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

[David Heidelberg <david@ixit.cz>]

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@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.

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@vger.kernel.org
>> Signed-off-by: David Heidelberg <david@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";
> 
> 
> 
> 

-- 
David Heidelberg