summaryrefslogtreecommitdiffstats
path: root/libsensors/GyroSensor.cpp
blob: 0b0a438df7669cfbc0c8829bd87d569812f4aa8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/*
 * 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.
 */

#include <fcntl.h>
#include <errno.h>
#include <math.h>
#include <poll.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/select.h>
#include <cutils/log.h>

#include "GyroSensor.h"

#define FETCH_FULL_EVENT_BEFORE_RETURN 1
#define IGNORE_EVENT_TIME 350000000
/*****************************************************************************/

GyroSensor::GyroSensor()
    : SensorBase(NULL, "gyro_sensor"),
      mEnabled(0),
      mInputReader(4),
      mHasPendingEvent(false),
      mEnabledTime(0)
{
    mPendingEvent.version = sizeof(sensors_event_t);
    mPendingEvent.sensor = ID_GY;
    mPendingEvent.type = SENSOR_TYPE_GYROSCOPE;
    memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data));

    if (data_fd) {
        strcpy(input_sysfs_path, "/sys/class/input/");
        strcat(input_sysfs_path, input_name);
        strcat(input_sysfs_path, "/device/");
        input_sysfs_path_len = strlen(input_sysfs_path);
        enable(0, 1);
    }
}

GyroSensor::~GyroSensor() {
    if (mEnabled) {
        enable(0, 0);
    }
}

int GyroSensor::setInitialState() {
    struct input_absinfo absinfo_x;
    struct input_absinfo absinfo_y;
    struct input_absinfo absinfo_z;
    float value;
    if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_GYRO_X), &absinfo_x) &&
        !ioctl(data_fd, EVIOCGABS(EVENT_TYPE_GYRO_X), &absinfo_y) &&
        !ioctl(data_fd, EVIOCGABS(EVENT_TYPE_GYRO_X), &absinfo_z)) {
        value = absinfo_x.value;
        mPendingEvent.data[0] = value * CONVERT_GYRO_X;
        value = absinfo_x.value;
        mPendingEvent.data[1] = value * CONVERT_GYRO_Y;
        value = absinfo_x.value;
        mPendingEvent.data[2] = value * CONVERT_GYRO_Z;
        mHasPendingEvent = true;
    }
    return 0;
}

int GyroSensor::enable(int32_t, int en) {
    int flags = en ? 1 : 0;
    if (flags != mEnabled) {
        int fd;
        strcpy(&input_sysfs_path[input_sysfs_path_len], "enable");
        fd = open(input_sysfs_path, O_RDWR);
        if (fd >= 0) {
            char buf[2];
            int err;
            buf[1] = 0;
            if (flags) {
                buf[0] = '1';
                mEnabledTime = getTimestamp() + IGNORE_EVENT_TIME;
            } else {
                buf[0] = '0';
            }
            err = write(fd, buf, sizeof(buf));
            close(fd);
            mEnabled = flags;
            setInitialState();
            return 0;
        }
        return -1;
    }
    return 0;
}

bool GyroSensor::hasPendingEvents() const {
    return mHasPendingEvent;
}

int GyroSensor::setDelay(int32_t handle, int64_t delay_ns)
{
    int fd;
    strcpy(&input_sysfs_path[input_sysfs_path_len], "poll_delay");
    fd = open(input_sysfs_path, O_RDWR);
    if (fd >= 0) {
        char buf[80];
        sprintf(buf, "%lld", delay_ns);
        write(fd, buf, strlen(buf)+1);
        close(fd);
        return 0;
    }
    return -1;
}

int GyroSensor::readEvents(sensors_event_t* data, int count)
{
    if (count < 1)
        return -EINVAL;

    if (mHasPendingEvent) {
        mHasPendingEvent = false;
        mPendingEvent.timestamp = getTimestamp();
        *data = mPendingEvent;
        return mEnabled ? 1 : 0;
    }

    ssize_t n = mInputReader.fill(data_fd);
    if (n < 0)
        return n;

    int numEventReceived = 0;
    input_event const* event;

#if FETCH_FULL_EVENT_BEFORE_RETURN
again:
#endif
    while (count && mInputReader.readEvent(&event)) {
        int type = event->type;
        if (type == EV_REL) {
            float value = event->value;
            if (event->code == EVENT_TYPE_GYRO_X) {
                mPendingEvent.data[0] = value * CONVERT_GYRO_X;
            } else if (event->code == EVENT_TYPE_GYRO_Y) {
                mPendingEvent.data[1] = value * CONVERT_GYRO_Y;
            } else if (event->code == EVENT_TYPE_GYRO_Z) {
                mPendingEvent.data[2] = value * CONVERT_GYRO_Z;
            }
        } else if (type == EV_SYN) {
            mPendingEvent.timestamp = timevalToNano(event->time);
            if (mEnabled) {
                if (mPendingEvent.timestamp >= mEnabledTime) {
                    *data++ = mPendingEvent;
                    numEventReceived++;
                }
                count--;
            }
        } else {
            ALOGE("GyroSensor: unknown event (type=%d, code=%d)",
                    type, event->code);
        }
        mInputReader.next();
    }

#if FETCH_FULL_EVENT_BEFORE_RETURN
    /* if we didn't read a complete event, see if we can fill and
       try again instead of returning with nothing and redoing poll. */
    if (numEventReceived == 0 && mEnabled == 1) {
        n = mInputReader.fill(data_fd);
        if (n)
            goto again;
    }
#endif

    return numEventReceived;
}