[PATCH V6 2/2] rtc: zynqmp: Add calibration set and get support
Alexandre Belloni
alexandre.belloni at bootlin.com
Thu Jun 9 07:53:46 PDT 2022
On 09/06/2022 16:50:03+0200, Peter Korsgaard wrote:
> >>>>> "Srinivas" == Srinivas Neeli <srinivas.neeli at xilinx.com> writes:
>
> > Zynqmp RTC controller has a calibration feature to compensate
> > time deviation due to input clock inaccuracy.
> > Set and get calibration API's are used for setting and getting
> > calibration value from the controller calibration register.
> > As per RTC spec default calibration value is 0x7FFF.
>
> Where do you see that? ug1085 rev2.2 still lists:
>
> Programming Sequences
> init rtc
> 1. Write the value 0019_8231h into the calibration register, CALIB_WRITE.
>
This is a very weird value. Last time I had a look, I couldn't find an
explanation for it.
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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