2 * Copyright (C) 2014 Intel Corporation.
10 #include <sys/socket.h>
11 #include <utils/Log.h>
12 #include <hardware/sensors.h>
14 #include "enumeration.h"
16 #include "transform.h"
17 #include "calibration.h"
18 #include "description.h"
20 /* Currently active sensors count, per device */
21 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
22 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
24 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
26 static int poll_fd; /* epoll instance covering all enabled sensors */
28 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
30 /* We use pthread condition variables to get worker threads out of sleep */
31 static pthread_cond_t thread_release_cond [MAX_SENSORS];
32 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
35 * We associate tags to each of our poll set entries. These tags have the
37 * - a iio device number if the fd is a iio character device fd
38 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a
39 * pipe used by a sysfs data acquisition thread
41 #define THREAD_REPORT_TAG_BASE 0x00010000
44 static int enable_buffer(int dev_num, int enabled)
46 char sysfs_path[PATH_MAX];
48 sprintf(sysfs_path, ENABLE_PATH, dev_num);
50 /* Low level, non-multiplexed, enable/disable routine */
51 return sysfs_write_int(sysfs_path, enabled);
55 static int setup_trigger(int dev_num, const char* trigger_val)
57 char sysfs_path[PATH_MAX];
59 sprintf(sysfs_path, TRIGGER_PATH, dev_num);
61 return sysfs_write_str(sysfs_path, trigger_val);
65 void build_sensor_report_maps(int dev_num)
68 * Read sysfs files from a iio device's scan_element directory, and
69 * build a couple of tables from that data. These tables will tell, for
70 * each sensor, where to gather relevant data in a device report, i.e.
71 * the structure that we read from the /dev/iio:deviceX file in order to
72 * sensor report, itself being the data that we return to Android when a
73 * sensor poll completes. The mapping should be straightforward in the
74 * case where we have a single sensor active per iio device but, this is
75 * not the general case. In general several sensors can be handled
76 * through a single iio device, and the _en, _index and _type syfs
77 * entries all concur to paint a picture of what the structure of the
87 char spec_buf[MAX_TYPE_SPEC_LEN];
88 struct datum_info_t* ch_info;
90 char sysfs_path[PATH_MAX];
93 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
94 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
95 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
99 /* For each sensor that is linked to this device */
100 for (s=0; s<sensor_count; s++) {
101 if (sensor_info[s].dev_num != dev_num)
104 i = sensor_info[s].catalog_index;
106 /* Read channel details through sysfs attributes */
107 for (c=0; c<sensor_info[s].num_channels; c++) {
109 /* Read _type file */
110 sprintf(sysfs_path, CHANNEL_PATH "%s",
111 sensor_info[s].dev_num,
112 sensor_catalog[i].channel[c].type_path);
114 n = sysfs_read_str(sysfs_path, spec_buf,
118 ALOGW( "Failed to read type: %s\n",
123 ch_spec = sensor_info[s].channel[c].type_spec;
125 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
127 ch_info = &sensor_info[s].channel[c].type_info;
129 size = decode_type_spec(ch_spec, ch_info);
131 /* Read _index file */
132 sprintf(sysfs_path, CHANNEL_PATH "%s",
133 sensor_info[s].dev_num,
134 sensor_catalog[i].channel[c].index_path);
136 n = sysfs_read_int(sysfs_path, &ch_index);
139 ALOGW( "Failed to read index: %s\n",
144 if (ch_index >= MAX_SENSORS) {
145 ALOGE("Index out of bounds!: %s\n", sysfs_path);
149 /* Record what this index is about */
151 sensor_handle_from_index [ch_index] = s;
152 channel_number_from_index[ch_index] = c;
153 channel_size_from_index [ch_index] = size;
158 /* Stop sampling - if we are recovering from hal restart */
159 enable_buffer(dev_num, 0);
160 setup_trigger(dev_num, "\n");
162 /* Turn on channels we're aware of */
163 for (c=0;c<sensor_info[s].num_channels; c++) {
164 sprintf(sysfs_path, CHANNEL_PATH "%s",
165 sensor_info[s].dev_num,
166 sensor_catalog[i].channel[c].en_path);
167 sysfs_write_int(sysfs_path, 1);
171 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
174 * Now that we know which channels are defined, their sizes and their
175 * ordering, update channels offsets within device report. Note: there
176 * is a possibility that several sensors share the same index, with
177 * their data fields being isolated by masking and shifting as specified
178 * through the real bits and shift values in type attributes. This case
179 * is not currently supported. Also, the code below assumes no hole in
180 * the sequence of indices, so it is dependent on discovery of all
184 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
185 s = sensor_handle_from_index[i];
186 c = channel_number_from_index[i];
187 size = channel_size_from_index[i];
192 ALOGI("S%d C%d : offset %d, size %d, type %s\n",
193 s, c, offset, size, sensor_info[s].channel[c].type_spec);
195 sensor_info[s].channel[c].offset = offset;
196 sensor_info[s].channel[c].size = size;
203 int adjust_counters (int s, int enabled)
206 * Adjust counters based on sensor enable action. Return values are:
207 * -1 if there's an inconsistency: abort action in this case
208 * 0 if the operation was completed and we're all set
209 * 1 if we toggled the state of the sensor and there's work left
212 int dev_num = sensor_info[s].dev_num;
213 int catalog_index = sensor_info[s].catalog_index;
214 int sensor_type = sensor_catalog[catalog_index].type;
216 /* Refcount per sensor, in terms of enable count */
218 ALOGI("Enabling sensor %d (iio device %d: %s)\n",
219 s, dev_num, sensor_info[s].friendly_name);
221 sensor_info[s].enable_count++;
223 if (sensor_info[s].enable_count > 1)
224 return 0; /* The sensor was, and remains, in use */
226 switch (sensor_type) {
227 case SENSOR_TYPE_MAGNETIC_FIELD:
228 compass_read_data(&sensor_info[s]);
231 case SENSOR_TYPE_GYROSCOPE:
232 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
233 gyro_cal_init(&sensor_info[s]);
237 if (sensor_info[s].enable_count == 0)
238 return -1; /* Spurious disable call */
240 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
241 sensor_info[s].friendly_name);
243 sensor_info[s].enable_count--;
245 if (sensor_info[s].enable_count > 0)
246 return 0; /* The sensor was, and remains, in use */
248 /* Sensor disabled, lower report available flag */
249 sensor_info[s].report_pending = 0;
251 if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
252 compass_store_data(&sensor_info[s]);
256 /* If uncalibrated type and pair is already active don't adjust counters */
257 if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
258 sensor_info[sensor_info[s].pair_idx].enable_count != 0)
261 /* We changed the state of a sensor - adjust per iio device counters */
263 /* If this is a regular event-driven sensor */
264 if (sensor_info[s].num_channels) {
267 trig_sensors_per_dev[dev_num]++;
269 trig_sensors_per_dev[dev_num]--;
275 active_poll_sensors++;
276 poll_sensors_per_dev[dev_num]++;
280 active_poll_sensors--;
281 poll_sensors_per_dev[dev_num]--;
286 static int get_field_count (int s)
288 int catalog_index = sensor_info[s].catalog_index;
289 int sensor_type = sensor_catalog[catalog_index].type;
291 switch (sensor_type) {
292 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
293 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
294 case SENSOR_TYPE_ORIENTATION: /* degrees */
295 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
296 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
299 case SENSOR_TYPE_LIGHT: /* SI lux units */
300 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
301 case SENSOR_TYPE_TEMPERATURE: /* °C */
302 case SENSOR_TYPE_PROXIMITY: /* centimeters */
303 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
304 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
307 case SENSOR_TYPE_ROTATION_VECTOR:
311 ALOGE("Unknown sensor type!\n");
312 return 0; /* Drop sample */
317 static void time_add(struct timespec *out, struct timespec *in, int64_t ns)
319 int64_t target_ts = 1000000000LL * in->tv_sec + in->tv_nsec + ns;
321 out->tv_sec = target_ts / 1000000000;
322 out->tv_nsec = target_ts % 1000000000;
326 static void* acquisition_routine (void* param)
329 * Data acquisition routine run in a dedicated thread, covering a single
330 * sensor. This loop will periodically retrieve sampling data through
331 * sysfs, then package it as a sample and transfer it to our master poll
332 * loop through a report fd. Checks for a cancellation signal quite
333 * frequently, as the thread may be disposed of at any time. Note that
334 * Bionic does not provide pthread_cancel / pthread_testcancel...
339 struct sensors_event_t data = {0};
342 struct timespec entry_time;
343 struct timespec target_time;
346 ALOGV("Entering data acquisition thread for sensor %d\n", s);
348 if (s < 0 || s >= sensor_count) {
349 ALOGE("Invalid sensor handle!\n");
353 if (!sensor_info[s].sampling_rate) {
354 ALOGE("Zero rate in acquisition routine for sensor %d\n", s);
358 num_fields = get_field_count(s);
361 * Each condition variable is associated to a mutex that has to be
362 * locked by the thread that's waiting on it. We use these condition
363 * variables to get the acquisition threads out of sleep quickly after
364 * the sampling rate is adjusted, or the sensor is disabled.
366 pthread_mutex_lock(&thread_release_mutex[s]);
369 /* Pinpoint the moment we start sampling */
370 clock_gettime(CLOCK_REALTIME, &entry_time);
372 ALOGV("Acquiring sample data for sensor %d through sysfs\n", s);
374 /* Read values through sysfs */
375 for (c=0; c<num_fields; c++) {
376 data.data[c] = acquire_immediate_value(s, c);
378 /* Check and honor termination requests */
379 if (sensor_info[s].thread_data_fd[1] == -1)
382 ALOGV("\tfield %d: %f\n", c, data.data[c]);
386 /* If the sample looks good */
387 if (sensor_info[s].ops.finalize(s, &data)) {
389 /* Pipe it for transmission to poll loop */
390 ret = write( sensor_info[s].thread_data_fd[1],
392 num_fields * sizeof(float));
395 /* Check and honor termination requests */
396 if (sensor_info[s].thread_data_fd[1] == -1)
400 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
402 time_add(&target_time, &entry_time, period);
405 * Wait until the sampling time elapses, or a rate change is
406 * signaled, or a thread exit is requested.
408 ret = pthread_cond_timedwait( &thread_release_cond[s],
409 &thread_release_mutex[s],
412 /* Check and honor termination requests */
413 if (sensor_info[s].thread_data_fd[1] == -1)
418 ALOGV("Acquisition thread for S%d exiting\n", s);
419 pthread_mutex_unlock(&thread_release_mutex[s]);
425 static void start_acquisition_thread (int s)
427 int incoming_data_fd;
430 struct epoll_event ev = {0};
432 ALOGV("Initializing acquisition context for sensor %d\n", s);
434 /* Create condition variable and mutex for quick thread release */
435 ret = pthread_cond_init(&thread_release_cond[s], NULL);
436 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
438 /* Create a pipe for inter thread communication */
439 ret = pipe(sensor_info[s].thread_data_fd);
441 incoming_data_fd = sensor_info[s].thread_data_fd[0];
444 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
446 /* Add incoming side of pipe to our poll set, with a suitable tag */
447 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
449 /* Create and start worker thread */
450 ret = pthread_create( &sensor_info[s].acquisition_thread,
457 static void stop_acquisition_thread (int s)
459 int incoming_data_fd = sensor_info[s].thread_data_fd[0];
460 int outgoing_data_fd = sensor_info[s].thread_data_fd[1];
462 ALOGV("Tearing down acquisition context for sensor %d\n", s);
464 /* Delete the incoming side of the pipe from our poll set */
465 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
467 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
468 sensor_info[s].thread_data_fd[0] = -1;
469 sensor_info[s].thread_data_fd[1] = -1;
471 /* Close both sides of our pipe */
472 close(incoming_data_fd);
473 close(outgoing_data_fd);
475 /* Stop acquisition thread and clean up thread handle */
476 pthread_cond_signal(&thread_release_cond[s]);
477 pthread_join(sensor_info[s].acquisition_thread, NULL);
479 /* Clean up our sensor descriptor */
480 sensor_info[s].acquisition_thread = -1;
482 /* Delete condition variable and mutex */
483 pthread_cond_destroy(&thread_release_cond[s]);
484 pthread_mutex_destroy(&thread_release_mutex[s]);
488 int sensor_activate(int s, int enabled)
490 char device_name[PATH_MAX];
491 struct epoll_event ev = {0};
494 int dev_num = sensor_info[s].dev_num;
495 int is_poll_sensor = !sensor_info[s].num_channels;
497 /* If we want to activate gyro calibrated and gyro uncalibrated is activated
498 * Deactivate gyro uncalibrated - Uncalibrated releases handler
499 * Activate gyro calibrated - Calibrated has handler
500 * Reactivate gyro uncalibrated - Uncalibrated gets data from calibrated */
502 /* If we want to deactivate gyro calibrated and gyro uncalibrated is active
503 * Deactivate gyro uncalibrated - Uncalibrated no longer gets data from handler
504 * Deactivate gyro calibrated - Calibrated releases handler
505 * Reactivate gyro uncalibrated - Uncalibrated has handler */
507 if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
508 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
510 sensor_activate(sensor_info[s].pair_idx, 0);
511 ret = sensor_activate(s, enabled);
512 sensor_activate(sensor_info[s].pair_idx, 1);
516 ret = adjust_counters(s, enabled);
518 /* If the operation was neutral in terms of state, we're done */
523 if (!is_poll_sensor) {
526 enable_buffer(dev_num, 0);
527 setup_trigger(dev_num, "\n");
529 /* If there's at least one sensor enabled on this iio device */
530 if (trig_sensors_per_dev[dev_num]) {
533 setup_trigger(dev_num, sensor_info[s].trigger_name);
534 enable_buffer(dev_num, 1);
539 * Make sure we have a fd on the character device ; conversely, close
540 * the fd if no one is using associated sensors anymore. The assumption
541 * here is that the underlying driver will power on the relevant
542 * hardware block while someone holds a fd on the device.
544 dev_fd = device_fd[dev_num];
548 stop_acquisition_thread(s);
550 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
551 !trig_sensors_per_dev[dev_num]) {
553 * Stop watching this fd. This should be a no-op
554 * in case this fd was not in the poll set.
556 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
559 device_fd[dev_num] = -1;
565 /* First enabled sensor on this iio device */
566 sprintf(device_name, DEV_FILE_PATH, dev_num);
567 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
569 device_fd[dev_num] = dev_fd;
572 ALOGE("Could not open fd on %s (%s)\n",
573 device_name, strerror(errno));
574 adjust_counters(s, 0);
578 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
580 if (!is_poll_sensor) {
582 /* Add this iio device fd to the set of watched fds */
584 ev.data.u32 = dev_num;
586 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
589 ALOGE( "Failed adding %d to poll set (%s)\n",
590 dev_fd, strerror(errno));
594 /* Note: poll-mode fds are not readable */
598 /* Ensure that on-change sensors send at least one event after enable */
599 sensor_info[s].prev_val = -1;
602 start_acquisition_thread(s);
608 static int integrate_device_report(int dev_num)
612 unsigned char buf[MAX_SENSOR_REPORT_SIZE] = { 0 };
613 unsigned char previous_report[MAX_SENSOR_REPORT_SIZE];
615 unsigned char *target;
616 unsigned char *source;
620 /* There's an incoming report on the specified iio device char dev fd */
622 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
623 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
627 if (device_fd[dev_num] == -1) {
628 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
632 ts = get_timestamp();
634 len = read(device_fd[dev_num], buf, MAX_SENSOR_REPORT_SIZE);
637 ALOGE("Could not read report from iio device %d (%s)\n",
638 dev_num, strerror(errno));
642 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
644 /* Map device report to sensor reports */
646 for (s=0; s<MAX_SENSORS; s++)
647 if (sensor_info[s].dev_num == dev_num &&
648 sensor_info[s].enable_count) {
652 /* Copy data from device to sensor report buffer */
653 for (c=0; c<sensor_info[s].num_channels; c++) {
655 target = sensor_info[s].report_buffer +
658 source = buf + sensor_info[s].channel[c].offset;
660 size = sensor_info[s].channel[c].size;
662 memcpy(target, source, size);
667 ALOGV("Sensor %d report available (%d bytes)\n", s,
670 sensor_info[s].report_ts = ts;
671 sensor_info[s].report_pending = 1;
672 sensor_info[s].report_initialized = 1;
679 static int propagate_sensor_report(int s, struct sensors_event_t *data)
681 /* There's a sensor report pending for this sensor ; transmit it */
683 int catalog_index = sensor_info[s].catalog_index;
684 int sensor_type = sensor_catalog[catalog_index].type;
685 int num_fields = get_field_count(s);
687 unsigned char* current_sample;
689 /* If there's nothing to return... we're done */
694 /* Only return uncalibrated event if also gyro active */
695 if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
696 sensor_info[sensor_info[s].pair_idx].enable_count != 0)
699 memset(data, 0, sizeof(sensors_event_t));
701 data->version = sizeof(sensors_event_t);
703 data->type = sensor_type;
704 data->timestamp = sensor_info[s].report_ts;
706 ALOGV("Sample on sensor %d (type %d):\n", s, sensor_type);
708 current_sample = sensor_info[s].report_buffer;
710 /* If this is a poll sensor */
711 if (!sensor_info[s].num_channels) {
712 /* Use the data provided by the acquisition thread */
713 ALOGV("Reporting data from worker thread for S%d\n", s);
714 memcpy(data->data, current_sample, num_fields * sizeof(float));
718 /* Convert the data into the expected Android-level format */
719 for (c=0; c<num_fields; c++) {
721 data->data[c] = sensor_info[s].ops.transform
722 (s, c, current_sample);
724 ALOGV("\tfield %d: %f\n", c, data->data[c]);
725 current_sample += sensor_info[s].channel[c].size;
729 * The finalize routine, in addition to its late sample processing duty,
730 * has the final say on whether or not the sample gets sent to Android.
732 return sensor_info[s].ops.finalize(s, data);
736 static void synthetize_duplicate_samples (void)
739 * Some sensor types (ex: gyroscope) are defined as continuously firing
740 * by Android, despite the fact that we can be dealing with iio drivers
741 * that only report events for new samples. For these we generate
742 * reports periodically, duplicating the last data we got from the
743 * driver. This is not necessary for polling sensors.
751 for (s=0; s<sensor_count; s++) {
753 /* Ignore disabled sensors */
754 if (!sensor_info[s].enable_count)
757 /* If the sensor can generate duplicates, leave it alone */
758 if (!(sensor_info[s].quirks & QUIRK_TERSE_DRIVER))
761 /* If we haven't seen a sample, there's nothing to duplicate */
762 if (!sensor_info[s].report_initialized)
765 /* If a sample was recently buffered, leave it alone too */
766 if (sensor_info[s].report_pending)
769 /* We also need a valid sampling rate to be configured */
770 if (!sensor_info[s].sampling_rate)
773 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
775 current_ts = get_timestamp();
776 target_ts = sensor_info[s].report_ts + period;
778 if (target_ts <= current_ts) {
779 /* Mark the sensor for event generation */
780 sensor_info[s].report_ts = current_ts;
781 sensor_info[s].report_pending = 1;
787 static void integrate_thread_report (uint32_t tag)
789 int s = tag - THREAD_REPORT_TAG_BASE;
793 expected_len = get_field_count(s) * sizeof(float);
795 len = read(sensor_info[s].thread_data_fd[0],
796 sensor_info[s].report_buffer,
799 if (len == expected_len) {
800 sensor_info[s].report_ts = get_timestamp();
801 sensor_info[s].report_pending = 1;
806 static int get_poll_wait_timeout (void)
809 * Compute an appropriate timeout value, in ms, for the epoll_wait
810 * call that's going to await for iio device reports and incoming
811 * reports from our sensor sysfs data reader threads.
815 int64_t target_ts = INT64_MAX;
820 * Check if have have to deal with "terse" drivers that only send events
821 * when there is motion, despite the fact that the associated Android
822 * sensor type is continuous rather than on-change. In that case we have
823 * to duplicate events. Check deadline for the nearest upcoming event.
825 for (s=0; s<sensor_count; s++)
826 if (sensor_info[s].enable_count &&
827 (sensor_info[s].quirks & QUIRK_TERSE_DRIVER) &&
828 sensor_info[s].sampling_rate) {
829 period = (int64_t) (1000000000.0 /
830 sensor_info[s].sampling_rate);
832 if (sensor_info[s].report_ts + period < target_ts)
833 target_ts = sensor_info[s].report_ts + period;
836 /* If we don't have such a driver to deal with */
837 if (target_ts == INT64_MAX)
838 return -1; /* Infinite wait */
840 ms_to_wait = (target_ts - get_timestamp()) / 1000000;
842 /* If the target timestamp is already behind us, don't wait */
850 int sensor_poll(struct sensors_event_t* data, int count)
855 struct epoll_event ev[MAX_DEVICES];
859 /* Get one or more events from our collection of sensors */
861 return_available_sensor_reports:
865 /* Check our sensor collection for available reports */
866 for (s=0; s<sensor_count && returned_events < count; s++)
867 if (sensor_info[s].report_pending) {
870 sensor_info[s].report_pending = 0;
872 /* Report this event if it looks OK */
873 event_count = propagate_sensor_report(s, &data[returned_events]);
875 /* Duplicate only if both cal & uncal are active */
876 if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
877 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
878 struct gyro_cal* gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
880 memcpy(&data[returned_events + event_count], &data[returned_events],
881 sizeof(struct sensors_event_t) * event_count);
882 for (i = 0; i < event_count; i++) {
883 data[returned_events + i].type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
884 data[returned_events + i].sensor = sensor_info[s].pair_idx;
886 data[returned_events + i].data[0] = data[returned_events + i].data[0] + gyro_data->bias[0];
887 data[returned_events + i].data[1] = data[returned_events + i].data[1] + gyro_data->bias[1];
888 data[returned_events + i].data[2] = data[returned_events + i].data[2] + gyro_data->bias[2];
890 data[returned_events + i].uncalibrated_gyro.bias[0] = gyro_data->bias[0];
891 data[returned_events + i].uncalibrated_gyro.bias[1] = gyro_data->bias[1];
892 data[returned_events + i].uncalibrated_gyro.bias[2] = gyro_data->bias[2];
896 sensor_info[sensor_info[s].pair_idx].report_pending = 0;
897 returned_events += event_count;
899 * If the sample was deemed invalid or unreportable,
900 * e.g. had the same value as the previously reported
901 * value for a 'on change' sensor, silently drop it.
906 return returned_events;
910 ALOGV("Awaiting sensor data\n");
912 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
915 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
919 /* Synthetize duplicate samples if needed */
920 synthetize_duplicate_samples();
922 ALOGV("%d fds signalled\n", nfds);
924 /* For each of the signalled sources */
925 for (i=0; i<nfds; i++)
926 if (ev[i].events == EPOLLIN)
927 switch (ev[i].data.u32) {
928 case 0 ... MAX_DEVICES-1:
929 /* Read report from iio char dev fd */
930 integrate_device_report(ev[i].data.u32);
933 case THREAD_REPORT_TAG_BASE ...
934 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
935 /* Get report from acquisition thread */
936 integrate_thread_report(ev[i].data.u32);
940 ALOGW("Unexpected event source!\n");
944 goto return_available_sensor_reports;
948 int sensor_set_delay(int s, int64_t ns)
950 /* Set the rate at which a specific sensor should report events */
952 /* See Android sensors.h for indication on sensor trigger modes */
954 char sysfs_path[PATH_MAX];
955 char avail_sysfs_path[PATH_MAX];
956 int dev_num = sensor_info[s].dev_num;
957 int i = sensor_info[s].catalog_index;
958 const char *prefix = sensor_catalog[i].tag;
959 float new_sampling_rate; /* Granted sampling rate after arbitration */
960 float cur_sampling_rate; /* Currently used sampling rate */
961 int per_sensor_sampling_rate;
962 int per_device_sampling_rate;
963 float max_supported_rate = 0;
970 ALOGE("Rejecting zero delay request on sensor %d\n", s);
974 new_sampling_rate = 1000000000LL/ns;
977 * Artificially limit ourselves to 1 Hz or higher. This is mostly to
978 * avoid setting up the stage for divisions by zero.
980 if (new_sampling_rate < 1)
981 new_sampling_rate = 1;
983 sensor_info[s].sampling_rate = new_sampling_rate;
985 /* If we're dealing with a poll-mode sensor */
986 if (!sensor_info[s].num_channels) {
987 /* Interrupt current sleep so the new sampling gets used */
988 pthread_cond_signal(&thread_release_cond[s]);
992 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
994 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
995 per_sensor_sampling_rate = 1;
996 per_device_sampling_rate = 0;
998 per_sensor_sampling_rate = 0;
1000 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
1002 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
1003 per_device_sampling_rate = 1;
1005 per_device_sampling_rate = 0;
1008 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
1009 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
1013 /* Coordinate with others active sensors on the same device, if any */
1014 if (per_device_sampling_rate)
1015 for (n=0; n<sensor_count; n++)
1016 if (n != s && sensor_info[n].dev_num == dev_num &&
1017 sensor_info[n].num_channels &&
1018 sensor_info[n].enable_count &&
1019 sensor_info[n].sampling_rate > new_sampling_rate)
1020 new_sampling_rate= sensor_info[n].sampling_rate;
1022 /* Check if we have contraints on allowed sampling rates */
1024 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
1026 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
1029 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
1031 /* While we're not at the end of the string */
1032 while (*cursor && cursor[0]) {
1034 /* Decode a single value */
1035 sr = strtod(cursor, NULL);
1037 if (sr > max_supported_rate)
1038 max_supported_rate = sr;
1040 /* If this matches the selected rate, we're happy */
1041 if (new_sampling_rate == sr)
1045 * If we reached a higher value than the desired rate,
1046 * adjust selected rate so it matches the first higher
1047 * available one and stop parsing - this makes the
1048 * assumption that rates are sorted by increasing value
1049 * in the allowed frequencies string.
1051 if (sr > new_sampling_rate) {
1052 new_sampling_rate = sr;
1057 while (cursor[0] && !isspace(cursor[0]))
1061 while (cursor[0] && isspace(cursor[0]))
1067 if (max_supported_rate &&
1068 new_sampling_rate > max_supported_rate) {
1069 new_sampling_rate = max_supported_rate;
1073 /* If the desired rate is already active we're all set */
1074 if (new_sampling_rate == cur_sampling_rate)
1077 ALOGI("Sensor %d sampling rate set to %g\n", s, new_sampling_rate);
1079 if (trig_sensors_per_dev[dev_num])
1080 enable_buffer(dev_num, 0);
1082 sysfs_write_float(sysfs_path, new_sampling_rate);
1084 if (trig_sensors_per_dev[dev_num])
1085 enable_buffer(dev_num, 1);
1091 int allocate_control_data (void)
1095 for (i=0; i<MAX_DEVICES; i++)
1098 poll_fd = epoll_create(MAX_DEVICES);
1100 if (poll_fd == -1) {
1101 ALOGE("Can't create epoll instance for iio sensors!\n");
1109 void delete_control_data (void)