diff options
| author | Mark Godfrey <mark.godfrey@stericsson.com> | 2011-10-04 09:58:45 +0100 |
|---|---|---|
| committer | Philippe Langlais <philippe.langlais@stericsson.com> | 2011-12-06 10:50:51 +0100 |
| commit | 4c7cafa745afbe4da8c1a90769e0b7fb0e28aef5 (patch) | |
| tree | ba1b3c3b96b8cd848570123969cb2531b613aaa6 /Documentation | |
| parent | de998a7b1f60746a338b89bb81fc386b18765210 (diff) | |
rtc: ab8500: Add calibration attribute to AB8500 RealTimeClock
The rtc_calibration attribute allows user-space to get and set
the AB8500's RtcCalibration register. The AB8500 will then use the value in
this register to compensate for RTC drift every 60 seconds.
ST Ericsson ID: 362204
Change-Id: I32a4bda5d6cc0812dcb53d721088e8b844c25b46
Signed-off-by: Mark Godfrey <mark.godfrey@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/32922
Reviewed-by: Linus WALLEIJ <linus.walleij@stericsson.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-rtc-rtc0-device-rtc_calibration | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-rtc-rtc0-device-rtc_calibration b/Documentation/ABI/testing/sysfs-class-rtc-rtc0-device-rtc_calibration new file mode 100644 index 00000000000..ae217d4a3a6 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-rtc-rtc0-device-rtc_calibration @@ -0,0 +1,13 @@ +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. + |