Re: [PATCH 1/2] pinctrl: core: configure pinmux from pins debug file

From: Drew Fustini
Date: Wed May 19 2021 - 06:02:47 EST

On Tue, May 18, 2021 at 05:01:30PM +0300, Andy Shevchenko wrote:
> On Tue, May 18, 2021 at 4:57 PM Dario Binacchi <dariobin@xxxxxxxxx> wrote:
> > > Il 17/05/2021 22:02 Andy Shevchenko <andy.shevchenko@xxxxxxxxx> ha scritto:
> > > On Sun, May 16, 2021 at 7:43 PM Dario Binacchi <dariobin@xxxxxxxxx> wrote:
> ...
> > > Can't you use strncpy_from_user() ?
> >
> > Ok, I'll use strncpy_from_user() in the next version of the patch
> Don't be in a hurry.
> We need to settle down the interface first. We still haven't heard
> from the maintainer (Linus?) about it. Neither we have a clear view if
> we need to revert that patch that dropped pinconf-config (Drew, what
> do you think?).

Vladimir Zapolskiy wrote in e73339037f6b ("pinctrl: remove unused
'pinconf-config' debugfs interface"):

Of course it might be possible to increase MAX_NAME_LEN, and then add
.pin_config_dbg_parse_modify callbacks to the drivers, but the whole
idea of such a limited debug option looks inviable. A more flexible
way to functionally substitute the original approach is to implicitly
or explicitly use pinctrl_select_state() function whenever needed.

This makes me think it is not a good idea to bring back pinconf-config.
The pinmux-select debugfs file that I add added in commit 6199f6becc86
("pinctrl: pinmux: Add pinmux-select debugfs file") provides a method to
activate a pin function and pin group which I think provides the same
capability as long as the possible pin functions are described in dts.