From 1511e20fbbdfe7bf30b9de73f06fc981eb494f09 Mon Sep 17 00:00:00 2001 From: Mathias Agopian Date: Thu, 29 Jul 2010 15:33:22 -0700 Subject: improved comments and added a minDelay attribute to sensor_t Change-Id: Ie00fe8260089614e15f1f8035b8392711dff048c --- include/hardware/sensors.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'include/hardware') diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h index 0a3d673..6dccddd 100644 --- a/include/hardware/sensors.h +++ b/include/hardware/sensors.h @@ -321,8 +321,12 @@ struct sensor_t { float resolution; /* rough estimate of this sensor's power consumption in mA */ float power; + /* minimum delay allowed between events in microseconds. A value of zero + * means that this sensor doesn't report events at a constant rate, but + * rather only when a new data is available */ + int32_t minDelay; /* reserved fields, must be zero */ - void* reserved[9]; + void* reserved[8]; }; @@ -344,7 +348,10 @@ struct sensors_poll_device_t { int handle, int enabled); /** - * Set the delay between sensor events in nanoseconds for a given sensor + * Set the delay between sensor events in nanoseconds for a given sensor. + * It is an error to set a delay inferior to the value defined by + * sensor_t::minDelay. If sensor_t::minDelay is zero, setDelay() is + * ignored and returns 0. * * @return 0 if successful, < 0 on error */ @@ -353,8 +360,10 @@ struct sensors_poll_device_t { /** * Returns an array of sensor data. + * This function must block until events are available. * * @return the number of events read on success, or -errno in case of an error. + * This function should never return 0 (no event). * */ int (*poll)(struct sensors_poll_device_t *dev, -- cgit v1.1