On Tue, Sep 16, 2014 at 7:48 AM, Javier Martinez Canillas <javier@xxxxxxxxxxxx> wrote: >> Clock list for s3c-rtc device: >> - rtc : CLK_RTC of CLK_GATE_IP_PERIR is gate clock for RTC. >> - rtc_src : XrtcXTI is 32.768.kHz source clock for RTC. > > Is this RTC source clock needed for all Exynos SoCs? It is at least needed on Exynos4412, which has the XrtcXTI thing exactly as you describe. However the very standard setup there is to hook it up to the CP clock output of the MAX76686 PMIC. This CP clock is on by default, so you can potentially live without that detail being present in the DT. However... one small issue with this setup is that when you enable CONFIG_COMMON_CLK_MAX77686, the CP clock gets exposed in Linux's common clock framework, and Linux then turns it off because it believes it is unused. Then the RTC stops ticking. So the rtc_src idea would also be good for Exynos4412. Maybe it would make sense to drop the needs_src_clk flag, and simply require/enable the src clock whenever it is present in the DT. Also, are you sure about the way you are treating this clock, all those enable/disable calls? You only seem to enable it when doing some particular driver operations e.g. reading the time, leaving it disabled at all other times. However I believe on Exynos4412 that if you disable this clock then the RTC will not tick. Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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