linux-kernel - Using Pull-up resistors on gpio-pca953x expander

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Message-ID: <CAHCN7xLuCqSFVnVQ-7ZWH-Dkd+w-_bJLnbSDyUip_8orhTwzZw@mail.gmail.com>
Date:   Wed, 15 Jan 2020 14:25:59 -0600
From:   Adam Ford <aford173@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Using Pull-up resistors on gpio-pca953x expander

The pca953x can support pull-up resistors, and I have a pcal6416 that
I'd like to enable them.

Ideally, I was hoping there would be a way to add enable to the device
tree, because the expander is connected to some buttons which are
grounded when pressed.  Without pull-up resistors enabled, the buttons
always appear to be pressed.

Is there some way to enable them?  I see the functionality is
available and called through gc->set_config = pca953x_gpio_set_config;

I don't know enough about the API to know how to enable this.  Can
someone give me some pointers?

Would you entertain my adding some device tree hooks to enable them?

adam