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