drivers/tty/serdev/core.c

   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
  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
  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
  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
  72 static bool is_serdev_device(const struct device *dev)
  73 {
  74         return dev->type == &serdev_device_type;
  75 }
  76
  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
  88 static int serdev_device_match(struct device *dev, 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  */
 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  */
 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
 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
 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
 190 static void devm_serdev_device_close(void *serdev)
 191 {
 192         serdev_device_close(serdev);
 193 }
 194
 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
 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  */
 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  */
 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
 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
 319 int serdev_device_write_room(struct serdev_device *serdev)
 320 {
 321         struct serdev_controller *ctrl = serdev->ctrl;
 322
 323         if (!ctrl || !ctrl->ops->write_room)
 324                 return 0;
 325
 326         return serdev->ctrl->ops->write_room(ctrl);
 327 }
 328 EXPORT_SYMBOL_GPL(serdev_device_write_room);
 329
 330 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
 331 {
 332         struct serdev_controller *ctrl = serdev->ctrl;
 333
 334         if (!ctrl || !ctrl->ops->set_baudrate)
 335                 return 0;
 336
 337         return ctrl->ops->set_baudrate(ctrl, speed);
 338
 339 }
 340 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
 341
 342 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
 343 {
 344         struct serdev_controller *ctrl = serdev->ctrl;
 345
 346         if (!ctrl || !ctrl->ops->set_flow_control)
 347                 return;
 348
 349         ctrl->ops->set_flow_control(ctrl, enable);
 350 }
 351 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
 352
 353 int serdev_device_set_parity(struct serdev_device *serdev,
 354                              enum serdev_parity parity)
 355 {
 356         struct serdev_controller *ctrl = serdev->ctrl;
 357
 358         if (!ctrl || !ctrl->ops->set_parity)
 359                 return -EOPNOTSUPP;
 360
 361         return ctrl->ops->set_parity(ctrl, parity);
 362 }
 363 EXPORT_SYMBOL_GPL(serdev_device_set_parity);
 364
 365 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
 366 {
 367         struct serdev_controller *ctrl = serdev->ctrl;
 368
 369         if (!ctrl || !ctrl->ops->wait_until_sent)
 370                 return;
 371
 372         ctrl->ops->wait_until_sent(ctrl, timeout);
 373 }
 374 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
 375
 376 int serdev_device_get_tiocm(struct serdev_device *serdev)
 377 {
 378         struct serdev_controller *ctrl = serdev->ctrl;
 379
 380         if (!ctrl || !ctrl->ops->get_tiocm)
 381                 return -EOPNOTSUPP;
 382
 383         return ctrl->ops->get_tiocm(ctrl);
 384 }
 385 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
 386
 387 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
 388 {
 389         struct serdev_controller *ctrl = serdev->ctrl;
 390
 391         if (!ctrl || !ctrl->ops->set_tiocm)
 392                 return -EOPNOTSUPP;
 393
 394         return ctrl->ops->set_tiocm(ctrl, set, clear);
 395 }
 396 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
 397
 398 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
 399 {
 400         struct serdev_controller *ctrl = serdev->ctrl;
 401
 402         if (!ctrl || !ctrl->ops->break_ctl)
 403                 return -EOPNOTSUPP;
 404
 405         return ctrl->ops->break_ctl(ctrl, break_state);
 406 }
 407 EXPORT_SYMBOL_GPL(serdev_device_break_ctl);
 408
 409 static int serdev_drv_probe(struct device *dev)
 410 {
 411         const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
 412         int ret;
 413
 414         ret = dev_pm_domain_attach(dev, true);
 415         if (ret)
 416                 return ret;
 417
 418         ret = sdrv->probe(to_serdev_device(dev));
 419         if (ret)
 420                 dev_pm_domain_detach(dev, true);
 421
 422         return ret;
 423 }
 424
 425 static void serdev_drv_remove(struct device *dev)
 426 {
 427         const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
 428         if (sdrv->remove)
 429                 sdrv->remove(to_serdev_device(dev));
 430
 431         dev_pm_domain_detach(dev, true);
 432 }
 433
 434 static 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  */
 448 struct 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 }
 465 EXPORT_SYMBOL_GPL(serdev_device_alloc);
 466
 467 /**
 468  * serdev_controller_alloc() - Allocate a new serdev controller
 469  * @host:       serial port hardware controller device
 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  */
 478 struct serdev_controller *serdev_controller_alloc(struct device *host,
 479                                                   struct device *parent,
 480                                                   size_t size)
 481 {
 482         struct serdev_controller *ctrl;
 483         int id;
 484
 485         if (WARN_ON(!parent))
 486                 return NULL;
 487
 488         ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
 489         if (!ctrl)
 490                 return NULL;
 491
 492         id = ida_alloc(&ctrl_ida, GFP_KERNEL);
 493         if (id < 0) {
 494                 dev_err(parent,
 495                         "unable to allocate serdev controller identifier.\n");
 496                 goto err_free;
 497         }
 498
 499         ctrl->nr = id;
 500
 501         device_initialize(&ctrl->dev);
 502         ctrl->dev.type = &serdev_ctrl_type;
 503         ctrl->dev.bus = &serdev_bus_type;
 504         ctrl->dev.parent = parent;
 505         ctrl->host = host;
 506         device_set_node(&ctrl->dev, dev_fwnode(host));
 507         serdev_controller_set_drvdata(ctrl, &ctrl[1]);
 508
 509         dev_set_name(&ctrl->dev, "serial%d", id);
 510
 511         pm_runtime_no_callbacks(&ctrl->dev);
 512         pm_suspend_ignore_children(&ctrl->dev, true);
 513
 514         dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
 515         return ctrl;
 516
 517 err_free:
 518         kfree(ctrl);
 519
 520         return NULL;
 521 }
 522 EXPORT_SYMBOL_GPL(serdev_controller_alloc);
 523
 524 static int of_serdev_register_devices(struct serdev_controller *ctrl)
 525 {
 526         struct device_node *node;
 527         struct serdev_device *serdev = NULL;
 528         int err;
 529         bool found = false;
 530
 531         for_each_available_child_of_node(ctrl->dev.of_node, node) {
 532                 if (!of_get_property(node, "compatible", NULL))
 533                         continue;
 534
 535                 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
 536
 537                 serdev = serdev_device_alloc(ctrl);
 538                 if (!serdev)
 539                         continue;
 540
 541                 device_set_node(&serdev->dev, of_fwnode_handle(node));
 542
 543                 err = serdev_device_add(serdev);
 544                 if (err) {
 545                         dev_err(&serdev->dev,
 546                                 "failure adding device. status %pe\n",
 547                                 ERR_PTR(err));
 548                         serdev_device_put(serdev);
 549                 } else
 550                         found = true;
 551         }
 552         if (!found)
 553                 return -ENODEV;
 554
 555         return 0;
 556 }
 557
 558 #ifdef CONFIG_ACPI
 559
 560 #define SERDEV_ACPI_MAX_SCAN_DEPTH 32
 561
 562 struct acpi_serdev_lookup {
 563         acpi_handle device_handle;
 564         acpi_handle controller_handle;
 565         int n;
 566         int index;
 567 };
 568
 569 /**
 570  * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
 571  * @ares:       ACPI resource
 572  * @uart:       Pointer to UARTSerialBus resource will be returned here
 573  *
 574  * Checks if the given ACPI resource is of type UARTSerialBus.
 575  * In this case, returns a pointer to it to the caller.
 576  *
 577  * Return: True if resource type is of UARTSerialBus, otherwise false.
 578  */
 579 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 580                                    struct acpi_resource_uart_serialbus **uart)
 581 {
 582         struct acpi_resource_uart_serialbus *sb;
 583
 584         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
 585                 return false;
 586
 587         sb = &ares->data.uart_serial_bus;
 588         if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
 589                 return false;
 590
 591         *uart = sb;
 592         return true;
 593 }
 594 EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
 595
 596 static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
 597 {
 598         struct acpi_serdev_lookup *lookup = data;
 599         struct acpi_resource_uart_serialbus *sb;
 600         acpi_status status;
 601
 602         if (!serdev_acpi_get_uart_resource(ares, &sb))
 603                 return 1;
 604
 605         if (lookup->index != -1 && lookup->n++ != lookup->index)
 606                 return 1;
 607
 608         status = acpi_get_handle(lookup->device_handle,
 609                                  sb->resource_source.string_ptr,
 610                                  &lookup->controller_handle);
 611         if (ACPI_FAILURE(status))
 612                 return 1;
 613
 614         /*
 615          * NOTE: Ideally, we would also want to retrieve other properties here,
 616          * once setting them before opening the device is supported by serdev.
 617          */
 618
 619         return 1;
 620 }
 621
 622 static int acpi_serdev_do_lookup(struct acpi_device *adev,
 623                                  struct acpi_serdev_lookup *lookup)
 624 {
 625         struct list_head resource_list;
 626         int ret;
 627
 628         lookup->device_handle = acpi_device_handle(adev);
 629         lookup->controller_handle = NULL;
 630         lookup->n = 0;
 631
 632         INIT_LIST_HEAD(&resource_list);
 633         ret = acpi_dev_get_resources(adev, &resource_list,
 634                                      acpi_serdev_parse_resource, lookup);
 635         acpi_dev_free_resource_list(&resource_list);
 636
 637         if (ret < 0)
 638                 return -EINVAL;
 639
 640         return 0;
 641 }
 642
 643 static int acpi_serdev_check_resources(struct serdev_controller *ctrl,
 644                                        struct acpi_device *adev)
 645 {
 646         struct acpi_serdev_lookup lookup;
 647         int ret;
 648
 649         if (acpi_bus_get_status(adev) || !adev->status.present)
 650                 return -EINVAL;
 651
 652         /* Look for UARTSerialBusV2 resource */
 653         lookup.index = -1;      // we only care for the last device
 654
 655         ret = acpi_serdev_do_lookup(adev, &lookup);
 656         if (ret)
 657                 return ret;
 658
 659         /*
 660          * Apple machines provide an empty resource template, so on those
 661          * machines just look for immediate children with a "baud" property
 662          * (from the _DSM method) instead.
 663          */
 664         if (!lookup.controller_handle && x86_apple_machine &&
 665             !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL))
 666                 acpi_get_parent(adev->handle, &lookup.controller_handle);
 667
 668         /* Make sure controller and ResourceSource handle match */
 669         if (!device_match_acpi_handle(ctrl->host, lookup.controller_handle))
 670                 return -ENODEV;
 671
 672         return 0;
 673 }
 674
 675 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
 676                                                struct acpi_device *adev)
 677 {
 678         struct serdev_device *serdev;
 679         int err;
 680
 681         serdev = serdev_device_alloc(ctrl);
 682         if (!serdev) {
 683                 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
 684                         dev_name(&adev->dev));
 685                 return AE_NO_MEMORY;
 686         }
 687
 688         ACPI_COMPANION_SET(&serdev->dev, adev);
 689         acpi_device_set_enumerated(adev);
 690
 691         err = serdev_device_add(serdev);
 692         if (err) {
 693                 dev_err(&serdev->dev,
 694                         "failure adding ACPI serdev device. status %pe\n",
 695                         ERR_PTR(err));
 696                 serdev_device_put(serdev);
 697         }
 698
 699         return AE_OK;
 700 }
 701
 702 static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
 703         { "INT3511", 0 },
 704         { "INT3512", 0 },
 705         { },
 706 };
 707
 708 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
 709                                           void *data, void **return_value)
 710 {
 711         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 712         struct serdev_controller *ctrl = data;
 713
 714         if (!adev || acpi_device_enumerated(adev))
 715                 return AE_OK;
 716
 717         /* Skip if black listed */
 718         if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
 719                 return AE_OK;
 720
 721         if (acpi_serdev_check_resources(ctrl, adev))
 722                 return AE_OK;
 723
 724         return acpi_serdev_register_device(ctrl, adev);
 725 }
 726
 727
 728 static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
 729 {
 730         acpi_status status;
 731         bool skip;
 732         int ret;
 733
 734         if (!has_acpi_companion(ctrl->host))
 735                 return -ENODEV;
 736
 737         /*
 738          * Skip registration on boards where the ACPI tables are known to
 739          * contain buggy devices. Note serdev_controller_add() must still
 740          * succeed in this case, so that the proper serdev devices can be
 741          * added "manually" later.
 742          */
 743         ret = acpi_quirk_skip_serdev_enumeration(ctrl->host, &skip);
 744         if (ret)
 745                 return ret;
 746         if (skip)
 747                 return 0;
 748
 749         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 750                                      SERDEV_ACPI_MAX_SCAN_DEPTH,
 751                                      acpi_serdev_add_device, NULL, ctrl, NULL);
 752         if (ACPI_FAILURE(status))
 753                 dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n");
 754
 755         if (!ctrl->serdev)
 756                 return -ENODEV;
 757
 758         return 0;
 759 }
 760 #else
 761 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
 762 {
 763         return -ENODEV;
 764 }
 765 #endif /* CONFIG_ACPI */
 766
 767 /**
 768  * serdev_controller_add() - Add an serdev controller
 769  * @ctrl:       controller to be registered.
 770  *
 771  * Register a controller previously allocated via serdev_controller_alloc() with
 772  * the serdev core.
 773  */
 774 int serdev_controller_add(struct serdev_controller *ctrl)
 775 {
 776         int ret_of, ret_acpi, ret;
 777
 778         /* Can't register until after driver model init */
 779         if (WARN_ON(!is_registered))
 780                 return -EAGAIN;
 781
 782         ret = device_add(&ctrl->dev);
 783         if (ret)
 784                 return ret;
 785
 786         pm_runtime_enable(&ctrl->dev);
 787
 788         ret_of = of_serdev_register_devices(ctrl);
 789         ret_acpi = acpi_serdev_register_devices(ctrl);
 790         if (ret_of && ret_acpi) {
 791                 dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
 792                         ERR_PTR(ret_of), ERR_PTR(ret_acpi));
 793                 ret = -ENODEV;
 794                 goto err_rpm_disable;
 795         }
 796
 797         dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
 798                 ctrl->nr, &ctrl->dev);
 799         return 0;
 800
 801 err_rpm_disable:
 802         pm_runtime_disable(&ctrl->dev);
 803         device_del(&ctrl->dev);
 804         return ret;
 805 };
 806 EXPORT_SYMBOL_GPL(serdev_controller_add);
 807
 808 /* Remove a device associated with a controller */
 809 static int serdev_remove_device(struct device *dev, void *data)
 810 {
 811         struct serdev_device *serdev = to_serdev_device(dev);
 812         if (dev->type == &serdev_device_type)
 813                 serdev_device_remove(serdev);
 814         return 0;
 815 }
 816
 817 /**
 818  * serdev_controller_remove(): remove an serdev controller
 819  * @ctrl:       controller to remove
 820  *
 821  * Remove a serdev controller.  Caller is responsible for calling
 822  * serdev_controller_put() to discard the allocated controller.
 823  */
 824 void serdev_controller_remove(struct serdev_controller *ctrl)
 825 {
 826         if (!ctrl)
 827                 return;
 828
 829         device_for_each_child(&ctrl->dev, NULL, serdev_remove_device);
 830         pm_runtime_disable(&ctrl->dev);
 831         device_del(&ctrl->dev);
 832 }
 833 EXPORT_SYMBOL_GPL(serdev_controller_remove);
 834
 835 /**
 836  * __serdev_device_driver_register() - Register client driver with serdev core
 837  * @sdrv:       client driver to be associated with client-device.
 838  * @owner:      client driver owner to set.
 839  *
 840  * This API will register the client driver with the serdev framework.
 841  * It is typically called from the driver's module-init function.
 842  */
 843 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
 844 {
 845         sdrv->driver.bus = &serdev_bus_type;
 846         sdrv->driver.owner = owner;
 847
 848         /* force drivers to async probe so I/O is possible in probe */
 849         sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
 850
 851         return driver_register(&sdrv->driver);
 852 }
 853 EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
 854
 855 static void __exit serdev_exit(void)
 856 {
 857         bus_unregister(&serdev_bus_type);
 858         ida_destroy(&ctrl_ida);
 859 }
 860 module_exit(serdev_exit);
 861
 862 static int __init serdev_init(void)
 863 {
 864         int ret;
 865
 866         ret = bus_register(&serdev_bus_type);
 867         if (ret)
 868                 return ret;
 869
 870         is_registered = true;
 871         return 0;
 872 }
 873 /* Must be before serial drivers register */
 874 postcore_initcall(serdev_init);
 875
 876 MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
 877 MODULE_LICENSE("GPL v2");
 878 MODULE_DESCRIPTION("Serial attached device bus");