linux-kernel - [PATCH 2/3] arm64: dts: imx8mq-librem5-r3: Mark buck3 as always on

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Date:   Thu, 11 Mar 2021 13:02:58 +0100
From:   Martin Kepplinger <martin.kepplinger@...i.sm>
To:     robh@...nel.org, shawnguo@...nel.org, kernel@...gutronix.de,
        festevam@...il.com, krzk@...nel.org
Cc:     kernel@...i.sm, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        phone-devel@...r.kernel.org,
        Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>,
        Martin Kepplinger <martin.kepplinger@...i.sm>
Subject: [PATCH 2/3] arm64: dts: imx8mq-librem5-r3: Mark buck3 as always on

From: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>

Commit 66d3f246d79f ("arm64: dts: librem5: Don't mark buck3 as always on")
removed always-on marking from GPU regulator, which is great for power
saving - however it introduces additional i2c0 traffic which can be deadly
for devices from the Dogwood batch.

To workaround the i2c0 shutdown issue on Dogwood, this commit marks
buck3 as always-on again - but only for Dogwood (r3).

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>
Signed-off-by: Martin Kepplinger <martin.kepplinger@...i.sm>
---
 arch/arm64/boot/dts/freescale/imx8mq-librem5-r3.dts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mq-librem5-r3.dts b/arch/arm64/boot/dts/freescale/imx8mq-librem5-r3.dts
index 0d38327043f8..cd3c3edd48fa 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq-librem5-r3.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mq-librem5-r3.dts
@@ -28,6 +28,10 @@ &bq25895 {
 	ti,termination-current = <144000>;  /* uA */
 };
 
+&buck3_reg {
+	regulator-always-on;
+};
+
 &proximity {
 	proximity-near-level = <25>;
 };
-- 
2.30.1