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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/serdev.h>
17#include <linux/slab.h>
18
19static bool is_registered;
20static DEFINE_IDA(ctrl_ida);
21
22static ssize_t modalias_show(struct device *dev,
23 struct device_attribute *attr, char *buf)
24{
25 int len;
26
27 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
28 if (len != -ENODEV)
29 return len;
30
31 return of_device_modalias(dev, buf, PAGE_SIZE);
32}
33static DEVICE_ATTR_RO(modalias);
34
35static struct attribute *serdev_device_attrs[] = {
36 &dev_attr_modalias.attr,
37 NULL,
38};
39ATTRIBUTE_GROUPS(serdev_device);
40
41static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
42{
43 int rc;
44
45 /* TODO: platform modalias */
46
47 rc = acpi_device_uevent_modalias(dev, env);
48 if (rc != -ENODEV)
49 return rc;
50
51 return of_device_uevent_modalias(dev, env);
52}
53
54static void serdev_device_release(struct device *dev)
55{
56 struct serdev_device *serdev = to_serdev_device(dev);
57 kfree(serdev);
58}
59
60static const struct device_type serdev_device_type = {
61 .groups = serdev_device_groups,
62 .uevent = serdev_device_uevent,
63 .release = serdev_device_release,
64};
65
66static bool is_serdev_device(const struct device *dev)
67{
68 return dev->type == &serdev_device_type;
69}
70
71static void serdev_ctrl_release(struct device *dev)
72{
73 struct serdev_controller *ctrl = to_serdev_controller(dev);
74 ida_simple_remove(&ctrl_ida, ctrl->nr);
75 kfree(ctrl);
76}
77
78static const struct device_type serdev_ctrl_type = {
79 .release = serdev_ctrl_release,
80};
81
82static int serdev_device_match(struct device *dev, struct device_driver *drv)
83{
84 if (!is_serdev_device(dev))
85 return 0;
86
87 /* TODO: platform matching */
88 if (acpi_driver_match_device(dev, drv))
89 return 1;
90
91 return of_driver_match_device(dev, drv);
92}
93
94/**
95 * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
96 * @serdev: serdev_device to be added
97 */
98int serdev_device_add(struct serdev_device *serdev)
99{
100 struct serdev_controller *ctrl = serdev->ctrl;
101 struct device *parent = serdev->dev.parent;
102 int err;
103
104 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
105
106 /* Only a single slave device is currently supported. */
107 if (ctrl->serdev) {
108 dev_err(&serdev->dev, "controller busy\n");
109 return -EBUSY;
110 }
111 ctrl->serdev = serdev;
112
113 err = device_add(&serdev->dev);
114 if (err < 0) {
115 dev_err(&serdev->dev, "Can't add %s, status %d\n",
116 dev_name(&serdev->dev), err);
117 goto err_clear_serdev;
118 }
119
120 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
121
122 return 0;
123
124err_clear_serdev:
125 ctrl->serdev = NULL;
126 return err;
127}
128EXPORT_SYMBOL_GPL(serdev_device_add);
129
130/**
131 * serdev_device_remove(): remove an serdev device
132 * @serdev: serdev_device to be removed
133 */
134void serdev_device_remove(struct serdev_device *serdev)
135{
136 struct serdev_controller *ctrl = serdev->ctrl;
137
138 device_unregister(&serdev->dev);
139 ctrl->serdev = NULL;
140}
141EXPORT_SYMBOL_GPL(serdev_device_remove);
142
143int serdev_device_open(struct serdev_device *serdev)
144{
145 struct serdev_controller *ctrl = serdev->ctrl;
146
147 if (!ctrl || !ctrl->ops->open)
148 return -EINVAL;
149
150 return ctrl->ops->open(ctrl);
151}
152EXPORT_SYMBOL_GPL(serdev_device_open);
153
154void serdev_device_close(struct serdev_device *serdev)
155{
156 struct serdev_controller *ctrl = serdev->ctrl;
157
158 if (!ctrl || !ctrl->ops->close)
159 return;
160
161 ctrl->ops->close(ctrl);
162}
163EXPORT_SYMBOL_GPL(serdev_device_close);
164
165static void devm_serdev_device_release(struct device *dev, void *dr)
166{
167 serdev_device_close(*(struct serdev_device **)dr);
168}
169
170int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
171{
172 struct serdev_device **dr;
173 int ret;
174
175 dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
176 if (!dr)
177 return -ENOMEM;
178
179 ret = serdev_device_open(serdev);
180 if (ret) {
181 devres_free(dr);
182 return ret;
183 }
184
185 *dr = serdev;
186 devres_add(dev, dr);
187
188 return 0;
189}
190EXPORT_SYMBOL_GPL(devm_serdev_device_open);
191
192void serdev_device_write_wakeup(struct serdev_device *serdev)
193{
194 complete(&serdev->write_comp);
195}
196EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
197
198int serdev_device_write_buf(struct serdev_device *serdev,
199 const unsigned char *buf, size_t count)
200{
201 struct serdev_controller *ctrl = serdev->ctrl;
202
203 if (!ctrl || !ctrl->ops->write_buf)
204 return -EINVAL;
205
206 return ctrl->ops->write_buf(ctrl, buf, count);
207}
208EXPORT_SYMBOL_GPL(serdev_device_write_buf);
209
210int serdev_device_write(struct serdev_device *serdev,
211 const unsigned char *buf, size_t count,
212 unsigned long timeout)
213{
214 struct serdev_controller *ctrl = serdev->ctrl;
215 int ret;
216
217 if (!ctrl || !ctrl->ops->write_buf ||
218 (timeout && !serdev->ops->write_wakeup))
219 return -EINVAL;
220
221 mutex_lock(&serdev->write_lock);
222 do {
223 reinit_completion(&serdev->write_comp);
224
225 ret = ctrl->ops->write_buf(ctrl, buf, count);
226 if (ret < 0)
227 break;
228
229 buf += ret;
230 count -= ret;
231
232 } while (count &&
233 (timeout = wait_for_completion_timeout(&serdev->write_comp,
234 timeout)));
235 mutex_unlock(&serdev->write_lock);
236 return ret < 0 ? ret : (count ? -ETIMEDOUT : 0);
237}
238EXPORT_SYMBOL_GPL(serdev_device_write);
239
240void serdev_device_write_flush(struct serdev_device *serdev)
241{
242 struct serdev_controller *ctrl = serdev->ctrl;
243
244 if (!ctrl || !ctrl->ops->write_flush)
245 return;
246
247 ctrl->ops->write_flush(ctrl);
248}
249EXPORT_SYMBOL_GPL(serdev_device_write_flush);
250
251int serdev_device_write_room(struct serdev_device *serdev)
252{
253 struct serdev_controller *ctrl = serdev->ctrl;
254
255 if (!ctrl || !ctrl->ops->write_room)
256 return 0;
257
258 return serdev->ctrl->ops->write_room(ctrl);
259}
260EXPORT_SYMBOL_GPL(serdev_device_write_room);
261
262unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
263{
264 struct serdev_controller *ctrl = serdev->ctrl;
265
266 if (!ctrl || !ctrl->ops->set_baudrate)
267 return 0;
268
269 return ctrl->ops->set_baudrate(ctrl, speed);
270
271}
272EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
273
274void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
275{
276 struct serdev_controller *ctrl = serdev->ctrl;
277
278 if (!ctrl || !ctrl->ops->set_flow_control)
279 return;
280
281 ctrl->ops->set_flow_control(ctrl, enable);
282}
283EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
284
285int serdev_device_set_parity(struct serdev_device *serdev,
286 enum serdev_parity parity)
287{
288 struct serdev_controller *ctrl = serdev->ctrl;
289
290 if (!ctrl || !ctrl->ops->set_parity)
291 return -ENOTSUPP;
292
293 return ctrl->ops->set_parity(ctrl, parity);
294}
295EXPORT_SYMBOL_GPL(serdev_device_set_parity);
296
297void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
298{
299 struct serdev_controller *ctrl = serdev->ctrl;
300
301 if (!ctrl || !ctrl->ops->wait_until_sent)
302 return;
303
304 ctrl->ops->wait_until_sent(ctrl, timeout);
305}
306EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
307
308int serdev_device_get_tiocm(struct serdev_device *serdev)
309{
310 struct serdev_controller *ctrl = serdev->ctrl;
311
312 if (!ctrl || !ctrl->ops->get_tiocm)
313 return -ENOTSUPP;
314
315 return ctrl->ops->get_tiocm(ctrl);
316}
317EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
318
319int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
320{
321 struct serdev_controller *ctrl = serdev->ctrl;
322
323 if (!ctrl || !ctrl->ops->set_tiocm)
324 return -ENOTSUPP;
325
326 return ctrl->ops->set_tiocm(ctrl, set, clear);
327}
328EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
329
330static int serdev_drv_probe(struct device *dev)
331{
332 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
333
334 return sdrv->probe(to_serdev_device(dev));
335}
336
337static int serdev_drv_remove(struct device *dev)
338{
339 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
340 if (sdrv->remove)
341 sdrv->remove(to_serdev_device(dev));
342 return 0;
343}
344
345static struct bus_type serdev_bus_type = {
346 .name = "serial",
347 .match = serdev_device_match,
348 .probe = serdev_drv_probe,
349 .remove = serdev_drv_remove,
350};
351
352/**
353 * serdev_device_alloc() - Allocate a new serdev device
354 * @ctrl: associated controller
355 *
356 * Caller is responsible for either calling serdev_device_add() to add the
357 * newly allocated controller, or calling serdev_device_put() to discard it.
358 */
359struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
360{
361 struct serdev_device *serdev;
362
363 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
364 if (!serdev)
365 return NULL;
366
367 serdev->ctrl = ctrl;
368 device_initialize(&serdev->dev);
369 serdev->dev.parent = &ctrl->dev;
370 serdev->dev.bus = &serdev_bus_type;
371 serdev->dev.type = &serdev_device_type;
372 init_completion(&serdev->write_comp);
373 mutex_init(&serdev->write_lock);
374 return serdev;
375}
376EXPORT_SYMBOL_GPL(serdev_device_alloc);
377
378/**
379 * serdev_controller_alloc() - Allocate a new serdev controller
380 * @parent: parent device
381 * @size: size of private data
382 *
383 * Caller is responsible for either calling serdev_controller_add() to add the
384 * newly allocated controller, or calling serdev_controller_put() to discard it.
385 * The allocated private data region may be accessed via
386 * serdev_controller_get_drvdata()
387 */
388struct serdev_controller *serdev_controller_alloc(struct device *parent,
389 size_t size)
390{
391 struct serdev_controller *ctrl;
392 int id;
393
394 if (WARN_ON(!parent))
395 return NULL;
396
397 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
398 if (!ctrl)
399 return NULL;
400
401 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
402 if (id < 0) {
403 dev_err(parent,
404 "unable to allocate serdev controller identifier.\n");
405 goto err_free;
406 }
407
408 ctrl->nr = id;
409
410 device_initialize(&ctrl->dev);
411 ctrl->dev.type = &serdev_ctrl_type;
412 ctrl->dev.bus = &serdev_bus_type;
413 ctrl->dev.parent = parent;
414 ctrl->dev.of_node = parent->of_node;
415 serdev_controller_set_drvdata(ctrl, &ctrl[1]);
416
417 dev_set_name(&ctrl->dev, "serial%d", id);
418
419 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
420 return ctrl;
421
422err_free:
423 kfree(ctrl);
424
425 return NULL;
426}
427EXPORT_SYMBOL_GPL(serdev_controller_alloc);
428
429static int of_serdev_register_devices(struct serdev_controller *ctrl)
430{
431 struct device_node *node;
432 struct serdev_device *serdev = NULL;
433 int err;
434 bool found = false;
435
436 for_each_available_child_of_node(ctrl->dev.of_node, node) {
437 if (!of_get_property(node, "compatible", NULL))
438 continue;
439
440 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
441
442 serdev = serdev_device_alloc(ctrl);
443 if (!serdev)
444 continue;
445
446 serdev->dev.of_node = node;
447
448 err = serdev_device_add(serdev);
449 if (err) {
450 dev_err(&serdev->dev,
451 "failure adding device. status %d\n", err);
452 serdev_device_put(serdev);
453 } else
454 found = true;
455 }
456 if (!found)
457 return -ENODEV;
458
459 return 0;
460}
461
462#ifdef CONFIG_ACPI
463static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
464 struct acpi_device *adev)
465{
466 struct serdev_device *serdev = NULL;
467 int err;
468
469 if (acpi_bus_get_status(adev) || !adev->status.present ||
470 acpi_device_enumerated(adev))
471 return AE_OK;
472
473 serdev = serdev_device_alloc(ctrl);
474 if (!serdev) {
475 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
476 dev_name(&adev->dev));
477 return AE_NO_MEMORY;
478 }
479
480 ACPI_COMPANION_SET(&serdev->dev, adev);
481 acpi_device_set_enumerated(adev);
482
483 err = serdev_device_add(serdev);
484 if (err) {
485 dev_err(&serdev->dev,
486 "failure adding ACPI serdev device. status %d\n", err);
487 serdev_device_put(serdev);
488 }
489
490 return AE_OK;
491}
492
493static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
494 void *data, void **return_value)
495{
496 struct serdev_controller *ctrl = data;
497 struct acpi_device *adev;
498
499 if (acpi_bus_get_device(handle, &adev))
500 return AE_OK;
501
502 return acpi_serdev_register_device(ctrl, adev);
503}
504
505static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
506{
507 acpi_status status;
508 acpi_handle handle;
509
510 handle = ACPI_HANDLE(ctrl->dev.parent);
511 if (!handle)
512 return -ENODEV;
513
514 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
515 acpi_serdev_add_device, NULL, ctrl, NULL);
516 if (ACPI_FAILURE(status))
517 dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");
518
519 if (!ctrl->serdev)
520 return -ENODEV;
521
522 return 0;
523}
524#else
525static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
526{
527 return -ENODEV;
528}
529#endif /* CONFIG_ACPI */
530
531/**
532 * serdev_controller_add() - Add an serdev controller
533 * @ctrl: controller to be registered.
534 *
535 * Register a controller previously allocated via serdev_controller_alloc() with
536 * the serdev core.
537 */
538int serdev_controller_add(struct serdev_controller *ctrl)
539{
540 int ret_of, ret_acpi, ret;
541
542 /* Can't register until after driver model init */
543 if (WARN_ON(!is_registered))
544 return -EAGAIN;
545
546 ret = device_add(&ctrl->dev);
547 if (ret)
548 return ret;
549
550 ret_of = of_serdev_register_devices(ctrl);
551 ret_acpi = acpi_serdev_register_devices(ctrl);
552 if (ret_of && ret_acpi) {
553 dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",
554 ret_of, ret_acpi);
555 ret = -ENODEV;
556 goto out_dev_del;
557 }
558
559 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
560 ctrl->nr, &ctrl->dev);
561 return 0;
562
563out_dev_del:
564 device_del(&ctrl->dev);
565 return ret;
566};
567EXPORT_SYMBOL_GPL(serdev_controller_add);
568
569/* Remove a device associated with a controller */
570static int serdev_remove_device(struct device *dev, void *data)
571{
572 struct serdev_device *serdev = to_serdev_device(dev);
573 if (dev->type == &serdev_device_type)
574 serdev_device_remove(serdev);
575 return 0;
576}
577
578/**
579 * serdev_controller_remove(): remove an serdev controller
580 * @ctrl: controller to remove
581 *
582 * Remove a serdev controller. Caller is responsible for calling
583 * serdev_controller_put() to discard the allocated controller.
584 */
585void serdev_controller_remove(struct serdev_controller *ctrl)
586{
587 int dummy;
588
589 if (!ctrl)
590 return;
591
592 dummy = device_for_each_child(&ctrl->dev, NULL,
593 serdev_remove_device);
594 device_del(&ctrl->dev);
595}
596EXPORT_SYMBOL_GPL(serdev_controller_remove);
597
598/**
599 * serdev_driver_register() - Register client driver with serdev core
600 * @sdrv: client driver to be associated with client-device.
601 *
602 * This API will register the client driver with the serdev framework.
603 * It is typically called from the driver's module-init function.
604 */
605int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
606{
607 sdrv->driver.bus = &serdev_bus_type;
608 sdrv->driver.owner = owner;
609
610 /* force drivers to async probe so I/O is possible in probe */
611 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
612
613 return driver_register(&sdrv->driver);
614}
615EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
616
617static void __exit serdev_exit(void)
618{
619 bus_unregister(&serdev_bus_type);
620}
621module_exit(serdev_exit);
622
623static int __init serdev_init(void)
624{
625 int ret;
626
627 ret = bus_register(&serdev_bus_type);
628 if (ret)
629 return ret;
630
631 is_registered = true;
632 return 0;
633}
634/* Must be before serial drivers register */
635postcore_initcall(serdev_init);
636
637MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
638MODULE_LICENSE("GPL v2");
639MODULE_DESCRIPTION("Serial attached device bus");