2 * Copyright (C) 2014-2015 Intel Corporation.
11 #include <sys/epoll.h>
12 #include <sys/ioctl.h>
13 #include <sys/socket.h>
14 #include <utils/Log.h>
15 #include <hardware/sensors.h>
16 #include <linux/ioctl.h>
18 #include "enumeration.h"
20 #include "transform.h"
21 #include "calibration.h"
22 #include "description.h"
23 #include "filtering.h"
24 #include <linux/iio/events.h>
25 /* Currently active sensors count, per device */
26 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
27 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
29 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
30 static int events_fd[MAX_DEVICES]; /* fd on the /sys/bus/iio/devices/iio:deviceX/events/<event_name> file */
31 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
32 static int expected_dev_report_size[MAX_DEVICES]; /* expected iio scan len */
33 static int poll_fd; /* epoll instance covering all enabled sensors */
35 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
37 /* We use pthread condition variables to get worker threads out of sleep */
38 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
39 static pthread_cond_t thread_release_cond [MAX_SENSORS];
40 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
43 * We associate tags to each of our poll set entries. These tags have the following values:
44 * - a iio device number if the fd is a iio character device fd
45 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a pipe used by a sysfs data acquisition thread
47 #define THREAD_REPORT_TAG_BASE 1000
49 /* If buffer enable fails, we may want to retry a few times before giving up */
50 #define ENABLE_BUFFER_RETRIES 3
51 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
54 inline int is_enabled (int s)
56 return sensor[s].directly_enabled || sensor[s].ref_count;
60 static int check_state_change (int s, int enabled, int from_virtual)
63 if (sensor[s].directly_enabled)
64 return 0; /* We're being enabled but already were directly activated: no change. */
67 sensor[s].directly_enabled = 1; /* We're being directly enabled */
69 if (sensor[s].ref_count)
70 return 0; /* We were already indirectly enabled */
72 return 1; /* Do continue enabling this sensor */
76 return 0; /* We are being disabled but already were: no change */
78 if (from_virtual && sensor[s].directly_enabled)
79 return 0; /* We're indirectly disabled but the base is still active */
81 sensor[s].directly_enabled = 0; /* We're now directly disabled */
83 if (!from_virtual && sensor[s].ref_count)
84 return 0; /* We still have ref counts */
86 return 1; /* Do continue disabling this sensor */
90 static int enable_buffer (int dev_num, int enabled)
92 char sysfs_path[PATH_MAX];
93 int retries = ENABLE_BUFFER_RETRIES;
95 sprintf(sysfs_path, ENABLE_PATH, dev_num);
98 /* Low level, non-multiplexed, enable/disable routine */
99 if (sysfs_write_int(sysfs_path, enabled) > 0)
102 ALOGE("Failed enabling buffer on dev%d, retrying", dev_num);
103 usleep(ENABLE_BUFFER_RETRY_DELAY_MS*1000);
107 ALOGE("Could not enable buffer\n");
112 static int setup_trigger (int s, const char* trigger_val)
114 char sysfs_path[PATH_MAX];
115 int ret = -1, attempts = 5;
117 sprintf(sysfs_path, TRIGGER_PATH, sensor[s].dev_num);
119 if (trigger_val[0] != '\n')
120 ALOGI("Setting S%d (%s) trigger to %s\n", s, sensor[s].friendly_name, trigger_val);
122 while (ret == -1 && attempts) {
123 ret = sysfs_write_str(sysfs_path, trigger_val);
128 sensor[s].selected_trigger = trigger_val;
130 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s, sensor[s].friendly_name, trigger_val);
134 static int enable_event(int dev_num, const char *name, int enabled)
136 char sysfs_path[PATH_MAX];
138 sprintf(sysfs_path, EVENTS_PATH "%s", dev_num, name);
139 return sysfs_write_int(sysfs_path, enabled);
142 static int enable_sensor(int dev_num, const char *tag, int enabled)
144 char sysfs_path[PATH_MAX];
146 sprintf(sysfs_path, SENSOR_ENABLE_PATH, dev_num, tag);
147 return sysfs_write_int(sysfs_path, enabled);
150 static void enable_iio_timestamp (int dev_num, int known_channels)
152 /* Check if we have a dedicated iio timestamp channel */
154 char spec_buf[MAX_TYPE_SPEC_LEN];
155 char sysfs_path[PATH_MAX];
158 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
160 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
165 if (strcmp(spec_buf, "le:s64/64>>0"))
168 /* OK, type is int64_t as expected, in little endian representation */
170 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
172 if (sysfs_read_int(sysfs_path, &n))
175 /* Check that the timestamp comes after the other fields we read */
176 if (n != known_channels)
179 /* Try enabling that channel */
180 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
182 sysfs_write_int(sysfs_path, 1);
184 if (sysfs_read_int(sysfs_path, &n))
188 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
189 has_iio_ts[dev_num] = 1;
194 static int decode_type_spec (const char type_buf[MAX_TYPE_SPEC_LEN], datum_info_t *type_info)
196 /* Return size in bytes for this type specification, or -1 in error */
199 unsigned int realbits, storagebits, shift;
202 /* Valid specs: "le:u10/16>>0", "le:s16/32>>0" or "le:s32/32>>0" */
204 tokens = sscanf(type_buf, "%ce:%c%u/%u>>%u", &endianness, &sign, &realbits, &storagebits, &shift);
206 if (tokens != 5 || (endianness != 'b' && endianness != 'l') || (sign != 'u' && sign != 's') ||
207 realbits > storagebits || (storagebits != 16 && storagebits != 32 && storagebits != 64)) {
208 ALOGE("Invalid iio channel type spec: %s\n", type_buf);
212 type_info->endianness = endianness;
213 type_info->sign = sign;
214 type_info->realbits = (short) realbits;
215 type_info->storagebits = (short) storagebits;
216 type_info->shift = (short) shift;
218 return storagebits / 8;
222 void build_sensor_report_maps (int dev_num)
225 * Read sysfs files from a iio device's scan_element directory, and build a couple of tables from that data. These tables will tell, for
226 * each sensor, where to gather relevant data in a device report, i.e. the structure that we read from the /dev/iio:deviceX file in order to
227 * sensor report, itself being the data that we return to Android when a sensor poll completes. The mapping should be straightforward in the
228 * case where we have a single sensor active per iio device but, this is not the general case. In general several sensors can be handled
229 * through a single iio device, and the _en, _index and _type syfs entries all concur to paint a picture of what the structure of the
239 char spec_buf[MAX_TYPE_SPEC_LEN];
240 datum_info_t* ch_info;
242 char sysfs_path[PATH_MAX];
245 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
246 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
247 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
251 /* For each sensor that is linked to this device */
252 for (s=0; s<sensor_count; s++) {
253 if (sensor[s].dev_num != dev_num)
256 i = sensor[s].catalog_index;
258 /* Read channel details through sysfs attributes */
259 for (c=0; c<sensor[s].num_channels; c++) {
261 /* Read _type file */
262 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].type_path);
264 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
267 ALOGW( "Failed to read type: %s\n", sysfs_path);
271 ch_spec = sensor[s].channel[c].type_spec;
273 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
275 ch_info = &sensor[s].channel[c].type_info;
277 size = decode_type_spec(ch_spec, ch_info);
279 /* Read _index file */
280 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].index_path);
282 n = sysfs_read_int(sysfs_path, &ch_index);
285 ALOGW( "Failed to read index: %s\n", sysfs_path);
289 if (ch_index >= MAX_SENSORS) {
290 ALOGE("Index out of bounds!: %s\n", sysfs_path);
294 /* Record what this index is about */
296 sensor_handle_from_index [ch_index] = s;
297 channel_number_from_index[ch_index] = c;
298 channel_size_from_index [ch_index] = size;
303 /* Stop sampling - if we are recovering from hal restart */
304 enable_buffer(dev_num, 0);
305 setup_trigger(s, "\n");
307 /* Turn on channels we're aware of */
308 for (c=0;c<sensor[s].num_channels; c++) {
309 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].en_path);
310 sysfs_write_int(sysfs_path, 1);
314 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
317 * Now that we know which channels are defined, their sizes and their ordering, update channels offsets within device report. Note: there
318 * is a possibility that several sensors share the same index, with their data fields being isolated by masking and shifting as specified
319 * through the real bits and shift values in type attributes. This case is not currently supported. Also, the code below assumes no hole in
320 * the sequence of indices, so it is dependent on discovery of all sensors.
324 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
325 s = sensor_handle_from_index[i];
326 c = channel_number_from_index[i];
327 size = channel_size_from_index[i];
332 ALOGI("S%d C%d : offset %d, size %d, type %s\n", s, c, offset, size, sensor[s].channel[c].type_spec);
334 sensor[s].channel[c].offset = offset;
335 sensor[s].channel[c].size = size;
340 /* Enable the timestamp channel if there is one available */
341 enable_iio_timestamp(dev_num, known_channels);
343 /* Add padding and timestamp size if it's enabled on this iio device */
344 if (has_iio_ts[dev_num])
345 offset = (offset+7)/8*8 + sizeof(int64_t);
347 expected_dev_report_size[dev_num] = offset;
348 ALOGI("Expecting %d scan length on iio dev %d\n", offset, dev_num);
350 if (expected_dev_report_size[dev_num] > MAX_DEVICE_REPORT_SIZE) {
351 ALOGE("Unexpectedly large scan buffer on iio dev%d: %d bytes\n", dev_num, expected_dev_report_size[dev_num]);
353 expected_dev_report_size[dev_num] = MAX_DEVICE_REPORT_SIZE;
358 int adjust_counters (int s, int enabled, int from_virtual)
361 * Adjust counters based on sensor enable action. Return values are:
362 * 0 if the operation was completed and we're all set
363 * 1 if we toggled the state of the sensor and there's work left
364 * -1 in case of an error
367 int dev_num = sensor[s].dev_num;
369 if (!check_state_change(s, enabled, from_virtual))
370 return 0; /* The state of the sensor remains the same: we're done */
373 ALOGI("Enabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
375 switch (sensor[s].type) {
376 case SENSOR_TYPE_ACCELEROMETER:
380 case SENSOR_TYPE_MAGNETIC_FIELD:
381 compass_read_data(s);
384 case SENSOR_TYPE_GYROSCOPE:
389 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
391 /* Sensor disabled, lower report available flag */
392 sensor[s].report_pending = 0;
394 /* Save calibration data to persistent storage */
395 switch (sensor[s].type) {
396 case SENSOR_TYPE_ACCELEROMETER:
400 case SENSOR_TYPE_MAGNETIC_FIELD:
401 compass_store_data(s);
404 case SENSOR_TYPE_GYROSCOPE:
410 /* We changed the state of a sensor: adjust device ref counts */
412 switch(sensor[s].mode) {
415 trig_sensors_per_dev[dev_num]++;
417 trig_sensors_per_dev[dev_num]--;
422 active_poll_sensors++;
423 poll_sensors_per_dev[dev_num]++;
426 active_poll_sensors--;
427 poll_sensors_per_dev[dev_num]--;
433 /* Invalid sensor mode */
439 static int get_field_count (int s, size_t *field_size)
441 *field_size = sizeof(float);
443 switch (sensor[s].type) {
444 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
445 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
446 case SENSOR_TYPE_ORIENTATION: /* degrees */
447 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
448 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
451 case SENSOR_TYPE_INTERNAL_INTENSITY:
452 case SENSOR_TYPE_INTERNAL_ILLUMINANCE:
453 case SENSOR_TYPE_LIGHT: /* SI lux units */
454 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
455 case SENSOR_TYPE_TEMPERATURE: /* °C */
456 case SENSOR_TYPE_PROXIMITY: /* centimeters */
457 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
458 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
459 case SENSOR_TYPE_STEP_DETECTOR: /* event: always 1 */
462 case SENSOR_TYPE_ROTATION_VECTOR:
465 case SENSOR_TYPE_STEP_COUNTER: /* number of steps */
466 *field_size = sizeof(uint64_t);
469 ALOGE("Unknown sensor type!\n");
470 return 0; /* Drop sample */
475 * CTS acceptable thresholds:
476 * EventGapVerification.java: (th <= 1.8)
477 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
479 #define THRESHOLD 1.10
480 #define MAX_DELAY 500000000 /* 500 ms */
482 void set_report_ts(int s, int64_t ts)
484 int64_t maxTs, period;
487 * A bit of a hack to please a bunch of cts tests. They
488 * expect the timestamp to be exacly according to the set-up
489 * frequency but if we're simply getting the timestamp at hal level
490 * this may not be the case. Perhaps we'll get rid of this when
491 * we'll be reading the timestamp from the iio channel for all sensors
493 if (sensor[s].report_ts && sensor[s].sampling_rate &&
494 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
496 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
497 maxTs = sensor[s].report_ts + THRESHOLD * period;
498 /* If we're too far behind get back on track */
499 if (ts - maxTs >= MAX_DELAY)
501 sensor[s].report_ts = (ts < maxTs ? ts : maxTs);
503 sensor[s].report_ts = ts;
507 static void* acquisition_routine (void* param)
510 * Data acquisition routine run in a dedicated thread, covering a single sensor. This loop will periodically retrieve sampling data through
511 * sysfs, then package it as a sample and transfer it to our master poll loop through a report fd. Checks for a cancellation signal quite
512 * frequently, as the thread may be disposed of at any time. Note that Bionic does not provide pthread_cancel / pthread_testcancel...
515 int s = (int) (size_t) param;
517 sensors_event_t data = {0};
520 struct timespec target_time;
521 int64_t timestamp, period, start, stop;
524 if (s < 0 || s >= sensor_count) {
525 ALOGE("Invalid sensor handle!\n");
529 ALOGI("Entering S%d (%s) data acquisition thread: rate:%g\n", s, sensor[s].friendly_name, sensor[s].sampling_rate);
531 if (sensor[s].sampling_rate <= 0) {
532 ALOGE("Invalid rate in acquisition routine for sensor %d: %g\n", s, sensor[s].sampling_rate);
536 /* Initialize data fields that will be shared by all sensor reports */
537 data.version = sizeof(sensors_event_t);
539 data.type = sensor_desc[s].type;
541 num_fields = get_field_count(s, &field_size);
544 * Each condition variable is associated to a mutex that has to be locked by the thread that's waiting on it. We use these condition
545 * variables to get the acquisition threads out of sleep quickly after the sampling rate is adjusted, or the sensor is disabled.
547 pthread_mutex_lock(&thread_release_mutex[s]);
549 /* Pinpoint the moment we start sampling */
550 timestamp = get_timestamp_monotonic();
552 /* Check and honor termination requests */
553 while (sensor[s].thread_data_fd[1] != -1) {
554 start = get_timestamp_boot();
556 /* Read values through sysfs */
557 for (c=0; c<num_fields; c++) {
558 if (field_size == sizeof(uint64_t))
559 data.u64.data[c] = acquire_immediate_uint64_value(s, c);
561 data.data[c] = acquire_immediate_float_value(s, c);
563 /* Check and honor termination requests */
564 if (sensor[s].thread_data_fd[1] == -1)
567 stop = get_timestamp_boot();
568 set_report_ts(s, start/2 + stop/2);
569 data.timestamp = sensor[s].report_ts;
570 /* If the sample looks good */
571 if (sensor[s].ops.finalize(s, &data)) {
573 /* Pipe it for transmission to poll loop */
574 ret = write(sensor[s].thread_data_fd[1], &data, sizeof(sensors_event_t));
576 if (ret != sizeof(sensors_event_t))
577 ALOGE("S%d write failure: wrote %d, got %d\n", s, sizeof(sensors_event_t), ret);
580 /* Check and honor termination requests */
581 if (sensor[s].thread_data_fd[1] == -1)
584 /* Recalculate period assuming sensor[s].sampling_rate can be changed dynamically during the thread run */
585 if (sensor[s].sampling_rate <= 0) {
586 ALOGE("Unexpected sampling rate for sensor %d: %g\n", s, sensor[s].sampling_rate);
590 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
592 set_timestamp(&target_time, timestamp);
594 /* Wait until the sampling time elapses, or a rate change is signaled, or a thread exit is requested */
595 ret = pthread_cond_timedwait(&thread_release_cond[s], &thread_release_mutex[s], &target_time);
599 ALOGV("Acquisition thread for S%d exiting\n", s);
600 pthread_mutex_unlock(&thread_release_mutex[s]);
606 static void start_acquisition_thread (int s)
608 int incoming_data_fd;
611 struct epoll_event ev = {0};
613 ALOGV("Initializing acquisition context for sensor %d\n", s);
615 /* Create condition variable and mutex for quick thread release */
616 ret = pthread_condattr_init(&thread_cond_attr[s]);
617 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
618 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
619 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
621 /* Create a pipe for inter thread communication */
622 ret = pipe(sensor[s].thread_data_fd);
624 incoming_data_fd = sensor[s].thread_data_fd[0];
627 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
629 /* Add incoming side of pipe to our poll set, with a suitable tag */
630 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
632 ALOGE("Failed adding %d to poll set (%s)\n",
633 incoming_data_fd, strerror(errno));
636 /* Create and start worker thread */
637 ret = pthread_create(&sensor[s].acquisition_thread, NULL, acquisition_routine, (void*) (size_t) s);
641 static void stop_acquisition_thread (int s)
643 int incoming_data_fd = sensor[s].thread_data_fd[0];
644 int outgoing_data_fd = sensor[s].thread_data_fd[1];
646 ALOGV("Tearing down acquisition context for sensor %d\n", s);
648 /* Delete the incoming side of the pipe from our poll set */
649 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
651 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
652 sensor[s].thread_data_fd[0] = -1;
653 sensor[s].thread_data_fd[1] = -1;
655 /* Close both sides of our pipe */
656 close(incoming_data_fd);
657 close(outgoing_data_fd);
659 /* Stop acquisition thread and clean up thread handle */
660 pthread_cond_signal(&thread_release_cond[s]);
661 pthread_join(sensor[s].acquisition_thread, NULL);
663 /* Clean up our sensor descriptor */
664 sensor[s].acquisition_thread = -1;
666 /* Delete condition variable and mutex */
667 pthread_cond_destroy(&thread_release_cond[s]);
668 pthread_mutex_destroy(&thread_release_mutex[s]);
672 static int is_fast_accelerometer (int s)
675 * Some games don't react well to accelerometers using any-motion triggers. Even very low thresholds seem to trip them, and they tend to
676 * request fairly high event rates. Favor continuous triggers if the sensor is an accelerometer and uses a sampling rate of at least 25.
679 if (sensor[s].type != SENSOR_TYPE_ACCELEROMETER)
682 if (sensor[s].sampling_rate < 25)
689 static void tentative_switch_trigger (int s)
692 * Under certain situations it may be beneficial to use an alternate trigger:
694 * - for applications using the accelerometer with high sampling rates, prefer the continuous trigger over the any-motion one, to avoid
695 * jumps related to motion thresholds
698 if (is_fast_accelerometer(s) && !(sensor[s].quirks & QUIRK_TERSE_DRIVER) && sensor[s].selected_trigger == sensor[s].motion_trigger_name)
699 setup_trigger(s, sensor[s].init_trigger_name);
703 static float get_group_max_sampling_rate (int s)
705 /* Review the sampling rates of linked sensors and return the maximum */
709 float arbitrated_rate = 0;
712 arbitrated_rate = sensor[s].requested_rate;
714 /* If any of the currently active sensors built on top of this one need a higher sampling rate, switch to this rate */
715 for (i = 0; i < sensor_count; i++)
716 for (vi = 0; vi < sensor[i].base_count; vi++)
717 if (sensor[i].base[vi] == s && is_enabled(i) && sensor[i].requested_rate > arbitrated_rate) /* If sensor i depends on sensor s */
718 arbitrated_rate = sensor[i].requested_rate;
720 /* If any of the currently active sensors we rely on is using a higher sampling rate, switch to this rate */
721 for (vi = 0; vi < sensor[s].base_count; vi++) {
722 i = sensor[s].base[vi];
723 if (is_enabled(i) && sensor[i].requested_rate > arbitrated_rate)
724 arbitrated_rate = sensor[i].requested_rate;
727 return arbitrated_rate;
731 static int sensor_set_rate (int s, float requested_rate)
733 /* Set the rate at which a specific sensor should report events. See Android sensors.h for indication on sensor trigger modes */
735 char sysfs_path[PATH_MAX];
736 char avail_sysfs_path[PATH_MAX];
737 int dev_num = sensor[s].dev_num;
738 int i = sensor[s].catalog_index;
739 const char *prefix = sensor_catalog[i].tag;
740 int per_sensor_sampling_rate;
741 int per_device_sampling_rate;
746 float group_max_sampling_rate;
747 float cur_sampling_rate; /* Currently used sampling rate */
748 float arb_sampling_rate; /* Granted sampling rate after arbitration */
749 char hrtimer_sampling_path[PATH_MAX];
750 char trigger_path[PATH_MAX];
752 ALOGV("Sampling rate %g requested on sensor %d (%s)\n", requested_rate, s, sensor[s].friendly_name);
754 sensor[s].requested_rate = requested_rate;
756 arb_sampling_rate = requested_rate;
758 if (arb_sampling_rate < sensor[s].min_supported_rate) {
759 ALOGV("Sampling rate %g too low for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].min_supported_rate);
760 arb_sampling_rate = sensor[s].min_supported_rate;
763 /* If one of the linked sensors uses a higher rate, adopt it */
764 group_max_sampling_rate = get_group_max_sampling_rate(s);
766 if (arb_sampling_rate < group_max_sampling_rate) {
767 ALOGV("Using %s sampling rate to %g too due to dependency\n", sensor[s].friendly_name, arb_sampling_rate);
768 arb_sampling_rate = group_max_sampling_rate;
771 if (sensor[s].max_supported_rate && arb_sampling_rate > sensor[s].max_supported_rate) {
772 ALOGV("Sampling rate %g too high for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].max_supported_rate);
773 arb_sampling_rate = sensor[s].max_supported_rate;
776 sensor[s].sampling_rate = arb_sampling_rate;
778 /* If the sensor is virtual, we're done */
779 if (sensor[s].is_virtual)
782 /* If we're dealing with a poll-mode sensor */
783 if (sensor[s].mode == MODE_POLL) {
785 pthread_cond_signal(&thread_release_cond[s]); /* Wake up thread so the new sampling rate gets used */
789 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
791 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
792 per_sensor_sampling_rate = 1;
793 per_device_sampling_rate = 0;
795 per_sensor_sampling_rate = 0;
797 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
799 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
800 per_device_sampling_rate = 1;
802 per_device_sampling_rate = 0;
805 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
806 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
810 /* Check if we have contraints on allowed sampling rates */
812 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
814 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0) {
817 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
819 /* While we're not at the end of the string */
820 while (*cursor && cursor[0]) {
822 /* Decode a single value */
823 sr = strtod(cursor, NULL);
825 /* If this matches the selected rate, we're happy. Have some tolerance for rounding errors and avoid needless jumps to higher rates */
826 if (fabs(arb_sampling_rate - sr) <= 0.01) {
827 arb_sampling_rate = sr;
832 * If we reached a higher value than the desired rate, adjust selected rate so it matches the first higher available one and
833 * stop parsing - this makes the assumption that rates are sorted by increasing value in the allowed frequencies string.
835 if (sr > arb_sampling_rate) {
836 arb_sampling_rate = sr;
841 while (cursor[0] && !isspace(cursor[0]))
845 while (cursor[0] && isspace(cursor[0]))
850 if (sensor[s].max_supported_rate &&
851 arb_sampling_rate > sensor[s].max_supported_rate) {
852 arb_sampling_rate = sensor[s].max_supported_rate;
855 /* Record the rate that was agreed upon with the sensor taken in isolation ; this avoid uncontrolled ripple effects between colocated sensor rates */
856 sensor[s].semi_arbitrated_rate = arb_sampling_rate;
858 /* Coordinate with others active sensors on the same device, if any */
859 if (per_device_sampling_rate)
860 for (n=0; n<sensor_count; n++)
861 if (n != s && sensor[n].dev_num == dev_num && sensor[n].num_channels && is_enabled(n) &&
862 sensor[n].semi_arbitrated_rate > arb_sampling_rate) {
863 ALOGV("Sampling rate shared between %s and %s, using %g instead of %g\n", sensor[s].friendly_name, sensor[n].friendly_name,
864 sensor[n].semi_arbitrated_rate, arb_sampling_rate);
865 arb_sampling_rate = sensor[n].semi_arbitrated_rate;
868 sensor[s].sampling_rate = arb_sampling_rate;
870 /* Update actual sampling rate field for this sensor and others which may be sharing the same sampling rate */
871 if (per_device_sampling_rate)
872 for (n=0; n<sensor_count; n++)
873 if (sensor[n].dev_num == dev_num && n != s && sensor[n].num_channels)
874 sensor[n].sampling_rate = arb_sampling_rate;
876 /* If the desired rate is already active we're all set */
877 if (arb_sampling_rate == cur_sampling_rate)
880 ALOGI("Sensor %d (%s) sampling rate set to %g\n", s, sensor[s].friendly_name, arb_sampling_rate);
882 if (sensor[s].hrtimer_trigger_name[0] != '\0') {
883 snprintf(trigger_path, PATH_MAX, "%s%s%d/", IIO_DEVICES, "trigger", sensor[s].trigger_nr);
884 snprintf (hrtimer_sampling_path, PATH_MAX, "%s%s", trigger_path, "sampling_frequency");
885 sysfs_write_float(hrtimer_sampling_path, arb_sampling_rate);
888 if (trig_sensors_per_dev[dev_num])
889 enable_buffer(dev_num, 0);
891 sysfs_write_float(sysfs_path, arb_sampling_rate);
893 /* Check if it makes sense to use an alternate trigger */
894 tentative_switch_trigger(s);
896 if (trig_sensors_per_dev[dev_num])
897 enable_buffer(dev_num, 1);
903 static void reapply_sampling_rates (int s)
906 * The specified sensor was either enabled or disabled. Other sensors in the same group may have constraints related to this sensor
907 * sampling rate on their own sampling rate, so reevaluate them by retrying to use their requested sampling rate, rather than the one
908 * that ended up being used after arbitration.
913 if (sensor[s].is_virtual) {
914 /* Take care of downwards dependencies */
915 for (i=0; i<sensor[s].base_count; i++) {
916 base = sensor[s].base[i];
917 sensor_set_rate(base, sensor[base].requested_rate);
923 for (i=0; i<sensor_count; i++)
924 for (j=0; j<sensor[i].base_count; j++)
925 if (sensor[i].base[j] == s) /* If sensor i depends on sensor s */
926 sensor_set_rate(i, sensor[i].requested_rate);
930 static int sensor_activate_virtual (int s, int enabled, int from_virtual)
934 sensor[s].event_count = 0;
935 sensor[s].meta_data_pending = 0;
937 if (!check_state_change(s, enabled, from_virtual))
938 return 0; /* The state of the sensor remains the same ; we're done */
941 ALOGI("Enabling sensor %d (%s)\n", s, sensor[s].friendly_name);
943 ALOGI("Disabling sensor %d (%s)\n", s, sensor[s].friendly_name);
945 sensor[s].report_pending = 0;
947 for (i=0; i<sensor[s].base_count; i++) {
949 base = sensor[s].base[i];
950 sensor_activate(base, enabled, 1);
953 sensor[base].ref_count++;
955 sensor[base].ref_count--;
958 /* Reevaluate sampling rates of linked sensors */
959 reapply_sampling_rates(s);
964 int sensor_activate (int s, int enabled, int from_virtual)
966 char device_name[PATH_MAX];
967 struct epoll_event ev = {0};
968 int dev_fd, event_fd;
970 int dev_num = sensor[s].dev_num;
972 int catalog_index = sensor[s].catalog_index;
974 if (sensor[s].is_virtual)
975 return sensor_activate_virtual(s, enabled, from_virtual);
977 /* Prepare the report timestamp field for the first event, see set_report_ts method */
978 sensor[s].report_ts = 0;
980 ret = adjust_counters(s, enabled, from_virtual);
982 /* If the operation was neutral in terms of state, we're done */
986 sensor[s].event_count = 0;
987 sensor[s].meta_data_pending = 0;
990 setup_noise_filtering(s); /* Initialize filtering data if required */
992 if (sensor[s].mode == MODE_TRIGGER) {
995 enable_buffer(dev_num, 0);
996 setup_trigger(s, "\n");
998 /* If there's at least one sensor enabled on this iio device */
999 if (trig_sensors_per_dev[dev_num]) {
1001 /* Start sampling */
1002 if (sensor[s].hrtimer_trigger_name[0] != '\0')
1003 setup_trigger(s, sensor[s].hrtimer_trigger_name);
1005 setup_trigger(s, sensor[s].init_trigger_name);
1007 enable_buffer(dev_num, 1);
1009 } else if (sensor[s].mode == MODE_POLL) {
1010 if (sensor[s].needs_enable) {
1011 enable_sensor(dev_num, sensor_catalog[catalog_index].tag, enabled);
1016 * Make sure we have a fd on the character device ; conversely, close the fd if no one is using associated sensors anymore. The assumption
1017 * here is that the underlying driver will power on the relevant hardware block while someone holds a fd on the device.
1019 dev_fd = device_fd[dev_num];
1022 if (sensor[s].mode == MODE_POLL)
1023 stop_acquisition_thread(s);
1025 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1026 /* Stop watching this fd. This should be a no-op in case this fd was not in the poll set. */
1027 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
1030 device_fd[dev_num] = -1;
1033 if (sensor[s].mode == MODE_EVENT) {
1034 event_fd = events_fd[dev_num];
1036 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1037 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1038 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1041 epoll_ctl(poll_fd, EPOLL_CTL_DEL, event_fd, NULL);
1043 events_fd[dev_num] = -1;
1047 /* Release any filtering data we may have accumulated */
1048 release_noise_filtering_data(s);
1050 /* Reevaluate sampling rates of linked sensors */
1051 reapply_sampling_rates(s);
1056 /* First enabled sensor on this iio device */
1057 sprintf(device_name, DEV_FILE_PATH, dev_num);
1058 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
1060 device_fd[dev_num] = dev_fd;
1063 ALOGE("Could not open fd on %s (%s)\n", device_name, strerror(errno));
1064 adjust_counters(s, 0, from_virtual);
1068 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
1070 if (sensor[s].mode == MODE_TRIGGER) {
1072 /* Add this iio device fd to the set of watched fds */
1073 ev.events = EPOLLIN;
1074 ev.data.u32 = dev_num;
1076 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
1079 ALOGE("Failed adding %d to poll set (%s)\n", dev_fd, strerror(errno));
1083 /* Note: poll-mode fds are not readable */
1084 } else if (sensor[s].mode == MODE_EVENT) {
1085 event_fd = events_fd[dev_num];
1087 ret = ioctl(dev_fd, IIO_GET_EVENT_FD_IOCTL, &event_fd);
1088 if (ret == -1 || event_fd == -1) {
1089 ALOGE("Failed to retrieve event_fd from %d (%s)\n", dev_fd, strerror(errno));
1092 events_fd[dev_num] = event_fd;
1093 ALOGV("Opened fd=%d to receive events\n", event_fd);
1095 /* Add this event fd to the set of watched fds */
1096 ev.events = EPOLLIN;
1097 ev.data.u32 = dev_num;
1099 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, event_fd, &ev);
1101 ALOGE("Failed adding %d to poll set (%s)\n", event_fd, strerror(errno));
1104 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1106 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1107 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1110 if (!poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1112 device_fd[dev_num] = -1;
1117 /* Ensure that on-change sensors send at least one event after enable */
1118 get_field_count(s, &field_size);
1119 if (field_size == sizeof(uint64_t))
1120 sensor[s].prev_val.data64 = -1;
1122 sensor[s].prev_val.data = -1;
1124 if (sensor[s].mode == MODE_POLL)
1125 start_acquisition_thread(s);
1127 /* Reevaluate sampling rates of linked sensors */
1128 reapply_sampling_rates(s);
1134 static void enable_motion_trigger (int dev_num)
1137 * In the ideal case, we enumerate two triggers per iio device ; the default (periodically firing) trigger, and another one (the motion
1138 * trigger) that only fires up when motion is detected. This second one allows for lesser energy consumption, but requires periodic sample
1139 * duplication at the HAL level for sensors that Android defines as continuous. This "duplicate last sample" logic can only be engaged
1140 * once we got a first sample for the driver, so we start with the default trigger when an iio device is first opened, then adjust the
1141 * trigger when we got events for all active sensors. Unfortunately in the general case several sensors can be associated to a given iio
1142 * device, they can independently be controlled, and we have to adjust the trigger in use at the iio device level depending on whether or
1143 * not appropriate conditions are met at the sensor level.
1148 int active_sensors = trig_sensors_per_dev[dev_num];
1149 int candidate[MAX_SENSORS];
1150 int candidate_count = 0;
1152 if (!active_sensors)
1155 /* Check that all active sensors are ready to switch */
1157 for (s=0; s<MAX_SENSORS; s++)
1158 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels &&
1159 (!sensor[s].motion_trigger_name[0] || !sensor[s].report_initialized || is_fast_accelerometer(s) ||
1160 (sensor[s].quirks & QUIRK_FORCE_CONTINUOUS)))
1163 /* Record which particular sensors need to switch */
1165 for (s=0; s<MAX_SENSORS; s++)
1166 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels && sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1167 candidate[candidate_count++] = s;
1169 if (!candidate_count)
1172 /* Now engage the motion trigger for sensors which aren't using it */
1174 enable_buffer(dev_num, 0);
1176 for (i=0; i<candidate_count; i++) {
1178 setup_trigger(s, sensor[s].motion_trigger_name);
1181 enable_buffer(dev_num, 1);
1184 static void stamp_reports (int dev_num, int64_t ts)
1188 for (s=0; s<MAX_SENSORS; s++)
1189 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].mode != MODE_POLL) {
1190 if (sensor[s].quirks & QUIRK_SPOTTY)
1191 set_report_ts(s, ts);
1193 sensor[s].report_ts = ts;
1198 static int integrate_device_report_from_dev(int dev_num, int fd)
1202 unsigned char buf[MAX_DEVICE_REPORT_SIZE] = { 0 };
1204 unsigned char *target;
1205 unsigned char *source;
1208 int ts_offset = 0; /* Offset of iio timestamp, if provided */
1209 int64_t boot_to_rt_delta;
1211 /* There's an incoming report on the specified iio device char dev fd */
1213 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
1217 len = read(fd, buf, expected_dev_report_size[dev_num]);
1220 ALOGE("Could not read report from iio device %d (%s)\n", dev_num, strerror(errno));
1224 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
1226 /* Map device report to sensor reports */
1228 for (s=0; s<MAX_SENSORS; s++)
1229 if (sensor[s].dev_num == dev_num && is_enabled(s)) {
1233 /* Copy data from device to sensor report buffer */
1234 for (c=0; c<sensor[s].num_channels; c++) {
1236 target = sensor[s].report_buffer + sr_offset;
1238 source = buf + sensor[s].channel[c].offset;
1240 size = sensor[s].channel[c].size;
1242 memcpy(target, source, size);
1247 ALOGV("Sensor %d report available (%d bytes)\n", s, sr_offset);
1249 sensor[s].report_pending = DATA_TRIGGER;
1250 sensor[s].report_initialized = 1;
1252 ts_offset += sr_offset;
1255 /* Tentatively switch to an any-motion trigger if conditions are met */
1256 enable_motion_trigger(dev_num);
1258 /* If no iio timestamp channel was detected for this device, bail out */
1259 if (!has_iio_ts[dev_num]) {
1260 stamp_reports(dev_num, get_timestamp_boot());
1264 /* Don't trust the timestamp channel in any-motion mode */
1265 for (s=0; s<MAX_SENSORS; s++)
1266 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name) {
1267 stamp_reports(dev_num, get_timestamp_boot());
1271 /* Align on a 64 bits boundary */
1272 ts_offset = expected_dev_report_size[dev_num] - sizeof(int64_t);
1274 /* If we read an amount of data consistent with timestamp presence */
1275 if (len == expected_dev_report_size[dev_num])
1276 ts = *(int64_t*) (buf + ts_offset);
1279 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
1280 stamp_reports(dev_num, get_timestamp_boot());
1284 ALOGV("Driver timestamp on iio device %d: ts=%lld\n", dev_num, ts);
1286 boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1288 stamp_reports(dev_num, ts + boot_to_rt_delta);
1293 static int integrate_device_report_from_event(int dev_num, int fd)
1297 struct iio_event_data event;
1299 /* There's an incoming report on the specified iio device char dev fd */
1301 ALOGE("Ignoring stale report on event fd %d of device %d\n",
1306 len = read(fd, &event, sizeof(event));
1309 ALOGE("Could not read event from fd %d of device %d (%s)\n",
1310 fd, dev_num, strerror(errno));
1314 ts = event.timestamp;
1316 ALOGV("Read event %lld from fd %d of iio device %d\n", event.id, fd, dev_num);
1318 /* Map device report to sensor reports */
1319 for (s = 0; s < MAX_SENSORS; s++)
1320 if (sensor[s].dev_num == dev_num &&
1322 sensor[s].event_id = event.id;
1323 sensor[s].report_ts = ts;
1324 sensor[s].report_pending = 1;
1325 sensor[s].report_initialized = 1;
1326 ALOGV("Sensor %d report available (1 byte)\n", s);
1331 static int integrate_device_report(int dev_num)
1335 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
1336 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
1340 if (events_fd[dev_num] != -1) {
1341 ret = integrate_device_report_from_event(dev_num, events_fd[dev_num]);
1346 if (device_fd[dev_num] != -1)
1347 ret = integrate_device_report_from_dev(dev_num, device_fd[dev_num]);
1352 static int propagate_vsensor_report (int s, sensors_event_t *data)
1354 /* There's a new report stored in sensor.sample for this sensor; transmit it */
1356 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1359 data->type = sensor_desc[s].type; /* sensor_desc[s].type can differ from sensor[s].type ; internal types are remapped */
1364 static int propagate_sensor_report (int s, sensors_event_t *data)
1366 /* There's a sensor report pending for this sensor ; transmit it */
1369 int num_fields = get_field_count(s, &field_size);
1371 unsigned char* current_sample;
1374 /* If there's nothing to return... we're done */
1378 ALOGV("Sample on sensor %d (type %d):\n", s, sensor[s].type);
1380 if (sensor[s].mode == MODE_POLL) {
1381 /* We received a good sample but we're not directly enabled so we'll drop */
1382 if (!sensor[s].directly_enabled)
1384 /* Use the data provided by the acquisition thread */
1385 ALOGV("Reporting data from worker thread for S%d\n", s);
1386 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1387 data->timestamp = sensor[s].report_ts;
1391 memset(data, 0, sizeof(sensors_event_t));
1393 data->version = sizeof(sensors_event_t);
1395 data->type = sensor_desc[s].type; /* sensor_desc[s].type can differ from sensor[s].type ; internal types are remapped */
1396 data->timestamp = sensor[s].report_ts;
1398 if (sensor[s].mode == MODE_EVENT) {
1399 ALOGV("Reporting event\n");
1400 /* Android requires events to return 1.0 */
1401 int dir = IIO_EVENT_CODE_EXTRACT_DIR(sensor[s].event_id);
1402 switch (sensor[s].type) {
1403 case SENSOR_TYPE_PROXIMITY:
1404 if (dir == IIO_EV_DIR_FALLING)
1405 data->data[0] = 0.0;
1407 data->data[0] = 1.0;
1410 data->data[0] = 1.0;
1414 data->data[1] = 0.0;
1415 data->data[2] = 0.0;
1419 /* Convert the data into the expected Android-level format */
1421 current_sample = sensor[s].report_buffer;
1423 for (c=0; c<num_fields; c++) {
1425 data->data[c] = sensor[s].ops.transform (s, c, current_sample);
1427 ALOGV("\tfield %d: %g\n", c, data->data[c]);
1428 current_sample += sensor[s].channel[c].size;
1431 ret = sensor[s].ops.finalize(s, data);
1433 /* We will drop samples if the sensor is not directly enabled */
1434 if (!sensor[s].directly_enabled)
1437 /* The finalize routine, in addition to its late sample processing duty, has the final say on whether or not the sample gets sent to Android */
1442 static void synthetize_duplicate_samples (void)
1445 * Some sensor types (ex: gyroscope) are defined as continuously firing by Android, despite the fact that
1446 * we can be dealing with iio drivers that only report events for new samples. For these we generate reports
1447 * periodically, duplicating the last data we got from the driver. This is not necessary for polling sensors.
1455 for (s=0; s<sensor_count; s++) {
1457 /* Ignore disabled sensors */
1461 /* If the sensor is continuously firing, leave it alone */
1462 if (sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1465 /* If we haven't seen a sample, there's nothing to duplicate */
1466 if (!sensor[s].report_initialized)
1469 /* If a sample was recently buffered, leave it alone too */
1470 if (sensor[s].report_pending)
1473 /* We also need a valid sampling rate to be configured */
1474 if (!sensor[s].sampling_rate)
1477 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1479 current_ts = get_timestamp_boot();
1480 target_ts = sensor[s].report_ts + period;
1482 if (target_ts <= current_ts) {
1483 /* Mark the sensor for event generation */
1484 set_report_ts(s, current_ts);
1485 sensor[s].report_pending = DATA_DUPLICATE;
1491 static void integrate_thread_report (uint32_t tag)
1493 int s = tag - THREAD_REPORT_TAG_BASE;
1496 len = read(sensor[s].thread_data_fd[0], &sensor[s].sample, sizeof(sensors_event_t));
1498 if (len == sizeof(sensors_event_t))
1499 sensor[s].report_pending = DATA_SYSFS;
1503 static int get_poll_wait_timeout (void)
1506 * Compute an appropriate timeout value, in ms, for the epoll_wait call that's going to await
1507 * for iio device reports and incoming reports from our sensor sysfs data reader threads.
1511 int64_t target_ts = INT64_MAX;
1516 * Check if we're dealing with a driver that only send events when there is motion, despite the fact that the associated Android sensor
1517 * type is continuous rather than on-change. In that case we have to duplicate events. Check deadline for the nearest upcoming event.
1519 for (s=0; s<sensor_count; s++)
1520 if (is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name && sensor[s].sampling_rate) {
1521 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1523 if (sensor[s].report_ts + period < target_ts)
1524 target_ts = sensor[s].report_ts + period;
1527 /* If we don't have such a driver to deal with */
1528 if (target_ts == INT64_MAX)
1529 return -1; /* Infinite wait */
1531 ms_to_wait = (target_ts - get_timestamp_boot()) / 1000000;
1533 /* If the target timestamp is already behind us, don't wait */
1541 int sensor_poll (sensors_event_t* data, int count)
1546 struct epoll_event ev[MAX_DEVICES];
1547 int returned_events;
1550 /* Get one or more events from our collection of sensors */
1551 return_available_sensor_reports:
1553 /* Synthetize duplicate samples if needed */
1554 synthetize_duplicate_samples();
1556 returned_events = 0;
1558 /* Check our sensor collection for available reports */
1559 for (s=0; s<sensor_count && returned_events < count; s++) {
1561 if (sensor[s].report_pending) {
1564 if (sensor[s].is_virtual)
1565 event_count = propagate_vsensor_report(s, &data[returned_events]);
1567 /* Report this event if it looks OK */
1568 event_count = propagate_sensor_report(s, &data[returned_events]);
1571 sensor[s].report_pending = 0;
1572 returned_events += event_count;
1575 * If the sample was deemed invalid or unreportable, e.g. had the same value as the previously reported
1576 * value for a 'on change' sensor, silently drop it.
1580 while (sensor[s].meta_data_pending) {
1581 /* See sensors.h on these */
1582 data[returned_events].version = META_DATA_VERSION;
1583 data[returned_events].sensor = 0;
1584 data[returned_events].type = SENSOR_TYPE_META_DATA;
1585 data[returned_events].reserved0 = 0;
1586 data[returned_events].timestamp = 0;
1587 data[returned_events].meta_data.sensor = s;
1588 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1590 sensor[s].meta_data_pending--;
1594 if (returned_events)
1595 return returned_events;
1599 ALOGV("Awaiting sensor data\n");
1601 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1604 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1608 ALOGV("%d fds signalled\n", nfds);
1610 /* For each of the signalled sources */
1611 for (i=0; i<nfds; i++)
1612 if (ev[i].events == EPOLLIN)
1613 switch (ev[i].data.u32) {
1614 case 0 ... MAX_DEVICES-1:
1615 /* Read report from iio char dev fd */
1616 integrate_device_report(ev[i].data.u32);
1619 case THREAD_REPORT_TAG_BASE ...
1620 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1621 /* Get report from acquisition thread */
1622 integrate_thread_report(ev[i].data.u32);
1626 ALOGW("Unexpected event source!\n");
1630 goto return_available_sensor_reports;
1634 int sensor_set_delay (int s, int64_t ns)
1636 float requested_sampling_rate;
1639 ALOGE("Invalid delay requested on sensor %d: %lld\n", s, ns);
1643 requested_sampling_rate = 1000000000.0 / ns;
1645 ALOGV("Entering set delay S%d (%s): current rate: %g, requested: %g\n", s, sensor[s].friendly_name, sensor[s].sampling_rate, requested_sampling_rate);
1648 * Only try to adjust the low level sampling rate if it's different from the current one, as set by the HAL. This saves a few sysfs
1649 * reads and writes as well as buffer enable/disable operations, since at the iio level most drivers require the buffer to be turned off
1650 * in order to accept a sampling rate change. Of course that implies that this field has to be kept up to date and that only this library
1651 * is changing the sampling rate.
1654 if (requested_sampling_rate != sensor[s].sampling_rate)
1655 return sensor_set_rate(s, requested_sampling_rate);
1661 int sensor_flush (int s)
1663 /* If one shot or not enabled return -EINVAL */
1664 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE || !is_enabled(s))
1667 sensor[s].meta_data_pending++;
1672 int allocate_control_data (void)
1676 for (i=0; i<MAX_DEVICES; i++) {
1681 poll_fd = epoll_create(MAX_DEVICES);
1683 if (poll_fd == -1) {
1684 ALOGE("Can't create epoll instance for iio sensors!\n");
1692 void delete_control_data (void)