The RTC_HCTOSYS_DEVICE module defaults to rtc0 and should (highly)
preferable be assigned to a battery backed RTC module as it is used to
(re)initialize the system clock.

The R5S and R5C have a connector for a RTC battery which is used by
HYM8563 RTC. Both devices also have another RTC from the rk809 PMIC.
To make sure the HYM8563 is always assigned rtc0, add an alias for it.

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
---
 arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dtsi b/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dtsi
index a28b4af10d13..f4d042bdd328 100644
--- a/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dtsi
@@ -18,6 +18,7 @@ / {
 	aliases {
 		mmc0 = &sdmmc0;
 		mmc1 = &sdhci;
+		rtc0 = &hym8563;
 	};
 
 	chosen: chosen {
-- 
2.50.0

On Sun, 13 Jul 2025 18:16:36 +0200, Diederik de Haas wrote:
> The RTC_HCTOSYS_DEVICE module defaults to rtc0 and should (highly)
> preferable be assigned to a battery backed RTC module as it is used to
> (re)initialize the system clock.
> 
> The R5S and R5C have a connector for a RTC battery which is used by
> HYM8563 RTC. Both devices also have another RTC from the rk809 PMIC.
> To make sure the HYM8563 is always assigned rtc0, add an alias for it.
> 
> [...]

Applied, thanks!

[1/1] arm64: dts: rockchip: Add rtc0 alias for NanoPi R5S + R5C
      commit: a2df3aead3e023857330a803c664ee97a7bd9b97

Best regards,
-- 
Heiko Stuebner <heiko@sntech.de>