Re: [PATCH 01/31] swim: Assert strobe with stable outputs

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On Mon, 20 Jul 2026, Laurent Vivier wrote:

> Le 16/07/2026 =C3=A0 12:02, Finn Thain a =C3=A9crit=C2=A0:
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> > Keep the four phase pin directions set to output and hold their levels=
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> > constant during LSTRB signalling.
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> Perhaps you can also add a short comment to describe the changes you=20
> made to the defines.
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Can you clarify please? I think what you're asking is, shouldn't the PH3=20
pin be an input when it's not being used for LSTRB signalling?

It would be nice if we had specs for the relevant FDD models, to show that=
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no FDD ever drives the phase lines. Then I could write something more=20
authoritative. I don't have that information but I do have the chip specs.

The swim3.c driver never sets phase pin direction because the SWIM3 chip=20
doesn't implement that i.e. the four phase pins are permanently outputs.=20
Similary, the programming model for the IWM chip offers no way to use=20
phase lines as inputs, AFAICT. Same for the uPD72070 FDC chip.

I will add some of these observations to the commit log or the commentary=
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in the source code if you think it would help.

Thanks for your review.
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