1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <fcntl.h>
18#include <errno.h>
19#include <math.h>
20#include <poll.h>
21#include <string.h>
22#include <unistd.h>
23#include <dirent.h>
24#include <sys/select.h>
25#include <cutils/log.h>
26
27#include "AdxlSensor.h"
28
29#define ADXL_DATA_NAME				"ADXL34x accelerometer"
30#define ADXL_MAX_SAMPLE_RATE_VAL	11 /* 200 Hz */
31
32#define ADXL_UNIT_CONVERSION(value) ((value) * GRAVITY_EARTH / (256.0f))
33
34/*****************************************************************************/
35
36AdxlSensor::AdxlSensor()
37    : SensorBase(NULL, ADXL_DATA_NAME),
38      mEnabled(0),
39      mDelay(-1),
40      mInputReader(4),
41      mHasPendingEvent(false)
42{
43    mPendingEvent.version = sizeof(sensors_event_t);
44    mPendingEvent.sensor = ID_A;
45    mPendingEvent.type = SENSOR_TYPE_ACCELEROMETER;
46    memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data));
47
48    if (data_fd >= 0) {
49        strcpy(input_sysfs_path, "/sys/class/input/");
50        strcat(input_sysfs_path, input_name);
51        strcat(input_sysfs_path, "/device/device/");
52        input_sysfs_path_len = strlen(input_sysfs_path);
53		ALOGD("AdxlSensor: sysfs_path=%s", input_sysfs_path);
54    } else {
55		input_sysfs_path[0] = '\0';
56		input_sysfs_path_len = 0;
57	}
58}
59
60AdxlSensor::~AdxlSensor() {
61    if (mEnabled) {
62        setEnable(0, 0);
63    }
64}
65
66int AdxlSensor::setInitialState() {
67    struct input_absinfo absinfo;
68
69	if (mEnabled) {
70    	if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_ACCEL_X), &absinfo)) {
71			mPendingEvent.acceleration.x = ADXL_UNIT_CONVERSION(absinfo.value);
72		}
73    	if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_ACCEL_Y), &absinfo)) {
74			mPendingEvent.acceleration.y = ADXL_UNIT_CONVERSION(absinfo.value);
75		}
76		if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_ACCEL_Z), &absinfo)) {
77			mPendingEvent.acceleration.z = ADXL_UNIT_CONVERSION(absinfo.value);
78		}
79	}
80    return 0;
81}
82
83bool AdxlSensor::hasPendingEvents() const {
84    return mHasPendingEvent;
85}
86
87int AdxlSensor::setEnable(int32_t handle, int enabled) {
88    int err = 0;
89	char buffer[2];
90
91	/* handle check */
92	if (handle != ID_A) {
93		ALOGE("AdxlSensor: Invalid handle (%d)", handle);
94		return -EINVAL;
95	}
96
97	buffer[0] = '\0';
98	buffer[1] = '\0';
99
100	if (mEnabled <= 0) {
101		if(enabled) buffer[0] = '0';
102	} else if (mEnabled == 1) {
103		if(!enabled) buffer[0] = '1';
104	}
105    if (buffer[0] != '\0') {
106        strcpy(&input_sysfs_path[input_sysfs_path_len], "disable");
107		err = write_sys_attribute(input_sysfs_path, buffer, 1);
108		if (err != 0) {
109			return err;
110		}
111		ALOGD("AdxlSensor: Control set %s", buffer);
112   		setInitialState();
113    }
114
115	if (enabled) {
116		mEnabled++;
117		if (mEnabled > 32767) mEnabled = 32767;
118	} else {
119		mEnabled--;
120		if (mEnabled < 0) mEnabled = 0;
121	}
122	ALOGD("AdxlSensor: mEnabled = %d", mEnabled);
123
124    return err;
125}
126
127int AdxlSensor::setDelay(int32_t handle, int64_t delay_ns)
128{
129	int err = 0;
130	int rate_val;
131	int32_t us;
132	char buffer[16];
133	int bytes;
134
135	/* handle check */
136	if (handle != ID_A) {
137		ALOGE("AdxlSensor: Invalid handle (%d)", handle);
138		return -EINVAL;
139	}
140
141	if (mDelay != delay_ns) {
142		/*
143	 	* The ADXL34x Supports 16 sample rates ranging from 3200Hz-0.098Hz
144	 	* Calculate best fit and limit to max 200Hz (rate_val 11)
145	 	*/
146
147		us = (int32_t)(delay_ns / 1000);
148		for (rate_val = 0; rate_val < 16; rate_val++)
149			if (us  >= ((10000000) >> rate_val))
150				break;
151
152		if (rate_val > ADXL_MAX_SAMPLE_RATE_VAL) {
153			rate_val = ADXL_MAX_SAMPLE_RATE_VAL;
154		}
155
156    	strcpy(&input_sysfs_path[input_sysfs_path_len], "rate");
157   		bytes = sprintf(buffer, "%d", rate_val);
158		err = write_sys_attribute(input_sysfs_path, buffer, bytes);
159		if (err == 0) {
160			mDelay = delay_ns;
161			ALOGD("AdxlSensor: Control set delay %f ms requetsed, using %f ms",
162				delay_ns/1000000.0f, 1e6 / (3200000 >> (15 - rate_val)));
163		}
164	}
165
166	return err;
167}
168
169int64_t AdxlSensor::getDelay(int32_t handle)
170{
171	return (handle == ID_A) ? mDelay : 0;
172}
173
174int AdxlSensor::getEnable(int32_t handle)
175{
176	return (handle == ID_A) ? mEnabled : 0;
177}
178
179int AdxlSensor::readEvents(sensors_event_t* data, int count)
180{
181    if (count < 1)
182        return -EINVAL;
183
184    if (mHasPendingEvent) {
185        mHasPendingEvent = false;
186        mPendingEvent.timestamp = getTimestamp();
187        *data = mPendingEvent;
188        return mEnabled ? 1 : 0;
189    }
190
191    ssize_t n = mInputReader.fill(data_fd);
192    if (n < 0)
193        return n;
194
195    int numEventReceived = 0;
196    input_event const* event;
197
198    while (count && mInputReader.readEvent(&event)) {
199        int type = event->type;
200        if (type == EV_ABS) {
201            float value = event->value;
202            if (event->code == EVENT_TYPE_ACCEL_X) {
203                mPendingEvent.acceleration.x = ADXL_UNIT_CONVERSION(value);
204            } else if (event->code == EVENT_TYPE_ACCEL_Y) {
205                mPendingEvent.acceleration.y = ADXL_UNIT_CONVERSION(value);
206            } else if (event->code == EVENT_TYPE_ACCEL_Z) {
207                mPendingEvent.acceleration.z = ADXL_UNIT_CONVERSION(value);
208            }
209        } else if (type == EV_SYN) {
210            mPendingEvent.timestamp = timevalToNano(event->time);
211            if (mEnabled) {
212                *data++ = mPendingEvent;
213                count--;
214                numEventReceived++;
215            }
216        } else {
217            ALOGE("AdxlSensor: unknown event (type=%d, code=%d)",
218                    type, event->code);
219        }
220        mInputReader.next();
221    }
222
223    return numEventReceived;
224}
225
226