vibrator: add initial forcefeedback vibrator HAL

This HAL talks to vibrators which are exposed as input devices using the
forcefeedback API.

This version includes lots of debugging spam.
diff --git a/vibrator/Vibrator.cpp b/vibrator/Vibrator.cpp
new file mode 100644
index 0000000..3d1b413
--- /dev/null
+++ b/vibrator/Vibrator.cpp
@@ -0,0 +1,206 @@
+/*
+ * 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.
+ */
+
+/* Adapted from Crosshatch downstream:
+ * https://github.com/GrapheneOS/device_google_crosshatch/blob/c7f62a539b6cb4685348fbd747605cbfabf1b94d/vibrator/Vibrator.cpp
+ */
+
+#define LOG_TAG "VibratorService"
+
+#include <log/log.h>
+
+#include <hardware/hardware.h>
+#include <hardware/vibrator.h>
+#include <cutils/properties.h>
+#include <linux/input.h>
+
+#include "Vibrator.h"
+
+#include <cinttypes>
+#include <cmath>
+#include <iostream>
+#include <fstream>
+#include <cstring>
+
+
+namespace android {
+namespace hardware {
+namespace vibrator {
+namespace V1_1 {
+namespace implementation {
+
+using Status = ::android::hardware::vibrator::V1_0::Status;
+using EffectStrength = ::android::hardware::vibrator::V1_0::EffectStrength;
+using Effect = ::android::hardware::vibrator::V1_1::Effect_1_1;
+
+static constexpr int8_t MAX_TRIGGER_LATENCY_MS = 6;
+
+Vibrator::Vibrator(std::string devpath) :
+    mInputDevPath(devpath)
+{
+    std::memset(&mEffect, 0, sizeof(mEffect));
+    mEffect.type = FF_RUMBLE;
+    mEffect.id = -1;
+
+    mfd = openInputDev();
+    if (mfd < 0) {
+		ALOGE("CA:: %s() can't open FF input device %s", __func__, mInputDevPath.c_str());
+        return;
+	}
+}
+
+int Vibrator::openInputDev() {
+    return open(mInputDevPath.c_str(), O_RDWR|O_CLOEXEC);
+}
+
+Return<Status> Vibrator::on(uint32_t timeoutMs, uint32_t playCount) {
+    ALOGI("CA:: %s, timeoutMs = %d, playCount = %d, effect.id = %d, strong magnitude = %d, weak magnitude = %d", __func__, timeoutMs, playCount, mEffect.id, mEffect.u.rumble.strong_magnitude, mEffect.u.rumble.weak_magnitude);
+    struct input_event play;
+    int ret;
+
+    // Upload Rumble effect
+    ret = ioctl(mfd, EVIOCSFF, &mEffect);
+    if (ret < 0) {
+        ALOGE("CA:: %s() Couldn't upload rumble effect to device %s, ret = %d", __func__, mInputDevPath.c_str(), ret);
+        return Status::UNKNOWN_ERROR;
+	}
+
+    play.type = EV_FF;
+    play.code = mEffect.id;
+    play.value = playCount;
+    ret = write(mfd, (const void*) &play, sizeof(play));
+    if (ret != sizeof(play)) {
+        ALOGE("CA:: %s() failed to fully write play event to input device: %d", __func__, errno);
+        return Status::UNKNOWN_ERROR;
+    }
+
+    usleep(timeoutMs * 1000);
+    
+    return Status::OK;
+}
+
+// Methods from ::android::hardware::vibrator::V1_1::IVibrator follow.
+Return<Status> Vibrator::on(uint32_t timeoutMs) {
+    return(on(timeoutMs, 1));
+}
+
+Return<Status> Vibrator::off()  {
+    ALOGI("CA:: %s", __func__);
+    struct input_event stop;
+    int ret;
+
+    stop.type = EV_FF;
+    stop.code = mEffect.id;
+    stop.value = 0;
+    if (write(mfd, (const void*) &stop, sizeof(stop)) != sizeof(stop)) {
+        ALOGE("CA:: %s() failed to fully write stop event to input device", __func__);
+        return Status::UNKNOWN_ERROR;
+    }
+
+    // Unload rumble effect
+    ret = ioctl(mfd, EVIOCRMFF, &mEffect);
+    if (ret < 0) {
+		ALOGE("CA:: %s() Failed to remove rumble effect from device %s, ret = %d", __func__, mInputDevPath.c_str(), ret);
+        return Status::UNKNOWN_ERROR;
+	}
+    mEffect.id = -1;
+
+    return Status::OK;
+}
+
+Return<bool> Vibrator::supportsAmplitudeControl()  {
+    ALOGI("CA:: %s", __func__);
+    return false;
+}
+
+Return<Status> Vibrator::setAmplitude(uint8_t amplitude) {
+    ALOGI("CA:: %s", __func__);
+
+    if (!amplitude) {
+        return Status::BAD_VALUE;
+    }
+
+    return Status::OK;
+}
+
+Return<void> Vibrator::perform(V1_0::Effect effect, EffectStrength strength,
+        perform_cb _hidl_cb) {
+    return performWrapper(effect, strength, _hidl_cb);
+}
+
+Return<void> Vibrator::perform_1_1(V1_1::Effect_1_1 effect, EffectStrength strength,
+        perform_cb _hidl_cb) {
+    return performWrapper(effect, strength, _hidl_cb);
+}
+
+template <typename T>
+Return<void> Vibrator::performWrapper(T effect, EffectStrength strength, perform_cb _hidl_cb) {
+    ALOGI("CA:: %s, ", __func__);
+    auto validRange = hidl_enum_range<T>();
+    if (effect < *validRange.begin() || effect > *std::prev(validRange.end())) {
+        _hidl_cb(Status::UNSUPPORTED_OPERATION, 0);
+        return Void();
+    }
+    return performEffect(static_cast<Effect>(effect), strength, _hidl_cb);
+}
+
+Return<void> Vibrator::performEffect(Effect effect, EffectStrength strength,
+        perform_cb _hidl_cb) {
+    Status status = Status::OK;
+    uint32_t timeMs;
+    int playCount = 1;
+    mEffect.u.rumble.weak_magnitude = mEffect.u.rumble.strong_magnitude = 0;
+
+    ALOGI("CA:: %s() effect = %d", __func__, effect);
+
+    switch (effect) {
+    case Effect::TICK:
+        mEffect.u.rumble.weak_magnitude = 0x5000 + (int)strength * 0x1000;
+        timeMs = 9;
+        break;
+    case Effect::CLICK:
+        mEffect.u.rumble.strong_magnitude = 0x500 + (int)strength * 0x1000;
+        timeMs = 9;
+        break;
+    case Effect::DOUBLE_CLICK:
+        mEffect.u.rumble.strong_magnitude = 0x4000 + (int)strength * 0x1000;
+        playCount = 2;
+        timeMs = 130;
+        break;
+    default:
+        _hidl_cb(Status::UNSUPPORTED_OPERATION, 0);
+        return Void();
+    }
+
+    timeMs += MAX_TRIGGER_LATENCY_MS; // Add expected cold-start latency
+
+    on(timeMs, playCount);
+    // Android calls off() for us.
+    _hidl_cb(status, timeMs);
+
+    return Void();
+}
+
+Vibrator::~Vibrator() {
+    close(mfd);
+}
+
+
+} // namespace implementation
+}  // namespace V1_1
+}  // namespace vibrator
+}  // namespace hardware
+}  // namespace android
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