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

   1 /**
   2  * drivers/extcon/extcon-usbc-cros-ec - ChromeOS Embedded Controller extcon
   3  *
   4  * Copyright (C) 2017 Google, Inc
   5  * Author: Benson Leung <bleung@chromium.org>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  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
  17 #include <linux/extcon-provider.h>
  18 #include <linux/kernel.h>
  19 #include <linux/mfd/cros_ec.h>
  20 #include <linux/module.h>
  21 #include <linux/notifier.h>
  22 #include <linux/of.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25 #include <linux/sched.h>
  26
  27 struct cros_ec_extcon_info {
  28         struct device *dev;
  29         struct extcon_dev *edev;
  30
  31         int port_id;
  32
  33         struct cros_ec_device *ec;
  34
  35         struct notifier_block notifier;
  36
  37         unsigned int dr; /* data role */
  38         bool pr; /* power role (true if VBUS enabled) */
  39         bool dp; /* DisplayPort enabled */
  40         bool mux; /* SuperSpeed (usb3) enabled */
  41         unsigned int power_type;
  42 };
  43
  44 static const unsigned int usb_type_c_cable[] = {
  45         EXTCON_USB,
  46         EXTCON_USB_HOST,
  47         EXTCON_DISP_DP,
  48         EXTCON_NONE,
  49 };
  50
  51 enum usb_data_roles {
  52         DR_NONE,
  53         DR_HOST,
  54         DR_DEVICE,
  55 };
  56
  57 /**
  58  * cros_ec_pd_command() - Send a command to the EC.
  59  * @info: pointer to struct cros_ec_extcon_info
  60  * @command: EC command
  61  * @version: EC command version
  62  * @outdata: EC command output data
  63  * @outsize: Size of outdata
  64  * @indata: EC command input data
  65  * @insize: Size of indata
  66  *
  67  * Return: 0 on success, <0 on failure.
  68  */
  69 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
  70                               unsigned int command,
  71                               unsigned int version,
  72                               void *outdata,
  73                               unsigned int outsize,
  74                               void *indata,
  75                               unsigned int insize)
  76 {
  77         struct cros_ec_command *msg;
  78         int ret;
  79
  80         msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
  81         if (!msg)
  82                 return -ENOMEM;
  83
  84         msg->version = version;
  85         msg->command = command;
  86         msg->outsize = outsize;
  87         msg->insize = insize;
  88
  89         if (outsize)
  90                 memcpy(msg->data, outdata, outsize);
  91
  92         ret = cros_ec_cmd_xfer_status(info->ec, msg);
  93         if (ret >= 0 && insize)
  94                 memcpy(indata, msg->data, insize);
  95
  96         kfree(msg);
  97         return ret;
  98 }
  99
 100 /**
 101  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
 102  * to given port.
 103  * @info: pointer to struct cros_ec_extcon_info
 104  *
 105  * Return: power type on success, <0 on failure.
 106  */
 107 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
 108 {
 109         struct ec_params_usb_pd_power_info req;
 110         struct ec_response_usb_pd_power_info resp;
 111         int ret;
 112
 113         req.port = info->port_id;
 114         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
 115                                  &req, sizeof(req), &resp, sizeof(resp));
 116         if (ret < 0)
 117                 return ret;
 118
 119         return resp.type;
 120 }
 121
 122 /**
 123  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
 124  * @info: pointer to struct cros_ec_extcon_info
 125  *
 126  * Return: PD mux state on success, <0 on failure.
 127  */
 128 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
 129 {
 130         struct ec_params_usb_pd_mux_info req;
 131         struct ec_response_usb_pd_mux_info resp;
 132         int ret;
 133
 134         req.port = info->port_id;
 135         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
 136                                  &req, sizeof(req),
 137                                  &resp, sizeof(resp));
 138         if (ret < 0)
 139                 return ret;
 140
 141         return resp.flags;
 142 }
 143
 144 /**
 145  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
 146  * given port.
 147  * @info: pointer to struct cros_ec_extcon_info
 148  * @polarity: pointer to cable polarity (return value)
 149  *
 150  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
 151  * failure.
 152  */
 153 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
 154                                 bool *polarity)
 155 {
 156         struct ec_params_usb_pd_control pd_control;
 157         struct ec_response_usb_pd_control_v1 resp;
 158         int ret;
 159
 160         pd_control.port = info->port_id;
 161         pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
 162         pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
 163         pd_control.swap = USB_PD_CTRL_SWAP_NONE;
 164         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
 165                                  &pd_control, sizeof(pd_control),
 166                                  &resp, sizeof(resp));
 167         if (ret < 0)
 168                 return ret;
 169
 170         if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
 171                 return -ENOTCONN;
 172
 173         *polarity = resp.polarity;
 174
 175         return resp.role;
 176 }
 177
 178 /**
 179  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
 180  * @info: pointer to struct cros_ec_extcon_info
 181  *
 182  * Return: number of ports on success, <0 on failure.
 183  */
 184 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
 185 {
 186         struct ec_response_usb_pd_ports resp;
 187         int ret;
 188
 189         ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
 190                                  0, NULL, 0, &resp, sizeof(resp));
 191         if (ret < 0)
 192                 return ret;
 193
 194         return resp.num_ports;
 195 }
 196
 197 static const char *cros_ec_usb_role_string(unsigned int role)
 198 {
 199         return role == DR_NONE ? "DISCONNECTED" :
 200                 (role == DR_HOST ? "DFP" : "UFP");
 201 }
 202
 203 static const char *cros_ec_usb_power_type_string(unsigned int type)
 204 {
 205         switch (type) {
 206         case USB_CHG_TYPE_NONE:
 207                 return "USB_CHG_TYPE_NONE";
 208         case USB_CHG_TYPE_PD:
 209                 return "USB_CHG_TYPE_PD";
 210         case USB_CHG_TYPE_PROPRIETARY:
 211                 return "USB_CHG_TYPE_PROPRIETARY";
 212         case USB_CHG_TYPE_C:
 213                 return "USB_CHG_TYPE_C";
 214         case USB_CHG_TYPE_BC12_DCP:
 215                 return "USB_CHG_TYPE_BC12_DCP";
 216         case USB_CHG_TYPE_BC12_CDP:
 217                 return "USB_CHG_TYPE_BC12_CDP";
 218         case USB_CHG_TYPE_BC12_SDP:
 219                 return "USB_CHG_TYPE_BC12_SDP";
 220         case USB_CHG_TYPE_OTHER:
 221                 return "USB_CHG_TYPE_OTHER";
 222         case USB_CHG_TYPE_VBUS:
 223                 return "USB_CHG_TYPE_VBUS";
 224         case USB_CHG_TYPE_UNKNOWN:
 225                 return "USB_CHG_TYPE_UNKNOWN";
 226         default:
 227                 return "USB_CHG_TYPE_UNKNOWN";
 228         }
 229 }
 230
 231 static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
 232                                                 unsigned int role)
 233 {
 234         switch (type) {
 235         /* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
 236          * because they identify with USB_CHG_TYPE_C, but we can't return true
 237          * here from that code because that breaks Suzy-Q and other kinds of
 238          * USB Type-C cables and peripherals.
 239          */
 240         case USB_CHG_TYPE_PROPRIETARY:
 241         case USB_CHG_TYPE_BC12_DCP:
 242                 return true;
 243         case USB_CHG_TYPE_PD:
 244         case USB_CHG_TYPE_C:
 245         case USB_CHG_TYPE_BC12_CDP:
 246         case USB_CHG_TYPE_BC12_SDP:
 247         case USB_CHG_TYPE_OTHER:
 248         case USB_CHG_TYPE_VBUS:
 249         case USB_CHG_TYPE_UNKNOWN:
 250         case USB_CHG_TYPE_NONE:
 251         default:
 252                 return false;
 253         }
 254 }
 255
 256 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
 257                                        bool force)
 258 {
 259         struct device *dev = info->dev;
 260         int role, power_type;
 261         unsigned int dr = DR_NONE;
 262         bool pr = false;
 263         bool polarity = false;
 264         bool dp = false;
 265         bool mux = false;
 266         bool hpd = false;
 267
 268         power_type = cros_ec_usb_get_power_type(info);
 269         if (power_type < 0) {
 270                 dev_err(dev, "failed getting power type err = %d\n",
 271                         power_type);
 272                 return power_type;
 273         }
 274
 275         role = cros_ec_usb_get_role(info, &polarity);
 276         if (role < 0) {
 277                 if (role != -ENOTCONN) {
 278                         dev_err(dev, "failed getting role err = %d\n", role);
 279                         return role;
 280                 }
 281                 dev_dbg(dev, "disconnected\n");
 282         } else {
 283                 int pd_mux_state;
 284
 285                 dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
 286                 pr = (role & PD_CTRL_RESP_ROLE_POWER);
 287                 pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
 288                 if (pd_mux_state < 0)
 289                         pd_mux_state = USB_PD_MUX_USB_ENABLED;
 290
 291                 dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
 292                 mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
 293                 hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
 294
 295                 dev_dbg(dev,
 296                         "connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
 297                         role, power_type, dr, pr, polarity, mux, dp, hpd);
 298         }
 299
 300         /*
 301          * When there is no USB host (e.g. USB PD charger),
 302          * we are not really a UFP for the AP.
 303          */
 304         if (dr == DR_DEVICE &&
 305             cros_ec_usb_power_type_is_wall_wart(power_type, role))
 306                 dr = DR_NONE;
 307
 308         if (force || info->dr != dr || info->pr != pr || info->dp != dp ||
 309             info->mux != mux || info->power_type != power_type) {
 310                 bool host_connected = false, device_connected = false;
 311
 312                 dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
 313                         cros_ec_usb_power_type_string(power_type),
 314                         cros_ec_usb_role_string(dr));
 315                 info->dr = dr;
 316                 info->pr = pr;
 317                 info->dp = dp;
 318                 info->mux = mux;
 319                 info->power_type = power_type;
 320
 321                 if (dr == DR_DEVICE)
 322                         device_connected = true;
 323                 else if (dr == DR_HOST)
 324                         host_connected = true;
 325
 326                 extcon_set_state(info->edev, EXTCON_USB, device_connected);
 327                 extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
 328                 extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
 329                 extcon_set_property(info->edev, EXTCON_USB,
 330                                     EXTCON_PROP_USB_VBUS,
 331                                     (union extcon_property_value)(int)pr);
 332                 extcon_set_property(info->edev, EXTCON_USB_HOST,
 333                                     EXTCON_PROP_USB_VBUS,
 334                                     (union extcon_property_value)(int)pr);
 335                 extcon_set_property(info->edev, EXTCON_USB,
 336                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 337                                     (union extcon_property_value)(int)polarity);
 338                 extcon_set_property(info->edev, EXTCON_USB_HOST,
 339                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 340                                     (union extcon_property_value)(int)polarity);
 341                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 342                                     EXTCON_PROP_USB_TYPEC_POLARITY,
 343                                     (union extcon_property_value)(int)polarity);
 344                 extcon_set_property(info->edev, EXTCON_USB,
 345                                     EXTCON_PROP_USB_SS,
 346                                     (union extcon_property_value)(int)mux);
 347                 extcon_set_property(info->edev, EXTCON_USB_HOST,
 348                                     EXTCON_PROP_USB_SS,
 349                                     (union extcon_property_value)(int)mux);
 350                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 351                                     EXTCON_PROP_USB_SS,
 352                                     (union extcon_property_value)(int)mux);
 353                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 354                                     EXTCON_PROP_DISP_HPD,
 355                                     (union extcon_property_value)(int)hpd);
 356
 357                 extcon_sync(info->edev, EXTCON_USB);
 358                 extcon_sync(info->edev, EXTCON_USB_HOST);
 359                 extcon_sync(info->edev, EXTCON_DISP_DP);
 360
 361         } else if (hpd) {
 362                 extcon_set_property(info->edev, EXTCON_DISP_DP,
 363                                     EXTCON_PROP_DISP_HPD,
 364                                     (union extcon_property_value)(int)hpd);
 365                 extcon_sync(info->edev, EXTCON_DISP_DP);
 366         }
 367
 368         return 0;
 369 }
 370
 371 static int extcon_cros_ec_event(struct notifier_block *nb,
 372                                 unsigned long queued_during_suspend,
 373                                 void *_notify)
 374 {
 375         struct cros_ec_extcon_info *info;
 376         struct cros_ec_device *ec;
 377         u32 host_event;
 378
 379         info = container_of(nb, struct cros_ec_extcon_info, notifier);
 380         ec = info->ec;
 381
 382         host_event = cros_ec_get_host_event(ec);
 383         if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
 384                           EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
 385                 extcon_cros_ec_detect_cable(info, false);
 386                 return NOTIFY_OK;
 387         }
 388
 389         return NOTIFY_DONE;
 390 }
 391
 392 static int extcon_cros_ec_probe(struct platform_device *pdev)
 393 {
 394         struct cros_ec_extcon_info *info;
 395         struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
 396         struct device *dev = &pdev->dev;
 397         struct device_node *np = dev->of_node;
 398         int numports, ret;
 399
 400         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 401         if (!info)
 402                 return -ENOMEM;
 403
 404         info->dev = dev;
 405         info->ec = ec;
 406
 407         if (np) {
 408                 u32 port;
 409
 410                 ret = of_property_read_u32(np, "google,usb-port-id", &port);
 411                 if (ret < 0) {
 412                         dev_err(dev, "Missing google,usb-port-id property\n");
 413                         return ret;
 414                 }
 415                 info->port_id = port;
 416         } else {
 417                 info->port_id = pdev->id;
 418         }
 419
 420         numports = cros_ec_pd_get_num_ports(info);
 421         if (numports < 0) {
 422                 dev_err(dev, "failed getting number of ports! ret = %d\n",
 423                         numports);
 424                 return numports;
 425         }
 426
 427         if (info->port_id >= numports) {
 428                 dev_err(dev, "This system only supports %d ports\n", numports);
 429                 return -ENODEV;
 430         }
 431
 432         info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
 433         if (IS_ERR(info->edev)) {
 434                 dev_err(dev, "failed to allocate extcon device\n");
 435                 return -ENOMEM;
 436         }
 437
 438         ret = devm_extcon_dev_register(dev, info->edev);
 439         if (ret < 0) {
 440                 dev_err(dev, "failed to register extcon device\n");
 441                 return ret;
 442         }
 443
 444         extcon_set_property_capability(info->edev, EXTCON_USB,
 445                                        EXTCON_PROP_USB_VBUS);
 446         extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 447                                        EXTCON_PROP_USB_VBUS);
 448         extcon_set_property_capability(info->edev, EXTCON_USB,
 449                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 450         extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 451                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 452         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 453                                        EXTCON_PROP_USB_TYPEC_POLARITY);
 454         extcon_set_property_capability(info->edev, EXTCON_USB,
 455                                        EXTCON_PROP_USB_SS);
 456         extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 457                                        EXTCON_PROP_USB_SS);
 458         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 459                                        EXTCON_PROP_USB_SS);
 460         extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 461                                        EXTCON_PROP_DISP_HPD);
 462
 463         info->dr = DR_NONE;
 464         info->pr = false;
 465
 466         platform_set_drvdata(pdev, info);
 467
 468         /* Get PD events from the EC */
 469         info->notifier.notifier_call = extcon_cros_ec_event;
 470         ret = blocking_notifier_chain_register(&info->ec->event_notifier,
 471                                                &info->notifier);
 472         if (ret < 0) {
 473                 dev_err(dev, "failed to register notifier\n");
 474                 return ret;
 475         }
 476
 477         /* Perform initial detection */
 478         ret = extcon_cros_ec_detect_cable(info, true);
 479         if (ret < 0) {
 480                 dev_err(dev, "failed to detect initial cable state\n");
 481                 goto unregister_notifier;
 482         }
 483
 484         return 0;
 485
 486 unregister_notifier:
 487         blocking_notifier_chain_unregister(&info->ec->event_notifier,
 488                                            &info->notifier);
 489         return ret;
 490 }
 491
 492 static int extcon_cros_ec_remove(struct platform_device *pdev)
 493 {
 494         struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
 495
 496         blocking_notifier_chain_unregister(&info->ec->event_notifier,
 497                                            &info->notifier);
 498
 499         return 0;
 500 }
 501
 502 #ifdef CONFIG_PM_SLEEP
 503 static int extcon_cros_ec_suspend(struct device *dev)
 504 {
 505         return 0;
 506 }
 507
 508 static int extcon_cros_ec_resume(struct device *dev)
 509 {
 510         int ret;
 511         struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
 512
 513         ret = extcon_cros_ec_detect_cable(info, true);
 514         if (ret < 0)
 515                 dev_err(dev, "failed to detect cable state on resume\n");
 516
 517         return 0;
 518 }
 519
 520 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
 521         SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
 522 };
 523
 524 #define DEV_PM_OPS      (&extcon_cros_ec_dev_pm_ops)
 525 #else
 526 #define DEV_PM_OPS      NULL
 527 #endif /* CONFIG_PM_SLEEP */
 528
 529 #ifdef CONFIG_OF
 530 static const struct of_device_id extcon_cros_ec_of_match[] = {
 531         { .compatible = "google,extcon-usbc-cros-ec" },
 532         { /* sentinel */ }
 533 };
 534 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
 535 #endif /* CONFIG_OF */
 536
 537 static struct platform_driver extcon_cros_ec_driver = {
 538         .driver = {
 539                 .name  = "extcon-usbc-cros-ec",
 540                 .of_match_table = of_match_ptr(extcon_cros_ec_of_match),
 541                 .pm = DEV_PM_OPS,
 542         },
 543         .remove  = extcon_cros_ec_remove,
 544         .probe   = extcon_cros_ec_probe,
 545 };
 546
 547 module_platform_driver(extcon_cros_ec_driver);
 548
 549 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
 550 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
 551 MODULE_LICENSE("GPL");