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
25 static bool is_registered;
26 static DEFINE_IDA(ctrl_ida);
27
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)28 static ssize_t modalias_show(struct device *dev,
29 struct device_attribute *attr, char *buf)
30 {
31 int len;
32
33 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
34 if (len != -ENODEV)
35 return len;
36
37 return of_device_modalias(dev, buf, PAGE_SIZE);
38 }
39 static DEVICE_ATTR_RO(modalias);
40
41 static struct attribute *serdev_device_attrs[] = {
42 &dev_attr_modalias.attr,
43 NULL,
44 };
45 ATTRIBUTE_GROUPS(serdev_device);
46
serdev_device_uevent(const struct device * dev,struct kobj_uevent_env * env)47 static 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
serdev_device_release(struct device * dev)60 static void serdev_device_release(struct device *dev)
61 {
62 struct serdev_device *serdev = to_serdev_device(dev);
63 kfree(serdev);
64 }
65
66 static const struct device_type serdev_device_type = {
67 .groups = serdev_device_groups,
68 .uevent = serdev_device_uevent,
69 .release = serdev_device_release,
70 };
71
is_serdev_device(const struct device * dev)72 static bool is_serdev_device(const struct device *dev)
73 {
74 return dev->type == &serdev_device_type;
75 }
76
serdev_ctrl_release(struct device * dev)77 static void serdev_ctrl_release(struct device *dev)
78 {
79 struct serdev_controller *ctrl = to_serdev_controller(dev);
80 ida_free(&ctrl_ida, ctrl->nr);
81 kfree(ctrl);
82 }
83
84 static const struct device_type serdev_ctrl_type = {
85 .release = serdev_ctrl_release,
86 };
87
serdev_device_match(struct device * dev,const struct device_driver * drv)88 static 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 */
serdev_device_add(struct serdev_device * serdev)104 int serdev_device_add(struct serdev_device *serdev)
105 {
106 struct serdev_controller *ctrl = serdev->ctrl;
107 struct device *parent = serdev->dev.parent;
108 int err;
109
110 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
111
112 /* Only a single slave device is currently supported. */
113 if (ctrl->serdev) {
114 dev_err(&serdev->dev, "controller busy\n");
115 return -EBUSY;
116 }
117 ctrl->serdev = serdev;
118
119 err = device_add(&serdev->dev);
120 if (err < 0) {
121 dev_err(&serdev->dev, "Can't add %s, status %pe\n",
122 dev_name(&serdev->dev), ERR_PTR(err));
123 goto err_clear_serdev;
124 }
125
126 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
127
128 return 0;
129
130 err_clear_serdev:
131 ctrl->serdev = NULL;
132 return err;
133 }
134 EXPORT_SYMBOL_GPL(serdev_device_add);
135
136 /**
137 * serdev_device_remove(): remove an serdev device
138 * @serdev: serdev_device to be removed
139 */
serdev_device_remove(struct serdev_device * serdev)140 void serdev_device_remove(struct serdev_device *serdev)
141 {
142 struct serdev_controller *ctrl = serdev->ctrl;
143
144 device_unregister(&serdev->dev);
145 ctrl->serdev = NULL;
146 }
147 EXPORT_SYMBOL_GPL(serdev_device_remove);
148
serdev_device_open(struct serdev_device * serdev)149 int serdev_device_open(struct serdev_device *serdev)
150 {
151 struct serdev_controller *ctrl = serdev->ctrl;
152 int ret;
153
154 if (!ctrl || !ctrl->ops->open)
155 return -EINVAL;
156
157 ret = ctrl->ops->open(ctrl);
158 if (ret)
159 return ret;
160
161 ret = pm_runtime_get_sync(&ctrl->dev);
162 if (ret < 0) {
163 pm_runtime_put_noidle(&ctrl->dev);
164 goto err_close;
165 }
166
167 return 0;
168
169 err_close:
170 if (ctrl->ops->close)
171 ctrl->ops->close(ctrl);
172
173 return ret;
174 }
175 EXPORT_SYMBOL_GPL(serdev_device_open);
176
serdev_device_close(struct serdev_device * serdev)177 void serdev_device_close(struct serdev_device *serdev)
178 {
179 struct serdev_controller *ctrl = serdev->ctrl;
180
181 if (!ctrl || !ctrl->ops->close)
182 return;
183
184 pm_runtime_put(&ctrl->dev);
185
186 ctrl->ops->close(ctrl);
187 }
188 EXPORT_SYMBOL_GPL(serdev_device_close);
189
devm_serdev_device_close(void * serdev)190 static void devm_serdev_device_close(void *serdev)
191 {
192 serdev_device_close(serdev);
193 }
194
devm_serdev_device_open(struct device * dev,struct serdev_device * serdev)195 int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
196 {
197 int ret;
198
199 ret = serdev_device_open(serdev);
200 if (ret)
201 return ret;
202
203 return devm_add_action_or_reset(dev, devm_serdev_device_close, serdev);
204 }
205 EXPORT_SYMBOL_GPL(devm_serdev_device_open);
206
serdev_device_write_wakeup(struct serdev_device * serdev)207 void serdev_device_write_wakeup(struct serdev_device *serdev)
208 {
209 complete(&serdev->write_comp);
210 }
211 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
212
213 /**
214 * serdev_device_write_buf() - write data asynchronously
215 * @serdev: serdev device
216 * @buf: data to be written
217 * @count: number of bytes to write
218 *
219 * Write data to the device asynchronously.
220 *
221 * Note that any accepted data has only been buffered by the controller; use
222 * serdev_device_wait_until_sent() to make sure the controller write buffer
223 * has actually been emptied.
224 *
225 * Return: The number of bytes written (less than count if not enough room in
226 * the write buffer), or a negative errno on errors.
227 */
serdev_device_write_buf(struct serdev_device * serdev,const u8 * buf,size_t count)228 int serdev_device_write_buf(struct serdev_device *serdev, const u8 *buf, size_t count)
229 {
230 struct serdev_controller *ctrl = serdev->ctrl;
231
232 if (!ctrl || !ctrl->ops->write_buf)
233 return -EINVAL;
234
235 return ctrl->ops->write_buf(ctrl, buf, count);
236 }
237 EXPORT_SYMBOL_GPL(serdev_device_write_buf);
238
239 /**
240 * serdev_device_write() - write data synchronously
241 * @serdev: serdev device
242 * @buf: data to be written
243 * @count: number of bytes to write
244 * @timeout: timeout in jiffies, or 0 to wait indefinitely
245 *
246 * Write data to the device synchronously by repeatedly calling
247 * serdev_device_write() until the controller has accepted all data (unless
248 * interrupted by a timeout or a signal).
249 *
250 * Note that any accepted data has only been buffered by the controller; use
251 * serdev_device_wait_until_sent() to make sure the controller write buffer
252 * has actually been emptied.
253 *
254 * Note that this function depends on serdev_device_write_wakeup() being
255 * called in the serdev driver write_wakeup() callback.
256 *
257 * Return: The number of bytes written (less than count if interrupted),
258 * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
259 * a negative errno on errors.
260 */
serdev_device_write(struct serdev_device * serdev,const u8 * buf,size_t count,long timeout)261 ssize_t serdev_device_write(struct serdev_device *serdev, const u8 *buf,
262 size_t count, long timeout)
263 {
264 struct serdev_controller *ctrl = serdev->ctrl;
265 size_t written = 0;
266 ssize_t ret;
267
268 if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
269 return -EINVAL;
270
271 if (timeout == 0)
272 timeout = MAX_SCHEDULE_TIMEOUT;
273
274 mutex_lock(&serdev->write_lock);
275 do {
276 reinit_completion(&serdev->write_comp);
277
278 ret = ctrl->ops->write_buf(ctrl, buf, count);
279 if (ret < 0)
280 break;
281
282 written += ret;
283 buf += ret;
284 count -= ret;
285
286 if (count == 0)
287 break;
288
289 timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
290 timeout);
291 } while (timeout > 0);
292 mutex_unlock(&serdev->write_lock);
293
294 if (ret < 0)
295 return ret;
296
297 if (timeout <= 0 && written == 0) {
298 if (timeout == -ERESTARTSYS)
299 return -ERESTARTSYS;
300 else
301 return -ETIMEDOUT;
302 }
303
304 return written;
305 }
306 EXPORT_SYMBOL_GPL(serdev_device_write);
307
serdev_device_write_flush(struct serdev_device * serdev)308 void serdev_device_write_flush(struct serdev_device *serdev)
309 {
310 struct serdev_controller *ctrl = serdev->ctrl;
311
312 if (!ctrl || !ctrl->ops->write_flush)
313 return;
314
315 ctrl->ops->write_flush(ctrl);
316 }
317 EXPORT_SYMBOL_GPL(serdev_device_write_flush);
318
serdev_device_set_baudrate(struct serdev_device * serdev,unsigned int speed)319 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
320 {
321 struct serdev_controller *ctrl = serdev->ctrl;
322
323 if (!ctrl || !ctrl->ops->set_baudrate)
324 return 0;
325
326 return ctrl->ops->set_baudrate(ctrl, speed);
327
328 }
329 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
330
serdev_device_set_flow_control(struct serdev_device * serdev,bool enable)331 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
332 {
333 struct serdev_controller *ctrl = serdev->ctrl;
334
335 if (!ctrl || !ctrl->ops->set_flow_control)
336 return;
337
338 ctrl->ops->set_flow_control(ctrl, enable);
339 }
340 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
341
serdev_device_set_parity(struct serdev_device * serdev,enum serdev_parity parity)342 int serdev_device_set_parity(struct serdev_device *serdev,
343 enum serdev_parity parity)
344 {
345 struct serdev_controller *ctrl = serdev->ctrl;
346
347 if (!ctrl || !ctrl->ops->set_parity)
348 return -EOPNOTSUPP;
349
350 return ctrl->ops->set_parity(ctrl, parity);
351 }
352 EXPORT_SYMBOL_GPL(serdev_device_set_parity);
353
serdev_device_wait_until_sent(struct serdev_device * serdev,long timeout)354 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
355 {
356 struct serdev_controller *ctrl = serdev->ctrl;
357
358 if (!ctrl || !ctrl->ops->wait_until_sent)
359 return;
360
361 ctrl->ops->wait_until_sent(ctrl, timeout);
362 }
363 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
364
serdev_device_get_tiocm(struct serdev_device * serdev)365 int serdev_device_get_tiocm(struct serdev_device *serdev)
366 {
367 struct serdev_controller *ctrl = serdev->ctrl;
368
369 if (!ctrl || !ctrl->ops->get_tiocm)
370 return -EOPNOTSUPP;
371
372 return ctrl->ops->get_tiocm(ctrl);
373 }
374 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
375
serdev_device_set_tiocm(struct serdev_device * serdev,int set,int clear)376 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
377 {
378 struct serdev_controller *ctrl = serdev->ctrl;
379
380 if (!ctrl || !ctrl->ops->set_tiocm)
381 return -EOPNOTSUPP;
382
383 return ctrl->ops->set_tiocm(ctrl, set, clear);
384 }
385 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
386
serdev_device_break_ctl(struct serdev_device * serdev,int break_state)387 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
388 {
389 struct serdev_controller *ctrl = serdev->ctrl;
390
391 if (!ctrl || !ctrl->ops->break_ctl)
392 return -EOPNOTSUPP;
393
394 return ctrl->ops->break_ctl(ctrl, break_state);
395 }
396 EXPORT_SYMBOL_GPL(serdev_device_break_ctl);
397
serdev_drv_probe(struct device * dev)398 static int serdev_drv_probe(struct device *dev)
399 {
400 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
401 int ret;
402
403 ret = dev_pm_domain_attach(dev, true);
404 if (ret)
405 return ret;
406
407 ret = sdrv->probe(to_serdev_device(dev));
408 if (ret)
409 dev_pm_domain_detach(dev, true);
410
411 return ret;
412 }
413
serdev_drv_remove(struct device * dev)414 static void serdev_drv_remove(struct device *dev)
415 {
416 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
417 if (sdrv->remove)
418 sdrv->remove(to_serdev_device(dev));
419
420 dev_pm_domain_detach(dev, true);
421 }
422
423 static const struct bus_type serdev_bus_type = {
424 .name = "serial",
425 .match = serdev_device_match,
426 .probe = serdev_drv_probe,
427 .remove = serdev_drv_remove,
428 };
429
430 /**
431 * serdev_device_alloc() - Allocate a new serdev device
432 * @ctrl: associated controller
433 *
434 * Caller is responsible for either calling serdev_device_add() to add the
435 * newly allocated controller, or calling serdev_device_put() to discard it.
436 */
serdev_device_alloc(struct serdev_controller * ctrl)437 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
438 {
439 struct serdev_device *serdev;
440
441 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
442 if (!serdev)
443 return NULL;
444
445 serdev->ctrl = ctrl;
446 device_initialize(&serdev->dev);
447 serdev->dev.parent = &ctrl->dev;
448 serdev->dev.bus = &serdev_bus_type;
449 serdev->dev.type = &serdev_device_type;
450 init_completion(&serdev->write_comp);
451 mutex_init(&serdev->write_lock);
452 return serdev;
453 }
454 EXPORT_SYMBOL_GPL(serdev_device_alloc);
455
456 /**
457 * serdev_controller_alloc() - Allocate a new serdev controller
458 * @host: serial port hardware controller device
459 * @parent: parent device
460 * @size: size of private data
461 *
462 * Caller is responsible for either calling serdev_controller_add() to add the
463 * newly allocated controller, or calling serdev_controller_put() to discard it.
464 * The allocated private data region may be accessed via
465 * serdev_controller_get_drvdata()
466 */
serdev_controller_alloc(struct device * host,struct device * parent,size_t size)467 struct serdev_controller *serdev_controller_alloc(struct device *host,
468 struct device *parent,
469 size_t size)
470 {
471 struct serdev_controller *ctrl;
472 int id;
473
474 if (WARN_ON(!parent))
475 return NULL;
476
477 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
478 if (!ctrl)
479 return NULL;
480
481 id = ida_alloc(&ctrl_ida, GFP_KERNEL);
482 if (id < 0) {
483 dev_err(parent,
484 "unable to allocate serdev controller identifier.\n");
485 goto err_free;
486 }
487
488 ctrl->nr = id;
489
490 device_initialize(&ctrl->dev);
491 ctrl->dev.type = &serdev_ctrl_type;
492 ctrl->dev.bus = &serdev_bus_type;
493 ctrl->dev.parent = parent;
494 ctrl->host = host;
495 device_set_node(&ctrl->dev, dev_fwnode(host));
496 serdev_controller_set_drvdata(ctrl, &ctrl[1]);
497
498 dev_set_name(&ctrl->dev, "serial%d", id);
499
500 pm_runtime_no_callbacks(&ctrl->dev);
501 pm_suspend_ignore_children(&ctrl->dev, true);
502
503 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
504 return ctrl;
505
506 err_free:
507 kfree(ctrl);
508
509 return NULL;
510 }
511 EXPORT_SYMBOL_GPL(serdev_controller_alloc);
512
of_serdev_register_devices(struct serdev_controller * ctrl)513 static int of_serdev_register_devices(struct serdev_controller *ctrl)
514 {
515 struct device_node *node;
516 struct serdev_device *serdev = NULL;
517 int err;
518 bool found = false;
519
520 for_each_available_child_of_node(ctrl->dev.of_node, node) {
521 if (!of_property_present(node, "compatible"))
522 continue;
523
524 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
525
526 serdev = serdev_device_alloc(ctrl);
527 if (!serdev)
528 continue;
529
530 device_set_node(&serdev->dev, of_fwnode_handle(node));
531
532 err = serdev_device_add(serdev);
533 if (err) {
534 dev_err(&serdev->dev,
535 "failure adding device. status %pe\n",
536 ERR_PTR(err));
537 serdev_device_put(serdev);
538 } else
539 found = true;
540 }
541 if (!found)
542 return -ENODEV;
543
544 return 0;
545 }
546
547 #ifdef CONFIG_ACPI
548
549 #define SERDEV_ACPI_MAX_SCAN_DEPTH 32
550
551 struct acpi_serdev_lookup {
552 acpi_handle device_handle;
553 acpi_handle controller_handle;
554 int n;
555 int index;
556 };
557
558 /**
559 * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
560 * @ares: ACPI resource
561 * @uart: Pointer to UARTSerialBus resource will be returned here
562 *
563 * Checks if the given ACPI resource is of type UARTSerialBus.
564 * In this case, returns a pointer to it to the caller.
565 *
566 * Return: True if resource type is of UARTSerialBus, otherwise false.
567 */
serdev_acpi_get_uart_resource(struct acpi_resource * ares,struct acpi_resource_uart_serialbus ** uart)568 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
569 struct acpi_resource_uart_serialbus **uart)
570 {
571 struct acpi_resource_uart_serialbus *sb;
572
573 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
574 return false;
575
576 sb = &ares->data.uart_serial_bus;
577 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
578 return false;
579
580 *uart = sb;
581 return true;
582 }
583 EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
584
acpi_serdev_parse_resource(struct acpi_resource * ares,void * data)585 static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
586 {
587 struct acpi_serdev_lookup *lookup = data;
588 struct acpi_resource_uart_serialbus *sb;
589 acpi_status status;
590
591 if (!serdev_acpi_get_uart_resource(ares, &sb))
592 return 1;
593
594 if (lookup->index != -1 && lookup->n++ != lookup->index)
595 return 1;
596
597 status = acpi_get_handle(lookup->device_handle,
598 sb->resource_source.string_ptr,
599 &lookup->controller_handle);
600 if (ACPI_FAILURE(status))
601 return 1;
602
603 /*
604 * NOTE: Ideally, we would also want to retrieve other properties here,
605 * once setting them before opening the device is supported by serdev.
606 */
607
608 return 1;
609 }
610
acpi_serdev_do_lookup(struct acpi_device * adev,struct acpi_serdev_lookup * lookup)611 static int acpi_serdev_do_lookup(struct acpi_device *adev,
612 struct acpi_serdev_lookup *lookup)
613 {
614 struct list_head resource_list;
615 int ret;
616
617 lookup->device_handle = acpi_device_handle(adev);
618 lookup->controller_handle = NULL;
619 lookup->n = 0;
620
621 INIT_LIST_HEAD(&resource_list);
622 ret = acpi_dev_get_resources(adev, &resource_list,
623 acpi_serdev_parse_resource, lookup);
624 acpi_dev_free_resource_list(&resource_list);
625
626 if (ret < 0)
627 return -EINVAL;
628
629 return 0;
630 }
631
acpi_serdev_check_resources(struct serdev_controller * ctrl,struct acpi_device * adev)632 static int acpi_serdev_check_resources(struct serdev_controller *ctrl,
633 struct acpi_device *adev)
634 {
635 struct acpi_serdev_lookup lookup;
636 int ret;
637
638 if (acpi_bus_get_status(adev) || !adev->status.present)
639 return -EINVAL;
640
641 /* Look for UARTSerialBusV2 resource */
642 lookup.index = -1; // we only care for the last device
643
644 ret = acpi_serdev_do_lookup(adev, &lookup);
645 if (ret)
646 return ret;
647
648 /*
649 * Apple machines provide an empty resource template, so on those
650 * machines just look for immediate children with a "baud" property
651 * (from the _DSM method) instead.
652 */
653 if (!lookup.controller_handle && x86_apple_machine &&
654 !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL))
655 acpi_get_parent(adev->handle, &lookup.controller_handle);
656
657 /* Make sure controller and ResourceSource handle match */
658 if (!device_match_acpi_handle(ctrl->host, lookup.controller_handle))
659 return -ENODEV;
660
661 return 0;
662 }
663
acpi_serdev_register_device(struct serdev_controller * ctrl,struct acpi_device * adev)664 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
665 struct acpi_device *adev)
666 {
667 struct serdev_device *serdev;
668 int err;
669
670 serdev = serdev_device_alloc(ctrl);
671 if (!serdev) {
672 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
673 dev_name(&adev->dev));
674 return AE_NO_MEMORY;
675 }
676
677 ACPI_COMPANION_SET(&serdev->dev, adev);
678 acpi_device_set_enumerated(adev);
679
680 err = serdev_device_add(serdev);
681 if (err) {
682 dev_err(&serdev->dev,
683 "failure adding ACPI serdev device. status %pe\n",
684 ERR_PTR(err));
685 serdev_device_put(serdev);
686 }
687
688 return AE_OK;
689 }
690
691 static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
692 { "INT3511", 0 },
693 { "INT3512", 0 },
694 { },
695 };
696
acpi_serdev_add_device(acpi_handle handle,u32 level,void * data,void ** return_value)697 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
698 void *data, void **return_value)
699 {
700 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
701 struct serdev_controller *ctrl = data;
702
703 if (!adev || acpi_device_enumerated(adev))
704 return AE_OK;
705
706 /* Skip if black listed */
707 if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
708 return AE_OK;
709
710 if (acpi_serdev_check_resources(ctrl, adev))
711 return AE_OK;
712
713 return acpi_serdev_register_device(ctrl, adev);
714 }
715
716
acpi_serdev_register_devices(struct serdev_controller * ctrl)717 static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
718 {
719 acpi_status status;
720 bool skip;
721 int ret;
722
723 if (!has_acpi_companion(ctrl->host))
724 return -ENODEV;
725
726 /*
727 * Skip registration on boards where the ACPI tables are known to
728 * contain buggy devices. Note serdev_controller_add() must still
729 * succeed in this case, so that the proper serdev devices can be
730 * added "manually" later.
731 */
732 ret = acpi_quirk_skip_serdev_enumeration(ctrl->host, &skip);
733 if (ret)
734 return ret;
735 if (skip)
736 return 0;
737
738 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
739 SERDEV_ACPI_MAX_SCAN_DEPTH,
740 acpi_serdev_add_device, NULL, ctrl, NULL);
741 if (ACPI_FAILURE(status))
742 dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n");
743
744 if (!ctrl->serdev)
745 return -ENODEV;
746
747 return 0;
748 }
749 #else
acpi_serdev_register_devices(struct serdev_controller * ctrl)750 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
751 {
752 return -ENODEV;
753 }
754 #endif /* CONFIG_ACPI */
755
756 /**
757 * serdev_controller_add() - Add an serdev controller
758 * @ctrl: controller to be registered.
759 *
760 * Register a controller previously allocated via serdev_controller_alloc() with
761 * the serdev core.
762 */
serdev_controller_add(struct serdev_controller * ctrl)763 int serdev_controller_add(struct serdev_controller *ctrl)
764 {
765 int ret_of, ret_acpi, ret;
766
767 /* Can't register until after driver model init */
768 if (WARN_ON(!is_registered))
769 return -EAGAIN;
770
771 ret = device_add(&ctrl->dev);
772 if (ret)
773 return ret;
774
775 pm_runtime_enable(&ctrl->dev);
776
777 ret_of = of_serdev_register_devices(ctrl);
778 ret_acpi = acpi_serdev_register_devices(ctrl);
779 if (ret_of && ret_acpi) {
780 dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
781 ERR_PTR(ret_of), ERR_PTR(ret_acpi));
782 ret = -ENODEV;
783 goto err_rpm_disable;
784 }
785
786 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
787 ctrl->nr, &ctrl->dev);
788 return 0;
789
790 err_rpm_disable:
791 pm_runtime_disable(&ctrl->dev);
792 device_del(&ctrl->dev);
793 return ret;
794 };
795 EXPORT_SYMBOL_GPL(serdev_controller_add);
796
797 /* Remove a device associated with a controller */
serdev_remove_device(struct device * dev,void * data)798 static int serdev_remove_device(struct device *dev, void *data)
799 {
800 struct serdev_device *serdev = to_serdev_device(dev);
801 if (dev->type == &serdev_device_type)
802 serdev_device_remove(serdev);
803 return 0;
804 }
805
806 /**
807 * serdev_controller_remove(): remove an serdev controller
808 * @ctrl: controller to remove
809 *
810 * Remove a serdev controller. Caller is responsible for calling
811 * serdev_controller_put() to discard the allocated controller.
812 */
serdev_controller_remove(struct serdev_controller * ctrl)813 void serdev_controller_remove(struct serdev_controller *ctrl)
814 {
815 if (!ctrl)
816 return;
817
818 device_for_each_child(&ctrl->dev, NULL, serdev_remove_device);
819 pm_runtime_disable(&ctrl->dev);
820 device_del(&ctrl->dev);
821 }
822 EXPORT_SYMBOL_GPL(serdev_controller_remove);
823
824 /**
825 * __serdev_device_driver_register() - Register client driver with serdev core
826 * @sdrv: client driver to be associated with client-device.
827 * @owner: client driver owner to set.
828 *
829 * This API will register the client driver with the serdev framework.
830 * It is typically called from the driver's module-init function.
831 */
__serdev_device_driver_register(struct serdev_device_driver * sdrv,struct module * owner)832 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
833 {
834 sdrv->driver.bus = &serdev_bus_type;
835 sdrv->driver.owner = owner;
836
837 /* force drivers to async probe so I/O is possible in probe */
838 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
839
840 return driver_register(&sdrv->driver);
841 }
842 EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
843
serdev_exit(void)844 static void __exit serdev_exit(void)
845 {
846 bus_unregister(&serdev_bus_type);
847 ida_destroy(&ctrl_ida);
848 }
849 module_exit(serdev_exit);
850
serdev_init(void)851 static int __init serdev_init(void)
852 {
853 int ret;
854
855 ret = bus_register(&serdev_bus_type);
856 if (ret)
857 return ret;
858
859 is_registered = true;
860 return 0;
861 }
862 /* Must be before serial drivers register */
863 postcore_initcall(serdev_init);
864
865 MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
866 MODULE_LICENSE("GPL v2");
867 MODULE_DESCRIPTION("Serial attached device bus");
868