1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> 4 * 5 * Based on drivers/spmi/spmi.c: 6 * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved. 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/errno.h> 11 #include <linux/idr.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/of_device.h> 16 #include <linux/pm_domain.h> 17 #include <linux/pm_runtime.h> 18 #include <linux/property.h> 19 #include <linux/sched.h> 20 #include <linux/serdev.h> 21 #include <linux/slab.h> 22 23 #include <linux/platform_data/x86/apple.h> 24 25 static bool is_registered; 26 static DEFINE_IDA(ctrl_ida); 27 28 static ssize_t modalias_show(struct device *dev, 29 struct device_attribute *attr, char *buf) 30 { 31 int len; 32 33 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 34 if (len != -ENODEV) 35 return len; 36 37 return of_device_modalias(dev, buf, PAGE_SIZE); 38 } 39 static DEVICE_ATTR_RO(modalias); 40 41 static struct attribute *serdev_device_attrs[] = { 42 &dev_attr_modalias.attr, 43 NULL, 44 }; 45 ATTRIBUTE_GROUPS(serdev_device); 46 47 static int serdev_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 48 { 49 int rc; 50 51 /* TODO: platform modalias */ 52 53 rc = acpi_device_uevent_modalias(dev, env); 54 if (rc != -ENODEV) 55 return rc; 56 57 return of_device_uevent_modalias(dev, env); 58 } 59 60 static void serdev_device_release(struct device *dev) 61 { 62 struct serdev_device *serdev = to_serdev_device(dev); 63 kfree(serdev); 64 } 65 66 static const struct device_type serdev_device_type = { 67 .groups = serdev_device_groups, 68 .uevent = serdev_device_uevent, 69 .release = serdev_device_release, 70 }; 71 72 static bool is_serdev_device(const struct device *dev) 73 { 74 return dev->type == &serdev_device_type; 75 } 76 77 static void serdev_ctrl_release(struct device *dev) 78 { 79 struct serdev_controller *ctrl = to_serdev_controller(dev); 80 ida_free(&ctrl_ida, ctrl->nr); 81 kfree(ctrl); 82 } 83 84 static const struct device_type serdev_ctrl_type = { 85 .release = serdev_ctrl_release, 86 }; 87 88 static int serdev_device_match(struct device *dev, struct device_driver *drv) 89 { 90 if (!is_serdev_device(dev)) 91 return 0; 92 93 /* TODO: platform matching */ 94 if (acpi_driver_match_device(dev, drv)) 95 return 1; 96 97 return of_driver_match_device(dev, drv); 98 } 99 100 /** 101 * serdev_device_add() - add a device previously constructed via serdev_device_alloc() 102 * @serdev: serdev_device to be added 103 */ 104 int serdev_device_add(struct serdev_device *serdev) 105 { 106 struct serdev_controller *ctrl = serdev->ctrl; 107 struct device *parent = serdev->dev.parent; 108 int err; 109 110 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); 111 112 /* Only a single slave device is currently supported. */ 113 if (ctrl->serdev) { 114 dev_err(&serdev->dev, "controller busy\n"); 115 return -EBUSY; 116 } 117 ctrl->serdev = serdev; 118 119 err = device_add(&serdev->dev); 120 if (err < 0) { 121 dev_err(&serdev->dev, "Can't add %s, status %pe\n", 122 dev_name(&serdev->dev), ERR_PTR(err)); 123 goto err_clear_serdev; 124 } 125 126 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); 127 128 return 0; 129 130 err_clear_serdev: 131 ctrl->serdev = NULL; 132 return err; 133 } 134 EXPORT_SYMBOL_GPL(serdev_device_add); 135 136 /** 137 * serdev_device_remove(): remove an serdev device 138 * @serdev: serdev_device to be removed 139 */ 140 void serdev_device_remove(struct serdev_device *serdev) 141 { 142 struct serdev_controller *ctrl = serdev->ctrl; 143 144 device_unregister(&serdev->dev); 145 ctrl->serdev = NULL; 146 } 147 EXPORT_SYMBOL_GPL(serdev_device_remove); 148 149 int serdev_device_open(struct serdev_device *serdev) 150 { 151 struct serdev_controller *ctrl = serdev->ctrl; 152 int ret; 153 154 if (!ctrl || !ctrl->ops->open) 155 return -EINVAL; 156 157 ret = ctrl->ops->open(ctrl); 158 if (ret) 159 return ret; 160 161 ret = pm_runtime_get_sync(&ctrl->dev); 162 if (ret < 0) { 163 pm_runtime_put_noidle(&ctrl->dev); 164 goto err_close; 165 } 166 167 return 0; 168 169 err_close: 170 if (ctrl->ops->close) 171 ctrl->ops->close(ctrl); 172 173 return ret; 174 } 175 EXPORT_SYMBOL_GPL(serdev_device_open); 176 177 void serdev_device_close(struct serdev_device *serdev) 178 { 179 struct serdev_controller *ctrl = serdev->ctrl; 180 181 if (!ctrl || !ctrl->ops->close) 182 return; 183 184 pm_runtime_put(&ctrl->dev); 185 186 ctrl->ops->close(ctrl); 187 } 188 EXPORT_SYMBOL_GPL(serdev_device_close); 189 190 static void devm_serdev_device_close(void *serdev) 191 { 192 serdev_device_close(serdev); 193 } 194 195 int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev) 196 { 197 int ret; 198 199 ret = serdev_device_open(serdev); 200 if (ret) 201 return ret; 202 203 return devm_add_action_or_reset(dev, devm_serdev_device_close, serdev); 204 } 205 EXPORT_SYMBOL_GPL(devm_serdev_device_open); 206 207 void serdev_device_write_wakeup(struct serdev_device *serdev) 208 { 209 complete(&serdev->write_comp); 210 } 211 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); 212 213 /** 214 * serdev_device_write_buf() - write data asynchronously 215 * @serdev: serdev device 216 * @buf: data to be written 217 * @count: number of bytes to write 218 * 219 * Write data to the device asynchronously. 220 * 221 * Note that any accepted data has only been buffered by the controller; use 222 * serdev_device_wait_until_sent() to make sure the controller write buffer 223 * has actually been emptied. 224 * 225 * Return: The number of bytes written (less than count if not enough room in 226 * the write buffer), or a negative errno on errors. 227 */ 228 int serdev_device_write_buf(struct serdev_device *serdev, const u8 *buf, size_t count) 229 { 230 struct serdev_controller *ctrl = serdev->ctrl; 231 232 if (!ctrl || !ctrl->ops->write_buf) 233 return -EINVAL; 234 235 return ctrl->ops->write_buf(ctrl, buf, count); 236 } 237 EXPORT_SYMBOL_GPL(serdev_device_write_buf); 238 239 /** 240 * serdev_device_write() - write data synchronously 241 * @serdev: serdev device 242 * @buf: data to be written 243 * @count: number of bytes to write 244 * @timeout: timeout in jiffies, or 0 to wait indefinitely 245 * 246 * Write data to the device synchronously by repeatedly calling 247 * serdev_device_write() until the controller has accepted all data (unless 248 * interrupted by a timeout or a signal). 249 * 250 * Note that any accepted data has only been buffered by the controller; use 251 * serdev_device_wait_until_sent() to make sure the controller write buffer 252 * has actually been emptied. 253 * 254 * Note that this function depends on serdev_device_write_wakeup() being 255 * called in the serdev driver write_wakeup() callback. 256 * 257 * Return: The number of bytes written (less than count if interrupted), 258 * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or 259 * a negative errno on errors. 260 */ 261 ssize_t serdev_device_write(struct serdev_device *serdev, const u8 *buf, 262 size_t count, long timeout) 263 { 264 struct serdev_controller *ctrl = serdev->ctrl; 265 size_t written = 0; 266 ssize_t ret; 267 268 if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup) 269 return -EINVAL; 270 271 if (timeout == 0) 272 timeout = MAX_SCHEDULE_TIMEOUT; 273 274 mutex_lock(&serdev->write_lock); 275 do { 276 reinit_completion(&serdev->write_comp); 277 278 ret = ctrl->ops->write_buf(ctrl, buf, count); 279 if (ret < 0) 280 break; 281 282 written += ret; 283 buf += ret; 284 count -= ret; 285 286 if (count == 0) 287 break; 288 289 timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp, 290 timeout); 291 } while (timeout > 0); 292 mutex_unlock(&serdev->write_lock); 293 294 if (ret < 0) 295 return ret; 296 297 if (timeout <= 0 && written == 0) { 298 if (timeout == -ERESTARTSYS) 299 return -ERESTARTSYS; 300 else 301 return -ETIMEDOUT; 302 } 303 304 return written; 305 } 306 EXPORT_SYMBOL_GPL(serdev_device_write); 307 308 void serdev_device_write_flush(struct serdev_device *serdev) 309 { 310 struct serdev_controller *ctrl = serdev->ctrl; 311 312 if (!ctrl || !ctrl->ops->write_flush) 313 return; 314 315 ctrl->ops->write_flush(ctrl); 316 } 317 EXPORT_SYMBOL_GPL(serdev_device_write_flush); 318 319 int serdev_device_write_room(struct serdev_device *serdev) 320 { 321 struct serdev_controller *ctrl = serdev->ctrl; 322 323 if (!ctrl || !ctrl->ops->write_room) 324 return 0; 325 326 return serdev->ctrl->ops->write_room(ctrl); 327 } 328 EXPORT_SYMBOL_GPL(serdev_device_write_room); 329 330 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) 331 { 332 struct serdev_controller *ctrl = serdev->ctrl; 333 334 if (!ctrl || !ctrl->ops->set_baudrate) 335 return 0; 336 337 return ctrl->ops->set_baudrate(ctrl, speed); 338 339 } 340 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 341 342 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) 343 { 344 struct serdev_controller *ctrl = serdev->ctrl; 345 346 if (!ctrl || !ctrl->ops->set_flow_control) 347 return; 348 349 ctrl->ops->set_flow_control(ctrl, enable); 350 } 351 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 352 353 int serdev_device_set_parity(struct serdev_device *serdev, 354 enum serdev_parity parity) 355 { 356 struct serdev_controller *ctrl = serdev->ctrl; 357 358 if (!ctrl || !ctrl->ops->set_parity) 359 return -EOPNOTSUPP; 360 361 return ctrl->ops->set_parity(ctrl, parity); 362 } 363 EXPORT_SYMBOL_GPL(serdev_device_set_parity); 364 365 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) 366 { 367 struct serdev_controller *ctrl = serdev->ctrl; 368 369 if (!ctrl || !ctrl->ops->wait_until_sent) 370 return; 371 372 ctrl->ops->wait_until_sent(ctrl, timeout); 373 } 374 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 375 376 int serdev_device_get_tiocm(struct serdev_device *serdev) 377 { 378 struct serdev_controller *ctrl = serdev->ctrl; 379 380 if (!ctrl || !ctrl->ops->get_tiocm) 381 return -EOPNOTSUPP; 382 383 return ctrl->ops->get_tiocm(ctrl); 384 } 385 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 386 387 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 388 { 389 struct serdev_controller *ctrl = serdev->ctrl; 390 391 if (!ctrl || !ctrl->ops->set_tiocm) 392 return -EOPNOTSUPP; 393 394 return ctrl->ops->set_tiocm(ctrl, set, clear); 395 } 396 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 397 398 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state) 399 { 400 struct serdev_controller *ctrl = serdev->ctrl; 401 402 if (!ctrl || !ctrl->ops->break_ctl) 403 return -EOPNOTSUPP; 404 405 return ctrl->ops->break_ctl(ctrl, break_state); 406 } 407 EXPORT_SYMBOL_GPL(serdev_device_break_ctl); 408 409 static int serdev_drv_probe(struct device *dev) 410 { 411 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 412 int ret; 413 414 ret = dev_pm_domain_attach(dev, true); 415 if (ret) 416 return ret; 417 418 ret = sdrv->probe(to_serdev_device(dev)); 419 if (ret) 420 dev_pm_domain_detach(dev, true); 421 422 return ret; 423 } 424 425 static void serdev_drv_remove(struct device *dev) 426 { 427 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 428 if (sdrv->remove) 429 sdrv->remove(to_serdev_device(dev)); 430 431 dev_pm_domain_detach(dev, true); 432 } 433 434 static const struct bus_type serdev_bus_type = { 435 .name = "serial", 436 .match = serdev_device_match, 437 .probe = serdev_drv_probe, 438 .remove = serdev_drv_remove, 439 }; 440 441 /** 442 * serdev_device_alloc() - Allocate a new serdev device 443 * @ctrl: associated controller 444 * 445 * Caller is responsible for either calling serdev_device_add() to add the 446 * newly allocated controller, or calling serdev_device_put() to discard it. 447 */ 448 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 449 { 450 struct serdev_device *serdev; 451 452 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 453 if (!serdev) 454 return NULL; 455 456 serdev->ctrl = ctrl; 457 device_initialize(&serdev->dev); 458 serdev->dev.parent = &ctrl->dev; 459 serdev->dev.bus = &serdev_bus_type; 460 serdev->dev.type = &serdev_device_type; 461 init_completion(&serdev->write_comp); 462 mutex_init(&serdev->write_lock); 463 return serdev; 464 } 465 EXPORT_SYMBOL_GPL(serdev_device_alloc); 466 467 /** 468 * serdev_controller_alloc() - Allocate a new serdev controller 469 * @host: serial port hardware controller device 470 * @parent: parent device 471 * @size: size of private data 472 * 473 * Caller is responsible for either calling serdev_controller_add() to add the 474 * newly allocated controller, or calling serdev_controller_put() to discard it. 475 * The allocated private data region may be accessed via 476 * serdev_controller_get_drvdata() 477 */ 478 struct serdev_controller *serdev_controller_alloc(struct device *host, 479 struct device *parent, 480 size_t size) 481 { 482 struct serdev_controller *ctrl; 483 int id; 484 485 if (WARN_ON(!parent)) 486 return NULL; 487 488 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 489 if (!ctrl) 490 return NULL; 491 492 id = ida_alloc(&ctrl_ida, GFP_KERNEL); 493 if (id < 0) { 494 dev_err(parent, 495 "unable to allocate serdev controller identifier.\n"); 496 goto err_free; 497 } 498 499 ctrl->nr = id; 500 501 device_initialize(&ctrl->dev); 502 ctrl->dev.type = &serdev_ctrl_type; 503 ctrl->dev.bus = &serdev_bus_type; 504 ctrl->dev.parent = parent; 505 ctrl->host = host; 506 device_set_node(&ctrl->dev, dev_fwnode(host)); 507 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 508 509 dev_set_name(&ctrl->dev, "serial%d", id); 510 511 pm_runtime_no_callbacks(&ctrl->dev); 512 pm_suspend_ignore_children(&ctrl->dev, true); 513 514 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 515 return ctrl; 516 517 err_free: 518 kfree(ctrl); 519 520 return NULL; 521 } 522 EXPORT_SYMBOL_GPL(serdev_controller_alloc); 523 524 static int of_serdev_register_devices(struct serdev_controller *ctrl) 525 { 526 struct device_node *node; 527 struct serdev_device *serdev = NULL; 528 int err; 529 bool found = false; 530 531 for_each_available_child_of_node(ctrl->dev.of_node, node) { 532 if (!of_get_property(node, "compatible", NULL)) 533 continue; 534 535 dev_dbg(&ctrl->dev, "adding child %pOF\n", node); 536 537 serdev = serdev_device_alloc(ctrl); 538 if (!serdev) 539 continue; 540 541 device_set_node(&serdev->dev, of_fwnode_handle(node)); 542 543 err = serdev_device_add(serdev); 544 if (err) { 545 dev_err(&serdev->dev, 546 "failure adding device. status %pe\n", 547 ERR_PTR(err)); 548 serdev_device_put(serdev); 549 } else 550 found = true; 551 } 552 if (!found) 553 return -ENODEV; 554 555 return 0; 556 } 557 558 #ifdef CONFIG_ACPI 559 560 #define SERDEV_ACPI_MAX_SCAN_DEPTH 32 561 562 struct acpi_serdev_lookup { 563 acpi_handle device_handle; 564 acpi_handle controller_handle; 565 int n; 566 int index; 567 }; 568 569 /** 570 * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches 571 * @ares: ACPI resource 572 * @uart: Pointer to UARTSerialBus resource will be returned here 573 * 574 * Checks if the given ACPI resource is of type UARTSerialBus. 575 * In this case, returns a pointer to it to the caller. 576 * 577 * Return: True if resource type is of UARTSerialBus, otherwise false. 578 */ 579 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, 580 struct acpi_resource_uart_serialbus **uart) 581 { 582 struct acpi_resource_uart_serialbus *sb; 583 584 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) 585 return false; 586 587 sb = &ares->data.uart_serial_bus; 588 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART) 589 return false; 590 591 *uart = sb; 592 return true; 593 } 594 EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource); 595 596 static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data) 597 { 598 struct acpi_serdev_lookup *lookup = data; 599 struct acpi_resource_uart_serialbus *sb; 600 acpi_status status; 601 602 if (!serdev_acpi_get_uart_resource(ares, &sb)) 603 return 1; 604 605 if (lookup->index != -1 && lookup->n++ != lookup->index) 606 return 1; 607 608 status = acpi_get_handle(lookup->device_handle, 609 sb->resource_source.string_ptr, 610 &lookup->controller_handle); 611 if (ACPI_FAILURE(status)) 612 return 1; 613 614 /* 615 * NOTE: Ideally, we would also want to retrieve other properties here, 616 * once setting them before opening the device is supported by serdev. 617 */ 618 619 return 1; 620 } 621 622 static int acpi_serdev_do_lookup(struct acpi_device *adev, 623 struct acpi_serdev_lookup *lookup) 624 { 625 struct list_head resource_list; 626 int ret; 627 628 lookup->device_handle = acpi_device_handle(adev); 629 lookup->controller_handle = NULL; 630 lookup->n = 0; 631 632 INIT_LIST_HEAD(&resource_list); 633 ret = acpi_dev_get_resources(adev, &resource_list, 634 acpi_serdev_parse_resource, lookup); 635 acpi_dev_free_resource_list(&resource_list); 636 637 if (ret < 0) 638 return -EINVAL; 639 640 return 0; 641 } 642 643 static int acpi_serdev_check_resources(struct serdev_controller *ctrl, 644 struct acpi_device *adev) 645 { 646 struct acpi_serdev_lookup lookup; 647 int ret; 648 649 if (acpi_bus_get_status(adev) || !adev->status.present) 650 return -EINVAL; 651 652 /* Look for UARTSerialBusV2 resource */ 653 lookup.index = -1; // we only care for the last device 654 655 ret = acpi_serdev_do_lookup(adev, &lookup); 656 if (ret) 657 return ret; 658 659 /* 660 * Apple machines provide an empty resource template, so on those 661 * machines just look for immediate children with a "baud" property 662 * (from the _DSM method) instead. 663 */ 664 if (!lookup.controller_handle && x86_apple_machine && 665 !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL)) 666 acpi_get_parent(adev->handle, &lookup.controller_handle); 667 668 /* Make sure controller and ResourceSource handle match */ 669 if (!device_match_acpi_handle(ctrl->host, lookup.controller_handle)) 670 return -ENODEV; 671 672 return 0; 673 } 674 675 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, 676 struct acpi_device *adev) 677 { 678 struct serdev_device *serdev; 679 int err; 680 681 serdev = serdev_device_alloc(ctrl); 682 if (!serdev) { 683 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n", 684 dev_name(&adev->dev)); 685 return AE_NO_MEMORY; 686 } 687 688 ACPI_COMPANION_SET(&serdev->dev, adev); 689 acpi_device_set_enumerated(adev); 690 691 err = serdev_device_add(serdev); 692 if (err) { 693 dev_err(&serdev->dev, 694 "failure adding ACPI serdev device. status %pe\n", 695 ERR_PTR(err)); 696 serdev_device_put(serdev); 697 } 698 699 return AE_OK; 700 } 701 702 static const struct acpi_device_id serdev_acpi_devices_blacklist[] = { 703 { "INT3511", 0 }, 704 { "INT3512", 0 }, 705 { }, 706 }; 707 708 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, 709 void *data, void **return_value) 710 { 711 struct acpi_device *adev = acpi_fetch_acpi_dev(handle); 712 struct serdev_controller *ctrl = data; 713 714 if (!adev || acpi_device_enumerated(adev)) 715 return AE_OK; 716 717 /* Skip if black listed */ 718 if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist)) 719 return AE_OK; 720 721 if (acpi_serdev_check_resources(ctrl, adev)) 722 return AE_OK; 723 724 return acpi_serdev_register_device(ctrl, adev); 725 } 726 727 728 static int acpi_serdev_register_devices(struct serdev_controller *ctrl) 729 { 730 acpi_status status; 731 bool skip; 732 int ret; 733 734 if (!has_acpi_companion(ctrl->host)) 735 return -ENODEV; 736 737 /* 738 * Skip registration on boards where the ACPI tables are known to 739 * contain buggy devices. Note serdev_controller_add() must still 740 * succeed in this case, so that the proper serdev devices can be 741 * added "manually" later. 742 */ 743 ret = acpi_quirk_skip_serdev_enumeration(ctrl->host, &skip); 744 if (ret) 745 return ret; 746 if (skip) 747 return 0; 748 749 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 750 SERDEV_ACPI_MAX_SCAN_DEPTH, 751 acpi_serdev_add_device, NULL, ctrl, NULL); 752 if (ACPI_FAILURE(status)) 753 dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n"); 754 755 if (!ctrl->serdev) 756 return -ENODEV; 757 758 return 0; 759 } 760 #else 761 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl) 762 { 763 return -ENODEV; 764 } 765 #endif /* CONFIG_ACPI */ 766 767 /** 768 * serdev_controller_add() - Add an serdev controller 769 * @ctrl: controller to be registered. 770 * 771 * Register a controller previously allocated via serdev_controller_alloc() with 772 * the serdev core. 773 */ 774 int serdev_controller_add(struct serdev_controller *ctrl) 775 { 776 int ret_of, ret_acpi, ret; 777 778 /* Can't register until after driver model init */ 779 if (WARN_ON(!is_registered)) 780 return -EAGAIN; 781 782 ret = device_add(&ctrl->dev); 783 if (ret) 784 return ret; 785 786 pm_runtime_enable(&ctrl->dev); 787 788 ret_of = of_serdev_register_devices(ctrl); 789 ret_acpi = acpi_serdev_register_devices(ctrl); 790 if (ret_of && ret_acpi) { 791 dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n", 792 ERR_PTR(ret_of), ERR_PTR(ret_acpi)); 793 ret = -ENODEV; 794 goto err_rpm_disable; 795 } 796 797 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 798 ctrl->nr, &ctrl->dev); 799 return 0; 800 801 err_rpm_disable: 802 pm_runtime_disable(&ctrl->dev); 803 device_del(&ctrl->dev); 804 return ret; 805 }; 806 EXPORT_SYMBOL_GPL(serdev_controller_add); 807 808 /* Remove a device associated with a controller */ 809 static int serdev_remove_device(struct device *dev, void *data) 810 { 811 struct serdev_device *serdev = to_serdev_device(dev); 812 if (dev->type == &serdev_device_type) 813 serdev_device_remove(serdev); 814 return 0; 815 } 816 817 /** 818 * serdev_controller_remove(): remove an serdev controller 819 * @ctrl: controller to remove 820 * 821 * Remove a serdev controller. Caller is responsible for calling 822 * serdev_controller_put() to discard the allocated controller. 823 */ 824 void serdev_controller_remove(struct serdev_controller *ctrl) 825 { 826 if (!ctrl) 827 return; 828 829 device_for_each_child(&ctrl->dev, NULL, serdev_remove_device); 830 pm_runtime_disable(&ctrl->dev); 831 device_del(&ctrl->dev); 832 } 833 EXPORT_SYMBOL_GPL(serdev_controller_remove); 834 835 /** 836 * __serdev_device_driver_register() - Register client driver with serdev core 837 * @sdrv: client driver to be associated with client-device. 838 * @owner: client driver owner to set. 839 * 840 * This API will register the client driver with the serdev framework. 841 * It is typically called from the driver's module-init function. 842 */ 843 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 844 { 845 sdrv->driver.bus = &serdev_bus_type; 846 sdrv->driver.owner = owner; 847 848 /* force drivers to async probe so I/O is possible in probe */ 849 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 850 851 return driver_register(&sdrv->driver); 852 } 853 EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 854 855 static void __exit serdev_exit(void) 856 { 857 bus_unregister(&serdev_bus_type); 858 ida_destroy(&ctrl_ida); 859 } 860 module_exit(serdev_exit); 861 862 static int __init serdev_init(void) 863 { 864 int ret; 865 866 ret = bus_register(&serdev_bus_type); 867 if (ret) 868 return ret; 869 870 is_registered = true; 871 return 0; 872 } 873 /* Must be before serial drivers register */ 874 postcore_initcall(serdev_init); 875 876 MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 877 MODULE_LICENSE("GPL v2"); 878 MODULE_DESCRIPTION("Serial attached device bus"); 879