linux-kernel - Re: [PATCH v5 1/2] gpio: add GPO driver for PCA9570

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Message-ID: <CAHp75Vf4440V5Oh1SA5tjVgss134qGkx591ANDY3aQ+oecEzmw@mail.gmail.com>
Date:   Mon, 6 Jul 2020 15:00:05 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Bartosz Golaszewski <bgolaszewski@...libre.com>
Cc:     Sungbo Eo <mans0n@...ani.run>,
        Linus Walleij <linus.walleij@...aro.org>,
        Michael Walle <michael@...le.cc>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-gpio <linux-gpio@...r.kernel.org>
Subject: Re: [PATCH v5 1/2] gpio: add GPO driver for PCA9570

On Mon, Jul 6, 2020 at 2:21 PM Bartosz Golaszewski
<bgolaszewski@...libre.com> wrote:>
> On Sun, Jul 5, 2020 at 3:31 PM Sungbo Eo <mans0n@...ani.run> wrote:
> >
> > NXP PCA9570 is a 4-bit I2C GPO expander without interrupt functionality.
> > Its ports are controlled only by a data byte without register address.
> >

> > Datasheet: https://www.nxp.com/docs/en/data-sheet/PCA9570.pdf
> >

No blank line here.

> > Signed-off-by: Sungbo Eo <mans0n@...ani.run>

> This driver looks nice now but why did you remove the mutex in v3? I
> think when Andy commented on that, he meant not understanding why the
> error check is protected, not the i2c operations.

Right.

> Are you sure you don't need this lock?

It's a good point!

-- 
With Best Regards,
Andy Shevchenko