linux/drivers/extcon/extcon-usbc-cros-ec.c
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   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
  18struct 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
  35static const unsigned int usb_type_c_cable[] = {
  36        EXTCON_USB,
  37        EXTCON_USB_HOST,
  38        EXTCON_DISP_DP,
  39        EXTCON_NONE,
  40};
  41
  42enum 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 */
  60static 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 */
  98static 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 */
 119static 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 */
 144static 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 */
 175static 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
 188static 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
 194static 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
 222static 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
 247static 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
 362static 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
 383static 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
 477unregister_notifier:
 478        blocking_notifier_chain_unregister(&info->ec->event_notifier,
 479                                           &info->notifier);
 480        return ret;
 481}
 482
 483static 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
 494static int extcon_cros_ec_suspend(struct device *dev)
 495{
 496        return 0;
 497}
 498
 499static 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
 511static 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
 521static const struct of_device_id extcon_cros_ec_of_match[] = {
 522        { .compatible = "google,extcon-usbc-cros-ec" },
 523        { /* sentinel */ }
 524};
 525MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
 526#endif /* CONFIG_OF */
 527
 528static 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
 538module_platform_driver(extcon_cros_ec_driver);
 539
 540MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
 541MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
 542MODULE_LICENSE("GPL v2");
 543