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

[David Heidelberg]

On 03/08/2026 20:12, Sebastian Krzyszkowiak wrote:
> On sobota, 1 sierpnia 2026 02:35:23 czas środkowoeuropejski letni David
> Heidelberg via B4 Relay wrote:
> > From: David Heidelberg <david@xxxxxxx>
> >
> > 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);
> VCAM_AFVDD is.

I didn't realized we have datasheet here :)

> > 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 involved

it's copy-paste from previous commits.

> there. CSI_1V8 is passed to the rear camera module as DOVDD and is consumed by
> 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
> schematic).

I don't see the AFVDD in the [1], do you have it somewhere defined?

Thanks
David

[1] 
https://source.puri.sm/Librem5/linux/-/tree/pureos/latest/arch/arm64/boot/dts/freescale?ref_type=heads

> > Fixes: f00df2bdb512 ("arm64: dts: imx8mq-librem5: describe the voice coil
> > motor for focus control") Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: David Heidelberg <david@xxxxxxx>
> > ---
> >   arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > 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 = <&pinctrl_i2c4_gpio>;
> >   	scl-gpios = <&gpio5 20 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
> >   	sda-gpios = <&gpio5 21 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
> >   	status = "okay";
> >
> >   	vcm@c {
> >   		compatible = "dongwoon,dw9714";
> >   		reg = <0x0c>;
> > -		vcc-supply = <&reg_csi_1v8>;
> > +		vcc-supply = <&reg_vcam_2v8>;
> >   	};
> >
> >   	bat: fuel-gauge@36 {
> >   		compatible = "maxim,max17055";
> >   		reg = <0x36>;
> >   		interrupt-parent = <&gpio3>;
> >   		interrupts = <20 IRQ_TYPE_LEVEL_LOW>;
> >   		pinctrl-names = "default";

--
David Heidelberg