sensors: Implement udfps long press sensor

Change-Id: I49773535f47c538b1ff210245109dd63c18d32cb

sensors/v2/Sensor.cpp

@@ -361,6 +361,40 @@ bool SysfsPollingOneShotSensor::readFd(const int fd) {
     return readBool(fd, true /* seek */);
 }
 
+void UdfpsSensor::fillEventData(Event& event) {
+    event.u.data[0] = mScreenX;
+    event.u.data[1] = mScreenY;
+}
+
+bool UdfpsSensor::readFd(const int fd) {
+    char buffer[512];
+    int state = 0;
+    int rc;
+
+    rc = lseek(fd, 0, SEEK_SET);
+    if (rc < 0) {
+        ALOGE("failed to seek: %d", rc);
+        return false;
+    }
+    rc = read(fd, &buffer, sizeof(buffer));
+    if (rc < 0) {
+        ALOGE("failed to read state: %d", rc);
+        return false;
+    }
+    rc = sscanf(buffer, "%d,%d,%d", &mScreenX, &mScreenY, &state);
+    if (rc == 1) {
+        // If fod_press_status contains only one value,
+        // assume that just reports the state
+        state = mScreenX;
+        mScreenX = 0;
+        mScreenY = 0;
+    } else if (rc < 3) {
+        ALOGE("failed to parse fp state: %d", rc);
+        return false;
+    }
+    return state > 0;
+}
+
 }  // namespace implementation
 }  // namespace subhal
 }  // namespace V2_1

sensors/v2/Sensor.h

@@ -143,6 +143,23 @@ class SingleTapSensor : public SysfsPollingOneShotSensor {
                                           2)) {}
 };
 
+class UdfpsSensor : public SysfsPollingOneShotSensor {
+  public:
+    UdfpsSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+        : SysfsPollingOneShotSensor(
+                  sensorHandle, callback, "/sys/class/touch/touch_dev/fod_press_status",
+                  "/sys/class/touch/touch_dev/fod_longpress_gesture_enabled", "UDFPS Sensor",
+                  "org.lineageos.sensor.udfps",
+                  static_cast<SensorType>(static_cast<int32_t>(SensorType::DEVICE_PRIVATE_BASE) +
+                                          3)) {}
+    virtual void fillEventData(Event& event);
+    virtual bool readFd(const int fd);
+
+  private:
+    int mScreenX;
+    int mScreenY;
+};
+
 }  // namespace implementation
 }  // namespace subhal
 }  // namespace V2_1

sensors/v2/SensorsSubHal.cpp

@@ -17,6 +17,7 @@
 #include "SensorsSubHal.h"
 
 #include <android/hardware/sensors/2.1/types.h>
+#include <cutils/properties.h>
 #include <log/log.h>
 
 using ::android::hardware::sensors::V2_1::implementation::ISensorsSubHal;
@@ -39,6 +40,9 @@ SensorsSubHal::SensorsSubHal() : mCallback(nullptr), mNextHandle(1) {
     if (property_get_bool("ro.vendor.sensors.xiaomi.single_tap", false)) {
         AddSensor<SingleTapSensor>();
     }
+    if (property_get_bool("ro.vendor.sensors.xiaomi.udfps", false)) {
+        AddSensor<UdfpsSensor>();
+    }
 }
 
 Return<void> SensorsSubHal::getSensorsList_2_1(ISensors::getSensorsList_2_1_cb _hidl_cb) {