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"
36 #include <linux/iio/events.h>
37 /* Currently active sensors count, per device */
38 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
39 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
41 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
42 static int events_fd[MAX_DEVICES]; /* fd on the /sys/bus/iio/devices/iio:deviceX/events/<event_name> file */
43 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
44 static int expected_dev_report_size[MAX_DEVICES]; /* expected iio scan len */
45 static int poll_fd; /* epoll instance covering all enabled sensors */
47 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
49 static int flush_event_fd[2]; /* Pipe used for flush signaling */
51 /* We use pthread condition variables to get worker threads out of sleep */
52 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
53 static pthread_cond_t thread_release_cond [MAX_SENSORS];
54 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
56 #define FLUSH_REPORT_TAG 900
58 * We associate tags to each of our poll set entries. These tags have the following values:
59 * - a iio device number if the fd is a iio character device fd
60 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a pipe used by a sysfs data acquisition thread
62 #define THREAD_REPORT_TAG_BASE 1000
64 /* If buffer enable fails, we may want to retry a few times before giving up */
65 #define ENABLE_BUFFER_RETRIES 3
66 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
69 inline int is_enabled (int s)
71 return sensor[s].directly_enabled || sensor[s].ref_count;
75 static int check_state_change (int s, int enabled, int from_virtual)
78 if (sensor[s].directly_enabled)
79 return 0; /* We're being enabled but already were directly activated: no change. */
82 sensor[s].directly_enabled = 1; /* We're being directly enabled */
84 if (sensor[s].ref_count)
85 return 0; /* We were already indirectly enabled */
87 return 1; /* Do continue enabling this sensor */
91 return 0; /* We are being disabled but already were: no change */
93 if (from_virtual && sensor[s].directly_enabled)
94 return 0; /* We're indirectly disabled but the base is still active */
96 sensor[s].directly_enabled = 0; /* We're now directly disabled */
98 if (!from_virtual && sensor[s].ref_count)
99 return 0; /* We still have ref counts */
101 return 1; /* Do continue disabling this sensor */
105 static int enable_buffer (int dev_num, int enabled)
107 char sysfs_path[PATH_MAX];
108 int retries = ENABLE_BUFFER_RETRIES;
110 sprintf(sysfs_path, ENABLE_PATH, dev_num);
113 /* Low level, non-multiplexed, enable/disable routine */
114 if (sysfs_write_int(sysfs_path, enabled) > 0)
117 ALOGE("Failed enabling buffer on dev%d, retrying", dev_num);
118 usleep(ENABLE_BUFFER_RETRY_DELAY_MS*1000);
122 ALOGE("Could not enable buffer\n");
127 static int setup_trigger (int s, const char* trigger_val)
129 char sysfs_path[PATH_MAX];
130 int ret = -1, attempts = 5;
132 sprintf(sysfs_path, TRIGGER_PATH, sensor[s].dev_num);
134 if (trigger_val[0] != '\n')
135 ALOGI("Setting S%d (%s) trigger to %s\n", s, sensor[s].friendly_name, trigger_val);
137 while (ret == -1 && attempts) {
138 ret = sysfs_write_str(sysfs_path, trigger_val);
143 sensor[s].selected_trigger = trigger_val;
145 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s, sensor[s].friendly_name, trigger_val);
149 static int enable_event(int dev_num, const char *name, int enabled)
151 char sysfs_path[PATH_MAX];
153 sprintf(sysfs_path, EVENTS_PATH "%s", dev_num, name);
154 return sysfs_write_int(sysfs_path, enabled);
157 static int enable_sensor(int dev_num, const char *tag, int enabled)
159 char sysfs_path[PATH_MAX];
161 sprintf(sysfs_path, SENSOR_ENABLE_PATH, dev_num, tag);
162 return sysfs_write_int(sysfs_path, enabled);
165 static void enable_iio_timestamp (int dev_num, int known_channels)
167 /* Check if we have a dedicated iio timestamp channel */
169 char spec_buf[MAX_TYPE_SPEC_LEN];
170 char sysfs_path[PATH_MAX];
173 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
175 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
180 if (strcmp(spec_buf, "le:s64/64>>0"))
183 /* OK, type is int64_t as expected, in little endian representation */
185 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
187 if (sysfs_read_int(sysfs_path, &n))
190 /* Check that the timestamp comes after the other fields we read */
191 if (n != known_channels)
194 /* Try enabling that channel */
195 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
197 sysfs_write_int(sysfs_path, 1);
199 if (sysfs_read_int(sysfs_path, &n))
203 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
204 has_iio_ts[dev_num] = 1;
209 static int decode_type_spec (const char type_buf[MAX_TYPE_SPEC_LEN], datum_info_t *type_info)
211 /* Return size in bytes for this type specification, or -1 in error */
214 unsigned int realbits, storagebits, shift;
217 /* Valid specs: "le:u10/16>>0", "le:s16/32>>0" or "le:s32/32>>0" */
219 tokens = sscanf(type_buf, "%ce:%c%u/%u>>%u", &endianness, &sign, &realbits, &storagebits, &shift);
221 if (tokens != 5 || (endianness != 'b' && endianness != 'l') || (sign != 'u' && sign != 's') ||
222 realbits > storagebits || (storagebits != 16 && storagebits != 32 && storagebits != 64)) {
223 ALOGE("Invalid iio channel type spec: %s\n", type_buf);
227 type_info->endianness = endianness;
228 type_info->sign = sign;
229 type_info->realbits = (short) realbits;
230 type_info->storagebits = (short) storagebits;
231 type_info->shift = (short) shift;
233 return storagebits / 8;
237 void build_sensor_report_maps (int dev_num)
240 * 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
241 * 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
242 * sensor report, itself being the data that we return to Android when a sensor poll completes. The mapping should be straightforward in the
243 * 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
244 * 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
254 char spec_buf[MAX_TYPE_SPEC_LEN];
255 datum_info_t* ch_info;
257 char sysfs_path[PATH_MAX];
260 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
261 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
262 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
266 /* For each sensor that is linked to this device */
267 for (s=0; s<sensor_count; s++) {
268 if (sensor[s].dev_num != dev_num)
271 i = sensor[s].catalog_index;
273 /* Read channel details through sysfs attributes */
274 for (c=0; c<sensor[s].num_channels; c++) {
276 /* Read _type file */
277 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].type_path);
279 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
282 ALOGW( "Failed to read type: %s\n", sysfs_path);
286 ch_spec = sensor[s].channel[c].type_spec;
288 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
290 ch_info = &sensor[s].channel[c].type_info;
292 size = decode_type_spec(ch_spec, ch_info);
294 /* Read _index file */
295 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].index_path);
297 n = sysfs_read_int(sysfs_path, &ch_index);
300 ALOGW( "Failed to read index: %s\n", sysfs_path);
304 if (ch_index >= MAX_SENSORS) {
305 ALOGE("Index out of bounds!: %s\n", sysfs_path);
309 /* Record what this index is about */
311 sensor_handle_from_index [ch_index] = s;
312 channel_number_from_index[ch_index] = c;
313 channel_size_from_index [ch_index] = size;
318 sensor_update_max_range(s);
320 /* Stop sampling - if we are recovering from hal restart */
321 enable_buffer(dev_num, 0);
322 setup_trigger(s, "\n");
324 /* Turn on channels we're aware of */
325 for (c=0;c<sensor[s].num_channels; c++) {
326 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].en_path);
327 sysfs_write_int(sysfs_path, 1);
331 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
334 * Now that we know which channels are defined, their sizes and their ordering, update channels offsets within device report. Note: there
335 * is a possibility that several sensors share the same index, with their data fields being isolated by masking and shifting as specified
336 * through the real bits and shift values in type attributes. This case is not currently supported. Also, the code below assumes no hole in
337 * the sequence of indices, so it is dependent on discovery of all sensors.
341 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
342 s = sensor_handle_from_index[i];
343 c = channel_number_from_index[i];
344 size = channel_size_from_index[i];
349 ALOGI("S%d C%d : offset %d, size %d, type %s\n", s, c, offset, size, sensor[s].channel[c].type_spec);
351 sensor[s].channel[c].offset = offset;
352 sensor[s].channel[c].size = size;
357 /* Enable the timestamp channel if there is one available */
358 enable_iio_timestamp(dev_num, known_channels);
360 /* Add padding and timestamp size if it's enabled on this iio device */
361 if (has_iio_ts[dev_num])
362 offset = (offset+7)/8*8 + sizeof(int64_t);
364 expected_dev_report_size[dev_num] = offset;
365 ALOGI("Expecting %d scan length on iio dev %d\n", offset, dev_num);
367 if (expected_dev_report_size[dev_num] > MAX_DEVICE_REPORT_SIZE) {
368 ALOGE("Unexpectedly large scan buffer on iio dev%d: %d bytes\n", dev_num, expected_dev_report_size[dev_num]);
370 expected_dev_report_size[dev_num] = MAX_DEVICE_REPORT_SIZE;
375 int adjust_counters (int s, int enabled, int from_virtual)
378 * Adjust counters based on sensor enable action. Return values are:
379 * 0 if the operation was completed and we're all set
380 * 1 if we toggled the state of the sensor and there's work left
381 * -1 in case of an error
384 int dev_num = sensor[s].dev_num;
386 if (!check_state_change(s, enabled, from_virtual))
387 return 0; /* The state of the sensor remains the same: we're done */
390 ALOGI("Enabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
392 switch (sensor[s].type) {
393 case SENSOR_TYPE_ACCELEROMETER:
397 case SENSOR_TYPE_MAGNETIC_FIELD:
398 compass_read_data(s);
401 case SENSOR_TYPE_GYROSCOPE:
406 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
408 /* Sensor disabled, lower report available flag */
409 sensor[s].report_pending = 0;
411 /* Save calibration data to persistent storage */
412 switch (sensor[s].type) {
413 case SENSOR_TYPE_ACCELEROMETER:
417 case SENSOR_TYPE_MAGNETIC_FIELD:
418 compass_store_data(s);
421 case SENSOR_TYPE_GYROSCOPE:
427 /* We changed the state of a sensor: adjust device ref counts */
429 switch(sensor[s].mode) {
432 trig_sensors_per_dev[dev_num]++;
434 trig_sensors_per_dev[dev_num]--;
439 active_poll_sensors++;
440 poll_sensors_per_dev[dev_num]++;
443 active_poll_sensors--;
444 poll_sensors_per_dev[dev_num]--;
450 /* Invalid sensor mode */
456 static int get_field_count (int s, size_t *field_size)
458 *field_size = sizeof(float);
460 switch (sensor[s].type) {
461 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
462 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
463 case SENSOR_TYPE_ORIENTATION: /* degrees */
464 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
465 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
468 case SENSOR_TYPE_INTERNAL_INTENSITY:
469 case SENSOR_TYPE_INTERNAL_ILLUMINANCE:
470 case SENSOR_TYPE_LIGHT: /* SI lux units */
471 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
472 case SENSOR_TYPE_TEMPERATURE: /* °C */
473 case SENSOR_TYPE_PROXIMITY: /* centimeters */
474 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
475 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
476 case SENSOR_TYPE_STEP_DETECTOR: /* event: always 1 */
479 case SENSOR_TYPE_ROTATION_VECTOR:
482 case SENSOR_TYPE_STEP_COUNTER: /* number of steps */
483 *field_size = sizeof(uint64_t);
486 ALOGE("Unknown sensor type!\n");
487 return 0; /* Drop sample */
492 * CTS acceptable thresholds:
493 * EventGapVerification.java: (th <= 1.8)
494 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
496 #define THRESHOLD 1.10
497 #define MAX_DELAY 500000000 /* 500 ms */
499 void set_report_ts(int s, int64_t ts)
501 int64_t maxTs, period;
504 * A bit of a hack to please a bunch of cts tests. They
505 * expect the timestamp to be exacly according to the set-up
506 * frequency but if we're simply getting the timestamp at hal level
507 * this may not be the case. Perhaps we'll get rid of this when
508 * we'll be reading the timestamp from the iio channel for all sensors
510 if (sensor[s].report_ts && sensor[s].sampling_rate &&
511 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
513 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
514 maxTs = sensor[s].report_ts + THRESHOLD * period;
515 /* If we're too far behind get back on track */
516 if (ts - maxTs >= MAX_DELAY)
518 sensor[s].report_ts = (ts < maxTs ? ts : maxTs);
520 sensor[s].report_ts = ts;
524 static void* acquisition_routine (void* param)
527 * Data acquisition routine run in a dedicated thread, covering a single sensor. This loop will periodically retrieve sampling data through
528 * 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
529 * frequently, as the thread may be disposed of at any time. Note that Bionic does not provide pthread_cancel / pthread_testcancel...
532 int s = (int) (size_t) param;
534 sensors_event_t data = {0};
537 struct timespec target_time;
538 int64_t timestamp, period, start, stop;
541 if (s < 0 || s >= sensor_count) {
542 ALOGE("Invalid sensor handle!\n");
546 ALOGI("Entering S%d (%s) data acquisition thread: rate:%g\n", s, sensor[s].friendly_name, sensor[s].sampling_rate);
548 if (sensor[s].sampling_rate <= 0) {
549 ALOGE("Invalid rate in acquisition routine for sensor %d: %g\n", s, sensor[s].sampling_rate);
553 /* Initialize data fields that will be shared by all sensor reports */
554 data.version = sizeof(sensors_event_t);
556 data.type = sensor_desc[s].type;
558 num_fields = get_field_count(s, &field_size);
561 * 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
562 * variables to get the acquisition threads out of sleep quickly after the sampling rate is adjusted, or the sensor is disabled.
564 pthread_mutex_lock(&thread_release_mutex[s]);
566 /* Pinpoint the moment we start sampling */
567 timestamp = get_timestamp_monotonic();
569 /* Check and honor termination requests */
570 while (sensor[s].thread_data_fd[1] != -1) {
571 start = get_timestamp_boot();
573 /* Read values through sysfs */
574 for (c=0; c<num_fields; c++) {
575 if (field_size == sizeof(uint64_t))
576 data.u64.data[c] = acquire_immediate_uint64_value(s, c);
578 data.data[c] = acquire_immediate_float_value(s, c);
580 /* Check and honor termination requests */
581 if (sensor[s].thread_data_fd[1] == -1)
584 stop = get_timestamp_boot();
585 set_report_ts(s, start/2 + stop/2);
586 data.timestamp = sensor[s].report_ts;
587 /* If the sample looks good */
588 if (sensor[s].ops.finalize(s, &data)) {
590 /* Pipe it for transmission to poll loop */
591 ret = write(sensor[s].thread_data_fd[1], &data, sizeof(sensors_event_t));
593 if (ret != sizeof(sensors_event_t))
594 ALOGE("S%d write failure: wrote %d, got %d\n", s, sizeof(sensors_event_t), ret);
597 /* Check and honor termination requests */
598 if (sensor[s].thread_data_fd[1] == -1)
601 /* Recalculate period assuming sensor[s].sampling_rate can be changed dynamically during the thread run */
602 if (sensor[s].sampling_rate <= 0) {
603 ALOGE("Unexpected sampling rate for sensor %d: %g\n", s, sensor[s].sampling_rate);
607 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
609 set_timestamp(&target_time, timestamp);
611 /* Wait until the sampling time elapses, or a rate change is signaled, or a thread exit is requested */
612 ret = pthread_cond_timedwait(&thread_release_cond[s], &thread_release_mutex[s], &target_time);
616 ALOGV("Acquisition thread for S%d exiting\n", s);
617 pthread_mutex_unlock(&thread_release_mutex[s]);
623 static void start_acquisition_thread (int s)
625 int incoming_data_fd;
628 struct epoll_event ev = {0};
630 ALOGV("Initializing acquisition context for sensor %d\n", s);
632 /* Create condition variable and mutex for quick thread release */
633 ret = pthread_condattr_init(&thread_cond_attr[s]);
634 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
635 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
636 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
638 /* Create a pipe for inter thread communication */
639 ret = pipe(sensor[s].thread_data_fd);
641 incoming_data_fd = sensor[s].thread_data_fd[0];
644 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
646 /* Add incoming side of pipe to our poll set, with a suitable tag */
647 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
649 ALOGE("Failed adding %d to poll set (%s)\n",
650 incoming_data_fd, strerror(errno));
653 /* Create and start worker thread */
654 ret = pthread_create(&sensor[s].acquisition_thread, NULL, acquisition_routine, (void*) (size_t) s);
658 static void stop_acquisition_thread (int s)
660 int incoming_data_fd = sensor[s].thread_data_fd[0];
661 int outgoing_data_fd = sensor[s].thread_data_fd[1];
663 ALOGV("Tearing down acquisition context for sensor %d\n", s);
665 /* Delete the incoming side of the pipe from our poll set */
666 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
668 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
669 sensor[s].thread_data_fd[0] = -1;
670 sensor[s].thread_data_fd[1] = -1;
672 /* Close both sides of our pipe */
673 close(incoming_data_fd);
674 close(outgoing_data_fd);
676 /* Stop acquisition thread and clean up thread handle */
677 pthread_cond_signal(&thread_release_cond[s]);
678 pthread_join(sensor[s].acquisition_thread, NULL);
680 /* Clean up our sensor descriptor */
681 sensor[s].acquisition_thread = -1;
683 /* Delete condition variable and mutex */
684 pthread_cond_destroy(&thread_release_cond[s]);
685 pthread_mutex_destroy(&thread_release_mutex[s]);
689 static int is_fast_accelerometer (int s)
692 * Some games don't react well to accelerometers using any-motion triggers. Even very low thresholds seem to trip them, and they tend to
693 * request fairly high event rates. Favor continuous triggers if the sensor is an accelerometer and uses a sampling rate of at least 25.
696 if (sensor[s].type != SENSOR_TYPE_ACCELEROMETER)
699 if (sensor[s].sampling_rate < 25)
706 static void tentative_switch_trigger (int s)
709 * Under certain situations it may be beneficial to use an alternate trigger:
711 * - for applications using the accelerometer with high sampling rates, prefer the continuous trigger over the any-motion one, to avoid
712 * jumps related to motion thresholds
715 if (is_fast_accelerometer(s) && !(sensor[s].quirks & QUIRK_TERSE_DRIVER) && sensor[s].selected_trigger == sensor[s].motion_trigger_name)
716 setup_trigger(s, sensor[s].init_trigger_name);
720 static float get_group_max_sampling_rate (int s)
722 /* Review the sampling rates of linked sensors and return the maximum */
726 float arbitrated_rate = 0;
729 arbitrated_rate = sensor[s].requested_rate;
731 /* If any of the currently active sensors built on top of this one need a higher sampling rate, switch to this rate */
732 for (i = 0; i < sensor_count; i++)
733 for (vi = 0; vi < sensor[i].base_count; vi++)
734 if (sensor[i].base[vi] == s && is_enabled(i) && sensor[i].requested_rate > arbitrated_rate) /* If sensor i depends on sensor s */
735 arbitrated_rate = sensor[i].requested_rate;
737 /* If any of the currently active sensors we rely on is using a higher sampling rate, switch to this rate */
738 for (vi = 0; vi < sensor[s].base_count; vi++) {
739 i = sensor[s].base[vi];
740 if (is_enabled(i) && sensor[i].requested_rate > arbitrated_rate)
741 arbitrated_rate = sensor[i].requested_rate;
744 return arbitrated_rate;
747 extern float sensor_get_max_freq (int s);
749 static float select_closest_available_rate(int s, float requested_rate)
753 float selected_rate = 0;
754 float max_rate_from_prop = sensor_get_max_freq(s);
755 int dev_num = sensor[s].dev_num;
757 if (!sensor[s].avail_freqs_count)
758 return requested_rate;
760 for (j = 0; j < sensor[s].avail_freqs_count; j++) {
762 sr = sensor[s].avail_freqs[j];
764 /* If this matches the selected rate, we're happy. Have some tolerance for rounding errors and avoid needless jumps to higher rates */
765 if ((fabs(requested_rate - sr) <= 0.01) && (sr <= max_rate_from_prop)) {
769 /* Select rate if it's less than max freq */
770 if ((sr > selected_rate) && (sr <= max_rate_from_prop)) {
775 * If we reached a higher value than the desired rate, adjust selected rate so it matches the first higher available one and
776 * stop parsing - this makes the assumption that rates are sorted by increasing value in the allowed frequencies string.
778 if (sr > requested_rate) {
779 return selected_rate;
783 /* Check for wrong values */
784 if (selected_rate < 0.1) {
785 return requested_rate;
787 return selected_rate;
791 static int sensor_set_rate (int s, float requested_rate)
793 /* Set the rate at which a specific sensor should report events. See Android sensors.h for indication on sensor trigger modes */
795 char sysfs_path[PATH_MAX];
796 int dev_num = sensor[s].dev_num;
797 int i = sensor[s].catalog_index;
798 const char *prefix = sensor_catalog[i].tag;
799 int per_sensor_sampling_rate;
800 int per_device_sampling_rate;
803 float group_max_sampling_rate;
804 float cur_sampling_rate; /* Currently used sampling rate */
805 float arb_sampling_rate; /* Granted sampling rate after arbitration */
806 char hrtimer_sampling_path[PATH_MAX];
807 char trigger_path[PATH_MAX];
809 ALOGV("Sampling rate %g requested on sensor %d (%s)\n", requested_rate, s, sensor[s].friendly_name);
811 sensor[s].requested_rate = requested_rate;
813 arb_sampling_rate = requested_rate;
815 if (arb_sampling_rate < sensor[s].min_supported_rate) {
816 ALOGV("Sampling rate %g too low for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].min_supported_rate);
817 arb_sampling_rate = sensor[s].min_supported_rate;
820 /* If one of the linked sensors uses a higher rate, adopt it */
821 group_max_sampling_rate = get_group_max_sampling_rate(s);
823 if (arb_sampling_rate < group_max_sampling_rate) {
824 ALOGV("Using %s sampling rate to %g too due to dependency\n", sensor[s].friendly_name, arb_sampling_rate);
825 arb_sampling_rate = group_max_sampling_rate;
828 if (sensor[s].max_supported_rate && arb_sampling_rate > sensor[s].max_supported_rate) {
829 ALOGV("Sampling rate %g too high for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].max_supported_rate);
830 arb_sampling_rate = sensor[s].max_supported_rate;
833 sensor[s].sampling_rate = arb_sampling_rate;
835 /* If the sensor is virtual, we're done */
836 if (sensor[s].is_virtual)
839 /* If we're dealing with a poll-mode sensor */
840 if (sensor[s].mode == MODE_POLL) {
842 pthread_cond_signal(&thread_release_cond[s]); /* Wake up thread so the new sampling rate gets used */
846 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
848 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
849 per_sensor_sampling_rate = 1;
850 per_device_sampling_rate = 0;
852 per_sensor_sampling_rate = 0;
854 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
856 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
857 per_device_sampling_rate = 1;
859 per_device_sampling_rate = 0;
862 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
863 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
867 if (sensor[s].hrtimer_trigger_name[0] != '\0') {
868 snprintf(trigger_path, PATH_MAX, "%s%s%d/", IIO_DEVICES, "trigger", sensor[s].trigger_nr);
869 snprintf(hrtimer_sampling_path, PATH_MAX, "%s%s", trigger_path, "sampling_frequency");
870 /* Enforce frequency update when software trigger
871 * frequency and current sampling rate are different */
872 if (sysfs_read_float(hrtimer_sampling_path, &sr) != -1 && sr != cur_sampling_rate)
873 cur_sampling_rate = -1;
875 arb_sampling_rate = select_closest_available_rate(s, arb_sampling_rate);
878 /* Record the rate that was agreed upon with the sensor taken in isolation ; this avoid uncontrolled ripple effects between colocated sensor rates */
879 sensor[s].semi_arbitrated_rate = arb_sampling_rate;
881 /* Coordinate with others active sensors on the same device, if any */
882 if (per_device_sampling_rate)
883 for (n=0; n<sensor_count; n++)
884 if (n != s && sensor[n].dev_num == dev_num && sensor[n].num_channels && is_enabled(n) &&
885 sensor[n].semi_arbitrated_rate > arb_sampling_rate) {
886 ALOGV("Sampling rate shared between %s and %s, using %g instead of %g\n", sensor[s].friendly_name, sensor[n].friendly_name,
887 sensor[n].semi_arbitrated_rate, arb_sampling_rate);
888 arb_sampling_rate = sensor[n].semi_arbitrated_rate;
891 sensor[s].sampling_rate = arb_sampling_rate;
893 /* Update actual sampling rate field for this sensor and others which may be sharing the same sampling rate */
894 if (per_device_sampling_rate)
895 for (n=0; n<sensor_count; n++)
896 if (sensor[n].dev_num == dev_num && n != s && sensor[n].num_channels)
897 sensor[n].sampling_rate = arb_sampling_rate;
899 /* If the desired rate is already active we're all set */
900 if (arb_sampling_rate == cur_sampling_rate)
903 ALOGI("Sensor %d (%s) sampling rate set to %g\n", s, sensor[s].friendly_name, arb_sampling_rate);
905 if (sensor[s].hrtimer_trigger_name[0] != '\0')
906 sysfs_write_float(hrtimer_sampling_path, ceilf(arb_sampling_rate));
908 if (trig_sensors_per_dev[dev_num])
909 enable_buffer(dev_num, 0);
911 if (sensor[s].hrtimer_trigger_name[0] != '\0') {
912 sysfs_write_float(sysfs_path, select_closest_available_rate(s, arb_sampling_rate));
914 sysfs_write_float(sysfs_path, arb_sampling_rate);
917 /* Check if it makes sense to use an alternate trigger */
918 tentative_switch_trigger(s);
920 if (trig_sensors_per_dev[dev_num])
921 enable_buffer(dev_num, 1);
927 static void reapply_sampling_rates (int s)
930 * The specified sensor was either enabled or disabled. Other sensors in the same group may have constraints related to this sensor
931 * sampling rate on their own sampling rate, so reevaluate them by retrying to use their requested sampling rate, rather than the one
932 * that ended up being used after arbitration.
937 if (sensor[s].is_virtual) {
938 /* Take care of downwards dependencies */
939 for (i=0; i<sensor[s].base_count; i++) {
940 base = sensor[s].base[i];
941 sensor_set_rate(base, sensor[base].requested_rate);
947 for (i=0; i<sensor_count; i++)
948 for (j=0; j<sensor[i].base_count; j++)
949 if (sensor[i].base[j] == s) /* If sensor i depends on sensor s */
950 sensor_set_rate(i, sensor[i].requested_rate);
954 static int sensor_activate_virtual (int s, int enabled, int from_virtual)
958 sensor[s].event_count = 0;
959 sensor[s].meta_data_pending = 0;
961 if (!check_state_change(s, enabled, from_virtual))
962 return 0; /* The state of the sensor remains the same ; we're done */
965 ALOGI("Enabling sensor %d (%s)\n", s, sensor[s].friendly_name);
967 ALOGI("Disabling sensor %d (%s)\n", s, sensor[s].friendly_name);
969 sensor[s].report_pending = 0;
971 for (i=0; i<sensor[s].base_count; i++) {
973 base = sensor[s].base[i];
974 sensor_activate(base, enabled, 1);
977 sensor[base].ref_count++;
979 sensor[base].ref_count--;
982 /* Reevaluate sampling rates of linked sensors */
983 reapply_sampling_rates(s);
988 int sensor_activate (int s, int enabled, int from_virtual)
990 char device_name[PATH_MAX];
991 struct epoll_event ev = {0};
992 int dev_fd, event_fd;
994 int dev_num = sensor[s].dev_num;
996 int catalog_index = sensor[s].catalog_index;
998 if (sensor[s].is_virtual)
999 return sensor_activate_virtual(s, enabled, from_virtual);
1001 /* Prepare the report timestamp field for the first event, see set_report_ts method */
1002 sensor[s].report_ts = 0;
1004 ret = adjust_counters(s, enabled, from_virtual);
1006 /* If the operation was neutral in terms of state, we're done */
1010 sensor[s].event_count = 0;
1011 sensor[s].meta_data_pending = 0;
1014 setup_noise_filtering(s); /* Initialize filtering data if required */
1016 if (sensor[s].mode == MODE_TRIGGER) {
1019 enable_buffer(dev_num, 0);
1020 setup_trigger(s, "\n");
1022 /* If there's at least one sensor enabled on this iio device */
1023 if (trig_sensors_per_dev[dev_num]) {
1025 /* Start sampling */
1026 if (sensor[s].hrtimer_trigger_name[0] != '\0')
1027 setup_trigger(s, sensor[s].hrtimer_trigger_name);
1029 setup_trigger(s, sensor[s].init_trigger_name);
1031 enable_buffer(dev_num, 1);
1033 } else if (sensor[s].mode == MODE_POLL) {
1034 if (sensor[s].needs_enable) {
1035 enable_sensor(dev_num, sensor_catalog[catalog_index].tag, enabled);
1040 * Make sure we have a fd on the character device ; conversely, close the fd if no one is using associated sensors anymore. The assumption
1041 * here is that the underlying driver will power on the relevant hardware block while someone holds a fd on the device.
1043 dev_fd = device_fd[dev_num];
1046 if (sensor[s].mode == MODE_POLL)
1047 stop_acquisition_thread(s);
1049 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1050 /* Stop watching this fd. This should be a no-op in case this fd was not in the poll set. */
1051 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
1054 device_fd[dev_num] = -1;
1057 if (sensor[s].mode == MODE_EVENT) {
1058 event_fd = events_fd[dev_num];
1060 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1061 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1062 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1065 epoll_ctl(poll_fd, EPOLL_CTL_DEL, event_fd, NULL);
1067 events_fd[dev_num] = -1;
1071 /* Release any filtering data we may have accumulated */
1072 release_noise_filtering_data(s);
1074 /* Reevaluate sampling rates of linked sensors */
1075 reapply_sampling_rates(s);
1080 /* First enabled sensor on this iio device */
1081 sprintf(device_name, DEV_FILE_PATH, dev_num);
1082 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
1084 device_fd[dev_num] = dev_fd;
1087 ALOGE("Could not open fd on %s (%s)\n", device_name, strerror(errno));
1088 adjust_counters(s, 0, from_virtual);
1092 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
1094 if (sensor[s].mode == MODE_TRIGGER) {
1096 /* Add this iio device fd to the set of watched fds */
1097 ev.events = EPOLLIN;
1098 ev.data.u32 = dev_num;
1100 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
1103 ALOGE("Failed adding %d to poll set (%s)\n", dev_fd, strerror(errno));
1107 /* Note: poll-mode fds are not readable */
1108 } else if (sensor[s].mode == MODE_EVENT) {
1109 event_fd = events_fd[dev_num];
1111 ret = ioctl(dev_fd, IIO_GET_EVENT_FD_IOCTL, &event_fd);
1112 if (ret == -1 || event_fd == -1) {
1113 ALOGE("Failed to retrieve event_fd from %d (%s)\n", dev_fd, strerror(errno));
1116 events_fd[dev_num] = event_fd;
1117 ALOGV("Opened fd=%d to receive events\n", event_fd);
1119 /* Add this event fd to the set of watched fds */
1120 ev.events = EPOLLIN;
1121 ev.data.u32 = dev_num;
1123 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, event_fd, &ev);
1125 ALOGE("Failed adding %d to poll set (%s)\n", event_fd, strerror(errno));
1128 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1130 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1131 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1134 if (!poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1136 device_fd[dev_num] = -1;
1141 /* Ensure that on-change sensors send at least one event after enable */
1142 get_field_count(s, &field_size);
1143 if (field_size == sizeof(uint64_t))
1144 sensor[s].prev_val.data64 = -1;
1146 sensor[s].prev_val.data = -1;
1148 if (sensor[s].mode == MODE_POLL)
1149 start_acquisition_thread(s);
1151 /* Reevaluate sampling rates of linked sensors */
1152 reapply_sampling_rates(s);
1158 static void enable_motion_trigger (int dev_num)
1161 * In the ideal case, we enumerate two triggers per iio device ; the default (periodically firing) trigger, and another one (the motion
1162 * trigger) that only fires up when motion is detected. This second one allows for lesser energy consumption, but requires periodic sample
1163 * duplication at the HAL level for sensors that Android defines as continuous. This "duplicate last sample" logic can only be engaged
1164 * 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
1165 * trigger when we got events for all active sensors. Unfortunately in the general case several sensors can be associated to a given iio
1166 * device, they can independently be controlled, and we have to adjust the trigger in use at the iio device level depending on whether or
1167 * not appropriate conditions are met at the sensor level.
1172 int active_sensors = trig_sensors_per_dev[dev_num];
1173 int candidate[MAX_SENSORS];
1174 int candidate_count = 0;
1176 if (!active_sensors)
1179 /* Check that all active sensors are ready to switch */
1181 for (s=0; s<MAX_SENSORS; s++)
1182 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels &&
1183 (!sensor[s].motion_trigger_name[0] || !sensor[s].report_initialized || is_fast_accelerometer(s) ||
1184 (sensor[s].quirks & QUIRK_FORCE_CONTINUOUS)))
1187 /* Record which particular sensors need 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 && sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1191 candidate[candidate_count++] = s;
1193 if (!candidate_count)
1196 /* Now engage the motion trigger for sensors which aren't using it */
1198 enable_buffer(dev_num, 0);
1200 for (i=0; i<candidate_count; i++) {
1202 setup_trigger(s, sensor[s].motion_trigger_name);
1205 enable_buffer(dev_num, 1);
1208 static void stamp_reports (int dev_num, int64_t ts)
1212 for (s=0; s<MAX_SENSORS; s++)
1213 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].mode != MODE_POLL) {
1214 if (sensor[s].quirks & QUIRK_SPOTTY)
1215 set_report_ts(s, ts);
1217 sensor[s].report_ts = ts;
1222 static int integrate_device_report_from_dev(int dev_num, int fd)
1226 unsigned char buf[MAX_DEVICE_REPORT_SIZE] = { 0 };
1228 unsigned char *target;
1229 unsigned char *source;
1232 int ts_offset = 0; /* Offset of iio timestamp, if provided */
1233 int64_t boot_to_rt_delta;
1235 /* There's an incoming report on the specified iio device char dev fd */
1237 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
1241 len = read(fd, buf, expected_dev_report_size[dev_num]);
1244 ALOGE("Could not read report from iio device %d (%s)\n", dev_num, strerror(errno));
1248 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
1250 /* Map device report to sensor reports */
1252 for (s=0; s<MAX_SENSORS; s++)
1253 if (sensor[s].dev_num == dev_num && is_enabled(s)) {
1257 /* Copy data from device to sensor report buffer */
1258 for (c=0; c<sensor[s].num_channels; c++) {
1260 target = sensor[s].report_buffer + sr_offset;
1262 source = buf + sensor[s].channel[c].offset;
1264 size = sensor[s].channel[c].size;
1266 memcpy(target, source, size);
1271 ALOGV("Sensor %d report available (%d bytes)\n", s, sr_offset);
1273 sensor[s].report_pending = DATA_TRIGGER;
1274 sensor[s].report_initialized = 1;
1278 /* Tentatively switch to an any-motion trigger if conditions are met */
1279 enable_motion_trigger(dev_num);
1281 /* If no iio timestamp channel was detected for this device, bail out */
1282 if (!has_iio_ts[dev_num]) {
1283 stamp_reports(dev_num, get_timestamp_boot());
1287 /* Don't trust the timestamp channel in any-motion mode */
1288 for (s=0; s<MAX_SENSORS; s++)
1289 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name) {
1290 stamp_reports(dev_num, get_timestamp_boot());
1294 /* Align on a 64 bits boundary */
1295 ts_offset = expected_dev_report_size[dev_num] - sizeof(int64_t);
1297 /* If we read an amount of data consistent with timestamp presence */
1298 if (len == expected_dev_report_size[dev_num])
1299 ts = *(int64_t*) (buf + ts_offset);
1302 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
1303 stamp_reports(dev_num, get_timestamp_boot());
1307 ALOGV("Driver timestamp on iio device %d: ts=%lld\n", dev_num, ts);
1309 boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1311 stamp_reports(dev_num, ts + boot_to_rt_delta);
1316 static int integrate_device_report_from_event(int dev_num, int fd)
1320 struct iio_event_data event;
1321 int64_t boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1323 /* There's an incoming report on the specified iio device char dev fd */
1325 ALOGE("Ignoring stale report on event fd %d of device %d\n",
1330 len = read(fd, &event, sizeof(event));
1333 ALOGE("Could not read event from fd %d of device %d (%s)\n",
1334 fd, dev_num, strerror(errno));
1338 ts = event.timestamp + boot_to_rt_delta;
1340 ALOGV("Read event %lld from fd %d of iio device %d - ts %lld\n", event.id, fd, dev_num, ts);
1342 /* Map device report to sensor reports */
1343 for (s = 0; s < MAX_SENSORS; s++)
1344 if (sensor[s].dev_num == dev_num &&
1346 sensor[s].event_id = event.id;
1347 sensor[s].report_ts = ts;
1348 sensor[s].report_pending = 1;
1349 sensor[s].report_initialized = 1;
1350 ALOGV("Sensor %d report available (1 byte)\n", s);
1355 static int integrate_device_report(int dev_num)
1359 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
1360 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
1364 if (events_fd[dev_num] != -1) {
1365 ret = integrate_device_report_from_event(dev_num, events_fd[dev_num]);
1370 if (device_fd[dev_num] != -1)
1371 ret = integrate_device_report_from_dev(dev_num, device_fd[dev_num]);
1376 static int propagate_vsensor_report (int s, sensors_event_t *data)
1378 /* There's a new report stored in sensor.sample for this sensor; transmit it */
1380 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1383 data->type = sensor_desc[s].type; /* sensor_desc[s].type can differ from sensor[s].type ; internal types are remapped */
1388 static int propagate_sensor_report (int s, sensors_event_t *data)
1390 /* There's a sensor report pending for this sensor ; transmit it */
1393 int num_fields = get_field_count(s, &field_size);
1395 unsigned char* current_sample;
1398 /* If there's nothing to return... we're done */
1402 ALOGV("Sample on sensor %d (type %d):\n", s, sensor[s].type);
1404 if (sensor[s].mode == MODE_POLL) {
1405 /* We received a good sample but we're not directly enabled so we'll drop */
1406 if (!sensor[s].directly_enabled)
1408 /* Use the data provided by the acquisition thread */
1409 ALOGV("Reporting data from worker thread for S%d\n", s);
1410 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1411 data->timestamp = sensor[s].report_ts;
1415 memset(data, 0, sizeof(sensors_event_t));
1417 data->version = sizeof(sensors_event_t);
1419 data->type = sensor_desc[s].type; /* sensor_desc[s].type can differ from sensor[s].type ; internal types are remapped */
1420 data->timestamp = sensor[s].report_ts;
1422 if (sensor[s].mode == MODE_EVENT) {
1423 ALOGV("Reporting event\n");
1424 /* Android requires events to return 1.0 */
1425 int dir = IIO_EVENT_CODE_EXTRACT_DIR(sensor[s].event_id);
1426 switch (sensor[s].type) {
1427 case SENSOR_TYPE_PROXIMITY:
1428 if (dir == IIO_EV_DIR_FALLING)
1429 data->data[0] = 0.0;
1431 data->data[0] = 1.0;
1434 data->data[0] = 1.0;
1438 data->data[1] = 0.0;
1439 data->data[2] = 0.0;
1443 /* Convert the data into the expected Android-level format */
1445 current_sample = sensor[s].report_buffer;
1447 for (c=0; c<num_fields; c++) {
1449 data->data[c] = sensor[s].ops.transform (s, c, current_sample);
1451 ALOGV("\tfield %d: %g\n", c, data->data[c]);
1452 current_sample += sensor[s].channel[c].size;
1455 ret = sensor[s].ops.finalize(s, data);
1457 /* We will drop samples if the sensor is not directly enabled */
1458 if (!sensor[s].directly_enabled)
1461 /* 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 */
1466 static void synthetize_duplicate_samples (void)
1469 * Some sensor types (ex: gyroscope) are defined as continuously firing by Android, despite the fact that
1470 * we can be dealing with iio drivers that only report events for new samples. For these we generate reports
1471 * periodically, duplicating the last data we got from the driver. This is not necessary for polling sensors.
1479 for (s=0; s<sensor_count; s++) {
1481 /* Ignore disabled sensors */
1485 /* If the sensor is continuously firing, leave it alone */
1486 if (sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1489 /* If we haven't seen a sample, there's nothing to duplicate */
1490 if (!sensor[s].report_initialized)
1493 /* If a sample was recently buffered, leave it alone too */
1494 if (sensor[s].report_pending)
1497 /* We also need a valid sampling rate to be configured */
1498 if (!sensor[s].sampling_rate)
1501 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1503 current_ts = get_timestamp_boot();
1504 target_ts = sensor[s].report_ts + period;
1506 if (target_ts <= current_ts) {
1507 /* Mark the sensor for event generation */
1508 set_report_ts(s, current_ts);
1509 sensor[s].report_pending = DATA_DUPLICATE;
1515 static void integrate_thread_report (uint32_t tag)
1517 int s = tag - THREAD_REPORT_TAG_BASE;
1520 len = read(sensor[s].thread_data_fd[0], &sensor[s].sample, sizeof(sensors_event_t));
1522 if (len == sizeof(sensors_event_t))
1523 sensor[s].report_pending = DATA_SYSFS;
1527 static int get_poll_wait_timeout (void)
1530 * Compute an appropriate timeout value, in ms, for the epoll_wait call that's going to await
1531 * for iio device reports and incoming reports from our sensor sysfs data reader threads.
1535 int64_t target_ts = INT64_MAX;
1540 * Check if we're dealing with a driver that only send events when there is motion, despite the fact that the associated Android sensor
1541 * type is continuous rather than on-change. In that case we have to duplicate events. Check deadline for the nearest upcoming event.
1543 for (s=0; s<sensor_count; s++)
1544 if (is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name && sensor[s].sampling_rate) {
1545 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1547 if (sensor[s].report_ts + period < target_ts)
1548 target_ts = sensor[s].report_ts + period;
1551 /* If we don't have such a driver to deal with */
1552 if (target_ts == INT64_MAX)
1553 return -1; /* Infinite wait */
1555 ms_to_wait = (target_ts - get_timestamp_boot()) / 1000000;
1557 /* If the target timestamp is already behind us, don't wait */
1565 int sensor_poll (sensors_event_t* data, int count)
1570 struct epoll_event ev[MAX_DEVICES];
1571 int returned_events;
1574 /* Get one or more events from our collection of sensors */
1575 return_available_sensor_reports:
1577 /* Synthetize duplicate samples if needed */
1578 synthetize_duplicate_samples();
1580 returned_events = 0;
1582 /* Check our sensor collection for available reports */
1583 for (s=0; s<sensor_count && returned_events < count; s++) {
1585 if (sensor[s].report_pending) {
1588 if (sensor[s].is_virtual)
1589 event_count = propagate_vsensor_report(s, &data[returned_events]);
1591 /* Report this event if it looks OK */
1592 event_count = propagate_sensor_report(s, &data[returned_events]);
1595 sensor[s].report_pending = 0;
1596 returned_events += event_count;
1599 * If the sample was deemed invalid or unreportable, e.g. had the same value as the previously reported
1600 * value for a 'on change' sensor, silently drop it.
1604 while (sensor[s].meta_data_pending) {
1605 /* See sensors.h on these */
1606 data[returned_events].version = META_DATA_VERSION;
1607 data[returned_events].sensor = 0;
1608 data[returned_events].type = SENSOR_TYPE_META_DATA;
1609 data[returned_events].reserved0 = 0;
1610 data[returned_events].timestamp = 0;
1611 data[returned_events].meta_data.sensor = s;
1612 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1614 sensor[s].meta_data_pending--;
1618 if (returned_events)
1619 return returned_events;
1623 ALOGV("Awaiting sensor data\n");
1625 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1628 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1632 ALOGV("%d fds signalled\n", nfds);
1634 /* For each of the signalled sources */
1635 for (i=0; i<nfds; i++)
1636 if (ev[i].events == EPOLLIN)
1637 switch (ev[i].data.u32) {
1638 case 0 ... MAX_DEVICES-1:
1639 /* Read report from iio char dev fd */
1640 integrate_device_report(ev[i].data.u32);
1643 case THREAD_REPORT_TAG_BASE ...
1644 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1645 /* Get report from acquisition thread */
1646 integrate_thread_report(ev[i].data.u32);
1648 case FLUSH_REPORT_TAG:
1650 char flush_event_content;
1651 read(flush_event_fd[0], &flush_event_content, sizeof(flush_event_content));
1656 ALOGW("Unexpected event source!\n");
1660 goto return_available_sensor_reports;
1664 int sensor_set_delay (int s, int64_t ns)
1666 float requested_sampling_rate;
1669 ALOGE("Invalid delay requested on sensor %d: %lld\n", s, ns);
1673 requested_sampling_rate = 1000000000.0 / ns;
1675 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);
1678 * 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
1679 * reads and writes as well as buffer enable/disable operations, since at the iio level most drivers require the buffer to be turned off
1680 * 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
1681 * is changing the sampling rate.
1684 if (requested_sampling_rate != sensor[s].sampling_rate)
1685 return sensor_set_rate(s, requested_sampling_rate);
1691 int sensor_flush (int s)
1693 char flush_event_content = 0;
1694 /* If one shot or not enabled return -EINVAL */
1695 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE || !is_enabled(s))
1698 sensor[s].meta_data_pending++;
1699 write(flush_event_fd[1], &flush_event_content, sizeof(flush_event_content));
1704 int allocate_control_data (void)
1707 struct epoll_event ev = {0};
1709 for (i=0; i<MAX_DEVICES; i++) {
1714 poll_fd = epoll_create(MAX_DEVICES);
1716 if (poll_fd == -1) {
1717 ALOGE("Can't create epoll instance for iio sensors!\n");
1721 ret = pipe(flush_event_fd);
1723 ALOGE("Cannot create flush_event_fd");
1727 ev.events = EPOLLIN;
1728 ev.data.u32 = FLUSH_REPORT_TAG;
1729 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, flush_event_fd[0] , &ev);
1731 ALOGE("Failed adding %d to poll set (%s)\n",
1732 flush_event_fd[0], strerror(errno));
1740 void delete_control_data (void)