Messages in this thread | | | Subject | Re: [PATCH 3/4] rtc: ds1307: add calibration of_ for mt41txx chips. | From | Giulio Benetti <> | Date | Wed, 9 May 2018 20:33:56 +0200 |
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Hi Rob,
Il 08/05/2018 19:40, Rob Herring ha scritto: > On Tue, May 8, 2018 at 9:56 AM, Giulio Benetti > <giulio.benetti@micronovasrl.com> wrote: >> m41txx chips can hold a calibration value to get really near to real >> tick value. > > Typo in the subject. > >> Add calibration property(ranging between (-31) and 31), so on every probe >> calibration value will be written to rtc. >> This is because ic could loose supply due to low battery. >> >> Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com> >> --- >> .../devicetree/bindings/rtc/rtc-ds1307.txt | 2 ++ > > Put all the binding changes in separate patch (or maybe 2: new > compatible and new properties). > >> drivers/rtc/rtc-ds1307.c | 33 +++++++++++++++++++ >> 2 files changed, 35 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt >> index ce6469c1a516..d3d70a5495c5 100644 >> --- a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt >> +++ b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt >> @@ -34,6 +34,8 @@ Optional properties: >> - trickle-diode-disable : ds1339, ds1340 and ds 1388 only >> Do not use internal trickle charger diode >> Should be given if internal trickle charger diode should be disabled >> +- calibration: m41t0, m41t00, m41t11 only > > Needs a vendor prefix. > > Calibration of what and what are the units? > >> + Set calibration value to correct external bias, ranging between (-31) and 31. >> >> Example: >> rtc1: ds1339@68 {
This is not a problem anymore since I've used standard rtc sysfs "offset" instead of a dt-property as Alexandre pointed me out.
Thanks.
-- Giulio Benetti CTO
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