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/mod_devicetable.h> 24 #include <linux/platform_device.h> 25 #include <linux/pm.h> 26 #include <linux/slab.h> 27 #include <linux/uaccess.h> 28 29 #include "cros_ec_dev.h" 30 31 #define DRV_NAME "cros-ec-dev" 32 33 /* Device variables */ 34 #define CROS_MAX_DEV 128 35 static int ec_major; 36 37 static const struct attribute_group *cros_ec_groups[] = { 38 &cros_ec_attr_group, 39 &cros_ec_lightbar_attr_group, 40 &cros_ec_vbc_attr_group, 41 NULL, 42 }; 43 44 static struct class cros_class = { 45 .owner = THIS_MODULE, 46 .name = "chromeos", 47 .dev_groups = cros_ec_groups, 48 }; 49 50 /* Basic communication */ 51 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen) 52 { 53 struct ec_response_get_version *resp; 54 static const char * const current_image_name[] = { 55 "unknown", "read-only", "read-write", "invalid", 56 }; 57 struct cros_ec_command *msg; 58 int ret; 59 60 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL); 61 if (!msg) 62 return -ENOMEM; 63 64 msg->version = 0; 65 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset; 66 msg->insize = sizeof(*resp); 67 msg->outsize = 0; 68 69 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 70 if (ret < 0) 71 goto exit; 72 73 if (msg->result != EC_RES_SUCCESS) { 74 snprintf(str, maxlen, 75 "%s\nUnknown EC version: EC returned %d\n", 76 CROS_EC_DEV_VERSION, msg->result); 77 ret = -EINVAL; 78 goto exit; 79 } 80 81 resp = (struct ec_response_get_version *)msg->data; 82 if (resp->current_image >= ARRAY_SIZE(current_image_name)) 83 resp->current_image = 3; /* invalid */ 84 85 snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION, 86 resp->version_string_ro, resp->version_string_rw, 87 current_image_name[resp->current_image]); 88 89 ret = 0; 90 exit: 91 kfree(msg); 92 return ret; 93 } 94 95 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature) 96 { 97 struct cros_ec_command *msg; 98 int ret; 99 100 if (ec->features[0] == -1U && ec->features[1] == -1U) { 101 /* features bitmap not read yet */ 102 103 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL); 104 if (!msg) 105 return -ENOMEM; 106 107 msg->version = 0; 108 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset; 109 msg->insize = sizeof(ec->features); 110 msg->outsize = 0; 111 112 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 113 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 114 dev_warn(ec->dev, "cannot get EC features: %d/%d\n", 115 ret, msg->result); 116 memset(ec->features, 0, sizeof(ec->features)); 117 } else { 118 memcpy(ec->features, msg->data, sizeof(ec->features)); 119 } 120 121 dev_dbg(ec->dev, "EC features %08x %08x\n", 122 ec->features[0], ec->features[1]); 123 124 kfree(msg); 125 } 126 127 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature); 128 } 129 130 /* Device file ops */ 131 static int ec_device_open(struct inode *inode, struct file *filp) 132 { 133 struct cros_ec_dev *ec = container_of(inode->i_cdev, 134 struct cros_ec_dev, cdev); 135 filp->private_data = ec; 136 nonseekable_open(inode, filp); 137 return 0; 138 } 139 140 static int ec_device_release(struct inode *inode, struct file *filp) 141 { 142 return 0; 143 } 144 145 static ssize_t ec_device_read(struct file *filp, char __user *buffer, 146 size_t length, loff_t *offset) 147 { 148 struct cros_ec_dev *ec = filp->private_data; 149 char msg[sizeof(struct ec_response_get_version) + 150 sizeof(CROS_EC_DEV_VERSION)]; 151 size_t count; 152 int ret; 153 154 if (*offset != 0) 155 return 0; 156 157 ret = ec_get_version(ec, msg, sizeof(msg)); 158 if (ret) 159 return ret; 160 161 count = min(length, strlen(msg)); 162 163 if (copy_to_user(buffer, msg, count)) 164 return -EFAULT; 165 166 *offset = count; 167 return count; 168 } 169 170 /* Ioctls */ 171 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg) 172 { 173 long ret; 174 struct cros_ec_command u_cmd; 175 struct cros_ec_command *s_cmd; 176 177 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd))) 178 return -EFAULT; 179 180 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) || 181 (u_cmd.insize > EC_MAX_MSG_BYTES)) 182 return -EINVAL; 183 184 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize), 185 GFP_KERNEL); 186 if (!s_cmd) 187 return -ENOMEM; 188 189 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) { 190 ret = -EFAULT; 191 goto exit; 192 } 193 194 if (u_cmd.outsize != s_cmd->outsize || 195 u_cmd.insize != s_cmd->insize) { 196 ret = -EINVAL; 197 goto exit; 198 } 199 200 s_cmd->command += ec->cmd_offset; 201 ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd); 202 /* Only copy data to userland if data was received. */ 203 if (ret < 0) 204 goto exit; 205 206 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize)) 207 ret = -EFAULT; 208 exit: 209 kfree(s_cmd); 210 return ret; 211 } 212 213 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg) 214 { 215 struct cros_ec_device *ec_dev = ec->ec_dev; 216 struct cros_ec_readmem s_mem = { }; 217 long num; 218 219 /* Not every platform supports direct reads */ 220 if (!ec_dev->cmd_readmem) 221 return -ENOTTY; 222 223 if (copy_from_user(&s_mem, arg, sizeof(s_mem))) 224 return -EFAULT; 225 226 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes, 227 s_mem.buffer); 228 if (num <= 0) 229 return num; 230 231 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem))) 232 return -EFAULT; 233 234 return 0; 235 } 236 237 static long ec_device_ioctl(struct file *filp, unsigned int cmd, 238 unsigned long arg) 239 { 240 struct cros_ec_dev *ec = filp->private_data; 241 242 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC) 243 return -ENOTTY; 244 245 switch (cmd) { 246 case CROS_EC_DEV_IOCXCMD: 247 return ec_device_ioctl_xcmd(ec, (void __user *)arg); 248 case CROS_EC_DEV_IOCRDMEM: 249 return ec_device_ioctl_readmem(ec, (void __user *)arg); 250 } 251 252 return -ENOTTY; 253 } 254 255 /* Module initialization */ 256 static const struct file_operations fops = { 257 .open = ec_device_open, 258 .release = ec_device_release, 259 .read = ec_device_read, 260 .unlocked_ioctl = ec_device_ioctl, 261 #ifdef CONFIG_COMPAT 262 .compat_ioctl = ec_device_ioctl, 263 #endif 264 }; 265 266 static void cros_ec_sensors_register(struct cros_ec_dev *ec) 267 { 268 /* 269 * Issue a command to get the number of sensor reported. 270 * Build an array of sensors driver and register them all. 271 */ 272 int ret, i, id, sensor_num; 273 struct mfd_cell *sensor_cells; 274 struct cros_ec_sensor_platform *sensor_platforms; 275 int sensor_type[MOTIONSENSE_TYPE_MAX]; 276 struct ec_params_motion_sense *params; 277 struct ec_response_motion_sense *resp; 278 struct cros_ec_command *msg; 279 280 msg = kzalloc(sizeof(struct cros_ec_command) + 281 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL); 282 if (msg == NULL) 283 return; 284 285 msg->version = 2; 286 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset; 287 msg->outsize = sizeof(*params); 288 msg->insize = sizeof(*resp); 289 290 params = (struct ec_params_motion_sense *)msg->data; 291 params->cmd = MOTIONSENSE_CMD_DUMP; 292 293 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 294 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 295 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n", 296 ret, msg->result); 297 goto error; 298 } 299 300 resp = (struct ec_response_motion_sense *)msg->data; 301 sensor_num = resp->dump.sensor_count; 302 /* Allocate 1 extra sensors in FIFO are needed */ 303 sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell), 304 GFP_KERNEL); 305 if (sensor_cells == NULL) 306 goto error; 307 308 sensor_platforms = kcalloc(sensor_num + 1, 309 sizeof(struct cros_ec_sensor_platform), 310 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_cec_cells[] = { 382 { .name = "cros-ec-cec" } 383 }; 384 385 static const struct mfd_cell cros_ec_rtc_cells[] = { 386 { .name = "cros-ec-rtc" } 387 }; 388 389 static const struct mfd_cell cros_usbpd_charger_cells[] = { 390 { .name = "cros-usbpd-charger" } 391 }; 392 393 static int ec_device_probe(struct platform_device *pdev) 394 { 395 int retval = -ENOMEM; 396 struct device *dev = &pdev->dev; 397 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 398 struct cros_ec_dev *ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); 399 400 if (!ec) 401 return retval; 402 403 dev_set_drvdata(dev, ec); 404 ec->ec_dev = dev_get_drvdata(dev->parent); 405 ec->dev = dev; 406 ec->cmd_offset = ec_platform->cmd_offset; 407 ec->features[0] = -1U; /* Not cached yet */ 408 ec->features[1] = -1U; /* Not cached yet */ 409 device_initialize(&ec->class_dev); 410 cdev_init(&ec->cdev, &fops); 411 412 /* 413 * Add the class device 414 * Link to the character device for creating the /dev entry 415 * in devtmpfs. 416 */ 417 ec->class_dev.devt = MKDEV(ec_major, pdev->id); 418 ec->class_dev.class = &cros_class; 419 ec->class_dev.parent = dev; 420 421 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); 422 if (retval) { 423 dev_err(dev, "dev_set_name failed => %d\n", retval); 424 goto failed; 425 } 426 427 /* check whether this EC is a sensor hub. */ 428 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) 429 cros_ec_sensors_register(ec); 430 431 /* Check whether this EC instance has CEC host command support */ 432 if (cros_ec_check_features(ec, EC_FEATURE_CEC)) { 433 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 434 cros_ec_cec_cells, 435 ARRAY_SIZE(cros_ec_cec_cells), 436 NULL, 0, NULL); 437 if (retval) 438 dev_err(ec->dev, 439 "failed to add cros-ec-cec device: %d\n", 440 retval); 441 } 442 443 /* Check whether this EC instance has RTC host command support */ 444 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) { 445 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 446 cros_ec_rtc_cells, 447 ARRAY_SIZE(cros_ec_rtc_cells), 448 NULL, 0, NULL); 449 if (retval) 450 dev_err(ec->dev, 451 "failed to add cros-ec-rtc device: %d\n", 452 retval); 453 } 454 455 /* Check whether this EC instance has the PD charge manager */ 456 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) { 457 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 458 cros_usbpd_charger_cells, 459 ARRAY_SIZE(cros_usbpd_charger_cells), 460 NULL, 0, NULL); 461 if (retval) 462 dev_err(ec->dev, 463 "failed to add cros-usbpd-charger device: %d\n", 464 retval); 465 } 466 467 /* Take control of the lightbar from the EC. */ 468 lb_manual_suspend_ctrl(ec, 1); 469 470 /* We can now add the sysfs class, we know which parameter to show */ 471 retval = cdev_device_add(&ec->cdev, &ec->class_dev); 472 if (retval) { 473 dev_err(dev, "cdev_device_add failed => %d\n", retval); 474 goto failed; 475 } 476 477 if (cros_ec_debugfs_init(ec)) 478 dev_warn(dev, "failed to create debugfs directory\n"); 479 480 return 0; 481 482 failed: 483 put_device(&ec->class_dev); 484 return retval; 485 } 486 487 static int ec_device_remove(struct platform_device *pdev) 488 { 489 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 490 491 /* Let the EC take over the lightbar again. */ 492 lb_manual_suspend_ctrl(ec, 0); 493 494 cros_ec_debugfs_remove(ec); 495 496 cdev_del(&ec->cdev); 497 device_unregister(&ec->class_dev); 498 return 0; 499 } 500 501 static void ec_device_shutdown(struct platform_device *pdev) 502 { 503 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 504 505 /* Be sure to clear up debugfs delayed works */ 506 cros_ec_debugfs_remove(ec); 507 } 508 509 static const struct platform_device_id cros_ec_id[] = { 510 { DRV_NAME, 0 }, 511 { /* sentinel */ } 512 }; 513 MODULE_DEVICE_TABLE(platform, cros_ec_id); 514 515 static __maybe_unused int ec_device_suspend(struct device *dev) 516 { 517 struct cros_ec_dev *ec = dev_get_drvdata(dev); 518 519 cros_ec_debugfs_suspend(ec); 520 521 lb_suspend(ec); 522 523 return 0; 524 } 525 526 static __maybe_unused int ec_device_resume(struct device *dev) 527 { 528 struct cros_ec_dev *ec = dev_get_drvdata(dev); 529 530 cros_ec_debugfs_resume(ec); 531 532 lb_resume(ec); 533 534 return 0; 535 } 536 537 static const struct dev_pm_ops cros_ec_dev_pm_ops = { 538 #ifdef CONFIG_PM_SLEEP 539 .suspend = ec_device_suspend, 540 .resume = ec_device_resume, 541 #endif 542 }; 543 544 static struct platform_driver cros_ec_dev_driver = { 545 .driver = { 546 .name = DRV_NAME, 547 .pm = &cros_ec_dev_pm_ops, 548 }, 549 .probe = ec_device_probe, 550 .remove = ec_device_remove, 551 .shutdown = ec_device_shutdown, 552 }; 553 554 static int __init cros_ec_dev_init(void) 555 { 556 int ret; 557 dev_t dev = 0; 558 559 ret = class_register(&cros_class); 560 if (ret) { 561 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 562 return ret; 563 } 564 565 /* Get a range of minor numbers (starting with 0) to work with */ 566 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME); 567 if (ret < 0) { 568 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n"); 569 goto failed_chrdevreg; 570 } 571 ec_major = MAJOR(dev); 572 573 /* Register the driver */ 574 ret = platform_driver_register(&cros_ec_dev_driver); 575 if (ret < 0) { 576 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 577 goto failed_devreg; 578 } 579 return 0; 580 581 failed_devreg: 582 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV); 583 failed_chrdevreg: 584 class_unregister(&cros_class); 585 return ret; 586 } 587 588 static void __exit cros_ec_dev_exit(void) 589 { 590 platform_driver_unregister(&cros_ec_dev_driver); 591 unregister_chrdev(ec_major, CROS_EC_DEV_NAME); 592 class_unregister(&cros_class); 593 } 594 595 module_init(cros_ec_dev_init); 596 module_exit(cros_ec_dev_exit); 597 598 MODULE_ALIAS("platform:" DRV_NAME); 599 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 600 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 601 MODULE_VERSION("1.0"); 602 MODULE_LICENSE("GPL"); 603