[PATCH 3/3] arm64: dts: broadcom: Add RTC to Raspberry Pi 5 B

Sander Speetjens sander.speetjens at gmail.com
Wed Sep 9 07:13:00 PDT 2026


The Raspberry Pi 5 contains a RTC on a custom DA9091 PMIC that is accesed trought the firware mailbox.
This so we have a battery backed RTC, so the OS does not need network to get the time.

Signed-off-by: Sander Speetjens <sander.speetjens at gmail.com>
---
 arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi
index b7a6bc34ae1a..5a82dd585f32 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi
+++ b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi
@@ -102,6 +102,13 @@ wl_on_reg: wl-on-reg {
 		startup-delay-us = <150000>;
 		enable-active-high;
 	};
+
+	rpi_rtc: rpi-rtc {
+		compatible = "raspberrypi,rpi-rtc";
+		firmware = <&firmware>;
+		status = "okay";
+		trickle-charge-microvolt = <0>;
+	};
 };
 
 &pinctrl {
-- 
2.55.0




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