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"
20 #include "filtering.h"
22 /* Currently active sensors count, per device */
23 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
24 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
26 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
27 static int has_iio_ts[MAX_DEVICES]; /* ts channel available on this iio dev */
28 static int expected_dev_report_size[MAX_DEVICES]; /* expected iio scan len */
29 static int poll_fd; /* epoll instance covering all enabled sensors */
31 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
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 static void enable_iio_timestamp (int dev_num, int known_channels)
109 /* Check if we have a dedicated iio timestamp channel */
111 char spec_buf[MAX_TYPE_SPEC_LEN];
112 char sysfs_path[PATH_MAX];
115 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_type");
117 n = sysfs_read_str(sysfs_path, spec_buf, sizeof(spec_buf));
122 if (strcmp(spec_buf, "le:s64/64>>0"))
125 /* OK, type is int64_t as expected, in little endian representation */
127 sprintf(sysfs_path, CHANNEL_PATH"%s", dev_num, "in_timestamp_index");
129 if (sysfs_read_int(sysfs_path, &n))
132 /* Check that the timestamp comes after the other fields we read */
133 if (n != known_channels)
136 /* Try enabling that channel */
137 sprintf(sysfs_path, CHANNEL_PATH "%s", dev_num, "in_timestamp_en");
139 sysfs_write_int(sysfs_path, 1);
141 if (sysfs_read_int(sysfs_path, &n))
145 ALOGI("Detected timestamp channel on iio device %d\n", dev_num);
146 has_iio_ts[dev_num] = 1;
151 void build_sensor_report_maps (int dev_num)
154 * Read sysfs files from a iio device's scan_element directory, and
155 * build a couple of tables from that data. These tables will tell, for
156 * each sensor, where to gather relevant data in a device report, i.e.
157 * the structure that we read from the /dev/iio:deviceX file in order to
158 * sensor report, itself being the data that we return to Android when a
159 * sensor poll completes. The mapping should be straightforward in the
160 * case where we have a single sensor active per iio device but, this is
161 * not the general case. In general several sensors can be handled
162 * through a single iio device, and the _en, _index and _type syfs
163 * entries all concur to paint a picture of what the structure of the
173 char spec_buf[MAX_TYPE_SPEC_LEN];
174 struct datum_info_t* ch_info;
176 char sysfs_path[PATH_MAX];
179 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
180 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
181 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
185 /* For each sensor that is linked to this device */
186 for (s=0; s<sensor_count; s++) {
187 if (sensor_info[s].dev_num != dev_num)
190 i = sensor_info[s].catalog_index;
192 /* Read channel details through sysfs attributes */
193 for (c=0; c<sensor_info[s].num_channels; c++) {
195 /* Read _type file */
196 sprintf(sysfs_path, CHANNEL_PATH "%s",
197 sensor_info[s].dev_num,
198 sensor_catalog[i].channel[c].type_path);
200 n = sysfs_read_str(sysfs_path, spec_buf,
204 ALOGW( "Failed to read type: %s\n",
209 ch_spec = sensor_info[s].channel[c].type_spec;
211 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
213 ch_info = &sensor_info[s].channel[c].type_info;
215 size = decode_type_spec(ch_spec, ch_info);
217 /* Read _index file */
218 sprintf(sysfs_path, CHANNEL_PATH "%s",
219 sensor_info[s].dev_num,
220 sensor_catalog[i].channel[c].index_path);
222 n = sysfs_read_int(sysfs_path, &ch_index);
225 ALOGW( "Failed to read index: %s\n",
230 if (ch_index >= MAX_SENSORS) {
231 ALOGE("Index out of bounds!: %s\n", sysfs_path);
235 /* Record what this index is about */
237 sensor_handle_from_index [ch_index] = s;
238 channel_number_from_index[ch_index] = c;
239 channel_size_from_index [ch_index] = size;
244 /* Stop sampling - if we are recovering from hal restart */
245 enable_buffer(dev_num, 0);
246 setup_trigger(s, "\n");
248 /* Turn on channels we're aware of */
249 for (c=0;c<sensor_info[s].num_channels; c++) {
250 sprintf(sysfs_path, CHANNEL_PATH "%s",
251 sensor_info[s].dev_num,
252 sensor_catalog[i].channel[c].en_path);
253 sysfs_write_int(sysfs_path, 1);
257 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
260 * Now that we know which channels are defined, their sizes and their
261 * ordering, update channels offsets within device report. Note: there
262 * is a possibility that several sensors share the same index, with
263 * their data fields being isolated by masking and shifting as specified
264 * through the real bits and shift values in type attributes. This case
265 * is not currently supported. Also, the code below assumes no hole in
266 * the sequence of indices, so it is dependent on discovery of all
270 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
271 s = sensor_handle_from_index[i];
272 c = channel_number_from_index[i];
273 size = channel_size_from_index[i];
278 ALOGI("S%d C%d : offset %d, size %d, type %s\n",
279 s, c, offset, size, sensor_info[s].channel[c].type_spec);
281 sensor_info[s].channel[c].offset = offset;
282 sensor_info[s].channel[c].size = size;
287 /* Enable the timestamp channel if there is one available */
288 enable_iio_timestamp(dev_num, known_channels);
290 /* Add padding and timestamp size if it's enabled on this iio device */
291 if (has_iio_ts[dev_num])
292 offset = (offset+7)/8*8 + sizeof(int64_t);
294 expected_dev_report_size[dev_num] = offset;
295 ALOGI("Expecting %d scan length on iio dev %d\n", offset, dev_num);
297 if (expected_dev_report_size[dev_num] > MAX_DEVICE_REPORT_SIZE) {
298 ALOGE("Unexpectedly large scan buffer on iio dev%d: %d bytes\n",
299 dev_num, expected_dev_report_size[dev_num]);
301 expected_dev_report_size[dev_num] = MAX_DEVICE_REPORT_SIZE;
306 int adjust_counters (int s, int enabled)
309 * Adjust counters based on sensor enable action. Return values are:
310 * -1 if there's an inconsistency: abort action in this case
311 * 0 if the operation was completed and we're all set
312 * 1 if we toggled the state of the sensor and there's work left
315 int dev_num = sensor_info[s].dev_num;
317 /* Refcount per sensor, in terms of enable count */
319 ALOGI("Enabling sensor %d (iio device %d: %s)\n",
320 s, dev_num, sensor_info[s].friendly_name);
322 if (sensor_info[s].enabled)
323 return 0; /* The sensor was, and remains, in use */
325 sensor_info[s].enabled = 1;
327 switch (sensor_info[s].type) {
328 case SENSOR_TYPE_MAGNETIC_FIELD:
329 compass_read_data(&sensor_info[s]);
332 case SENSOR_TYPE_GYROSCOPE:
333 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
334 gyro_cal_init(&sensor_info[s]);
338 if (sensor_info[s].enabled == 0)
339 return 0; /* Spurious disable call */
341 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
342 sensor_info[s].friendly_name);
344 sensor_info[s].enabled = 0;
346 /* Sensor disabled, lower report available flag */
347 sensor_info[s].report_pending = 0;
349 if (sensor_info[s].type == SENSOR_TYPE_MAGNETIC_FIELD)
350 compass_store_data(&sensor_info[s]);
352 if(sensor_info[s].type == SENSOR_TYPE_GYROSCOPE ||
353 sensor_info[s].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED)
354 gyro_store_data(&sensor_info[s]);
358 /* If uncalibrated type and pair is already active don't adjust counters */
359 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
360 sensor_info[sensor_info[s].pair_idx].enabled != 0)
363 /* We changed the state of a sensor - adjust per iio device counters */
365 /* If this is a regular event-driven sensor */
366 if (sensor_info[s].num_channels) {
369 trig_sensors_per_dev[dev_num]++;
371 trig_sensors_per_dev[dev_num]--;
377 active_poll_sensors++;
378 poll_sensors_per_dev[dev_num]++;
382 active_poll_sensors--;
383 poll_sensors_per_dev[dev_num]--;
388 static int get_field_count (int s)
390 switch (sensor_info[s].type) {
391 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
392 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
393 case SENSOR_TYPE_ORIENTATION: /* degrees */
394 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
395 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
398 case SENSOR_TYPE_LIGHT: /* SI lux units */
399 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
400 case SENSOR_TYPE_TEMPERATURE: /* °C */
401 case SENSOR_TYPE_PROXIMITY: /* centimeters */
402 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
403 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
406 case SENSOR_TYPE_ROTATION_VECTOR:
410 ALOGE("Unknown sensor type!\n");
411 return 0; /* Drop sample */
416 static void* acquisition_routine (void* param)
419 * Data acquisition routine run in a dedicated thread, covering a single
420 * sensor. This loop will periodically retrieve sampling data through
421 * sysfs, then package it as a sample and transfer it to our master poll
422 * loop through a report fd. Checks for a cancellation signal quite
423 * frequently, as the thread may be disposed of at any time. Note that
424 * Bionic does not provide pthread_cancel / pthread_testcancel...
427 int s = (int) (size_t) param;
428 int num_fields, sample_size;
429 struct sensors_event_t data = {0};
432 struct timespec target_time;
433 int64_t timestamp, period, start, stop;
435 if (s < 0 || s >= sensor_count) {
436 ALOGE("Invalid sensor handle!\n");
440 ALOGI("Entering data acquisition thread S%d (%s): rate(%f), ts(%lld)\n", s,
441 sensor_info[s].friendly_name, sensor_info[s].sampling_rate, sensor_info[s].report_ts);
443 if (sensor_info[s].sampling_rate <= 0) {
444 ALOGE("Non-positive rate in acquisition routine for sensor %d: %f\n",
445 s, sensor_info[s].sampling_rate);
449 num_fields = get_field_count(s);
450 sample_size = sizeof(int64_t) + num_fields * sizeof(float);
453 * Each condition variable is associated to a mutex that has to be
454 * locked by the thread that's waiting on it. We use these condition
455 * variables to get the acquisition threads out of sleep quickly after
456 * the sampling rate is adjusted, or the sensor is disabled.
458 pthread_mutex_lock(&thread_release_mutex[s]);
460 /* Pinpoint the moment we start sampling */
461 timestamp = get_timestamp_monotonic();
463 /* Check and honor termination requests */
464 while (sensor_info[s].thread_data_fd[1] != -1) {
465 start = get_timestamp_boot();
466 /* Read values through sysfs */
467 for (c=0; c<num_fields; c++) {
468 data.data[c] = acquire_immediate_value(s, c);
469 /* Check and honor termination requests */
470 if (sensor_info[s].thread_data_fd[1] == -1)
473 stop = get_timestamp_boot();
474 data.timestamp = start/2 + stop/2;
476 /* If the sample looks good */
477 if (sensor_info[s].ops.finalize(s, &data)) {
479 /* Pipe it for transmission to poll loop */
480 ret = write( sensor_info[s].thread_data_fd[1],
481 &data.timestamp, sample_size);
483 if (ret != sample_size)
484 ALOGE("S%d acquisition thread: tried to write %d, ret: %d\n",
485 s, sample_size, ret);
488 /* Check and honor termination requests */
489 if (sensor_info[s].thread_data_fd[1] == -1)
492 /* Recalculate period asumming sensor_info[s].sampling_rate
493 * can be changed dynamically during the thread run */
494 if (sensor_info[s].sampling_rate <= 0) {
495 ALOGE("Non-positive rate in acquisition routine for sensor %d: %f\n",
496 s, sensor_info[s].sampling_rate);
500 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
502 set_timestamp(&target_time, timestamp);
505 * Wait until the sampling time elapses, or a rate change is
506 * signaled, or a thread exit is requested.
508 ret = pthread_cond_timedwait( &thread_release_cond[s],
509 &thread_release_mutex[s],
514 ALOGV("Acquisition thread for S%d exiting\n", s);
515 pthread_mutex_unlock(&thread_release_mutex[s]);
521 static void start_acquisition_thread (int s)
523 int incoming_data_fd;
526 struct epoll_event ev = {0};
528 ALOGV("Initializing acquisition context for sensor %d\n", s);
530 /* Create condition variable and mutex for quick thread release */
531 ret = pthread_condattr_init(&thread_cond_attr[s]);
532 ret = pthread_condattr_setclock(&thread_cond_attr[s], CLOCK_MONOTONIC);
533 ret = pthread_cond_init(&thread_release_cond[s], &thread_cond_attr[s]);
534 ret = pthread_mutex_init(&thread_release_mutex[s], NULL);
536 /* Create a pipe for inter thread communication */
537 ret = pipe(sensor_info[s].thread_data_fd);
539 incoming_data_fd = sensor_info[s].thread_data_fd[0];
542 ev.data.u32 = THREAD_REPORT_TAG_BASE + s;
544 /* Add incoming side of pipe to our poll set, with a suitable tag */
545 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, incoming_data_fd , &ev);
547 /* Create and start worker thread */
548 ret = pthread_create( &sensor_info[s].acquisition_thread,
555 static void stop_acquisition_thread (int s)
557 int incoming_data_fd = sensor_info[s].thread_data_fd[0];
558 int outgoing_data_fd = sensor_info[s].thread_data_fd[1];
560 ALOGV("Tearing down acquisition context for sensor %d\n", s);
562 /* Delete the incoming side of the pipe from our poll set */
563 epoll_ctl(poll_fd, EPOLL_CTL_DEL, incoming_data_fd, NULL);
565 /* Mark the pipe ends as invalid ; that's a cheap exit flag */
566 sensor_info[s].thread_data_fd[0] = -1;
567 sensor_info[s].thread_data_fd[1] = -1;
569 /* Close both sides of our pipe */
570 close(incoming_data_fd);
571 close(outgoing_data_fd);
573 /* Stop acquisition thread and clean up thread handle */
574 pthread_cond_signal(&thread_release_cond[s]);
575 pthread_join(sensor_info[s].acquisition_thread, NULL);
577 /* Clean up our sensor descriptor */
578 sensor_info[s].acquisition_thread = -1;
580 /* Delete condition variable and mutex */
581 pthread_cond_destroy(&thread_release_cond[s]);
582 pthread_mutex_destroy(&thread_release_mutex[s]);
586 int sensor_activate(int s, int enabled)
588 char device_name[PATH_MAX];
589 struct epoll_event ev = {0};
592 int dev_num = sensor_info[s].dev_num;
593 int is_poll_sensor = !sensor_info[s].num_channels;
595 /* Prepare the report timestamp field for the first event, see set_report_ts method */
596 sensor_info[s].report_ts = 0;
598 /* If we want to activate gyro calibrated and gyro uncalibrated is activated
599 * Deactivate gyro uncalibrated - Uncalibrated releases handler
600 * Activate gyro calibrated - Calibrated has handler
601 * Reactivate gyro uncalibrated - Uncalibrated gets data from calibrated */
603 /* If we want to deactivate gyro calibrated and gyro uncalibrated is active
604 * Deactivate gyro uncalibrated - Uncalibrated no longer gets data from handler
605 * Deactivate gyro calibrated - Calibrated releases handler
606 * Reactivate gyro uncalibrated - Uncalibrated has handler */
608 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE &&
609 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enabled != 0) {
611 sensor_activate(sensor_info[s].pair_idx, 0);
612 ret = sensor_activate(s, enabled);
613 sensor_activate(sensor_info[s].pair_idx, 1);
617 ret = adjust_counters(s, enabled);
619 /* If the operation was neutral in terms of state, we're done */
623 sensor_info[s].event_count = 0;
624 sensor_info[s].meta_data_pending = 0;
626 if (enabled && (sensor_info[s].quirks & QUIRK_NOISY))
627 /* Initialize filtering data if required */
628 setup_noise_filtering(s);
630 if (!is_poll_sensor) {
633 enable_buffer(dev_num, 0);
634 setup_trigger(s, "\n");
636 /* If there's at least one sensor enabled on this iio device */
637 if (trig_sensors_per_dev[dev_num]) {
640 setup_trigger(s, sensor_info[s].init_trigger_name);
641 enable_buffer(dev_num, 1);
646 * Make sure we have a fd on the character device ; conversely, close
647 * the fd if no one is using associated sensors anymore. The assumption
648 * here is that the underlying driver will power on the relevant
649 * hardware block while someone holds a fd on the device.
651 dev_fd = device_fd[dev_num];
655 stop_acquisition_thread(s);
657 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
658 !trig_sensors_per_dev[dev_num]) {
660 * Stop watching this fd. This should be a no-op
661 * in case this fd was not in the poll set.
663 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
666 device_fd[dev_num] = -1;
669 /* Release any filtering data we may have accumulated */
670 release_noise_filtering_data(s);
676 /* First enabled sensor on this iio device */
677 sprintf(device_name, DEV_FILE_PATH, dev_num);
678 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
680 device_fd[dev_num] = dev_fd;
683 ALOGE("Could not open fd on %s (%s)\n",
684 device_name, strerror(errno));
685 adjust_counters(s, 0);
689 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
691 if (!is_poll_sensor) {
693 /* Add this iio device fd to the set of watched fds */
695 ev.data.u32 = dev_num;
697 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
700 ALOGE( "Failed adding %d to poll set (%s)\n",
701 dev_fd, strerror(errno));
705 /* Note: poll-mode fds are not readable */
709 /* Ensure that on-change sensors send at least one event after enable */
710 sensor_info[s].prev_val = -1;
713 start_acquisition_thread(s);
719 static int is_fast_accelerometer (int s)
722 * Some games don't react well to accelerometers using any-motion
723 * triggers. Even very low thresholds seem to trip them, and they tend
724 * to request fairly high event rates. Favor continuous triggers if the
725 * sensor is an accelerometer and uses a sampling rate of at least 25.
728 if (sensor_info[s].type != SENSOR_TYPE_ACCELEROMETER)
731 if (sensor_info[s].sampling_rate < 25)
738 static void enable_motion_trigger (int dev_num)
741 * In the ideal case, we enumerate two triggers per iio device ; the
742 * default (periodically firing) trigger, and another one (the motion
743 * trigger) that only fires up when motion is detected. This second one
744 * allows for lesser energy consumption, but requires periodic sample
745 * duplication at the HAL level for sensors that Android defines as
746 * continuous. This "duplicate last sample" logic can only be engaged
747 * once we got a first sample for the driver, so we start with the
748 * default trigger when an iio device is first opened, then adjust the
749 * trigger when we got events for all active sensors. Unfortunately in
750 * the general case several sensors can be associated to a given iio
751 * device, they can independently be controlled, and we have to adjust
752 * the trigger in use at the iio device level depending on whether or
753 * not appropriate conditions are met at the sensor level.
758 int active_sensors = trig_sensors_per_dev[dev_num];
759 int candidate[MAX_SENSORS];
760 int candidate_count = 0;
765 /* Check that all active sensors are ready to switch */
767 for (s=0; s<MAX_SENSORS; s++)
768 if (sensor_info[s].dev_num == dev_num &&
769 sensor_info[s].enabled &&
770 sensor_info[s].num_channels &&
771 (!sensor_info[s].motion_trigger_name[0] ||
772 !sensor_info[s].report_initialized ||
773 is_fast_accelerometer(s) ||
774 (sensor_info[s].quirks & QUIRK_FORCE_CONTINUOUS))
778 /* Record which particular sensors need to switch */
780 for (s=0; s<MAX_SENSORS; s++)
781 if (sensor_info[s].dev_num == dev_num &&
782 sensor_info[s].enabled &&
783 sensor_info[s].num_channels &&
784 sensor_info[s].selected_trigger !=
785 sensor_info[s].motion_trigger_name)
786 candidate[candidate_count++] = s;
788 if (!candidate_count)
791 /* Now engage the motion trigger for sensors which aren't using it */
793 enable_buffer(dev_num, 0);
795 for (i=0; i<candidate_count; i++) {
797 setup_trigger(s, sensor_info[s].motion_trigger_name);
800 enable_buffer(dev_num, 1);
803 /* CTS acceptable thresholds:
804 * EventGapVerification.java: (th <= 1.8)
805 * FrequencyVerification.java: (0.9)*(expected freq) => (th <= 1.1111)
807 #define THRESHOLD 1.10
808 #define MAX_DELAY 500000000 /* 500 ms */
809 void set_report_ts(int s, int64_t ts)
811 int64_t maxTs, period;
812 int catalog_index = sensor_info[s].catalog_index;
813 int is_accel = (sensor_catalog[catalog_index].type == SENSOR_TYPE_ACCELEROMETER);
816 * A bit of a hack to please a bunch of cts tests. They
817 * expect the timestamp to be exacly according to the set-up
818 * frequency but if we're simply getting the timestamp at hal level
819 * this may not be the case. Perhaps we'll get rid of this when
820 * we'll be reading the timestamp from the iio channel for all sensors
822 if (sensor_info[s].report_ts && sensor_info[s].sampling_rate &&
823 REPORTING_MODE(sensor_desc[s].flags) == SENSOR_FLAG_CONTINUOUS_MODE)
825 period = (int64_t) (1000000000LL / sensor_info[s].sampling_rate);
826 maxTs = sensor_info[s].report_ts + (is_accel ? 1 : THRESHOLD) * period;
827 /* If we're too far behind get back on track */
828 if (ts - maxTs >= MAX_DELAY)
830 sensor_info[s].report_ts = (ts < maxTs ? ts : maxTs);
832 sensor_info[s].report_ts = ts;
837 static void stamp_reports (int dev_num, int64_t ts)
841 for (s=0; s<MAX_SENSORS; s++)
842 if (sensor_info[s].dev_num == dev_num &&
843 sensor_info[s].enabled)
844 set_report_ts(s, ts);
848 static int integrate_device_report (int dev_num)
852 unsigned char buf[MAX_DEVICE_REPORT_SIZE] = { 0 };
854 unsigned char *target;
855 unsigned char *source;
858 int ts_offset = 0; /* Offset of iio timestamp, if provided */
859 int64_t boot_to_rt_delta;
861 /* There's an incoming report on the specified iio device char dev fd */
863 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
864 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
868 if (device_fd[dev_num] == -1) {
869 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
873 len = read(device_fd[dev_num], buf, expected_dev_report_size[dev_num]);
876 ALOGE("Could not read report from iio device %d (%s)\n",
877 dev_num, strerror(errno));
881 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
883 /* Map device report to sensor reports */
885 for (s=0; s<MAX_SENSORS; s++)
886 if (sensor_info[s].dev_num == dev_num &&
887 sensor_info[s].enabled) {
891 /* Copy data from device to sensor report buffer */
892 for (c=0; c<sensor_info[s].num_channels; c++) {
894 target = sensor_info[s].report_buffer +
897 source = buf + sensor_info[s].channel[c].offset;
899 size = sensor_info[s].channel[c].size;
901 memcpy(target, source, size);
906 ALOGV("Sensor %d report available (%d bytes)\n", s,
909 sensor_info[s].report_pending = DATA_TRIGGER;
910 sensor_info[s].report_initialized = 1;
912 ts_offset += sr_offset;
915 /* Tentatively switch to an any-motion trigger if conditions are met */
916 enable_motion_trigger(dev_num);
918 /* If no iio timestamp channel was detected for this device, bail out */
919 if (!has_iio_ts[dev_num]) {
920 stamp_reports(dev_num, get_timestamp_boot());
924 /* Don't trust the timestamp channel in any-motion mode */
925 for (s=0; s<MAX_SENSORS; s++)
926 if (sensor_info[s].dev_num == dev_num &&
927 sensor_info[s].enabled &&
928 sensor_info[s].selected_trigger ==
929 sensor_info[s].motion_trigger_name) {
930 stamp_reports(dev_num, get_timestamp_boot());
934 /* Align on a 64 bits boundary */
935 ts_offset = (ts_offset + 7)/8*8;
937 /* If we read an amount of data consistent with timestamp presence */
938 if (len == expected_dev_report_size[dev_num])
939 ts = *(int64_t*) (buf + ts_offset);
942 ALOGV("Unreliable timestamp channel on iio dev %d\n", dev_num);
943 stamp_reports(dev_num, get_timestamp_boot());
947 ALOGV("Driver timestamp on iio device %d: ts=%lld\n", dev_num, ts);
949 boot_to_rt_delta = get_timestamp_boot() - get_timestamp_realtime();
951 stamp_reports(dev_num, ts + boot_to_rt_delta);
957 static int propagate_sensor_report (int s, struct sensors_event_t *data)
959 /* There's a sensor report pending for this sensor ; transmit it */
961 int num_fields = get_field_count(s);
963 unsigned char* current_sample;
965 /* If there's nothing to return... we're done */
970 /* Only return uncalibrated event if also gyro active */
971 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED &&
972 sensor_info[sensor_info[s].pair_idx].enabled != 0)
975 memset(data, 0, sizeof(sensors_event_t));
977 data->version = sizeof(sensors_event_t);
979 data->type = sensor_info[s].type;
980 data->timestamp = sensor_info[s].report_ts;
982 ALOGV("Sample on sensor %d (type %d):\n", s, sensor_info[s].type);
984 current_sample = sensor_info[s].report_buffer;
986 /* If this is a poll sensor */
987 if (!sensor_info[s].num_channels) {
988 /* Use the data provided by the acquisition thread */
989 ALOGV("Reporting data from worker thread for S%d\n", s);
990 memcpy(data->data, current_sample, num_fields * sizeof(float));
994 /* Convert the data into the expected Android-level format */
995 for (c=0; c<num_fields; c++) {
997 data->data[c] = sensor_info[s].ops.transform
998 (s, c, current_sample);
1000 ALOGV("\tfield %d: %f\n", c, data->data[c]);
1001 current_sample += sensor_info[s].channel[c].size;
1005 * The finalize routine, in addition to its late sample processing duty,
1006 * has the final say on whether or not the sample gets sent to Android.
1008 return sensor_info[s].ops.finalize(s, data);
1012 static void synthetize_duplicate_samples (void)
1015 * Some sensor types (ex: gyroscope) are defined as continuously firing
1016 * by Android, despite the fact that we can be dealing with iio drivers
1017 * that only report events for new samples. For these we generate
1018 * reports periodically, duplicating the last data we got from the
1019 * driver. This is not necessary for polling sensors.
1027 for (s=0; s<sensor_count; s++) {
1029 /* Ignore disabled sensors */
1030 if (!sensor_info[s].enabled)
1033 /* If the sensor is continuously firing, leave it alone */
1034 if (sensor_info[s].selected_trigger !=
1035 sensor_info[s].motion_trigger_name)
1038 /* If we haven't seen a sample, there's nothing to duplicate */
1039 if (!sensor_info[s].report_initialized)
1042 /* If a sample was recently buffered, leave it alone too */
1043 if (sensor_info[s].report_pending)
1046 /* We also need a valid sampling rate to be configured */
1047 if (!sensor_info[s].sampling_rate)
1050 period = (int64_t) (1000000000.0/ sensor_info[s].sampling_rate);
1052 current_ts = get_timestamp_boot();
1053 target_ts = sensor_info[s].report_ts + period;
1055 if (target_ts <= current_ts) {
1056 /* Mark the sensor for event generation */
1057 set_report_ts(s, current_ts);
1058 sensor_info[s].report_pending = DATA_DUPLICATE;
1064 static void integrate_thread_report (uint32_t tag)
1066 int s = tag - THREAD_REPORT_TAG_BASE;
1070 unsigned char current_sample[MAX_SENSOR_REPORT_SIZE];
1072 expected_len = sizeof(int64_t) + get_field_count(s) * sizeof(float);
1074 len = read(sensor_info[s].thread_data_fd[0],
1078 memcpy(×tamp, current_sample, sizeof(int64_t));
1079 memcpy(sensor_info[s].report_buffer, sizeof(int64_t) + current_sample,
1080 expected_len - sizeof(int64_t));
1082 if (len == expected_len) {
1083 set_report_ts(s, timestamp);
1084 sensor_info[s].report_pending = DATA_SYSFS;
1089 static int get_poll_wait_timeout (void)
1092 * Compute an appropriate timeout value, in ms, for the epoll_wait
1093 * call that's going to await for iio device reports and incoming
1094 * reports from our sensor sysfs data reader threads.
1098 int64_t target_ts = INT64_MAX;
1103 * Check if we're dealing with a driver that only send events when
1104 * there is motion, despite the fact that the associated Android sensor
1105 * type is continuous rather than on-change. In that case we have to
1106 * duplicate events. Check deadline for the nearest upcoming event.
1108 for (s=0; s<sensor_count; s++)
1109 if (sensor_info[s].enabled &&
1110 sensor_info[s].selected_trigger ==
1111 sensor_info[s].motion_trigger_name &&
1112 sensor_info[s].sampling_rate) {
1113 period = (int64_t) (1000000000.0 /
1114 sensor_info[s].sampling_rate);
1116 if (sensor_info[s].report_ts + period < target_ts)
1117 target_ts = sensor_info[s].report_ts + period;
1120 /* If we don't have such a driver to deal with */
1121 if (target_ts == INT64_MAX)
1122 return -1; /* Infinite wait */
1124 ms_to_wait = (target_ts - get_timestamp_boot()) / 1000000;
1126 /* If the target timestamp is already behind us, don't wait */
1134 int sensor_poll(struct sensors_event_t* data, int count)
1139 struct epoll_event ev[MAX_DEVICES];
1140 int returned_events;
1144 /* Get one or more events from our collection of sensors */
1146 return_available_sensor_reports:
1148 /* Synthetize duplicate samples if needed */
1149 synthetize_duplicate_samples();
1151 returned_events = 0;
1153 /* Check our sensor collection for available reports */
1154 for (s=0; s<sensor_count && returned_events < count; s++) {
1155 if (sensor_info[s].report_pending) {
1158 /* Report this event if it looks OK */
1159 event_count = propagate_sensor_report(s, &data[returned_events]);
1162 sensor_info[s].report_pending = 0;
1164 /* Duplicate only if both cal & uncal are active */
1165 if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE &&
1166 sensor_info[s].pair_idx && sensor_info[sensor_info[s].pair_idx].enabled != 0) {
1167 struct gyro_cal* gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
1169 memcpy(&data[returned_events + event_count], &data[returned_events],
1170 sizeof(struct sensors_event_t) * event_count);
1172 uncal_start = returned_events + event_count;
1173 for (i = 0; i < event_count; i++) {
1174 data[uncal_start + i].type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
1175 data[uncal_start + i].sensor = sensor_info[s].pair_idx;
1177 data[uncal_start + i].data[0] = data[returned_events + i].data[0] + gyro_data->bias_x;
1178 data[uncal_start + i].data[1] = data[returned_events + i].data[1] + gyro_data->bias_y;
1179 data[uncal_start + i].data[2] = data[returned_events + i].data[2] + gyro_data->bias_z;
1181 data[uncal_start + i].uncalibrated_gyro.bias[0] = gyro_data->bias_x;
1182 data[uncal_start + i].uncalibrated_gyro.bias[1] = gyro_data->bias_y;
1183 data[uncal_start + i].uncalibrated_gyro.bias[2] = gyro_data->bias_z;
1187 sensor_info[sensor_info[s].pair_idx].report_pending = 0;
1188 returned_events += event_count;
1190 * If the sample was deemed invalid or unreportable,
1191 * e.g. had the same value as the previously reported
1192 * value for a 'on change' sensor, silently drop it.
1195 while (sensor_info[s].meta_data_pending) {
1196 /* See sensors.h on these */
1197 data[returned_events].version = META_DATA_VERSION;
1198 data[returned_events].sensor = 0;
1199 data[returned_events].type = SENSOR_TYPE_META_DATA;
1200 data[returned_events].reserved0 = 0;
1201 data[returned_events].timestamp = 0;
1202 data[returned_events].meta_data.sensor = s;
1203 data[returned_events].meta_data.what = META_DATA_FLUSH_COMPLETE;
1205 sensor_info[s].meta_data_pending--;
1208 if (returned_events)
1209 return returned_events;
1213 ALOGV("Awaiting sensor data\n");
1215 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_wait_timeout());
1218 ALOGE("epoll_wait returned -1 (%s)\n", strerror(errno));
1222 ALOGV("%d fds signalled\n", nfds);
1224 /* For each of the signalled sources */
1225 for (i=0; i<nfds; i++)
1226 if (ev[i].events == EPOLLIN)
1227 switch (ev[i].data.u32) {
1228 case 0 ... MAX_DEVICES-1:
1229 /* Read report from iio char dev fd */
1230 integrate_device_report(ev[i].data.u32);
1233 case THREAD_REPORT_TAG_BASE ...
1234 THREAD_REPORT_TAG_BASE + MAX_SENSORS-1:
1235 /* Get report from acquisition thread */
1236 integrate_thread_report(ev[i].data.u32);
1240 ALOGW("Unexpected event source!\n");
1244 goto return_available_sensor_reports;
1248 static void tentative_switch_trigger (int s)
1251 * Under certain situations it may be beneficial to use an alternate
1254 * - for applications using the accelerometer with high sampling rates,
1255 * prefer the continuous trigger over the any-motion one, to avoid
1256 * jumps related to motion thresholds
1259 if (is_fast_accelerometer(s) &&
1260 !(sensor_info[s].quirks & QUIRK_TERSE_DRIVER) &&
1261 sensor_info[s].selected_trigger ==
1262 sensor_info[s].motion_trigger_name)
1263 setup_trigger(s, sensor_info[s].init_trigger_name);
1267 int sensor_set_delay(int s, int64_t ns)
1269 /* Set the rate at which a specific sensor should report events */
1271 /* See Android sensors.h for indication on sensor trigger modes */
1273 char sysfs_path[PATH_MAX];
1274 char avail_sysfs_path[PATH_MAX];
1275 int dev_num = sensor_info[s].dev_num;
1276 int i = sensor_info[s].catalog_index;
1277 const char *prefix = sensor_catalog[i].tag;
1278 float new_sampling_rate; /* Granted sampling rate after arbitration */
1279 float cur_sampling_rate; /* Currently used sampling rate */
1280 int per_sensor_sampling_rate;
1281 int per_device_sampling_rate;
1282 int32_t min_delay_us = sensor_desc[s].minDelay;
1283 max_delay_t max_delay_us = sensor_desc[s].maxDelay;
1284 float min_supported_rate = max_delay_us ? (1000000.0 / max_delay_us) : 1;
1285 float max_supported_rate =
1286 (min_delay_us && min_delay_us != -1) ? (1000000.0 / min_delay_us) : 0;
1287 char freqs_buf[100];
1293 ALOGE("Rejecting non-positive delay request on sensor %d, required delay: %lld\n", s, ns);
1297 new_sampling_rate = 1000000000LL/ns;
1299 ALOGV("Entering set delay S%d (%s): old rate(%f), new rate(%f)\n",
1300 s, sensor_info[s].friendly_name, sensor_info[s].sampling_rate,
1304 * Artificially limit ourselves to 1 Hz or higher. This is mostly to
1305 * avoid setting up the stage for divisions by zero.
1307 if (new_sampling_rate < min_supported_rate)
1308 new_sampling_rate = min_supported_rate;
1310 if (max_supported_rate &&
1311 new_sampling_rate > max_supported_rate) {
1312 new_sampling_rate = max_supported_rate;
1315 sensor_info[s].sampling_rate = new_sampling_rate;
1317 /* If we're dealing with a poll-mode sensor */
1318 if (!sensor_info[s].num_channels) {
1319 /* Interrupt current sleep so the new sampling gets used */
1320 pthread_cond_signal(&thread_release_cond[s]);
1324 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
1326 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1) {
1327 per_sensor_sampling_rate = 1;
1328 per_device_sampling_rate = 0;
1330 per_sensor_sampling_rate = 0;
1332 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
1334 if (sysfs_read_float(sysfs_path, &cur_sampling_rate) != -1)
1335 per_device_sampling_rate = 1;
1337 per_device_sampling_rate = 0;
1340 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
1341 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
1345 /* Coordinate with others active sensors on the same device, if any */
1346 if (per_device_sampling_rate)
1347 for (n=0; n<sensor_count; n++)
1348 if (n != s && sensor_info[n].dev_num == dev_num &&
1349 sensor_info[n].num_channels &&
1350 sensor_info[n].enabled &&
1351 sensor_info[n].sampling_rate > new_sampling_rate)
1352 new_sampling_rate= sensor_info[n].sampling_rate;
1354 /* Check if we have contraints on allowed sampling rates */
1356 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
1358 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
1361 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
1363 /* While we're not at the end of the string */
1364 while (*cursor && cursor[0]) {
1366 /* Decode a single value */
1367 sr = strtod(cursor, NULL);
1369 /* If this matches the selected rate, we're happy */
1370 if (new_sampling_rate == sr)
1374 * If we reached a higher value than the desired rate,
1375 * adjust selected rate so it matches the first higher
1376 * available one and stop parsing - this makes the
1377 * assumption that rates are sorted by increasing value
1378 * in the allowed frequencies string.
1380 if (sr > new_sampling_rate) {
1381 new_sampling_rate = sr;
1386 while (cursor[0] && !isspace(cursor[0]))
1390 while (cursor[0] && isspace(cursor[0]))
1395 if (max_supported_rate &&
1396 new_sampling_rate > max_supported_rate) {
1397 new_sampling_rate = max_supported_rate;
1400 /* If the desired rate is already active we're all set */
1401 if (new_sampling_rate == cur_sampling_rate)
1404 ALOGI("Sensor %d sampling rate set to %g\n", s, new_sampling_rate);
1406 if (trig_sensors_per_dev[dev_num])
1407 enable_buffer(dev_num, 0);
1409 sysfs_write_float(sysfs_path, new_sampling_rate);
1411 /* Check if it makes sense to use an alternate trigger */
1412 tentative_switch_trigger(s);
1414 if (trig_sensors_per_dev[dev_num])
1415 enable_buffer(dev_num, 1);
1420 int sensor_flush (int s)
1422 /* If one shot or not enabled return -EINVAL */
1423 if (sensor_desc[s].flags & SENSOR_FLAG_ONE_SHOT_MODE ||
1424 sensor_info[s].enabled == 0)
1427 sensor_info[s].meta_data_pending++;
1431 int allocate_control_data (void)
1435 for (i=0; i<MAX_DEVICES; i++)
1438 poll_fd = epoll_create(MAX_DEVICES);
1440 if (poll_fd == -1) {
1441 ALOGE("Can't create epoll instance for iio sensors!\n");
1449 void delete_control_data (void)