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