2 * Copyright (C) 2014 Intel Corporation.
10 #include <sys/epoll.h>
11 #include <sys/socket.h>
12 #include <utils/Log.h>
13 #include <hardware/sensors.h>
15 #include "enumeration.h"
17 #include "transform.h"
18 #include "calibration.h"
19 #include "description.h"
21 /* Currently active sensors count, per device */
22 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
23 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
25 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
27 static int poll_fd; /* epoll instance covering all enabled sensors */
29 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
31 /* We use pthread condition variables to get worker threads out of sleep */
32 static pthread_cond_t thread_release_cond [MAX_SENSORS];
33 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
36 * We associate tags to each of our poll set entries. These tags have the
38 * - a iio device number if the fd is a iio character device fd
39 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a
40 * pipe used by a sysfs data acquisition thread
42 #define THREAD_REPORT_TAG_BASE 0x00010000
44 /* When polling try to compensate for the iio overhead in
45 * order to try to get a frequency closer to the advertised one
47 #define OVERHEAD_THRESHOLD 0.97
48 #define ENABLE_BUFFER_RETRIES 10
49 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
51 static int enable_buffer(int dev_num, int enabled)
53 char sysfs_path[PATH_MAX];
54 int ret, retries, millisec;
55 struct timespec req = {0};
57 retries = ENABLE_BUFFER_RETRIES;
58 millisec = ENABLE_BUFFER_RETRY_DELAY_MS;
60 req.tv_nsec = millisec * 1000000L;
62 sprintf(sysfs_path, ENABLE_PATH, dev_num);
65 /* Low level, non-multiplexed, enable/disable routine */
66 ret = sysfs_write_int(sysfs_path, enabled);
70 ALOGE("Failed enabling buffer, retrying");
71 nanosleep(&req, (struct timespec *)NULL);
75 ALOGE("Could not enable buffer\n");
83 static void setup_trigger (int s, const char* trigger_val)
85 char sysfs_path[PATH_MAX];
87 sprintf(sysfs_path, TRIGGER_PATH, sensor_info[s].dev_num);
89 if (trigger_val[0] != '\n')
90 ALOGI("Setting S%d (%s) trigger to %s\n", s,
91 sensor_info[s].friendly_name, trigger_val);
93 sysfs_write_str(sysfs_path, trigger_val);
95 sensor_info[s].selected_trigger = trigger_val;
99 void build_sensor_report_maps(int dev_num)
102 * Read sysfs files from a iio device's scan_element directory, and
103 * build a couple of tables from that data. These tables will tell, for
104 * each sensor, where to gather relevant data in a device report, i.e.
105 * the structure that we read from the /dev/iio:deviceX file in order to
106 * sensor report, itself being the data that we return to Android when a
107 * sensor poll completes. The mapping should be straightforward in the
108 * case where we have a single sensor active per iio device but, this is
109 * not the general case. In general several sensors can be handled
110 * through a single iio device, and the _en, _index and _type syfs
111 * entries all concur to paint a picture of what the structure of the
121 char spec_buf[MAX_TYPE_SPEC_LEN];
122 struct datum_info_t* ch_info;
124 char sysfs_path[PATH_MAX];
127 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
128 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
129 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
133 /* For each sensor that is linked to this device */
134 for (s=0; s<sensor_count; s++) {
135 if (sensor_info[s].dev_num != dev_num)
138 i = sensor_info[s].catalog_index;
140 /* Read channel details through sysfs attributes */
141 for (c=0; c<sensor_info[s].num_channels; c++) {
143 /* Read _type file */
144 sprintf(sysfs_path, CHANNEL_PATH "%s",
145 sensor_info[s].dev_num,
146 sensor_catalog[i].channel[c].type_path);
148 n = sysfs_read_str(sysfs_path, spec_buf,
152 ALOGW( "Failed to read type: %s\n",
157 ch_spec = sensor_info[s].channel[c].type_spec;
159 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
161 ch_info = &sensor_info[s].channel[c].type_info;
163 size = decode_type_spec(ch_spec, ch_info);
165 /* Read _index file */
166 sprintf(sysfs_path, CHANNEL_PATH "%s",
167 sensor_info[s].dev_num,
168 sensor_catalog[i].channel[c].index_path);
170 n = sysfs_read_int(sysfs_path, &ch_index);
173 ALOGW( "Failed to read index: %s\n",
178 if (ch_index >= MAX_SENSORS) {
179 ALOGE("Index out of bounds!: %s\n", sysfs_path);
183 /* Record what this index is about */
185 sensor_handle_from_index [ch_index] = s;
186 channel_number_from_index[ch_index] = c;
187 channel_size_from_index [ch_index] = size;
192 /* Stop sampling - if we are recovering from hal restart */
193 enable_buffer(dev_num, 0);
194 setup_trigger(s, "\n");
196 /* Turn on channels we're aware of */
197 for (c=0;c<sensor_info[s].num_channels; c++) {
198 sprintf(sysfs_path, CHANNEL_PATH "%s",
199 sensor_info[s].dev_num,
200 sensor_catalog[i].channel[c].en_path);
201 sysfs_write_int(sysfs_path, 1);
205 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
208 * Now that we know which channels are defined, their sizes and their
209 * ordering, update channels offsets within device report. Note: there
210 * is a possibility that several sensors share the same index, with
211 * their data fields being isolated by masking and shifting as specified
212 * through the real bits and shift values in type attributes. This case
213 * is not currently supported. Also, the code below assumes no hole in
214 * the sequence of indices, so it is dependent on discovery of all
218 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
219 s = sensor_handle_from_index[i];
220 c = channel_number_from_index[i];
221 size = channel_size_from_index[i];
226 ALOGI("S%d C%d : offset %d, size %d, type %s\n",
227 s, c, offset, size, sensor_info[s].channel[c].type_spec);
229 sensor_info[s].channel[c].offset = offset;
230 sensor_info[s].channel[c].size = size;
237 int adjust_counters (int s, int enabled)
240 * Adjust counters based on sensor enable action. Return values are:
241 * -1 if there's an inconsistency: abort action in this case
242 * 0 if the operation was completed and we're all set
243 * 1 if we toggled the state of the sensor and there's work left
246 int dev_num = sensor_info[s].dev_num;
247 int catalog_index = sensor_info[s].catalog_index;
248 int sensor_type = sensor_catalog[catalog_index].type;
250 /* Refcount per sensor, in terms of enable count */
252 ALOGI("Enabling sensor %d (iio device %d: %s)\n",
253 s, dev_num, sensor_info[s].friendly_name);
255 sensor_info[s].enable_count++;
257 if (sensor_info[s].enable_count > 1)
258 return 0; /* The sensor was, and remains, in use */
260 switch (sensor_type) {
261 case SENSOR_TYPE_MAGNETIC_FIELD:
262 compass_read_data(&sensor_info[s]);
265 case SENSOR_TYPE_GYROSCOPE:
266 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
267 gyro_cal_init(&sensor_info[s]);
271 if (sensor_info[s].enable_count == 0)
272 return -1; /* Spurious disable call */
274 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
275 sensor_info[s].friendly_name);
277 sensor_info[s].enable_count--;
279 if (sensor_info[s].enable_count > 0)
280 return 0; /* The sensor was, and remains, in use */
282 /* Sensor disabled, lower report available flag */
283 sensor_info[s].report_pending = 0;
285 if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
286 compass_store_data(&sensor_info[s]);
290 /* If uncalibrated type and pair is already active don't adjust counters */
291 if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
292 sensor_info[sensor_info[s].pair_idx].enable_count != 0)
295 /* We changed the state of a sensor - adjust per iio device counters */
297 /* If this is a regular event-driven sensor */
298 if (sensor_info[s].num_channels) {
301 trig_sensors_per_dev[dev_num]++;
303 trig_sensors_per_dev[dev_num]--;
309 active_poll_sensors++;
310 poll_sensors_per_dev[dev_num]++;
314 active_poll_sensors--;
315 poll_sensors_per_dev[dev_num]--;
320 static int get_field_count (int s)
322 int catalog_index = sensor_info[s].catalog_index;
323 int sensor_type = sensor_catalog[catalog_index].type;
325 switch (sensor_type) {
326 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
327 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
328 case SENSOR_TYPE_ORIENTATION: /* degrees */
329 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
330 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
333 case SENSOR_TYPE_LIGHT: /* SI lux units */
334 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
335 case SENSOR_TYPE_TEMPERATURE: /* °C */
336 case SENSOR_TYPE_PROXIMITY: /* centimeters */
337 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
338 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
341 case SENSOR_TYPE_ROTATION_VECTOR:
345 ALOGE("Unknown sensor type!\n");
346 return 0; /* Drop sample */
351 static void time_add(struct timespec *out, struct timespec *in, int64_t ns)
353 int64_t target_ts = 1000000000LL * in->tv_sec + in->tv_nsec + ns;
355 out->tv_sec = target_ts / 1000000000;
356 out->tv_nsec = target_ts % 1000000000;
360 static void* acquisition_routine (void* param)
363 * Data acquisition routine run in a dedicated thread, covering a single
364 * sensor. This loop will periodically retrieve sampling data through
365 * sysfs, then package it as a sample and transfer it to our master poll
366 * loop through a report fd. Checks for a cancellation signal quite
367 * frequently, as the thread may be disposed of at any time. Note that
368 * Bionic does not provide pthread_cancel / pthread_testcancel...
371 int s = (int) (size_t) param;
373 struct sensors_event_t data = {0};
376 struct timespec entry_time;
377 struct timespec target_time;
380 ALOGI("Entering data acquisition thread S%d (%s): rate(%f), minDelay(%ld), maxDelay(%ld)\n",
381 s, sensor_info[s].friendly_name, sensor_info[s].sampling_rate,
382 sensor_desc[s].minDelay, sensor_desc[s].maxDelay);
384 if (s < 0 || s >= sensor_count) {
385 ALOGE("Invalid sensor handle!\n");
389 if (!sensor_info[s].sampling_rate) {
390 ALOGE("Zero rate in acquisition routine for sensor %d\n", s);
394 num_fields = get_field_count(s);
397 * Each condition variable is associated to a mutex that has to be
398 * locked by the thread that's waiting on it. We use these condition
399 * variables to get the acquisition threads out of sleep quickly after
400 * the sampling rate is adjusted, or the sensor is disabled.
402 pthread_mutex_lock(&thread_release_mutex[s]);
405 /* Pinpoint the moment we start sampling */
406 clock_gettime(CLOCK_REALTIME, &entry_time);
408 ALOGV("Acquiring sample data for sensor %d through sysfs\n", s);
410 /* Read values through sysfs */
411 for (c=0; c<num_fields; c++) {
412 data.data[c] = acquire_immediate_value(s, c);
414 /* Check and honor termination requests */
415 if (sensor_info[s].thread_data_fd[1] == -1)
418 ALOGV("\tfield %d: %f\n", c, data.data[c]);
422 /* If the sample looks good */
423 if (sensor_info[s].ops.finalize(s, &data)) {
425 /* Pipe it for transmission to poll loop */
426 ret = write( sensor_info[s].thread_data_fd[1],
428 num_fields * sizeof(float));
431 /* Check and honor termination requests */
432 if (sensor_info[s].thread_data_fd[1] == -1)
436 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
437 period = period * OVERHEAD_THRESHOLD;
438 time_add(&target_time, &entry_time, period);
441 * Wait until the sampling time elapses, or a rate change is
442 * signaled, or a thread exit is requested.
444 ret = pthread_cond_timedwait( &thread_release_cond[s],
445 &thread_release_mutex[s],
448 /* Check and honor termination requests */
449 if (sensor_info[s].thread_data_fd[1] == -1)
454 ALOGV("Acquisition thread for S%d exiting\n", s);
455 pthread_mutex_unlock(&thread_release_mutex[s]);
461 static void start_acquisition_thread (int s)
463 int incoming_data_fd;
466 struct epoll_event ev = {0};
468 ALOGV("Initializing acquisition context for sensor %d\n", s);
470 /* Create condition variable and mutex for quick thread release */
471 ret = pthread_cond_init(&thread_release_cond[s], NULL);
472 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
474 /* Create a pipe for inter thread communication */
475 ret = pipe(sensor_info[s].thread_data_fd);
477 incoming_data_fd = sensor_info[s].thread_data_fd[0];
480 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
482 /* Add incoming side of pipe to our poll set, with a suitable tag */
483 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
485 /* Create and start worker thread */
486 ret = pthread_create( &sensor_info[s].acquisition_thread,
493 static void stop_acquisition_thread (int s)
495 int incoming_data_fd = sensor_info[s].thread_data_fd[0];
496 int outgoing_data_fd = sensor_info[s].thread_data_fd[1];
498 ALOGV("Tearing down acquisition context for sensor %d\n", s);
500 /* Delete the incoming side of the pipe from our poll set */
501 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
503 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
504 sensor_info[s].thread_data_fd[0] = -1;
505 sensor_info[s].thread_data_fd[1] = -1;
507 /* Close both sides of our pipe */
508 close(incoming_data_fd);
509 close(outgoing_data_fd);
511 /* Stop acquisition thread and clean up thread handle */
512 pthread_cond_signal(&thread_release_cond[s]);
513 pthread_join(sensor_info[s].acquisition_thread, NULL);
515 /* Clean up our sensor descriptor */
516 sensor_info[s].acquisition_thread = -1;
518 /* Delete condition variable and mutex */
519 pthread_cond_destroy(&thread_release_cond[s]);
520 pthread_mutex_destroy(&thread_release_mutex[s]);
524 int sensor_activate(int s, int enabled)
526 char device_name[PATH_MAX];
527 struct epoll_event ev = {0};
530 int dev_num = sensor_info[s].dev_num;
531 int is_poll_sensor = !sensor_info[s].num_channels;
533 /* Prepare the report timestamp field for the first event, see set_report_ts method */
534 sensor_info[s].report_ts = 0;
536 /* If we want to activate gyro calibrated and gyro uncalibrated is activated
537 * Deactivate gyro uncalibrated - Uncalibrated releases handler
538 * Activate gyro calibrated - Calibrated has handler
539 * Reactivate gyro uncalibrated - Uncalibrated gets data from calibrated */
541 /* If we want to deactivate gyro calibrated and gyro uncalibrated is active
542 * Deactivate gyro uncalibrated - Uncalibrated no longer gets data from handler
543 * Deactivate gyro calibrated - Calibrated releases handler
544 * Reactivate gyro uncalibrated - Uncalibrated has handler */
546 if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
547 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
549 sensor_activate(sensor_info[s].pair_idx, 0);
550 ret = sensor_activate(s, enabled);
551 sensor_activate(sensor_info[s].pair_idx, 1);
555 ret = adjust_counters(s, enabled);
557 /* If the operation was neutral in terms of state, we're done */
562 if (!is_poll_sensor) {
565 enable_buffer(dev_num, 0);
566 setup_trigger(s, "\n");
568 /* If there's at least one sensor enabled on this iio device */
569 if (trig_sensors_per_dev[dev_num]) {
572 setup_trigger(s, sensor_info[s].init_trigger_name);
573 enable_buffer(dev_num, 1);
578 * Make sure we have a fd on the character device ; conversely, close
579 * the fd if no one is using associated sensors anymore. The assumption
580 * here is that the underlying driver will power on the relevant
581 * hardware block while someone holds a fd on the device.
583 dev_fd = device_fd[dev_num];
587 stop_acquisition_thread(s);
589 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
590 !trig_sensors_per_dev[dev_num]) {
592 * Stop watching this fd. This should be a no-op
593 * in case this fd was not in the poll set.
595 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
598 device_fd[dev_num] = -1;
601 /* If we recorded a trail of samples for filtering, delete it */
602 if (sensor_info[s].history) {
603 free(sensor_info[s].history);
604 sensor_info[s].history = NULL;
605 sensor_info[s].history_size = 0;
606 if (sensor_info[s].history_sum) {
607 free(sensor_info[s].history_sum);
608 sensor_info[s].history_sum = NULL;
616 /* First enabled sensor on this iio device */
617 sprintf(device_name, DEV_FILE_PATH, dev_num);
618 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
620 device_fd[dev_num] = dev_fd;
623 ALOGE("Could not open fd on %s (%s)\n",
624 device_name, strerror(errno));
625 adjust_counters(s, 0);
629 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
631 if (!is_poll_sensor) {
633 /* Add this iio device fd to the set of watched fds */
635 ev.data.u32 = dev_num;
637 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
640 ALOGE( "Failed adding %d to poll set (%s)\n",
641 dev_fd, strerror(errno));
645 /* Note: poll-mode fds are not readable */
649 /* Ensure that on-change sensors send at least one event after enable */
650 sensor_info[s].prev_val = -1;
653 start_acquisition_thread(s);
659 static int is_fast_accelerometer (int s)
662 * Some games don't react well to accelerometers using any-motion
663 * triggers. Even very low thresholds seem to trip them, and they tend
664 * to request fairly high event rates. Favor continuous triggers if the
665 * sensor is an accelerometer and uses a sampling rate of at least 25.
667 int catalog_index = sensor_info[s].catalog_index;
669 if (sensor_catalog[catalog_index].type != SENSOR_TYPE_ACCELEROMETER)
672 if (sensor_info[s].sampling_rate < 25)
679 static void enable_motion_trigger (int dev_num)
682 * In the ideal case, we enumerate two triggers per iio device ; the
683 * default (periodically firing) trigger, and another one (the motion
684 * trigger) that only fires up when motion is detected. This second one
685 * allows for lesser energy consumption, but requires periodic sample
686 * duplication at the HAL level for sensors that Android defines as
687 * continuous. This "duplicate last sample" logic can only be engaged
688 * once we got a first sample for the driver, so we start with the
689 * default trigger when an iio device is first opened, then adjust the
690 * trigger when we got events for all active sensors. Unfortunately in
691 * the general case several sensors can be associated to a given iio
692 * device, they can independently be controlled, and we have to adjust
693 * the trigger in use at the iio device level depending on whether or
694 * not appropriate conditions are met at the sensor level.
699 int active_sensors = trig_sensors_per_dev[dev_num];
700 int candidate[MAX_SENSORS];
701 int candidate_count = 0;
706 /* Check that all active sensors are ready to switch */
708 for (s=0; s<MAX_SENSORS; s++)
709 if (sensor_info[s].dev_num == dev_num &&
710 sensor_info[s].enable_count &&
711 sensor_info[s].num_channels &&
712 (!sensor_info[s].motion_trigger_name[0] ||
713 !sensor_info[s].report_initialized ||
714 is_fast_accelerometer(s))
718 /* Record which particular sensors need to switch */
720 for (s=0; s<MAX_SENSORS; s++)
721 if (sensor_info[s].dev_num == dev_num &&
722 sensor_info[s].enable_count &&
723 sensor_info[s].num_channels &&
724 !(sensor_info[s].quirks & QUIRK_CONTINUOUS_DRIVER) &&
725 sensor_info[s].selected_trigger !=
726 sensor_info[s].motion_trigger_name)
727 candidate[candidate_count++] = s;
729 if (!candidate_count)
732 /* Now engage the motion trigger for sensors which aren't using it */
734 enable_buffer(dev_num, 0);
736 for (i=0; i<candidate_count; i++) {
738 setup_trigger(s, sensor_info[s].motion_trigger_name);
741 enable_buffer(dev_num, 1);
744 void set_report_ts(int s, int64_t ts)
746 int64_t maxTs, period;
749 * A bit of a hack to please a bunch of cts tests. They
750 * expect the timestamp to be exacly according to the set-up
751 * frequency but if we're simply getting the timestamp at hal level
752 * this may not be the case. Perhaps we'll get rid of this when
753 * we'll be reading the timestamp from the iio channel for all sensors
755 if (sensor_info[s].report_ts && sensor_info[s].sampling_rate &&
756 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
758 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
759 maxTs = sensor_info[s].report_ts + period;
760 sensor_info[s].report_ts = (ts < maxTs ? ts : maxTs);
762 sensor_info[s].report_ts = ts;
766 static int integrate_device_report(int dev_num)
770 unsigned char buf[MAX_SENSOR_REPORT_SIZE] = { 0 };
772 unsigned char *target;
773 unsigned char *source;
777 /* There's an incoming report on the specified iio device char dev fd */
779 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
780 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
784 if (device_fd[dev_num] == -1) {
785 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
789 ts = get_timestamp();
791 len = read(device_fd[dev_num], buf, MAX_SENSOR_REPORT_SIZE);
794 ALOGE("Could not read report from iio device %d (%s)\n",
795 dev_num, strerror(errno));
799 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
801 /* Map device report to sensor reports */
803 for (s=0; s<MAX_SENSORS; s++)
804 if (sensor_info[s].dev_num == dev_num &&
805 sensor_info[s].enable_count) {
809 /* Copy data from device to sensor report buffer */
810 for (c=0; c<sensor_info[s].num_channels; c++) {
812 target = sensor_info[s].report_buffer +
815 source = buf + sensor_info[s].channel[c].offset;
817 size = sensor_info[s].channel[c].size;
819 memcpy(target, source, size);
824 ALOGV("Sensor %d report available (%d bytes)\n", s,
827 set_report_ts(s, ts);
828 sensor_info[s].report_pending = 1;
829 sensor_info[s].report_initialized = 1;
832 /* Tentatively switch to an any-motion trigger if conditions are met */
833 enable_motion_trigger(dev_num);
839 static int propagate_sensor_report(int s, struct sensors_event_t *data)
841 /* There's a sensor report pending for this sensor ; transmit it */
843 int catalog_index = sensor_info[s].catalog_index;
844 int sensor_type = sensor_catalog[catalog_index].type;
845 int num_fields = get_field_count(s);
847 unsigned char* current_sample;
849 /* If there's nothing to return... we're done */
854 /* Only return uncalibrated event if also gyro active */
855 if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
856 sensor_info[sensor_info[s].pair_idx].enable_count != 0)
859 memset(data, 0, sizeof(sensors_event_t));
861 data->version = sizeof(sensors_event_t);
863 data->type = sensor_type;
864 data->timestamp = sensor_info[s].report_ts;
866 ALOGV("Sample on sensor %d (type %d):\n", s, sensor_type);
868 current_sample = sensor_info[s].report_buffer;
870 /* If this is a poll sensor */
871 if (!sensor_info[s].num_channels) {
872 /* Use the data provided by the acquisition thread */
873 ALOGV("Reporting data from worker thread for S%d\n", s);
874 memcpy(data->data, current_sample, num_fields * sizeof(float));
878 /* Convert the data into the expected Android-level format */
879 for (c=0; c<num_fields; c++) {
881 data->data[c] = sensor_info[s].ops.transform
882 (s, c, current_sample);
884 ALOGV("\tfield %d: %f\n", c, data->data[c]);
885 current_sample += sensor_info[s].channel[c].size;
889 * The finalize routine, in addition to its late sample processing duty,
890 * has the final say on whether or not the sample gets sent to Android.
892 return sensor_info[s].ops.finalize(s, data);
896 static void synthetize_duplicate_samples (void)
899 * Some sensor types (ex: gyroscope) are defined as continuously firing
900 * by Android, despite the fact that we can be dealing with iio drivers
901 * that only report events for new samples. For these we generate
902 * reports periodically, duplicating the last data we got from the
903 * driver. This is not necessary for polling sensors.
911 for (s=0; s<sensor_count; s++) {
913 /* Ignore disabled sensors */
914 if (!sensor_info[s].enable_count)
917 /* If the sensor is continuously firing, leave it alone */
918 if ( sensor_info[s].selected_trigger !=
919 sensor_info[s].motion_trigger_name)
922 /* If we haven't seen a sample, there's nothing to duplicate */
923 if (!sensor_info[s].report_initialized)
926 /* If a sample was recently buffered, leave it alone too */
927 if (sensor_info[s].report_pending)
930 /* We also need a valid sampling rate to be configured */
931 if (!sensor_info[s].sampling_rate)
934 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
936 current_ts = get_timestamp();
937 target_ts = sensor_info[s].report_ts + period;
939 if (target_ts <= current_ts) {
940 /* Mark the sensor for event generation */
941 set_report_ts(s, current_ts);
942 sensor_info[s].report_pending = 1;
948 static void integrate_thread_report (uint32_t tag)
950 int s = tag - THREAD_REPORT_TAG_BASE;
954 expected_len = get_field_count(s) * sizeof(float);
956 len = read(sensor_info[s].thread_data_fd[0],
957 sensor_info[s].report_buffer,
960 if (len == expected_len) {
961 set_report_ts(s, get_timestamp());
962 sensor_info[s].report_pending = 1;
967 static int get_poll_wait_timeout (void)
970 * Compute an appropriate timeout value, in ms, for the epoll_wait
971 * call that's going to await for iio device reports and incoming
972 * reports from our sensor sysfs data reader threads.
976 int64_t target_ts = INT64_MAX;
981 * Check if have have to deal with "terse" drivers that only send events
982 * when there is motion, despite the fact that the associated Android
983 * sensor type is continuous rather than on-change. In that case we have
984 * to duplicate events. Check deadline for the nearest upcoming event.
986 for (s=0; s<sensor_count; s++)
987 if (sensor_info[s].enable_count &&
988 sensor_info[s].selected_trigger ==
989 sensor_info[s].motion_trigger_name &&
990 sensor_info[s].sampling_rate) {
991 period = (int64_t) (1000000000.0 /
992 sensor_info[s].sampling_rate);
994 if (sensor_info[s].report_ts + period < target_ts)
995 target_ts = sensor_info[s].report_ts + period;
998 /* If we don't have such a driver to deal with */
999 if (target_ts == INT64_MAX)
1000 return -1; /* Infinite wait */
1002 ms_to_wait = (target_ts - get_timestamp()) / 1000000;
1004 /* If the target timestamp is already behind us, don't wait */
1012 int sensor_poll(struct sensors_event_t* data, int count)
1017 struct epoll_event ev[MAX_DEVICES];
1018 int returned_events;
1022 /* Get one or more events from our collection of sensors */
1024 return_available_sensor_reports:
1026 /* Synthetize duplicate samples if needed */
1027 synthetize_duplicate_samples();
1029 returned_events = 0;
1031 /* Check our sensor collection for available reports */
1032 for (s=0; s<sensor_count && returned_events < count; s++)
1033 if (sensor_info[s].report_pending) {
1036 sensor_info[s].report_pending = 0;
1038 /* Report this event if it looks OK */
1039 event_count = propagate_sensor_report(s, &data[returned_events]);
1041 /* Duplicate only if both cal & uncal are active */
1042 if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
1043 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
1044 struct gyro_cal* gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
1046 memcpy(&data[returned_events + event_count], &data[returned_events],
1047 sizeof(struct sensors_event_t) * event_count);
1049 uncal_start = returned_events + event_count;
1050 for (i = 0; i < event_count; i++) {
1051 data[uncal_start + i].type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
1052 data[uncal_start + i].sensor = sensor_info[s].pair_idx;
1054 data[uncal_start + i].data[0] = data[returned_events + i].data[0] + gyro_data->bias_x;
1055 data[uncal_start + i].data[1] = data[returned_events + i].data[1] + gyro_data->bias_y;
1056 data[uncal_start + i].data[2] = data[returned_events + i].data[2] + gyro_data->bias_z;
1058 data[uncal_start + i].uncalibrated_gyro.bias[0] = gyro_data->bias_x;
1059 data[uncal_start + i].uncalibrated_gyro.bias[1] = gyro_data->bias_y;
1060 data[uncal_start + i].uncalibrated_gyro.bias[2] = gyro_data->bias_z;
1064 sensor_info[sensor_info[s].pair_idx].report_pending = 0;
1065 returned_events += event_count;
1067 * If the sample was deemed invalid or unreportable,
1068 * e.g. had the same value as the previously reported
1069 * value for a 'on change' sensor, silently drop it.
1073 if (returned_events)
1074 return returned_events;
1078 ALOGV("Awaiting sensor data\n");
1080 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1083 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1087 ALOGV("%d fds signalled\n", nfds);
1089 /* For each of the signalled sources */
1090 for (i=0; i<nfds; i++)
1091 if (ev[i].events == EPOLLIN)
1092 switch (ev[i].data.u32) {
1093 case 0 ... MAX_DEVICES-1:
1094 /* Read report from iio char dev fd */
1095 integrate_device_report(ev[i].data.u32);
1098 case THREAD_REPORT_TAG_BASE ...
1099 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1100 /* Get report from acquisition thread */
1101 integrate_thread_report(ev[i].data.u32);
1105 ALOGW("Unexpected event source!\n");
1109 goto return_available_sensor_reports;
1113 int sensor_set_delay(int s, int64_t ns)
1115 /* Set the rate at which a specific sensor should report events */
1117 /* See Android sensors.h for indication on sensor trigger modes */
1119 char sysfs_path[PATH_MAX];
1120 char avail_sysfs_path[PATH_MAX];
1121 int dev_num = sensor_info[s].dev_num;
1122 int i = sensor_info[s].catalog_index;
1123 const char *prefix = sensor_catalog[i].tag;
1124 float new_sampling_rate; /* Granted sampling rate after arbitration */
1125 float cur_sampling_rate; /* Currently used sampling rate */
1126 int per_sensor_sampling_rate;
1127 int per_device_sampling_rate;
1128 int32_t min_delay_us = sensor_desc[s].minDelay;
1129 max_delay_t max_delay_us = sensor_desc[s].maxDelay;
1130 float min_supported_rate = max_delay_us ? (1000000.0f / max_delay_us) : 1;
1131 float max_supported_rate =
1132 (min_delay_us && min_delay_us != -1) ? (1000000.0f / min_delay_us) : 0;
1133 char freqs_buf[100];
1139 ALOGE("Rejecting zero delay request on sensor %d\n", s);
1143 new_sampling_rate = 1000000000LL/ns;
1146 * Artificially limit ourselves to 1 Hz or higher. This is mostly to
1147 * avoid setting up the stage for divisions by zero.
1149 if (new_sampling_rate < min_supported_rate)
1150 new_sampling_rate = min_supported_rate;
1152 if (max_supported_rate &&
1153 new_sampling_rate > max_supported_rate) {
1154 new_sampling_rate = max_supported_rate;
1157 sensor_info[s].sampling_rate = new_sampling_rate;
1159 /* If we're dealing with a poll-mode sensor */
1160 if (!sensor_info[s].num_channels) {
1161 /* Interrupt current sleep so the new sampling gets used */
1162 pthread_cond_signal(&thread_release_cond[s]);
1166 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
1168 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
1169 per_sensor_sampling_rate = 1;
1170 per_device_sampling_rate = 0;
1172 per_sensor_sampling_rate = 0;
1174 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
1176 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
1177 per_device_sampling_rate = 1;
1179 per_device_sampling_rate = 0;
1182 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
1183 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
1187 /* Coordinate with others active sensors on the same device, if any */
1188 if (per_device_sampling_rate)
1189 for (n=0; n<sensor_count; n++)
1190 if (n != s && sensor_info[n].dev_num == dev_num &&
1191 sensor_info[n].num_channels &&
1192 sensor_info[n].enable_count &&
1193 sensor_info[n].sampling_rate > new_sampling_rate)
1194 new_sampling_rate= sensor_info[n].sampling_rate;
1196 /* Check if we have contraints on allowed sampling rates */
1198 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
1200 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
1203 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
1205 /* While we're not at the end of the string */
1206 while (*cursor && cursor[0]) {
1208 /* Decode a single value */
1209 sr = strtod(cursor, NULL);
1211 /* If this matches the selected rate, we're happy */
1212 if (new_sampling_rate == sr)
1216 * If we reached a higher value than the desired rate,
1217 * adjust selected rate so it matches the first higher
1218 * available one and stop parsing - this makes the
1219 * assumption that rates are sorted by increasing value
1220 * in the allowed frequencies string.
1222 if (sr > new_sampling_rate) {
1223 new_sampling_rate = sr;
1228 while (cursor[0] && !isspace(cursor[0]))
1232 while (cursor[0] && isspace(cursor[0]))
1238 if (max_supported_rate &&
1239 new_sampling_rate > max_supported_rate) {
1240 new_sampling_rate = max_supported_rate;
1244 /* If the desired rate is already active we're all set */
1245 if (new_sampling_rate == cur_sampling_rate)
1248 ALOGI("Sensor %d sampling rate set to %g\n", s, new_sampling_rate);
1250 if (trig_sensors_per_dev[dev_num])
1251 enable_buffer(dev_num, 0);
1253 sysfs_write_float(sysfs_path, new_sampling_rate);
1255 /* Switch back to continuous sampling for accelerometer based games */
1256 if (is_fast_accelerometer(s) && sensor_info[s].selected_trigger !=
1257 sensor_info[s].init_trigger_name)
1258 setup_trigger(s, sensor_info[s].init_trigger_name);
1260 if (trig_sensors_per_dev[dev_num])
1261 enable_buffer(dev_num, 1);
1267 int allocate_control_data (void)
1271 for (i=0; i<MAX_DEVICES; i++)
1274 poll_fd = epoll_create(MAX_DEVICES);
1276 if (poll_fd == -1) {
1277 ALOGE("Can't create epoll instance for iio sensors!\n");
1285 void delete_control_data (void)