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/sched.h> 19#include <linux/serdev.h> 20#include <linux/slab.h> 21#include <linux/platform_data/x86/apple.h> 22 23static bool is_registered; 24static DEFINE_IDA(ctrl_ida); 25 26static ssize_t modalias_show(struct device *dev, 27 struct device_attribute *attr, char *buf) 28{ 29 int len; 30 31 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 32 if (len != -ENODEV) 33 return len; 34 35 return of_device_modalias(dev, buf, PAGE_SIZE); 36} 37static DEVICE_ATTR_RO(modalias); 38 39static struct attribute *serdev_device_attrs[] = { 40 &dev_attr_modalias.attr, 41 NULL, 42}; 43ATTRIBUTE_GROUPS(serdev_device); 44 45static int serdev_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 46{ 47 int rc; 48 49 /* TODO: platform modalias */ 50 51 rc = acpi_device_uevent_modalias(dev, env); 52 if (rc != -ENODEV) 53 return rc; 54 55 return of_device_uevent_modalias(dev, env); 56} 57 58static void serdev_device_release(struct device *dev) 59{ 60 struct serdev_device *serdev = to_serdev_device(dev); 61 kfree(serdev); 62} 63 64static const struct device_type serdev_device_type = { 65 .groups = serdev_device_groups, 66 .uevent = serdev_device_uevent, 67 .release = serdev_device_release, 68}; 69 70static bool is_serdev_device(const struct device *dev) 71{ 72 return dev->type == &serdev_device_type; 73} 74 75static void serdev_ctrl_release(struct device *dev) 76{ 77 struct serdev_controller *ctrl = to_serdev_controller(dev); 78 ida_simple_remove(&ctrl_ida, ctrl->nr); 79 kfree(ctrl); 80} 81 82static const struct device_type serdev_ctrl_type = { 83 .release = serdev_ctrl_release, 84}; 85 86static int serdev_device_match(struct device *dev, struct device_driver *drv) 87{ 88 if (!is_serdev_device(dev)) 89 return 0; 90 91 /* TODO: platform matching */ 92 if (acpi_driver_match_device(dev, drv)) 93 return 1; 94 95 return of_driver_match_device(dev, drv); 96} 97 98/** 99 * serdev_device_add() - add a device previously constructed via serdev_device_alloc() 100 * @serdev: serdev_device to be added 101 */ 102int serdev_device_add(struct serdev_device *serdev) 103{ 104 struct serdev_controller *ctrl = serdev->ctrl; 105 struct device *parent = serdev->dev.parent; 106 int err; 107 108 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); 109 110 /* Only a single slave device is currently supported. */ 111 if (ctrl->serdev) { 112 dev_err(&serdev->dev, "controller busy\n"); 113 return -EBUSY; 114 } 115 ctrl->serdev = serdev; 116 117 err = device_add(&serdev->dev); 118 if (err < 0) { 119 dev_err(&serdev->dev, "Can't add %s, status %pe\n", 120 dev_name(&serdev->dev), ERR_PTR(err)); 121 goto err_clear_serdev; 122 } 123 124 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); 125 126 return 0; 127 128err_clear_serdev: 129 ctrl->serdev = NULL; 130 return err; 131} 132EXPORT_SYMBOL_GPL(serdev_device_add); 133 134/** 135 * serdev_device_remove(): remove an serdev device 136 * @serdev: serdev_device to be removed 137 */ 138void serdev_device_remove(struct serdev_device *serdev) 139{ 140 struct serdev_controller *ctrl = serdev->ctrl; 141 142 device_unregister(&serdev->dev); 143 ctrl->serdev = NULL; 144} 145EXPORT_SYMBOL_GPL(serdev_device_remove); 146 147int serdev_device_open(struct serdev_device *serdev) 148{ 149 struct serdev_controller *ctrl = serdev->ctrl; 150 int ret; 151 152 if (!ctrl || !ctrl->ops->open) 153 return -EINVAL; 154 155 ret = ctrl->ops->open(ctrl); 156 if (ret) 157 return ret; 158 159 ret = pm_runtime_get_sync(&ctrl->dev); 160 if (ret < 0) { 161 pm_runtime_put_noidle(&ctrl->dev); 162 goto err_close; 163 } 164 165 return 0; 166 167err_close: 168 if (ctrl->ops->close) 169 ctrl->ops->close(ctrl); 170 171 return ret; 172} 173EXPORT_SYMBOL_GPL(serdev_device_open); 174 175void serdev_device_close(struct serdev_device *serdev) 176{ 177 struct serdev_controller *ctrl = serdev->ctrl; 178 179 if (!ctrl || !ctrl->ops->close) 180 return; 181 182 pm_runtime_put(&ctrl->dev); 183 184 ctrl->ops->close(ctrl); 185} 186EXPORT_SYMBOL_GPL(serdev_device_close); 187 188static void devm_serdev_device_release(struct device *dev, void *dr) 189{ 190 serdev_device_close(*(struct serdev_device **)dr); 191} 192 193int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev) 194{ 195 struct serdev_device **dr; 196 int ret; 197 198 dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL); 199 if (!dr) 200 return -ENOMEM; 201 202 ret = serdev_device_open(serdev); 203 if (ret) { 204 devres_free(dr); 205 return ret; 206 } 207 208 *dr = serdev; 209 devres_add(dev, dr); 210 211 return 0; 212} 213EXPORT_SYMBOL_GPL(devm_serdev_device_open); 214 215void serdev_device_write_wakeup(struct serdev_device *serdev) 216{ 217 complete(&serdev->write_comp); 218} 219EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); 220 221/** 222 * serdev_device_write_buf() - write data asynchronously 223 * @serdev: serdev device 224 * @buf: data to be written 225 * @count: number of bytes to write 226 * 227 * Write data to the device asynchronously. 228 * 229 * Note that any accepted data has only been buffered by the controller; use 230 * serdev_device_wait_until_sent() to make sure the controller write buffer 231 * has actually been emptied. 232 * 233 * Return: The number of bytes written (less than count if not enough room in 234 * the write buffer), or a negative errno on errors. 235 */ 236int serdev_device_write_buf(struct serdev_device *serdev, 237 const unsigned char *buf, size_t count) 238{ 239 struct serdev_controller *ctrl = serdev->ctrl; 240 241 if (!ctrl || !ctrl->ops->write_buf) 242 return -EINVAL; 243 244 return ctrl->ops->write_buf(ctrl, buf, count); 245} 246EXPORT_SYMBOL_GPL(serdev_device_write_buf); 247 248/** 249 * serdev_device_write() - write data synchronously 250 * @serdev: serdev device 251 * @buf: data to be written 252 * @count: number of bytes to write 253 * @timeout: timeout in jiffies, or 0 to wait indefinitely 254 * 255 * Write data to the device synchronously by repeatedly calling 256 * serdev_device_write() until the controller has accepted all data (unless 257 * interrupted by a timeout or a signal). 258 * 259 * Note that any accepted data has only been buffered by the controller; use 260 * serdev_device_wait_until_sent() to make sure the controller write buffer 261 * has actually been emptied. 262 * 263 * Note that this function depends on serdev_device_write_wakeup() being 264 * called in the serdev driver write_wakeup() callback. 265 * 266 * Return: The number of bytes written (less than count if interrupted), 267 * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or 268 * a negative errno on errors. 269 */ 270int serdev_device_write(struct serdev_device *serdev, 271 const unsigned char *buf, size_t count, 272 long timeout) 273{ 274 struct serdev_controller *ctrl = serdev->ctrl; 275 int written = 0; 276 int ret; 277 278 if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup) 279 return -EINVAL; 280 281 if (timeout == 0) 282 timeout = MAX_SCHEDULE_TIMEOUT; 283 284 mutex_lock(&serdev->write_lock); 285 do { 286 reinit_completion(&serdev->write_comp); 287 288 ret = ctrl->ops->write_buf(ctrl, buf, count); 289 if (ret < 0) 290 break; 291 292 written += ret; 293 buf += ret; 294 count -= ret; 295 296 if (count == 0) 297 break; 298 299 timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp, 300 timeout); 301 } while (timeout > 0); 302 mutex_unlock(&serdev->write_lock); 303 304 if (ret < 0) 305 return ret; 306 307 if (timeout <= 0 && written == 0) { 308 if (timeout == -ERESTARTSYS) 309 return -ERESTARTSYS; 310 else 311 return -ETIMEDOUT; 312 } 313 314 return written; 315} 316EXPORT_SYMBOL_GPL(serdev_device_write); 317 318void serdev_device_write_flush(struct serdev_device *serdev) 319{ 320 struct serdev_controller *ctrl = serdev->ctrl; 321 322 if (!ctrl || !ctrl->ops->write_flush) 323 return; 324 325 ctrl->ops->write_flush(ctrl); 326} 327EXPORT_SYMBOL_GPL(serdev_device_write_flush); 328 329int serdev_device_write_room(struct serdev_device *serdev) 330{ 331 struct serdev_controller *ctrl = serdev->ctrl; 332 333 if (!ctrl || !ctrl->ops->write_room) 334 return 0; 335 336 return serdev->ctrl->ops->write_room(ctrl); 337} 338EXPORT_SYMBOL_GPL(serdev_device_write_room); 339 340unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) 341{ 342 struct serdev_controller *ctrl = serdev->ctrl; 343 344 if (!ctrl || !ctrl->ops->set_baudrate) 345 return 0; 346 347 return ctrl->ops->set_baudrate(ctrl, speed); 348 349} 350EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 351 352void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) 353{ 354 struct serdev_controller *ctrl = serdev->ctrl; 355 356 if (!ctrl || !ctrl->ops->set_flow_control) 357 return; 358 359 ctrl->ops->set_flow_control(ctrl, enable); 360} 361EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 362 363int serdev_device_set_parity(struct serdev_device *serdev, 364 enum serdev_parity parity) 365{ 366 struct serdev_controller *ctrl = serdev->ctrl; 367 368 if (!ctrl || !ctrl->ops->set_parity) 369 return -EOPNOTSUPP; 370 371 return ctrl->ops->set_parity(ctrl, parity); 372} 373EXPORT_SYMBOL_GPL(serdev_device_set_parity); 374 375void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) 376{ 377 struct serdev_controller *ctrl = serdev->ctrl; 378 379 if (!ctrl || !ctrl->ops->wait_until_sent) 380 return; 381 382 ctrl->ops->wait_until_sent(ctrl, timeout); 383} 384EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 385 386int serdev_device_get_tiocm(struct serdev_device *serdev) 387{ 388 struct serdev_controller *ctrl = serdev->ctrl; 389 390 if (!ctrl || !ctrl->ops->get_tiocm) 391 return -EOPNOTSUPP; 392 393 return ctrl->ops->get_tiocm(ctrl); 394} 395EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 396 397int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 398{ 399 struct serdev_controller *ctrl = serdev->ctrl; 400 401 if (!ctrl || !ctrl->ops->set_tiocm) 402 return -EOPNOTSUPP; 403 404 return ctrl->ops->set_tiocm(ctrl, set, clear); 405} 406EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 407 408int serdev_device_break_ctl(struct serdev_device *serdev, int break_state) 409{ 410 struct serdev_controller *ctrl = serdev->ctrl; 411 412 if (!ctrl || !ctrl->ops->break_ctl) 413 return -EOPNOTSUPP; 414 415 return ctrl->ops->break_ctl(ctrl, break_state); 416} 417EXPORT_SYMBOL_GPL(serdev_device_break_ctl); 418 419static int serdev_drv_probe(struct device *dev) 420{ 421 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 422 int ret; 423 424 ret = dev_pm_domain_attach(dev, true); 425 if (ret) 426 return ret; 427 428 ret = sdrv->probe(to_serdev_device(dev)); 429 if (ret) 430 dev_pm_domain_detach(dev, true); 431 432 return ret; 433} 434 435static void serdev_drv_remove(struct device *dev) 436{ 437 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 438 if (sdrv->remove) 439 sdrv->remove(to_serdev_device(dev)); 440 441 dev_pm_domain_detach(dev, true); 442} 443 444static struct bus_type serdev_bus_type = { 445 .name = "serial", 446 .match = serdev_device_match, 447 .probe = serdev_drv_probe, 448 .remove = serdev_drv_remove, 449}; 450 451/** 452 * serdev_device_alloc() - Allocate a new serdev device 453 * @ctrl: associated controller 454 * 455 * Caller is responsible for either calling serdev_device_add() to add the 456 * newly allocated controller, or calling serdev_device_put() to discard it. 457 */ 458struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 459{ 460 struct serdev_device *serdev; 461 462 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 463 if (!serdev) 464 return NULL; 465 466 serdev->ctrl = ctrl; 467 device_initialize(&serdev->dev); 468 serdev->dev.parent = &ctrl->dev; 469 serdev->dev.bus = &serdev_bus_type; 470 serdev->dev.type = &serdev_device_type; 471 init_completion(&serdev->write_comp); 472 mutex_init(&serdev->write_lock); 473 return serdev; 474} 475EXPORT_SYMBOL_GPL(serdev_device_alloc); 476 477/** 478 * serdev_controller_alloc() - Allocate a new serdev controller 479 * @parent: parent device 480 * @size: size of private data 481 * 482 * Caller is responsible for either calling serdev_controller_add() to add the 483 * newly allocated controller, or calling serdev_controller_put() to discard it. 484 * The allocated private data region may be accessed via 485 * serdev_controller_get_drvdata() 486 */ 487struct serdev_controller *serdev_controller_alloc(struct device *parent, 488 size_t size) 489{ 490 struct serdev_controller *ctrl; 491 int id; 492 493 if (WARN_ON(!parent)) 494 return NULL; 495 496 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 497 if (!ctrl) 498 return NULL; 499 500 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); 501 if (id < 0) { 502 dev_err(parent, 503 "unable to allocate serdev controller identifier.\n"); 504 goto err_free; 505 } 506 507 ctrl->nr = id; 508 509 device_initialize(&ctrl->dev); 510 ctrl->dev.type = &serdev_ctrl_type; 511 ctrl->dev.bus = &serdev_bus_type; 512 ctrl->dev.parent = parent; 513 ctrl->dev.of_node = parent->of_node; 514 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 515 516 dev_set_name(&ctrl->dev, "serial%d", id); 517 518 pm_runtime_no_callbacks(&ctrl->dev); 519 pm_suspend_ignore_children(&ctrl->dev, true); 520 521 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 522 return ctrl; 523 524err_free: 525 kfree(ctrl); 526 527 return NULL; 528} 529EXPORT_SYMBOL_GPL(serdev_controller_alloc); 530 531static int of_serdev_register_devices(struct serdev_controller *ctrl) 532{ 533 struct device_node *node; 534 struct serdev_device *serdev = NULL; 535 int err; 536 bool found = false; 537 538 for_each_available_child_of_node(ctrl->dev.of_node, node) { 539 if (!of_get_property(node, "compatible", NULL)) 540 continue; 541 542 dev_dbg(&ctrl->dev, "adding child %pOF\n", node); 543 544 serdev = serdev_device_alloc(ctrl); 545 if (!serdev) 546 continue; 547 548 device_set_node(&serdev->dev, of_fwnode_handle(node)); 549 550 err = serdev_device_add(serdev); 551 if (err) { 552 dev_err(&serdev->dev, 553 "failure adding device. status %pe\n", 554 ERR_PTR(err)); 555 serdev_device_put(serdev); 556 } else 557 found = true; 558 } 559 if (!found) 560 return -ENODEV; 561 562 return 0; 563} 564 565#ifdef CONFIG_ACPI 566 567#define SERDEV_ACPI_MAX_SCAN_DEPTH 32 568 569struct acpi_serdev_lookup { 570 acpi_handle device_handle; 571 acpi_handle controller_handle; 572 int n; 573 int index; 574}; 575 576/** 577 * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches 578 * @ares: ACPI resource 579 * @uart: Pointer to UARTSerialBus resource will be returned here 580 * 581 * Checks if the given ACPI resource is of type UARTSerialBus. 582 * In this case, returns a pointer to it to the caller. 583 * 584 * Return: True if resource type is of UARTSerialBus, otherwise false. 585 */ 586bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, 587 struct acpi_resource_uart_serialbus **uart) 588{ 589 struct acpi_resource_uart_serialbus *sb; 590 591 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) 592 return false; 593 594 sb = &ares->data.uart_serial_bus; 595 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART) 596 return false; 597 598 *uart = sb; 599 return true; 600} 601EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource); 602 603static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data) 604{ 605 struct acpi_serdev_lookup *lookup = data; 606 struct acpi_resource_uart_serialbus *sb; 607 acpi_status status; 608 609 if (!serdev_acpi_get_uart_resource(ares, &sb)) 610 return 1; 611 612 if (lookup->index != -1 && lookup->n++ != lookup->index) 613 return 1; 614 615 status = acpi_get_handle(lookup->device_handle, 616 sb->resource_source.string_ptr, 617 &lookup->controller_handle); 618 if (ACPI_FAILURE(status)) 619 return 1; 620 621 /* 622 * NOTE: Ideally, we would also want to retrieve other properties here, 623 * once setting them before opening the device is supported by serdev. 624 */ 625 626 return 1; 627} 628 629static int acpi_serdev_do_lookup(struct acpi_device *adev, 630 struct acpi_serdev_lookup *lookup) 631{ 632 struct list_head resource_list; 633 int ret; 634 635 lookup->device_handle = acpi_device_handle(adev); 636 lookup->controller_handle = NULL; 637 lookup->n = 0; 638 639 INIT_LIST_HEAD(&resource_list); 640 ret = acpi_dev_get_resources(adev, &resource_list, 641 acpi_serdev_parse_resource, lookup); 642 acpi_dev_free_resource_list(&resource_list); 643 644 if (ret < 0) 645 return -EINVAL; 646 647 return 0; 648} 649 650static int acpi_serdev_check_resources(struct serdev_controller *ctrl, 651 struct acpi_device *adev) 652{ 653 struct acpi_serdev_lookup lookup; 654 int ret; 655 656 if (acpi_bus_get_status(adev) || !adev->status.present) 657 return -EINVAL; 658 659 /* Look for UARTSerialBusV2 resource */ 660 lookup.index = -1; // we only care for the last device 661 662 ret = acpi_serdev_do_lookup(adev, &lookup); 663 if (ret) 664 return ret; 665 666 /* 667 * Apple machines provide an empty resource template, so on those 668 * machines just look for immediate children with a "baud" property 669 * (from the _DSM method) instead. 670 */ 671 if (!lookup.controller_handle && x86_apple_machine && 672 !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL)) 673 acpi_get_parent(adev->handle, &lookup.controller_handle); 674 675 /* Make sure controller and ResourceSource handle match */ 676 if (ACPI_HANDLE(ctrl->dev.parent) != lookup.controller_handle) 677 return -ENODEV; 678 679 return 0; 680} 681 682static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, 683 struct acpi_device *adev) 684{ 685 struct serdev_device *serdev; 686 int err; 687 688 serdev = serdev_device_alloc(ctrl); 689 if (!serdev) { 690 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n", 691 dev_name(&adev->dev)); 692 return AE_NO_MEMORY; 693 } 694 695 ACPI_COMPANION_SET(&serdev->dev, adev); 696 acpi_device_set_enumerated(adev); 697 698 err = serdev_device_add(serdev); 699 if (err) { 700 dev_err(&serdev->dev, 701 "failure adding ACPI serdev device. status %pe\n", 702 ERR_PTR(err)); 703 serdev_device_put(serdev); 704 } 705 706 return AE_OK; 707} 708 709static const struct acpi_device_id serdev_acpi_devices_blacklist[] = { 710 { "INT3511", 0 }, 711 { "INT3512", 0 }, 712 { }, 713}; 714 715static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, 716 void *data, void **return_value) 717{ 718 struct acpi_device *adev = acpi_fetch_acpi_dev(handle); 719 struct serdev_controller *ctrl = data; 720 721 if (!adev || acpi_device_enumerated(adev)) 722 return AE_OK; 723 724 /* Skip if black listed */ 725 if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist)) 726 return AE_OK; 727 728 if (acpi_serdev_check_resources(ctrl, adev)) 729 return AE_OK; 730 731 return acpi_serdev_register_device(ctrl, adev); 732} 733 734 735static int acpi_serdev_register_devices(struct serdev_controller *ctrl) 736{ 737 acpi_status status; 738 bool skip; 739 int ret; 740 741 if (!has_acpi_companion(ctrl->dev.parent)) 742 return -ENODEV; 743 744 /* 745 * Skip registration on boards where the ACPI tables are known to 746 * contain buggy devices. Note serdev_controller_add() must still 747 * succeed in this case, so that the proper serdev devices can be 748 * added "manually" later. 749 */ 750 ret = acpi_quirk_skip_serdev_enumeration(ctrl->dev.parent, &skip); 751 if (ret) 752 return ret; 753 if (skip) 754 return 0; 755 756 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 757 SERDEV_ACPI_MAX_SCAN_DEPTH, 758 acpi_serdev_add_device, NULL, ctrl, NULL); 759 if (ACPI_FAILURE(status)) 760 dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n"); 761 762 if (!ctrl->serdev) 763 return -ENODEV; 764 765 return 0; 766} 767#else 768static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl) 769{ 770 return -ENODEV; 771} 772#endif /* CONFIG_ACPI */ 773 774/** 775 * serdev_controller_add() - Add an serdev controller 776 * @ctrl: controller to be registered. 777 * 778 * Register a controller previously allocated via serdev_controller_alloc() with 779 * the serdev core. 780 */ 781int serdev_controller_add(struct serdev_controller *ctrl) 782{ 783 int ret_of, ret_acpi, ret; 784 785 /* Can't register until after driver model init */ 786 if (WARN_ON(!is_registered)) 787 return -EAGAIN; 788 789 ret = device_add(&ctrl->dev); 790 if (ret) 791 return ret; 792 793 pm_runtime_enable(&ctrl->dev); 794 795 ret_of = of_serdev_register_devices(ctrl); 796 ret_acpi = acpi_serdev_register_devices(ctrl); 797 if (ret_of && ret_acpi) { 798 dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n", 799 ERR_PTR(ret_of), ERR_PTR(ret_acpi)); 800 ret = -ENODEV; 801 goto err_rpm_disable; 802 } 803 804 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 805 ctrl->nr, &ctrl->dev); 806 return 0; 807 808err_rpm_disable: 809 pm_runtime_disable(&ctrl->dev); 810 device_del(&ctrl->dev); 811 return ret; 812}; 813EXPORT_SYMBOL_GPL(serdev_controller_add); 814 815/* Remove a device associated with a controller */ 816static int serdev_remove_device(struct device *dev, void *data) 817{ 818 struct serdev_device *serdev = to_serdev_device(dev); 819 if (dev->type == &serdev_device_type) 820 serdev_device_remove(serdev); 821 return 0; 822} 823 824/** 825 * serdev_controller_remove(): remove an serdev controller 826 * @ctrl: controller to remove 827 * 828 * Remove a serdev controller. Caller is responsible for calling 829 * serdev_controller_put() to discard the allocated controller. 830 */ 831void serdev_controller_remove(struct serdev_controller *ctrl) 832{ 833 if (!ctrl) 834 return; 835 836 device_for_each_child(&ctrl->dev, NULL, serdev_remove_device); 837 pm_runtime_disable(&ctrl->dev); 838 device_del(&ctrl->dev); 839} 840EXPORT_SYMBOL_GPL(serdev_controller_remove); 841 842/** 843 * __serdev_device_driver_register() - Register client driver with serdev core 844 * @sdrv: client driver to be associated with client-device. 845 * @owner: client driver owner to set. 846 * 847 * This API will register the client driver with the serdev framework. 848 * It is typically called from the driver's module-init function. 849 */ 850int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 851{ 852 sdrv->driver.bus = &serdev_bus_type; 853 sdrv->driver.owner = owner; 854 855 /* force drivers to async probe so I/O is possible in probe */ 856 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 857 858 return driver_register(&sdrv->driver); 859} 860EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 861 862static void __exit serdev_exit(void) 863{ 864 bus_unregister(&serdev_bus_type); 865 ida_destroy(&ctrl_ida); 866} 867module_exit(serdev_exit); 868 869static int __init serdev_init(void) 870{ 871 int ret; 872 873 ret = bus_register(&serdev_bus_type); 874 if (ret) 875 return ret; 876 877 is_registered = true; 878 return 0; 879} 880/* Must be before serial drivers register */ 881postcore_initcall(serdev_init); 882 883MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 884MODULE_LICENSE("GPL v2"); 885MODULE_DESCRIPTION("Serial attached device bus"); 886