drivers/mfd/cros_ec_dev.c

   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         .id_table = cros_ec_id,
 550         .probe = ec_device_probe,
 551         .remove = ec_device_remove,
 552         .shutdown = ec_device_shutdown,
 553 };
 554
 555 static int __init cros_ec_dev_init(void)
 556 {
 557         int ret;
 558         dev_t dev = 0;
 559
 560         ret  = class_register(&cros_class);
 561         if (ret) {
 562                 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
 563                 return ret;
 564         }
 565
 566         /* Get a range of minor numbers (starting with 0) to work with */
 567         ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
 568         if (ret < 0) {
 569                 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
 570                 goto failed_chrdevreg;
 571         }
 572         ec_major = MAJOR(dev);
 573
 574         /* Register the driver */
 575         ret = platform_driver_register(&cros_ec_dev_driver);
 576         if (ret < 0) {
 577                 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
 578                 goto failed_devreg;
 579         }
 580         return 0;
 581
 582 failed_devreg:
 583         unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
 584 failed_chrdevreg:
 585         class_unregister(&cros_class);
 586         return ret;
 587 }
 588
 589 static void __exit cros_ec_dev_exit(void)
 590 {
 591         platform_driver_unregister(&cros_ec_dev_driver);
 592         unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
 593         class_unregister(&cros_class);
 594 }
 595
 596 module_init(cros_ec_dev_init);
 597 module_exit(cros_ec_dev_exit);
 598
 599 MODULE_ALIAS("platform:" DRV_NAME);
 600 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
 601 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
 602 MODULE_VERSION("1.0");
 603 MODULE_LICENSE("GPL");