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 23 static bool is_registered; 24 static DEFINE_IDA(ctrl_ida); 25 26 static 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 } 37 static DEVICE_ATTR_RO(modalias); 38 39 static struct attribute *serdev_device_attrs[] = { 40 &dev_attr_modalias.attr, 41 NULL, 42 }; 43 ATTRIBUTE_GROUPS(serdev_device); 44 45 static int serdev_device_uevent(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 58 static void serdev_device_release(struct device *dev) 59 { 60 struct serdev_device *serdev = to_serdev_device(dev); 61 kfree(serdev); 62 } 63 64 static const struct device_type serdev_device_type = { 65 .groups = serdev_device_groups, 66 .uevent = serdev_device_uevent, 67 .release = serdev_device_release, 68 }; 69 70 static bool is_serdev_device(const struct device *dev) 71 { 72 return dev->type == &serdev_device_type; 73 } 74 75 static 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 82 static const struct device_type serdev_ctrl_type = { 83 .release = serdev_ctrl_release, 84 }; 85 86 static 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 */ 102 int 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; 127 128 err_clear_serdev: 129 ctrl->serdev = NULL; 130 return err; 131 } 132 EXPORT_SYMBOL_GPL(serdev_device_add); 133 134 /** 135 * serdev_device_remove(): remove an serdev device 136 * @serdev: serdev_device to be removed 137 */ 138 void 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 } 145 EXPORT_SYMBOL_GPL(serdev_device_remove); 146 147 int 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; 166 167 err_close: 168 if (ctrl->ops->close) 169 ctrl->ops->close(ctrl); 170 171 return ret; 172 } 173 EXPORT_SYMBOL_GPL(serdev_device_open); 174 175 void 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 } 186 EXPORT_SYMBOL_GPL(serdev_device_close); 187 188 static void devm_serdev_device_release(struct device *dev, void *dr) 189 { 190 serdev_device_close(*(struct serdev_device **)dr); 191 } 192 193 int 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 } 213 EXPORT_SYMBOL_GPL(devm_serdev_device_open); 214 215 void serdev_device_write_wakeup(struct serdev_device *serdev) 216 { 217 complete(&serdev->write_comp); 218 } 219 EXPORT_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 */ 236 int 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 } 246 EXPORT_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 */ 270 int 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 } 316 EXPORT_SYMBOL_GPL(serdev_device_write); 317 318 void 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 } 327 EXPORT_SYMBOL_GPL(serdev_device_write_flush); 328 329 int 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 } 338 EXPORT_SYMBOL_GPL(serdev_device_write_room); 339 340 unsigned 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 } 350 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 351 352 void 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 } 361 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 362 363 int 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 -ENOTSUPP; 370 371 return ctrl->ops->set_parity(ctrl, parity); 372 } 373 EXPORT_SYMBOL_GPL(serdev_device_set_parity); 374 375 void 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 } 384 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 385 386 int 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 -ENOTSUPP; 392 393 return ctrl->ops->get_tiocm(ctrl); 394 } 395 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 396 397 int 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 -ENOTSUPP; 403 404 return ctrl->ops->set_tiocm(ctrl, set, clear); 405 } 406 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 407 408 static int serdev_drv_probe(struct device *dev) 409 { 410 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 411 int ret; 412 413 ret = dev_pm_domain_attach(dev, true); 414 if (ret) 415 return ret; 416 417 ret = sdrv->probe(to_serdev_device(dev)); 418 if (ret) 419 dev_pm_domain_detach(dev, true); 420 421 return ret; 422 } 423 424 static int serdev_drv_remove(struct device *dev) 425 { 426 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 427 if (sdrv->remove) 428 sdrv->remove(to_serdev_device(dev)); 429 430 dev_pm_domain_detach(dev, true); 431 432 return 0; 433 } 434 435 static struct bus_type serdev_bus_type = { 436 .name = "serial", 437 .match = serdev_device_match, 438 .probe = serdev_drv_probe, 439 .remove = serdev_drv_remove, 440 }; 441 442 /** 443 * serdev_device_alloc() - Allocate a new serdev device 444 * @ctrl: associated controller 445 * 446 * Caller is responsible for either calling serdev_device_add() to add the 447 * newly allocated controller, or calling serdev_device_put() to discard it. 448 */ 449 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 450 { 451 struct serdev_device *serdev; 452 453 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 454 if (!serdev) 455 return NULL; 456 457 serdev->ctrl = ctrl; 458 device_initialize(&serdev->dev); 459 serdev->dev.parent = &ctrl->dev; 460 serdev->dev.bus = &serdev_bus_type; 461 serdev->dev.type = &serdev_device_type; 462 init_completion(&serdev->write_comp); 463 mutex_init(&serdev->write_lock); 464 return serdev; 465 } 466 EXPORT_SYMBOL_GPL(serdev_device_alloc); 467 468 /** 469 * serdev_controller_alloc() - Allocate a new serdev controller 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 *parent, 479 size_t size) 480 { 481 struct serdev_controller *ctrl; 482 int id; 483 484 if (WARN_ON(!parent)) 485 return NULL; 486 487 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 488 if (!ctrl) 489 return NULL; 490 491 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); 492 if (id < 0) { 493 dev_err(parent, 494 "unable to allocate serdev controller identifier.\n"); 495 goto err_free; 496 } 497 498 ctrl->nr = id; 499 500 device_initialize(&ctrl->dev); 501 ctrl->dev.type = &serdev_ctrl_type; 502 ctrl->dev.bus = &serdev_bus_type; 503 ctrl->dev.parent = parent; 504 ctrl->dev.of_node = parent->of_node; 505 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 506 507 dev_set_name(&ctrl->dev, "serial%d", id); 508 509 pm_runtime_no_callbacks(&ctrl->dev); 510 pm_suspend_ignore_children(&ctrl->dev, true); 511 512 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 513 return ctrl; 514 515 err_free: 516 kfree(ctrl); 517 518 return NULL; 519 } 520 EXPORT_SYMBOL_GPL(serdev_controller_alloc); 521 522 static int of_serdev_register_devices(struct serdev_controller *ctrl) 523 { 524 struct device_node *node; 525 struct serdev_device *serdev = NULL; 526 int err; 527 bool found = false; 528 529 for_each_available_child_of_node(ctrl->dev.of_node, node) { 530 if (!of_get_property(node, "compatible", NULL)) 531 continue; 532 533 dev_dbg(&ctrl->dev, "adding child %pOF\n", node); 534 535 serdev = serdev_device_alloc(ctrl); 536 if (!serdev) 537 continue; 538 539 serdev->dev.of_node = node; 540 541 err = serdev_device_add(serdev); 542 if (err) { 543 dev_err(&serdev->dev, 544 "failure adding device. status %pe\n", 545 ERR_PTR(err)); 546 serdev_device_put(serdev); 547 } else 548 found = true; 549 } 550 if (!found) 551 return -ENODEV; 552 553 return 0; 554 } 555 556 #ifdef CONFIG_ACPI 557 558 #define SERDEV_ACPI_MAX_SCAN_DEPTH 32 559 560 struct acpi_serdev_lookup { 561 acpi_handle device_handle; 562 acpi_handle controller_handle; 563 int n; 564 int index; 565 }; 566 567 static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data) 568 { 569 struct acpi_serdev_lookup *lookup = data; 570 struct acpi_resource_uart_serialbus *sb; 571 acpi_status status; 572 573 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) 574 return 1; 575 576 if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART) 577 return 1; 578 579 if (lookup->index != -1 && lookup->n++ != lookup->index) 580 return 1; 581 582 sb = &ares->data.uart_serial_bus; 583 584 status = acpi_get_handle(lookup->device_handle, 585 sb->resource_source.string_ptr, 586 &lookup->controller_handle); 587 if (ACPI_FAILURE(status)) 588 return 1; 589 590 /* 591 * NOTE: Ideally, we would also want to retreive other properties here, 592 * once setting them before opening the device is supported by serdev. 593 */ 594 595 return 1; 596 } 597 598 static int acpi_serdev_do_lookup(struct acpi_device *adev, 599 struct acpi_serdev_lookup *lookup) 600 { 601 struct list_head resource_list; 602 int ret; 603 604 lookup->device_handle = acpi_device_handle(adev); 605 lookup->controller_handle = NULL; 606 lookup->n = 0; 607 608 INIT_LIST_HEAD(&resource_list); 609 ret = acpi_dev_get_resources(adev, &resource_list, 610 acpi_serdev_parse_resource, lookup); 611 acpi_dev_free_resource_list(&resource_list); 612 613 if (ret < 0) 614 return -EINVAL; 615 616 return 0; 617 } 618 619 static int acpi_serdev_check_resources(struct serdev_controller *ctrl, 620 struct acpi_device *adev) 621 { 622 struct acpi_serdev_lookup lookup; 623 int ret; 624 625 if (acpi_bus_get_status(adev) || !adev->status.present) 626 return -EINVAL; 627 628 /* Look for UARTSerialBusV2 resource */ 629 lookup.index = -1; // we only care for the last device 630 631 ret = acpi_serdev_do_lookup(adev, &lookup); 632 if (ret) 633 return ret; 634 635 /* 636 * Apple machines provide an empty resource template, so on those 637 * machines just look for immediate children with a "baud" property 638 * (from the _DSM method) instead. 639 */ 640 if (!lookup.controller_handle && x86_apple_machine && 641 !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL)) 642 acpi_get_parent(adev->handle, &lookup.controller_handle); 643 644 /* Make sure controller and ResourceSource handle match */ 645 if (ACPI_HANDLE(ctrl->dev.parent) != lookup.controller_handle) 646 return -ENODEV; 647 648 return 0; 649 } 650 651 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, 652 struct acpi_device *adev) 653 { 654 struct serdev_device *serdev; 655 int err; 656 657 serdev = serdev_device_alloc(ctrl); 658 if (!serdev) { 659 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n", 660 dev_name(&adev->dev)); 661 return AE_NO_MEMORY; 662 } 663 664 ACPI_COMPANION_SET(&serdev->dev, adev); 665 acpi_device_set_enumerated(adev); 666 667 err = serdev_device_add(serdev); 668 if (err) { 669 dev_err(&serdev->dev, 670 "failure adding ACPI serdev device. status %pe\n", 671 ERR_PTR(err)); 672 serdev_device_put(serdev); 673 } 674 675 return AE_OK; 676 } 677 678 static const struct acpi_device_id serdev_acpi_devices_blacklist[] = { 679 { "INT3511", 0 }, 680 { "INT3512", 0 }, 681 { }, 682 }; 683 684 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, 685 void *data, void **return_value) 686 { 687 struct serdev_controller *ctrl = data; 688 struct acpi_device *adev; 689 690 if (acpi_bus_get_device(handle, &adev)) 691 return AE_OK; 692 693 if (acpi_device_enumerated(adev)) 694 return AE_OK; 695 696 /* Skip if black listed */ 697 if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist)) 698 return AE_OK; 699 700 if (acpi_serdev_check_resources(ctrl, adev)) 701 return AE_OK; 702 703 return acpi_serdev_register_device(ctrl, adev); 704 } 705 706 707 static int acpi_serdev_register_devices(struct serdev_controller *ctrl) 708 { 709 acpi_status status; 710 711 if (!has_acpi_companion(ctrl->dev.parent)) 712 return -ENODEV; 713 714 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 715 SERDEV_ACPI_MAX_SCAN_DEPTH, 716 acpi_serdev_add_device, NULL, ctrl, NULL); 717 if (ACPI_FAILURE(status)) 718 dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n"); 719 720 if (!ctrl->serdev) 721 return -ENODEV; 722 723 return 0; 724 } 725 #else 726 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl) 727 { 728 return -ENODEV; 729 } 730 #endif /* CONFIG_ACPI */ 731 732 /** 733 * serdev_controller_add() - Add an serdev controller 734 * @ctrl: controller to be registered. 735 * 736 * Register a controller previously allocated via serdev_controller_alloc() with 737 * the serdev core. 738 */ 739 int serdev_controller_add(struct serdev_controller *ctrl) 740 { 741 int ret_of, ret_acpi, ret; 742 743 /* Can't register until after driver model init */ 744 if (WARN_ON(!is_registered)) 745 return -EAGAIN; 746 747 ret = device_add(&ctrl->dev); 748 if (ret) 749 return ret; 750 751 pm_runtime_enable(&ctrl->dev); 752 753 ret_of = of_serdev_register_devices(ctrl); 754 ret_acpi = acpi_serdev_register_devices(ctrl); 755 if (ret_of && ret_acpi) { 756 dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n", 757 ERR_PTR(ret_of), ERR_PTR(ret_acpi)); 758 ret = -ENODEV; 759 goto err_rpm_disable; 760 } 761 762 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 763 ctrl->nr, &ctrl->dev); 764 return 0; 765 766 err_rpm_disable: 767 pm_runtime_disable(&ctrl->dev); 768 device_del(&ctrl->dev); 769 return ret; 770 }; 771 EXPORT_SYMBOL_GPL(serdev_controller_add); 772 773 /* Remove a device associated with a controller */ 774 static int serdev_remove_device(struct device *dev, void *data) 775 { 776 struct serdev_device *serdev = to_serdev_device(dev); 777 if (dev->type == &serdev_device_type) 778 serdev_device_remove(serdev); 779 return 0; 780 } 781 782 /** 783 * serdev_controller_remove(): remove an serdev controller 784 * @ctrl: controller to remove 785 * 786 * Remove a serdev controller. Caller is responsible for calling 787 * serdev_controller_put() to discard the allocated controller. 788 */ 789 void serdev_controller_remove(struct serdev_controller *ctrl) 790 { 791 if (!ctrl) 792 return; 793 794 device_for_each_child(&ctrl->dev, NULL, serdev_remove_device); 795 pm_runtime_disable(&ctrl->dev); 796 device_del(&ctrl->dev); 797 } 798 EXPORT_SYMBOL_GPL(serdev_controller_remove); 799 800 /** 801 * serdev_driver_register() - Register client driver with serdev core 802 * @sdrv: client driver to be associated with client-device. 803 * @owner: client driver owner to set. 804 * 805 * This API will register the client driver with the serdev framework. 806 * It is typically called from the driver's module-init function. 807 */ 808 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 809 { 810 sdrv->driver.bus = &serdev_bus_type; 811 sdrv->driver.owner = owner; 812 813 /* force drivers to async probe so I/O is possible in probe */ 814 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 815 816 return driver_register(&sdrv->driver); 817 } 818 EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 819 820 static void __exit serdev_exit(void) 821 { 822 bus_unregister(&serdev_bus_type); 823 ida_destroy(&ctrl_ida); 824 } 825 module_exit(serdev_exit); 826 827 static int __init serdev_init(void) 828 { 829 int ret; 830 831 ret = bus_register(&serdev_bus_type); 832 if (ret) 833 return ret; 834 835 is_registered = true; 836 return 0; 837 } 838 /* Must be before serial drivers register */ 839 postcore_initcall(serdev_init); 840 841 MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 842 MODULE_LICENSE("GPL v2"); 843 MODULE_DESCRIPTION("Serial attached device bus"); 844