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 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 60 AdxlSensor::~AdxlSensor() { 61 if (mEnabled) { 62 setEnable(0, 0); 63 } 64 } 65 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 83 bool AdxlSensor::hasPendingEvents() const { 84 return mHasPendingEvent; 85 } 86 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 } 126 127 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 } 168 169 int64_t AdxlSensor::getDelay(int32_t handle) 170 { 171 return (handle == ID_A) ? mDelay : 0; 172 } 173 174 int AdxlSensor::getEnable(int32_t handle) 175 { 176 return (handle == ID_A) ? mEnabled : 0; 177 } 178 179 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
