linux-kernel - Re: [PATCH 1/1] HID: mcp2221: add GPIO functionality support

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Date:   Thu, 16 Apr 2020 13:24:33 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Rishi Gupta <gupt21@...il.com>
Cc:     Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Jiri Kosina <jikos@...nel.org>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Linux Input <linux-input@...r.kernel.org>
Subject: Re: [PATCH 1/1] HID: mcp2221: add GPIO functionality support

On Tue, Apr 14, 2020 at 6:48 PM Rishi Gupta <gupt21@...il.com> wrote:

> MCP2221 has 4 pins that can be used as GPIO or configured
> for alternate functionality such as clock generation and
> IRQ detection. This patch adds support for GPIO functionality.
>
> To set direction of a pin or to toggle its state after it
> has been configured as GPIO, driver sends command to mcp2221
> and parses response received from mcp2221. Based on this
> response either 0 or appropriate error code is returned to
> GPIO framework.
>
> To get the direction or current state of a pin, driver
> sends command and read response from the device. Based on
> the response received from device direction or value
> is sent to the GPIO framework.
>
> Command from driver to mcp2221 device are output report.
> Response received from mcp2221 is input report.
>
> Datasheet (page 45-48) contains details about how to decode
> the response received from device:
> http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf
>
> Signed-off-by: Rishi Gupta <gupt21@...il.com>

This looks good to me.
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>

Yours,
Linus Walleij