|  | What:           Attribute for calibrating ST-Ericsson AB8500 Real Time Clock | 
|  | Date:           Oct 2011 | 
|  | KernelVersion:  3.0 | 
|  | Contact:        Mark Godfrey <mark.godfrey@stericsson.com> | 
|  | Description:    The rtc_calibration attribute allows the userspace to | 
|  | calibrate the AB8500.s 32KHz Real Time Clock. | 
|  | Every 60 seconds the AB8500 will correct the RTC's value | 
|  | by adding to it the value of this attribute. | 
|  | The range of the attribute is -127 to +127 in units of | 
|  | 30.5 micro-seconds (half-parts-per-million of the 32KHz clock) | 
|  | Users:          The /vendor/st-ericsson/base_utilities/core/rtc_calibration | 
|  | daemon uses this interface. |