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

source code of linux/drivers/tty/serdev/core.c

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