linux-kernel - Re: [PATCH RESEND v3 12/17] iio: adc: ad7768-1: Add GPIO controller support

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Message-ID: <CACRpkdbw3BkpzPQp2PdV8M61V2XXaLcmuOpGTsxSoiQTH7wZXw@mail.gmail.com>
Date: Fri, 28 Feb 2025 09:52:15 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: David Lechner <dlechner@...libre.com>
Cc: Jonathan Santos <Jonathan.Santos@...log.com>, linux-iio@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Sergiu Cuciurean <sergiu.cuciurean@...log.com>, lars@...afoo.de, Michael.Hennerich@...log.com, 
	marcelo.schmitt@...log.com, jic23@...nel.org, robh@...nel.org, 
	krzk+dt@...nel.org, conor+dt@...nel.org, jonath4nns@...il.com, 
	marcelo.schmitt1@...il.com
Subject: Re: [PATCH RESEND v3 12/17] iio: adc: ad7768-1: Add GPIO controller support

On Thu, Feb 20, 2025 at 11:27 PM David Lechner <dlechner@...libre.com> wrote:
> On 2/19/25 2:34 PM, Linus Walleij wrote:

> > Is it not possible to use the gpio regmap library in this driver
> > like we do in drivers/iio/addac/stx104.c?
> >
> > It cuts down the code size of simple GPIO chips on random
> > chips quite a lot.
>
> I think the answer is "no" since we need to hold a conditional lock
> while accessing registers. Namely: iio_device_claim_direct_mode()/
> iio_device_release_direct_mode().

Sorry for potentially dumb question, but if this is required to access
the registers, why is it not done in the regmap abstraction itself?
It's kind of that stuff regmap is supposed to hide.

Yours,
Linus Walleij