[PATCH v2 0/7] rtc: sun6i: Fix the RTC accuracy

Alexandre Belloni alexandre.belloni at free-electrons.com
Tue Jan 24 09:49:35 PST 2017


Hi,

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!

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com



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