* Copyright (C) 2014 Intel Corporation.
*/
+#include <stdlib.h>
+#include <ctype.h>
#include <fcntl.h>
+#include <pthread.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <utils/Log.h>
#include "enumeration.h"
#include "utils.h"
#include "transform.h"
+#include "calibration.h"
+#include "description.h"
/* Currently active sensors count, per device */
static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
static int poll_fd; /* epoll instance covering all enabled sensors */
-static int poll_socket_pair[2]; /* used to unblock the poll loop */
-
-/* Timestamp for the moment when we last exited a poll operation */
-static int64_t last_poll_exit_ts;
-
static int active_poll_sensors; /* Number of enabled poll-mode sensors */
-/* Cap the time between poll operations to this, to counter runaway polls */
-#define POLL_MIN_INTERVAL 10000 /* uS */
+/* We use pthread condition variables to get worker threads out of sleep */
+static pthread_cond_t thread_release_cond [MAX_SENSORS];
+static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
-#define INVALID_DEV_NUM ((uint32_t) -1)
+/*
+ * We associate tags to each of our poll set entries. These tags have the
+ * following values:
+ * - a iio device number if the fd is a iio character device fd
+ * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a
+ * pipe used by a sysfs data acquisition thread
+ * */
+#define THREAD_REPORT_TAG_BASE 0x00010000
static int enable_buffer(int dev_num, int enabled)
}
-static void refresh_sensor_report_maps(int dev_num)
+void build_sensor_report_maps(int dev_num)
{
/*
* Read sysfs files from a iio device's scan_element directory, and
int c;
int n;
int i;
- int ch_enabled;
int ch_index;
char* ch_spec;
char spec_buf[MAX_TYPE_SPEC_LEN];
struct datum_info_t* ch_info;
int size;
char sysfs_path[PATH_MAX];
- int active_channels;
+ int known_channels;
int offset;
- int channel_count;
int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
- active_channels = 0;
+ known_channels = 0;
/* For each sensor that is linked to this device */
for (s=0; s<sensor_count; s++) {
i = sensor_info[s].catalog_index;
- /* Read channel status through syfs attributes */
+ /* Read channel details through sysfs attributes */
for (c=0; c<sensor_info[s].num_channels; c++) {
- /* Read _en file */
- sprintf(sysfs_path, CHANNEL_PATH "%s",
- sensor_info[s].dev_num,
- sensor_catalog[i].channel[c].en_path);
-
- n = sysfs_read_int(sysfs_path, &ch_enabled);
-
- if (n == -1) {
- ALOGW( "Failed to read _en flag: %s\n",
- sysfs_path);
- continue;
- }
-
- if (!ch_enabled != 1) {
- sensor_info[s].channel[c].size = 0;
- }
-
/* Read _type file */
sprintf(sysfs_path, CHANNEL_PATH "%s",
sensor_info[s].dev_num,
channel_number_from_index[ch_index] = c;
channel_size_from_index [ch_index] = size;
- active_channels++;
+ known_channels++;
+ }
+
+ /* Stop sampling - if we are recovering from hal restart */
+ enable_buffer(dev_num, 0);
+ setup_trigger(dev_num, "\n");
+
+ /* Turn on channels we're aware of */
+ for (c=0;c<sensor_info[s].num_channels; c++) {
+ sprintf(sysfs_path, CHANNEL_PATH "%s",
+ sensor_info[s].dev_num,
+ sensor_catalog[i].channel[c].en_path);
+ sysfs_write_int(sysfs_path, 1);
}
}
- ALOGI("Found %d enabled channels for iio device %d\n", active_channels,
- dev_num);
+ ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
/*
- * Now that we know which channels are enabled, their sizes and their
+ * Now that we know which channels are defined, their sizes and their
* ordering, update channels offsets within device report. Note: there
* is a possibility that several sensors share the same index, with
* their data fields being isolated by masking and shifting as specified
*/
int dev_num = sensor_info[s].dev_num;
+ int catalog_index = sensor_info[s].catalog_index;
+ int sensor_type = sensor_catalog[catalog_index].type;
/* Refcount per sensor, in terms of enable count */
if (enabled) {
ALOGI("Enabling sensor %d (iio device %d: %s)\n",
- s, dev_num, sensor_info[s].internal_name);
+ s, dev_num, sensor_info[s].friendly_name);
sensor_info[s].enable_count++;
- if (sensor_info[s].enable_count != 1)
+ if (sensor_info[s].enable_count > 1)
return 0; /* The sensor was, and remains, in use */
+
+ switch (sensor_type) {
+ case SENSOR_TYPE_MAGNETIC_FIELD:
+ compass_read_data(&sensor_info[s]);
+ break;
+
+ case SENSOR_TYPE_GYROSCOPE:
+ case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
+ gyro_cal_init(&sensor_info[s]);
+ break;
+ }
} else {
if (sensor_info[s].enable_count == 0)
return -1; /* Spurious disable call */
- ALOGI("Disabling sensor %d (iio device %d)\n", s, dev_num);
+ ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
+ sensor_info[s].friendly_name);
sensor_info[s].enable_count--;
if (sensor_info[s].enable_count > 0)
return 0; /* The sensor was, and remains, in use */
- /* Sensor disabled, clear up pending data */
-
+ /* Sensor disabled, lower report available flag */
sensor_info[s].report_pending = 0;
- memset(sensor_info[s].report_buffer, 0, MAX_SENSOR_REPORT_SIZE);
+
+ if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
+ compass_store_data(&sensor_info[s]);
}
+
+ /* If uncalibrated type and pair is already active don't adjust counters */
+ if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
+ sensor_info[sensor_info[s].pair_idx].enable_count != 0)
+ return 0;
+
/* We changed the state of a sensor - adjust per iio device counters */
/* If this is a regular event-driven sensor */
}
+static int get_field_count (int s)
+{
+ int catalog_index = sensor_info[s].catalog_index;
+ int sensor_type = sensor_catalog[catalog_index].type;
+
+ switch (sensor_type) {
+ case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
+ case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
+ case SENSOR_TYPE_ORIENTATION: /* degrees */
+ case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
+ case SENSOR_TYPE_GYROSCOPE: /* radians/s */
+ return 3;
+
+ case SENSOR_TYPE_LIGHT: /* SI lux units */
+ case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
+ case SENSOR_TYPE_TEMPERATURE: /* °C */
+ case SENSOR_TYPE_PROXIMITY: /* centimeters */
+ case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
+ case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
+ return 1;
+
+ case SENSOR_TYPE_ROTATION_VECTOR:
+ return 4;
+
+ default:
+ ALOGE("Unknown sensor type!\n");
+ return 0; /* Drop sample */
+ }
+}
+
+
+static void time_add(struct timespec *out, struct timespec *in, int64_t ns)
+{
+ int64_t target_ts = 1000000000LL * in->tv_sec + in->tv_nsec + ns;
+
+ out->tv_sec = target_ts / 1000000000;
+ out->tv_nsec = target_ts % 1000000000;
+}
+
+
+static void* acquisition_routine (void* param)
+{
+ /*
+ * Data acquisition routine run in a dedicated thread, covering a single
+ * sensor. This loop will periodically retrieve sampling data through
+ * sysfs, then package it as a sample and transfer it to our master poll
+ * loop through a report fd. Checks for a cancellation signal quite
+ * frequently, as the thread may be disposed of at any time. Note that
+ * Bionic does not provide pthread_cancel / pthread_testcancel...
+ */
+
+ int s = (int) param;
+ int num_fields;
+ struct sensors_event_t data = {0};
+ int c;
+ int ret;
+ struct timespec entry_time;
+ struct timespec target_time;
+ int64_t period;
+
+ ALOGV("Entering data acquisition thread for sensor %d\n", s);
+
+ if (s < 0 || s >= sensor_count) {
+ ALOGE("Invalid sensor handle!\n");
+ return NULL;
+ }
+
+ if (!sensor_info[s].sampling_rate) {
+ ALOGE("Zero rate in acquisition routine for sensor %d\n", s);
+ return NULL;
+ }
+
+ num_fields = get_field_count(s);
+
+ /*
+ * Each condition variable is associated to a mutex that has to be
+ * locked by the thread that's waiting on it. We use these condition
+ * variables to get the acquisition threads out of sleep quickly after
+ * the sampling rate is adjusted, or the sensor is disabled.
+ */
+ pthread_mutex_lock(&thread_release_mutex[s]);
+
+ while (1) {
+ /* Pinpoint the moment we start sampling */
+ clock_gettime(CLOCK_REALTIME, &entry_time);
+
+ ALOGV("Acquiring sample data for sensor %d through sysfs\n", s);
+
+ /* Read values through sysfs */
+ for (c=0; c<num_fields; c++) {
+ data.data[c] = acquire_immediate_value(s, c);
+
+ /* Check and honor termination requests */
+ if (sensor_info[s].thread_data_fd[1] == -1)
+ goto exit;
+
+ ALOGV("\tfield %d: %f\n", c, data.data[c]);
+
+ }
+
+ /* If the sample looks good */
+ if (sensor_info[s].ops.finalize(s, &data)) {
+
+ /* Pipe it for transmission to poll loop */
+ ret = write( sensor_info[s].thread_data_fd[1],
+ data.data,
+ num_fields * sizeof(float));
+ }
+
+ /* Check and honor termination requests */
+ if (sensor_info[s].thread_data_fd[1] == -1)
+ goto exit;
+
+
+ period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
+
+ time_add(&target_time, &entry_time, period);
+
+ /*
+ * Wait until the sampling time elapses, or a rate change is
+ * signaled, or a thread exit is requested.
+ */
+ ret = pthread_cond_timedwait( &thread_release_cond[s],
+ &thread_release_mutex[s],
+ &target_time);
+
+ /* Check and honor termination requests */
+ if (sensor_info[s].thread_data_fd[1] == -1)
+ goto exit;
+ }
+
+exit:
+ ALOGV("Acquisition thread for S%d exiting\n", s);
+ pthread_mutex_unlock(&thread_release_mutex[s]);
+ pthread_exit(0);
+ return NULL;
+}
+
+
+static void start_acquisition_thread (int s)
+{
+ int incoming_data_fd;
+ int ret;
+
+ struct epoll_event ev = {0};
+
+ ALOGV("Initializing acquisition context for sensor %d\n", s);
+
+ /* Create condition variable and mutex for quick thread release */
+ ret = pthread_cond_init(&thread_release_cond[s], NULL);
+ ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
+
+ /* Create a pipe for inter thread communication */
+ ret = pipe(sensor_info[s].thread_data_fd);
+
+ incoming_data_fd = sensor_info[s].thread_data_fd[0];
+
+ ev.events = EPOLLIN;
+ ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
+
+ /* Add incoming side of pipe to our poll set, with a suitable tag */
+ ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
+
+ /* Create and start worker thread */
+ ret = pthread_create( &sensor_info[s].acquisition_thread,
+ NULL,
+ acquisition_routine,
+ (void*) s);
+}
+
+
+static void stop_acquisition_thread (int s)
+{
+ int incoming_data_fd = sensor_info[s].thread_data_fd[0];
+ int outgoing_data_fd = sensor_info[s].thread_data_fd[1];
+
+ ALOGV("Tearing down acquisition context for sensor %d\n", s);
+
+ /* Delete the incoming side of the pipe from our poll set */
+ epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
+
+ /* Mark the pipe ends as invalid ; that's a cheap exit flag */
+ sensor_info[s].thread_data_fd[0] = -1;
+ sensor_info[s].thread_data_fd[1] = -1;
+
+ /* Close both sides of our pipe */
+ close(incoming_data_fd);
+ close(outgoing_data_fd);
+
+ /* Stop acquisition thread and clean up thread handle */
+ pthread_cond_signal(&thread_release_cond[s]);
+ pthread_join(sensor_info[s].acquisition_thread, NULL);
+
+ /* Clean up our sensor descriptor */
+ sensor_info[s].acquisition_thread = -1;
+
+ /* Delete condition variable and mutex */
+ pthread_cond_destroy(&thread_release_cond[s]);
+ pthread_mutex_destroy(&thread_release_mutex[s]);
+}
+
+
int sensor_activate(int s, int enabled)
{
- char sysfs_path[PATH_MAX];
char device_name[PATH_MAX];
- char trigger_name[MAX_NAME_SIZE + 16];
- int c;
struct epoll_event ev = {0};
int dev_fd;
int ret;
int dev_num = sensor_info[s].dev_num;
- int i = sensor_info[s].catalog_index;
int is_poll_sensor = !sensor_info[s].num_channels;
- ret = adjust_counters(s, enabled);
+ /* If we want to activate gyro calibrated and gyro uncalibrated is activated
+ * Deactivate gyro uncalibrated - Uncalibrated releases handler
+ * Activate gyro calibrated - Calibrated has handler
+ * Reactivate gyro uncalibrated - Uncalibrated gets data from calibrated */
- /* If the operation was neutral in terms of state, we're done */
- if (ret <= 0)
- return ret;
+ /* If we want to deactivate gyro calibrated and gyro uncalibrated is active
+ * Deactivate gyro uncalibrated - Uncalibrated no longer gets data from handler
+ * Deactivate gyro calibrated - Calibrated releases handler
+ * Reactivate gyro uncalibrated - Uncalibrated has handler */
- if (!is_poll_sensor) {
- /* Changes have to be made while the buffer is turned off */
- enable_buffer(dev_num, 0);
+ if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
+ sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
- /* Configure trigger */
- switch (trig_sensors_per_dev[dev_num]) {
- case 0:
- setup_trigger(dev_num, "none");
- break;
+ sensor_activate(sensor_info[s].pair_idx, 0);
+ ret = sensor_activate(s, enabled);
+ sensor_activate(sensor_info[s].pair_idx, 1);
+ return ret;
+ }
- case 1:
- sprintf(trigger_name, "%s-dev%d",
- sensor_info[s].internal_name, dev_num);
+ ret = adjust_counters(s, enabled);
- setup_trigger(dev_num, trigger_name);
- break;
+ /* If the operation was neutral in terms of state, we're done */
+ if (ret <= 0)
+ return ret;
- default:
- /* The trigger is already set */
- break;
- }
- /*
- * Turn channels associated to this sensor on or off, and update
- * the channels maps for all sensors associated to this device.
- */
- for (c=0;c<sensor_info[s].num_channels; c++) {
- sprintf(sysfs_path, CHANNEL_PATH "%s",
- sensor_info[s].dev_num,
- sensor_catalog[i].channel[c].en_path);
+ if (!is_poll_sensor) {
- sysfs_write_int(sysfs_path, enabled);
- }
+ /* Stop sampling */
+ enable_buffer(dev_num, 0);
+ setup_trigger(dev_num, "\n");
- /* If there's at least one sensor left */
+ /* If there's at least one sensor enabled on this iio device */
if (trig_sensors_per_dev[dev_num]) {
- refresh_sensor_report_maps(dev_num);
+
+ /* Start sampling */
+ setup_trigger(dev_num, sensor_info[s].trigger_name);
enable_buffer(dev_num, 1);
}
}
/*
* Make sure we have a fd on the character device ; conversely, close
- * the fd if no one is using associated sensor anymore. The assumption
+ * the fd if no one is using associated sensors anymore. The assumption
* here is that the underlying driver will power on the relevant
- * hardware block while someone hold a fd on the device.
+ * hardware block while someone holds a fd on the device.
*/
dev_fd = device_fd[dev_num];
if (!enabled) {
+ if (is_poll_sensor)
+ stop_acquisition_thread(s);
+
if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
!trig_sensors_per_dev[dev_num]) {
/*
close(dev_fd);
device_fd[dev_num] = -1;
}
+
+ /* If we recorded a trail of samples for filtering, delete it */
+ if (sensor_info[s].history) {
+ free(sensor_info[s].history);
+ sensor_info[s].history = NULL;
+ sensor_info[s].history_size = 0;
+ }
return 0;
}
}
}
- /* Release the polling loop so an updated timeout gets used */
- write(poll_socket_pair[1], "", 1);
+ /* Ensure that on-change sensors send at least one event after enable */
+ sensor_info[s].prev_val = -1;
+
+ if (is_poll_sensor)
+ start_acquisition_thread(s);
return 0;
}
{
int len;
int s,c;
- unsigned char buf[MAX_SENSOR_REPORT_SIZE * MAX_SENSORS] = { 0 };
+ unsigned char buf[MAX_SENSOR_REPORT_SIZE] = { 0 };
int sr_offset;
unsigned char *target;
unsigned char *source;
int size;
- int expected_size = 0;
+ int64_t ts;
- /* There's an incoming report on the specified fd */
+ /* There's an incoming report on the specified iio device char dev fd */
- if (dev_num < 0 || dev_num >= MAX_DEVICES ||
- !trig_sensors_per_dev[dev_num]) {
+ if (dev_num < 0 || dev_num >= MAX_DEVICES) {
ALOGE("Event reported on unexpected iio device %d\n", dev_num);
return -1;
}
- for (s=0; s<MAX_SENSORS; s++)
- if (sensor_info[s].dev_num == dev_num)
- for (c=0; c<sensor_info[s].num_channels; c++)
- expected_size += sensor_info[s].channel[c].size;
+ if (device_fd[dev_num] == -1) {
+ ALOGE("Ignoring stale report on iio device %d\n", dev_num);
+ return -1;
+ }
+
+ ts = get_timestamp();
- len = read(device_fd[dev_num], buf, expected_size);
+ len = read(device_fd[dev_num], buf, MAX_SENSOR_REPORT_SIZE);
if (len == -1) {
ALOGE("Could not read report from iio device %d (%s)\n",
ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
+ /* Map device report to sensor reports */
+
for (s=0; s<MAX_SENSORS; s++)
- if (sensor_info[s].dev_num == dev_num) {
+ if (sensor_info[s].dev_num == dev_num &&
+ sensor_info[s].enable_count) {
+
sr_offset = 0;
/* Copy data from device to sensor report buffer */
sr_offset += size;
}
- if (sensor_info[s].enable_count) {
- ALOGV("Sensor %d report available (%d bytes)\n",
- s, sr_offset);
+ ALOGV("Sensor %d report available (%d bytes)\n", s,
+ sr_offset);
- sensor_info[s].report_pending = 1;
- }
+ sensor_info[s].report_ts = ts;
+ sensor_info[s].report_pending = 1;
+ sensor_info[s].report_initialized = 1;
}
return 0;
}
-static float acquire_immediate_value(int s, int c)
+static int propagate_sensor_report(int s, struct sensors_event_t *data)
{
- char sysfs_path[PATH_MAX];
- float val;
- int ret;
- int dev_num = sensor_info[s].dev_num;
- int i = sensor_info[s].catalog_index;
- const char* raw_path = sensor_catalog[i].channel[c].raw_path;
- const char* input_path = sensor_catalog[i].channel[c].input_path;
- float scale = sensor_info[s].scale;
- float offset = sensor_info[s].offset;
+ /* There's a sensor report pending for this sensor ; transmit it */
- /* Acquire a sample value for sensor s / channel c through sysfs */
+ int catalog_index = sensor_info[s].catalog_index;
+ int sensor_type = sensor_catalog[catalog_index].type;
+ int num_fields = get_field_count(s);
+ int c;
+ unsigned char* current_sample;
- if (input_path[0]) {
- sprintf(sysfs_path, BASE_PATH "%s", dev_num, input_path);
- ret = sysfs_read_float(sysfs_path, &val);
+ /* If there's nothing to return... we're done */
+ if (!num_fields)
+ return 0;
- if (!ret) {
- return val;
- }
- };
- if (!raw_path[0])
- return 0;
+ /* Only return uncalibrated event if also gyro active */
+ if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
+ sensor_info[sensor_info[s].pair_idx].enable_count != 0)
+ return 0;
- sprintf(sysfs_path, BASE_PATH "%s", dev_num, raw_path);
- ret = sysfs_read_float(sysfs_path, &val);
+ memset(data, 0, sizeof(sensors_event_t));
- if (ret == -1)
- return 0;
+ data->version = sizeof(sensors_event_t);
+ data->sensor = s;
+ data->type = sensor_type;
+ data->timestamp = sensor_info[s].report_ts;
- return (val + offset) * scale;
-}
+ ALOGV("Sample on sensor %d (type %d):\n", s, sensor_type);
+ current_sample = sensor_info[s].report_buffer;
-static void propagate_sensor_report(int s, struct sensors_event_t* data)
-{
- /* There's a sensor report pending for this sensor ; transmit it */
+ /* If this is a poll sensor */
+ if (!sensor_info[s].num_channels) {
+ /* Use the data provided by the acquisition thread */
+ ALOGV("Reporting data from worker thread for S%d\n", s);
+ memcpy(data->data, current_sample, num_fields * sizeof(float));
+ return 1;
+ }
- int catalog_index = sensor_info[s].catalog_index;
- int sensor_type = sensor_catalog[catalog_index].type;
- int num_fields;
- int c;
- unsigned char* current_sample;
+ /* Convert the data into the expected Android-level format */
+ for (c=0; c<num_fields; c++) {
- memset(data, 0, sizeof(sensors_event_t));
+ data->data[c] = sensor_info[s].ops.transform
+ (s, c, current_sample);
- data->version = sizeof(sensors_event_t);
- data->sensor = s;
- data->type = sensor_type;
- data->timestamp = get_timestamp();
+ ALOGV("\tfield %d: %f\n", c, data->data[c]);
+ current_sample += sensor_info[s].channel[c].size;
+ }
- switch (sensor_type) {
- case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
- case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
- case SENSOR_TYPE_ORIENTATION: /* degrees */
- case SENSOR_TYPE_GYROSCOPE: /* radians/s */
- num_fields = 3;
- break;
+ /*
+ * The finalize routine, in addition to its late sample processing duty,
+ * has the final say on whether or not the sample gets sent to Android.
+ */
+ return sensor_info[s].ops.finalize(s, data);
+}
- case SENSOR_TYPE_LIGHT: /* SI lux units */
- case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
- case SENSOR_TYPE_TEMPERATURE: /* °C */
- case SENSOR_TYPE_PROXIMITY: /* centimeters */
- case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
- case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
- num_fields = 1;
- break;
- case SENSOR_TYPE_ROTATION_VECTOR:
- num_fields = 4;
- break;
+static void synthetize_duplicate_samples (void)
+{
+ /*
+ * Some sensor types (ex: gyroscope) are defined as continuously firing
+ * by Android, despite the fact that we can be dealing with iio drivers
+ * that only report events for new samples. For these we generate
+ * reports periodically, duplicating the last data we got from the
+ * driver. This is not necessary for polling sensors.
+ */
- case SENSOR_TYPE_DEVICE_PRIVATE_BASE: /* hidden for now */
- num_fields = 0;
- break;
+ int s;
+ int64_t current_ts;
+ int64_t target_ts;
+ int64_t period;
- default:
- ALOGE("Unknown sensor type!\n");
- num_fields = 0;
- break;
- }
+ for (s=0; s<sensor_count; s++) {
- ALOGV("Sample on sensor %d (type %d):\n", s, sensor_type);
+ /* Ignore disabled sensors */
+ if (!sensor_info[s].enable_count)
+ continue;
- /* If we're dealing with a poll-mode sensor */
- if (!sensor_info[s].num_channels) {
+ /* If the sensor can generate duplicates, leave it alone */
+ if (!(sensor_info[s].quirks & QUIRK_TERSE_DRIVER))
+ continue;
- /* Read values through sysfs rather than from a report buffer */
- for (c=0; c<num_fields; c++) {
+ /* If we haven't seen a sample, there's nothing to duplicate */
+ if (!sensor_info[s].report_initialized)
+ continue;
- data->data[c] = acquire_immediate_value(s, c);
+ /* If a sample was recently buffered, leave it alone too */
+ if (sensor_info[s].report_pending)
+ continue;
- ALOGV("\tfield %d: %f\n", c, data->data[c]);
- }
+ /* We also need a valid sampling rate to be configured */
+ if (!sensor_info[s].sampling_rate)
+ continue;
- finalize_sample(s, data);
- return;
+ period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
+
+ current_ts = get_timestamp();
+ target_ts = sensor_info[s].report_ts + period;
+
+ if (target_ts <= current_ts) {
+ /* Mark the sensor for event generation */
+ sensor_info[s].report_ts = current_ts;
+ sensor_info[s].report_pending = 1;
+ }
}
+}
- /* Convert the data into the expected Android-level format */
- current_sample = sensor_info[s].report_buffer;
+static void integrate_thread_report (uint32_t tag)
+{
+ int s = tag - THREAD_REPORT_TAG_BASE;
+ int len;
+ int expected_len;
- for (c=0; c<num_fields; c++) {
+ expected_len = get_field_count(s) * sizeof(float);
- data->data[c] = transform_sample(s, c, current_sample);
+ len = read(sensor_info[s].thread_data_fd[0],
+ sensor_info[s].report_buffer,
+ expected_len);
- ALOGV("\tfield %d: %f\n", c, data->data[c]);
- current_sample += sensor_info[s].channel[c].size;
+ if (len == expected_len) {
+ sensor_info[s].report_ts = get_timestamp();
+ sensor_info[s].report_pending = 1;
}
-
- finalize_sample(s, data);
}
-static int get_poll_time (void)
+static int get_poll_wait_timeout (void)
{
- if (!active_poll_sensors)
- return -1; /* Infinite wait */
+ /*
+ * Compute an appropriate timeout value, in ms, for the epoll_wait
+ * call that's going to await for iio device reports and incoming
+ * reports from our sensor sysfs data reader threads.
+ */
- return 100; /* ms ... this needs to be dynamic */
-}
+ int s;
+ int64_t target_ts = INT64_MAX;
+ int64_t ms_to_wait;
+ int64_t period;
+
+ /*
+ * Check if have have to deal with "terse" drivers that only send events
+ * when there is motion, despite the fact that the associated Android
+ * sensor type is continuous rather than on-change. In that case we have
+ * to duplicate events. Check deadline for the nearest upcoming event.
+ */
+ for (s=0; s<sensor_count; s++)
+ if (sensor_info[s].enable_count &&
+ (sensor_info[s].quirks & QUIRK_TERSE_DRIVER) &&
+ sensor_info[s].sampling_rate) {
+ period = (int64_t) (1000000000.0 /
+ sensor_info[s].sampling_rate);
+
+ if (sensor_info[s].report_ts + period < target_ts)
+ target_ts = sensor_info[s].report_ts + period;
+ }
+ /* If we don't have such a driver to deal with */
+ if (target_ts == INT64_MAX)
+ return -1; /* Infinite wait */
-static void acknowledge_release (void)
-{
- /* A write to our socket circuit was performed to release epoll */
- char buf;
- read(poll_socket_pair[0], &buf, 1);
+ ms_to_wait = (target_ts - get_timestamp()) / 1000000;
+
+ /*
+ * If the target timestamp is very close or already behind us, wait
+ * nonetheless for a millisecond in order to a) avoid busy loops, and
+ * b) give a chance for the driver to report data before we repeat the
+ * last received sample.
+ */
+ if (ms_to_wait <= 0)
+ return 1;
+
+ return ms_to_wait;
}
int s;
int i;
int nfds;
- int delta;
struct epoll_event ev[MAX_DEVICES];
+ int returned_events;
+ int event_count;
/* Get one or more events from our collection of sensors */
-return_first_available_sensor_report:
+return_available_sensor_reports:
- /* If there's at least one available report */
- for (s=0; s<sensor_count; s++)
- if (sensor_info[s].report_pending) {
+ returned_events = 0;
- /* Return that up */
- propagate_sensor_report(s, data);
+ /* Check our sensor collection for available reports */
+ for (s=0; s<sensor_count && returned_events < count; s++)
+ if (sensor_info[s].report_pending) {
+ event_count = 0;
+ /* Lower flag */
sensor_info[s].report_pending = 0;
- ALOGV("Report on sensor %d\n", s);
- return 1;
+
+ /* Report this event if it looks OK */
+ event_count = propagate_sensor_report(s, &data[returned_events]);
+
+ /* Duplicate only if both cal & uncal are active */
+ if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
+ sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
+ struct gyro_cal* gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
+
+ memcpy(&data[returned_events + event_count], &data[returned_events],
+ sizeof(struct sensors_event_t) * event_count);
+ for (i = 0; i < event_count; i++) {
+ data[returned_events + i].type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
+ data[returned_events + i].sensor = sensor_info[s].pair_idx;
+
+ data[returned_events + i].data[0] = data[returned_events + i].data[0] + gyro_data->bias[0];
+ data[returned_events + i].data[1] = data[returned_events + i].data[1] + gyro_data->bias[1];
+ data[returned_events + i].data[2] = data[returned_events + i].data[2] + gyro_data->bias[2];
+
+ data[returned_events + i].uncalibrated_gyro.bias[0] = gyro_data->bias[0];
+ data[returned_events + i].uncalibrated_gyro.bias[1] = gyro_data->bias[1];
+ data[returned_events + i].uncalibrated_gyro.bias[2] = gyro_data->bias[2];
+ }
+ event_count <<= 1;
+ }
+ sensor_info[sensor_info[s].pair_idx].report_pending = 0;
+ returned_events += event_count;
+ /*
+ * If the sample was deemed invalid or unreportable,
+ * e.g. had the same value as the previously reported
+ * value for a 'on change' sensor, silently drop it.
+ */
}
-await_event:
- /* Keep a minimum time interval between poll operations */
- delta = (get_timestamp() - last_poll_exit_ts)/1000;
+ if (returned_events)
+ return returned_events;
- if (delta > 0 && delta < POLL_MIN_INTERVAL)
- usleep(POLL_MIN_INTERVAL - delta);
+await_event:
ALOGV("Awaiting sensor data\n");
- nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_time());
-
- last_poll_exit_ts = get_timestamp();
+ nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
if (nfds == -1) {
- ALOGI("epoll_wait returned -1 (%s)\n", strerror(errno));
+ ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
goto await_event;
}
+ /* Synthetize duplicate samples if needed */
+ synthetize_duplicate_samples();
+
ALOGV("%d fds signalled\n", nfds);
- /* For each of the devices for which a report is available */
+ /* For each of the signalled sources */
for (i=0; i<nfds; i++)
- if (ev[i].events == EPOLLIN) {
- if (ev[i].data.u32 == INVALID_DEV_NUM) {
- acknowledge_release();
- goto await_event;
- } else
- /* Read report */
- integrate_device_report(ev[i].data.u32);
- }
-
- /* It's a good time to invalidate poll-mode sensor values */
- if (active_poll_sensors)
- for (s=0; s<sensor_count; s++)
- if (sensor_info[s].enable_count &&
- !sensor_info[s].num_channels)
- sensor_info[s].report_pending = 1;
+ if (ev[i].events == EPOLLIN)
+ switch (ev[i].data.u32) {
+ case 0 ... MAX_DEVICES-1:
+ /* Read report from iio char dev fd */
+ integrate_device_report(ev[i].data.u32);
+ break;
+
+ case THREAD_REPORT_TAG_BASE ...
+ THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
+ /* Get report from acquisition thread */
+ integrate_thread_report(ev[i].data.u32);
+ break;
+
+ default:
+ ALOGW("Unexpected event source!\n");
+ break;
+ }
- goto return_first_available_sensor_report;
+ goto return_available_sensor_reports;
}
/* See Android sensors.h for indication on sensor trigger modes */
char sysfs_path[PATH_MAX];
+ char avail_sysfs_path[PATH_MAX];
int dev_num = sensor_info[s].dev_num;
int i = sensor_info[s].catalog_index;
const char *prefix = sensor_catalog[i].tag;
- int new_sampling_rate = (int) (1000000000L/ns);
- int cur_sampling_rate;
+ float new_sampling_rate; /* Granted sampling rate after arbitration */
+ float cur_sampling_rate; /* Currently used sampling rate */
+ int per_sensor_sampling_rate;
+ int per_device_sampling_rate;
+ float max_supported_rate = 0;
+ char freqs_buf[100];
+ char* cursor;
+ int n;
+ float sr;
+
+ if (!ns) {
+ ALOGE("Rejecting zero delay request on sensor %d\n", s);
+ return -EINVAL;
+ }
+
+ new_sampling_rate = 1000000000LL/ns;
+
+ /*
+ * Artificially limit ourselves to 1 Hz or higher. This is mostly to
+ * avoid setting up the stage for divisions by zero.
+ */
+ if (new_sampling_rate < 1)
+ new_sampling_rate = 1;
+
+ sensor_info[s].sampling_rate = new_sampling_rate;
+
+ /* If we're dealing with a poll-mode sensor */
+ if (!sensor_info[s].num_channels) {
+ /* Interrupt current sleep so the new sampling gets used */
+ pthread_cond_signal(&thread_release_cond[s]);
+ return 0;
+ }
+
+ sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
+
+ if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
+ per_sensor_sampling_rate = 1;
+ per_device_sampling_rate = 0;
+ } else {
+ per_sensor_sampling_rate = 0;
+
+ sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
+
+ if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
+ per_device_sampling_rate = 1;
+ else
+ per_device_sampling_rate = 0;
+ }
+
+ if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
+ ALOGE("No way to adjust sampling rate on sensor %d\n", s);
+ return -ENOSYS;
+ }
+
+ /* Coordinate with others active sensors on the same device, if any */
+ if (per_device_sampling_rate)
+ for (n=0; n<sensor_count; n++)
+ if (n != s && sensor_info[n].dev_num == dev_num &&
+ sensor_info[n].num_channels &&
+ sensor_info[n].enable_count &&
+ sensor_info[n].sampling_rate > new_sampling_rate)
+ new_sampling_rate= sensor_info[n].sampling_rate;
+
+ /* Check if we have contraints on allowed sampling rates */
+
+ sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
+
+ if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
+ cursor = freqs_buf;
+
+ /* Decode allowed sampling rates string, ex: "10 20 50 100" */
+
+ /* While we're not at the end of the string */
+ while (*cursor && cursor[0]) {
+
+ /* Decode a single value */
+ sr = strtod(cursor, NULL);
+
+ if (sr > max_supported_rate)
+ max_supported_rate = sr;
- ALOGI("sensor_set_delay: sampling rate set to %d\n", new_sampling_rate);
+ /* If this matches the selected rate, we're happy */
+ if (new_sampling_rate == sr)
+ break;
- sprintf(sysfs_path, COMMON_SAMPLING_PATH, dev_num, prefix);
+ /*
+ * If we reached a higher value than the desired rate,
+ * adjust selected rate so it matches the first higher
+ * available one and stop parsing - this makes the
+ * assumption that rates are sorted by increasing value
+ * in the allowed frequencies string.
+ */
+ if (sr > new_sampling_rate) {
+ new_sampling_rate = sr;
+ break;
+ }
- if (sysfs_read_int(sysfs_path, &cur_sampling_rate) != -1)
- if (new_sampling_rate != cur_sampling_rate) {
+ /* Skip digits */
+ while (cursor[0] && !isspace(cursor[0]))
+ cursor++;
- if (trig_sensors_per_dev[dev_num])
- enable_buffer(dev_num, 0);
+ /* Skip spaces */
+ while (cursor[0] && isspace(cursor[0]))
+ cursor++;
+ }
+ }
- sysfs_write_int(sysfs_path, new_sampling_rate);
- if (trig_sensors_per_dev[dev_num])
- enable_buffer(dev_num, 1);
+ if (max_supported_rate &&
+ new_sampling_rate > max_supported_rate) {
+ new_sampling_rate = max_supported_rate;
}
- sensor_info[s].sampling_rate = new_sampling_rate;
- /* Release the polling loop so an updated timeout value gets used */
- write(poll_socket_pair[1], "", 1);
+ /* If the desired rate is already active we're all set */
+ if (new_sampling_rate == cur_sampling_rate)
+ return 0;
+
+ ALOGI("Sensor %d sampling rate set to %g\n", s, new_sampling_rate);
+
+ if (trig_sensors_per_dev[dev_num])
+ enable_buffer(dev_num, 0);
+
+ sysfs_write_float(sysfs_path, new_sampling_rate);
+
+ if (trig_sensors_per_dev[dev_num])
+ enable_buffer(dev_num, 1);
return 0;
}
int allocate_control_data (void)
{
int i;
- struct epoll_event ev = {0};
for (i=0; i<MAX_DEVICES; i++)
device_fd[i] = -1;
return -1;
}
- /* Create and add "unblocking" fd to the set of watched fds */
-
- if (socketpair(AF_UNIX, SOCK_STREAM, 0, poll_socket_pair) == -1) {
- ALOGE("Can't create socket pair for iio sensors!\n");
- close(poll_fd);
- return -1;
- }
-
- ev.events = EPOLLIN;
- ev.data.u32 = INVALID_DEV_NUM;
-
- epoll_ctl(poll_fd, EPOLL_CTL_ADD, poll_socket_pair[0], &ev);
-
return poll_fd;
}