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1// SPDX-License-Identifier: GPL-2.02/*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 25static bool is_registered;26static DEFINE_IDA(ctrl_ida);27 28static 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}39static DEVICE_ATTR_RO(modalias);40 41static struct attribute *serdev_device_attrs[] = {42 &dev_attr_modalias.attr,43 NULL,44};45ATTRIBUTE_GROUPS(serdev_device);46 47static 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 60static void serdev_device_release(struct device *dev)61{62 struct serdev_device *serdev = to_serdev_device(dev);63 kfree(serdev);64}65 66static const struct device_type serdev_device_type = {67 .groups = serdev_device_groups,68 .uevent = serdev_device_uevent,69 .release = serdev_device_release,70};71 72static bool is_serdev_device(const struct device *dev)73{74 return dev->type == &serdev_device_type;75}76 77static 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 84static const struct device_type serdev_ctrl_type = {85 .release = serdev_ctrl_release,86};87 88static int serdev_device_match(struct device *dev, const 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 added103 */104int 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 130err_clear_serdev:131 ctrl->serdev = NULL;132 return err;133}134EXPORT_SYMBOL_GPL(serdev_device_add);135 136/**137 * serdev_device_remove(): remove an serdev device138 * @serdev: serdev_device to be removed139 */140void 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}147EXPORT_SYMBOL_GPL(serdev_device_remove);148 149int 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 169err_close:170 if (ctrl->ops->close)171 ctrl->ops->close(ctrl);172 173 return ret;174}175EXPORT_SYMBOL_GPL(serdev_device_open);176 177void 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}188EXPORT_SYMBOL_GPL(serdev_device_close);189 190static void devm_serdev_device_close(void *serdev)191{192 serdev_device_close(serdev);193}194 195int 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}205EXPORT_SYMBOL_GPL(devm_serdev_device_open);206 207void serdev_device_write_wakeup(struct serdev_device *serdev)208{209 complete(&serdev->write_comp);210}211EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);212 213/**214 * serdev_device_write_buf() - write data asynchronously215 * @serdev: serdev device216 * @buf: data to be written217 * @count: number of bytes to write218 *219 * Write data to the device asynchronously.220 *221 * Note that any accepted data has only been buffered by the controller; use222 * serdev_device_wait_until_sent() to make sure the controller write buffer223 * has actually been emptied.224 *225 * Return: The number of bytes written (less than count if not enough room in226 * the write buffer), or a negative errno on errors.227 */228int 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}237EXPORT_SYMBOL_GPL(serdev_device_write_buf);238 239/**240 * serdev_device_write() - write data synchronously241 * @serdev: serdev device242 * @buf: data to be written243 * @count: number of bytes to write244 * @timeout: timeout in jiffies, or 0 to wait indefinitely245 *246 * Write data to the device synchronously by repeatedly calling247 * serdev_device_write() until the controller has accepted all data (unless248 * interrupted by a timeout or a signal).249 *250 * Note that any accepted data has only been buffered by the controller; use251 * serdev_device_wait_until_sent() to make sure the controller write buffer252 * has actually been emptied.253 *254 * Note that this function depends on serdev_device_write_wakeup() being255 * 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, or259 * a negative errno on errors.260 */261ssize_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 else301 return -ETIMEDOUT;302 }303 304 return written;305}306EXPORT_SYMBOL_GPL(serdev_device_write);307 308void 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}317EXPORT_SYMBOL_GPL(serdev_device_write_flush);318 319int 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}328EXPORT_SYMBOL_GPL(serdev_device_write_room);329 330unsigned 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}340EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);341 342void 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}351EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);352 353int 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}363EXPORT_SYMBOL_GPL(serdev_device_set_parity);364 365void 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}374EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);375 376int 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}385EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);386 387int 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}396EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);397 398int 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}407EXPORT_SYMBOL_GPL(serdev_device_break_ctl);408 409static 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 425static 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 434static 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 device443 * @ctrl: associated controller444 *445 * Caller is responsible for either calling serdev_device_add() to add the446 * newly allocated controller, or calling serdev_device_put() to discard it.447 */448struct 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}465EXPORT_SYMBOL_GPL(serdev_device_alloc);466 467/**468 * serdev_controller_alloc() - Allocate a new serdev controller469 * @host: serial port hardware controller device470 * @parent: parent device471 * @size: size of private data472 *473 * Caller is responsible for either calling serdev_controller_add() to add the474 * newly allocated controller, or calling serdev_controller_put() to discard it.475 * The allocated private data region may be accessed via476 * serdev_controller_get_drvdata()477 */478struct 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 517err_free:518 kfree(ctrl);519 520 return NULL;521}522EXPORT_SYMBOL_GPL(serdev_controller_alloc);523 524static 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_property_present(node, "compatible"))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 } else550 found = true;551 }552 if (!found)553 return -ENODEV;554 555 return 0;556}557 558#ifdef CONFIG_ACPI559 560#define SERDEV_ACPI_MAX_SCAN_DEPTH 32561 562struct 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 matches571 * @ares: ACPI resource572 * @uart: Pointer to UARTSerialBus resource will be returned here573 *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 */579bool 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}594EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);595 596static 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 622static 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 643static 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 device654 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 those661 * machines just look for immediate children with a "baud" property662 * (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 675static 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 702static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {703 { "INT3511", 0 },704 { "INT3512", 0 },705 { },706};707 708static 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 728static 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 to739 * contain buggy devices. Note serdev_controller_add() must still740 * succeed in this case, so that the proper serdev devices can be741 * 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#else761static 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 controller769 * @ctrl: controller to be registered.770 *771 * Register a controller previously allocated via serdev_controller_alloc() with772 * the serdev core.773 */774int 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 801err_rpm_disable:802 pm_runtime_disable(&ctrl->dev);803 device_del(&ctrl->dev);804 return ret;805};806EXPORT_SYMBOL_GPL(serdev_controller_add);807 808/* Remove a device associated with a controller */809static 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 controller819 * @ctrl: controller to remove820 *821 * Remove a serdev controller. Caller is responsible for calling822 * serdev_controller_put() to discard the allocated controller.823 */824void 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}833EXPORT_SYMBOL_GPL(serdev_controller_remove);834 835/**836 * __serdev_device_driver_register() - Register client driver with serdev core837 * @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 */843int __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}853EXPORT_SYMBOL_GPL(__serdev_device_driver_register);854 855static void __exit serdev_exit(void)856{857 bus_unregister(&serdev_bus_type);858 ida_destroy(&ctrl_ida);859}860module_exit(serdev_exit);861 862static 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 */874postcore_initcall(serdev_init);875 876MODULE_AUTHOR("Rob Herring <robh@kernel.org>");877MODULE_LICENSE("GPL v2");878MODULE_DESCRIPTION("Serial attached device bus");879