linux-kernel - 回复: 回复: [PATCH v1 1/2] dt-bindings: ASoC: Add PDM controller for the StarFive JH8100 SoC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID:
 <NTZPR01MB0956A8DCFEF13E4905D97B479F27A@NTZPR01MB0956.CHNPR01.prod.partner.outlook.cn>
Date: Fri, 8 Mar 2024 09:19:32 +0000
From: Xingyu Wu <xingyu.wu@...rfivetech.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>, Liam Girdwood
	<lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, Takashi Iwai
	<tiwai@...e.com>, Jaroslav Kysela <perex@...ex.cz>, Rob Herring
	<robh+dt@...nel.org>, Krzysztof Kozlowski
	<krzysztof.kozlowski+dt@...aro.org>, Conor Dooley
	<conor.dooley@...rochip.com>
CC: Walker Chen <walker.chen@...rfivetech.com>, "devicetree@...r.kernel.org"
	<devicetree@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "alsa-devel@...a-project.org"
	<alsa-devel@...a-project.org>, "linux-sound@...r.kernel.org"
	<linux-sound@...r.kernel.org>
Subject:
 回复: 回复: [PATCH v1 1/2] dt-bindings: ASoC: Add PDM controller for the StarFive JH8100 SoC

> On 08/03/2024 08:49, Xingyu Wu wrote:
> >>> +
> >>> +  starfive,pdm-modulex:
> >>> +    $ref: /schemas/types.yaml#/definitions/uint32
> >>> +    enum: [0, 1]
> >>> +    description:
> >>> +      The module x will be using in PDM controller. Default use module 0.
> >>
> >> This is an index of the block instance? If so, then it's not allowed.
> >> Otherwise I don't understand the description.
> >>
> >
> > No, this is just one instance. The PDM have two internal and independent
> modules or called channels.
> > They can be configured and used separately, and the user can choose which
> channel to use.
> >
> 
> Do the modulex differ? Why different boards would choose one over another?
> 

They are same. The choice between them is base on the match with I2S.
The DMA data channel of hardware between them is fixed linked:
PDM module 0 --> I2S channel 0,
PDM module 1 --> I2S channel 1
I2S uses higher-number channels first for capture (like channel 1), so PDM should skips module 0 and uses module 1.
Oh, I just thought of a way to fix them that change the priority of I2S channel to use lower-number channels first and PDM need not skip module0.

Best regards,
Xingyu Wu