1aaa6f6acSMauro Carvalho ChehabWhat: /sys/class/rtc/rtc0/device/rtc_calibration 2dda367acSMark GodfreyDate: Oct 2011 3dda367acSMark GodfreyKernelVersion: 3.0 4dda367acSMark GodfreyContact: Mark Godfrey <mark.godfrey@stericsson.com> 5aaa6f6acSMauro Carvalho ChehabDescription: Attribute for calibrating ST-Ericsson AB8500 Real Time Clock 6aaa6f6acSMauro Carvalho Chehab The rtc_calibration attribute allows the userspace to 7dda367acSMark Godfrey calibrate the AB8500.s 32KHz Real Time Clock. 8dda367acSMark Godfrey Every 60 seconds the AB8500 will correct the RTC's value 9dda367acSMark Godfrey by adding to it the value of this attribute. 10*54a19b4dSMauro Carvalho Chehab 11dda367acSMark Godfrey The range of the attribute is -127 to +127 in units of 12dda367acSMark Godfrey 30.5 micro-seconds (half-parts-per-million of the 32KHz clock) 13dda367acSMark GodfreyUsers: The /vendor/st-ericsson/base_utilities/core/rtc_calibration 14dda367acSMark Godfrey daemon uses this interface. 15