drivers/mfd/cros_ec_dev.c

   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/mfd/core.h>
   9 #include <linux/mfd/cros_ec.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/platform_data/cros_ec_chardev.h>
  15 #include <linux/platform_data/cros_ec_commands.h>
  16 #include <linux/platform_data/cros_ec_proto.h>
  17 #include <linux/slab.h>
  18
  19 #define DRV_NAME "cros-ec-dev"
  20
  21 static struct class cros_class = {
  22         .owner          = THIS_MODULE,
  23         .name           = "chromeos",
  24 };
  25
  26 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
  27 {
  28         struct cros_ec_command *msg;
  29         int ret;
  30
  31         if (ec->features[0] == -1U && ec->features[1] == -1U) {
  32                 /* features bitmap not read yet */
  33                 msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
  34                 if (!msg)
  35                         return -ENOMEM;
  36
  37                 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
  38                 msg->insize = sizeof(ec->features);
  39
  40                 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
  41                 if (ret < 0) {
  42                         dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
  43                                  ret, msg->result);
  44                         memset(ec->features, 0, sizeof(ec->features));
  45                 } else {
  46                         memcpy(ec->features, msg->data, sizeof(ec->features));
  47                 }
  48
  49                 dev_dbg(ec->dev, "EC features %08x %08x\n",
  50                         ec->features[0], ec->features[1]);
  51
  52                 kfree(msg);
  53         }
  54
  55         return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
  56 }
  57
  58 static void cros_ec_class_release(struct device *dev)
  59 {
  60         kfree(to_cros_ec_dev(dev));
  61 }
  62
  63 static void cros_ec_sensors_register(struct cros_ec_dev *ec)
  64 {
  65         /*
  66          * Issue a command to get the number of sensor reported.
  67          * Build an array of sensors driver and register them all.
  68          */
  69         int ret, i, id, sensor_num;
  70         struct mfd_cell *sensor_cells;
  71         struct cros_ec_sensor_platform *sensor_platforms;
  72         int sensor_type[MOTIONSENSE_TYPE_MAX];
  73         struct ec_params_motion_sense *params;
  74         struct ec_response_motion_sense *resp;
  75         struct cros_ec_command *msg;
  76
  77         msg = kzalloc(sizeof(struct cros_ec_command) +
  78                       max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
  79         if (msg == NULL)
  80                 return;
  81
  82         msg->version = 2;
  83         msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
  84         msg->outsize = sizeof(*params);
  85         msg->insize = sizeof(*resp);
  86
  87         params = (struct ec_params_motion_sense *)msg->data;
  88         params->cmd = MOTIONSENSE_CMD_DUMP;
  89
  90         ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
  91         if (ret < 0) {
  92                 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
  93                          ret, msg->result);
  94                 goto error;
  95         }
  96
  97         resp = (struct ec_response_motion_sense *)msg->data;
  98         sensor_num = resp->dump.sensor_count;
  99         /*
 100          * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
 101          */
 102         sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
 103                                GFP_KERNEL);
 104         if (sensor_cells == NULL)
 105                 goto error;
 106
 107         sensor_platforms = kcalloc(sensor_num,
 108                                    sizeof(struct cros_ec_sensor_platform),
 109                                    GFP_KERNEL);
 110         if (sensor_platforms == NULL)
 111                 goto error_platforms;
 112
 113         memset(sensor_type, 0, sizeof(sensor_type));
 114         id = 0;
 115         for (i = 0; i < sensor_num; i++) {
 116                 params->cmd = MOTIONSENSE_CMD_INFO;
 117                 params->info.sensor_num = i;
 118                 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 119                 if (ret < 0) {
 120                         dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
 121                                  i, ret, msg->result);
 122                         continue;
 123                 }
 124                 switch (resp->info.type) {
 125                 case MOTIONSENSE_TYPE_ACCEL:
 126                         sensor_cells[id].name = "cros-ec-accel";
 127                         break;
 128                 case MOTIONSENSE_TYPE_BARO:
 129                         sensor_cells[id].name = "cros-ec-baro";
 130                         break;
 131                 case MOTIONSENSE_TYPE_GYRO:
 132                         sensor_cells[id].name = "cros-ec-gyro";
 133                         break;
 134                 case MOTIONSENSE_TYPE_MAG:
 135                         sensor_cells[id].name = "cros-ec-mag";
 136                         break;
 137                 case MOTIONSENSE_TYPE_PROX:
 138                         sensor_cells[id].name = "cros-ec-prox";
 139                         break;
 140                 case MOTIONSENSE_TYPE_LIGHT:
 141                         sensor_cells[id].name = "cros-ec-light";
 142                         break;
 143                 case MOTIONSENSE_TYPE_ACTIVITY:
 144                         sensor_cells[id].name = "cros-ec-activity";
 145                         break;
 146                 default:
 147                         dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
 148                         continue;
 149                 }
 150                 sensor_platforms[id].sensor_num = i;
 151                 sensor_cells[id].id = sensor_type[resp->info.type];
 152                 sensor_cells[id].platform_data = &sensor_platforms[id];
 153                 sensor_cells[id].pdata_size =
 154                         sizeof(struct cros_ec_sensor_platform);
 155
 156                 sensor_type[resp->info.type]++;
 157                 id++;
 158         }
 159
 160         if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
 161                 ec->has_kb_wake_angle = true;
 162
 163         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 164                 sensor_cells[id].name = "cros-ec-ring";
 165                 id++;
 166         }
 167         if (cros_ec_check_features(ec,
 168                                 EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
 169                 sensor_cells[id].name = "cros-ec-lid-angle";
 170                 id++;
 171         }
 172
 173         ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
 174                               NULL, 0, NULL);
 175         if (ret)
 176                 dev_err(ec->dev, "failed to add EC sensors\n");
 177
 178         kfree(sensor_platforms);
 179 error_platforms:
 180         kfree(sensor_cells);
 181 error:
 182         kfree(msg);
 183 }
 184
 185 static struct cros_ec_sensor_platform sensor_platforms[] = {
 186         { .sensor_num = 0 },
 187         { .sensor_num = 1 }
 188 };
 189
 190 static const struct mfd_cell cros_ec_accel_legacy_cells[] = {
 191         {
 192                 .name = "cros-ec-accel-legacy",
 193                 .platform_data = &sensor_platforms[0],
 194                 .pdata_size = sizeof(struct cros_ec_sensor_platform),
 195         },
 196         {
 197                 .name = "cros-ec-accel-legacy",
 198                 .platform_data = &sensor_platforms[1],
 199                 .pdata_size = sizeof(struct cros_ec_sensor_platform),
 200         }
 201 };
 202
 203 static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
 204 {
 205         struct cros_ec_device *ec_dev = ec->ec_dev;
 206         u8 status;
 207         int ret;
 208
 209         /*
 210          * ECs that need legacy support are the main EC, directly connected to
 211          * the AP.
 212          */
 213         if (ec->cmd_offset != 0)
 214                 return;
 215
 216         /*
 217          * Check if EC supports direct memory reads and if EC has
 218          * accelerometers.
 219          */
 220         if (ec_dev->cmd_readmem) {
 221                 ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1,
 222                                           &status);
 223                 if (ret < 0) {
 224                         dev_warn(ec->dev, "EC direct read error.\n");
 225                         return;
 226                 }
 227
 228                 /* Check if EC has accelerometers. */
 229                 if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
 230                         dev_info(ec->dev, "EC does not have accelerometers.\n");
 231                         return;
 232                 }
 233         }
 234
 235         /*
 236          * The device may still support accelerometers:
 237          * it would be an older ARM based device that do not suppor the
 238          * EC_CMD_GET_FEATURES command.
 239          *
 240          * Register 2 accelerometers, we will fail in the IIO driver if there
 241          * are no sensors.
 242          */
 243         ret = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
 244                               cros_ec_accel_legacy_cells,
 245                               ARRAY_SIZE(cros_ec_accel_legacy_cells),
 246                               NULL, 0, NULL);
 247         if (ret)
 248                 dev_err(ec_dev->dev, "failed to add EC sensors\n");
 249 }
 250
 251 static const struct mfd_cell cros_ec_cec_cells[] = {
 252         { .name = "cros-ec-cec" }
 253 };
 254
 255 static const struct mfd_cell cros_ec_rtc_cells[] = {
 256         { .name = "cros-ec-rtc" }
 257 };
 258
 259 static const struct mfd_cell cros_usbpd_charger_cells[] = {
 260         { .name = "cros-usbpd-charger" },
 261         { .name = "cros-usbpd-logger" },
 262 };
 263
 264 static const struct mfd_cell cros_ec_platform_cells[] = {
 265         { .name = "cros-ec-chardev" },
 266         { .name = "cros-ec-debugfs" },
 267         { .name = "cros-ec-lightbar" },
 268         { .name = "cros-ec-sysfs" },
 269 };
 270
 271 static const struct mfd_cell cros_ec_vbc_cells[] = {
 272         { .name = "cros-ec-vbc" }
 273 };
 274
 275 static int ec_device_probe(struct platform_device *pdev)
 276 {
 277         int retval = -ENOMEM;
 278         struct device_node *node;
 279         struct device *dev = &pdev->dev;
 280         struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
 281         struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
 282
 283         if (!ec)
 284                 return retval;
 285
 286         dev_set_drvdata(dev, ec);
 287         ec->ec_dev = dev_get_drvdata(dev->parent);
 288         ec->dev = dev;
 289         ec->cmd_offset = ec_platform->cmd_offset;
 290         ec->features[0] = -1U; /* Not cached yet */
 291         ec->features[1] = -1U; /* Not cached yet */
 292         device_initialize(&ec->class_dev);
 293
 294         /* Check whether this is actually a Fingerprint MCU rather than an EC */
 295         if (cros_ec_check_features(ec, EC_FEATURE_FINGERPRINT)) {
 296                 dev_info(dev, "CrOS Fingerprint MCU detected.\n");
 297                 /*
 298                  * Help userspace differentiating ECs from FP MCU,
 299                  * regardless of the probing order.
 300                  */
 301                 ec_platform->ec_name = CROS_EC_DEV_FP_NAME;
 302         }
 303
 304         /*
 305          * Check whether this is actually an Integrated Sensor Hub (ISH)
 306          * rather than an EC.
 307          */
 308         if (cros_ec_check_features(ec, EC_FEATURE_ISH)) {
 309                 dev_info(dev, "CrOS ISH MCU detected.\n");
 310                 /*
 311                  * Help userspace differentiating ECs from ISH MCU,
 312                  * regardless of the probing order.
 313                  */
 314                 ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
 315         }
 316
 317         /* Check whether this is actually a Touchpad MCU rather than an EC */
 318         if (cros_ec_check_features(ec, EC_FEATURE_TOUCHPAD)) {
 319                 dev_info(dev, "CrOS Touchpad MCU detected.\n");
 320                 /*
 321                  * Help userspace differentiating ECs from TP MCU,
 322                  * regardless of the probing order.
 323                  */
 324                 ec_platform->ec_name = CROS_EC_DEV_TP_NAME;
 325         }
 326
 327         /* Check whether this is actually a SCP rather than an EC. */
 328         if (cros_ec_check_features(ec, EC_FEATURE_SCP)) {
 329                 dev_info(dev, "CrOS SCP MCU detected.\n");
 330                 /*
 331                  * Help userspace differentiating ECs from SCP,
 332                  * regardless of the probing order.
 333                  */
 334                 ec_platform->ec_name = CROS_EC_DEV_SCP_NAME;
 335         }
 336
 337         /*
 338          * Add the class device
 339          */
 340         ec->class_dev.class = &cros_class;
 341         ec->class_dev.parent = dev;
 342         ec->class_dev.release = cros_ec_class_release;
 343
 344         retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
 345         if (retval) {
 346                 dev_err(dev, "dev_set_name failed => %d\n", retval);
 347                 goto failed;
 348         }
 349
 350         retval = device_add(&ec->class_dev);
 351         if (retval)
 352                 goto failed;
 353
 354         /* check whether this EC is a sensor hub. */
 355         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
 356                 cros_ec_sensors_register(ec);
 357         else
 358                 /* Workaroud for older EC firmware */
 359                 cros_ec_accel_legacy_register(ec);
 360
 361         /* Check whether this EC instance has CEC host command support */
 362         if (cros_ec_check_features(ec, EC_FEATURE_CEC)) {
 363                 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
 364                                          cros_ec_cec_cells,
 365                                          ARRAY_SIZE(cros_ec_cec_cells),
 366                                          NULL, 0, NULL);
 367                 if (retval)
 368                         dev_err(ec->dev,
 369                                 "failed to add cros-ec-cec device: %d\n",
 370                                 retval);
 371         }
 372
 373         /* Check whether this EC instance has RTC host command support */
 374         if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
 375                 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
 376                                          cros_ec_rtc_cells,
 377                                          ARRAY_SIZE(cros_ec_rtc_cells),
 378                                          NULL, 0, NULL);
 379                 if (retval)
 380                         dev_err(ec->dev,
 381                                 "failed to add cros-ec-rtc device: %d\n",
 382                                 retval);
 383         }
 384
 385         /* Check whether this EC instance has the PD charge manager */
 386         if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
 387                 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
 388                                          cros_usbpd_charger_cells,
 389                                          ARRAY_SIZE(cros_usbpd_charger_cells),
 390                                          NULL, 0, NULL);
 391                 if (retval)
 392                         dev_err(ec->dev,
 393                                 "failed to add cros-usbpd-charger device: %d\n",
 394                                 retval);
 395         }
 396
 397         retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
 398                                  cros_ec_platform_cells,
 399                                  ARRAY_SIZE(cros_ec_platform_cells),
 400                                  NULL, 0, NULL);
 401         if (retval)
 402                 dev_warn(ec->dev,
 403                          "failed to add cros-ec platform devices: %d\n",
 404                          retval);
 405
 406         /* Check whether this EC instance has a VBC NVRAM */
 407         node = ec->ec_dev->dev->of_node;
 408         if (of_property_read_bool(node, "google,has-vbc-nvram")) {
 409                 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
 410                                          cros_ec_vbc_cells,
 411                                          ARRAY_SIZE(cros_ec_vbc_cells),
 412                                          NULL, 0, NULL);
 413                 if (retval)
 414                         dev_warn(ec->dev, "failed to add VBC devices: %d\n",
 415                                  retval);
 416         }
 417
 418         return 0;
 419
 420 failed:
 421         put_device(&ec->class_dev);
 422         return retval;
 423 }
 424
 425 static int ec_device_remove(struct platform_device *pdev)
 426 {
 427         struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
 428
 429         mfd_remove_devices(ec->dev);
 430         device_unregister(&ec->class_dev);
 431         return 0;
 432 }
 433
 434 static const struct platform_device_id cros_ec_id[] = {
 435         { DRV_NAME, 0 },
 436         { /* sentinel */ }
 437 };
 438 MODULE_DEVICE_TABLE(platform, cros_ec_id);
 439
 440 static struct platform_driver cros_ec_dev_driver = {
 441         .driver = {
 442                 .name = DRV_NAME,
 443         },
 444         .id_table = cros_ec_id,
 445         .probe = ec_device_probe,
 446         .remove = ec_device_remove,
 447 };
 448
 449 static int __init cros_ec_dev_init(void)
 450 {
 451         int ret;
 452
 453         ret  = class_register(&cros_class);
 454         if (ret) {
 455                 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
 456                 return ret;
 457         }
 458
 459         /* Register the driver */
 460         ret = platform_driver_register(&cros_ec_dev_driver);
 461         if (ret < 0) {
 462                 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
 463                 goto failed_devreg;
 464         }
 465         return 0;
 466
 467 failed_devreg:
 468         class_unregister(&cros_class);
 469         return ret;
 470 }
 471
 472 static void __exit cros_ec_dev_exit(void)
 473 {
 474         platform_driver_unregister(&cros_ec_dev_driver);
 475         class_unregister(&cros_class);
 476 }
 477
 478 module_init(cros_ec_dev_init);
 479 module_exit(cros_ec_dev_exit);
 480
 481 MODULE_ALIAS("platform:" DRV_NAME);
 482 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
 483 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
 484 MODULE_VERSION("1.0");
 485 MODULE_LICENSE("GPL");