drivers/tty/serdev/core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <[email protected]>
   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_simple_remove(&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,
 229                             const unsigned char *buf, size_t count)
 230 {
 231         struct serdev_controller *ctrl = serdev->ctrl;
 232
 233         if (!ctrl || !ctrl->ops->write_buf)
 234                 return -EINVAL;
 235
 236         return ctrl->ops->write_buf(ctrl, buf, count);
 237 }
 238 EXPORT_SYMBOL_GPL(serdev_device_write_buf);
 239
 240 /**
 241  * serdev_device_write() - write data synchronously
 242  * @serdev:     serdev device
 243  * @buf:        data to be written
 244  * @count:      number of bytes to write
 245  * @timeout:    timeout in jiffies, or 0 to wait indefinitely
 246  *
 247  * Write data to the device synchronously by repeatedly calling
 248  * serdev_device_write() until the controller has accepted all data (unless
 249  * interrupted by a timeout or a signal).
 250  *
 251  * Note that any accepted data has only been buffered by the controller; use
 252  * serdev_device_wait_until_sent() to make sure the controller write buffer
 253  * has actually been emptied.
 254  *
 255  * Note that this function depends on serdev_device_write_wakeup() being
 256  * called in the serdev driver write_wakeup() callback.
 257  *
 258  * Return: The number of bytes written (less than count if interrupted),
 259  * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
 260  * a negative errno on errors.
 261  */
 262 int serdev_device_write(struct serdev_device *serdev,
 263                         const unsigned char *buf, size_t count,
 264                         long timeout)
 265 {
 266         struct serdev_controller *ctrl = serdev->ctrl;
 267         int written = 0;
 268         int ret;
 269
 270         if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
 271                 return -EINVAL;
 272
 273         if (timeout == 0)
 274                 timeout = MAX_SCHEDULE_TIMEOUT;
 275
 276         mutex_lock(&serdev->write_lock);
 277         do {
 278                 reinit_completion(&serdev->write_comp);
 279
 280                 ret = ctrl->ops->write_buf(ctrl, buf, count);
 281                 if (ret < 0)
 282                         break;
 283
 284                 written += ret;
 285                 buf += ret;
 286                 count -= ret;
 287
 288                 if (count == 0)
 289                         break;
 290
 291                 timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
 292                                                                     timeout);
 293         } while (timeout > 0);
 294         mutex_unlock(&serdev->write_lock);
 295
 296         if (ret < 0)
 297                 return ret;
 298
 299         if (timeout <= 0 && written == 0) {
 300                 if (timeout == -ERESTARTSYS)
 301                         return -ERESTARTSYS;
 302                 else
 303                         return -ETIMEDOUT;
 304         }
 305
 306         return written;
 307 }
 308 EXPORT_SYMBOL_GPL(serdev_device_write);
 309
 310 void serdev_device_write_flush(struct serdev_device *serdev)
 311 {
 312         struct serdev_controller *ctrl = serdev->ctrl;
 313
 314         if (!ctrl || !ctrl->ops->write_flush)
 315                 return;
 316
 317         ctrl->ops->write_flush(ctrl);
 318 }
 319 EXPORT_SYMBOL_GPL(serdev_device_write_flush);
 320
 321 int serdev_device_write_room(struct serdev_device *serdev)
 322 {
 323         struct serdev_controller *ctrl = serdev->ctrl;
 324
 325         if (!ctrl || !ctrl->ops->write_room)
 326                 return 0;
 327
 328         return serdev->ctrl->ops->write_room(ctrl);
 329 }
 330 EXPORT_SYMBOL_GPL(serdev_device_write_room);
 331
 332 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
 333 {
 334         struct serdev_controller *ctrl = serdev->ctrl;
 335
 336         if (!ctrl || !ctrl->ops->set_baudrate)
 337                 return 0;
 338
 339         return ctrl->ops->set_baudrate(ctrl, speed);
 340
 341 }
 342 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
 343
 344 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
 345 {
 346         struct serdev_controller *ctrl = serdev->ctrl;
 347
 348         if (!ctrl || !ctrl->ops->set_flow_control)
 349                 return;
 350
 351         ctrl->ops->set_flow_control(ctrl, enable);
 352 }
 353 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
 354
 355 int serdev_device_set_parity(struct serdev_device *serdev,
 356                              enum serdev_parity parity)
 357 {
 358         struct serdev_controller *ctrl = serdev->ctrl;
 359
 360         if (!ctrl || !ctrl->ops->set_parity)
 361                 return -EOPNOTSUPP;
 362
 363         return ctrl->ops->set_parity(ctrl, parity);
 364 }
 365 EXPORT_SYMBOL_GPL(serdev_device_set_parity);
 366
 367 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
 368 {
 369         struct serdev_controller *ctrl = serdev->ctrl;
 370
 371         if (!ctrl || !ctrl->ops->wait_until_sent)
 372                 return;
 373
 374         ctrl->ops->wait_until_sent(ctrl, timeout);
 375 }
 376 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
 377
 378 int serdev_device_get_tiocm(struct serdev_device *serdev)
 379 {
 380         struct serdev_controller *ctrl = serdev->ctrl;
 381
 382         if (!ctrl || !ctrl->ops->get_tiocm)
 383                 return -EOPNOTSUPP;
 384
 385         return ctrl->ops->get_tiocm(ctrl);
 386 }
 387 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
 388
 389 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
 390 {
 391         struct serdev_controller *ctrl = serdev->ctrl;
 392
 393         if (!ctrl || !ctrl->ops->set_tiocm)
 394                 return -EOPNOTSUPP;
 395
 396         return ctrl->ops->set_tiocm(ctrl, set, clear);
 397 }
 398 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
 399
 400 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
 401 {
 402         struct serdev_controller *ctrl = serdev->ctrl;
 403
 404         if (!ctrl || !ctrl->ops->break_ctl)
 405                 return -EOPNOTSUPP;
 406
 407         return ctrl->ops->break_ctl(ctrl, break_state);
 408 }
 409 EXPORT_SYMBOL_GPL(serdev_device_break_ctl);
 410
 411 static int serdev_drv_probe(struct device *dev)
 412 {
 413         const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
 414         int ret;
 415
 416         ret = dev_pm_domain_attach(dev, true);
 417         if (ret)
 418                 return ret;
 419
 420         ret = sdrv->probe(to_serdev_device(dev));
 421         if (ret)
 422                 dev_pm_domain_detach(dev, true);
 423
 424         return ret;
 425 }
 426
 427 static void serdev_drv_remove(struct device *dev)
 428 {
 429         const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
 430         if (sdrv->remove)
 431                 sdrv->remove(to_serdev_device(dev));
 432
 433         dev_pm_domain_detach(dev, true);
 434 }
 435
 436 static struct bus_type serdev_bus_type = {
 437         .name           = "serial",
 438         .match          = serdev_device_match,
 439         .probe          = serdev_drv_probe,
 440         .remove         = serdev_drv_remove,
 441 };
 442
 443 /**
 444  * serdev_device_alloc() - Allocate a new serdev device
 445  * @ctrl:       associated controller
 446  *
 447  * Caller is responsible for either calling serdev_device_add() to add the
 448  * newly allocated controller, or calling serdev_device_put() to discard it.
 449  */
 450 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
 451 {
 452         struct serdev_device *serdev;
 453
 454         serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
 455         if (!serdev)
 456                 return NULL;
 457
 458         serdev->ctrl = ctrl;
 459         device_initialize(&serdev->dev);
 460         serdev->dev.parent = &ctrl->dev;
 461         serdev->dev.bus = &serdev_bus_type;
 462         serdev->dev.type = &serdev_device_type;
 463         init_completion(&serdev->write_comp);
 464         mutex_init(&serdev->write_lock);
 465         return serdev;
 466 }
 467 EXPORT_SYMBOL_GPL(serdev_device_alloc);
 468
 469 /**
 470  * serdev_controller_alloc() - Allocate a new serdev controller
 471  * @parent:     parent device
 472  * @size:       size of private data
 473  *
 474  * Caller is responsible for either calling serdev_controller_add() to add the
 475  * newly allocated controller, or calling serdev_controller_put() to discard it.
 476  * The allocated private data region may be accessed via
 477  * serdev_controller_get_drvdata()
 478  */
 479 struct serdev_controller *serdev_controller_alloc(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_simple_get(&ctrl_ida, 0, 0, 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         device_set_node(&ctrl->dev, dev_fwnode(parent));
 506         serdev_controller_set_drvdata(ctrl, &ctrl[1]);
 507
 508         dev_set_name(&ctrl->dev, "serial%d", id);
 509
 510         pm_runtime_no_callbacks(&ctrl->dev);
 511         pm_suspend_ignore_children(&ctrl->dev, true);
 512
 513         dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
 514         return ctrl;
 515
 516 err_free:
 517         kfree(ctrl);
 518
 519         return NULL;
 520 }
 521 EXPORT_SYMBOL_GPL(serdev_controller_alloc);
 522
 523 static int of_serdev_register_devices(struct serdev_controller *ctrl)
 524 {
 525         struct device_node *node;
 526         struct serdev_device *serdev = NULL;
 527         int err;
 528         bool found = false;
 529
 530         for_each_available_child_of_node(ctrl->dev.of_node, node) {
 531                 if (!of_get_property(node, "compatible", NULL))
 532                         continue;
 533
 534                 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
 535
 536                 serdev = serdev_device_alloc(ctrl);
 537                 if (!serdev)
 538                         continue;
 539
 540                 device_set_node(&serdev->dev, of_fwnode_handle(node));
 541
 542                 err = serdev_device_add(serdev);
 543                 if (err) {
 544                         dev_err(&serdev->dev,
 545                                 "failure adding device. status %pe\n",
 546                                 ERR_PTR(err));
 547                         serdev_device_put(serdev);
 548                 } else
 549                         found = true;
 550         }
 551         if (!found)
 552                 return -ENODEV;
 553
 554         return 0;
 555 }
 556
 557 #ifdef CONFIG_ACPI
 558
 559 #define SERDEV_ACPI_MAX_SCAN_DEPTH 32
 560
 561 struct acpi_serdev_lookup {
 562         acpi_handle device_handle;
 563         acpi_handle controller_handle;
 564         int n;
 565         int index;
 566 };
 567
 568 /**
 569  * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
 570  * @ares:       ACPI resource
 571  * @uart:       Pointer to UARTSerialBus resource will be returned here
 572  *
 573  * Checks if the given ACPI resource is of type UARTSerialBus.
 574  * In this case, returns a pointer to it to the caller.
 575  *
 576  * Return: True if resource type is of UARTSerialBus, otherwise false.
 577  */
 578 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 579                                    struct acpi_resource_uart_serialbus **uart)
 580 {
 581         struct acpi_resource_uart_serialbus *sb;
 582
 583         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
 584                 return false;
 585
 586         sb = &ares->data.uart_serial_bus;
 587         if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
 588                 return false;
 589
 590         *uart = sb;
 591         return true;
 592 }
 593 EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
 594
 595 static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
 596 {
 597         struct acpi_serdev_lookup *lookup = data;
 598         struct acpi_resource_uart_serialbus *sb;
 599         acpi_status status;
 600
 601         if (!serdev_acpi_get_uart_resource(ares, &sb))
 602                 return 1;
 603
 604         if (lookup->index != -1 && lookup->n++ != lookup->index)
 605                 return 1;
 606
 607         status = acpi_get_handle(lookup->device_handle,
 608                                  sb->resource_source.string_ptr,
 609                                  &lookup->controller_handle);
 610         if (ACPI_FAILURE(status))
 611                 return 1;
 612
 613         /*
 614          * NOTE: Ideally, we would also want to retrieve other properties here,
 615          * once setting them before opening the device is supported by serdev.
 616          */
 617
 618         return 1;
 619 }
 620
 621 static int acpi_serdev_do_lookup(struct acpi_device *adev,
 622                                  struct acpi_serdev_lookup *lookup)
 623 {
 624         struct list_head resource_list;
 625         int ret;
 626
 627         lookup->device_handle = acpi_device_handle(adev);
 628         lookup->controller_handle = NULL;
 629         lookup->n = 0;
 630
 631         INIT_LIST_HEAD(&resource_list);
 632         ret = acpi_dev_get_resources(adev, &resource_list,
 633                                      acpi_serdev_parse_resource, lookup);
 634         acpi_dev_free_resource_list(&resource_list);
 635
 636         if (ret < 0)
 637                 return -EINVAL;
 638
 639         return 0;
 640 }
 641
 642 static int acpi_serdev_check_resources(struct serdev_controller *ctrl,
 643                                        struct acpi_device *adev)
 644 {
 645         struct acpi_serdev_lookup lookup;
 646         int ret;
 647
 648         if (acpi_bus_get_status(adev) || !adev->status.present)
 649                 return -EINVAL;
 650
 651         /* Look for UARTSerialBusV2 resource */
 652         lookup.index = -1;      // we only care for the last device
 653
 654         ret = acpi_serdev_do_lookup(adev, &lookup);
 655         if (ret)
 656                 return ret;
 657
 658         /*
 659          * Apple machines provide an empty resource template, so on those
 660          * machines just look for immediate children with a "baud" property
 661          * (from the _DSM method) instead.
 662          */
 663         if (!lookup.controller_handle && x86_apple_machine &&
 664             !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL))
 665                 acpi_get_parent(adev->handle, &lookup.controller_handle);
 666
 667         /* Make sure controller and ResourceSource handle match */
 668         if (!device_match_acpi_handle(ctrl->dev.parent, lookup.controller_handle))
 669                 return -ENODEV;
 670
 671         return 0;
 672 }
 673
 674 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
 675                                                struct acpi_device *adev)
 676 {
 677         struct serdev_device *serdev;
 678         int err;
 679
 680         serdev = serdev_device_alloc(ctrl);
 681         if (!serdev) {
 682                 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
 683                         dev_name(&adev->dev));
 684                 return AE_NO_MEMORY;
 685         }
 686
 687         ACPI_COMPANION_SET(&serdev->dev, adev);
 688         acpi_device_set_enumerated(adev);
 689
 690         err = serdev_device_add(serdev);
 691         if (err) {
 692                 dev_err(&serdev->dev,
 693                         "failure adding ACPI serdev device. status %pe\n",
 694                         ERR_PTR(err));
 695                 serdev_device_put(serdev);
 696         }
 697
 698         return AE_OK;
 699 }
 700
 701 static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
 702         { "INT3511", 0 },
 703         { "INT3512", 0 },
 704         { },
 705 };
 706
 707 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
 708                                           void *data, void **return_value)
 709 {
 710         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 711         struct serdev_controller *ctrl = data;
 712
 713         if (!adev || acpi_device_enumerated(adev))
 714                 return AE_OK;
 715
 716         /* Skip if black listed */
 717         if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
 718                 return AE_OK;
 719
 720         if (acpi_serdev_check_resources(ctrl, adev))
 721                 return AE_OK;
 722
 723         return acpi_serdev_register_device(ctrl, adev);
 724 }
 725
 726
 727 static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
 728 {
 729         acpi_status status;
 730         bool skip;
 731         int ret;
 732
 733         if (!has_acpi_companion(ctrl->dev.parent))
 734                 return -ENODEV;
 735
 736         /*
 737          * Skip registration on boards where the ACPI tables are known to
 738          * contain buggy devices. Note serdev_controller_add() must still
 739          * succeed in this case, so that the proper serdev devices can be
 740          * added "manually" later.
 741          */
 742         ret = acpi_quirk_skip_serdev_enumeration(ctrl->dev.parent, &skip);
 743         if (ret)
 744                 return ret;
 745         if (skip)
 746                 return 0;
 747
 748         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 749                                      SERDEV_ACPI_MAX_SCAN_DEPTH,
 750                                      acpi_serdev_add_device, NULL, ctrl, NULL);
 751         if (ACPI_FAILURE(status))
 752                 dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n");
 753
 754         if (!ctrl->serdev)
 755                 return -ENODEV;
 756
 757         return 0;
 758 }
 759 #else
 760 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
 761 {
 762         return -ENODEV;
 763 }
 764 #endif /* CONFIG_ACPI */
 765
 766 /**
 767  * serdev_controller_add() - Add an serdev controller
 768  * @ctrl:       controller to be registered.
 769  *
 770  * Register a controller previously allocated via serdev_controller_alloc() with
 771  * the serdev core.
 772  */
 773 int serdev_controller_add(struct serdev_controller *ctrl)
 774 {
 775         int ret_of, ret_acpi, ret;
 776
 777         /* Can't register until after driver model init */
 778         if (WARN_ON(!is_registered))
 779                 return -EAGAIN;
 780
 781         ret = device_add(&ctrl->dev);
 782         if (ret)
 783                 return ret;
 784
 785         pm_runtime_enable(&ctrl->dev);
 786
 787         ret_of = of_serdev_register_devices(ctrl);
 788         ret_acpi = acpi_serdev_register_devices(ctrl);
 789         if (ret_of && ret_acpi) {
 790                 dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
 791                         ERR_PTR(ret_of), ERR_PTR(ret_acpi));
 792                 ret = -ENODEV;
 793                 goto err_rpm_disable;
 794         }
 795
 796         dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
 797                 ctrl->nr, &ctrl->dev);
 798         return 0;
 799
 800 err_rpm_disable:
 801         pm_runtime_disable(&ctrl->dev);
 802         device_del(&ctrl->dev);
 803         return ret;
 804 };
 805 EXPORT_SYMBOL_GPL(serdev_controller_add);
 806
 807 /* Remove a device associated with a controller */
 808 static int serdev_remove_device(struct device *dev, void *data)
 809 {
 810         struct serdev_device *serdev = to_serdev_device(dev);
 811         if (dev->type == &serdev_device_type)
 812                 serdev_device_remove(serdev);
 813         return 0;
 814 }
 815
 816 /**
 817  * serdev_controller_remove(): remove an serdev controller
 818  * @ctrl:       controller to remove
 819  *
 820  * Remove a serdev controller.  Caller is responsible for calling
 821  * serdev_controller_put() to discard the allocated controller.
 822  */
 823 void serdev_controller_remove(struct serdev_controller *ctrl)
 824 {
 825         if (!ctrl)
 826                 return;
 827
 828         device_for_each_child(&ctrl->dev, NULL, serdev_remove_device);
 829         pm_runtime_disable(&ctrl->dev);
 830         device_del(&ctrl->dev);
 831 }
 832 EXPORT_SYMBOL_GPL(serdev_controller_remove);
 833
 834 /**
 835  * __serdev_device_driver_register() - Register client driver with serdev core
 836  * @sdrv:       client driver to be associated with client-device.
 837  * @owner:      client driver owner to set.
 838  *
 839  * This API will register the client driver with the serdev framework.
 840  * It is typically called from the driver's module-init function.
 841  */
 842 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
 843 {
 844         sdrv->driver.bus = &serdev_bus_type;
 845         sdrv->driver.owner = owner;
 846
 847         /* force drivers to async probe so I/O is possible in probe */
 848         sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
 849
 850         return driver_register(&sdrv->driver);
 851 }
 852 EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
 853
 854 static void __exit serdev_exit(void)
 855 {
 856         bus_unregister(&serdev_bus_type);
 857         ida_destroy(&ctrl_ida);
 858 }
 859 module_exit(serdev_exit);
 860
 861 static int __init serdev_init(void)
 862 {
 863         int ret;
 864
 865         ret = bus_register(&serdev_bus_type);
 866         if (ret)
 867                 return ret;
 868
 869         is_registered = true;
 870         return 0;
 871 }
 872 /* Must be before serial drivers register */
 873 postcore_initcall(serdev_init);
 874
 875 MODULE_AUTHOR("Rob Herring <[email protected]>");
 876 MODULE_LICENSE("GPL v2");
 877 MODULE_DESCRIPTION("Serial attached device bus");