linux-kernel - Re: [PATCH 2/2] PCI: mvebu: switch to using gpiod API

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Message-ID: <CACRpkdZh0BF1jjPB4FSTg12_=aOpK-kMiOFD+A8p5unr1+4+Ow@mail.gmail.com>
Date:   Wed, 14 Sep 2022 12:35:36 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Pali Rohár <pali@...nel.org>,
        Shawn Guo <shawn.guo@...aro.org>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Wilczyński <kw@...ux.com>,
        linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] PCI: mvebu: switch to using gpiod API

On Wed, Sep 7, 2022 at 12:41 AM Dmitry Torokhov
<dmitry.torokhov@...il.com> wrote:

> Linus, do you think we should introduce GPIOD_OUT_INACTIVE /
> GPIOD_OUT_ACTIVE or GPIOD_OUT_DEASSERTED / GPIOD_OUT_ASSERTED and
> deprecate existing GPIOD_OUT_LOW and GPIO_OUT_HIGH?

They should rather be replaced everywhere in one go.

I think it is just a half-measure unless we also add
#define GPIOD_ASSERTED 1
#define GPIOD_DEASSERTED 0
to be used instead of 1/0 in gpiod_set_value().

It would also imply changing the signature of the function
gpiod_set_value() to gpiod_set_state() as we are not
really setting a value but a state.

I have thought about changing this, but the problem is that I felt
it should be accompanied with a change fixing as many users
as possible.

I think this is one of those occasions where we should merge
the new defines, and then send Linus Torvalds a sed script
that he can run at the end of the merge window to change all
gpiod_set_value(...., 1) -> gpiod_set_state(...., GPIOD_ASSERTED);
everywhere.

After all users are changed, the GPIOD_ASSERTED/DEASSERTED
defined can be turned into an enum.

That would be the silver bullet against a lot of confusion IMO.

We would need Bartosz' input on this.

Yours,
Linus Walleij