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

[Sebastian Krzyszkowiak]

On sobota, 1 sierpnia 2026 02:35:23 czas środkowoeuropejski letni David 
Heidelberg via B4 Relay wrote:
> From: David Heidelberg <da...@ixit.cz>
> 
> 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.

> 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 
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).

> 
> Fixes: f00df2bdb512 ("arm64: dts: imx8mq-librem5: describe the voice coil
> motor for focus control") Cc: sta...@vger.kernel.org
> Signed-off-by: David Heidelberg <da...@ixit.cz>
> ---
>  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";