device_xiaomi_rosemary/usb/Usb.cpp

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "android.hardware.usb@1.1-service.rosemary"

#include <android-base/logging.h>
#include <assert.h>
#include <chrono>
#include <dirent.h>
#include <pthread.h>
#include <regex>
#include <stdio.h>
#include <sys/types.h>
#include <thread>
#include <unistd.h>
#include <unordered_map>

#include <cutils/uevent.h>
#include <sys/epoll.h>
#include <utils/Errors.h>
#include <utils/StrongPointer.h>

#include "Usb.h"

namespace android {
namespace hardware {
namespace usb {
namespace V1_1 {
namespace implementation {

// Set by the signal handler to destroy the thread
volatile bool destroyThread;

static int32_t readFile(const std::string &filename, std::string *contents) {
  FILE *fp;
  ssize_t read = 0;
  char *line = NULL;
  size_t len = 0;

  fp = fopen(filename.c_str(), "r");
  if (fp != NULL) {
    if ((read = getline(&line, &len, fp)) != -1) {
      char *pos;
      if ((pos = strchr(line, '\n')) != NULL) *pos = '\0';
      *contents = line;
    }
    free(line);
    fclose(fp);
    return 0;
  } else {
    ALOGE("fopen failed in readFile %s, errno=%d", filename.c_str(), errno);
  }

  return -1;
}

static int32_t writeFile(const std::string &filename,
                         const std::string &contents) { // Might remove later
  FILE *fp;
  int ret;

  fp = fopen(filename.c_str(), "w");
  if (fp != NULL) {
    ret = fputs(contents.c_str(), fp);
    fclose(fp);
    if (ret == EOF) {
      ALOGE("fputs failed in writeFile %s", filename.c_str());
      return -1;
    }
    return 0;
  } else {
    ALOGE("fopen failed in writeFile %s, errno=%d", filename.c_str(), errno);
  }

  return -1;
}

std::string appendRoleNodeHelper(const std::string &portName,
                                 PortRoleType type) {
  std::string node("/sys/class/dual_role_usb/" + portName); // We have /sys/class/dual_role_usb, not /sys/class/typec

  switch (type) {
    case PortRoleType::DATA_ROLE:
      return node + "/data_role";
    case PortRoleType::POWER_ROLE:
      return node + "/power_role";
    case PortRoleType::MODE:
      return node + "/mode"; // We have a separate file for mode
    default:
      return node + "/mode"; // Disassembly shows no separate case for non-matches and MODE case could be removed, leaving just default, but let's keep it like that for now in case we need to change something.
  }
}

std::string convertRoletoString(PortRole role) {
  if (role.type == PortRoleType::POWER_ROLE) {
    if (role.role == static_cast<uint32_t>(PortPowerRole::SOURCE)) return "source";
    else if (role.role == static_cast<uint32_t>(PortPowerRole::SINK)) return "sink";
  } else if (role.type == PortRoleType::DATA_ROLE) {
    if (role.role == static_cast<uint32_t>(PortDataRole::HOST)) return "host";
    if (role.role == static_cast<uint32_t>(PortDataRole::DEVICE)) return "device";
  } else if (role.type == PortRoleType::MODE) {
    if (role.role == static_cast<uint32_t>(PortMode_1_1::UFP)) return "ufp"; // We probably call these 'ufp' and 'dfp', as seen in switchToDrp for example
    if (role.role == static_cast<uint32_t>(PortMode_1_1::DFP)) return "dfp";
  }
  return "none";
}

void extractRole(std::string *roleName) { // Might remove later.
  std::size_t first, last;

  first = roleName->find("[");
  last = roleName->find("]");

  if (first != std::string::npos && last != std::string::npos) {
    *roleName = roleName->substr(first + 1, last - first - 1);
  }
}

void switchToDrp(const std::string &portName) {
  std::string filename =
      appendRoleNodeHelper(std::string(portName.c_str()), PortRoleType::MODE);
  FILE *fp;

  if (filename != "") {
    fp = fopen(filename.c_str(), "w");
    if (fp != NULL) {
      int ret = fputs("dfp", fp); // Change dual -> dfp. Based on disassembly of stock HAL.
      fclose(fp);
      if (ret == EOF)
        ALOGE("Fatal: Error while switching back to drp");
    } else {
      ALOGE("Fatal: Cannot open file to switch back to drp");
    }
  } else {
    ALOGE("Fatal: invalid node type");
  }
}

Usb::Usb()
        : mLock(PTHREAD_MUTEX_INITIALIZER),
          mRoleSwitchLock(PTHREAD_MUTEX_INITIALIZER),
          mPartnerLock(PTHREAD_MUTEX_INITIALIZER),
          mPartnerUp(false) {
    pthread_condattr_t attr;
    if (pthread_condattr_init(&attr)) {
        ALOGE("pthread_condattr_init failed: %s", strerror(errno));
        abort();
    }
    if (pthread_condattr_setclock(&attr, CLOCK_MONOTONIC)) {
        ALOGE("pthread_condattr_setclock failed: %s", strerror(errno));
        abort();
    }
    if (pthread_cond_init(&mPartnerCV, &attr))  {
        ALOGE("pthread_cond_init failed: %s", strerror(errno));
        abort();
    }
    if (pthread_condattr_destroy(&attr)) {
        ALOGE("pthread_condattr_destroy failed: %s", strerror(errno));
        abort();
    }
}


Return<void> Usb::switchRole(const hidl_string &portName,
                             const V1_0::PortRole &newRole) {
  std::string filename =
      appendRoleNodeHelper(std::string(portName.c_str()), newRole.type);
  std::string written;
  FILE *fp;
  bool roleSwitch = false;

  if (filename == "") {
    ALOGE("Fatal: invalid node type");
    return Void();
  }

  pthread_mutex_lock(&mRoleSwitchLock);

  /*
     It looks like we have some type of loop in the stock HAL.
     The loop starts at 0x4860 and ends at 0x4D4C in android.hardware.usb@1.1-service-mediatek from V12.0.1.0.QJOEUXM
     We break out of the loop only if the value at W24 register is equal to zero. Before loop start, we can see that W24 is set to 0x14 = 20.
     We can also see that before deciding to break out or restart, W24 is decremented by 1 and there is an usleep call.
     The amount of useconds to sleep is stored in register W19. This register is set to 0xC350 = 50000 before the loop.

     We can conclude that the program attempts to write the role 20 times and waits 50000 useconds before trying again.
  */
  for (int i = 0; i < 20; ++i) {
    ALOGI("filename write: %s role:%s", filename.c_str(),
          convertRoletoString(newRole).c_str());

    // We don't need to check role type and use a separate way of setting mode, as we simply have a "mode" file for doing that

    fp = fopen(filename.c_str(), "w");
    if (fp != NULL) {
      int ret = fputs(convertRoletoString(newRole).c_str(), fp);
      fclose(fp);
      if ((ret != EOF) && !readFile(filename, &written)) {
        // extractRole(&written);
        ALOGI("written: %s", written.c_str());
        if (written == convertRoletoString(newRole)) {
          roleSwitch = true;
          break; // Role switched, stop retrying.
        } else {
          ALOGE("Role switch failed");
        }
      } else {
        ALOGE("failed to update the new role");
      }
    } else {
      ALOGE("fopen failed");
    }

    usleep(50000);
  }

  pthread_mutex_lock(&mLock);
  if (mCallback_1_0 != NULL) {
    Return<void> ret =
        mCallback_1_0->notifyRoleSwitchStatus(portName, newRole,
        roleSwitch ? Status::SUCCESS : Status::ERROR);
    if (!ret.isOk())
      ALOGE("RoleSwitchStatus error %s", ret.description().c_str());
  } else {
    ALOGE("Not notifying the userspace. Callback is not set");
  }
  pthread_mutex_unlock(&mLock);
  pthread_mutex_unlock(&mRoleSwitchLock);

  return Void();
}


Status getCurrentRoleHelper(const std::string &portName, bool connected,
                            PortRoleType type, uint32_t *currentRole) {
  std::string filename;
  std::string roleName;
  // Accessory stuff removed - stock HAL doesn't have that
  // Mode

  if (type == PortRoleType::POWER_ROLE) {
    filename = "/sys/class/dual_role_usb/" + portName + "/power_role";
    *currentRole = static_cast<uint32_t>(PortPowerRole::NONE);
  } else if (type == PortRoleType::DATA_ROLE) {
    filename = "/sys/class/dual_role_usb/" + portName + "/data_role";
    *currentRole = static_cast<uint32_t>(PortDataRole::NONE);
  } else if (type == PortRoleType::MODE) {
    filename = "/sys/class/dual_role_usb/" + portName + "/mode"; // We have a separate file for setting mode.
    *currentRole = static_cast<uint32_t>(PortMode_1_1::NONE);
  } else {
    return Status::ERROR;
  }

  if (!connected) return Status::SUCCESS;

  if (readFile(filename, &roleName)) {
    ALOGE("getCurrentRole: Failed to open filesystem node: %s",
          filename.c_str());
    return Status::ERROR;
  }

  // extractRole(&roleName); // Probably don't need to extract. The role names on our device are just single words

  // We have simple role names and don't need to make a distinction based on role type
  if (roleName == "source") {
      *currentRole = static_cast<uint32_t>(PortPowerRole::SOURCE);
  } else if (roleName == "sink") {
      *currentRole = static_cast<uint32_t>(PortPowerRole::SINK);
  } else if (roleName == "host") {
      *currentRole = static_cast<uint32_t>(PortDataRole::HOST);
  } else if (roleName == "dfp") {
      *currentRole = static_cast<uint32_t>(PortMode_1_1::DFP);
  } else if (roleName == "device") {
      *currentRole = static_cast<uint32_t>(PortDataRole::DEVICE);
  } else if (roleName == "ufp") {
      *currentRole = static_cast<uint32_t>(PortMode_1_1::UFP);
  } else if (roleName != "none") {
    /* case for none has already been addressed.
     * so we check if the role isnt none.
     */
    return Status::UNRECOGNIZED_ROLE;
  }

  return Status::SUCCESS;
}

Status getTypeCPortNamesHelper(std::unordered_map<std::string, bool> *names) {
  DIR *dp;

  dp = opendir("/sys/class/dual_role_usb");
  if (dp != NULL) {
    struct dirent *ep;

    while ((ep = readdir(dp))) {
      if (ep->d_type == DT_LNK) {
        // We don't have -partner suffixes
          std::unordered_map<std::string, bool>::const_iterator portName =
              names->find(ep->d_name);
          if (portName == names->end()) {
            names->insert({ep->d_name, true}); // True by default - otherwise getPortStatusHelper will never say if role can be switched
          }
      }
    }
    closedir(dp);
    return Status::SUCCESS;
  }

  ALOGE("Failed to open /sys/class/dual_role_usb");
  return Status::ERROR;
}

bool canSwitchRoleHelper(const std::string &portName, PortRoleType /*type*/) {
  std::string filename = "/sys/class/tcpc/type_c_port0/pe_ready";
  std::string supportsPD;

  if (!readFile(filename, &supportsPD)) {
    if (supportsPD == "yes") {
      return true;
    }
  }

  return false;
}

/*
 * Reuse the same method for both V1_0 and V1_1 callback objects.
 * The caller of this method would reconstruct the V1_0::PortStatus
 * object if required.
 */
Status getPortStatusHelper(hidl_vec<PortStatus_1_1> *currentPortStatus_1_1,
    bool V1_0) {
  std::unordered_map<std::string, bool> names;
  Status result = getTypeCPortNamesHelper(&names);
  int i = -1;

  if (result == Status::SUCCESS) {
    currentPortStatus_1_1->resize(names.size());
    for (const std::pair<std::string, bool>& port : names) {
      i++;
      ALOGI("%s", port.first.c_str());
      (*currentPortStatus_1_1)[i].status.portName = port.first;

      uint32_t currentRole;
      if (getCurrentRoleHelper(port.first, port.second,
                               PortRoleType::POWER_ROLE,
                               &currentRole) == Status::SUCCESS) {
        (*currentPortStatus_1_1)[i].status.currentPowerRole =
            static_cast<PortPowerRole>(currentRole);
      } else {
        ALOGE("Error while retreiving portNames");
        goto done;
      }

      if (getCurrentRoleHelper(port.first, port.second, PortRoleType::DATA_ROLE,
                               &currentRole) == Status::SUCCESS) {
        /* HACK: Our device has broken roles: they appear to be permanently set
           to NONE and don't respond to configfs writes. This causes Android to
           not see the USB port as connected, breaking the USB settings.

           To get USB preferences to work, we have to spoof some roles. */
        if (port.second == true && currentRole == static_cast<uint32_t>(PortDataRole::NONE)) {
          currentRole = static_cast<uint32_t>(PortDataRole::DEVICE);
        }

        (*currentPortStatus_1_1)[i].status.currentDataRole =
            static_cast<PortDataRole>(currentRole);
      } else {
        ALOGE("Error while retreiving current port role");
        goto done;
      }

      if (getCurrentRoleHelper(port.first, port.second, PortRoleType::MODE,
                               &currentRole) == Status::SUCCESS) {
        // HACK: see above
        if (port.second == true && currentRole == static_cast<uint32_t>(PortMode_1_1::NONE)) {
          currentRole = static_cast<uint32_t>(PortMode_1_1::UFP);
        }

        (*currentPortStatus_1_1)[i].currentMode =
            static_cast<PortMode_1_1>(currentRole);
        (*currentPortStatus_1_1)[i].status.currentMode =
            static_cast<V1_0::PortMode>(currentRole);
      } else {
        ALOGE("Error while retreiving current data role");
        goto done;
      }

      // Treat mode change like any type of role change - we have the "mode" file in our port directory.
      (*currentPortStatus_1_1)[i].status.canChangeMode =
          port.second ? canSwitchRoleHelper(port.first, PortRoleType::MODE)
                      : false;
      (*currentPortStatus_1_1)[i].status.canChangeDataRole =
          port.second ? canSwitchRoleHelper(port.first, PortRoleType::DATA_ROLE)
                      : false;
      (*currentPortStatus_1_1)[i].status.canChangePowerRole =
          port.second ? canSwitchRoleHelper(port.first, PortRoleType::POWER_ROLE)
                      : false;

      ALOGI("connected:%d canChangeMode:%d canChagedata:%d canChangePower:%d",
            port.second, (*currentPortStatus_1_1)[i].status.canChangeMode,
            (*currentPortStatus_1_1)[i].status.canChangeDataRole,
            (*currentPortStatus_1_1)[i].status.canChangePowerRole);

      if (V1_0) {
        (*currentPortStatus_1_1)[i].status.supportedModes = V1_0::PortMode::DFP;
      } else {
        (*currentPortStatus_1_1)[i].supportedModes = PortMode_1_1::UFP | PortMode_1_1::DFP;
        (*currentPortStatus_1_1)[i].status.supportedModes = V1_0::PortMode::NONE;
        (*currentPortStatus_1_1)[i].status.currentMode = V1_0::PortMode::NONE;
      }
    }
    return Status::SUCCESS;
  }
done:
  return Status::ERROR;
}

Return<void> Usb::queryPortStatus() {
  hidl_vec<PortStatus_1_1> currentPortStatus_1_1;
  hidl_vec<V1_0::PortStatus> currentPortStatus;
  Status status;
  sp<IUsbCallback> callback_V1_1 = IUsbCallback::castFrom(mCallback_1_0);

  pthread_mutex_lock(&mLock);
  if (mCallback_1_0 != NULL) {
    if (callback_V1_1 != NULL) {
      status = getPortStatusHelper(&currentPortStatus_1_1, false);
    } else {
      status = getPortStatusHelper(&currentPortStatus_1_1, true);
      currentPortStatus.resize(currentPortStatus_1_1.size());
      for (unsigned long i = 0; i < currentPortStatus_1_1.size(); i++)
        currentPortStatus[i] = currentPortStatus_1_1[i].status;
    }

    Return<void> ret;

    if (callback_V1_1 != NULL)
      ret = callback_V1_1->notifyPortStatusChange_1_1(currentPortStatus_1_1, status);
    else
      ret = mCallback_1_0->notifyPortStatusChange(currentPortStatus, status);

    if (!ret.isOk())
      ALOGE("queryPortStatus_1_1 error %s", ret.description().c_str());
  } else {
    ALOGI("Notifying userspace skipped. Callback is NULL");
  }
  pthread_mutex_unlock(&mLock);

  return Void();
}

struct data {
  int uevent_fd;
  android::hardware::usb::V1_1::implementation::Usb *usb;
};

static void uevent_event(uint32_t /*epevents*/, struct data *payload) {
  char msg[UEVENT_MSG_LEN + 2];
  char *cp;
  int n;

  n = uevent_kernel_multicast_recv(payload->uevent_fd, msg, UEVENT_MSG_LEN);
  if (n <= 0) return;
  if (n >= UEVENT_MSG_LEN) /* overflow -- discard */
    return;

  msg[n] = '\0';
  msg[n + 1] = '\0';
  cp = msg;

  while (*cp) {
    // Removed regex matching for -partner, as we don't seem to have that in the stock HAL and in /sys/class/dual_role_usb.
    if (!strncmp(cp, "SUBSYSTEM=dual_role_usb", strlen("SUBSYSTEM=dual_role_usb"))) { // Stock HAL looks for dual_role_usb, and it checks the SUBSYSTEM instead of DEVNAME. 0x62D4 in android.hardware.usb@1.1-service-mediatek from V12.0.1.0.QJOEUXM
      hidl_vec<PortStatus_1_1> currentPortStatus_1_1;
      ALOGI("uevent received %s", cp);
      pthread_mutex_lock(&payload->usb->mLock);
      if (payload->usb->mCallback_1_0 != NULL) {
        sp<IUsbCallback> callback_V1_1 = IUsbCallback::castFrom(payload->usb->mCallback_1_0);
        Return<void> ret;

        // V1_1 callback
        if (callback_V1_1 != NULL) {
          Status status = getPortStatusHelper(&currentPortStatus_1_1, false);
          ret = callback_V1_1->notifyPortStatusChange_1_1(
              currentPortStatus_1_1, status);
        } else { // V1_0 callback
          Status status = getPortStatusHelper(&currentPortStatus_1_1, true);

          /*
           * Copying the result from getPortStatusHelper
           * into V1_0::PortStatus to pass back through
           * the V1_0 callback object.
           */
          hidl_vec<V1_0::PortStatus> currentPortStatus;
          currentPortStatus.resize(currentPortStatus_1_1.size());
          for (unsigned long i = 0; i < currentPortStatus_1_1.size(); i++)
            currentPortStatus[i] = currentPortStatus_1_1[i].status;

          ret = payload->usb->mCallback_1_0->notifyPortStatusChange(
              currentPortStatus, status);
        }
        if (!ret.isOk()) ALOGE("error %s", ret.description().c_str());
      } else {
        ALOGI("Notifying userspace skipped. Callback is NULL");
      }
      pthread_mutex_unlock(&payload->usb->mLock);

      //Role switch is not in progress and port is in disconnected state
      if (!pthread_mutex_trylock(&payload->usb->mRoleSwitchLock)) {
        for (unsigned long i = 0; i < currentPortStatus_1_1.size(); i++) {
          DIR *dp = opendir(std::string("/sys/class/dual_role_usb/"
              + std::string(currentPortStatus_1_1[i].status.portName.c_str())).c_str()); // Stock HAL did not append -partner. Based on disassembly - 0x65E0 in android.hardware.usb@1.1-service-mediatek from V12.0.1.0.QJOEUXM
          if (dp == NULL) {
              //PortRole role = {.role = static_cast<uint32_t>(PortMode::UFP)};
              switchToDrp(currentPortStatus_1_1[i].status.portName);
          } else {
              closedir(dp);
          }
        }
        pthread_mutex_unlock(&payload->usb->mRoleSwitchLock);
      }
      break;
    } // Removed autosuspend regex match stuff - we don't even have the path that regex was looking for on a live device, and there are no mentions of auto suspend stuff in strings from the stock HAL whatsoever. The functions related to auto suspend afterwards have been nuked too.

    /* advance to after the next \0 */
    while (*cp++) {}
  }
}

void *work(void *param) {
  int epoll_fd, uevent_fd;
  struct epoll_event ev;
  int nevents = 0;
  struct data payload;

  ALOGE("creating thread");

  uevent_fd = uevent_open_socket(64 * 1024, true);

  if (uevent_fd < 0) {
    ALOGE("uevent_init: uevent_open_socket failed\n");
    return NULL;
  }

  payload.uevent_fd = uevent_fd;
  payload.usb = (android::hardware::usb::V1_1::implementation::Usb *)param;

  fcntl(uevent_fd, F_SETFL, O_NONBLOCK);

  ev.events = EPOLLIN;
  ev.data.ptr = (void *)uevent_event;

  epoll_fd = epoll_create(64);
  if (epoll_fd == -1) {
    ALOGE("epoll_create failed; errno=%d", errno);
    goto error;
  }

  if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, uevent_fd, &ev) == -1) {
    ALOGE("epoll_ctl failed; errno=%d", errno);
    goto error;
  }

  while (!destroyThread) {
    struct epoll_event events[64];

    nevents = epoll_wait(epoll_fd, events, 64, -1);
    if (nevents == -1) {
      if (errno == EINTR) continue;
      ALOGE("usb epoll_wait failed; errno=%d", errno);
      break;
    }

    for (int n = 0; n < nevents; ++n) {
      if (events[n].data.ptr)
        (*(void (*)(int, struct data *payload))events[n].data.ptr)(
            events[n].events, &payload);
    }
  }

  ALOGI("exiting worker thread");
error:
  close(uevent_fd);

  if (epoll_fd >= 0) close(epoll_fd);

  return NULL;
}

void sighandler(int sig) {
  if (sig == SIGUSR1) {
    destroyThread = true;
    ALOGI("destroy set");
    return;
  }
  signal(SIGUSR1, sighandler);
}

Return<void> Usb::setCallback(const sp<V1_0::IUsbCallback> &callback) {

  sp<IUsbCallback> callback_V1_1 = IUsbCallback::castFrom(callback);

  if (callback != NULL)
      if (callback_V1_1 == NULL)
          ALOGI("Registering 1.0 callback");

  pthread_mutex_lock(&mLock);
  /*
   * When both the old callback and new callback values are NULL,
   * there is no need to spin off the worker thread.
   * When both the values are not NULL, we would already have a
   * worker thread running, so updating the callback object would
   * be suffice.
   */
  if ((mCallback_1_0 == NULL && callback == NULL) ||
      (mCallback_1_0 != NULL && callback != NULL)) {
    /*
     * Always store as V1_0 callback object. Type cast to V1_1
     * when the callback is actually invoked.
     */
    mCallback_1_0 = callback;
    pthread_mutex_unlock(&mLock);
    return Void();
  }

  mCallback_1_0 = callback;
  ALOGI("registering callback");

  // Kill the worker thread if the new callback is NULL.
  if (mCallback_1_0 == NULL) {
    pthread_mutex_unlock(&mLock);
    if (!pthread_kill(mPoll, SIGUSR1)) {
      pthread_join(mPoll, NULL);
      ALOGI("pthread destroyed");
    }
    return Void();
  }

  destroyThread = false;
  signal(SIGUSR1, sighandler);

  /*
   * Create a background thread if the old callback value is NULL
   * and being updated with a new value.
   */
  if (pthread_create(&mPoll, NULL, work, this)) {
    ALOGE("pthread creation failed %d", errno);
    mCallback_1_0 = NULL;
  }

  pthread_mutex_unlock(&mLock);
  return Void();
}

}  // namespace implementation
}  // namespace V1_0
}  // namespace usb
}  // namespace hardware
}  // namespace android