1*4882a593SmuzhiyunWhat: /sys/class/rtc/rtc0/device/rtc_calibration 2*4882a593SmuzhiyunDate: Oct 2011 3*4882a593SmuzhiyunKernelVersion: 3.0 4*4882a593SmuzhiyunContact: Mark Godfrey <mark.godfrey@stericsson.com> 5*4882a593SmuzhiyunDescription: Attribute for calibrating ST-Ericsson AB8500 Real Time Clock 6*4882a593Smuzhiyun The rtc_calibration attribute allows the userspace to 7*4882a593Smuzhiyun calibrate the AB8500.s 32KHz Real Time Clock. 8*4882a593Smuzhiyun Every 60 seconds the AB8500 will correct the RTC's value 9*4882a593Smuzhiyun by adding to it the value of this attribute. 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun The range of the attribute is -127 to +127 in units of 12*4882a593Smuzhiyun 30.5 micro-seconds (half-parts-per-million of the 32KHz clock) 13*4882a593SmuzhiyunUsers: The /vendor/st-ericsson/base_utilities/core/rtc_calibration 14*4882a593Smuzhiyun daemon uses this interface. 15