drivers/extcon/extcon-usbc-cros-ec.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // ChromeOS Embedded Controller extcon
   3 //
   4 // Copyright (C) 2017 Google, Inc.
   5 // Author: Benson Leung <bleung@chromium.org>
   6
   7 #include <linux/extcon-provider.h>
   8 #include <linux/kernel.h>
   9 #include <linux/mfd/cros_ec.h>
  10 #include <linux/module.h>
  11 #include <linux/notifier.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/slab.h>
  15 #include <linux/sched.h>
  16
  17 struct cros_ec_extcon_info {
  18         struct device *dev;
  19         struct extcon_dev *edev;
  20
  21         int port_id;
  22
  23         struct cros_ec_device *ec;
  24
  25         struct notifier_block notifier;
  26
  27         unsigned int dr; /* data role */
  28         bool pr; /* power role (true if VBUS enabled) */
  29         bool dp; /* DisplayPort enabled */
  30         bool mux; /* SuperSpeed (usb3) enabled */
  31         unsigned int power_type;
  32 };
  33
  34 static const unsigned int usb_type_c_cable[] = {
  35         EXTCON_USB,
  36         EXTCON_USB_HOST,
  37         EXTCON_DISP_DP,
  38         EXTCON_NONE,
  39 };
  40
  41 enum usb_data_roles {
  42         DR_NONE,
  43         DR_HOST,
  44         DR_DEVICE,
  45 };
  46
  47 /**
  48  * cros_ec_pd_command() - Send a command to the EC.
  49  * @info: pointer to struct cros_ec_extcon_info
  50  * @command: EC command
  51  * @version: EC command version
  52  * @outdata: EC command output data
  53  * @outsize: Size of outdata
  54  * @indata: EC command input data
  55  * @insize: Size of indata
  56  *
  57  * Return: 0 on success, <0 on failure.
  58  */
  59 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
  60                               unsigned int command,
  61                               unsigned int version,
  62                               void *outdata,
  63                               unsigned int outsize,
  64                               void *indata,
  65                               unsigned int insize)
  66 {
  67         struct cros_ec_command *msg;
  68         int ret;
  69
  70         msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
  71         if (!msg)
  72                 return -ENOMEM;
  73
  74         msg->version = version;
  75         msg->command = command;
  76         msg->outsize = outsize;
  77         msg->insize = insize;
  78
  79         if (outsize)
  80                 memcpy(msg->data, outdata, outsize);
  81
  82         ret = cros_ec_cmd_xfer_status(info->ec, msg);
  83         if (ret >= 0 && insize)
  84                 memcpy(indata, msg->data, insize);
  85
  86         kfree(msg);
  87         return ret;
  88 }
  89
  90 /**
  91  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
  92  * to given port.
  93  * @info: pointer to struct cros_ec_extcon_info
  94  *
  95  * Return: power type on success, <0 on failure.
  96  */
  97 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
  98 {
  99         struct ec_params_usb_pd_power_info req;
 100         struct ec_response_usb_pd_power_info resp;
 101         int ret;
 102
 103         req.port = info->port_id;
 104         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
 105                                  &req, sizeof(req), &resp, sizeof(resp));
 106         if (ret < 0)
 107                 return ret;
 108
 109         return resp.type;
 110 }
 111
 112 /**
 113  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
 114  * @info: pointer to struct cros_ec_extcon_info
 115  *
 116  * Return: PD mux state on success, <0 on failure.
 117  */
 118 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
 119 {
 120         struct ec_params_usb_pd_mux_info req;
 121         struct ec_response_usb_pd_mux_info resp;
 122         int ret;
 123
 124         req.port = info->port_id;
 125         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
 126                                  &req, sizeof(req),
 127                                  &resp, sizeof(resp));
 128         if (ret < 0)
 129                 return ret;
 130
 131         return resp.flags;
 132 }
 133
 134 /**
 135  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
 136  * given port.
 137  * @info: pointer to struct cros_ec_extcon_info
 138  * @polarity: pointer to cable polarity (return value)
 139  *
 140  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
 141  * failure.
 142  */
 143 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
 144                                 bool *polarity)
 145 {
 146         struct ec_params_usb_pd_control pd_control;
 147         struct ec_response_usb_pd_control_v1 resp;
 148         int ret;
 149
 150         pd_control.port = info->port_id;
 151         pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
 152         pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
 153         pd_control.swap = USB_PD_CTRL_SWAP_NONE;
 154         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
 155                                  &pd_control, sizeof(pd_control),
 156                                  &resp, sizeof(resp));
 157         if (ret < 0)
 158                 return ret;
 159
 160         if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
 161                 return -ENOTCONN;
 162
 163         *polarity = resp.polarity;
 164
 165         return resp.role;
 166 }
 167
 168 /**
 169  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
 170  * @info: pointer to struct cros_ec_extcon_info
 171  *
 172  * Return: number of ports on success, <0 on failure.
 173  */
 174 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
 175 {
 176         struct ec_response_usb_pd_ports resp;
 177         int ret;
 178
 179         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
 180                                  0, NULL, 0, &resp, sizeof(resp));
 181         if (ret < 0)
 182                 return ret;
 183
 184         return resp.num_ports;
 185 }
 186
 187 static const char *cros_ec_usb_role_string(unsigned int role)
 188 {
 189         return role == DR_NONE ? "DISCONNECTED" :
 190                 (role == DR_HOST ? "DFP" : "UFP");
 191 }
 192
 193 static const char *cros_ec_usb_power_type_string(unsigned int type)
 194 {
 195         switch (type) {
 196         case USB_CHG_TYPE_NONE:
 197                 return "USB_CHG_TYPE_NONE";
 198         case USB_CHG_TYPE_PD:
 199                 return "USB_CHG_TYPE_PD";
 200         case USB_CHG_TYPE_PROPRIETARY:
 201                 return "USB_CHG_TYPE_PROPRIETARY";
 202         case USB_CHG_TYPE_C:
 203                 return "USB_CHG_TYPE_C";
 204         case USB_CHG_TYPE_BC12_DCP:
 205                 return "USB_CHG_TYPE_BC12_DCP";
 206         case USB_CHG_TYPE_BC12_CDP:
 207                 return "USB_CHG_TYPE_BC12_CDP";
 208         case USB_CHG_TYPE_BC12_SDP:
 209                 return "USB_CHG_TYPE_BC12_SDP";
 210         case USB_CHG_TYPE_OTHER:
 211                 return "USB_CHG_TYPE_OTHER";
 212         case USB_CHG_TYPE_VBUS:
 213                 return "USB_CHG_TYPE_VBUS";
 214         case USB_CHG_TYPE_UNKNOWN:
 215                 return "USB_CHG_TYPE_UNKNOWN";
 216         default:
 217                 return "USB_CHG_TYPE_UNKNOWN";
 218         }
 219 }
 220
 221 static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
 222                                                 unsigned int role)
 223 {
 224         switch (type) {
 225         /* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
 226          * because they identify with USB_CHG_TYPE_C, but we can't return true
 227          * here from that code because that breaks Suzy-Q and other kinds of
 228          * USB Type-C cables and peripherals.
 229          */
 230         case USB_CHG_TYPE_PROPRIETARY:
 231         case USB_CHG_TYPE_BC12_DCP:
 232                 return true;
 233         case USB_CHG_TYPE_PD:
 234         case USB_CHG_TYPE_C:
 235         case USB_CHG_TYPE_BC12_CDP:
 236         case USB_CHG_TYPE_BC12_SDP:
 237         case USB_CHG_TYPE_OTHER:
 238         case USB_CHG_TYPE_VBUS:
 239         case USB_CHG_TYPE_UNKNOWN:
 240         case USB_CHG_TYPE_NONE:
 241         default:
 242                 return false;
 243         }
 244 }
 245
 246 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
 247                                        bool force)
 248 {
 249         struct device *dev = info->dev;
 250         int role, power_type;
 251         unsigned int dr = DR_NONE;
 252         bool pr = false;
 253         bool polarity = false;
 254         bool dp = false;
 255         bool mux = false;
 256         bool hpd = false;
 257
 258         power_type = cros_ec_usb_get_power_type(info);
 259         if (power_type < 0) {
 260                 dev_err(dev, "failed getting power type err = %d\n",
 261                         power_type);
 262                 return power_type;
 263         }
 264
 265         role = cros_ec_usb_get_role(info, &polarity);
 266         if (role < 0) {
 267                 if (role != -ENOTCONN) {
 268                         dev_err(dev, "failed getting role err = %d\n", role);
 269                         return role;
 270                 }
 271                 dev_dbg(dev, "disconnected\n");
 272         } else {
 273                 int pd_mux_state;
 274
 275                 dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
 276                 pr = (role & PD_CTRL_RESP_ROLE_POWER);
 277                 pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
 278                 if (pd_mux_state < 0)
 279                         pd_mux_state = USB_PD_MUX_USB_ENABLED;
 280
 281                 dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
 282                 mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
 283                 hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
 284
 285                 dev_dbg(dev,
 286                         "connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
 287                         role, power_type, dr, pr, polarity, mux, dp, hpd);
 288         }
 289
 290         /*
 291          * When there is no USB host (e.g. USB PD charger),
 292          * we are not really a UFP for the AP.
 293          */
 294         if (dr == DR_DEVICE &&
 295             cros_ec_usb_power_type_is_wall_wart(power_type, role))
 296                 dr = DR_NONE;
 297
 298         if (force || info->dr != dr || info->pr != pr || info->dp != dp ||
 299             info->mux != mux || info->power_type != power_type) {
 300                 bool host_connected = false, device_connected = false;
 301
 302                 dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
 303                         cros_ec_usb_power_type_string(power_type),
 304                         cros_ec_usb_role_string(dr));
 305                 info->dr = dr;
 306                 info->pr = pr;
 307                 info->dp = dp;
 308                 info->mux = mux;
 309                 info->power_type = power_type;
 310
 311                 if (dr == DR_DEVICE)
 312                         device_connected = true;
 313                 else if (dr == DR_HOST)
 314                         host_connected = true;
 315
 316                 extcon_set_state(info->edev, EXTCON_USB, device_connected);
 317                 extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
 318                 extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
 319                 extcon_set_property(info->edev, EXTCON_USB,
 320                                     EXTCON_PROP_USB_VBUS,
 321                                     (union extcon_property_value)(int)pr);
 322                 extcon_set_property(info->edev, EXTCON_USB_HOST,
 323                                     EXTCON_PROP_USB_VBUS,
 324                                     (union extcon_property_value)(int)pr);
 325                 extcon_set_property(info->edev, EXTCON_USB,
 326                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 327                                     (union extcon_property_value)(int)polarity);
 328                 extcon_set_property(info->edev, EXTCON_USB_HOST,
 329                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 330                                     (union extcon_property_value)(int)polarity);
 331                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 332                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 333                                     (union extcon_property_value)(int)polarity);
 334                 extcon_set_property(info->edev, EXTCON_USB,
 335                                     EXTCON_PROP_USB_SS,
 336                                     (union extcon_property_value)(int)mux);
 337                 extcon_set_property(info->edev, EXTCON_USB_HOST,
 338                                     EXTCON_PROP_USB_SS,
 339                                     (union extcon_property_value)(int)mux);
 340                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 341                                     EXTCON_PROP_USB_SS,
 342                                     (union extcon_property_value)(int)mux);
 343                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 344                                     EXTCON_PROP_DISP_HPD,
 345                                     (union extcon_property_value)(int)hpd);
 346
 347                 extcon_sync(info->edev, EXTCON_USB);
 348                 extcon_sync(info->edev, EXTCON_USB_HOST);
 349                 extcon_sync(info->edev, EXTCON_DISP_DP);
 350
 351         } else if (hpd) {
 352                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 353                                     EXTCON_PROP_DISP_HPD,
 354                                     (union extcon_property_value)(int)hpd);
 355                 extcon_sync(info->edev, EXTCON_DISP_DP);
 356         }
 357
 358         return 0;
 359 }
 360
 361 static int extcon_cros_ec_event(struct notifier_block *nb,
 362                                 unsigned long queued_during_suspend,
 363                                 void *_notify)
 364 {
 365         struct cros_ec_extcon_info *info;
 366         struct cros_ec_device *ec;
 367         u32 host_event;
 368
 369         info = container_of(nb, struct cros_ec_extcon_info, notifier);
 370         ec = info->ec;
 371
 372         host_event = cros_ec_get_host_event(ec);
 373         if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
 374                           EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
 375                 extcon_cros_ec_detect_cable(info, false);
 376                 return NOTIFY_OK;
 377         }
 378
 379         return NOTIFY_DONE;
 380 }
 381
 382 static int extcon_cros_ec_probe(struct platform_device *pdev)
 383 {
 384         struct cros_ec_extcon_info *info;
 385         struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
 386         struct device *dev = &pdev->dev;
 387         struct device_node *np = dev->of_node;
 388         int numports, ret;
 389
 390         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 391         if (!info)
 392                 return -ENOMEM;
 393
 394         info->dev = dev;
 395         info->ec = ec;
 396
 397         if (np) {
 398                 u32 port;
 399
 400                 ret = of_property_read_u32(np, "google,usb-port-id", &port);
 401                 if (ret < 0) {
 402                         dev_err(dev, "Missing google,usb-port-id property\n");
 403                         return ret;
 404                 }
 405                 info->port_id = port;
 406         } else {
 407                 info->port_id = pdev->id;
 408         }
 409
 410         numports = cros_ec_pd_get_num_ports(info);
 411         if (numports < 0) {
 412                 dev_err(dev, "failed getting number of ports! ret = %d\n",
 413                         numports);
 414                 return numports;
 415         }
 416
 417         if (info->port_id >= numports) {
 418                 dev_err(dev, "This system only supports %d ports\n", numports);
 419                 return -ENODEV;
 420         }
 421
 422         info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
 423         if (IS_ERR(info->edev)) {
 424                 dev_err(dev, "failed to allocate extcon device\n");
 425                 return -ENOMEM;
 426         }
 427
 428         ret = devm_extcon_dev_register(dev, info->edev);
 429         if (ret < 0) {
 430                 dev_err(dev, "failed to register extcon device\n");
 431                 return ret;
 432         }
 433
 434         extcon_set_property_capability(info->edev, EXTCON_USB,
 435                                        EXTCON_PROP_USB_VBUS);
 436         extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 437                                        EXTCON_PROP_USB_VBUS);
 438         extcon_set_property_capability(info->edev, EXTCON_USB,
 439                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 440         extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 441                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 442         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 443                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 444         extcon_set_property_capability(info->edev, EXTCON_USB,
 445                                        EXTCON_PROP_USB_SS);
 446         extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 447                                        EXTCON_PROP_USB_SS);
 448         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 449                                        EXTCON_PROP_USB_SS);
 450         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 451                                        EXTCON_PROP_DISP_HPD);
 452
 453         info->dr = DR_NONE;
 454         info->pr = false;
 455
 456         platform_set_drvdata(pdev, info);
 457
 458         /* Get PD events from the EC */
 459         info->notifier.notifier_call = extcon_cros_ec_event;
 460         ret = blocking_notifier_chain_register(&info->ec->event_notifier,
 461                                                &info->notifier);
 462         if (ret < 0) {
 463                 dev_err(dev, "failed to register notifier\n");
 464                 return ret;
 465         }
 466
 467         /* Perform initial detection */
 468         ret = extcon_cros_ec_detect_cable(info, true);
 469         if (ret < 0) {
 470                 dev_err(dev, "failed to detect initial cable state\n");
 471                 goto unregister_notifier;
 472         }
 473
 474         return 0;
 475
 476 unregister_notifier:
 477         blocking_notifier_chain_unregister(&info->ec->event_notifier,
 478                                            &info->notifier);
 479         return ret;
 480 }
 481
 482 static int extcon_cros_ec_remove(struct platform_device *pdev)
 483 {
 484         struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
 485
 486         blocking_notifier_chain_unregister(&info->ec->event_notifier,
 487                                            &info->notifier);
 488
 489         return 0;
 490 }
 491
 492 #ifdef CONFIG_PM_SLEEP
 493 static int extcon_cros_ec_suspend(struct device *dev)
 494 {
 495         return 0;
 496 }
 497
 498 static int extcon_cros_ec_resume(struct device *dev)
 499 {
 500         int ret;
 501         struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
 502
 503         ret = extcon_cros_ec_detect_cable(info, true);
 504         if (ret < 0)
 505                 dev_err(dev, "failed to detect cable state on resume\n");
 506
 507         return 0;
 508 }
 509
 510 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
 511         SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
 512 };
 513
 514 #define DEV_PM_OPS      (&extcon_cros_ec_dev_pm_ops)
 515 #else
 516 #define DEV_PM_OPS      NULL
 517 #endif /* CONFIG_PM_SLEEP */
 518
 519 #ifdef CONFIG_OF
 520 static const struct of_device_id extcon_cros_ec_of_match[] = {
 521         { .compatible = "google,extcon-usbc-cros-ec" },
 522         { /* sentinel */ }
 523 };
 524 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
 525 #endif /* CONFIG_OF */
 526
 527 static struct platform_driver extcon_cros_ec_driver = {
 528         .driver = {
 529                 .name  = "extcon-usbc-cros-ec",
 530                 .of_match_table = of_match_ptr(extcon_cros_ec_of_match),
 531                 .pm = DEV_PM_OPS,
 532         },
 533         .remove  = extcon_cros_ec_remove,
 534         .probe   = extcon_cros_ec_probe,
 535 };
 536
 537 module_platform_driver(extcon_cros_ec_driver);
 538
 539 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
 540 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
 541 MODULE_LICENSE("GPL v2");