diff options
Diffstat (limited to 'include/hardware/sensors.h')
| -rw-r--r-- | include/hardware/sensors.h | 49 |
1 files changed, 36 insertions, 13 deletions
diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h index f938d1b..b377051 100644 --- a/include/hardware/sensors.h +++ b/include/hardware/sensors.h @@ -451,6 +451,9 @@ enum { * SENSOR_TYPE_MAGNETIC_FIELD must be present and both must return the * same sensor_t::name and sensor_t::vendor. * + * Minimum filtering should be applied to this sensor. In particular, low pass + * filters should be avoided. + * * See SENSOR_TYPE_MAGNETIC_FIELD for more information */ #define SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED (14) @@ -608,7 +611,7 @@ enum { * * A sensor of this type returns the number of steps taken by the user since * the last reboot while activated. The value is returned as a uint64_t and is - * reset to zero only on a system reboot. + * reset to zero only on a system / android reboot. * * The timestamp of the event is set to the time when the first step * for that event was taken. @@ -662,7 +665,9 @@ enum { * of using a gyroscope. * * This sensor must be based on a magnetometer. It cannot be implemented using - * a gyroscope, and gyroscope input cannot be used by this sensor. + * a gyroscope, and gyroscope input cannot be used by this sensor, as the + * goal of this sensor is to be low power. + * The accelerometer can be (and usually is) used. * * Just like SENSOR_TYPE_ROTATION_VECTOR, this sensor reports an estimated * heading accuracy: @@ -909,6 +914,10 @@ typedef struct sensors_poll_device_1 { * handle is the handle of the sensor to change. * enabled set to 1 to enable, or 0 to disable the sensor. * + * if enabled is set to 1, the sensor is activated even if + * setDelay() wasn't called before. In this case, a default rate + * should be used. + * * unless otherwise noted in the sensor types definitions, an * activated sensor never prevents the SoC to go into suspend * mode; that is, the HAL shall not hold a partial wake-lock on @@ -918,10 +927,10 @@ typedef struct sensors_poll_device_1 { * receiving an event and they must still accept to be deactivated * through a call to activate(..., ..., 0). * - * if "enabled" is true and the sensor is already activated, this + * if "enabled" is 1 and the sensor is already activated, this * function is a no-op and succeeds. * - * if "enabled" is false and the sensor is already de-activated, + * if "enabled" is 0 and the sensor is already de-activated, * this function is a no-op and succeeds. * * return 0 on success, negative errno code otherwise @@ -945,6 +954,9 @@ typedef struct sensors_poll_device_1 { * sensor_t::minDelay unless sensor_t::minDelay is 0, in which * case it is clamped to >= 1ms. * + * setDelay will not be called when the sensor is in batching mode. + * In this case, batch() will be called with the new period. + * * @return 0 if successful, < 0 on error */ int (*setDelay)(struct sensors_poll_device_t *dev, @@ -1074,19 +1086,30 @@ typedef struct sensors_poll_device_1 { * if a batch call with SENSORS_BATCH_DRY_RUN is successful, * the same call without SENSORS_BATCH_DRY_RUN must succeed as well). * - * If successful, 0 is returned. - * If the specified sensor doesn't support batch mode, -EINVAL is returned. - * If the specified sensor's trigger-mode is one-shot, -EINVAL is returned. - * If WAKE_UPON_FIFO_FULL is specified and the specified sensor's internal - * FIFO is too small to store at least 10 seconds worth of data at the - * given rate, -EINVAL is returned. Note that as stated above, this has to - * be determined at compile time, and not based on the state of the system. - * If some other constraints above cannot be satisfied, -EINVAL is returned. + * When timeout is not 0: + * If successful, 0 is returned. + * If the specified sensor doesn't support batch mode, return -EINVAL. + * If the specified sensor's trigger-mode is one-shot, return -EINVAL. + * If WAKE_UPON_FIFO_FULL is specified and the specified sensor's internal + * FIFO is too small to store at least 10 seconds worth of data at the + * given rate, -EINVAL is returned. Note that as stated above, this has to + * be determined at compile time, and not based on the state of the + * system. + * If some other constraints above cannot be satisfied, return -EINVAL. * * Note: the timeout parameter, when > 0, has no impact on whether this * function succeeds or fails. * - * If timeout is set to 0, this function must succeed. + * When timeout is 0: + * The caller will never set the wake_upon_fifo_full flag. + * The function must succeed, and batch mode must be deactivated. + * + * Independently of whether DRY_RUN is specified, When the call to batch() + * fails, no state should be changed. In particular, a failed call to + * batch() should not change the rate of the sensor. Example: + * setDelay(..., 10ms) + * batch(..., 20ms, ...) fails + * rate should stay 10ms. * * * IMPLEMENTATION NOTES: |