From 83fd3794799ef20608c1b2b6daecb9591b6985df Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Queru <jbq@google.com>
Date: Wed, 25 Nov 2009 07:39:31 -0800
Subject: Initial commit

---
 sensors.c | 592 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 592 insertions(+)
 create mode 100644 sensors.c

diff --git a/sensors.c b/sensors.c
new file mode 100644
index 0000000..39787f5
--- /dev/null
+++ b/sensors.c
@@ -0,0 +1,592 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "Sensors"
+
+#include <hardware/sensors.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <dirent.h>
+#include <math.h>
+#include <poll.h>
+#include <pthread.h>
+
+#include <linux/input.h>
+#include <linux/akm8976.h>
+
+#include <cutils/atomic.h>
+#include <cutils/log.h>
+#include <cutils/native_handle.h>
+
+/*****************************************************************************/
+
+#define MAX_NUM_SENSORS 4
+
+#define SUPPORTED_SENSORS  ((1<<MAX_NUM_SENSORS)-1)
+
+#define ID_A  (0)
+#define ID_M  (1)
+#define ID_O  (2)
+#define ID_T  (3)
+
+#define SENSORS_ACCELERATION   (1<<ID_A)
+#define SENSORS_MAGNETIC_FIELD (1<<ID_M)
+#define SENSORS_ORIENTATION    (1<<ID_O)
+#define SENSORS_TEMPERATURE    (1<<ID_T)
+
+/*****************************************************************************/
+
+struct sensors_control_context_t {
+    struct sensors_control_device_t device;
+    int akmd_fd;
+    uint32_t active_sensors;
+};
+
+struct sensors_data_context_t {
+    struct sensors_data_device_t device;
+    int events_fd;
+    sensors_data_t sensors[MAX_NUM_SENSORS];
+    uint32_t pendingSensors;
+};
+
+/*
+ * The SENSORS Module
+ */
+
+static const struct sensor_t sSensorList[] = {
+        { "AK8976A 3-axis Accelerometer",
+                "The Android Open Source Project",
+                1, SENSORS_HANDLE_BASE+ID_A,
+                SENSOR_TYPE_ACCELEROMETER, 2.8f, 1.0f/4032.0f, 3.0f, { } },
+        { "AK8976A 3-axis Magnetic field sensor",
+                "The Android Open Source Project",
+                1, SENSORS_HANDLE_BASE+ID_M,
+                SENSOR_TYPE_MAGNETIC_FIELD, 2000.0f, 1.0f, 6.7f, { } },
+        { "AK8976A Orientation sensor",
+                "The Android Open Source Project",
+                1, SENSORS_HANDLE_BASE+ID_O,
+                SENSOR_TYPE_ORIENTATION, 360.0f, 1.0f, 9.7f, { } },
+        { "AK8976A Temperature sensor",
+                "The Android Open Source Project",
+                1, SENSORS_HANDLE_BASE+ID_T,
+                SENSOR_TYPE_TEMPERATURE, 80.0f, 1.0f, 0.0f, { } },
+};
+
+static int open_sensors(const struct hw_module_t* module, const char* name,
+        struct hw_device_t** device);
+
+static uint32_t sensors__get_sensors_list(struct sensors_module_t* module,
+        struct sensor_t const** list) 
+{
+    *list = sSensorList;
+    return sizeof(sSensorList)/sizeof(sSensorList[0]);
+}
+
+static struct hw_module_methods_t sensors_module_methods = {
+    .open = open_sensors
+};
+
+struct sensors_module_t HAL_MODULE_INFO_SYM = {
+    .common = {
+        .tag = HARDWARE_MODULE_TAG,
+        .version_major = 1,
+        .version_minor = 0,
+        .id = SENSORS_HARDWARE_MODULE_ID,
+        .name = "AK8976A SENSORS Module",
+        .author = "The Android Open Source Project",
+        .methods = &sensors_module_methods,
+    },
+    .get_sensors_list = sensors__get_sensors_list
+};
+
+/*****************************************************************************/
+
+#define AKM_DEVICE_NAME     "/dev/akm8976_aot"
+
+
+// sensor IDs must be a power of two and
+// must match values in SensorManager.java
+#define EVENT_TYPE_ACCEL_X          ABS_X
+#define EVENT_TYPE_ACCEL_Y          ABS_Z
+#define EVENT_TYPE_ACCEL_Z          ABS_Y
+#define EVENT_TYPE_ACCEL_STATUS     ABS_WHEEL
+
+#define EVENT_TYPE_YAW              ABS_RX
+#define EVENT_TYPE_PITCH            ABS_RY
+#define EVENT_TYPE_ROLL             ABS_RZ
+#define EVENT_TYPE_ORIENT_STATUS    ABS_RUDDER
+
+#define EVENT_TYPE_MAGV_X           ABS_HAT0X
+#define EVENT_TYPE_MAGV_Y           ABS_HAT0Y
+#define EVENT_TYPE_MAGV_Z           ABS_BRAKE
+
+#define EVENT_TYPE_TEMPERATURE      ABS_THROTTLE
+#define EVENT_TYPE_STEP_COUNT       ABS_GAS
+
+// 720 LSG = 1G
+#define LSG                         (720.0f)
+
+// conversion of acceleration data to SI units (m/s^2)
+#define CONVERT_A                   (GRAVITY_EARTH / LSG)
+#define CONVERT_A_X                 (-CONVERT_A)
+#define CONVERT_A_Y                 (CONVERT_A)
+#define CONVERT_A_Z                 (-CONVERT_A)
+
+// conversion of magnetic data to uT units
+#define CONVERT_M                   (1.0f/16.0f)
+#define CONVERT_M_X                 (-CONVERT_M)
+#define CONVERT_M_Y                 (-CONVERT_M)
+#define CONVERT_M_Z                 (CONVERT_M)
+
+#define SENSOR_STATE_MASK           (0x7FFF)
+
+/*****************************************************************************/
+
+static int open_input(int mode)
+{
+    /* scan all input drivers and look for "compass" */
+    int fd = -1;
+    const char *dirname = "/dev/input";
+    char devname[PATH_MAX];
+    char *filename;
+    DIR *dir;
+    struct dirent *de;
+    dir = opendir(dirname);
+    if(dir == NULL)
+        return -1;
+    strcpy(devname, dirname);
+    filename = devname + strlen(devname);
+    *filename++ = '/';
+    while((de = readdir(dir))) {
+        if(de->d_name[0] == '.' &&
+           (de->d_name[1] == '\0' ||
+            (de->d_name[1] == '.' && de->d_name[2] == '\0')))
+            continue;
+        strcpy(filename, de->d_name);
+        fd = open(devname, mode);
+        if (fd>=0) {
+            char name[80];
+            if (ioctl(fd, EVIOCGNAME(sizeof(name) - 1), &name) < 1) {
+                name[0] = '\0';
+            }
+            if (!strcmp(name, "compass")) {
+                //LOGD("using %s (name=%s)", devname, name);
+                break;
+            }
+            close(fd);
+            fd = -1;
+        }
+    }
+    closedir(dir);
+
+    if (fd < 0) {
+        LOGE("Couldn't find or open 'compass' driver (%s)", strerror(errno));
+    }
+    return fd;
+}
+
+static int open_akm(struct sensors_control_context_t* dev)
+{
+    if (dev->akmd_fd <= 0) {
+        dev->akmd_fd = open(AKM_DEVICE_NAME, O_RDONLY);
+        //LOGD("%s, fd=%d", __PRETTY_FUNCTION__, dev->akmd_fd);
+        LOGE_IF(dev->akmd_fd<0, "Couldn't open %s (%s)",
+                AKM_DEVICE_NAME, strerror(errno));
+        if (dev->akmd_fd >= 0) {
+            dev->active_sensors = 0;
+        }
+    }
+    return dev->akmd_fd;
+}
+
+static void close_akm(struct sensors_control_context_t* dev)
+{
+    if (dev->akmd_fd > 0) {
+        //LOGD("%s, fd=%d", __PRETTY_FUNCTION__, dev->akmd_fd);
+        close(dev->akmd_fd);
+        dev->akmd_fd = -1;
+    }
+}
+
+static void enable_disable(int fd, uint32_t sensors, uint32_t mask)
+{
+    if (fd<0) return;
+    short flags;
+    
+    if (mask & SENSORS_ORIENTATION) {
+        flags = (sensors & SENSORS_ORIENTATION) ? 1 : 0;
+        if (ioctl(fd, ECS_IOCTL_APP_SET_MFLAG, &flags) < 0) {
+            LOGE("ECS_IOCTL_APP_SET_MFLAG error (%s)", strerror(errno));
+        }
+    }
+    if (mask & SENSORS_ACCELERATION) {
+        flags = (sensors & SENSORS_ACCELERATION) ? 1 : 0;
+        if (ioctl(fd, ECS_IOCTL_APP_SET_AFLAG, &flags) < 0) {
+            LOGE("ECS_IOCTL_APP_SET_AFLAG error (%s)", strerror(errno));
+        }
+    }
+    if (mask & SENSORS_TEMPERATURE) {
+        flags = (sensors & SENSORS_TEMPERATURE) ? 1 : 0;
+        if (ioctl(fd, ECS_IOCTL_APP_SET_TFLAG, &flags) < 0) {
+            LOGE("ECS_IOCTL_APP_SET_TFLAG error (%s)", strerror(errno));
+        }
+    }
+    if (mask & SENSORS_MAGNETIC_FIELD) {
+        flags = (sensors & SENSORS_MAGNETIC_FIELD) ? 1 : 0;
+        if (ioctl(fd, ECS_IOCTL_APP_SET_MVFLAG, &flags) < 0) {
+            LOGE("ECS_IOCTL_APP_SET_MVFLAG error (%s)", strerror(errno));
+        }
+    }
+}
+
+static uint32_t read_sensors_state(int fd)
+{
+    if (fd<0) return 0;
+    short flags;
+    uint32_t sensors = 0;
+    // read the actual value of all sensors
+    if (!ioctl(fd, ECS_IOCTL_APP_GET_MFLAG, &flags)) {
+        if (flags)  sensors |= SENSORS_ORIENTATION;
+        else        sensors &= ~SENSORS_ORIENTATION;
+    }
+    if (!ioctl(fd, ECS_IOCTL_APP_GET_AFLAG, &flags)) {
+        if (flags)  sensors |= SENSORS_ACCELERATION;
+        else        sensors &= ~SENSORS_ACCELERATION;
+    }
+    if (!ioctl(fd, ECS_IOCTL_APP_GET_TFLAG, &flags)) {
+        if (flags)  sensors |= SENSORS_TEMPERATURE;
+        else        sensors &= ~SENSORS_TEMPERATURE;
+    }
+    if (!ioctl(fd, ECS_IOCTL_APP_GET_MVFLAG, &flags)) {
+        if (flags)  sensors |= SENSORS_MAGNETIC_FIELD;
+        else        sensors &= ~SENSORS_MAGNETIC_FIELD;
+    }
+    return sensors;
+}
+
+/*****************************************************************************/
+
+static native_handle_t* control__open_data_source(struct sensors_control_context_t *dev)
+{
+    native_handle_t* handle;
+    int fd = open_input(O_RDONLY);
+    if (fd < 0) {
+        return NULL;
+    }
+
+    handle = native_handle_create(1, 0);
+    handle->data[0] = fd;
+    return handle;
+}
+
+static int control__activate(struct sensors_control_context_t *dev,
+        int handle, int enabled)
+{
+    if ((handle<SENSORS_HANDLE_BASE) || 
+            (handle>=SENSORS_HANDLE_BASE+MAX_NUM_SENSORS)) {
+        return -1;
+    }
+
+    uint32_t mask = (1<<handle);
+    uint32_t sensors = enabled ? mask : 0;
+    
+    uint32_t active = dev->active_sensors;
+    uint32_t new_sensors = (active & ~mask) | (sensors & mask);
+    uint32_t changed = active ^ new_sensors;
+    if (changed) {
+        int fd = open_akm(dev);
+        if (fd >= 0) {
+            if (!active && new_sensors) {
+                // force all sensors to be updated
+                changed = SUPPORTED_SENSORS;
+            }
+
+            enable_disable(fd, new_sensors, changed);
+
+            LOGD("sensors=%08x, real=%08x",
+                    new_sensors, read_sensors_state(fd));
+
+            if (active && !new_sensors) {
+                // close the driver
+                close_akm(dev);
+            }
+            dev->active_sensors = active = new_sensors;
+        } else {
+            active = -1;
+        }
+    }
+    return 0;
+}
+
+static int control__set_delay(struct sensors_control_context_t *dev, int32_t ms)
+{
+#ifdef ECS_IOCTL_APP_SET_DELAY
+    if (dev->akmd_fd <= 0) {
+        return -1;
+    }
+    short delay = ms;
+    if (!ioctl(dev->akmd_fd, ECS_IOCTL_APP_SET_DELAY, &delay)) {
+        return -errno;
+    }
+    return 0;
+#else
+    return -1;
+#endif
+}
+
+static int control__wake(struct sensors_control_context_t *dev)
+{
+    int err = 0;
+    int fd = open_input(O_WRONLY);
+    if (fd > 0) {
+        struct input_event event[1];
+        event[0].type = EV_SYN;
+        event[0].code = SYN_CONFIG;
+        event[0].value = 0;
+        err = write(fd, event, sizeof(event));
+        LOGD_IF(err<0, "control__wake, err=%d (%s)", errno, strerror(errno));
+        close(fd);
+    }
+    return err;
+}
+
+/*****************************************************************************/
+
+static int data__data_open(struct sensors_data_context_t *dev, native_handle_t* handle)
+{
+    int i;    
+    memset(&dev->sensors, 0, sizeof(dev->sensors));
+    
+    for (i=0 ; i<MAX_NUM_SENSORS ; i++) {
+        // by default all sensors have high accuracy
+        // (we do this because we don't get an update if the value doesn't
+        // change).
+        dev->sensors[i].vector.status = SENSOR_STATUS_ACCURACY_HIGH;
+    }
+    dev->pendingSensors = 0;
+    dev->events_fd = dup(handle->data[0]);
+    //LOGD("data__data_open: fd = %d", handle->data[0]);
+    native_handle_close(handle);
+    native_handle_delete(handle);
+    return 0;
+}
+
+static int data__data_close(struct sensors_data_context_t *dev)
+{
+    if (dev->events_fd > 0) {
+        //LOGD("(data close) about to close fd=%d", dev->events_fd);
+        close(dev->events_fd);
+        dev->events_fd = -1;
+    }
+    return 0;
+}
+
+static int pick_sensor(struct sensors_data_context_t *dev,
+        sensors_data_t* values)
+{
+    uint32_t mask = SUPPORTED_SENSORS;
+    while (mask) {
+        uint32_t i = 31 - __builtin_clz(mask);
+        mask &= ~(1<<i);
+        if (dev->pendingSensors & (1<<i)) {
+            dev->pendingSensors &= ~(1<<i);
+            *values = dev->sensors[i];
+            values->sensor = (1<<i);
+            LOGD_IF(0, "%d [%f, %f, %f]", (1<<i),
+                    values->vector.x,
+                    values->vector.y,
+                    values->vector.z);
+            return i;
+        }
+    }
+    LOGE("No sensor to return!!! pendingSensors=%08x", dev->pendingSensors);
+    // we may end-up in a busy loop, slow things down, just in case.
+    usleep(100000);
+    return -1;
+}
+
+static int data__poll(struct sensors_data_context_t *dev, sensors_data_t* values)
+{
+    int fd = dev->events_fd;
+    if (fd < 0) {
+        LOGE("invalid file descriptor, fd=%d", fd);
+        return -1;
+    }
+
+    // there are pending sensors, returns them now...
+    if (dev->pendingSensors) {
+        return pick_sensor(dev, values);
+    }
+
+    // wait until we get a complete event for an enabled sensor
+    uint32_t new_sensors = 0;
+    while (1) {
+        /* read the next event */
+        struct input_event event;
+        int nread = read(fd, &event, sizeof(event));
+        if (nread == sizeof(event)) {
+            uint32_t v;
+            if (event.type == EV_ABS) {
+                //LOGD("type: %d code: %d value: %-5d time: %ds",
+                //        event.type, event.code, event.value,
+                //      (int)event.time.tv_sec);
+                switch (event.code) {
+
+                    case EVENT_TYPE_ACCEL_X:
+                        new_sensors |= SENSORS_ACCELERATION;
+                        dev->sensors[ID_A].acceleration.x = event.value * CONVERT_A_X;
+                        break;
+                    case EVENT_TYPE_ACCEL_Y:
+                        new_sensors |= SENSORS_ACCELERATION;
+                        dev->sensors[ID_A].acceleration.y = event.value * CONVERT_A_Y;
+                        break;
+                    case EVENT_TYPE_ACCEL_Z:
+                        new_sensors |= SENSORS_ACCELERATION;
+                        dev->sensors[ID_A].acceleration.z = event.value * CONVERT_A_Z;
+                        break;
+
+                    case EVENT_TYPE_MAGV_X:
+                        new_sensors |= SENSORS_MAGNETIC_FIELD;
+                        dev->sensors[ID_M].magnetic.x = event.value * CONVERT_M_X;
+                        break;
+                    case EVENT_TYPE_MAGV_Y:
+                        new_sensors |= SENSORS_MAGNETIC_FIELD;
+                        dev->sensors[ID_M].magnetic.y = event.value * CONVERT_M_Y;
+                        break;
+                    case EVENT_TYPE_MAGV_Z:
+                        new_sensors |= SENSORS_MAGNETIC_FIELD;
+                        dev->sensors[ID_M].magnetic.z = event.value * CONVERT_M_Z;
+                        break;
+
+                    case EVENT_TYPE_YAW:
+                        new_sensors |= SENSORS_ORIENTATION;
+                        dev->sensors[ID_O].orientation.azimuth =  event.value;
+                        break;
+                    case EVENT_TYPE_PITCH:
+                        new_sensors |= SENSORS_ORIENTATION;
+                        dev->sensors[ID_O].orientation.pitch = event.value;
+                        break;
+                    case EVENT_TYPE_ROLL:
+                        new_sensors |= SENSORS_ORIENTATION;
+                        dev->sensors[ID_O].orientation.roll = -event.value;
+                        break;
+
+                    case EVENT_TYPE_TEMPERATURE:
+                        new_sensors |= SENSORS_TEMPERATURE;
+                        dev->sensors[ID_T].temperature = event.value;
+                        break;
+
+                    case EVENT_TYPE_STEP_COUNT:
+                        // step count (only reported in MODE_FFD)
+                        // we do nothing with it for now.
+                        break;
+                    case EVENT_TYPE_ACCEL_STATUS:
+                        // accuracy of the calibration (never returned!)
+                        //LOGD("G-Sensor status %d", event.value);
+                        break;
+                    case EVENT_TYPE_ORIENT_STATUS:
+                        // accuracy of the calibration
+                        v = (uint32_t)(event.value & SENSOR_STATE_MASK);
+                        LOGD_IF(dev->sensors[ID_O].orientation.status != (uint8_t)v,
+                                "M-Sensor status %d", v);
+                        dev->sensors[ID_O].orientation.status = (uint8_t)v;
+                        break;
+                }
+            } else if (event.type == EV_SYN) {
+                if (event.code == SYN_CONFIG) {
+                    // we use SYN_CONFIG to signal that we need to exit the
+                    // main loop.
+                    //LOGD("got empty message: value=%d", event.value);
+                    return 0x7FFFFFFF;
+                }
+                if (new_sensors) {
+                    dev->pendingSensors = new_sensors;
+                    int64_t t = event.time.tv_sec*1000000000LL +
+                            event.time.tv_usec*1000;
+                    while (new_sensors) {
+                        uint32_t i = 31 - __builtin_clz(new_sensors);
+                        new_sensors &= ~(1<<i);
+                        dev->sensors[i].time = t;
+                    }
+                    return pick_sensor(dev, values);
+                }
+            }
+        }
+    }
+}
+
+/*****************************************************************************/
+
+static int control__close(struct hw_device_t *dev) 
+{
+    struct sensors_control_context_t* ctx = (struct sensors_control_context_t*)dev;
+    if (ctx) {
+        if (ctx->akmd_fd > 0)
+            close(ctx->akmd_fd);
+        free(ctx);
+    }
+    return 0;
+}
+
+static int data__close(struct hw_device_t *dev) 
+{
+    struct sensors_data_context_t* ctx = (struct sensors_data_context_t*)dev;
+    if (ctx) {
+        if (ctx->events_fd > 0) {
+            //LOGD("(device close) about to close fd=%d", ctx->events_fd);
+            close(ctx->events_fd);
+        }
+        free(ctx);
+    }
+    return 0;
+}
+
+
+/** Open a new instance of a sensor device using name */
+static int open_sensors(const struct hw_module_t* module, const char* name,
+        struct hw_device_t** device)
+{
+    int status = -EINVAL;
+    if (!strcmp(name, SENSORS_HARDWARE_CONTROL)) {
+        struct sensors_control_context_t *dev;
+        dev = malloc(sizeof(*dev));
+        memset(dev, 0, sizeof(*dev));
+        dev->akmd_fd = -1;
+        dev->device.common.tag = HARDWARE_DEVICE_TAG;
+        dev->device.common.version = 0;
+        dev->device.common.module = module;
+        dev->device.common.close = control__close;
+        dev->device.open_data_source = control__open_data_source;
+        dev->device.activate = control__activate;
+        dev->device.set_delay= control__set_delay;
+        dev->device.wake = control__wake;
+        *device = &dev->device.common;
+    } else if (!strcmp(name, SENSORS_HARDWARE_DATA)) {
+        struct sensors_data_context_t *dev;
+        dev = malloc(sizeof(*dev));
+        memset(dev, 0, sizeof(*dev));
+        dev->events_fd = -1;
+        dev->device.common.tag = HARDWARE_DEVICE_TAG;
+        dev->device.common.version = 0;
+        dev->device.common.module = module;
+        dev->device.common.close = data__close;
+        dev->device.data_open = data__data_open;
+        dev->device.data_close = data__data_close;
+        dev->device.poll = data__poll;
+        *device = &dev->device.common;
+    }
+    return status;
+}
-- 
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