { 3395 if (ctlr->bits_per_word_mask) { 3396 /* Only 32 bits fit in the mask */ 3397 if (bits_per_word > 32) 3398 return -EINVAL; 3399 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word))) 3400 return -EINVAL; 3401 } 3402 3403 return 0; 3404 } 3405 3406 /** 3407 * spi_setup - setup SPI mode and clock rate 3408 * @spi: the device whose settings are being modified 3409 * Context: can sleep, and no requests are queued to the device 3410 * 3411 * SPI protocol drivers may need to update the transfer mode if the 3412 * device doesn't work with its default. They may likewise need 3413 * to update clock rates or word sizes from initial values. This function 3414 * changes those settings, and must be called from a context that can sleep. 3415 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take 3416 * effect the next time the device is selected and data is transferred to 3417 * or from it. When this function returns, the spi device is deselected. 3418 * 3419 * Note that this call will fail if the protocol driver specifies an option 3420 * that the underlying controller or its driver does not support. For 3421 * example, not all hardware supports wire transfers using nine bit words, 3422 * LSB-first wire encoding, or active-high chipselects. 3423 * 3424 * Return: zero on success, else a negative error code. 3425 */ 3426 int spi_setup(struct spi_device *spi) 3427 { 3428 unsigned bad_bits, ugly_bits; 3429 int status; 3430 3431 /* 3432 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO 3433 * are set at the same time 3434 */ 3435 if ((hweight_long(spi->mode & 3436 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) || 3437 (hweight_long(spi->mode & 3438 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) { 3439 dev_err(&spi->dev, 3440 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n"); 3441 return -EINVAL; 3442 } 3443 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden 3444 */ 3445 if ((spi->mode & SPI_3WIRE) && (spi->mode & 3446 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | 3447 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) 3448 return -EINVAL; 3449 /* help drivers fail *cleanly* when they need options 3450 * that aren't supported with their current controller 3451 * SPI_CS_WORD has a fallback software implementation, 3452 * so it is ignored here. 3453 */ 3454 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | 3455 SPI_NO_TX | SPI_NO_RX); 3456 /* nothing prevents from working with active-high CS in case if it 3457 * is driven by GPIO. 3458 */ 3459 if (gpio_is_valid(spi->cs_gpio)) 3460 bad_bits &= ~SPI_CS_HIGH; 3461 ugly_bits = bad_bits & 3462 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | 3463 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL); 3464 if (ugly_bits) { 3465 dev_warn(&spi->dev, 3466 "setup: ignoring unsupported mode bits %x\n", 3467 ugly_bits); 3468 spi->mode &= ~ugly_bits; 3469 bad_bits &= ~ugly_bits; 3470 } 3471 if (bad_bits) { 3472 dev_err(&spi->dev, "setup: unsupported mode bits %x\n", 3473 bad_bits); 3474 return -EINVAL; 3475 } 3476 3477 if (!spi->bits_per_word) 3478 spi->bits_per_word = 8; 3479 3480 status = __spi_validate_bits_per_word(spi->controller, 3481 spi->bits_per_word); 3482 if (status) 3483 return status; 3484 3485 if (spi->controller->max_speed_hz && 3486 (!spi->max_speed_hz || 3487 spi->max_speed_hz > spi->controller->max_speed_hz)) 3488 spi->max_speed_hz = spi->controller->max_speed_hz; 3489 3490 mutex_lock(&spi->controller->io_mutex); 3491 3492 if (spi->controller->setup) { 3493 status = spi->controller->setup(spi); 3494 if (status) { 3495 mutex_unlock(&spi->controller->io_mutex); 3496 dev_err(&spi->controller->dev, "Failed to setup device: %d\n", 3497 status); 3498 return status; 3499 } 3500 } 3501 3502 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { 3503 status = pm_runtime_get_sync(spi->controller->dev.parent); 3504 if (status < 0) { 3505 mutex_unlock(&spi->controller->io_mutex); 3506 pm_runtime_put_noidle(spi->controller->dev.parent); 3507 dev_err(&spi->controller->dev, "Failed to power device: %d\n", 3508 status); 3509 return status; 3510 } 3511 3512 /* 3513 * We do not want to return positive value from pm_runtime_get, 3514 * there are many instances of devices calling spi_setup() and 3515 * checking for a non-zero return value instead of a negative 3516 * return value. 3517 */ 3518 status = 0; 3519 3520 spi_set_cs(spi, false, true); 3521 pm_runtime_mark_last_busy(spi->controller->dev.parent); 3522 pm_runtime_put_autosuspend(spi->controller->dev.parent); 3523 } else { 3524 spi_set_cs(spi, false, true); 3525 } 3526 3527 mutex_unlock(&spi->controller->io_mutex); 3528 3529 if (spi->rt && !spi->controller->rt) { 3530 spi->controller->rt = true; 3531 spi_set_thread_rt(spi->controller); 3532 } 3533 3534 trace_spi_setup(spi, status); 3535 3536 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n", 3537 spi->mode & SPI_MODE_X_MASK, 3538 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", 3539 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", 3540 (spi->mode & SPI_3WIRE) ? "3wire, " : "", 3541 (spi->mode & SPI_LOOP) ? "loopback, " : "", 3542 spi->bits_per_word, spi->max_speed_hz, 3543 status); 3544 3545 return status; 3546 } 3547 EXPORT_SYMBOL_GPL(spi_setup); 3548 3549 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, 3550 struct spi_device *spi) 3551 { 3552 int delay1, delay2; 3553 3554 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); 3555 if (delay1 < 0) 3556 return delay1; 3557 3558 delay2 = spi_delay_to_ns(&spi->word_delay, xfer); 3559 if (delay2 < 0) 3560 return delay2; 3561 3562 if (delay1 < delay2) 3563 memcpy(&xfer->word_delay, &spi->word_delay, 3564 sizeof(xfer->word_delay)); 3565 3566 return 0; 3567 } 3568 3569 static int __spi_validate(struct spi_device *spi, struct spi_message *message) 3570 { 3571 struct spi_controller *ctlr = spi->controller; 3572 struct spi_transfer *xfer; 3573 int w_size; 3574 3575 if (list_empty(&message->transfers)) 3576 return -EINVAL; 3577 3578 /* If an SPI controller does not support toggling the CS line on each 3579 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO 3580 * for the CS line, we can emulate the CS-per-word hardware function by 3581 * splitting transfers into one-word transfers and ensuring that 3582 * cs_change is set for each transfer. 3583 */ 3584 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || 3585 spi->cs_gpiod || 3586 gpio_is_valid(spi->cs_gpio))) { 3587 size_t maxsize; 3588 int ret; 3589 3590 maxsize = (spi->bits_per_word + 7) / 8; 3591 3592 /* spi_split_transfers_maxsize() requires message->spi */ 3593 message->spi = spi; 3594 3595 ret = spi_split_transfers_maxsize(ctlr, message, maxsize, 3596 GFP_KERNEL); 3597 if (ret) 3598 return ret; 3599 3600 list_for_each_entry(xfer, &message->transfers, transfer_list) { 3601 /* don't change cs_change on the last entry in the list */ 3602 if (list_is_last(&xfer->transfer_list, &message->transfers)) 3603 break; 3604 xfer->cs_change = 1; 3605 } 3606 } 3607 3608 /* Half-duplex links include original MicroWire, and ones with 3609 * only one data pin like SPI_3WIRE (switches direction) or where 3610 * either MOSI or MISO is missing. They can also be caused by 3611 * software limitations. 3612 */ 3613 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) || 3614 (spi->mode & SPI_3WIRE)) { 3615 unsigned flags = ctlr->flags; 3616 3617 list_for_each_entry(xfer, &message->transfers, transfer_list) { 3618 if (xfer->rx_buf && xfer->tx_buf) 3619 return -EINVAL; 3620 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf) 3621 return -EINVAL; 3622 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf) 3623 return -EINVAL; 3624 } 3625 } 3626 3627 /** 3628 * Set transfer bits_per_word and max speed as spi device default if 3629 * it is not set for this transfer. 3630 * Set transfer tx_nbits and rx_nbits as single transfer default 3631 * (SPI_NBITS_SINGLE) if it is not set for this transfer. 3632 * Ensure transfer word_delay is at least as long as that required by 3633 * device itself. 3634 */ 3635 message->frame_length = 0; 3636 list_for_each_entry(xfer, &message->transfers, transfer_list) { 3637 xfer->effective_speed_hz = 0; 3638 message->frame_length += xfer->len; 3639 if (!xfer->bits_per_word) 3640 xfer->bits_per_word = spi->bits_per_word; 3641 3642 if (!xfer->speed_hz) 3643 xfer->speed_hz = spi->max_speed_hz; 3644 3645 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz) 3646 xfer->speed_hz = ctlr->max_speed_hz; 3647 3648 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word)) 3649 return -EINVAL; 3650 3651 /* 3652 * SPI transfer length should be multiple of SPI word size 3653 * where SPI word size should be power-of-two multiple 3654 */ 3655 if (xfer->bits_per_word <= 8) 3656 w_size = 1; 3657 else if (xfer->bits_per_word <= 16) 3658 w_size = 2; 3659 else 3660 w_size = 4; 3661 3662 /* No partial transfers accepted */ 3663 if (xfer->len % w_size) 3664 return -EINVAL; 3665 3666 if (xfer->speed_hz && ctlr->min_speed_hz && 3667 xfer->speed_hz < ctlr->min_speed_hz) 3668 return -EINVAL; 3669 3670 if (xfer->tx_buf && !xfer->tx_nbits) 3671 xfer->tx_nbits = SPI_NBITS_SINGLE; 3672 if (xfer->rx_buf && !xfer->rx_nbits) 3673 xfer->rx_nbits = SPI_NBITS_SINGLE; 3674 /* check transfer tx/rx_nbits: 3675 * 1. check the value matches one of single, dual and quad 3676 * 2. check tx/rx_nbits match the mode in spi_device 3677 */ 3678 if (xfer->tx_buf) { 3679 if (spi->mode & SPI_NO_TX) 3680 return -EINVAL; 3681 if (xfer->tx_nbits != SPI_NBITS_SINGLE && 3682 xfer->tx_nbits != SPI_NBITS_DUAL && 3683 xfer->tx_nbits != SPI_NBITS_QUAD) 3684 return -EINVAL; 3685 if ((xfer->tx_nbits == SPI_NBITS_DUAL) && 3686 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) 3687 return -EINVAL; 3688 if ((xfer->tx_nbits == SPI_NBITS_QUAD) && 3689 !(spi->mode & SPI_TX_QUAD)) 3690 return -EINVAL; 3691 } 3692 /* check transfer rx_nbits */ 3693 if (xfer->rx_buf) { 3694 if (spi->mode & SPI_NO_RX) 3695 return -EINVAL; 3696 if (xfer->rx_nbits != SPI_NBITS_SINGLE && 3697 xfer->rx_nbits != SPI_NBITS_DUAL && 3698 xfer->rx_nbits != SPI_NBITS_QUAD) 3699 return -EINVAL; 3700 if ((xfer->rx_nbits == SPI_NBITS_DUAL) && 3701 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) 3702 return -EINVAL; 3703 if ((xfer->rx_nbits == SPI_NBITS_QUAD) && 3704 !(spi->mode & SPI_RX_QUAD)) 3705 return -EINVAL; 3706 } 3707 3708 if (_spi_xfer_word_delay_update(xfer, spi)) 3709 return -EINVAL; 3710 } 3711 3712 message->status = -EINPROGRESS; 3713 3714 return 0; 3715 } 3716 3717 static int __spi_async(struct spi_device *spi, struct spi_message *message) 3718 { 3719 struct spi_controller *ctlr = spi->controller; 3720 struct spi_transfer *xfer; 3721 3722 /* 3723 * Some controllers do not support doing regular SPI transfers. Return 3724 * ENOTSUPP when this is the case. 3725 */ 3726 if (!ctlr->transfer) 3727 return -ENOTSUPP; 3728 3729 message->spi = spi; 3730 3731 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async); 3732 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async); 3733 3734 trace_spi_message_submit(message); 3735 3736 if (!ctlr->ptp_sts_supported) { 3737 list_for_each_entry(xfer, &message->transfers, transfer_list) { 3738 xfer->ptp_sts_word_pre = 0; 3739 ptp_read_system_prets(xfer->ptp_sts); 3740 } 3741 } 3742 3743 return ctlr->transfer(spi, message); 3744 } 3745 3746 /** 3747 * spi_async - asynchronous SPI transfer 3748 * @spi: device with which data will be exchanged 3749 * @message: describes the data transfers, including completion callback 3750 * Context: any (irqs may be blocked, etc) 3751 * 3752 * This call may be used in_irq and other contexts which can't sleep, 3753 * as well as from task contexts which can sleep. 3754 * 3755 * The completion callback is invoked in a context which can't sleep. 3756 * Before that invocation, the value of message->status is undefined. 3757 * When the callback is issued, message->status holds either zero (to 3758 * indicate complete success) or a negative error code. After that 3759 * callback returns, the driver which issued the transfer request may 3760 * deallocate the associated memory; it's no longer in use by any SPI 3761 * core or controller driver code. 3762 * 3763 * Note that although all messages to a spi_device are handled in 3764 * FIFO order, messages may go to different devices in other orders. 3765 * Some device might be higher priority, or have various "hard" access 3766 * time requirements, for example. 3767 * 3768 * On detection of any fault during the transfer, processing of 3769 * the entire message is aborted, and the device is deselected. 3770 * Until returning from the associated message completion callback, 3771 * no other spi_message queued to that device will be processed. 3772 * (This rule applies equally to all the synchronous transfer calls, 3773 * which are wrappers around this core asynchronous primitive.) 3774 * 3775 * Return: zero on success, else a negative error code. 3776 */ 3777 int spi_async(struct spi_device *spi, struct spi_message *message) 3778 { 3779 struct spi_controller *ctlr = spi->controller; 3780 int ret; 3781 unsigned long flags; 3782 3783 ret = __spi_validate(spi, message); 3784 if (ret != 0) 3785 return ret; 3786 3787 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 3788 3789 if (ctlr->bus_lock_flag) 3790 ret = -EBUSY; 3791 else 3792 ret = __spi_async(spi, message); 3793 3794 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 3795 3796 return ret; 3797 } 3798 EXPORT_SYMBOL_GPL(spi_async); 3799 3800 /** 3801 * spi_async_locked - version of spi_async with exclusive bus usage 3802 * @spi: device with which data will be exchanged 3803 * @message: describes the data transfers, including completion callback 3804 * Context: any (irqs may be blocked, etc) 3805 * 3806 * This call may be used in_irq and other contexts which can't sleep, 3807 * as well as from task contexts which can sleep. 3808 * 3809 * The completion callback is invoked in a context which can't sleep. 3810 * Before that invocation, the value of message->status is undefined. 3811 * When the callback is issued, message->status holds either zero (to 3812 * indicate complete success) or a negative error code. After that 3813 * callback returns, the driver which issued the transfer request may 3814 * deallocate the associated memory; it's no longer in use by any SPI 3815 * core or controller driver code. 3816 * 3817 * Note that although all messages to a spi_device are handled in 3818 * FIFO order, messages may go to different devices in other orders. 3819 * Some device might be higher priority, or have various "hard" access 3820 * time requirements, for example. 3821 * 3822 * On detection of any fault during the transfer, processing of 3823 * the entire message is aborted, and the device is deselected. 3824 * Until returning from the associated message completion callback, 3825 * no other spi_message queued to that device will be processed. 3826 * (This rule applies equally to all the synchronous transfer calls, 3827 * which are wrappers around this core asynchronous primitive.) 3828 * 3829 * Return: zero on success, else a negative error code. 3830 */ 3831 int spi_async_locked(struct spi_device *spi, struct spi_message *message) 3832 { 3833 struct spi_controller *ctlr = spi->controller; 3834 int ret; 3835 unsigned long flags; 3836 3837 ret = __spi_validate(spi, message); 3838 if (ret != 0) 3839 return ret; 3840 3841 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 3842 3843 ret = __spi_async(spi, message); 3844 3845 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 3846 3847 return ret; 3848 3849 } 3850 EXPORT_SYMBOL_GPL(spi_async_locked); 3851 3852 /*-------------------------------------------------------------------------*/ 3853 3854 /* Utility methods for SPI protocol drivers, layered on 3855 * top of the core. Some other utility methods are defined as 3856 * inline functions. 3857 */ 3858 3859 static void spi_complete(void *arg) 3860 { 3861 complete(arg); 3862 } 3863 3864 static int __spi_sync(struct spi_device *spi, struct spi_message *message) 3865 { 3866 DECLARE_COMPLETION_ONSTACK(done); 3867 int status; 3868 struct spi_controller *ctlr = spi->controller; 3869 unsigned long flags; 3870 3871 status = __spi_validate(spi, message); 3872 if (status != 0) 3873 return status; 3874 3875 message->complete = spi_complete; 3876 message->context = &done; 3877 message->spi = spi; 3878 3879 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync); 3880 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync); 3881 3882 /* If we're not using the legacy transfer method then we will 3883 * try to transfer in the calling context so special case. 3884 * This code would be less tricky if we could remove the 3885 * support for driver implemented message queues. 3886 */ 3887 if (ctlr->transfer == spi_queued_transfer) { 3888 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 3889 3890 trace_spi_message_submit(message); 3891 3892 status = __spi_queued_transfer(spi, message, false); 3893 3894 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 3895 } else { 3896 status = spi_async_locked(spi, message); 3897 } 3898 3899 if (status == 0) { 3900 /* Push out the messages in the calling context if we 3901 * can. 3902 */ 3903 if (ctlr->transfer == spi_queued_transfer) { 3904 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, 3905 spi_sync_immediate); 3906 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, 3907 spi_sync_immediate); 3908 __spi_pump_messages(ctlr, false); 3909 } 3910 3911 wait_for_completion(&done); 3912 status = message->status; 3913 } 3914 message->context = NULL; 3915 return status; 3916 } 3917 3918 /** 3919 * spi_sync - blocking/synchronous SPI data transfers 3920 * @spi: device with which data will be exchanged 3921 * @message: describes the data transfers 3922 * Context: can sleep 3923 * 3924 * This call may only be used from a context that may sleep. The sleep 3925 * is non-interruptible, and has no timeout. Low-overhead controller 3926 * drivers may DMA directly into and out of the message buffers. 3927 * 3928 * Note that the SPI device's chip select is active during the message, 3929 * and then is normally disabled between messages. Drivers for some 3930 * frequently-used devices may want to minimize costs of selecting a chip, 3931 * by leaving it selected in anticipation that the next message will go 3932 * to the same chip. (That may increase power usage.) 3933 * 3934 * Also, the caller is guaranteeing that the memory associated with the 3935 * message will not be freed before this call returns. 3936 * 3937 * Return: zero on success, else a negative error code. 3938 */ 3939 int spi_sync(struct spi_device *spi, struct spi_message *message) 3940 { 3941 int ret; 3942 3943 mutex_lock(&spi->controller->bus_lock_mutex); 3944 ret = __spi_sync(spi, message); 3945 mutex_unlock(&spi->controller->bus_lock_mutex); 3946 3947 return ret; 3948 } 3949 EXPORT_SYMBOL_GPL(spi_sync); 3950 3951 /** 3952 * spi_sync_locked - version of spi_sync with exclusive bus usage 3953 * @spi: device with which data will be exchanged 3954 * @message: describes the data transfers 3955 * Context: can sleep 3956 * 3957 * This call may only be used from a context that may sleep. The sleep 3958 * is non-interruptible, and has no timeout. Low-overhead controller 3959 * drivers may DMA directly into and out of the message buffers. 3960 * 3961 * This call should be used by drivers that require exclusive access to the 3962 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must 3963 * be released by a spi_bus_unlock call when the exclusive access is over. 3964 * 3965 * Return: zero on success, else a negative error code. 3966 */ 3967 int spi_sync_locked(struct spi_device *spi, struct spi_message *message) 3968 { 3969 return __spi_sync(spi, message); 3970 } 3971 EXPORT_SYMBOL_GPL(spi_sync_locked); 3972 3973 /** 3974 * spi_bus_lock - obtain a lock for exclusive SPI bus usage 3975 * @ctlr: SPI bus master that should be locked for exclusive bus access 3976 * Context: can sleep 3977 * 3978 * This call may only be used from a context that may sleep. The sleep 3979 * is non-interruptible, and has no timeout. 3980 * 3981 * This call should be used by drivers that require exclusive access to the 3982 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the 3983 * exclusive access is over. Data transfer must be done by spi_sync_locked 3984 * and spi_async_locked calls when the SPI bus lock is held. 3985 * 3986 * Return: always zero. 3987 */ 3988 int spi_bus_lock(struct spi_controller *ctlr) 3989 { 3990 unsigned long flags; 3991 3992 mutex_lock(&ctlr->bus_lock_mutex); 3993 3994 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); 3995 ctlr->bus_lock_flag = 1; 3996 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); 3997 3998 /* mutex remains locked until spi_bus_unlock is called */ 3999 4000 return 0; 4001 } 4002 EXPORT_SYMBOL_GPL(spi_bus_lock); 4003 4004 /** 4005 * spi_bus_unlock - release the lock for exclusive SPI bus usage 4006 * @ctlr: SPI bus master that was locked for exclusive bus access 4007 * Context: can sleep 4008 * 4009 * This call may only be used from a context that may sleep. The sleep 4010 * is non-interruptible, and has no timeout. 4011 * 4012 * This call releases an SPI bus lock previously obtained by an spi_bus_lock 4013 * call. 4014 * 4015 * Return: always zero. 4016 */ 4017 int spi_bus_unlock(struct spi_controller *ctlr) 4018 { 4019 ctlr->bus_lock_flag = 0; 4020 4021 mutex_unlock(&ctlr->bus_lock_mutex); 4022 4023 return 0; 4024 } 4025 EXPORT_SYMBOL_GPL(spi_bus_unlock); 4026 4027 /* portable code must never pass more than 32 bytes */ 4028 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) 4029 4030 static u8 *buf; 4031 4032 /** 4033 * spi_write_then_read - SPI synchronous write followed by read 4034 * @spi: device with which data will be exchanged 4035 * @txbuf: data to be written (need not be dma-safe) 4036 * @n_tx: size of txbuf, in bytes 4037 * @rxbuf: buffer into which data will be read (need not be dma-safe) 4038 * @n_rx: size of rxbuf, in bytes 4039 * Context: can sleep 4040 * 4041 * This performs a half duplex MicroWire style transaction with the 4042 * device, sending txbuf and then reading rxbuf. The return value 4043 * is zero for success, else a negative errno status code. 4044 * This call may only be used from a context that may sleep. 4045 * 4046 * Parameters to this routine are always copied using a small buffer. 4047 * Performance-sensitive or bulk transfer code should instead use 4048 * spi_{async,sync}() calls with dma-safe buffers. 4049 * 4050 * Return: zero on success, else a negative error code. 4051 */ 4052 int spi_write_then_read(struct spi_device *spi, 4053 const void *txbuf, unsigned n_tx, 4054 void *rxbuf, unsigned n_rx) 4055 { 4056 static DEFINE_MUTEX(lock); 4057 4058 int status; 4059 struct spi_message message; 4060 struct spi_transfer x[2]; 4061 u8 *local_buf; 4062 4063 /* Use preallocated DMA-safe buffer if we can. We can't avoid 4064 * copying here, (as a pure convenience thing), but we can 4065 * keep heap costs out of the hot path unless someone else is 4066 * using the pre-allocated buffer or the transfer is too large. 4067 */ 4068 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { 4069 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), 4070 GFP_KERNEL | GFP_DMA); 4071 if (!local_buf) 4072 return -ENOMEM; 4073 } else { 4074 local_buf = buf; 4075 } 4076 4077 spi_message_init(&message); 4078 memset(x, 0, sizeof(x)); 4079 if (n_tx) { 4080 x[0].len = n_tx; 4081 spi_message_add_tail(&x[0], &message); 4082 } 4083 if (n_rx) { 4084 x[1].len = n_rx; 4085 spi_message_add_tail(&x[1], &message); 4086 } 4087 4088 memcpy(local_buf, txbuf, n_tx); 4089 x[0].tx_buf = local_buf; 4090 x[1].rx_buf = local_buf + n_tx; 4091 4092 /* do the i/o */ 4093 status = spi_sync(spi, &message); 4094 if (status == 0) 4095 memcpy(rxbuf, x[1].rx_buf, n_rx); 4096 4097 if (x[0].tx_buf == buf) 4098 mutex_unlock(&lock); 4099 else 4100 kfree(local_buf); 4101 4102 return status; 4103 } 4104 EXPORT_SYMBOL_GPL(spi_write_then_read); 4105 4106 /*-------------------------------------------------------------------------*/ 4107 4108 #if IS_ENABLED(CONFIG_OF) 4109 /* must call put_device() when done with returned spi_device device */ 4110 struct spi_device *of_find_spi_device_by_node(struct device_node *node) 4111 { 4112 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node); 4113 4114 return dev ? to_spi_device(dev) : NULL; 4115 } 4116 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node); 4117 #endif /* IS_ENABLED(CONFIG_OF) */ 4118 4119 #if IS_ENABLED(CONFIG_OF_DYNAMIC) 4120 /* the spi controllers are not using spi_bus, so we find it with another way */ 4121 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node) 4122 { 4123 struct device *dev; 4124 4125 dev = class_find_device_by_of_node(&spi_master_class, node); 4126 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) 4127 dev = class_find_device_by_of_node(&spi_slave_class, node); 4128 if (!dev) 4129 return NULL; 4130 4131 /* reference got in class_find_device */ 4132 return container_of(dev, struct spi_controller, dev); 4133 } 4134 4135 static int of_spi_notify(struct notifier_block *nb, unsigned long action, 4136 void *arg) 4137 { 4138 struct of_reconfig_data *rd = arg; 4139 struct spi_controller *ctlr; 4140 struct spi_device *spi; 4141 4142 switch (of_reconfig_get_state_change(action, arg)) { 4143 case OF_RECONFIG_CHANGE_ADD: 4144 ctlr = of_find_spi_controller_by_node(rd->dn->parent); 4145 if (ctlr == NULL) 4146 return NOTIFY_OK; /* not for us */ 4147 4148 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { 4149 put_device(&ctlr->dev); 4150 return NOTIFY_OK; 4151 } 4152 4153 spi = of_register_spi_device(ctlr, rd->dn); 4154 put_device(&ctlr->dev); 4155 4156 if (IS_ERR(spi)) { 4157 pr_err("%s: failed to create for '%pOF'\n", 4158 __func__, rd->dn); 4159 of_node_clear_flag(rd->dn, OF_POPULATED); 4160 return notifier_from_errno(PTR_ERR(spi)); 4161 } 4162 break; 4163 4164 case OF_RECONFIG_CHANGE_REMOVE: 4165 /* already depopulated? */ 4166 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 4167 return NOTIFY_OK; 4168 4169 /* find our device by node */ 4170 spi = of_find_spi_device_by_node(rd->dn); 4171 if (spi == NULL) 4172 return NOTIFY_OK; /* no? not meant for us */ 4173 4174 /* unregister takes one ref away */ 4175 spi_unregister_device(spi); 4176 4177 /* and put the reference of the find */ 4178 put_device(&spi->dev); 4179 break; 4180 } 4181 4182 return NOTIFY_OK; 4183 } 4184 4185 static struct notifier_block spi_of_notifier = { 4186 .notifier_call = of_spi_notify, 4187 }; 4188 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ 4189 extern struct notifier_block spi_of_notifier; 4190 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ 4191 4192 #if IS_ENABLED(CONFIG_ACPI) 4193 static int spi_acpi_controller_match(struct device *dev, const void *data) 4194 { 4195 return ACPI_COMPANION(dev->parent) == data; 4196 } 4197 4198 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev) 4199 { 4200 struct device *dev; 4201 4202 dev = class_find_device(&spi_master_class, NULL, adev, 4203 spi_acpi_controller_match); 4204 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) 4205 dev = class_find_device(&spi_slave_class, NULL, adev, 4206 spi_acpi_controller_match); 4207 if (!dev) 4208 return NULL; 4209 4210 return container_of(dev, struct spi_controller, dev); 4211 } 4212 4213 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) 4214 { 4215 struct device *dev; 4216 4217 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev); 4218 return to_spi_device(dev); 4219 } 4220 4221 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, 4222 void *arg) 4223 { 4224 struct acpi_device *adev = arg; 4225 struct spi_controller *ctlr; 4226 struct spi_device *spi; 4227 4228 switch (value) { 4229 case ACPI_RECONFIG_DEVICE_ADD: 4230 ctlr = acpi_spi_find_controller_by_adev(adev->parent); 4231 if (!ctlr) 4232 break; 4233 4234 acpi_register_spi_device(ctlr, adev); 4235 put_device(&ctlr->dev); 4236 break; 4237 case ACPI_RECONFIG_DEVICE_REMOVE: 4238 if (!acpi_device_enumerated(adev)) 4239 break; 4240 4241 spi = acpi_spi_find_device_by_adev(adev); 4242 if (!spi) 4243 break; 4244 4245 spi_unregister_device(spi); 4246 put_device(&spi->dev); 4247 break; 4248 } 4249 4250 return NOTIFY_OK; 4251 } 4252 4253 static struct notifier_block spi_acpi_notifier = { 4254 .notifier_call = acpi_spi_notify, 4255 }; 4256 #else 4257 extern struct notifier_block spi_acpi_notifier; 4258 #endif 4259 4260 static int __init spi_init(void) 4261 { 4262 int status; 4263 4264 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); 4265 if (!buf) { 4266 status = -ENOMEM; 4267 goto err0; 4268 } 4269 4270 status = bus_register(&spi_bus_type); 4271 if (status < 0) 4272 goto err1; 4273 4274 status = class_register(&spi_master_class); 4275 if (status < 0) 4276 goto err2; 4277 4278 if (IS_ENABLED(CONFIG_SPI_SLAVE)) { 4279 status = class_register(&spi_slave_class); 4280 if (status < 0) 4281 goto err3; 4282 } 4283 4284 if (IS_ENABLED(CONFIG_OF_DYNAMIC)) 4285 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); 4286 if (IS_ENABLED(CONFIG_ACPI)) 4287 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); 4288 4289 return 0; 4290 4291 err3: 4292 class_unregister(&spi_master_class); 4293 err2: 4294 bus_unregister(&spi_bus_type); 4295 err1: 4296 kfree(buf); 4297 buf = NULL; 4298 err0: 4299 return status; 4300 } 4301 4302 /* board_info is normally registered in arch_initcall(), 4303 * but even essential drivers wait till later 4304 * 4305 * REVISIT only boardinfo really needs static linking. the rest (device and 4306 * driver registration) _could_ be dynamically linked (modular) ... costs 4307 * include needing to have boardinfo data structures be much more public. 4308 */ 4309 postcore_initcall(spi_init); 4310