manta: senors: add HAL for light and pressure sensors

This HAL supports sensors using Industrial I/O subsystem.
These sensor devices will be located in /sys/bus/iio/devices.

Light Sensor:
    IIO device name: lightsensor-level
    chan_type: IIO_LIGHT
    channel: in_illuminance0_input
    event: /dev/iio:device? (assigned dynamically)

Pressure Sensor:
    IIO device name: barometer
    chan_type: IIO_PRESSURE (This is not yet defined in main stream.)
    channel: in_pressure0_input
    event: /dev/iio:device? (assigned dynamically)

TODO: iio/events.h and iio/types.h should be moved to
    external/kernel-headers/original.

Change-Id: Ifbeb2f8e7ef7ac09f5b0727a2376c652e5f9e800
Signed-off-by: Won Hyoung Lee <whlee@sta.samsung.com>
diff --git a/libsensors/SensorBase.h b/libsensors/SensorBase.h
new file mode 100644
index 0000000..5331be1
--- /dev/null
+++ b/libsensors/SensorBase.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+
+#ifndef ANDROID_SENSOR_BASE_H
+#define ANDROID_SENSOR_BASE_H
+
+#include <stdint.h>
+#include <errno.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+/*****************************************************************************/
+struct sensors_event_t;
+
+class SensorBase {
+protected:
+    const char* mDevName;
+    const char* mDataName;
+    char        mInputName[PATH_MAX];
+    int         mDevFd;
+    int         mDataFd;
+
+    int findTypeByName(const char *name, const char *type);
+    int openInput(const char* inputName);
+    static int64_t getTimestamp();
+    int openDevice();
+    int closeDevice();
+
+public:
+    SensorBase(const char* dev_name,
+               const char* data_name);
+
+    virtual ~SensorBase();
+
+    virtual int readEvents(sensors_event_t* data, int count) = 0;
+    virtual bool hasPendingEvents() const;
+    virtual int getFd() const;
+    virtual int setDelay(int32_t handle, int64_t ns);
+    virtual int enable(int32_t handle, int enabled) = 0;
+};
+
+/*****************************************************************************/
+
+#endif  // ANDROID_SENSOR_BASE_H