/*
 * 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.
 */

#define LOG_TAG "Sensors"

#include <hardware/sensors.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <math.h>
#include <poll.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>

#include <linux/input.h>

#include <cutils/atomic.h>
#include <utils/Log.h>

#include "sensors.h"

#if defined SENSORHAL_ACC_ADXL346
#include "AdxlSensor.h"
#elif defined SENSORHAL_ACC_KXTF9
#include "KionixSensor.h"
#else
#error "Sensor configuration ERROR: No sensor is defined."
#endif

#include "AkmSensor.h"

/*****************************************************************************/

#define DELAY_OUT_TIME 0x7FFFFFFF

#define LIGHT_SENSOR_POLLTIME    2000000000


#define SENSORS_ACCELERATION     (1<<ID_A)
#define SENSORS_MAGNETIC_FIELD   (1<<ID_M)
#define SENSORS_ORIENTATION      (1<<ID_O)

#define SENSORS_ACCELERATION_HANDLE     0
#define SENSORS_MAGNETIC_FIELD_HANDLE   1
#define SENSORS_ORIENTATION_HANDLE      2

/*****************************************************************************/

/* The SENSORS Module */
static const struct sensor_t sSensorList[] = {
        { "AK8975 3-axis Magnetic field sensor",
          "Asahi Kasei Microdevices",
          1,
		  SENSORS_MAGNETIC_FIELD_HANDLE,
          SENSOR_TYPE_MAGNETIC_FIELD, 1228.8f,
		  CONVERT_M, 0.35f, 10000, 0, 0, 0, 0, 0, 0, { } },
#ifdef SENSORHAL_ACC_ADXL346
        { "Analog Devices ADXL345/6 3-axis Accelerometer",
          "ADI",
          1, SENSORS_ACCELERATION_HANDLE,
          SENSOR_TYPE_ACCELEROMETER, (GRAVITY_EARTH * 16.0f),
		  (GRAVITY_EARTH * 16.0f) / 4096.0f, 0.145f, 10000, 0, 0, 0, 0, 0, 0, { } },
        { "AK8975 Orientation sensor",
          "Asahi Kasei Microdevices",
          1, SENSORS_ORIENTATION_HANDLE,
          SENSOR_TYPE_ORIENTATION, 360.0f,
		  CONVERT_O, 0.495f, 10000, 0, 0, 0, 0, 0, 0, { } }
#endif
#ifdef SENSORHAL_ACC_KXTF9
        { "Kionix KXTF9 3-axis Accelerometer",
          "Kionix",
          1, SENSORS_ACCELERATION_HANDLE,
          SENSOR_TYPE_ACCELEROMETER, (GRAVITY_EARTH * 2.0f),
		  (GRAVITY_EARTH) / 1024.0f, 0.7f, 10000, 0, 0, 0, 0, 0, 0, { } },
        { "AK8975 Orientation sensor",
          "Asahi Kasei Microdevices",
          1, SENSORS_ORIENTATION_HANDLE,
          SENSOR_TYPE_ORIENTATION, 360.0f,
		  CONVERT_O, 1.05f, 10000, 0, 0, 0, 0, 0, 0, { } }
#endif
};


static int open_sensors(const struct hw_module_t* module, const char* id,
                        struct hw_device_t** device);

static int sensors__get_sensors_list(struct sensors_module_t* module,
                                     struct sensor_t const** list)
{
        *list = sSensorList;
        return ARRAY_SIZE(sSensorList);
}

static struct hw_module_methods_t sensors_module_methods = {
        .open = open_sensors
};

struct sensors_module_t HAL_MODULE_INFO_SYM = {
        .common = {
                .tag = HARDWARE_MODULE_TAG,
                .version_major = 1,
                .version_minor = 0,
                .id = SENSORS_HARDWARE_MODULE_ID,
                .name = "AKM Sensor module",
                .author = "Asahi Kasei Microdevices",
                .methods = &sensors_module_methods,
                .dso  = NULL,
                .reserved = {0},
        },
        .get_sensors_list = sensors__get_sensors_list,
};

struct sensors_poll_context_t {
    struct sensors_poll_device_t device; // must be first

        sensors_poll_context_t();
        ~sensors_poll_context_t();
    int activate(int handle, int enabled);
    int setDelay(int handle, int64_t ns);
    int setDelay_sub(int handle, int64_t ns);
    int pollEvents(sensors_event_t* data, int count);

private:
    enum {
        acc          = 0,
        akm          = 1,
        numSensorDrivers,
        numFds,
    };

    static const size_t wake = numFds - 1;
    static const char WAKE_MESSAGE = 'W';
    struct pollfd mPollFds[numFds];
    int mWritePipeFd;
    SensorBase* mSensors[numSensorDrivers];

	/* These function will be different depends on
	 * which sensor is implemented in AKMD program.
	 */
    int handleToDriver(int handle);
	int proxy_enable(int handle, int enabled);
	int proxy_setDelay(int handle, int64_t ns);
};

/*****************************************************************************/

sensors_poll_context_t::sensors_poll_context_t()
{
#ifdef SENSORHAL_ACC_ADXL346
    mSensors[acc] = new AdxlSensor();
#endif
#ifdef SENSORHAL_ACC_KXTF9
    mSensors[acc] = new KionixSensor();
#endif
    mPollFds[acc].fd = mSensors[acc]->getFd();
    mPollFds[acc].events = POLLIN;
    mPollFds[acc].revents = 0;

    mSensors[akm] = new AkmSensor();
    mPollFds[akm].fd = mSensors[akm]->getFd();
    mPollFds[akm].events = POLLIN;
    mPollFds[akm].revents = 0;

    int wakeFds[2];
    int result = pipe(wakeFds);
    ALOGE_IF(result<0, "error creating wake pipe (%s)", strerror(errno));
    fcntl(wakeFds[0], F_SETFL, O_NONBLOCK);
    fcntl(wakeFds[1], F_SETFL, O_NONBLOCK);
    mWritePipeFd = wakeFds[1];

    mPollFds[wake].fd = wakeFds[0];
    mPollFds[wake].events = POLLIN;
    mPollFds[wake].revents = 0;
}

sensors_poll_context_t::~sensors_poll_context_t() {
    for (int i=0 ; i<numSensorDrivers ; i++) {
        delete mSensors[i];
    }
    close(mPollFds[wake].fd);
    close(mWritePipeFd);
}

int sensors_poll_context_t::handleToDriver(int handle) {
	switch (handle) {
		case ID_A:
			return acc;
		case ID_M:
		case ID_O:
			return akm;
	}
	return -EINVAL;
}

int sensors_poll_context_t::activate(int handle, int enabled) {
	int drv = handleToDriver(handle);
	int err;

	switch (handle) {
		case ID_A:
		case ID_M:
			/* No dependencies */
			break;

		case ID_O:
			/* These sensors depend on ID_A and ID_M */
			mSensors[handleToDriver(ID_A)]->setEnable(ID_A, enabled);
			mSensors[handleToDriver(ID_M)]->setEnable(ID_M, enabled);
			break;

		default:
			return -EINVAL;
	}
	err = mSensors[drv]->setEnable(handle, enabled);

    if (enabled && !err) {
        const char wakeMessage(WAKE_MESSAGE);
        int result = write(mWritePipeFd, &wakeMessage, 1);
        ALOGE_IF(result<0, "error sending wake message (%s)", strerror(errno));
    }
    return err;
}

int sensors_poll_context_t::setDelay(int handle, int64_t ns) {
	switch (handle) {
		case ID_A:
		case ID_M:
			/* No dependencies */
			break;

		case ID_O:
			/* These sensors depend on ID_A and ID_M */
			setDelay_sub(ID_A, ns);
			setDelay_sub(ID_M, ns);
			break;

		default:
			return -EINVAL;
	}
	return setDelay_sub(handle, ns);
}

int sensors_poll_context_t::setDelay_sub(int handle, int64_t ns) {
	int drv = handleToDriver(handle);
	int en = mSensors[drv]->getEnable(handle);
	int64_t cur = mSensors[drv]->getDelay(handle);
	int err = 0;

	if (en <= 1) {
		/* no dependencies */
		if (cur != ns) {
			err = mSensors[drv]->setDelay(handle, ns);
		}
	} else {
		/* has dependencies, choose shorter interval */
		if (cur > ns) {
			err = mSensors[drv]->setDelay(handle, ns);
		}
	}
	return err;
}

int sensors_poll_context_t::pollEvents(sensors_event_t* data, int count)
{
    int nbEvents = 0;
    int n = 0;

    do {
        // see if we have some leftover from the last poll()
        for (int i=0 ; count && i<numSensorDrivers ; i++) {
            SensorBase* const sensor(mSensors[i]);
            if ((mPollFds[i].revents & POLLIN) || (sensor->hasPendingEvents())) {
                int nb = sensor->readEvents(data, count);
                if (nb < count) {
                    // no more data for this sensor
                    mPollFds[i].revents = 0;
                }
				if ((0 != nb) && (acc == i)) {
					((AkmSensor*)(mSensors[akm]))->setAccel(&data[nb-1]);
				}
                count -= nb;
                nbEvents += nb;
                data += nb;
            }
        }

        if (count) {
            // we still have some room, so try to see if we can get
            // some events immediately or just wait if we don't have
            // anything to return
            n = poll(mPollFds, numFds, nbEvents ? 0 : -1);
            if (n<0) {
                ALOGE("poll() failed (%s)", strerror(errno));
                return -errno;
            }
            if (mPollFds[wake].revents & POLLIN) {
                char msg;
                int result = read(mPollFds[wake].fd, &msg, 1);
                ALOGE_IF(result<0, "error reading from wake pipe (%s)", strerror(errno));
                ALOGE_IF(msg != WAKE_MESSAGE, "unknown message on wake queue (0x%02x)", int(msg));
                mPollFds[wake].revents = 0;
            }
        }
        // if we have events and space, go read them
    } while (n && count);

    return nbEvents;
}

/*****************************************************************************/

static int poll__close(struct hw_device_t *dev)
{
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    if (ctx) {
        delete ctx;
    }
    return 0;
}

static int poll__activate(struct sensors_poll_device_t *dev,
        int handle, int enabled) {
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->activate(handle, enabled);
}

static int poll__setDelay(struct sensors_poll_device_t *dev,
        int handle, int64_t ns) {
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->setDelay(handle, ns);
}

static int poll__poll(struct sensors_poll_device_t *dev,
        sensors_event_t* data, int count) {
    sensors_poll_context_t *ctx = (sensors_poll_context_t *)dev;
    return ctx->pollEvents(data, count);
}

/*****************************************************************************/

/** Open a new instance of a sensor device using name */
static int open_sensors(const struct hw_module_t* module, const char* id,
                        struct hw_device_t** device)
{
        int status = -EINVAL;
        sensors_poll_context_t *dev = new sensors_poll_context_t();

        memset(&dev->device, 0, sizeof(sensors_poll_device_t));

        dev->device.common.tag = HARDWARE_DEVICE_TAG;
        dev->device.common.version  = 0;
        dev->device.common.module   = const_cast<hw_module_t*>(module);
        dev->device.common.close    = poll__close;
        dev->device.activate        = poll__activate;
        dev->device.setDelay        = poll__setDelay;
        dev->device.poll            = poll__poll;

        *device = &dev->device.common;
        status = 0;

        return status;
}