Hid Utilities for HID based dynamic sensor

An HID utility library for constructing HID based dynamic sensor.

Primary functionality is in HidParser.h, which parses HID
descriptor into useful data structures. Supporting classes and
structures can be used individually as well.

Test: run tests in HidUtils/test
Bug: 37482274
Change-Id: Icfb59414bb6a1e7b6cdd1078a1a83820e70bbef8

1 files changed, 319 insertions, 0 deletions

diff --git a/modules/sensors/dynamic_sensor/HidUtils/HidParser.cpp b/modules/sensors/dynamic_sensor/HidUtils/HidParser.cpp
new file mode 100644
index 00000000..5efaf65a
--- /dev/null
+++ b/modules/sensors/dynamic_sensor/HidUtils/HidParser.cpp
@@ -0,0 +1,319 @@
+/*
+ * 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.
+ */
+#include "HidDefs.h"
+#include "HidParser.h"
+#include "HidLog.h"
+#include <iostream>
+#include <iomanip>
+
+namespace HidUtil {
+
+void HidParser::reset() {
+    mGlobalStack = HidGlobalStack();
+    mLocal = HidLocal();
+    mTree = std::make_shared<HidTreeNode>();
+    mCurrent = mTree;
+}
+
+bool HidParser::parse(const std::vector<HidItem> &token) {
+    // Clean up internal states of the parser for a new stream of descriptor token
+    reset();
+
+    bool ret = true;
+    using namespace HidDef::TagType;
+
+    for (auto &i : token) {
+        switch (i.type) {
+            case MAIN:
+                ret = processMainTag(i);
+                break;
+            case GLOBAL:
+                ret = mGlobalStack.append(i);
+                break;
+            case LOCAL:
+                ret = mLocal.append(i);
+                break;
+            default:
+                LOG_E << "HidParser found illegal HidItem: " << i << LOG_ENDL;
+                ret = false;
+        }
+
+        // in case a parse failure, quit prematurely
+        if (!ret) {
+            break;
+        }
+    }
+    return ret;
+}
+
+bool HidParser::processMainTag(const HidItem &i) {
+    using namespace HidDef::MainTag;
+    using namespace HidDef::ReportFlag;
+
+    bool ret = true;
+    switch (i.tag) {
+        case COLLECTION: {
+            unsigned int collectionType;
+            if (!i.dataAsUnsigned(&collectionType)) {
+                LOG_E << "Cannot get collection type at offset " << i.offset << LOG_ENDL;
+                ret = false;
+                break;
+            }
+            unsigned int fullUsage =
+                    mGlobalStack.top().usagePage.get(0) << 16 | mLocal.getUsage(0);
+            mCurrent = mCurrent->addChild(
+                    std::make_shared<HidTreeNode>(mCurrent, collectionType, fullUsage));
+            break;
+        }
+        case END_COLLECTION:
+            mCurrent = mCurrent->getParent();
+            if (!mCurrent) {
+                // trigger parse failure so that mCurrent will not be accessed
+                LOG_E << "unmatched END_COLLECTION at " << i.offset << LOG_ENDL;
+                ret = false;
+            }
+            break;
+        case INPUT:
+        case OUTPUT:
+        case FEATURE: {
+            unsigned int reportType = i.tag;
+            unsigned int flag;
+            if (!i.dataAsUnsigned(&flag)) {
+                LOG_E << "Cannot get report flag at offset " << i.offset << LOG_ENDL;
+                ret = false;
+                break;
+            }
+            const HidGlobal &top = mGlobalStack.top();
+
+            // usage page, local min/max, report size and count have to be defined at report
+            // definition.
+            if (!(top.usagePage.isSet() && top.logicalMin.isSet() && top.logicalMax.isSet()
+                  && top.reportSize.isSet() && top.reportCount.isSet())) {
+                LOG_E << "Report defined at " << i.offset
+                      << " does not have all mandatory fields set" << LOG_ENDL;
+                ret = false;
+                break;
+            }
+            if (top.reportSize.get(0) > 32) {
+                LOG_E << "Report defined at " << i.offset
+                      << " has unsupported report size(> 32 bit)" << LOG_ENDL;
+                ret = false;
+                break;
+            }
+
+            HidReport report(reportType, flag, top, mLocal);
+            mReport.push_back(report);
+            std::shared_ptr<HidTreeNode> node(new HidReportNode(mCurrent, report));
+            mCurrent->addChild(node);
+            break;
+        }
+        default:
+            LOG_E << "unknown main tag, " << i << LOG_ENDL;
+            ret = false;
+    }
+    // locals is cleared after any main tag according to HID spec
+    mLocal.clear();
+    return ret;
+}
+
+bool HidParser::parse(const unsigned char *begin, size_t size) {
+    std::vector<HidItem> hidItemVector = HidItem::tokenize(begin, size);
+    return parse(hidItemVector);
+}
+
+void HidParser::filterTree() {
+    if (mTree != nullptr) {
+        filterTree(mTree);
+    }
+}
+
+void HidParser::filterTree(std::shared_ptr<HidTreeNode> &node) {
+    if (node->isReportCollection()) {
+        std::shared_ptr<HidReportNode> reportNode =
+                std::static_pointer_cast<HidReportNode>(node->getChildren().front());
+        if (reportNode != nullptr) {
+            reportNode->collapse(node->getFullUsage());
+            node = reportNode;
+        }
+    } else {
+        for (auto &i : node->getChildren()) {
+            filterTree(i);
+        }
+    }
+}
+
+HidParser::DigestVector HidParser::generateDigest(
+        const std::unordered_set<unsigned int> &interestedUsage) {
+    DigestVector digestVector;
+    digest(&digestVector, mTree, interestedUsage);
+    return digestVector;
+}
+
+void HidParser::digest(HidParser::DigestVector *digestVector,
+                       const std::shared_ptr<HidTreeNode> &node,
+                       const std::unordered_set<unsigned int> &interestedUsage) {
+    if (digestVector == nullptr) {
+        return;
+    }
+
+    if (node->isUsageCollection()
+            && interestedUsage.find(node->getFullUsage()) != interestedUsage.end()) {
+        // this collection contains the usage interested
+        ReportSetGroup reportSetGroup;
+
+        // one layer deep search
+        for (auto &i : node->getChildren()) {
+            // skip all nodes that is not a report node
+            if (i->getNodeType() != HidTreeNode::TYPE_REPORT) {
+                continue;
+            }
+            const HidReport &report =
+                    std::static_pointer_cast<HidReportNode>(i)->getReport();
+
+            unsigned int id = report.getReportId();;
+            if (reportSetGroup.find(id) == reportSetGroup.end()) {
+                // create an id group if it is not created
+                reportSetGroup.emplace(id, ReportSet());
+            }
+
+            ReportSet &reportGroup = reportSetGroup[id];
+            switch(report.getType()) {
+                using namespace HidDef::MainTag;
+                case FEATURE:
+                    reportGroup[REPORT_TYPE_FEATURE].push_back(report);
+                    break;
+                case INPUT:
+                    reportGroup[REPORT_TYPE_INPUT].push_back(report);
+                    break;
+                case OUTPUT:
+                    reportGroup[REPORT_TYPE_OUTPUT].push_back(report);
+                    break;
+            }
+        }
+        ReportDigest digest = {
+            .fullUsage = node->getFullUsage(),
+            .packets = convertGroupToPacket(reportSetGroup)
+        };
+        digestVector->emplace_back(digest);
+    } else {
+        for (const auto &child : node->getChildren()) {
+            if (child->getNodeType() == HidTreeNode::TYPE_NORMAL) {
+                // only follow into collection nodes
+                digest(digestVector, child, interestedUsage);
+            }
+        }
+    }
+}
+
+std::vector<HidParser::ReportPacket> HidParser::convertGroupToPacket(
+        const HidParser::ReportSetGroup &group) {
+    std::vector<ReportPacket> packets;
+
+    const std::vector<int> types = {REPORT_TYPE_FEATURE, REPORT_TYPE_INPUT, REPORT_TYPE_OUTPUT};
+
+    for (const auto &setPair : group) {
+        unsigned int id = setPair.first;
+        for (auto type : types) {
+            const auto &reports = setPair.second[type]; // feature
+
+            // template
+            ReportPacket packet = {
+                .type = type,
+                .id = id,
+                .bitSize = 0
+            };
+
+            for (const auto &r : reports) {
+                auto logical = r.getLogicalRange();
+                auto physical = r.getPhysicalRange();
+
+                int64_t offset = physical.first - logical.first;
+                double scale = static_cast<double>((physical.second - physical.first))
+                        / (logical.second - logical.first);
+                scale *= r.getExponentValue();
+
+                ReportItem digest = {
+                    .usage = r.getFullUsage(),
+                    .id = id,
+                    .minRaw = logical.first,
+                    .maxRaw = logical.second,
+                    .a = scale,
+                    .b = offset,
+                    .bitOffset = packet.bitSize,
+                    .bitSize = r.getSize(),
+                    .count = r.getCount(),
+                    .unit = r.getUnit(),
+                };
+                packet.reports.push_back(digest);
+                packet.bitSize += digest.bitSize * digest.count;
+            }
+            if (!packet.reports.empty()) {
+                packets.push_back(std::move(packet));
+            }
+        }
+    }
+    return packets;
+}
+
+static std::string reportTypeToString(int reportType) {
+    switch (reportType) {
+        case HidParser::REPORT_TYPE_INPUT:
+            return "INPUT";
+        case HidParser::REPORT_TYPE_OUTPUT:
+            return "OUTPUT";
+        case HidParser::REPORT_TYPE_FEATURE:
+            return "FEATURE";
+        default:
+            return "INVALID REPORT";
+    }
+}
+
+std::ostream& operator<<(std::ostream &os, const HidParser::DigestVector &digests) {
+    for (const auto &i : digests) {
+        os << "Usage: 0x" << std::hex  << i.fullUsage << std::dec
+           << ", " << i.packets.size() << " report packet:" << LOG_ENDL;
+        for (const auto &packet : i.packets) {
+            os << reportTypeToString(packet.type) << " id: " << packet.id
+               << " size: " << packet.bitSize
+               << "b(" << packet.getByteSize() << "B), "
+               << packet.reports.size() << " entries" << LOG_ENDL;
+
+            for (const auto &report : packet.reports) {
+                double min, max;
+                report.decode(report.mask(report.minRaw), &min);
+                report.decode(report.mask(report.maxRaw), &max);
+
+                os << "  " << report.bitOffset << " size: " << report.bitSize
+                   << ", count: " << report.count
+                   << ", usage: " << std::hex << std::setfill('0') << std::setw(8)
+                   << report.usage << std::dec
+                   << ", min: " << report.minRaw << ", max: " << report.maxRaw
+                   << ", minDecoded: " << min
+                   << ", maxDecoded: " << max
+                   << ", a: " << report.a << ", b: " << report.b
+                   << std::hex
+                   << ", minRawHex: 0x" << report.mask(report.minRaw)
+                   << ", maxRawHex: 0x" << report.mask(report.maxRaw)
+                   << ", rawMasked: 0x" << report.rawMask()
+                   << std::dec << LOG_ENDL;
+            }
+        }
+        os << LOG_ENDL;
+    }
+    os << LOG_ENDL;
+    return os;
+}
+} // namespace HidUtil