[PATCH v2] arm64: dts: rockchip: add HYM8563 RTC to Radxa CM5 IO board

Brian Mayer bleemayer at gmail.com
Sun Jul 5 11:19:19 PDT 2026


Hello again, to clarify: I tested the v1 patch in my radxa cm5, but since
this v2 only contains name changes I didn't test. I added the missing
agent tag and am sending the patch inline. Thanks.

The Radxa CM5 IO carrier has a Haoyu HYM8563 real-time clock on I2C6 at
address 0x51, with its interrupt line on GPIO0_B0 and a CR1220 backup
battery holder. Without a device tree node, no /dev/rtc* appears even
when CONFIG_RTC_DRV_HYM8563 is enabled.

Describe the RTC, wire the interrupt pin with a pull-up, mark it as a
wakeup source, and point the rtc0 alias at it so RTC_HCTOSYS/SYSTOHC use
the external clock. Wiring matches Radxa's downstream board support and
uses schematic names for the rtc_int_l pinctrl entry.

Assisted-by: Grok:grok-build
Signed-off-by: Brian Mayer <bleemayer at gmail.com>
---
 .../dts/rockchip/rk3588s-radxa-cm5-io.dts     | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Changes in v2:
- Rename pinctrl to rtc_int_l / rtc-int-l to match schematics
- Drop Tested-by (covered by Signed-off-by)
- Add Assisted-by: Grok:grok-build
- Send inline with git send-email (not as attachment)

diff --git a/arch/arm64/boot/dts/rockchip/rk3588s-radxa-cm5-io.dts b/arch/arm64/boot/dts/rockchip/rk3588s-radxa-cm5-io.dts
index af4a9bc01..d22db4d18 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588s-radxa-cm5-io.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3588s-radxa-cm5-io.dts
@@ -19,6 +19,7 @@ / {
 	aliases {
 		ethernet0 = &gmac1;
 		mmc1 = &sdmmc;
+		rtc0 = &hym8563;
 	};
 
 	chosen {
@@ -198,6 +199,18 @@ usbc0_dp_altmode_mux: endpoint {
 			};
 		};
 	};
+
+	hym8563: rtc at 51 {
+		compatible = "haoyu,hym8563";
+		reg = <0x51>;
+		#clock-cells = <0>;
+		clock-output-names = "hym8563";
+		interrupt-parent = <&gpio0>;
+		interrupts = <RK_PB0 IRQ_TYPE_LEVEL_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&rtc_int_l>;
+		wakeup-source;
+	};
 };
 
 &i2s5_8ch {
@@ -221,6 +234,12 @@ usbc0_int: usbc0-int {
 		};
 	};
 
+	hym8563 {
+		rtc_int_l: rtc-int-l {
+			rockchip,pins = <0 RK_PB0 RK_FUNC_GPIO &pcfg_pull_up>;
+		};
+	};
+
 	hdmi {
 		hdmi0_tx_on_h: hdmi0-tx-on-h {
 			rockchip,pins = <4 RK_PB6 RK_FUNC_GPIO &pcfg_pull_none>;

base-commit: 87320be9f0d24fce67631b7eef919f0b79c3e45c
-- 
2.54.0




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