1 /* 2 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> 3 * 4 * Based on drivers/spmi/spmi.c: 5 * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 and 9 * only version 2 as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/errno.h> 18 #include <linux/idr.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/of_device.h> 23 #include <linux/serdev.h> 24 #include <linux/slab.h> 25 26 static bool is_registered; 27 static DEFINE_IDA(ctrl_ida); 28 29 static void serdev_device_release(struct device *dev) 30 { 31 struct serdev_device *serdev = to_serdev_device(dev); 32 kfree(serdev); 33 } 34 35 static const struct device_type serdev_device_type = { 36 .release = serdev_device_release, 37 }; 38 39 static void serdev_ctrl_release(struct device *dev) 40 { 41 struct serdev_controller *ctrl = to_serdev_controller(dev); 42 ida_simple_remove(&ctrl_ida, ctrl->nr); 43 kfree(ctrl); 44 } 45 46 static const struct device_type serdev_ctrl_type = { 47 .release = serdev_ctrl_release, 48 }; 49 50 static int serdev_device_match(struct device *dev, struct device_driver *drv) 51 { 52 /* TODO: ACPI and platform matching */ 53 return of_driver_match_device(dev, drv); 54 } 55 56 static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env) 57 { 58 /* TODO: ACPI and platform modalias */ 59 return of_device_uevent_modalias(dev, env); 60 } 61 62 /** 63 * serdev_device_add() - add a device previously constructed via serdev_device_alloc() 64 * @serdev: serdev_device to be added 65 */ 66 int serdev_device_add(struct serdev_device *serdev) 67 { 68 struct device *parent = serdev->dev.parent; 69 int err; 70 71 dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); 72 73 err = device_add(&serdev->dev); 74 if (err < 0) { 75 dev_err(&serdev->dev, "Can't add %s, status %d\n", 76 dev_name(&serdev->dev), err); 77 goto err_device_add; 78 } 79 80 dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); 81 82 err_device_add: 83 return err; 84 } 85 EXPORT_SYMBOL_GPL(serdev_device_add); 86 87 /** 88 * serdev_device_remove(): remove an serdev device 89 * @serdev: serdev_device to be removed 90 */ 91 void serdev_device_remove(struct serdev_device *serdev) 92 { 93 device_unregister(&serdev->dev); 94 } 95 EXPORT_SYMBOL_GPL(serdev_device_remove); 96 97 int serdev_device_open(struct serdev_device *serdev) 98 { 99 struct serdev_controller *ctrl = serdev->ctrl; 100 101 if (!ctrl || !ctrl->ops->open) 102 return -EINVAL; 103 104 return ctrl->ops->open(ctrl); 105 } 106 EXPORT_SYMBOL_GPL(serdev_device_open); 107 108 void serdev_device_close(struct serdev_device *serdev) 109 { 110 struct serdev_controller *ctrl = serdev->ctrl; 111 112 if (!ctrl || !ctrl->ops->close) 113 return; 114 115 ctrl->ops->close(ctrl); 116 } 117 EXPORT_SYMBOL_GPL(serdev_device_close); 118 119 void serdev_device_write_wakeup(struct serdev_device *serdev) 120 { 121 complete(&serdev->write_comp); 122 } 123 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); 124 125 int serdev_device_write_buf(struct serdev_device *serdev, 126 const unsigned char *buf, size_t count) 127 { 128 struct serdev_controller *ctrl = serdev->ctrl; 129 130 if (!ctrl || !ctrl->ops->write_buf) 131 return -EINVAL; 132 133 return ctrl->ops->write_buf(ctrl, buf, count); 134 } 135 EXPORT_SYMBOL_GPL(serdev_device_write_buf); 136 137 int serdev_device_write(struct serdev_device *serdev, 138 const unsigned char *buf, size_t count, 139 unsigned long timeout) 140 { 141 struct serdev_controller *ctrl = serdev->ctrl; 142 int ret; 143 144 if (!ctrl || !ctrl->ops->write_buf || 145 (timeout && !serdev->ops->write_wakeup)) 146 return -EINVAL; 147 148 mutex_lock(&serdev->write_lock); 149 do { 150 reinit_completion(&serdev->write_comp); 151 152 ret = ctrl->ops->write_buf(ctrl, buf, count); 153 if (ret < 0) 154 break; 155 156 buf += ret; 157 count -= ret; 158 159 } while (count && 160 (timeout = wait_for_completion_timeout(&serdev->write_comp, 161 timeout))); 162 mutex_unlock(&serdev->write_lock); 163 return ret < 0 ? ret : (count ? -ETIMEDOUT : 0); 164 } 165 EXPORT_SYMBOL_GPL(serdev_device_write); 166 167 void serdev_device_write_flush(struct serdev_device *serdev) 168 { 169 struct serdev_controller *ctrl = serdev->ctrl; 170 171 if (!ctrl || !ctrl->ops->write_flush) 172 return; 173 174 ctrl->ops->write_flush(ctrl); 175 } 176 EXPORT_SYMBOL_GPL(serdev_device_write_flush); 177 178 int serdev_device_write_room(struct serdev_device *serdev) 179 { 180 struct serdev_controller *ctrl = serdev->ctrl; 181 182 if (!ctrl || !ctrl->ops->write_room) 183 return 0; 184 185 return serdev->ctrl->ops->write_room(ctrl); 186 } 187 EXPORT_SYMBOL_GPL(serdev_device_write_room); 188 189 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) 190 { 191 struct serdev_controller *ctrl = serdev->ctrl; 192 193 if (!ctrl || !ctrl->ops->set_baudrate) 194 return 0; 195 196 return ctrl->ops->set_baudrate(ctrl, speed); 197 198 } 199 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 200 201 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) 202 { 203 struct serdev_controller *ctrl = serdev->ctrl; 204 205 if (!ctrl || !ctrl->ops->set_flow_control) 206 return; 207 208 ctrl->ops->set_flow_control(ctrl, enable); 209 } 210 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 211 212 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) 213 { 214 struct serdev_controller *ctrl = serdev->ctrl; 215 216 if (!ctrl || !ctrl->ops->wait_until_sent) 217 return; 218 219 ctrl->ops->wait_until_sent(ctrl, timeout); 220 } 221 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 222 223 int serdev_device_get_tiocm(struct serdev_device *serdev) 224 { 225 struct serdev_controller *ctrl = serdev->ctrl; 226 227 if (!ctrl || !ctrl->ops->get_tiocm) 228 return -ENOTSUPP; 229 230 return ctrl->ops->get_tiocm(ctrl); 231 } 232 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 233 234 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 235 { 236 struct serdev_controller *ctrl = serdev->ctrl; 237 238 if (!ctrl || !ctrl->ops->set_tiocm) 239 return -ENOTSUPP; 240 241 return ctrl->ops->set_tiocm(ctrl, set, clear); 242 } 243 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 244 245 static int serdev_drv_probe(struct device *dev) 246 { 247 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 248 249 return sdrv->probe(to_serdev_device(dev)); 250 } 251 252 static int serdev_drv_remove(struct device *dev) 253 { 254 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 255 256 sdrv->remove(to_serdev_device(dev)); 257 return 0; 258 } 259 260 static ssize_t modalias_show(struct device *dev, 261 struct device_attribute *attr, char *buf) 262 { 263 return of_device_modalias(dev, buf, PAGE_SIZE); 264 } 265 DEVICE_ATTR_RO(modalias); 266 267 static struct attribute *serdev_device_attrs[] = { 268 &dev_attr_modalias.attr, 269 NULL, 270 }; 271 ATTRIBUTE_GROUPS(serdev_device); 272 273 static struct bus_type serdev_bus_type = { 274 .name = "serial", 275 .match = serdev_device_match, 276 .probe = serdev_drv_probe, 277 .remove = serdev_drv_remove, 278 .uevent = serdev_uevent, 279 .dev_groups = serdev_device_groups, 280 }; 281 282 /** 283 * serdev_controller_alloc() - Allocate a new serdev device 284 * @ctrl: associated controller 285 * 286 * Caller is responsible for either calling serdev_device_add() to add the 287 * newly allocated controller, or calling serdev_device_put() to discard it. 288 */ 289 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 290 { 291 struct serdev_device *serdev; 292 293 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 294 if (!serdev) 295 return NULL; 296 297 serdev->ctrl = ctrl; 298 ctrl->serdev = serdev; 299 device_initialize(&serdev->dev); 300 serdev->dev.parent = &ctrl->dev; 301 serdev->dev.bus = &serdev_bus_type; 302 serdev->dev.type = &serdev_device_type; 303 init_completion(&serdev->write_comp); 304 mutex_init(&serdev->write_lock); 305 return serdev; 306 } 307 EXPORT_SYMBOL_GPL(serdev_device_alloc); 308 309 /** 310 * serdev_controller_alloc() - Allocate a new serdev controller 311 * @parent: parent device 312 * @size: size of private data 313 * 314 * Caller is responsible for either calling serdev_controller_add() to add the 315 * newly allocated controller, or calling serdev_controller_put() to discard it. 316 * The allocated private data region may be accessed via 317 * serdev_controller_get_drvdata() 318 */ 319 struct serdev_controller *serdev_controller_alloc(struct device *parent, 320 size_t size) 321 { 322 struct serdev_controller *ctrl; 323 int id; 324 325 if (WARN_ON(!parent)) 326 return NULL; 327 328 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 329 if (!ctrl) 330 return NULL; 331 332 device_initialize(&ctrl->dev); 333 ctrl->dev.type = &serdev_ctrl_type; 334 ctrl->dev.bus = &serdev_bus_type; 335 ctrl->dev.parent = parent; 336 ctrl->dev.of_node = parent->of_node; 337 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 338 339 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); 340 if (id < 0) { 341 dev_err(parent, 342 "unable to allocate serdev controller identifier.\n"); 343 serdev_controller_put(ctrl); 344 return NULL; 345 } 346 347 ctrl->nr = id; 348 dev_set_name(&ctrl->dev, "serial%d", id); 349 350 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 351 return ctrl; 352 } 353 EXPORT_SYMBOL_GPL(serdev_controller_alloc); 354 355 static int of_serdev_register_devices(struct serdev_controller *ctrl) 356 { 357 struct device_node *node; 358 struct serdev_device *serdev = NULL; 359 int err; 360 bool found = false; 361 362 for_each_available_child_of_node(ctrl->dev.of_node, node) { 363 if (!of_get_property(node, "compatible", NULL)) 364 continue; 365 366 dev_dbg(&ctrl->dev, "adding child %pOF\n", node); 367 368 serdev = serdev_device_alloc(ctrl); 369 if (!serdev) 370 continue; 371 372 serdev->dev.of_node = node; 373 374 err = serdev_device_add(serdev); 375 if (err) { 376 dev_err(&serdev->dev, 377 "failure adding device. status %d\n", err); 378 serdev_device_put(serdev); 379 } else 380 found = true; 381 } 382 if (!found) 383 return -ENODEV; 384 385 return 0; 386 } 387 388 /** 389 * serdev_controller_add() - Add an serdev controller 390 * @ctrl: controller to be registered. 391 * 392 * Register a controller previously allocated via serdev_controller_alloc() with 393 * the serdev core. 394 */ 395 int serdev_controller_add(struct serdev_controller *ctrl) 396 { 397 int ret; 398 399 /* Can't register until after driver model init */ 400 if (WARN_ON(!is_registered)) 401 return -EAGAIN; 402 403 ret = device_add(&ctrl->dev); 404 if (ret) 405 return ret; 406 407 ret = of_serdev_register_devices(ctrl); 408 if (ret) 409 goto out_dev_del; 410 411 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 412 ctrl->nr, &ctrl->dev); 413 return 0; 414 415 out_dev_del: 416 device_del(&ctrl->dev); 417 return ret; 418 }; 419 EXPORT_SYMBOL_GPL(serdev_controller_add); 420 421 /* Remove a device associated with a controller */ 422 static int serdev_remove_device(struct device *dev, void *data) 423 { 424 struct serdev_device *serdev = to_serdev_device(dev); 425 if (dev->type == &serdev_device_type) 426 serdev_device_remove(serdev); 427 return 0; 428 } 429 430 /** 431 * serdev_controller_remove(): remove an serdev controller 432 * @ctrl: controller to remove 433 * 434 * Remove a serdev controller. Caller is responsible for calling 435 * serdev_controller_put() to discard the allocated controller. 436 */ 437 void serdev_controller_remove(struct serdev_controller *ctrl) 438 { 439 int dummy; 440 441 if (!ctrl) 442 return; 443 444 dummy = device_for_each_child(&ctrl->dev, NULL, 445 serdev_remove_device); 446 device_del(&ctrl->dev); 447 } 448 EXPORT_SYMBOL_GPL(serdev_controller_remove); 449 450 /** 451 * serdev_driver_register() - Register client driver with serdev core 452 * @sdrv: client driver to be associated with client-device. 453 * 454 * This API will register the client driver with the serdev framework. 455 * It is typically called from the driver's module-init function. 456 */ 457 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 458 { 459 sdrv->driver.bus = &serdev_bus_type; 460 sdrv->driver.owner = owner; 461 462 /* force drivers to async probe so I/O is possible in probe */ 463 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 464 465 return driver_register(&sdrv->driver); 466 } 467 EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 468 469 static void __exit serdev_exit(void) 470 { 471 bus_unregister(&serdev_bus_type); 472 } 473 module_exit(serdev_exit); 474 475 static int __init serdev_init(void) 476 { 477 int ret; 478 479 ret = bus_register(&serdev_bus_type); 480 if (ret) 481 return ret; 482 483 is_registered = true; 484 return 0; 485 } 486 /* Must be before serial drivers register */ 487 postcore_initcall(serdev_init); 488 489 MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 490 MODULE_LICENSE("GPL v2"); 491 MODULE_DESCRIPTION("Serial attached device bus"); 492