2 * Copyright (C) 2014 Intel Corporation.
11 #include <sys/epoll.h>
12 #include <sys/socket.h>
13 #include <utils/Log.h>
14 #include <hardware/sensors.h>
16 #include "enumeration.h"
18 #include "transform.h"
19 #include "calibration.h"
20 #include "description.h"
21 #include "filtering.h"
23 /* Currently active sensors count, per device */
24 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
25 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
27 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
28 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
29 static int expected_dev_report_size[MAX_DEVICES]; /* expected iio scan len */
30 static int poll_fd; /* epoll instance covering all enabled sensors */
32 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
34 /* We use pthread condition variables to get worker threads out of sleep */
35 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
36 static pthread_cond_t thread_release_cond [MAX_SENSORS];
37 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
40 * We associate tags to each of our poll set entries. These tags have the
42 * - a iio device number if the fd is a iio character device fd
43 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a pipe used by a sysfs data acquisition thread
45 #define THREAD_REPORT_TAG_BASE 0x00010000
47 #define ENABLE_BUFFER_RETRIES 10
48 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
51 inline int is_enabled (int s)
53 return sensor[s].directly_enabled || sensor[s].ref_count;
57 static int check_state_change (int s, int enabled, int from_virtual)
60 if (sensor[s].directly_enabled)
61 return 0; /* We're being enabled but already were directly activated: no change. */
64 sensor[s].directly_enabled = 1; /* We're being directly enabled */
66 if (sensor[s].ref_count)
67 return 0; /* We were already indirectly enabled */
69 return 1; /* Do continue enabling this sensor */
73 return 0; /* We are being disabled but already were: no change */
75 if (from_virtual && sensor[s].directly_enabled)
76 return 0; /* We're indirectly disabled but the base is still active */
78 sensor[s].directly_enabled = 0; /* We're now directly disabled */
80 if (!from_virtual && sensor[s].ref_count)
81 return 0; /* We still have ref counts */
83 return 1; /* Do continue disabling this sensor */
87 static int enable_buffer(int dev_num, int enabled)
89 char sysfs_path[PATH_MAX];
90 int ret, retries, millisec;
91 struct timespec req = {0};
93 retries = ENABLE_BUFFER_RETRIES;
94 millisec = ENABLE_BUFFER_RETRY_DELAY_MS;
96 req.tv_nsec = millisec * 1000000L;
98 sprintf(sysfs_path, ENABLE_PATH, dev_num);
101 /* Low level, non-multiplexed, enable/disable routine */
102 ret = sysfs_write_int(sysfs_path, enabled);
106 ALOGE("Failed enabling buffer, retrying");
107 nanosleep(&req, (struct timespec *)NULL);
111 ALOGE("Could not enable buffer\n");
119 static int setup_trigger (int s, const char* trigger_val)
121 char sysfs_path[PATH_MAX];
122 int ret = -1, attempts = 5;
124 sprintf(sysfs_path, TRIGGER_PATH, sensor[s].dev_num);
126 if (trigger_val[0] != '\n')
127 ALOGI("Setting S%d (%s) trigger to %s\n", s, sensor[s].friendly_name, trigger_val);
129 while (ret == -1 && attempts) {
130 ret = sysfs_write_str(sysfs_path, trigger_val);
135 sensor[s].selected_trigger = trigger_val;
137 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s, sensor[s].friendly_name, trigger_val);
142 static void enable_iio_timestamp (int dev_num, int known_channels)
144 /* Check if we have a dedicated iio timestamp channel */
146 char spec_buf[MAX_TYPE_SPEC_LEN];
147 char sysfs_path[PATH_MAX];
150 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
152 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
157 if (strcmp(spec_buf, "le:s64/64>>0"))
160 /* OK, type is int64_t as expected, in little endian representation */
162 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
164 if (sysfs_read_int(sysfs_path, &n))
167 /* Check that the timestamp comes after the other fields we read */
168 if (n != known_channels)
171 /* Try enabling that channel */
172 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
174 sysfs_write_int(sysfs_path, 1);
176 if (sysfs_read_int(sysfs_path, &n))
180 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
181 has_iio_ts[dev_num] = 1;
186 static int decode_type_spec (const char type_buf[MAX_TYPE_SPEC_LEN],
187 datum_info_t *type_info)
189 /* Return size in bytes for this type specification, or -1 in error */
192 unsigned int realbits, storagebits, shift;
195 /* Valid specs: "le:u10/16>>0", "le:s16/32>>0" or "le:s32/32>>0" */
197 tokens = sscanf(type_buf, "%ce:%c%u/%u>>%u", &endianness, &sign, &realbits, &storagebits, &shift);
199 if (tokens != 5 || (endianness != 'b' && endianness != 'l') || (sign != 'u' && sign != 's') ||
200 realbits > storagebits || (storagebits != 16 && storagebits != 32 && storagebits != 64)) {
201 ALOGE("Invalid iio channel type spec: %s\n", type_buf);
205 type_info->endianness = endianness;
206 type_info->sign = sign;
207 type_info->realbits = (short) realbits;
208 type_info->storagebits = (short) storagebits;
209 type_info->shift = (short) shift;
211 return storagebits / 8;
215 void build_sensor_report_maps (int dev_num)
218 * 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
219 * 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
220 * sensor report, itself being the data that we return to Android when a sensor poll completes. The mapping should be straightforward in the
221 * 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
222 * 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
232 char spec_buf[MAX_TYPE_SPEC_LEN];
233 datum_info_t* ch_info;
235 char sysfs_path[PATH_MAX];
238 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
239 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
240 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
244 /* For each sensor that is linked to this device */
245 for (s=0; s<sensor_count; s++) {
246 if (sensor[s].dev_num != dev_num)
249 i = sensor[s].catalog_index;
251 /* Read channel details through sysfs attributes */
252 for (c=0; c<sensor[s].num_channels; c++) {
254 /* Read _type file */
255 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].type_path);
257 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
260 ALOGW( "Failed to read type: %s\n", sysfs_path);
264 ch_spec = sensor[s].channel[c].type_spec;
266 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
268 ch_info = &sensor[s].channel[c].type_info;
270 size = decode_type_spec(ch_spec, ch_info);
272 /* Read _index file */
273 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].index_path);
275 n = sysfs_read_int(sysfs_path, &ch_index);
278 ALOGW( "Failed to read index: %s\n", sysfs_path);
282 if (ch_index >= MAX_SENSORS) {
283 ALOGE("Index out of bounds!: %s\n", sysfs_path);
287 /* Record what this index is about */
289 sensor_handle_from_index [ch_index] = s;
290 channel_number_from_index[ch_index] = c;
291 channel_size_from_index [ch_index] = size;
296 /* Stop sampling - if we are recovering from hal restart */
297 enable_buffer(dev_num, 0);
298 setup_trigger(s, "\n");
300 /* Turn on channels we're aware of */
301 for (c=0;c<sensor[s].num_channels; c++) {
302 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].en_path);
303 sysfs_write_int(sysfs_path, 1);
307 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
310 * Now that we know which channels are defined, their sizes and their ordering, update channels offsets within device report. Note: there
311 * is a possibility that several sensors share the same index, with their data fields being isolated by masking and shifting as specified
312 * through the real bits and shift values in type attributes. This case is not currently supported. Also, the code below assumes no hole in
313 * the sequence of indices, so it is dependent on discovery of all sensors.
317 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
318 s = sensor_handle_from_index[i];
319 c = channel_number_from_index[i];
320 size = channel_size_from_index[i];
325 ALOGI("S%d C%d : offset %d, size %d, type %s\n", s, c, offset, size, sensor[s].channel[c].type_spec);
327 sensor[s].channel[c].offset = offset;
328 sensor[s].channel[c].size = size;
333 /* Enable the timestamp channel if there is one available */
334 enable_iio_timestamp(dev_num, known_channels);
336 /* Add padding and timestamp size if it's enabled on this iio device */
337 if (has_iio_ts[dev_num])
338 offset = (offset+7)/8*8 + sizeof(int64_t);
340 expected_dev_report_size[dev_num] = offset;
341 ALOGI("Expecting %d scan length on iio dev %d\n", offset, dev_num);
343 if (expected_dev_report_size[dev_num] > MAX_DEVICE_REPORT_SIZE) {
344 ALOGE("Unexpectedly large scan buffer on iio dev%d: %d bytes\n", dev_num, expected_dev_report_size[dev_num]);
346 expected_dev_report_size[dev_num] = MAX_DEVICE_REPORT_SIZE;
351 int adjust_counters (int s, int enabled, int from_virtual)
354 * Adjust counters based on sensor enable action. Return values are:
355 * 0 if the operation was completed and we're all set
356 * 1 if we toggled the state of the sensor and there's work left
359 int dev_num = sensor[s].dev_num;
361 if (!check_state_change(s, enabled, from_virtual))
362 return 0; /* The state of the sensor remains the same: we're done */
365 ALOGI("Enabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
367 switch (sensor[s].type) {
368 case SENSOR_TYPE_MAGNETIC_FIELD:
369 compass_read_data(&sensor[s]);
372 case SENSOR_TYPE_GYROSCOPE:
373 gyro_cal_init(&sensor[s]);
377 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
379 /* Sensor disabled, lower report available flag */
380 sensor[s].report_pending = 0;
382 if (sensor[s].type == SENSOR_TYPE_MAGNETIC_FIELD)
383 compass_store_data(&sensor[s]);
385 if (sensor[s].type == SENSOR_TYPE_GYROSCOPE)
386 gyro_store_data(&sensor[s]);
389 /* We changed the state of a sensor: adjust device ref counts */
391 if (!sensor[s].is_polling) {
394 trig_sensors_per_dev[dev_num]++;
396 trig_sensors_per_dev[dev_num]--;
402 active_poll_sensors++;
403 poll_sensors_per_dev[dev_num]++;
407 active_poll_sensors--;
408 poll_sensors_per_dev[dev_num]--;
413 static int get_field_count (int s)
415 switch (sensor[s].type) {
416 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
417 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
418 case SENSOR_TYPE_ORIENTATION: /* degrees */
419 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
420 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
423 case SENSOR_TYPE_LIGHT: /* SI lux units */
424 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
425 case SENSOR_TYPE_TEMPERATURE: /* °C */
426 case SENSOR_TYPE_PROXIMITY: /* centimeters */
427 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
428 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
431 case SENSOR_TYPE_ROTATION_VECTOR:
435 ALOGE("Unknown sensor type!\n");
436 return 0; /* Drop sample */
441 static void* acquisition_routine (void* param)
444 * Data acquisition routine run in a dedicated thread, covering a single sensor. This loop will periodically retrieve sampling data through
445 * 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
446 * frequently, as the thread may be disposed of at any time. Note that Bionic does not provide pthread_cancel / pthread_testcancel...
449 int s = (int) (size_t) param;
450 int num_fields, sample_size;
451 sensors_event_t data = {0};
454 struct timespec target_time;
455 int64_t timestamp, period, start, stop;
457 if (s < 0 || s >= sensor_count) {
458 ALOGE("Invalid sensor handle!\n");
462 ALOGI("Entering data acquisition thread S%d (%s), rate:%g\n", s, sensor[s].friendly_name, sensor[s].sampling_rate);
464 if (sensor[s].sampling_rate <= 0) {
465 ALOGE("Invalid rate in acquisition routine for sensor %d: %g\n", s, sensor[s].sampling_rate);
469 num_fields = get_field_count(s);
470 sample_size = sizeof(int64_t) + num_fields * sizeof(float);
473 * 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
474 * variables to get the acquisition threads out of sleep quickly after the sampling rate is adjusted, or the sensor is disabled.
476 pthread_mutex_lock(&thread_release_mutex[s]);
478 /* Pinpoint the moment we start sampling */
479 timestamp = get_timestamp_monotonic();
481 /* Check and honor termination requests */
482 while (sensor[s].thread_data_fd[1] != -1) {
483 start = get_timestamp_boot();
484 /* Read values through sysfs */
485 for (c=0; c<num_fields; c++) {
486 data.data[c] = acquire_immediate_value(s, c);
487 /* Check and honor termination requests */
488 if (sensor[s].thread_data_fd[1] == -1)
491 stop = get_timestamp_boot();
492 data.timestamp = start/2 + stop/2;
494 /* If the sample looks good */
495 if (sensor[s].ops.finalize(s, &data)) {
497 /* Pipe it for transmission to poll loop */
498 ret = write(sensor[s].thread_data_fd[1], &data.timestamp, sample_size);
500 if (ret != sample_size)
501 ALOGE("S%d write failure: wrote %d, got %d\n", s, sample_size, ret);
504 /* Check and honor termination requests */
505 if (sensor[s].thread_data_fd[1] == -1)
508 /* Recalculate period assuming sensor[s].sampling_rate can be changed dynamically during the thread run */
509 if (sensor[s].sampling_rate <= 0) {
510 ALOGE("Unexpected sampling rate for sensor %d: %g\n", s, sensor[s].sampling_rate);
514 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
516 set_timestamp(&target_time, timestamp);
518 /* Wait until the sampling time elapses, or a rate change is signaled, or a thread exit is requested.
520 ret = pthread_cond_timedwait(&thread_release_cond[s], &thread_release_mutex[s], &target_time);
524 ALOGV("Acquisition thread for S%d exiting\n", s);
525 pthread_mutex_unlock(&thread_release_mutex[s]);
531 static void start_acquisition_thread (int s)
533 int incoming_data_fd;
536 struct epoll_event ev = {0};
538 ALOGV("Initializing acquisition context for sensor %d\n", s);
540 /* Create condition variable and mutex for quick thread release */
541 ret = pthread_condattr_init(&thread_cond_attr[s]);
542 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
543 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
544 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
546 /* Create a pipe for inter thread communication */
547 ret = pipe(sensor[s].thread_data_fd);
549 incoming_data_fd = sensor[s].thread_data_fd[0];
552 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
554 /* Add incoming side of pipe to our poll set, with a suitable tag */
555 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
557 /* Create and start worker thread */
558 ret = pthread_create( &sensor[s].acquisition_thread, NULL, acquisition_routine, (void*) (size_t) s);
562 static void stop_acquisition_thread (int s)
564 int incoming_data_fd = sensor[s].thread_data_fd[0];
565 int outgoing_data_fd = sensor[s].thread_data_fd[1];
567 ALOGV("Tearing down acquisition context for sensor %d\n", s);
569 /* Delete the incoming side of the pipe from our poll set */
570 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
572 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
573 sensor[s].thread_data_fd[0] = -1;
574 sensor[s].thread_data_fd[1] = -1;
576 /* Close both sides of our pipe */
577 close(incoming_data_fd);
578 close(outgoing_data_fd);
580 /* Stop acquisition thread and clean up thread handle */
581 pthread_cond_signal(&thread_release_cond[s]);
582 pthread_join(sensor[s].acquisition_thread, NULL);
584 /* Clean up our sensor descriptor */
585 sensor[s].acquisition_thread = -1;
587 /* Delete condition variable and mutex */
588 pthread_cond_destroy(&thread_release_cond[s]);
589 pthread_mutex_destroy(&thread_release_mutex[s]);
593 static int is_fast_accelerometer (int s)
596 * Some games don't react well to accelerometers using any-motion
597 * triggers. Even very low thresholds seem to trip them, and they tend
598 * to request fairly high event rates. Favor continuous triggers if the
599 * sensor is an accelerometer and uses a sampling rate of at least 25.
602 if (sensor[s].type != SENSOR_TYPE_ACCELEROMETER)
605 if (sensor[s].sampling_rate < 25)
612 static void tentative_switch_trigger (int s)
615 * Under certain situations it may be beneficial to use an alternate trigger:
617 * - for applications using the accelerometer with high sampling rates, prefer the continuous trigger over the any-motion one, to avoid
618 * jumps related to motion thresholds
621 if (is_fast_accelerometer(s) && !(sensor[s].quirks & QUIRK_TERSE_DRIVER) && sensor[s].selected_trigger == sensor[s].motion_trigger_name)
622 setup_trigger(s, sensor[s].init_trigger_name);
626 static float get_group_max_sampling_rate (int s)
628 /* Review the sampling rates of linked sensors and return the maximum */
632 float arbitrated_rate = 0;
635 arbitrated_rate = sensor[s].requested_rate;
637 /* If any of the currently active sensors built on top of this one need a higher sampling rate, switch to this rate */
638 for (i = 0; i < sensor_count; i++)
639 for (vi = 0; vi < sensor[i].base_count; vi++)
640 if (sensor[i].base[vi] == s && is_enabled(i) && sensor[i].requested_rate > arbitrated_rate) /* If sensor i depends on sensor s */
641 arbitrated_rate = sensor[i].requested_rate;
643 /* If any of the currently active sensors we rely on is using a higher sampling rate, switch to this rate */
644 for (vi = 0; vi < sensor[s].base_count; vi++) {
645 i = sensor[s].base[vi];
646 if (is_enabled(i) && sensor[i].requested_rate > arbitrated_rate)
647 arbitrated_rate = sensor[i].requested_rate;
650 return arbitrated_rate;
654 static int sensor_set_rate (int s, float requested_rate)
656 /* Set the rate at which a specific sensor should report events. See Android sensors.h for indication on sensor trigger modes */
658 char sysfs_path[PATH_MAX];
659 char avail_sysfs_path[PATH_MAX];
660 int dev_num = sensor[s].dev_num;
661 int i = sensor[s].catalog_index;
662 const char *prefix = sensor_catalog[i].tag;
663 int per_sensor_sampling_rate;
664 int per_device_sampling_rate;
669 float group_max_sampling_rate;
670 float cur_sampling_rate; /* Currently used sampling rate */
671 float arb_sampling_rate; /* Granted sampling rate after arbitration */
673 ALOGV("Sampling rate %g requested on sensor %d (%s)\n", requested_rate, s, sensor[s].friendly_name);
675 sensor[s].requested_rate = requested_rate;
677 arb_sampling_rate = requested_rate;
679 if (arb_sampling_rate < sensor[s].min_supported_rate) {
680 ALOGV("Sampling rate %g too low for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].min_supported_rate);
681 arb_sampling_rate = sensor[s].min_supported_rate;
684 /* If one of the linked sensors uses a higher rate, adopt it */
685 group_max_sampling_rate = get_group_max_sampling_rate(s);
687 if (arb_sampling_rate < group_max_sampling_rate) {
688 ALOGV("Using %s sampling rate to %g too due to dependency\n", sensor[s].friendly_name, arb_sampling_rate);
689 arb_sampling_rate = group_max_sampling_rate;
692 if (sensor[s].max_supported_rate && arb_sampling_rate > sensor[s].max_supported_rate) {
693 ALOGV("Sampling rate %g too high for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].max_supported_rate);
694 arb_sampling_rate = sensor[s].max_supported_rate;
697 sensor[s].sampling_rate = arb_sampling_rate;
699 /* If the sensor is virtual, we're done */
700 if (sensor[s].is_virtual)
703 /* If we're dealing with a poll-mode sensor */
704 if (sensor[s].is_polling) {
706 pthread_cond_signal(&thread_release_cond[s]); /* Wake up thread so the new sampling rate gets used */
710 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
712 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
713 per_sensor_sampling_rate = 1;
714 per_device_sampling_rate = 0;
716 per_sensor_sampling_rate = 0;
718 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
720 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
721 per_device_sampling_rate = 1;
723 per_device_sampling_rate = 0;
726 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
727 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
731 /* Check if we have contraints on allowed sampling rates */
733 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
735 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
738 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
740 /* While we're not at the end of the string */
741 while (*cursor && cursor[0]) {
743 /* Decode a single value */
744 sr = strtod(cursor, NULL);
746 /* If this matches the selected rate, we're happy. Have some tolerance for rounding errors and avoid needless jumps to higher rates */
747 if (fabs(arb_sampling_rate - sr) <= 0.001) {
748 arb_sampling_rate = sr;
753 * If we reached a higher value than the desired rate, adjust selected rate so it matches the first higher
754 * available one and stop parsing - this makes the assumption that rates are sorted by increasing value
755 * in the allowed frequencies string.
757 if (sr > arb_sampling_rate) {
758 arb_sampling_rate = sr;
763 while (cursor[0] && !isspace(cursor[0]))
767 while (cursor[0] && isspace(cursor[0]))
772 if (sensor[s].max_supported_rate &&
773 arb_sampling_rate > sensor[s].max_supported_rate) {
774 arb_sampling_rate = sensor[s].max_supported_rate;
778 /* Coordinate with others active sensors on the same device, if any */
779 if (per_device_sampling_rate)
780 for (n=0; n<sensor_count; n++)
781 if (n != s && sensor[n].dev_num == dev_num && sensor[n].num_channels && is_enabled(n) && sensor[n].sampling_rate > arb_sampling_rate) {
782 ALOGV("Sampling rate shared between %s and %s, using %g instead of %g\n", sensor[s].friendly_name, sensor[n].friendly_name,
783 sensor[n].sampling_rate, arb_sampling_rate);
784 arb_sampling_rate = sensor[n].sampling_rate;
787 sensor[s].sampling_rate = arb_sampling_rate;
789 /* Update actual sampling rate field for this sensor and others which may be sharing the same sampling rate */
790 if (per_device_sampling_rate)
791 for (n=0; n<sensor_count; n++)
792 if (sensor[n].dev_num == dev_num && n != s && sensor[n].num_channels)
793 sensor[n].sampling_rate = arb_sampling_rate;
795 /* If the desired rate is already active we're all set */
796 if (arb_sampling_rate == cur_sampling_rate)
799 ALOGI("Sensor %d (%s) sampling rate set to %g\n",
800 s, sensor[s].friendly_name, arb_sampling_rate);
802 if (trig_sensors_per_dev[dev_num])
803 enable_buffer(dev_num, 0);
805 sysfs_write_float(sysfs_path, arb_sampling_rate);
807 /* Check if it makes sense to use an alternate trigger */
808 tentative_switch_trigger(s);
810 if (trig_sensors_per_dev[dev_num])
811 enable_buffer(dev_num, 1);
817 static void reapply_sampling_rates (int s)
820 * The specified sensor was either enabled or disabled. Other sensors in the same group may have constraints related to this sensor
821 * sampling rate on their own sampling rate, so reevaluate them by retrying to use their requested sampling rate, rather than the one
822 * that ended up being used after arbitration.
825 int i, j, base, user;
827 if (sensor[s].is_virtual) {
828 /* Take care of downwards dependencies */
829 for (i=0; i<sensor[s].base_count; i++) {
830 base = sensor[s].base[i];
831 sensor_set_rate(base, sensor[base].requested_rate);
837 for (i=0; i<sensor_count; i++)
838 for (j=0; j<sensor[i].base_count; j++)
839 if (sensor[i].base[j] == s) /* If sensor i depends on sensor s */
840 sensor_set_rate(i, sensor[i].requested_rate);
844 static int sensor_activate_virtual (int s, int enabled, int from_virtual)
848 sensor[s].event_count = 0;
849 sensor[s].meta_data_pending = 0;
851 if (!check_state_change(s, enabled, from_virtual))
852 return 0; /* The state of the sensor remains the same ; we're done */
855 ALOGI("Enabling sensor %d (%s)\n", s, sensor[s].friendly_name);
857 ALOGI("Disabling sensor %d (%s)\n", s, sensor[s].friendly_name);
859 sensor[s].report_pending = 0;
861 for (i=0; i<sensor[s].base_count; i++) {
863 base = sensor[s].base[i];
864 sensor_activate(base, enabled, 1);
867 sensor[base].ref_count++;
869 sensor[base].ref_count--;
872 /* Reevaluate sampling rates of linked sensors */
873 reapply_sampling_rates(s);
878 int sensor_activate (int s, int enabled, int from_virtual)
880 char device_name[PATH_MAX];
881 struct epoll_event ev = {0};
884 int dev_num = sensor[s].dev_num;
886 if (sensor[s].is_virtual)
887 return sensor_activate_virtual(s, enabled, from_virtual);
889 /* Prepare the report timestamp field for the first event, see set_report_ts method */
890 sensor[s].report_ts = 0;
892 ret = adjust_counters(s, enabled, from_virtual);
894 /* If the operation was neutral in terms of state, we're done */
898 sensor[s].event_count = 0;
899 sensor[s].meta_data_pending = 0;
901 if (enabled && (sensor[s].quirks & QUIRK_NOISY))
902 setup_noise_filtering(s); /* Initialize filtering data if required */
904 if (!sensor[s].is_polling) {
907 enable_buffer(dev_num, 0);
908 setup_trigger(s, "\n");
910 /* If there's at least one sensor enabled on this iio device */
911 if (trig_sensors_per_dev[dev_num]) {
914 setup_trigger(s, sensor[s].init_trigger_name);
915 enable_buffer(dev_num, 1);
920 * Make sure we have a fd on the character device ; conversely, close the fd if no one is using associated sensors anymore. The assumption
921 * here is that the underlying driver will power on the relevant hardware block while someone holds a fd on the device.
923 dev_fd = device_fd[dev_num];
926 if (sensor[s].is_polling)
927 stop_acquisition_thread(s);
929 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
930 /* Stop watching this fd. This should be a no-op in case this fd was not in the poll set. */
931 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
934 device_fd[dev_num] = -1;
937 /* Release any filtering data we may have accumulated */
938 release_noise_filtering_data(s);
940 /* Reevaluate sampling rates of linked sensors */
941 reapply_sampling_rates(s);
946 /* First enabled sensor on this iio device */
947 sprintf(device_name, DEV_FILE_PATH, dev_num);
948 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
950 device_fd[dev_num] = dev_fd;
953 ALOGE("Could not open fd on %s (%s)\n", device_name, strerror(errno));
954 adjust_counters(s, 0, from_virtual);
958 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
960 if (!sensor[s].is_polling) {
962 /* Add this iio device fd to the set of watched fds */
964 ev.data.u32 = dev_num;
966 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
969 ALOGE("Failed adding %d to poll set (%s)\n", dev_fd, strerror(errno));
973 /* Note: poll-mode fds are not readable */
977 /* Ensure that on-change sensors send at least one event after enable */
978 sensor[s].prev_val = -1;
980 if (sensor[s].is_polling)
981 start_acquisition_thread(s);
983 /* Reevaluate sampling rates of linked sensors */
984 reapply_sampling_rates(s);
990 static void enable_motion_trigger (int dev_num)
993 * In the ideal case, we enumerate two triggers per iio device ; the default (periodically firing) trigger, and another one (the motion
994 * trigger) that only fires up when motion is detected. This second one allows for lesser energy consumption, but requires periodic sample
995 * duplication at the HAL level for sensors that Android defines as continuous. This "duplicate last sample" logic can only be engaged
996 * 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
997 * trigger when we got events for all active sensors. Unfortunately in the general case several sensors can be associated to a given iio
998 * device, they can independently be controlled, and we have to adjust the trigger in use at the iio device level depending on whether or
999 * not appropriate conditions are met at the sensor level.
1004 int active_sensors = trig_sensors_per_dev[dev_num];
1005 int candidate[MAX_SENSORS];
1006 int candidate_count = 0;
1008 if (!active_sensors)
1011 /* Check that all active sensors are ready to switch */
1013 for (s=0; s<MAX_SENSORS; s++)
1014 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels &&
1015 (!sensor[s].motion_trigger_name[0] || !sensor[s].report_initialized || is_fast_accelerometer(s) ||
1016 (sensor[s].quirks & QUIRK_FORCE_CONTINUOUS)))
1019 /* Record which particular sensors need to switch */
1021 for (s=0; s<MAX_SENSORS; s++)
1022 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels && sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1023 candidate[candidate_count++] = s;
1025 if (!candidate_count)
1028 /* Now engage the motion trigger for sensors which aren't using it */
1030 enable_buffer(dev_num, 0);
1032 for (i=0; i<candidate_count; i++) {
1034 setup_trigger(s, sensor[s].motion_trigger_name);
1037 enable_buffer(dev_num, 1);
1042 * CTS acceptable thresholds:
1043 * EventGapVerification.java: (th <= 1.8)
1044 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
1046 #define THRESHOLD 1.10
1047 #define MAX_DELAY 500000000 /* 500 ms */
1049 void set_report_ts(int s, int64_t ts)
1051 int64_t maxTs, period;
1054 * A bit of a hack to please a bunch of cts tests. They
1055 * expect the timestamp to be exacly according to the set-up
1056 * frequency but if we're simply getting the timestamp at hal level
1057 * this may not be the case. Perhaps we'll get rid of this when
1058 * we'll be reading the timestamp from the iio channel for all sensors
1060 if (sensor[s].report_ts && sensor[s].sampling_rate &&
1061 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
1063 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1064 maxTs = sensor[s].report_ts + THRESHOLD * period;
1065 /* If we're too far behind get back on track */
1066 if (ts - maxTs >= MAX_DELAY)
1068 sensor[s].report_ts = (ts < maxTs ? ts : maxTs);
1070 sensor[s].report_ts = ts;
1075 static void stamp_reports (int dev_num, int64_t ts)
1079 for (s=0; s<MAX_SENSORS; s++)
1080 if (sensor[s].dev_num == dev_num &&
1082 set_report_ts(s, ts);
1086 static int integrate_device_report (int dev_num)
1090 unsigned char buf[MAX_DEVICE_REPORT_SIZE] = { 0 };
1092 unsigned char *target;
1093 unsigned char *source;
1096 int ts_offset = 0; /* Offset of iio timestamp, if provided */
1097 int64_t boot_to_rt_delta;
1099 /* There's an incoming report on the specified iio device char dev fd */
1101 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
1102 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
1106 if (device_fd[dev_num] == -1) {
1107 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
1111 len = read(device_fd[dev_num], buf, expected_dev_report_size[dev_num]);
1114 ALOGE("Could not read report from iio device %d (%s)\n", dev_num, strerror(errno));
1118 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
1120 /* Map device report to sensor reports */
1122 for (s=0; s<MAX_SENSORS; s++)
1123 if (sensor[s].dev_num == dev_num && is_enabled(s)) {
1127 /* Copy data from device to sensor report buffer */
1128 for (c=0; c<sensor[s].num_channels; c++) {
1130 target = sensor[s].report_buffer + sr_offset;
1132 source = buf + sensor[s].channel[c].offset;
1134 size = sensor[s].channel[c].size;
1136 memcpy(target, source, size);
1141 ALOGV("Sensor %d report available (%d bytes)\n", s, sr_offset);
1143 sensor[s].report_pending = DATA_TRIGGER;
1144 sensor[s].report_initialized = 1;
1146 ts_offset += sr_offset;
1149 /* Tentatively switch to an any-motion trigger if conditions are met */
1150 enable_motion_trigger(dev_num);
1152 /* If no iio timestamp channel was detected for this device, bail out */
1153 if (!has_iio_ts[dev_num]) {
1154 stamp_reports(dev_num, get_timestamp_boot());
1158 /* Don't trust the timestamp channel in any-motion mode */
1159 for (s=0; s<MAX_SENSORS; s++)
1160 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name) {
1161 stamp_reports(dev_num, get_timestamp_boot());
1165 /* Align on a 64 bits boundary */
1166 ts_offset = (ts_offset + 7)/8*8;
1168 /* If we read an amount of data consistent with timestamp presence */
1169 if (len == expected_dev_report_size[dev_num])
1170 ts = *(int64_t*) (buf + ts_offset);
1173 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
1174 stamp_reports(dev_num, get_timestamp_boot());
1178 ALOGV("Driver timestamp on iio device %d: ts=%lld\n", dev_num, ts);
1180 boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1182 stamp_reports(dev_num, ts + boot_to_rt_delta);
1188 static int propagate_vsensor_report (int s, sensors_event_t *data)
1190 /* There's a new report stored in sensor.sample for this sensor; transmit it */
1192 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1195 data->type = sensor[s].type;
1200 static int propagate_sensor_report (int s, sensors_event_t *data)
1202 /* There's a sensor report pending for this sensor ; transmit it */
1204 int num_fields = get_field_count(s);
1206 unsigned char* current_sample;
1208 /* If there's nothing to return... we're done */
1212 memset(data, 0, sizeof(sensors_event_t));
1214 data->version = sizeof(sensors_event_t);
1216 data->type = sensor[s].type;
1217 data->timestamp = sensor[s].report_ts;
1219 ALOGV("Sample on sensor %d (type %d):\n", s, sensor[s].type);
1221 current_sample = sensor[s].report_buffer;
1223 /* If this is a poll sensor */
1224 if (sensor[s].is_polling) {
1225 /* Use the data provided by the acquisition thread */
1226 ALOGV("Reporting data from worker thread for S%d\n", s);
1227 memcpy(data->data, current_sample, num_fields * sizeof(float));
1231 /* Convert the data into the expected Android-level format */
1232 for (c=0; c<num_fields; c++) {
1234 data->data[c] = sensor[s].ops.transform (s, c, current_sample);
1236 ALOGV("\tfield %d: %g\n", c, data->data[c]);
1237 current_sample += sensor[s].channel[c].size;
1240 /* 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 */
1241 return sensor[s].ops.finalize(s, data);
1245 static void synthetize_duplicate_samples (void)
1248 * Some sensor types (ex: gyroscope) are defined as continuously firing by Android, despite the fact that we can be dealing with iio drivers
1249 * that only report events for new samples. For these we generate reports periodically, duplicating the last data we got from the
1250 * driver. This is not necessary for polling sensors.
1258 for (s=0; s<sensor_count; s++) {
1260 /* Ignore disabled sensors */
1264 /* If the sensor is continuously firing, leave it alone */
1265 if (sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1268 /* If we haven't seen a sample, there's nothing to duplicate */
1269 if (!sensor[s].report_initialized)
1272 /* If a sample was recently buffered, leave it alone too */
1273 if (sensor[s].report_pending)
1276 /* We also need a valid sampling rate to be configured */
1277 if (!sensor[s].sampling_rate)
1280 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1282 current_ts = get_timestamp_boot();
1283 target_ts = sensor[s].report_ts + period;
1285 if (target_ts <= current_ts) {
1286 /* Mark the sensor for event generation */
1287 set_report_ts(s, current_ts);
1288 sensor[s].report_pending = DATA_DUPLICATE;
1294 static void integrate_thread_report (uint32_t tag)
1296 int s = tag - THREAD_REPORT_TAG_BASE;
1300 unsigned char current_sample[MAX_SENSOR_REPORT_SIZE];
1302 expected_len = sizeof(int64_t) + get_field_count(s) * sizeof(float);
1304 len = read(sensor[s].thread_data_fd[0],
1308 memcpy(×tamp, current_sample, sizeof(int64_t));
1309 memcpy(sensor[s].report_buffer, sizeof(int64_t) + current_sample, expected_len - sizeof(int64_t));
1311 if (len == expected_len) {
1312 set_report_ts(s, timestamp);
1313 sensor[s].report_pending = DATA_SYSFS;
1318 static int get_poll_wait_timeout (void)
1321 * Compute an appropriate timeout value, in ms, for the epoll_wait call that's going to await
1322 * for iio device reports and incoming reports from our sensor sysfs data reader threads.
1326 int64_t target_ts = INT64_MAX;
1331 * Check if we're dealing with a driver that only send events when there is motion, despite the fact that the associated Android sensor
1332 * type is continuous rather than on-change. In that case we have to duplicate events. Check deadline for the nearest upcoming event.
1334 for (s=0; s<sensor_count; s++)
1335 if (is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name && sensor[s].sampling_rate) {
1336 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1338 if (sensor[s].report_ts + period < target_ts)
1339 target_ts = sensor[s].report_ts + period;
1342 /* If we don't have such a driver to deal with */
1343 if (target_ts == INT64_MAX)
1344 return -1; /* Infinite wait */
1346 ms_to_wait = (target_ts - get_timestamp_boot()) / 1000000;
1348 /* If the target timestamp is already behind us, don't wait */
1356 int sensor_poll (sensors_event_t* data, int count)
1361 struct epoll_event ev[MAX_DEVICES];
1362 int returned_events;
1366 /* Get one or more events from our collection of sensors */
1367 return_available_sensor_reports:
1369 /* Synthetize duplicate samples if needed */
1370 synthetize_duplicate_samples();
1372 returned_events = 0;
1373 /* Check our sensor collection for available reports */
1374 for (s=0; s<sensor_count && returned_events < count; s++) {
1375 if (sensor[s].report_pending) {
1378 if (sensor[s].is_virtual)
1379 event_count = propagate_vsensor_report(s, &data[returned_events]);
1381 /* Report this event if it looks OK */
1382 event_count = propagate_sensor_report(s, &data[returned_events]);
1385 sensor[s].report_pending = 0;
1386 returned_events += event_count;
1389 * If the sample was deemed invalid or unreportable, e.g. had the same value as the previously reported
1390 * value for a 'on change' sensor, silently drop it.
1394 while (sensor[s].meta_data_pending) {
1395 /* See sensors.h on these */
1396 data[returned_events].version = META_DATA_VERSION;
1397 data[returned_events].sensor = 0;
1398 data[returned_events].type = SENSOR_TYPE_META_DATA;
1399 data[returned_events].reserved0 = 0;
1400 data[returned_events].timestamp = 0;
1401 data[returned_events].meta_data.sensor = s;
1402 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1404 sensor[s].meta_data_pending--;
1408 if (returned_events)
1409 return returned_events;
1413 ALOGV("Awaiting sensor data\n");
1415 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1418 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1422 ALOGV("%d fds signalled\n", nfds);
1424 /* For each of the signalled sources */
1425 for (i=0; i<nfds; i++)
1426 if (ev[i].events == EPOLLIN)
1427 switch (ev[i].data.u32) {
1428 case 0 ... MAX_DEVICES-1:
1429 /* Read report from iio char dev fd */
1430 integrate_device_report(ev[i].data.u32);
1433 case THREAD_REPORT_TAG_BASE ...
1434 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1435 /* Get report from acquisition thread */
1436 integrate_thread_report(ev[i].data.u32);
1440 ALOGW("Unexpected event source!\n");
1444 goto return_available_sensor_reports;
1448 int sensor_set_delay (int s, int64_t ns)
1450 float requested_sampling_rate;
1453 ALOGE("Invalid delay requested on sensor %d: %lld\n", s, ns);
1457 requested_sampling_rate = 1000000000.0 / ns;
1459 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);
1462 * 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
1463 * reads and writes as well as buffer enable/disable operations, since at the iio level most drivers require the buffer to be turned off
1464 * 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
1465 * is changing the sampling rate.
1468 if (requested_sampling_rate != sensor[s].sampling_rate)
1469 return sensor_set_rate(s, requested_sampling_rate);
1475 int sensor_flush (int s)
1477 /* If one shot or not enabled return -EINVAL */
1478 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE || !is_enabled(s))
1481 sensor[s].meta_data_pending++;
1486 int allocate_control_data (void)
1490 for (i=0; i<MAX_DEVICES; i++)
1493 poll_fd = epoll_create(MAX_DEVICES);
1495 if (poll_fd == -1) {
1496 ALOGE("Can't create epoll instance for iio sensors!\n");
1504 void delete_control_data (void)