[PATCH 3/5] arm64: dts: rockchip: Fix mic-in-differential usage on rk3568-rock-3a

[Jonas Karlman]

Hi Cristian,

On 2024-06-21 03:23, Cristian Ciocaltea wrote:
> On 6/19/24 3:56 PM, Cristian Ciocaltea wrote:
>> Hi Jonas,
>>
>> On 6/19/24 3:22 PM, Jonas Karlman wrote:
>>> Hi Cristian,
>>>
>>> On 2024-06-19 13:23, Cristian Ciocaltea wrote:
>>>> The 'mic-in-differential' DT property supported by the RK809/RK817 audio
>>>> codec driver is actually valid if prefixed with 'rockchip,':
>>>>
>>>>   DTC_CHK arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dtb
>>>>   rk3568-rock-3a.dtb: pmic at 20: codec: 'mic-in-differential' does not match any of the regexes: 'pinctrl-[0-9]+'
>>>> 	from schema $id: http://devicetree.org/schemas/mfd/rockchip,rk809.yaml#
>>>>
>>>> Make use of the correct property name.
>>>>
>>>> Fixes: a84ffd2ef1ff ("arm64: dts: rockchip: Fix mic-in-differential usage on rock-3a")
>>>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
>>>> ---
>>>>  arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts | 2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts b/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>> index ebdedea15ad1..0b54dfe92d6e 100644
>>>> --- a/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>> +++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>> @@ -533,7 +533,7 @@ regulator-state-mem {
>>>>  		};
>>>>  
>>>>  		codec {
>>>> -			mic-in-differential;
>>>> +			rockchip,mic-in-differential;
>>>
>>> If I understand the schematics correctly, only one wire is connected so
>>> this board cannot really use differential signaling, and this should
>>> probably instead be dropped.
>>
>> Thanks for pointing this out, I will drop it in v2.
> 
> I've also checked the schematics which indicate the PMIC RK809 CODEC
> receives both MIC1_INN and MIC1_INP signals; the former comes from the
> Jack input, while the latter is generated by the SLM42Q3AT MEMS Microphone.
> 
> However, I'm not sure the Mic presence on the board is dependent on the
> HW revision - on REV V1.3 the "NC_" prefix under U24 component label
> suggests it is not connected.  So maybe we should keep the property?!

There is no such mic on the board, at least on the rev 1.3 that I have.

This prop should be used to indicate that the attached microphone uses
differential signaling, e.g. should have its two output signals
connected to both INP(+) and INN(-).

The SLM42Q3AT or the single wire from headphone jack indicate that a
single-ended microphone is/can be used/wired on this board.

The current use of non-working mic-in-differential was wrong, adding
the rockchip,mic-in-differential would change behavior and wrongly
describe hw of this board.

Regards,
Jonas

> 
> Cristian