linux-kernel - Re: [PATCH v3 5/6] arm64: dts: imx8mp: Add fsl,dsp-ctrl property for dsp

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Message-ID: <CAEnQRZDZSj2tkMzaqZfaO0e8drO3U2j_qxoZSNocAS1Qaq1Q-Q@mail.gmail.com>
Date: Wed, 12 Feb 2025 11:14:50 +0200
From: Daniel Baluta <daniel.baluta@...il.com>
To: Krzysztof Kozlowski <krzk@...nel.org>
Cc: Daniel Baluta <daniel.baluta@....com>, shawnguo@...nel.org, s.hauer@...gutronix.de, 
	kernel@...gutronix.de, robh@...nel.org, krzk+dt@...nel.org, 
	conor+dt@...nel.org, festevam@...il.com, devicetree@...r.kernel.org, 
	imx@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org, 
	linux-kernel@...r.kernel.org, frank.li@....com, aisheng.dong@....com, 
	laurentiu.mihalcea@....com, shengjiu.wang@....com, iuliana.prodan@....com, 
	a.fatoum@...gutronix.de
Subject: Re: [PATCH v3 5/6] arm64: dts: imx8mp: Add fsl,dsp-ctrl property for dsp

On Wed, Dec 11, 2024 at 11:07 AM Krzysztof Kozlowski <krzk@...nel.org> wrote:
>
> On Tue, Dec 10, 2024 at 02:53:37PM +0200, Daniel Baluta wrote:
> > Audio block control contains a set of registers some of them used for
> > DSP configuration.
> >
> > Drivers (rproc, SOF) are using fsl,dsp-ctrl property to access those
> > registers in order to control the operations of the DSP (e.g for
> > start, reset, etc).
>
> This should have been implemented as reset controller, not syscon. It's
> really poor choice to call everything syscon. It does not scale, does
> not provide you runtime PM or probe ordering (device links). Quick look
> at your drivers suggest that you have exacvtly that problems.

Hi Krzysztof,

The bits we are using from audio-blck-ctrl for controlling the DSP are
not for reset!
They are only for Run/Stall the DSP.

The reset is done via DAP interface. I will sent a separate patch to abstract
the reset interaction using a reset controller. But for Run/Stall bits we need
to use a syscon.

thanks,
Daniel.