1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space 4 * 5 * Copyright (C) 2014 Google, Inc. 6 */ 7 8 #include <linux/fs.h> 9 #include <linux/mfd/core.h> 10 #include <linux/module.h> 11 #include <linux/mod_devicetable.h> 12 #include <linux/of_platform.h> 13 #include <linux/platform_device.h> 14 #include <linux/pm.h> 15 #include <linux/slab.h> 16 #include <linux/uaccess.h> 17 18 #include "cros_ec_dev.h" 19 20 #define DRV_NAME "cros-ec-dev" 21 22 /* Device variables */ 23 #define CROS_MAX_DEV 128 24 static int ec_major; 25 26 static struct class cros_class = { 27 .owner = THIS_MODULE, 28 .name = "chromeos", 29 }; 30 31 /* Basic communication */ 32 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen) 33 { 34 struct ec_response_get_version *resp; 35 static const char * const current_image_name[] = { 36 "unknown", "read-only", "read-write", "invalid", 37 }; 38 struct cros_ec_command *msg; 39 int ret; 40 41 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL); 42 if (!msg) 43 return -ENOMEM; 44 45 msg->version = 0; 46 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset; 47 msg->insize = sizeof(*resp); 48 msg->outsize = 0; 49 50 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 51 if (ret < 0) 52 goto exit; 53 54 if (msg->result != EC_RES_SUCCESS) { 55 snprintf(str, maxlen, 56 "%s\nUnknown EC version: EC returned %d\n", 57 CROS_EC_DEV_VERSION, msg->result); 58 ret = -EINVAL; 59 goto exit; 60 } 61 62 resp = (struct ec_response_get_version *)msg->data; 63 if (resp->current_image >= ARRAY_SIZE(current_image_name)) 64 resp->current_image = 3; /* invalid */ 65 66 snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION, 67 resp->version_string_ro, resp->version_string_rw, 68 current_image_name[resp->current_image]); 69 70 ret = 0; 71 exit: 72 kfree(msg); 73 return ret; 74 } 75 76 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature) 77 { 78 struct cros_ec_command *msg; 79 int ret; 80 81 if (ec->features[0] == -1U && ec->features[1] == -1U) { 82 /* features bitmap not read yet */ 83 84 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL); 85 if (!msg) 86 return -ENOMEM; 87 88 msg->version = 0; 89 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset; 90 msg->insize = sizeof(ec->features); 91 msg->outsize = 0; 92 93 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 94 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 95 dev_warn(ec->dev, "cannot get EC features: %d/%d\n", 96 ret, msg->result); 97 memset(ec->features, 0, sizeof(ec->features)); 98 } else { 99 memcpy(ec->features, msg->data, sizeof(ec->features)); 100 } 101 102 dev_dbg(ec->dev, "EC features %08x %08x\n", 103 ec->features[0], ec->features[1]); 104 105 kfree(msg); 106 } 107 108 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature); 109 } 110 111 /* Device file ops */ 112 static int ec_device_open(struct inode *inode, struct file *filp) 113 { 114 struct cros_ec_dev *ec = container_of(inode->i_cdev, 115 struct cros_ec_dev, cdev); 116 filp->private_data = ec; 117 nonseekable_open(inode, filp); 118 return 0; 119 } 120 121 static int ec_device_release(struct inode *inode, struct file *filp) 122 { 123 return 0; 124 } 125 126 static ssize_t ec_device_read(struct file *filp, char __user *buffer, 127 size_t length, loff_t *offset) 128 { 129 struct cros_ec_dev *ec = filp->private_data; 130 char msg[sizeof(struct ec_response_get_version) + 131 sizeof(CROS_EC_DEV_VERSION)]; 132 size_t count; 133 int ret; 134 135 if (*offset != 0) 136 return 0; 137 138 ret = ec_get_version(ec, msg, sizeof(msg)); 139 if (ret) 140 return ret; 141 142 count = min(length, strlen(msg)); 143 144 if (copy_to_user(buffer, msg, count)) 145 return -EFAULT; 146 147 *offset = count; 148 return count; 149 } 150 151 /* Ioctls */ 152 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg) 153 { 154 long ret; 155 struct cros_ec_command u_cmd; 156 struct cros_ec_command *s_cmd; 157 158 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd))) 159 return -EFAULT; 160 161 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) || 162 (u_cmd.insize > EC_MAX_MSG_BYTES)) 163 return -EINVAL; 164 165 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize), 166 GFP_KERNEL); 167 if (!s_cmd) 168 return -ENOMEM; 169 170 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) { 171 ret = -EFAULT; 172 goto exit; 173 } 174 175 if (u_cmd.outsize != s_cmd->outsize || 176 u_cmd.insize != s_cmd->insize) { 177 ret = -EINVAL; 178 goto exit; 179 } 180 181 s_cmd->command += ec->cmd_offset; 182 ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd); 183 /* Only copy data to userland if data was received. */ 184 if (ret < 0) 185 goto exit; 186 187 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize)) 188 ret = -EFAULT; 189 exit: 190 kfree(s_cmd); 191 return ret; 192 } 193 194 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg) 195 { 196 struct cros_ec_device *ec_dev = ec->ec_dev; 197 struct cros_ec_readmem s_mem = { }; 198 long num; 199 200 /* Not every platform supports direct reads */ 201 if (!ec_dev->cmd_readmem) 202 return -ENOTTY; 203 204 if (copy_from_user(&s_mem, arg, sizeof(s_mem))) 205 return -EFAULT; 206 207 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes, 208 s_mem.buffer); 209 if (num <= 0) 210 return num; 211 212 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem))) 213 return -EFAULT; 214 215 return num; 216 } 217 218 static long ec_device_ioctl(struct file *filp, unsigned int cmd, 219 unsigned long arg) 220 { 221 struct cros_ec_dev *ec = filp->private_data; 222 223 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC) 224 return -ENOTTY; 225 226 switch (cmd) { 227 case CROS_EC_DEV_IOCXCMD: 228 return ec_device_ioctl_xcmd(ec, (void __user *)arg); 229 case CROS_EC_DEV_IOCRDMEM: 230 return ec_device_ioctl_readmem(ec, (void __user *)arg); 231 } 232 233 return -ENOTTY; 234 } 235 236 /* Module initialization */ 237 static const struct file_operations fops = { 238 .open = ec_device_open, 239 .release = ec_device_release, 240 .read = ec_device_read, 241 .unlocked_ioctl = ec_device_ioctl, 242 #ifdef CONFIG_COMPAT 243 .compat_ioctl = ec_device_ioctl, 244 #endif 245 }; 246 247 static void cros_ec_class_release(struct device *dev) 248 { 249 kfree(to_cros_ec_dev(dev)); 250 } 251 252 static void cros_ec_sensors_register(struct cros_ec_dev *ec) 253 { 254 /* 255 * Issue a command to get the number of sensor reported. 256 * Build an array of sensors driver and register them all. 257 */ 258 int ret, i, id, sensor_num; 259 struct mfd_cell *sensor_cells; 260 struct cros_ec_sensor_platform *sensor_platforms; 261 int sensor_type[MOTIONSENSE_TYPE_MAX]; 262 struct ec_params_motion_sense *params; 263 struct ec_response_motion_sense *resp; 264 struct cros_ec_command *msg; 265 266 msg = kzalloc(sizeof(struct cros_ec_command) + 267 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL); 268 if (msg == NULL) 269 return; 270 271 msg->version = 2; 272 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset; 273 msg->outsize = sizeof(*params); 274 msg->insize = sizeof(*resp); 275 276 params = (struct ec_params_motion_sense *)msg->data; 277 params->cmd = MOTIONSENSE_CMD_DUMP; 278 279 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 280 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 281 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n", 282 ret, msg->result); 283 goto error; 284 } 285 286 resp = (struct ec_response_motion_sense *)msg->data; 287 sensor_num = resp->dump.sensor_count; 288 /* Allocate 1 extra sensors in FIFO are needed */ 289 sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell), 290 GFP_KERNEL); 291 if (sensor_cells == NULL) 292 goto error; 293 294 sensor_platforms = kcalloc(sensor_num + 1, 295 sizeof(struct cros_ec_sensor_platform), 296 GFP_KERNEL); 297 if (sensor_platforms == NULL) 298 goto error_platforms; 299 300 memset(sensor_type, 0, sizeof(sensor_type)); 301 id = 0; 302 for (i = 0; i < sensor_num; i++) { 303 params->cmd = MOTIONSENSE_CMD_INFO; 304 params->info.sensor_num = i; 305 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 306 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 307 dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n", 308 i, ret, msg->result); 309 continue; 310 } 311 switch (resp->info.type) { 312 case MOTIONSENSE_TYPE_ACCEL: 313 sensor_cells[id].name = "cros-ec-accel"; 314 break; 315 case MOTIONSENSE_TYPE_BARO: 316 sensor_cells[id].name = "cros-ec-baro"; 317 break; 318 case MOTIONSENSE_TYPE_GYRO: 319 sensor_cells[id].name = "cros-ec-gyro"; 320 break; 321 case MOTIONSENSE_TYPE_MAG: 322 sensor_cells[id].name = "cros-ec-mag"; 323 break; 324 case MOTIONSENSE_TYPE_PROX: 325 sensor_cells[id].name = "cros-ec-prox"; 326 break; 327 case MOTIONSENSE_TYPE_LIGHT: 328 sensor_cells[id].name = "cros-ec-light"; 329 break; 330 case MOTIONSENSE_TYPE_ACTIVITY: 331 sensor_cells[id].name = "cros-ec-activity"; 332 break; 333 default: 334 dev_warn(ec->dev, "unknown type %d\n", resp->info.type); 335 continue; 336 } 337 sensor_platforms[id].sensor_num = i; 338 sensor_cells[id].id = sensor_type[resp->info.type]; 339 sensor_cells[id].platform_data = &sensor_platforms[id]; 340 sensor_cells[id].pdata_size = 341 sizeof(struct cros_ec_sensor_platform); 342 343 sensor_type[resp->info.type]++; 344 id++; 345 } 346 347 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) 348 ec->has_kb_wake_angle = true; 349 350 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) { 351 sensor_cells[id].name = "cros-ec-ring"; 352 id++; 353 } 354 355 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id, 356 NULL, 0, NULL); 357 if (ret) 358 dev_err(ec->dev, "failed to add EC sensors\n"); 359 360 kfree(sensor_platforms); 361 error_platforms: 362 kfree(sensor_cells); 363 error: 364 kfree(msg); 365 } 366 367 static const struct mfd_cell cros_ec_cec_cells[] = { 368 { .name = "cros-ec-cec" } 369 }; 370 371 static const struct mfd_cell cros_ec_rtc_cells[] = { 372 { .name = "cros-ec-rtc" } 373 }; 374 375 static const struct mfd_cell cros_usbpd_charger_cells[] = { 376 { .name = "cros-usbpd-charger" }, 377 { .name = "cros-usbpd-logger" }, 378 }; 379 380 static const struct mfd_cell cros_ec_platform_cells[] = { 381 { .name = "cros-ec-debugfs" }, 382 { .name = "cros-ec-lightbar" }, 383 { .name = "cros-ec-sysfs" }, 384 }; 385 386 static const struct mfd_cell cros_ec_vbc_cells[] = { 387 { .name = "cros-ec-vbc" } 388 }; 389 390 static int ec_device_probe(struct platform_device *pdev) 391 { 392 int retval = -ENOMEM; 393 struct device_node *node; 394 struct device *dev = &pdev->dev; 395 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 396 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL); 397 398 if (!ec) 399 return retval; 400 401 dev_set_drvdata(dev, ec); 402 ec->ec_dev = dev_get_drvdata(dev->parent); 403 ec->dev = dev; 404 ec->cmd_offset = ec_platform->cmd_offset; 405 ec->features[0] = -1U; /* Not cached yet */ 406 ec->features[1] = -1U; /* Not cached yet */ 407 device_initialize(&ec->class_dev); 408 cdev_init(&ec->cdev, &fops); 409 410 /* Check whether this is actually a Fingerprint MCU rather than an EC */ 411 if (cros_ec_check_features(ec, EC_FEATURE_FINGERPRINT)) { 412 dev_info(dev, "CrOS Fingerprint MCU detected.\n"); 413 /* 414 * Help userspace differentiating ECs from FP MCU, 415 * regardless of the probing order. 416 */ 417 ec_platform->ec_name = CROS_EC_DEV_FP_NAME; 418 } 419 420 /* 421 * Check whether this is actually an Integrated Sensor Hub (ISH) 422 * rather than an EC. 423 */ 424 if (cros_ec_check_features(ec, EC_FEATURE_ISH)) { 425 dev_info(dev, "CrOS ISH MCU detected.\n"); 426 /* 427 * Help userspace differentiating ECs from ISH MCU, 428 * regardless of the probing order. 429 */ 430 ec_platform->ec_name = CROS_EC_DEV_ISH_NAME; 431 } 432 433 /* Check whether this is actually a Touchpad MCU rather than an EC */ 434 if (cros_ec_check_features(ec, EC_FEATURE_TOUCHPAD)) { 435 dev_info(dev, "CrOS Touchpad MCU detected.\n"); 436 /* 437 * Help userspace differentiating ECs from TP MCU, 438 * regardless of the probing order. 439 */ 440 ec_platform->ec_name = CROS_EC_DEV_TP_NAME; 441 } 442 443 /* 444 * Add the class device 445 * Link to the character device for creating the /dev entry 446 * in devtmpfs. 447 */ 448 ec->class_dev.devt = MKDEV(ec_major, pdev->id); 449 ec->class_dev.class = &cros_class; 450 ec->class_dev.parent = dev; 451 ec->class_dev.release = cros_ec_class_release; 452 453 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); 454 if (retval) { 455 dev_err(dev, "dev_set_name failed => %d\n", retval); 456 goto failed; 457 } 458 459 /* check whether this EC is a sensor hub. */ 460 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) 461 cros_ec_sensors_register(ec); 462 463 /* Check whether this EC instance has CEC host command support */ 464 if (cros_ec_check_features(ec, EC_FEATURE_CEC)) { 465 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 466 cros_ec_cec_cells, 467 ARRAY_SIZE(cros_ec_cec_cells), 468 NULL, 0, NULL); 469 if (retval) 470 dev_err(ec->dev, 471 "failed to add cros-ec-cec device: %d\n", 472 retval); 473 } 474 475 /* Check whether this EC instance has RTC host command support */ 476 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) { 477 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 478 cros_ec_rtc_cells, 479 ARRAY_SIZE(cros_ec_rtc_cells), 480 NULL, 0, NULL); 481 if (retval) 482 dev_err(ec->dev, 483 "failed to add cros-ec-rtc device: %d\n", 484 retval); 485 } 486 487 /* Check whether this EC instance has the PD charge manager */ 488 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) { 489 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 490 cros_usbpd_charger_cells, 491 ARRAY_SIZE(cros_usbpd_charger_cells), 492 NULL, 0, NULL); 493 if (retval) 494 dev_err(ec->dev, 495 "failed to add cros-usbpd-charger device: %d\n", 496 retval); 497 } 498 499 /* We can now add the sysfs class, we know which parameter to show */ 500 retval = cdev_device_add(&ec->cdev, &ec->class_dev); 501 if (retval) { 502 dev_err(dev, "cdev_device_add failed => %d\n", retval); 503 goto failed; 504 } 505 506 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 507 cros_ec_platform_cells, 508 ARRAY_SIZE(cros_ec_platform_cells), 509 NULL, 0, NULL); 510 if (retval) 511 dev_warn(ec->dev, 512 "failed to add cros-ec platform devices: %d\n", 513 retval); 514 515 /* Check whether this EC instance has a VBC NVRAM */ 516 node = ec->ec_dev->dev->of_node; 517 if (of_property_read_bool(node, "google,has-vbc-nvram")) { 518 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, 519 cros_ec_vbc_cells, 520 ARRAY_SIZE(cros_ec_vbc_cells), 521 NULL, 0, NULL); 522 if (retval) 523 dev_warn(ec->dev, "failed to add VBC devices: %d\n", 524 retval); 525 } 526 527 return 0; 528 529 failed: 530 put_device(&ec->class_dev); 531 return retval; 532 } 533 534 static int ec_device_remove(struct platform_device *pdev) 535 { 536 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 537 538 mfd_remove_devices(ec->dev); 539 cdev_del(&ec->cdev); 540 device_unregister(&ec->class_dev); 541 return 0; 542 } 543 544 static const struct platform_device_id cros_ec_id[] = { 545 { DRV_NAME, 0 }, 546 { /* sentinel */ } 547 }; 548 MODULE_DEVICE_TABLE(platform, cros_ec_id); 549 550 static struct platform_driver cros_ec_dev_driver = { 551 .driver = { 552 .name = DRV_NAME, 553 }, 554 .id_table = cros_ec_id, 555 .probe = ec_device_probe, 556 .remove = ec_device_remove, 557 }; 558 559 static int __init cros_ec_dev_init(void) 560 { 561 int ret; 562 dev_t dev = 0; 563 564 ret = class_register(&cros_class); 565 if (ret) { 566 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 567 return ret; 568 } 569 570 /* Get a range of minor numbers (starting with 0) to work with */ 571 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME); 572 if (ret < 0) { 573 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n"); 574 goto failed_chrdevreg; 575 } 576 ec_major = MAJOR(dev); 577 578 /* Register the driver */ 579 ret = platform_driver_register(&cros_ec_dev_driver); 580 if (ret < 0) { 581 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 582 goto failed_devreg; 583 } 584 return 0; 585 586 failed_devreg: 587 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV); 588 failed_chrdevreg: 589 class_unregister(&cros_class); 590 return ret; 591 } 592 593 static void __exit cros_ec_dev_exit(void) 594 { 595 platform_driver_unregister(&cros_ec_dev_driver); 596 unregister_chrdev(ec_major, CROS_EC_DEV_NAME); 597 class_unregister(&cros_class); 598 } 599 600 module_init(cros_ec_dev_init); 601 module_exit(cros_ec_dev_exit); 602 603 MODULE_ALIAS("platform:" DRV_NAME); 604 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 605 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 606 MODULE_VERSION("1.0"); 607 MODULE_LICENSE("GPL"); 608