2 // Copyright (c) 2015 Intel Corporation
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
8 // http://www.apache.org/licenses/LICENSE-2.0
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
23 #include <sys/epoll.h>
24 #include <sys/ioctl.h>
25 #include <sys/socket.h>
26 #include <utils/Log.h>
27 #include <hardware/sensors.h>
28 #include <linux/ioctl.h>
30 #include "enumeration.h"
32 #include "transform.h"
33 #include "calibration.h"
34 #include "description.h"
35 #include "filtering.h"
37 #include <linux/iio/events.h>
38 #include <linux/iio/types.h>
42 /* Currently active sensors count, per device */
43 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
44 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
46 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
47 static int events_fd[MAX_DEVICES]; /* fd on the /sys/bus/iio/devices/iio:deviceX/events/<event_name> file */
48 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
49 static int expected_dev_report_size[MAX_DEVICES]; /* expected iio scan len */
50 static int poll_fd; /* epoll instance covering all enabled sensors */
52 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
54 static int flush_event_fd[2]; /* Pipe used for flush signaling */
56 /* We use pthread condition variables to get worker threads out of sleep */
57 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
58 static pthread_cond_t thread_release_cond [MAX_SENSORS];
59 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
61 #define FLUSH_REPORT_TAG 900
63 * We associate tags to each of our poll set entries. These tags have the following values:
64 * - a iio device number if the fd is a iio character device fd
65 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a pipe used by a sysfs data acquisition thread
67 #define THREAD_REPORT_TAG_BASE 1000
69 /* If buffer enable fails, we may want to retry a few times before giving up */
70 #define ENABLE_BUFFER_RETRIES 3
71 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
74 inline int is_enabled (int s)
76 return sensor[s].directly_enabled || sensor[s].ref_count;
80 static int check_state_change (int s, int enabled, int from_virtual)
83 if (sensor[s].directly_enabled)
84 return 0; /* We're being enabled but already were directly activated: no change. */
87 sensor[s].directly_enabled = 1; /* We're being directly enabled */
89 if (sensor[s].ref_count)
90 return 0; /* We were already indirectly enabled */
92 return 1; /* Do continue enabling this sensor */
96 return 0; /* We are being disabled but already were: no change */
98 if (from_virtual && sensor[s].directly_enabled)
99 return 0; /* We're indirectly disabled but the base is still active */
101 sensor[s].directly_enabled = 0; /* We're now directly disabled */
103 if (!from_virtual && sensor[s].ref_count)
104 return 0; /* We still have ref counts */
106 return 1; /* Do continue disabling this sensor */
110 static int enable_buffer (int dev_num, int enabled)
112 char sysfs_path[PATH_MAX];
113 int retries = ENABLE_BUFFER_RETRIES;
115 sprintf(sysfs_path, ENABLE_PATH, dev_num);
118 /* Low level, non-multiplexed, enable/disable routine */
119 if (sysfs_write_int(sysfs_path, enabled) > 0)
122 ALOGE("Failed enabling buffer on dev%d, retrying", dev_num);
123 usleep(ENABLE_BUFFER_RETRY_DELAY_MS*1000);
127 ALOGE("Could not enable buffer\n");
132 static int setup_trigger (int s, const char* trigger_val)
134 char sysfs_path[PATH_MAX];
135 int ret = -1, attempts = 5;
137 sprintf(sysfs_path, TRIGGER_PATH, sensor[s].dev_num);
139 if (trigger_val[0] != '\n')
140 ALOGI("Setting S%d (%s) trigger to %s\n", s, sensor[s].friendly_name, trigger_val);
142 while (ret == -1 && attempts) {
143 ret = sysfs_write_str(sysfs_path, trigger_val);
148 sensor[s].selected_trigger = trigger_val;
150 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s, sensor[s].friendly_name, trigger_val);
154 static int enable_event(int dev_num, const char *name, int enabled)
156 char sysfs_path[PATH_MAX];
158 sprintf(sysfs_path, EVENTS_PATH "%s", dev_num, name);
159 return sysfs_write_int(sysfs_path, enabled);
162 static int enable_sensor(int dev_num, const char *tag, int enabled)
164 char sysfs_path[PATH_MAX];
166 sprintf(sysfs_path, SENSOR_ENABLE_PATH, dev_num, tag);
167 return sysfs_write_int(sysfs_path, enabled);
170 static void enable_iio_timestamp (int dev_num, int known_channels)
172 /* Check if we have a dedicated iio timestamp channel */
174 char spec_buf[MAX_TYPE_SPEC_LEN];
175 char sysfs_path[PATH_MAX];
178 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
180 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
185 if (strcmp(spec_buf, "le:s64/64>>0"))
188 /* OK, type is int64_t as expected, in little endian representation */
190 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
192 if (sysfs_read_int(sysfs_path, &n))
195 /* Check that the timestamp comes after the other fields we read */
196 if (n != known_channels)
199 /* Try enabling that channel */
200 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
202 sysfs_write_int(sysfs_path, 1);
204 if (sysfs_read_int(sysfs_path, &n))
208 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
209 has_iio_ts[dev_num] = 1;
214 static int decode_type_spec (const char type_buf[MAX_TYPE_SPEC_LEN], datum_info_t *type_info)
216 /* Return size in bytes for this type specification, or -1 in error */
219 unsigned int realbits, storagebits, shift;
222 /* Valid specs: "le:u10/16>>0", "le:s16/32>>0" or "le:s32/32>>0" */
224 tokens = sscanf(type_buf, "%ce:%c%u/%u>>%u", &endianness, &sign, &realbits, &storagebits, &shift);
226 if (tokens != 5 || (endianness != 'b' && endianness != 'l') || (sign != 'u' && sign != 's') ||
227 realbits > storagebits || (storagebits != 16 && storagebits != 32 && storagebits != 64)) {
228 ALOGE("Invalid iio channel type spec: %s\n", type_buf);
232 type_info->endianness = endianness;
233 type_info->sign = sign;
234 type_info->realbits = (short) realbits;
235 type_info->storagebits = (short) storagebits;
236 type_info->shift = (short) shift;
238 return storagebits / 8;
242 void build_sensor_report_maps (int dev_num)
245 * 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
246 * 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
247 * sensor report, itself being the data that we return to Android when a sensor poll completes. The mapping should be straightforward in the
248 * 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
249 * 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
259 char spec_buf[MAX_TYPE_SPEC_LEN];
260 datum_info_t* ch_info;
262 char sysfs_path[PATH_MAX];
265 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
266 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
267 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
271 /* For each sensor that is linked to this device */
272 for (s=0; s<sensor_count; s++) {
273 if (sensor[s].dev_num != dev_num)
276 i = sensor[s].catalog_index;
278 /* Read channel details through sysfs attributes */
279 for (c=0; c<sensor[s].num_channels; c++) {
281 /* Read _type file */
282 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].type_path);
284 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
287 ALOGW( "Failed to read type: %s\n", sysfs_path);
291 ch_spec = sensor[s].channel[c].type_spec;
293 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
295 ch_info = &sensor[s].channel[c].type_info;
297 size = decode_type_spec(ch_spec, ch_info);
299 /* Read _index file */
300 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].index_path);
302 n = sysfs_read_int(sysfs_path, &ch_index);
305 ALOGW( "Failed to read index: %s\n", sysfs_path);
309 if (ch_index >= MAX_SENSORS) {
310 ALOGE("Index out of bounds!: %s\n", sysfs_path);
314 /* Record what this index is about */
316 sensor_handle_from_index [ch_index] = s;
317 channel_number_from_index[ch_index] = c;
318 channel_size_from_index [ch_index] = size;
323 sensor_update_max_range(s);
325 /* Stop sampling - if we are recovering from hal restart */
326 enable_buffer(dev_num, 0);
327 setup_trigger(s, "\n");
329 /* Turn on channels we're aware of */
330 for (c=0;c<sensor[s].num_channels; c++) {
331 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].en_path);
332 sysfs_write_int(sysfs_path, 1);
336 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
339 * Now that we know which channels are defined, their sizes and their ordering, update channels offsets within device report. Note: there
340 * is a possibility that several sensors share the same index, with their data fields being isolated by masking and shifting as specified
341 * through the real bits and shift values in type attributes. This case is not currently supported. Also, the code below assumes no hole in
342 * the sequence of indices, so it is dependent on discovery of all sensors.
346 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
347 s = sensor_handle_from_index[i];
348 c = channel_number_from_index[i];
349 size = channel_size_from_index[i];
354 ALOGI("S%d C%d : offset %d, size %d, type %s\n", s, c, offset, size, sensor[s].channel[c].type_spec);
356 sensor[s].channel[c].offset = offset;
357 sensor[s].channel[c].size = size;
362 /* Enable the timestamp channel if there is one available */
363 enable_iio_timestamp(dev_num, known_channels);
365 /* Add padding and timestamp size if it's enabled on this iio device */
366 if (has_iio_ts[dev_num])
367 offset = (offset+7)/8*8 + sizeof(int64_t);
369 expected_dev_report_size[dev_num] = offset;
370 ALOGI("Expecting %d scan length on iio dev %d\n", offset, dev_num);
372 if (expected_dev_report_size[dev_num] > MAX_DEVICE_REPORT_SIZE) {
373 ALOGE("Unexpectedly large scan buffer on iio dev%d: %d bytes\n", dev_num, expected_dev_report_size[dev_num]);
375 expected_dev_report_size[dev_num] = MAX_DEVICE_REPORT_SIZE;
380 int adjust_counters (int s, int enabled, int from_virtual)
383 * Adjust counters based on sensor enable action. Return values are:
384 * 0 if the operation was completed and we're all set
385 * 1 if we toggled the state of the sensor and there's work left
386 * -1 in case of an error
389 int dev_num = sensor[s].dev_num;
391 if (!check_state_change(s, enabled, from_virtual))
392 return 0; /* The state of the sensor remains the same: we're done */
395 ALOGI("Enabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
397 switch (sensor[s].type) {
398 case SENSOR_TYPE_ACCELEROMETER:
402 case SENSOR_TYPE_MAGNETIC_FIELD:
403 compass_read_data(s);
406 case SENSOR_TYPE_GYROSCOPE:
411 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
413 /* Sensor disabled, lower report available flag */
414 sensor[s].report_pending = 0;
416 /* Save calibration data to persistent storage */
417 switch (sensor[s].type) {
418 case SENSOR_TYPE_ACCELEROMETER:
422 case SENSOR_TYPE_MAGNETIC_FIELD:
423 compass_store_data(s);
426 case SENSOR_TYPE_GYROSCOPE:
432 /* We changed the state of a sensor: adjust device ref counts */
434 switch(sensor[s].mode) {
437 trig_sensors_per_dev[dev_num]++;
439 trig_sensors_per_dev[dev_num]--;
444 active_poll_sensors++;
445 poll_sensors_per_dev[dev_num]++;
448 active_poll_sensors--;
449 poll_sensors_per_dev[dev_num]--;
455 /* Invalid sensor mode */
461 static int get_field_count (int s, size_t *field_size)
463 *field_size = sizeof(float);
465 switch (sensor[s].type) {
466 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
467 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
468 case SENSOR_TYPE_ORIENTATION: /* degrees */
469 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
470 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
473 case SENSOR_TYPE_INTERNAL_INTENSITY:
474 case SENSOR_TYPE_INTERNAL_ILLUMINANCE:
475 case SENSOR_TYPE_LIGHT: /* SI lux units */
476 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
477 case SENSOR_TYPE_TEMPERATURE: /* °C */
478 case SENSOR_TYPE_PROXIMITY: /* centimeters */
479 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
480 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
481 case SENSOR_TYPE_STEP_DETECTOR: /* event: always 1 */
484 case SENSOR_TYPE_ROTATION_VECTOR:
487 case SENSOR_TYPE_STEP_COUNTER: /* number of steps */
488 *field_size = sizeof(uint64_t);
491 ALOGE("Unknown sensor type!\n");
492 return 0; /* Drop sample */
497 * CTS acceptable thresholds:
498 * EventGapVerification.java: (th <= 1.8)
499 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
501 #define THRESHOLD 1.10
502 #define MAX_DELAY 500000000 /* 500 ms */
504 void set_report_ts(int s, int64_t ts)
506 int64_t maxTs, period;
509 * A bit of a hack to please a bunch of cts tests. They
510 * expect the timestamp to be exacly according to the set-up
511 * frequency but if we're simply getting the timestamp at hal level
512 * this may not be the case. Perhaps we'll get rid of this when
513 * we'll be reading the timestamp from the iio channel for all sensors
515 if (sensor[s].report_ts && sensor[s].sampling_rate &&
516 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
518 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
519 maxTs = sensor[s].report_ts + THRESHOLD * period;
520 /* If we're too far behind get back on track */
521 if (ts - maxTs >= MAX_DELAY)
523 sensor[s].report_ts = (ts < maxTs ? ts : maxTs);
525 sensor[s].report_ts = ts;
529 static void* acquisition_routine (void* param)
532 * Data acquisition routine run in a dedicated thread, covering a single sensor. This loop will periodically retrieve sampling data through
533 * 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
534 * frequently, as the thread may be disposed of at any time. Note that Bionic does not provide pthread_cancel / pthread_testcancel...
537 int s = (int) (size_t) param;
539 sensors_event_t data = {0};
542 struct timespec target_time;
543 int64_t timestamp, period, start, stop;
546 if (s < 0 || s >= sensor_count) {
547 ALOGE("Invalid sensor handle!\n");
551 ALOGI("Entering S%d (%s) data acquisition thread: rate:%g\n", s, sensor[s].friendly_name, sensor[s].sampling_rate);
553 if (sensor[s].sampling_rate <= 0) {
554 ALOGE("Invalid rate in acquisition routine for sensor %d: %g\n", s, sensor[s].sampling_rate);
558 /* Initialize data fields that will be shared by all sensor reports */
559 data.version = sizeof(sensors_event_t);
561 data.type = sensor_desc[s].type;
563 num_fields = get_field_count(s, &field_size);
566 * 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
567 * variables to get the acquisition threads out of sleep quickly after the sampling rate is adjusted, or the sensor is disabled.
569 pthread_mutex_lock(&thread_release_mutex[s]);
571 /* Pinpoint the moment we start sampling */
572 timestamp = get_timestamp_monotonic();
574 /* Check and honor termination requests */
575 while (sensor[s].thread_data_fd[1] != -1) {
576 start = get_timestamp_boot();
578 /* Read values through sysfs */
579 for (c=0; c<num_fields; c++) {
580 if (field_size == sizeof(uint64_t))
581 data.u64.data[c] = acquire_immediate_uint64_value(s, c);
583 data.data[c] = acquire_immediate_float_value(s, c);
585 /* Check and honor termination requests */
586 if (sensor[s].thread_data_fd[1] == -1)
589 stop = get_timestamp_boot();
590 set_report_ts(s, start/2 + stop/2);
591 data.timestamp = sensor[s].report_ts;
592 /* If the sample looks good */
593 if (sensor[s].ops.finalize(s, &data)) {
595 /* Pipe it for transmission to poll loop */
596 ret = write(sensor[s].thread_data_fd[1], &data, sizeof(sensors_event_t));
598 if (ret != sizeof(sensors_event_t))
599 ALOGE("S%d write failure: wrote %zd, got %d\n", s, sizeof(sensors_event_t), ret);
602 /* Check and honor termination requests */
603 if (sensor[s].thread_data_fd[1] == -1)
606 /* Recalculate period assuming sensor[s].sampling_rate can be changed dynamically during the thread run */
607 if (sensor[s].sampling_rate <= 0) {
608 ALOGE("Unexpected sampling rate for sensor %d: %g\n", s, sensor[s].sampling_rate);
612 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
614 set_timestamp(&target_time, timestamp);
616 /* Wait until the sampling time elapses, or a rate change is signaled, or a thread exit is requested */
617 ret = pthread_cond_timedwait(&thread_release_cond[s], &thread_release_mutex[s], &target_time);
621 ALOGV("Acquisition thread for S%d exiting\n", s);
622 pthread_mutex_unlock(&thread_release_mutex[s]);
628 static void start_acquisition_thread (int s)
630 int incoming_data_fd;
633 struct epoll_event ev = {0};
635 ALOGV("Initializing acquisition context for sensor %d\n", s);
637 /* Create condition variable and mutex for quick thread release */
638 ret = pthread_condattr_init(&thread_cond_attr[s]);
639 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
640 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
641 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
643 /* Create a pipe for inter thread communication */
644 ret = pipe(sensor[s].thread_data_fd);
646 incoming_data_fd = sensor[s].thread_data_fd[0];
649 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
651 /* Add incoming side of pipe to our poll set, with a suitable tag */
652 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
654 ALOGE("Failed adding %d to poll set (%s)\n",
655 incoming_data_fd, strerror(errno));
658 /* Create and start worker thread */
659 ret = pthread_create(&sensor[s].acquisition_thread, NULL, acquisition_routine, (void*) (size_t) s);
663 static void stop_acquisition_thread (int s)
665 int incoming_data_fd = sensor[s].thread_data_fd[0];
666 int outgoing_data_fd = sensor[s].thread_data_fd[1];
668 ALOGV("Tearing down acquisition context for sensor %d\n", s);
670 /* Delete the incoming side of the pipe from our poll set */
671 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
673 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
674 sensor[s].thread_data_fd[0] = -1;
675 sensor[s].thread_data_fd[1] = -1;
677 /* Close both sides of our pipe */
678 close(incoming_data_fd);
679 close(outgoing_data_fd);
681 /* Stop acquisition thread and clean up thread handle */
682 pthread_cond_signal(&thread_release_cond[s]);
683 pthread_join(sensor[s].acquisition_thread, NULL);
685 /* Clean up our sensor descriptor */
686 sensor[s].acquisition_thread = -1;
688 /* Delete condition variable and mutex */
689 pthread_cond_destroy(&thread_release_cond[s]);
690 pthread_mutex_destroy(&thread_release_mutex[s]);
694 static int is_fast_accelerometer (int s)
697 * Some games don't react well to accelerometers using any-motion triggers. Even very low thresholds seem to trip them, and they tend to
698 * request fairly high event rates. Favor continuous triggers if the sensor is an accelerometer and uses a sampling rate of at least 25.
701 if (sensor[s].type != SENSOR_TYPE_ACCELEROMETER)
704 if (sensor[s].sampling_rate < 25)
711 static void tentative_switch_trigger (int s)
714 * Under certain situations it may be beneficial to use an alternate trigger:
716 * - for applications using the accelerometer with high sampling rates, prefer the continuous trigger over the any-motion one, to avoid
717 * jumps related to motion thresholds
720 if (is_fast_accelerometer(s) && !(sensor[s].quirks & QUIRK_TERSE_DRIVER) && sensor[s].selected_trigger == sensor[s].motion_trigger_name)
721 setup_trigger(s, sensor[s].init_trigger_name);
725 static float get_group_max_sampling_rate (int s)
727 /* Review the sampling rates of linked sensors and return the maximum */
731 float arbitrated_rate = 0;
734 arbitrated_rate = sensor[s].requested_rate;
736 /* If any of the currently active sensors built on top of this one need a higher sampling rate, switch to this rate */
737 for (i = 0; i < sensor_count; i++)
738 for (vi = 0; vi < sensor[i].base_count; vi++)
739 if (sensor[i].base[vi] == s && is_enabled(i) && sensor[i].requested_rate > arbitrated_rate) /* If sensor i depends on sensor s */
740 arbitrated_rate = sensor[i].requested_rate;
742 /* If any of the currently active sensors we rely on is using a higher sampling rate, switch to this rate */
743 for (vi = 0; vi < sensor[s].base_count; vi++) {
744 i = sensor[s].base[vi];
745 if (is_enabled(i) && sensor[i].requested_rate > arbitrated_rate)
746 arbitrated_rate = sensor[i].requested_rate;
749 return arbitrated_rate;
752 extern float sensor_get_max_freq (int s);
754 static float select_closest_available_rate(int s, float requested_rate)
758 float selected_rate = 0;
759 float max_rate_from_prop = sensor_get_max_freq(s);
761 if (!sensor[s].avail_freqs_count)
762 return requested_rate;
764 for (j = 0; j < sensor[s].avail_freqs_count; j++) {
766 sr = sensor[s].avail_freqs[j];
768 /* If this matches the selected rate, we're happy. Have some tolerance for rounding errors and avoid needless jumps to higher rates */
769 if ((fabs(requested_rate - sr) <= 0.01) && (sr <= max_rate_from_prop)) {
773 /* Select rate if it's less than max freq */
774 if ((sr > selected_rate) && (sr <= max_rate_from_prop)) {
779 * If we reached a higher value than the desired rate, adjust selected rate so it matches the first higher available one and
780 * stop parsing - this makes the assumption that rates are sorted by increasing value in the allowed frequencies string.
782 if (sr > requested_rate) {
783 return selected_rate;
787 /* Check for wrong values */
788 if (selected_rate < 0.1) {
789 return requested_rate;
791 return selected_rate;
795 static int sensor_set_rate (int s, float requested_rate)
797 /* Set the rate at which a specific sensor should report events. See Android sensors.h for indication on sensor trigger modes */
799 char sysfs_path[PATH_MAX];
800 int dev_num = sensor[s].dev_num;
801 int i = sensor[s].catalog_index;
802 const char *prefix = sensor_catalog[i].tag;
803 int per_sensor_sampling_rate;
804 int per_device_sampling_rate;
807 float group_max_sampling_rate;
808 float cur_sampling_rate; /* Currently used sampling rate */
809 float arb_sampling_rate; /* Granted sampling rate after arbitration */
810 char hrtimer_sampling_path[PATH_MAX];
811 char trigger_path[PATH_MAX];
813 ALOGV("Sampling rate %g requested on sensor %d (%s)\n", requested_rate, s, sensor[s].friendly_name);
815 sensor[s].requested_rate = requested_rate;
817 arb_sampling_rate = requested_rate;
819 if (arb_sampling_rate < sensor[s].min_supported_rate) {
820 ALOGV("Sampling rate %g too low for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].min_supported_rate);
821 arb_sampling_rate = sensor[s].min_supported_rate;
824 /* If one of the linked sensors uses a higher rate, adopt it */
825 group_max_sampling_rate = get_group_max_sampling_rate(s);
827 if (arb_sampling_rate < group_max_sampling_rate) {
828 ALOGV("Using %s sampling rate to %g too due to dependency\n", sensor[s].friendly_name, arb_sampling_rate);
829 arb_sampling_rate = group_max_sampling_rate;
832 if (sensor[s].max_supported_rate && arb_sampling_rate > sensor[s].max_supported_rate) {
833 ALOGV("Sampling rate %g too high for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].max_supported_rate);
834 arb_sampling_rate = sensor[s].max_supported_rate;
837 sensor[s].sampling_rate = arb_sampling_rate;
839 /* If the sensor is virtual, we're done */
840 if (sensor[s].is_virtual)
843 /* If we're dealing with a poll-mode sensor */
844 if (sensor[s].mode == MODE_POLL) {
846 pthread_cond_signal(&thread_release_cond[s]); /* Wake up thread so the new sampling rate gets used */
850 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
852 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
853 per_sensor_sampling_rate = 1;
854 per_device_sampling_rate = 0;
856 per_sensor_sampling_rate = 0;
858 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
860 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
861 per_device_sampling_rate = 1;
863 per_device_sampling_rate = 0;
866 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
867 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
871 if (sensor[s].hrtimer_trigger_name[0] != '\0') {
872 snprintf(trigger_path, PATH_MAX, "%s%s%d/", IIO_DEVICES, "trigger", sensor[s].trigger_nr);
873 snprintf(hrtimer_sampling_path, PATH_MAX, "%s%s", trigger_path, "sampling_frequency");
874 /* Enforce frequency update when software trigger
875 * frequency and current sampling rate are different */
876 if (sysfs_read_float(hrtimer_sampling_path, &sr) != -1 && sr != cur_sampling_rate)
877 cur_sampling_rate = -1;
879 arb_sampling_rate = select_closest_available_rate(s, arb_sampling_rate);
882 /* Record the rate that was agreed upon with the sensor taken in isolation ; this avoid uncontrolled ripple effects between colocated sensor rates */
883 sensor[s].semi_arbitrated_rate = arb_sampling_rate;
885 /* Coordinate with others active sensors on the same device, if any */
886 if (per_device_sampling_rate)
887 for (n=0; n<sensor_count; n++)
888 if (n != s && sensor[n].dev_num == dev_num && sensor[n].num_channels && is_enabled(n) &&
889 sensor[n].semi_arbitrated_rate > arb_sampling_rate) {
890 ALOGV("Sampling rate shared between %s and %s, using %g instead of %g\n", sensor[s].friendly_name, sensor[n].friendly_name,
891 sensor[n].semi_arbitrated_rate, arb_sampling_rate);
892 arb_sampling_rate = sensor[n].semi_arbitrated_rate;
895 sensor[s].sampling_rate = arb_sampling_rate;
897 /* Update actual sampling rate field for this sensor and others which may be sharing the same sampling rate */
898 if (per_device_sampling_rate)
899 for (n=0; n<sensor_count; n++)
900 if (sensor[n].dev_num == dev_num && n != s && sensor[n].num_channels)
901 sensor[n].sampling_rate = arb_sampling_rate;
903 /* If the desired rate is already active we're all set */
904 if (arb_sampling_rate == cur_sampling_rate)
907 ALOGI("Sensor %d (%s) sampling rate set to %g\n", s, sensor[s].friendly_name, arb_sampling_rate);
909 if (sensor[s].hrtimer_trigger_name[0] != '\0')
910 sysfs_write_float(hrtimer_sampling_path, ceilf(arb_sampling_rate));
912 if (trig_sensors_per_dev[dev_num])
913 enable_buffer(dev_num, 0);
915 if (sensor[s].hrtimer_trigger_name[0] != '\0') {
916 sysfs_write_float(sysfs_path, select_closest_available_rate(s, arb_sampling_rate));
918 sysfs_write_float(sysfs_path, arb_sampling_rate);
921 /* Check if it makes sense to use an alternate trigger */
922 tentative_switch_trigger(s);
924 if (trig_sensors_per_dev[dev_num])
925 enable_buffer(dev_num, 1);
931 static void reapply_sampling_rates (int s)
934 * The specified sensor was either enabled or disabled. Other sensors in the same group may have constraints related to this sensor
935 * sampling rate on their own sampling rate, so reevaluate them by retrying to use their requested sampling rate, rather than the one
936 * that ended up being used after arbitration.
941 if (sensor[s].is_virtual) {
942 /* Take care of downwards dependencies */
943 for (i=0; i<sensor[s].base_count; i++) {
944 base = sensor[s].base[i];
945 sensor_set_rate(base, sensor[base].requested_rate);
951 for (i=0; i<sensor_count; i++)
952 for (j=0; j<sensor[i].base_count; j++)
953 if (sensor[i].base[j] == s) /* If sensor i depends on sensor s */
954 sensor_set_rate(i, sensor[i].requested_rate);
958 static int sensor_activate_virtual (int s, int enabled, int from_virtual)
962 sensor[s].event_count = 0;
963 sensor[s].meta_data_pending = 0;
965 if (!check_state_change(s, enabled, from_virtual))
966 return 0; /* The state of the sensor remains the same ; we're done */
969 ALOGI("Enabling sensor %d (%s)\n", s, sensor[s].friendly_name);
971 ALOGI("Disabling sensor %d (%s)\n", s, sensor[s].friendly_name);
973 sensor[s].report_pending = 0;
975 for (i=0; i<sensor[s].base_count; i++) {
977 base = sensor[s].base[i];
978 sensor_activate(base, enabled, 1);
981 sensor[base].ref_count++;
983 sensor[base].ref_count--;
986 /* Reevaluate sampling rates of linked sensors */
987 reapply_sampling_rates(s);
992 int sensor_activate (int s, int enabled, int from_virtual)
994 char device_name[PATH_MAX];
995 struct epoll_event ev = {0};
996 int dev_fd, event_fd;
998 int dev_num = sensor[s].dev_num;
1000 int catalog_index = sensor[s].catalog_index;
1002 if (sensor[s].is_virtual)
1003 return sensor_activate_virtual(s, enabled, from_virtual);
1005 /* Prepare the report timestamp field for the first event, see set_report_ts method */
1006 sensor[s].report_ts = 0;
1008 ret = adjust_counters(s, enabled, from_virtual);
1010 /* If the operation was neutral in terms of state, we're done */
1014 sensor[s].event_count = 0;
1015 sensor[s].meta_data_pending = 0;
1018 setup_noise_filtering(s); /* Initialize filtering data if required */
1020 if (sensor[s].mode == MODE_TRIGGER) {
1023 enable_buffer(dev_num, 0);
1024 setup_trigger(s, "\n");
1026 /* If there's at least one sensor enabled on this iio device */
1027 if (trig_sensors_per_dev[dev_num]) {
1029 /* Start sampling */
1030 if (sensor[s].hrtimer_trigger_name[0] != '\0')
1031 setup_trigger(s, sensor[s].hrtimer_trigger_name);
1033 setup_trigger(s, sensor[s].init_trigger_name);
1035 enable_buffer(dev_num, 1);
1037 } else if (sensor[s].mode == MODE_POLL) {
1038 if (sensor[s].needs_enable) {
1039 enable_sensor(dev_num, sensor_catalog[catalog_index].tag, enabled);
1044 * Make sure we have a fd on the character device ; conversely, close the fd if no one is using associated sensors anymore. The assumption
1045 * here is that the underlying driver will power on the relevant hardware block while someone holds a fd on the device.
1047 dev_fd = device_fd[dev_num];
1050 if (sensor[s].mode == MODE_POLL)
1051 stop_acquisition_thread(s);
1053 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1054 /* Stop watching this fd. This should be a no-op in case this fd was not in the poll set. */
1055 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
1058 device_fd[dev_num] = -1;
1061 if (sensor[s].mode == MODE_EVENT) {
1062 event_fd = events_fd[dev_num];
1064 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1065 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1066 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1069 epoll_ctl(poll_fd, EPOLL_CTL_DEL, event_fd, NULL);
1071 events_fd[dev_num] = -1;
1075 /* Release any filtering data we may have accumulated */
1076 release_noise_filtering_data(s);
1078 /* Reevaluate sampling rates of linked sensors */
1079 reapply_sampling_rates(s);
1084 /* First enabled sensor on this iio device */
1085 sprintf(device_name, DEV_FILE_PATH, dev_num);
1086 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
1088 device_fd[dev_num] = dev_fd;
1091 ALOGE("Could not open fd on %s (%s)\n", device_name, strerror(errno));
1092 adjust_counters(s, 0, from_virtual);
1096 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
1098 if (sensor[s].mode == MODE_TRIGGER) {
1100 /* Add this iio device fd to the set of watched fds */
1101 ev.events = EPOLLIN;
1102 ev.data.u32 = dev_num;
1104 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
1107 ALOGE("Failed adding %d to poll set (%s)\n", dev_fd, strerror(errno));
1111 /* Note: poll-mode fds are not readable */
1112 #ifdef __NO_EVENTS__
1115 } else if (sensor[s].mode == MODE_EVENT) {
1116 event_fd = events_fd[dev_num];
1118 ret = ioctl(dev_fd, IIO_GET_EVENT_FD_IOCTL, &event_fd);
1119 if (ret == -1 || event_fd == -1) {
1120 ALOGE("Failed to retrieve event_fd from %d (%s)\n", dev_fd, strerror(errno));
1123 events_fd[dev_num] = event_fd;
1124 ALOGV("Opened fd=%d to receive events\n", event_fd);
1126 /* Add this event fd to the set of watched fds */
1127 ev.events = EPOLLIN;
1128 ev.data.u32 = dev_num;
1130 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, event_fd, &ev);
1132 ALOGE("Failed adding %d to poll set (%s)\n", event_fd, strerror(errno));
1135 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1137 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1138 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1141 if (!poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1143 device_fd[dev_num] = -1;
1149 /* Ensure that on-change sensors send at least one event after enable */
1150 get_field_count(s, &field_size);
1151 if (field_size == sizeof(uint64_t))
1152 sensor[s].prev_val.data64 = -1;
1154 sensor[s].prev_val.data = -1;
1156 if (sensor[s].mode == MODE_POLL)
1157 start_acquisition_thread(s);
1159 /* Reevaluate sampling rates of linked sensors */
1160 reapply_sampling_rates(s);
1166 static void enable_motion_trigger (int dev_num)
1169 * In the ideal case, we enumerate two triggers per iio device ; the default (periodically firing) trigger, and another one (the motion
1170 * trigger) that only fires up when motion is detected. This second one allows for lesser energy consumption, but requires periodic sample
1171 * duplication at the HAL level for sensors that Android defines as continuous. This "duplicate last sample" logic can only be engaged
1172 * 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
1173 * trigger when we got events for all active sensors. Unfortunately in the general case several sensors can be associated to a given iio
1174 * device, they can independently be controlled, and we have to adjust the trigger in use at the iio device level depending on whether or
1175 * not appropriate conditions are met at the sensor level.
1180 int active_sensors = trig_sensors_per_dev[dev_num];
1181 int candidate[MAX_SENSORS];
1182 int candidate_count = 0;
1184 if (!active_sensors)
1187 /* Check that all active sensors are ready to switch */
1189 for (s=0; s<MAX_SENSORS; s++)
1190 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels &&
1191 (!sensor[s].motion_trigger_name[0] || !sensor[s].report_initialized || is_fast_accelerometer(s) ||
1192 (sensor[s].quirks & QUIRK_FORCE_CONTINUOUS)))
1195 /* Record which particular sensors need to switch */
1197 for (s=0; s<MAX_SENSORS; s++)
1198 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels && sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1199 candidate[candidate_count++] = s;
1201 if (!candidate_count)
1204 /* Now engage the motion trigger for sensors which aren't using it */
1206 enable_buffer(dev_num, 0);
1208 for (i=0; i<candidate_count; i++) {
1210 setup_trigger(s, sensor[s].motion_trigger_name);
1213 enable_buffer(dev_num, 1);
1216 static void stamp_reports (int dev_num, int64_t ts)
1220 for (s=0; s<MAX_SENSORS; s++)
1221 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].mode != MODE_POLL) {
1222 if (sensor[s].quirks & QUIRK_SPOTTY)
1223 set_report_ts(s, ts);
1225 sensor[s].report_ts = ts;
1230 static int integrate_device_report_from_dev(int dev_num, int fd)
1234 unsigned char buf[MAX_DEVICE_REPORT_SIZE] = { 0 };
1236 unsigned char *target;
1237 unsigned char *source;
1240 int ts_offset = 0; /* Offset of iio timestamp, if provided */
1241 int64_t boot_to_rt_delta;
1243 /* There's an incoming report on the specified iio device char dev fd */
1245 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
1249 len = read(fd, buf, expected_dev_report_size[dev_num]);
1252 ALOGE("Could not read report from iio device %d (%s)\n", dev_num, strerror(errno));
1256 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
1258 /* Map device report to sensor reports */
1260 for (s=0; s<MAX_SENSORS; s++)
1261 if (sensor[s].dev_num == dev_num && is_enabled(s)) {
1265 /* Copy data from device to sensor report buffer */
1266 for (c=0; c<sensor[s].num_channels; c++) {
1268 target = sensor[s].report_buffer + sr_offset;
1270 source = buf + sensor[s].channel[c].offset;
1272 size = sensor[s].channel[c].size;
1274 memcpy(target, source, size);
1279 ALOGV("Sensor %d report available (%d bytes)\n", s, sr_offset);
1281 sensor[s].report_pending = DATA_TRIGGER;
1282 sensor[s].report_initialized = 1;
1286 /* Tentatively switch to an any-motion trigger if conditions are met */
1287 enable_motion_trigger(dev_num);
1289 /* If no iio timestamp channel was detected for this device, bail out */
1290 if (!has_iio_ts[dev_num]) {
1291 stamp_reports(dev_num, get_timestamp_boot());
1295 /* Don't trust the timestamp channel in any-motion mode */
1296 for (s=0; s<MAX_SENSORS; s++)
1297 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name) {
1298 stamp_reports(dev_num, get_timestamp_boot());
1302 /* Align on a 64 bits boundary */
1303 ts_offset = expected_dev_report_size[dev_num] - sizeof(int64_t);
1305 /* If we read an amount of data consistent with timestamp presence */
1306 if (len == expected_dev_report_size[dev_num])
1307 ts = *(int64_t*) (buf + ts_offset);
1310 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
1311 stamp_reports(dev_num, get_timestamp_boot());
1315 ALOGV("Driver timestamp on iio device %d: ts=%jd\n", dev_num, ts);
1317 boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1319 stamp_reports(dev_num, ts + boot_to_rt_delta);
1324 #ifndef __NO_EVENTS__
1325 static int integrate_device_report_from_event(int dev_num, int fd)
1329 struct iio_event_data event;
1330 int64_t boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1332 /* There's an incoming report on the specified iio device char dev fd */
1334 ALOGE("Ignoring stale report on event fd %d of device %d\n",
1339 len = read(fd, &event, sizeof(event));
1342 ALOGE("Could not read event from fd %d of device %d (%s)\n",
1343 fd, dev_num, strerror(errno));
1347 ts = event.timestamp + boot_to_rt_delta;
1349 ALOGV("Read event %lld from fd %d of iio device %d - ts %jd\n", event.id, fd, dev_num, ts);
1351 /* Map device report to sensor reports */
1352 for (s = 0; s < MAX_SENSORS; s++)
1353 if (sensor[s].dev_num == dev_num &&
1355 sensor[s].event_id = event.id;
1356 sensor[s].report_ts = ts;
1357 sensor[s].report_pending = 1;
1358 sensor[s].report_initialized = 1;
1359 ALOGV("Sensor %d report available (1 byte)\n", s);
1365 static int integrate_device_report(int dev_num)
1369 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
1370 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
1374 #ifndef __NO_EVENTS__
1375 if (events_fd[dev_num] != -1) {
1376 ret = integrate_device_report_from_event(dev_num, events_fd[dev_num]);
1382 if (device_fd[dev_num] != -1)
1383 ret = integrate_device_report_from_dev(dev_num, device_fd[dev_num]);
1388 static int propagate_vsensor_report (int s, sensors_event_t *data)
1390 /* There's a new report stored in sensor.sample for this sensor; transmit it */
1392 memcpy(data, &sensor[s].sample, 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 */
1400 static int propagate_sensor_report (int s, sensors_event_t *data)
1402 /* There's a sensor report pending for this sensor ; transmit it */
1405 int num_fields = get_field_count(s, &field_size);
1407 unsigned char* current_sample;
1410 /* If there's nothing to return... we're done */
1414 ALOGV("Sample on sensor %d (type %d):\n", s, sensor[s].type);
1416 if (sensor[s].mode == MODE_POLL) {
1417 /* We received a good sample but we're not directly enabled so we'll drop */
1418 if (!sensor[s].directly_enabled)
1420 /* Use the data provided by the acquisition thread */
1421 ALOGV("Reporting data from worker thread for S%d\n", s);
1422 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1423 data->timestamp = sensor[s].report_ts;
1427 memset(data, 0, sizeof(sensors_event_t));
1429 data->version = sizeof(sensors_event_t);
1431 data->type = sensor_desc[s].type; /* sensor_desc[s].type can differ from sensor[s].type ; internal types are remapped */
1432 data->timestamp = sensor[s].report_ts;
1434 #ifndef __NO_EVENTS__
1435 if (sensor[s].mode == MODE_EVENT) {
1436 ALOGV("Reporting event\n");
1437 /* Android requires events to return 1.0 */
1438 int dir = IIO_EVENT_CODE_EXTRACT_DIR(sensor[s].event_id);
1439 switch (sensor[s].type) {
1440 case SENSOR_TYPE_PROXIMITY:
1441 if (dir == IIO_EV_DIR_FALLING)
1442 data->data[0] = 0.0;
1444 data->data[0] = 1.0;
1447 data->data[0] = 1.0;
1451 data->data[1] = 0.0;
1452 data->data[2] = 0.0;
1457 /* Convert the data into the expected Android-level format */
1459 current_sample = sensor[s].report_buffer;
1461 for (c=0; c<num_fields; c++) {
1463 data->data[c] = sensor[s].ops.transform (s, c, current_sample);
1465 ALOGV("\tfield %d: %g\n", c, data->data[c]);
1466 current_sample += sensor[s].channel[c].size;
1469 ret = sensor[s].ops.finalize(s, data);
1471 /* We will drop samples if the sensor is not directly enabled */
1472 if (!sensor[s].directly_enabled)
1475 /* 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 */
1480 static void synthetize_duplicate_samples (void)
1483 * Some sensor types (ex: gyroscope) are defined as continuously firing by Android, despite the fact that
1484 * we can be dealing with iio drivers that only report events for new samples. For these we generate reports
1485 * periodically, duplicating the last data we got from the driver. This is not necessary for polling sensors.
1493 for (s=0; s<sensor_count; s++) {
1495 /* Ignore disabled sensors */
1499 /* If the sensor is continuously firing, leave it alone */
1500 if (sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1503 /* If we haven't seen a sample, there's nothing to duplicate */
1504 if (!sensor[s].report_initialized)
1507 /* If a sample was recently buffered, leave it alone too */
1508 if (sensor[s].report_pending)
1511 /* We also need a valid sampling rate to be configured */
1512 if (!sensor[s].sampling_rate)
1515 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1517 current_ts = get_timestamp_boot();
1518 target_ts = sensor[s].report_ts + period;
1520 if (target_ts <= current_ts) {
1521 /* Mark the sensor for event generation */
1522 set_report_ts(s, current_ts);
1523 sensor[s].report_pending = DATA_DUPLICATE;
1529 static void integrate_thread_report (uint32_t tag)
1531 int s = tag - THREAD_REPORT_TAG_BASE;
1534 len = read(sensor[s].thread_data_fd[0], &sensor[s].sample, sizeof(sensors_event_t));
1536 if (len == sizeof(sensors_event_t))
1537 sensor[s].report_pending = DATA_SYSFS;
1541 static int get_poll_wait_timeout (void)
1544 * Compute an appropriate timeout value, in ms, for the epoll_wait call that's going to await
1545 * for iio device reports and incoming reports from our sensor sysfs data reader threads.
1549 int64_t target_ts = INT64_MAX;
1554 * Check if we're dealing with a driver that only send events when there is motion, despite the fact that the associated Android sensor
1555 * type is continuous rather than on-change. In that case we have to duplicate events. Check deadline for the nearest upcoming event.
1557 for (s=0; s<sensor_count; s++)
1558 if (is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name && sensor[s].sampling_rate) {
1559 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1561 if (sensor[s].report_ts + period < target_ts)
1562 target_ts = sensor[s].report_ts + period;
1565 /* If we don't have such a driver to deal with */
1566 if (target_ts == INT64_MAX)
1567 return -1; /* Infinite wait */
1569 ms_to_wait = (target_ts - get_timestamp_boot()) / 1000000;
1571 /* If the target timestamp is already behind us, don't wait */
1579 int sensor_poll (sensors_event_t* data, int count)
1584 struct epoll_event ev[MAX_DEVICES];
1585 int returned_events;
1588 /* Get one or more events from our collection of sensors */
1589 return_available_sensor_reports:
1591 /* Synthetize duplicate samples if needed */
1592 synthetize_duplicate_samples();
1594 returned_events = 0;
1596 /* Check our sensor collection for available reports */
1597 for (s=0; s<sensor_count && returned_events < count; s++) {
1599 if (sensor[s].report_pending) {
1602 if (sensor[s].is_virtual)
1603 event_count = propagate_vsensor_report(s, &data[returned_events]);
1605 /* Report this event if it looks OK */
1606 event_count = propagate_sensor_report(s, &data[returned_events]);
1609 sensor[s].report_pending = 0;
1610 returned_events += event_count;
1613 * If the sample was deemed invalid or unreportable, e.g. had the same value as the previously reported
1614 * value for a 'on change' sensor, silently drop it.
1618 while (sensor[s].meta_data_pending) {
1619 /* See sensors.h on these */
1620 data[returned_events].version = META_DATA_VERSION;
1621 data[returned_events].sensor = 0;
1622 data[returned_events].type = SENSOR_TYPE_META_DATA;
1623 data[returned_events].reserved0 = 0;
1624 data[returned_events].timestamp = 0;
1625 data[returned_events].meta_data.sensor = s;
1626 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1628 sensor[s].meta_data_pending--;
1632 if (returned_events)
1633 return returned_events;
1637 ALOGV("Awaiting sensor data\n");
1639 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1642 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1646 ALOGV("%d fds signalled\n", nfds);
1648 /* For each of the signalled sources */
1649 for (i=0; i<nfds; i++)
1650 if (ev[i].events == EPOLLIN)
1651 switch (ev[i].data.u32) {
1652 case 0 ... MAX_DEVICES-1:
1653 /* Read report from iio char dev fd */
1654 integrate_device_report(ev[i].data.u32);
1657 case THREAD_REPORT_TAG_BASE ...
1658 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1659 /* Get report from acquisition thread */
1660 integrate_thread_report(ev[i].data.u32);
1662 case FLUSH_REPORT_TAG:
1664 char flush_event_content;
1665 read(flush_event_fd[0], &flush_event_content, sizeof(flush_event_content));
1670 ALOGW("Unexpected event source!\n");
1674 goto return_available_sensor_reports;
1678 int sensor_set_delay (int s, int64_t ns)
1680 float requested_sampling_rate;
1683 ALOGE("Invalid delay requested on sensor %d: %jd\n", s, ns);
1687 requested_sampling_rate = 1000000000.0 / ns;
1689 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);
1692 * 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
1693 * reads and writes as well as buffer enable/disable operations, since at the iio level most drivers require the buffer to be turned off
1694 * 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
1695 * is changing the sampling rate.
1698 if (requested_sampling_rate != sensor[s].sampling_rate)
1699 return sensor_set_rate(s, requested_sampling_rate);
1705 int sensor_flush (int s)
1707 char flush_event_content = 0;
1708 /* If one shot or not enabled return -EINVAL */
1709 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE || !is_enabled(s))
1712 sensor[s].meta_data_pending++;
1713 write(flush_event_fd[1], &flush_event_content, sizeof(flush_event_content));
1718 int allocate_control_data (void)
1721 struct epoll_event ev = {0};
1723 for (i=0; i<MAX_DEVICES; i++) {
1728 poll_fd = epoll_create(MAX_DEVICES);
1730 if (poll_fd == -1) {
1731 ALOGE("Can't create epoll instance for iio sensors!\n");
1735 ret = pipe(flush_event_fd);
1737 ALOGE("Cannot create flush_event_fd");
1741 ev.events = EPOLLIN;
1742 ev.data.u32 = FLUSH_REPORT_TAG;
1743 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, flush_event_fd[0] , &ev);
1745 ALOGE("Failed adding %d to poll set (%s)\n",
1746 flush_event_fd[0], strerror(errno));
1754 void delete_control_data (void)