Re: [PATCH v9 07/20] gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL

From: Bartosz Golaszewski
Date: Thu Sep 24 2020 - 10:29:20 EST


On Wed, Sep 23, 2020 at 1:12 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
>

[snip!]

>
> > + /* Bias requires explicit direction. */
> > + if ((flags & GPIO_V2_LINE_BIAS_FLAGS) &&
> > + !(flags & GPIO_V2_LINE_DIRECTION_FLAGS))
> > + return -EINVAL;
>
> Okay, since this is strict we probably may relax it in the future if
> it will be a use case.
> ...
>
> > + /* Only one bias flag can be set. */
>
> Ditto. (Some controllers allow to set both simultaneously, though I
> can't imagine good use case for that)
>

This is an abstraction layer. Only because some controllers allow
this, doesn't mean we should reflect this in our abstraction layer -
especially if we know well that this has no purpose.

Bartosz