linux-kernel - Re: [PATCH v6 2/2] input: joystick: driver for Adafruit Seesaw Gamepad

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Message-ID: <ZWJ3sFfrVQA3djmi@nixie71>
Date:   Sat, 25 Nov 2023 16:39:44 -0600
From:   Jeff LaBundy <jeff@...undy.com>
To:     Thomas Weißschuh <linux@...ssschuh.net>
Cc:     Anshul Dalal <anshulusr@...il.com>, linux-input@...r.kernel.org,
        devicetree@...r.kernel.org,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Shuah Khan <skhan@...uxfoundation.org>,
        linux-kernel-mentees@...ts.linuxfoundation.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v6 2/2] input: joystick: driver for Adafruit Seesaw
 Gamepad

Hi Thomas and Anshul,

On Fri, Oct 27, 2023 at 06:14:58AM +0000, Thomas Weißschuh wrote:

[...]

> > +struct seesaw_data {
> > +	__be16 x;
> > +	__be16 y;
> 
> The fact that these are big endian is now an implementation detail
> hidden within seesaw_read_data(), so the __be16 can go away.
> 
> > +	u32 button_state;
> > +} __packed;
> 
> While this was requested by Jeff I don't think it's correct.
> The struct is never received in this form from the device.
> I guess he also got confused, like me, by the fact that data is directly
> read into the fields of the struct.

Apologies for some confusion on my part here; Thomas is correct and
my comment can be disregarded. Originally I thought this struct was
mapped to a continguous range of registers, but after studying the
documentation some more, that is clearly not the case :)

Kind regards,
Jeff LaBundy