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
AdxlSensor()36 AdxlSensor::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
~AdxlSensor()60 AdxlSensor::~AdxlSensor() {
61 if (mEnabled) {
62 setEnable(0, 0);
63 }
64 }
65
setInitialState()66 int 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
hasPendingEvents() const83 bool AdxlSensor::hasPendingEvents() const {
84 return mHasPendingEvent;
85 }
86
setEnable(int32_t handle,int enabled)87 int 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
setDelay(int32_t handle,int64_t delay_ns)127 int 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
getDelay(int32_t handle)169 int64_t AdxlSensor::getDelay(int32_t handle)
170 {
171 return (handle == ID_A) ? mDelay : 0;
172 }
173
getEnable(int32_t handle)174 int AdxlSensor::getEnable(int32_t handle)
175 {
176 return (handle == ID_A) ? mEnabled : 0;
177 }
178
readEvents(sensors_event_t * data,int count)179 int 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