[PATCH v2 0/7] rtc: sun6i: Fix the RTC accuracy
maxime.ripard at free-electrons.com
Wed Jan 25 07:36:02 PST 2017
On Tue, Jan 24, 2017 at 06:49:35PM +0100, Alexandre Belloni wrote:
> On 23/01/2017 at 11:41:45 +0100, Maxime Ripard wrote :
> > Hi,
> > The RTC used in the A31 and later SoC has an accuracy issue, which is
> > already significant even after a couple of hours.
> > This is due to the fact that the oscillator used by default is an internal
> > and very inaccurate one.
> > A first attempt at fixing that by switching to the external oscillator was
> > done in the patch "rtc: sun6i: Switch to the external oscillator". However,
> > it turned out to be problematic since it was tracked properly in the clock
> > framework, which might lead to some clocks being disabled, even though
> > their devices were not notified.
> > This is a second attempt, this time by making it part of the CCF. It
> > turned out to be a bit more complicated than one would expect since the mux
> > found inside the RTC also controls one of the input of the main clock unit.
> > Therefore, it needs to be probed before the main clock unit driver.
> > Let me know what you think,
> > Maxime
> > Changes from v1:
> > - Force the muxing to the external oscillator even for old DT
> > - Make the patches a bit more stable friendly
> > - Change the bindings to have a cell of 1, to account for the external
> > output of the oscillator
> > - Split the driver remove() removal into a separate patch and switched to
> > devm
> > - Reordered the patches
> > Maxime Ripard (7):
> > rtc: sun6i: Disable the build as a module
> > rtc: sun6i: Add some locking
> > rtc: sun6i: Switch to the external oscillator
> > rtc: sun6i: Expose the 32kHz oscillator
> > rtc: sun6i: Switch to devm_rtc_device_register
> > ARM: sun8i: a23/a33: Enable the real LOSC and use it
> > ARM: sun8i: a23/a33: Add the oscillators accuracy
> I've applied 1/7 to 5/7. Thanks!
And I just applied patches 6 and 7. Thanks!
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
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