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From: Chen-Yu Tsai <wens@kernel.org>
To: Chen-Yu Tsai <wens@csie.org>, Jernej Skrabec <jernej@kernel.org>,
	Samuel Holland <samuel@sholland.org>,
	Andre Przywara <andre.przywara@arm.com>
Cc: linux-sunxi@lists.linux.dev, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] arm64: dts: allwinner: t527: avaota-a1: hook up external 32k crystal
Date: Sat, 13 Sep 2025 18:24:49 +0800	[thread overview]
Message-ID: <20250913102450.3935943-2-wens@kernel.org> (raw)
In-Reply-To: <20250913102450.3935943-1-wens@kernel.org>

From: Chen-Yu Tsai <wens@csie.org>

When the board was added, its external 32.768 KHz crystal was described
but not hooked up correctly. This meant the device had to fall back to
the SoC's internal oscillator or divide a 32 KHz clock from the main
oscillator, neither of which are accurate for the RTC. As a result the
RTC clock will drift badly.

Hook the crystal up to the RTC block and request the correct clock rate.

Fixes: dbe54efa32af ("arm64: dts: allwinner: a523: add Avaota-A1 router support")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm64/boot/dts/allwinner/sun55i-t527-avaota-a1.dts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun55i-t527-avaota-a1.dts b/arch/arm64/boot/dts/allwinner/sun55i-t527-avaota-a1.dts
index 535387912d9b..054d0357c139 100644
--- a/arch/arm64/boot/dts/allwinner/sun55i-t527-avaota-a1.dts
+++ b/arch/arm64/boot/dts/allwinner/sun55i-t527-avaota-a1.dts
@@ -354,6 +354,14 @@ &r_pio {
 	vcc-pm-supply = <&reg_aldo3>;
 };
 
+&rtc {
+	clocks = <&r_ccu CLK_BUS_R_RTC>, <&osc24M>,
+		 <&r_ccu CLK_R_AHB>, <&ext_osc32k>;
+	clock-names = "bus", "hosc", "ahb", "ext-osc32k";
+	assigned-clocks = <&rtc CLK_OSC32K>;
+	assigned-clock-rates = <32768>;
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_pb_pins>;
-- 
2.39.5



  reply	other threads:[~2025-09-13 10:25 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-13 10:24 [PATCH 1/3] arm64: dts: allwinner: a527: cubie-a5e: Drop external 32.768 KHz crystal Chen-Yu Tsai
2025-09-13 10:24 ` Chen-Yu Tsai [this message]
2025-09-13 11:31   ` [PATCH 2/3] arm64: dts: allwinner: t527: avaota-a1: hook up external 32k crystal Jernej Škrabec
2025-09-13 10:24 ` [PATCH 3/3] arm64: dts: allwinner: t527: orangepi-4a: " Chen-Yu Tsai
2025-09-13 11:31   ` Jernej Škrabec
2025-09-13 11:30 ` [PATCH 1/3] arm64: dts: allwinner: a527: cubie-a5e: Drop external 32.768 KHz crystal Jernej Škrabec
2025-09-14 16:29 ` Chen-Yu Tsai

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