Re: [PATCH 06/15] rtc: sun6i: Add support for different variants

[Maxime Ripard <maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org>]

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On Wed, Nov 28, 2018 at 05:30:03PM +0800, Chen-Yu Tsai wrote:
> Amongst the Allwinner SoCs that have seen some kind of coverage by the
> linux-sunxi community, whether it be mainline Linux or U-boot support,
> or just available datasheets, most newer chips use the RTC design first
> seen in the A31 (sun6i).
> 
> Overall there have been some minor differences. This patch covers the
> following:
> 
>   - average clock rate of the internal RC oscillator
>     + presence of fixed and adjustable prescaler for this clock
>   - availability of an external (to the SoC) clock output
> 
> One major difference regarding the H6 is the 24 MHz crystal is now
> routed through the RTC, as a digitally compensated oscillator (DCXO).
> This is not covered in this patch and will be supported later.
> 
> Other differences are either unrelated to RTC or clock functionality,
> such as boot or crypto related registers, or the driver simply doesn't
> use the feature in question. One example of the latter is the
> calibration function for the RC oscillator. We consider this clock to
> be very bad and avoid using it.
> 
> Signed-off-by: Chen-Yu Tsai <wens-jdAy2FN1RRM@public.gmane.org>

Acked-by: Maxime Ripard <maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org>

Maxime

-- 
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com