thermal: add private methods for thermal-engine use

Add private HAL implementation methods for use in interacting with
the thermal-engine daemon:

* getSkinSensorType returns the "type" (name) of the skin sensor
  for walleye vs. taimen
* notifyThrottling pushes throttling start/stop events to the HAL
  for forwarding to IThermalCallback in the generic framework.

Bug: 30982366
Test: manual on walleye (with artifically low threshold)
Change-Id: I082c100df22880bfd53c2cb5c78b0be47c58894e

thermal/Thermal.cpp

@@ -150,6 +150,32 @@ Return<void> Thermal::registerThermalCallback(
     return Void();
 }
 
+// Local functions used internally by thermal-engine follow.
+
+std::string Thermal::getSkinSensorType() {
+    return getTargetSkinSensorType();
+}
+
+void Thermal::notifyThrottling(
+    bool isThrottling, const Temperature& temperature) {
+    if (gThermalCallback != nullptr) {
+        Return<void> ret =
+            gThermalCallback->notifyThrottling(isThrottling, temperature);
+        if (!ret.isOk()) {
+          if (ret.isDeadObject()) {
+              gThermalCallback = nullptr;
+              LOG(WARNING) << "Dropped throttling event, ThermalCallback died";
+          } else {
+              LOG(WARNING) <<
+                  "Failed to send throttling event to ThermalCallback";
+          }
+        }
+    } else {
+        LOG(WARNING) <<
+            "Dropped throttling event, no ThermalCallback registered";
+    }
+}
+
 }  // namespace implementation
 }  // namespace V1_1
 }  // namespace thermal

thermal/Thermal.h

@@ -43,6 +43,9 @@ using ::android::hidl::base::V1_0::IBase;
 using ::android::sp;
 
 struct Thermal : public IThermal {
+    // Local functions used internally by thermal-engine follow.
+    std::string getSkinSensorType();
+    void notifyThrottling(bool isThrottling, const Temperature& temperature);
     Thermal();
     // Methods from ::android::hardware::thermal::V1_0::IThermal follow.
     Return<void> getTemperatures(getTemperatures_cb _hidl_cb)  override;

thermal/thermal-helper.cpp

@@ -36,6 +36,7 @@ namespace implementation {
 using ::android::hardware::thermal::V1_0::TemperatureType;
 
 static unsigned int gSkinSensorNum;
+static std::string gSkinSensorType;
 static unsigned int gTsensOffset;
 static unsigned int gSkinThrottlingThreshold;
 static unsigned int gSkinShutdownThreshold;
@@ -51,6 +52,7 @@ bool initThermal() {
     if (hardware == "walleye") {
         LOG(ERROR) << "Initialization on Walleye";
         gSkinSensorNum = kWalleyeSkinSensorNum;
+        gSkinSensorType = kWalleyeSkinSensorType;
         gTsensOffset = kWalleyeTsensOffset;
         gSkinThrottlingThreshold = kWalleyeSkinThrottlingThreshold;
         gSkinShutdownThreshold = kWalleyeSkinShutdownThreshold;
@@ -60,6 +62,7 @@ bool initThermal() {
         if (rev == "rev_a" || rev == "rev_b") {
             LOG(ERROR) << "Initialization on Taimen pre revision C";
             gSkinSensorNum = kTaimenRabSkinSensorNum;
+            gSkinSensorType = kTaimenRabSkinSensorType;
             gTsensOffset = kTaimenRabTsensOffset;
             gSkinThrottlingThreshold = kTaimenRabSkinThrottlingThreshold;
             gSkinShutdownThreshold = kTaimenRabSkinShutdownThreshold;
@@ -67,6 +70,7 @@ bool initThermal() {
         } else {
             LOG(ERROR) << "Initialization on Taimen revision C and later";
             gSkinSensorNum = kTaimenRcSkinSensorNum;
+            gSkinSensorType = kTaimenRcSkinSensorType;
             gTsensOffset = kTaimenRcTsensOffset;
             gSkinThrottlingThreshold = kTaimenRcSkinThrottlingThreshold;
             gSkinShutdownThreshold = kTaimenRcSkinShutdownThreshold;
@@ -288,6 +292,10 @@ ssize_t fillCpuUsages(hidl_vec<CpuUsage> *cpuUsages) {
     return kCpuNum;
 }
 
+std::string getTargetSkinSensorType() {
+    return gSkinSensorType;
+}
+
 }  // namespace implementation
 }  // namespace V1_1
 }  // namespace thermal

thermal/thermal-helper.h

@@ -47,18 +47,21 @@ constexpr const char *kCpuOnlineFileFormat = "/sys/devices/system/cpu/cpu%d/onli
 
 // thermal-engine.conf
 constexpr unsigned int kWalleyeSkinSensorNum = 9;
+constexpr auto         kWalleyeSkinSensorType = "back_therm";
 constexpr unsigned int kWalleyeTsensOffset = 11;
 constexpr unsigned int kWalleyeSkinThrottlingThreshold = 40;
 constexpr unsigned int kWalleyeSkinShutdownThreshold = 56;
 constexpr unsigned int kWalleyeVrThrottledBelowMin = 52;
 
 constexpr unsigned int kTaimenRabSkinSensorNum = 8;
+constexpr auto         kTaimenRabSkinSensorType = "bd_therm";
 constexpr unsigned int kTaimenRabTsensOffset = 9;
 constexpr unsigned int kTaimenRabSkinThrottlingThreshold = 49;
 constexpr unsigned int kTaimenRabSkinShutdownThreshold = 66;
 constexpr unsigned int kTaimenRabVrThrottledBelowMin = 62;
 
 constexpr unsigned int kTaimenRcSkinSensorNum = 8;
+constexpr auto         kTaimenRcSkinSensorType = "bd_therm2";
 constexpr unsigned int kTaimenRcTsensOffset = 9;
 constexpr unsigned int kTaimenRcSkinThrottlingThreshold = 38;
 constexpr unsigned int kTaimenRcSkinShutdownThreshold = 54;
@@ -90,6 +93,7 @@ constexpr unsigned int kBatteryShutdownThreshold = 60;
 bool initThermal();
 ssize_t fillTemperatures(hidl_vec<Temperature> *temperatures);
 ssize_t fillCpuUsages(hidl_vec<CpuUsage> *cpuUsages);
+std::string getTargetSkinSensorType();
 
 }  // namespace implementation
 }  // namespace V1_1