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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Tue, 30 Oct 2018 13:08:14 +0100
Message-ID: <CACRpkdbS_aOpFORVnK3QJUsF1p-mVxtMas-q6fOp7emTx281Lg@mail.gmail.com>
Subject: Re: [PATCH 2/2] pinctrl: pinctrl-npcm7xx: Set BGPIOF_VOLATILE_REG
To:     kunyi@google.com
Cc:     "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Tomer Maimon <tmaimon77@gmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        avifishman70@gmail.com,
        OpenBMC Maillist <openbmc@lists.ozlabs.org>,
        Mark Brown <broonie@kernel.org>
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On Wed, Oct 17, 2018 at 11:30 PM Kun Yi <kunyi@google.com> wrote:

> Indicate that the pins are both controlled by the pinctrl driver and the
> generic GPIO driver, thus GPIO driver should read the register value
> before updating, instead of using the stored shadow register values.
>
> Signed-off-by: Kun Yi <kunyi@google.com>

This is quite a rough measure, if we instead use regmap-mmio
we can exercise fine control over what register are volatile and
not instead of saying that all of them or some of them are.

Yours,
Linus Walleij