From: Marek Vasut marex@denx.de
[ Upstream commit 3a0670824979a986a2314c921aa092e60730eeae ]
The DHCOM SoM has two RTC, one is the STM32 RTC built into the SoC and another is Microcrystal RV RTC. By default, only the later has battery backup, the former does not. The order in which the RTCs are probed on boot is random, which means the kernel might pick up system time from the STM32 RTC which has no battery backup. This then leads to incorrect initial system time setup, even though the HW RTC has correct time configured in it.
Add DT alias entries, so that the RTCs get assigned fixed IDs and the HW RTC is always picked by the kernel as the default RTC, thus resulting in correct system time in early userspace.
Fixes: 34e0c7847dcf ("ARM: dts: stm32: Add DH Electronics DHCOM STM32MP1 SoM and PDK2 board") Signed-off-by: Marek Vasut marex@denx.de Cc: Alexandre Torgue alexandre.torgue@foss.st.com Cc: Patrice Chotard patrice.chotard@foss.st.com Cc: Patrick Delaunay patrick.delaunay@foss.st.com Cc: linux-stm32@st-md-mailman.stormreply.com To: linux-arm-kernel@lists.infradead.org Signed-off-by: Alexandre Torgue alexandre.torgue@foss.st.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi index 2af0a6752674..8349c9099e30 100644 --- a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi +++ b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi @@ -12,6 +12,8 @@ aliases { ethernet0 = ðernet0; ethernet1 = &ksz8851; + rtc0 = &hwrtc; + rtc1 = &rtc; };
memory@c0000000 { @@ -248,7 +250,7 @@ /delete-property/dmas; /delete-property/dma-names;
- rtc@32 { + hwrtc: rtc@32 { compatible = "microcrystal,rv8803"; reg = <0x32>; };