Merge remote-tracking branches 'asoc/topic/max9878', 'asoc/topic/max98927', 'asoc...
[sfrench/cifs-2.6.git] / Documentation / ABI / testing / sysfs-class-rtc-rtc0-device-rtc_calibration
1 What:           /sys/class/rtc/rtc0/device/rtc_calibration
2 Date:           Oct 2011
3 KernelVersion:  3.0
4 Contact:        Mark Godfrey <mark.godfrey@stericsson.com>
5 Description:    Attribute for calibrating ST-Ericsson AB8500 Real Time Clock
6                 The rtc_calibration attribute allows the userspace to
7                 calibrate the AB8500.s 32KHz Real Time Clock.
8                 Every 60 seconds the AB8500 will correct the RTC's value
9                 by adding to it the value of this attribute.
10                 The range of the attribute is -127 to +127 in units of
11                 30.5 micro-seconds (half-parts-per-million of the 32KHz clock)
12 Users:          The /vendor/st-ericsson/base_utilities/core/rtc_calibration
13                 daemon uses this interface.