linux-kernel - Re: [PATCH] pinctrl: msm: Use dynamic GPIO numbering

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Sun, 8 Nov 2020 20:41:36 +0530
From:   Arun KS <arunks.linux@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>
Cc:     Bjorn Andersson <bjorn.andersson@...aro.org>,
        MSM <linux-arm-msm@...r.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Timur Tabi <timur@...eaurora.org>,
        Arun KS <getarunks@...il.com>
Subject: Re: [PATCH] pinctrl: msm: Use dynamic GPIO numbering

On Thu, Nov 5, 2020 at 3:46 PM Linus Walleij <linus.walleij@...aro.org> wrote:
>
> On Fri, Oct 23, 2020 at 4:21 PM Arun KS <arunks.linux@...il.com> wrote:
>
> > Im only concerned because, after this change, the use of gpio number
> > from user space has become a little difficult.
>
> This makes me a bit puzzled so I need to push back a bit
> here.
>
> What is this userspace and what interface is it using?
>
> We recommend using the GPIO character device with
> libgpiod for userspace applications:
> https://www.kernel.org/doc/html/latest/driver-api/gpio/using-gpio.html

Thanks Linus. Makes sense. Basically using the gpiochipset and offset
to it will solve my problem. Earlier, while using the sysfs interface,
it used to be one to one mapping with real gpio numbers.

Regards,
Arun
>
> Is there any problem with this?
>
> sysfs is deprecated for years now:
> https://www.kernel.org/doc/html/latest/admin-guide/gpio/sysfs.html
>
> Yours,
> Linus Walleij