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 } 117 118 memcpy(ec->features, msg->data, sizeof(ec->features)); 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 struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, 268 class_dev); 269 kfree(ec); 270 } 271 272 static void cros_ec_sensors_register(struct cros_ec_dev *ec) 273 { 274 /* 275 * Issue a command to get the number of sensor reported. 276 * Build an array of sensors driver and register them all. 277 */ 278 int ret, i, id, sensor_num; 279 struct mfd_cell *sensor_cells; 280 struct cros_ec_sensor_platform *sensor_platforms; 281 int sensor_type[MOTIONSENSE_TYPE_MAX]; 282 struct ec_params_motion_sense *params; 283 struct ec_response_motion_sense *resp; 284 struct cros_ec_command *msg; 285 286 msg = kzalloc(sizeof(struct cros_ec_command) + 287 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL); 288 if (msg == NULL) 289 return; 290 291 msg->version = 2; 292 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset; 293 msg->outsize = sizeof(*params); 294 msg->insize = sizeof(*resp); 295 296 params = (struct ec_params_motion_sense *)msg->data; 297 params->cmd = MOTIONSENSE_CMD_DUMP; 298 299 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 300 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 301 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n", 302 ret, msg->result); 303 goto error; 304 } 305 306 resp = (struct ec_response_motion_sense *)msg->data; 307 sensor_num = resp->dump.sensor_count; 308 /* Allocate 2 extra sensors in case lid angle or FIFO are needed */ 309 sensor_cells = kzalloc(sizeof(struct mfd_cell) * (sensor_num + 2), 310 GFP_KERNEL); 311 if (sensor_cells == NULL) 312 goto error; 313 314 sensor_platforms = kzalloc(sizeof(struct cros_ec_sensor_platform) * 315 (sensor_num + 1), GFP_KERNEL); 316 if (sensor_platforms == NULL) 317 goto error_platforms; 318 319 memset(sensor_type, 0, sizeof(sensor_type)); 320 id = 0; 321 for (i = 0; i < sensor_num; i++) { 322 params->cmd = MOTIONSENSE_CMD_INFO; 323 params->info.sensor_num = i; 324 ret = cros_ec_cmd_xfer(ec->ec_dev, msg); 325 if (ret < 0 || msg->result != EC_RES_SUCCESS) { 326 dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n", 327 i, ret, msg->result); 328 continue; 329 } 330 switch (resp->info.type) { 331 case MOTIONSENSE_TYPE_ACCEL: 332 sensor_cells[id].name = "cros-ec-accel"; 333 break; 334 case MOTIONSENSE_TYPE_BARO: 335 sensor_cells[id].name = "cros-ec-baro"; 336 break; 337 case MOTIONSENSE_TYPE_GYRO: 338 sensor_cells[id].name = "cros-ec-gyro"; 339 break; 340 case MOTIONSENSE_TYPE_MAG: 341 sensor_cells[id].name = "cros-ec-mag"; 342 break; 343 case MOTIONSENSE_TYPE_PROX: 344 sensor_cells[id].name = "cros-ec-prox"; 345 break; 346 case MOTIONSENSE_TYPE_LIGHT: 347 sensor_cells[id].name = "cros-ec-light"; 348 break; 349 case MOTIONSENSE_TYPE_ACTIVITY: 350 sensor_cells[id].name = "cros-ec-activity"; 351 break; 352 default: 353 dev_warn(ec->dev, "unknown type %d\n", resp->info.type); 354 continue; 355 } 356 sensor_platforms[id].sensor_num = i; 357 sensor_cells[id].id = sensor_type[resp->info.type]; 358 sensor_cells[id].platform_data = &sensor_platforms[id]; 359 sensor_cells[id].pdata_size = 360 sizeof(struct cros_ec_sensor_platform); 361 362 sensor_type[resp->info.type]++; 363 id++; 364 } 365 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) { 366 sensor_platforms[id].sensor_num = sensor_num; 367 368 sensor_cells[id].name = "cros-ec-angle"; 369 sensor_cells[id].id = 0; 370 sensor_cells[id].platform_data = &sensor_platforms[id]; 371 sensor_cells[id].pdata_size = 372 sizeof(struct cros_ec_sensor_platform); 373 id++; 374 } 375 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) { 376 sensor_cells[id].name = "cros-ec-ring"; 377 id++; 378 } 379 380 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id, 381 NULL, 0, NULL); 382 if (ret) 383 dev_err(ec->dev, "failed to add EC sensors\n"); 384 385 kfree(sensor_platforms); 386 error_platforms: 387 kfree(sensor_cells); 388 error: 389 kfree(msg); 390 } 391 392 static int ec_device_probe(struct platform_device *pdev) 393 { 394 int retval = -ENOMEM; 395 struct device *dev = &pdev->dev; 396 struct cros_ec_platform *ec_platform = dev_get_platdata(dev); 397 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL); 398 399 if (!ec) 400 return retval; 401 402 dev_set_drvdata(dev, ec); 403 ec->ec_dev = dev_get_drvdata(dev->parent); 404 ec->dev = dev; 405 ec->cmd_offset = ec_platform->cmd_offset; 406 ec->features[0] = -1U; /* Not cached yet */ 407 ec->features[1] = -1U; /* Not cached yet */ 408 device_initialize(&ec->class_dev); 409 cdev_init(&ec->cdev, &fops); 410 411 /* 412 * Add the class device 413 * Link to the character device for creating the /dev entry 414 * in devtmpfs. 415 */ 416 ec->class_dev.devt = MKDEV(ec_major, pdev->id); 417 ec->class_dev.class = &cros_class; 418 ec->class_dev.parent = dev; 419 ec->class_dev.release = __remove; 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 retval = cdev_device_add(&ec->cdev, &ec->class_dev); 428 if (retval) { 429 dev_err(dev, "cdev_device_add failed => %d\n", retval); 430 goto failed; 431 } 432 433 if (cros_ec_debugfs_init(ec)) 434 dev_warn(dev, "failed to create debugfs directory\n"); 435 436 /* check whether this EC is a sensor hub. */ 437 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) 438 cros_ec_sensors_register(ec); 439 440 /* Take control of the lightbar from the EC. */ 441 lb_manual_suspend_ctrl(ec, 1); 442 443 return 0; 444 445 failed: 446 put_device(&ec->class_dev); 447 return retval; 448 } 449 450 static int ec_device_remove(struct platform_device *pdev) 451 { 452 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); 453 454 /* Let the EC take over the lightbar again. */ 455 lb_manual_suspend_ctrl(ec, 0); 456 457 cros_ec_debugfs_remove(ec); 458 459 cdev_del(&ec->cdev); 460 device_unregister(&ec->class_dev); 461 return 0; 462 } 463 464 static const struct platform_device_id cros_ec_id[] = { 465 { DRV_NAME, 0 }, 466 { /* sentinel */ }, 467 }; 468 MODULE_DEVICE_TABLE(platform, cros_ec_id); 469 470 static __maybe_unused int ec_device_suspend(struct device *dev) 471 { 472 struct cros_ec_dev *ec = dev_get_drvdata(dev); 473 474 lb_suspend(ec); 475 476 return 0; 477 } 478 479 static __maybe_unused int ec_device_resume(struct device *dev) 480 { 481 struct cros_ec_dev *ec = dev_get_drvdata(dev); 482 483 lb_resume(ec); 484 485 return 0; 486 } 487 488 static const struct dev_pm_ops cros_ec_dev_pm_ops = { 489 #ifdef CONFIG_PM_SLEEP 490 .suspend = ec_device_suspend, 491 .resume = ec_device_resume, 492 #endif 493 }; 494 495 static struct platform_driver cros_ec_dev_driver = { 496 .driver = { 497 .name = DRV_NAME, 498 .pm = &cros_ec_dev_pm_ops, 499 }, 500 .probe = ec_device_probe, 501 .remove = ec_device_remove, 502 }; 503 504 static int __init cros_ec_dev_init(void) 505 { 506 int ret; 507 dev_t dev = 0; 508 509 ret = class_register(&cros_class); 510 if (ret) { 511 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); 512 return ret; 513 } 514 515 /* Get a range of minor numbers (starting with 0) to work with */ 516 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME); 517 if (ret < 0) { 518 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n"); 519 goto failed_chrdevreg; 520 } 521 ec_major = MAJOR(dev); 522 523 /* Register the driver */ 524 ret = platform_driver_register(&cros_ec_dev_driver); 525 if (ret < 0) { 526 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret); 527 goto failed_devreg; 528 } 529 return 0; 530 531 failed_devreg: 532 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV); 533 failed_chrdevreg: 534 class_unregister(&cros_class); 535 return ret; 536 } 537 538 static void __exit cros_ec_dev_exit(void) 539 { 540 platform_driver_unregister(&cros_ec_dev_driver); 541 unregister_chrdev(ec_major, CROS_EC_DEV_NAME); 542 class_unregister(&cros_class); 543 } 544 545 module_init(cros_ec_dev_init); 546 module_exit(cros_ec_dev_exit); 547 548 MODULE_ALIAS("platform:" DRV_NAME); 549 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); 550 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); 551 MODULE_VERSION("1.0"); 552 MODULE_LICENSE("GPL"); 553