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/serdev.h> 19 #include <linux/slab.h> 20 21 static bool is_registered; 22 static DEFINE_IDA(ctrl_ida); 23 24 static ssize_t modalias_show(struct device *dev, 25 struct device_attribute *attr, char *buf) 26 { 27 int len; 28 29 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 30 if (len != -ENODEV) 31 return len; 32 33 return of_device_modalias(dev, buf, PAGE_SIZE); 34 } 35 static DEVICE_ATTR_RO(modalias); 36 37 static struct attribute *serdev_device_attrs[] = { 38 &dev_attr_modalias.attr, 39 NULL, 40 }; 41 ATTRIBUTE_GROUPS(serdev_device); 42 43 static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env) 44 { 45 int rc; 46 47 /* TODO: platform modalias */ 48 49 rc = acpi_device_uevent_modalias(dev, env); 50 if (rc != -ENODEV) 51 return rc; 52 53 return of_device_uevent_modalias(dev, env); 54 } 55 56 static void serdev_device_release(struct device *dev) 57 { 58 struct serdev_device *serdev = to_serdev_device(dev); 59 kfree(serdev); 60 } 61 62 static const struct device_type serdev_device_type = { 63 .groups = serdev_device_groups, 64 .uevent = serdev_device_uevent, 65 .release = serdev_device_release, 66 }; 67 68 static bool is_serdev_device(const struct device *dev) 69 { 70 return dev->type == &serdev_device_type; 71 } 72 73 static void serdev_ctrl_release(struct device *dev) 74 { 75 struct serdev_controller *ctrl = to_serdev_controller(dev); 76 ida_simple_remove(&ctrl_ida, ctrl->nr); 77 kfree(ctrl); 78 } 79 80 static const struct device_type serdev_ctrl_type = { 81 .release = serdev_ctrl_release, 82 }; 83 84 static int serdev_device_match(struct device *dev, struct device_driver *drv) 85 { 86 if (!is_serdev_device(dev)) 87 return 0; 88 89 /* TODO: platform matching */ 90 if (acpi_driver_match_device(dev, drv)) 91 return 1; 92 93 return of_driver_match_device(dev, drv); 94 } 95 96 /** 97 * serdev_device_add() - add a device previously constructed via serdev_device_alloc() 98 * @serdev: serdev_device to be added 99 */ 100 int serdev_device_add(struct serdev_device *serdev) 101 { 102 struct serdev_controller *ctrl = serdev->ctrl; 103 struct device *parent = serdev->dev.parent; 104 int err; 105 106 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); 107 108 /* Only a single slave device is currently supported. */ 109 if (ctrl->serdev) { 110 dev_err(&serdev->dev, "controller busy\n"); 111 return -EBUSY; 112 } 113 ctrl->serdev = serdev; 114 115 err = device_add(&serdev->dev); 116 if (err < 0) { 117 dev_err(&serdev->dev, "Can't add %s, status %d\n", 118 dev_name(&serdev->dev), err); 119 goto err_clear_serdev; 120 } 121 122 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); 123 124 return 0; 125 126 err_clear_serdev: 127 ctrl->serdev = NULL; 128 return err; 129 } 130 EXPORT_SYMBOL_GPL(serdev_device_add); 131 132 /** 133 * serdev_device_remove(): remove an serdev device 134 * @serdev: serdev_device to be removed 135 */ 136 void serdev_device_remove(struct serdev_device *serdev) 137 { 138 struct serdev_controller *ctrl = serdev->ctrl; 139 140 device_unregister(&serdev->dev); 141 ctrl->serdev = NULL; 142 } 143 EXPORT_SYMBOL_GPL(serdev_device_remove); 144 145 int serdev_device_open(struct serdev_device *serdev) 146 { 147 struct serdev_controller *ctrl = serdev->ctrl; 148 int ret; 149 150 if (!ctrl || !ctrl->ops->open) 151 return -EINVAL; 152 153 ret = ctrl->ops->open(ctrl); 154 if (ret) 155 return ret; 156 157 ret = pm_runtime_get_sync(&ctrl->dev); 158 if (ret < 0) { 159 pm_runtime_put_noidle(&ctrl->dev); 160 goto err_close; 161 } 162 163 return 0; 164 165 err_close: 166 if (ctrl->ops->close) 167 ctrl->ops->close(ctrl); 168 169 return ret; 170 } 171 EXPORT_SYMBOL_GPL(serdev_device_open); 172 173 void serdev_device_close(struct serdev_device *serdev) 174 { 175 struct serdev_controller *ctrl = serdev->ctrl; 176 177 if (!ctrl || !ctrl->ops->close) 178 return; 179 180 pm_runtime_put(&ctrl->dev); 181 182 ctrl->ops->close(ctrl); 183 } 184 EXPORT_SYMBOL_GPL(serdev_device_close); 185 186 static void devm_serdev_device_release(struct device *dev, void *dr) 187 { 188 serdev_device_close(*(struct serdev_device **)dr); 189 } 190 191 int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev) 192 { 193 struct serdev_device **dr; 194 int ret; 195 196 dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL); 197 if (!dr) 198 return -ENOMEM; 199 200 ret = serdev_device_open(serdev); 201 if (ret) { 202 devres_free(dr); 203 return ret; 204 } 205 206 *dr = serdev; 207 devres_add(dev, dr); 208 209 return 0; 210 } 211 EXPORT_SYMBOL_GPL(devm_serdev_device_open); 212 213 void serdev_device_write_wakeup(struct serdev_device *serdev) 214 { 215 complete(&serdev->write_comp); 216 } 217 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); 218 219 int serdev_device_write_buf(struct serdev_device *serdev, 220 const unsigned char *buf, size_t count) 221 { 222 struct serdev_controller *ctrl = serdev->ctrl; 223 224 if (!ctrl || !ctrl->ops->write_buf) 225 return -EINVAL; 226 227 return ctrl->ops->write_buf(ctrl, buf, count); 228 } 229 EXPORT_SYMBOL_GPL(serdev_device_write_buf); 230 231 int serdev_device_write(struct serdev_device *serdev, 232 const unsigned char *buf, size_t count, 233 unsigned long timeout) 234 { 235 struct serdev_controller *ctrl = serdev->ctrl; 236 int ret; 237 238 if (!ctrl || !ctrl->ops->write_buf || 239 (timeout && !serdev->ops->write_wakeup)) 240 return -EINVAL; 241 242 mutex_lock(&serdev->write_lock); 243 do { 244 reinit_completion(&serdev->write_comp); 245 246 ret = ctrl->ops->write_buf(ctrl, buf, count); 247 if (ret < 0) 248 break; 249 250 buf += ret; 251 count -= ret; 252 253 } while (count && 254 (timeout = wait_for_completion_timeout(&serdev->write_comp, 255 timeout))); 256 mutex_unlock(&serdev->write_lock); 257 return ret < 0 ? ret : (count ? -ETIMEDOUT : 0); 258 } 259 EXPORT_SYMBOL_GPL(serdev_device_write); 260 261 void serdev_device_write_flush(struct serdev_device *serdev) 262 { 263 struct serdev_controller *ctrl = serdev->ctrl; 264 265 if (!ctrl || !ctrl->ops->write_flush) 266 return; 267 268 ctrl->ops->write_flush(ctrl); 269 } 270 EXPORT_SYMBOL_GPL(serdev_device_write_flush); 271 272 int serdev_device_write_room(struct serdev_device *serdev) 273 { 274 struct serdev_controller *ctrl = serdev->ctrl; 275 276 if (!ctrl || !ctrl->ops->write_room) 277 return 0; 278 279 return serdev->ctrl->ops->write_room(ctrl); 280 } 281 EXPORT_SYMBOL_GPL(serdev_device_write_room); 282 283 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) 284 { 285 struct serdev_controller *ctrl = serdev->ctrl; 286 287 if (!ctrl || !ctrl->ops->set_baudrate) 288 return 0; 289 290 return ctrl->ops->set_baudrate(ctrl, speed); 291 292 } 293 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 294 295 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) 296 { 297 struct serdev_controller *ctrl = serdev->ctrl; 298 299 if (!ctrl || !ctrl->ops->set_flow_control) 300 return; 301 302 ctrl->ops->set_flow_control(ctrl, enable); 303 } 304 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 305 306 int serdev_device_set_parity(struct serdev_device *serdev, 307 enum serdev_parity parity) 308 { 309 struct serdev_controller *ctrl = serdev->ctrl; 310 311 if (!ctrl || !ctrl->ops->set_parity) 312 return -ENOTSUPP; 313 314 return ctrl->ops->set_parity(ctrl, parity); 315 } 316 EXPORT_SYMBOL_GPL(serdev_device_set_parity); 317 318 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) 319 { 320 struct serdev_controller *ctrl = serdev->ctrl; 321 322 if (!ctrl || !ctrl->ops->wait_until_sent) 323 return; 324 325 ctrl->ops->wait_until_sent(ctrl, timeout); 326 } 327 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 328 329 int serdev_device_get_tiocm(struct serdev_device *serdev) 330 { 331 struct serdev_controller *ctrl = serdev->ctrl; 332 333 if (!ctrl || !ctrl->ops->get_tiocm) 334 return -ENOTSUPP; 335 336 return ctrl->ops->get_tiocm(ctrl); 337 } 338 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 339 340 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 341 { 342 struct serdev_controller *ctrl = serdev->ctrl; 343 344 if (!ctrl || !ctrl->ops->set_tiocm) 345 return -ENOTSUPP; 346 347 return ctrl->ops->set_tiocm(ctrl, set, clear); 348 } 349 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 350 351 static int serdev_drv_probe(struct device *dev) 352 { 353 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 354 int ret; 355 356 ret = dev_pm_domain_attach(dev, true); 357 if (ret) 358 return ret; 359 360 ret = sdrv->probe(to_serdev_device(dev)); 361 if (ret) 362 dev_pm_domain_detach(dev, true); 363 364 return ret; 365 } 366 367 static int serdev_drv_remove(struct device *dev) 368 { 369 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 370 if (sdrv->remove) 371 sdrv->remove(to_serdev_device(dev)); 372 373 dev_pm_domain_detach(dev, true); 374 375 return 0; 376 } 377 378 static struct bus_type serdev_bus_type = { 379 .name = "serial", 380 .match = serdev_device_match, 381 .probe = serdev_drv_probe, 382 .remove = serdev_drv_remove, 383 }; 384 385 /** 386 * serdev_device_alloc() - Allocate a new serdev device 387 * @ctrl: associated controller 388 * 389 * Caller is responsible for either calling serdev_device_add() to add the 390 * newly allocated controller, or calling serdev_device_put() to discard it. 391 */ 392 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 393 { 394 struct serdev_device *serdev; 395 396 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 397 if (!serdev) 398 return NULL; 399 400 serdev->ctrl = ctrl; 401 device_initialize(&serdev->dev); 402 serdev->dev.parent = &ctrl->dev; 403 serdev->dev.bus = &serdev_bus_type; 404 serdev->dev.type = &serdev_device_type; 405 init_completion(&serdev->write_comp); 406 mutex_init(&serdev->write_lock); 407 return serdev; 408 } 409 EXPORT_SYMBOL_GPL(serdev_device_alloc); 410 411 /** 412 * serdev_controller_alloc() - Allocate a new serdev controller 413 * @parent: parent device 414 * @size: size of private data 415 * 416 * Caller is responsible for either calling serdev_controller_add() to add the 417 * newly allocated controller, or calling serdev_controller_put() to discard it. 418 * The allocated private data region may be accessed via 419 * serdev_controller_get_drvdata() 420 */ 421 struct serdev_controller *serdev_controller_alloc(struct device *parent, 422 size_t size) 423 { 424 struct serdev_controller *ctrl; 425 int id; 426 427 if (WARN_ON(!parent)) 428 return NULL; 429 430 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 431 if (!ctrl) 432 return NULL; 433 434 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); 435 if (id < 0) { 436 dev_err(parent, 437 "unable to allocate serdev controller identifier.\n"); 438 goto err_free; 439 } 440 441 ctrl->nr = id; 442 443 device_initialize(&ctrl->dev); 444 ctrl->dev.type = &serdev_ctrl_type; 445 ctrl->dev.bus = &serdev_bus_type; 446 ctrl->dev.parent = parent; 447 ctrl->dev.of_node = parent->of_node; 448 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 449 450 dev_set_name(&ctrl->dev, "serial%d", id); 451 452 pm_runtime_no_callbacks(&ctrl->dev); 453 pm_suspend_ignore_children(&ctrl->dev, true); 454 455 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 456 return ctrl; 457 458 err_free: 459 kfree(ctrl); 460 461 return NULL; 462 } 463 EXPORT_SYMBOL_GPL(serdev_controller_alloc); 464 465 static int of_serdev_register_devices(struct serdev_controller *ctrl) 466 { 467 struct device_node *node; 468 struct serdev_device *serdev = NULL; 469 int err; 470 bool found = false; 471 472 for_each_available_child_of_node(ctrl->dev.of_node, node) { 473 if (!of_get_property(node, "compatible", NULL)) 474 continue; 475 476 dev_dbg(&ctrl->dev, "adding child %pOF\n", node); 477 478 serdev = serdev_device_alloc(ctrl); 479 if (!serdev) 480 continue; 481 482 serdev->dev.of_node = node; 483 484 err = serdev_device_add(serdev); 485 if (err) { 486 dev_err(&serdev->dev, 487 "failure adding device. status %d\n", err); 488 serdev_device_put(serdev); 489 } else 490 found = true; 491 } 492 if (!found) 493 return -ENODEV; 494 495 return 0; 496 } 497 498 #ifdef CONFIG_ACPI 499 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, 500 struct acpi_device *adev) 501 { 502 struct serdev_device *serdev = NULL; 503 int err; 504 505 if (acpi_bus_get_status(adev) || !adev->status.present || 506 acpi_device_enumerated(adev)) 507 return AE_OK; 508 509 serdev = serdev_device_alloc(ctrl); 510 if (!serdev) { 511 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n", 512 dev_name(&adev->dev)); 513 return AE_NO_MEMORY; 514 } 515 516 ACPI_COMPANION_SET(&serdev->dev, adev); 517 acpi_device_set_enumerated(adev); 518 519 err = serdev_device_add(serdev); 520 if (err) { 521 dev_err(&serdev->dev, 522 "failure adding ACPI serdev device. status %d\n", err); 523 serdev_device_put(serdev); 524 } 525 526 return AE_OK; 527 } 528 529 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, 530 void *data, void **return_value) 531 { 532 struct serdev_controller *ctrl = data; 533 struct acpi_device *adev; 534 535 if (acpi_bus_get_device(handle, &adev)) 536 return AE_OK; 537 538 return acpi_serdev_register_device(ctrl, adev); 539 } 540 541 static int acpi_serdev_register_devices(struct serdev_controller *ctrl) 542 { 543 acpi_status status; 544 acpi_handle handle; 545 546 handle = ACPI_HANDLE(ctrl->dev.parent); 547 if (!handle) 548 return -ENODEV; 549 550 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, 551 acpi_serdev_add_device, NULL, ctrl, NULL); 552 if (ACPI_FAILURE(status)) 553 dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n"); 554 555 if (!ctrl->serdev) 556 return -ENODEV; 557 558 return 0; 559 } 560 #else 561 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl) 562 { 563 return -ENODEV; 564 } 565 #endif /* CONFIG_ACPI */ 566 567 /** 568 * serdev_controller_add() - Add an serdev controller 569 * @ctrl: controller to be registered. 570 * 571 * Register a controller previously allocated via serdev_controller_alloc() with 572 * the serdev core. 573 */ 574 int serdev_controller_add(struct serdev_controller *ctrl) 575 { 576 int ret_of, ret_acpi, ret; 577 578 /* Can't register until after driver model init */ 579 if (WARN_ON(!is_registered)) 580 return -EAGAIN; 581 582 ret = device_add(&ctrl->dev); 583 if (ret) 584 return ret; 585 586 pm_runtime_enable(&ctrl->dev); 587 588 ret_of = of_serdev_register_devices(ctrl); 589 ret_acpi = acpi_serdev_register_devices(ctrl); 590 if (ret_of && ret_acpi) { 591 dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n", 592 ret_of, ret_acpi); 593 ret = -ENODEV; 594 goto err_rpm_disable; 595 } 596 597 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 598 ctrl->nr, &ctrl->dev); 599 return 0; 600 601 err_rpm_disable: 602 pm_runtime_disable(&ctrl->dev); 603 device_del(&ctrl->dev); 604 return ret; 605 }; 606 EXPORT_SYMBOL_GPL(serdev_controller_add); 607 608 /* Remove a device associated with a controller */ 609 static int serdev_remove_device(struct device *dev, void *data) 610 { 611 struct serdev_device *serdev = to_serdev_device(dev); 612 if (dev->type == &serdev_device_type) 613 serdev_device_remove(serdev); 614 return 0; 615 } 616 617 /** 618 * serdev_controller_remove(): remove an serdev controller 619 * @ctrl: controller to remove 620 * 621 * Remove a serdev controller. Caller is responsible for calling 622 * serdev_controller_put() to discard the allocated controller. 623 */ 624 void serdev_controller_remove(struct serdev_controller *ctrl) 625 { 626 int dummy; 627 628 if (!ctrl) 629 return; 630 631 dummy = device_for_each_child(&ctrl->dev, NULL, 632 serdev_remove_device); 633 pm_runtime_disable(&ctrl->dev); 634 device_del(&ctrl->dev); 635 } 636 EXPORT_SYMBOL_GPL(serdev_controller_remove); 637 638 /** 639 * serdev_driver_register() - Register client driver with serdev core 640 * @sdrv: client driver to be associated with client-device. 641 * 642 * This API will register the client driver with the serdev framework. 643 * It is typically called from the driver's module-init function. 644 */ 645 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 646 { 647 sdrv->driver.bus = &serdev_bus_type; 648 sdrv->driver.owner = owner; 649 650 /* force drivers to async probe so I/O is possible in probe */ 651 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 652 653 return driver_register(&sdrv->driver); 654 } 655 EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 656 657 static void __exit serdev_exit(void) 658 { 659 bus_unregister(&serdev_bus_type); 660 ida_destroy(&ctrl_ida); 661 } 662 module_exit(serdev_exit); 663 664 static int __init serdev_init(void) 665 { 666 int ret; 667 668 ret = bus_register(&serdev_bus_type); 669 if (ret) 670 return ret; 671 672 is_registered = true; 673 return 0; 674 } 675 /* Must be before serial drivers register */ 676 postcore_initcall(serdev_init); 677 678 MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 679 MODULE_LICENSE("GPL v2"); 680 MODULE_DESCRIPTION("Serial attached device bus"); 681