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 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 and 10 * only version 2 as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include <linux/acpi.h> 19 #include <linux/errno.h> 20 #include <linux/idr.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/of.h> 24 #include <linux/of_device.h> 25 #include <linux/serdev.h> 26 #include <linux/slab.h> 27 28 static bool is_registered; 29 static DEFINE_IDA(ctrl_ida); 30 31 static void serdev_device_release(struct device *dev) 32 { 33 struct serdev_device *serdev = to_serdev_device(dev); 34 kfree(serdev); 35 } 36 37 static const struct device_type serdev_device_type = { 38 .release = serdev_device_release, 39 }; 40 41 static void serdev_ctrl_release(struct device *dev) 42 { 43 struct serdev_controller *ctrl = to_serdev_controller(dev); 44 ida_simple_remove(&ctrl_ida, ctrl->nr); 45 kfree(ctrl); 46 } 47 48 static const struct device_type serdev_ctrl_type = { 49 .release = serdev_ctrl_release, 50 }; 51 52 static int serdev_device_match(struct device *dev, struct device_driver *drv) 53 { 54 /* TODO: platform matching */ 55 if (acpi_driver_match_device(dev, drv)) 56 return 1; 57 58 return of_driver_match_device(dev, drv); 59 } 60 61 static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env) 62 { 63 int rc; 64 65 /* TODO: platform modalias */ 66 rc = acpi_device_uevent_modalias(dev, env); 67 if (rc != -ENODEV) 68 return rc; 69 70 return of_device_uevent_modalias(dev, env); 71 } 72 73 /** 74 * serdev_device_add() - add a device previously constructed via serdev_device_alloc() 75 * @serdev: serdev_device to be added 76 */ 77 int serdev_device_add(struct serdev_device *serdev) 78 { 79 struct serdev_controller *ctrl = serdev->ctrl; 80 struct device *parent = serdev->dev.parent; 81 int err; 82 83 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); 84 85 /* Only a single slave device is currently supported. */ 86 if (ctrl->serdev) { 87 dev_err(&serdev->dev, "controller busy\n"); 88 return -EBUSY; 89 } 90 ctrl->serdev = serdev; 91 92 err = device_add(&serdev->dev); 93 if (err < 0) { 94 dev_err(&serdev->dev, "Can't add %s, status %d\n", 95 dev_name(&serdev->dev), err); 96 goto err_clear_serdev; 97 } 98 99 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); 100 101 return 0; 102 103 err_clear_serdev: 104 ctrl->serdev = NULL; 105 return err; 106 } 107 EXPORT_SYMBOL_GPL(serdev_device_add); 108 109 /** 110 * serdev_device_remove(): remove an serdev device 111 * @serdev: serdev_device to be removed 112 */ 113 void serdev_device_remove(struct serdev_device *serdev) 114 { 115 struct serdev_controller *ctrl = serdev->ctrl; 116 117 device_unregister(&serdev->dev); 118 ctrl->serdev = NULL; 119 } 120 EXPORT_SYMBOL_GPL(serdev_device_remove); 121 122 int serdev_device_open(struct serdev_device *serdev) 123 { 124 struct serdev_controller *ctrl = serdev->ctrl; 125 126 if (!ctrl || !ctrl->ops->open) 127 return -EINVAL; 128 129 return ctrl->ops->open(ctrl); 130 } 131 EXPORT_SYMBOL_GPL(serdev_device_open); 132 133 void serdev_device_close(struct serdev_device *serdev) 134 { 135 struct serdev_controller *ctrl = serdev->ctrl; 136 137 if (!ctrl || !ctrl->ops->close) 138 return; 139 140 ctrl->ops->close(ctrl); 141 } 142 EXPORT_SYMBOL_GPL(serdev_device_close); 143 144 void serdev_device_write_wakeup(struct serdev_device *serdev) 145 { 146 complete(&serdev->write_comp); 147 } 148 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); 149 150 int serdev_device_write_buf(struct serdev_device *serdev, 151 const unsigned char *buf, size_t count) 152 { 153 struct serdev_controller *ctrl = serdev->ctrl; 154 155 if (!ctrl || !ctrl->ops->write_buf) 156 return -EINVAL; 157 158 return ctrl->ops->write_buf(ctrl, buf, count); 159 } 160 EXPORT_SYMBOL_GPL(serdev_device_write_buf); 161 162 int serdev_device_write(struct serdev_device *serdev, 163 const unsigned char *buf, size_t count, 164 unsigned long timeout) 165 { 166 struct serdev_controller *ctrl = serdev->ctrl; 167 int ret; 168 169 if (!ctrl || !ctrl->ops->write_buf || 170 (timeout && !serdev->ops->write_wakeup)) 171 return -EINVAL; 172 173 mutex_lock(&serdev->write_lock); 174 do { 175 reinit_completion(&serdev->write_comp); 176 177 ret = ctrl->ops->write_buf(ctrl, buf, count); 178 if (ret < 0) 179 break; 180 181 buf += ret; 182 count -= ret; 183 184 } while (count && 185 (timeout = wait_for_completion_timeout(&serdev->write_comp, 186 timeout))); 187 mutex_unlock(&serdev->write_lock); 188 return ret < 0 ? ret : (count ? -ETIMEDOUT : 0); 189 } 190 EXPORT_SYMBOL_GPL(serdev_device_write); 191 192 void serdev_device_write_flush(struct serdev_device *serdev) 193 { 194 struct serdev_controller *ctrl = serdev->ctrl; 195 196 if (!ctrl || !ctrl->ops->write_flush) 197 return; 198 199 ctrl->ops->write_flush(ctrl); 200 } 201 EXPORT_SYMBOL_GPL(serdev_device_write_flush); 202 203 int serdev_device_write_room(struct serdev_device *serdev) 204 { 205 struct serdev_controller *ctrl = serdev->ctrl; 206 207 if (!ctrl || !ctrl->ops->write_room) 208 return 0; 209 210 return serdev->ctrl->ops->write_room(ctrl); 211 } 212 EXPORT_SYMBOL_GPL(serdev_device_write_room); 213 214 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) 215 { 216 struct serdev_controller *ctrl = serdev->ctrl; 217 218 if (!ctrl || !ctrl->ops->set_baudrate) 219 return 0; 220 221 return ctrl->ops->set_baudrate(ctrl, speed); 222 223 } 224 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 225 226 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) 227 { 228 struct serdev_controller *ctrl = serdev->ctrl; 229 230 if (!ctrl || !ctrl->ops->set_flow_control) 231 return; 232 233 ctrl->ops->set_flow_control(ctrl, enable); 234 } 235 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 236 237 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) 238 { 239 struct serdev_controller *ctrl = serdev->ctrl; 240 241 if (!ctrl || !ctrl->ops->wait_until_sent) 242 return; 243 244 ctrl->ops->wait_until_sent(ctrl, timeout); 245 } 246 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 247 248 int serdev_device_get_tiocm(struct serdev_device *serdev) 249 { 250 struct serdev_controller *ctrl = serdev->ctrl; 251 252 if (!ctrl || !ctrl->ops->get_tiocm) 253 return -ENOTSUPP; 254 255 return ctrl->ops->get_tiocm(ctrl); 256 } 257 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 258 259 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 260 { 261 struct serdev_controller *ctrl = serdev->ctrl; 262 263 if (!ctrl || !ctrl->ops->set_tiocm) 264 return -ENOTSUPP; 265 266 return ctrl->ops->set_tiocm(ctrl, set, clear); 267 } 268 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 269 270 static int serdev_drv_probe(struct device *dev) 271 { 272 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 273 274 return sdrv->probe(to_serdev_device(dev)); 275 } 276 277 static int serdev_drv_remove(struct device *dev) 278 { 279 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 280 281 sdrv->remove(to_serdev_device(dev)); 282 return 0; 283 } 284 285 static ssize_t modalias_show(struct device *dev, 286 struct device_attribute *attr, char *buf) 287 { 288 int len; 289 290 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); 291 if (len != -ENODEV) 292 return len; 293 294 return of_device_modalias(dev, buf, PAGE_SIZE); 295 } 296 DEVICE_ATTR_RO(modalias); 297 298 static struct attribute *serdev_device_attrs[] = { 299 &dev_attr_modalias.attr, 300 NULL, 301 }; 302 ATTRIBUTE_GROUPS(serdev_device); 303 304 static struct bus_type serdev_bus_type = { 305 .name = "serial", 306 .match = serdev_device_match, 307 .probe = serdev_drv_probe, 308 .remove = serdev_drv_remove, 309 .uevent = serdev_uevent, 310 .dev_groups = serdev_device_groups, 311 }; 312 313 /** 314 * serdev_controller_alloc() - Allocate a new serdev device 315 * @ctrl: associated controller 316 * 317 * Caller is responsible for either calling serdev_device_add() to add the 318 * newly allocated controller, or calling serdev_device_put() to discard it. 319 */ 320 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 321 { 322 struct serdev_device *serdev; 323 324 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 325 if (!serdev) 326 return NULL; 327 328 serdev->ctrl = ctrl; 329 device_initialize(&serdev->dev); 330 serdev->dev.parent = &ctrl->dev; 331 serdev->dev.bus = &serdev_bus_type; 332 serdev->dev.type = &serdev_device_type; 333 init_completion(&serdev->write_comp); 334 mutex_init(&serdev->write_lock); 335 return serdev; 336 } 337 EXPORT_SYMBOL_GPL(serdev_device_alloc); 338 339 /** 340 * serdev_controller_alloc() - Allocate a new serdev controller 341 * @parent: parent device 342 * @size: size of private data 343 * 344 * Caller is responsible for either calling serdev_controller_add() to add the 345 * newly allocated controller, or calling serdev_controller_put() to discard it. 346 * The allocated private data region may be accessed via 347 * serdev_controller_get_drvdata() 348 */ 349 struct serdev_controller *serdev_controller_alloc(struct device *parent, 350 size_t size) 351 { 352 struct serdev_controller *ctrl; 353 int id; 354 355 if (WARN_ON(!parent)) 356 return NULL; 357 358 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 359 if (!ctrl) 360 return NULL; 361 362 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); 363 if (id < 0) { 364 dev_err(parent, 365 "unable to allocate serdev controller identifier.\n"); 366 goto err_free; 367 } 368 369 ctrl->nr = id; 370 371 device_initialize(&ctrl->dev); 372 ctrl->dev.type = &serdev_ctrl_type; 373 ctrl->dev.bus = &serdev_bus_type; 374 ctrl->dev.parent = parent; 375 ctrl->dev.of_node = parent->of_node; 376 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 377 378 dev_set_name(&ctrl->dev, "serial%d", id); 379 380 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 381 return ctrl; 382 383 err_free: 384 kfree(ctrl); 385 386 return NULL; 387 } 388 EXPORT_SYMBOL_GPL(serdev_controller_alloc); 389 390 static int of_serdev_register_devices(struct serdev_controller *ctrl) 391 { 392 struct device_node *node; 393 struct serdev_device *serdev = NULL; 394 int err; 395 bool found = false; 396 397 for_each_available_child_of_node(ctrl->dev.of_node, node) { 398 if (!of_get_property(node, "compatible", NULL)) 399 continue; 400 401 dev_dbg(&ctrl->dev, "adding child %pOF\n", node); 402 403 serdev = serdev_device_alloc(ctrl); 404 if (!serdev) 405 continue; 406 407 serdev->dev.of_node = node; 408 409 err = serdev_device_add(serdev); 410 if (err) { 411 dev_err(&serdev->dev, 412 "failure adding device. status %d\n", err); 413 serdev_device_put(serdev); 414 } else 415 found = true; 416 } 417 if (!found) 418 return -ENODEV; 419 420 return 0; 421 } 422 423 #ifdef CONFIG_ACPI 424 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, 425 struct acpi_device *adev) 426 { 427 struct serdev_device *serdev = NULL; 428 int err; 429 430 if (acpi_bus_get_status(adev) || !adev->status.present || 431 acpi_device_enumerated(adev)) 432 return AE_OK; 433 434 serdev = serdev_device_alloc(ctrl); 435 if (!serdev) { 436 dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n", 437 dev_name(&adev->dev)); 438 return AE_NO_MEMORY; 439 } 440 441 ACPI_COMPANION_SET(&serdev->dev, adev); 442 acpi_device_set_enumerated(adev); 443 444 err = serdev_device_add(serdev); 445 if (err) { 446 dev_err(&serdev->dev, 447 "failure adding ACPI serdev device. status %d\n", err); 448 serdev_device_put(serdev); 449 } 450 451 return AE_OK; 452 } 453 454 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, 455 void *data, void **return_value) 456 { 457 struct serdev_controller *ctrl = data; 458 struct acpi_device *adev; 459 460 if (acpi_bus_get_device(handle, &adev)) 461 return AE_OK; 462 463 return acpi_serdev_register_device(ctrl, adev); 464 } 465 466 static int acpi_serdev_register_devices(struct serdev_controller *ctrl) 467 { 468 acpi_status status; 469 acpi_handle handle; 470 471 handle = ACPI_HANDLE(ctrl->dev.parent); 472 if (!handle) 473 return -ENODEV; 474 475 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, 476 acpi_serdev_add_device, NULL, ctrl, NULL); 477 if (ACPI_FAILURE(status)) 478 dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n"); 479 480 if (!ctrl->serdev) 481 return -ENODEV; 482 483 return 0; 484 } 485 #else 486 static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl) 487 { 488 return -ENODEV; 489 } 490 #endif /* CONFIG_ACPI */ 491 492 /** 493 * serdev_controller_add() - Add an serdev controller 494 * @ctrl: controller to be registered. 495 * 496 * Register a controller previously allocated via serdev_controller_alloc() with 497 * the serdev core. 498 */ 499 int serdev_controller_add(struct serdev_controller *ctrl) 500 { 501 int ret_of, ret_acpi, ret; 502 503 /* Can't register until after driver model init */ 504 if (WARN_ON(!is_registered)) 505 return -EAGAIN; 506 507 ret = device_add(&ctrl->dev); 508 if (ret) 509 return ret; 510 511 ret_of = of_serdev_register_devices(ctrl); 512 ret_acpi = acpi_serdev_register_devices(ctrl); 513 if (ret_of && ret_acpi) { 514 dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n", 515 ret_of, ret_acpi); 516 ret = -ENODEV; 517 goto out_dev_del; 518 } 519 520 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 521 ctrl->nr, &ctrl->dev); 522 return 0; 523 524 out_dev_del: 525 device_del(&ctrl->dev); 526 return ret; 527 }; 528 EXPORT_SYMBOL_GPL(serdev_controller_add); 529 530 /* Remove a device associated with a controller */ 531 static int serdev_remove_device(struct device *dev, void *data) 532 { 533 struct serdev_device *serdev = to_serdev_device(dev); 534 if (dev->type == &serdev_device_type) 535 serdev_device_remove(serdev); 536 return 0; 537 } 538 539 /** 540 * serdev_controller_remove(): remove an serdev controller 541 * @ctrl: controller to remove 542 * 543 * Remove a serdev controller. Caller is responsible for calling 544 * serdev_controller_put() to discard the allocated controller. 545 */ 546 void serdev_controller_remove(struct serdev_controller *ctrl) 547 { 548 int dummy; 549 550 if (!ctrl) 551 return; 552 553 dummy = device_for_each_child(&ctrl->dev, NULL, 554 serdev_remove_device); 555 device_del(&ctrl->dev); 556 } 557 EXPORT_SYMBOL_GPL(serdev_controller_remove); 558 559 /** 560 * serdev_driver_register() - Register client driver with serdev core 561 * @sdrv: client driver to be associated with client-device. 562 * 563 * This API will register the client driver with the serdev framework. 564 * It is typically called from the driver's module-init function. 565 */ 566 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 567 { 568 sdrv->driver.bus = &serdev_bus_type; 569 sdrv->driver.owner = owner; 570 571 /* force drivers to async probe so I/O is possible in probe */ 572 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 573 574 return driver_register(&sdrv->driver); 575 } 576 EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 577 578 static void __exit serdev_exit(void) 579 { 580 bus_unregister(&serdev_bus_type); 581 } 582 module_exit(serdev_exit); 583 584 static int __init serdev_init(void) 585 { 586 int ret; 587 588 ret = bus_register(&serdev_bus_type); 589 if (ret) 590 return ret; 591 592 is_registered = true; 593 return 0; 594 } 595 /* Must be before serial drivers register */ 596 postcore_initcall(serdev_init); 597 598 MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 599 MODULE_LICENSE("GPL v2"); 600 MODULE_DESCRIPTION("Serial attached device bus"); 601