1 /* 2 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space 3 * 4 * Copyright (C) 2014 Google, Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 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 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/fs.h> 21 #include <linux/mfd/core.h> 22 #include <linux/module.h> 23 #include <linux/platform_device.h> 24 #include <linux/pm.h> 25 #include <linux/slab.h> 26 #include <linux/uaccess.h> 27 28 #include "cros_ec_dev.h" 29 30 #define DRV_NAME "cros-ec-dev" 31 32 /* Device variables */ 33 #define CROS_MAX_DEV 128 34 static int ec_major; 35 36 static const struct attribute_group *cros_ec_groups[] = { 37 &cros_ec_attr_group, 38 &cros_ec_lightbar_attr_group, 39 &cros_ec_vbc_attr_group, 40 NULL, 41 }; 42 43 static struct class cros_class = { 44 .owner = THIS_MODULE, 45 .name = "chromeos", 46 .dev_groups = cros_ec_groups, 47 }; 48 49 /* Basic communication */ 50 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen) 51 { 52 struct ec_response_get_version *resp; 53 static const char * const current_image_name[] = { 54 "unknown", "read-only", "read-write", "invalid", 55 }; 56 struct cros_ec_command *msg; 57 int ret; 58 59 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL); 60 if (!msg) 61 return -ENOMEM; 62 63 msg->version = 0; 64 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset; 65 msg->insize = sizeof(*resp); 66 msg->outsize = 0; 67 68 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 69 if (ret < 0) 70 goto exit; 71 72 if (msg->result != EC_RES_SUCCESS) { 73 snprintf(str, maxlen, 74 "%s\nUnknown EC version: EC returned %d\n", 75 CROS_EC_DEV_VERSION, msg->result); 76 ret = -EINVAL; 77 goto exit; 78 } 79 80 resp = (struct ec_response_get_version *)msg->data; 81 if (resp->current_image >= ARRAY_SIZE(current_image_name)) 82 resp->current_image = 3; /* invalid */ 83 84 snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION, 85 resp->version_string_ro, resp->version_string_rw, 86 current_image_name[resp->current_image]); 87 88 ret = 0; 89 exit: 90 kfree(msg); 91 return ret; 92 } 93 94 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature) 95 { 96 struct cros_ec_command *msg; 97 int ret; 98 99 if (ec->features[0] == -1U && ec->features[1] == -1U) { 100 /* features bitmap not read yet */ 101 102 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL); 103 if (!msg) 104 return -ENOMEM; 105 106 msg->version = 0; 107 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset; 108 msg->insize = sizeof(ec->features); 109 msg->outsize = 0; 110 111 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 112 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 113 dev_warn(ec->dev, "cannot get EC features: %d/%d\n", 114 ret, msg->result); 115 memset(ec->features, 0, sizeof(ec->features)); 116 } else { 117 memcpy(ec->features, msg->data, sizeof(ec->features)); 118 } 119 120 dev_dbg(ec->dev, "EC features %08x %08x\n", 121 ec->features[0], ec->features[1]); 122 123 kfree(msg); 124 } 125 126 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature); 127 } 128 129 /* Device file ops */ 130 static int ec_device_open(struct inode *inode, struct file *filp) 131 { 132 struct cros_ec_dev *ec = container_of(inode->i_cdev, 133 struct cros_ec_dev, cdev); 134 filp->private_data = ec; 135 nonseekable_open(inode, filp); 136 return 0; 137 } 138 139 static int ec_device_release(struct inode *inode, struct file *filp) 140 { 141 return 0; 142 } 143 144 static ssize_t ec_device_read(struct file *filp, char __user *buffer, 145 size_t length, loff_t *offset) 146 { 147 struct cros_ec_dev *ec = filp->private_data; 148 char msg[sizeof(struct ec_response_get_version) + 149 sizeof(CROS_EC_DEV_VERSION)]; 150 size_t count; 151 int ret; 152 153 if (*offset != 0) 154 return 0; 155 156 ret = ec_get_version(ec, msg, sizeof(msg)); 157 if (ret) 158 return ret; 159 160 count = min(length, strlen(msg)); 161 162 if (copy_to_user(buffer, msg, count)) 163 return -EFAULT; 164 165 *offset = count; 166 return count; 167 } 168 169 /* Ioctls */ 170 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg) 171 { 172 long ret; 173 struct cros_ec_command u_cmd; 174 struct cros_ec_command *s_cmd; 175 176 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd))) 177 return -EFAULT; 178 179 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) || 180 (u_cmd.insize > EC_MAX_MSG_BYTES)) 181 return -EINVAL; 182 183 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize), 184 GFP_KERNEL); 185 if (!s_cmd) 186 return -ENOMEM; 187 188 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) { 189 ret = -EFAULT; 190 goto exit; 191 } 192 193 if (u_cmd.outsize != s_cmd->outsize || 194 u_cmd.insize != s_cmd->insize) { 195 ret = -EINVAL; 196 goto exit; 197 } 198 199 s_cmd->command += ec->cmd_offset; 200 ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd); 201 /* Only copy data to userland if data was received. */ 202 if (ret < 0) 203 goto exit; 204 205 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize)) 206 ret = -EFAULT; 207 exit: 208 kfree(s_cmd); 209 return ret; 210 } 211 212 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg) 213 { 214 struct cros_ec_device *ec_dev = ec->ec_dev; 215 struct cros_ec_readmem s_mem = { }; 216 long num; 217 218 /* Not every platform supports direct reads */ 219 if (!ec_dev->cmd_readmem) 220 return -ENOTTY; 221 222 if (copy_from_user(&s_mem, arg, sizeof(s_mem))) 223 return -EFAULT; 224 225 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes, 226 s_mem.buffer); 227 if (num <= 0) 228 return num; 229 230 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem))) 231 return -EFAULT; 232 233 return 0; 234 } 235 236 static long ec_device_ioctl(struct file *filp, unsigned int cmd, 237 unsigned long arg) 238 { 239 struct cros_ec_dev *ec = filp->private_data; 240 241 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC) 242 return -ENOTTY; 243 244 switch (cmd) { 245 case CROS_EC_DEV_IOCXCMD: 246 return ec_device_ioctl_xcmd(ec, (void __user *)arg); 247 case CROS_EC_DEV_IOCRDMEM: 248 return ec_device_ioctl_readmem(ec, (void __user *)arg); 249 } 250 251 return -ENOTTY; 252 } 253 254 /* Module initialization */ 255 static const struct file_operations fops = { 256 .open = ec_device_open, 257 .release = ec_device_release, 258 .read = ec_device_read, 259 .unlocked_ioctl = ec_device_ioctl, 260 #ifdef CONFIG_COMPAT 261 .compat_ioctl = ec_device_ioctl, 262 #endif 263 }; 264 265 static void __remove(struct device *dev) { } 266 267 static void cros_ec_sensors_register(struct cros_ec_dev *ec) 268 { 269 /* 270 * Issue a command to get the number of sensor reported. 271 * Build an array of sensors driver and register them all. 272 */ 273 int ret, i, id, sensor_num; 274 struct mfd_cell *sensor_cells; 275 struct cros_ec_sensor_platform *sensor_platforms; 276 int sensor_type[MOTIONSENSE_TYPE_MAX]; 277 struct ec_params_motion_sense *params; 278 struct ec_response_motion_sense *resp; 279 struct cros_ec_command *msg; 280 281 msg = kzalloc(sizeof(struct cros_ec_command) + 282 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL); 283 if (msg == NULL) 284 return; 285 286 msg->version = 2; 287 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset; 288 msg->outsize = sizeof(*params); 289 msg->insize = sizeof(*resp); 290 291 params = (struct ec_params_motion_sense *)msg->data; 292 params->cmd = MOTIONSENSE_CMD_DUMP; 293 294 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 295 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 296 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n", 297 ret, msg->result); 298 goto error; 299 } 300 301 resp = (struct ec_response_motion_sense *)msg->data; 302 sensor_num = resp->dump.sensor_count; 303 /* Allocate 1 extra sensors in FIFO are needed */ 304 sensor_cells = kzalloc(sizeof(struct mfd_cell) * (sensor_num + 1), 305 GFP_KERNEL); 306 if (sensor_cells == NULL) 307 goto error; 308 309 sensor_platforms = kzalloc(sizeof(struct cros_ec_sensor_platform) * 310 (sensor_num + 1), GFP_KERNEL); 311 if (sensor_platforms == NULL) 312 goto error_platforms; 313 314 memset(sensor_type, 0, sizeof(sensor_type)); 315 id = 0; 316 for (i = 0; i < sensor_num; i++) { 317 params->cmd = MOTIONSENSE_CMD_INFO; 318 params->info.sensor_num = i; 319 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 320 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 321 dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n", 322 i, ret, msg->result); 323 continue; 324 } 325 switch (resp->info.type) { 326 case MOTIONSENSE_TYPE_ACCEL: 327 sensor_cells[id].name = "cros-ec-accel"; 328 break; 329 case MOTIONSENSE_TYPE_BARO: 330 sensor_cells[id].name = "cros-ec-baro"; 331 break; 332 case MOTIONSENSE_TYPE_GYRO: 333 sensor_cells[id].name = "cros-ec-gyro"; 334 break; 335 case MOTIONSENSE_TYPE_MAG: 336 sensor_cells[id].name = "cros-ec-mag"; 337 break; 338 case MOTIONSENSE_TYPE_PROX: 339 sensor_cells[id].name = "cros-ec-prox"; 340 break; 341 case MOTIONSENSE_TYPE_LIGHT: 342 sensor_cells[id].name = "cros-ec-light"; 343 break; 344 case MOTIONSENSE_TYPE_ACTIVITY: 345 sensor_cells[id].name = "cros-ec-activity"; 346 break; 347 default: 348 dev_warn(ec->dev, "unknown type %d\n", resp->info.type); 349 continue; 350 } 351 sensor_platforms[id].sensor_num = i; 352 sensor_cells[id].id = sensor_type[resp->info.type]; 353 sensor_cells[id].platform_data = &sensor_platforms[id]; 354 sensor_cells[id].pdata_size = 355 sizeof(struct cros_ec_sensor_platform); 356 357 sensor_type[resp->info.type]++; 358 id++; 359 } 360 361 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) 362 ec->has_kb_wake_angle = true; 363 364 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) { 365 sensor_cells[id].name = "cros-ec-ring"; 366 id++; 367 } 368 369 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id, 370 NULL, 0, NULL); 371 if (ret) 372 dev_err(ec->dev, "failed to add EC sensors\n"); 373 374 kfree(sensor_platforms); 375 error_platforms: 376 kfree(sensor_cells); 377 error: 378 kfree(msg); 379 } 380 381 static const struct mfd_cell cros_ec_rtc_cells[] = { 382 { .name = "cros-ec-rtc" } 383 }; 384 385 static int ec_device_probe(struct platform_device *pdev) 386 { 387 int retval = -ENOMEM; 388 struct device *dev = &pdev->dev; 389 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 390 struct cros_ec_dev *ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); 391 392 if (!ec) 393 return retval; 394 395 dev_set_drvdata(dev, ec); 396 ec->ec_dev = dev_get_drvdata(dev->parent); 397 ec->dev = dev; 398 ec->cmd_offset = ec_platform->cmd_offset; 399 ec->features[0] = -1U; /* Not cached yet */ 400 ec->features[1] = -1U; /* Not cached yet */ 401 device_initialize(&ec->class_dev); 402 cdev_init(&ec->cdev, &fops); 403 404 /* 405 * Add the class device 406 * Link to the character device for creating the /dev entry 407 * in devtmpfs. 408 */ 409 ec->class_dev.devt = MKDEV(ec_major, pdev->id); 410 ec->class_dev.class = &cros_class; 411 ec->class_dev.parent = dev; 412 413 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); 414 if (retval) { 415 dev_err(dev, "dev_set_name failed => %d\n", retval); 416 goto failed; 417 } 418 419 /* check whether this EC is a sensor hub. */ 420 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) 421 cros_ec_sensors_register(ec); 422 423 /* Check whether this EC instance has RTC host command support */ 424 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) { 425 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 426 cros_ec_rtc_cells, 427 ARRAY_SIZE(cros_ec_rtc_cells), 428 NULL, 0, NULL); 429 if (retval) 430 dev_err(ec->dev, 431 "failed to add cros-ec-rtc device: %d\n", 432 retval); 433 } 434 435 /* Take control of the lightbar from the EC. */ 436 lb_manual_suspend_ctrl(ec, 1); 437 438 /* We can now add the sysfs class, we know which parameter to show */ 439 retval = cdev_device_add(&ec->cdev, &ec->class_dev); 440 if (retval) { 441 dev_err(dev, "cdev_device_add failed => %d\n", retval); 442 goto failed; 443 } 444 445 if (cros_ec_debugfs_init(ec)) 446 dev_warn(dev, "failed to create debugfs directory\n"); 447 448 return 0; 449 450 failed: 451 put_device(&ec->class_dev); 452 return retval; 453 } 454 455 static int ec_device_remove(struct platform_device *pdev) 456 { 457 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 458 459 /* Let the EC take over the lightbar again. */ 460 lb_manual_suspend_ctrl(ec, 0); 461 462 cros_ec_debugfs_remove(ec); 463 464 cdev_del(&ec->cdev); 465 device_unregister(&ec->class_dev); 466 return 0; 467 } 468 469 static void ec_device_shutdown(struct platform_device *pdev) 470 { 471 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 472 473 /* Be sure to clear up debugfs delayed works */ 474 cros_ec_debugfs_remove(ec); 475 } 476 477 static const struct platform_device_id cros_ec_id[] = { 478 { DRV_NAME, 0 }, 479 { /* sentinel */ } 480 }; 481 MODULE_DEVICE_TABLE(platform, cros_ec_id); 482 483 static __maybe_unused int ec_device_suspend(struct device *dev) 484 { 485 struct cros_ec_dev *ec = dev_get_drvdata(dev); 486 487 cros_ec_debugfs_suspend(ec); 488 489 lb_suspend(ec); 490 491 return 0; 492 } 493 494 static __maybe_unused int ec_device_resume(struct device *dev) 495 { 496 struct cros_ec_dev *ec = dev_get_drvdata(dev); 497 498 cros_ec_debugfs_resume(ec); 499 500 lb_resume(ec); 501 502 return 0; 503 } 504 505 static const struct dev_pm_ops cros_ec_dev_pm_ops = { 506 #ifdef CONFIG_PM_SLEEP 507 .suspend = ec_device_suspend, 508 .resume = ec_device_resume, 509 #endif 510 }; 511 512 static struct platform_driver cros_ec_dev_driver = { 513 .driver = { 514 .name = DRV_NAME, 515 .pm = &cros_ec_dev_pm_ops, 516 }, 517 .probe = ec_device_probe, 518 .remove = ec_device_remove, 519 .shutdown = ec_device_shutdown, 520 }; 521 522 static int __init cros_ec_dev_init(void) 523 { 524 int ret; 525 dev_t dev = 0; 526 527 ret = class_register(&cros_class); 528 if (ret) { 529 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 530 return ret; 531 } 532 533 /* Get a range of minor numbers (starting with 0) to work with */ 534 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME); 535 if (ret < 0) { 536 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n"); 537 goto failed_chrdevreg; 538 } 539 ec_major = MAJOR(dev); 540 541 /* Register the driver */ 542 ret = platform_driver_register(&cros_ec_dev_driver); 543 if (ret < 0) { 544 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 545 goto failed_devreg; 546 } 547 return 0; 548 549 failed_devreg: 550 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV); 551 failed_chrdevreg: 552 class_unregister(&cros_class); 553 return ret; 554 } 555 556 static void __exit cros_ec_dev_exit(void) 557 { 558 platform_driver_unregister(&cros_ec_dev_driver); 559 unregister_chrdev(ec_major, CROS_EC_DEV_NAME); 560 class_unregister(&cros_class); 561 } 562 563 module_init(cros_ec_dev_init); 564 module_exit(cros_ec_dev_exit); 565 566 MODULE_ALIAS("platform:" DRV_NAME); 567 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 568 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 569 MODULE_VERSION("1.0"); 570 MODULE_LICENSE("GPL"); 571