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"
20 #include "filtering.h"
22 /* Currently active sensors count, per device */
23 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
24 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
26 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
27 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
29 static int poll_fd; /* epoll instance covering all enabled sensors */
31 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
33 int64_t ts_delta; /* delta between SystemClock.getNanos and our timestamp */
35 /* We use pthread condition variables to get worker threads out of sleep */
36 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
37 static pthread_cond_t thread_release_cond [MAX_SENSORS];
38 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
41 * We associate tags to each of our poll set entries. These tags have the
43 * - a iio device number if the fd is a iio character device fd
44 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a
45 * pipe used by a sysfs data acquisition thread
47 #define THREAD_REPORT_TAG_BASE 0x00010000
49 #define ENABLE_BUFFER_RETRIES 10
50 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
52 static int enable_buffer(int dev_num, int enabled)
54 char sysfs_path[PATH_MAX];
55 int ret, retries, millisec;
56 struct timespec req = {0};
58 retries = ENABLE_BUFFER_RETRIES;
59 millisec = ENABLE_BUFFER_RETRY_DELAY_MS;
61 req.tv_nsec = millisec * 1000000L;
63 sprintf(sysfs_path, ENABLE_PATH, dev_num);
66 /* Low level, non-multiplexed, enable/disable routine */
67 ret = sysfs_write_int(sysfs_path, enabled);
71 ALOGE("Failed enabling buffer, retrying");
72 nanosleep(&req, (struct timespec *)NULL);
76 ALOGE("Could not enable buffer\n");
84 static int setup_trigger (int s, const char* trigger_val)
86 char sysfs_path[PATH_MAX];
87 int ret = -1, attempts = 5;
89 sprintf(sysfs_path, TRIGGER_PATH, sensor_info[s].dev_num);
91 if (trigger_val[0] != '\n')
92 ALOGI("Setting S%d (%s) trigger to %s\n", s,
93 sensor_info[s].friendly_name, trigger_val);
95 while (ret == -1 && attempts) {
96 ret = sysfs_write_str(sysfs_path, trigger_val);
101 sensor_info[s].selected_trigger = trigger_val;
103 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s,
104 sensor_info[s].friendly_name, trigger_val);
109 static void enable_iio_timestamp (int dev_num, int known_channels)
111 /* Check if we have a dedicated iio timestamp channel */
113 char spec_buf[MAX_TYPE_SPEC_LEN];
114 char sysfs_path[PATH_MAX];
117 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
119 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
124 if (strcmp(spec_buf, "le:s64/64>>0"))
127 /* OK, type is int64_t as expected, in little endian representation */
129 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
131 if (sysfs_read_int(sysfs_path, &n))
134 /* Check that the timestamp comes after the other fields we read */
135 if (n != known_channels)
138 /* Try enabling that channel */
139 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
141 sysfs_write_int(sysfs_path, 1);
143 if (sysfs_read_int(sysfs_path, &n))
147 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
148 has_iio_ts[dev_num] = 1;
153 void build_sensor_report_maps (int dev_num)
156 * Read sysfs files from a iio device's scan_element directory, and
157 * build a couple of tables from that data. These tables will tell, for
158 * each sensor, where to gather relevant data in a device report, i.e.
159 * the structure that we read from the /dev/iio:deviceX file in order to
160 * sensor report, itself being the data that we return to Android when a
161 * sensor poll completes. The mapping should be straightforward in the
162 * case where we have a single sensor active per iio device but, this is
163 * not the general case. In general several sensors can be handled
164 * through a single iio device, and the _en, _index and _type syfs
165 * entries all concur to paint a picture of what the structure of the
175 char spec_buf[MAX_TYPE_SPEC_LEN];
176 struct datum_info_t* ch_info;
178 char sysfs_path[PATH_MAX];
181 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
182 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
183 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
187 /* For each sensor that is linked to this device */
188 for (s=0; s<sensor_count; s++) {
189 if (sensor_info[s].dev_num != dev_num)
192 i = sensor_info[s].catalog_index;
194 /* Read channel details through sysfs attributes */
195 for (c=0; c<sensor_info[s].num_channels; c++) {
197 /* Read _type file */
198 sprintf(sysfs_path, CHANNEL_PATH "%s",
199 sensor_info[s].dev_num,
200 sensor_catalog[i].channel[c].type_path);
202 n = sysfs_read_str(sysfs_path, spec_buf,
206 ALOGW( "Failed to read type: %s\n",
211 ch_spec = sensor_info[s].channel[c].type_spec;
213 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
215 ch_info = &sensor_info[s].channel[c].type_info;
217 size = decode_type_spec(ch_spec, ch_info);
219 /* Read _index file */
220 sprintf(sysfs_path, CHANNEL_PATH "%s",
221 sensor_info[s].dev_num,
222 sensor_catalog[i].channel[c].index_path);
224 n = sysfs_read_int(sysfs_path, &ch_index);
227 ALOGW( "Failed to read index: %s\n",
232 if (ch_index >= MAX_SENSORS) {
233 ALOGE("Index out of bounds!: %s\n", sysfs_path);
237 /* Record what this index is about */
239 sensor_handle_from_index [ch_index] = s;
240 channel_number_from_index[ch_index] = c;
241 channel_size_from_index [ch_index] = size;
246 /* Stop sampling - if we are recovering from hal restart */
247 enable_buffer(dev_num, 0);
248 setup_trigger(s, "\n");
250 /* Turn on channels we're aware of */
251 for (c=0;c<sensor_info[s].num_channels; c++) {
252 sprintf(sysfs_path, CHANNEL_PATH "%s",
253 sensor_info[s].dev_num,
254 sensor_catalog[i].channel[c].en_path);
255 sysfs_write_int(sysfs_path, 1);
259 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
262 * Now that we know which channels are defined, their sizes and their
263 * ordering, update channels offsets within device report. Note: there
264 * is a possibility that several sensors share the same index, with
265 * their data fields being isolated by masking and shifting as specified
266 * through the real bits and shift values in type attributes. This case
267 * is not currently supported. Also, the code below assumes no hole in
268 * the sequence of indices, so it is dependent on discovery of all
272 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
273 s = sensor_handle_from_index[i];
274 c = channel_number_from_index[i];
275 size = channel_size_from_index[i];
280 ALOGI("S%d C%d : offset %d, size %d, type %s\n",
281 s, c, offset, size, sensor_info[s].channel[c].type_spec);
283 sensor_info[s].channel[c].offset = offset;
284 sensor_info[s].channel[c].size = size;
289 /* Enable the timestamp channel if there is one available */
290 enable_iio_timestamp(dev_num, known_channels);
294 int adjust_counters (int s, int enabled)
297 * Adjust counters based on sensor enable action. Return values are:
298 * -1 if there's an inconsistency: abort action in this case
299 * 0 if the operation was completed and we're all set
300 * 1 if we toggled the state of the sensor and there's work left
303 int dev_num = sensor_info[s].dev_num;
305 /* Refcount per sensor, in terms of enable count */
307 ALOGI("Enabling sensor %d (iio device %d: %s)\n",
308 s, dev_num, sensor_info[s].friendly_name);
310 if (sensor_info[s].enabled)
311 return 0; /* The sensor was, and remains, in use */
313 sensor_info[s].enabled = 1;
315 switch (sensor_info[s].type) {
316 case SENSOR_TYPE_MAGNETIC_FIELD:
317 compass_read_data(&sensor_info[s]);
320 case SENSOR_TYPE_GYROSCOPE:
321 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
322 gyro_cal_init(&sensor_info[s]);
326 if (sensor_info[s].enabled == 0)
327 return 0; /* Spurious disable call */
329 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
330 sensor_info[s].friendly_name);
332 sensor_info[s].enabled = 0;
334 /* Sensor disabled, lower report available flag */
335 sensor_info[s].report_pending = 0;
337 if (sensor_info[s].type == SENSOR_TYPE_MAGNETIC_FIELD)
338 compass_store_data(&sensor_info[s]);
340 if(sensor_info[s].type == SENSOR_TYPE_GYROSCOPE ||
341 sensor_info[s].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED)
342 gyro_store_data(&sensor_info[s]);
346 /* If uncalibrated type and pair is already active don't adjust counters */
347 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
348 sensor_info[sensor_info[s].pair_idx].enabled != 0)
351 /* We changed the state of a sensor - adjust per iio device counters */
353 /* If this is a regular event-driven sensor */
354 if (sensor_info[s].num_channels) {
357 trig_sensors_per_dev[dev_num]++;
359 trig_sensors_per_dev[dev_num]--;
365 active_poll_sensors++;
366 poll_sensors_per_dev[dev_num]++;
370 active_poll_sensors--;
371 poll_sensors_per_dev[dev_num]--;
376 static int get_field_count (int s)
378 switch (sensor_info[s].type) {
379 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
380 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
381 case SENSOR_TYPE_ORIENTATION: /* degrees */
382 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
383 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
386 case SENSOR_TYPE_LIGHT: /* SI lux units */
387 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
388 case SENSOR_TYPE_TEMPERATURE: /* °C */
389 case SENSOR_TYPE_PROXIMITY: /* centimeters */
390 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
391 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
394 case SENSOR_TYPE_ROTATION_VECTOR:
398 ALOGE("Unknown sensor type!\n");
399 return 0; /* Drop sample */
404 static void* acquisition_routine (void* param)
407 * Data acquisition routine run in a dedicated thread, covering a single
408 * sensor. This loop will periodically retrieve sampling data through
409 * sysfs, then package it as a sample and transfer it to our master poll
410 * loop through a report fd. Checks for a cancellation signal quite
411 * frequently, as the thread may be disposed of at any time. Note that
412 * Bionic does not provide pthread_cancel / pthread_testcancel...
415 int s = (int) (size_t) param;
416 int num_fields, sample_size;
417 struct sensors_event_t data = {0};
420 struct timespec target_time;
421 int64_t timestamp, period, start, stop;
423 if (s < 0 || s >= sensor_count) {
424 ALOGE("Invalid sensor handle!\n");
428 ALOGI("Entering data acquisition thread S%d (%s): rate(%f), ts(%lld)\n", s,
429 sensor_info[s].friendly_name, sensor_info[s].sampling_rate, sensor_info[s].report_ts);
431 if (sensor_info[s].sampling_rate <= 0) {
432 ALOGE("Non-positive rate in acquisition routine for sensor %d: %f\n",
433 s, sensor_info[s].sampling_rate);
437 num_fields = get_field_count(s);
438 sample_size = sizeof(int64_t) + num_fields * sizeof(float);
441 * Each condition variable is associated to a mutex that has to be
442 * locked by the thread that's waiting on it. We use these condition
443 * variables to get the acquisition threads out of sleep quickly after
444 * the sampling rate is adjusted, or the sensor is disabled.
446 pthread_mutex_lock(&thread_release_mutex[s]);
448 /* Pinpoint the moment we start sampling */
449 timestamp = get_timestamp_monotonic();
451 /* Check and honor termination requests */
452 while (sensor_info[s].thread_data_fd[1] != -1) {
453 start = get_timestamp();
454 /* Read values through sysfs */
455 for (c=0; c<num_fields; c++) {
456 data.data[c] = acquire_immediate_value(s, c);
457 /* Check and honor termination requests */
458 if (sensor_info[s].thread_data_fd[1] == -1)
461 stop = get_timestamp();
462 data.timestamp = start/2 + stop/2;
464 /* If the sample looks good */
465 if (sensor_info[s].ops.finalize(s, &data)) {
467 /* Pipe it for transmission to poll loop */
468 ret = write( sensor_info[s].thread_data_fd[1],
469 &data.timestamp, sample_size);
471 if (ret != sample_size)
472 ALOGE("S%d acquisition thread: tried to write %d, ret: %d\n",
473 s, sample_size, ret);
476 /* Check and honor termination requests */
477 if (sensor_info[s].thread_data_fd[1] == -1)
480 /* Recalculate period asumming sensor_info[s].sampling_rate
481 * can be changed dynamically during the thread run */
482 if (sensor_info[s].sampling_rate <= 0) {
483 ALOGE("Non-positive rate in acquisition routine for sensor %d: %f\n",
484 s, sensor_info[s].sampling_rate);
488 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
490 set_timestamp(&target_time, timestamp);
493 * Wait until the sampling time elapses, or a rate change is
494 * signaled, or a thread exit is requested.
496 ret = pthread_cond_timedwait( &thread_release_cond[s],
497 &thread_release_mutex[s],
502 ALOGV("Acquisition thread for S%d exiting\n", s);
503 pthread_mutex_unlock(&thread_release_mutex[s]);
509 static void start_acquisition_thread (int s)
511 int incoming_data_fd;
514 struct epoll_event ev = {0};
516 ALOGV("Initializing acquisition context for sensor %d\n", s);
518 /* Create condition variable and mutex for quick thread release */
519 ret = pthread_condattr_init(&thread_cond_attr[s]);
520 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
521 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
522 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
524 /* Create a pipe for inter thread communication */
525 ret = pipe(sensor_info[s].thread_data_fd);
527 incoming_data_fd = sensor_info[s].thread_data_fd[0];
530 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
532 /* Add incoming side of pipe to our poll set, with a suitable tag */
533 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
535 /* Create and start worker thread */
536 ret = pthread_create( &sensor_info[s].acquisition_thread,
543 static void stop_acquisition_thread (int s)
545 int incoming_data_fd = sensor_info[s].thread_data_fd[0];
546 int outgoing_data_fd = sensor_info[s].thread_data_fd[1];
548 ALOGV("Tearing down acquisition context for sensor %d\n", s);
550 /* Delete the incoming side of the pipe from our poll set */
551 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
553 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
554 sensor_info[s].thread_data_fd[0] = -1;
555 sensor_info[s].thread_data_fd[1] = -1;
557 /* Close both sides of our pipe */
558 close(incoming_data_fd);
559 close(outgoing_data_fd);
561 /* Stop acquisition thread and clean up thread handle */
562 pthread_cond_signal(&thread_release_cond[s]);
563 pthread_join(sensor_info[s].acquisition_thread, NULL);
565 /* Clean up our sensor descriptor */
566 sensor_info[s].acquisition_thread = -1;
568 /* Delete condition variable and mutex */
569 pthread_cond_destroy(&thread_release_cond[s]);
570 pthread_mutex_destroy(&thread_release_mutex[s]);
574 int sensor_activate(int s, int enabled)
576 char device_name[PATH_MAX];
577 struct epoll_event ev = {0};
580 int dev_num = sensor_info[s].dev_num;
581 int is_poll_sensor = !sensor_info[s].num_channels;
583 /* Prepare the report timestamp field for the first event, see set_report_ts method */
584 sensor_info[s].report_ts = 0;
585 ts_delta = load_timestamp_sys_clock() - get_timestamp_monotonic();
588 /* If we want to activate gyro calibrated and gyro uncalibrated is activated
589 * Deactivate gyro uncalibrated - Uncalibrated releases handler
590 * Activate gyro calibrated - Calibrated has handler
591 * Reactivate gyro uncalibrated - Uncalibrated gets data from calibrated */
593 /* If we want to deactivate gyro calibrated and gyro uncalibrated is active
594 * Deactivate gyro uncalibrated - Uncalibrated no longer gets data from handler
595 * Deactivate gyro calibrated - Calibrated releases handler
596 * Reactivate gyro uncalibrated - Uncalibrated has handler */
598 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE &&
599 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enabled != 0) {
601 sensor_activate(sensor_info[s].pair_idx, 0);
602 ret = sensor_activate(s, enabled);
603 sensor_activate(sensor_info[s].pair_idx, 1);
607 ret = adjust_counters(s, enabled);
609 /* If the operation was neutral in terms of state, we're done */
613 sensor_info[s].event_count = 0;
614 sensor_info[s].meta_data_pending = 0;
616 if (enabled && (sensor_info[s].quirks & QUIRK_NOISY))
617 /* Initialize filtering data if required */
618 setup_noise_filtering(s);
620 if (!is_poll_sensor) {
623 enable_buffer(dev_num, 0);
624 setup_trigger(s, "\n");
626 /* If there's at least one sensor enabled on this iio device */
627 if (trig_sensors_per_dev[dev_num]) {
630 setup_trigger(s, sensor_info[s].init_trigger_name);
631 enable_buffer(dev_num, 1);
636 * Make sure we have a fd on the character device ; conversely, close
637 * the fd if no one is using associated sensors anymore. The assumption
638 * here is that the underlying driver will power on the relevant
639 * hardware block while someone holds a fd on the device.
641 dev_fd = device_fd[dev_num];
645 stop_acquisition_thread(s);
647 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
648 !trig_sensors_per_dev[dev_num]) {
650 * Stop watching this fd. This should be a no-op
651 * in case this fd was not in the poll set.
653 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
656 device_fd[dev_num] = -1;
659 /* Release any filtering data we may have accumulated */
660 release_noise_filtering_data(s);
666 /* First enabled sensor on this iio device */
667 sprintf(device_name, DEV_FILE_PATH, dev_num);
668 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
670 device_fd[dev_num] = dev_fd;
673 ALOGE("Could not open fd on %s (%s)\n",
674 device_name, strerror(errno));
675 adjust_counters(s, 0);
679 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
681 if (!is_poll_sensor) {
683 /* Add this iio device fd to the set of watched fds */
685 ev.data.u32 = dev_num;
687 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
690 ALOGE( "Failed adding %d to poll set (%s)\n",
691 dev_fd, strerror(errno));
695 /* Note: poll-mode fds are not readable */
699 /* Ensure that on-change sensors send at least one event after enable */
700 sensor_info[s].prev_val = -1;
703 start_acquisition_thread(s);
709 static int is_fast_accelerometer (int s)
712 * Some games don't react well to accelerometers using any-motion
713 * triggers. Even very low thresholds seem to trip them, and they tend
714 * to request fairly high event rates. Favor continuous triggers if the
715 * sensor is an accelerometer and uses a sampling rate of at least 25.
718 if (sensor_info[s].type != SENSOR_TYPE_ACCELEROMETER)
721 if (sensor_info[s].sampling_rate < 25)
728 static void enable_motion_trigger (int dev_num)
731 * In the ideal case, we enumerate two triggers per iio device ; the
732 * default (periodically firing) trigger, and another one (the motion
733 * trigger) that only fires up when motion is detected. This second one
734 * allows for lesser energy consumption, but requires periodic sample
735 * duplication at the HAL level for sensors that Android defines as
736 * continuous. This "duplicate last sample" logic can only be engaged
737 * once we got a first sample for the driver, so we start with the
738 * default trigger when an iio device is first opened, then adjust the
739 * trigger when we got events for all active sensors. Unfortunately in
740 * the general case several sensors can be associated to a given iio
741 * device, they can independently be controlled, and we have to adjust
742 * the trigger in use at the iio device level depending on whether or
743 * not appropriate conditions are met at the sensor level.
748 int active_sensors = trig_sensors_per_dev[dev_num];
749 int candidate[MAX_SENSORS];
750 int candidate_count = 0;
755 /* Check that all active sensors are ready to switch */
757 for (s=0; s<MAX_SENSORS; s++)
758 if (sensor_info[s].dev_num == dev_num &&
759 sensor_info[s].enabled &&
760 sensor_info[s].num_channels &&
761 (!sensor_info[s].motion_trigger_name[0] ||
762 !sensor_info[s].report_initialized ||
763 is_fast_accelerometer(s) ||
764 (sensor_info[s].quirks & QUIRK_FORCE_CONTINUOUS))
768 /* Record which particular sensors need to switch */
770 for (s=0; s<MAX_SENSORS; s++)
771 if (sensor_info[s].dev_num == dev_num &&
772 sensor_info[s].enabled &&
773 sensor_info[s].num_channels &&
774 sensor_info[s].selected_trigger !=
775 sensor_info[s].motion_trigger_name)
776 candidate[candidate_count++] = s;
778 if (!candidate_count)
781 /* Now engage the motion trigger for sensors which aren't using it */
783 enable_buffer(dev_num, 0);
785 for (i=0; i<candidate_count; i++) {
787 setup_trigger(s, sensor_info[s].motion_trigger_name);
790 enable_buffer(dev_num, 1);
793 /* CTS acceptable thresholds:
794 * EventGapVerification.java: (th <= 1.8)
795 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
797 #define THRESHOLD 1.10
798 #define MAX_DELAY 500000000 /* 500 ms */
799 void set_report_ts(int s, int64_t ts)
801 int64_t maxTs, period;
802 int catalog_index = sensor_info[s].catalog_index;
803 int is_accel = (sensor_catalog[catalog_index].type == SENSOR_TYPE_ACCELEROMETER);
806 * A bit of a hack to please a bunch of cts tests. They
807 * expect the timestamp to be exacly according to the set-up
808 * frequency but if we're simply getting the timestamp at hal level
809 * this may not be the case. Perhaps we'll get rid of this when
810 * we'll be reading the timestamp from the iio channel for all sensors
812 if (sensor_info[s].report_ts && sensor_info[s].sampling_rate &&
813 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
815 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
816 maxTs = sensor_info[s].report_ts + (is_accel ? 1 : THRESHOLD) * period;
817 /* If we're too far behind get back on track */
818 if (ts - maxTs >= MAX_DELAY)
820 sensor_info[s].report_ts = (ts < maxTs ? ts : maxTs);
822 sensor_info[s].report_ts = ts;
827 static int integrate_device_report (int dev_num)
831 unsigned char buf[MAX_SENSOR_REPORT_SIZE] = { 0 };
833 unsigned char *target;
834 unsigned char *source;
837 int ts_offset = 0; /* Offset of iio timestamp, if provided */
839 /* There's an incoming report on the specified iio device char dev fd */
841 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
842 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
846 if (device_fd[dev_num] == -1) {
847 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
851 len = read(device_fd[dev_num], buf, MAX_SENSOR_REPORT_SIZE);
854 ALOGE("Could not read report from iio device %d (%s)\n",
855 dev_num, strerror(errno));
859 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
861 /* Map device report to sensor reports */
863 for (s=0; s<MAX_SENSORS; s++)
864 if (sensor_info[s].dev_num == dev_num &&
865 sensor_info[s].enabled) {
869 /* Copy data from device to sensor report buffer */
870 for (c=0; c<sensor_info[s].num_channels; c++) {
872 target = sensor_info[s].report_buffer +
875 source = buf + sensor_info[s].channel[c].offset;
877 size = sensor_info[s].channel[c].size;
879 memcpy(target, source, size);
884 ALOGV("Sensor %d report available (%d bytes)\n", s,
887 sensor_info[s].report_pending = DATA_TRIGGER;
888 sensor_info[s].report_initialized = 1;
889 set_report_ts(s, get_timestamp());
891 ts_offset += sr_offset;
894 /* Tentatively switch to an any-motion trigger if conditions are met */
895 enable_motion_trigger(dev_num);
897 /* If no iio timestamp channel was detected for this device, bail out */
898 if (!has_iio_ts[dev_num])
901 /* Align on a 64 bits boundary */
902 ts_offset = (ts_offset + 7)/8*8;
904 /* If we read an amount of data consistent with timestamp presence */
905 if (len == ts_offset + (int) sizeof(int64_t))
906 ts = *(int64_t*) (buf + ts_offset);
909 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
913 ALOGV("Driver timestamp on iio device %d: ts=%lld\n", dev_num, ts);
915 for (s=0; s<MAX_SENSORS; s++)
916 if (sensor_info[s].dev_num == dev_num && sensor_info[s].enabled)
917 set_report_ts(s, ts);
923 static int propagate_sensor_report (int s, struct sensors_event_t *data)
925 /* There's a sensor report pending for this sensor ; transmit it */
927 int num_fields = get_field_count(s);
929 unsigned char* current_sample;
931 /* If there's nothing to return... we're done */
936 /* Only return uncalibrated event if also gyro active */
937 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
938 sensor_info[sensor_info[s].pair_idx].enabled != 0)
941 memset(data, 0, sizeof(sensors_event_t));
943 data->version = sizeof(sensors_event_t);
945 data->type = sensor_info[s].type;
946 data->timestamp = sensor_info[s].report_ts;
948 ALOGV("Sample on sensor %d (type %d):\n", s, sensor_info[s].type);
950 current_sample = sensor_info[s].report_buffer;
952 /* If this is a poll sensor */
953 if (!sensor_info[s].num_channels) {
954 /* Use the data provided by the acquisition thread */
955 ALOGV("Reporting data from worker thread for S%d\n", s);
956 memcpy(data->data, current_sample, num_fields * sizeof(float));
960 /* Convert the data into the expected Android-level format */
961 for (c=0; c<num_fields; c++) {
963 data->data[c] = sensor_info[s].ops.transform
964 (s, c, current_sample);
966 ALOGV("\tfield %d: %f\n", c, data->data[c]);
967 current_sample += sensor_info[s].channel[c].size;
971 * The finalize routine, in addition to its late sample processing duty,
972 * has the final say on whether or not the sample gets sent to Android.
974 return sensor_info[s].ops.finalize(s, data);
978 static void synthetize_duplicate_samples (void)
981 * Some sensor types (ex: gyroscope) are defined as continuously firing
982 * by Android, despite the fact that we can be dealing with iio drivers
983 * that only report events for new samples. For these we generate
984 * reports periodically, duplicating the last data we got from the
985 * driver. This is not necessary for polling sensors.
993 for (s=0; s<sensor_count; s++) {
995 /* Ignore disabled sensors */
996 if (!sensor_info[s].enabled)
999 /* If the sensor is continuously firing, leave it alone */
1000 if (sensor_info[s].selected_trigger !=
1001 sensor_info[s].motion_trigger_name)
1004 /* If we haven't seen a sample, there's nothing to duplicate */
1005 if (!sensor_info[s].report_initialized)
1008 /* If a sample was recently buffered, leave it alone too */
1009 if (sensor_info[s].report_pending)
1012 /* We also need a valid sampling rate to be configured */
1013 if (!sensor_info[s].sampling_rate)
1016 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
1018 current_ts = get_timestamp();
1019 target_ts = sensor_info[s].report_ts + period;
1021 if (target_ts <= current_ts) {
1022 /* Mark the sensor for event generation */
1023 set_report_ts(s, current_ts);
1024 sensor_info[s].report_pending = DATA_DUPLICATE;
1030 static void integrate_thread_report (uint32_t tag)
1032 int s = tag - THREAD_REPORT_TAG_BASE;
1036 unsigned char current_sample[MAX_SENSOR_REPORT_SIZE];
1038 expected_len = sizeof(int64_t) + get_field_count(s) * sizeof(float);
1040 len = read(sensor_info[s].thread_data_fd[0],
1044 memcpy(×tamp, current_sample, sizeof(int64_t));
1045 memcpy(sensor_info[s].report_buffer, sizeof(int64_t) + current_sample,
1046 expected_len - sizeof(int64_t));
1048 if (len == expected_len) {
1049 set_report_ts(s, timestamp);
1050 sensor_info[s].report_pending = DATA_SYSFS;
1055 static int get_poll_wait_timeout (void)
1058 * Compute an appropriate timeout value, in ms, for the epoll_wait
1059 * call that's going to await for iio device reports and incoming
1060 * reports from our sensor sysfs data reader threads.
1064 int64_t target_ts = INT64_MAX;
1069 * Check if we're dealing with a driver that only send events when
1070 * there is motion, despite the fact that the associated Android sensor
1071 * type is continuous rather than on-change. In that case we have to
1072 * duplicate events. Check deadline for the nearest upcoming event.
1074 for (s=0; s<sensor_count; s++)
1075 if (sensor_info[s].enabled &&
1076 sensor_info[s].selected_trigger ==
1077 sensor_info[s].motion_trigger_name &&
1078 sensor_info[s].sampling_rate) {
1079 period = (int64_t) (1000000000.0 /
1080 sensor_info[s].sampling_rate);
1082 if (sensor_info[s].report_ts + period < target_ts)
1083 target_ts = sensor_info[s].report_ts + period;
1086 /* If we don't have such a driver to deal with */
1087 if (target_ts == INT64_MAX)
1088 return -1; /* Infinite wait */
1090 ms_to_wait = (target_ts - get_timestamp()) / 1000000;
1092 /* If the target timestamp is already behind us, don't wait */
1100 int sensor_poll(struct sensors_event_t* data, int count)
1105 struct epoll_event ev[MAX_DEVICES];
1106 int returned_events;
1110 /* Get one or more events from our collection of sensors */
1112 return_available_sensor_reports:
1114 /* Synthetize duplicate samples if needed */
1115 synthetize_duplicate_samples();
1117 returned_events = 0;
1119 /* Check our sensor collection for available reports */
1120 for (s=0; s<sensor_count && returned_events < count; s++) {
1121 if (sensor_info[s].report_pending) {
1124 /* Report this event if it looks OK */
1125 event_count = propagate_sensor_report(s, &data[returned_events]);
1128 sensor_info[s].report_pending = 0;
1130 /* Duplicate only if both cal & uncal are active */
1131 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE &&
1132 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enabled != 0) {
1133 struct gyro_cal* gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
1135 memcpy(&data[returned_events + event_count], &data[returned_events],
1136 sizeof(struct sensors_event_t) * event_count);
1138 uncal_start = returned_events + event_count;
1139 for (i = 0; i < event_count; i++) {
1140 data[uncal_start + i].type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
1141 data[uncal_start + i].sensor = sensor_info[s].pair_idx;
1143 data[uncal_start + i].data[0] = data[returned_events + i].data[0] + gyro_data->bias_x;
1144 data[uncal_start + i].data[1] = data[returned_events + i].data[1] + gyro_data->bias_y;
1145 data[uncal_start + i].data[2] = data[returned_events + i].data[2] + gyro_data->bias_z;
1147 data[uncal_start + i].uncalibrated_gyro.bias[0] = gyro_data->bias_x;
1148 data[uncal_start + i].uncalibrated_gyro.bias[1] = gyro_data->bias_y;
1149 data[uncal_start + i].uncalibrated_gyro.bias[2] = gyro_data->bias_z;
1153 sensor_info[sensor_info[s].pair_idx].report_pending = 0;
1154 returned_events += event_count;
1156 * If the sample was deemed invalid or unreportable,
1157 * e.g. had the same value as the previously reported
1158 * value for a 'on change' sensor, silently drop it.
1161 while (sensor_info[s].meta_data_pending) {
1162 /* See sensors.h on these */
1163 data[returned_events].version = META_DATA_VERSION;
1164 data[returned_events].sensor = 0;
1165 data[returned_events].type = SENSOR_TYPE_META_DATA;
1166 data[returned_events].reserved0 = 0;
1167 data[returned_events].timestamp = 0;
1168 data[returned_events].meta_data.sensor = s;
1169 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1171 sensor_info[s].meta_data_pending--;
1174 if (returned_events)
1175 return returned_events;
1179 ALOGV("Awaiting sensor data\n");
1181 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1184 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1188 ALOGV("%d fds signalled\n", nfds);
1190 /* For each of the signalled sources */
1191 for (i=0; i<nfds; i++)
1192 if (ev[i].events == EPOLLIN)
1193 switch (ev[i].data.u32) {
1194 case 0 ... MAX_DEVICES-1:
1195 /* Read report from iio char dev fd */
1196 integrate_device_report(ev[i].data.u32);
1199 case THREAD_REPORT_TAG_BASE ...
1200 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1201 /* Get report from acquisition thread */
1202 integrate_thread_report(ev[i].data.u32);
1206 ALOGW("Unexpected event source!\n");
1210 goto return_available_sensor_reports;
1214 static void tentative_switch_trigger (int s)
1217 * Under certain situations it may be beneficial to use an alternate
1220 * - for applications using the accelerometer with high sampling rates,
1221 * prefer the continuous trigger over the any-motion one, to avoid
1222 * jumps related to motion thresholds
1225 if (is_fast_accelerometer(s) &&
1226 !(sensor_info[s].quirks & QUIRK_TERSE_DRIVER) &&
1227 sensor_info[s].selected_trigger ==
1228 sensor_info[s].motion_trigger_name)
1229 setup_trigger(s, sensor_info[s].init_trigger_name);
1233 int sensor_set_delay(int s, int64_t ns)
1235 /* Set the rate at which a specific sensor should report events */
1237 /* See Android sensors.h for indication on sensor trigger modes */
1239 char sysfs_path[PATH_MAX];
1240 char avail_sysfs_path[PATH_MAX];
1241 int dev_num = sensor_info[s].dev_num;
1242 int i = sensor_info[s].catalog_index;
1243 const char *prefix = sensor_catalog[i].tag;
1244 float new_sampling_rate; /* Granted sampling rate after arbitration */
1245 float cur_sampling_rate; /* Currently used sampling rate */
1246 int per_sensor_sampling_rate;
1247 int per_device_sampling_rate;
1248 int32_t min_delay_us = sensor_desc[s].minDelay;
1249 max_delay_t max_delay_us = sensor_desc[s].maxDelay;
1250 float min_supported_rate = max_delay_us ? (1000000.0f / max_delay_us) : 1;
1251 float max_supported_rate =
1252 (min_delay_us && min_delay_us != -1) ? (1000000.0f / min_delay_us) : 0;
1253 char freqs_buf[100];
1259 ALOGE("Rejecting non-positive delay request on sensor %d, required delay: %lld\n", s, ns);
1263 new_sampling_rate = 1000000000LL/ns;
1265 ALOGV("Entering set delay S%d (%s): old rate(%f), new rate(%f)\n",
1266 s, sensor_info[s].friendly_name, sensor_info[s].sampling_rate,
1270 * Artificially limit ourselves to 1 Hz or higher. This is mostly to
1271 * avoid setting up the stage for divisions by zero.
1273 if (new_sampling_rate < min_supported_rate)
1274 new_sampling_rate = min_supported_rate;
1276 if (max_supported_rate &&
1277 new_sampling_rate > max_supported_rate) {
1278 new_sampling_rate = max_supported_rate;
1281 sensor_info[s].sampling_rate = new_sampling_rate;
1283 /* If we're dealing with a poll-mode sensor */
1284 if (!sensor_info[s].num_channels) {
1285 /* Interrupt current sleep so the new sampling gets used */
1286 pthread_cond_signal(&thread_release_cond[s]);
1290 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
1292 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
1293 per_sensor_sampling_rate = 1;
1294 per_device_sampling_rate = 0;
1296 per_sensor_sampling_rate = 0;
1298 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
1300 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
1301 per_device_sampling_rate = 1;
1303 per_device_sampling_rate = 0;
1306 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
1307 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
1311 /* Coordinate with others active sensors on the same device, if any */
1312 if (per_device_sampling_rate)
1313 for (n=0; n<sensor_count; n++)
1314 if (n != s && sensor_info[n].dev_num == dev_num &&
1315 sensor_info[n].num_channels &&
1316 sensor_info[n].enabled &&
1317 sensor_info[n].sampling_rate > new_sampling_rate)
1318 new_sampling_rate= sensor_info[n].sampling_rate;
1320 /* Check if we have contraints on allowed sampling rates */
1322 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
1324 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
1327 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
1329 /* While we're not at the end of the string */
1330 while (*cursor && cursor[0]) {
1332 /* Decode a single value */
1333 sr = strtod(cursor, NULL);
1335 /* If this matches the selected rate, we're happy */
1336 if (new_sampling_rate == sr)
1340 * If we reached a higher value than the desired rate,
1341 * adjust selected rate so it matches the first higher
1342 * available one and stop parsing - this makes the
1343 * assumption that rates are sorted by increasing value
1344 * in the allowed frequencies string.
1346 if (sr > new_sampling_rate) {
1347 new_sampling_rate = sr;
1352 while (cursor[0] && !isspace(cursor[0]))
1356 while (cursor[0] && isspace(cursor[0]))
1361 if (max_supported_rate &&
1362 new_sampling_rate > max_supported_rate) {
1363 new_sampling_rate = max_supported_rate;
1366 /* If the desired rate is already active we're all set */
1367 if (new_sampling_rate == cur_sampling_rate)
1370 ALOGI("Sensor %d sampling rate set to %g\n", s, new_sampling_rate);
1372 if (trig_sensors_per_dev[dev_num])
1373 enable_buffer(dev_num, 0);
1375 sysfs_write_float(sysfs_path, new_sampling_rate);
1377 /* Check if it makes sense to use an alternate trigger */
1378 tentative_switch_trigger(s);
1380 if (trig_sensors_per_dev[dev_num])
1381 enable_buffer(dev_num, 1);
1386 int sensor_flush (int s)
1388 /* If one shot or not enabled return -EINVAL */
1389 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE ||
1390 sensor_info[s].enabled == 0)
1393 sensor_info[s].meta_data_pending++;
1397 int allocate_control_data (void)
1401 for (i=0; i<MAX_DEVICES; i++)
1404 poll_fd = epoll_create(MAX_DEVICES);
1406 if (poll_fd == -1) {
1407 ALOGE("Can't create epoll instance for iio sensors!\n");
1415 void delete_control_data (void)