[PATCH v1 4/4] arm64: dts: imx8mq-librem5: Set BQ25895 input voltage limit

[Vincent Cloutier <vincent.cloutier@icloud.com>]

From: Vincent Cloutier <vincent@cloutier.co>

Purism's production Librem 5 kernels used a 3.9 V absolute VINDPM
threshold for years, from the 2019 board support through the releases
preceding the March 2026 charging update. Use this established board
setting for the BQ25895 input voltage limit.

Set input-voltage-limit-microvolt to 3900000 to select absolute VINDPM
and program the 3.9 V threshold through the generic binding.

Tested on Librem 5r4: REG0D remained 0x8d across an attached boot, unplug,
and flipped replug.

Assisted-by: OpenCode:gpt-5.6-sol
Assisted-by: OpenCode:gpt-6-astra
Signed-off-by: Vincent Cloutier <vincent@cloutier.co>
---
 arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
index 099195279e84..8badebfcdbb4 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
@@ -1195,6 +1195,7 @@ bq25895: charger@6a {
 		pinctrl-0 = <&pinctrl_charger_in>;
 		interrupt-parent = <&gpio3>;
 		interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
+		input-voltage-limit-microvolt = <3900000>;
 		ti,battery-regulation-voltage = <4208000>; /* uV */
 		ti,termination-current = <128000>;  /* uA */
 		ti,precharge-current = <128000>; /* uA */
-- 
2.55.0