2 * Copyright (C) 2014-2015 Intel Corporation.
11 #include <sys/epoll.h>
12 #include <sys/ioctl.h>
13 #include <sys/socket.h>
14 #include <utils/Log.h>
15 #include <hardware/sensors.h>
16 #include <linux/ioctl.h>
18 #include "enumeration.h"
20 #include "transform.h"
21 #include "calibration.h"
22 #include "description.h"
23 #include "filtering.h"
25 /* Couple of temporary defines until we get a suitable linux/iio/events.h include */
27 struct iio_event_data {
32 #define IIO_GET_EVENT_FD_IOCTL _IOR('i', 0x90, int)
34 /* Currently active sensors count, per device */
35 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
36 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
38 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
39 static int events_fd[MAX_DEVICES]; /* fd on the /sys/bus/iio/devices/iio:deviceX/events/<event_name> file */
40 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
41 static int expected_dev_report_size[MAX_DEVICES]; /* expected iio scan len */
42 static int poll_fd; /* epoll instance covering all enabled sensors */
44 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
46 /* We use pthread condition variables to get worker threads out of sleep */
47 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
48 static pthread_cond_t thread_release_cond [MAX_SENSORS];
49 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
52 * We associate tags to each of our poll set entries. These tags have the following values:
53 * - a iio device number if the fd is a iio character device fd
54 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a pipe used by a sysfs data acquisition thread
56 #define THREAD_REPORT_TAG_BASE 1000
58 /* If buffer enable fails, we may want to retry a few times before giving up */
59 #define ENABLE_BUFFER_RETRIES 3
60 #define ENABLE_BUFFER_RETRY_DELAY_MS 10
63 inline int is_enabled (int s)
65 return sensor[s].directly_enabled || sensor[s].ref_count;
69 static int check_state_change (int s, int enabled, int from_virtual)
72 if (sensor[s].directly_enabled)
73 return 0; /* We're being enabled but already were directly activated: no change. */
76 sensor[s].directly_enabled = 1; /* We're being directly enabled */
78 if (sensor[s].ref_count)
79 return 0; /* We were already indirectly enabled */
81 return 1; /* Do continue enabling this sensor */
85 return 0; /* We are being disabled but already were: no change */
87 if (from_virtual && sensor[s].directly_enabled)
88 return 0; /* We're indirectly disabled but the base is still active */
90 sensor[s].directly_enabled = 0; /* We're now directly disabled */
92 if (!from_virtual && sensor[s].ref_count)
93 return 0; /* We still have ref counts */
95 return 1; /* Do continue disabling this sensor */
99 static int enable_buffer (int dev_num, int enabled)
101 char sysfs_path[PATH_MAX];
102 int retries = ENABLE_BUFFER_RETRIES;
104 sprintf(sysfs_path, ENABLE_PATH, dev_num);
107 /* Low level, non-multiplexed, enable/disable routine */
108 if (sysfs_write_int(sysfs_path, enabled) > 0)
111 ALOGE("Failed enabling buffer on dev%d, retrying", dev_num);
112 usleep(ENABLE_BUFFER_RETRY_DELAY_MS*1000);
116 ALOGE("Could not enable buffer\n");
121 static int setup_trigger (int s, const char* trigger_val)
123 char sysfs_path[PATH_MAX];
124 int ret = -1, attempts = 5;
126 sprintf(sysfs_path, TRIGGER_PATH, sensor[s].dev_num);
128 if (trigger_val[0] != '\n')
129 ALOGI("Setting S%d (%s) trigger to %s\n", s, sensor[s].friendly_name, trigger_val);
131 while (ret == -1 && attempts) {
132 ret = sysfs_write_str(sysfs_path, trigger_val);
137 sensor[s].selected_trigger = trigger_val;
139 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s, sensor[s].friendly_name, trigger_val);
143 static int enable_event(int dev_num, const char *name, int enabled)
145 char sysfs_path[PATH_MAX];
147 sprintf(sysfs_path, EVENTS_PATH "%s", dev_num, name);
148 return sysfs_write_int(sysfs_path, enabled);
151 static int enable_sensor(int dev_num, const char *tag, int enabled)
153 char sysfs_path[PATH_MAX];
155 sprintf(sysfs_path, SENSOR_ENABLE_PATH, dev_num, tag);
156 return sysfs_write_int(sysfs_path, enabled);
159 static void enable_iio_timestamp (int dev_num, int known_channels)
161 /* Check if we have a dedicated iio timestamp channel */
163 char spec_buf[MAX_TYPE_SPEC_LEN];
164 char sysfs_path[PATH_MAX];
167 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
169 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
174 if (strcmp(spec_buf, "le:s64/64>>0"))
177 /* OK, type is int64_t as expected, in little endian representation */
179 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
181 if (sysfs_read_int(sysfs_path, &n))
184 /* Check that the timestamp comes after the other fields we read */
185 if (n != known_channels)
188 /* Try enabling that channel */
189 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
191 sysfs_write_int(sysfs_path, 1);
193 if (sysfs_read_int(sysfs_path, &n))
197 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
198 has_iio_ts[dev_num] = 1;
203 static int decode_type_spec (const char type_buf[MAX_TYPE_SPEC_LEN], datum_info_t *type_info)
205 /* Return size in bytes for this type specification, or -1 in error */
208 unsigned int realbits, storagebits, shift;
211 /* Valid specs: "le:u10/16>>0", "le:s16/32>>0" or "le:s32/32>>0" */
213 tokens = sscanf(type_buf, "%ce:%c%u/%u>>%u", &endianness, &sign, &realbits, &storagebits, &shift);
215 if (tokens != 5 || (endianness != 'b' && endianness != 'l') || (sign != 'u' && sign != 's') ||
216 realbits > storagebits || (storagebits != 16 && storagebits != 32 && storagebits != 64)) {
217 ALOGE("Invalid iio channel type spec: %s\n", type_buf);
221 type_info->endianness = endianness;
222 type_info->sign = sign;
223 type_info->realbits = (short) realbits;
224 type_info->storagebits = (short) storagebits;
225 type_info->shift = (short) shift;
227 return storagebits / 8;
231 void build_sensor_report_maps (int dev_num)
234 * 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
235 * 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
236 * sensor report, itself being the data that we return to Android when a sensor poll completes. The mapping should be straightforward in the
237 * 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
238 * 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
248 char spec_buf[MAX_TYPE_SPEC_LEN];
249 datum_info_t* ch_info;
251 char sysfs_path[PATH_MAX];
254 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
255 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
256 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
260 /* For each sensor that is linked to this device */
261 for (s=0; s<sensor_count; s++) {
262 if (sensor[s].dev_num != dev_num)
265 i = sensor[s].catalog_index;
267 /* Read channel details through sysfs attributes */
268 for (c=0; c<sensor[s].num_channels; c++) {
270 /* Read _type file */
271 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].type_path);
273 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
276 ALOGW( "Failed to read type: %s\n", sysfs_path);
280 ch_spec = sensor[s].channel[c].type_spec;
282 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
284 ch_info = &sensor[s].channel[c].type_info;
286 size = decode_type_spec(ch_spec, ch_info);
288 /* Read _index file */
289 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].index_path);
291 n = sysfs_read_int(sysfs_path, &ch_index);
294 ALOGW( "Failed to read index: %s\n", sysfs_path);
298 if (ch_index >= MAX_SENSORS) {
299 ALOGE("Index out of bounds!: %s\n", sysfs_path);
303 /* Record what this index is about */
305 sensor_handle_from_index [ch_index] = s;
306 channel_number_from_index[ch_index] = c;
307 channel_size_from_index [ch_index] = size;
312 /* Stop sampling - if we are recovering from hal restart */
313 enable_buffer(dev_num, 0);
314 setup_trigger(s, "\n");
316 /* Turn on channels we're aware of */
317 for (c=0;c<sensor[s].num_channels; c++) {
318 sprintf(sysfs_path, CHANNEL_PATH "%s", sensor[s].dev_num, sensor_catalog[i].channel[c].en_path);
319 sysfs_write_int(sysfs_path, 1);
323 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
326 * Now that we know which channels are defined, their sizes and their ordering, update channels offsets within device report. Note: there
327 * is a possibility that several sensors share the same index, with their data fields being isolated by masking and shifting as specified
328 * through the real bits and shift values in type attributes. This case is not currently supported. Also, the code below assumes no hole in
329 * the sequence of indices, so it is dependent on discovery of all sensors.
333 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
334 s = sensor_handle_from_index[i];
335 c = channel_number_from_index[i];
336 size = channel_size_from_index[i];
341 ALOGI("S%d C%d : offset %d, size %d, type %s\n", s, c, offset, size, sensor[s].channel[c].type_spec);
343 sensor[s].channel[c].offset = offset;
344 sensor[s].channel[c].size = size;
349 /* Enable the timestamp channel if there is one available */
350 enable_iio_timestamp(dev_num, known_channels);
352 /* Add padding and timestamp size if it's enabled on this iio device */
353 if (has_iio_ts[dev_num])
354 offset = (offset+7)/8*8 + sizeof(int64_t);
356 expected_dev_report_size[dev_num] = offset;
357 ALOGI("Expecting %d scan length on iio dev %d\n", offset, dev_num);
359 if (expected_dev_report_size[dev_num] > MAX_DEVICE_REPORT_SIZE) {
360 ALOGE("Unexpectedly large scan buffer on iio dev%d: %d bytes\n", dev_num, expected_dev_report_size[dev_num]);
362 expected_dev_report_size[dev_num] = MAX_DEVICE_REPORT_SIZE;
367 int adjust_counters (int s, int enabled, int from_virtual)
370 * Adjust counters based on sensor enable action. Return values are:
371 * 0 if the operation was completed and we're all set
372 * 1 if we toggled the state of the sensor and there's work left
373 * -1 in case of an error
376 int dev_num = sensor[s].dev_num;
378 if (!check_state_change(s, enabled, from_virtual))
379 return 0; /* The state of the sensor remains the same: we're done */
382 ALOGI("Enabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
384 switch (sensor[s].type) {
385 case SENSOR_TYPE_MAGNETIC_FIELD:
386 compass_read_data(&sensor[s]);
389 case SENSOR_TYPE_GYROSCOPE:
390 gyro_cal_init(&sensor[s]);
394 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num, sensor[s].friendly_name);
396 /* Sensor disabled, lower report available flag */
397 sensor[s].report_pending = 0;
399 if (sensor[s].type == SENSOR_TYPE_MAGNETIC_FIELD)
400 compass_store_data(&sensor[s]);
402 if (sensor[s].type == SENSOR_TYPE_GYROSCOPE)
403 gyro_store_data(&sensor[s]);
406 /* We changed the state of a sensor: adjust device ref counts */
408 switch(sensor[s].mode) {
411 trig_sensors_per_dev[dev_num]++;
413 trig_sensors_per_dev[dev_num]--;
418 active_poll_sensors++;
419 poll_sensors_per_dev[dev_num]++;
422 active_poll_sensors--;
423 poll_sensors_per_dev[dev_num]--;
429 /* Invalid sensor mode */
435 static int get_field_count (int s, size_t *field_size)
437 *field_size = sizeof(float);
438 switch (sensor[s].type) {
439 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
440 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
441 case SENSOR_TYPE_ORIENTATION: /* degrees */
442 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
443 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
446 case SENSOR_TYPE_LIGHT: /* SI lux units */
447 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
448 case SENSOR_TYPE_TEMPERATURE: /* °C */
449 case SENSOR_TYPE_PROXIMITY: /* centimeters */
450 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
451 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
452 case SENSOR_TYPE_STEP_DETECTOR: /* event: always 1 */
455 case SENSOR_TYPE_ROTATION_VECTOR:
458 case SENSOR_TYPE_STEP_COUNTER: /* number of steps */
459 *field_size = sizeof(uint64_t);
462 ALOGE("Unknown sensor type!\n");
463 return 0; /* Drop sample */
468 * CTS acceptable thresholds:
469 * EventGapVerification.java: (th <= 1.8)
470 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
472 #define THRESHOLD 1.10
473 #define MAX_DELAY 500000000 /* 500 ms */
475 void set_report_ts(int s, int64_t ts)
477 int64_t maxTs, period;
480 * A bit of a hack to please a bunch of cts tests. They
481 * expect the timestamp to be exacly according to the set-up
482 * frequency but if we're simply getting the timestamp at hal level
483 * this may not be the case. Perhaps we'll get rid of this when
484 * we'll be reading the timestamp from the iio channel for all sensors
486 if (sensor[s].report_ts && sensor[s].sampling_rate &&
487 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
489 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
490 maxTs = sensor[s].report_ts + THRESHOLD * period;
491 /* If we're too far behind get back on track */
492 if (ts - maxTs >= MAX_DELAY)
494 sensor[s].report_ts = (ts < maxTs ? ts : maxTs);
496 sensor[s].report_ts = ts;
500 static void* acquisition_routine (void* param)
503 * Data acquisition routine run in a dedicated thread, covering a single sensor. This loop will periodically retrieve sampling data through
504 * 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
505 * frequently, as the thread may be disposed of at any time. Note that Bionic does not provide pthread_cancel / pthread_testcancel...
508 int s = (int) (size_t) param;
510 sensors_event_t data = {0};
513 struct timespec target_time;
514 int64_t timestamp, period, start, stop;
517 if (s < 0 || s >= sensor_count) {
518 ALOGE("Invalid sensor handle!\n");
522 ALOGI("Entering S%d (%s) data acquisition thread: rate:%g\n", s, sensor[s].friendly_name, sensor[s].sampling_rate);
524 if (sensor[s].sampling_rate <= 0) {
525 ALOGE("Invalid rate in acquisition routine for sensor %d: %g\n", s, sensor[s].sampling_rate);
529 /* Initialize data fields that will be shared by all sensor reports */
530 data.version = sizeof(sensors_event_t);
532 data.type = sensor[s].type;
534 num_fields = get_field_count(s, &field_size);
537 * 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
538 * variables to get the acquisition threads out of sleep quickly after the sampling rate is adjusted, or the sensor is disabled.
540 pthread_mutex_lock(&thread_release_mutex[s]);
542 /* Pinpoint the moment we start sampling */
543 timestamp = get_timestamp_monotonic();
545 /* Check and honor termination requests */
546 while (sensor[s].thread_data_fd[1] != -1) {
547 start = get_timestamp_boot();
549 /* Read values through sysfs */
550 for (c=0; c<num_fields; c++) {
551 if (field_size == sizeof(uint64_t))
552 data.u64.data[c] = acquire_immediate_uint64_value(s, c);
554 data.data[c] = acquire_immediate_float_value(s, c);
556 /* Check and honor termination requests */
557 if (sensor[s].thread_data_fd[1] == -1)
560 stop = get_timestamp_boot();
561 set_report_ts(s, start/2 + stop/2);
562 data.timestamp = sensor[s].report_ts;
563 /* If the sample looks good */
564 if (sensor[s].ops.finalize(s, &data)) {
566 /* Pipe it for transmission to poll loop */
567 ret = write(sensor[s].thread_data_fd[1], &data, sizeof(sensors_event_t));
569 if (ret != sizeof(sensors_event_t))
570 ALOGE("S%d write failure: wrote %d, got %d\n", s, sizeof(sensors_event_t), ret);
573 /* Check and honor termination requests */
574 if (sensor[s].thread_data_fd[1] == -1)
577 /* Recalculate period assuming sensor[s].sampling_rate can be changed dynamically during the thread run */
578 if (sensor[s].sampling_rate <= 0) {
579 ALOGE("Unexpected sampling rate for sensor %d: %g\n", s, sensor[s].sampling_rate);
583 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
585 set_timestamp(&target_time, timestamp);
587 /* Wait until the sampling time elapses, or a rate change is signaled, or a thread exit is requested */
588 ret = pthread_cond_timedwait(&thread_release_cond[s], &thread_release_mutex[s], &target_time);
592 ALOGV("Acquisition thread for S%d exiting\n", s);
593 pthread_mutex_unlock(&thread_release_mutex[s]);
599 static void start_acquisition_thread (int s)
601 int incoming_data_fd;
604 struct epoll_event ev = {0};
606 ALOGV("Initializing acquisition context for sensor %d\n", s);
608 /* Create condition variable and mutex for quick thread release */
609 ret = pthread_condattr_init(&thread_cond_attr[s]);
610 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
611 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
612 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
614 /* Create a pipe for inter thread communication */
615 ret = pipe(sensor[s].thread_data_fd);
617 incoming_data_fd = sensor[s].thread_data_fd[0];
620 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
622 /* Add incoming side of pipe to our poll set, with a suitable tag */
623 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
625 ALOGE("Failed adding %d to poll set (%s)\n",
626 incoming_data_fd, strerror(errno));
629 /* Create and start worker thread */
630 ret = pthread_create(&sensor[s].acquisition_thread, NULL, acquisition_routine, (void*) (size_t) s);
634 static void stop_acquisition_thread (int s)
636 int incoming_data_fd = sensor[s].thread_data_fd[0];
637 int outgoing_data_fd = sensor[s].thread_data_fd[1];
639 ALOGV("Tearing down acquisition context for sensor %d\n", s);
641 /* Delete the incoming side of the pipe from our poll set */
642 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
644 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
645 sensor[s].thread_data_fd[0] = -1;
646 sensor[s].thread_data_fd[1] = -1;
648 /* Close both sides of our pipe */
649 close(incoming_data_fd);
650 close(outgoing_data_fd);
652 /* Stop acquisition thread and clean up thread handle */
653 pthread_cond_signal(&thread_release_cond[s]);
654 pthread_join(sensor[s].acquisition_thread, NULL);
656 /* Clean up our sensor descriptor */
657 sensor[s].acquisition_thread = -1;
659 /* Delete condition variable and mutex */
660 pthread_cond_destroy(&thread_release_cond[s]);
661 pthread_mutex_destroy(&thread_release_mutex[s]);
665 static int is_fast_accelerometer (int s)
668 * Some games don't react well to accelerometers using any-motion triggers. Even very low thresholds seem to trip them, and they tend to
669 * request fairly high event rates. Favor continuous triggers if the sensor is an accelerometer and uses a sampling rate of at least 25.
672 if (sensor[s].type != SENSOR_TYPE_ACCELEROMETER)
675 if (sensor[s].sampling_rate < 25)
682 static void tentative_switch_trigger (int s)
685 * Under certain situations it may be beneficial to use an alternate trigger:
687 * - for applications using the accelerometer with high sampling rates, prefer the continuous trigger over the any-motion one, to avoid
688 * jumps related to motion thresholds
691 if (is_fast_accelerometer(s) && !(sensor[s].quirks & QUIRK_TERSE_DRIVER) && sensor[s].selected_trigger == sensor[s].motion_trigger_name)
692 setup_trigger(s, sensor[s].init_trigger_name);
696 static float get_group_max_sampling_rate (int s)
698 /* Review the sampling rates of linked sensors and return the maximum */
702 float arbitrated_rate = 0;
705 arbitrated_rate = sensor[s].requested_rate;
707 /* If any of the currently active sensors built on top of this one need a higher sampling rate, switch to this rate */
708 for (i = 0; i < sensor_count; i++)
709 for (vi = 0; vi < sensor[i].base_count; vi++)
710 if (sensor[i].base[vi] == s && is_enabled(i) && sensor[i].requested_rate > arbitrated_rate) /* If sensor i depends on sensor s */
711 arbitrated_rate = sensor[i].requested_rate;
713 /* If any of the currently active sensors we rely on is using a higher sampling rate, switch to this rate */
714 for (vi = 0; vi < sensor[s].base_count; vi++) {
715 i = sensor[s].base[vi];
716 if (is_enabled(i) && sensor[i].requested_rate > arbitrated_rate)
717 arbitrated_rate = sensor[i].requested_rate;
720 return arbitrated_rate;
724 static int sensor_set_rate (int s, float requested_rate)
726 /* Set the rate at which a specific sensor should report events. See Android sensors.h for indication on sensor trigger modes */
728 char sysfs_path[PATH_MAX];
729 char avail_sysfs_path[PATH_MAX];
730 int dev_num = sensor[s].dev_num;
731 int i = sensor[s].catalog_index;
732 const char *prefix = sensor_catalog[i].tag;
733 int per_sensor_sampling_rate;
734 int per_device_sampling_rate;
739 float group_max_sampling_rate;
740 float cur_sampling_rate; /* Currently used sampling rate */
741 float arb_sampling_rate; /* Granted sampling rate after arbitration */
743 ALOGV("Sampling rate %g requested on sensor %d (%s)\n", requested_rate, s, sensor[s].friendly_name);
745 sensor[s].requested_rate = requested_rate;
747 arb_sampling_rate = requested_rate;
749 if (arb_sampling_rate < sensor[s].min_supported_rate) {
750 ALOGV("Sampling rate %g too low for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].min_supported_rate);
751 arb_sampling_rate = sensor[s].min_supported_rate;
754 /* If one of the linked sensors uses a higher rate, adopt it */
755 group_max_sampling_rate = get_group_max_sampling_rate(s);
757 if (arb_sampling_rate < group_max_sampling_rate) {
758 ALOGV("Using %s sampling rate to %g too due to dependency\n", sensor[s].friendly_name, arb_sampling_rate);
759 arb_sampling_rate = group_max_sampling_rate;
762 if (sensor[s].max_supported_rate && arb_sampling_rate > sensor[s].max_supported_rate) {
763 ALOGV("Sampling rate %g too high for %s, using %g instead\n", arb_sampling_rate, sensor[s].friendly_name, sensor[s].max_supported_rate);
764 arb_sampling_rate = sensor[s].max_supported_rate;
767 sensor[s].sampling_rate = arb_sampling_rate;
769 /* If the sensor is virtual, we're done */
770 if (sensor[s].is_virtual)
773 /* If we're dealing with a poll-mode sensor */
774 if (sensor[s].mode == MODE_POLL) {
776 pthread_cond_signal(&thread_release_cond[s]); /* Wake up thread so the new sampling rate gets used */
780 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
782 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
783 per_sensor_sampling_rate = 1;
784 per_device_sampling_rate = 0;
786 per_sensor_sampling_rate = 0;
788 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
790 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
791 per_device_sampling_rate = 1;
793 per_device_sampling_rate = 0;
796 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
797 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
801 /* Check if we have contraints on allowed sampling rates */
803 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
805 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0) {
808 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
810 /* While we're not at the end of the string */
811 while (*cursor && cursor[0]) {
813 /* Decode a single value */
814 sr = strtod(cursor, NULL);
816 /* If this matches the selected rate, we're happy. Have some tolerance for rounding errors and avoid needless jumps to higher rates */
817 if (fabs(arb_sampling_rate - sr) <= 0.001) {
818 arb_sampling_rate = sr;
823 * If we reached a higher value than the desired rate, adjust selected rate so it matches the first higher available one and
824 * stop parsing - this makes the assumption that rates are sorted by increasing value in the allowed frequencies string.
826 if (sr > arb_sampling_rate) {
827 arb_sampling_rate = sr;
832 while (cursor[0] && !isspace(cursor[0]))
836 while (cursor[0] && isspace(cursor[0]))
841 if (sensor[s].max_supported_rate &&
842 arb_sampling_rate > sensor[s].max_supported_rate) {
843 arb_sampling_rate = sensor[s].max_supported_rate;
846 /* Record the rate that was agreed upon with the sensor taken in isolation ; this avoid uncontrolled ripple effects between colocated sensor rates */
847 sensor[s].semi_arbitrated_rate = arb_sampling_rate;
849 /* Coordinate with others active sensors on the same device, if any */
850 if (per_device_sampling_rate)
851 for (n=0; n<sensor_count; n++)
852 if (n != s && sensor[n].dev_num == dev_num && sensor[n].num_channels && is_enabled(n) &&
853 sensor[n].semi_arbitrated_rate > arb_sampling_rate) {
854 ALOGV("Sampling rate shared between %s and %s, using %g instead of %g\n", sensor[s].friendly_name, sensor[n].friendly_name,
855 sensor[n].semi_arbitrated_rate, arb_sampling_rate);
856 arb_sampling_rate = sensor[n].semi_arbitrated_rate;
859 sensor[s].sampling_rate = arb_sampling_rate;
861 /* Update actual sampling rate field for this sensor and others which may be sharing the same sampling rate */
862 if (per_device_sampling_rate)
863 for (n=0; n<sensor_count; n++)
864 if (sensor[n].dev_num == dev_num && n != s && sensor[n].num_channels)
865 sensor[n].sampling_rate = arb_sampling_rate;
867 /* If the desired rate is already active we're all set */
868 if (arb_sampling_rate == cur_sampling_rate)
871 ALOGI("Sensor %d (%s) sampling rate set to %g\n", s, sensor[s].friendly_name, arb_sampling_rate);
873 if (trig_sensors_per_dev[dev_num])
874 enable_buffer(dev_num, 0);
876 sysfs_write_float(sysfs_path, arb_sampling_rate);
878 /* Check if it makes sense to use an alternate trigger */
879 tentative_switch_trigger(s);
881 if (trig_sensors_per_dev[dev_num])
882 enable_buffer(dev_num, 1);
888 static void reapply_sampling_rates (int s)
891 * The specified sensor was either enabled or disabled. Other sensors in the same group may have constraints related to this sensor
892 * sampling rate on their own sampling rate, so reevaluate them by retrying to use their requested sampling rate, rather than the one
893 * that ended up being used after arbitration.
898 if (sensor[s].is_virtual) {
899 /* Take care of downwards dependencies */
900 for (i=0; i<sensor[s].base_count; i++) {
901 base = sensor[s].base[i];
902 sensor_set_rate(base, sensor[base].requested_rate);
908 for (i=0; i<sensor_count; i++)
909 for (j=0; j<sensor[i].base_count; j++)
910 if (sensor[i].base[j] == s) /* If sensor i depends on sensor s */
911 sensor_set_rate(i, sensor[i].requested_rate);
915 static int sensor_activate_virtual (int s, int enabled, int from_virtual)
919 sensor[s].event_count = 0;
920 sensor[s].meta_data_pending = 0;
922 if (!check_state_change(s, enabled, from_virtual))
923 return 0; /* The state of the sensor remains the same ; we're done */
926 ALOGI("Enabling sensor %d (%s)\n", s, sensor[s].friendly_name);
928 ALOGI("Disabling sensor %d (%s)\n", s, sensor[s].friendly_name);
930 sensor[s].report_pending = 0;
932 for (i=0; i<sensor[s].base_count; i++) {
934 base = sensor[s].base[i];
935 sensor_activate(base, enabled, 1);
938 sensor[base].ref_count++;
940 sensor[base].ref_count--;
943 /* Reevaluate sampling rates of linked sensors */
944 reapply_sampling_rates(s);
949 int sensor_activate (int s, int enabled, int from_virtual)
951 char device_name[PATH_MAX];
952 struct epoll_event ev = {0};
953 int dev_fd, event_fd;
955 int dev_num = sensor[s].dev_num;
957 int catalog_index = sensor[s].catalog_index;
959 if (sensor[s].is_virtual)
960 return sensor_activate_virtual(s, enabled, from_virtual);
962 /* Prepare the report timestamp field for the first event, see set_report_ts method */
963 sensor[s].report_ts = 0;
965 ret = adjust_counters(s, enabled, from_virtual);
967 /* If the operation was neutral in terms of state, we're done */
971 sensor[s].event_count = 0;
972 sensor[s].meta_data_pending = 0;
975 setup_noise_filtering(s); /* Initialize filtering data if required */
977 if (sensor[s].mode == MODE_TRIGGER) {
980 enable_buffer(dev_num, 0);
981 setup_trigger(s, "\n");
983 /* If there's at least one sensor enabled on this iio device */
984 if (trig_sensors_per_dev[dev_num]) {
987 setup_trigger(s, sensor[s].init_trigger_name);
988 enable_buffer(dev_num, 1);
990 } else if (sensor[s].mode == MODE_POLL) {
991 if (sensor[s].needs_enable) {
992 enable_sensor(dev_num, sensor_catalog[catalog_index].tag, enabled);
997 * Make sure we have a fd on the character device ; conversely, close the fd if no one is using associated sensors anymore. The assumption
998 * here is that the underlying driver will power on the relevant hardware block while someone holds a fd on the device.
1000 dev_fd = device_fd[dev_num];
1003 if (sensor[s].mode == MODE_POLL)
1004 stop_acquisition_thread(s);
1006 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1007 /* Stop watching this fd. This should be a no-op in case this fd was not in the poll set. */
1008 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
1011 device_fd[dev_num] = -1;
1014 if (sensor[s].mode == MODE_EVENT) {
1015 event_fd = events_fd[dev_num];
1017 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1018 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1019 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1022 epoll_ctl(poll_fd, EPOLL_CTL_DEL, event_fd, NULL);
1024 events_fd[dev_num] = -1;
1028 /* Release any filtering data we may have accumulated */
1029 release_noise_filtering_data(s);
1031 /* Reevaluate sampling rates of linked sensors */
1032 reapply_sampling_rates(s);
1037 /* First enabled sensor on this iio device */
1038 sprintf(device_name, DEV_FILE_PATH, dev_num);
1039 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
1041 device_fd[dev_num] = dev_fd;
1044 ALOGE("Could not open fd on %s (%s)\n", device_name, strerror(errno));
1045 adjust_counters(s, 0, from_virtual);
1049 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
1051 if (sensor[s].mode == MODE_TRIGGER) {
1053 /* Add this iio device fd to the set of watched fds */
1054 ev.events = EPOLLIN;
1055 ev.data.u32 = dev_num;
1057 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
1060 ALOGE("Failed adding %d to poll set (%s)\n", dev_fd, strerror(errno));
1064 /* Note: poll-mode fds are not readable */
1065 } else if (sensor[s].mode == MODE_EVENT) {
1066 event_fd = events_fd[dev_num];
1068 ret = ioctl(dev_fd, IIO_GET_EVENT_FD_IOCTL, &event_fd);
1069 if (ret == -1 || event_fd == -1) {
1070 ALOGE("Failed to retrieve event_fd from %d (%s)\n", dev_fd, strerror(errno));
1073 events_fd[dev_num] = event_fd;
1074 ALOGV("Opened fd=%d to receive events\n", event_fd);
1076 /* Add this event fd to the set of watched fds */
1077 ev.events = EPOLLIN;
1078 ev.data.u32 = dev_num;
1080 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, event_fd, &ev);
1082 ALOGE("Failed adding %d to poll set (%s)\n", event_fd, strerror(errno));
1085 for (c = 0; c < sensor_catalog[catalog_index].num_channels; c++) {
1087 for (d = 0; d < sensor_catalog[catalog_index].channel[c].num_events; d++)
1088 enable_event(dev_num, sensor_catalog[catalog_index].channel[c].event[d].ev_en_path, enabled);
1091 if (!poll_sensors_per_dev[dev_num] && !trig_sensors_per_dev[dev_num]) {
1093 device_fd[dev_num] = -1;
1098 /* Ensure that on-change sensors send at least one event after enable */
1099 get_field_count(s, &field_size);
1100 if (field_size == sizeof(uint64_t))
1101 sensor[s].prev_val.data64 = -1;
1103 sensor[s].prev_val.data = -1;
1105 if (sensor[s].mode == MODE_POLL)
1106 start_acquisition_thread(s);
1108 /* Reevaluate sampling rates of linked sensors */
1109 reapply_sampling_rates(s);
1115 static void enable_motion_trigger (int dev_num)
1118 * In the ideal case, we enumerate two triggers per iio device ; the default (periodically firing) trigger, and another one (the motion
1119 * trigger) that only fires up when motion is detected. This second one allows for lesser energy consumption, but requires periodic sample
1120 * duplication at the HAL level for sensors that Android defines as continuous. This "duplicate last sample" logic can only be engaged
1121 * 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
1122 * trigger when we got events for all active sensors. Unfortunately in the general case several sensors can be associated to a given iio
1123 * device, they can independently be controlled, and we have to adjust the trigger in use at the iio device level depending on whether or
1124 * not appropriate conditions are met at the sensor level.
1129 int active_sensors = trig_sensors_per_dev[dev_num];
1130 int candidate[MAX_SENSORS];
1131 int candidate_count = 0;
1133 if (!active_sensors)
1136 /* Check that all active sensors are ready to switch */
1138 for (s=0; s<MAX_SENSORS; s++)
1139 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels &&
1140 (!sensor[s].motion_trigger_name[0] || !sensor[s].report_initialized || is_fast_accelerometer(s) ||
1141 (sensor[s].quirks & QUIRK_FORCE_CONTINUOUS)))
1144 /* Record which particular sensors need to switch */
1146 for (s=0; s<MAX_SENSORS; s++)
1147 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].num_channels && sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1148 candidate[candidate_count++] = s;
1150 if (!candidate_count)
1153 /* Now engage the motion trigger for sensors which aren't using it */
1155 enable_buffer(dev_num, 0);
1157 for (i=0; i<candidate_count; i++) {
1159 setup_trigger(s, sensor[s].motion_trigger_name);
1162 enable_buffer(dev_num, 1);
1165 static void stamp_reports (int dev_num, int64_t ts)
1169 for (s=0; s<MAX_SENSORS; s++)
1170 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].mode != MODE_POLL)
1171 set_report_ts(s, ts);
1175 static int integrate_device_report_from_dev(int dev_num, int fd)
1179 unsigned char buf[MAX_DEVICE_REPORT_SIZE] = { 0 };
1181 unsigned char *target;
1182 unsigned char *source;
1185 int ts_offset = 0; /* Offset of iio timestamp, if provided */
1186 int64_t boot_to_rt_delta;
1188 /* There's an incoming report on the specified iio device char dev fd */
1190 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
1194 len = read(fd, buf, expected_dev_report_size[dev_num]);
1197 ALOGE("Could not read report from iio device %d (%s)\n", dev_num, strerror(errno));
1201 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
1203 /* Map device report to sensor reports */
1205 for (s=0; s<MAX_SENSORS; s++)
1206 if (sensor[s].dev_num == dev_num && is_enabled(s)) {
1210 /* Copy data from device to sensor report buffer */
1211 for (c=0; c<sensor[s].num_channels; c++) {
1213 target = sensor[s].report_buffer + sr_offset;
1215 source = buf + sensor[s].channel[c].offset;
1217 size = sensor[s].channel[c].size;
1219 memcpy(target, source, size);
1224 ALOGV("Sensor %d report available (%d bytes)\n", s, sr_offset);
1226 sensor[s].report_pending = DATA_TRIGGER;
1227 sensor[s].report_initialized = 1;
1229 ts_offset += sr_offset;
1232 /* Tentatively switch to an any-motion trigger if conditions are met */
1233 enable_motion_trigger(dev_num);
1235 /* If no iio timestamp channel was detected for this device, bail out */
1236 if (!has_iio_ts[dev_num]) {
1237 stamp_reports(dev_num, get_timestamp_boot());
1241 /* Don't trust the timestamp channel in any-motion mode */
1242 for (s=0; s<MAX_SENSORS; s++)
1243 if (sensor[s].dev_num == dev_num && is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name) {
1244 stamp_reports(dev_num, get_timestamp_boot());
1248 /* Align on a 64 bits boundary */
1249 ts_offset = expected_dev_report_size[dev_num] - sizeof(int64_t);
1251 /* If we read an amount of data consistent with timestamp presence */
1252 if (len == expected_dev_report_size[dev_num])
1253 ts = *(int64_t*) (buf + ts_offset);
1256 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
1257 stamp_reports(dev_num, get_timestamp_boot());
1261 ALOGV("Driver timestamp on iio device %d: ts=%lld\n", dev_num, ts);
1263 boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
1265 stamp_reports(dev_num, ts + boot_to_rt_delta);
1270 static int integrate_device_report_from_event(int dev_num, int fd)
1274 struct iio_event_data event;
1276 /* There's an incoming report on the specified iio device char dev fd */
1278 ALOGE("Ignoring stale report on event fd %d of device %d\n",
1283 len = read(fd, &event, sizeof(event));
1286 ALOGE("Could not read event from fd %d of device %d (%s)\n",
1287 fd, dev_num, strerror(errno));
1291 ts = event.timestamp;
1293 ALOGV("Read event %lld from fd %d of iio device %d\n", event.id, fd, dev_num);
1295 /* Map device report to sensor reports */
1296 for (s = 0; s < MAX_SENSORS; s++)
1297 if (sensor[s].dev_num == dev_num &&
1299 sensor[s].report_ts = ts;
1300 sensor[s].report_pending = 1;
1301 sensor[s].report_initialized = 1;
1302 ALOGV("Sensor %d report available (1 byte)\n", s);
1307 static int integrate_device_report(int dev_num)
1311 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
1312 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
1316 if (events_fd[dev_num] != -1) {
1317 ret = integrate_device_report_from_event(dev_num, events_fd[dev_num]);
1322 if (device_fd[dev_num] != -1)
1323 ret = integrate_device_report_from_dev(dev_num, device_fd[dev_num]);
1328 static int propagate_vsensor_report (int s, sensors_event_t *data)
1330 /* There's a new report stored in sensor.sample for this sensor; transmit it */
1332 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1335 data->type = sensor[s].type;
1340 static int propagate_sensor_report (int s, sensors_event_t *data)
1342 /* There's a sensor report pending for this sensor ; transmit it */
1345 int num_fields = get_field_count(s, &field_size);
1347 unsigned char* current_sample;
1350 /* If there's nothing to return... we're done */
1354 ALOGV("Sample on sensor %d (type %d):\n", s, sensor[s].type);
1356 if (sensor[s].mode == MODE_POLL) {
1357 /* We received a good sample but we're not directly enabled so we'll drop */
1358 if (!sensor[s].directly_enabled)
1360 /* Use the data provided by the acquisition thread */
1361 ALOGV("Reporting data from worker thread for S%d\n", s);
1362 memcpy(data, &sensor[s].sample, sizeof(sensors_event_t));
1363 data->timestamp = sensor[s].report_ts;
1367 memset(data, 0, sizeof(sensors_event_t));
1369 data->version = sizeof(sensors_event_t);
1371 data->type = sensor[s].type;
1372 data->timestamp = sensor[s].report_ts;
1374 if (sensor[s].mode == MODE_EVENT) {
1375 ALOGV("Reporting event\n");
1376 /* Android requires events to return 1.0 */
1377 data->data[0] = 1.0;
1378 data->data[1] = 0.0;
1379 data->data[2] = 0.0;
1383 /* Convert the data into the expected Android-level format */
1385 current_sample = sensor[s].report_buffer;
1387 for (c=0; c<num_fields; c++) {
1389 data->data[c] = sensor[s].ops.transform (s, c, current_sample);
1391 ALOGV("\tfield %d: %g\n", c, data->data[c]);
1392 current_sample += sensor[s].channel[c].size;
1395 ret = sensor[s].ops.finalize(s, data);
1397 /* We will drop samples if the sensor is not directly enabled */
1398 if (!sensor[s].directly_enabled)
1401 /* 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 */
1406 static void synthetize_duplicate_samples (void)
1409 * Some sensor types (ex: gyroscope) are defined as continuously firing by Android, despite the fact that
1410 * we can be dealing with iio drivers that only report events for new samples. For these we generate reports
1411 * periodically, duplicating the last data we got from the driver. This is not necessary for polling sensors.
1419 for (s=0; s<sensor_count; s++) {
1421 /* Ignore disabled sensors */
1425 /* If the sensor is continuously firing, leave it alone */
1426 if (sensor[s].selected_trigger != sensor[s].motion_trigger_name)
1429 /* If we haven't seen a sample, there's nothing to duplicate */
1430 if (!sensor[s].report_initialized)
1433 /* If a sample was recently buffered, leave it alone too */
1434 if (sensor[s].report_pending)
1437 /* We also need a valid sampling rate to be configured */
1438 if (!sensor[s].sampling_rate)
1441 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1443 current_ts = get_timestamp_boot();
1444 target_ts = sensor[s].report_ts + period;
1446 if (target_ts <= current_ts) {
1447 /* Mark the sensor for event generation */
1448 set_report_ts(s, current_ts);
1449 sensor[s].report_pending = DATA_DUPLICATE;
1455 static void integrate_thread_report (uint32_t tag)
1457 int s = tag - THREAD_REPORT_TAG_BASE;
1460 len = read(sensor[s].thread_data_fd[0], &sensor[s].sample, sizeof(sensors_event_t));
1462 if (len == sizeof(sensors_event_t))
1463 sensor[s].report_pending = DATA_SYSFS;
1467 static int get_poll_wait_timeout (void)
1470 * Compute an appropriate timeout value, in ms, for the epoll_wait call that's going to await
1471 * for iio device reports and incoming reports from our sensor sysfs data reader threads.
1475 int64_t target_ts = INT64_MAX;
1480 * Check if we're dealing with a driver that only send events when there is motion, despite the fact that the associated Android sensor
1481 * type is continuous rather than on-change. In that case we have to duplicate events. Check deadline for the nearest upcoming event.
1483 for (s=0; s<sensor_count; s++)
1484 if (is_enabled(s) && sensor[s].selected_trigger == sensor[s].motion_trigger_name && sensor[s].sampling_rate) {
1485 period = (int64_t) (1000000000.0 / sensor[s].sampling_rate);
1487 if (sensor[s].report_ts + period < target_ts)
1488 target_ts = sensor[s].report_ts + period;
1491 /* If we don't have such a driver to deal with */
1492 if (target_ts == INT64_MAX)
1493 return -1; /* Infinite wait */
1495 ms_to_wait = (target_ts - get_timestamp_boot()) / 1000000;
1497 /* If the target timestamp is already behind us, don't wait */
1505 int sensor_poll (sensors_event_t* data, int count)
1510 struct epoll_event ev[MAX_DEVICES];
1511 int returned_events;
1514 /* Get one or more events from our collection of sensors */
1515 return_available_sensor_reports:
1517 /* Synthetize duplicate samples if needed */
1518 synthetize_duplicate_samples();
1520 returned_events = 0;
1522 /* Check our sensor collection for available reports */
1523 for (s=0; s<sensor_count && returned_events < count; s++) {
1525 if (sensor[s].report_pending) {
1528 if (sensor[s].is_virtual)
1529 event_count = propagate_vsensor_report(s, &data[returned_events]);
1531 /* Report this event if it looks OK */
1532 event_count = propagate_sensor_report(s, &data[returned_events]);
1535 sensor[s].report_pending = 0;
1536 returned_events += event_count;
1539 * If the sample was deemed invalid or unreportable, e.g. had the same value as the previously reported
1540 * value for a 'on change' sensor, silently drop it.
1544 while (sensor[s].meta_data_pending) {
1545 /* See sensors.h on these */
1546 data[returned_events].version = META_DATA_VERSION;
1547 data[returned_events].sensor = 0;
1548 data[returned_events].type = SENSOR_TYPE_META_DATA;
1549 data[returned_events].reserved0 = 0;
1550 data[returned_events].timestamp = 0;
1551 data[returned_events].meta_data.sensor = s;
1552 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1554 sensor[s].meta_data_pending--;
1558 if (returned_events)
1559 return returned_events;
1563 ALOGV("Awaiting sensor data\n");
1565 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1568 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1572 ALOGV("%d fds signalled\n", nfds);
1574 /* For each of the signalled sources */
1575 for (i=0; i<nfds; i++)
1576 if (ev[i].events == EPOLLIN)
1577 switch (ev[i].data.u32) {
1578 case 0 ... MAX_DEVICES-1:
1579 /* Read report from iio char dev fd */
1580 integrate_device_report(ev[i].data.u32);
1583 case THREAD_REPORT_TAG_BASE ...
1584 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1585 /* Get report from acquisition thread */
1586 integrate_thread_report(ev[i].data.u32);
1590 ALOGW("Unexpected event source!\n");
1594 goto return_available_sensor_reports;
1598 int sensor_set_delay (int s, int64_t ns)
1600 float requested_sampling_rate;
1603 ALOGE("Invalid delay requested on sensor %d: %lld\n", s, ns);
1607 requested_sampling_rate = 1000000000.0 / ns;
1609 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);
1612 * 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
1613 * reads and writes as well as buffer enable/disable operations, since at the iio level most drivers require the buffer to be turned off
1614 * 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
1615 * is changing the sampling rate.
1618 if (requested_sampling_rate != sensor[s].sampling_rate)
1619 return sensor_set_rate(s, requested_sampling_rate);
1625 int sensor_flush (int s)
1627 /* If one shot or not enabled return -EINVAL */
1628 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE || !is_enabled(s))
1631 sensor[s].meta_data_pending++;
1636 int allocate_control_data (void)
1640 for (i=0; i<MAX_DEVICES; i++) {
1645 poll_fd = epoll_create(MAX_DEVICES);
1647 if (poll_fd == -1) {
1648 ALOGE("Can't create epoll instance for iio sensors!\n");
1656 void delete_control_data (void)