2 * Copyright (C) 2014 Intel Corporation.
9 #include <sys/socket.h>
10 #include <utils/Log.h>
11 #include <hardware/sensors.h>
13 #include "enumeration.h"
15 #include "transform.h"
16 #include "calibration.h"
18 /* Currently active sensors count, per device */
19 static int poll_sensors_per_dev[MAX_DEVICES]; /* poll-mode sensors */
20 static int trig_sensors_per_dev[MAX_DEVICES]; /* trigger, event based */
22 static int device_fd[MAX_DEVICES]; /* fd on the /dev/iio:deviceX file */
24 static int poll_fd; /* epoll instance covering all enabled sensors */
26 static int poll_socket_pair[2]; /* used to unblock the poll loop */
28 /* Timestamp for the moment when we last exited a poll operation */
29 static int64_t last_poll_exit_ts;
31 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
33 #define INVALID_DEV_NUM ((uint32_t) -1)
36 static int enable_buffer(int dev_num, int enabled)
38 char sysfs_path[PATH_MAX];
40 sprintf(sysfs_path, ENABLE_PATH, dev_num);
42 /* Low level, non-multiplexed, enable/disable routine */
43 return sysfs_write_int(sysfs_path, enabled);
47 static int setup_trigger(int dev_num, const char* trigger_val)
49 char sysfs_path[PATH_MAX];
51 sprintf(sysfs_path, TRIGGER_PATH, dev_num);
53 return sysfs_write_str(sysfs_path, trigger_val);
57 void build_sensor_report_maps(int dev_num)
60 * Read sysfs files from a iio device's scan_element directory, and
61 * build a couple of tables from that data. These tables will tell, for
62 * each sensor, where to gather relevant data in a device report, i.e.
63 * the structure that we read from the /dev/iio:deviceX file in order to
64 * sensor report, itself being the data that we return to Android when a
65 * sensor poll completes. The mapping should be straightforward in the
66 * case where we have a single sensor active per iio device but, this is
67 * not the general case. In general several sensors can be handled
68 * through a single iio device, and the _en, _index and _type syfs
69 * entries all concur to paint a picture of what the structure of the
79 char spec_buf[MAX_TYPE_SPEC_LEN];
80 struct datum_info_t* ch_info;
82 char sysfs_path[PATH_MAX];
85 int channel_size_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
86 int sensor_handle_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
87 int channel_number_from_index[MAX_SENSORS * MAX_CHANNELS] = { 0 };
91 /* For each sensor that is linked to this device */
92 for (s=0; s<sensor_count; s++) {
93 if (sensor_info[s].dev_num != dev_num)
96 i = sensor_info[s].catalog_index;
98 /* Read channel details through sysfs attributes */
99 for (c=0; c<sensor_info[s].num_channels; c++) {
101 /* Read _type file */
102 sprintf(sysfs_path, CHANNEL_PATH "%s",
103 sensor_info[s].dev_num,
104 sensor_catalog[i].channel[c].type_path);
106 n = sysfs_read_str(sysfs_path, spec_buf,
110 ALOGW( "Failed to read type: %s\n",
115 ch_spec = sensor_info[s].channel[c].type_spec;
117 memcpy(ch_spec, spec_buf, sizeof(spec_buf));
119 ch_info = &sensor_info[s].channel[c].type_info;
121 size = decode_type_spec(ch_spec, ch_info);
123 /* Read _index file */
124 sprintf(sysfs_path, CHANNEL_PATH "%s",
125 sensor_info[s].dev_num,
126 sensor_catalog[i].channel[c].index_path);
128 n = sysfs_read_int(sysfs_path, &ch_index);
131 ALOGW( "Failed to read index: %s\n",
136 if (ch_index >= MAX_SENSORS) {
137 ALOGE("Index out of bounds!: %s\n", sysfs_path);
141 /* Record what this index is about */
143 sensor_handle_from_index [ch_index] = s;
144 channel_number_from_index[ch_index] = c;
145 channel_size_from_index [ch_index] = size;
150 /* Turn on channels we're aware of */
151 for (c=0;c<sensor_info[s].num_channels; c++) {
152 sprintf(sysfs_path, CHANNEL_PATH "%s",
153 sensor_info[s].dev_num,
154 sensor_catalog[i].channel[c].en_path);
156 sysfs_write_int(sysfs_path, 1);
160 ALOGI("Found %d channels on iio device %d\n", known_channels, dev_num);
163 * Now that we know which channels are defined, their sizes and their
164 * ordering, update channels offsets within device report. Note: there
165 * is a possibility that several sensors share the same index, with
166 * their data fields being isolated by masking and shifting as specified
167 * through the real bits and shift values in type attributes. This case
168 * is not currently supported. Also, the code below assumes no hole in
169 * the sequence of indices, so it is dependent on discovery of all
173 for (i=0; i<MAX_SENSORS * MAX_CHANNELS; i++) {
174 s = sensor_handle_from_index[i];
175 c = channel_number_from_index[i];
176 size = channel_size_from_index[i];
181 ALOGI("S%d C%d : offset %d, size %d, type %s\n",
182 s, c, offset, size, sensor_info[s].channel[c].type_spec);
184 sensor_info[s].channel[c].offset = offset;
185 sensor_info[s].channel[c].size = size;
192 int adjust_counters (int s, int enabled)
195 * Adjust counters based on sensor enable action. Return values are:
196 * -1 if there's an inconsistency: abort action in this case
197 * 0 if the operation was completed and we're all set
198 * 1 if we toggled the state of the sensor and there's work left
201 int dev_num = sensor_info[s].dev_num;
202 int catalog_index = sensor_info[s].catalog_index;
203 int sensor_type = sensor_catalog[catalog_index].type;
205 /* Refcount per sensor, in terms of enable count */
207 ALOGI("Enabling sensor %d (iio device %d: %s)\n",
208 s, dev_num, sensor_info[s].friendly_name);
210 sensor_info[s].enable_count++;
212 if (sensor_info[s].enable_count != 1) {
213 return 0; /* The sensor was, and remains, in use */
215 if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
216 compass_read_data(COMPASS_CALIBRATION_PATH);
219 if (sensor_info[s].enable_count == 0)
220 return -1; /* Spurious disable call */
222 ALOGI("Disabling sensor %d (iio device %d: %s)\n", s, dev_num,
223 sensor_info[s].friendly_name);
225 if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
226 compass_store_data(COMPASS_CALIBRATION_PATH);
228 sensor_info[s].enable_count--;
230 if (sensor_info[s].enable_count > 0)
231 return 0; /* The sensor was, and remains, in use */
233 /* Sensor disabled, lower report available flag */
234 sensor_info[s].report_pending = 0;
237 /* We changed the state of a sensor - adjust per iio device counters */
239 /* If this is a regular event-driven sensor */
240 if (sensor_info[s].num_channels) {
243 trig_sensors_per_dev[dev_num]++;
245 trig_sensors_per_dev[dev_num]--;
251 active_poll_sensors++;
252 poll_sensors_per_dev[dev_num]++;
256 active_poll_sensors--;
257 poll_sensors_per_dev[dev_num]--;
262 int sensor_activate(int s, int enabled)
264 char device_name[PATH_MAX];
265 char trigger_name[MAX_NAME_SIZE + 16];
267 struct epoll_event ev = {0};
270 int dev_num = sensor_info[s].dev_num;
271 int i = sensor_info[s].catalog_index;
272 int is_poll_sensor = !sensor_info[s].num_channels;
274 ret = adjust_counters(s, enabled);
276 /* If the operation was neutral in terms of state, we're done */
280 if (!is_poll_sensor) {
283 enable_buffer(dev_num, 0);
284 setup_trigger(dev_num, "\n");
286 /* If there's at least one sensor enabled on this iio device */
287 if (trig_sensors_per_dev[dev_num]) {
288 sprintf(trigger_name, "%s-dev%d",
289 sensor_info[s].internal_name, dev_num);
292 setup_trigger(dev_num, trigger_name);
293 enable_buffer(dev_num, 1);
298 * Make sure we have a fd on the character device ; conversely, close
299 * the fd if no one is using associated sensor anymore. The assumption
300 * here is that the underlying driver will power on the relevant
301 * hardware block while someone hold a fd on the device.
303 dev_fd = device_fd[dev_num];
306 if (dev_fd != -1 && !poll_sensors_per_dev[dev_num] &&
307 !trig_sensors_per_dev[dev_num]) {
309 * Stop watching this fd. This should be a no-op
310 * in case this fd was not in the poll set.
312 epoll_ctl(poll_fd, EPOLL_CTL_DEL, dev_fd, NULL);
315 device_fd[dev_num] = -1;
321 /* First enabled sensor on this iio device */
322 sprintf(device_name, DEV_FILE_PATH, dev_num);
323 dev_fd = open(device_name, O_RDONLY | O_NONBLOCK);
325 device_fd[dev_num] = dev_fd;
328 ALOGE("Could not open fd on %s (%s)\n",
329 device_name, strerror(errno));
330 adjust_counters(s, 0);
334 ALOGV("Opened %s: fd=%d\n", device_name, dev_fd);
336 if (!is_poll_sensor) {
338 /* Add this iio device fd to the set of watched fds */
340 ev.data.u32 = dev_num;
342 ret = epoll_ctl(poll_fd, EPOLL_CTL_ADD, dev_fd, &ev);
345 ALOGE( "Failed adding %d to poll set (%s)\n",
346 dev_fd, strerror(errno));
350 /* Note: poll-mode fds are not readable */
354 /* Release the polling loop so an updated timeout gets used */
355 write(poll_socket_pair[1], "", 1);
361 static int integrate_device_report(int dev_num)
365 unsigned char buf[MAX_SENSOR_REPORT_SIZE] = { 0 };
367 unsigned char *target;
368 unsigned char *source;
372 /* There's an incoming report on the specified fd */
374 if (dev_num < 0 || dev_num >= MAX_DEVICES) {
375 ALOGE("Event reported on unexpected iio device %d\n", dev_num);
379 if (device_fd[dev_num] == -1) {
380 ALOGE("Ignoring stale report on iio device %d\n", dev_num);
384 ts = get_timestamp();
386 len = read(device_fd[dev_num], buf, MAX_SENSOR_REPORT_SIZE);
389 ALOGE("Could not read report from iio device %d (%s)\n",
390 dev_num, strerror(errno));
394 ALOGV("Read %d bytes from iio device %d\n", len, dev_num);
396 for (s=0; s<MAX_SENSORS; s++)
397 if (sensor_info[s].dev_num == dev_num &&
398 sensor_info[s].enable_count) {
402 /* Copy data from device to sensor report buffer */
403 for (c=0; c<sensor_info[s].num_channels; c++) {
405 target = sensor_info[s].report_buffer +
408 source = buf + sensor_info[s].channel[c].offset;
410 size = sensor_info[s].channel[c].size;
412 memcpy(target, source, size);
417 ALOGV("Sensor %d report available (%d bytes)\n", s,
420 sensor_info[s].report_ts = ts;
421 sensor_info[s].report_pending = 1;
428 static void propagate_sensor_report(int s, struct sensors_event_t* data)
430 /* There's a sensor report pending for this sensor ; transmit it */
432 int catalog_index = sensor_info[s].catalog_index;
433 int sensor_type = sensor_catalog[catalog_index].type;
436 unsigned char* current_sample;
437 int64_t current_ts = get_timestamp();
439 memset(data, 0, sizeof(sensors_event_t));
441 data->version = sizeof(sensors_event_t);
443 data->type = sensor_type;
445 if (sensor_info[s].report_ts)
446 data->timestamp = sensor_info[s].report_ts;
448 data->timestamp = current_ts;
450 switch (sensor_type) {
451 case SENSOR_TYPE_ACCELEROMETER: /* m/s^2 */
452 case SENSOR_TYPE_MAGNETIC_FIELD: /* micro-tesla */
453 case SENSOR_TYPE_ORIENTATION: /* degrees */
454 case SENSOR_TYPE_GYROSCOPE: /* radians/s */
458 case SENSOR_TYPE_LIGHT: /* SI lux units */
459 case SENSOR_TYPE_AMBIENT_TEMPERATURE: /* °C */
460 case SENSOR_TYPE_TEMPERATURE: /* °C */
461 case SENSOR_TYPE_PROXIMITY: /* centimeters */
462 case SENSOR_TYPE_PRESSURE: /* hecto-pascal */
463 case SENSOR_TYPE_RELATIVE_HUMIDITY: /* percent */
467 case SENSOR_TYPE_ROTATION_VECTOR:
471 case SENSOR_TYPE_DEVICE_PRIVATE_BASE: /* hidden for now */
476 ALOGE("Unknown sensor type!\n");
481 ALOGV("Sample on sensor %d (type %d):\n", s, sensor_type);
483 /* Take note of current time counter value for rate control purposes */
484 sensor_info[s].last_integration_ts = current_ts;
486 /* If we're dealing with a poll-mode sensor */
487 if (!sensor_info[s].num_channels) {
489 /* Read values through sysfs rather than from a report buffer */
490 for (c=0; c<num_fields; c++) {
492 data->data[c] = acquire_immediate_value(s, c);
494 ALOGV("\tfield %d: %f\n", c, data->data[c]);
497 sensor_info[s].ops.finalize(s, data);
501 /* Convert the data into the expected Android-level format */
503 current_sample = sensor_info[s].report_buffer;
505 for (c=0; c<num_fields; c++) {
507 data->data[c] = sensor_info[s].ops.transform
508 (s, c, current_sample);
510 ALOGV("\tfield %d: %f\n", c, data->data[c]);
511 current_sample += sensor_info[s].channel[c].size;
514 sensor_info[s].ops.finalize(s, data);
518 static int get_poll_time (void)
521 int64_t lowest_target_ts;
525 if (!active_poll_sensors)
526 return -1; /* Infinite wait */
528 /* Check if we should schedule a poll-mode sensor event delivery */
530 lowest_target_ts = INT64_MAX;
532 for (s=0; s<sensor_count; s++)
533 if (sensor_info[s].enable_count &&
534 sensor_info[s].sampling_rate &&
535 !sensor_info[s].num_channels) {
536 target_ts = sensor_info[s].last_integration_ts +
537 1000000000LL/sensor_info[s].sampling_rate;
539 if (target_ts < lowest_target_ts)
540 lowest_target_ts = target_ts;
543 if (lowest_target_ts == INT64_MAX)
546 current_ts = get_timestamp();
548 if (lowest_target_ts <= current_ts)
551 return (lowest_target_ts - current_ts)/1000000; /* ms */
555 static void acknowledge_release (void)
557 /* A write to our socket circuit was performed to release epoll */
559 read(poll_socket_pair[0], &buf, 1);
563 int sensor_poll(struct sensors_event_t* data, int count)
569 struct epoll_event ev[MAX_DEVICES];
572 /* Get one or more events from our collection of sensors */
574 return_first_available_sensor_report:
576 /* If there's at least one available report */
577 for (s=0; s<sensor_count; s++)
578 if (sensor_info[s].report_pending) {
581 propagate_sensor_report(s, data);
582 sensor_info[s].report_pending = 0;
583 ALOGV("Report on sensor %d\n", s);
588 ALOGV("Awaiting sensor data\n");
590 nfds = epoll_wait(poll_fd, ev, MAX_DEVICES, get_poll_time());
592 last_poll_exit_ts = get_timestamp();
595 ALOGI("epoll_wait returned -1 (%s)\n", strerror(errno));
599 ALOGV("%d fds signalled\n", nfds);
601 /* For each of the devices for which a report is available */
602 for (i=0; i<nfds; i++)
603 if (ev[i].events == EPOLLIN) {
604 if (ev[i].data.u32 == INVALID_DEV_NUM) {
605 acknowledge_release();
609 integrate_device_report(ev[i].data.u32);
612 /* Check poll-mode sensors and fire up an event if it's time to do so */
613 if (active_poll_sensors)
614 for (s=0; s<sensor_count; s++)
615 if (sensor_info[s].enable_count &&
616 !sensor_info[s].num_channels &&
617 sensor_info[s].sampling_rate) {
618 target_ts = sensor_info[s].last_integration_ts +
619 1000000000LL/sensor_info[s].sampling_rate;
621 if (last_poll_exit_ts >= target_ts)
622 sensor_info[s].report_pending = 1;
625 goto return_first_available_sensor_report;
629 int sensor_set_delay(int s, int64_t ns)
631 /* Set the rate at which a specific sensor should report events */
633 /* See Android sensors.h for indication on sensor trigger modes */
635 char sysfs_path[PATH_MAX];
636 char avail_sysfs_path[PATH_MAX];
637 int dev_num = sensor_info[s].dev_num;
638 int i = sensor_info[s].catalog_index;
639 const char *prefix = sensor_catalog[i].tag;
640 int new_sampling_rate; /* Granted sampling rate after arbitration */
641 int cur_sampling_rate; /* Currently used sampling rate */
642 int req_sampling_rate; /* Requested ; may be different from granted */
643 int per_sensor_sampling_rate;
644 int per_device_sampling_rate;
645 int max_supported_rate = 0;
652 ALOGE("Rejecting zero delay request on sensor %d\n", s);
656 new_sampling_rate = req_sampling_rate = (int) (1000000000L/ns);
658 if (!new_sampling_rate) {
659 ALOGI("Sub-HZ sampling rate requested on on sensor %d\n", s);
660 new_sampling_rate = 1;
663 sensor_info[s].sampling_rate = new_sampling_rate;
665 /* If we're dealing with a poll-mode sensor, release poll and return */
666 if (!sensor_info[s].num_channels)
669 sprintf(sysfs_path, SENSOR_SAMPLING_PATH, dev_num, prefix);
671 if (sysfs_read_int(sysfs_path, &cur_sampling_rate) != -1) {
672 per_sensor_sampling_rate = 1;
673 per_device_sampling_rate = 0;
675 per_sensor_sampling_rate = 0;
677 sprintf(sysfs_path, DEVICE_SAMPLING_PATH, dev_num);
679 if (sysfs_read_int(sysfs_path, &cur_sampling_rate) != -1)
680 per_device_sampling_rate = 1;
682 per_device_sampling_rate = 0;
685 if (!per_sensor_sampling_rate && !per_device_sampling_rate) {
686 ALOGE("No way to adjust sampling rate on sensor %d\n", s);
690 /* Coordinate with others active sensors on the same device, if any */
691 if (per_device_sampling_rate)
692 for (n=0; n<sensor_count; n++)
693 if (n != s && sensor_info[n].dev_num == dev_num &&
694 sensor_info[n].num_channels &&
695 sensor_info[n].enable_count &&
696 sensor_info[n].sampling_rate > new_sampling_rate)
697 new_sampling_rate= sensor_info[n].sampling_rate;
699 /* Check if we have contraints on allowed sampling rates */
701 sprintf(avail_sysfs_path, DEVICE_AVAIL_FREQ_PATH, dev_num);
703 if (sysfs_read_str(avail_sysfs_path, freqs_buf, sizeof(freqs_buf)) > 0){
706 /* Decode allowed sampling rates string, ex: "10 20 50 100" */
708 /* While we're not at the end of the string */
709 while (*cursor && cursor[0]) {
711 /* Decode a single integer value */
714 if (n > max_supported_rate)
715 max_supported_rate = n;
717 /* If this matches the selected rate, we're happy */
718 if (new_sampling_rate == n)
722 * If we reached a higher value than the desired rate,
723 * adjust selected rate so it matches the first higher
724 * available one and stop parsing - this makes the
725 * assumption that rates are sorted by increasing value
726 * in the allowed frequencies string.
728 if (n > new_sampling_rate) {
730 "Increasing sampling rate on sensor %d from %d to %d\n",
731 s, req_sampling_rate, n);
733 new_sampling_rate = n;
738 while (cursor[0] && !isspace(cursor[0]))
742 while (cursor[0] && isspace(cursor[0]))
747 /* Cap sampling rate at 1000 events per second for now*/
751 if (max_supported_rate && new_sampling_rate > max_supported_rate)
752 limit = max_supported_rate;
754 if (new_sampling_rate > limit) {
756 new_sampling_rate = limit;
758 ALOGI( "Can't support %d sampling rate, lowering to %d\n",
759 req_sampling_rate, new_sampling_rate);
762 /* If the desired rate is already active we're all set */
763 if (new_sampling_rate == cur_sampling_rate)
766 ALOGI("Sensor %d sampling rate switched to %d\n", s, new_sampling_rate);
768 if (trig_sensors_per_dev[dev_num])
769 enable_buffer(dev_num, 0);
771 sysfs_write_int(sysfs_path, new_sampling_rate);
773 if (trig_sensors_per_dev[dev_num])
774 enable_buffer(dev_num, 1);
777 /* Release the polling loop so an updated timeout value gets used */
778 write(poll_socket_pair[1], "", 1);
785 int allocate_control_data (void)
788 struct epoll_event ev = {0};
790 for (i=0; i<MAX_DEVICES; i++)
793 poll_fd = epoll_create(MAX_DEVICES);
796 ALOGE("Can't create epoll instance for iio sensors!\n");
800 /* Create and add "unblocking" fd to the set of watched fds */
802 if (socketpair(AF_UNIX, SOCK_STREAM, 0, poll_socket_pair) == -1) {
803 ALOGE("Can't create socket pair for iio sensors!\n");
809 ev.data.u32 = INVALID_DEV_NUM;
811 epoll_ctl(poll_fd, EPOLL_CTL_ADD, poll_socket_pair[0], &ev);
817 void delete_control_data (void)