2 * Copyright (C) 2014 Intel Corporation.
10 #include <sys/epoll.h>
11 #include <sys/socket.h>
12 #include <utils/Log.h>
13 #include <hardware/sensors.h>
15 #include "enumeration.h"
17 #include "transform.h"
18 #include "calibration.h"
19 #include "description.h"
21 /* Currently active sensors count, per device */
22 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
23 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
25 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
27 static int poll_fd; /* epoll instance covering all enabled sensors */
29 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
31 int64_t ts_delta; /* delta between SystemClock.getNanos and our timestamp */
33 /* We use pthread condition variables to get worker threads out of sleep */
34 static pthread_condattr_t thread_cond_attr [MAX_SENSORS];
35 static pthread_cond_t thread_release_cond [MAX_SENSORS];
36 static pthread_mutex_t thread_release_mutex [MAX_SENSORS];
39 * We associate tags to each of our poll set entries. These tags have the
41 * - a iio device number if the fd is a iio character device fd
42 * - THREAD_REPORT_TAG_BASE + sensor handle if the fd is the receiving end of a
43 * 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
50 static int enable_buffer(int dev_num, int enabled)
52 char sysfs_path[PATH_MAX];
53 int ret, retries, millisec;
54 struct timespec req = {0};
56 retries = ENABLE_BUFFER_RETRIES;
57 millisec = ENABLE_BUFFER_RETRY_DELAY_MS;
59 req.tv_nsec = millisec * 1000000L;
61 sprintf(sysfs_path, ENABLE_PATH, dev_num);
64 /* Low level, non-multiplexed, enable/disable routine */
65 ret = sysfs_write_int(sysfs_path, enabled);
69 ALOGE("Failed enabling buffer, retrying");
70 nanosleep(&req, (struct timespec *)NULL);
74 ALOGE("Could not enable buffer\n");
82 static int setup_trigger (int s, const char* trigger_val)
84 char sysfs_path[PATH_MAX];
85 int ret = -1, attempts = 5;
87 sprintf(sysfs_path, TRIGGER_PATH, sensor_info[s].dev_num);
89 if (trigger_val[0] != '\n')
90 ALOGI("Setting S%d (%s) trigger to %s\n", s,
91 sensor_info[s].friendly_name, trigger_val);
93 while (ret == -1 && attempts) {
94 ret = sysfs_write_str(sysfs_path, trigger_val);
99 sensor_info[s].selected_trigger = trigger_val;
101 ALOGE("Setting S%d (%s) trigger to %s FAILED.\n", s,
102 sensor_info[s].friendly_name, trigger_val);
107 void build_sensor_report_maps(int dev_num)
110 * Read sysfs files from a iio device's scan_element directory, and
111 * build a couple of tables from that data. These tables will tell, for
112 * each sensor, where to gather relevant data in a device report, i.e.
113 * the structure that we read from the /dev/iio:deviceX file in order to
114 * sensor report, itself being the data that we return to Android when a
115 * sensor poll completes. The mapping should be straightforward in the
116 * case where we have a single sensor active per iio device but, this is
117 * not the general case. In general several sensors can be handled
118 * through a single iio device, and the _en, _index and _type syfs
119 * entries all concur to paint a picture of what the structure of the
129 char spec_buf[MAX_TYPE_SPEC_LEN];
130 struct datum_info_t* ch_info;
132 char sysfs_path[PATH_MAX];
135 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
136 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
137 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
141 /* For each sensor that is linked to this device */
142 for (s=0; s<sensor_count; s++) {
143 if (sensor_info[s].dev_num != dev_num)
146 i = sensor_info[s].catalog_index;
148 /* Read channel details through sysfs attributes */
149 for (c=0; c<sensor_info[s].num_channels; c++) {
151 /* Read _type file */
152 sprintf(sysfs_path, CHANNEL_PATH "%s",
153 sensor_info[s].dev_num,
154 sensor_catalog[i].channel[c].type_path);
156 n = sysfs_read_str(sysfs_path, spec_buf,
160 ALOGW( "Failed to read type: %s\n",
165 ch_spec = sensor_info[s].channel[c].type_spec;
167 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
169 ch_info = &sensor_info[s].channel[c].type_info;
171 size = decode_type_spec(ch_spec, ch_info);
173 /* Read _index file */
174 sprintf(sysfs_path, CHANNEL_PATH "%s",
175 sensor_info[s].dev_num,
176 sensor_catalog[i].channel[c].index_path);
178 n = sysfs_read_int(sysfs_path, &ch_index);
181 ALOGW( "Failed to read index: %s\n",
186 if (ch_index >= MAX_SENSORS) {
187 ALOGE("Index out of bounds!: %s\n", sysfs_path);
191 /* Record what this index is about */
193 sensor_handle_from_index [ch_index] = s;
194 channel_number_from_index[ch_index] = c;
195 channel_size_from_index [ch_index] = size;
200 /* Stop sampling - if we are recovering from hal restart */
201 enable_buffer(dev_num, 0);
202 setup_trigger(s, "\n");
204 /* Turn on channels we're aware of */
205 for (c=0;c<sensor_info[s].num_channels; c++) {
206 sprintf(sysfs_path, CHANNEL_PATH "%s",
207 sensor_info[s].dev_num,
208 sensor_catalog[i].channel[c].en_path);
209 sysfs_write_int(sysfs_path, 1);
213 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
216 * Now that we know which channels are defined, their sizes and their
217 * ordering, update channels offsets within device report. Note: there
218 * is a possibility that several sensors share the same index, with
219 * their data fields being isolated by masking and shifting as specified
220 * through the real bits and shift values in type attributes. This case
221 * is not currently supported. Also, the code below assumes no hole in
222 * the sequence of indices, so it is dependent on discovery of all
226 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
227 s = sensor_handle_from_index[i];
228 c = channel_number_from_index[i];
229 size = channel_size_from_index[i];
234 ALOGI("S%d C%d : offset %d, size %d, type %s\n",
235 s, c, offset, size, sensor_info[s].channel[c].type_spec);
237 sensor_info[s].channel[c].offset = offset;
238 sensor_info[s].channel[c].size = size;
245 int adjust_counters (int s, int enabled)
248 * Adjust counters based on sensor enable action. Return values are:
249 * -1 if there's an inconsistency: abort action in this case
250 * 0 if the operation was completed and we're all set
251 * 1 if we toggled the state of the sensor and there's work left
254 int dev_num = sensor_info[s].dev_num;
255 int catalog_index = sensor_info[s].catalog_index;
256 int sensor_type = sensor_catalog[catalog_index].type;
258 /* Refcount per sensor, in terms of enable count */
260 ALOGI("Enabling sensor %d (iio device %d: %s)\n",
261 s, dev_num, sensor_info[s].friendly_name);
263 sensor_info[s].enable_count++;
265 if (sensor_info[s].enable_count > 1)
266 return 0; /* The sensor was, and remains, in use */
268 switch (sensor_type) {
269 case SENSOR_TYPE_MAGNETIC_FIELD:
270 compass_read_data(&sensor_info[s]);
273 case SENSOR_TYPE_GYROSCOPE:
274 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
275 gyro_cal_init(&sensor_info[s]);
279 if (sensor_info[s].enable_count == 0)
280 return -1; /* Spurious disable call */
282 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
283 sensor_info[s].friendly_name);
285 sensor_info[s].enable_count--;
287 if (sensor_info[s].enable_count > 0)
288 return 0; /* The sensor was, and remains, in use */
290 /* Sensor disabled, lower report available flag */
291 sensor_info[s].report_pending = 0;
293 if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
294 compass_store_data(&sensor_info[s]);
298 /* If uncalibrated type and pair is already active don't adjust counters */
299 if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
300 sensor_info[sensor_info[s].pair_idx].enable_count != 0)
303 /* We changed the state of a sensor - adjust per iio device counters */
305 /* If this is a regular event-driven sensor */
306 if (sensor_info[s].num_channels) {
309 trig_sensors_per_dev[dev_num]++;
311 trig_sensors_per_dev[dev_num]--;
317 active_poll_sensors++;
318 poll_sensors_per_dev[dev_num]++;
322 active_poll_sensors--;
323 poll_sensors_per_dev[dev_num]--;
328 static int get_field_count (int s)
330 int catalog_index = sensor_info[s].catalog_index;
331 int sensor_type = sensor_catalog[catalog_index].type;
333 switch (sensor_type) {
334 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
335 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
336 case SENSOR_TYPE_ORIENTATION: /* degrees */
337 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
338 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
341 case SENSOR_TYPE_LIGHT: /* SI lux units */
342 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
343 case SENSOR_TYPE_TEMPERATURE: /* °C */
344 case SENSOR_TYPE_PROXIMITY: /* centimeters */
345 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
346 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
349 case SENSOR_TYPE_ROTATION_VECTOR:
353 ALOGE("Unknown sensor type!\n");
354 return 0; /* Drop sample */
360 static void* acquisition_routine (void* param)
363 * Data acquisition routine run in a dedicated thread, covering a single
364 * sensor. This loop will periodically retrieve sampling data through
365 * sysfs, then package it as a sample and transfer it to our master poll
366 * loop through a report fd. Checks for a cancellation signal quite
367 * frequently, as the thread may be disposed of at any time. Note that
368 * Bionic does not provide pthread_cancel / pthread_testcancel...
371 int s = (int) (size_t) param;
372 int num_fields, sample_size;
373 struct sensors_event_t data = {0};
376 struct timespec target_time;
377 int64_t timestamp, period;
379 if (s < 0 || s >= sensor_count) {
380 ALOGE("Invalid sensor handle!\n");
384 ALOGI("Entering data acquisition thread S%d (%s): rate(%f), ts(%lld)\n", s,
385 sensor_info[s].friendly_name, sensor_info[s].sampling_rate, sensor_info[s].report_ts);
387 if (sensor_info[s].sampling_rate <= 0) {
388 ALOGE("Non-positive rate in acquisition routine for sensor %d: %f\n",
389 s, sensor_info[s].sampling_rate);
393 num_fields = get_field_count(s);
394 sample_size = num_fields * sizeof(float);
397 * Each condition variable is associated to a mutex that has to be
398 * locked by the thread that's waiting on it. We use these condition
399 * variables to get the acquisition threads out of sleep quickly after
400 * the sampling rate is adjusted, or the sensor is disabled.
402 pthread_mutex_lock(&thread_release_mutex[s]);
404 /* Pinpoint the moment we start sampling */
405 timestamp = get_timestamp_monotonic();
407 /* Check and honor termination requests */
408 while (sensor_info[s].thread_data_fd[1] != -1) {
410 /* Read values through sysfs */
411 for (c=0; c<num_fields; c++) {
412 data.data[c] = acquire_immediate_value(s, c);
413 /* Check and honor termination requests */
414 if (sensor_info[s].thread_data_fd[1] == -1)
418 /* If the sample looks good */
419 if (sensor_info[s].ops.finalize(s, &data)) {
421 /* Pipe it for transmission to poll loop */
422 ret = write( sensor_info[s].thread_data_fd[1],
423 data.data, sample_size);
424 if (ret != sample_size)
425 ALOGE("S%d acquisition thread: tried to write %d, ret: %d\n",
426 s, sample_size, ret);
429 /* Check and honor termination requests */
430 if (sensor_info[s].thread_data_fd[1] == -1)
433 /* Recalculate period asumming sensor_info[s].sampling_rate
434 * can be changed dynamically during the thread run */
435 if (sensor_info[s].sampling_rate <= 0) {
436 ALOGE("Non-positive rate in acquisition routine for sensor %d: %f\n",
437 s, sensor_info[s].sampling_rate);
441 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
443 set_timestamp(&target_time, timestamp);
446 * Wait until the sampling time elapses, or a rate change is
447 * signaled, or a thread exit is requested.
449 ret = pthread_cond_timedwait( &thread_release_cond[s],
450 &thread_release_mutex[s],
455 ALOGV("Acquisition thread for S%d exiting\n", s);
456 pthread_mutex_unlock(&thread_release_mutex[s]);
462 static void start_acquisition_thread (int s)
464 int incoming_data_fd;
467 struct epoll_event ev = {0};
469 ALOGV("Initializing acquisition context for sensor %d\n", s);
471 /* Create condition variable and mutex for quick thread release */
472 ret = pthread_condattr_init(&thread_cond_attr[s]);
473 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
474 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
475 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
477 /* Create a pipe for inter thread communication */
478 ret = pipe(sensor_info[s].thread_data_fd);
480 incoming_data_fd = sensor_info[s].thread_data_fd[0];
483 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
485 /* Add incoming side of pipe to our poll set, with a suitable tag */
486 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
488 /* Create and start worker thread */
489 ret = pthread_create( &sensor_info[s].acquisition_thread,
496 static void stop_acquisition_thread (int s)
498 int incoming_data_fd = sensor_info[s].thread_data_fd[0];
499 int outgoing_data_fd = sensor_info[s].thread_data_fd[1];
501 ALOGV("Tearing down acquisition context for sensor %d\n", s);
503 /* Delete the incoming side of the pipe from our poll set */
504 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
506 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
507 sensor_info[s].thread_data_fd[0] = -1;
508 sensor_info[s].thread_data_fd[1] = -1;
510 /* Close both sides of our pipe */
511 close(incoming_data_fd);
512 close(outgoing_data_fd);
514 /* Stop acquisition thread and clean up thread handle */
515 pthread_cond_signal(&thread_release_cond[s]);
516 pthread_join(sensor_info[s].acquisition_thread, NULL);
518 /* Clean up our sensor descriptor */
519 sensor_info[s].acquisition_thread = -1;
521 /* Delete condition variable and mutex */
522 pthread_cond_destroy(&thread_release_cond[s]);
523 pthread_mutex_destroy(&thread_release_mutex[s]);
527 int sensor_activate(int s, int enabled)
529 char device_name[PATH_MAX];
530 struct epoll_event ev = {0};
533 int dev_num = sensor_info[s].dev_num;
534 int is_poll_sensor = !sensor_info[s].num_channels;
536 /* Prepare the report timestamp field for the first event, see set_report_ts method */
537 sensor_info[s].report_ts = 0;
538 ts_delta = load_timestamp_sys_clock() - get_timestamp_monotonic();
541 /* If we want to activate gyro calibrated and gyro uncalibrated is activated
542 * Deactivate gyro uncalibrated - Uncalibrated releases handler
543 * Activate gyro calibrated - Calibrated has handler
544 * Reactivate gyro uncalibrated - Uncalibrated gets data from calibrated */
546 /* If we want to deactivate gyro calibrated and gyro uncalibrated is active
547 * Deactivate gyro uncalibrated - Uncalibrated no longer gets data from handler
548 * Deactivate gyro calibrated - Calibrated releases handler
549 * Reactivate gyro uncalibrated - Uncalibrated has handler */
551 if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
552 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
554 sensor_activate(sensor_info[s].pair_idx, 0);
555 ret = sensor_activate(s, enabled);
556 sensor_activate(sensor_info[s].pair_idx, 1);
560 ret = adjust_counters(s, enabled);
562 /* If the operation was neutral in terms of state, we're done */
567 if (!is_poll_sensor) {
570 enable_buffer(dev_num, 0);
571 setup_trigger(s, "\n");
573 /* If there's at least one sensor enabled on this iio device */
574 if (trig_sensors_per_dev[dev_num]) {
577 setup_trigger(s, sensor_info[s].init_trigger_name);
578 enable_buffer(dev_num, 1);
583 * Make sure we have a fd on the character device ; conversely, close
584 * the fd if no one is using associated sensors anymore. The assumption
585 * here is that the underlying driver will power on the relevant
586 * hardware block while someone holds a fd on the device.
588 dev_fd = device_fd[dev_num];
592 stop_acquisition_thread(s);
594 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
595 !trig_sensors_per_dev[dev_num]) {
597 * Stop watching this fd. This should be a no-op
598 * in case this fd was not in the poll set.
600 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
603 device_fd[dev_num] = -1;
606 /* If we recorded a trail of samples for filtering, delete it */
607 if (sensor_info[s].history) {
608 free(sensor_info[s].history);
609 sensor_info[s].history = NULL;
610 sensor_info[s].history_size = 0;
611 if (sensor_info[s].history_sum) {
612 free(sensor_info[s].history_sum);
613 sensor_info[s].history_sum = NULL;
621 /* First enabled sensor on this iio device */
622 sprintf(device_name, DEV_FILE_PATH, dev_num);
623 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
625 device_fd[dev_num] = dev_fd;
628 ALOGE("Could not open fd on %s (%s)\n",
629 device_name, strerror(errno));
630 adjust_counters(s, 0);
634 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
636 if (!is_poll_sensor) {
638 /* Add this iio device fd to the set of watched fds */
640 ev.data.u32 = dev_num;
642 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
645 ALOGE( "Failed adding %d to poll set (%s)\n",
646 dev_fd, strerror(errno));
650 /* Note: poll-mode fds are not readable */
654 /* Ensure that on-change sensors send at least one event after enable */
655 sensor_info[s].prev_val = -1;
658 start_acquisition_thread(s);
664 static int is_fast_accelerometer (int s)
667 * Some games don't react well to accelerometers using any-motion
668 * triggers. Even very low thresholds seem to trip them, and they tend
669 * to request fairly high event rates. Favor continuous triggers if the
670 * sensor is an accelerometer and uses a sampling rate of at least 25.
672 int catalog_index = sensor_info[s].catalog_index;
674 if (sensor_catalog[catalog_index].type != SENSOR_TYPE_ACCELEROMETER)
677 if (sensor_info[s].sampling_rate < 25)
684 static void enable_motion_trigger (int dev_num)
687 * In the ideal case, we enumerate two triggers per iio device ; the
688 * default (periodically firing) trigger, and another one (the motion
689 * trigger) that only fires up when motion is detected. This second one
690 * allows for lesser energy consumption, but requires periodic sample
691 * duplication at the HAL level for sensors that Android defines as
692 * continuous. This "duplicate last sample" logic can only be engaged
693 * once we got a first sample for the driver, so we start with the
694 * default trigger when an iio device is first opened, then adjust the
695 * trigger when we got events for all active sensors. Unfortunately in
696 * the general case several sensors can be associated to a given iio
697 * device, they can independently be controlled, and we have to adjust
698 * the trigger in use at the iio device level depending on whether or
699 * not appropriate conditions are met at the sensor level.
704 int active_sensors = trig_sensors_per_dev[dev_num];
705 int candidate[MAX_SENSORS];
706 int candidate_count = 0;
711 /* Check that all active sensors are ready to switch */
713 for (s=0; s<MAX_SENSORS; s++)
714 if (sensor_info[s].dev_num == dev_num &&
715 sensor_info[s].enable_count &&
716 sensor_info[s].num_channels &&
717 (!sensor_info[s].motion_trigger_name[0] ||
718 !sensor_info[s].report_initialized ||
719 is_fast_accelerometer(s))
723 /* Record which particular sensors need to switch */
725 for (s=0; s<MAX_SENSORS; s++)
726 if (sensor_info[s].dev_num == dev_num &&
727 sensor_info[s].enable_count &&
728 sensor_info[s].num_channels &&
729 !(sensor_info[s].quirks & QUIRK_CONTINUOUS_DRIVER) &&
730 sensor_info[s].selected_trigger !=
731 sensor_info[s].motion_trigger_name)
732 candidate[candidate_count++] = s;
734 if (!candidate_count)
737 /* Now engage the motion trigger for sensors which aren't using it */
739 enable_buffer(dev_num, 0);
741 for (i=0; i<candidate_count; i++) {
743 setup_trigger(s, sensor_info[s].motion_trigger_name);
746 enable_buffer(dev_num, 1);
749 /* CTS acceptable thresholds:
750 * EventGapVerification.java: (th <= 1.8)
751 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
753 #define THRESHOLD 1.10
754 void set_report_ts(int s, int64_t ts)
756 int64_t maxTs, period;
757 int catalog_index = sensor_info[s].catalog_index;
758 int is_accel = (sensor_catalog[catalog_index].type == SENSOR_TYPE_ACCELEROMETER);
761 * A bit of a hack to please a bunch of cts tests. They
762 * expect the timestamp to be exacly according to the set-up
763 * frequency but if we're simply getting the timestamp at hal level
764 * this may not be the case. Perhaps we'll get rid of this when
765 * we'll be reading the timestamp from the iio channel for all sensors
767 if (sensor_info[s].report_ts && sensor_info[s].sampling_rate &&
768 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
770 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
771 maxTs = sensor_info[s].report_ts + (is_accel ? 1 : THRESHOLD) * period;
772 sensor_info[s].report_ts = (ts < maxTs ? ts : maxTs);
774 sensor_info[s].report_ts = ts;
778 static int integrate_device_report(int dev_num)
782 unsigned char buf[MAX_SENSOR_REPORT_SIZE] = { 0 };
784 unsigned char *target;
785 unsigned char *source;
788 /* There's an incoming report on the specified iio device char dev fd */
790 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
791 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
795 if (device_fd[dev_num] == -1) {
796 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
802 len = read(device_fd[dev_num], buf, MAX_SENSOR_REPORT_SIZE);
805 ALOGE("Could not read report from iio device %d (%s)\n",
806 dev_num, strerror(errno));
810 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
812 /* Map device report to sensor reports */
814 for (s=0; s<MAX_SENSORS; s++)
815 if (sensor_info[s].dev_num == dev_num &&
816 sensor_info[s].enable_count) {
820 /* Copy data from device to sensor report buffer */
821 for (c=0; c<sensor_info[s].num_channels; c++) {
823 target = sensor_info[s].report_buffer +
826 source = buf + sensor_info[s].channel[c].offset;
828 size = sensor_info[s].channel[c].size;
830 memcpy(target, source, size);
835 ALOGV("Sensor %d report available (%d bytes)\n", s,
838 set_report_ts(s, get_timestamp());
839 sensor_info[s].report_pending = 1;
840 sensor_info[s].report_initialized = 1;
843 /* Tentatively switch to an any-motion trigger if conditions are met */
844 enable_motion_trigger(dev_num);
850 static int propagate_sensor_report(int s, struct sensors_event_t *data)
852 /* There's a sensor report pending for this sensor ; transmit it */
854 int catalog_index = sensor_info[s].catalog_index;
855 int sensor_type = sensor_catalog[catalog_index].type;
856 int num_fields = get_field_count(s);
858 unsigned char* current_sample;
860 /* If there's nothing to return... we're done */
865 /* Only return uncalibrated event if also gyro active */
866 if (sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
867 sensor_info[sensor_info[s].pair_idx].enable_count != 0)
870 memset(data, 0, sizeof(sensors_event_t));
872 data->version = sizeof(sensors_event_t);
874 data->type = sensor_type;
875 data->timestamp = sensor_info[s].report_ts;
877 ALOGV("Sample on sensor %d (type %d):\n", s, sensor_type);
879 current_sample = sensor_info[s].report_buffer;
881 /* If this is a poll sensor */
882 if (!sensor_info[s].num_channels) {
883 /* Use the data provided by the acquisition thread */
884 ALOGV("Reporting data from worker thread for S%d\n", s);
885 memcpy(data->data, current_sample, num_fields * sizeof(float));
889 /* Convert the data into the expected Android-level format */
890 for (c=0; c<num_fields; c++) {
892 data->data[c] = sensor_info[s].ops.transform
893 (s, c, current_sample);
895 ALOGV("\tfield %d: %f\n", c, data->data[c]);
896 current_sample += sensor_info[s].channel[c].size;
900 * The finalize routine, in addition to its late sample processing duty,
901 * has the final say on whether or not the sample gets sent to Android.
903 return sensor_info[s].ops.finalize(s, data);
907 static void synthetize_duplicate_samples (void)
910 * Some sensor types (ex: gyroscope) are defined as continuously firing
911 * by Android, despite the fact that we can be dealing with iio drivers
912 * that only report events for new samples. For these we generate
913 * reports periodically, duplicating the last data we got from the
914 * driver. This is not necessary for polling sensors.
922 for (s=0; s<sensor_count; s++) {
924 /* Ignore disabled sensors */
925 if (!sensor_info[s].enable_count)
928 /* If the sensor is continuously firing, leave it alone */
929 if (sensor_info[s].selected_trigger !=
930 sensor_info[s].motion_trigger_name)
933 /* If we haven't seen a sample, there's nothing to duplicate */
934 if (!sensor_info[s].report_initialized)
937 /* If a sample was recently buffered, leave it alone too */
938 if (sensor_info[s].report_pending)
941 /* We also need a valid sampling rate to be configured */
942 if (!sensor_info[s].sampling_rate)
945 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
947 current_ts = get_timestamp();
948 target_ts = sensor_info[s].report_ts + period;
950 if (target_ts <= current_ts) {
951 /* Mark the sensor for event generation */
952 set_report_ts(s, current_ts);
953 sensor_info[s].report_pending = 1;
959 static void integrate_thread_report (uint32_t tag)
961 int s = tag - THREAD_REPORT_TAG_BASE;
965 expected_len = get_field_count(s) * sizeof(float);
967 len = read(sensor_info[s].thread_data_fd[0],
968 sensor_info[s].report_buffer,
971 if (len == expected_len) {
972 set_report_ts(s, get_timestamp());
973 sensor_info[s].report_pending = 1;
978 static int get_poll_wait_timeout (void)
981 * Compute an appropriate timeout value, in ms, for the epoll_wait
982 * call that's going to await for iio device reports and incoming
983 * reports from our sensor sysfs data reader threads.
987 int64_t target_ts = INT64_MAX;
992 * Check if we're dealing with a driver that only send events when
993 * there is motion, despite the fact that the associated Android sensor
994 * type is continuous rather than on-change. In that case we have to
995 * duplicate events. Check deadline for the nearest upcoming event.
997 for (s=0; s<sensor_count; s++)
998 if (sensor_info[s].enable_count &&
999 sensor_info[s].selected_trigger ==
1000 sensor_info[s].motion_trigger_name &&
1001 sensor_info[s].sampling_rate) {
1002 period = (int64_t) (1000000000.0 /
1003 sensor_info[s].sampling_rate);
1005 if (sensor_info[s].report_ts + period < target_ts)
1006 target_ts = sensor_info[s].report_ts + period;
1009 /* If we don't have such a driver to deal with */
1010 if (target_ts == INT64_MAX)
1011 return -1; /* Infinite wait */
1013 ms_to_wait = (target_ts - get_timestamp()) / 1000000;
1015 /* If the target timestamp is already behind us, don't wait */
1023 int sensor_poll(struct sensors_event_t* data, int count)
1028 struct epoll_event ev[MAX_DEVICES];
1029 int returned_events;
1033 /* Get one or more events from our collection of sensors */
1035 return_available_sensor_reports:
1037 /* Synthetize duplicate samples if needed */
1038 synthetize_duplicate_samples();
1040 returned_events = 0;
1042 /* Check our sensor collection for available reports */
1043 for (s=0; s<sensor_count && returned_events < count; s++) {
1044 if (sensor_info[s].report_pending) {
1047 sensor_info[s].report_pending = 0;
1049 /* Report this event if it looks OK */
1050 event_count = propagate_sensor_report(s, &data[returned_events]);
1052 /* Duplicate only if both cal & uncal are active */
1053 if (sensor_catalog[sensor_info[s].catalog_index].type == SENSOR_TYPE_GYROSCOPE &&
1054 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enable_count != 0) {
1055 struct gyro_cal* gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
1057 memcpy(&data[returned_events + event_count], &data[returned_events],
1058 sizeof(struct sensors_event_t) * event_count);
1060 uncal_start = returned_events + event_count;
1061 for (i = 0; i < event_count; i++) {
1062 data[uncal_start + i].type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
1063 data[uncal_start + i].sensor = sensor_info[s].pair_idx;
1065 data[uncal_start + i].data[0] = data[returned_events + i].data[0] + gyro_data->bias_x;
1066 data[uncal_start + i].data[1] = data[returned_events + i].data[1] + gyro_data->bias_y;
1067 data[uncal_start + i].data[2] = data[returned_events + i].data[2] + gyro_data->bias_z;
1069 data[uncal_start + i].uncalibrated_gyro.bias[0] = gyro_data->bias_x;
1070 data[uncal_start + i].uncalibrated_gyro.bias[1] = gyro_data->bias_y;
1071 data[uncal_start + i].uncalibrated_gyro.bias[2] = gyro_data->bias_z;
1075 sensor_info[sensor_info[s].pair_idx].report_pending = 0;
1076 returned_events += event_count;
1078 * If the sample was deemed invalid or unreportable,
1079 * e.g. had the same value as the previously reported
1080 * value for a 'on change' sensor, silently drop it.
1083 while (sensor_info[s].meta_data_pending) {
1084 /* See sensors.h on these */
1085 data[returned_events].version = META_DATA_VERSION;
1086 data[returned_events].sensor = 0;
1087 data[returned_events].type = SENSOR_TYPE_META_DATA;
1088 data[returned_events].reserved0 = 0;
1089 data[returned_events].timestamp = 0;
1090 data[returned_events].meta_data.sensor = s;
1091 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1093 sensor_info[s].meta_data_pending--;
1096 if (returned_events)
1097 return returned_events;
1101 ALOGV("Awaiting sensor data\n");
1103 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1106 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1110 ALOGV("%d fds signalled\n", nfds);
1112 /* For each of the signalled sources */
1113 for (i=0; i<nfds; i++)
1114 if (ev[i].events == EPOLLIN)
1115 switch (ev[i].data.u32) {
1116 case 0 ... MAX_DEVICES-1:
1117 /* Read report from iio char dev fd */
1118 integrate_device_report(ev[i].data.u32);
1121 case THREAD_REPORT_TAG_BASE ...
1122 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1123 /* Get report from acquisition thread */
1124 integrate_thread_report(ev[i].data.u32);
1128 ALOGW("Unexpected event source!\n");
1132 goto return_available_sensor_reports;
1136 static void tentative_switch_trigger (int s)
1139 * Under certain situations it may be beneficial to use an alternate
1142 * - for applications using the accelerometer with high sampling rates,
1143 * prefer the continuous trigger over the any-motion one, to avoid
1144 * jumps related to motion thresholds
1147 if (is_fast_accelerometer(s) &&
1148 !(sensor_info[s].quirks & QUIRK_TERSE_DRIVER) &&
1149 sensor_info[s].selected_trigger ==
1150 sensor_info[s].motion_trigger_name)
1151 setup_trigger(s, sensor_info[s].init_trigger_name);
1155 int sensor_set_delay(int s, int64_t ns)
1157 /* Set the rate at which a specific sensor should report events */
1159 /* See Android sensors.h for indication on sensor trigger modes */
1161 char sysfs_path[PATH_MAX];
1162 char avail_sysfs_path[PATH_MAX];
1163 int dev_num = sensor_info[s].dev_num;
1164 int i = sensor_info[s].catalog_index;
1165 const char *prefix = sensor_catalog[i].tag;
1166 float new_sampling_rate; /* Granted sampling rate after arbitration */
1167 float cur_sampling_rate; /* Currently used sampling rate */
1168 int per_sensor_sampling_rate;
1169 int per_device_sampling_rate;
1170 int32_t min_delay_us = sensor_desc[s].minDelay;
1171 max_delay_t max_delay_us = sensor_desc[s].maxDelay;
1172 float min_supported_rate = max_delay_us ? (1000000.0f / max_delay_us) : 1;
1173 float max_supported_rate =
1174 (min_delay_us && min_delay_us != -1) ? (1000000.0f / min_delay_us) : 0;
1175 char freqs_buf[100];
1181 ALOGE("Rejecting non-positive delay request on sensor %d, required delay: %lld\n", s, ns);
1185 new_sampling_rate = 1000000000LL/ns;
1187 ALOGV("Entering set delay S%d (%s): old rate(%f), new rate(%f)\n",
1188 s, sensor_info[s].friendly_name, sensor_info[s].sampling_rate,
1192 * Artificially limit ourselves to 1 Hz or higher. This is mostly to
1193 * avoid setting up the stage for divisions by zero.
1195 if (new_sampling_rate < min_supported_rate)
1196 new_sampling_rate = min_supported_rate;
1198 if (max_supported_rate &&
1199 new_sampling_rate > max_supported_rate) {
1200 new_sampling_rate = max_supported_rate;
1203 sensor_info[s].sampling_rate = new_sampling_rate;
1205 /* If we're dealing with a poll-mode sensor */
1206 if (!sensor_info[s].num_channels) {
1207 /* Interrupt current sleep so the new sampling gets used */
1208 pthread_cond_signal(&thread_release_cond[s]);
1212 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
1214 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
1215 per_sensor_sampling_rate = 1;
1216 per_device_sampling_rate = 0;
1218 per_sensor_sampling_rate = 0;
1220 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
1222 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
1223 per_device_sampling_rate = 1;
1225 per_device_sampling_rate = 0;
1228 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
1229 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
1233 /* Coordinate with others active sensors on the same device, if any */
1234 if (per_device_sampling_rate)
1235 for (n=0; n<sensor_count; n++)
1236 if (n != s && sensor_info[n].dev_num == dev_num &&
1237 sensor_info[n].num_channels &&
1238 sensor_info[n].enable_count &&
1239 sensor_info[n].sampling_rate > new_sampling_rate)
1240 new_sampling_rate= sensor_info[n].sampling_rate;
1242 /* Check if we have contraints on allowed sampling rates */
1244 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
1246 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
1249 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
1251 /* While we're not at the end of the string */
1252 while (*cursor && cursor[0]) {
1254 /* Decode a single value */
1255 sr = strtod(cursor, NULL);
1257 /* If this matches the selected rate, we're happy */
1258 if (new_sampling_rate == sr)
1262 * If we reached a higher value than the desired rate,
1263 * adjust selected rate so it matches the first higher
1264 * available one and stop parsing - this makes the
1265 * assumption that rates are sorted by increasing value
1266 * in the allowed frequencies string.
1268 if (sr > new_sampling_rate) {
1269 new_sampling_rate = sr;
1274 while (cursor[0] && !isspace(cursor[0]))
1278 while (cursor[0] && isspace(cursor[0]))
1283 if (max_supported_rate &&
1284 new_sampling_rate > max_supported_rate) {
1285 new_sampling_rate = max_supported_rate;
1288 /* If the desired rate is already active we're all set */
1289 if (new_sampling_rate == cur_sampling_rate)
1292 ALOGI("Sensor %d sampling rate set to %g\n", s, new_sampling_rate);
1294 if (trig_sensors_per_dev[dev_num])
1295 enable_buffer(dev_num, 0);
1297 sysfs_write_float(sysfs_path, new_sampling_rate);
1299 /* Check if it makes sense to use an alternate trigger */
1300 tentative_switch_trigger(s);
1302 if (trig_sensors_per_dev[dev_num])
1303 enable_buffer(dev_num, 1);
1308 int sensor_flush (int s)
1310 /* If one shot or not enabled return -EINVAL */
1311 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE ||
1312 sensor_info[s].enable_count == 0)
1315 sensor_info[s].meta_data_pending++;
1319 int allocate_control_data (void)
1323 for (i=0; i<MAX_DEVICES; i++)
1326 poll_fd = epoll_create(MAX_DEVICES);
1328 if (poll_fd == -1) {
1329 ALOGE("Can't create epoll instance for iio sensors!\n");
1337 void delete_control_data (void)