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To:     Sam Protsenko <semen.protsenko@linaro.org>
Cc:     Alessandro Zummo <a.zummo@towertech.it>, linux-rtc@vger.kernel.org,
        Linux Samsung SOC <linux-samsung-soc@vger.kernel.org>,
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        Alexandre Belloni <alexandre.belloni@bootlin.com>
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From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Subject: Re: [PATCH 2/4] rtc: s3c: Add time range
Message-ID: <effeb83b-7923-7086-5b4f-36266015e137@canonical.com>
Date:   Wed, 20 Oct 2021 08:29:50 +0200
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On 19/10/2021 21:12, Sam Protsenko wrote:
> Krzysztof, do you have by chance the doc for different SoCs supported
> by S3C RTC driver? I can implement proper values for min/max range for
> each SoC, as Alexandre asked, by adding those to driver data. But I
> need max year register value (100, 1000, etc) for each of those chips:
> 
>   - "samsung,s3c2410-rtc"
>   - "samsung,s3c2416-rtc"
>   - "samsung,s3c2443-rtc"
>   - "samsung,s3c6410-rtc"
>   - "samsung,exynos3250-rtc"
> 
> For example Exynos850 TRM states that BCDYEAR register has [11:0] bits
> for holding the year value in BCD format, so it's 10^(12/4)=1000 years
> max.
> 

I think all S3C chips have only 8-bit wide year, so 2000-2099, while
S5Pv210 and Exynos has 12-bit (1000 years). However I doubt there is big
benefit of supporting more than 2100. :) If you still want, you would
need to create the patch carefully because not many people can test it...


Best regards,
Krzysztof