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 <unistd.h> 22 #include <dirent.h> 23 #include <sys/select.h> 24 #include <cutils/log.h> 25 26 #include "AdxlSensor.h" 27 28 #define ADXL_DATA_NAME "ADXL34x accelerometer" 29 #define ADXL_MAX_SAMPLE_RATE_VAL 11 /* 200 Hz */ 30 31 #define ADXL_UNIT_CONVERSION(value) ((value) * GRAVITY_EARTH / (256.0f)) 32 33 /*****************************************************************************/ 34 35 AdxlSensor::AdxlSensor() 36 : SensorBase(NULL, ADXL_DATA_NAME), 37 mEnabled(0), 38 mDelay(-1), 39 mInputReader(4), 40 mHasPendingEvent(false) 41 { 42 mPendingEvent.version = sizeof(sensors_event_t); 43 mPendingEvent.sensor = ID_A; 44 mPendingEvent.type = SENSOR_TYPE_ACCELEROMETER; 45 memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data)); 46 47 if (data_fd >= 0) { 48 strcpy(input_sysfs_path, "/sys/class/input/"); 49 strcat(input_sysfs_path, input_name); 50 strcat(input_sysfs_path, "/device/device/"); 51 input_sysfs_path_len = strlen(input_sysfs_path); 52 ALOGD("AdxlSensor: sysfs_path=%s", input_sysfs_path); 53 } else { 54 input_sysfs_path[0] = '\0'; 55 input_sysfs_path_len = 0; 56 } 57 } 58 59 AdxlSensor::~AdxlSensor() { 60 if (mEnabled) { 61 setEnable(0, 0); 62 } 63 } 64 65 int AdxlSensor::setInitialState() { 66 struct input_absinfo absinfo; 67 68 if (mEnabled) { 69 if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_ACCEL_X), &absinfo)) { 70 mPendingEvent.acceleration.x = ADXL_UNIT_CONVERSION(absinfo.value); 71 } 72 if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_ACCEL_Y), &absinfo)) { 73 mPendingEvent.acceleration.y = ADXL_UNIT_CONVERSION(absinfo.value); 74 } 75 if (!ioctl(data_fd, EVIOCGABS(EVENT_TYPE_ACCEL_Z), &absinfo)) { 76 mPendingEvent.acceleration.z = ADXL_UNIT_CONVERSION(absinfo.value); 77 } 78 } 79 return 0; 80 } 81 82 bool AdxlSensor::hasPendingEvents() const { 83 return mHasPendingEvent; 84 } 85 86 int AdxlSensor::setEnable(int32_t handle, int enabled) { 87 int err = 0; 88 char buffer[2]; 89 90 /* handle check */ 91 if (handle != ID_A) { 92 ALOGE("AdxlSensor: Invalid handle (%d)", handle); 93 return -EINVAL; 94 } 95 96 buffer[0] = '\0'; 97 buffer[1] = '\0'; 98 99 if (mEnabled <= 0) { 100 if(enabled) buffer[0] = '0'; 101 } else if (mEnabled == 1) { 102 if(!enabled) buffer[0] = '1'; 103 } 104 if (buffer[0] != '\0') { 105 strcpy(&input_sysfs_path[input_sysfs_path_len], "disable"); 106 err = write_sys_attribute(input_sysfs_path, buffer, 1); 107 if (err != 0) { 108 return err; 109 } 110 ALOGD("AdxlSensor: Control set %s", buffer); 111 setInitialState(); 112 } 113 114 if (enabled) { 115 mEnabled++; 116 if (mEnabled > 32767) mEnabled = 32767; 117 } else { 118 mEnabled--; 119 if (mEnabled < 0) mEnabled = 0; 120 } 121 ALOGD("AdxlSensor: mEnabled = %d", mEnabled); 122 123 return err; 124 } 125 126 int AdxlSensor::setDelay(int32_t handle, int64_t delay_ns) 127 { 128 int err = 0; 129 int rate_val; 130 int32_t us; 131 char buffer[16]; 132 int bytes; 133 134 /* handle check */ 135 if (handle != ID_A) { 136 ALOGE("AdxlSensor: Invalid handle (%d)", handle); 137 return -EINVAL; 138 } 139 140 if (mDelay != delay_ns) { 141 /* 142 * The ADXL34x Supports 16 sample rates ranging from 3200Hz-0.098Hz 143 * Calculate best fit and limit to max 200Hz (rate_val 11) 144 */ 145 146 us = (int32_t)(delay_ns / 1000); 147 for (rate_val = 0; rate_val < 16; rate_val++) 148 if (us >= ((10000000) >> rate_val)) 149 break; 150 151 if (rate_val > ADXL_MAX_SAMPLE_RATE_VAL) { 152 rate_val = ADXL_MAX_SAMPLE_RATE_VAL; 153 } 154 155 strcpy(&input_sysfs_path[input_sysfs_path_len], "rate"); 156 bytes = sprintf(buffer, "%d", rate_val); 157 err = write_sys_attribute(input_sysfs_path, buffer, bytes); 158 if (err == 0) { 159 mDelay = delay_ns; 160 ALOGD("AdxlSensor: Control set delay %f ms requetsed, using %f ms", 161 delay_ns/1000000.0f, 1e6 / (3200000 >> (15 - rate_val))); 162 } 163 } 164 165 return err; 166 } 167 168 int64_t AdxlSensor::getDelay(int32_t handle) 169 { 170 return (handle == ID_A) ? mDelay : 0; 171 } 172 173 int AdxlSensor::getEnable(int32_t handle) 174 { 175 return (handle == ID_A) ? mEnabled : 0; 176 } 177 178 int AdxlSensor::readEvents(sensors_event_t* data, int count) 179 { 180 if (count < 1) 181 return -EINVAL; 182 183 if (mHasPendingEvent) { 184 mHasPendingEvent = false; 185 mPendingEvent.timestamp = getTimestamp(); 186 *data = mPendingEvent; 187 return mEnabled ? 1 : 0; 188 } 189 190 ssize_t n = mInputReader.fill(data_fd); 191 if (n < 0) 192 return n; 193 194 int numEventReceived = 0; 195 input_event const* event; 196 197 while (count && mInputReader.readEvent(&event)) { 198 int type = event->type; 199 if (type == EV_ABS) { 200 float value = event->value; 201 if (event->code == EVENT_TYPE_ACCEL_X) { 202 mPendingEvent.acceleration.x = ADXL_UNIT_CONVERSION(value); 203 } else if (event->code == EVENT_TYPE_ACCEL_Y) { 204 mPendingEvent.acceleration.y = ADXL_UNIT_CONVERSION(value); 205 } else if (event->code == EVENT_TYPE_ACCEL_Z) { 206 mPendingEvent.acceleration.z = ADXL_UNIT_CONVERSION(value); 207 } 208 } else if (type == EV_SYN) { 209 mPendingEvent.timestamp = timevalToNano(event->time); 210 if (mEnabled) { 211 *data++ = mPendingEvent; 212 count--; 213 numEventReceived++; 214 } 215 } else { 216 ALOGE("AdxlSensor: unknown event (type=%d, code=%d)", 217 type, event->code); 218 } 219 mInputReader.next(); 220 } 221 222 return numEventReceived; 223 } 224 225
