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(struct serdev_device *serdev, 126 const unsigned char *buf, size_t count, 127 unsigned long timeout) 128 { 129 struct serdev_controller *ctrl = serdev->ctrl; 130 int ret; 131 132 if (!ctrl || !ctrl->ops->write_buf || 133 (timeout && !serdev->ops->write_wakeup)) 134 return -EINVAL; 135 136 mutex_lock(&serdev->write_lock); 137 do { 138 reinit_completion(&serdev->write_comp); 139 140 ret = ctrl->ops->write_buf(ctrl, buf, count); 141 if (ret < 0) 142 break; 143 144 buf += ret; 145 count -= ret; 146 147 } while (count && 148 (timeout = wait_for_completion_timeout(&serdev->write_comp, 149 timeout))); 150 mutex_unlock(&serdev->write_lock); 151 return ret < 0 ? ret : (count ? -ETIMEDOUT : 0); 152 } 153 EXPORT_SYMBOL_GPL(serdev_device_write); 154 155 void serdev_device_write_flush(struct serdev_device *serdev) 156 { 157 struct serdev_controller *ctrl = serdev->ctrl; 158 159 if (!ctrl || !ctrl->ops->write_flush) 160 return; 161 162 ctrl->ops->write_flush(ctrl); 163 } 164 EXPORT_SYMBOL_GPL(serdev_device_write_flush); 165 166 int serdev_device_write_room(struct serdev_device *serdev) 167 { 168 struct serdev_controller *ctrl = serdev->ctrl; 169 170 if (!ctrl || !ctrl->ops->write_room) 171 return 0; 172 173 return serdev->ctrl->ops->write_room(ctrl); 174 } 175 EXPORT_SYMBOL_GPL(serdev_device_write_room); 176 177 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) 178 { 179 struct serdev_controller *ctrl = serdev->ctrl; 180 181 if (!ctrl || !ctrl->ops->set_baudrate) 182 return 0; 183 184 return ctrl->ops->set_baudrate(ctrl, speed); 185 186 } 187 EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); 188 189 void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) 190 { 191 struct serdev_controller *ctrl = serdev->ctrl; 192 193 if (!ctrl || !ctrl->ops->set_flow_control) 194 return; 195 196 ctrl->ops->set_flow_control(ctrl, enable); 197 } 198 EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); 199 200 void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) 201 { 202 struct serdev_controller *ctrl = serdev->ctrl; 203 204 if (!ctrl || !ctrl->ops->wait_until_sent) 205 return; 206 207 ctrl->ops->wait_until_sent(ctrl, timeout); 208 } 209 EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); 210 211 int serdev_device_get_tiocm(struct serdev_device *serdev) 212 { 213 struct serdev_controller *ctrl = serdev->ctrl; 214 215 if (!ctrl || !ctrl->ops->get_tiocm) 216 return -ENOTSUPP; 217 218 return ctrl->ops->get_tiocm(ctrl); 219 } 220 EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); 221 222 int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 223 { 224 struct serdev_controller *ctrl = serdev->ctrl; 225 226 if (!ctrl || !ctrl->ops->set_tiocm) 227 return -ENOTSUPP; 228 229 return ctrl->ops->set_tiocm(ctrl, set, clear); 230 } 231 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); 232 233 static int serdev_drv_probe(struct device *dev) 234 { 235 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 236 237 return sdrv->probe(to_serdev_device(dev)); 238 } 239 240 static int serdev_drv_remove(struct device *dev) 241 { 242 const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); 243 244 sdrv->remove(to_serdev_device(dev)); 245 return 0; 246 } 247 248 static ssize_t modalias_show(struct device *dev, 249 struct device_attribute *attr, char *buf) 250 { 251 return of_device_modalias(dev, buf, PAGE_SIZE); 252 } 253 254 static struct device_attribute serdev_device_attrs[] = { 255 __ATTR_RO(modalias), 256 __ATTR_NULL 257 }; 258 259 static struct bus_type serdev_bus_type = { 260 .name = "serial", 261 .match = serdev_device_match, 262 .probe = serdev_drv_probe, 263 .remove = serdev_drv_remove, 264 .uevent = serdev_uevent, 265 .dev_attrs = serdev_device_attrs, 266 }; 267 268 /** 269 * serdev_controller_alloc() - Allocate a new serdev device 270 * @ctrl: associated controller 271 * 272 * Caller is responsible for either calling serdev_device_add() to add the 273 * newly allocated controller, or calling serdev_device_put() to discard it. 274 */ 275 struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 276 { 277 struct serdev_device *serdev; 278 279 serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); 280 if (!serdev) 281 return NULL; 282 283 serdev->ctrl = ctrl; 284 ctrl->serdev = serdev; 285 device_initialize(&serdev->dev); 286 serdev->dev.parent = &ctrl->dev; 287 serdev->dev.bus = &serdev_bus_type; 288 serdev->dev.type = &serdev_device_type; 289 init_completion(&serdev->write_comp); 290 mutex_init(&serdev->write_lock); 291 return serdev; 292 } 293 EXPORT_SYMBOL_GPL(serdev_device_alloc); 294 295 /** 296 * serdev_controller_alloc() - Allocate a new serdev controller 297 * @parent: parent device 298 * @size: size of private data 299 * 300 * Caller is responsible for either calling serdev_controller_add() to add the 301 * newly allocated controller, or calling serdev_controller_put() to discard it. 302 * The allocated private data region may be accessed via 303 * serdev_controller_get_drvdata() 304 */ 305 struct serdev_controller *serdev_controller_alloc(struct device *parent, 306 size_t size) 307 { 308 struct serdev_controller *ctrl; 309 int id; 310 311 if (WARN_ON(!parent)) 312 return NULL; 313 314 ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); 315 if (!ctrl) 316 return NULL; 317 318 device_initialize(&ctrl->dev); 319 ctrl->dev.type = &serdev_ctrl_type; 320 ctrl->dev.bus = &serdev_bus_type; 321 ctrl->dev.parent = parent; 322 ctrl->dev.of_node = parent->of_node; 323 serdev_controller_set_drvdata(ctrl, &ctrl[1]); 324 325 id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL); 326 if (id < 0) { 327 dev_err(parent, 328 "unable to allocate serdev controller identifier.\n"); 329 serdev_controller_put(ctrl); 330 return NULL; 331 } 332 333 ctrl->nr = id; 334 dev_set_name(&ctrl->dev, "serial%d", id); 335 336 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); 337 return ctrl; 338 } 339 EXPORT_SYMBOL_GPL(serdev_controller_alloc); 340 341 static int of_serdev_register_devices(struct serdev_controller *ctrl) 342 { 343 struct device_node *node; 344 struct serdev_device *serdev = NULL; 345 int err; 346 bool found = false; 347 348 for_each_available_child_of_node(ctrl->dev.of_node, node) { 349 if (!of_get_property(node, "compatible", NULL)) 350 continue; 351 352 dev_dbg(&ctrl->dev, "adding child %s\n", node->full_name); 353 354 serdev = serdev_device_alloc(ctrl); 355 if (!serdev) 356 continue; 357 358 serdev->dev.of_node = node; 359 360 err = serdev_device_add(serdev); 361 if (err) { 362 dev_err(&serdev->dev, 363 "failure adding device. status %d\n", err); 364 serdev_device_put(serdev); 365 } else 366 found = true; 367 } 368 if (!found) 369 return -ENODEV; 370 371 return 0; 372 } 373 374 /** 375 * serdev_controller_add() - Add an serdev controller 376 * @ctrl: controller to be registered. 377 * 378 * Register a controller previously allocated via serdev_controller_alloc() with 379 * the serdev core. 380 */ 381 int serdev_controller_add(struct serdev_controller *ctrl) 382 { 383 int ret; 384 385 /* Can't register until after driver model init */ 386 if (WARN_ON(!is_registered)) 387 return -EAGAIN; 388 389 ret = device_add(&ctrl->dev); 390 if (ret) 391 return ret; 392 393 ret = of_serdev_register_devices(ctrl); 394 if (ret) 395 goto out_dev_del; 396 397 dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", 398 ctrl->nr, &ctrl->dev); 399 return 0; 400 401 out_dev_del: 402 device_del(&ctrl->dev); 403 return ret; 404 }; 405 EXPORT_SYMBOL_GPL(serdev_controller_add); 406 407 /* Remove a device associated with a controller */ 408 static int serdev_remove_device(struct device *dev, void *data) 409 { 410 struct serdev_device *serdev = to_serdev_device(dev); 411 if (dev->type == &serdev_device_type) 412 serdev_device_remove(serdev); 413 return 0; 414 } 415 416 /** 417 * serdev_controller_remove(): remove an serdev controller 418 * @ctrl: controller to remove 419 * 420 * Remove a serdev controller. Caller is responsible for calling 421 * serdev_controller_put() to discard the allocated controller. 422 */ 423 void serdev_controller_remove(struct serdev_controller *ctrl) 424 { 425 int dummy; 426 427 if (!ctrl) 428 return; 429 430 dummy = device_for_each_child(&ctrl->dev, NULL, 431 serdev_remove_device); 432 device_del(&ctrl->dev); 433 } 434 EXPORT_SYMBOL_GPL(serdev_controller_remove); 435 436 /** 437 * serdev_driver_register() - Register client driver with serdev core 438 * @sdrv: client driver to be associated with client-device. 439 * 440 * This API will register the client driver with the serdev framework. 441 * It is typically called from the driver's module-init function. 442 */ 443 int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) 444 { 445 sdrv->driver.bus = &serdev_bus_type; 446 sdrv->driver.owner = owner; 447 448 /* force drivers to async probe so I/O is possible in probe */ 449 sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; 450 451 return driver_register(&sdrv->driver); 452 } 453 EXPORT_SYMBOL_GPL(__serdev_device_driver_register); 454 455 static void __exit serdev_exit(void) 456 { 457 bus_unregister(&serdev_bus_type); 458 } 459 module_exit(serdev_exit); 460 461 static int __init serdev_init(void) 462 { 463 int ret; 464 465 ret = bus_register(&serdev_bus_type); 466 if (ret) 467 return ret; 468 469 is_registered = true; 470 return 0; 471 } 472 /* Must be before serial drivers register */ 473 postcore_initcall(serdev_init); 474 475 MODULE_AUTHOR("Rob Herring <robh@kernel.org>"); 476 MODULE_LICENSE("GPL v2"); 477 MODULE_DESCRIPTION("Serial attached device bus"); 478