Re: [PATCH 4/4] arm64: dts: imx8mq-librem5: Dongwoon DW9714 coil requires higher voltage

On sobota, 1 sierpnia 2026 02:35:23 czas =C5=9Brodkowoeuropejski letni Davi=
d=20
Heidelberg via B4 Relay wrote:
> From: David Heidelberg <[email protected]>
>=20
> By datasheet the VDD (in-kernel named vcc) range is between 2.3 to 4.3 V.
> Usually it's around 2.8 V. Here it matches the reg_vcam_2v8.

It doesn't - VCAM_2V8 isn't connected to DW9714 (and neither is CSI_1V8);=20
VCAM_AFVDD is.

> 1.8 V here is likely used for i2c level shifter.

I'm not sure where you've got an I2C level shifter from, there's none invol=
ved=20
there. CSI_1V8 is passed to the rear camera module as DOVDD and is consumed=
 by=20
S5K3L6 as VDDIO, and both S5K3L6 and DW9714 are connected to I2C4_SDA/
I2C4_SCL, operating at the 1.8V level, only though an EMI filter (F7 in the=
=20
schematic).

>=20
> Fixes: f00df2bdb512 ("arm64: dts: imx8mq-librem5: describe the voice coil
> motor for focus control") Cc: [email protected]
> Signed-off-by: David Heidelberg <[email protected]>
> ---
>  arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
> b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi index
> f5d529c5baf3e..583cba2d3bebf 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
> @@ -1167,17 +1167,17 @@ &i2c4 {
>  	pinctrl-1 =3D <&pinctrl_i2c4_gpio>;
>  	scl-gpios =3D <&gpio5 20 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
>  	sda-gpios =3D <&gpio5 21 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
>  	status =3D "okay";
>=20
>  	vcm@c {
>  		compatible =3D "dongwoon,dw9714";
>  		reg =3D <0x0c>;
> -		vcc-supply =3D <&reg_csi_1v8>;
> +		vcc-supply =3D <&reg_vcam_2v8>;
>  	};
>=20
>  	bat: fuel-gauge@36 {
>  		compatible =3D "maxim,max17055";
>  		reg =3D <0x36>;
>  		interrupt-parent =3D <&gpio3>;
>  		interrupts =3D <20 IRQ_TYPE_LEVEL_LOW>;
>  		pinctrl-names =3D "default";